History Of Civil Engineering

History Of Civil Engineering                                    • Initially, all civil engineers including those who do not have the practice of military engineering, said he started in the eighteenth century France.

• First "Civil Engineer" was an Englishman, John Smeaton of the 1761st

• Civil engineers have saved more lives than all the doctors in history - the development of drinking water and sanitation.

• Henry H. White built the first building will be completed in Bacon KY (Georgetown) College in 1840.

• Fall of 1886, established "State College" (UK) degree in civil engineering.

• John Wesley Gunn of Lexington has received a first degree in civil engineering from A & M College (England) in 1890.

Marine engineering

What is incorporated in the method of underwater pipeline crossings?                                                                                                 Tube immersed under water crossing method associated with the following basic steps:

(I) precast units along the tunnel (steel or concrete shell), a dry dock or shipyard

(Ii) the floats and the trailer with movable partitions for the site

(Iii) Immerse the specimens in a pre-excavated trench

(Iv) Combining a unit for a

(V) covers the complete tunnel

An immersed tunnel steel is sometimes adopted because of ease of manufacture and its relative ease. In addition, shorter construction time required compared to concrete immersed tubes
How does the direction of the approaching speed of ships affected by the pier?

One of the main effects of the angle of speeds approaching vessel is its effect on energy to be absorbed by the defense system. Consider more ships berth at the dock themselves at the same speed but with a different approach, although their kinetic energy is the same, the amount of energy absorbed by the wing is different. The amount of energy absorbed by the wing is:

approach speeds of ships

where W = absorbed by the fender

m = mass of the spacecraft

v = velocity of the ship

k = radius of gyration of the ship

r = distance between the center of gravity of the ship at the contact point for the wings

So, when the direction of approaching the speed of the ship is a normal wing (ie, phi = 90), the amount of energy absorbed is less than the vessel at a speed tangent to the beach.

What Is The Design Of Landings In The Pillars?                                                                    Landings has been designed as a resting place for passengers during docking and undocking of vessels. Typically, the data say landing near the top and the average low water to facilitate the embarkation and disembarkation of passengers (BS6349: Part 2: 1988). Therefore, the level of landing steps may be different from place to place because of different high and say the average level of low water in different places.

If Morison Equation And Diffraction Analysis Will Be Adopted In Determining The Strength Of The Waves On Stilts?                                                       The choice between the Morison equation and diffraction analysis in determining wave forces on the piles depends on the ratio between the diameters of the piles of wavelength. If the relationship between the diameter of the wavelength of the batteries is less than 0.2, the Morison equation is usually

recommended. The reason behind this is that the effect of viscosity and separation is considerably lower than that. On the contrary, if the relationship between the diameter of the mass of the wavelength greater than 0.2, the waves are scattered with a negligible impact of separation. Such as diffraction analysis was adopted to calculate the wave forces on piles

Hudson And The Formula For Van Der Meer Formula Is Commonly Used In The Design Of The Armor. Which Is The Best Choice?                         Hudson formula is often adopted in the preliminary design to obtain rough initial estimate of the size of stone. The formula is derived from the regular wave tests. But this formula does not take into account the following, as Van der Meer formula do: wave period, the level of damage, the permeability of the structure and duration of storm. In addition, the Hudson formula relates to the use of regular waves only.

Compared to the formula of Hudson, Van der Meer formula is more complicated and is derived from the results of a series of physical model tests. They include the examination of the period of the wave, the duration of storm, the level of damage defined and the permeability of the structure. The choice of the appropriate formula depends on the design objectives (ie preliminary design or detailed design).

What Are The Factors That Determine The Stability Of A Single Armored Unit?                                      There are three main factors governing the stability of an armored unit, namely the severity, the treatment of inter-and algae clip. Obviously, it is beyond doubt that the ability of the armored unit to stay in place must be closely related to the gravitational force. Moreover, the geometry of the armored unit affecting its stability. For example, the difference in the ability to intertangle reluctance to get out of the wave varies. Moreover, the forces pushing gravity also affects the stability of the armored unit that depends on friction forces in all directions.
If A Small Boat To Take Into Account The Design Of Wings?                                                                The smaller ship should also be taken into account when designing a system fender. Vertically and the fender system, type and size of all vessels must be considered taking into account the influence of tides in the region. In fact, plans to visit a fender system, engineers must take into account the height and depth as well as smaller and larger vessels in a point of contact is a fender. It is not uncommon for the design of a fender system considers only the largest of the ships dock and pier, which should be avoided, because it does not necessarily work for small boats in the dock of the shipyard.
                                                              

                                                                                                                                                                    If The Wings Rigid Or Flexible To Be Designed To Dock At Piers?                                                        The elasticity of the wings is related to the ability to release the energy stored in the docking of ships. But it has no effect on the reaction force and the deflection of the fender system. The amount of energy that can absorb a wing depends on the deflection curve of reaction and is represented by the area under the curve. The higher is the reaction force would be the largest amount of energy absorbed by the fender, provided that the hull strength is sufficient to withstand the force without permanent deformation. While rigid and flexible wings can have the same deflection under the maximum reaction force acting on the boat dock, the amount of energy absorbed by the rigid wings are much higher than in soft wings. Therefore, rigid wings used for docking.

On the other hand, in mooring operations where vessels are constantly subjected to wave action, it is desirable to keep the pull of the rope to a low value. In this regard, it recommends the use of flaps  Water Can Help Dispel Some Of The Energy Coupling?                                                                                                          Depending on the composition of the pier, the water could help to dissipate the energy of the pier. For example, the closed door, which is a solid wall going straight to the bottom of the sea, the quay wall to repel any water that moves the ship and creates a cushion effect, which dissipates the energy of the pier ( 10-20%). In contrast, an open yard, with piles everywhere and the water can flow through the bottom of the platform, not cushion the effect of the water.

Similarly, the most important is the draft of vessels, less water can escape trapped under the ship to the dampening effect of water can be enhanced to dissipate some energy coupling.
                                                                                                                                                                                                                               

Wood Engineering

 What should be the slope of the roof to avoid stagnation?                                                                                                                                     As with standard roof beams should be a continuous upward slope is equal to 1 / 4 inch / foot (20.8 mm / m) between the discharge and the peak of the roof, above the minimum recommended camber avoid stagnation.

In the case of sufficient slope that is less than 20.8 mm / m, we note that the stiffness of the supporting members or act 5lb/ft2 239.4 N/mm2 load does not cause the diversion of more than 1 / 2 inch or 12.7 mm                                                                                                                                                       What is stress and the radial curvature factor?
For a constant area of ​​cross section of the radial force caused by bending moment in a Member State is calculated using this formula

fr = 3M/2Rbd

where

M = bending moment in lb (N m)

R = radius of center members, (mm)

b = width of cross section, in (mm)

d = depth of section, in. (mm)

When we have a curved portion, the curvature factor is introduced and is calculated as

Cc = 1000-2000 (T / R) 2

where

t is the thickness of rolling (mm)

R is the radius of curvature of the lamination (mm).
What Correction Factors Must Be Done In Design Values?
Its always some variation in the design values ​​calculated by the wood. Therefore, we must apply the necessary adjustment for them.

The extreme fiber bending

Fb = FbCDCMCtCLCFCVCfuCrCcCf

where

FB - adjusted design value

Fb = value of extreme fiber bending

CD load duration factor =

CM = wet service factor

CCT = temperature coefficient

CL = beam stability factor

CF = factor measurement applies only to the visually classified sawn and round timber bending members

Cv = volume factor applies only when the rays are glued or laminated

Cfu = constant factor in the use of only one size of timber beams 2-4 (50.8 to 101.6 mm), and laminated wood beams

Cr = repetitive member factor applies only to the size of the beams, 2-4 (to101.6 50.8 mm) thick

Cc = curvature factor applies only to glulam beams curved parts

CF = form

When the bars are glued, laminated, we have to use smaller of the two-CL or CC

The design value of the voltage

Ft = FtCDCMCtCF

where

FT '- design value adjusted

Ft - Design value for the tension.

Adjustment for shear

Fv = FvCDCMCtCH

where

Fv '- Design adjusted value

Fv-value for the CH-cut design and is the shear factor> = 1 Fvparallel allow for the grain to the wood members.

Adjustments for compression perpendicular to the direction of

Fc1'is the value of the project

FC1 '= Fc1CDCtCb

where

Fc1is design value in compression perpendicular to grain

CB lubrication factor.

The value of the survey corrected for compression parallel to grain

FC = FcCDCMCtCFCp

where

Fc is a compression design value parallel to grain

CP Factor column stability.

Design value adjusted to bring the wood grain parallel to the end

FG '= FgCDCt

where

Fg is the design value for the fine grain, keeping parallel to the grain.

The adjusted value of the survey's modulus E '

E '= ECMCTC

where E = design value of the module

CT = buckling stiffness factor

C = correction factors appropriate
                                                            

Surveying

Introduction to contour                                                                                              Thinning is the science of representation of the vertical dimension of the field in a two-dimensional map. We can understand the outline considering a simple example.

Suppose a right circular cone with a base diameter of 5 m in height and 5 meters is upright on its base. Leave the base to rest on a horizontal plane at zero, as shown in Figure 1.
                                                                                                                                            Zero, the outline of a cone is a circle of 5 meters in diameter. This circle is the boundary of the cone height 0m. We draw on the first corner, an appropriate scale on paper.

Now let's see a piece of 1 meter above the bottom of the cone. This produces a more rounded contour of the corresponding diameter of the cone height of 1m. We do this a second circle, outline map of the same scale. The second circle is smaller in diameter than the first one is a concentric circle inside the first circle.

Similarly, we will continue to draw the shape of a cone-2m, 3m, 4m and 5m at the boundary of our map. We conical structure of the map object is ready. Looking on the map are called contour lines. (See Figure-2)

                                                                                                        As the cone, in this example, the draft hills rising from the ground. The contour map of the terrain will be similar to the cone, except that instead of perfect circles, the level curves

irregular shapes. The important point to note here the similarity is that the mountainous terrain would be represented by contours with elevation increasing toward the center.

In contrast, a pond or depression can be represented by contour lines with decreasing height toward the center.

Explain the terms used in the irregularities                                Define the contour line

A contour line is an imaginary boundary of the land is obtained by joining points of equal elevation. In our example of the cone, each circle is a contour line connecting poDefine Contour Line
A Contour line is an imaginary outline of the terrain obtained by joining its points of equal elevation. In our example of the cone, each circle is a contour line joining points of same level.

Define Contour Interval (CI)
Contour interval is the difference between the levels of consecutive contour lines on a map. The contour interval is a constant in a given map. In our example, the contour interval is 1m.

Define Horizontal Equivalent (HE)
Horizontal equivalent is the horizontal distance between two consecutive contour lines measured to the scale of the map.ints on the same level.

Define the contour interval (CI)

Contours is the difference between consecutive contours on a map. The contour interval is a constant for a given map. In our example, the contour interval of 1m.

Define the equivalent horizontal (HE)

Horizontal equivalent is the horizontal distance between two consecutive contours measured in the scale of the map.

                                                                    Gradient

Gradient of the slope up or down the field between two consecutive contours. The slope or gradient is usually in the format specified in S 1, where 1 represents the vertical component of the slope S and the horizontal component is measured in the same unit.

Slope of two consecutive curves can also express Q, Tan (Theta), as follows:

Q tan (theta) = CI / HE ... both measured in the same department.

What is the difference between equidistance and equal horizontal                                                                                                   There are three main differences between the contour interval and the horizontal equivalent of the following:

S. No interval between the horizontal lines

1 It is based on vertical levels representing the horizontal distance

2 No measuring or scaling is not necessary, because the contour lines are marked with contour lines on a map the distance is measured and converted into distance by multiplying the actual scale of the map

3 In a given map the contour interval is a constant horizontal equivalent varies with the slope. Minimum slope indicates a greater distance

What are the characteristics of the contour lines?   Contours clearly shows characteristics of the soil, as follows:

i) All points on a contour line is the same height.

ii) There are two edges meet or intersect, except in rare cases of long vertical cliff or wall

iii) the contour lines close together indicate a steep slope

iv) Widely spaced contours indicate the slope

v) Equally spaced contours indicate a uniform slope

vi) Closed contour lines with a higher elevation to the center indicates Hills

vii) Closed contour lines to reduce the levels of the center indicates the direction of the pond or other depression.

viii) the contour of the ridge show a greater height at the edges of the loop. Contour lines of the cross-ridge at right angles.

ix lines) contour of the valley show the reduction of the contour lines in the circuit. The contour lines at right angles to the valley.

x) All edges must be sealed with either a map of the border or outside of it.

What areas of contours using?
 Contour maps are useful because they provide valuable information on the ground. Some of these uses are as follows:

i) The nature of the soil and slope can be estimated

ii) the work of the Earth can be estimated for construction projects such as road works, railways, canals, dams, etc. iii) It is possible to find an appropriate place for a project of the contour map of the region.

iv) Inter-visibility of points can be viewed using the contour maps. This is very helpful for locating the communication towers.

v) the military uses contour maps of strategic planning.

What methods of  imperfections?                                                 Two ways are Contouring: -

i) direct method

ii) the indirect

Direct method

In the direct method points to the same height of the land is physically located, and then plotted on a map. This is a very laborious process and requires more time and resources than the indirect method.

Indirect method

In the indirect method of contour in the three methods to be followed:

) Transversal Method

B) square or grid method

C) Method Tacheometric

Explanation of the method of weight loss of the    crosssection?                                                           Method Cross section is the most suitable for the preparation of contour maps of the works of roads, railways, canals, etc.

Usually, this type of terrain has a band very long, but narrow.

The steps are:

i) The axis of the strip is marked first

ii) lines perpendicular to the longitudinal axis of the tape is marked dividing the strip into equal sections

iii) the perpendicular lines are divided into equally spaced divisions, forming the rectangular grid.

iv) levels taken at the intersection lattice for the cross section profile of a strip of land.

v) the contour map is drawn in the office by interpolating the points of equal elevation on the basis of the decision levels at the site.

We are grateful to Mr. Iyer engineeringcivil.com Ramasesh to submit this information useful for us.
Explain Squares Slimming grid method?
 Squares or grid method is suitable for the formulation of the plains or gently sloping grounds.

They agreed steps are as follows:

i) Mark the square grids on the ground to detect. Grid size depends on how the study.

Generally, a grid of 1m x 1m is chosen for small jobs and a larger grid for major work

ii) The levels are taken all over the place and the intersection of the diagonal.

iii) levels taken at the intersection of the diagonals used for verification of the interpolation.

vi) Contour map in the office were drawn by interpolation of points based on the levels of the same height in the corners of the square.
Tacheometric explanation of the method for remodeling?                                                           

Tacheometric method is adopted for contouring of very steep hills.

The steps are as follows:
i) Set up the tacheometer at the top of the steep hill. Tacheometer is a theodolite fitted with stadia diaphragm. The stadia diaphragm has three horizontal parallel hairs instead of one as found in a conventional cross hair diaphragm.

ii) With the help of a tacheometer it is possible to determine the horizontal distance of the point from the telescope as well its vertical level.

iii) The steep hill is surveyed at three levels – the base of the hill, the mid-level of the hill and the top level of the hill.

iv) Using the tacheometer reading are taken all around the hill at equal angular intervals on all these three
levels.

v) The radial plot thus obtained is worked in the office to interpolate points of equal elevation for contour mapping.

                                                                            

Steelworks

If high-performance steel or mild steel reinforcement was designed as a road?
On high-performance steel is the preferred material for the strengthening of concrete pavement for the following reasons:

(I) The main aim of reinforcing steel in concrete is to control cracking. If mild steel is adopted for the reinforcement, initiation of cracking of mild steel becomes overloaded and

will be exposed. High Yield Steel provides the resistance to crack growth. The situation described above is a general with an abnormal load of cement on the road over the limits of design.

(II), high-performance steel is less prone to deformation and bending during routine operations management.

(Iii) In today's market, the steel mesh reinforcement is normally high-performance steel and use steel as reinforcement of the route requires the award of special orders from suppliers.

Analysis and design of the tubular structure 2-D modeling with USFOS
USFOS is the analysis tool to predict both the strength of structures subjected to accidental loads and the residual strength of damaged structures after such charges. It is based on a finite element model. USFOS encompasses the static analysis of the fall, the nonlinear analysis of time series and dynamic analysis of the eigenvalues ​​in general, jackets, accessories, jack-up, and floats. With the main purpose of this paper is to analyze two types of offshore structures in 2-D and study the mechanism of progressive collapse of these two fields, due to different combinations of loads in the X and Y axis First the boundary conditions were established for the vertical elements, using modeling and USFOS were tested to collapse under the burden of four possible combinations. Behavioral differences of the two frameworks have been studied and brace-chord sizes have been fixed.

This type of analysis is useful for testing if a jacket sea with some specified size can tolerate the stress that comes to her from the waves, wind or the effects of ships. Using the built-in redundancy in most offshore structures progressive collapse limit state can be used to design accidental injury or extreme loads. In conjunction with the traditional elastic load-shifting is generally not considered. Reduce or plastic design limit states, it is possible to local failure of performance or buckling, and even the partial collapse if the overall integrity of the structure preserved. In short, the designers of plastic limit state design to take advantage of any spare capacity in the structure.

Behavioral studies Hollow double wall steel composite concrete columns                                                                        This document includes the experimental study of eight concrete filled double skin steel tubular (DSCFT) beam columns placed concentric circular section filled with self-compacting concrete. Tests on the samples was done by applying eccentric loads. The main experimental parameters of beam-columns, slenderness and eccentricity of the load. Test samples studied the behavior of the deviation of the load, the effect of confinement, and the strength of the columns. Experimental observations have shown for the stress-strain curves. Characteristics such as strength, stiffness, ductility and failure are discussed. Predicted load vs deformation relationships are in good agreement with the results of beam-column tests. Columns filled with SCC of DSCFT showed good strength and ductility. The changes are proposed equations to find the maximum compressive strength of the columns filled with SCC DSCFT.

What is the purpose of strengthening the skin depth of the bar?
In BS8110 states that secondary reinforcement should be provided for exceeding 750 deep beams at a distance measured depth 2 / 3 of the face in tension. Experimental work has shown that less or about half the depth of deep beams, the maximum width of cracks caused by bending can be two to three times greater than the width of the crack, even on the surface where the origin of the crack forms.

The presence of cracks is not desirable from an aesthetic point of view. It also raises potential problems of corrosion of reinforcing deep beams. To guard against cracking of the building has been designed on the sides of deep beams to limit the formation of wide cracks in bending. Although the main function of enhancing the skin is the crack width control can be used to provide resistance to bending of the section.

What is the difference between performance of concrete bonding between epoxy and galvanized bars?

Based on the findings of the Board 211 ads, the union of galvanized bars in concrete is lower due to early for the release of hydrogen when the zinc reacts with calcium hydroxide in the concrete and the presence of hydrogen tends to reduce the strength of the bond between galvanized bars and concrete. However, the union will increase over time until the full bond strength of galvanized bars is not reached.

Epoxy-coated bars are bond strength of 20% below the bar at the bottom of the concrete components while bars on top of it there is not much difference compared to the uncoated side bars.

What kind of reinforcing bar corrosion resistant, epoxy-coated bars, stainless steel or galvanized rods?
Based on the experience carried out by the Building Research Establishment, it was shown that the corrosion resistance of galvanized steel, were the worst among the three types of reinforcement bar. For galvanized steel rods began to corrosion occurs when a certain chloride content in concrete (equivalent to 0.4% by weight of cement) was exceeded. But for the epoxy bars, extended the time it takes to cracks that occur when comparing with galvanized steel bars.

The best stainless steel reinforcement corrosion resistant all. Specifically, the austenitic stainless steel has remained non-corrosive, even chlorine contamination occurred in the concrete experience. Reference is made to KWJ Treadaway (1988).

Tie reinforcement son next to and above Class F4 and F5 finishes shall be stainless steel. Why?

If the son of plain steel fasteners are used for reinforcement adjacent to the class F4 and F5 are finished, raise the issue with rust stains which can degrade the appearance of exposed surfaces of concrete. The rate of corrosion of mild steel son home correspond to normal steel reinforcement. But to tie the son with very small diameter, after long exposure he has a good chance of completely rust and the rust will stain the formwork and significantly affect the finishing of concrete. Therefore, the stainless steel wire tie to specified locations in the vicinity of high-quality finish to prevent rust stains from corroded son writing.

Note: Tie the wires are wires used for connecting and strengthening of steel reinforcement bars.
If the ordinary steel tie wires are used to confirm the F4 and F5 the next class to run out, will cause problems with rust stains, which can alter the appearance of exposed concrete surfaces. Amount of corrosion of ordinary steel tie wire is similar to that of normal steel reinforcement. However, tying the threads of a very small diameter, while a long exposure, is a great opportunity to completely rust and rust stains, mold and these significantly affect the concrete surface. Therefore, stainless steel wire binding posts are set in the vicinity of a high quality finish to avoid rust staining typing corroded cables.

Note: The son of this type is the child for fixing and connecting the reinforcing steel bars.

What is the effect of corrosion on steel frames?
Corrosion of rebar in a concrete structure is undesirable in the following ways:

(I) the presence of rust weakens the bond strength of d'armature because corrosion occurs in the ribs raised and bridges the gap between the ribs, the smoothing of the original shape distorted. In strains of the essence of the relationship between concrete and deformed bars of the mechanical lock between the ribs raised and concrete. The reduction of the mechanical blocking of corrosion resulting from the decrease in bond strength with concrete.

(Ii) the presence of corrosion reduces the effective cross-sectional area of ​​reinforcement. Therefore, the ability of available traction force of the reinforcement was reduced by a significant reduction in the surface of the section.

(Iii) corrosion products occupy about three times the initial volume of the steel from which it is formed. These drastic increase in the volume generates significant forces defects near the reinforcement. Therefore, cracks are formed along the reinforcement when the tensile strength of concrete is exceeded.

Column reinforcement, why sometimes designed helical reinforcement instead of normal links?
Use of links to the design of columns in Britain is very popular. But American engineers tend to use stronger links rather normal helical spiral reinforcement due to a potential benefit to protect the columns / cells against seismic loads. Moreover, when the graph drops non-state crack-free concrete and hoop first, followed by any failure of all columns. Concrete cylindrical shells without reinforcement gives a warning before the sudden failure of columns as suggested by GP Manning (1924). In addition, it can take up to a higher workload than usual link reinforcement.

For example, helical reinforcement is taken in the design of batteries thrown overboard by the government.

Note: helical reinforcement concerns the reinforcement is cut in a spiral.

Preload Of Engineering

The economy of RCC water tank rests on solid ground vis-à-vis the prestressing of concrete water tanks resting on firm ground
Water tanks are used to store water and are designed as crack free structures, to eliminate any leakage. In this paper design of two types of circular water tank resting on ground is presented. Both reinforced concrete (RC) and prestressed concrete (PSC) alternatives are considered in the design and are compared considering the total cost of the tank. These water tank are subjected to the same type of capacity and dimensions. As an objective function with the properties of tank that are tank capacity, width &length etc.

A computer program has been developed for solving numerical examples using the Indian std. Indian Standard Code 456-2000, IS-3370-I,II,III,IV & IS 1343-1980. The paper gives idea for safe design with minimum cost of the tank and give the designer the relationship curve between design variable thus design of tank can be more economical ,reliable and simple. The paper helps in understanding the design philosophy for the safe and economical design of water tank.                                                                                          What is stress corrosion of prestressing steel                        Stress corrosion cracking is a crystalline metals under tensile stresses in the presence of corrosive materials. Conditions of stress corrosion cracking occurs in the steel tensile stresses due to external loads or stress-induced internally (eg tendons). In addition, the presence of corrosive agents is essential to stress corrosion cracking start. A key feature is that the stress corrosion fracture of material with no damage observed from the outside. Therefore, stress corrosion cracking caused by the obvious warning signs.
The length of the steel work, if more than one wire or tape is the same, because all the cables / wires out at the same time?
 If the child thread / individually highlighted in the same conduit, then these

stressed the wire / wire stand against the dull and the trap. Therefore, trapped in cable friction is high and is desirable.
 

What are the characteristics of the mortar inside the tendon ducts?

 An oath is a pre serve the following purposes:

(I) To protect the tendon against corrosion.

(Ii) improving the limited capacity of the tendon.

(Iii) the link between the structural and the tendon.

(Iv) In case of failure, the anchor is not subject to all the strain energy.
Because spalling confirmation is required for prestressing anchor is prevented?
  Prestressed anchor blocks of work generally consists of balancing pop reinforcement reinforcement, reinforcement and erosion. Reinforcement of rupture is used when the tensile forces are induced during the operation of the preload and the maximum pressure occurs when the trajectories of the breakdown voltage are concave towards the line of action of the load. The reinforcement is needed to resist these lateral tensile forces. For the reinforcement of balance is necessary when there are several anchorages of prestressing loads are applied sequentially.

During the pre-load, the stresses generated in the chipping area behind the loading of the faces of the anchor blocks. In the area between two anchors, a volume surrounded by concrete compressive stress trajectories. The forces are induced in the opposite direction to the applied forces and forces the output of the concrete anchor. On the other hand, limitations of scale are in place thanks to the compatibility restriction on the effect of Poisson's ratio.
In such circumstances it is used by engineers to lift one end, and at both ends in the preload works?
 During the operation of preload at one end, frictional losses occur and the prestressing force along the tendon decreases until it reaches the other end. These frictional losses include the friction due to a change of curvature of the tendon sheath and also wobble effect due to the difference in the alignment of the canal from the midline. Therefore, the prestressing force in the mid-range or at the other end will be significantly reduced in case of loss of friction is high. Therefore, the bias from both ends of a single span that is half preload tendon at one end, and the remaining half at the other end is made to ensure uniform distribution and to provide symmetry the prestressing force along the structure.

In fact, the stress at the other end is only possible to take advantage of low cost compared with the emphasis on both ends. Number of segments (for example, two blocks) and the irregular arc, lifting is usually done at the end of the longest period in order to obtain a position of force majeure claim the largest positive moment. On the contrary, hijacking the end of a shorter period would be, if the negative moment of the interim control preload on the force. If, however, the entire span is long enough to lift both ends should be considered.

What forces blood parasites?                                                                                                                               In isostatic structures, donors would be some concrete structures to fold up. Therefore precambering usually done to counteract this effect and make it more pleasing in appearance. But for the deformation of statically indeterminate structures of concrete members is hampered by restrictions, and the forces of parasites then developed by the leading force in addition to the bending moment generated by the eccentricity of tendons. The forces developed on the support modifies the response of concrete members subjected to external loads and produce secondary moments (or moments parasites) in the structure.
What are the major potential benefits in the form of use of precast girder bridge prestressed concrete slab above site?                                                                                                             The potential benefits of using the bridge is prestressed precast beams supporting in situ concrete slab above are:

(I) For bridges built over rivers and roads, this form of bridge provides the platform for work by the precast beams so that construction of temporary structures is not necessary.

(Ii) that forms a bridge usually requires no cross beams or membranes (except for the location of the bridge supports), which reduces construction time and costs.

(Iii) It creates the potential for the simultaneous construction of taking several

Why kind of tension is better, preload preload internal or external?                                                                                        Different places the time interval (the third or fourth in points), the tendons are deviated from the correct profile of the concrete span preload external switches. Advantages of external prestressing are listed below:

(I) Due to the lack of connection between the tendon and its structure, exterior prestressing allows the removal and replacement of tendons or two at a time that the bridge could be adapted in case of damage and capacity could be increased easily. This is essential for bridges in urban areas where traffic problems is not desirable.

(Ii) it is usually easy access to anchor points and allows easy inspection.

(Iii) allows adjustment and control of the forces of the tendons.

(Iv) allows the designer more freedom in selecting the cross sectional shape of the bridges.

(V) web could be made thinner, so there is a reduction in dead load.

(Vi) is improved by reducing friction losses, as unintentionally as angular oscillation is eliminated. In addition, the use of polyethylene pipes external prestressing a coefficient of friction lower than the internal corrugated steel pipe prestressing.

(Vii) improvement of the concrete placement networks due to air channels.

A significant difference between the tendon internal and external post-tensioning steel is in the variation of eccentricity of the cable. Deflected shape of the external tendons is not exactly like the bars because of

moving the external tendons are controlled by evil. This is a second-order effect on the workload, and it is very important to the ultimate load.

Based on previous research, to include a small shallow (less than 3 m deep) with internal preload requires less steel reinforcement. However, deep cross section of the bridge, employment

Preload external results in a small amount of steel reinforcement.

Soil Engineering

If adopted high preload in the struts braced excavation?
Pre-loading in the struts braced excavation helps eliminate potential movement. The use of preload reduces the shear stress in the soil, previously established by the excavation. Because of the rigidity of the soil, they can use high preload the struts are not desirable, because the movement of strut local departure could cause damage to public services nearby.
For Peck, the pressure boundary of braced excavation, the total weight or actual weight used in the trapezoidal and rectangular envelope?
Asset utilization and rest the theory is not applicable in the braced excavation. Basically spacers higher tendency to be more crowded, while lower spacers appear to be less responsible in comparison with the theory of the pressure force.

Peck measured reinforcement loads are converted to the pressure of the earth. For example, the limit of the pressure of cohesionless soils is 0.65rHKa

where

r = soil density

H = height of the excavation

Ka = coefficient of active pressure

Some engineers consider r the total weight of the soil to apply any pressure. However, Peck said, "the pressures are not substantially affect the coefficient of active earth pressure and redistribution of

rectangle or a trapezoid. "So an effective weight of soil to use for r the pressure of water is added separately.
The excavation was prepared, why Rankine's theory of lateral earth pressure is not applied?
The excavation was prepared, piling was built first, followed by the installation of braces, as a result of the excavations. After installing the first row of tabs, the depth of excavation is small, so that there is a great performance from the earth. However, as the excavation takes place, the performance of the ground before installing the line number of the spacers. The first row of slats prevents the transfer of near surface. Therefore, the deformation of the walls increases with depth with the lowest land. Because of the effect of the construction method of excavation was prepared, unlike the condition of deformation of the Rankine theory. This is attributed to the effects of the ark in which there is a redistribution of loads up. The top of the excavation will be mounted in the state of elastic equilibrium, while the fund is in a state of plastic equilibrium.
What is the difference between the method of the land of free technical support and method fixed earth support?

For free earth support method, the soils at the lower part of piling is incapable of inducing effective restraint so that it would not result in negative bending moments. In essence, the passive pressures in front of the sheet piles are insufficient to prevent lateral deflection and rotations at the lower end of piling. No passive resistance is developed on the backside of the piling below the line of excavation.

For fixed earth support method, the piling is driven deep enough so that the soil under the line of excavation provides the required restraint against deformations and rotations. In short, the lower end of piling is essentially fixed.                                                                                                                                           Is bleeding to test a prerequisite for the grout?
Bleeding is a form of segregation, where a layer of water migrates to the surface of the grout in the initial phase of the process of cement hydration. Later, some liquid water reabsorbed in the grout due to additional hydration reactions. Even without the problem of bleeding, there is an overall reduction in the volume of grout after treatment of hydration compared to the total individual initial reaction of cement and water. Bleeding tests should be performed to grout for the following reasons:

(I) During the riser duct bleeding water from the mixture of slurry to the formation of channel paths inside the grout mixture. These channels act as potential pathways for materials to go aggressive, because these

channels would not be closed when the additional hydration of the grout.

(Ii) the loss of volume by bleeding inside the product shall render the milk mixture affecting the properties and performance of the grout. It also increases the possibility of corrosion of steel elements protected by the grout. (Tendons, etc.)

(Iii) The test of bleeding, there is a usual requirement for a total re-absorption of water after 24 hours the composition of the grout, because for some cold countries, this layer of water, causing serious problems freezing, leading to freezing.
The presence of colluvial slopes good?

Colluvium refer to the deposit same area running down the mountain slopes under the influence of gravity. It differs from the remaining land, degradation of the discontinuity, part of the textures preserved. The rolling action colluvium destroy these features.

Colluvium shows some important features that deserve attention:

(I) seems to be stronger than the residual soil to erosion and tends to provide protection to the ground below.

(Ii) the relatively low permeability compared to the rest of the ground below to form a perched water table at the base of a thunderstorm.

(Iii) the remains of earth, when the slope cut out the presence of relict joints can affect slope stability. But the base layer of colluvium is also a location map of potential error.
Dykes and decomposed dolerite slope stability?
Decomposed dolerite dikes are rich in clay show a high plasticity. In addition, the material is generally low permeability of the decomposed granite, which has many sides.

The presence of dolerite dykes degrades the direction parallel to the surface of the slope after slope failure can cause intense and prolonged rains. Shortages due to the permeability of the decomposed dolerite dykes, to sit in groundwater could be developed for the dams, and this is substantially more positive pore water pressure, which reduces the shear strength of soil.

The presence of dolerite dikes broken in a direction perpendicular to the surface of the slope can also cause a break in the slope after the storm. The low permeability of the materials tend to act as the construction of dams on the level of local groundwater for water coming down from the upper slopes. The increase in water level behind the "prey" leads to increased water pressure of the pores to reduce the resistance of the soil on slopes, leading to later failure.

What are the effects of pile groups, the stability of a slope?
Soil moisture on the slopes of Hong Kong usually consists of colluvium and rock weathering on fresh. Groundwater flow of the sloping terrain, and can participate in the race and the flow of water main. As the permeability of the soil tends to decrease with depth, the flow of groundwater can occur above the water table, which includes a tour of the lower surface of the water.

The presence of a lot of teams below the water table to prevent the flow of groundwater, which increases the level of groundwater. Significant developments in the slopes with a lot of influence has its roots in a sort groundwater is cut off. Growth of the lower surface of the water due to the effects of dam groups reduce the pile of slope stability, reducing the shear strength of the soil and eventually lead to failures slope.

Rising groundwater levels tend to increase with the angle of the slope and

depth of the groundwater flow.

How can you fill in the geogrid reinforcement?
Geogrid can fill the other side of the grid to meet the key to the other side of the grid. This is why it is different than the capacity of interlocking strips of soil reinforcement. Placing on both sides of the fill could be obtained from the condensation and the static load over the filling.

To trigger intersect the plane of the geogrid, the work must be done to expand the ground and defeat the forces of friction.

Piles Engineering

What are the effects of pile groups on slope stability?
Soil moisture on the slopes of Hong Kong usually consists of colluvium and rock weathering on fresh. Groundwater flow of the sloping terrain, and can participate in the race and the flow of water main. As the permeability of the soil tends to decrease with depth, the flow of groundwater can occur above the water table, which includes a tour of the lower surface of the water. The presence of a lot of teams below the water table to prevent the flow of groundwater, which increases the level of groundwater. Significant developments in the slopes with a lot of influence has its roots in a sort groundwater is cut off. Growth of the lower surface of the water due to the effects of dam groups reduce the pile of slope stability, reducing the shear strength of the soil and eventually lead to failures slope.

The rise in groundwater levels tend to increase with the angle of the slope and
depth of groundwater.

What are the problems associated with prestressed concrete piles                                                           The origin of Daido piles come from Japan where the prestressed concrete piles used as a replacement layer. The holes are pre-formed in the soil and the batteries are placed inside these holes Daido pre-formed with subsequent sealing of the cavity between the studs and the adjacent land. However, in Hong Kong Daido piles are constructed by driving into the ground by hammers instead of the replacement method originally conceived. Since the installation method of Daido piles are modified design problems that the deformation of the shoe pile tip, the crushing of concrete at the pile tip, etc. occur. See BW Choy (1993).

If compression is used to freshly placed concrete piles?                                                                                                                                                     In normal practice, belief in self-compression of concrete designed to produce mixtures of adequate compression. The use of the vibrating poker vibrators are rarely adopted for the compaction system

concrete piles. In fact, apart from considerations of the impracticality of using vibrating device in long piles there is serious concern about the possible presence of total lock in with the extraction of underwear problems. In the worst case scenario, temporary enclosures and cages frames extracted by lifting the pile of intestines. This is another reason that accounts for not using vibrating machines to piles of mining clothes.

Is the quality of concrete deterioration due to free fall method of concrete placement in the bored piles?
Based on studies of STS Consultants Ltd., it was found that the concrete set in a free fall of less than 120 feet do not have the problem of segregation and the concrete would not be adversely affected, provided that the "pile hole and the ground is dry and free of debris. Furthermore, it has been suggested previously that during the free fall of concrete into a pile of concrete falls hitting the holes in the strengthening of the cage to cause segregation. However, in accordance with experimental results from STS Consultants Ltd., a large cage of fresh concrete reinforcement has no significant effect on concrete

In addition, long bored piles, it is not practical to perform concrete vibration. Concrete set of free fall of the method, the shock caused by the free fall should be sufficient to cause vibration. On the other hand, the concrete method Tremie September seems to be a lack of vibration and this may affect the strength and integrity of the concrete. The results showed that the strength of the vibration of the concrete was slightly higher than actual unvibrated. Increased vibration turned out to be real advantage but not essential force to plan a lot of strength.

Why sheath used in bunkers built on the slopes?              
For the skyscrapers built on steep slopes cut in buildings are usually supported by piles of large diameter. Although the depth of piles based on some tracks, due to lateral wind loads on buildings can cause failures and cause slop slope. Depth gradient is somewhat unstable, prone to failure slope.

Therefore, a ring of compressible material called a sheath is inserted into cells in order to reduce the lateral load transfer, the buildings of the tracks.
What is the purpose of sealing the root of the tree?       Grout in the operation of the trees, the tubes of tube-to-cuff is fixed in a regular space reinforcement cage. After the concrete strips / drilled shafts, a small volume of water injected at high pressure in the pipes to break the concrete. The cracking process must be carried out within 24 hours after concreting. The aim of cracking is to create a way for the suspension to pass. About a week after the concreting of the strip, the slurry is then performed in the hoses to improve friction between the foundation and surrounding soil.

Can hammer down a hole under the bottom surface of the water?                                                                                                          

Down the hole hammer has been used extensively to form pre-bored holes as rock sockets for mini piles and pre-bored H piles. The hammer functions by driving repeatedly a drill bit using compressed air on the rock. However, the use of down the hole hammer is normally limited to hole diameter of 600mm.

In using down the hole hammer, compressed air serves to drive the drill bit and to expel the cuttings which are blown out to the air at ground level. However, for driving the hammer about 30m below ground water level, the air pressure has difficulty in coping with great water pressure. Moreover, blowing of cuttings by compressed air also dewaters the nearby soils. As a result, settlement of nearby ground may occur which is undesirable.                                                                          

Why not reverse circulation drilling normal function of the conditions of the surface rocks?
Reverse circulation drill (RCD) is normally used for a large rock socket diameter. Method, strain, and download the power of cutting roller rock bits in a cycle of operations, and

grinding bit on the rock. The cuts are removed by reverse circulation. The water and cuttings are transported by air through a central drill pipe, which is also used to run the drill.

In order to facilitate the grinding action of rock, about 15 tons of force used in each cut. So great a little 'strength, drill core is intended to accommodate the body by binding to a bunch of boring posts. Therefore, during the

drilling activity, a lot of housing is prevented by increasing the weight of the drilling and casing pile and the friction developed in the pile and the body. Therefore, in shallow rock conditions, the reduced length of the pile of intestines, can affect the stability of the drilling RCD.

When clamps are used at work prestressed battery?    The use of prestressed clamps get rid of the need for reinforcements in the interior. Tensioning clamps are anchored in the rocks and granular soils and searches can be done with a shovel instead of digging reach large and small blades. It offers fewer restrictions and allows free movement of the excavations.

Bridge Engineering

Lateral torsional buckling of Long Bridge Suspension Span: geometrically linear analysis under wind load
Now, many long-term suspension bridges were built and their lengths to keep growing. As a result, the beam stiffness is relatively small and the wind forces have also declined. Therefore, the analysis of many experiments were carried out Futter. On the other hand, so it is important to study the lateral torsional buckling of suspension bridges, but research has not been done for decades. Of course, just use Hirai-Okauchi proposed formulation about 60 to confirm the stability with the problem. It contains a theoretical equation and the boundary conditions ideal for the application of the formulation is limited. Therefore, the need for a modern revision of the discharge of the suspension bridge is increasing. A suspension bridge span of time shows a fairly linear and nonlinear, when it shows its initial state and wind loads are applied. Therefore, the needs of some techniques.

Bridge is presented as the structural modeling and initial conditions of gravity. After this is presented how to analyze the lateral buckling of the bridge span length of torque with wind load. The wind load is calculated by the static coefficient of the wind. Finally, the result is displayed and the conclusion is presented.

What is stress corrosion cracking of prestressing steel?
Corrosion cracking of metals is the crystal under tensile stresses in the presence of corrosive agents. The conditions for stress corrosion to occur is that the steel is subjected to tensile stresses caused by stress loading induced external or internal (eg tension). Moreover, the presence of corrosive agents are essential to cause stress corrosion. A key element of stress corrosion fractures is that the material without any damage observed from the outside. Therefore, stress corrosion occurs without any obvious warning signs.
In prestressing work, if more than one wire or strand is included in the same duct, why should all wires/strands be stressed at the same time?                                If the son / strands are stressed individually within the same channel so they

Beach said / son will focus on these dull them and trap them. Therefore, the friction is high and son trapped undesirable.

Why is scaling building necessary support work in the anchor blocks?
Prestressed anchor blocks of work generally consists of balancing pop reinforcement reinforcement, reinforcement and erosion. Reinforcement of rupture is used when the tensile forces are induced during the operation of the preload and the maximum pressure occurs when the trajectories of the breakdown voltage are concave towards the line of action of the load. The reinforcement is needed to resist these lateral tensile forces. For the reinforcement of balance is necessary when there are several anchorages of prestressing loads are applied sequentially.

During the pre-load, the stresses generated in the chipping area behind the loading of the faces of the anchor blocks. In the area between two anchors, a volume surrounded by concrete compressive stress trajectories. The forces are induced in the opposite direction to the applied forces and forces the output of the concrete anchor. On the other hand, limitations of scale are in place thanks to the compatibility restriction on the effect of Poisson's ratio.

What are the three main types of reinforcement used in the preload?                                                                                                                    (I) strengthening Chipping

Peeling stresses are established behind the congested area of ​​anchor blocks and this leads to break with the concrete surface. These charges caused by the incompatibility of the effects of stress with fish, or form channels of stress.

(ii) Equilibrium reinforcement
Equilibrium reinforcement is required where there are several anchorages in which prestressing loads are applied sequentially.

(iii) Bursting Reinforcement
Tensile stresses are induced during prestressing operation and the maximum bursting stress occurs where the stress trajectories are concave towards the line of action of the load. Reinforcement is needed to resist these lateral tensile forces.

When should engineers use jacking at one end, and only at both ends of the prestressing work?
During the operation of preload on one end, frictional losses will occur and the prestressing force along the tendon decreases until it reaches the other end. These losses include the friction induced by the friction due to a change of curvature of the tendon sheath, and the wobbling effect due to misalignment of the axes drivers. Therefore, the prestressing force in the middle range or at the other end will be greatly reduced in the case of loss of friction is high. Therefore, the preload, the two ends of a single tranche, ie through the tendon prestressing total at one end and the other half at the other extreme is to allow a homogeneous distribution and to provide symmetry of the prestressing force along the structure.

Indeed, said only one end has the potential advantage of lower costs compared to the stress on both ends. For more spans (for example, two pins) with the length of the span jacking odd is usually carried out at the end of a longer period for giving a higher preload force at the point of maximum positive moment. On the contrary, jacking from the end of the shorter performed if the negative stage, intermediate supports control the prestressing force. But if the total length of the span is long enough, jacking from both ends into account.

What are the reactive forces of prestressing?                  Statically determined structures, the prestressing forces would cause the concrete structures, deflected upward. So precambering are mostly opposed to this end and make it look nice. However, statically indeterminate structures, the deformations of reinforced concrete structures to support and contain the forces of parasitic diseases have been developed for prestressing force, as well as the bending moment produced by the eccentricity of the tendons. Developed to support the forces of reaction to modify the concrete structures subject to external loads and moments to produce a second (or parasitic moments) structure.
How does the vortex-induced vibration on the stability of bridges along?                                                                                   When the wind flows around a bridge, would be useless in contact with the surface and shape of the boundary layer. At one point, the boundary layer tends to separate from the body due to excessive curvature of the bridge. This leads to the formation of vortices which revised the pressure distribution on the surface of the bridge. The vortex can not be formed symmetrically in the body of bridges and different lifting forces are formed around the body. Accordingly, the motion of bodies under this bridge cross the vortex must be incoming wind flow. As the frequency of vortices approaches the natural frequency of bridges, resonant vibrations often occur, whose magnitude depends on the damping in the system and the movement of wind on bridges. These oscillations are "locked in" the system and lead to dangerous amplification failure and fatigue.

concrete engineering

This work aims to study the evolution of resistance of Portland cement pastes and mortars, two mineral additives such as limestone filler and the finely ground slag.

Effects of the addition of two additions to mineral mortars Portland cement paste, were conducted to evaluate the development of strength depending on the age and condition of treatment. This study is a simplified approach to show the contribution of mineral additives on the development of mechanical strength and porosity is obtained using the method of exchange of methanol. In addition, to confirm that this study and is based on laboratory testing stations approximate equations were obtained

In which direction should the main weight of the strengthening of a series of concrete sidewalk?

Steels for concrete pavement is generally in the form of a long e-type. The road is usually the length is usually much longer than its width and, consequently, the cross is covered with broken

in the design. The reinforcement is needed in the longitudinal direction in order to limit the formation of transverse cracks, while the transverse steel to ensure the rigidity of the support acts mesh fabric. Mesh concrete slab over the main burden of the plot should be placed in the critical (ie the longitudinal direction) to control cracking. However, if the concrete road is wide enough, the strengthening of those will be placed in the transverse direction in this

cases to verify the longitudinal cracks.

What is the Marshall mix design for asphalt materials?
Marshall Mix Design Method was originally developed for the Mississippi Highway Department Marshal Bruce in 1939. The idea behind the Marshall method of mix design, selection of an asphalt binder content of the density of the event, which meets at least the stability and range of flow rates.

Marshall method of mix design mainly consists of the following steps:

(I) Determination of physical properties, size and gradation of aggregates.

(Ii) the selection of the types of bituminous binders.

(Iii) Prepare the initial samples, each with different content binder asphalt.

For example, three samples every 4.5, 5.0, 5.5, 6.0 and 6.5 percent of asphalt in the dry weight of a total of 15 samples. There should be at least two samples above and two below the optimum asphalt content estimated.

(Iv) Draw the following graphs:

() Asphalt binder content vs. density

(B) Asphalt binder content vs. Marshall stability

(C) Asphalt binder content vs. flow

(D) Asphalt binder content vs. air voids

(E) the asphalt binder content vs. holes in the mineral aggregate

(F) content of asphalt vs. empty notebook filled with asphalt

(V) Determine the asphalt binder content for the air voids content of 4 percent

(We) Determine the properties of the optimum asphalt binder content by reference to the graphics. Compare each of these values ​​against the design, and if everyone respects the design so that the optimum asphalt binder content selected is acceptable. Otherwise, the mixture should be rethought.

What is the principle of Design Mix Asphalt?                                                                                                                                    The main objective is to design asphalt mixes with a blend of economic aggregates with asphalt to achieve the following objectives:

(I) to facilitate easy placement of bituminous materials without experiencing segregation;

(Ii) to ensure that adequate stability under load is not carried out on the sidewalk and the distortion of movement;

(Iii) the sustainability of asphalt than enough;

(Iv) sufficient air voids

The design of the asphalt mix, high durability is usually done at the expense of lower stability. Therefore, a balance must be struck between sustainability and stability requirements.

The economy of RCC water tank rests on solid ground vis-à-vis the prestressing of concrete water tanks resting on firm groundWater tanks are used to store water and are designed as structures for cracks, eliminate leaks. In this paper design of two types of water tank on the basis of a circular field is presented. As reinforced concrete (RC) and prestressed concrete (PSC) are considered in the design of alternatives are compared and given the total cost of the tank. These reservoirs are subject to the same capacity and size. As an objective function with the properties of the deposits that are the tank capacity, width and length, etc.

A computer program was developed to solve using standard numerical examples from India. Indian Standard Code 456-2000, SE-3370-I, II, III, IV & IS 1343-1980. The document gives the idea for the design of security with minimal cost of the tank and give the designer of the relationship between design variable and design curves of the tank may be more economical, reliable and simple. The document helps to understand the design philosophy for the design of water tank safely and economically.

Behavioral studies of double-walled hollow steel concrete composite columns                                                                             This book contains an experimental study in eight double-skin concrete filled steel tubular (DSCFT) concentrically positioned around the beam columns filled with self-sealing concrete. Tests of samples was performed by applying an eccentric load. The main parameters of the experimental beam-column were the ratio of slenderness and eccentricity of the load. Test examines the behavior of individual load-deflection effect of childbirth, and the strength of the columns. Experimental observations have shown the load-deflection curves. Several properties such as strength, stiffness, toughness, and troubleshooting are discussed. Against the expected load ratios are good with the deformation of the beam-column test results. DSCFT columns filled with SCC, showing good strength and toughness. Modified equations are proposed to find the maximum compression force DSCFT columns filled with SCC.

The presence of rust have adverse effects on the performance of the rebar obligations?

In fact, the presence of rust in bars may not have adverse impact to the bond performance and it depends on the types of bar reinforcement under consideration.

For plain round bars, the rust on bars improves the bond performance by the formation of rough surfaces which increases the friction between steel and concrete.

However, for deformed bars, the same theory cannot apply. The presence of rust impairs the bond strength because corrosion occurs at the raised ribs and subsequently fills the gap between ribs, thus evening out the original deformed shape. In essence, the bond between concrete and deformed bars originates from the mechanical lock between the raised ribs and concrete. On the contrary, the bond between concrete and plain round bars derives from the adhesion and interface friction. With such differences in mechanism in bonding, the behaviour of bond between deformed bars and plain round bars in the presence of rust varies. Reference is made to CIRIA Report 147.

The presence of rust have a negative impact on the strengthening of the bond market performance bar?

In fact, the presence of rust in bars may not have adverse impact to the bond performance and it depends on the types of bar reinforcement under consideration.

For plain round bars, the rust on bars improves the bond performance by the formation of rough surfaces which increases the friction between steel and concrete.

However, for deformed bars, the same theory cannot apply. The presence of rust impairs the bond strength because corrosion occurs at the raised ribs and subsequently fills the gap between ribs, thus evening out the original deformed shape. In essence, the bond between concrete and deformed bars originates from the mechanical lock between the raised ribs and concrete. On the contrary, the bond between concrete and plain round bars derives from the adhesion and interface friction. With such differences in mechanism in bonding, the behaviour of bond between deformed bars and plain round bars in the presence of rust varies. Reference is made to CIRIA Report 147.

The History Of The Profession Of Civil Engineer

Civil engineering is a professional engineering discipline that deals with the design, construction and maintenance of integrated physical and natural environment, including works such as bridges, roads, canals, dams and buildings. [1] [2] [3] Civil engineering is the ancient discipline after military engineering, [4] and has been defined to distinguish non-military engineering military engineering. [5] is traditionally divided into several sub-disciplines such as environmental engineering, geotechnical engineering, structural engineering, transportation engineering, municipal engineering and urban water resources engineering, materials engineering, coastal engineering, [4] topography construction and engineering [6] Civil engineering takes place at all levels. municipal public sector, through national governments and the private sector of individual owners of international companies.

Contents

[Hide]

* 1 History of the profession of civil engineer

* 2 History of Civil Engineering

Engineer 3 *

OR 3.1 Training and licensure

OR 3.2 Careers

* 4 sub-sectors

o 4.1 Coastal Engineering

Ø 4.2 Civil Engineering

o 4.3 earthquake engineering

or 4.4 Environmental Engineering

Ø 4.5 Geotechnical

or 4.6 Water Resources Engineering

OR 4.7 Materials Engineering

Ø 4.8 Structural design

or 4.9 Topography

OR 4.10 Transportation Engineering

o 4.11 City Engineer or City

* 5 See also

* 6 References

* 7 External links

[Edit] The history of the civil engineering profession

See also: History of structural engineering

Engineering was one aspect of life from the beginning of human existence. The first civil engineering practices may have begun between 4000 and 2000 BC in ancient Egypt and Mesopotamia (ancient Iraq) when humans began to abandon a nomadic existence, causing a housing need. Meanwhile, transport has become more important leading to the development of the wheel and sailing.

Until modern times, there was no clear difference between civil engineering and architecture, and the term engineer and architect were mainly geographical variations, referring to the same person, often in the same direction. [7] The construction of the pyramids in Egypt (c. 2700-2500 BC) can be considered the first instances of large structure constructions. Other ancient historic civil engineering works are the water management Qanat (the oldest of more than 3000 years and more than 71 km [8]), which Iktinos Parthenon ancient Greece (447-438 BC), the Appian Way Roman engineers (c . 312 BC), Great Wall of China by General Meng T'ien Ch'in emperor Shih Huang orders Ti (about 220 BC) [6], and built on ancient stupas in Sri Lanka Jetavanaramaya and extensive irrigation works in Anuradhapura . The Romans developed civil structures throughout their empire, including, in particular pipes, insulae, ports, bridges, dams and roads.

The Archimedes screw was operated by hand and could raise water efficiently.

In the 18th century civil engineering term was coined to include all things civil, as opposed to military engineering. [5] The first self-proclaimed civil engineer John Smeaton, who built the Eddystone lighthouse. [4] [6] In 1771, Smeaton and some of his colleagues formed Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Although no evidence of technical meetings, which was little more than a social society.

In 1818, the Institution of Civil Engineers was founded in London, and in 1820 the eminent engineer Thomas Telford became its first president. The institution received a Royal Charter in 1828, to officially recognize civil engineering as a profession. Its charter defined civil engineering as:

the art of directing the great sources of power in nature for the use and convenience of man as the means of production and circulation in the states, both foreign and domestic trade, as applied in the construction of roads, bridges, aqueducts , canals, river navigation and docks for internal reporting and exchange, and construction of ports, docks, seawalls, breakwaters and lighthouses, and the art of navigation by artificial power for the purposes of trade and the construction and use of machinery, and the drainage of cities and villages [9].

The first private school to teach in civil engineering from the United States became Norwich University founded in 1819 by Captain Alden Partridge. [10] The first degree in civil engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835. [11] The first such degree to be awarded to a woman, was granted by Cornell University, Nora Stanton Blatch in 1905 [12].

[Edit] History of Civil Engineering

Pont du Gard, France, the Roman aqueduct was built around 19 BC.

Construction of water projects is the application of principles of physics and science, and its history is closely related to the development of understanding of physics and mathematics throughout history. Since engineering is a profession full, a series of individual sub-disciplines, special, its history is linked to knowledge structures, materials science, geography, geology, soils, hydrology, environment, mechanics and other fields.

The entire design of ancient and medieval history, most architectural and construction made by craftsmen such as masons and carpenters, rising to the role of the manufacturer. The information was stored in advance and rarely displaces corporations. Structures, roads and infrastructure, there have been frequent, and have been gradually increasing scale. [13]

One of the first examples of a scientific approach to physical and mathematical problems applicable to civil engineering works of Archimedes in orders of 3 century BC, including Archimedes Principle, which supports our concept of buoyancy, and practical solutions, such as Archimedes' screw '. Brahmagupta, Indian mathematician, arithmetic is used in the 7 th century AD, which is based on the Hindu-Arabic numerals, quarrying (by volume) calculations. [14]

[Edit] Civil engineers

[Edit] Education and licensure

Main article: Master

The Institution of Civil Engineers headquarters in London

Civil engineers usually have a university degree majoring in civil engineering. The duration of studies of this degree is three to five years and the title is usually designated as an engineering degree, although some colleges to designate a Bachelor of Science degree. The degree generally includes units covering physics, mathematics, project management, design and specific issues of civil engineering. Initially cover topics such as most if not all, of the sub-disciplines of civil engineering. Students then choose to specialize in one or more sub-disciplines towards the end of the measure [15]. While a student (BEng / BSc) usually provide students with the skills to succeed in the industry accredited colleges offer scholarships to some degree in Engineering (MEng / MSc) that allow students more specialized in their particular area interest in engineering [16].

In most countries, an engineering degree is the first step towards a vocational qualification and training certificate from a professional. After completing the training program certified by an engineer must meet several requirements (including work experience and examination), before certification. Once certified, the engineer is designated as a professional engineer (U.S., Canada and South Africa), Chartered Engineer (in most Commonwealth countries), Chartered Professional Engineer (Australia and New Zealand) or European Engineer ( much of the European Union). There are relevant international organizations, professional engineering agreements, which is designed for engineers in practice across international boundaries.

Benefits of certification vary depending on location. For example, the United States and Canada "only a licensed engineer may prepare, sign and seal, and leave the technical plans and drawings to give authority for approval, or seal technical work of planning for public and private clients. ". [17] This requirement is imposed by state and provincial, as engineers Quebec law. [18] In other countries, not by laws. Australia, the licensing of engineers has been limited to the state of Queensland. Practically all certifying bodies maintain the ethics that they expect all members to comply or risk expulsion. [19] In this way, these organizations play an important role in maintaining the ethical standards of the profession. Even in countries where certification has little or no legal effect on the work of engineers in contract law. In cases where the engineer does not work, may be subject to negligence, tort law and, in extreme cases, the equivalent of criminal negligence. [Edit] engineering works must also comply with numerous other rules and regulations such as building codes and legislation on environmental legislation.

[Edit] Career

There is no typical career path for civil engineers. Most people who have completed the construction of 'water to start asking a low degree of responsibility, and because of new engineers to demonstrate their competence, they are confident with the tasks that are larger implications and require greater accountability. However, every branch of civil engineering career change. In some sectors and firms, entry-level hardware engineers to work primarily monitoring construction in the area, serving as "eyes and ears" top designers, while in other areas, entry-level technicians to perform routine analysis and design and interpretation. Experienced engineers are usually more complex analysis or design work, or managing complex engineering projects or management of other engineers, or as part of specialist advice, including forensic engineering.

[Edit] Sub-disciplines

Falkirk Wheel in Scotland.

In general, the construction of water applies to the entire user interface of human created fixed projects to a larger world. General closely with engineers surveyors and engineers to meet and serve fixed projects to a specific site and the terrain by designing grading, drainage, paving, water, sewerage, electric supply and communications, and land divisions. General engineers spend much time visiting the projects, to develop a consensus at European level, and preparation of construction plans. General engineering is also known as website design, a branch of civil engineering that focuses mainly on the intestinal conversion in March by a user to another.

Civil engineers typically apply the principles of geotechnical engineering, structural engineering, environmental engineering, transport engineering and construction works projects for residential, commercial, industrial and public sectors of all sizes and levels of the building.

[Edit] Coastal Engineering

Main article: coastal areas

Coastal planning and managing coastal areas. In some jurisdictions the terms of the fortress and protection of coastal areas is used to refer to protection against flooding and erosion. The term coastal defense is the more traditional term, but coastal management has become increasingly popular as the field has expanded to include, which can be used to request the erosion of the country.

The construction industry for buildings with more

[Edit] Construction engineer

Article: construction engineering

The design of the buildings related to the design and implementation models for transportation, site development, hydraulic, environmental, structural and geotechnical engineers. Because construction companies are typically higher business risk than other companies in civil engineering, civil engineers usually take a lot of the role, which is a business like any other in nature: drafting and reviewing agreements, to assess the logistical operations, and closely monitoring prices of necessary supplies.

[Edit] Earthquake Engineering

Main article: Earthquake Engineering

Earthquake engineering covers the ability of structures to withstand hazardous exposure to earthquake sites in your particular region.

Earthquakes and massive pyramid El Castillo, Chichen Itza

Earthquake engineering is a discipline in the broader category of construction engineering. The main objectives of earthquake engineering are: [20]

Snapshot of shake-table video [2], the basic test-isolated (right) and regular (left) building model

* Understand the interaction of structures with weak foundations.

* Describe the consequences of possible earthquakes.

* Design, build and maintain structures to achieve the exposure to the earthquake of up to expectations and in accordance with building regulations.

[Edit] Environmental Technology

Main article: Environmental technology

A filter bed, a part of the treatment

Environmental engineering deals with the treatment of chemical, biological and / or thermal waste, purifying water and air, and rehabilitation of contaminated sites, due to prior waste disposal or contamination accidental. Among the topics covered by environmental engineering are pollutant transport, water purification, wastewater treatment, air pollution, solid waste and hazardous waste. Environmental engineers may be involved in reducing pollution, green technology and industrial ecology. Environmental technology also deals with the collection of information on the environmental consequences of proposed measures and assess the impact of the proposed measures are intended to help policy makers and policies in the decision-making.

Environmental technology is the modern term for sanitary engineering, although traditionally, sanitary engineering had not included the majority of hazardous waste and remediation of the environment covered by the terms of the environment of engineering. Certain other terms used are the public health engineering and engineering environmental health.

[Edit] Geotechnics

The construction of a dam embankment, Navarra, Spain

Main article: Geotechnical

Geotechnical engineering is a field of civil engineering dealing with the rocks and soil that civil engineering systems support. Knowledge in the fields of geology, materials science and testing, mechanics and hydraulics are applied by geotechnical engineers to design safe and economical foundations, retaining walls and similar structures. Environmental concerns related to groundwater and waste disposal have spawned a new field of study called geoenvironmental engineering in biology and chemistry are important. [21] [22]

Some of the unique challenges of geotechnical engineering are the result of variability and soil properties. The boundary conditions are often well defined in other branches of civil engineering, but with soil, clearly defining these conditions can be impossible. The material properties and behavior of soils are also difficult to predict due to soil variability and limited research. This contrasts with the properties of the material that is relatively clear of steel and concrete used in other areas of civil engineering. Soil mechanics, which describes the behavior of soils, is also complicated because the soils are not linear (stress-dependent) strength, stiffness and dilatancy (volume change associated with the application of shear) [21].

[Edit] Water Resources Planning

See also: hydraulic engineering and hydrology

Hoover Dam