Forces that are acting perpendicular to the longitudinal axis of the beam cause bending stresses which are termed as flexural stresses, beside flexural stresses beams also undergo shear stresses and normal stresses.
We know from the basic concepts of internal forces in the beams that whenever some load either dead load, live load, imposed load, superimposed load or whatever is applied, it…
Concrete is one of the widest used construction material whether it is a dam or a house or a bridge or flyover. Concrete is basically of three components water, aggregate and cement. Aggregate acts as a filling agent while cement mostly Portland cement act as a binding…
Intersection is an area shared by two or more roads. This area is designated for the vehicles to turn to different directions to reach their desired destinations. Its main function is to guide vehicles to their respective directions. Traffic intersections are complex…
Mass transportation is any kind of transportation system in which large numbers of people are carried within a single vehicle or combination of vehicles. Airplanes, railways, buses, trolleys, light rail systems, and subways are examples of mass transportation systems. The term mass transit is commonly used as a synonym for mass transportation.
Mass transit system refers to public shared…
Construction on the palm islands began in 2001. Divers surveyed the seabed and workers constructed a crescent-shaped breakwater from blasted mountain rock. The Crescent of Palm Jumeirah stands a little more than 13 feet above low tide sea level and sits in 34 feet of water…
A bridge is a structure that is used to cross some form of barrier, making it easier get to one place from another. Other barriers, such as rivers, have always confronted travelers and traders who wanted to take the shortest, quickest and safest route to complete their…
CHANGSHA, June 27 (Xinhua) — A 2-tonne truck was driven onto the world\’s longest and highest glass bridge in Zhangjiajie, Hunan Province in central China, on Sunday in a safety test ahead of its slated opening in July.
The 430-meter bridge tucked between two steep cliffs is 300 meters above the ground.
To further convince the public of the bridge\’s sturdiness, 20…
Negative skin friction occurs when concrete piles are situated in soft soils, consolidating soil-mass, etc., resulting in a downward force that increases loading on shaft piles and reduces the bearing capacity of the piles. A new concept based on the shifting rate of piles…
TMB is used as an alternative to drilling and blasting (DB) methods. TBMs are used to excavate tunnels with a circular cross section through a variety of subterranean matter; hard rock, sand or almost anything in between.
As the TBM moves forward, the round cutter heads…
To determine the orientation of guided bearings, one should understand the movement of curved region of a prestressed bridge. Movement of prestress and creep are tangential to the curvature of the bridge (or along longitudinal axis) while the movement due to temperature and shrinkage effects are in a direction towards the fixed pier. If the direction of guided bearings is aligned towards the fixed…
What are the advantages of piers constructed monolithically with the bridge deck over usage of bearings?
May 27, 2016
Basically, piers constructed monolithically with the bridge deck are advantageous in the following ways:(i) Movement of the bridge deck is achieved by the bending deformation of long and slender piers. In this way, it saves the construction cost of bearings by using…
Diaphragms are adopted in concrete box girder bridges to transfer loads from bridge decks to bearings. Since the depth of diaphragms normally exceeds the width by two times, they are usually designed as deep beams. However, diaphragms may not be necessary in case bridge…
In roller bearing for a given movement the roller bearing exhibit a change in pressure centre from its original position by one-half of its movement based on David J. Lee.
However, with sliding bearing a sliding plate is attached to the upper superstructure and the moving part of bearing element is built in the substructure. It follows that there is no change in pressure center after the…
An escalator is a type of vertical transportation in the form of a moving staircase – a conveyor transport device for carrying people between floors of a building. The device consists of a motor-driven chain of individually linked steps that move up or down on tracks…
Why is the span length ratio of end span/approach span to its neighboring inner spans usually about 0.75?
May 27, 2016
From aesthetic point of view, an odd number of spans with a decrease in length in the direction of abutment is desirable. Moreover, spans of equal length are found to be boring. However, the arrangement of irregular span lengths is not recommended because it gives a feeling…
In the design of a simply supported skew bridge, which direction of reinforcement should be provided?
May 27, 2016
In the conventional design of steel reinforcement for a simply supported skew bridge, a set of reinforcement is usually placed parallel to free edge while the other set is designed parallel to the fixed edge. However, this kind of arrangement is not the most efficient way of placing the reinforcement. The reason is that in some parts of the bridge, the moment of resistance is provided by an obtuse…