Bridge Piers: Types and Requirements

Hello, folks! Today, we will talk about bridge piers. This is a two-part article, and it's the first part. You will find the second part here.

Any bridge structure is a blend of two parts: substructure and superstructure. For bridges with bearings, all the segments which move the loads from bearing to the ground is called substructure.

Substructure comprises bridge pier, projections, wing dividers, piles and so on while the superstructure comprises deck, supports or any part on which the traffic moves securely, for example, street way, braces, curves, and so on. In this article we attempt to talk about the piers, its capacity and its sorts.

Bridge Pier bolster the ranges of the bridge and move the loads from superstructure to the establishment. Piers ought to be sufficiently able to take the both vertical and even load. Its principle work is to move the load from the bridge superstructure establishment underneath it.

They are exposed to immense hub loads and bi-hub minutes and shear powers transverse and longitudinal. Said that, piers are typically pressure components of a bridge. Piers are alluded to as Bents as well.



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Published By
Rajib Dey
www.constructioncost.co
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How to measure steel for pier, pile and circular column with circular ties

This construction video offers detailed guidelines for measuring the steel quantity in circular column, piers, and piles.

Some vital information on circular column, pier and pile :-

Circular columns are uniform about any centroidal axis. The circular column contains a smaller cross section area (0.785 times the square column) but greater second moment of area (1.178 times the square column). There is less susceptibility for Circular column to buckling and it needs little more reinforcement to bear the identical load like a square column. Besides, circular sections contain unvarying torsion characteristics. Least number of bars necessary in a circular column is 6. There does not exist any weak corners as well as stress concentration in circular columns.

A pier refers to an elevated structure usually supported with well-spaced foundation system. The foundation system ranges from a Pile, Caisson or simple brick pillar that is formed on the basis of the sub-soil condition. The Pile and Caisson are set of deep foundations.

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Published By

Rajib Dey

www.constructioncost.co

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Types of pile foundations and their usages

There exist three types of construction piles foundations which range from driven piles, Cast-in-situ piles and Driven and cast-in-situ piles.

Driven Pile Foundations: Driven pile foundations are formed with concrete, steel or timber. These piles have to pass through prefabrication process prior to set up at the construction site. Driven piles are known as concrete when these are created with concrete. These piles are possessed through a pile hammer.

When driven piles are consumed with the granular soils, the correspond volume of soil is dislocated. This allows shrinkage of soil all over the sides of piles as well as the compression of soil. The piles which condense the soil alongside, it is known as compaction pile. This compression of soil enhances its bearing capability.

Saturated silty soils and cohesive soils contain inferior drainage capacity. As a result, these soils are not compressed once driven piles are drilled over it. The water must be discharged for the soil chosen to be compressed. So stresses are expanded beside the piles and must be transmitted through pore water only. The outcome will be enhancing the pore water pressure and reducing the bearing capability of the soil.

Cast-in-situ Pile Foundations: Cast-in-situ piles refer to concrete pile. These piles are created with drilling holes in the ground following the necessary depth and then the hole is filled up with concrete. If required, reinforcements are also utilized in the concrete. These piles consist of small diameter correspond to drilled piers.

Cast-in-situ piles denote straight bored piles or having one or more bulbs at intervals which have to be casted. The piles having one or more bulbs are recognized as under-reamed piles.

Driven and Cast-in-situ Piles: Driven and cast-in-situ piles provide same benefits provided by both driven and cast-in-situ piles. The process for setting up a driven and cast-in-situ pile is given below :-

A steel shell of diameter of pile is driven into the ground through a mandrel placed into the shell. Once the shell is driven, the mandrel is separated and concrete is discharged in the shell.

The shell is formed with corrugated and reinforced lean sheet steel (mono-tube piles) or pipes (Armco welded pipes or common seamless pipes). These types of piles are described as the shell type piles.

To form the shell-less type, the shell is removed once the concrete is arranged. Considering both the types of piles, the bottom of the shell is locked by a conical tip that can be disconnected from the shell. A broaden bulb may be created in both types of piles by driving the concrete beyond the shell. Franki piles belong to this type. Sometimes, the shell will be remained in place and the tube is concreted. The extensive use of this type of pile can be found in piling over water.

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Published By

Rajib Dey

www.quantity-takeoff.com

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