Define seismic isolation bearings - bridge bearing, Civil Engineering

Assignment Help:

Define Seismic Isolation Bearings  - Bridge Bearing?

Many bridges had been built before the proper seismic design specifications were known to us. These bridges require strengthening and enhancing the ductility of substructures in order to sustain the earthquake forces. Conventional retrofitting methods are costlier (more than 3 times) than providing 'Seismic Isolation Bearings' (SIB). The studies have shown that:

(a) The SIB eliminated the in-plane torsional rotation of the bridge and resulted in a more uniform distribution of seismic forces among substructures in the transverse direction.

(b) The modifications in the response of the bridge resulted as a result of use of SIB because the effective fundamental period of the bridge get elongated due to the flexibility provided by the SIB.

(c) Average retrofitting cost using SIB is calculated as only 30% of that using conventional retrofitting methods.

An isolation bearing induce sufficient lateral flexibility in a bridge structure and increase the period of vibration, resulting in a reduced force response. The increased lateral flexibility is associated with larger horizontal displacements at the bearing level. In the longitudinal direction, the stiffness of a bridge with isolation bearings is the sum of the stiffness of all piers and abutments including the bearings. In a bridge with conventional bearings. However, the longitudinal stiffness incorporates the stiffness of a fixed support alone. The isolation bearings should also include a restoring force to return the superstructure to its pre-earthquake position.


Related Discussions:- Define seismic isolation bearings - bridge bearing

State average increase of pressure in the clay stratum, A building was to b...

A building was to be constructed on a clay stratum. Preliminary analysis showed a settlement of 60 mm in 6 years and an ultimate settlement of 250 mm. The average enhance of pressu

Crushing strength test - tests on stones, Crushing Strength Test: F...

Crushing Strength Test: For conducting this test, specimen of size 40 × 40 × 40 mm is build from parent stone. Then finely the sides are dressed and placed in water for thr

Surveying, How to read verniers and main scale readings on theodolite of 10...

How to read verniers and main scale readings on theodolite of 10"?

Leveling, how to find the correction on leveling calculation

how to find the correction on leveling calculation

Pavement layers and their functions, Pavement Layers And Their Functions ...

Pavement Layers And Their Functions Flexible Pavement A typical modern flexible pavement for high traffic is composed of layers as under (Figure). Figure: L

What is an ice dam sock, If you have never used an ice dam melting sock on ...

If you have never used an ice dam melting sock on your roof before, you will search that they give an inexpensive method for removing roof ice dams and improving your home's heatin

Local scour at obstructions in rivers, Q. Local Scour at obstructions in ri...

Q. Local Scour at obstructions in rivers? When the water flow in river is deflected by obstructions such as bridge piers, scouring would occur arising from formation of vortexe

Design of elastomeric bearings, Q. Design of elastomeric bearings? The ...

Q. Design of elastomeric bearings? The standard drawings of bridge bearings issued by RDSO are on the basis of UIC 772-R. To maintain uniformity of approach, the design of elas

Basic considerations governing selection of road alignment, Basic Considera...

Basic Considerations Governing Selection of Road Alignment: The following considerations shall be kept in view in selecting the road alignment: Roads in Plain Areas (a)

Illustrate the concept of load balancing, Concept of load balancing In ...

Concept of load balancing In above cases of concentric and eccentric pre-stressing, straight tendon profiles (or tendon shapes) along the beam span have been considered. If a t

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd