Frankitex

The International Journal Of Engineering And Science (IJES)

The effect of varying load on Design of Elastomeric

pad bearing

Neeraj Kumar

Assistant Professor, Department of Civil Engineering, Bipin Tripathi Kumoan Institute of Technology (BTKIT) Dwarahat, Almora, Uttrakhand

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ABSTRACT

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Bearings are an important part of overall transportation and structural system. Bearings are provided in bridges to transmit the load from the superstructure to the substructure and thereby to soil mass in such a manner that the bearing stresses induced are within permissible limits. It accommodates certain relative movements between the superstructure and the substructure

. This paper describes the design of elastomeric pad bearing with loads varying from

300 KN to 1500KN. In this paper shows that rotation (α bimax) and permissible rotation with increasing load decreases and shape factor(S) increases with increasing load of elastomeric pad bearing.

Keywords:

Bridge, bearing, elastomeric bearing, elastomeric pad bearing, rotation and shape factor

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I. INTRODUCTION

Bearings are provided in bridges to transmit the load from the superstructure to the substructure and thereby to soil mass in such a manner that the bearing stresses induced

are within permissible limits. It accommodates certain relative movements between the superstructure and the substructure. Bearing are basically classified in two types based on D.O.F. as Fixed bearing and Expansion bearing. The expansion bearing s are that bearing in which rotation and translation both occurring. Expansion bearing are of five types as Sliding plate bearing , sliding-cum- rocker bearing, Steel roller -cum-rocker bearing, R.C. rocker expansion bearing, Elastomeric bearing. Elastomeric Bearing consisting of one or more internal layers of elastomeric bond to internal steel is laminated

by the process of vulcanization. The bearing shall cater for translation and / or rotation

of the superstructure by elastic deformation

. Elastomeric bearing are four types as

-a) Laminated Bearing 

b) Pad Bearing

 c) Strip bearing

, d) Pot Bearing

Elastomeric Pad Bearing is that bearing which is the Sandwich structure made of elastomer and natural rubber. In this steel bearing is not used. This bearing will

be vulcanised in a mould under pressure. It is also widely used because it is able to prevent and reduce the movement of the bridge due to few factors (like earthquake, creep,etc)

The following guidelines that considered when selecting a bearing are:

i.

Transverse and vertical load capacity

ii.

Movement capability

iii.

Durability and environment condition

iv.

Life cycle costing of bearing including initial cost and maintenance cost with frequency

v.

Aesthetic consideration

vi.

Unique factors specific to particular bridge

vii.

Effect of bearing selected on the subsurface because of longitudinal forces created by bearing friction or some specific cap width Generally, only one type of bearing should be used for each structure