Performance of Novel Rectangular Partially Bonded Steel Mesh–Reinforced Elastomeric Bearings for Seismic Isolation of Bridges
Amir Abbas Karimi, Hamid Toopchi‐Nezhad, Parham Memarzadeh
Abstract
Steel plates have traditionally been the reinforcement of choice for conventional elastomeric bridge bearings. In addition, these bearings are often employed under fixed boundary conditions (bonded application) as seismic isolators. The main objective of this study is to develop a new type of elastomeric bearing with improved lateral flexibility and superior seismic isolation efficiency. The new bearing is a partially bonded mesh-reinforced (MR) elastomeric bearing. MR bearings employ high-strength steel mesh reinforcement layers instead of steel-reinforcing plates. Additionally, the bearing is utilized in a partially bonded application; that is, only a limited region at the central portion of the bearing contact surfaces is bonded to the top and bottom supports. Given this specific boundary condition and the bending flexibility of the mesh reinforcement layers, the MR bearing experiences lateral rollover deformations under shear loads. During lateral rollover deformation, the upper and lower surfaces of the bearing partially roll off the contact supports. This experimental study compared the cyclic lateral responses of bonded plate-reinforced (PR) bearings (as reference bearings) and their partially bonded MR-bearing counterparts. The elastomer material properties and geometrical characteristics of the two bearing types were identical. The experimental results suggest that partially bonded MR bearings are feasible, perform more flexibly in the lateral direction, and exhibit greater energy-dissipation capability than PR bearings.