近断层地震作用下基础隔震层组合限位振动台实验研究

近断层脉冲型地震作用下,基础隔震结构隔震层会产生过大变形,导致隔震支座侧倾失稳,隔震体系破坏。设计制作了3层基础隔震钢框架实验模型和11种U型钢板I型铅棒组合限位器,进行了U型钢板静力加载实验和近断层脉冲型地震作用下基础隔震层软碰撞限位振动台模型实验。实验表明：①静力加载时,U型钢板具有很好的弹性性能;②动力作用下,组合限位器残余变形较小,仍具有良好限位复位能力;③近断层地震作用下,基础隔震层软限位效果良好,同时控制上部结构层间变形在允许范围内。

Shaking Table Test Study on Combined Displacement Restraint of Base Isolation Layer under Near-fault Ground Motion

The near-fault pulse-type ground motion may bring about excessive deformation ot base isolation layer. The isolation bearings will buckle and the isolation system will be destroyed. Eleven kinds of U-shaped steel plate and I-shaped lead rod displacement reslraint devices were de- signed and tested. A 3-story base isolation frame model was made of steel and the shaking table model tests were carried out under near-field pulse-type ground motion. The test results show that： （1） The U-shaped steel plate limiting devices has favorable elastic properties under the stat- ic loading test; （2） The combined limiting devices have smaller residual deformation under dy- namic test, but still have better capacity of limiting and restoring deformation; （3） The base iso- lation layer obtains desired results of soft limiting deformation under near-fault ground motion, meanwhile the storey deformation of upper structure can be controlled within the allowed range.