基于概率统计方法的隔震结构可靠度

该文用概率统计的方法分析隔震结构的抗震可靠度。对两个实际的隔震结构建立三维有限元模型并进行时程分析，求得层相对加速度、层间位移角、隔震支座剪应变和压应力等结构的动力响应参数，同时，收集隔震支座力学性能的实验数据并结合数值模拟，用假设检验方法，明确了隔震结构的各动力响应参数和隔震支座的抗力参数均服从对数正态分布，再用最大似然估计法，得到了隔震结构各动力响应和隔震支座抗力的概率特征参数。给定隔震结构的失效模式，建立以结构抗力和反应为变量的功能函数，采用一次二阶矩法，分析隔震体系的抗震可靠度，结果发现：按目前《建筑抗震设计规范》的隔震结构，与非隔震结构相比，即使上部结构的水平地震作用减小60%~70%，也不一定能达到“中震不坏”和“极大震不倒”的抗震性能目标，说明在编的《建筑隔震设计规范》对隔震建筑提出更高的要求。

STUDY ON ASEISMIC RELIABILITY OF ISOLATED STRUCTURES BASED ON PROBABILITY STATISTICS METHOD

Probability statistics method is used to investigate the aseismic reliability of isolated structures. For two existing isolated buildings. The finite element models were built and dynamic responses were calculated by time history analysis, including the relative story acceleration, story drift, shear strain and compressive stress of rubber isolators. The mechanical properties of rubber isolators were gathered by experiment and numerical simulation. Structures dynamic responses and isolators mechanical properties are proved to follow a lognormal distribution by a hypothesis test, and two probability characteristic parameters are calculated by the maximum likelihood estimation. With the combination of given failure modes and performance functions of resistances and responses, the aseismic reliability of isolated structures is investigated by a second moments method. It shows that:if isolated structures conform to the code for aseismic design of building, and horizontal seismic effects of superstructures reduce 60% to 70% compared with non-isolated structures, it is possible to fail to reach the demand "repairable under rare ground earthquake, not collapsed under very rare ground earthquake". Thusly, Code for aseismic design of seismic isolated buildings on editing proposes a higher request for isolated buildings.