RC桥墩残余位移指标影响因素分析及贝叶斯估计

Influence factors analysis and Bayesian estimation for residual displacement index of RC pier

为揭示拟静力作用下钢筋混凝土(RC)桥墩残余位移指标参数影响规律,并给出变形极限状态残余位移指标贝叶斯估计。采用OpenSees软件建立RC桥墩拟静力试验构件模型,基于试验结果模拟进行模型验证。通过256个RC桥墩拟静力数值分析计算结果,研究残余位移指标统计特性及主要影响因素。在此基础上,采用线性回归分析方法,建立桥墩残余位移指标先验概率分布模型。应用贝叶斯理论,通过小样本试验数据更新,建立拟静力作用下残余位移指标后验概率分布模型。结果表明,RC桥墩残余位移指标主要影响因素为轴压比,且随轴压比的增大而减小。建立的后验概率分布模型能够准确估计残余位移指标,从而为RC桥墩抗震设计或评估中考虑残余位移随机性提供了便利。

Here,to reveal effect laws of parameters on residual displacement index of RC pier under quasi-static force action,Bayesian estimation of residual displacement index in deformation limit state was deduced.The quasi-static test component model of a RC pier was established with the software OpenSees,and the model was verified using simulation based on test results.Based on quasi-static numerical analysis calculation results of 256 RC piers,statistical characteristics of the residual displacement index and main influencing factors were studied.Then,the linear regression analysis method was used to establish the prior probability distribution model of RC pier residual displacement index.Based on Bayesian theory,the posterior probability distribution model of RC bier residual displacement index under quasi-static action was established through updating small sample test data.The results showed that the main influencing factor of residual displacement index of RC pier is axial compression ratio,the index decreases with increase in axial compression ratio;the established posterior probability distribution model can be used to accurately estimate RC bier residual displacement index,it can provide conveniences for aseismic design of RC bier or considering the randomness of its residual displacement in evaluation.