基于谱随机有限元的地基沉降可靠度分析  

Reliability analysis of foundation settlement based on spectral stochastic finite element method

作　　者：胡晚亭 吕令毅[1] Hu Wanting;Lü Lingyi(School of Civil Engineering, Southeast University, Nanjing 210096)

机构地区：[1]东南大学土木工程学院,南京210096

出　　处：《工程建设》2018年第4期11-15,共5页Engineering Construction

摘　　要：通过在Winkler地基沉降计算中引入地基参数的随机场模型,建立了地基沉降的随机计算模型。在随机场离散和随机位移响应混沌多项式展开的基础上,推导了地基沉降的谱随机有限元方程。选用不同变异系数的地基随机场对结构进行了可靠度分析,分析结果表明:地基随机场的变异性对位移随机响应均值的影响极小,对标准差的影响较大;随着地基参数变异性的增大,地基沉降对限值的超越概率增加,结构可靠度降低;与蒙特卡洛模拟结果相比,谱随机有限元法的分析结果稳定可靠,且计算效率较高。A stochastic computational model of soil settlement was established by introducing a random field model of Winkler elastic foundation into soil settlement calculation. Based on the discretization of the random field and the polynomial chaos expansion of the stochastic displacement response,a spectral stochastic finite element equation for soil settlement was derived. Different coefficients of variation of soil random field were selected to conduct the reliability analysis. The results show that the variability of the soil random field has little influence on the mean value of the random displacement response,but has a great influence on the standard deviation. With the increase of soil variability,the excess probability of soil settlement increases while the structure reliability decreases. Compared with the Monte Carlo simulation results,the SSFEM analysis is stable and reliable and has a higher computational efficiency.

关 键 词：谱随机有限元 WINKLER地基 随机场 地基沉降 可靠度 

分 类 号：TB114.3[理学—概率论与数理统计] TU433[理学—数学]