摘要
基于ANSYS概率设计系统(PDS),首次在引水暗渠灰土挤密桩复合地基承载力可靠性分析中运用非线性随机有限元法.以灰土挤密桩竖向荷载、弹性模量、泊松比及岩土的黏聚力等作为随机变量,并考虑了随机变量之间的相互作用,采用蒙特卡罗数值模拟法中的拉丁超立方进行抽样,计算出引洮工程引水暗渠湿陷性黄土灰土挤密桩复合地基以灰土挤密桩桩端最大应力为控制条件的失效概率为7.37%,可靠性指标为1.44.对随机变量进行了敏感度和相关性分析,判断出对失效概率影响较大的参数为土体的泊松比,其次为土体黏聚力、桩体弹性模量及土体弹性模量,其中,土体泊松比、土体黏聚力及土体弹性模量与灰土挤密桩结构最大轴向应力呈负相关,且相关性依次降低,桩体弹性模量与灰土挤密桩结构最大轴向应力呈正相关.研究结果可为工程施工、设计提供参考和依据.
In collapsible loess foundation construction of diversion channel,using lime-soil compaction pile treating thick collapsible loess foundation is a rising technology in the fields of engineering.Taking Gansu Yintao water supply proj ect as an example,based on ANSYS probabilistic design system （PDS）,the reliability analysis of bearing capacity on the diversion culvert lime soil compaction pile composite ground was first analyzed by nonlinear stochastic finite element method.Taking the vertical load,elastic modulus, Poisson ratio and cohesion force of the rock-soil of lime-soil compaction pile as random variables,and allowing for the interactions between these random variables,sampling by Latin Hypercube method in Monte Carle numerical simulation,using the maximum stress of lime-soil compaction pile as a control index,the failure probability of the lime soil compaction pile compound foundation in diversion culvert of Gansu Province Yintao water supply project was calculated as 7.37% and the reliability index was 1.44.The degrees of sensitivity and correlations of the random variable were analyzed,and the parameter which greatly affected the failure probability was soil Poisson＇s ratio,followed by soil cohesion,elastic modulus of pile and soil modulus of elasticity,wherein,Poisson ratio,soil cohesion and elastic modulus of lime soil compaction pile structure,the maximum axial stress negative correlation,and the correlation was lower and lower,the elastic modulus of pile of lime soil compaction pile structure was positively related with the maximum axial stress.The research results could provide evidences for design and construction of proj ects.
出处
《甘肃农业大学学报》
CAS
CSCD
北大核心
2015年第1期160-164,170,共6页
Journal of Gansu Agricultural University
关键词
随机有限元
概率
灰土挤密桩
蒙特卡罗法
敏感度
stochastic finite element method
probability
lime-soil compaction pile
Monte Carle meth-od
degree of sensitivity
