考虑砂土颗粒破碎的圆孔扩张半解析分析  

Semi-analytical solution to cavity expansion in crushable sands

作　　者：蒋明镜[1] 孙渝刚[1] 

机构地区：[1]同济大学土木学院地下建筑与工程系,岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2009年第11期1645-1651,共7页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50679057);上海市浦江人才计划(06PJ14088)

摘　　要：圆孔扩张理论在岩土工程中应用较广。采用修正的临界状态模型来描述砂土三种不同压缩变形机制:颗粒重分布,颗粒破碎和拟弹性变形,结合空间滑动面(SMP)屈服准则和不相关联流动法则,通过编写Matlab微分方程求解程序,获得考虑砂土颗粒破碎的圆孔(柱孔和球孔)扩张问题的半解析解答。以加拿大Quebec砂土为例,将该圆孔扩张解答结果与基于常规临界状态模型的解答进行比较分析,结果表明:颗粒破碎对砂土在高应力及临界状态的应力解答及变形特征影响显著,在采用圆孔扩张理论解释静力触探试验及旁压试验时应考虑颗粒破碎的影响。The cavity expansion theory has been widely used in geotechnical engineering. A modified critical state model is employed to account for the three different modes of compressive deformation, i.e., particle rearrangement, particle crushing and pseudoelastic deformation. In combination with the spatial mobilization plane （SMP） failure criterion and non-associated flow rule, the semi-analytical solutions are obtained to expansion in crushable sands by using the Matlab differential equation solver. In comparison to those solutions where a conventional critical state line is used, the results obtained for Quebec sand indicate that particle crushing does occur at high stress and critical states and affects the stress fields surrounding the cavity and the deformation behaviour. This leads to conclusion that particle crushing has to be taken in account when the cavity expansion theory is used to interpret cone penetration tests and pressuremeter tests.

关 键 词：修正的临界状态模型 空间滑动面屈服准则 临界状态线 颗粒破碎 圆孔扩张 

分 类 号：TU411[建筑科学—岩土工程]