地裂缝带路基土不均匀轴向变形的铰接组合元件模拟  

A Combined Element Model with Hinged Connection for Simulating Inhomogeneous Axial Deformation of Subgrade Soil in Ground Fissure Zone

作　　者：卢全中[1,2] 李力[1,2] 彭建兵[1,2] 陈树峰[1,2] 胡鹏[1,2] 吴辉龙 

机构地区：[1]长安大学地质工程系,陕西西安710054 [2]长安大学西部矿产资源与地质工程教育部重点实验室,陕西西安710054

出　　处：《中国铁道科学》2015年第1期11-17,共7页China Railway Science

基　　金：国家自然科学基金资助项目(41130753;41272284);国家重大基础研究计划项目(2014CB744702);国土资源大调查项目(12120113004900);陕西省科技统筹创新工程计划项目(2011KTZB03-02-02);国家留学基金资助项目(201206565031)

摘　　要：地裂缝带路基土具有不均匀胶结的结构性,在三轴压缩条件下可发生不均匀变形。由于采用传统单元件以及刚性连接建立的组合元件模型不能反映其变形特性,因此将传统元件模型的刚性连接局部变为铰链连接,建立能反映不均匀轴向变形的铰接元件模型。运用该模型对三轴压缩条件下地裂缝带路基土的应力应变关系进行模拟的结果表明,该模型能较好反映地裂缝带路基土的不同变形阶段,同时还可以体现试样的渐进性破损和不均匀轴向变形现象。对几种简单铰接元件模型和传统固接模型的对比结果表明,铰接元件模型在弹性变形阶段的弹性模量相对较小,而屈服应力明显增大,反映了铰接元件模型的变形协调能力。Subgrade soil in ground fissure zone may undergo inhomogeneous deformation under triaxial compression due to its structure with uneven cementation. The traditional combined element model with single element and rigid connection can not reflect the inhomogeneous deformation characteristics. Accordingly, a hinged element model was proposed to simulate the inhomogeneous axial deformation by changing part of the rigid connection into hinged one. The model was adopted to simulate the stress-strain relations of subgrade soil in ground fissure zone under triaxial compression. Results show that the hinged model not only can better reflect the different deformation stages of subgrade soil in ground fissure zone but also can visualize the progressive damage and inhomogeneous axial deformation of the sample. Several simple hinged element models were compared to the corresponding traditional models with fixed connection, and the results illustrate that the elastic modulus calculated by hinged element models was smaller during elastie deformation stage, while the yield stress increased obviously, which reflected its coordination of deformation.

关 键 词：地裂缝带 路基土 不均匀轴向变形 组合元件模型 铰接模型 应力应变关系 

分 类 号：U213.14[交通运输工程—道路与铁道工程] TU43[建筑科学—岩土工程]