川西崩坡积混合土循环荷载下非饱和动本构模型

发布时间：2018-03-26 01:13

本文选题：非饱和土　切入点：崩坡积混合土　出处：《岩土力学》2017年08期

【摘要】：在川西地区,由砂砾石与黏土颗粒构成的混合土路基经常会发生沉降变形问题。对于交通荷载作用下土体中的累积变形,可通过建立循环荷载作用下的动本构模型进行描述。在边界面弹塑性理论的框架内,综合考虑崩坡积混合土非饱和状态和细颗粒含量两大主要影响因素,结合能比较真实描述非饱和土体湿陷性能的LC(loading-collapse)屈服曲线,同时基于可移动映射中心的映射准则,采用经典的修正剑桥模型作为塑性势方程,构建了混合土的非饱和动本构模型,其参数可通过拟合或常规试验获得。通过与试验结果进行对比,该模型不仅可以较好地反映非饱和混合土在静载和循环荷载下的力学特性,而且能够真实地预测土体在加、卸载过程中的滞回特性。其结果可为川西混合土路基沉降变形预测提供理论依据。
[Abstract]:In western Sichuan, the settlement of mixed soil subgrade composed of sand gravel and clay particles often occurs. The dynamic constitutive model under cyclic loading can be established. In the framework of the elastoplastic theory of boundary surface, two main factors affecting the unsaturated state and fine particle content of sloping mixed soil are considered synthetically. Based on the mapping criterion of movable mapping center and the classical modified Cambridge model as the plastic potential equation, the unsaturated constitutive model of mixed soil is constructed by combining the LC loading-collapse yield curve which can describe the collapsibility energy of unsaturated soil truly, and based on the mapping criterion of the movable mapping center, the modified Cambridge model is used as the plastic potential equation to construct the unsaturated constitutive model of the mixed soil. Compared with the experimental results, the model can not only reflect the mechanical properties of unsaturated mixed soil under static and cyclic loads, but also predict the addition of soil. The results can provide theoretical basis for prediction of settlement and deformation of mixed soil subgrade in western Sichuan.
【作者单位】：西南交通大学土木工程学院;
【基金】：国家自然科学基金非饱和崩坡积混合土动力特性的细粒效应与累积变形研究(No.41572245)~~
【分类号】：U416.1

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