含水率对膨胀土力学性质和非等长双排桩支护变形影响分析

The Moisture Impact Analysis on the Mechanical Properties of the Expansive Soil and the Supporting Deformation of the Isometric Double-row Piles

膨胀土的力学性质很不稳定,极易受到水的影响,引起重大工程事故。以成都东郊膨胀土基坑工程为背景,把含水率作为影响膨胀土力学性质和非等长双排桩变形的主要因素;对膨胀土进行室内直接剪切实验,利用Excel对实验数据进行线性回归,分析了含水率对膨胀土抗剪强度τ、黏聚力c和内摩擦角φ的影响规律及原因。结合有限元分析软件MIDAS/GTS对非等长双排桩支护结构进行建模分析,分别讨论了不同内聚力c和内摩擦角φ对桩体最大位移和A、B型桩最大弯矩的影响规律,并给出成都东郊地区膨胀土的建议含水率。

The mechanical properties of expansive soil is very unstable,highly vulnerable to the influence of water,and causing major engineering accident. Chengdu expansive soil foundation pit engineering in the east suburb as the background of study,and considering the moisture content as the factories of affecting the expansive soil mechanics properties and the main factors of the isometric double row pile deformation,direct shear tests for expansive soils were made indoor,the Excel was used to linear regression of experimental data,and the influence rules and reasons of moisture content of expansive soil shear strength τ,cohesive force c and internal friction angle were analyzed. Combining with the finite element analysis software MIDAS / GTS for the isometric retaining structure with double-row piles modeling analysis,and the influence rules of different cohesion c and internal friction angle φfor the maximal displacement of pile body and the influence law of A and B type maximum bending moment of pile were discussed,and given the advice of the expansive soil moisture content in the east suburb of chengdu area was given.