THE APPLICATION OF MODIFIED CAM-CLAY MODEL IN DPC PILE-SOIL INTERFACE
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摘要: 针对DPC桩-土结构层开展大型直剪试验,基于试验分析,在考虑DPC桩-土结构层注浆影响上引入临界应力比,构建了可描述应变软化的修正剑桥模型应力应变方程。直剪试验表明DPC桩-土结构层剪切特性表现为剪切软化,具有明显的峰值强度和残余强度,呈现出明显的结构性,其特征与超固结的黏土的剪切应力应变曲线特性类似。推导出的修正剑桥模型能较好的解释实验结果,所得出的结论对DPC桩的设计有一定的指导意义。Abstract: A series of large direct shear tests were carried out for the DPC pile-soil structure layer. Based on the experimental analysis, the critical stress ratio was introduced considering the influence of DPC pile-soil layer grouting, and a modified cam-clay model which can describe the strain softening was constructed. The direct shear tests show that the shear behavior of DPC pile-soil structure layer is shear softening, with obvious peak strength and residual strength, and the structure layer shows structural properties. The results of these tests are well reflected in the modified Cam-clay model. The conclusion has guiding significance for the design of DPC piles.
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表 1 试验土的基本物理力学参数值
Table 1. The fundamental physical and mechanical parameters of the tested soils
桩周土 最优含
水率/%最大干密度/
(g·cm3)液限
WL塑限
WP粘聚力/
kPa内摩擦角/
(°)粉质黏土 18.5 1.71 24.1 16.53 11.6 31 素填土 14.4 1.88 40.7 25.1 23.1 33 表 2 模型参数值
Table 2. Values of the model parameters
DPC桩—结构层 λ κ e0 v M Mz β η DPC桩—粉质粘土 0.11 0.025 0.66 0.30 0.24 1.7 0.35 1.50 DPC桩—素填土 0.12 0.021 0.58 0.25 0.92 2.3 0.30 1.33 -
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