卸荷状态下黏性土的变形和强度试验研究
Experimental research on deformation and strength of cohesive soil under lateral extension
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摘要: 南京河西地区原状黏性土应力路径试验表明,不排水情况下,侧向卸荷试验得到的割线模量E5′0要大于轴向加荷试验得到的割线模量E5 0,且大致有E5′0=1.7 E5 0关系;轴向加荷和侧向卸荷条件下得到的有效抗剪强度指标基本一致。上述结论在工程实例数值模拟分析中的应用明显改善了地面沉降预测结果与实测结果的吻合程度。Abstract: Stress paths tests of undisturbed cohesive soils in Hexi area of Nanjing were used to simulate the stress state in excavation.It was indicated that the secant modulus E5′0 obtained from the lateral extension tests was larger than E50 from the axial compression tests and the approximate relation between them was E5′0 =1.7 E50.The same parameters of effective shear strength were obtained form the axial compression and the lateral extension tests.The predicted values of surface settlement in numerical analysis were obviously improved with the application of test results,and there were good agreement between the measured results and the numerical results.