深部土层失水变形时土与井壁相互作用试验与理论研究

Testing and theoretical studies on the interaction between soil and shaft wall during deep soil compression due to losing water

介绍了用高压直剪仪和三轴伺服仪测定大埋深土与井壁相互作用试验方法 ,得到了土与井壁相互作用剪应力 -位移曲线、单位刚度系数和强度等参数。结合试验结果 ,分析了深部土层失水变形时 ,土与井壁接触带相互作用深部为塑性浅部为弹性的变形特点。建立了土与井壁相互作用理想弹塑性分析模型 ,得到了计算井壁附加竖直位移、应变和附加应力的解析公式 ,并讨论了其随深度和深部土层压缩量等因素变化的规律。最后给出计算实例 。

A method for testing the interaction between soil and shaft wall by high pressure direct shear apparatus and triaxial servo test system has been presented. The shear stress-displacement curves, coefficient of unit stiffness and strength parameters of the interaction between soil and shaft wall are obtained. Combining the tested results, it is analyzed for the deformation characteristics of the interaction on the interface zone between soil and shaft wall during the compression of the deep soils due to losing water, which is plastic and elastic in the deep and shallow part respectively.An elastic perfectly plastic analysis model of the interaction between soil and shaft wall has been set up. Some analytic formulae to calculate the additional vertical displacement, strain and stress of the shaft lining are obtained. The variation law of these values of the shaft lining with the depth, compression value of the deep soils and so on are discussed. Finally presented are two cases with calculated results to show the practicability of the theoretic research.