基于Q_(1)黄土直剪试验的单屈服面扩展模型研究

Study on Single Yield Surface Extended Model Based on Direct Shear Test of Q_(1) Loess

为了准确模拟Q_(1)黄土直剪受力状态的硬化响应,提出单屈服面扩展模型。以典型黄土-泥岩接触面滑坡滑带土附近Q_(1)黄土为研究对象,通过固结排水直剪试验获得一系列硬化响应,并获得模型常数;运用MATLAB实现模型数值计算,并模拟验证试验结果;同时,对模型屈服面的敏感性进行探讨。结果显示:单屈服面扩展模型可准确描述Q_(1)黄土直剪硬化力学响应;Q_(1)黄土硬化参数为0.35~0.02;含水率和硬化参数影响屈服面大小和弯曲状态;随着含水率增加,逐渐出现较低硬化参数的屈服面,而较高硬化参数的模型屈服面逐渐消失。单屈服面扩展模型丰富了岩土接触面本构模型,并为接触面滑坡的变形预测提供了依据。

A single yield surface extended model has been proposed to accurately simulate the hardening response of Q_(1)loess under direct shear stress.Taking Q_(1)loess near the sliding zone soil of typical loess-mudstone interface as the research object,a series of hardening responses have been obtained by direct shear test of consolidation drainage,and the model constants have been obtained as well.MATLAB has been used to achieve the numerical calculation of the model and verification of the experimental results by simulation.The sensitivity of the yield surface of the model has also been studied.The results show that the single yield surface extended model can accurately describe the mechanical response of Q_(1)loess under direct shear hardening.The hardening parameters of Q_(1)loess ranges from 0.35 to 0.02.Yield surface size and bending state will be affected by water content and hardening parameters.With the increase of water content,the yield surface of the model with lower hardening parameters gradually appears,while the yield surface of the model with higher hardening parameters gradually disappears.The single yield surface extended model enriches the constitutive model of rock-soil contact surface and provides a basis for deformation prediction of landslide on contact surface.