物性参数对成都天然状态黏土抗剪强度的影响分析

Influence of Physical Parameters on the Shear Strength of Chengdu Natural Clay Strength

为揭示成都黏土抗剪强度参数与物理参数的关系及计算公式,以成都龙泉驿黏土为研究对象,采用数理分析和实验相结合的方法,研究非饱和黏土的天然密度、天然含水率、孔隙比、液性指数等物理指标对抗剪强度参数变化规律的影响。首先,基于各物理参数与抗剪参数的独立影响,通过曲线拟合得到抗剪强度指标随天然含水率、天然密度、孔隙比、液性指数变化的基本规律和拟合公式;其次,采用物理参数的不同组合方式对成都黏土抗剪强度参数进行多元回归分析;最后利用乘法效应建立了考虑天然含水率和天然密度同时变化时抗剪强度指标的计算公式。研究结果表明:成都黏土抗剪强度参数与天然密度和天然含水率密切相关,二者的交互影响可按照乘法效应进行组合,并给出不同方法得到成都黏土抗剪强度参数经验计算表达式。研究结果对成都黏土地区的工程抗震设计、防灾减灾的研究有参考意义。

In order to reveal the correlation and calculation formulas of the shear strength parameters and physical parameters of Chengdu clay,taking Chengdu Longquanyi clay as the research subject,mathematical analysis and experimental methods were used to analyze the influence of physical indexes such as natural density,natural water content,porosity ratio,and liquidity index of unsaturated Chengdu clay on the change rule of shear strength parameters.Firstly,based on the independent influence of each physical parameter and shear parameter,the curve fitting is analyzed,and the basic law and fitting formula of the change of shear strength index with natural water content,natural density,porosity ratio,liquidity index are obtained.Secondly,multiple combinations of physical parameters are used to perform multiple regression analysis on the shear strength parameters of Chengdu clay.Finally,the formula for calculating the shear strength index considering the simultaneous changes of natural water content and natural density is established considering multiplicative effects.The results show that the shear strength parameters of Chengdu clay are closely related to the natural density and natural water content.The interaction between the two can be combined according to the multiplicative effect,and different methods are given to obtain the empirical calculation expressions of the shear strength parameters of Chengdu clay.The research results are very important for the research of engineering seismic design,disaster prevention and mitigation in the clay soil area of Chengdu.