中文摘要：

随着乐山城镇化建设延伸至浅切丘陵区,其广泛分布的第四系粉质黏土成为工程建设的地质背景。针对工程地质特性将其划分为常年饱水沟谷区坡洪积粉质黏土（A类）、季节性饱水沟谷区坡洪积粉质黏土（B类）以及沟缘、斜坡区残坡积粉质黏土（C类）;并对三类粉质黏土部分物理力学参数变异性进行对比研究。基于χ^2拟合优度检验及可靠性截断概率,建立了浅切丘陵区粉质黏土概率密度函数及其最优概率分布模型,给出了各类粉质黏土物理力学参数的建议取值范围。结果表明：①粉质黏土力学参数变异性〉物理参数,不同类粉质黏土参数变异性A类〉B类〉C类;②物理参数最优分布模型多为正态分布,力学参数最优分布模型多为对数正态分布;③对比不同类粉质黏土,B类、C类粉质黏土参数的最优分布模型多为正态分布,A类粉质黏土参数最优模型多为对数正态分布。以P=0.683为样本参数可靠性截断概率,给出了乐山浅切丘陵区粉质黏土参数建议值范围,为该地区岩土工程可靠性设计提供科学依据。

英文摘要：

With the urbanization construction in Leshan extends to the shallow hilly region,the wide distribution of quaternary silty clay has become geological background of engineering construction. The quaternary silty clay can be divided into three types according to its characteristics of engineering geology,including the perennial water saturated zone gully slope alluvial silty clay（ type A）,the seasonal water saturated zone gully slope alluvial silty clay（ type B） and silty clay of slope area（ type C）,and the variation of partial physical and mechanical parameters have been compared and studied. Based on χ^2goodness of fit test and reliability probabilistic truncation,shallow hilly area clay probability density function and the optimal probability distribution model,and gave recommended range of all kinds of physical and mechanical parameters were established. The result shows that：（ 1） the variation of mechanical parameters of silty clay parameters 〉physical parameters,different types of silty clay parameter variability,type A 〉type B 〉type C; （2） the optimal distribution model of physical parameters is normal distribution,and the optimal distribution model of the mechanical parameters is mostly logarithmic normal distribution; （3） compared with different kinds of silty clay,the optimal distribution model of type B and type C silty clay parameters are mostly normal distribution,and the optimal model of type A silty clay parameter is log-normal distribution. Taking the P = 0. 683 as the sample parameter reliability truncation probability,the proposed value range of silty clay parameters in Leshan shallow hilly region is given,which provides a scientific basis for reliability design of geotechnical engineering in this area.