三峡库区碎石土抗剪强度指标的试验研究

以现场取得的碎石土为原料,通过筛分试验,确定其平均级配,以平均级配为基础,利用代替法设计试验级配。在试样含水量的确定上,抛弃了传统含水量的确定方法,结合碎石土的特点,以碎石土中细粒的多少来确定试样的含水量。在制样上抛弃了以往用控制干密度制样的方法,改用相同竖向压力下制样的新方法。对库区不同碎石含量、不同含水量的碎石土剪切强度进行了试验研究。根据抗剪强度与细粒含水量及碎石含量的变化关系,以细粒的液性指数和碎石含量为指标,提出了碎石土抗剪强度的实用计算公式。

Experiment research on shear strength index of gravel-soil in Three-Gorge reservoir area

With the in-situ gravel-soil as trial materials, mean gradation is determined by particle size analysis. On the basis of the mean gradation, test grading is designed with substitution method. According to the character of gravel-soil, the water content of samples is determined according to the content of clay, abandoning accustomed way for the decision of soil. The samples are made under same vertical pressure, giving up the traditional method by controlling dry density. Density and shear strength of gravel-soil with different content of gravel and water in the Three Georges Reservoir Zone (TGRZ) are considered with laboratory studies. According to the relation between shear strength and water content of clay and content of gravel, a practical formula for shear strength of gravel-soil is put forward with liquidity index of clay and content of gravel.