某水电站坝址左岸堆积体强度参数试验研究

Strength Parameters for Stack Body of Some Hydroelectric Power Station Left Bank

以某水电站坝址左岸堆积体为例,采用室内土工试验中大剪试验和三轴试验2种试验方法,测得碎石土的抗剪强度参数并进行对比分析。试验结果表明,三轴试验比大剪试验测得的碎石土抗剪强度参数值更真实、准确。并进一步提出2种试验结果的适用条件:大剪试验中的快剪适用于渗透系数小、受荷速度快的高塑性粘土,各向异性且剪破面未知的土体不宜采用快剪,对于渗透性较强的粗粒土,快剪的结果较三轴试验差异较大;三轴试验中的不固结不排水试验适合于一般粘性土、砂类土,但特易扰动土除外,其试验结果较接近实际。

With a stack body of some hydroelectric power station left bank as an example,in order to obtain rubble anti-shear intensity parameters,the results of the direct shear test and triaxial compression test were compared and analyzed.Experimental results show that： the rubble anti-shear intensity parameters measured by the triaxial compression test are more true and accurate and the applicable conditions of the two test results are also expounded;fast-shear test is fit for a high-speed plastic clay which has a smaller permeability coefficient and is to be loaded fast,but it is not fit for the soil which possesses anisotropy and unknown shear-breaking surface,in addition,in comparison with triaxial compression test,the results of fast-shear test are quite different for coarse-grained soil which possesses stronger permeability;the non-consolidated and undrained shear test is suit for general clay and sand soil,except soil disturbed easily,and the test results are closer to the real.