制样误差对结构面直剪试验结果影响定量研究

在结构面直剪试验制样过程中,所产生的误差会对试验结果带来很大的影响。研究结构面制样误差对试验结果的影响具有十分重大的意义。推导结构面倾斜时的正、剪应力的修正公式,并研究控制结构面倾斜的2个参数爬坡角α、偏角β对试验结果的影响。定量分析结果表明:试验结果误差对控制结构面倾斜的因子爬坡角α敏感,而偏角β对试验结果影响较小,可忽略;最后提出了2种试验结果误差修正方法,并给出一修正实例。

QUANTITATIVE STUDY OF STRUCTURAL PLANE DIRECT SHEAR TEST RESULTS INFLUENCED BY SAMPLE PREPARATION ERRORS

How to obtain reasonable shear strength parameters of structural planes is one of the important topics in rock mechanics. Direct shear test is widely used to determine the shear strength parameters of rock joints. Sample preparation errors have great effects on shear strength obtained from the test. Great deviation between test results and true values will be generated unless the test results are amended. However，this kind of preparation errors can not be avoided under the current situation. So，it is significant to study the test results influenced by sample preparation errors. Normal and shear stresses correction formulae are deduced in this paper. In addition，the influence of parameters a and b on test results is also interpreted. Quantitative analysis shows that test results are sensitive to climbing angle a，while b has little effect on the test results，which is so tiny that it could be ignored. Two methods are put forward to amend the results，and an instance is also cited.