直剪试验的面积校正方法及误差分析  

Correcting Method and Error Analysis for Sample Area in Direct Shear Test

作　　者：徐志伟[1] 周国庆[1] 刘志强[1] 周金生[1] 田秋红[1] 

机构地区：[1]中国矿业大学建筑工程学院深部岩土力学与地下工程国家重点实验室,江苏徐州221008

出　　处：《中国矿业大学学报》2007年第5期658-662,共5页Journal of China University of Mining & Technology

基　　金：国家自然科学基金重点项目(50534040);江苏省自然科学基金项目(BK2007040)

摘　　要：为定量估计不同尺寸试样直剪仪因试样面积减小对剪应力和强度指标的影响,对传统直剪仪和国内近年研发的几种大型直剪仪进行了剪应力面积校正和误差分析.用解析公式研究了不同尺寸试样不考虑面积减小的剪应力近似计算产生的误差随水平位移的变化趋势.结果表明:当位移不超过试样直径7.725%,标准直剪仪(Φ61.8 mm)和大型非标直剪仪的剪应力近似计算相对误差都不会超过10%,试样面积减小对剪应力-位移变化规律影响远大于对强度指标的影响,对后者的影响基本可忽略.In order to quantitatively estimate the influence of sample area decreasing on the shear stress and strength parameters, the sample area correction of shear stress and the error of conventional direct shear apparatus （DSA） and several large-sized DSA recently developed in China were analyzed. The variation of the error generated by shear stress approximate calculation without regard to the area reduction with the horizontal displacement of different-sized samples was studied using an analytic formula. The results show that the relative errors of the shear stress approximate calculation of standard DSA （Ф61.8 mm） and nonstandard DSA are less than 10% if the horizontal displacement does not exceed 7. 725% sample diameter. The influence of sample area decreasing on the shear stress-displacement relation is much bigger than on the shear strength parameters, and it can almost be ignored for the latter.

关 键 词：直剪试验 应力 校正 方法 

分 类 号：TU411[建筑科学—岩土工程]