直剪试验有效剪切面积动态变化的改进计算  

The Improved Calculation of the Dynamic Changes of the Effective Shear Area in the Direct Shear Test

作　　者：刘海波[1] 张丽华[1] 林大超[1] 范丽萍[2] 

机构地区：[1]华北科技学院土木工程系,北京101601 [2]北京科技大学土木与环境工程学院,北京100083

出　　处：《沈阳建筑大学学报（自然科学版）》2010年第3期503-506,共4页Journal of Shenyang Jianzhu University：Natural Science

基　　金：国家十一五科技支撑计划项目(2007BAB18B01)

摘　　要：目的研究直剪试验过程中随着剪切面的动态变化的改进计算公式,以使剪切实验的结果更加准确.方法在试验工程中,针对直剪仪上下盒相对移动,有效剪切面积逐渐减小这一实际,采用数学分析的方法,力求从理论上探寻直剪试验的准确计算公式.结果推导出了改进后的理论公式,为验证理论分析的正确性,采取了不同土样并保证试验土样条件完全一致情况下,对改进前后通过试验得到的土体抗剪强度指标数值进行对比分析,结果表明改进后的计算方法得到的黏聚力比原方法最大减少了28.3%;内摩擦角比原方法最大减少了26.2%,也就是说改进后的方法更加接近了真实值.结论改进后的计算公式原理清晰,计算简便,具有一定的实用性.The formula was studied for shear plane for the dynamic changes in the paper and find out the improved method of direct shear test,so that more accurate results of shear experiments can be obtained.During the trial project,for the direct shear test box up and down in relative movement and the effective shear area is gradually decreased in the practice,this paper employs mathematical analysis methods,and strive to explore exact formula of the direct shear test.As a result,the improved theoretical formula was deduced.In oder to verify the correctness of theoretical analysis,this paper takes a different soil samples and test soil samples in ensuring the conditions exactly the same circumstances,the values of the testing of soil shear strength before and after the improvement has been comparatively analyzed,the results show that the original test method to a large extent,overestimated the soil shear strength indicators,sticky cohesion error decreased as much as 28.3%;internal friction angle decreased by as much as 26.2%.The improved formula,clear and simple,has a certain practical significance.

关 键 词：直剪试验 有效剪切面积 黏聚力 内摩擦角 改进计算 

分 类 号：TU411.7[建筑科学—岩土工程]