基于孔穴扩张和临界状态的黏土超固结比估算

黏土超固结比常规测试方法很难消除应力释放和土体扰动的影响,提出基于孔穴扩张和临界状态概念的利用旁压试验估算黏土超固结比的新方法,该方法能够充分利用旁压试验成果和临界状态参数。运用该方法估算了4种不同类型黏土的超固结比,并与改进的固结试验得到的超固结比展开对比。结果表明:在重度超固结比黏土中,该方法与固结试验获得的超固结比变动范围相近;在轻度超固结比黏土中,该方法获得的超固结比稍大于固结试验获得的超固结比;估算结果能够满足工程勘察要求。该方法作为一种估算黏土超固结比的原位测试新方法,扩大了旁压试验成果的应用范围,具有一定的工程实用价值。

Determination of OCR of clays by lateral pressure test based on cavity expansion and critical state concepts

It is difficult to eliminate the effects of stress release and soil disturbance when using conventional test method to determine the ratio of over consolidation (OCR) of clays. A new determination method of clay OCR by lateral pressure test using cavity expansion and critical state concepts is presented, which can make full use of lateral pressure test results and critical state parameters. The new method is used to estimate OCR of 4 types of clays and the results are compared with those values obtained from improved consolidation test. The results show that for over consolidated clays, the OCR obtained by the new method is in agreement with that of consolidation test, and the OCR obtained by the new method is slightly larger than that of consolidation test for lightly over consolidated clays, which all meet the requirements of engineering survey. As a new in-situ method to evaluate OCR of clays, the new method expands the application scope of the lateral pressure test and has certain engineering application value.