饱和黏性土抗剪强度的试验方法

Test method for shear strength of saturated cohesive soil

饱和黏性土的工程特性,与其应力状态密切相关。自然状态的地基土固结应力状态以及工程设计工况的应力状态,是确定地基土抗剪强度试验方法必须考虑的问题。通过原状土的土工试验,分析研究饱和黏性土抗剪强度试验方法及对其抗剪强度指标的影响,提出现场取得的不扰动土样,在试验室进行抗剪强度试验,必须进行恢复土样初始应力状态的预处理;应针对实际工程问题需要,确定固结压力及排水条件进行土样的剪切试验;资料整理时应区分工程应用的应力条件,小于前期固结压力的压力段和大于前期固结压力的压力段分别进行统计分析,确定抗剪强度指标。

The engineering properties of saturated cohesive soil are closely related to its stress state.In order to choose the method for shear strength tests correctly,the stress state of foundation soil under natural condition and engineering design must be considered.Through geotechnical tests on undisturbed soil,the influence of test methods on shear strength indexes is analyzed.It is proposed that disturbed soil samples derived from the field should be pretreated in the lab for shear strength tests so as to restore their initial stress state.According to the need of practical engineering problems,shear tests on soil samples should be performed to determine consolidation pressure and drainage conditions.In order to determine shear strength indexes,stress conditions of engineering application are supposed to be distinguished.Moreover,statistical analysis about the test data should be carried out respectively for the pressure section which is greater than the previous consolidation pressure and that which is smaller than the previous consolidation pressure.