用快剪试验推求先期固结压力

Determination of pre-consolidation pressure using quick direct shear tests

土体先期固结压力是判断土体应力历史的关键性指标。依据Wroth在一维固结条件下提出的不排水强度与超固结比(OCR)的关系式,利用快速直剪的剪切强度计算临界状态孔隙水压力系数Λ0,从而计算出OCR以及先期固结压力。对南京某黏土的重塑饱和黏土的试验分析结果表明,快剪试验确定的超固结比与设计超固结比基本一致,因此可作为求解土体先期固结压力的一个途径。

The preconsolidation pressure of soil is a very important index to decide the history of soil stress. In this paper, based on the relationship between undrained shear strength and over consolidation ratio（OCR） proposed by Wroth C. P. under one-dimensional consolidation condition, the critical state pore water pressure coefficient（Λ0） is calculated by the quick shear strength, and then OCR and pre-consolidation pressure can be obtained. The test results of the saturated remolded clay acquired in Nanjing show that the calculated OCR is approximately equal to the design, indicating the proposed method can be used as an way to determine the pre-consolidation pressure.