基于CPTU测试的先期固结压力确定方法试验研究

先期固结压力是土的重要力学特性参数,对变形计算和强度分析有较大影响。目前,先期固结压力的确定主要依赖于室内固结试验,但土样的采取会出现扰动,难以代表土层的真正实际状况,且室内固结试验耗时,效率较低。本文在总结国际上基于孔压静力触探(CPTU)测试确定应力历史的研究成果基础上,以高质量“未扰动”土样的固结试验得到的先期固结压力作为参考值,根据三个场地的CPTU试验,对不同预测方法进行了比较。结论表明:采用净锥尖阻力可较可靠地确定土的先期固结压力。

On preconsolidation pressure of clays from piezocone tests

The preconsolidation pressure is an important parameter for soil deformation calculation and strength analysis. The previous methods to obtain the preconsolidation pressure were generally based on the laboratory oedometer test, which was of time consuming and low accuracy due to disturbance. Based on the review of available methods for interpreting stress history from piezocone tests, the effectiveness of different empirical methods was compared according to the piezocone tests at three typical sites in China with the Vertek-Hogentogler CPTU system. It was shown that the method based on the net tip resistance was sufficiently accurate for determining the preconsolidation pressure.