一种基于能量孔隙水压力模型的饱和砂土液化风险评估方法

An energy-based pore water pressure model for evaluating liquefaction of saturated sands

根据场地液化风险评估结果,采用相应措施对场地进行治理,可避免液化引起的破坏,因此场地液化评估具有重要的研究价值。基于双向动三轴数值试验,以地震波阿里亚斯强度为能量参数,建立一种新的能量孔隙水压力模型,同时研究固结压力和固结比对孔隙水压力模型的影响;利用饱和福建标准砂动三轴试验结果验证该能量孔隙水压力模型的合理性和准确性;基于能量孔隙水压力模型,考虑渗透性以及剪应力折减函数对孔隙水压力的影响,建立一种新的场地液化风险评估方法,并利用离心机振动台试验和数值试验验证该评估方法。结果表明,该评估方法能够准确地预测出土体孔隙水压力的产生和累积规律,因此可用于场地液化风险的评估。

Evaluation of site liquefaction,according to which some remediation measures can be adopted to avoid liquefaction-induced damage,has important research value. Based on cyclic triaxial numerical tests,in this paper, a new energy-based pore pressure model for evaluating site liquefaction was proposed by taking the Arias intensity of seismic waves as the energy parameter,and the effects of the consolidation pressure and the consolidation ratio on the proposed model were discussed. The energy-based pore pressure model was verified by the cyclic triaxial tests results. Based on the verified model,a new method taking into consideration of the permeability and the shear stress reduction coefficient was proposed for evaluating the liquefaction. The new method was verified by centrifuge tests and numerical simulation. The results show that the new method can accurately predict the generation and accumulation of the excess pore pressure and hence,can be used to evaluate the liquefaction of ground.