宁波软土地区基坑数值计算中HS模型参数试验研究

土体HS模型已成为软土基坑数值模拟中较为常用的本构模型之一，但由于其模型参数较多，很多参数无法从勘察报告中直接获取。为了解决模型参数的取值问题，选取宁波地区典型的2种土样（淤泥质土、粉质黏土），开展标准固结试验、三轴固结排水剪切试验以及三轴固结排水加载-卸载-再加载试验，获得土体应力-应变关系。根据曲线确定宁波地区典型土层的HS模型参数Erefoed、Eref50、Erefur、c′、φ′ 和Rf，以及模型参数之间的关系。并将试验结果与上海软土地区、天津软土地区取得的模量关系进行对比分析。最后对宁波新典路过街通道深基坑工程进行三维有限元分析，计算结果与实测数据较为接近，从而验证HS 模型及试验获取的HS参数在宁波地区基坑开挖数值计算中的适用性。

Experimental Study of Parameters of HS Model for Numerical  Analysis of Foundation Pits in Ningbo Soft Soil Area

The hardening soil (HS) model has been one of the most widely used constitutive models in numerical simulation of soft soil foundation pits. However, due to its more model parameters, many parameters cannot be obtained directly from the investigation report. In order to solve the problem of model parameter values, the two kinds of typical soil samples, sludge and silty clay, are selected in Ningbo area. The stress strain curves of soil are obtained through standard consolidation test, triaxial consolidated drained test and triaxial consolidated drained loading unloading reloading test. And then the HS model parameters of the typical soils in Ningbo, i.e.Erefoed、Eref50、Erefur, c′, φ′and Rf, are determined according to the stress strain curves. Meanwhile, the relationships among the parameters are obtained. The test results are compared with those of soft soil in Shanghai and Tianjin. Finally, three dimensional finite element analysis is carried out for the cross street tunnel foundation pit on Xindian Road. The calculation results are close to the monitored data, which proves that the HS model and its parameters obtained by test are applicable to numerical analysis of foundation pits in Ningbo.