饱和砂土爆炸液化特性研究

Study on characteristics of explosion liquefaction of saturated sandy soil

基于有效应力动力分析法,在Byrne有效应力弹塑性模型的基础上,提出了一个能够考虑主应力轴旋转、饱和砂土含有少量气体、饱和砂土液化后的应变软化和应力重分布特性的弹塑性模型。将该模型编制成分析模块,并与通用岩土分析软件FLAC接口,进而对饱和砂土分别在单点、两点(微差)和多点(微差)爆炸地震波荷载作用下进行数值模拟分析,分别考虑了水平、微倾以及斜坡场地等3种工况,并且对爆炸地震波荷载与天然地震波荷载作用下饱和砂土的动力特性进行了对比研究。数值模拟结果表明,该模型能够很好地表现饱和砂土的爆炸液化气特性;不同动载和不同场地条件下,饱和砂土表现的动力特性以及液化行为也不尽相同。

According to effective stress dynamic analysis method and based on Byme＇s effective stress elastoplastic model, a new modified model is presented. This new model can consider these aspects such as rotation of principal stress axes, a little of gas, strain softening and stress redistributing after liquefaction. The analytical modules are programmed and interfaced with the FLAC code; then numerical simulating analysis of saturated sandy soil under single-point, two-point and multi-point explosion seismic waves respectively are carded out by using FLAC code which is a two-dimensional explicit program. The 3 kinds of fields such as the level, little-obliquity and slope grounds are considered; and the difference of the characteristic of saturated sandy soil between under explosion seismic waves loadings and natural seismic waves loadings are contrastively investigated. The results of numerical simulating indicate that the explosion liquefaction characteristics of saturated sandy soil can be well described with this model; the dynamic characteristics and liquefaction behavior of saturated sandy soil are different under different fields and different dynamic loadings.