可液化土层的位置对土层-地下结构地震反应的影响

发布时间：2018-10-14 12:18

【摘要】：为了研究不同位置的液化土层对地下结构地震反应的影响,采用PL-Fin土体液化本构模型,使用FLAC3D进行了研究,总结了液化土层发生液化大变形时刻液化区分布、孔隙水压力与超静孔隙水压力比变化规律及差异、地下结构的位移及差异沉降规律,并与非液化场地下的地下结构地震反应进行了对比.主要结论有:当结构底部存在液化土层时,引起的结构位移最大,使结构下沉;结构两侧的土体液化会引起结构上浮,并使侧墙水平向向层间位移和顶底板竖向层间位移增加;结构整体位于液化土层中时,土体位移、结构位移和结构层间位移差都不是最大值,仅研究结构整体位于液化土层的规律存在不足;结构周围、两侧、底部、底部45°位置、左右两侧和底部45°位置以及底部和底部45°位置存在液化土层(B+C)位置共计6种工况下结构顶板y向层间位移变化规律基本一致,但车站不同位置存在液化土层,土层液化的反应和对结构的影响存在一定差异;液化大变形发生在孔隙水压力和超孔压比突增后的1~3s后,因此可由孔隙水压力和超孔压比的突变判断是否发生液化大变形.
[Abstract]:In order to study the influence of different positions of liquefaction soil layer on seismic response of underground structure, PL-Fin soil liquefaction constitutive model and FLAC3D were used to study the distribution of liquefaction zone at the time of liquefaction and large deformation. The variation and difference of pore water pressure to excess pore water pressure, the displacement and differential settlement of underground structure, and the seismic response of underground structure in non-liquefaction field are compared. The main conclusions are as follows: when there is liquefaction soil layer at the bottom of the structure, the displacement of the structure will be the largest, which will cause the structure to sink, and the liquefaction of the soil on both sides of the structure will cause the structure to float, and increase the horizontal displacement of the lateral wall and the vertical displacement of the roof and floor. When the whole structure is located in the liquefaction soil, the difference of soil displacement, structural displacement and the displacement between the layers is not the maximum. There is a liquefied soil layer at 45 掳position on the left and right sides and 45 掳position on the bottom and bottom at the bottom and bottom. Under six working conditions, the displacement of the roof y to the floor of the structure is basically the same, but there is a liquefied soil layer in different positions of the station. There are some differences between the reaction of soil liquefaction and the influence on the structure, and the large deformation of liquefaction occurs after 1 ~ 3 seconds after the increase of pore water pressure and super-pore pressure ratio, so it can be judged by the sudden change of pore water pressure and super-pore pressure ratio whether or not liquefaction large deformation occurs.
【作者单位】：北京工业大学城市与工程安全减灾省部共建教育部重点实验室;
【基金】：国家科技重大专项资助项目(51421005,41272337) 北京市自然科学基金委员会-北京市科学技术研究院联合资助项目(L140004)~~
【分类号】：TU435

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