双向地震作用下可液化土中矩形地铁车站上浮响应规律  

Uplift Response Law of Rectangular Subway Station in Liquefiable Soil Under Bidirectional Earthquake

作　　者：胡记磊 杨兵 沈文翔 HU Jilei;YANG Bing;SHEN Wenxiang(Key Laboratory of Geological Hazards on Three Gorges Reservoir Area,Ministry of Education,China Three Gorges University,Yichang 443002,China;College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡库区地质灾害教育部重点实验室(三峡大学),湖北宜昌443002 [2]三峡大学土木与建筑学院,湖北宜昌443002

出　　处：《三峡大学学报（自然科学版）》2024年第5期41-47,共7页Journal of China Three Gorges University：Natural Sciences

基　　金：湖北省教育厅科学技术研究计划重点项目(D20211204)。

摘　　要：为了研究双向地震作用下土体的液化响应特性和地下结构的上浮规律,采用有限元-有限差分耦合数值方法,对比了水平单向和双向地震作用下土体超孔隙水压力、结构加速度、结构位移等方面的差异,并进一步探究震后孔压消散对地下结构上浮的影响以及地下结构的上浮机理.结果表明:和水平地震作用相比,双向(水平+竖直)地震作用会加大结构两侧的液化程度,使超孔隙水压力的消散时间更长,并且结构的水平加速度响应被放大.在地震作用过程中,竖向地震对结构上浮的影响并不明显,地震结束后,双向地震作用下结构的竖向位移震荡较大,和水平地震作用相比最终上浮量偏小;双向地震会加大结构的变形,但结构的变形主要发生在震中,震后基本不发展.此外,在地震过程中及地震后地下结构的竖向位移与土体的固结沉降、土体的流动,以及土体的超孔隙水压力消散有关.因此,建立在近断层液化场地中的地下结构的抗震设计应考虑竖向地震作用带来的影响.To study the liquefaction response of soil and the uplift law of underground structures under bidirectional earthquakes,the coupled finite element-finite difference numerical method was used to compare the differences of soil excess pore water pressure,structural acceleration,and displacement under horizontal and bidirectional earthquakes.The influence of soil excess pore water pressure dissipation on the uplift of underground structures and the uplift mechanism of underground structures were further studied.The results show that compared with the horizontal seismic action,the bidirectional(horizontal+vertical)seismic action will increase the degree of liquefaction on both sides of the structure and make the soil excess pore water pressure dissipate for a longer time.The horizontal acceleration response of the subway station will be amplified.During an earthquake,the effect of the vertical earthquake on structure uplift is not obvious.After the earthquake,the vertical displacement of the structure will fluctuate greatly.Compared with the horizontal seismic action,the final uplift displacement will be smaller.Bidirectional seismic action will increase the deformation of subway stations,but the deformation of the station mainly occurs during the earthquake,and it does not develop after the earthquake.In addition,the vertical displacement of the underground structure during and after the earthquake is related to the consolidation and settlement of the soil,the flow of the soil,and the dissipation of excess pore water pressure.Therefore,the impact of the vertical earthquake should be considered in the seismic design of underground structures built in liquefaction sites near faults.

关 键 词：竖向地震 液化 地铁结构 上浮响应规律 

分 类 号：TU43[建筑科学—岩土工程]