海底管线周围海床的地震液化分析  

Numerical Analysis of Liquefaction of Porous Seabed around Submarine Pipeline under Seismic Loading

作　　者：张小玲[2] 栾茂田[1,2] 张其一[2] 

机构地区：[1]海岸和近海工程国家重点实验室,大连116024 [2]大连理工大学,土木水利学院岩土工程研究所,大连116024

出　　处：《北京工业大学学报》2009年第5期592-597,共6页Journal of Beijing University of Technology

基　　金：国家自然科学基金重点基金资助项目(50439010);教育部科学技术研究项目重大项目(305003);国家自然科学基金资助项目(50579006,50179006).

摘　　要：地震荷载作用下海床液化是海底管线失稳的主要原因之一.本文建立了地震荷载作用下海底管线周围海床液化的有限元模型,采用土工静力-动力液压三轴-扭剪多功能剪切仪,将不排水循环扭剪试验条件下得到的孔隙水压力增长模式引入到二维动力固结方程中,基于有限元方法对推广的固结方程进行数值求解,得到了地震荷载作用下海床中累积孔隙水压力的发展过程与变化规律.通过变动参数计算了海床土性参数和管线几何尺寸对由地震所引起的管线周围海床中累积孔隙水压力分布的影响,进一步对管线周围海床的液化势进行了评判.The liquefaction of seabed under seismic loading is one of the main reasons that govern the overall stability of submarine pipeline.In this paper,a FEM numerical analysis method on liquefaction around a buried pipeline in sandy seabed under seismic loading is presented.The advanced soil static and dynamic universal triaxial and torsional shear apparatus is employed to perform cyclic torsional shear tests subjected to cyclic loading,and the mode of dynamic increase of pore pressure under undrained conditions gained from tests is incorporated with two-dimensional dynamic consolidation equation and a numerical procedure based on FEM is developed to assess the accumulative pore pressure.By numerical computations,the accumulation process of pore pressure and liquefaction potential of seabed soil during seismic loading can be evaluated.Based on the numerical model presented in this paper,the effects of soil characteristic parameters and pipeline geometry on the seismic-induced accumulative pore pressure around submarine pipeline and along the depth of seabed are studied in detail.

关 键 词：海底管线 地震荷载 累积孔隙水压力 液化 

分 类 号：TU279.7+6[建筑科学—建筑设计及理论] TU435TU441