地震荷载作用下海底滑坡特征及其机理
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摘要
通过多种勘察手段,分析了厦门沪救码头海底滑坡成因及滑坡附近的地形、地层和海洋水动力条件等因素,采用动力有限元法和强度折减法相结合的方法分析海底滑坡在地震荷载作用下的动力响应、海底滑坡动力稳定性的影响因素以及地震荷载与海底滑坡失稳状态之间的关系.结果表明,在地震荷载作用下,软土层之间存在拉应力效应并导致海底滑坡崩塌滑动的危险;动力有限元法和强度折减法相结合并以计算不收敛为判据的方法,适用于分析海底滑坡的地震整体稳定性.当地震作用时,厦门沪救码头海底滑坡的整体稳定安全系数为1.50.
According to a variety of survey methods,the status of the seabed slide near the Hujiu terminal in Xiamen city and the topography,stratigraphy,marine hydrodynamics in the surrounding ground and other factors were identified and the sliding mechanism was analyzed.Based on it,the dynamic numerical analytical method were used to discuss the dynamic response of the slide and the factors influencing the stability of slide,the relationship between instability failure and earthquake motions were identified and analyzed by the dynamic finite element method and strength reduction method.As the results,there is obvious negative response phase between the surface soils for it has quite different mechanical characteristics,so that the tensile stress occurs which leads to collapse of seabed slides.
According to a variety of survey methods,the status of the seabed slide near the Hujiu terminal in Xiamen city and the topography,stratigraphy,marine hydrodynamics in the surrounding ground and other factors were identified and the sliding mechanism was analyzed.Based on it,the dynamic numerical analytical method were used to discuss the dynamic response of the slide and the factors influencing the stability of slide,the relationship between instability failure and earthquake motions were identified and analyzed by the dynamic finite element method and strength reduction method.As the results,there is obvious negative response phase between the surface soils for it has quite different mechanical characteristics,so that the tensile stress occurs which leads to collapse of seabed slides.
引文
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[4]Bromhead E N.The stability of slopes[M].2nd ed.USA:Surrey University Press,1994.
[5]顾小芸.海底边坡稳定分析方法综述[J].力学进展,1989,19(1):50-58.GU Xiao-yun.State of the ART:Analytical methodsof submarine slope stability[J].Advances in Mechan-ics,1989,19(1):50-58.
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