CAJ | 학술논문

强地震易造成地基中倾斜砂土夹层液化后产生永久变形和位移，并诱发流滑现象，进而对上部结构产生严重破坏。基于 FE-FD耦合有限元方法，综合考虑倾斜砂土夹层的坡度、厚度、埋深以及海水水位因素，对某近海人工岛二维结构模型进行了数值模拟分析。结果表明：砂土层的坡度、厚度、埋深以及水位因素对人工岛的地震液化灾害有着不同程度的影响，其中坡度的影响最显著，而水位的影响最不明显，特别是水位对超孔隙水压力增长的影响非常小。人工岛的侧向扩展是在地震过程中饱和倾斜砂土夹层完全液化被触发后才得以发生，而且是在地震作用过程中某段时间内沿液化层斜面的有限滑动，其灾害程度比水平砂土层液化造成的破坏要大得多，而且易造成岛体不均匀沉降，对护岸造成严重破坏。该分析结论可为近海岸工程地震液化灾害评价分析提供参考依据。
강지진역조성지기중경사사토협층액화후산생영구변형화위이，병유발류활현상，진이대상부결구산생엄중파배。기우 FE-FD우합유한원방법，종합고필경사사토협층적파도、후도、매심이급해수수위인소，대모근해인공도이유결구모형진행료수치모의분석。결과표명：사토층적파도、후도、매심이급수위인소대인공도적지진액화재해유착불동정도적영향，기중파도적영향최현저，이수위적영향최불명현，특별시수위대초공극수압력증장적영향비상소。인공도적측향확전시재지진과정중포화경사사토협층완전액화피촉발후재득이발생，이차시재지진작용과정중모단시간내연액화층사면적유한활동，기재해정도비수평사토층액화조성적파배요대득다，이차역조성도체불균균침강，대호안조성엄중파배。해분석결론가위근해안공정지진액화재해평개분석제공삼고의거。
Liquefaction due to strong earthquake easily causes permanent displacement and strain of sloping sand layer in the fundament and induces the phenomena of flow slides,and then brings serious damages to the superstructure. Considering sloping sand layers' gradient, thickness, depth and seawater level synthetically, a two-dimensional offshore artificial island model was simulated numerically by FE-FD coupling finite element analysis method.The experimental results indicate that these four influence factors have different effects on the large deformation of artificial island in the course of seismic liquefaction.The influence of gradient is the greatest,and the influence of seawater level is the most non-obvious,and especially,its effect on excess pore water pressure is very small. Lateral spreading of artificial island j ust occurs after total liquefaction of saturated sloping sand layer in the course of seismic,which is a limit slide along the slope during a period of time.Its degree of damage is much bigger than that of damage induced by liquefaction of horizontal sand layer,and it easily causes serious differential settlement and damage of revetment of artificial island. These analytical results can provide reference for hazard evaluation of offshore engineering due to seismic liquefaction.