文档介绍：中文摘要随着经济的快速发展,沿海城市都在进行大规模的基础设施、高层建筑、地铁和高速公路的建设,然而这些城市广泛分布着软粘土,引发了许多岩土工程新问题,很多情况下由于对软粘土在动荷载作用下的一些特性不清楚,导致了重大的灾难。天津是我国重要的沿海城市之一,最近几年国家大力投资发展天津经济, 其中滨海新区是天津重点发展的地区之一,然而这一地区处于华北地震活跃带, 周围地区潜在发生中等破坏性以上的地震的可能性大,而且广泛分布着深厚软粘土层,软粘土动力特性复杂,工程性质极为不良。从研究现状来看,研究多集中于交通荷载分析,对软粘土在地震荷载作用下的动力特性的研究较少,目前还未发现有合适的本构模型能够同时考虑软粘土的循环软化特性和在循环荷载作用下的复杂的动力特性。因此本文以应力控制的循环动三轴试验为基础,重点研究了固结压力、循环应力比和振动频率对滨海新区饱和软粘土的动力特性的影响, 并提出了软化指数这一概念,考虑了饱和软粘土在地震荷载作用下的循环软化效应,建立了在上述三种影响因素下的循环软化模型,最后以临界状态理论和边界面理论为出发点,提出了地震荷载作用下考虑软粘土循环软化效应的边界面模型,并利用该模型对饱和软粘土的动应力一应变关系进行了模拟,通过模拟结果和试验结果的对比分析,验证了模型的合理性,从而为滨海新区的建设提供了理论依据。因此,本课题具有重大的理论意义和工程实用价值。本文最后对该课题进一步研究的方向和需要解决的问题进行了简要的讨论, 提出该课题具有很好的研究前景和科研价值。关键词:饱和软粘土;地震荷载;本构模型;软化指数:边界面 ABSTRACT With therapiddevelopment ofeconomy,infrastructure,high building,subway and highway are being under construction inmany coastal there are so mallv softclays inthecities thatithasinduced many problems on thegeotechnical many conditions some properties of the softclays under dynamic loading are notknown clearly,SO some seriouscatastrophes is one ofthecoastalcities,and inthepast few years thegovernment has invested much money todevelop theeconomy ofTianjin where the Binhai new area is one of areas ofwhich thegovernment focuses on ,the area is inthe seismic zone ofnorth China,and ispossible thatthe potential destructive earthquake may occur around ,the deep layer ofsoftclays the dynamic properties ofwhich plicated iswidely distributed,and theengineering properties ofthesoftclays arevery thepresent research point view,Iittle effort hasbeen made tobehaviors ofsaturatedsoftclaysubjected toseismic loading. Most oftheconstitutive models intheliterature are not capable ofcapturing both cyclic softenanddynamic properties ofsoftclays under cyclic loading simultaneously. So based on thecyclic stress controlled triaxialtests,the effectoftheconsolidation pressure,cyclic stressratio andvibration行equency on thedynamic pro