岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
3期
762-768
,共7页
刚性桩复合地基%弹塑性本构模型%无限元%地震强度%抗震性能
剛性樁複閤地基%彈塑性本構模型%無限元%地震彊度%抗震性能
강성장복합지기%탄소성본구모형%무한원%지진강도%항진성능
rigid pile composite foundation%elastoplastic constitutive model%infinite elements%earthquake intensity%seismic performance
基于复合地基-上部结构相互作用的静力分析已取得一定的研究成果,但其在动力荷载作用下,特别是地震作用下的动力响应却相当匮乏.首先借助有关试验通过ABAQUS和EERA的模拟分析,验证了基于Drucker-Prager屈服准则的弹塑性模型能较好地反映土体非线性动力特性以及采用有限元与无限元耦合的方法对土体无限边界的模拟.在此基础上,针对实际问题建立了刚性桩复合地基-筏板-上部结构体系整体有限元模型,对其进行动力弹塑性时程分析,并讨论了该复合地基与桩基对地震响应的差异.深入研究了不同强度地震作用下,刚性桩复合地基的工作机制,包括桩体、褥垫层、筏板的动力响应以及上部结构的地震反应和抗震性能.结果表明,小震时褥垫层基本没有减震效果,大震时复合地基的抗震性能优于桩基.地震越强烈,减震效果越明显,但作用有限,减震系数一般在0.8以上,可为工程实践提供参考.
基于複閤地基-上部結構相互作用的靜力分析已取得一定的研究成果,但其在動力荷載作用下,特彆是地震作用下的動力響應卻相噹匱乏.首先藉助有關試驗通過ABAQUS和EERA的模擬分析,驗證瞭基于Drucker-Prager屈服準則的彈塑性模型能較好地反映土體非線性動力特性以及採用有限元與無限元耦閤的方法對土體無限邊界的模擬.在此基礎上,針對實際問題建立瞭剛性樁複閤地基-筏闆-上部結構體繫整體有限元模型,對其進行動力彈塑性時程分析,併討論瞭該複閤地基與樁基對地震響應的差異.深入研究瞭不同彊度地震作用下,剛性樁複閤地基的工作機製,包括樁體、褥墊層、筏闆的動力響應以及上部結構的地震反應和抗震性能.結果錶明,小震時褥墊層基本沒有減震效果,大震時複閤地基的抗震性能優于樁基.地震越彊烈,減震效果越明顯,但作用有限,減震繫數一般在0.8以上,可為工程實踐提供參攷.
기우복합지기-상부결구상호작용적정력분석이취득일정적연구성과,단기재동력하재작용하,특별시지진작용하적동력향응각상당궤핍.수선차조유관시험통과ABAQUS화EERA적모의분석,험증료기우Drucker-Prager굴복준칙적탄소성모형능교호지반영토체비선성동력특성이급채용유한원여무한원우합적방법대토체무한변계적모의.재차기출상,침대실제문제건립료강성장복합지기-벌판-상부결구체계정체유한원모형,대기진행동력탄소성시정분석,병토론료해복합지기여장기대지진향응적차이.심입연구료불동강도지진작용하,강성장복합지기적공작궤제,포괄장체、욕점층、벌판적동력향응이급상부결구적지진반응화항진성능.결과표명,소진시욕점층기본몰유감진효과,대진시복합지기적항진성능우우장기.지진월강렬,감진효과월명현,단작용유한,감진계수일반재0.8이상,가위공정실천제공삼고.
Some results of static analysis considering the interaction between superstructure and composite foundation are obtained. However, the research on the response under dynamic loading, especially under earthquake loading, is very inadequate. Via relevant tests, ABAQUS are verified by comparison with EERA. The results show that the elastoplastic constitutive model based on Drucker-Prager yield criterion and the method of finite element and infinite element coupling can adequately simulate the nonlinear dynamic characteristics of soil and the infinite boundary. To the actual problem,the whole finite element model of rigid pile composite foundation-raft-superstructure system is established. And dynamic elastoplastic time-history analysis is made; the differences between rigid pile composite foundation and pile foundation in seismic response are analyzed. The seismic mechanism of rigid pile composite foundation, including the dynamic responses of piles, cushion and raft, is studied under different earthquake intensities;and the earthquake response and seismic performance of superstructure are analyzed deeply. It is shown that cushion has no damping effect almost under minor earthquake; rigid pile composite foundation is superior in seismic performance to pile foundation under major earthquake. The stronger earthquake is, the better damping effect is. But it is limited, the damping coefficient is over 0.8 generally. The results can provide references to engineering practice.