土石坝坡极限抗震能力的下限有限元法  

Lower bound FEM for limit aseismic capability of earth-rockfill dams

作　　者：杨昕光[1] 迟世春[1] 

机构地区：[1]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024

出　　处：《岩土工程学报》2013年第7期1202-1209,共8页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50979014;51179024);高等学校博士点基金项目(20090041110016)

摘　　要：基于极限分析下限定理,假设材料严格服从Mohr–Coulomb屈服准则,同时考虑了堆石料内摩擦角较大以及抗剪强度具有非线性的特性,提出了一个用于求解土石坝坝坡极限抗震能力的有限元计算方法。该方法通过静力平衡条件、应力间断面连续条件、边界条件、屈服条件以及所求极限荷载,形成标准的二次锥规划数学模型,并用内点法进行优化迭代求解,得到土石坝坡极限抗震能力的下限值。对一条形基础地基承载力进行下限极限分析,通过与已有计算结果比较表明所提方法的具有很高的计算精度。运用所提方法对一典型心墙土石坝进行抗震极限分析,其计算结果符合土石坝坡在地震作用下的一般破坏规律,证明此方法具有很高的实用价值。An FEM based on the lower bound theorem of limit analysis is proposed to study the limit aseismic capability of earth-rock-fill dams.Considering the large internal friction angel and non-linear shear strength parameters of rockfill materials,the proposed method formulates the limit analysis as a second-order cone programming（SOCP） problem with constraints based on the conditions of equilibrium,stress discontinuity,stress boundary and native Mohr-Coulomb yield criterion.The lower bound of the limit aseismic capability is then obtained by means of the interior-point algorithm and the iterative approach.Comparison with the published solutions illustrates the correctness and effectiveness of the proposed method for a smooth strip footing problem.The proposed approach is also applied to the seismic stability analysis of a typical rockfill dam with core wall so that the limit aseismic capability of the dam is obtained.The results proclaim the seismic failure mechanisms of earth-rockfill dams and demonstrate the practical value of the proposed method.

关 键 词：土石坝 极限抗震能力 下限定理 二次锥规划 

分 类 号：TV641[水利工程—水利水电工程]