超深覆盖层上高沥青心墙坝防渗墙受力状态的精细化分析  

Refined analysis on stress state of cutoff wall of high asphaltic core dam on super-deep overburden

作　　者：邹德高[1,2] 屈永倩 孔宪京[1,2] 陈楷 刘京茂[1,2] 龚瑾 ZOU De-gao;QU Yong-qian;KONG Xian-jing;CHEN Kai;LIU Jing-mao;GONG Jin(State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China;Institute of Earthquake Engineering,School of Hydraulic Engineering,Dalian University of Technology,Dalian,Liaoning 116024,China)

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 [2]大连理工大学水利工程学院工程抗震研究所,辽宁大连116024

出　　处：《岩土力学》2023年第6期1826-1836,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52192674,No.52109151,No.U1965206);云南省重大科技专项计划(No.202102AF080002);中央高校基本科研业务费(No.DUT23RC(3)001)。

摘　　要：混凝土防渗墙是深厚覆盖层地基上修建土石坝的主要坝基防渗结构,是保证大坝安全的关键防线,因此,精细模拟防渗墙的受力状态,对于合理评价深厚覆盖层上土石坝工程具有重要意义。联合增量迭代法和有限元-比例边界有限元耦合方法,实现了土石坝应力变形的跨尺度精细化分析,克服了中点增量法求解局部强非线性问题时精度低的缺陷;发现了防渗墙-心墙接头附近和防渗墙底部土体剪切带的局部大应变特性,阐明了传统方法无法描述土体局部大应变而高估防渗墙应力的机制;提出了设置薄层单元来模拟应变局部效应的高效计算方法,实现了超深覆盖层上高沥青心墙坝防渗墙受力状态的三维精细化分析。本研究发展的有限元-比例边界元-增量迭代法-预设薄层单元的跨尺度非线性分析方法可为深厚覆盖层上土石坝防渗墙的安全评价和设计优化提供理论和技术支持。The concrete cutoff wall is the main anti-seepage structure of the rockfill dam resting on the deep overburden foundation,and is the key to ensuring the dam safety.Therefore,it is of great significance to accurately simulate the stress state of cutoff wall for evaluation of the rockfill dam resting on the deep overburden.Combining the incremental iteration method and the finite element-scaled boundary finite element coupling method(FEM-SBFEM),this paper realizes the trans-scale refined numerical analysis of the stress and deformation of the rockfill dam,which overcomes the low precision of the conventional midpoint increment method in solving local strong nonlinear problems.The characteristics of local large strain in band-shaped connected zone between cutoff wall and core wall and the bottom of cutoff wall are found.The overestimate of cutoff stress is due to the failure of conventional methods to describe local large strain of soil.The three-dimensional efficient refined analysis of cutoff wall of high asphaltic core dam on the super-deep overburden is performed by setting thin-layer elements to simulate the local large strain.The proposed trans-scale analysis method based on FEM-SBFEM-incremental iteration method-embedding thin-layer elements provides theoretical and technical support for the safety evaluation and design optimization of cutoff wall of rockfill dam resting on deep overburden.

关 键 词：防渗墙 精细化分析 深厚覆盖层 土石坝 

分 类 号：TV641[水利工程—水利水电工程]