SH波不同入射方位下沥青混凝土心墙土石坝响应特性及安全评价研究  

Study on response characteristics and safety evaluation of asphalt concrete core embankment dam under different incident azimuths of SH waves

作　　者：王飞 宋志强[2] 刘云贺[2] 李闯[2] 胡安奎 WANG Fei;SONG Zhi-qiang;LIU Yun-he;LI Chuang;HU An-kui(School of Energy and Power Engineering,Xihua University,Chengdu 610039,China;State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi’an University of Technology,Xi’an 710048,China)

机构地区：[1]西华大学能源与动力工程学院,四川成都610039 [2]西安理工大学省部共建西北旱区生态水利国家重点实验室,陕西西安710048

出　　处：《振动工程学报》2024年第6期1043-1054,共12页Journal of Vibration Engineering

基　　金：国家自然科学基金重点项目(52039008);四川省科技计划资助项目(2024NSFSC0986);陕西省自然科学基础研究计划项目(2022JM-276);陕西省教育厅青年创新团队科研计划项目(22JP052);省部共建西北旱区生态水利国家重点实验室(西安理工大学)开放研究基金资助课题(2022KFKT009)。

摘　　要：地震波空间斜入射下沥青混凝土心墙和坝体的破坏模式及安全评价的研究存在较大不足。考虑SH波入射方位角的空间任意性,基于波场叠加原理构建了地基边界上的非一致自由场,建立了SH波三维空间斜入射下的波动输入方法;基于试验结果建立了沥青混凝土瞬时抗拉强度随应变速率变化的经验公式,提出了依据瞬时拉应力和瞬时抗拉强度判别单元抗拉破坏的心墙安全评价方法;分析了入射方位角对过渡料与心墙之间的位错、心墙应力的影响规律,开展了坝体单元抗剪破坏评价,明确了不同入射方位下心墙和坝体的抗震薄弱部位。结果表明:地震波振动方向平行于水流向是过渡料位错、心墙拉应力和坝体局部动剪切破坏的最不利激振方位。与振动方向平行于坝轴向相比,振动方向平行于水流向时过渡料水平向脱开和竖直位错分别增大19.25倍和2.19倍,心墙最大拉应力增加1.8倍,上游坝坡单元发生动剪切破坏的深度加深。相对本文提出的心墙抗拉破坏判别方法,传统判别方法会导致心墙的破坏程度被高估。Current studies on the failure modes and safety evaluation of asphalt concrete core walls and dam bodies under the spatial oblique incidence of seismic waves are significantly lacking.This paper considers the spatial variability of the SH wave incident azi-muth,and constructs the non-uniform free field on the foundation boundary based on the wave field superposition principle.It estab-lishes a wave input method for SH waves with three-dimensional space oblique incidence.An empirical formula is then established for the change in the instantaneous tensile strength of asphalt concrete with the strain rate,based on the test results.A new method for core wall safety evaluation,based on instantaneous tensile stress and instantaneous tensile strength,is proposed to judge the tensile failure of elements.The influence of the incident azimuth on the dislocation between the transition material and the core wall,and the stress of the core wall,are analyzed.A shear failure evaluation of the dam body is carried out,and the seismic weak parts of the core wall and the dam body under different incident orientations are clarified.The results show that the seismic wave vi-bration direction parallel to the water flow direction is the most unfavorable excitation direction for transition material dislocation,core wall tensile stress,and local dynamic shear failure of the dam body.Compared with the vibration direction parallel to the dam axis direction,the horizontal detachment and vertical dislocation of the transition material increased by 19.25 times and 2.19 times respectively when the vibration direction was parallel to the water flow direction.The maximum tensile stress of the core wall in-creased by 1.8 times,and the dynamic shear failure depth of the upstream dam slope element deepened.Moreover,compared with the core tensile failure judgment method proposed in this paper,the traditional judgment method will lead to an overestimation of the damage degree of the core wall.

关 键 词：沥青混凝土心墙土石坝 入射方位 位错 心墙抗拉破坏 坝体抗剪破坏 

分 类 号：TV312[水利工程—水工结构工程] TV641.41