摘要
混凝土–堆石组合坝主要由上游混凝土墙与下游俯斜式堆石体构成,作为一种新型坝体结构,目前对其地震土压力的研究鲜有报道。对此,开展混凝土–堆石组合坝大型振动台物理模拟试验研究,分析地震作用下墙体的位移、动土压力及合力作用点的分布规律等。研究结果表明:1)混凝土–堆石组合坝中上游墙体的位移量相对较小,墙体顶部位移比墙底大,呈现出RBT(绕墙体底部转动)的位移模式。2)墙底动土压力与输入的地震波相比具有明显的滞后性。3)墙背的总动土压力随着峰值加速度(PGA)的增大而增大,当PGA≤0.2g时,总动土压力沿墙高近似呈线性分布;当PGA≥0.4g时,总动土压力呈现出明显的非线性分布规律。4)受俯斜式堆石体及墙体位移模式的影响,在地震烈度8度以下,混凝土–堆石组合坝中上游墙体合力作用点普遍低于M–O理论规定的0.33H;但在地震烈度8度以上,合力作用点趋近又高于0.33H。试验结果初步揭示了混凝土–堆石组合坝中上游墙体的位移及动土压力响应特征,为其在地震作用下的抗震设计等提供参考。
The concrete-rockfill combination dam(CRCD)is mainly composed of the upstream concrete wall and downstream declivitous rockfill.As a new type of dam structure,its dynamic characteristics are not studied thoroughly so far.A physical simulation test of CRCD was conducted utilizing the large-scale shaking table.The displacement,dynamic earth pressure and the distribution of resultant point were analyzed.The results show that:1)The displacements of CRCD wall were relatively small,and the top displacement of the wall was larger than that of the bottom wall,as well as it owns RBT model(rotation around a certain point under the wall-bottom).2)The dynamic earth pressure at the bottom of the wall was obviously lagging behind the input seismic wave.3)The total dynamic earth pressure on the back face of wall increased with the increase of peak ground acceleration(PGA).When PGA≤0.2g,the total dynamic earth pressure was approximately linearly distributed along the wall height.When PGA≥0.4g,the total dynamic earth pressure showed a significant nonlinear distribution.4)Under the influence of the declivitous rockfill body and the displacement model of the wall,when the seismic intensity was less than 8 degrees,the point of resultant force for total dynamic earth pressure was generally lower than the 0.33H proposed by the Mononobe–Okabe(M–O)theory.But when the seismic intensity was above 8 degrees,the results were higher than 0.33H.The results revealed the dynamic response characteristics of displacement and earth pressure,and provided a reference for the anti-seismic design of CRCD.
作者
王建新
杨贵
刘汉龙
唐新军
WANG Jianxin;YANG Gui;LIU Hanlong;TANG Xinjun(College of Hydraulic and Civil Eng.,Xinjiang Agricultural Univ.,Urumqi 830052,China;Key Lab.of Water Conservancy Eng.Safety and Water Disaster Prevention of Xinjiang,Urumqi 830001,China;College of Civil and Transportation Eng.,Hohai Univ.,Nanjing 210098,China;College of Civil Eng.,Chongqing Univ.,Chongqing 400045,China)
出处
《工程科学与技术》
EI
CAS
CSCD
北大核心
2020年第2期103-109,共7页
Advanced Engineering Sciences
基金
新疆农业大学校前期课题(XJAU201717)。
关键词
水利工程
混凝土–堆石组合坝
大型振动台
位移模式
动土压力
hydraulic engineering
concrete–rockfill combination dam
large-scale shaking table
displacement model
dynamic earth pressure
