横缝对高拱坝系统非线性地震响应的影响分析

Effect of Transverse Joints on Nonlinear Seismic Response of High Arch Dam System

对带横缝高拱坝系统非线性地震响应的影响进行了分析研究.坝体材料采用混凝土损伤塑性本构模型,采用指数型动接触本构模型模拟各个坝段之间的横缝接触作用,具体模拟了横缝张开、闭合和滑移非线性,研究了横缝条数分别为1,3,5,7,11,21,40条时高拱坝的地震响应;探讨了径向摩擦因数分别取0.0,0.2,0.4,0.6,0.8时,拱坝横缝的最大开度、径向位移响应变化规律.研究表明:7条横缝模拟时的最大开度与11、21和40条横缝模拟的结果接近;最大开度的横缝位置并非在大坝中部,而是在靠近左右两个坝肩位置的横缝处,7条横缝时最大开度出现在第1条横缝,11、21和40条横缝时最大开度均出现在第3条横缝处,且这4个最大开度横缝在大坝上的位置基本相同;缝面考虑径向摩擦的横缝开度要大于径向自由的横缝开度;径向完全自由时静荷载作用下的顺河向位移明显大于径向有摩擦的情况,且后者在地震荷载下的顺河向位移响应变幅要大于前者;摩擦因数增加到一定时,大坝的顺河向位移响应曲线基本一致.研究结果可供有关设计施工部门参考.

The effect of transverse joints on nonlinear seismic response of high arch dam system is presented in this paper.The concrete damage plastic constitutive model is taken to describe the damage behavior and an exponential dynamic contact constitutive model is adopted to simulate the contact action of the transverse joints between the dam monoliths.The opening,closing and sliding nonlinearity of the transverse joints are simulated,and the seismic responses of the high arch dam with transverse joints number of 1,3,5,7,11,21,and40 are studied.When the radial friction coefficients are 0.0,0.2,0.4,0.6,and0.8,the maximum opening of the transverse joint and the radial displacement response of the arch dam are discussed.The results show that the maximum opening of 7 transverse joints is close to that of 11,21 and40 transverse joints.The transverse joints with the maximum opening are not located in the middle of the dam,but near the left and right abutments.The maximum opening of 7 transverse joints appears in the first transverse joint,and the maximum opening of11,21and40 transverse joints all appear in the third transverse joint,and the positions of the four maximum opening transverse joints on the dam are basically the same.The opening of the transverse joint considering the radial friction is larger than that of the radial free.When the radial is completely free,the along-river displacement under static load is obviously greater than that under radial friction,and the variation amplitude of the latter under seismic load is greater than that of the former.When the friction coefficient increases to a certain,the response curve of the dam's displacement along the river is basically the same.The research results can be referenced by relevant design and construction departments.