强震作用下高拱坝横缝张开非线性反应的研究

Study on Non-linear Response of Transverse Joints of High Arch Dams Under Strong Earthquakes

采用接触单元模拟拱坝横缝,对高拱坝在强震作用下横缝张开的非线性反应进行了系统的研究.首先,从横缝的最大张开度、坝体的应力分布及坝体的最大位移等不同角度研究了横缝模拟条数的最佳方案;进而研究了库水位变化对横缝张开度、坝体应力和位移的影响.研究结果表明:为了有效地反映在强震中横缝张开效应对拱坝应力状态的影响,在分析中至少需要模拟3条大体均匀布设的横缝;但是,为了能充分反映横缝在强震过程中张开的实际情况,则至少需要模拟21条横缝;随着库水位的增高,拱坝横缝在强震中的最大张开度逐渐减小.

The non-linear response of transverse joints of arch dams during strong earthquakes is researched by using contact elements to simulate the transverse joints.First,the optimum numbers of simulating transverse joints are studied by analyzing the maximum transverse joint open ing,stress distribution and maximum displacement of an arch dam.Then,the influences of different upstream water levels on the joint opening,stress and displacement of dams are analyzed.The results are as follows :(1)In order to reflect effectively the influences of the transverse joint openings on the stress distribution of dams during strong earthquakes,the minimum transverse joint number simulated in the analy sis is3;(2)To reflect the realistic transverse joint openings,the minimum number is21;and(3)The joint openings gradually reduce with the raise of water levels.