相邻两坝块对横缝开度的贡献分析

Analysis of Contribution to Transverse Joints Opening from Adjacent Two Dam Brocks

采用三维无厚度横缝单元模拟施工期混凝土坝横缝开合行为,采用Newton-Raphson迭代法和预处理共轭梯度法计算,开发了横缝开度仿真计算程序,进行了向家坝相邻两坝块对横缝开度贡献度大小的分析.选取4种相邻高差,分别是横缝相邻高差为12m、18m、24m、30m,计算各工况下横缝开度,绘制典型点横缝开度过程线、横缝左右点位移过程线、横缝开度云图等,整理了相邻坝块高差、相邻坝块温度过程差异、一期控温、二期降温等因素对横缝开度的影响.计算结果表明:二期温降对横缝张开贡献大;先浇块对横缝开度贡献更大,且前期温度差异阶段越长,先浇块对缝宽贡献越大.

This paper adopts the 3D joint element to simulate concrete dam transverse joint during the opening act;it uses the Newton-Raphson iterative method and preprocessing conj ugate gradient method to calculate. A joint opening simulation program is developed;and the margin of contribution of the adjacent two dam block joints of Xiangjiaba to contraction opening is analyzed.We choose four kinds of adjacent level differ-ences;they are respectively 12 m,18 m,and 24 m,30 m for the joints adjacent level,calculating the joints o-pening under different conditions and drawing the process line of typical point j oints opening and transverse j oints aperture point displacement as well as the picture of opening j oints.We also analyzed the factors that influence contraction j oints opening such as adj acent difference,temperature process differences,the first pe-riod of temperature control and second stage cooling of it.The calculation results show that the second phase of temperature drop influences more on joints opening;first poured pieces contribute more to the joints open-ing and the longer the temperature difference between the stages,the bigger contribution of the first poured pieces will do to the width of the j oints.