特高拱坝体形适应性分析研究

Analysis on adaptability of shape for extra-high arch dam

以西北地区某240 m特高拱坝为例,采用拱梁分载法,选择对拱坝体形设计影响较大且具有一定不确定性的参数,即地基综合变形模量、坝体混凝土弹性模量和线膨胀系数等进行敏感性分析,研究拱坝体形设计的合理性和适应性。经体形优化设计调整,对得到的拱坝体形进行关键参数的敏感性分析计算。由计算成果可知,当地基综合变形模量、坝体混凝土弹性模量和线膨胀系数在一定范围内浮动时,坝体应力、位移均满足设计要求,说明拱坝体形适应性较好。此研究方法将影响拱坝设计的不确定因素提前考虑,既可以减轻后续设计阶段体形优化调整的工作量,又可以保证拱坝建成后保持良好的工作状态,对类似工程设计具有重要的参考意义。

By taking an extra-high arch dam with the height of 240 m in Northwest China as the study case, the parameters with certain uncertainties and larger impacts on the design of the shape of arch dam, i.e. the integrated deformation modulus of foun- dation, the elastic modulus and linear expansion coefficient of dam concrete, etc. , are selected herein for making the relevant sensitivity analyses and then studying the reasonability and adaptability of the design of the shape for the arch dam. Through the adjustment of the optimized design of the shape, the sensitivity analyses and calculations on the sensitivities of the obtained key parameters of the shape for the arch dam are made. It is known from the calculation results that when the integrated deformation modulus of foundation, the elastic modulus and linear expansion coefficient of dam concrete are fluctuated within certain ranges, both the stress and displacement of the dam body can meet the design requirements, thus it is indicated that the adaptability of the shape for the arch dam is better. The study is to influence the advanced consideration made on the uncertain factors in the de- sign of the arch dam, that is to say, not only the work-load for the adjustment of the shape optimization during the period of the successive design can be decreased, but the arch dam can also be ensured to keep a better working behavior after the comple- tion. The study has important reference significance for the design of the similar project.