某拱坝基础垫座方案优化研究

Research on the Optimization of Foundation Pedestal Scheme for an Arch Dam

修建在深V河谷中的拱坝,由于坝址河道极为狭窄导致坝体底部无法成拱,通常采用设置垫座的方式来提高拱坝的稳定性。选取垫座弹性模量与坝体弹性模量比K_1、垫座高度与总坝高比K_2、垫座厚度与坝体底部厚度比K_3为参数,采用有限元法对比分析不同方案下拱坝坝肩、坝踵、坝趾及垫座底面处的应力。结果表明:坝体应力与垫座材料、形状等因素有关,最优方案为K_1取2. 5,K_2取0. 3,K_3取1. 5。

For the arch dam built in deep V valley,the bottom of dam cannot be arched due to the extremely narrow river channel at dam site,so the pedestal is usually used to improve the stability of arch dam.In order to analyze the influences of pedestal on the stability of an arch dam,three parameters of the ratio of elastic modulus between pedestal and dam body K 1,the ratio of height between pedestal and dam body K 2,and the ratio of thickness between pedestal and dam bottom K 3 are selected to compare and analyze the stresses at arch dam abutment,dam heel and dam toe,and the bottom of pedestal under different schemes by finite element method.The results show that the stress of dam body is related to the material and shape of pedestal,and the optimal scheme with K 1=2.5,K 2=0.3 and K 3=1.5 is obtained through comparison.