深厚覆盖层地基溢洪道应力变形有限元分析

Stress-Deformation Finite Element Analysis of Spillway Built on Overburden Foundation

受地形、地质条件限制,金佛山水利枢纽溢洪道将建立在第四系覆盖层地基上,为了解覆盖层地基的变形对溢洪道结构安全的影响,采用邓肯E-v非线性模型和线弹性模型,对不同工况下溢洪道的应力变形进行了有限元分析,研究了溢洪道在垫层竣工、结构竣工和泄水运行期时的地基变形、结构应力分布及伸缩缝变形。结果表明,地基变形、溢洪道结构应力分布与伸缩缝变形等分布符合一般规律,其中地基最终沉降量绝大部分发生在溢洪道垫层施工和结构施工期间,均在覆盖层厚度大处沉降量大,故建议对覆盖层天然地基进行处理,以减小施工期间地基的沉降变形。

Restrained by the terrain and geological conditions,the spillway of Jinfoshan hydro project will be established on the weathered bedrock.In order to get the influence of deformation of overburden foundation on structure safety of spillway,Duncan E-V nonlinear model and linear elastic model were adopted to make finite element analysis of spillway stress deformation at different operating conditions.And then it analyzed the foundation＇deformation,distribution of stress and the contraction joint deformation of the spillway on every period of cushion course completion,completed structure and discharging operation.The results show that the deformation of foundation,the spillway structure stress distribution and contraction joint deformation distribution was conform to the general rules.The final settlement occurred predominantly in the period of the construction of spillway cushion and structure,and where the thickness of cover layer is larger,the greater the settlement amount is.Therefore,it was necessary to dispose the natural foundation of cover layer for reducing foundation＇s settlement deformation during construction.