杨房沟高拱坝建基面嵌深优化的分析与评价

Analysis and evaluation of optimization on embedded depth of foundation surface for Yangfanggou High Arch Dam

高拱坝建基面嵌深方面尚未形成具有普适性的评价体系,以杨房沟拱坝建基面嵌深的定量分析与评价为目标,在常规拱坝变形受力分析的基础上,使用三维非线性有限元(TFINE程序)对杨房沟拱坝的可行性研究阶段和施工图阶段的两种建基面嵌深方案进行坝体关键参数、位移、应力和拱端推力的变形应力对比分析。采用塑性屈服区、不平衡力和余能范数评价坝体的整体稳定性和坝踵开裂风险,并基于多重网格法进行坝肩抗滑稳定分析。结果表明,杨房沟拱坝施工图阶段的建基面外移方案较可行性研究方案整体上改善了坝体的变形应力、稳定性和安全度等指标,具有良好的经济效益。研究成果论证了杨房沟拱坝施工图阶段建基面优化设计方案的合理性,同时也可为其他类似工程优化设计的安全分析与综合评价的量化分析提供参考。

As no any universal evaluation systems are created in the aspect of the embedded depth of the foundation surface for high arch dam yet,the quantitative analysis and evaluation on the embedded depth of the foundation surface for Yangfanggou High Arch Dam are taken as the study objectives herein,for which the comparative analyses on the key parameters of the dam body,such as displacement,stress and deformation stress of arch abutment thrust,in both the schemes of the embedded depth of the foundation surface from the feasible study phase and the construction documents designphase of the arch dam are made on the basis of the deformation stress analysis of the conventional arch dam. The integral stability of the dam body and the cracking risk of the dam heel are evaluated with the plastic yielding zone,unbalanced force and complementary energy norm,and then the anti-slidingstability analysis of the dam abutment is carried out based on multi-grid method. The result shows that the scheme of outward shift of foundation surface made in the construction documents designphase of Yangfanggou High Arch Dam integrally improves the quantitative analysis indexes of the dam body,i. e. deformation stress,stability,safety,etc. if compared with those of the feasible study scheme,thus has a better economic benefit. The study result demonstrates the reasonability of the optimal design of the foundation surface made in the construction documents designphase of the arch dam,meanwhile,some references can be provided for the safety analysis and the quantitative analysis for the comprehensive evaluation of the optimal design of the other similar project as well.