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本文综述了七年来,对二滩水电站拱坝坝肩稳定进行的分析研究工作成果和方法,研究成果主要有: (1) 运用二十个地质力学模型试验分析坝肩稳定的安全度;分析软弱带即纤闪石化玄武岩对坝肩稳定的影响,探求对它的处理方案,研究河岸风化卸荷带利用和减少开挖的可能性,选择优化的大坝建基面,分析了坝与基础的共同作用。 (2) 运用有限元方法,计算坝肩稳定的安全度,破坏机制,以便和模型试验相对比。本文综述了1/250比例模型的相似律:用4520块石膏块体做成了比例模型,模拟了岩体的块体结构,纤闪石化软弱带及岩体的三组裂隙节理和断裂。本文提出了石膏块体比例相似模拟岩体结构的关系及尺寸效应,弹塑性及脆性材料试验方法等,还提出了连续破坏的记录。本文用20个模型的相互对比方法,得出了坝肩稳定的安全度及锚索方案,混凝土置换,高压灌浆等处理方案的可能性;比较了抛物线拱坝,不同坝型拱坝的稳定度,认为在这里修筑拱坝是可行的。本文还综述了有限元方法计算稳定的弹性模型,弹塑性-脆性模型,两者做了比较,计算结果与实验成果基本一致。
This paper reviews the achievements and methods of the analysis and research on the stability of arch dam abutments at Ertan hydropower station over the past seven years. The main results are as follows: (1) Twenty geomechanical model tests are used to analyze the stability of dam abutments; the weaknesses are analyzed. With the effect of lepidite petrolite basalt on abutment stabilization, the treatment plan for it was explored to study the use of river bank weathering unloading zone and reduce the possibility of excavation. The optimized dam foundation surface was selected and the dam foundation was analyzed. collective effect. (2) Use the finite element method to calculate the stability of the abutment stability and the failure mechanism to compare it with the model test. This paper reviews the similarity law of the 1/250 scale model: a proportion model is built with 4520 blocks of plaster, which simulates the bulk structure of the rock mass, the fission-softening weak zone and the three groups of fracture joints and fractures of the rock mass. This paper proposes the relationship between the proportion of gypsum blocks simulated rock mass structure and the size effect, elasto-plastic and brittle materials test methods, etc. It also proposes a continuous destruction record. In this paper, the stability of the dam abutment, the possibility of the anchor cable scheme, concrete replacement, and high-pressure grouting are obtained by using the comparison method of 20 models. The stability of arch dams with different arches is compared. It is considered feasible to build an arch dam here. This paper also summarizes the finite element method to calculate the stable elastic model, elasto-plastic-brittle model, the two are compared, the calculation results are basically consistent with the experimental results.