【摘要】 针对某深厚覆盖层上引水式电站首部枢纽工程坝基覆盖层深厚以及设计防渗方案经济成本过高的问题，根据该工程坝址区的地质结构、地形地貌以及防渗系统设计情况，建立了三维渗流分析有限元模型。首先分析了设计防渗方案下的库区渗流场分布特性以及各建筑物的渗漏量和关键部位的渗透稳定性，结果表明设计防渗方案满足工程要求，其次在设计防渗方案的基础上计算分析了改变防渗帷幕深度及左、右岸帷幕灌浆洞长度变化对渗漏量的影响，并根据分析结果对设计防渗方案进行了优化。优化研究结果表明：库区防渗帷幕深度可以缩短至微透水带与弱透水带中线；左、右岸帷幕灌浆洞长度均可缩短10 m左右。优化方案可在库区总渗漏量得到有效控制的基础上适当降低防渗经济成本。更多还原

【Abstract】 In view of the deep overburden foundation of the head hydraulic project of a diversion power station which results in high cost for the construction of the seepage control system according to the designed scheme, a three-dimensional finite element model for seepage analysis is established according to the geological structure, landform and seepage control system design of the dam site area of the project. Firstly, the distribution characteristics of seepage field in the reservoir area, the amount of seepage through various buildings and the seepage stability of the key parts are analyzed. The results show that the designed scheme meets the above requirements. Secondly, based on the designed scheme, the influence of changing the depth of impervious curtain and the length of curtain grouting holes on the left and right banks on the leakage is calculated and analyzed. Then the anti-seepage scheme is optimized according to the analysis results. The optimization results show that the depth of impervious curtain can be shortened to the middle line between the micro permeable zone and weak permeable zone, and the length of curtain grouting holes on the left and right banks can be shortened by about 10 m, so as to reduce the economic cost of seepage control system on the basis of effective control of the total leakage in the reservoir area.更多还原