糯扎渡水电站建设中的主要技术难题与对策

Key Technical Problems and its Treatment in the Construction of Nuozhadu Hydropower Project

糯扎渡水电站工程建设过程中遇到的主要难题有:心墙堆石坝施工程序复杂,质量要求高;溢洪道泄量大、水头高、流速大;水库属典型的水温分层型水库,电站进水口采用叠梁门分层取水,水流流态、塔体结构和体形非常复杂。通过深入开展相关基础理论和关键技术研究,大坝心墙防渗体采用掺35%级配碎石的掺砾粘土料填筑,并有针对性地对坝基和坝体渗透、应力和变形、抗震等方面采取相应措施,保障了工程安全;溢洪道消力塘采用护坡不护底方式挑流消能,消能效果好,且节约了工程投资;叠梁闸门分层取水可持续取到水库的上层水,将低温水下泄对下游水生生物的影响降至最低。

The main problems encountered in the construction of Nuozhadu Hydropower Project include： （a）complex construction process and high construction quality requirement of rockfill dam, （b）large-discharge, high-head and large-flow spillway construction; and （e） very complex flow pattern, structure and shape of multi-level intake with stoplog gates as the reservoir with typical stratified water temperature. Based on the researches on basic theories and key technologies, above problems are solved. The core wall of dam is filled by clay soil mixed with 35% artificial gravel, and some special measures are taken to control dam foundation and body seepage, dam stress and deformation and dam seismic performance for ensuring the safety of the core rockfill dam. By arranging apron slabs on slopes as protection and adopting ski-jump energy dissipation, the stilling basin of spillway has a good energy dissipation effect and need less construction costs. In order to minimize the impact of water discharge on downstream aquatic organisms, the multi-level intake with stoplog gate are used to ensure the top layer water in reservoir being diverted for power generation.