拉西瓦水电站主要工程地质问题及研究方法

拉西瓦水电站主要工程地质问题包括区域构造稳定性、坝区高地应力场、高陡岩质边坡稳定性、厂房洞群围岩稳定性等。对区域构造稳定性采用了地质地貌调查及绝对年龄测定、现今活动状况长期监测及坝区微地震监测等方法；对高地应力场采用了多种方法实测并根据实测成果进行数值模拟分析；对高陡边坡采用了稳定性整体计算机扫描技术，分析各种可能的结构块体组合和边坡浅表部不稳定块体分区评价；对洞室稳定性主要采取了多种方法的围岩分类，在此基础上分析了洞周块体稳定性并评价了岩爆发生发育规律。

Major Engineering Geology Problems of Laxiwa Hydropower Project and Research Methods

The major engineering geology problems cover regional tectonic stability, high crustal stress of the dam area, stability of high steep rock slope, and stability of powerhouse cavern. For the regional tectonic stability, several methods were used to investigate the geology and topography, determine absolute age, monitor present activity and microseismicity of the project region. Methods were applied to measure the high crustal stress fields, and the numerical simulation analyses were made based upon the measured results. The computer scanner technique were utilized for the stability of high steep slope to analyze various possible combination of structure blocks and zoning evaluation of unstable blocks in the shallow surface of the slope. The classification of surrounding rock was mainly adopted for the stability of the cavern in order to analyze the stability of surrounding cavern and evaluate developed rule of rock explosion.