白鹤滩水电站左岸进水口直立边墙预裂方法研究

Study on presplitting method for vertical side-wall of left bank inlet for Baihetan Hydropower Station

白鹤滩水电站左岸进水口直立高边墙受到高地应力及柱状节理地质条件影响,围岩变形、岩爆、片帮及松弛垮塌等现象突出。左岸进水口直立边墙的预裂爆破质量直接关系到进水口的安全稳定及后续混凝土施工的经济性,是水电站厂房工程的重要组成部分。对直立边墙开发情况及质量缺陷分析,得出技术不熟练且熟练工少、样架搭设不规范、钻孔角度偏差是三个主要影响因素。通过制定并落实相应的对策,并对实施效果进行检查和评价,进而提高了白鹤滩水电站左岸进水扩直立边墙预裂开挖效果,为其他类似工程实施提供了经验借鉴。

As the high vertical side-wall of the left bank inlet for Baihetan Hydropower Station is impacted by the high ground stress and the geological condition of column joint therein,the phenomena of surrounding rock deformation,rock burst,spalling,relaxation collapse,etc. are significant. Therefore,the presplitting blasting quality of the vertical side-wall is directly related to the safety and stability of the left bank inlet and the economical efficiency of the successive concrete construction,which is an important part of the project of the powerhouse of the hydropower station. It is obtained from the analysis on both the excavation and the quality defects that the main impacting factors are nonproficient technology and lack of skilled workers,non-standardized erection of presplitting hole sample holder and angle deviation of drilling hole. Through making and implementing the relevant countermeasures and the inspection and evaluation made on the implementation effect,the presplitting excavation effect of the vertical side-wall of the left bank inlet for Baihetan hydropower Station is then enhanced; which can provide references for the similar projects.