尾矿库坝基防渗帷幕注浆工艺适用性与改进研究

国内有色金属矿山尾矿库多存在库区渗漏和场地污染问题,很多防渗工程中采用了帷幕注浆技术。但是限于场地条件差异,对于很多薄覆盖层下风化基岩注浆施工而言,存在浆液扩散难、防渗效果差等问题。究其根本原因,除了注浆材料和浆液类型的适用性以外,注浆工艺与地质条件的匹配度是重要影响因素之一。研究结合某尾矿库坝基防渗工程,对常规注浆工艺的适用性进行了试验验证。针对常规工艺存在的注浆压力难增大、易发生地面冒浆和孔内固管事故问题,优化改进形成“孔内封闭局部循环”注浆工艺及装置。新工艺经过现场实际验证,适用性优于常规工艺,可以有效提高注浆质量、减少地面冒浆和孔内事故,适于在类似地质条件的帷幕注浆项目中推广应用。

Research on Applicability and Improvement of Curtain Grouting Technology for Tailings Dam Foundation Anti-Seepage

There are many problems of leakage and site pollution in tailings pond of nonferrous metal mines in China. Curtain grouting technology is used in many anti-seepage projects. However, due to the difference of site conditions, there are some problems in grouting construction of weathered bedrock under thin overburden, such as slurry diffusion difficult and poor anti-seepage effect. Besides the applicability of grouting materials and grout types, the matching degree between grouting technology and geological conditions is one of the important factors. The applicability of the conventional grouting technology is verified by the test combined with the anti-seepage engineering of a tailings dam foundation. Aiming at the problems existing in the conventional technology, such as difficult to increase the grouting pressure, easy to occur ground slurry and pipe consolidation accidents in the hole, the grouting technology and device of "local circulation in hole closure" was optimized and improved. The applicability of the new technology is better than that of the conventional technology, which can effectively improve the grouting quality, reduce the ground grouting and hole accidents, and is suitable for popularization and application in curtain grouting projects with similar geological conditions.