水封洞库工程预灌浆策略及实施要点

Pre-excavation grouting strategy and implementation points of water sealed cavern project

国内大型水封洞库建设及运行过程中,渗水量过大是目前存在的普遍难题,甚至限制了水封洞库工程的应用和推广。通过对已建洞库灌浆实施过程和实施效果的剖析,指出低灌浆压力条件下普通水泥灌浆材料在花岗岩裂隙中的可灌性较差,是导致前期普遍采用的后灌浆方法实施效果不理想的主要原因。提出洞库工程应采用预灌浆为主的灌浆策略;结合洞库工程实际情况,提出了预灌浆建议流程,并对预灌浆实施过程中灌浆判据、灌浆压力、停灌原则、灌浆材料、灌浆设备、灌浆效率等关键问题加以解析和说明。相关研究和分析能够为后续洞库工程灌浆作业实施厘清思路并指明方向。

During the construction and operation of large underground water sealed caverns in China,excessive seepage is a common problem,which even limits the application and promotion of water sealed caverns.Through the analysis of the grouting implementation process and implementation effect of the built cavern,it is pointed out that the poor grout ability of ordinary cement grouting materials into granite cracks under the condition of low grouting pressure is the main reason for the unsatisfactory implementation effect of the post grouting method commonly used in the early stage.It is proposed that the grouting strategy of pre-excavation grouting should be adopted in the tunnel and reservoir engineering;Combined with the actual situation of the underground water sealed cavern project,this paper puts forward the recommended process of pre-excavation grouting,and analyzes and explains the key problems in the implementation of pre-excavation grouting,such as grouting criterion,grouting pressure,stopping grouting principle,grouting materials,grouting equipment,grouting efficiency and so on.Relevant research and analysis can clarify ideas and point out the direction for the implementation of grouting operation in subsequent underground water sealed cavern engineering.