超细水泥注浆在青岛地铁隧道初期支护渗漏水治理中的试验研究

微裂隙型渗漏水是城市地铁隧道建设中经常遇到的工程问题,由于岩体裂隙网络发育空间的不均一性及裂隙尺寸微小导致的可注性差,其治理难度较大。针对青岛地铁二号线花岗岩地层微裂隙型渗漏水,通过工程地质与水文地质分析总结该类型渗漏水的治理难点,通过现场试验手段优选注浆材料,对比注浆效果与P-Q-t曲线,最终优选出800目超细水泥作为最佳注浆材料;提出孔口止浆与止浆塞止浆2种孔口管封闭工艺,并针对该类型渗漏水治理提出了止浆深度及注浆终压选择方法。通过工程对比与理论分析,确定了适用于青岛地铁隧道微裂隙型渗漏水的钻孔布置方法及注浆参数。研究成果成功应用于青岛地铁隧道渗漏水治理工程中,取得了良好的治理效果,可为类似工程提供借鉴。

Experimental Study on Control of Water Leakage of Primary Support of Tunnel of Qingdao Metro by Micro-cement Grouting

Water seeping from fissures is often encountered in the construction of tunnels of Metro works. Due to the non uniformity of the fissure development and the small dimension of the fissures, it is difficult to perform grouting for the fissures. Therefore, it is very difficult to control the fissure water seepage. During the construction of Line 2 of Qingdao Metro, fissure water seepage occurs in the granite section. In the paper, the difficulties in the control of the fissure water seepage in Line 2 of Qingdao Metro are summarized by means of analysis on the engineering geological conditions and the hydro geological conditions; the grouting materials are optimized by field experiment, the grouting effect and the P Q t curves are compared, and Type 800 micro cement is finally adopted as the optimum grouting material; two grout stopping techniques, i.e., grout stopping at the orifice and grout stopping by plugs, are proposed, and the methods for the selection of grout stopping depth and grouting completion pressure are proposed; grouting hole arrangement methods and grouting parameters suitable for the fissure water seepage of Qingdao Metro are determined by means of engineering analogy and theoretical analysis. The study result has been used in the control of the fissure water of Qingdao Metro and satisfactory effect has been achieved. The paper can provide reference for similar projects in the future.