Study and Application of Key Technical Parameters of Pre-grouting in High-pressure Water-rich Deep Shaft Face
(1. Engineering Management Center of China State Railway Group Co., Ltd., Beijing 100844; 2. China Railway Tunnel Group Co., Ltd.,Guangzhou 511457; 3. China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031)
Abstract：
In the shaft construction of the Gaoligongshan Tunnel, the maximum water inrush of a single advanced geologic exploration borehole is 126.9 m3/h, and the pre-grouting technology is used on the faces for grouting reinforcement and water blocking. A total of 12 pre-grouting cycles were conducted for the main shaft face and 11 pregrouting cycles were conducted for the auxiliary shaft face. The results of application show that (1) the face pregrouting method is employed to effectively solve the difficulties in grouting reinforcement and water blocking technologies for high-pressure water-rich deep shafts and ensure safe and normal construction of shafts; (2) it is appropriate to use 10 m3/h as the reference value of water inrush control during the normal construction of shafts. When the face water inrush is equal to or greater than 10 m3/h, grouting and water blocking measures shall be taken; (3) before the excavation of shafts, it is better to use 1.4 L/(min·m) as the reference value of water inrush control of a single advanced exploration borehole. When the length of an advanced exploration borehole cycle is 60 m, the reference value is 5.0 m3/h; (4) for the pre-grouting in the shaft face, it is better to use 1.0 L/(min·m) as the reference value of water inrush control of an inspection hole. When the length of a grouting cycle is 60 m, the reference value is 3.6 m3/h;(5) based on the water inrush of an inspection hole, grouting and water blocking rate, water inrush of a shaft during excavation, and efficiency of well completion, 60 m should be used as the length of a cyclic grouting section when pre-grouting is conducted in the shaft face.
ZHANG Minqing1 XIN Weike1 JIA Dapeng1 SI Jingzhao2 WANG Huanlong3
.Study and Application of Key Technical Parameters of Pre-grouting in High-pressure Water-rich Deep Shaft Face[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(6): 177-186
2022, Vol. 59 