Abstract Foundation pit dewatering in water-rich sand and pebble strata is always a huge challenge in engineering industry. As for the ultra-deep shaft dewatering in strongly permeable deep and thick sand and pebble strata in Lan?zhou, this paper conducts theoretical calculations and model tests, develops an effective model test system, prepares materials similar to sand and pebble soils, and carries out a focused study on the impact of grouting reinforcement at the foundation pit base on pit dewatering. The results of the study show that: (1) the Yellow River has an important influence on the pit dewatering, with a steep and steep dewatering funnel curve on the side close to the Yellow River and a gentle dewatering funnel curve on the side far away from the Yellow River; (2) the grouting at the foundation base reduces the hydraulic gradient, improves the safety of pit construction, and can effectively reduce the amount of water pumped in the pit, but has a limited effect on the amount of water pumped outside the pit; (3) there is an optimal value of permeability coefficient in the foundation base reinforcement area, and for this project, it is recommended to use 1×10-6 m/s as the target permeability coefficient in the reinforcement area.
Abstract：
Foundation pit dewatering in water-rich sand and pebble strata is always a huge challenge in engineering industry. As for the ultra-deep shaft dewatering in strongly permeable deep and thick sand and pebble strata in Lan?zhou, this paper conducts theoretical calculations and model tests, develops an effective model test system, prepares materials similar to sand and pebble soils, and carries out a focused study on the impact of grouting reinforcement at the foundation pit base on pit dewatering. The results of the study show that: (1) the Yellow River has an important influence on the pit dewatering, with a steep and steep dewatering funnel curve on the side close to the Yellow River and a gentle dewatering funnel curve on the side far away from the Yellow River; (2) the grouting at the foundation base reduces the hydraulic gradient, improves the safety of pit construction, and can effectively reduce the amount of water pumped in the pit, but has a limited effect on the amount of water pumped outside the pit; (3) there is an optimal value of permeability coefficient in the foundation base reinforcement area, and for this project, it is recommended to use 1×10-6 m/s as the target permeability coefficient in the reinforcement area.
WANG Fei
.A Model Test Study on the Dewatering in the Construction of Ultra-deep Shafts in Deep and Thick Sand and Pebble Strata[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(1): 176-182
2022, Vol. 59 