Abstract:
The comprehensive utility tunnel in the Beijing sub-center project passes above the shield-driven run? ning tunnel between Haojiafu station and Dongxiayuan station of Beijing metro line 6, the box culvert jacking technology is designed to construction the utility tunnel and it is prone to resulting in excessive vertical displacement of the existing metro tunnel during jacking construction. The key technical points concerning structure counter weight,jacking force calculation and jack configuration as well as controlling of axis and elevation variations of box culvert structure were introduced in detail. Reinforcement measures of soil mass at both sides of jacking area by high pressure jet grouting pile and soil mass beneath box culvert by deep-hole grouting were carried out, decreasing the frictional resistance induced by tunnel excavation and improving bearing capacity of the strata above the existing metro tunnel. The monitoring data show that the deformation of the existing metro tunnel caused by jacking construction is strictly controlled within the scope of the requirements of metro operation and design.
XU Futian
.Application of Jacking Technology with Adjustable Counter Weights in Box Culvert Construction above Existing Metro Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(4): 182-187