ABSTRACT
The foundation is composed by raft foundation, column base, continuous beam foundation and anti-floating anchor. The left and right lines of the tunnel are across the building. The position relation of the hotel and the tunnel in two-dimensional space is shown in Figure 1. The distance from the basement floor of the building to tunnel excavation line is more than 11 m. Strata types include miscellaneous fill, coarse gravel sandstone, heavily weathered granite lamprophyre and lamprophyre in part area. Groundwater is rich pore fluid in Quaternary loose layer and bedrock fissure water. The phenomenon of water dripping appears frequently during tunnel excavation. It is possible that the subsidence value of the strata is great or
1 INTRODUCTION
Rock and soil mass surrounding a tunnel will be inevitably disturbed by tunnel excavation. The original equilibrium state of geotechnical body was destroyed. The original in situ stress will redistribute which leads to the subsidence and deformation of surface. Thereby, the safety of the existing buildings on the ground will be threatened. It should strictly control subsidence and deformation of the strata and the buildings on the ground for buildings safety when anomalies occur during tunnel excavation. Pre-recovery measures should be taken to control further damage to the buildings and ensure the structure safety when subsidence value and deformation value exceeds the allowable value. The practice shows that the grouting is one of the effective measures to reinforce strata, reduce strata subsidence and protect the existing buildings on the ground (Yuan 2010).
