Study On Movement Of Airport Runway Induced By Shallow Tunneling Under The Protection Of Ultra-long Pipe-roofing

The engineering, located in between Beijing Capital international Airport Terminal2and Terminal3, is proposed to built at the capital international airport change expansion project, including MRT tunnel by transit passengers and Car tunnel by pass luggage, catering truck, car ferry. The engineering build the world’s longest pipe-roofing construction, tunnel section width in China is particularly rare, and tunnel construction below airport runway is no precedent in airport non-stop flight conditions. The study integrated of theoretical analysis, field monitoring test and finite element3D modeling, analyze the airport runway settlement deformation law caused by large section and shallow cover pipe-roofing excavation construction, and explore the grouting technology and construction sequence optimization. The mainly drawing conclusion as follows:(l)Field monitoring data show, the surface deformation occurs mainly in pipe-roofing and tunnel excavation. The surface maximum settlement is about-15mm in pipe-roofing excavation, and the surface maximum settlement is about-7.5mm in tunnel excavation due to the grouting effect.(2)The measured data show that comparing the data inside and outside the runway, the settlement difference is significant. In construction process, the means of grouting in real time tracking compensation by monitoring information can effectively control the deformation of the ground surface.(3)The results of numerical simulation shows, the law of surface subsidence similar to the measured data. The numerical simulation method provide reference for the future similar engineering modeling.