Case Study of Underground Shield Tunnels in Interchange Piles Foundation Underpinning Construction

Abstract

Technology of shield tunneling has been widely used in modern city subway system building, however, due to the limit of urban construction land resources, it is inevitable for the new building structures conflicted with existing one. Thus, it is essential to taking correct measures to guarantee the safety of existing structure. In this case, a typical case of metro shield tunnel crossing through city overpass bridge piles underpinning construction project is studied by the numerical method and site field monitoring. According to the existing overpass bridge structure, geological conditions and site operation environment, a suitable construction method of piles foundation underpinning plan for this project is adopted. In order to ensure the structure safety of the existed overpass bridge during the pile foundation underpinning construction, a numerical simulation model is established which takes the whole foundation underpinning structure and construction steps into consideration. The numerical simulation result shows that the stress and the settlement of the piles foundation underpinning structure is reasonable. After the comparing of the site monitoring data with the numerical model simulation results, it is found that the site settlement and stress results are highly consistent with the calculated results, and it proves the feasibility of the piles foundation underpinning construction scheme. Eventually, the site gauging settlement data of the overpass pier and the pile cap indicate that the original overpass structure is barely affected by the shield tunnel construction, the construction method can provide reference and experience for the future similar projects.

Study on Numerical Simulation Uplift of Bridge pile Foundation

“…Many scholars at home and abroad have studied the problem of bridge settlement. Fang [1] studied the impact of the existing bridge on the settlement of all parts of the newly built adjacent bridge piles; Zhou [2] put forward a method to calculate the long-term settlement of pile foundation, considering the creep characteristics of layered soil consolidation at the pile; Zhang [3] analyzed the in uence of pressure water on the settlement of cluster pile foundation by means of indoor three-axial test and nite element numerical simulation; Liu [4] analyzed the causes of the surface and the settlement of the bridge, and believed that the settlement was caused by the collapse of the uncompacted area caused by the in uence of rain; Liu [5]studied the cause of the settlement disease of the double-pillar pier foundation of a new highway bridge, and found that the insu cient bearing capacity and the pile body defects caused the uneven settlement of the pile foundation; Wang [6] adopted the method of nite element analysis to establish the model of high-speed railway bridge and analyzed the settlement of highway and bridge; Zhang [7] uses numerical simulation, and believes that the construction of shield tunneling technology under existing Bridges has little impact on the settlement of existing Bridges.…”

Full‐Scale Laboratory Test of Cutting Large‐Diameter Piles Directly by Shield Cutterhead

“…Due to the complex construction environment in cities and limitations of alignment planning of the tunnel, tunnels adjacent to the existing piles of buildings appear frequently [1][2][3][4]. In particular cases, tunnels are passing through the existing piles [5][6][7]. e shield tunneling method is widely used in tunnel engineering, for its advantage of safety, e ciency, high mechanization degree, and small disturbance.…”

“…e shield tunneling method is widely used in tunnel engineering, for its advantage of safety, e ciency, high mechanization degree, and small disturbance. Compared to the methods of tunnel rerouting and pile underpinning [6,8], cutting the piles directly using the shield cutter is more economical and e cient when shield tunnels pass through the existing reinforced concrete (RC) piles, and it has wide application prospects. During the process of shield cutting piles, parameters con guration of cutter and shield working is crucial.…”

Intelligent Planning and Research on Urban Traffic Congestion

“…This will ensure collisions between pedestrians, electric vehicles, bicycles, and cars are avoided at ground traffic intersections. Therefore, how to choose the construction location of an overpass and what type of overpass to build [24] will directly affect the traffic situation of the entire urban road traffic network. If the site selection is correct, it will effectively alleviate the traffic situation in the surrounding area.…”