Pile Active Underpinning of Existing Building Foundation with Undercrossing Shield Construction

Abstract

Undercrossing shield construction of a subway, the tunnel vault is about 3.0m away from the foundation pile tip of the existing building. In order to analyze the influence of shield undercrossing construction on the existing building and the influence of the existing building load on the tunnel structure, the calculation and analysis are carried out for the existing foundation forms, foundation reinforcement into raft, addition of equal length piles and increase of unequal length piles. Using the method of foundation reinforcement into raft foundation and long pile tip exceeding 0.5m below the tunnel floor can transmit the load of the upper building structure to the soil layer below the tunnel floor and reduce the load of the tunnel roof, thereby achieving the underpinning effect. According to the allowable deformation value of existing building, allowable internal force of segment and allowable deformation value of segment, using this underpinning method can meet the requirements of the various of allowable values of existing building, tunnels, etc.

Influence of Shield Tunnel Oblique Penetration Construction on Existing Large‐Span Masonry Structures

“…Wang et al [12] proposed a new method to assess the risk of shield tunnel excavation on nearby existing buildings and verifed the reliability of the method. Zhang et al [13] and Ma et al [14] studied the impact of shield construction on building foundation and pile foundation based on monitoring data and analyzed the distribution characteristics and change rules of building settlement. Based on settlement monitoring data, Wang et al [15] analyzed the efect of shield tunneling construction on the settlement of adjacent building foundations and analyzed the distribution of pore pressure in sandy soils with high water content as well as the distribution characteristics of soil displacement and plastic zone.…”