Structure optimisation of a diaphragm wall with special modelling methods in a large-scale circular ventilating shaft considering shield crossing. (May 2017)

• Record Type: Journal Article
• Authors: Wu, Guojun; Chen, Weizong; Bian, Hanbian; Yuan, Jianqiang
• Is Part Of: Tunnelling and underground space technology. Volume 65(2017)
• Page Start: 35
• Page End: 41
• Publication Date: 2017-05
• Subjects: Optimisation -- Circular diaphragm wall -- Shield tunnel crossing -- Ventilating shaft -- Numerical simulation; Tunneling -- Periodicals; Underground construction -- Periodicals; Tunnels -- Periodicals; Underground areas -- Periodicals; 624.193
• DOI: 10.1016/j.tust.2017.02.010
• Languages: English
• ISSNs: 0886-7798

Abstract

Highlights: A numerical model considering the effect of panel joints and shield crossing the ventilating shaft is proposed. Modelling of vertical panel joints with HINGE mode in connection types is presented. Modelling of the effect of excavation of shield crossing is presented. Change of joint stiffness with respect to the displacements of the wall panels is of minor influence. Abstract: In the design of a circular diaphragm wall, it is most important to determine the number of wall panels and vertical joint stiffness to achieve a desired retaining structure style. In this paper, a numerical model with special methods considering the modelling of panel joints and shield crossing the ventilating shaft was proposed: the joints between panels were simulated with the hinge mode of connection type, the interaction between surrounding soils and diaphragm wall simulated with ground springs, and the excavated soils within the shield tunnel simulated with solid elements were performed to model the stress release when shield crossing. With this model, six different operating cases considering the change of number of panels and joint stiffness were analysed in the Meizizhou ventilating shaft. The numerical results suggested the diaphragm wall with 24 panels and joint stiffness 100% of the panel stiffness (i.e., case 1) was optimal considering shield crossing the shaft in terms of evaluating the displacements, hoop stresses and vertical bending moments of wall panels.