Journal of Shanghai Jiao Tong University ›› 2022, Vol. 56 ›› Issue (6): 722-729.doi: 10.16183/j.cnki.jsjtu.2021.149

• Naval Architecture, Ocean and Civil Engineering • Previous Articles     Next Articles

Interaction Mechanisms of Synchronously Performed Adjacent Excavations

YANG Qirun1, LI Mingguang1, CHEN Jinjian1(), WU Hang2   

  1. 1. Department of Civil Engineering; Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure, Shanghai Jiao Tong University, Shanghai 200240, China
    2. Shanghai Urban Construction Design and Research Institute (Group) Co., Ltd., Shanghai 200125, China
  • Received:2021-05-08 Online:2022-06-28 Published:2022-07-04
  • Contact: CHEN Jinjian E-mail:chenjj29@sjtu.edu.cn

Abstract:

An adjacent excavation model based on the hardening soil-small strain (HSS) constitutive model was established by using the numerical method, which was compared with the single excavation model and the adjacent excavation model without considering the wall-soil friction. The stress deformation characteristics of adjacent excavation implemented simultaneously were obtained, and the interaction mechanism of adjacent excavations were revealed. The results show that two kinds of arching effects exist in the confined soil. One is the arching effect caused by uneven deformation of walls, and the other is the arching effect caused by the wall-soil friction, both of which affect the lateral earth pressure acting on the retaining walls. With the decrease of the excavation spacing, the former is weakened, resulting in the weakening of the transfer of lateral earth pressure between the soil near the excavation face to bracing soil, while the latter is enhanced, leading to the decrease of magnitude of the lateral earth pressure acting on adjacent retaining walls. Under the action of the arching effects, the curve of lateral earth pressure develops from an R-shaped distribution to a linear distribution and then returns to an R-shaped distribution with the decrease of the spacing. The maximum horizontal displacement of non-adjacent walls increases, and the maximum horizontal displacement of adjacent walls increases primarily and then decreases.

Key words: adjacent excavations, arching effect, earth pressure, wall deformation

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