JOURNAL OF YANGTZE RIVER SCIENTIFIC RESEARCH INSTI ›› 2020, Vol. 37 ›› Issue (9): 70-78.DOI: 10.11988/ckyyb.20190563

• ROCKSOIL ENGINEERING • Previous Articles     Next Articles

Influence of Partial Over-excavation on Safety Performance of Excavation Retained by Cantilever Contiguous Retaining Piles

LEI Ya-wei1,2, ZHENG Gang1,3, CHENG Xue-song1,3, HUANG Tian-ming1,4, LI Xi-yuan1   

  1. 1. Department of Civil Engineering, Tianjin University, Tianjin 300072, China;
    2. China Construction Second Engineering Bureau Ltd., Beijing 100160, China;
    3. Ministry of Education Key Laboratory of Coast Civil Structure Safety, Tianjin University, Tianjin 300072, China;
    4. Zhejiang Zhefeng Engineering Consulting Co. Ltd., Hangzhou 310000, China
  • Received:2019-05-15 Revised:2019-07-25 Online:2020-09-01 Published:2020-09-25

Abstract: Although collapse cases caused by partial over-excavation are seen frequently, studies on the overall safety performance and the progressive collapse mechanism caused by partial over-excavation are still in lack. In this study, the load transfer mechanism of cantilever contiguous retaining piles of long strip excavation subjected to partial over-excavation were investigated by finite difference method and model test. Results revealed that with the increase of over-excavation depth, the internal force of the piles beyond over-excavation zone increased by a large margin due to soil arch effect, while the bending moment of piles within over-excavation zone increased first and then decreased or continued to decrease. When the excavation depth in a large area remained the same, the increments in bending moment and displacement of adjacent piles intensified gradually and tended to be stable along with the widening of partial over-excavation range. The research results reveal the load transfer rules reflecting the influence of partial over-excavation on internal force of piles.

Key words: excavation collapse, cantilever contiguous piles, partial over-excavation, finite difference method, bending moment of piles

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