Lagged settlement in sandy cobble strata and earth pressure on shield tunnel

Journal article (2019)

Authors

Jizhi Huang South China University of Technology
Y. Zhang Fuzhou University, Materials and Environment - CEG
Xiaowei Ouyang Guangzhou University
Guoyuan Xu South China University of Technology
Research Group
Materials and Environment (CEG) (TU Delft)
Copyright: © 2019 Jizhi Huang, Y. Zhang, Xiaowei Ouyang, Guoyuan Xu
DOI: https://doi.org/10.3934/mbe.2019309
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Published Date

2019

Language

English

Faculty

Civil Engineering & Geosciences

Department

Materials- Mechanics- Management & Design

Research Group

Materials and Environment

Abstract

Lagged settlement is a typical accident induced by shield construction in sandy cobble strata. This paper analyzed the process and mechanism of lagged settlement, results show that all phases are in accord with the characteristics of ellipsoid theory of particle flows. Based on this theory, a method for calculating coefficient of lateral earth pressure and loosened earth pressure is proposed in this research. For the coefficient of lateral earth pressure, the boundary of loosened ellipsoid is divided into two parts, the arch zone and the excavation zone, and the lateral pressure coefficients are derived respectively according to the stress state. For loosened earth pressure on tunnel, the Terzaghi earth pressure theory and Protodyakonov earth pressure theory are adapted in different conditions according to the state of loosened cobble soil. Theories developed in this study can be applied on determination of shield excavation parameters, as well as calculation of loosened earth pressure and control of tunnel support.