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Mechanical Response and Resilence Evolution Characteristics of Tunnel
Structures under Additional Loads
(1. Guangzhou Municipal Engineering Design & Research Institute Co., Ltd., Guangzhou 510060；
2. School of Civil Engineering, Guangzhou University, Guangzhou 510006)
Abstract Changes in external loads inevitably induce mechanical disturbances in tunnel structures, making it cru?
cial to evaluate their resilence reasonably and ensure safety. This study, based on a typical project, conducts a simulation analysis of the mechanical response of tunnel structures under additional loads. A resilence evaluation method and fortification standards for tunnels subjected to additional loads are developed. The analysis includes the resilence evolution of a specific tunnel and proposes limits for external loading during subsequent construction based on resilence requirements. The research results indicate that the response of the tunnel crown is most significant under unilateral additional loading, exhibiting characteristics of a cantilever with three-sided constraints and spatial deformation
effects. A slight warping occurs on the unloaded side, leading to longitudinal twisting of the tunnel. Under additional loads, the maximum bending moment in the tunnel structure increases by 14.26%, and the maximum crack width increases by 27%. Both the maximum internal force and deformation are controllable; however, resilence is affected after structural damage. The midpoint of the tunnel structure enters a plastic state, and there is a linear relationship between the additional load and crack width, which approximates a cubic function relationship with redundancy.The resilence analysis of the case study demonstrates the feasibility of the evaluation method based on redundancy and proposes additional load limits in line with engineering characteristics and resilence requirements, providing a scientific basis for on-site implementation.
Abstract：
Changes in external loads inevitably induce mechanical disturbances in tunnel structures, making it cru?
cial to evaluate their resilence reasonably and ensure safety. This study, based on a typical project, conducts a simulation analysis of the mechanical response of tunnel structures under additional loads. A resilence evaluation method and fortification standards for tunnels subjected to additional loads are developed. The analysis includes the resilence evolution of a specific tunnel and proposes limits for external loading during subsequent construction based on resilence requirements. The research results indicate that the response of the tunnel crown is most significant under unilateral additional loading, exhibiting characteristics of a cantilever with three-sided constraints and spatial deformation
effects. A slight warping occurs on the unloaded side, leading to longitudinal twisting of the tunnel. Under additional loads, the maximum bending moment in the tunnel structure increases by 14.26%, and the maximum crack width increases by 27%. Both the maximum internal force and deformation are controllable; however, resilence is affected after structural damage. The midpoint of the tunnel structure enters a plastic state, and there is a linear relationship between the additional load and crack width, which approximates a cubic function relationship with redundancy.The resilence analysis of the case study demonstrates the feasibility of the evaluation method based on redundancy and proposes additional load limits in line with engineering characteristics and resilence requirements, providing a scientific basis for on-site implementation.
LIU Liying1 YANG Chunshan1 YU Zhiyuan2 OU Zhenfeng1
.Mechanical Response and Resilence Evolution Characteristics of Tunnel
Structures under Additional Loads[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(5): 167-173
2024, Vol. 61 