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Study on Stress Response and Deformation Mechanism of Pipe Sections under Complex Deflection Modes
(1. School of Civil and Environmental Engineering, Changsha University of Science and Technology, Changsha 410114;
2. China Communications Road Construction (Kunming) City Investment Development Co., Ltd., Kunming 650000)
Abstract To investigate the influence of deflection on the mechanical behavior of pipe sections, large-scale indoor model tests and numerical simulations were conducted. The stress distribution characteristics between pipe sections under three types of complex contact conditions were systematically analyzed, with a focus on the influence of jacking load levels, deflection modes, and deflection angles on pipe deformation and stress development. The results indicate that under unidirectional deflection, the pipe exhibits a horizontally biased compression state, and the axial stress increases significantly with increasing deflection angle and load, with the strain distribution showing a “horizontal cone” pattern. An increase in deflection angle results in local extrusion deformation, causing abrupt stress variation. Under diagonal deflection, opposite stress concentrations occur at the deflection cross-sections (1-1 and 2-2), and the overall stress level is lower than that under unidirectional deflection. The axial force transfer at the joint reveals that, with increasing load, the contact pressure at the top of the joint increases and the deformation strain shows nonlinear growth. Moreover, a larger deflection angle changes the contact condition at the joint, making the jacking force transfer path more pronounced. In addition, under combined deflection modes, axial stress varies linearly with deflection angle, while reduced contact area significantly affects the load-transfer characteristics.
Abstract：
To investigate the influence of deflection on the mechanical behavior of pipe sections, large-scale indoor model tests and numerical simulations were conducted. The stress distribution characteristics between pipe sections under three types of complex contact conditions were systematically analyzed, with a focus on the influence of jacking load levels, deflection modes, and deflection angles on pipe deformation and stress development. The results indicate that under unidirectional deflection, the pipe exhibits a horizontally biased compression state, and the axial stress increases significantly with increasing deflection angle and load, with the strain distribution showing a “horizontal cone” pattern. An increase in deflection angle results in local extrusion deformation, causing abrupt stress variation. Under diagonal deflection, opposite stress concentrations occur at the deflection cross-sections (1-1 and 2-2), and the overall stress level is lower than that under unidirectional deflection. The axial force transfer at the joint reveals that, with increasing load, the contact pressure at the top of the joint increases and the deformation strain shows nonlinear growth. Moreover, a larger deflection angle changes the contact condition at the joint, making the jacking force transfer path more pronounced. In addition, under combined deflection modes, axial stress varies linearly with deflection angle, while reduced contact area significantly affects the load-transfer characteristics.
ZHANG Yongjie1 ZHANG Xinyu1 CHEN Jianhua1,
2 OU Xuefeng1 LUO Zhimin1 WU Hanghui1
.Study on Stress Response and Deformation Mechanism of Pipe Sections under Complex Deflection Modes[J] MODERN TUNNELLING TECHNOLOGY, 2025,V62(5): 172-
2025, Vol. 62 