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Analysis of Stress Characteristics of Specially Lined Segment of Superlargediameter Shield Main Tunnel during Mechanically Excavating Cross Passage
(1. College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060; 2. China Railway 14th Bureau Group Mega Shield Construction Engineering Co., Ltd., Nanjing 210000)
Abstract In this paper, the 6# cross passage of Haizhu Bay Tunnel, the first mechanically built cross passage of a superlarge-diameter shield main tunnel in China, is used as the example. First, the suitability of different types of specially lined segments in construction of mechanically built cross passage of a superlarge-diameter shield main tunnel is analyzed. Then the dynamic explicit finite element method is used to create a fine model that takes into account cutterhead cutting and material damage failure, so as to investigate the stress characteristics of inlaid steel plate specially lined segment during construction of mechanically built cross passage. As the results indicate: In the mechanical construction process, the superlarge-diameter main tunnel experiences elliptical deformation. After cutting of the opening, both sides of the opening exhibit noticeable compressive stress concentration. Under the effect of the advancing cutterhead, major deformation increment and inter-ring dislocation are concentrated at the two sides of the opening. When inlaid steel plate specially lined segment is installed, the stress concentration of the structure at the sides of the hole in the cutting process is obviously abated, the deformation at the opening side is decreased by 0.5~1.5 mm, and the structure is made safer. Before construction, the inlaid steel plate of the special lining is welded into the whole structure, to enhance the integrity of the segments and to keep the inter-ring dislocation deformation of main tunnel at a low value.
Abstract：
In this paper, the 6# cross passage of Haizhu Bay Tunnel, the first mechanically built cross passage of a superlarge-diameter shield main tunnel in China, is used as the example. First, the suitability of different types of specially lined segments in construction of mechanically built cross passage of a superlarge-diameter shield main tunnel is analyzed. Then the dynamic explicit finite element method is used to create a fine model that takes into account cutterhead cutting and material damage failure, so as to investigate the stress characteristics of inlaid steel plate specially lined segment during construction of mechanically built cross passage. As the results indicate: In the mechanical construction process, the superlarge-diameter main tunnel experiences elliptical deformation. After cutting of the opening, both sides of the opening exhibit noticeable compressive stress concentration. Under the effect of the advancing cutterhead, major deformation increment and inter-ring dislocation are concentrated at the two sides of the opening. When inlaid steel plate specially lined segment is installed, the stress concentration of the structure at the sides of the hole in the cutting process is obviously abated, the deformation at the opening side is decreased by 0.5~1.5 mm, and the structure is made safer. Before construction, the inlaid steel plate of the special lining is welded into the whole structure, to enhance the integrity of the segments and to keep the inter-ring dislocation deformation of main tunnel at a low value.
ZHENG Zhenji1 HUANG Shuhua2 CHEN Xiangsheng1 ZHANG Liang2 LIU Haoming1 SHENG Jian2 SU Dong1
.Analysis of Stress Characteristics of Specially Lined Segment of Superlargediameter Shield Main Tunnel during Mechanically Excavating Cross Passage[J] MODERN TUNNELLING TECHNOLOGY, 2024,V61(1): 117-124
2024, Vol. 61 