The influence of secondary lining construction time on longitudinal mechanical properties of shield tunnel
WANG Hongchao1, HU Jun2, ZHOU Yongqiang2,3, FU Xiaodong2,3
(1.China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, Sichuan, China; 2.State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Wuhan 430071, Hubei, China;
3.University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: To solve the problem of local damage and water seepage and leakage of lining structure caused by the longitudinal uneven deformation in shield tunnels, the influence law of construction time of the secondary lining and the reasonable construction time were researched in this paper. Based on this, a three-dimension longitudinal refined numerical model of double-layered lining shield tunnel was established, and the mechanical properties of the bolts and the interface between segment and secondary lining were realistically simulated. The deformation degree of segment lining when the secondary lining was constructed was used as the construction time of secondary lining, and the influence of the construction time of secondary lining on the longitudinal mechanical properties of double-layered lining shield tunnel was analyzed through the longitudinal equivalent flexural stiffness, longitudinal deformations and longitudinal internal forces of shield tunnel. The researches shown that the ability of shield tunnel structure to resist longitudinal deformation was improved and the longitudinal internal force of segment lining was reduced owing to the construction of secondary lining. The earlier the construction time, the better the effect. However, the secondary lining load-bearing became prominent and the load-bearing capacity of segment lining could not be utilized sufficiently when the secondary lining was constructed early, resulting in a waste of structural capacity. Considering the longitudinal internal force situation of the double-layered lining structure, the reasonable degree was introduced as the judgment criterion, and the reasonable construction time of secondary lining was determined to be 37.5%~62.5%. In this condition, the segment lining deformation was within the tolerance range, and the requirements of engineering economy and structural reliability of tunnel structure could be satisfied at the same time.
王宏超, 胡军, 周永强, 付晓东. 二次衬砌施作时机对盾构隧道纵向力学性能的影响分析[J]. 隧道与地下工程灾害防治, .
WANG Hongchao, HU Jun, ZHOU Yongqiang, FU Xiaodong. The influence of secondary lining construction time on longitudinal mechanical properties of shield tunnel. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-18.
