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Study on Mechanical Characteristics of Super Large Section Riser Pipe by Vertical Jacking Method
(1. Shandong Electric Power Engineering Consulting Institute Co. Ltd., Jinan 250013；2. Department of Geotechnical Engineering,Tongji University, Shanghai 200092)
Abstract In the construction process of the vertical jacking method, an important control factor for the structural safety is the opening size of the vertical method. The larger the ratio of the radius on the open riser compared to the original tunnel, the greater impact on the safety of the structure would happen after the opening. According to the background of the construction process of the super large section jacking riser opening in a water intake and drainage project, the dynamic construction process is transformed into a simulated working condition, and the structural stress characteristics of the super large section jacking riser are summarized by numerical simulation method. The research results show that: (1) There are two possible deformation trends of the structure during the construction process, one is the overall sinking trend of the structure under the jacking condition, and the other is the vertical duck egg deformation trend of the opening ring under the opening condition; (2) The axial force at the bottom of the opening ring is greatly reduced under the jacking condition. The maximum tensile force is 400 kN and the change trend of the open ring is greater than that of the closed ring. The internal force conditions of the unfilled and full water conditions are similar to the initial conditions; (3) The shear of the joint is mainly between the open ring and the closed ring. The maximum radial shear force reaches 30 kN/m under the jacking condition, and the inter-ring radial shear force reaches 60 kN/m under the opening condition; (4) The opening condition during the construction is the control condition; (5) Under the jacking condition and the opening condition, the checking design of the annular joint shall be carried out.
Abstract：
In the construction process of the vertical jacking method, an important control factor for the structural safety is the opening size of the vertical method. The larger the ratio of the radius on the open riser compared to the original tunnel, the greater impact on the safety of the structure would happen after the opening. According to the background of the construction process of the super large section jacking riser opening in a water intake and drainage project, the dynamic construction process is transformed into a simulated working condition, and the structural stress characteristics of the super large section jacking riser are summarized by numerical simulation method. The research results show that: (1) There are two possible deformation trends of the structure during the construction process, one is the overall sinking trend of the structure under the jacking condition, and the other is the vertical duck egg deformation trend of the opening ring under the opening condition; (2) The axial force at the bottom of the opening ring is greatly reduced under the jacking condition. The maximum tensile force is 400 kN and the change trend of the open ring is greater than that of the closed ring. The internal force conditions of the unfilled and full water conditions are similar to the initial conditions; (3) The shear of the joint is mainly between the open ring and the closed ring. The maximum radial shear force reaches 30 kN/m under the jacking condition, and the inter-ring radial shear force reaches 60 kN/m under the opening condition; (4) The opening condition during the construction is the control condition; (5) Under the jacking condition and the opening condition, the checking design of the annular joint shall be carried out.
HAN Chao1 GAO Yimin2 ZHOU Guangjie1 ZHANG Lei1 LIU Xian2
.Study on Mechanical Characteristics of Super Large Section Riser Pipe by Vertical Jacking Method[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(5): 125-135
2022, Vol. 59 