Back Analysis of Water and Earth Loads on Shield Tunnel and Structure Ultimate Limit State Assessment: A Case Study
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A method based on the least-squares method was proposed for the back analysis of water and earth loads using in situ monitoring data of a limited amount of structural strain values for a shallow shield tunnel buried in the soil stratum. Theoretical formulas were used to calculate the internal forces, conduct an assessment of the ultimate limit state, and determine the safety factors of compression and shear. Based upon all of the above, an assessment system was established, and its procedures were illustrated. The highlights of this assessment system are that only a few strain monitoring points are required for the back analysis of the external loads, the internal forces in every position of the segment are calculated by the uniform rigidity ring model, and the safety assessment is conducted by the proposed ultimate limit state formulas. According to the in situ monitoring project in Nanjing subway line 1, the monitoring data of internal forces were close to the back analysis data, which proves the reliability of this method.
KeywordsShield tunnel Water and earth loads In situ monitoring Back analysis Ultimate limit states
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Financial support for this work provided by the National Key R & D Program of China (Grant No. 2016YFC0802205), and the National Science Foundation of China (Grant No. 51678500) is gratefully acknowledged.
- 2.Gao, Y.; Xu, F.; Zhang, Q.; et al.: Geotechnical monitoring and analyses on the stability and health of a large cross-section railway tunnel constructed in a seismic area. Measurement (2017). https://doi.org/10.1016/j.measurement.2017.10.039
- 3.Yan, Q.X.; Zhang, C.; Lin, G.; et al.: Field monitoring of deformations and internal forces of surrounding rocks and lining structures in the construction of the Gangkou double-arched tunnel—a case study. Appl. Sci. (2017). https://doi.org/10.3390/app7020169
- 11.International Organization for Standardization: General Principles on Reliability for Structures. https://www.iso.org/obp/ui/#iso:std:iso:2394:ed-4:v1:en
- 12.Ministry of Housing and Urban-Rural Development of the People’s Republic of China: Unified Standard for Reliability Design of Engineering Structures. China architecture and building press, Beijing (2008)Google Scholar
- 13.Ghasemi, S.H.; Nowak, A.S.: Reliability analysis of circular tunnel with consideration of the strength limit state. Geomech. Eng. 15(3), 878–888 (2018)Google Scholar
- 19.Yan, Q.X.; Chen, H.; Chen, W.Y.; et al.: Dynamic characteristic and fatigue accumulative damage of a cross shield tunnel structure under vibration load. Shock Vib. (2018). https://doi.org/10.1155/2018/9525680
- 20.He, B.G.; Zhang, Z.Q.; Ma, T.F.: Loading simulation of water pressure for model test of large-span tunnel. Eng. Mech. 32(1), 128–136 (2015)Google Scholar
- 21.Zhu, W.: Specification and Explanation of Tunnel (Shield Tunnel). Chinese architecture and building press, Beijing (2001)Google Scholar
- 25.Koizumi, A.: Design of Shield Tunnel Segments: From The Limited State Method to the Allowable Stress Method. Marzuzen, Tokyo (2010)Google Scholar
- 26.Japan Society of Civil Engineers Committee: Standard specification for concrete structures. http://www.jsce-int.org/system/files/JGC16_Standard_Specifications_Materials_and_Construction_1.1.pdf
- 27.Koizumi, A.: Seismic Studies and Examples of Shield Tunnel. China architecture and building press, Beijing (2009)Google Scholar