Numerical Simulation of Mechanical Characteristics and Safety Performance for Pre-Cracked Tunnel Lining with the Extended Finite Element Method

• Published in: Buildings (Basel) Vol. 14; no. 1; p. 123
• Main Authors: Lu, Xin, Liu, Yong, Hou, Xiaolong, Chen, Cai, Gao, Ruidan
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.01.2024
• Subjects: Analysis; Axial forces; Bending moments; Computer simulation; Concavity; Concrete; Convexity; Cracks; extended finite element method; Finite element analysis; Finite element method; Geology; Highway construction; Impact analysis; lining cracks; Load; Mathematical analysis; Mathematical models; Mechanical properties; Methods; Onsite; Safety; safety analysis; Safety and security measures; Safety factors; Shear strength; Shoulder; Simulation; Simulation methods; Simulation models; tunnel engineering; Tunnel linings; China; Shaanxi China
• ISSN: 2075-5309; 2075-5309
• DOI: 10.3390/buildings14010123

The service performance of tunnel lining is affected by crack properties and development states. In this paper, numerical simulation models were established to investigate the mechanics characteristics and safety performance for lining structures under different cracks based on the extended finite element method (XFEM). Analyze multiple quantitative factors in simulation, including changes in crack location, crack length, and crack distribution range in the lining structure. The axial force and bending moment of the preset cracks in the lining structures were first studied. The maximum safety factor attenuation rate (Dkmax) was proposed to analyze the impact of longitudinal and annular cracks on the safety performance. The axial force at the vault of the lining arch is the most significantly affected by the combined longitudinal cracks at multiple locations. When the length of a longitudinal crack increases from 1 m to 6 m, the axial force value at the crack point decreases by 33.77%, 36.15%, and 11.32%. However, the bending moment value increases by 4.47 times, 2.50 times, and 1.69 times. Under the influence of longitudinal cracks in an “arch crown + arch shoulder”, “arch crown + arch waist”, and “arch crown + arch shoulder + arch waist”, the axial force in the arch vault increased by 21.55%, decreased by 17.52%, and decreased by 13.45%. The distribution pattern of the bending moment under the influence of circumferential cracks shows convexity at the arch shoulder and arch foot, and concavity at the arch waist and side walls. The safety factor scatter curve with longitudinal cracks shows a gradual transition from a “W” shape to a “U” shape. The safety factor curve with circumferential cracks presents an approximately symmetrical wave-shaped distribution.