Cracking Analysis of Shield Construction Segments Based on Boss Unevenness

Abstract

As the most basic structural unit of shield tunnel, the segment will cause tunnel quality problems and ultimately affect the service life of the tunnel. Based on the actual project, this paper takes the segmental cracking phenomenon in the a large diameter shield tunnel as the research object, and analyzes the influence of the three protruding bosses of the cracked segment itself and the adjacent small ring on the segment cracking. Mechanical analysis, and finite element simulation of the force form of the tube under the unevenness of the boss. Through analysis, it is found that the three bosses of the cracked tube itself have little effect on the cracking of the segment, and the unevenness of the annular seam is the main cause of cracking of the segment. The analysis of this paper can take effective control measures to reduce the impact of cracks in shield tunnels on the normal construction of shield tunnels.