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Analysis of Factors Affecting Intersected Tunnel Construction
(1 School of Civil Engineering, Central South University, Changsha 410075;
2 China Construction Fifth Engineering Division Corp. Ltd., Changsha 410004)
Abstract Considering the three factors of rock classification, crossing angle, and rock pillar height, 100 cases were assumed to implement numerical modeling calculation and the law of the three factors affecting construction of intersected tunnels was discussed regarding crown settlement and internal force change of the primary support in an existing tunnel. Study results show that crown settlement and shotcrete axial force present a trend of significantly increasing with the enlargement of the crossing angle. When the rock pillar height increases and rock mass is poor, the induced crown settlement of the existing tunnel becomes larger while the increasing rate of the shotcrete axial force becomes smaller. The structural deformation of existing tunnels can be used as a key review indicator during the design and construction of intersected tunnels.
Abstract:
Considering the three factors of rock classification, crossing angle, and rock pillar height, 100 cases were assumed to implement numerical modeling calculation and the law of the three factors affecting construction of intersected tunnels was discussed regarding crown settlement and internal force change of the primary support in an existing tunnel. Study results show that crown settlement and shotcrete axial force present a trend of significantly increasing with the enlargement of the crossing angle. When the rock pillar height increases and rock mass is poor, the induced crown settlement of the existing tunnel becomes larger while the increasing rate of the shotcrete axial force becomes smaller. The structural deformation of existing tunnels can be used as a key review indicator during the design and construction of intersected tunnels.