Mechanical Behavior Near the Intersection of A Shaft and Horizontal Tunnel During Tunneling

• Main Authors: Yi-Fung Chu, 朱義豐
• Other Authors: Chee-nan Chen
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/82385541661245613591

碩士 === 國立臺灣科技大學 === 營建工程系 === 90 === Shafts have the function both ventilation and increasing working faces during tunneling for long tunnel construction. The mechanical behavior near the connection of a shaft and horizontal tunnel should be three-dimensional. It is not suitable to analyze the intersection behavior by using two-dimensional numerical simulation. A three-dimensional finite difference program FLAC3D was used in this research. At First, the numerical model was established by simulating the No. 2 Shaft of Ping-Lin Tunnel. The in-situ rock parameters and Mohr-Coulomb Failure Criteria were used for analysis. At second, tracing four monitoring lines during excavation performed the variation of stress around intersection. Two monitoring lines are horizontal and one of them is near intersection. The other two monitoring lines are vertical and one is also near intersection. The intersection effect is studied by the comparison of the four monitoring lines. The results show that the stress on excavation surface near intersection is uniaxial if the tunneling passing the horizontal monitoring line, meanwhile the stress behind the excavation is biaxial. The peak tangential stress appears around the interface of plastic and elastic region behind the excavated surface.