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Influence of Tunnel Base Rock Mass Properties on the Dynamic Response of High-Speed Railway Tunnels
(1 Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500; 2 School of Civil Engineering, Central South University, Changsha 410075)
Abstract Aimed at common problems emerging in tunnel operation, such as softening and disengagement of surrounding rock, and using a high-speed railway tunnel in surrounding rock of grade V as an example, a relevant dynamic response model for multiple working conditions is established. The influences of rock softening and disengagement on the tunnel's dynamic response and operation performance are analyzed based on a concrete damage model and cumulative damage theory. The results show that the applied force of the tunnel deteriorates with the softening and disengagement of bedrock, and its dynamic response indexes, such as dynamic displacement, accelerated velocity, dynamic stress and dynamic damage, increase: of these, the variation of rock mass properties at the tunnel base has the most obvious impact on the vibration response of the tunnel base structure. With the rock disengagement width increasing from 0 to 1.5 m, the maximum increases of accelerated velocity, dynamic tensile stress and dynamic compressive stress are 13.9%, 91.1% and 18.1%, respectively, and the dynamic damage is increased by 17.6 times; with an increase of the rock disengagement width, the fatigue life of the base structure decreases sharply, seriously affecting the tunnel's operation performance.
Abstract：
Aimed at common problems emerging in tunnel operation, such as softening and disengagement of surrounding rock, and using a high-speed railway tunnel in surrounding rock of grade V as an example, a relevant dynamic response model for multiple working conditions is established. The influences of rock softening and disengagement on the tunnel's dynamic response and operation performance are analyzed based on a concrete damage model and cumulative damage theory. The results show that the applied force of the tunnel deteriorates with the softening and disengagement of bedrock, and its dynamic response indexes, such as dynamic displacement, accelerated velocity, dynamic stress and dynamic damage, increase: of these, the variation of rock mass properties at the tunnel base has the most obvious impact on the vibration response of the tunnel base structure. With the rock disengagement width increasing from 0 to 1.5 m, the maximum increases of accelerated velocity, dynamic tensile stress and dynamic compressive stress are 13.9%, 91.1% and 18.1%, respectively, and the dynamic damage is increased by 17.6 times; with an increase of the rock disengagement width, the fatigue life of the base structure decreases sharply, seriously affecting the tunnel's operation performance.
DING Zu-De-1,
DU Yong-Gang-1,
PENG Li-Min-2 etc
.Influence of Tunnel Base Rock Mass Properties on the Dynamic Response of High-Speed Railway Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2015,V52(3): 88-94
2015, Vol. 52 