Abstract The construction of the Liangshan Tunnel on the Xiamen-Shenzhen Railway was severely blocked when passing through the L7 weak water-rich zone that intersects the tunnel from DK96+505 to DK96+533, with a length of around 2.3 km. In this context, a pre-reinforcement solution was determined based on various economic and technical comparisons. The solution adopted an advance reinforcement ring using full-ring horizontal jet grouting piles, a large pipe-roof advance support with supplementary grouting at the arch wall, and ground conditioning by horizontal jet grouting piles at the face. The support mechanism and effects of this pre-reinforcement system are introduced and a detailed analysis is discussed. The results show that the reinforcement effect is significant provided the thickness of the reinforcement ring is 0~3m, and that the full-ring horizontal jet grouting piles have the dual function of bearing weight and stopping water as well as reducing the external load born by the support system. An advance cycle of 0.5 m is recommended considering these various factors.
Abstract：
The construction of the Liangshan Tunnel on the Xiamen-Shenzhen Railway was severely blocked when passing through the L7 weak water-rich zone that intersects the tunnel from DK96+505 to DK96+533, with a length of around 2.3 km. In this context, a pre-reinforcement solution was determined based on various economic and technical comparisons. The solution adopted an advance reinforcement ring using full-ring horizontal jet grouting piles, a large pipe-roof advance support with supplementary grouting at the arch wall, and ground conditioning by horizontal jet grouting piles at the face. The support mechanism and effects of this pre-reinforcement system are introduced and a detailed analysis is discussed. The results show that the reinforcement effect is significant provided the thickness of the reinforcement ring is 0~3m, and that the full-ring horizontal jet grouting piles have the dual function of bearing weight and stopping water as well as reducing the external load born by the support system. An advance cycle of 0.5 m is recommended considering these various factors.
.On the Support Mechanism of the Pre-Reinforcement System
for the L7 Deep, Weak Water-Rich Zone Passed Through
by the Liangshan Tunnel[J] MODERN TUNNELLING TECHNOLOGY, 2013,V50(4): 138-145
2013, Vol. 50 