Abstract In order to solve the large deformation problem of Shanenshan No.2 Tunnel of the China-Lao's Railway, the design principle of the support resistant limiting damper(SRLD)was introduced, and the energy-consuming support scheme with the SRLD was designed according to the field working conditions from the point of rational utilization of the load-bearing capacity behind the peak of the surrounding rock. Based on the comprehensive analysis of the working state, structural deformation and internal force monitoring results of the primary support of the test section, the rationality of using the SRLD to treat the tunnel with carbonaceous SLATE stratum was verified. The results showed that after tunnel excavation, the system energy was dissipated mainly through the plastic strain energy of surrounding rock, while the energy dissipated by support was limited. Therefore, if the plastic deformation ability of surrounding rock could be fully utilized and the energy could be dissipated by surrounding rock itself, the energy conservation and conversion could be accomplished, thus reducing the pressure of surrounding rock. The SRLD was a pressure yielding control system, suitable for small eccentric pressure environments controlled by deformation pressure, which assised the surrounding rock to dissipate energy in an elastic-plastic state under reduced surrounding rock pressure, without damage. The SRLD was successfully applied in the double-lane section of Shannon Hill Tunnel No. 2, which significantly reduced the pressure on the surrounding rock compared to the “strong support and hard roof”, and avoided problems such as cracking of the initial support and buckling of the steel frame without strengthening the initial support parameters, thus improving the economy of the project while ensuring safety.
DAI Jun,YANG Xing,WANG Jianjun, et al. Application of support resistant limiting damper in large-section double-track railway tunnel[J]. Hazard Control in Tunnelling and Underground Engineering,
2022, 4(4): 44-51.
