Pressure from surrounding rock of three shallow tunnels with large section and small spacing

Abstract

With the increasing traffic demand, the closely built three or more tunnels with large section play a significant role in the tunnel construction. However, the interaction among tunnels has important influences on the security and economy of tunnel engineering, and the calculation of pressure from the surrounding rock during the excavation is one of the problems that need to be solved urgently. Based on the practical engineering of three tunnels, the load model of three tunnels was proposed in consideration of the interaction and excavation sequence between tunnels. In comparison with the load model of single tunnel, the construction mechanical characteristics of the three tunnels were analyzed. The results show that the rock pressure of three tunnels calculated by the current tunnel design code is not reliable, and the interaction force increases with the spacing between tunnels.

Keywords

three-tunnel model / large section / small clear spacing / load model

References

[1] KimH. J.Estimation for tunnel lining loads [M], 1997CanadaUniversity of Alberta90-95

[2] BartonN., LienR., LundeJ.. Engineering classification of rock masses for the design of tunnel support [J]. Rock Mechanics and Rock Engineering, 1974, 6(4): 183-236

[3] BieniawskiZ. T.Engineering rock mass classification [M], 1989New YorkJohn Wiley & Sons28-38

[4] ChenW. F.Limit analysis and soil plasticity [M], 1975AmsterdamElsevier158-178

[5] YangX. L., HuangF.. Collapse mechanism of shallow tunnel based on nonlinear Hoek-Brown failure criterion [J]. Tunnelling and Underground Space Technology, 2011, 26(6): 686-691

[6] CONSTANTOPOULOS I V, MOTHERWEL J T, HALL J R. Dynamic analysis of tunnels [C]// Proceedings of the Third International Conference in Geomechanics. Aachen, 1979: 262–265.

[7] HuangF., ZhangD.-b., SunZ.-b., WuBen.. Influence of pore water pressure on upper bound analysis of collapse shape for square tunnel in Hoek-Brown media [J]. Journal of Central South University of Technology, 2011, 18(2): 530-535

[8] XU Z X. Tunnel design method using field measurement data [C]// ISRM Symposium: Design and Performance of Underground Excavation. London, England, 1984, 221–229.

[9] XiaC.-c., GongJ.-w., TangY., ZhuH.-hua.. Study on site monitoring of large-section highway tunnels with small clear spacing [J]. Chinese Journal of Rock Mechanics and Engineering, 2007, 26(1): 44-50

[10] WangS.-ping.Model test study on the tunnel within cracked surrounding rocks [D], 2004HangzhouZhejiang University

[11] KimT. H., ObaraT., YoshikawaM., OhyagiS.. Experimental study on the flow field behind a backward-facing step using a detonation-driven shock tunnel [J]. Shock Waves, 2006, 15(1): 1-12

[12] SaatiV., MortazviA.. Numerical modeling of in situ stress calculation using borehole slotter test [J]. Tunnelling and Underground Space Technology, 2011, 26(1): 172-178

[13] KookJ. H., MongeauL.. Analysis of the periodic pressure fluctuations induced by flow over a cavity [J]. Journal of Sound and Vibration, 2002, 251(5): 823-846

[14] JDG D70-2004.Code for Design of Road Tunnel [S], 2004BeijingChina Communications Press

[15] TB 10003-2001.Code for Design of Railway tunnel [S], 2001BeijingChina Railway Press

[16] MaJ.-qiu.Construction technology and mechanical property of three horizontal tunnels with large section and small spacing [D], 2010ChangshaCentral South University