Safety thickness analysis of tunnel floor in karst region based on catastrophe theory

Abstract

Based on the tunnel shape, span and depth, the previous elliptical plate model and clamped beam model were modified. The modified model was applied to different situations. For the elliptical plate model, the water effects were considered. For the clamped beam model, water and horizontal stress were considered. Corresponding potential functions and cusp catastrophe models of rock system were established based on the catastrophe theory. The expressions of critical safety thickness were derived with necessary and sufficient conditions. The method was applied to the practical engineering. Some parameters related to the stability were discussed. The results show that elastic modulus and thickness are advantageous to the floor stability, and that the load, span, horizontal stress and water are disadvantageous to the floor stability.

Keywords

karst / catastrophe theory / safety thickness / tunnel floor / stability / water

References

[1] LiuC-q, PengH-jun. Analysis of the safe distance between a tunnel face and karst cave [J]. Modern Tunneling Technology, 2012, 49(3): 109-113

[2] GuoMingStudy on concealed karst cave’s influence on karst tunnel stability and treatment technology on tunnel of E-xi mountains [D], 2014ShandongShandong University

[3] PesendorferM, LoewS. Subsurface exploration and transient pressure testing from a deep tunnel in fractured and karstified limestones [J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(1): 121-137

[4] FraldiM, GuarracinoF. Analytical solutions for collapse mechanisms in tunnels with arbitrary cross sections [J]. International Journal of Solids & Structures, 2010, 47(2): 216-223

[5] FraldiM, GuarracinoF. Limit analysis of collapse mechanisms in cavities and tunnels according to the Hoek–Brown failure criterion [J]. International Journal of Rock Mechanics & Mining Sciences, 2009, 46(4): 665-673

[6] JiangC, ZhaoM-h, CaoW-gui. Stability analysis of subgrade cave roofs in karst region [J]. Journal of Centre South University, 2008, 15(S2): 38-44

[7] MoY-c, ZhouX-jun. Safe thickness analysis of cave under the road in karst region based on catastrophe theory [J]. Subgrade Engineering, 2008, 2: 31-33

[8] YangX L, XuJ S, LiY X, YanR M. Collapse mechanism of tunnel roof considering joined influences of nonlinearity and non-associated flow rule [J]. Geomechanics and Engineering, 2016, 10(1): 21-35

[9] YangX L, LongZ X. Seismic and static 3D stability of two-stage rock slope based on Hoek-Brown failure criterion [J]. Canadian Geotechnical Journal, 2016, 53(3): 551-558

[10] AliR K, RezaR, MohamadA H. The stress state around lined non-circular hydraulic tunnels below the water table using complex variable method [J]. International Journal of Mining Science and Technology, 2015, 78: 207-216

[11] LiuX Y, YuanD J. Mechanical analysis of anti-buoyancy safety for a shield tunnel under water in sands [J]. Tunnelling and Underground Space Technology, 2015, 47: 153-161

[12] LiY X, YangX L. Stability analysis of crack slope considering nonlinearity and water pressure [J]. KSCE Journal of Civil Engineering, 2016, 20(6): 2289-2296

[13] YuY, ZhuC K, ChongD Y, LiuY, LiS C. Catastrophe mechanism and disaster counter measure for soft rock roadway surrounding rock in Meihe mine [J]. International Journal of Mining Science and Technology, 2015, 25: 407-413

[14] YanC-b, XuG-y, ZuoY-jun. Destabilization analysis of overlapping underground chambers induced by blasting vibration with catastrophe theory [J]. Transactions of Nonferrous Metals Society of China, 2006, 16: 735-740

[15] ZhaoY L, PengQ Y, WanW. Fluid-solid coupling analysis of rock pillar stability for concealed karst cave ahead of a roadway based on catastrophic theory [J]. International Journal of Mining Science and Technology, 2014, 16: 737-745

[16] LiX P, LiY N. Research on risk assessment system for water inrush in the karst tunnel construction based on GIS: Case study on the diversion tunnel groups of the Jinping II Hydropower Station [J]. Tunnelling and Underground Space Technology, 2014, 40: 182-191

[17] YangX L, DuD C. Upper bound analysis for bearing capacity of nonhomogeneous and anisotropic clay foundation [J]. KSCE Journal of Civil Engineering, 2016

[18] LiL-pingStudy on catastrophe evolution mechanism of karst water inrush and its engineering application of high risk karst tunnel [D], 2009Ji’nanShandong University

[19] YangX L, YanR M. Collapse mechanism for deep tunnel subjected to seepage force in layered soils [J]. Geomechanics and Engineering, 2015, 8(5): 741-756

[20] YangX-l, YaoC, ZhangJ-hua. Safe retaining pressures for pressurized tunnel face using nonlinear failure criterion and reliability theory [J]. Journal of Central South University, 2016, 23(3): 708-720

[21] XieKThe study of thickness and robustness of karst tunnel floor which can keep the floor stable—Make the tunnel of XianRen as an example [D], 2013ChengduChengdu University of Technology

[22] Compilation Committee of Engineering Geology [M]. Beijing: China Architecture and Building Press, 1992: 160–170. (in Chinese)