Abstract
Mud inrush in mountain tunnel is an independent geological hazard type different from water inrush, landslide and debris flow. The intrinsic factor of mud inrush is the instability failure of disaster medium. Its essence is that when the cohesion decreases gradually with the increase of void ratio to the point where the movement of soil particles cannot be restricted, soil particles and groundwater form slurry and gush out. Thus, accurate calculation of cohesion with variable void ratios is crucial for analyzing the reliability of disaster medium. In this study, the disaster medium was regarded as graded soil and a structural model was established wherein soil particles were simplified as cubes and the inter-particle pores were represented by the clearance between cubes. On the basis of the structure model of disaster medium, a function between the soil particle distance and void ratio was derived. Cohesion is equivalent to the resultant force between soil particles per unit area; thus, a cohesion function was derived in which the void ratio is the main variable. This function considers the influence of gradation characteristics on cohesion variation and is generally applicable to various types of disaster medium. A series of direct shear tests were carried out to determine the cohesion variation for different types of disaster medium with variable void ratios. By comparing the variation of cohesion obtained through direct shear tests with those deduced by the proposed cohesion function, we verified the validity and general applicability of the cohesion function. It is of great significance because the cohesion function can accurately predict the variation of cohesion by using the void ratio, and effectively evaluate the possibility of mud inrush according to the initial mechanical properties of disaster medium.
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References
Arroyo H, Rojas E, Perez-Rea MD, et al. (2013) Simulation of the shear strength for unsaturated soils. Comptes Rendus Mecanique 341(11–12): 727–742. https://doi.org/10.1016/jxrme.2013.10.005
Ghanbari E, Hamidi A (2015). Improvement parameters in dynamic compaction adjacent to the slopes. Journal of Rock Mechanics and Geotechnical Engineering 7(2): 233–236. https://doi.org/10.1016/j.jrmge.2015.02.002
Han JY (2001) Discussion on error of parameters in direct shear test. Dam Observation and Geotechnical Tests 25(02): 43–44. (In Chinese) https://doi.org/10.3969/j.issn.1671-3893.2001.02.013
Havaee S, Mosaddeghi MR, Ayoubi S (2015) In situ surface shear strength as affected by soil characteristics and land use in calcareous soils of central Iran. Geoderma 237–238: 137–148. https://doi.org/10.1016/j.geoderma.2014.08.016
Ibrahim, Kamal Mohamed Hafez I (2015) Effect of percentage of low plastic fines on the unsaturated shear strength of compacted gravel soil. Ain Shams Engineering Journal 6(2): 413–419. https://doi.org/10.1016/j.asej.2014.10.012
Khezri N, Mohamad H, Hajihassani M, Fatahi B (2015). The stability of shallow circular tunnels in soil considering variations in cohesion with depth. Tunnelling and Underground Space Technology 49: 230–240. https://doi.org/10.1016/j.tust.2015.04.014
Li BX, Miao TD (2006) Research on water sensitivity of loess shear strength. Chinese Journal of Rock Mechanics and Engineering 25(05): 1003–1008. (In Chinese) https://doi.org/10.3321/j.issn:1000-6915.2006.05.022
Lifshitz EM (1956) The Theory of Molecular Attractive Forces between Sol ids. Soviet Physics 2(1): 73–83.
Malizia JP, Shakoor A (2018) Effect of water content and density on strength and deformation behavior of clay soils. Engineering Geology 244: 125–131. https://doi.org/10.1016/j.enggeo.2018.07.028
Mo LL, Zhao XS, Wang X (2015) Data processing method of direct shear test based on Excel. Railway Engineering 09: 102–105. (In Chinese) https://doi.org/10.3969/j.issn.1003-1995.2015.09.29
Munday JN, Capasso F, Parsegian VA (2009) Measured long-range repulsive Casimir-Lifshitz forces. Nature 457(7226): 170–173. https://doi.org/10.1038/nature07610
Nam S, Gutierrez M, Diplas P, Petrie J (2011) Determination of the shear strength of unsaturated soils using the multistage direct shear test. Engineering Geology 122(3–4): 272–280. https://doi.org/10.1016/j.enggeo.2011.06.003
Pham BT, Son LH, Hoang TA, et al. (2018) Prediction of shear strength of soft soil using machine learning methods. CATENA 166: 181–191. https://doi.org/10.1016/j.catena.2018.04.004
Wei J, Shi B, Li J, et al. (2018) Shear strength of purple soil bun ds under different soil water contents and dry densities: A case study in the Three Gorges Reservoir Area, China. CATENA 1 66: 124–133. https://doi.org/10.1016/jxatena.2018.03.021
Xu XT, Jian WB, Liu K (2015) Effect of water content and dry density on shear strength parameters of residual soil. Chinese Journal of Underground Space and Engineering 11(02): 364–369. (In Chinese)
Yuan JP, Zhan B, Chen SC (2013) Effects of water content and compaction degree on mechanical characteristics of roadbed. Journal of Water Resources and Architectural Engineering 11(02): 98–102. (In Chinese) https://doi.org/10.3969/j.issn.1672-1144.2013.02.023
Zhang CL, Wang XS, Zou XY, et al. (2018) Estimation of surface shear strength of undisturbed soils in the eastern part of northern China’s wind erosion area. Soil and Tillage Research 178: 1–10. https://doi.org/10.1016/j.still.2017.12.014
Zhang K, Li MZ, Yang BB (2016) Research on effect of water content and dry density on shear strength of remolded loess. Journal of Anhui University of Science and Technology (Natural Science) 36(03): 74–79. (In Chinese) https://doi.org/10.3969/j.issn.1672-1098.2016.03.015
Zhang ZG (2006) Techniques to deal with the mud-outburst in a karst in Lazhidong tunnel. Modern Tunnelling Technology 43(06): 56–59. (In Chinese) https://doi.org/10.3969/j.issn.1009-6582.2006.06.011
Zhao Y, Li PF, Tian SM (2013). Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China. Journal of Rock Mechanics and Geotechnical Engineering 5(6): 468–477. (In Chinese) https://doi.org/10.1016/j.jrmge.2013.07.009
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The research reported in this manuscript was funded by the National Natural Science Foundation of China (Grant No. U1706223) and the Natural Science Foundation of Shandong Province (Grant No. ZR2017MEE070).
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Yang, T., Zhang, Qs., Zhang, X. et al. Cohesion variation during instability evolution of disaster medium in mud inrush of mountain tunnel. J. Mt. Sci. 16, 2519–2531 (2019). https://doi.org/10.1007/s11629-019-5651-0
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DOI: https://doi.org/10.1007/s11629-019-5651-0