Analysis of Experimental Results on the Bearing Capacity of Sand in Low-Gravity Conditions
Tóm tắt
With advancements in space exploration, operations in low-gravity environments such as the lunar surface are expected to be conducted. Geotechnical engineering problems such as those associated with the foundation bearing capacity considerably influence the feasibility and safety of these operations. In this study, the findings of experiments conducted by Japan Aerospace Exploration Agency (JAXA) scientists on parabolic flight, aimed at measuring the ultimate bearing capacity of shallow foundations under 1/6 g to 2 g of gravity, are analysed. Specifically, the results are analysed to calculate the ultimate friction angle based on the classical Terzaghi limiting equilibrium solution in soil mechanics. The friction angle of foundation sand increases as the gravity level decreases. This finding is verified through advanced arbitrary Lagrangian–Eulerian (ALE) finite element simulations based on a simple Mohr–Coulomb model. Moreover, the underlying mechanism for this phenomenon is examined considering an ALE finite element simulation based on a newly developed rheological model known as the Tsinghua–MiDi sand model. The pressure-sensitive and rate-dependency constitutive behaviour of sand is clarified. Notably, this phenomenon increases the viscous shear stress and ultimate friction angles in low-gravity conditions. The coupled effects of the loading rate and low-gravity level on the bearing capacity of foundation sand are predicted. The findings can provide a novel theoretical prospective for geotechnical studies in space exploration engineering in low-gravity conditions.
Tài liệu tham khảo
布野 泰広. JAXA長期ビジョン: JAXA2025. J. Soc. Mech. Eng. 108 (2005)
Angelopoulos, V.: The ARTEMIS mission. The ARTEMIS mission. 3–25 (2010). https://doi.org/10.1007/s11214-010-9687-2
Boles, W.W., Scott, W.D., Connolly, J.F.: Excavation forces in reduced gravity environment. J. Aerosp. Eng. 10(2), 99–103 (1997). https://doi.org/10.1061/(ASCE)0893-1321(1997)10:2(99)
Cheng, X., Xiao, S., Cao, A.S., Hou, M.: A review and analysis of granular shear experiments under low effective stress conditions. Granul. Matter 21, 104 (2019). https://doi.org/10.1007/s10035-019-0955-x
Cheng, X., Xiao, S., Cao, A.S., Hou, M.: A unified constitutive model for pressure sensitive shear flow transitions in moderate dense granular materials. Sci. Rep. 11, 19669 (2021). https://doi.org/10.1038/s41598-021-99006-4
Gallage, C.P.K., Towhata, I., Nishimura, S.: Laboratory investigation on rate dependent properties of sand undergoing low confining effective stress. Soils Found. 45(4), 43–60 (2005). https://doi.org/10.3208/sandf.45.4_43
Hu, W., Tang, B., Kang, Q.: Progress of microgravity experimental satellite SJ-10. Aeron Aero Open Access J. 1(3), 125–127 (2017). https://doi.org/10.15406/aaoaj.2017.01.00016
Hu, W., Zhao, J., Long, M., Zhang, X., Liu, Q., Hou, M., Kang, Q., Wang, Y., Xu, S., Kong, W., Zhang, H., Wang, S., Sun, Y., Hang, H., Huang, Y., Cai, W., Zhao, Y., Dai, J., Zheng, H., Duan, E., Wang, J.: Space program SJ-10 of microgravity research. Microgravity Sci. Technol. 26, 159–169 (2014). https://doi.org/10.1007/s12217-014-9390-0
Kobayashi, T., Ochiai, H., Suyama, Y., Aoki, S., Yasufuku, N., Omine, K.: Bearing capacity of shallow foundations in a low gravity environment. Soils Found. 49(1), 115–134 (2009). https://doi.org/10.3208/sandf.49.115
Lin, X.U., Zou, Y., Jia, Y.: China’s planning for deep space exploration and lunar exploration before 2030. Chin. J. Space Sci. 38(05), 11–12 (2018)
MiDi, G.D.R.: On dense granular flows. Eur. Phys. J. e. 14(4), 341–365 (2004). https://doi.org/10.1140/epje/i2003-10153-0
Scott, C.R.: An introduction to soil mechanics and foundations, 3rd edn. Applied Science Publishers LTD, London (1980)
Sture S.: One-year results report, STS-79/Mir 4 and STS-89/Mir8 missions: mechanics of granular materials. NASA MSFC report, University of Colorado (1999)
Sture, S., Costes, N.C., Batiste, S.N., Lankton, M.R., AlShibli, K.A., Jeremic, B., Swanson, R.A., Frank, M.: Mechanics of granular materials at low effective stress. J. Aerosp. Eng. 11(3), 67–72 (1998). https://doi.org/10.1061/(ASCE)0893-1321(1998)11:3(67)
Towhata, I., Anh, T.T.L., Yamada, S., Motamed, R., Kobayashi, Y.: Zero-gravity triaxial shear tests on mechanical properties of liquefied sand and performance assessment of mitigations against large ground deformation. International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics. 11 (2010). https://scholarsmine.mst.edu/icrageesd/05icrageesd/session12/11
Towhata, I., Vargas-Monge, W., Orense, R.P., Yao, M.: Shaking table tests on subgrade reaction of pipe embedded in sandy liquefied subsoil. Soil Dyn. Earthq. Eng. 18(5), 347–361 (1999). https://doi.org/10.1016/S0267-7261(99)00008-1
Wang, Y., Zhao, H., Zhang, Y., Qiu, J., Mao, X., Wang, X.: Establishing and evaluation of the microgravity level in the SJ-10 recoverable satellite. Aerosp. Chin. 17(04), 3–13 (2016)
White, B.R., Klein, S.P.: Dynamic shear of granular material under variable gravity conditions. AIAA J. 28, 1701 (1990). https://doi.org/10.2514/3.10461
Xiao, S.: Research on constitutive model and numerical simulation of sand rheology under low effective stress. Tsinghua University (2021)
Zhao, H., Qiu, J., Tang, B., Kang, Q., Hu, W.: The SJ-10 recoverable microgravity satellite of China. J. Space Explor. 5(1), 101 (2016)