Abstract
The inner structure of sliding soil is quite inhomogeneous, which makes it very hard to investigate the mechanical properties. In this paper, intact sliding soil samples collected from the Huangtupo landslide is verified to be rock and soil aggregates (RSA) firstly. Because of the grain-size limitations for general indoor shear tests and the unpredictability of test data obtained by reshaped sample, a new method which combines CT scanning for undisturbed samples, mechanical tests for fine-grained subdomain and numerical test is proposed. With the advantages of repeatability and parallel comparison, deep research into the mechanical properties and deformation mechanisms for sliding soil is carried out. The research shows that, for the RSA in this paper, which the coarse particles content is about 30 %, fine-grained subdomain is still the frame part of RSA, compared with pure fine-grained soil, the internal friction angle does not obviously increase, but the cohesion increased by at least 80 %. Meanwhile, coupling deformation between coarse particles and fine-grained subdomain is a complex mechanical process; coarse particles will support an effective resistance to the fine fraction, and in Mohr-Coulomb model, it is reflected by obvious increase of cohesion. Based on the mechanical trace preservations on a block of gravel, this external friction effect is verified. Then, by seven groups of large-size stacked ring shear test for the RSA samples, these analyses and judgements are verified. The comprehensive research method can also be widely used in achieving the mechanical and failure characteristic of RSA.
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References
Ahad B-K, Ali AM (2007) Numerical and experimental direct shear tests for coarse-grained soils. Particuology 7:83–91
Cheng Z, Wu L, Ding H (2007) Research on movement of particles of the fabric of granular material. Rock Soil Mech 28:29–33, in Chinese
Cundall PA, Strack ODL (1979) A discrete numerical model of granular assemblies. Geotechnique 29(1):47–65
Fang Y-s, Ishibashi I (1986) Static earth pressure with various wall movements. J Geotech Eng 112(3):317–333
Frost RJ (1973) Some testing experiences and characteristics of boulder-gravel fills in earth dams. Am Soc Testing Mater Spec Tech Publ 523:207
Fumagalli E (1969) Tests on cohesionless materials for rock-fill dams. J Soil Mech Found Div ASCE 95(SM1):313–332
Indrawan GB, Rahardjo H, Leong EC (2006) Effects of coarse-grained materials on properties of residual soil. Eng Geol 82(3):154–164
Itasca Consulting Subdomain, Inc (2005) FLAC 3D (fast Lagrangian analysis of continua in 3 dimensions) user manuals (Version 3.0). Minneapolis
Jiang J, Xiang W, Zeng W et al (2012) Research on the water-rock (soil) interaction mechanism of Huangtupo riverside landslide in Three Gorges Reservoir. Chin J Geotech Eng 34(7):1209–1216 (in Chinese)
Li X, Qiulin L, Jianmin H et al (2007) Study on in-situ tests of mechanical characteristics of soil-rock aggregate. Chin J Rock Mech Eng 26(12):2377–2384 (in Chinese)
Liao Q, Li X, Hao Z et al (2006) Current status and future trends of studies on RSA (RSA). J Eng Geol 14(6):800–807 (in Chinese)
Lowe J (1964) Shear strength of coarse embankment dam materials. In Proceedings of the 8th International Congress on Large Dams. pp. 745–761
Marsal RJ (1967) Large scale testing of rockfill material. J Soil Mech Found Div 93:27–43
Marsal RJ (1973) Mechanical properties of rockfill. In: Hirshfield RC, Polous SJ (eds) Embankment dam engineering, Casagrando volume. Wiley, New York, pp 109–200
Ng T-T (2004) Shear strength of assemblies of ellipsoidal particles. Geotechnique 54(10):659–669
Salgado R, Bandini P, Karim A (2000) Shear strength and stiffness of silty sand. Geotech Geoenviron Eng 126(5):451–462
Xu W, Hu R (2009) Conception, classification and signification of soil and rock mixture. Hydrogeol Eng Geol 36(4):50–57 (in Chinese)
Xu W, Hu R, Yue Z et al (2007) Mesostructural character and numerical simulation of mechanical properties of soil-rock mixtures. Chin J Rock Mech Eng 26(2):300–311 (in Chinese)
Xu W, Hu R, Yue Z (2009) Development of the random mesostructure generating system of soil-rock mixture and study of its mesostructural mechanics based on numerical tests. Chin J Rock Mech Eng 28(8):1652–1665, in Chinese
Zeller J, Wullimann R (1957) The shear strength of the shell materials for the Go-Schenenalp Dam, Switzerland. In Proceedings of 4th InstitutionalJournal on Soil Mechanics and Foundation Engineering (Vol. 2, pp. 399–404). London
Acknowledgments
This work is supported by cooperation frame of the International Bureau of the German Federal Ministry of Education and the Three Gorges Research Center for Geo-hazard, Ministry of Education. The research is sponsored by National Natural Science Foundation of China (NSFC, Grant No. 51409011) and the Basic Scientific Research Operating Expenses of Central-Level Public Academies and Institutes (Grant No. CKSF2014057/YT and CKSF2015051/YT)
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Jiang, J., Xiang, W., Rohn, J. et al. Research on mechanical parameters of coarse-grained sliding soil based on CT scanning and numerical tests. Landslides 13, 1261–1272 (2016). https://doi.org/10.1007/s10346-015-0635-9
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DOI: https://doi.org/10.1007/s10346-015-0635-9