Microtremor survey and stability analysis of a soil-rock mixture landslide: a case study in Baidian town, China

• Published in: Landslides Vol. 15; no. 10; pp. 1951 - 1961
• Main Authors: Gao, Wen-wei, Gao, Wei, Hu, Rui-lin, Xu, Pei-fen, Xia, Jia-guo
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2018; Springer Nature B.V
• Subjects: Agriculture; Case studies; Civil Engineering; Computer simulation; Earth and Environmental Science; Earth Sciences; Failure surface; Finite element method; Geography; Landslides; Mathematical models; Mechanical properties; Mountain regions; Natural Hazards; Numerical methods; Numerical simulations; Original Paper; Rocks; Safety; Safety factors; Shear tests; Slope; Slope stability; Soil; Soil analysis; Soil improvement; Soil mixtures; Soil stability; Soil strength; Soils; Stability analysis; Surface stability; Surveying; Microtremor survey method; Numerical method; Soil-rock mixtures; Factor of safety
• ISSN: 1612-510X; 1612-5118
• DOI: 10.1007/s10346-018-1009-x

Soil-rock mixtures (S-RM) are widely distributed in mountainous regions, and there are different genetic types and scales of S-RM slopes. The stability of these slopes is very important for slope safety during the construction and operation of engineering projects. Since the mechanical properties of an S-RM are mainly dominated by its random component, accurately investigating the structure of an S-RM slope is the fundamental basis for evaluating the mechanism of a landslide. In this paper, in situ direct shear tests are used to obtain the “soil” strength parameters of the S-RM, the microtremor survey method (MSM) is introduced to detect the S-RM slope and the numerical method of FEM is utilised to simulate the failure characteristics and stability of the S-RM slope. Based on the MSM, the strata structure and proportions of solitary rock blocks in the S-RM slope are investigated, and three possible models of the S-RM slope are established. By using the strength reduction method in numerical simulations, the potential failure surface and stability of a slope of homogeneous soil and that with solitary rock blocks are discussed. The study results show that the MSM is an effective method to estimate the proportion of rock blocks in the S-RM slope. The presence of solitary rock blocks makes the slope potential slide surface complicated. The factor of safety of the S-RM slope is higher than that of the homogeneous soil slope, the rock blocks at the toe of the slope are favourable for slope stability and the rock blocks near the surface of the slope squeeze the lower soil and improve the safety factor of the slope.