Study of creep characteristic of tertiary argillaceous rock in loess area

Document Type

Article

Publication Date

9-1-2010

Abstract

Time-dependent behavior of rock mass is one of the important factors influencing the deformation and long-term stability of slope. The large scale incised-rock landslide in the loess area is progressively deformed under the influence of deadweight and groundwater, etc. This kind of landslides was finally formed after creeping, cracking and shearing, on the basis of the previous surface due to the preliminary creeping behavior of argillaceous rock. It aims to study the creeping behavior of argillaceous rock after the analysis of physico-mechanical properties, in which the Liujiaquan landslide was taken for example in Jintai District of Baoji. The analysis of clay minerals in argillaceous rock shows that the rock is mainly composed of mixed-layer illite-montmorillonite and illite. It also noted that the rock is formed in the latest period of geological time, and characterized with lower strength, light cementation and expansibility. Compared with the results of quick shear test, it is found that the value of friction coefficient reduces by 66% and the value of cohesion by 80% in the process of rheological shearing. Meanwhile, the displacement increases with time, and the deformation behavior is identified to be nonlinear viscoelastic in low loading and linear viscoplastic in high loading. It can be concluded that the creeping behavior is the main property of argillaceous rock in the process of preliminary landsliding in the studied area. In addition, the generalized Kelvin and Bingham models were combined to describe the rheological properties. The calculation curves of the model and experimental points could well fit the decay creep stage and steady state creep stage of the argillaceous rock. Hence, the suitability of selected models was proved. Finally, the parameters of rheological constitutive model of argillaceous rock were identified using genetic algorithm. Comparing the curves fitted by genetic algorithm with experimental data, it is found that the fitting results and the test results are matched very well. The genetic algorithm can be used to identify the rock rheological model parameters.

Publication Source (Journal or Book title)

Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering

First Page

4008

Last Page

4015

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