https://www.jstage.jst.go.jp/article/sandf/50/2/50_2_309/_pdf

Landslide model test system and its application on the study of shiliushubao landslide in three gorges reservoir area

This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton’s empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

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The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

Laboratory techniques for demonstrating rock mass behaviour

SYNOPSIS The base friction apparatus which is capable of supplying the compressed air on the surface of the model can provide the application of the simularity between in-situ and the model for the behaviour of practical rock structures. This paper describes first, a new base friction apparatus which has the stiff metal plate with uretan rubber in stead of endless belt and has a lateral loading system. and next, the phenomenena of cave-in and surface subsidence in shallow coal mining are studied not only for continuous but also discontinuous model.

P. Baumgartner

Papers

Development of a tiltable base friction frame for kinematic studies of caving at various depths