Study of Shear Constitutive Model for Schistose Rock Mass

Based on the direct shear tests of schist and shale at dry and water-saturated states, combed with the advantages and disadvantages of models for rock mass and structure surface, we proposed shear stress-displacement constitutive model of schistose rock mass. The model is in the form of piecewise exponential function and its advantages are as follows: Piecewise function can reasonably describe the nonlinear pre-peak shear hardening and post-peak shear softening characteristics; Regard peak strength, peak displacement and residual strength as critical points, so it can accurately describe the strength characteristics of the material; The fitting degree is high with direct shear tests both at dry and water-saturated states; Only one parameter value is needed to obtain by fitting experimental curves while others are convenient to determine. All of those are benefit to applications in engineering practice.

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Adjustment of rock mass strength parameters using direct shear tests carried out on large blocks

Rock Mechanics for Resources, Energy and Environment ◽

10.1201/b15683-27 ◽

2013 ◽

pp. 175-180

Author(s):

G Zapata ◽

A Assis

Keyword(s):

Rock Mass ◽

Direct Shear ◽

Shear Tests ◽

Strength Parameters ◽

Rock Mass Strength ◽

Direct Shear Tests

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Evaluation of the anisotropy and directionality of a jointed rock mass under numerical direct shear tests

Engineering Geology ◽

10.1016/j.enggeo.2017.03.004 ◽

2017 ◽

Vol 225 ◽

pp. 29-41 ◽

Cited By ~ 21

Author(s):

Peitao Wang ◽

Fenhua Ren ◽

Shengjun Miao ◽

Meifeng Cai ◽

Tianhong Yang

Keyword(s):

Rock Mass ◽

Jointed Rock ◽

Jointed Rock Mass ◽

Direct Shear ◽

Shear Tests ◽

Direct Shear Tests

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Sand- and Clay-Photocured-Geomembrane Interface Shear Characteristics Using Direct Shear Test

Sustainability ◽

10.3390/su13158201 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8201

Author(s):

Lihua Li ◽

Han Yan ◽

Henglin Xiao ◽

Wentao Li ◽

Zhangshuai Geng

Keyword(s):

Soil Surface ◽

Friction Angle ◽

Direct Shear ◽

Tensile Crack ◽

Shear Tests ◽

Interface Shear ◽

Direct Shear Tests ◽

Carbon Black Powder ◽

Shear Characteristics ◽

Impermeable Layer

It is well known that geomembranes frequently and easily fail at the seams, which has been a ubiquitous problem in various applications. To avoid the failure of geomembrane at the seams, photocuring was carried out with 1~5% photoinitiator and 2% carbon black powder. This geomembrane can be sprayed and cured on the soil surface. The obtained geomembrane was then used as a barrier, separator, or reinforcement. In this study, the direct shear tests were carried out with the aim to investigate the interfacial characteristics of photocured geomembrane–clay/sand. The results show that a 2% photoinitiator has a significant effect on the impermeable layer for the photocured geomembrane–clay interface. As for the photocured geomembrane–sand interface, it is reasonable to choose a geomembrane made from a 4% photoinitiator at the boundary of the drainage layer and the impermeable layer in the landfill. In the cover system, it is reasonable to choose a 5% photoinitiator geomembrane. Moreover, as for the interface between the photocurable geomembrane and clay/sand, the friction coefficient increases initially and decreases afterward with the increase of normal stress. Furthermore, the friction angle of the interface between photocurable geomembrane and sand is larger than that of the photocurable geomembrane–clay interface. In other words, the interface between photocurable geomembrane and sand has better shear and tensile crack resistance.

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