Numerical Analysis of the Influence of Bolt Set on the Shear Resistance of Jointed Rock Masses

Bolt reinforcement is a standard reinforcement method for jointed rock masses. However, regarding rock anchoring, the mechanical characteristics of the joint surface, as well as the angle between the bolt and the joint sliding surface, are important factors that affect rock support. Therefore, to understand the influence of a set angle, length, normal load, and other conditions that affect the shear strength of bolt joints, this study uses numerical software to establish the shear sliding model of bolt rock masses and analyzes the influence of the setting conditions of the bolt on the shear strength of a bolt rock mass, which can be done by changing the setting method of the bolt and normal mechanical conditions of the sliding surface. The results show that the shear strength of the anchor joint is not affected after the anchor reaches a certain length. The angle of the anchor strongly influences the shear strength of the anchor joint, and the shear strength curve is V-shaped, where the anchor angle is less than 90°. Moreover, the shear strength curve indicates a downward trend when the anchor angle is greater than 90°, and the shear strength of the anchorage joint increases with the increase of the normal load. Under the same anchor length (4 cm) in the anchor angle and shear strength coordinate system, the shear strength curve of the single anchor is above the shear strength curve of the double anchor, which is exclusively in the local anchor angle section under the condition of a large normal load and a large anchor angle. The shear strength curve of the double anchor is above the shear strength curve of the single anchor.

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An alternate approach for deriving rock slope shear strength parameters within weak jointed rock masses

Proceedings of the First Asia Pacific Slope Stability in Mining Conference ◽

10.36487/acg_rep/1604_50_narendranathan ◽

2016 ◽

Author(s):

Sanjive Narendranathan ◽

Simon McBeath ◽

Kweku Ayemin ◽

Eng Lee

Keyword(s):

Shear Strength ◽

Rock Slope ◽

Jointed Rock ◽

Rock Masses ◽

Shear Strength Parameters ◽

Strength Parameters ◽

Jointed Rock Masses

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Analysis of Changes in the Micromorphology of Sandstone Joint Surface under Dry-Wet Cycling

Advances in Materials Science and Engineering ◽

10.1155/2019/8758203 ◽

2019 ◽

Vol 2019 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

Jingcheng Fang ◽

Huafeng Deng ◽

Yu Qi ◽

Yao Xiao ◽

Hengbin Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Friction Angle ◽

Jointed Rock ◽

Joint Surface ◽

Roughness Coefficient ◽

Rock Masses ◽

Jointed Rock Masses ◽

Bank Slope ◽

Steep Decrease ◽

The Face

Changes in the micromorphology of joint surface under dry-wet cycling have a direct effect on the mechanical properties of the jointed rock masses, which in turn affects the deformation stability of the bank slope of a reservoir. In this study, we design and carry out a test that aims to quantity the effects of repeated rise and fall of a reservoir on the properties of a jointed rock masses. The results are as follows: first, the roughness, local gradient, and undulation of the joint surface gradually decreased under repeated dry-wet cycling. In addition, the height parameters and texture parameters showed a steep decrease followed by a slow decline. The deterioration was particularly obvious over the first 5 dry-wet cycles. Second, the roughness coefficient of the joint surface, the compressive strength of the face wall, and the basic friction angle were gradually reduced under dry-wet cycling. The shear strength of the jointed rock masses (obtained both quantitatively and experimentally) showed a deteriorating trend controlled by the deterioration of the micromorphology, the strength of the face wall, and the frictional properties of the joint surface. Finally, the dry-wet cycling process determined trends of changes in the microstructure parameters and mechanical properties of the joint surface. Our research results provide a good basis for the analysis of the deterioration and failure of rock masses within the hydrofluctuation belt of a bank slope.

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