Abstract

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.

Highlights

  • Jointed rock masses are standard in slopes, water conservancy, hydropower, mining, as well as highway construction, among other projects

  • Under the same anchor angle, the shear strength increases with the increase of normal load

  • The influence of the bolt length on the shear strength of the anchorage joint surface was small, and the shear strength curve was near the horizontal line in the coordinate system with the length of the horizontal axis

Read more

Summary

Introduction

Jointed rock masses are standard in slopes, water conservancy, hydropower, mining, as well as highway construction, among other projects. The harder the lithology is, the greater the increase of the shear strength of the bolt-on joint rock surface and the more significant the reinforcement effect of the bolt is. The results showed that the change of an anchor angle and the normal stress of a joint had a significant influence on the peak shear strength of the anchor rock. The test results showed that the shear strength of the anchored cement block decreased with the increase of the anchor angle. Because of the above issues, this study intends to use discrete element software to analyze and calculate the influence of the joint surface on the shear strength of the anchorage under the conditions of various anchor angles, normal loads, anchor lengths, and a number of anchor bolts. Comparison of calculation results of single and double anchor cables with a length of 4cm

Experimental Model Design
Numerical Model
Numerical Calculation Group
Shear Strength Curves of Different Bolt Lengths
Shear Strength Curve under the Same Normal Load
Shear Strength Curve under the Same Anchor Angle
Shear Strength Analysis of Single Bolts and Double Bolts
Conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.