Abstract

Existing analytical models usually fail to match with the actual conditions due to ignoring the nonlinear behavior of the surrounding material reaction force, which changes progressively with the joint shear displacement from elastic stage to yield stage. To tackle this problem, this study proposes a new analytical model to describe the bolt deformation and bolt contribution from elastic stage to plastic stage. The developed model is verified by available experimental direct shear tests of bolted joints and compared with existing models. Then, based on this model, the effects of the joint dilation angle, the bolt installation angle, the friction angle, and the surrounding material strength on bolt contribution are also analyzed and its implication is further discussed. Our results show that the proposed model can precisely describe the evolution of bolt contribution from elastic stage to plastic stage. Compared with surrounding material strength, the augmentation of the joint dilation angle and friction angle is more beneficial to increase the bolt contribution and the optimal installation angle. The work presented is to attempt to provide a reference for the understanding of bolting mechanism of jointed rock mass, the development of bolting theories and the practice of bolting engineering.

Highlights

  • Grouted bolt is an important technique for fractured rock mass reinforcement, widely used in the slope, tun‐ nel, and dam, and so on

  • Bolt lateral deformation are established from elastic stage to plastic stage considering the progressive yield of surrounding material based on the structure mechanical model; (2) The theoretical model of the bolt contribution to the bolt axial force and the bolt transverse shear force with the shear displacement are proposed in both the elastic and the plastic stages; (3) The developed model is validated by available experimental direct shear tests of bolted joints; (4) According to the proposed model, the effect of the contribution factors on contribution of bolt are systematically ana‐ lyzed using this proposed analytical model

  • In order to analyze the influence of the different factors affecting the bolt contribution at the yield limit and failure respec‐ tively, we carried out a parametric study

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Summary

Introduction

Grouted bolt is an important technique for fractured rock mass reinforcement, widely used in the slope, tun‐ nel, and dam, and so on. Bolt lateral deformation are established from elastic stage to plastic stage considering the progressive yield of surrounding material based on the structure mechanical model; (2) The theoretical model of the bolt contribution to the bolt axial force and the bolt transverse shear force with the shear displacement are proposed in both the elastic and the plastic stages; (3) The developed model is validated by available experimental direct shear tests of bolted joints; (4) According to the proposed model, the effect of the contribution factors (i.e., bolt inclina‐ tion angle, joint dilation angle, friction angle, and grout strength) on contribution of bolt are systematically ana‐ lyzed using this proposed analytical model.

Mechanical behavior of the bolt in elastic domain
Mechanical behavior of the bolt after yielding
Bolt contribution to joint shear resistance
Model validation
Analysis of the bolt contribution
Influence of bolt installation angle on the ratio f
Influence of bolt installation angle on the bolt contribution
Discussion
Conclusion
Full Text
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