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| Fracture spacing analysis of equally-spaced fractures in layered rocks based on a bond-slip model for rock interface#br# |
| CHANG Xu1，BAI Kebin2，ZHANG Xu3，YU Jin1，WANG Shuren3 |
(1. School of Civil Engineering，Huaqiao University，Xiamen，Fujian 361021，China；2. China Railway Strait Construction
Group Co.，Ltd.，Xiamen，Fujian 361021，China；3. School of Civil Engineering，Henan Polytechnic University，
Jiaozuo，Henan 454000，China)
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Abstract Equally-spaced fractures can be commonly found in layered rocks. How to predict the fracture spacing has important significance and practical value for the stability analysis of layered rocks. Considering softening behavior of the shear stress along the rock interface，a tri-linear bond slip model was adopted to calculate the full-range evolution of the shear stress along the rock interface and the tensile stress in fractured layered rocks. A failure criterion for the layered rock considering the influence of the overload was developed and then the analytical expressions for predicting the fracture spacing in fractured layered rocks under different bond conditions were proposed. The feasibility of the proposed calculation formula was verified by finite element simulation and field data. The evolution of the fracture spacing and the influencing factors were analyzed. The results indicate that the proposed analytical solutions can be used to predict the fracture spacing for the rock interface under different conditions，such as bond，part bond，shear stress softening and complete slip.
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2022, Vol. 41 
