Effects of Interface Behavior on Fracture Spacing in Layered Rock

Abstract

To better understand the periodically distributed fractures in rock sequences, the effects of the layer interfaces on the evolution of the stress distribution in a fracture-bound block and on the fracture infilling process are discussed. A three-layer model is developed based on a cohesive zone model (CZM) for layer interfaces and a plastic-damaged model for rock layers. The results indicate that the interface shear strength can greatly influence the stress distribution in a fracture-bound block so that the ratio of the fracture spacing to the layer thickness (S/T f ) is not the dominant factor in the stress state. If interface debonding occurs, the tensile stress in a fracture-bound block can decrease to zero even for a higher S/T f ratio. If the interface shear strength is high enough, a new fracture can further infill between two adjacent preexisting fractures even if the S/T f ratio is at a low level. The fracture process implies that there is a critical value for the interfacial shear strength that controls the fracture pattern between the central layer and its neighboring layers to be either interface debonding or layer-parallel fracture. Both interfacial debonding and layer-parallel fracture can separate the central layer from its neighboring layers and thus lead to fracture saturation. Further analysis indicates that the critical shear strength increases linearly with increasing tensile strength of the central layer.

Flexural Capacity of Steel‐Concrete Composite Beams under Hogging Moment

“…Skills. FE models are established using the ABAQUS program [22], which is extensively adopted in analyzing rock and composite structures (Chang et al [13,14]). Steel beams are modeled by using four-node reduced integral format shell elements (S4R).…”

“…Zhu et al [12] presented a numerical study on the property of studs and its application to steel-concrete composite beams. Chang et al [13,14] investigated the property of rock and composite structures through ABA-QUS. Mirza and Uy [15] researched the mechanical behavior of composite beam-column flush end-plate connections subjected to high-consequence, low-probability loading via ABAQUS.…”

Brittleness Evaluation of Glutenite Based On Energy Balance and Damage Evolution

“…The brittleness and fracability of glutenite are affected not only by the mechanical properties of matrix, but also by gravel size and volume content, and mechanical properties of different rock structures. Fracture propagation behavior and the hydraulic fracturing effect of glutenite reservoirs are controlled by mechanical properties [15,55,56], geological conditions [57][58][59][60], and technical parameters [60][61][62]. The effect of glutenite brittleness on hydraulic fracture propagation mechanisms and fracturing needs further study.…”

Study on crack propagation in layered rock under the three-point bending conditions

“…Numerous academics used numerical calculations to continue studying the process of rock crack propagation (Chang et al, 2015;Yin et al, 2015;Guo et al, 2017;Yin and Meng, 2018;Han et al, 2019). However, it is still unknown how the bedding plane affects the way that layered rock cracks spread.…”