A strain-based fatigue damage model for naturally fractured marble subjected to freeze-thaw and uniaxial cyclic loads

Abstract

The naturally fractured rock in the open pit slope is susceptible to irreversible damage caused by fatigue loads related to freeze-thaw weathering, blasting vibration, earthquakes and tramcar traffic. To ensure the safety of rock mass and reveal how natural fracture affects the damage modelling characteristics is of great concern. Hence, this work aims at investigating the fatigue damage evolution of rock from volumetric deformation caused by F-T and cyclic loads. The rock structural deterioration and damage accumulation were investigated as well as the stimulated natural fracture pattern. Results show the frost heaving force acted on natural fracture results in the rock volumetric changes. The damage variable expressed by volumetric strain presents a linear relationship with freeze-thaw cycles. In addition, the axial, lateral and volumetric strain of marble exposed to cyclic loads present a two-stage pattern, they first increase quickly and then get to steady and last for a long time. A new fatigue damage model was established by considering the freeze-thaw damage and mechanical damage simultaneously. The proposed coupling damage model can well describe rock damage accumulation. Moreover, the CT images further reveal the influence of the natural fracture on rock volumetric deformation and the final damage accumulation. It is suggested that the opening-mode natural fractures contribute a lot to rock freeze-thaw deformation and fatigue deformation.

On fracture and damage evolution modelling of fissure‐hole containing granite induced by multistage constant‐amplitude variable‐frequency cyclic loads

“…The fracture behaviors and damage evolution of flawed rock are of importance to rock mechanics and engineering. The pre‐existence of the crack‐like flaws and hole‐like flaws alter the integrity of the rock structure and would trigger the instability in rock engineering 1,2 . Thus, investigations on the structural deterioration characteristics and the associated damage evolution mechanism of flawed rock are crucial to predict geohazards in rock engineering.…”

The Effect of Hydraulic Coupling on Mechanical Deformation Characteristics of Shallow Coal Seam in Western Mining Area

“…In the asymmetrical trapezoidal evolution stage, the overburden broke locally, and the increase in the height of the trapezoidal fracture was lower. The damage can be used to describe the random characteristics of the development direction of the overburden fracture [6,42,43]. This defines that the fracture rate R f can be formulated as follows:…”

Insight into the fracture evolution behavior of pre‐flawed hollow‐cylinder granite under multi‐stage increasing‐amplitude cyclic loads: A lab‐scale testing

“…[12][13][14][15][16] In recent years, rock mass instability events resulting from the stress disturbance in civil and mining engineering emerge frequently, and many studies have paid attention to revealing the cyclic or fatigue mechanical behaviors of crack-like rock. [17][18][19] In summary, the above studies have greatly broadened the understanding of the failure mechanism of jointed rock.…”

“…The above studies mainly focus on the deformation, strength, and crack propagation with respect to joint inclination and rock bridge angle under static loading conditions 12–16 . In recent years, rock mass instability events resulting from the stress disturbance in civil and mining engineering emerge frequently, and many studies have paid attention to revealing the cyclic or fatigue mechanical behaviors of crack‐like rock 17–19 . In summary, the above studies have greatly broadened the understanding of the failure mechanism of jointed rock.…”