Development of a damage rheological model and its application in the analysis of mechanical properties of jointed rock masses

Abstract

Fossil fuel resources (eg, coal, oil, and natural gas) exist in underground reservoirs, where discontinuities are widespread and influence the stability of rock structures. The mechanical behavior of jointed rock masses significantly affects the long‐term stability of rock engineering. A major challenge in this area is to link the time‐dependent deformation with damage influence induced by distribution of joints in rock masses. In this paper, a damage mechanical theory is adopted which deals with several groups of joints distributed in rock masses. Based on the geometrical distribution of joints, a damage model considering the influence of normal vector and area density of joints is used to describe the discontinuities. A damage rheological model for jointed rock masses is developed and programmed in the finite difference software FLAC3D, and an example of jointed rock masses is used to verify the validity of the model. The damage rheological model could predict the visco‐elastic strain which corresponds to primary creep property, visco‐plastic strain which corresponds to steady state creep property, and damage strain which reflects the damage effect of joints to rock masses. Finally, we use this model to predict the displacements and damage zones in the rock masses surrounding an underground opening.

Analysis of fractures of a hard rock specimen via unloading of central hole with different sectional shapes

“…During recent years, some scholars have employed rock specimens with a central hole for simulation of failure behavior of deep tunnels at a laboratory scale and focused on the quantitative characterization of stress concentration and crack propagation behavior around the holes investigated the failure properties of Iddefjord granite samples containing prefabricated holes under uniaxial compression tests at laboratory and numerical scales and rockburst phenomena such as rock block ejection, and slabbing failure similar to in situ measurements was observed around the prefabricated holes under high compressive stress.…”

“…The excavation damaged zone (EDZ) is affected by multiple factors, such as unloading rate, rock lithology, tunnel shape, and in situ stresses . It is widely confirmed that tunnel shape plays an important role in affecting the failure intensity and destruction area of tunnels at great depth . This is primarily because the stress concentration, displacement, and deformation distribution are strongly related to the tunnel structure (straight line or curve) and cross‐sectional area.…”

Stability analysis of underground water-sealed oil storage caverns in China：A case study

“…To verify the results of the empirical analyses, FLAC3D (Ding and Liu, 2018;Wang et al, 2019;Yang et al, 2019;Zhu et al, 2018) was used to calculate the deformation and depth of the plastic zones around caverns, owing to the staged excavation and rock support. Plane strain analysis was used because of the large ratio of length to cross-section dimension of the underground caverns.…”

Anisotropic modeling of layered rocks incorporating planes of weakness and volumetric stress

“…In the design and stability analysis of this type of underground structure, it is necessary to consider the anisotropic deformation and failure characteristics of the layered rocks. Thus, mechanical models need to be established that can sufficiently reflect the anisotropic characteristics of layered rocks and thoroughly explain their transversely isotropic deformation and failure characteristics . These models should be based on the mechanical properties and field monitoring information of the layered rocks to improve the accuracy of the calculations of the deformation and failure of the deep surrounding layered rocks and ensure the safety and stability of deep underground structures …”

“…Thus, mechanical models need to be established that can sufficiently reflect the anisotropic characteristics of layered rocks and thoroughly explain their transversely isotropic deformation and failure characteristics. 7,8 These models should be based on the mechanical properties and field monitoring information of the layered rocks to improve the accuracy of the calculations of the deformation and failure of the deep surrounding layered rocks and ensure the safety and stability of deep underground structures. 9,10 Critical progress has been made in research on the yield criteria and constitutive models for layered rocks.…”