Lu Ren

• PhD candidate
• South China University of Technology

Layered rocks (LR) exhibit inherent anisotropic stiffness and strength induced by oriented rough weakness planes, along with stress induced anisotropy and friction related plastic deformation occurs during loading. Furthermore, microcracks located in intact rock matrix (IRM) of LR are also critically important for friction and damage dissipation pr...

In this paper, we propose a novel three-dimensional micromechanics-based failure criterion to assess the load-bearing capacity of quasi-brittle materials under complex multiaxial stress conditions. This criterion not only inherits benefits of the multi-scale friction-damage coupling modeling approach but also accounts for the effect of the intermed...

The diffuse damage and localized cracking of quasi-brittle materials (i.e., rocks and concrete) under compression can be delineated by a matrix-microcrack system, wherein a solid matrix phase is weakened by a large number of randomly oriented and distributed microcracks, and the macroscopic cracking is formed by a progressive evolution of microcrac...

Temperature serves as a critical yet elusive factor impacting the mechanical properties of deep rocks. In this work, we shall develop a new micro‐thermomechanical model for rocks based on the Mori‐Tanaka homogenization scheme. Free energy and thermodynamic forces are deduced within the framework of irreversible thermodynamics, including the local s...

In recent years, urban road collapse incidents have been occurring with increasing frequency, particularly in populous cities. To mitigate road collapses, geophysical prospecting plays a crucial role in urban road inspections. Ground Penetrating Radar (GPR), a non-destructive technology, is extensively employed for detecting urban road damage, with...

The Cosserat continuum, which contains a length scale factor reported to link with the material's grain size, is seemingly reasonable to describe the size effect of granular media. However, the physical meaning of is still unclear, and its potential in describing the size effect is seldom studied. In this work, the performance of the conventional C...

Layered rocks (LR) are composed of intact rock matrix (IRM) and various oriented rough weakness planes (e.g., fractures, bedding planes, and foliations). New microcracks can also be created and propagate in IRM during subsequent loading history. Effects of induced microcracks and pre-existing weakness planes on macroscopic mechanical behaviour of L...

This paper is devoted to establishing a nonlinear constitutive model incorpo-rating crack closure effect for capturing the whole process of rock deformationand failure behavior under compression. The model formulated in the frame-work of irreversible thermodynamics is based on the additive decompositionof the total strain into crack closure strain,...

Ice-rich permafrost in the Qinghai–Tibet Plateau (QTP), China, is becoming susceptible to thermokarst landforms, and the most dramatic among these terrain-altering landforms is retrogressive thaw slump (RTS). Concurrently, RTS development can in turn affect the eco-environment, and especially soil erosion and carbon emission, during their evolution...

The purpose of this research is to explore the feasibility of using calcium carbide residue (CCR), a by-product from acetylene gas production, as a solid alkaline activator on the strength development in CCR-Portland cement-stabilized dredged sludge (CPDS). The effects of cement content, CCR content and curing time on the strength development of CP...

In cold regions, engineering structures are subjected to a combined action of freeze-thaw cycling and loading. The performance degradation of quasi-brittle geomaterials has a significant influence on the stability of the structures in such areas. In this work, a physically-based elastoplastic damage model for quasi-brittle geomaterials under freeze...