A nonlinear rheological shear constitutive model of bolted joints considering initial damage and damage evolution

Abstract

Understanding the shear mechanics mechanism of bolted joints is of great significance for predicting and preventing geological disasters. Most current studies seldom consider the rheological effects of bolted joints. In this paper, a comprehensive rheological constitutive model is proposed, accounting for initial damage and damage evolution across different rheological stages and bolt characteristics. The model incorporates an elastoplastic Hooke body for instantaneous deformation, parametric nonlinear Kelvin and viscous models for attenuation and steady creep stages, and a visco-plastic model based on time-dependent shear strength for accelerated creep stage. Additionally, a bolt-rock cooperative deformation model is introduced, considering the evolution of the bolt's elastic modulus. The resulting elasto-viscoplastic constitutive model effectively describes the shear rheological behavior of bolted joints, with its validity and superiority demonstrated through comparisons with shear creep tests and the Maxwell model. This research aims to provide valuable theoretical guidance for the construction and reinforcement of rock mass engineering projects.

Investigation of the Degradation Mechanism of the Tensile Mechanical Properties of Sandstone under the Corrosion of Various pH Solutions

“…Scholars have conducted relevant studies on Brazilian splitting by combining acoustic emission [21], scattering [22,23], strain testing [24] and other technologies. In view of the lithology and anisotropy of the rock [25][26][27], the damage modes, mechanical properties and strength characteristics were investigated [28,29]. Therefore, the study of the tensile mechanical properties of rocks in chemical solutions is useful for guiding engineering.…”