Nonlinear shear constitutive model for peak shear-type joints based on improved Harris damage function
- PDF / 7,897,423 Bytes
- 14 Pages / 595.276 x 790.866 pts Page_size
- 96 Downloads / 176 Views
(2020) 20:95
ORIGINAL ARTICLE
Nonlinear shear constitutive model for peak shear‑type joints based on improved Harris damage function Shijie Xie1 · Hang Lin1 · Yixian Wang2 · Rihong Cao1 · Rui Yong3 · Shigui Du3 · Jiangteng Li1 Received: 1 April 2020 / Revised: 29 June 2020 / Accepted: 17 July 2020 © Wroclaw University of Science and Technology 2020
Abstract The majority of jointed rock mass failures mainly occur along the joints in shear mode, which promotes a wide investigation on the proposal of a reasonable and reliable shear constitutive model of rock joints. In this paper, based on Improved Harris function and laboratory shear tests, a new constitutive model of saw-tooth joints was proposed. Firstly, a series of laboratory direct shear tests were carried out on saw-tooth joint specimens made of rock-like materials (cement mortar) to obtain the shear stress-displacement curves. Subsequently, the test results were divided into sliding failure type and peak shear type according to whether there is a significant stress drop between peak stress and residual stress. It is assumed that rock elements can be divided into undamaged parts and damaged parts during the shearing process. The stress-displacement relation of the undamaged part satisfies Hooke’s law, while the damaged part provides residual stress. Via the comparison with commonly used micro-element failure probability density functions, the Improved Harris distribution function was selected as the standard to characterize the strength of micro rock units. Finally, derived from the theory of damage statistical mechanics, a damage statistical constitutive model was proposed, which can reflect the deformation characteristics of rock joints. Compared with previous models and experimental data, the model proposed in this paper can represent the trend of peak shear curve variation with higher accuracy, the parameters are easy to be solved and have obvious physical significance, which verifies the advantages and applicability of this model. Keywords Joint · Direct shear test · Constitutive model · Statistical damage theory · Improved Harris distribution
* Hang Lin [email protected] * Jiangteng Li [email protected] Shijie Xie [email protected] Yixian Wang [email protected] Rihong Cao [email protected] Rui Yong [email protected] Shigui Du [email protected] 1
School of Resources and Safety Engineering, Central South University, Changsha, Hunan 410083, China
2
School of Civil Engineering, Hefei University of Technology, Hefei 230009, China
3
School of Civil and Environmental Engineering, Ningbo University, Ningbo, Zhejiang 315211, China
1 Introduction As a ubiquitous geological structure, rock joints prominently affect the deformation performance and safety of engineering projects [1]. In the current engineering designs involving foundation, hydropower station, rock slope, and rock underground excavation, the deformation behavior of rock joints is crucial to the project [2]. Existing researches on the shear mechanical properties of
Data Loading...
