Title: Generalized Zhang-Zhu (GZZ) rock mass strength criterion and its application

Length: 3-4 hours

 

 

Accurately determining the strength of fractured rock masses is the core and primary task of rock mechanics research. A reliable strength criterion is an important basis for analyzing the evolution process of the mechanical properties of surrounding rocks under unloading conditions and the mechanisms of disasters. Currently, the majority of strength criteria are only applicable to rocks, involving numerous strength parameters obtained mainly through fitting of experimental data or in-situ deformation-based back analysis. The two-dimensional Hoek-Brown (H-B) strength criterion is widely used in shallow rock engineering design but does not consider the influence of intermediate principal stress. The Generalized Zhang-Zhu (GZZ) strength criterion can accurately reflect the influence of intermediate principal stress on rock mass strength, revealing the dual nonlinear tensile-compressive (brittle-ductile) transformation laws of rock strength and failure modes on the π-plane and meridian plane. Most importantly, GZZ rock mass strength criterion shares parameter systems with the two-dimensional H-B strength criterion, and it is a true three-dimensional H-B strength criterion. This theoretical short course can provide an overall understanding of GZZ strength criterion, three-dimensional forward analysis and real-time design in rock engineering.

 

 

• To introduce the theoretical basis, advantages, and evolution of the GZZ rock mass strength criterion;

• To present parameter determination, modification and constitutive model of GZZ criterion;

• To discuss effective application of GZZ strength criterion in real-time identification and digital active control of surrounding rocks, especially in deep tunnels.

 

 

 

Lianyang Zhang, Ph.D., P.E., F.ASCE

Delbert R. Lewis Distinguished Professor

Department of Civil and Architectural Engineering and Mechanics

University of Arizona, Tucson, Arizona, USA

 

Hehua ZHU, Ph.D., P.E.

Professor, Academician of CAE Member

Department of Geotechnical Engineering

College of Civil Engineering, Tongji University, Shanghai, CHINA