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Jian Zhao

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Publications associées (155)

Analysis and prediction of TBM performance in blocky rock conditions at the Lotschberg Base Tunnel

Jian Zhao, Andrea Delisio

This paper focuses on the analysis of the TBM performance recorded during the excavation of the Lotschberg Base Tunnel. The southern part of the tunnel was excavated by two gripper TBMs, partly through blocky rock masses at great depth. The jointed nature ...

Elsevier2013

Review of the TBM performance in blocky rocks with potential face stability issues

Jian Zhao, Andrea Delisio

In blocky/jointed rock masses, the combined effects of the rock mass structure and the in-situ state of stress may lead to severe instabilities of the excavation face which may become "blocky". Large breakout and rock block detachment from the tunnel face ...

Crc Press-Taylor & Francis Group2013

A thin-layer interface model for wave propagation through filled rock joints

Jian Zhao, Jianbo Zhu, Wei Wu

The present study essentially employs a thin-layer interface model for filled rock joints to analyze wave propagation across the jointed rock masses. The thin-layer interface model treats the rough-surfaced joint and the filling material as a continuum med ...

Elsevier2013

Parallelization of the distinct lattice spring model

Jiannong Fang, Jian Zhao, Gaofeng Zhao, Liang Sun

The distinct lattice spring model (DLSM) is a newly developed numerical tool for modeling rock dynamics problems, i.e. dynamic failure and wave propagation. In this paper, parallelization of DLSM is presented. With the development of parallel computing tec ...

Wiley-Blackwell2013

Case studies of TBM tunneling performance in rock-soil interface mixed ground

Jian Zhao, Ákos Tóth

This paper investigates the performance of tunnel boring machines (TBMs) in rock-soil mixed-face ground based on TBM tunneling projects in Singapore. Currently several methods are available to estimate TBM tunneling performance in homogenous rock or soil. ...

Elsevier2013

A newly developed soil abrasion testing method for tunnelling using shield machines

Jian Zhao

The importance of the effect of ground abrasivity on the performance of a tunnel boring machine (TBM) is important for many tunnelling projects. In recent years, many abrasivity devices have been developed to measure soil abrasivity for specific conditions ...

Geological Society2013

Some Fundamental Issues and Verification of 3DEC in Modeling Wave Propagation in Jointed Rock Masses

Jian Zhao, Jianbo Zhu

Discontinuities in rock masses greatly influence stress wave transmission. Before performing numerical modeling on complicated cases, benchmarking modeling must be performed first to validate the numerical code through comparison with theoretical solutions ...

Springer Vienna2012

A Discrete Element Model for Predicting Shear Strength and Degradation of Rock Joint by Using Compressive and Tensile Test Data

Jian Zhao, Tohid Kazerani

A discrete element model is proposed to examine rock strength and failure. The model is implemented by UDEC, which is developed for this purpose. The material is represented as a collection of irregular-sized deformable particles interacting at their cohes ...

Springer Vienna2012

Loading Rate Dependency of Dynamic Responses of Rock Joints at Low Loading Rate

Jian Zhao, Wei Wu

Springer Verlag2012

Wave propagation across rock joints filled with viscoelastic medium using modified recursive method

Jian Zhao, Jianbo Zhu, Wei Wu

Rock joints have significant effects on wave propagation. When the joints are filled with saturated sand or clay, the filling materials exhibit viscoelastic behavior on wave propagation. In the present study, wave propagation across single and multiple par ...

Elsevier2012

A MLS-based lattice spring model for simulating elasticity of materials

Jiannong Fang, Jian Zhao, Gaofeng Zhao

A MLS-based lattice spring model is presented for numerical modeling of elasticity of materials. In the model, shear springs between particles are introduced in addition to normal springs. However, the unknowns contain only particle displacements but no pa ...

World Scientific Publ Co Pte Ltd2012

Study of wave attenuation across parallel fractures using propagator matrix method

Jian Zhao, Jianbo Zhu

Stress wave attenuation across fractured rock masses is a great concern of underground structure safety. This paper presents an analytical study on wave attenuation across parallel fractures at arbitrary incidence angles, where multiple reflections occurri ...

Wiley-Blackwell2012

Modelling the time-dependent rheological behaviour of heterogeneous brittle rocks

Jian Zhao, Tao Xu, Michael Heap

A 2-D numerical model for brittle creep and stress relaxation is proposed for the time-dependent brittle deformation of heterogeneous brittle rock under uniaxial loading conditions. The model accounts for material heterogeneity through a stochastic local f ...

Blackwell Publishing Ltd, Oxford2012

A coupled distinct lattice spring model for rock failure under dynamic loads

Jiannong Fang, Jian Zhao, Gaofeng Zhao

It is necessary to take into account the micro discretization of natural rock when studying its macroscopic failure behavior. This requirement has resulted in renewed and increased interest in the discrete or framework/lattice numerical modeling techniques ...

Elsevier2012

A time-domain recursive method to analyse transient wave propagation across rock joints

Jian Zhao

The present investigation is concerned with transient wave propagation in a rock mass with a set of parallel joints by using a recursive method. According to the displacement field of a rock mass with a set of parallel joints, the interaction between four ...

Blackwell Publishing Ltd, Oxford2012

Seismic response of a single and a set of filled joints of viscoelastic deformational behaviour

Jian Zhao, Jianbo Zhu, Gaofeng Zhao

Rock joints are often filled with weak medium, for example, saturated clay or sand, of viscoelastic nature. Their effects on wave propagation can be modelled as displacement and stress discontinuity conditions. The viscoelastic behaviour of the filled join ...

Blackwell Publishing Ltd, Oxford2011

Validation study of the distinct lattice spring model (DLSM) on P-wave propagation across multiple parallel joints

Jian Zhao, Jianbo Zhu, Gaofeng Zhao

A validation study of the distinct lattice spring model (DLSM) for wave propagation problems is performed. DLSM is a microstructure-based numerical model, which is meshless and has advantages in modelling dynamic problems where stress wave propagation is i ...

Elsevier2011

Analysis of stochastic seismic wave interaction with a slippery rock fault

Jian Zhao

Stochastic seismic wave interaction with a slippery rock fault is studied, based on the principle of conservation of momentum at the wave fronts along the fault. By using the displacement discontinuity method, the wave propagation equations are derived for ...

Springer Verlag2011

Three-phase medium model for filled rock joint and interaction with stress waves

Jian Zhao

A three-phase medium model is proposed in describing the dynamic property of filled rock joints and an analytical study on longitudinal wave transmission normally across a three-phase rock joint is presented. Parameters in the three-phase medium model were ...

Wiley-Blackwell2011

Rock damage control in bedrock blasting excavation for a nuclear power plant

Jian Zhao

Drill and blast is a major method for bed rock excavation in nuclear power plant engineering. Under blasting excavation, blast-induced vibration propagates in rock mass and induces damage to surrounding rock. Studying the characteristics of wave propagatio ...

Elsevier2011

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