Finite Element Analysis of Dongjusi Railway Tunnel within Hard Rock Mass Based on the Unified Rock Mass Strength Criterion

2007 ◽  
pp. 2994-2997
Author(s):  
Yuan Hua ◽  
Tai Quan Zhou ◽  
Guo Liang Dai
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rock Mass ◽  
Hard Rock ◽  
Strength Criterion ◽  
Railway Tunnel ◽  
Element Analysis ◽  
Rock Mass Strength

Reliability Analysis of Railway Tunnel Construction Process within Soft and Weak Rock Mass Using the Unified Elasto-Plastic Strength Criterion

2007 ◽  
Vol 353-358 ◽  
pp. 2521-2524
Author(s):  
Jun Ying Lian ◽  
Tai Quan Zhou ◽  
Yuan Hua ◽  
Guo Liang Dai
Keyword(s):  
Finite Element Analysis ◽  
Rock Mass ◽  
Reliability Analysis ◽  
Strength Criterion ◽  
Nonlinear Finite Element ◽  
Weak Rock ◽  
Railway Tunnel ◽  
Element Analysis ◽  
Plastic Strength ◽  
Weak Rock Mass

Variability in the physical properties of rock mass is a major source of uncertainty encountered in railway tunnel stability analysis. The conventional safety factor method on stability assessment of railway tunnel within soft and weak rock mass can not represent the variability of rock mass. A formulation to compute the reliability of soft and weak rock mass, in which physical non-linearity is taken into account, is proposed. To consider the intermediate principal stress effect on the rock mass strength, the unified elasto-plastic strength criterion is proposed in the nonlinear finite element analysis. The unified rock mass elasto-plastic material model is implemented in ABAQUS user interface. The reliability analysis is performed in two steps. Firstly, the failure response is obtained by fitting the limit state function of the rock mass using the quadratic polynomial based on the nonlinear finite element analysis of the rock mass. Secondly, the JC method is proposed to obtain the design point and the reliability index of rock mass. As a case for study, the reliability analysis of Jinhuashan railway tunnel within soft and weak rock mass is studied using the proposed method. The two dimensional analysis is performed to consider the excavation stage effect and the unloading effect on the rock mass. Computation result shows that the rock mass is in stability.

Finite Element Analysis of Dongjusi Railway Tunnel within Hard Rock Mass Based on the Unified Rock Mass Strength Criterion

2007 ◽  
Vol 353-358 ◽  
pp. 2994-2997
Author(s):  
Yuan Hua ◽  
Tai Quan Zhou ◽  
Guo Liang Dai
Keyword(s):  
Rock Mass ◽  
Principal Stress ◽  
Hard Rock ◽  
Plastic Material ◽  
Strength Criterion ◽  
Intermediate Principal Stress ◽  
Stress Effect ◽  
Railway Tunnel ◽  
Rock Mass Strength ◽  
Intermediate Principal Stress Effect

The twin shear strength criterion has been proposed to consider the intermediate principal stress effect on the rock mass strength. The unified rock mass strength criterion could consider the intermediate principal stress effect on the rock mass strength. The unified rock mass elasto-plastic material model is implemented in ABAQUS user interface. As a case for study, the stability analysis of Dongjusi railway tunnel within hard rock mass is studied using the unified rock mass strength material. For comparison, the Hoek-Brown empirical strength criterion is also chosen for the rock mass material modeling. The computation results show that the plastic zone calculated using the unified rock mass strength criterion is smaller than that using the Hoek-Brown empirical strength criterion. The railway tunnel lining structure is designed according to the unified rock mass strength criterion and greatly makes use of the rock mass potential strength, which decreases engineering cost.

Chosen of Strength Criterion for Different Region of Blade

2012 ◽  
Vol 608-609 ◽  
pp. 755-758
Author(s):  
De Tian ◽  
Qi Li ◽  
Jian Mei Zhang ◽  
Xiao Dong Zhang ◽  
Ning Bo Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Strength Criterion ◽  
Fatigue Index ◽  
Element Analysis ◽  
Strength Criteria ◽  
Security And Reliability ◽  
Blade Model ◽  
Dangerous Section

Use software Pro/E to build a blade model based on 1.5MW wind turbine, analyze stress characteristics of different regions including spar cap, webs and trailing edge of the dangerous section of blade at related loads by using different strength criteria to make finite element analysis to check the strength, through comparing the F.I.(fatigue index) and stress bringing about the idea that using different strength criteria to analyze different material of different regions can ensure the security and reliability of the designed blade at large extent.

scholarly journals Tunnel support design by comparison of empirical and finite element analysis of the Nahakki tunnel in mohmand agency, pakistan

2016 ◽  
Vol 38 (1) ◽  
pp. 75-84
Author(s):  
Asif Riaz ◽  
Syed Muhammad Jamil ◽  
Muhammad Asif ◽  
Kamran Akhtar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rock Mass ◽  
Support Systems ◽  
Classification Systems ◽  
Geological Strength Index ◽  
Support Design ◽  
Element Analysis ◽  
Tunnel Support ◽  
Geological Conditions

Abstract The paper analyses the geological conditions of study area, rock mass strength parameters with suitable support structure propositions for the under construction Nahakki tunnel in Mohmand Agency. Geology of study area varies from mica schist to graphitic marble/phyllite to schist. The tunnel ground is classified and divided by the empisical classification systems like Rock mass rating (RMR), Q system (Q), and Geological strength index (GSI). Tunnel support measures are selected based on RMR and Q classification systems. Computer based finite element analysis (FEM) has given yet another dimension to design approach. FEM software Phase2 version 7.017 is used to calculate and compare deformations and stress concentrations around the tunnel, analyze interaction of support systems with excavated rock masses and verify and check the validity of empirically determined excavation and support systems.

Surrounding Rock Rupture Modeling of Tunnel Based on ANSYS

2014 ◽  
Vol 490-491 ◽  
pp. 863-866
Author(s):  
Bai Cheng Ren
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rock Mass ◽  
Surrounding Rock ◽  
Analysis Software ◽  
Element Analysis ◽  
Tunnel Excavation ◽  
Real Condition ◽  
Supporting System ◽  
The Real

This article is based on the real condition of a tunnel. By using displacement and stress contours get from finite element analysis software ANSYS, the simulation of the tunnel excavation is modeled and the regulation of overlying rock’s displacement and stress is deducted during the evacuation of the tunnel. The analysis result to overlying rock mass’ rupture regularity can be helpful for the control of surrounding rock’s stability and the improvement of supporting system. The result shows finite element analysis software ANASYS can be used to guide tunnel constructions during the evacuation.

Étude par éléments finis du comportement à l'arrachement des ancrages injectés dans le roc

1990 ◽  
Vol 17 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Brahim Benmokrane
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rock Mass ◽  
Field Tests ◽  
Element Analysis ◽  
Great Cost ◽  
Quadrilateral Elements ◽  
Failure Loads ◽  
Rock Anchors ◽  
Éléments Finis

The uplift behavior of grouted rock anchors is little known despite their increasing use within the last few years and during which their field of application has been greatly broadened. The behavior of anchors is usually controlled at great cost after installation through field tests. Generally, their design is based on experience and an engineer with lesser experience finds it extremely difficult to design one. Furthermore, present methods for dimensioning anchors generally result in oversizing the anchors' grouted length without a corresponding improvement in the safety factor. To provide a more fundamental approach to designing grouted rock anchors, a finite element analysis of the uplift behavior has been carried out. The results of the analysis using isoparametric quadrilateral elements with eight nodes are presented in this article. Results of failure loads and modes obtained from anchors installed in the field are well predicted by the model. Key words: rock mass, grouted anchor, cement grout, finite elements, uplift of an anchor.

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