The Numerical Experimental Investigation on Damage Zone of Surrounding Rock of Deep Tunnel Based on the Elastic-Plastic-Brittle Constitutive Model

2012 ◽  
Vol 204-208 ◽  
pp. 1454-1459
Author(s):  
Da Guo Wang ◽  
Jin Xi Miao ◽  
Qiang Li
Keyword(s):  
Constitutive Model ◽  
Present Model ◽  
Damage Zone ◽  
Ductile Failure ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Surrounding Rock ◽  
Deep Tunnel ◽  
Elastic Plastic ◽  
Whole Process

A particular elastic-plastic-brittle constitutive model, considering the heterogeneity of rock and the features of deep engineering, is presented, in which the multiple yield criteria based on stress space and ductile failure criteria based on strain space are adopted, and the numerical method is FEM. Through the simulation of the compression test of rock samples, the results show that the present model is rational and accurate. The elastoplastic damage mechanism of the surrounding rock mass of deep tunnel is studied and through the display of centralization, extension and transfer of stresses, it is shown that the present model can be used to predict reliably the whole process of formation of broken zone.

Response, Localization, and Rupture of Anisotropic Tubes Under Combined Pressure and Tension

2020 ◽  
Vol 88 (1) ◽  
Author(s):  
Martin Scales ◽  
Kelin Chen ◽  
Stelios Kyriakides
Keyword(s):  
Constitutive Model ◽  
Ductile Failure ◽  
Failure Criteria ◽  
Yield Function ◽  
Local Deformation ◽  
Al Alloys ◽  
Biaxial Stress ◽  
Image Correlation ◽  
Element Analysis ◽  
Von Mises

Abstract The inelastic response and failure of Al-6061-T6 tubes under combined internal pressure and tension is investigated as part of a broader study of ductile failure of Al-alloys. A custom experimental setup is used to load thin-walled tubes to failure under radial paths in the axial-hoop stress space. All loading paths achieve nominal stress maxima beyond which deformation localizes into a narrow band. 3D digital image correlation (DIC) was used to monitor the deformations in the test section and successfully captured the rapid growth of strain within the localization bands where they burst. The biaxial stress states generated are first used to calibrate the nonquadratic anisotropic Yld04-3D yield function (Barlat et al., 2005, “Linear Transformation-based Anisotropic Yield Functions,” Int. J. Plasticity, 21(5), pp. 1009–1039). The constitutive model is then incorporated through a UMAT into a finite element analysis and used to simulate numerically the experiments. The same calculations were performed using von Mises (VM) and an isotropic nonquadratic yield function. The material hardening responses adopted were extracted for each constitutive model from the necked zone of a tensile test using an inverse method. The use of solid elements captures the evolution of local deformation deep into the localizing part of the response, producing strain levels that are required in the application of failure criteria. The results demonstrate that the adoption of a nonquadratic yield function, together with a correct material hardening response are essential for large deformation predictions in localizing zones in Al-alloys. Including the anisotropy in such a constitutive model produces results that are closest to the experiments.

Three Dimensional Elastic-Plastic Numerical Simulation of Tunnel Excavation Sequence of Dalian Speed Railway

2012 ◽  
Vol 170-173 ◽  
pp. 1474-1478
Author(s):  
An Nan Jiang ◽  
Hong Wei Yang ◽  
Hong Fu Xin ◽  
Bing Bai
Keyword(s):  
Numerical Simulation ◽  
Damage Zone ◽  
Three Dimensional ◽  
Ground Surface ◽  
Soft Rock ◽  
Vertical Displacement ◽  
Stability Control ◽  
Surrounding Rock ◽  
Railway Tunnel ◽  
Elastic Plastic

Dalian speed railway tunnel is located in complex soft rock and soil, the road foundation deform and surrounding rock stability control is a concern problem. Along with the unloading process of excavation, surrounding rock moving to inner hole, while exceeding the elastic limitation, the plastic deform and the surrounding rock destroy then occurred. The paper adopted three dimensional elastic-plastic method based on Mohr-Coulomb yielding criterion and carried out numerical simulation of excavation process, in order to analyze and compare the surrounding rock vertical displacement contour, ground surface settlement and damage zone corresponding to different construction sequence. The elastic-plastic numerical method can reflect the damage and destroy character of nonlinear soil material of surrounding rock corresponding to different construction scheme, the simulation result has active guiding meaning for the Dalian speed railway tunnel construction design and dynamic analysis.

Influence of Soft Rock Factor and Time Dependence in Deep Tunnel

2013 ◽  
Vol 353-356 ◽  
pp. 1625-1629
Author(s):  
Yan Chen ◽  
Xiao Chun Zhang ◽  
Hua Rong Wang ◽  
Nan Tong Zhang
Keyword(s):  
High Stress ◽  
Soft Rock ◽  
Reference Value ◽  
Simulation Method ◽  
Internal Force ◽  
Surrounding Rock ◽  
Deep Tunnel ◽  
Plastic Properties ◽  
Whole Process ◽  
Rock Tunnels

With the development of highway tunnel engineering, the stability of the tunnel become the chief problem in designing and constructing. Tunnel surrounding rock under high stress based on the actual engineering background, model test process of excavation in soft rock tunnels under the distribution factors was finished in triaxial test mechine. Through sensor test, the whole process of tunnel became instable was reflected, and the different conditions of the change rule of surrounding rock stress was budgeted and analysed. the numerical simulation method was used to study dependency of deep tunnel with soft rock in it and the lining deformation time. in which nonlinear Drucker-Prager plastic coupling and creep constitutive model were used to describe the nonlinear viscous-elastic-plastic properties of high stress soft rock. The characteristies of tunnel lining deformation and internal force variation were studied with the above model. Soft rock thickness, soft rock tunnel location effect on inner force and deformation of the structure were discussed. The results have reference value in evaluation of long-term stability of deep tunnel.

Numerical Simulation of Blasting-Induced Damage in Grouting Curtain of Sandstone Aquifer for Vertical Shaft

2015 ◽  
Vol 723 ◽  
pp. 271-278
Author(s):  
Yu Liang Zhou ◽  
Dong Feng Yuan ◽  
Jun Zheng ◽  
Hua Wang
Keyword(s):  
Numerical Simulation ◽  
Prevention And Control ◽  
Damage Zone ◽  
Surrounding Rock ◽  
Damage Effect ◽  
Vertical Shaft ◽  
Control Methods ◽  
Sandstone Aquifer ◽  
And Control ◽  
Dynamic Damage

To provide a theoretical basis for water prevention and control methods and reasonable supporting techniques for vertical shaft, and to ensure the shaft construction to pass the sandstone aquifer safely and rapidly, numerical simulation using dynamic damage constitutive model, which was a user-defined constitutive modules in FLAC3D, a lagrangian analysis code in three dimensions, has been applied to investigate the dynamic damage effect in the surrounding rock of the grouting curtain near the driving working face for vertical shaft excavated by blasting. The results indicate that the distribution of the damage zone in the surrounding rock of the shaft, which decreases the effective thickness of the grouting curtain, was like a ellip-se, and that the depth of the damage zone in the surrounding rock of the shaft grouting curtain is fewer than that of the driving face floor. It can be concluded that the centre part of the driving face floor, especially the cutting hole zones, and the shaft wall in the greater horizontal stress side are the " key parts " for shaft water prevention and control methods.

A Practical Saturated Sand Elastic-Plastic Dynamic Constitutive Model and Application

2012 ◽  
Vol 446-449 ◽  
pp. 1621-1626 ◽  
Author(s):  
Yan Mei Zhang ◽  
Dong Hua Ruan
Keyword(s):  
Constitutive Model ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Stone Columns ◽  
Saturated Sand ◽  
Multidimensional Model ◽  
Excess Pore Water Pressure ◽  
Elastic Plastic ◽  
Excess Pore

A practical saturated sand elastic-plastic dynamic constitutive model was developed on the base of Handin-Drnevich class nonlinear lag model and multidimensional model. In this model, during the calculation of loading before soil reaches yielding, unloading and inverse loading, corrected Handin-Drnevich equivalent nonlinear model was adopted; after soil yielding, based on the idea of multidimensional model, the composite hardening law which combines isotropy hardening and follow-up hardening, corrected Mohr-Coulomb yielding criterion and correlation flow principle were adopted. A fully coupled three dimension effective stress dynamic analysis procedure was developed on the base of this model. The seismic response of liquefaction foundation reinforced by stone columns was analyzed by the developed procedure. The research shows that with the diameter of stone columns increasing, the excess pore water pressure in soil between piles decreases; with the spacing of columns increasing, the excess pore water pressure increases. The influence of both is major in middle and lower level of composite foundation.

scholarly journals Triaxial Compressive Failure Characteristics and Constitutive Model Study of Jurassic-Cretaceous Weakly Cemented Sandstone

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jinlong Cai ◽  
Wei Zou
Keyword(s):  
Constitutive Model ◽  
Residual Strength ◽  
Triaxial Compression ◽  
Volumetric Strain ◽  
Ductile Failure ◽  
Mathematical Expression ◽  
Confining Pressure ◽  
Mining Area ◽  
Peak Strength ◽  
Correction Coefficient

A conventional triaxial compression test of Jurassic-Cretaceous typical weakly consolidated sandstone from a mining area in Ordos, China, was conducted using an MTS816 tester. Results showed that, before the peak, the rock had a distinct yield stage. When the specimen reached its peak strength, the strength decreased rapidly and showed an obvious brittle failure. When the confining pressure was increased to 15 MPa, the decrease of strength was slow and the rock tended toward ductile failure. With the increase of confining pressure, the cyclic strain initially increased slightly, whereas the volumetric strain increased greatly and the rock sample was in a compression state. When the load reached a critical value, the curve was reversely bent, resulting in volume expansion, whereas the peak strength, residual strength, and elastic modulus increased with confining pressure, and Poisson’s ratio decreased with the confining pressure. In the model based on macroscopic failure rock, the expression of the relationship between fracture angle and confining pressure provided a solid theoretical basis for the direction and failure mode of the macroscopic crack. Based on the rock strength theory and Weibull random distribution assumption of rock element strength, the damage variable correction coefficient was introduced when the residual strength was considered. Then, the mathematical expression of the 3D damage statistical constitutive model was established. Finally, the theoretical curve of the established constitutive model was compared with the triaxial test curve, which showed a high degree of coincidence.

scholarly journals Research on Dynamic Response Characteristics for Basement Structure of Heavy Haul Railway Tunnel with Defects

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2893
Author(s):  
Jinfei Chai
Keyword(s):  
Constitutive Model ◽  
Dynamic Response ◽  
Principal Stress ◽  
Surrounding Rock ◽  
Railway Tunnel ◽  
Basement Structure ◽  
Measuring Point ◽  
Heavy Haul ◽  
Damage Constitutive Model ◽  
Heavy Haul Railway

Based on the basic principle of thermodynamics, an elastoplastic damage constitutive model of concrete is constructed in this paper. The model is realized and verified in FLAC3D, which provides a solid foundation for the study of dynamic response and fatigue damage to the base structure of a heavy haul railway tunnel. The dynamic response and damage distribution of the base structure of a heavy-duty railway tunnel with defects were numerically simulated by the concrete elastic-plastic damage constitutive model. Then, by analyzing the response characteristics of the tunnel basement structure under different surrounding rock softening degrees, different foundation suspension range and different foundation structure damage degree are determined. The results show the following: (1) The elastoplastic damage constitutive model of concrete can well describe the stress–strain relationship of materials, especially with the simulation results of post peak softening being in good agreement with the test results, and the simulation effect of the unloading–reloading process of the cyclic loading and unloading test also meet the requirements. (2) The initial stress field and dynamic response of the tunnel basement structure under the action of train vibration load are very different from the ideal state of the structure design when the surrounding rock of the base is softened, the base is suspended, or the basement structure is damaged. With the surrounding rock softening, basement hanging, or basement structure damage developing to a certain extent, the basement structure will be damaged. (3) The horizontal dynamic stress amplitude increases with the increase in the softening degree of the basement surrounding rock. The horizontal dynamic stress of the measuring point increases with the increase in the width of the hanging out area when the hanging out area is located directly below the loading line. When the degree of damage to the basement structure is aggravated, the horizontal dynamic tensile stress of each measuring point gradually decreases. (4) The maximum principal stress increment increases with the increase in the fracture degree of the basement structure, while the minimum principal stress increment decreases with the increase in the fracture degree of the basement structure, but the variation range of the large and minimum principal stress increments is small. The research results have important theoretical and practical significance for further analysis of the damage mechanism and control technology of the foundation structure of a heavy haul railway tunnel with defects.

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