scholarly journals Simple approach for solution of the quasi-plane-strain problem in a circular tunnel in a strain-softening rock mass considering the out-of-plane stress effect

2020 ◽  
Vol 5 (4) ◽  
pp. 339-353
Author(s):  
Jinfeng Zou ◽  
Lu Liu ◽  
Mingyao Xia
Keyword(s):  
Rock Mass ◽  
Plane Strain ◽  
Plane Stress ◽  
Strain Softening ◽  
Simple Approach ◽  
Stress Effect ◽  
Circular Tunnel ◽  
Plane Strain Problem ◽  
Out Of Plane

scholarly journals Strain-Softening Analyses of a Circular Bore under the Influence of Axial Stress

2021 ◽  
Vol 11 (17) ◽  
pp. 7937
Author(s):  
Xuechao Dong ◽  
Mingwei Guo ◽  
Shuilin Wang
Keyword(s):  
Rock Mass ◽  
Plane Stress ◽  
Strain Softening ◽  
Hydrostatic Stress ◽  
Axial Stress ◽  
Perfectly Plastic ◽  
Out Of Plane ◽  
Softening Process ◽  
Elastic Perfectly Plastic ◽  
Proper Consideration

Strain-softening analyses were performed around a circular bore in a Mohr–Coulomb rock mass subjected to a hydrostatic stress field in cross section and out-of-plane stress along the axis of the bore. Numerical procedures that simplify the strain-softening process in a step manner were employed, and on the basis of the theoretical solutions of the elastic–brittle–plastic(EBP) medium, the strain-softening results of the displacements, stresses and the plastic zones around the circular bore were obtained. The numerical solution was validated based on the fact that the strain-softening process became EBP when the softening slope was very steep and elastic-perfectly plastic(EP) when the softening slope was near zero. The results illustrated that the stresses and displacements in the rock mass surrounding the bore was affected by axial stress and that a proper consideration of out-of-plane stress is necessary. Moreover, the presented results can be used for the verification of numerical codes.

scholarly journals An Improved Stress and Strain Increment Approaches for Circular Tunnel in Strain-Softening Surrounding Rock Considering Seepage Force

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Ling Wang ◽  
Jin-feng Zou ◽  
Yu-ming Sheng
Keyword(s):  
Rock Mass ◽  
Plastic Zone ◽  
Radial Displacement ◽  
Axisymmetric Problem ◽  
Strain Softening ◽  
Strain Increment ◽  
Surrounding Rock ◽  
Stress And Strain ◽  
Seepage Force ◽  
Circular Tunnel

Considering the effect of seepage force, a dimensionless approach was introduced to improve the stress and strain increment approach on the stresses and radial displacement around a circular tunnel excavated in a strain-softening generalized Hoek–Brown or Mohr–Coulomb rock mass. The circular tunnel can be simplified as axisymmetric problem, and the plastic zone was divided into a finite number of concentric rings which satisfy the equilibrium and compatibility equations. Increments of stresses and strains for each ring were obtained by solving the equilibrium and compatibility equations. Then, the stresses and displacements in softening zone can be calculated. The correctness and reliability of the proposed approach were performed by the existing solutions.

Prediction of critical strains and critical support pressures for circular tunnel excavated in strain-softening rock mass

2017 ◽  
Vol 224 ◽  
pp. 43-61 ◽  
Author(s):  
Lan Cui ◽  
Jun-Jie Zheng ◽  
You-Kou Dong ◽  
Biao Zhang ◽  
An Wang
Keyword(s):  
Rock Mass ◽  
Strain Softening ◽  
Circular Tunnel ◽  
Critical Strains

Residual Stress in EB-PVD Thermal Barrier Coatings

2006 ◽  
Vol 524-525 ◽  
pp. 879-884 ◽  
Author(s):  
Kenji Suzuki ◽  
Keisuke Tanaka ◽  
Takahisa Shobu
Keyword(s):  
Residual Stress ◽  
Plane Strain ◽  
Plane Stress ◽  
Physical Vapor Deposition ◽  
Preferred Orientation ◽  
X Rays ◽  
Scanning Method ◽  
Bond Coating ◽  
Out Of Plane ◽  
Steep Decrease

A NiCoCrAlY bond coating was low-pressure plasma sprayed on a stainless steel sub- strate. Zirconia with 8 wt% yttria was deposited on the bond coating using an electron beam-physical vapor deposition (EB-PVD) method. The top coating had the preferred orientation with the h111i axis direction perpendicular to the coating plane. The distribution of the in-plane residual stress in the top coating was measured using laboratory Cr-K X-rays with a progressive layer removal method. The value of the in-plane stresses was determined by the sin2 method after the separation of the 133 and 331 peaks. The distribution of the out-of-plane strain in the top coating was measured using the strain scanning method with hard synchrotron X-rays. The out-of-plane strain was obtained from the 333 peak which had strong intensity due to the preferred orientation. The measured value of the in-plane stress in the top coating was a large compression, and showed a steep decrease near the in- terface between the top and the bond coatings. The distribution of the out-of-plane stress showed a compression, and its magnitude was smaller than that of the in-plane stress.

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