Study on Rockmass Deterioration Model Based on the Unified Strength Theory

2012 ◽  
Vol 468-471 ◽  
pp. 2521-2527
Author(s):  
Xue Ying Zhang
Keyword(s):  
Finite Difference ◽  
Strain Softening ◽  
Triaxial Tests ◽  
Strength Theory ◽  
Elastoplastic Model ◽  
Unified Strength Theory ◽  
True Triaxial ◽  
New Model ◽  
Deterioration Model ◽  
Model Based

Strain softening model;Unified strength theory;Rockmass deterioration model;FLAC3D Abstract:Aiming at the problem that traditional elasto-plastic constitutive models have not been successful in predicting the depth and extent of brittle failed of hard rocks under high geo-stress condition, a new rockmass deterioration model(RDM) based on the unified strength theory is put forward in the basis of strain softening model and cohesion weaking and friction strengthening (CWFS)model. In the new model, the influence of intermediatemain stress to characteristic of rockmechanics is considered. Based on the method of lagrangian finite difference, a finite difference format of unified strain- softening elastoplastic model with strength parameters of c and φ is established. The constitutive unified elastoplastic model is imported into FLAC3D using a dynamic-link library file developed by VC++.Based on the new model, the traditional triaxial tests (with different confining pressure) and true triaxial tests (with intermediate principal stress ratio) are simulated in FLAC3D, and the measured data are compared with the results that are are simulated by strain softening model and CWFS model. The analytic results suggest that the rockmass deterioration model based on the twin shear unified strength theory has more strong applicability

Unified Three-Dimensional Revision of Modified Cam Clay Model

2007 ◽  
Vol 340-341 ◽  
pp. 1267-1272
Author(s):  
Hang Zhou Li ◽  
Hong Jian Liao ◽  
Kyoji Sassa ◽  
Gong Hui Wang
Keyword(s):  
Three Dimensional ◽  
Yield Function ◽  
Triaxial Tests ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
True Triaxial ◽  
Proposed Model ◽  
Modified Cam Clay ◽  
Stress States ◽  
Cam Clay

According to unified strength parameters obtained from unified strength theory, the slope of critical state line is modified to reflect critical states of different geomaterials under general stress states. Yield function that can consider the effect of the third deviatoricic invariant is proposed, and an elasto-plastic constitutive model is established by adopting non-associated flow rules; furthermore, methods of overcoming singular points on the yield surface are discussed. The proposed model is verified by true triaxial tests of clay, and results show that the model can well predict stress-strain relationships.

scholarly journals Triaxial Compression Performance Research of Steel Slag Concrete on the Unified Strength Theory

2020 ◽  
Vol 11 (1) ◽  
pp. 128
Author(s):  
Zhiheng Deng ◽  
Jingkai Zhou ◽  
Beiquan Chen ◽  
Xiaoyan Wen ◽  
Bing Liu
Keyword(s):  
Failure Modes ◽  
Triaxial Compression ◽  
Steel Slag ◽  
Peak Stress ◽  
Triaxial Tests ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
True Triaxial ◽  
Compression Performance ◽  
Triaxial Compressive Strength

To better explore the mechanical properties of steel slag concrete (SSC) under triaxial compression, true triaxial tests were performed on SSC with three replacement ratios (30%, 70%, 100%) by a servo-controlled setup (TAWZ-5000/3000). Through the test, failure modes, peak stress, and corresponding strain of SSC are obtained. Results show that the failure modes of SSC are plate-splitting and slant-shear. Compared with the corresponding uniaxial strength, the triaxial compressive strength of SSC is significantly improved and is influenced by the stress ratio and the replacement ratio. Finally, based on unified strength theory, the strength failure criterion formula of SSC with different replacement rates under triaxial compression is given.

Unified Solution of Expansion of Cylindrical Cavity of Elastic-Brittle-Plastic Strain-Softening Materials with Different Elastic Modulus in Tensile and Compression

2006 ◽  
Vol 324-325 ◽  
pp. 823-826
Author(s):  
Jian Zhong Xia ◽  
Zhan You Luo ◽  
Wei Tang Wang ◽  
Wei Liu
Keyword(s):  
Elastic Modulus ◽  
Plastic Zone ◽  
Cylindrical Cavity ◽  
Strain Softening ◽  
Strength Theory ◽  
Displacement Fields ◽  
Unified Strength Theory ◽  
Expansion Pressure ◽  
Stress And Displacement Fields ◽  
Pressure Stress

For strain-softening materials with different elastic modulus of tensile compression, two controlling parameters were introduced to take into account the different modulus and strainsoftening properties. By means of twin shear unified strength theory, unified solutions calculating stress and displacement fields of expansion of cylindrical cavity were derived. The effects caused by different elastic modulus in tensile and compression, different models and strain-softening rates on stress and displacement fields, development of plastic zone were analyzed. The results show the ultimate expansion pressure, stress and displacement fields and development of plastic zone vary with the changes of different elastic modular, different models and strain-softening properties.

STUDY ON SOFTENING CONSTITUTIVE MODEL OF SOFT ROCK USING STRAIN SPACE BASED UNIFIED STRENGTH THEORY

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5375-5380 ◽  
Author(s):  
LI SONG ◽  
CHONGDU CHO ◽  
SHENG LU ◽  
HONGJIAN LIAO
Keyword(s):  
Constitutive Model ◽  
Constitutive Equations ◽  
Strain Softening ◽  
Soft Rock ◽  
Elastoplastic Strain ◽  
Strength Theory ◽  
Unified Strength Theory ◽  
Softening Behavior ◽  
Simulation Results ◽  
Strain Space

This study attempts to modify the unified strength theory by considering compression as a positive load in geotechnical engineering. It also aims to establish a unified elastoplastic strain softening constitutive model which can accurately describe the strain softening behavior of one kind of soft rocks distributed in Japan. The hardening function parameters of the unified elastoplastic strain softening constitutive model are determined from experiments. In addition, numerical simulations of this model are performed to compare the pre-peak, post-peak and the residual strengths of soft rock predicted by this study and experimental results. Simulation results demonstrated that the proposed constitutive equations in strain space can well describe the softening behavior and accurately predict the peak and residual strengths of soft rock. While the proposed equation is applicative for normally consolidated state and overconsolidated state according to the simulation results.

scholarly journals Elastoplastic Model and Three-Dimensional Method for Unsaturated Soils

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Jinjin Fang ◽  
Yixin Feng
Keyword(s):  
Constitutive Model ◽  
Unsaturated Soils ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Degree Of Saturation ◽  
Triaxial Tests ◽  
Model Parameters ◽  
Elastoplastic Model ◽  
True Triaxial ◽  
Elastoplastic Constitutive Model

This paper proposed a new elastoplastic constitutive model to predict the deformation and strength behaviour of unsaturated soils. Applying the modified Cambridge model as a generalization, the degree of saturation is introduced into the elastoplastic model of unsaturated soil. Under the condition of ensuring that the model parameters are unchanged, the model is transformed into three dimensions based on the SMP criterion transformation stress method. Enhanced modified van Genuchten model under true triaxial conditions is also proposed in this paper to describe hydromechanical behaviours of unsaturated soils. The proposed constitutive model can capture the observed mechanical and hydraulic behaviours. Then, the model is validated via equal p and equal b value true triaxial tests, and the results show that a reasonable agreement can be obtained.

Bovine Serum Albumin Adsorption onto Colloidal Al2O3Particles:  A New Model Based on Zeta Potential and UV−Vis Measurements

Langmuir ◽  
2004 ◽  
Vol 20 (23) ◽  
pp. 10055-10061 ◽  
Author(s):  
Kurosch Rezwan ◽  
Lorenz P. Meier ◽  
Mandana Rezwan ◽  
Janos Vörös ◽  
Marcus Textor ◽  
...  
Keyword(s):  
Bovine Serum Albumin ◽  
Zeta Potential ◽  
Serum Albumin ◽  
Bovine Serum ◽  
New Model ◽  
Model Based ◽  
Bovine Serum Albumin Adsorption ◽  
Albumin Adsorption

scholarly journals An Improved Image Denoising Model Based on Nonlocal Means Filter

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yan Jin ◽  
Wenyu Jiang ◽  
Jianlong Shao ◽  
Jin Lu
Keyword(s):  
Image Denoising ◽  
Natural Images ◽  
Nonlocal Means ◽  
New Model ◽  
Model Based ◽  
Better Than

The nonlocal means filter plays an important role in image denoising. We propose in this paper an image denoising model which is a suitable improvement of the nonlocal means filter. We compare this model with the nonlocal means filter, both theoretically and experimentally. Experiment results show that this new model provides good results for image denoising. Particularly, it is better than the nonlocal means filter when we consider the denoising for natural images with high textures.

scholarly journals Through-wall yield collapse pressure of casing based on unified strength theory

2016 ◽  
Vol 43 (3) ◽  
pp. 506-513 ◽  
Author(s):  
Yuanhua LIN ◽  
Kuanhai DENG ◽  
Yongxing SUN ◽  
Dezhi ZENG ◽  
Tianguo XIA
Keyword(s):  
Strength Theory ◽  
Unified Strength Theory ◽  
Collapse Pressure
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