Analysis of Drained Cavity Unloading–Contraction Considering Different Degrees of Intermediate Principal Stress with Unified Strength Theory

2020 ◽  
Vol 20 (7) ◽  
pp. 04020086
Author(s):  
Chunfeng Zhao ◽  
You-Bao Wang ◽  
Cheng Zhao ◽  
Yue Wu ◽  
Yi Fei
2013 ◽  
Vol 535-536 ◽  
pp. 561-564 ◽  
Author(s):  
Hang Zhou Li ◽  
Hong Jian Liao ◽  
Bo Han ◽  
Li Song

It is fundamental to predict the stress-strain behavior of soils to control the stability of the geotechnical engineering. A Duncan-Chang constitutive model is analyzed and found that it ignores the effect of the intermediate principal stress. A unified strength theory is investigated and revised. The lode parameter is introduced into the unified strength theory. The unified friction angle and cohesion which may reflect the influence of the intermediate principal stress and verified by the polyaxial tests are obtained. The compressive strength revised from the unified strength theory is used to replace the Mohr-Coulomb criterion and introduced into the Duncan-Chang model. A modified constitutive model is proposed, which is verified by the plane strain tests. The result shows that the modified constitutive can reflect the effect of the intermediate principal stress, and the Duncan-Chang model is a special case of the modified model when b=0.


2013 ◽  
Vol 535-536 ◽  
pp. 300-305
Author(s):  
Zong Yuan Ma ◽  
Hong Jian Liao ◽  
Fa Ning Dang

Using the finite difference code FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimensions) and UST (Unified Strength Theory), the influence of the intermediate principal stress effect on the problems of flat punch are analyzed in this paper. The values of the ultimate bearing capacity resulting from numerical analyses and the analytical solution of Prandtl’s strip punch problem are compared. The three-dimensional problems of strip, rectangular, square and circular punches on a semi infinite metallic medium have been analyzed.


2012 ◽  
Vol 166-169 ◽  
pp. 3095-3099
Author(s):  
Huai Feng Tong

Analysis of stress state of soil around the pile and grouting pressure of small non-sand concrete pile is given based on the expansion elastic theory of cylindrical cavity and the unified strength theory, the grouting pressure formula is obtained in the elastic limit state and elastic-plastic state of soil around the pile considered the intermediate principal stress, and the relationship is obtained between the grouting pressure and the plastic radius; When the soil around the pile is in different stress state, the correlativity of crack and densification of grouting is analyzed, and the relationship between the grouting pressure and the plastic radius is discussed with the right coefficient of the intermediate principal stress and initial press under different values. The obtained results have provided efficient analysis means for grouting optimal design of post-processing technology with small non-sand concrete pile.


2011 ◽  
Vol 99-100 ◽  
pp. 965-971
Author(s):  
Zhi Ping Dai ◽  
Cheng Zhao ◽  
Chun Feng Zhao

As it ignorance the effect of intermediate principal stress, traditional Duncan - Chang model has limitation when applied into geotechnical engineering. It was improved through incorporating the effect of intermediate principal stress based on unified strength theory. Under the help of customized modification platform in ABAQUS, the applicability and stability of the improved model and the reliability of subroutine were validated through simulation of several examples. The results show the improved model can better reflect the deformation behavior of soil through taking the influence of intermediate principal stress into consideration. The improved model in paper can be applied into dense sand, fine sand and clay.


2011 ◽  
Vol 137 ◽  
pp. 59-64
Author(s):  
Zong Yuan Ma ◽  
Hong Jian Liao ◽  
Mao Hong Yu

Numerical computations using finite difference method and unified strength theory are reported to analyze the slope stability problem. The Factor of safety of plane strain and axisymmetric slopes was calculated by strength reducing method, and the influences of intermediate principal stress on slope stability problem was analyzed. The associative and non-associative flow rule was taking into account in plane strain slope problem analysis. The intermediate principal stress has equivalent influences on slope stability problem under associative and non-associative flow rule. The Factor of safety of plane strain slope is lower than the axisymmetric situation. The influence of intermediate principal stress on slope stability under plane strain condition is heavier than axisymmetry.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zongshan Zou ◽  
Jun Yang ◽  
Zhongming Wang ◽  
Hongyan Liu

For the deficiencies that the existing calculation theory for the Plastic Zone of Tunnel Surrounding Rock (PZTSR) does not consider the effect of the intermediate principal stress σ2 and interaction between the surrounding rock and support structure on the PZTSR under unequal stress, the Unified Strength Theory (UST) for the rock is adopted to replace the often used Mohr-Coulomb (M-C) strength criterion to consider the effect of σ2 on the PZTSR. Meanwhile, the interaction mechanism between the surrounding rock and support structure is also considered in the proposed model. Finally, the effect of the initial elastic displacement of the surrounding rock, stiffness of the support structure, and the coefficient b of the intermediate principal stress on the plastic zone is discussed. The results show that the PZTSR will increase nonlinearly with increasing the initial elastic displacement of the surrounding rock, and when it increases to a certain value, its increase extent will be much obvious. With increasing the stiffness of the support structure, the PZTSR will gradually decrease nonlinearly, but the decrease extent is not very much. With increasing b, the PZTSR will decrease; namely, σ2 can improve the stress condition of the surrounding rock and reduce the PZTSR.


2021 ◽  
Vol 293 ◽  
pp. 02019
Author(s):  
Pei Zhou

Unified strength theory considering the influence of the intermediate principal stress is widely used in geotechnical engineering, but the singularities bring inconvenience to the numerical calculation. A series of equivalent area circle yield criteria based on unified strength theory are derived. The parameters of the new yield criteria and Drucker-Prager criteria are discussed, and the flow vector coefficients of the new yield criteria are given. The new series of yield criteria are very convenient for numerical calculation and can be served as reference for the evaluation of the effects of strength theory.


2010 ◽  
Vol 168-170 ◽  
pp. 1370-1376
Author(s):  
We Long Yu ◽  
Jian Zhang ◽  
Xiu Hua Sun ◽  
Rui Lin Hu ◽  
Xin Wei

Estimating passive earth pressure accurately is very important when designing retaining wall. Based on the unified strength theory and plane strain assumption, an analytical solution has been developed to determine the passive lateral earth pressure distribution on a retaining structure when the backfill is cohesive and inclined considering the effect of the intermediate principal stress. The solution derived encompasses both Bell’s equation (for cohesive or cohesionless backfill with a horizontal ground surface) and Rankine’s solution (for cohesionless backfill with an inclined ground surface).


2013 ◽  
Vol 353-356 ◽  
pp. 1005-1010
Author(s):  
Xiang Qiu Wang ◽  
Wen Tao Yang

The bearing capacity of slime friction pile based on the Mohr-Coulombs strength criterion couldnt make full use of the potential strengths ability of rock-soil. But the double shear unified strength theory can depict really the bearing characteristics of rock-soil because it can consider the effect of intermediate principal stress comprehensively. On this condition, based on the Mindlins displacement solution and the double shear unified strength theory, a calculated formula of bearing capacity was proposed for the slime friction pile, and then the distribution regularities of lateral friction-resistance force for the slime friction pile were discussed.


2010 ◽  
Vol 160-162 ◽  
pp. 1205-1210 ◽  
Author(s):  
Zhao Qiang Zhang ◽  
Shu Lian Xiao ◽  
Jin Song Lei

Based on the Unified Strength Theory(UST),the ultimate load calculation formula for the recycled aggregate concrete-filled steel tubular short columns is derived in this paper,in which the decrease of longitudinal stress because of the hoop tensile tension is considered. The influence of intermediate principal stress on the ultimate load is studied and the failure mechanism is also discussed. The results show that the intermediate principal stress have important effect on the ultimate load which increases with the strength parameter .Through the comparison between the experimental results and the calculating results obtained in this paper,the deviation is small,and it shows that the formula have significance in exerting material potential.


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