scholarly journals FLEXURAL STRESS ANALYSIS OF RIGID PAVEMENTS USING AXI-SYMMETRIC AND PLANE STRAIN FEM

2017 ◽  
Vol 24 (4) ◽  
pp. 443-451
Author(s):  
V.A. Sawant ◽  
M.S. Norazzlina
Keyword(s):  
Plane Strain ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Climatic Conditions ◽  
Finite Element Analyses ◽  
Flexural Stress ◽  
Rigid Pavement ◽  
Rigid Pavements ◽  
Pca Method ◽  
Portland Cement Association

The design of pavement involves a study of soils and paving materials, their response under load for different climatic conditions. In the present study, an attempt has been made to compare stresses predicted using two finite element analyses. First analysis is based on the twodimensional plane strain assumption where as in second approach axi-symmetric condition is assumed to consider three-dimensional behavior of rigid pavement. The results are compared with flexural stresses obtained from conventional Portland Cement Association method. The computed flexural stresses obtained from axi-symmetric condition are found to be in close agreement with PCA method. Results of plane strain analysis show a fair agreement after application of an appropriate multiplication factor  

C-Specimen Fracture Toughness Testing: Effect of Side Grooves and η Factor

2003 ◽  
Author(s):  
Y. Kim ◽  
Y. J. Chao ◽  
M. J. Pechersky ◽  
M. J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Plane Strain ◽  
Crack Front ◽  
Testing Effect ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
J Integral ◽  
Η Factor

Elastic-plastic crack front fields in arc-shaped tension specimens (C-specimens) were analyzed by a three-dimensional finite element method. The effect of side grooves on the ductile fracture behavior was investigated by studying the J-integral distribution, plane-strain constraint parameter, and development of plastic zones and comparing to experimental data. The applicability of the η factor (derived for use with compact tension specimens) for the calculation of J-integral values for the C-specimen was also investigated. The results show that side grooves promote and establish near plane strain conditions at the crack front in sub-size specimens. It was also found that a two-dimensional plane-strain analysis in conjunction with the standard American Society for Testing and Materials (ASTM) tests was sufficient to determine the fracture toughness values from side-grooved C-specimen. The results indicate the η factor for compact tension specimen as specified in the ASTM standards appears to produce reliable results for the calculation of J of C-specimens.

An evaluation of simplified techniques for estimating three-dimensional undrained ground movements due to tunnelling in soft soils

1992 ◽  
Vol 29 (1) ◽  
pp. 39-52 ◽  
Author(s):  
R. K. Rowe ◽  
K. M. Lee
Keyword(s):  
Plane Strain ◽  
Deformation Behaviour ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Cumulative Probability ◽  
Element Analysis ◽  
Cross Sectional ◽  
Soft Soils ◽  
Longitudinal Plane ◽  
Stress Changes

A number of simplified approaches have been used by various researchers to estimate the three-dimensional stress changes and ground deformations due to shallow tunnels in soft soils. The effectiveness of these simplified analyses, such as (i) axisymmetric analysis, (ii) longitudinal plane strain analysis, and (iii) empirical cumulative probability distribution approach, has been examined by comparison of results with those from a full three-dimensional elastoplastic finite-element analysis. For tunnels located at shallow depths, axisymmetric analyses are generally found to be unable to predict the correct magnitude of displacement around a tunnel heading. However, the trend of the three-dimensional deformation behaviour near the tunnel heading can be reasonably approximated by the average of the normalized displacement curves predicted by the two axisymmetric assumptions as described in this paper. The three-dimensional distribution of the displacement near the ground surface, on the other hand, can be approximately predicted by the cumulative probability approach, provided that the three empirical parameters required by the equations are reasonably estimated. In this paper, these parameters were estimated from the result of a two-dimensional plane strain cross-sectional analysis. Finally, it was found that modelling of three-dimensional deformations by a longitudinal plane strain analysis did not give good results for the cases examined. Key words : tunnelling, soft ground, analysis.

C-Specimen Fracture Toughness Testing: Effect of Side Grooves and η Factor

2004 ◽  
Vol 126 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Y. Kim ◽  
Y. J. Chao ◽  
M. J. Pechersky ◽  
M. J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Plane Strain ◽  
Crack Front ◽  
Testing Effect ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
J Integral ◽  
Η Factor

Elastic-plastic crack front fields in arc-shaped tension specimens (C-specimens) were analyzed by a three-dimensional finite element method. The effect of side grooves on the ductile fracture behavior was investigated by studying the J-integral distribution, plane-strain constraint parameter, and development of plastic zones and comparing to experimental data. The applicability of the η factor (derived for use with compact tension specimens) for the calculation of J-integral values for the C-specimen was also investigated. The results show that side grooves promote and establish near plane strain conditions at the crack front in sub-size specimens. It was also found that a two-dimensional plane-strain analysis in conjunction with the standard American Society for Testing and Materials (ASTM) tests was sufficient to determine the fracture toughness values from side-grooved C-specimen. The results indicate the η factor for compact tension specimen as specified in the ASTM standards appears to produce reliable results for the calculation of J of C-specimens.

A simplified plane strain analysis of lateral wall deflection for excavations with cross walls

2012 ◽  
Vol 49 (10) ◽  
pp. 1134-1146 ◽  
Author(s):  
Pio-Go Hsieh ◽  
Chang-Yu Ou ◽  
Chiang Shih
Keyword(s):  
Plane Strain ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Lateral Wall ◽  
Diaphragm Wall ◽  
Beam Model ◽  
Two Dimensional ◽  
Wall Deflection ◽  
Dimensional Plane ◽  
Proposed Model

Previous studies have shown that installation of cross walls in deep excavations can reduce lateral wall deflection to a very small amount. To predict the lateral wall deflection for excavations with cross walls, it is necessary to perform a three-dimensional numerical analysis because the deflection behavior of the diaphragm wall with cross walls is by nature three dimensional. However for the analysis and design of excavations, two-dimensional plane strain analysis is mostly used in practice . For this reason, based on the deflection behavior of continuous beams and the superimposition principle, an equivalent beam model suitable for two-dimensional plane strain analysis was derived to predict lateral wall deflection for excavations with cross walls. Three excavation cases were employed to verify the proposed model. Case studies confirm the proposed equivalent beam model for excavations with cross walls installed from near the ground surface down to at least more than half the embedded depth of the diaphragm wall. For the case with a limited cross-wall depth, the proposed model yields a conservative predicted lateral wall deflection.

Stability analysis of three-dimensional slopes under water drawdown conditions

2014 ◽  
Vol 51 (11) ◽  
pp. 1355-1364 ◽  
Author(s):  
Yufeng Gao ◽  
Desheng Zhu ◽  
Fei Zhang ◽  
G.H. Lei ◽  
Hongyu Qin
Keyword(s):  
Plane Strain ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Stability Of Slopes ◽  
Water Drawdown ◽  
Influence Of Water ◽  
The Difference ◽  
Large Width ◽  
3D Effect ◽  
Rotational Failure

The traditional approaches for evaluating the stability of slopes or earth dams subjected to water drawdown are performed under plane-strain two-dimensional (2D) condition. Three-dimensional (3D) effect is neglected in assessment of the safety of a slope limited by rigid structures or a dam constrained by a narrow valley. Based on the kinematic approach of limit analysis, a 3D rotational failure mechanism is adopted here to investigate the influence of water drawdown on stability of 3D slopes. Several stability charts are presented to conveniently estimate the safety factor of 3D slopes under four different types of drawdown processes. An example is given to demonstrate the difference in the safety factors obtained from 2D and 3D analyses. When a slope is constrained to a large width (the ratio of the width to the height B/H ≥ 10.0), the 3D effect can be neglected and the plane-strain analysis is appropriate to assess its safety.

scholarly journals Toward the Development of Load Transfer Efficiency Evaluation of Rigid Pavements by a Rolling Wheel Deflectometer

2020 ◽  
Vol 5 (1) ◽  
pp. 7
Author(s):  
Pawan Deep ◽  
Mathias B. Andersen ◽  
Nick Thom ◽  
Davide Lo Presti
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Transfer Efficiency ◽  
Falling Weight Deflectometer ◽  
Rigid Pavement ◽  
Important Indicator ◽  
Rigid Pavements ◽  
Load Transfer Efficiency ◽  
Rolling Wheel ◽  
Falling Weight

The jointed rigid pavement is currently evaluated by the Falling weight deflectometer which is rather slow for the testing of the jointed pavements. Continuous nondestructive evaluation of rigid pavements with a rolling wheel deflectometer can be used to measure the load transfer and is investigated. Load transfer is an important indicator of the rigid pavement’s condition and this is the primary factor which is studied. Continuous data from experimental measurements across a joint allows for the determination of not only the load transfer efficiency provided parameters characterizing the pavement is known. A three-dimensional semi-analytical model was implemented for simulating the pavement response near a joint and used for interpretation and verification of the experimental data. Results show that this development is promising for the use of a rolling wheel deflectometer for rapid evaluation of joints.

Three-dimensional analysis of soil – steel bridges

1995 ◽  
Vol 22 (6) ◽  
pp. 1155-1163 ◽  
Author(s):  
Youssef Girges ◽  
George Abdel-Sayed
Keyword(s):  
Plane Strain ◽  
Dimensional Analysis ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Middle Part ◽  
Steel Bridges ◽  
Steel Shell ◽  
Live Load ◽  
Two Dimensional ◽  
Element Analysis

The present design of soil–steel bridges is based on plane-strain analysis by considering a slice of a unit width of the conduit wall and the surrounding soil. This two-dimensional analysis neglects the third-dimensional effect of the steel shell and the soil continuum which could be significant especially when the load varies in the longitudinal direction, as in the case of live load acting over a shallow cover. The structure is also subjected to a varying dead load due to the variation in the depth of cover from maximum at the middle part of the conduit to zero at the conduit edges. A three-dimensional finite element analysis is presented in this paper to examine the actual three-dimensional behaviour of soil-steel bridges. The thrust and bending moment around the conduit walls as well as the stability of a single conduit are presented and compared with the results obtained from plane-strain analysis. Also, the live load dispersion in the soil above the conduit is examined and compared with some present codes. The study leads to evaluation of the degree of approximation inherited with the practical approaches of the two-dimensional analysis. Key words: conduit, corrugated steel, three-dimensional analysis, stability, soil–steel bridges.

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