Experimental Studies on Bearing Capacity of Post-Tensioned Unbonded Prestressed Concrete Hollowed Floors

2011 ◽  
Vol 368-373 ◽  
pp. 159-163 ◽  
Author(s):  
Xiao Hua Yang ◽  
Chao Yang Zhou ◽  
Xue Jun He ◽  
Zhi Qing Yang
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Plastic Hinge ◽  
Experimental Studies ◽  
Load Test ◽  
Test Results ◽  
Three Stages ◽  
Hinge Model ◽  
Good Agreement ◽  
Post Tensioned

A 1/4 scales four-storey model of post-tensioned unbonded prestressed concrete hollow slab-column structure has been made to do the ultimate load test on the second-storey floor. By measuring the floor deflection, stresses of steel bars and cracks of floors, the bearing capacity of floor is explored. The bearing capacity tests of floor are divided into three stages: elastic stage, crack growth stage and destruction stage. Based on the test results and crack developments in floor, a improved plastic hinge model is carried out to predict the ultimate loads. The calculated results of the ultimate loads with improved plastic hinge model are in good agreement with the experiment data.

Research on Post-Tensioned Unbonded Prestressed Concrete Hollowed Floor

2011 ◽  
Vol 94-96 ◽  
pp. 1456-1462
Author(s):  
Xiao Hua Yang ◽  
Chao Yang Zhou ◽  
Xue Jun He ◽  
Teng Chen
Keyword(s):  
Prestressed Concrete ◽  
Experimental Studies ◽  
Load Carrying Capacity ◽  
Structure Model ◽  
Test Results ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Direction Parallel ◽  
Load Carrying ◽  
Post Tensioned

In order to study the mechanical behaviors of post-tensioned unbonded prestressed concrete hollowed floors, a 1/4 scale post-tensioned unbonded prestressed reinforced concrete hollow slab-column structure model is used to act uniform distributed load on the floor. The test results showed that the load carrying capacity is enough. The points of maximum displacement are at the centers of slabs. By means of the experimental studies and elastic finite element analysis methods, the results showed that post-tensioned unbonded prestressed concrete hollowed floor presents anisotropy with layout of circular-tubes in one way. In direction parallel to layout of hollowed tubes, the continuity of floor is destruction and bending stiffness of slab is weakened. For studying the deformations of slab, it can still be considered continuous cross-slab in two directions.

scholarly journals Prediction of Effects of Geogrid Reinforced Granular Fill on the Behaviour of Static Liquefaction

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
A. Hemalatha ◽  
N. Mahendran ◽  
G. Ganesh Prabhu
Keyword(s):  
Bearing Capacity ◽  
Load Test ◽  
Test Results ◽  
Plate Load Test ◽  
Large Size ◽  
Static Liquefaction ◽  
Granular Fill ◽  
Size Dimension ◽  
Subgrade Modulus ◽  
Different Thickness

The experimental investigation on the effects of granular fill and geogrid reinforced granular fill on the behaviour of the static liquefaction potential of the subsoil is reported in this study. A series of plate load test were carried out with different thickness of the granular fill, number of geogrid layers, and size/dimension of the footing. The test results were presented in terms of bearing capacity and subgrade modulus for the settlement ofδ10,δ15, andδ20. The experimental results revealed that the introduction of granular fill significantly increases the bearing capacity and effectively control the settlement behaviour of the footing. The introduction of geogrid in granular fill enhanced the Percentage of Control in Settlement and Bearing Capacity Ratio by a maximum of 328.54% and 203.41%, respectively. The introduction of geogrid in granular fill interrupts the failure zone of the granular fill and enhances the subgrade modulus of the footing by a maximum of 255.55%; in addition subgrade modulus of the footing was increased with an increase in the number of geogrid layers. Based on the test results it is suggested that the footing with large size has beneficial improvement on the reinforced granular fill.

Load Test Analysis of Long-Span Prestressed Concrete Continuous Beam Bridge

2014 ◽  
Vol 1030-1032 ◽  
pp. 798-801
Author(s):  
Hua Su
Keyword(s):  
Bearing Capacity ◽  
Prestressed Concrete ◽  
Highway Bridges ◽  
Load Test ◽  
Beam Model ◽  
Test Analysis ◽  
Single Beam ◽  
Long Span ◽  
Continuous Beam Bridge ◽  
Girder Bridge

This paper takes a 45+60+45m prestressed concrete continuous box Girder Bridge as background, based on “Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridges” (JTG/T J21-2011), single beam model and solid model are built for schematic design of load test. Compare the measured value and the theoretical value, and evaluate the bridge bearing capacity, finally provide technical base for project checking and accepting.

Bearing capacity of strip footings on sand over clay

2019 ◽  
Vol 56 (5) ◽  
pp. 699-709 ◽  
Author(s):  
Seyednima Salimi Eshkevari ◽  
Andrew J. Abbo ◽  
George Kouretzis
Keyword(s):  
Bearing Capacity ◽  
Finite Thickness ◽  
Experimental Studies ◽  
Shallow Foundations ◽  
Sand Layer ◽  
Test Results ◽  
Capacity Model ◽  
Proposed Model ◽  
Undrained Strength ◽  
Strip Footings

Estimation of the bearing capacity of shallow foundations on layered soil profiles, such as a sand layer of finite thickness over clay, is mainly based on empirical models resulting from the interpretation of experimental test results. While it is generally accepted that such models may be applicable to soil properties and footing geometries outside the range tested experimentally, they offer limited insights on how the assumed failure mechanism affects their range of application. In particular, the contribution of the sand layer to the overall capacity is accounted for via simple considerations, which are valid only for a specific range of problem parameters. This paper addresses the estimation of the undrained bearing capacity of a rigid strip footing resting on the surface of a sand layer of finite thickness overlying clay, using finite element limit analysis (FELA). The rigorous upper and lower bound theorems of plasticity are employed to bracket the true bearing capacity of the footing, and identify the geometry of possible failure mechanisms. Insights gained from FELA simulations are used to develop a new simple bearing capacity model, which captures the variation in shear resistance from the sand layer with the dimensionless undrained strength of the clay layer. The proposed model provides results that are in close agreement with published experimental studies, and allows treating simple problems, such as the design of working platforms, without having to resort to numerical simulations.

The Bearing Capacity of Rigid Piles Under Inclined Loads in Sand. II: Batter Piles

1973 ◽  
Vol 10 (1) ◽  
pp. 71-85 ◽  
Author(s):  
G. G. Meyerhof ◽  
Gopal Ranjan
Keyword(s):  
Bearing Capacity ◽  
Previous Investigation ◽  
Test Results ◽  
Inclined Load ◽  
Inclined Loads ◽  
Loading Tests ◽  
Batter Piles ◽  
Laterally Loaded ◽  
Ultimate Resistance ◽  
Good Agreement

Following the previous investigation reported in the first part on vertical piles, this second part of the paper presents an analysis of the results of loading tests on rigid batter piles under inclined load in sand. The bearing capacity of axially loaded batter piles is discussed by comparing experimental results and theoretical estimates. The theory for ultimate resistance of rigid vertical piles under horizontal loads is extended to that of laterally loaded batter piles. Model test results are compared with those of theoretical estimates and good agreement is found. Methods of analysis of vertical piles under inclined loads are extended to those of rigid batter piles under inclined loads in sand and the analysis is compared with some test results.

Estimation of Ultimate Tendon Stress in Reinforced Concrete Beams Prestressed with External FRP Tendons

2013 ◽  
Vol 798-799 ◽  
pp. 374-377
Author(s):  
Shuan Jiang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Plastic Hinge ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Test Results ◽  
Stress Increment ◽  
Hinge Zone ◽  
Good Agreement

The ultimate tendon stress is the key to calculation of flexural capacity in reinforced concrete beam prestressed with external FRP tendons (RCBPEFT). Based on the theory of equivalent plastic hinge zone, the general formulas for calculating the ultimate tendon stress increment and ultimate tendon stress in RCBPEFT are therefore proposed. Comparisons indicate that the predictions are in good agreement with the test results.

scholarly journals The Bearing Capacity of Circular Footings in Sand: Comparison between Model Tests and Numerical Simulations Based on a Nonlinear Mohr Failure Envelope

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Sven Krabbenhoft ◽  
Johan Clausen ◽  
Lars Damkilde
Keyword(s):  
Bearing Capacity ◽  
Yield Criterion ◽  
Friction Angle ◽  
Triaxial Tests ◽  
Test Results ◽  
Finite Element Program ◽  
Model Foundation ◽  
Element Program ◽  
Confining Pressures ◽  
Good Agreement

This paper presents the results of a series of triaxial tests with dry sand at confining pressures varying from 1.5 kPa to 100 kPa at relative densities of 0.20, 0.59, and 0.84. The results, which are in reasonable accordance with an equation given by Bolton, show that the friction angle is strongly dependent on the stress level and on the basis of the test results, a nonlinear Mohr failure criterion has been proposed. This yield criterion has been implemented in a finite element program and an analysis of the bearing capacity of a circular shaped model foundation, diameter 100 mm, has been conducted. Comparisons have been made with results from 1g model scale tests with a foundation of similar size and a good agreement between numerical results and test results has been found.

scholarly journals Indirect Determination of Residual Prestressing Force in Post-Tensioned Concrete Beam

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1338
Author(s):  
Jakub Kraľovanec ◽  
Martin Moravčík ◽  
Petra Bujňáková ◽  
Jozef Jošt
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beam ◽  
Load Test ◽  
Material Behavior ◽  
Nonlinear Material ◽  
Significant Deterioration ◽  
Indirect Determination ◽  
Prestressing Force ◽  
Post Tensioned

A diagnostic survey on the precast prestressed bridge Nižná confirmed significant deterioration due to environmental distress. Evidently, decisive failures of the structure have a similar character as in the previous precast prestressed bridge in Podbiel in the northern part of Slovakia. These failures result from the unsuitable concept of the first generation of precast prestressed concrete beams, which was used in the former Czechoslovakia in the second half of the 20th century. Subsequently, experimental verification using the proof-load test was also executed. This bridge was built in 1956, so at the time of testing, it was 60 years old. The paper presents the indirect determination of prestressing level in one precast post-tensioned concrete beam using the saw-cut method. Experimental measurement was executed during the bridge demolition. Subsequently, a 2D numerical model in ATENA 2D Software, with the assumption of nonlinear material behavior for verification of experimental results, was performed. Finally, the residual prestressing force was evaluated and compared with the expected state of prestressing according to Eurocodes after 60 years of service.

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