scholarly journals Cracking of the End Diaphragm of a Post-tensioned Beam Bridge

2019 ◽  
Vol 60 (1) ◽  
pp. 89-104
Author(s):  
Mikko Kuusela ◽  
Olli Asp ◽  
Anssi Laaksonen
Keyword(s):  
Front Surface ◽  
Main Beam ◽  
Fe Model ◽  
Structural Behaviour ◽  
Field Surveys ◽  
Cracking Potential ◽  
Beam Bridge ◽  
Bridge Bearings ◽  
Cracking Tendency ◽  
Post Tensioned

Abstract In concrete beam bridges, the end diaphragm at the end of the bridge is a common structural component that connects the main beams and transfers the beam loads to the bridge bearings. In integral bridges the end diaphragm also retains the soil of embankments due to the absence of abutments. Cracking of the front surface on the end diaphragm has been detected in post-tensioned beam bridges in Finland and Sweden. Presumably the post-tensioning of the bridge and the shaping and detailing of the connection of the end diaphragm and main beam have an effect on cracking tendency. The aim of this study is to examine the structural behaviour and the cracking potential of end diaphragms using linear analysis of the post-tensioned bridge and to find measures to prevent the cracking. The observations collected through field surveys are compared to results of linear FE analysis to clarify the cause of the cracking. The verification of model is performed by comparison of patterns of cracking observed in field surveys and the distribution of maximum tensile stresses in the FE model. With model variations, the effectiveness of measures for the prevention of cracking are observed.

scholarly journals Analisis dan Perancangan Sistem Informasi Persediaan, Pembelian, dan Penjualan pada Toko Sinar Jaya

2010 ◽  
Vol 1 (2) ◽  
pp. 1073
Author(s):  
Wawan Saputra
Keyword(s):  
Information Systems ◽  
Business Processes ◽  
Main Beam ◽  
Analysis Method ◽  
Business Systems ◽  
Literature Study ◽  
Field Surveys ◽  
Analysis And Design ◽  
Object Oriented Design ◽  
Information Systems Strategy

Increased sales and business systems development is a main beam that moves Toko Sinar Jaya on sales of goods primary to secondary to achieving progress in its business. The purpose of this paper is to analyze the potential of information systems strategy implementation and also to develop information systems at Toko Sinar Jaya and to design an application system based on an analysis of existing systems. The research methodology used is the method of analysis and design methods, in which the analysis method used consisted of literature study method, field surveys, and interviews of business processes that are running, whereas in the method of design using object-oriented design and design analysis. Result to be achieved is to provide facilities such as applications that are useful for recording data inventory, purchasing, and sales for Toko Sinar Jaya. 

scholarly journals Finite Element Modeling of Post-Tensioned Two-Way Concrete Slabs under Flexural Loading

2018 ◽  
Vol 4 (1) ◽  
pp. 1 ◽  
Author(s):  
Abbas Haraj Mohammed ◽  
Khattab Saleem Abdul-Razzaq ◽  
Taha Khalid Mohammedali ◽  
Dia Eddin Nassani K. ◽  
Ali K. Hussein
Keyword(s):  
Finite Element ◽  
Failure Load ◽  
Concrete Slab ◽  
Analytical Investigation ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Element Analysis ◽  
Optimum Position ◽  
Post Tensioned

Post-Tensioned (PT) method is a widely used technique to prevent cracking and to minimize the deflection which is resulted by loads. In this method, stress is applied after concrete placing and reach adequate hardening and strength. This paper investigates the structural behaviour of PT two-way concrete slabs. The main objective of this study involves a detailed flexural behavior analytical investigation of PT concrete two-way slab with the different bonded tendon layout. This will be achieved by non-linear Finite Element (FE) analysis programs method, to choose the most effective and optimum position of tendon layout with different number of tendons and applied load on the concrete two-way slab. A parametric study was conducted to investigate the effect of tendons layout on the overall behavior of post-tensioned two-way concrete slab. The result obtained from finite element analysis showed that the failure load in PT in both directions increased about 89 % as compared with slab PT in one direction.

Experimental study of two-way post-tensioned flat slabs in fire

2018 ◽  
Vol 9 (3) ◽  
pp. 237-251 ◽  
Author(s):  
Li Zhang ◽  
Ya Wei ◽  
Francis Tat Kwong Au ◽  
Jing Li
Keyword(s):  
Design Methodology ◽  
Structural Integrity ◽  
Elevated Temperatures ◽  
Testing Temperature ◽  
Structural Behaviour ◽  
Content Type ◽  
Flat Slabs ◽  
Temperature Distributions ◽  
In Fire ◽  
Post Tensioned

Purpose This study aims to investigate the influence of tendon layout, pre-stressing force, bond condition and concrete spalling on the structural behaviour of two-way post-tensioned flat slabs at elevated temperatures. Design/methodology/approach Fire tests of four scale specimens of two-way post-tensioned concrete flat slabs were performed and analysed. Three of them were provided with bonded tendons, while the other was unbonded for comparison. The fabrication of specimens, phenomena observed during testing, temperature distributions, deflections and occurrence of concrete spalling were examined. Findings Different degrees of concrete spalling observed at the soffit had significant effects on the temperature distribution and stress redistribution. This was the major reason for the progressive concrete spalling observed, resulting in loss of structural integrity and stiffness. Originality/value The structural behaviour of two-way post-tensioned concrete flat slabs at elevated temperatures is less understood compared to their one-way counterparts. Therefore, the present study has focused on the structural behaviour of two-way post-tensioned concrete flat slabs with bonded tendons in fire, a field in which relatively little information on experimental work can be found.

scholarly journals Dynamic Response of Cable-Supported Façades Subjected to High-Level Air Blast Loads: Numerical Simulations and Mitigation Techniques

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Claudio Amadio ◽  
Chiara Bedon
Keyword(s):  
Fe Model ◽  
Blast Loads ◽  
Structural Effects ◽  
Structural Behaviour ◽  
Dynamic Simulations ◽  
Axial Forces ◽  
Glass Panels ◽  
Nonlinear Dynamic Analyses ◽  
High Level ◽  
The Impact

A glazing façade subjected to blast loads has a structural behaviour that strongly differs from the typical response of a glazing system subjected to ordinary loads. Consequently, sophisticated modelling techniques are required to identify correctly its criticalities. The paper investigates the behaviour of a cable-supported façade subjected to high-level blast loading. Nonlinear dynamic analyses are performed in ABAQUS/Explicit using a sophisticated FE-model (M01), calibrated to dynamic experimental and numerical results. The structural effects of the total design blast impulse, as well as only its positive phase, are analyzed. At the same time, the possible cracking of glass panels is taken into account, since this phenomenon could modify the response of the entire façade. Finally, deep investigations are dedicated to the bearing cables, since subjecting them to elevated axial forces and their collapse could compromise the integrity of the cladding wall. Based on results of previous studies, frictional devices differently applied at their ends are presented to improve the response of the façade under the impact of a high-level explosion. Structural effects of various solutions are highlighted through dynamic simulations. Single vertical devices, if appropriately calibrated, allow reducing significantly the axial forces in cables, and lightly the tensile stresses in glass panes.

scholarly journals Numerical Investigation on the Influence of Web Opening on the Structural Behaviour of RC Deep Beams

2019 ◽  
Vol 12 (3) ◽  
Author(s):  
Abdulnasser Mohammed Abbas
Keyword(s):  
Computer Network ◽  
Three Dimensional ◽  
Element Model ◽  
Fe Model ◽  
Deep Beam ◽  
Structural Behaviour ◽  
Deep Beams ◽  
Dimensional Finite Element ◽  
Reinforcement Model ◽  
Three Dimensional Finite Element

Nowadays, the deep beams become utilized more in a considerable number of structures. It is necessary sometimes to introduce a hole within the web of the beam as a pipe or a duct for many purposes such as water supply, sewage, electricity, air conditioning, and computer network. In this study, a deep beam sample taken from a past experimental study is numerically analysed using a three-dimensional finite element model. ABAQUS tools are used to simulate the whole FE models.  The dimensions of the considered deep beam are 820x400x180 mm, with two openings of a diameter 90 mm located at 200 mm from both of the ends. The proposed model and the experimental work have reasonably agreed with a difference of 2 % in mid-span deflection. Furthermore, special reinforcements of 12 mm bar diameter are offered to the original FE model around the holes in two types, Z-shape and circular, to improve the structural behaviour of the deep beam and to minimize the crack concentrations in these zones. The gained results show that the additional reinforcement minimizes the mid-span deflection of the deep beam. As compared with the original proposed FE model, the Z-shape decreases the deflection by 44.9 % while the lowering in the defection of the circular shape is 9.4 %. Moreover, the concentration of stresses and cracks that gained from using the Z-shape reinforcement model found to be lower than those induced in the circular reinforcement model.

Structural Health Monitoring of a Historical Masonry Bell Tower Using Operational Modal Analysis

2017 ◽  
Vol 747 ◽  
pp. 440-447 ◽  
Author(s):  
Elisa Bassoli ◽  
Marianna Forghieri ◽  
Loris Vincenzi ◽  
Marco Bovo ◽  
Claudio Mazzotti
Keyword(s):  
Modal Analysis ◽  
Monitoring System ◽  
Structural Response ◽  
Operational Modal Analysis ◽  
Evolutionary Strategy ◽  
Fe Model ◽  
Structural Behaviour ◽  
Structural Health ◽  
Bell Tower ◽  
Historical Masonry

This paper addresses the modal and structural identification of the historical masonry bell tower of Ficarolo, in Italy. After the seismic sequence of May 2012, the tower reported a serious damage pattern. Retrofitting interventions were designed and they mainly consisted in the rebuilding of cracked zones and the strengthening of masonry walls with carbon bars embedded in the masonry with epoxy resin. Afterwards, a continuous dynamic monitoring system has been installed on the tower. From the recorded structural response under ambient excitation, the dynamic characteristics of the tower are identified using Operational Modal Analysis techniques. Results of the first months of continuous monitoring are presented in this paper. Moreover, in order to analyse the evolution of the structural behaviour, the effect of changing temperature on the identified natural frequencies is investigated. The experimental modal parameters are also used to identify the elastic modulus of the reinforced masonry through the calibration of a Finite Element (FE) model of the tower. In addition, the influence of the soil-foundation system on the structural behaviour is evaluated. The calibration procedure is performed adopting an improved surrogate-assisted evolutionary strategy. The calibrated FE model can be adopted to simulate the structural response to far-field earthquakes. Moreover, the monitoring system can give valuable information on the structural behaviour and the structural health in the case of seismic events.

Application of Flexibility Method to a Chain Suspension Stiffening Beam Bridge

2011 ◽  
Vol 255-260 ◽  
pp. 1220-1224
Author(s):  
Wen Jie Niu ◽  
Zhen Yu Wang
Keyword(s):  
Suspension Bridge ◽  
Main Beam ◽  
Live Load ◽  
Structural Members ◽  
Equilibrium Equations ◽  
Actual Structure ◽  
Influence Line ◽  
A Chain ◽  
Beam Bridge ◽  
Main Bridge

This paper intended to determine the influence line for structural members in a Chain Suspension Stiffening Beam Bridge (CSSBB). In an engineering case, flexibility method determined the redundant bar force in CSSBB as the unit live load stayed at different positions on the main bridge beam. These calculated redundant bar forces composed the influence line. The foregoing flexibility method considers suspenders deformation. Results indicate that redundant bar force is maximal when the unit live load stays at the main beam midpoint in Figure 2. The redundant bar force in Figure 3 is the actual force in bar 3 in the actual structure in Figure 2. The redundant bar forces and internal load equilibrium equations can determine the influence lines for other structural members. Simple-supported Beam Bridge (SSBB) can be constructed easily while and wire (cable) suspension bridge are suitable when the bridge is to cross a wide river. CSSBB and arch bridge demonstrates less deflection and less moment at the beam midpoint than the SSBB.

scholarly journals Drying Shrinkage and Cracking Tendency of Concrete Pavement Mixtures with Variable Packing Densities of Aggregates and Paste Contents

2020 ◽  
Vol 322 ◽  
pp. 01045
Author(s):  
Jan Olek ◽  
Adam Rudy
Keyword(s):  
Packing Density ◽  
Drying Shrinkage ◽  
Concrete Pavement ◽  
Concrete Mixture ◽  
Concrete Pavements ◽  
Saturation Ratio ◽  
Cracking Potential ◽  
Paste Content ◽  
Cracking Tendency ◽  
Packing Densities

Excessive drying shrinkage, and associated cracking, can lead to serious durability problem in concrete pavements and bridges. In the course of this study, the magnitude of drying shrinkage and cracking potential was evaluated for several concrete pavement mixtures as a function of packing density of the aggregate and paste contents. The results indicated that both, the shrinkage and the cracking potential depend on the volume of voids between aggregate particles (packing density), paste content of concrete mixture, and the paste-aggregate void saturation ratio.

Sign in / Sign up

Export Citation Format

Share Document