scholarly journals Deformation of Overlong Isolated Buildings Caused by Thermal and Concrete Shrinkage

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yu Dang ◽  
Ying-ke Liu
Keyword(s):  
Thermal Strain ◽  
Thermal Action ◽  
Thermal Design ◽  
Reinforced Concrete Frame ◽  
Distribution Method ◽  
Temperature Variations ◽  
Concrete Frame ◽  
Concrete Shrinkage ◽  
Theoretical Predictions ◽  
Stress And Deformation

Temperature variations and concrete shrinkage influence structural behavior by reducing the strength of materials and changing their thermal strain contributions. This problem is particularly important for isolated buildings that are characterized by large horizontal dimensions and are sensitive to thermal action and shrinkage. In this study, the measurement of an overlong isolated building shows that the deformations of some isolators exceed the allowed deviation during the construction phase because the building is completely exposed. These deformations are induced by climatic thermal changes and shrinkage effects and cause the complex dynamic behavior and instability of the structure. To ensure the safety of overlong isolated buildings, the structural stress and deformation caused by temperature variations and shrinkage effects are studied. A three-story frame model is developed, and the rule of deformation within isolated frame buildings is analyzed by the deformation distribution method. The theoretical predictions are consistent with the experimental measurements. Therefore, the theoretical model is used to predict the deformation of isolated buildings caused by temperature variations and shrinkage effects. For reinforced concrete frame isolated buildings, expansion joint distances are proposed according to different thermal design regions and heating design conditions.

scholarly journals The Thermal Response of Concrete Frame Buildings in Arabic Area Considering Time Dependent Properties of Concrete

2019 ◽  
Vol 8 (3) ◽  
pp. 7329-7335
Keyword(s):  
Reinforced Concrete ◽  
Thermal Design ◽  
Time Dependent ◽  
Column Height ◽  
Slab Thickness ◽  
Clear Understanding ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Concrete Properties ◽  
Frame Buildings

The Arabic area is known for its high temperatures especially during the summer period. It affects the structural displacements and stresses in concrete elements. The main objectives of this paper are to study the effects of thermal loads on the response of super-long reinforced concrete frame buildings in the Arabic area and regions with similar temperature variation patterns, accounting for various design aspects considering both methodologies of time dependent properties of concrete as per CEB FIP 90 code and non-time dependent properties as per ACI 224.3R. To achieve these objectives a total of 272 one story reinforced concrete frame buildings are numerically modelled and analyzed using the finite element procedures of ETABS. The models are divided into two different groups. The first group is with columns fixed supports, the second group is with columns hinged supports. Each group is analyzed twice: once with time dependent concrete properties, and another with non-time dependent concrete properties. The study findings are utilized to develop a clear understanding about mentioned variables effects at thermal deformations and columns reactions to aid structural engineers in the thermal design of super-long buildings with similar conditions of this study within time. The horizontal deformations values increase proportionally with the increase of slab length and column height. The horizontal reactions increase proportionally with the increase of slab length and slab thickness values. Fixed columns horizontal reactions are more than horizontal reactions related to hinged columns conditions while column height is inversely proportional with the lateral reaction’s values. Time dependent properties deformations and reactions ratios are around 160% the non-time dependent properties result for all cases. Ignoring this difference imposes defects, additional cracks and damages at the structures and related serviceability conditions for 70 years period.

Mechanical Simulation of Reinforced Concrete Frame Structure

2012 ◽  
Vol 256-259 ◽  
pp. 689-692
Author(s):  
Hui Na Jia ◽  
Gao Wei Yue
Keyword(s):  
Reinforced Concrete ◽  
Constant Load ◽  
Frame Structure ◽  
Reinforced Concrete Frame ◽  
Element Analysis ◽  
Concrete Frame ◽  
The Finite Element Analysis ◽  
Reinforced Concrete Frame Structure ◽  
Calculation Results ◽  
Stress And Deformation

In this paper the theoretical model of reinforced concrete frame structure is established to numerically simulate and analyze its overall morphology with the finite element analysis method. The calculation results shows that at the bottom of the structure the stress and deformation is much larger than other parts with the action of constant load, live load and wind load. And with modal analysis and buckling analysis natural frequency and vibration mode are obtained to avoid resonance and predict the buckling load.

Research on Temperature Stress of Annular Super-Long Frame Structure by Finite Element Method

2013 ◽  
Vol 639-640 ◽  
pp. 1200-1205 ◽  
Author(s):  
Zhi Yong Yang ◽  
Liang Zhao ◽  
Peng Zhang ◽  
Yu Xiang Xing
Keyword(s):  
Temperature Effect ◽  
Temperature Stress ◽  
Temperature Effects ◽  
Frame Structure ◽  
Expansion Joint ◽  
Reinforced Concrete Frame ◽  
Concrete Frame ◽  
Concrete Shrinkage ◽  
Temperature Load ◽  
Apparent Influence

The temperature stress calculation of multi-storey structure is very complicated. Many researches have been taken for the frame structures with rectangular plane, but very few references about annular plane. Based on the ANSYS program, the structure temperature effect of a multi-storey reinforced concrete frame which plane shaped like the elliptic is analyzed in this paper. The overall temperature load and concrete shrinkage equivalent temperature are considered in the analysis. The results reflect that curvature has an apparent influence on the temperature stress of annular super-long structure. Besides, the structure temperature effects are studied on both cases of the structure with expansion joint and without it, which shows that reasonable installation of expansion joint can decrease the temperature stress of annular structure. The influence of structure member rigidity on temperature effect is also discussed by changing the size of the section; all of these could offer reference for engineering design.

scholarly journals Numerical Investigation of Innovative Support Frame of Openings in the Segmental Tunnel Lining

2020 ◽  
Vol 14 (1) ◽  
pp. 358-369
Author(s):  
Sanaz Ebrahimi ◽  
Mir Raouf Hadei ◽  
Alireza Rashiddel ◽  
Mohsen Hajihassani
Keyword(s):  
Support System ◽  
Steel Structures ◽  
Steel Frame ◽  
Concrete Lining ◽  
Reinforced Concrete Frame ◽  
Maximum Displacement ◽  
Segmental Lining ◽  
Concrete Frame ◽  
Temporary Support ◽  
Stress And Deformation

Introduction: To supply safety in the tunnels, it is necessary to construct escape routes and emergency exits that are performed by locating cross passages. Methods: These passages connect two tunnels transversely and apply escape routes. Using temporary steel structures to supply the ring stability in practice and reinforced concrete frame to stabilize the ring permanently can be appropriate to form a solid frame that transfers the opened ring's load to the opening surroundings. In this paper, a 3D finite element simulation was performed to analyze the influence of opening construction in the segmental concrete lining and a temporary support system. Using the simulation, stress and deformation distribution of the steel frame, bolts, and segmental lining were obtained. Results: The results show that by increasing the number of bolts from 18 to 30, the induced stress in the steel frame and bolts decreased to 76 and 59 percent, respectively. In addition, the maximum displacement in the segmental lining and the maximum opening value of the joints decline to 62.7 and 75 percent, respectively. Conclusion: Finally, it can be concluded that the steel frame can be used as a temporary support system.

scholarly journals Shear Behavior of a Reinforced Concrete Frame Retrofitted with a Hinged Steel Damping System

2020 ◽  
Vol 12 (24) ◽  
pp. 10360
Author(s):  
Hyun-Do Yun ◽  
Sun-Woong Kim ◽  
Wan-Shin Park ◽  
Sun-Woo Kim
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Seismic Retrofitting ◽  
Reinforced Concrete Frame ◽  
Main Research ◽  
Torsion Spring ◽  
Concrete Frame ◽  
Energy Dissipation Capacity ◽  
Research Questions ◽  
Torsion Springs

The purpose of this study was to experimentally evaluate the effect of a hinged steel damping system on the shear behavior of a nonductile reinforced concrete frame with an opening. For the experimental test, a total of three full-scale reinforced concrete frame specimens were planned, based on the “no retrofitting” (NR) specimens with non-seismic details. The main research questions were whether the hinged steel damping system is reinforced and whether torsion springs are installed in the hinged steel damping system. From the results of the experiment, the hinged steel damping system (DR specimen) was found to be effective in seismic retrofitting, while isolating the opening of the reinforced concrete (RC) frame, and the torsion spring installed at the hinged connection (DSR specimen) was evaluated to be effective in controlling the amount of deformation of the upper and lower dampers. The strength, stiffness, and energy dissipation capacity of the DSR specimen were slightly improved compared to the DR specimen, and it was confirmed that stress redistribution was induced by the rotational stiffness of the torsion spring installed in the hinge connection between the upper and lower frames.

scholarly journals Challenges in Evaluating Seismic Collapse Risk for RC Buildings

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Jin Zhou ◽  
Zhelun Zhang ◽  
Tessa Williams ◽  
Sashi K. Kunnath
Keyword(s):  
Ground Motion ◽  
Seismic Vulnerability ◽  
Ground Motions ◽  
Primary System ◽  
Fragility Functions ◽  
Reinforced Concrete Frame ◽  
Ground Motion Selection ◽  
Concrete Frame ◽  
Frame Building ◽  
Seismic Collapse

AbstractThe development of fragility functions that express the probability of collapse of a building as a function of some ground motion intensity measure is an effective tool to assess seismic vulnerability of structures. However, a number of factors ranging from ground motion selection to modeling decisions can influence the quantification of collapse probability. A methodical investigation was carried out to examine the effects of component modeling and ground motion selection in establishing demand and collapse risk of a typical reinforced concrete frame building. The primary system considered in this study is a modern 6-story RC moment frame building that was designed to current code provisions in a seismically active region. Both concentrated and distributed plasticity beam–column elements were used to model the building frame and several options were considered in constitutive modeling for both options. Incremental dynamic analyses (IDA) were carried out using two suites of ground motions—the first set comprised site-dependent ground motions, while the second set was a compilation of hazard-consistent motions using the conditional scenario spectra approach. Findings from the study highlight the influence of modeling decisions and ground motion selection in the development of seismic collapse fragility functions and the characterization of risk for various demand levels.

scholarly journals Rational Choice of Reinforcement of Reinforced Concrete Frame Corners Subjected to Opening Bending Moment

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3438
Author(s):  
Michał Szczecina ◽  
Andrzej Winnicki
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Plasticity Model ◽  
Reinforced Concrete Frame ◽  
Moment Frame ◽  
Concrete Frame ◽  
Rational Reinforcement ◽  
Eurocode 2 ◽  
Analysis Of Results

This paper discusses a choice of the most rational reinforcement details for frame corners subjected to opening bending moment. Frame corners formed from elements of both the same and different cross section heights are considered. The case of corners formed of elements of different cross section is not considered in Eurocode 2 and is very rarely described in handbooks. Several reinforcement details with both the same and different cross section heights are presented. The authors introduce a new reinforcement detail for the different cross section heights. The considered details are comprised of the primary reinforcement in the form of straight bars and loops and the additional reinforcement in the form of diagonal bars or stirrups or a combination of both diagonal stirrups and bars. Two methods of static analysis, strut-and-tie method (S&T) and finite element method (FEM), are used in the research. FEM calculations are performed with Abaqus software using the Concrete Damaged Plasticity model (CDP) for concrete and the classical metal plasticity model for reinforcing steel. The crucial CDP parameters, relaxation time and dilatation angle, were calibrated in numerical tests in Abaqus. The analysis of results from the S&T and FE methods allowed for the determination of the most rational reinforcement details.

Deformation Characteristics of Reinforced Concrete Beam-Column Joint Cores under Earthquake Loading

2003 ◽  
Vol 6 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Sayed A. Attaalla ◽  
Mehran Agbabian
Keyword(s):  
Reinforced Concrete ◽  
Shear Deformation ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Frame ◽  
Bond Failure ◽  
Strain Compatibility ◽  
Concrete Frame ◽  
Column Joint ◽  
Reinforced Concrete Frame Structures

The characteristics of the shear deformation inside the beam-column joint core of reinforced concrete frame structures subjected to seismic loading are discussed in this paper. The paper presents the formulation of an analytical model based on experimental observations. The model is intended to predict the expansions of beam-column joint core in the horizontal and vertical directions. The model describes the strain compatibility inside the joint in an average sense. Its predictions are verified utilizing experimental measurements obtained from tests conducted on beam-column connections. The model is found to adequately predict the components of shear deformation in the joint core and satisfactorily estimates the average strains in the joint hoops up to bond failure. The model may be considered as a simple, yet, important step towards analytical understanding of the sophisticated shear mechanism inside the joint and may be implemented in a controlled-deformation design technique of the joint.

Resistance of Reinforced Concrete Frames with Masonry Infill Walls to In-Plane Vertical Loading

2016 ◽  
Vol 711 ◽  
pp. 982-988
Author(s):  
Alex Brodsky ◽  
David Z. Yankelevsky
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Progressive Collapse ◽  
Lateral Loading ◽  
Masonry Walls ◽  
Reinforced Concrete Frame ◽  
Masonry Infill ◽  
Concrete Frame ◽  
Vertical Loading ◽  
Infill Masonry

Numerous studies have been conducted on the in plane behavior of masonry infill walls to lateral loading simulating earthquake action on buildings. The present study is focused on a problem that has almost not been studied regarding the vertical (opposed to lateral) in-plane action on these walls. This may be of concern when a supporting column of a multi-storey reinforced concrete frame with infill masonry walls undergoes a severe damage due to an extreme loading such as a strong earthquake, car impact or military or terror action in proximity to the column. The loss of the supporting column may cause a fully or partly progressive collapse to a bare reinforced concrete frame, without infill masonry walls. The presence of the infill masonry walls may restrain the process and prevent the development of a progressive collapse. The aim of the present study is to test the in-plane composite action of Reinforced Concrete (RC) frames with infill masonry walls under vertical loading through laboratory experiments and evaluate the contributions of infill masonry walls, in an attempt to examine the infill masonry wall added resistance to the bare frame under these circumstances. Preliminary results of laboratory tests that have been conducted on reinforced concrete infilled frames without a support at their end, under monotonic vertical loading along that column axis will be presented. The observed damages and failure modes under vertical loading are clearly different from the already known failure modes observed in the case of lateral loading.

Sign in / Sign up

Export Citation Format

Share Document