scholarly journals Influence of Infill Wall Configuration on Failure Modes of RC Frames

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xiaojie Zhou ◽  
Xiaoyuan Kou ◽  
Quanmin Peng ◽  
Jintao Cui
Keyword(s):  
Bearing Capacity ◽  
Rc Frame ◽  
Infill Wall ◽  
Bearing Capacity Ratio ◽  
Short Column ◽  
Shear Span ◽  
Capacity Ratio ◽  
Rc Frames ◽  
Shear Bearing Capacity ◽  
Lateral Constraint

An improper configuration of masonry infill walls in RC frame may lead to short column effect on the columns, which is harmful to the seismic behavior of the structure. In this study, a bare frame and two single-story, single-bay RC frames, partially infilled with masonry, were tested under cyclic loading. The failure mechanism and seismic performance of these partially infilled RC frames (with an infill height of 600 mm) with different types of connections were analysed. Based on the experiment, nonlinear finite element simulation and analysis were conducted to study the effects of the infill walls and connections. The results show that both mechanical performance and failure mode are affected by the infill height, the type of connection between the frame and the infill, and the ratio of shear bearing capacity of the frame column to that of the infill. For the masonry-infilled frame with rigid connection, the higher the infill wall is, the lower the shear bearing capacity ratio will be. Thus, the effect of the lateral constraint of the infill wall on the column increases, and the shear span ratio of the free segment of the column decreases, resulting in the short column effect. Based on the analysis results, a value of 2.0 is suggested for the critical shear bearing capacity ratio of the frame column to the infill wall. If the shear bearing capacity ratio is less than 2.0 and the shear span ratio of the column free segment is not more than 2.0, the short column effect will occur. For the infilled frame with flexible connection, both the lateral constraint from the wall to the column and the wall-frame interaction decrease; this reduces or prevents the short column effect. The conclusion can present guidance for the design and construction of masonry-infilled RC frame structure.

scholarly journals Behaviour of eccentrically inclined loaded rectangular foundation on reinforced sand

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sujata Gupta ◽  
Anupam Mital
Keyword(s):  
Bearing Capacity ◽  
Loading Conditions ◽  
Test Results ◽  
Bearing Capacity Ratio ◽  
Reinforced Sand ◽  
The Core ◽  
Capacity Ratio ◽  
Core Boundary ◽  
Rectangular Foundation ◽  
Increasing Load

Abstract This study presents the behaviour of model footing resting over unreinforced and reinforced sand bed under different loading conditions carried out experimentally. The parameters investigated in this study includes the number of reinforced layers (N = 0, 1, 2, 3, 4), embedment ratio (Df /B = 0, 0.5, 1.0), eccentric and inclined ratio (e/L, e/B = 0, 0.05, 0.10, 0.15) and (a = 0°, 7°, 14°). The test sand was reinforced with bi-axial geogrid (Bx20/20). The test results show that the ultimate bearing capacities decrease with axial eccentricity and inclination of applied loads. The test results also show that the depth of model footing increase zero to B (B = width of model footing), an increase of ultimate bearing capacity (UBC) approximated at 93%. Similarly, the multi-layered geogrid reinforced sand (N = 0 to 4) increases the UBC by about 75%. The bearing capacity ratio (BCR) of the model footing increases with an increasing load eccentricity to the core boundary of footing; if the load eccentricities increase continuity, the BCR decreases. The tilt of the model footing is increased by increasing the eccentricity and decreases with increasing the number of reinforcing layers.

Cyclic Performance of Two-Story Ductile RC Frames With Infill Walls

2005 ◽  
Author(s):  
Yung-Hsin Yeh ◽  
Wen-I Liao
Keyword(s):  
Model Building ◽  
General Purpose ◽  
Rc Frame ◽  
Building Structures ◽  
Base Shear ◽  
Concrete Frames ◽  
Infill Wall ◽  
Infill Walls ◽  
Rc Frames ◽  
Short Beam

This paper presents the results of the experimental and analytical investigations conducted on four 0.8 scale 2-story one bay ductile reinforced concrete frames with infill nonstructural walls subjected to cyclically increasing loads. The material properties and the member sizes of beams and columns in the four RC frame specimens are identical, but with different types of infill nonstructural wall. These four frames are the pure frame, frame with short column, frame with short beam and frame with wing walls. The four RC frame specimens were designed and constructed according to the general prototype building structures in Taiwan. Test results indicate that the ductility behavior of the frames with infill wall is similar to those of the pure frame. The ultimate base shear strength of the frames with infill walls is higher than those of the pure frame. Analytical results show that the proposed simplified multi-linear beam-column element implemented in a general purpose structural analysis program can accurately simulate the cyclic responses of the RC frame specimen incorporating the elastic flexural stiffness computations suggested by the model building codes.

PERBAIKAN TANAH LEMPUNG BERLANAU MENGGUNAKAN KOMBINASI PERKUATAN ANYAMAN BAMBU DAN GRID BAMBU

2019 ◽  
Vol 18 (1) ◽  
pp. 67-79
Author(s):  
Aef Saefudin ◽  
Sri Wulandari
Keyword(s):  
Bearing Capacity ◽  
Bearing Capacity Ratio ◽  
Capacity Ratio

Berbagai metode perbaikan tanah telah banyak dikembangkan, salah satunya dengan perkuatan tanah sebagai alternatif pemecahan masalah terhadap daya dukung tanah yang rendah dan besarnya penurunan. Dalam penelitian ini, anyaman bambu dan grid bambu digunakan sebagai material perkuatan yang diharapkan dapat menjadi alternatif material perkuatan untuk meningkatkan daya dukung tanah lempung dengan variasi kedalaman perkuatan, jarak grid dan spasi lapis perkuatan. Tujuan dari penelitian ini adalah untuk mengetahui peningkatan daya dukung dari setiap variasi dengan nilai daya dukung tanpa perkuatan. Metodologi peneltian yang digunakan adalah pengujian dengan skala laboratorium. Data yang didapatkan dari pengujian tersebut kemudian dianalisa dengan membandingkan nilai daya dukung antara tanah tanpa perkuatan dengan menggunakan perkuatan yang dinyatakan dalam Bearing Capacity Ratio (BCR). Dari studi model di laboratorium diperoleh hasil bahwa dengan adanya pengurangan kedalaman perkuatan, jarak grid dan pengurangan spasi lapis perkuatan akan memberikan angka rasio daya dukung (BCR) yang semakin besar. Hasil diperoleh kombinasi yang memberikan nilai daya dukung tertinggi adalah penggunaan jarak grid 5 cm perkuatan dengan jarak kedalaman 0,15B (B adalah lebar pondasi) dengan spasi perkuatan (z) 0.4B. Nilai daya dukung tersebut sebesar 68 kPa dengan rasio daya dukung (BCR) sebesar 4 atau persen peningkatannya sebesar 300%.

scholarly journals Advanced Composite Retrofit of RC Columns and Frames with Prior Damages—Pseudodynamic Finite Element Analyses and Design Approaches

Fibers ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 56
Author(s):  
Theodoros Rousakis ◽  
Evgenia Anagnostou ◽  
Theodora Fanaradelli
Keyword(s):  
Finite Element ◽  
Brick Wall ◽  
Rc Frame ◽  
Base Shear ◽  
Infill Wall ◽  
Rc Columns ◽  
Premature Failure ◽  
Displacement Ductility ◽  
Lap Splices ◽  
Rc Frames

This study develops three-dimensional (3D) finite element (FE) models of composite retrofits in deficient reinforced concrete (RC) columns and frames. The aim is to investigate critical cases of RC columns with inadequate lap splices of bars or corroded steel reinforcements and the beneficial effects of external FRP jacketing to avoid their premature failure and structural collapse. Similarly, the RC-frame FE models explore the effects of an innovative intervention that includes an orthoblock brick infill wall and an advanced seismic joint made of highly deformable polymer at the boundary interface with the RC frame. The experimental validation of the technique in RC frames is presented in earlier published papers by the authors (as well as for a four-column structure), revealing the potential to extend the contribution of the infills at high displacement ductility levels of the frames, while exhibiting limited infill damages. The analytical results of the advanced FE models of RC columns and frames compare well with the available experimental results. Therefore, this study’s research extends to critical cases of FE models of RC frames with inadequate lap splices or corroded steel reinforcements, without or with brick wall infills with seismic joints. The advanced pseudodynamic analyses reveal that for different reinforcement detailing of RC columns, the effects of inadequate lap-spliced bars may be more detrimental in isolated RC columns than in RC frames. It seems that in RC frames, additional critical regions without lap splices are engaged and redistribution of damage is observed. The detrimental effects of corroded steel bars are somewhat greater in bare RC frames than in isolated RC columns, as all reinforcements in the frame are considered corroded. Further, all critical cases of RC frames with prior damages at risk of collapse may receive the innovative composite retrofit and achieve higher base shear load than the original RC frame without corroded or lap-spliced bars, at comparable top displacement ductility. Finally, the FE analyses are utilized to propose modified design equations for the shear strength and chord rotation in cases of failure of columns with deficiencies or prior damages in RC structures.

scholarly journals Multi-Platform Simulation of Infilled Shear-Critical Reinforced Concrete Frames Subjected to Earthquake Excitations

2021 ◽  
Author(s):  
Xu Huang ◽  
Alex Brodsky
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Simulation Method ◽  
Fe Model ◽  
Nonlinear Behaviour ◽  
Rc Frame ◽  
Seismic Performance Assessment ◽  
Infill Wall ◽  
Rc Frames ◽  
Macro Modeling

Abstract This paper proposes a multi-platform simulation method for seismic performance assessment of masonry infilled reinforced concrete (RC) frames, especially for those who tend to fail in shear during an earthquake due to inadequate reinforcing details. The method is based on a micro-macro modeling approach where a detailed finite element (FE) model of the RC frame is incorporated with a strut model of the infill wall. It takes advantage of the strut model in terms of computational efficiency and the FE model based on the Modified Compression Field Theory (MCFT) to capture the nonlinear behaviour of the RC frame with explicit modeling of the beam-column joint failure and shear failure of the frame. The proposed method is validated against previously tested frames subjected to lateral loads, and its advantages over the conventional struct models are demonstrated through both quasi-static and dynamic analyses.

scholarly journals BEHAVIOR OF STRIP FOOTING ON REINFORCED SAND SLOPE

2015 ◽  
Vol 21 (3) ◽  
pp. 376-383 ◽  
Author(s):  
Enas B. Altalhe ◽  
Mohd Raihan Taha ◽  
Fathi M. Abdrabbo
Keyword(s):  
Bearing Capacity ◽  
Reinforced Soil ◽  
Strip Footing ◽  
Reinforced Slope ◽  
Bearing Capacity Ratio ◽  
Reinforced Sand ◽  
Capacity Ratio ◽  
Soil Slopes ◽  
Loading Tests ◽  
Slope System

This study evaluated the effects of single, double, and triple reinforcing layers on the bearing capacity ratio (BCR) of strip footing on a sand slope system. Seventy-two laboratory-loading tests were conducted on a stripfooting model on a reinforced sand slope. Moreover, this study illustrated the effects of the different parameters of two reinforcing layers on the bearing capacity of a double-reinforced sand slope. The BCR increased from 1.06 to 3.00 for single-reinforced slope soils, 1.09 to 7.73 for double-reinforced slope soils, and up to 8.00 for three-layered reinforced systems. For double-reinforced soil slopes, the most effective spacing between the two reinforcing layers is 0.3 B.

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