Seismic Design and Construction Practices for RC Structural Wall Buildings

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 245-256 ◽  
Author(s):  
Leonardo M. Massone ◽  
Patricio Bonelli ◽  
René Lagos ◽  
Carl Lüders ◽  
Jack Moehle ◽  
...  
Keyword(s):  
Linear Models ◽  
Principal Direction ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Load Resistance ◽  
Floor Plan ◽  
Structural Walls ◽  
Cross Sectional ◽  
Structural Wall ◽  
Wall Area

Reinforced concrete buildings utilizing structural walls for lateral load resistance are the predominant form of construction in Chile for buildings over four stories. Typical buildings include a large number of walls, with ratios of wall cross-sectional area to floor plan area of roughly 3% in each principal direction. Based on the good performance of RC buildings in the March 1985 earthquake, requirements for closely spaced transverse reinforcement at wall boundaries were excluded when Chile adopted a new concrete code in 1996 based on ACI 318-95. In recent years, use of three-dimensional linear models along with modal response spectrum analysis has become common. Since 1985, nearly 10,000 new buildings have been permitted. Although the newer buildings have similar wall area to floor plan areas as older buildings, newer walls are thinner and buildings are taller, leading to significantly higher wall axial load ratios.

scholarly journals Seismic Performance of a Tall Multi Storey Tower Connected by a large Podium

2019 ◽  
Vol 8 (2) ◽  
pp. 3545-3551
Keyword(s):  
Shear Force ◽  
Response Spectrum ◽  
Seismic Load ◽  
Response Spectrum Method ◽  
Structural Walls ◽  
Structural Wall ◽  
Spectrum Method ◽  
Unfavorable Effect ◽  
Tower Structure ◽  
Tower Height

The present work focus on the effect of podium structure of single tower structure connected by a common podium at the interface level under seismic load. For this purpose, the simulation model with varying tower height and podium height is created in the ETABs and it is analyzed for the equivalent static and response spectrum method. In this study, the effect on the top displacement of the tower connected with podium structure under equivalent static and response spectrum method of analysis is observed. The backstay forces that are developed to resist the lateral overturning actions at the interface when the lateral horizontal forces are transferred from the tower to the podium are studied. The unfavorable effect of podium on the shear force distribution at and above the interface level of the structural wall is observed. The positioning of the tower on the podium structure is found to be the reason for the differential displacement between the structural walls.

scholarly journals Comparative Parametric Analysis of Opening Area Usage of Shear Wall in Different Percentages Relating to Wall Area Used for Multistorey Building

2021 ◽  
Vol 9 (11) ◽  
pp. 494-501
Author(s):  
Krishna Pal Singh
Keyword(s):  
Load Transfer ◽  
Response Spectrum ◽  
Shear Wall ◽  
Seismic Zone ◽  
Structural Wall ◽  
Wall Area ◽  
Area Reduction ◽  
Earthquake Effects ◽  
Result Analysis ◽  
The Cost

Abstract: It is highly recommend that the structure should be efficient in terms of the cost in diverse manner. To reduce the overall cost of the project, the cost cutting should be done in every construction stages. The dual systems in building structure consist of structural walls and moment resisting frames. The structural wall members are made up of RCC, which is a costly structural member. The purpose of current study is to explore the reduction in shear wall area in multi-storey building for reduction of overall project cost. Total 5 buildings abbreviated as SOA, SOB, SOC, SOD and SOE framed in analytical software supposed to be situated at Seismic Zone III. After the comparative result analysis, it proves that, the reduction in shear wall area should be adapted to a certain limit due to load transfer criteria of the members 20 % wall deduction is sufficient. Building SOD with 80% coverage performs best of all. Keywords: Deduction Area, Earthquake Effects, Opening Area, Shear Wall, Response spectrum, Wall Area Reduction, Wall Deduction Ratio.

scholarly journals Performance of a Multi-Storey Complex Building with CFST Columns.

2020 ◽  
Vol 9 (7) ◽  
pp. 195-201
Keyword(s):  
Agricultural Land ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Steel Tube ◽  
Seismic Zone ◽  
Cross Sectional ◽  
Seismic Zones ◽  
Complex Building ◽  
Cfst Columns ◽  
Vertical Development

Due to rapid on-going horizontal development and restricted vertical development of buildings has resulted in congestion of cities and shrinkage of agricultural land, particularly in high seismic zones. For vertical development, there is a need for the construction of buildings as high as possible. The restriction to the vertical development is due to the reason that high rise structures are more vulnerable to lateral loads acting on the building resulting from the seismic events. With a background in view, the current work studies the seismic responses of a multi-storey complex building with concrete-filled steel tube columns (CFST). In present work, CFST columns of different sizes were used for the study of a Ground+12 storey building with plan dimensions 35m x 30m, situated in seismic Zone-V and medium soil type as per IS 1893-2016 classification. The Response spectrum analysis was carried out for different building models as per IS 1893:2016 provisions. E-TABS software was used for three-dimensional modelling and analysis of buildings. Several response parameters like fundamental time period, maximum storey displacement, maximum storey drift, storey shear and overturning moment are considered in this study to evaluate the performance of the building. It was concluded that CFST columns perform well for high seismic zones even at smaller cross-sectional dimensions.

scholarly journals The Structural Performance of Reinforced Concrete Members with Monolithic Non-Structural Walls under Static and Dynamic Loads

Buildings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 87
Author(s):  
Walid Ahmad Safi ◽  
Yo Hibino ◽  
Koichi Kusunoki ◽  
Tomohisa Mukai ◽  
Yasushi Sanada ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Tests ◽  
Base Shear ◽  
Reinforced Concrete Frame ◽  
Concrete Wall ◽  
Structural Walls ◽  
Cross Sectional ◽  
Structural Wall ◽  
Drift Capacity ◽  
Concrete Frame

The required base shear and drift limit for post-disaster management buildings have increased in the Japanese Building Code following major seismic events. One method to satisfy these requirements for reinforced concrete frame buildings is to cast exterior non-structural concrete wall elements to be monolithic with frame elements, but without anchoring the longitudinal wall reinforcing. This provides additional stiffness and strength while limiting significant damage in the non-structural wall. In this study, the structural performances of such elements were evaluated using static and dynamic experimental tests. The result indicates that non-structural walls that were neither isolated by seismic slits nor anchored to the adjacent walls with longitudinal reinforcements experienced less damage and higher deformability compared with walls having seismic slits. The confinement reinforcing impact was not observed on the strength and drift capacity of the beam member, owing to the large number of transverse reinforcements. However, the confinements limited the damage and nearly prevented concrete crushing. The maximum horizontal load of the specimen could be predicted using cross-sectional analysis, and the authors propose a simple equation to predict it with sufficient accuracy.

scholarly journals Checking the Stability Criteria of Multi-Storied Building by Varying Opening Area Percentages in Shear Wall Used in Periphery with Seismic Zone III

2021 ◽  
Vol 9 (11) ◽  
pp. 127-135
Author(s):  
Mr. Prashant Sharma
Keyword(s):  
Response Spectrum ◽  
Shear Walls ◽  
Shear Wall ◽  
Load Resistance ◽  
Response Analysis ◽  
Seismic Zone ◽  
Wall Area ◽  
Axial Forces ◽  
Cost Cutting ◽  
The Cost

Abstract: To decrease the overall cost of the project, it is highly recommended dropping the cost in different manners. To make economic structure, structure without losing the stiffness standards and the cost cutting should be done at every construction stages. The dual systems in building structure consist of structural walls and moment resisting frames. The walls are made up of RCC, which is expensive material. The purpose of current study is to discover the effect of reducing shear wall area in multistorey building to decrease cost. The buildings are provided with shear walls to improve the lateral load resistance. Post parametric analysis results shows that, the reduction in shear wall area should be modified to a certain limit up to 20 % for cost cutting. But in this study, the opening areas of shear wall are increased above 20% to 36.75% and verify the results of post analysis. In this study 8 cases are analysed with 0%, 11%, 14.20%, 20%, 33.20%, 29.05%, 35%, & 36.75% opening in shear wall and analysis is perform by Response Analysis Method of dynamic analysis using Staad.pro V8i software in Zone III of multistorey building (G+18). The effects of opening in the wall are studied by considering the moments, shear, and torsion, and axial forces in the beams and columns. It is observed that after a certain percentage of shear opening in walls the building fails in the drift at a certain height. To resolve this problem the flared area of height 0.5 m at the height of failure is provided to counteract the effect of drift. It was observed that by the introduction of shear belt the drift reduces which made the structure stable. Finally in this study, the opening of shear wall area is increased up to 35% and concrete area is reduced 1170.20 m2 , which is 534.2m2 more than the previous studies. Keywords: Shear Wall, Opening Area, Multi-storeyed Building, Seismic effects, Response Spectrum Method

scholarly journals Accuracy and Reproducibility of Facial Measurements of Digital Photographs and Wrapped Cone Beam Computed Tomography (CBCT) Photographs

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 757
Author(s):  
Maged Sultan Alhammadi ◽  
Abeer Abdulkareem Al-mashraqi ◽  
Rayid Hussain Alnami ◽  
Nawaf Mohammad Ashqar ◽  
Omar Hassan Alamir ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Cone Beam Computed Tomography ◽  
High Reliability ◽  
Three Dimensional ◽  
Cone Beam ◽  
Cross Sectional ◽  
Facial Profile ◽  
Digital Photographs ◽  
Gonial Angle

The study sought to assess whether the soft tissue facial profile measurements of direct Cone Beam Computed Tomography (CBCT) and wrapped CBCT images of non-standardized facial photographs are accurate compared to the standardized digital photographs. In this cross-sectional study, 60 patients with an age range of 18–30 years, who were indicated for CBCT, were enrolled. Two facial photographs were taken per patient: standardized and random (non-standardized). The non-standardized ones were wrapped with the CBCT images. The most used soft tissue facial profile landmarks/parameters (linear and angular) were measured on direct soft tissue three-dimensional (3D) images and on the photographs wrapped over the 3D-CBCT images, and then compared to the standardized photographs. The reliability analysis was performed using concordance correlation coefficients (CCC) and depicted graphically using Bland–Altman plots. Most of the linear and angular measurements showed high reliability (0.91 to 0.998). Nevertheless, four soft tissue measurements were unreliable; namely, posterior gonial angle (0.085 and 0.11 for wrapped and direct CBCT soft tissue, respectively), mandibular plane angle (0.006 and 0.0016 for wrapped and direct CBCT soft tissue, respectively), posterior facial height (0.63 and 0.62 for wrapped and direct CBCT soft tissue, respectively) and total soft tissue facial convexity (0.52 for both wrapped and direct CBCT soft tissue, respectively). The soft tissue facial profile measurements from either the direct 3D-CBCT images or the wrapped CBCT images of non-standardized frontal photographs were accurate, and can be used to analyze most of the soft tissue facial profile measurements.

scholarly journals A Numerical Study of Sub-Millisecond Integrated Mix-and-Inject Microfluidic Devices for Sample Delivery at Synchrotron and XFELs

2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey
Keyword(s):  
Molecular Dynamics ◽  
Flow Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Liquid Jets ◽  
Mixing Efficiency ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Time Required

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.

Human density, economic level and frequency of canine helminths in Buenos Aires

2021 ◽  
Vol 95 ◽  
Author(s):  
D. Rubel ◽  
N. Flaibani
Keyword(s):  
Linear Models ◽  
Buenos Aires ◽  
Toxocara Canis ◽  
The Other ◽  
Green Spaces ◽  
Cross Sectional ◽  
Independent Variables ◽  
Economic Level ◽  
Faecal Samples ◽  
Human Density

Abstract The aim of this study was to explore through cross-sectional study the variation in the prevalence of parasitic helminths in canine faeces collected from green spaces of Buenos Aires according to the human density (HD) and economic level (EL) in the surroundings. HD and EL were considered as independent variables with three categories each. Twenty public squares (one hectare of surface) were randomly selected for each existing combination of the two independent variables. Ten random samples of fresh canine faeces were obtained in each square and analysed for helminths by the sedimentation and flotation techniques. The prevalence for each of the species was analysed using generalized linear models (GLM). The prevalence was modelled with a binomial error distribution and a logit link function. Helminth eggs were detected in 45 out of the 200 (22.5%) faecal samples collected and in 18 of the 20 green spaces sampled. The species observed were Ancylostoma caninum (13% of samples), Trichuris vulpis (8%) and Toxocara canis (4.5%). The GLM indicated that the prevalence of A. caninum in the slum areas (very high HD and very low EL) was higher than that in the other areas studied. However, the HD seemed to contribute more than the EL to the variations in the prevalence of A. caninum in faecal samples. The GLM showed no differences in the prevalence of the other parasite species for the different levels of the independent variables.

scholarly journals The Relationships Between Serum DHEA-S and AMH Levels in Infertile Women: A Retrospective Cross-Sectional Study

2021 ◽  
Vol 10 (6) ◽  
pp. 1211
Author(s):  
Li-Te Lin ◽  
Kuan-Hao Tsui
Keyword(s):  
Generalized Linear Models ◽  
Large Scale ◽  
Linear Models ◽  
Positive Association ◽  
Cross Sectional Study ◽  
Dehydroepiandrosterone Sulphate ◽  
Sectional Study ◽  
Cross Sectional ◽  
Infertile Women ◽  
The Relationship

The relationship between serum dehydroepiandrosterone sulphate (DHEA-S) and anti-Mullerian hormone (AMH) levels has not been fully established. Therefore, we performed a large-scale cross-sectional study to investigate the association between serum DHEA-S and AMH levels. The study included a total of 2155 infertile women aged 20 to 46 years who were divided into four quartile groups (Q1 to Q4) based on serum DHEA-S levels. We found that there was a weak positive association between serum DHEA-S and AMH levels in infertile women (r = 0.190, p < 0.001). After adjusting for potential confounders, serum DHEA-S levels positively correlated with serum AMH levels in infertile women (β = 0.103, p < 0.001). Infertile women in the highest DHEA-S quartile category (Q4) showed significantly higher serum AMH levels (p < 0.001) compared with women in the lowest DHEA-S quartile category (Q1). The serum AMH levels significantly increased across increasing DHEA-S quartile categories in infertile women (p = 0.014) using generalized linear models after adjustment for potential confounders. Our data show that serum DHEA-S levels are positively associated with serum AMH levels.

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