scholarly journals A Study on Positioning of Different Shapes of Shear Walls in L Shaped Building Subjected to Seismic Forces

2016 ◽  
Vol V5 (07) ◽  
Author(s):  
Md Afroz Patel ◽  
Prof. Shaik Abdulla ◽  
Keyword(s):  
Shear Walls ◽  
Different Shapes ◽  
Seismic Forces

Effects of openings on the seismic behavior and performance level of concrete shear walls

2019 ◽  
Author(s):  
Hossein Alimohammadi ◽  
Mostafa Dalvi Esfahani ◽  
Mohammadali Lotfollahi Yaghin
Keyword(s):  
Static Analysis ◽  
Cross Section ◽  
Seismic Behavior ◽  
Shear Walls ◽  
Shear Wall ◽  
Constant Cross Section ◽  
Added Resistance ◽  
Different Shapes ◽  
And Performance ◽  
Abaqus Software

In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.

The Role of Building Foundations in Seismic Retrofit

1996 ◽  
Vol 12 (4) ◽  
pp. 925-942 ◽  
Author(s):  
Charles W. Roeder ◽  
Sunirmal Banerjee ◽  
Debbie R. Jung ◽  
Sean K. Smith
Keyword(s):  
Shear Walls ◽  
Economic Loss ◽  
Seismic Retrofit ◽  
Life Safety ◽  
Collapse Potential ◽  
Steel Bracing ◽  
Potential Damage ◽  
Minimal Work ◽  
Seismic Forces ◽  
The Cost

Existing buildings which do not satisfy modern seismic design requirements may be rehabilitated economically by the addition of steel bracing or reinforced concrete shear walls. However, steel bracing and concrete shear walls can place severe demands on the building foundation, and the existing foundations are likely to be inadequate. Strengthening of existing foundations may be exceedingly expensive, and the cost of the foundation work may dominate the seismic retrofit effort. Several foundation retrofit strategies are described and discussed. These strategies are invariably expensive, and the engineer may be tempted to place the major investment into strengthening or stiffening the structure with minimal work on the foundation. This concept may lead to increased potential for uplift and temporary overload of footings. In some cases this practice may have beneficial effect regarding the overall seismic response of the structure. It may reduce both seismic forces and maximum displacements experienced by the structure. The reduced foundation retrofit is unlikely to increase the collapse potential or life-safety risks of the building, while the structural retrofit should significantly improve the life-safety concerns. However, the combination of structural rehabilitation combined with minimal foundation rehabilitation are likely to increase the potential damage and economic loss during an earthquake.

Investigations of RC Shear Wall-Frame Structures with Various Openings in Walls under Earthquake Loading

2014 ◽  
Vol 1020 ◽  
pp. 242-247
Author(s):  
Tigran Dadayan ◽  
Ehsan Roudi
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Frame Structures ◽  
High Rise ◽  
Frame Buildings ◽  
Computer Analyses ◽  
The Republic ◽  
Rc Shear Wall ◽  
Almost All ◽  
Seismic Forces

Almost all high-rise buildings have been constructed in the Republic of Armenia for past twenty-five years are Reinforced Concrete (RC) shear wall–frame structures, where shear walls provide most of the stiffness of buildings. The walls in these buildings are designed to sustain earthquake and wind loads. Vulnerability of them during earthquake action depends on many different factors. Some of them are the openings and its location in the walls. Usage of ground stories as parking and garages is demanded large openings in shear walls therefore determination of ultimate sizes of openings is important problems for designers. In this paper, FEM (Finite Element Method) models are used for investigation of stress-strain state of RC wall–frame buildings with various openings in the walls under action of seismic forces. Limitation of size and position of openings are considered in the paper taking into account of building code of Armenia. Various schemes of openings are considered in the article. The existing experimental data of shear walls were performed in various laboratories have been compared with our numerical investigation of RC models based on nonlinear computer analyses. Dynamic analyses of structures using accelerograms are showed sequence of damages in RC wall-frame models. The recommendations for limitation of ratio area of an opening to the whole area of a wall are proposed at the end of the article.

scholarly journals Seismic forces in base-isolated masonry structures

1977 ◽  
Vol 10 (2) ◽  
pp. 55-68 ◽  
Author(s):  
M. J. N. Priestley ◽  
R. L. Crosbie ◽  
A. J. Carr
Keyword(s):  
Base Isolation ◽  
Substantial Reduction ◽  
Shear Walls ◽  
Degree Of Freedom ◽  
Higher Mode Effects ◽  
Mode Effects ◽  
Short Period ◽  
Margin Of Safety ◽  
Isolation Systems ◽  
Seismic Forces

Dynamic analyses of four, eight and twelve storey masonry shear walls supported on base-isolation systems are described. Each wall was modelled as a multi-degree-of-freedom cantilever. Results are presented which indicate behaviour is more complex due to the significance of higher mode effects, than was previously believed on the basis of simple single-degree-of-freedom models. The influence of different types of base-isolation, and of the stiffness of the gravity supporting system, are discussed. Tentative design recommendations are proposed which provide a substantial reduction in design forces for short period structures while still maintaining an adequate margin of safety against the formation of wall hinges.

scholarly journals Effect of Shear wall Geometry on Ten Storey Building with Raft and Fixed base Foundation

2019 ◽  
Vol 9 (1) ◽  
pp. 205-208
Keyword(s):  
Shear Walls ◽  
Shear Wall ◽  
Soil Conditions ◽  
High Rise ◽  
Seismic Zones ◽  
Raft Foundation ◽  
Mat Foundation ◽  
Different Shapes ◽  
Wall Geometry ◽  
Storey Building

:Raft foundation is widely used for high-rise buildings where presence of shear wall is very common. Shear Wall resists a major portion of the lateral load of high-rise buildings. So, presence of shear wall on mat foundation causes significant change in pattern and intensity of loading on mat foundation. The present work involved an investigation of effect of shear wall geometry in different seismic zones with and without the presence of raft foundation. Multi storey building with ten storey is analysed for the storey drift, storey displacement and base shear. The analysis of building is done by response spectrum analysis. The different shapes of shear walls C,L,F,I with same plan area is considered. The effect of shear wall geometry is studied in zone II, zone III, zone IV, zone V. Loads and load combinations selected based on IS 456-2000 and IS 875-1987 code. Three types of soil conditions are considered typeI ,typeII, typeIII.Raft foundation is designed by meshing the slab into equal quadrilaterals.Assigning of area springs to the each quadrilateral.Meshing is done inorder to convert the infinite solution into finite solution.The different shapes of the shear walls is analysed in zone V with the raft foundation in type III.The results are compared with and without the raft foundation ,conclusions are drawn that the best shape of the shear wall suits in different seismic zones.

scholarly journals Parametric Study of Seismic Response Analysis of High Rise Structure

2019 ◽  
pp. 311-317
Author(s):  
Mayuri Chordiya ◽  
S. S. Angalekar
Keyword(s):  
Shear Walls ◽  
Response Analysis ◽  
Load Factor ◽  
Lateral Loads ◽  
Maximum Displacement ◽  
Structural Wall ◽  
Multistory Buildings ◽  
High Rise ◽  
Earthquake Resistant Design ◽  
Seismic Forces

High rise structures with complex planning and irregular vertical elevations are trending nowadays. Such high rise structures are more susceptible to seismic forces which are quite devastating and cause a huge loss to human lives and property. Hence it is very important to study the behavior of such structure to help structural engineers to create better earthquake resistant design. The usefulness of the shear walls in the structural planning of the multistory buildings to resist the lateral forces has been recognized long back. Shear walls also dissipates a great amount of energy if detailed properly, however there are many factors such as placement of shear walls, its thickness, aspect ratio, plan of the building which affects the response of the building towards lateral loads. In the present study attempt is made to study the effect of different location of shear walls on the response of the building in terms of time period and maximum displacement. The detailed investigation is carried out for zone II of Seismic zones of India as per IS 1893 (part 1):2016, considering primary loads (dead, live and seismic loads) and their combinations with appropriate load factor. Analysis is carried out in ETABS 2016. Further a case study of a U-shaped plan is carried out, to reduce the torsional irregularity structural wall system with spandrels and seismic joints were provided at certain locations.

scholarly journals Shear Walls Induced RC Structures

2021 ◽  
Vol 12 (2) ◽  
pp. 1827-1834
Author(s):  
Kesava Rao B, Et. al.
Keyword(s):  
Dynamic Analysis ◽  
Response Spectrum ◽  
Pushover Analysis ◽  
Shear Walls ◽  
Shear Wall ◽  
Lateral Force ◽  
Wind Pressure ◽  
Earthquake Response ◽  
Rc Structures ◽  
Seismic Forces

In recent years, the construction of skyscrapers has been on the rise to overcome the shortage of land. These buildings are subject to an external lateral force, such as an earthquake and wind pressure. Pushover analysis (POA) has been broadly used in predicting the earthquake response of structures, and shear walls have been shown to be lateral drag elements. Therefore, in the present work, the effect of placing a shear wall on the periphery symmetrically, the periphery asymmetrically and in the center of the building is performed using the ETABS software. Using the response spectrum methodand thetime history method, a dynamic analysis is performed. Responses such as floor shear, floor displacement, and lateral floor shifts due to seismic forces are evaluated for various locations of the shear wall. According to the results and analysis, the shear wall on the symmetrical periphery of the structure is reducing the displacement and deviation of the floor compared to other cases.

Seismic Consolidation of ’60s Pilotis R.C. Building for Social Housings with SCC-Steel Shear Walls

2014 ◽  
Vol 638-640 ◽  
pp. 1937-1942 ◽  
Author(s):  
Marco Andreini ◽  
Anna de Falco ◽  
Linda Giresini ◽  
Mauro Sassu
Keyword(s):  
Social Housing ◽  
Load Capacity ◽  
Shear Walls ◽  
Base Shear ◽  
Ground Floor ◽  
Steel Columns ◽  
The Poor ◽  
Seismic Forces

The reinforcement of a r.c. building for social housing has been achieved by using Steel-Concrete Composite (SCC) walls at the ground floor, preceded by temporary brick pillars for structural deficiency to vertical loads, due to the poor load capacity of the r.c. columns. The SCC walls have been realized first by placing steel columns on both sides of the existing pillars and, after removal of the temporary brick piers, by merging the steel columns in the cast of the new walls. The top of the walls has been connected to the upper floor in order to ensure the diffusion of the seismic forces. Foundations have been reinforced to support the seismic base shear.

scholarly journals A note on the earthquake performance of reinforced concrete shear walls

1969 ◽  
Vol 2 (2) ◽  
pp. 193-198
Author(s):  
Karl V. Steinbrugge ◽  
Henry J. Degenkolb
Keyword(s):  
Reinforced Concrete ◽  
Shear Walls ◽  
The United States ◽  
Concrete Walls ◽  
Reinforced Concrete Walls ◽  
Structural Panel ◽  
Earthquake Performance ◽  
Seismic Loadings ◽  
Strength And Stiffness ◽  
Seismic Forces

A great many one and two story buildings as well as many buildings as tall as 10 stories or higher have cast in situ reinforced concrete walls designed to act as shear walls for resisting seismic forces. Allowable design stresses in reinforced concrete shear walls have been increased in recent years in many building codes, although in one major code they have been drastically reduced. Concurrently, modern architectural trends have often resulted in the reduction of certain reserve strength features neglected in seismic design such as "non-structural" panel walls of brick or of reinforced concrete since these elements are often replaced by glass or by insulated metal panels. This, in effect, results in greater applied seismic forces on the shear walls. The frequent elimination of deep spandrel beams in favor of thin slabs which may meet glass or metal walls also tends to increase stresses in the shear walls since the strength and stiffness of the spandrels were often neglected when interior shear walls existed. In summary, it has been the experience in the United States and in many other countries in the world that the effective factor of safety in reinforced concrete shear walled structures has often been substantially reduced for seismic loadings. In many cases, inadequate methods of analysis have neglected critical stresses at boundaries and openings.

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