Shear Wall Thickness Research Articles

Blast Mitigation of Reinforced Concrete Structures Incorporating Shear Walls in Modern Building Designs

Material science advancements have resulted in the development of high-strength concrete and steel reinforcement, allowing more efficient and stable buildings against natural and manmade disasters. Increasing security concerns and the potential threat from terrorist activities have led to the safety and resilience of structures against blast loads in modern construction. The present study investigates the performance of reinforced concrete shear walls in mitigating blast-induced vibrations. The study examines four different reinforced concrete buildings based on their shapes, namely square, rectangular, C-shaped, and L-shaped, to understand the blast behaviours with and without shear walls. The study presents a methodology to protect the regular and irregular buildings equipped with shear walls against blast loads at varying standoff distances of 100 m, 200 m, 300 m, and 400 m, respectively. The study also compares the efficiency of passive control dampers and shear walls in enhancing the buildings’ performance against blast vibrations. The best placement of the shear walls is also evaluated for all the selected buildings. The study also considers the effect of shear wall thickness in mitigating blast-induced vibrations in multi-storey buildings. The study also discusses the design guidelines and reinforcement detailing of shear walls to protect buildings against detrimental blast effects.

Comparison of thickness shear wall against drift floor using pushover method

Lateral load or earthquake disaster can damage the structure of a highrise building. Therefore, calculations are needed to avoid massive damage to the structure when an earthquake occurs and give a load to the structure. One of the efforts that is done to resist the earthquake is using shear wall. On this research, there will be a comparison of shear wall thickness that will be used for the building model. Where there is existing model with the shear wall thickness 400 mm, modified model with the shear wall thickness 350 mm and 300 mm, and model without shear wall. Earthquake standards is using SNI 1726-2019, load standards are using SNI 1727-2013, concrete design is using SNI 2847-2019, and for the structure analysis is using ETABS Program. First step is calculating the Demand Capacity Ratio (DCR) of the structure element to determine if the structure needed to be analyse using non-linear static (pushover) or not. And then there will be drift ratio calculation to determine the building performance level using Federal Emergency Management Agency (FEMA) 356 provisions.

Study on Seismic Performance of Connecting Prefabricated Coupling Beam and Shear Wall with Equivalent Bars

This study proposes a new type of method for the connection of the prefabricated coupling beam and shear wall to solve the problems in the construction of assembled frame‐shear wall structures. To investigate the seismic properties of this new type of assembled coupling beam, experiments with 2 groups of test pieces under low‐period cycling loads were completed. Furthermore, this study studied some important influence factors. Results show that this novel coupling beam has a similar performance to the cast‐in‐place coupling beam. The bearing capacity and energy dissipation capacity of cast‐in‐place structures increase with the increase in end block thickness and the ductility inversely, yet the bearing capacity, seismic energy dissipation capacity, and ductility of assembled coupling beam structure decrease with the increase in end block thickness. Numerical simulation shows that increasing the area of equivalent steel bars will increase its yield load but will also reduce the seismic energy dissipation capacity and ductility. The thicker the shear wall thickness, the higher specimen’s bearing capacity, the stronger the seismic energy dissipation capacity, and the worse the ductility is.

ANALISIS PERENCANAAN GEDUNG PERPUSTAKAAN STAIN PAREPARE DENGAN MENGGUNAKAN MODIFIKASI METODE FLAT SLAB

The Analysis of Library Building Plan of Sekolah Tinggi Agama Islam Parepare by using A Modication of Flat Slab Method.
 The research aimed to know the dimensions of main structure, create construction structure using at slab based on ETABS Program that was analyzed according to SNI 2847:2013. Counting the reinforcement needed by main structure and create a nal design based on the modication result of Library Building as well as analyze the mass participation in earthquake areas.
 The analysis result showed that the thickness of the whole flat floor was 22 cm and drop panel was 120 cm x 120 cm with 12 cm thick, column dimension K1 for Floor 1 with 70/70, K1 floor 2-4 with 60/60, K1 floor 5 with 50/50, column 2 floor 1-5 with 50/35 and K3 floor 1-5 with 30 x 30, the thickness of shear wall was 30 cm. The reinforcement of flat slab produced reinforcement D16 mm, main column reinforcement K1 22D22, column K2 9D22, column K8D12. Final Plan of library building modification based on technical drawing form consisted of the Picture of structure plan, pieces, and detail of the reinforcement. In earthquake area with Category C, it was showed by mass partition control on mode 4 and 5 had achieved 93% and 94% and was able to restrain the load of earthquake plan.

Construction technology of super high rise ultra-thin shear wall bearing heavy tonnage tower crane under energy saving and emission reduction

Lanzhou·Famous City Plaza Project There are two internal climbing boom tower cranes in the core tube of 1# building. From the 50th floor, the thickness of shear wall is reduced to 200mm, and the design wall thickness and reinforcement can not meet the stress requirements of boom tower cranes. Through the finite element analysis software ANSYS simulation analysis, the core tube shear wall and coupling beam are strengthened, the reinforcement is increased, and the concrete strength grade is improved. At the same time, the steel beam of the boom tower crane is reinforced to reduce the load borne by the shear wall, and then the seamless steel pipe and jack are used to push back the load of the steel beam from the bottom, which solves the problem of insufficient bearing capacity of the ultra-thin shear wall to the boom tower crane, makes the boom tower crane work normally, and ensures the construction safety and the construction period.

Evaluation of effective location and thickness of shear wall on performance of multi-storey building subjected to lateral load

The aim of the present study is to identify the optimum thickness of the shear divider and suitable position of shear divider in the structure. In this present study G+20 storeys building is considered which is positioned in a zone IV with soil type as medium. The linear static analysis method is used for analysis by using etabs 2016 software. We have considered four different thickness of shear wall such as 150mm, 175mm, 200mm and 225mm.and again considered the three different position in the buildings such as shear divider at corner, shear divider at mid span of the structure and core divider at center of the structure. The parameters considered are storey dislocation, storey drift, Overturning moment, base shear and modal time period.

Analysis of shear walls for a suitable opening

The main purpose of shear walls in reinforced concrete structures is to resist the lateral forces affecting the structure. However, the openings created for architectural reasons significantly change the behaviour of the shear wall and cause short column formation and sudden collapse of the structure due to the openings on them. In this study, opening shear walls were analysed analytically. Twenty-nine different frames were selected and analysed according to predetermined parameters such as frame height, frame spacing, shear wall thickness, opening/frame height ratio, concrete flexibility, modulus and moment of inertia of frame columns. In this context, a total of 5200 linear elastic analyses were performed. The analysis was carried out on seven different parameters. As a result of the analysis, it has been found that there is a non-linear relationship between the opening width and the stresses in the columns, and a nonlinear relationship is predicted that it can directly trigger short column formation.

Optimal Design and Seismic Resistance of Reinforced Concrete Structures Braced with Shear Walls

This study optimized a building structure braced with shear walls using the CAFE software. First, the position of shear walls and initial design of shear wall thickness were decided. Preliminary analysis was conducted using the ETABS (extended 3D analysis of building systems) software to confirm the feasibility of the initial design. Subsequently, the influence of beam–column elements and shear walls on structural mechanics was explored. Next, this study proposed the optimal and most economical design of the structure of the building braced with shear walls. Finally, the relationship between the seismic resistance and optimization was identified.

Performance-Based Plastic Design of Moment Frame-Steel Plate Shear Wall as a Dual System

Steel Plate Shear Wall (SPSW) is an emerging seismic load-resistant system that, compared to other systems, enjoys the advantages of stable ductile behavior, fewer detailing requirements, rapid constructability, and economy. American seismic provisions decree that a SPSW should be designed as a moment frame with a web infill plate. Specifically, in case of buildings taller than 160 ft, it decrees that a dual system must be used. This paper presents a method of Performance-Based Plastic Design (PBPD) to design steel moment frame-SPSW as a dual lateral load-resisting system. PBPD method uses pre-selected target drift and yield mechanism as its main criteria. For a specified hazard level, the design base shear is calculated based on energy work balance method, employing pre-selected target drift. Plastic design of dual frame system has been performed to meet the pre-selected yield mechanism. As presented in the paper, design procedure involves solving a system of five equations with five variables to determine the proportion of SPSW and moment frame shear, shear wall thickness, and beam/ column sections. It has been considered that a four-story structure is designed with the proposed method. Seismic performance of this dual frame system, designed with the proposed method, is evaluated by nonlinear static and dynamic analysis for both Design Basis Earthquake (DBE) and Maximum Credible Earthquake (MCE). Result analysis is in accord with the assumptions, satisfying all the performance objectives. PBPD is a direct design method in which no iteration is needed to achieve the performance objectives. Determining the proportion of SPSW and moment frame shear is an exclusive capability of this procedure.

Effect of Vertical Stiffness Irregularity onMulti-Storey Shear Wall-framed Structuresusing Response Spectrum Analysis

Urbanization has led to housing problems. This has resulted in the rise of several Multi-storey and Highrise buildings. Hence Structural Dynamics study has been steadily increasing over the years. The modern trend is towards tall and slender structures (Irregular) and innovative architecturally designed structures like the Baha‟i temple (Lotus shaped). These buildings are affected by environmental factors like wind, earthquake and waterways. Millions of people world-wide annually die due to earthquakes which are responsible for billions of rupees of property damage. This has necessitated the study of Earthquake Engineering. However, study and research in the field of Irregular Buildings under seismic conditions is gaining momentum. The provision of shear wall in building has been found effective and economical. In this paper, a 10 storey building in Zone IV is presented to reduce the effect of earthquake using reinforced concrete shear wall-framed structures in the building. The results were tabulated by performing Response spectrum analysis using ETABS version 9.7.4 in the form of maximum storey displacements, base shear reactions, mode shapes and storey drifts. Effect of Irregularity was studied by creating openings in shear wall and by varying the thickness of Shear wall, along the storey‟s.

A method for determination of the dimensions of seismic shear walls in buildings

A lateral load carrying system consisting of only shear walls is used generally for structures having 14 storeys or more. It can be seen that the effect of earthquakes in the systems consisting of the shear walls or shear walls-core are very small. For resisting earthquake effects it is proposed to construct shear walls which are perpendicular to each other in plan and having the cross sectional area 1.5% of the building. Unfortunately in this proposal, the effect of number of storeys and the division of shear wall area to the necessary parts is not taken into consideration. In this paper, these factors are considered as, number of storeys, plan area of a storey, earthquake risk zone, material properties and shear wall thickness. The criteria for determination of the dimensions of earthquake shear walls which are suitable for architectural considerations of the building are given. For various storey areas and 10 storeys, the lengths of shear walls which ensure the suggested criteria, having the same length are given in diagrams. It is also shown how to find the length of shear walls under the same conditions if there are more than 10 storeys.

Influence of Wall Thickness and Concrete Grade of Shear Wall Amount

Engineering examples and finite element structural analysis software SATWE was used to calculate by adjusting the shear wall thickness and grade to study the dynamic characteristics of concrete structures; analysis of seismic shear, natural vibration cycles, maximum interlayer displacement angle, lateral displacement stiffness to weight ratio and shear weight ratio of these parameters change rules, resulting in changes in shear wall thickness greater impact on shear wall amount.

STUDY OF SHEAR WALLS IN MULTISTORIED BUILDINGS WITH DIFFERENT THICKNESS AND REINFORCEMENT PERCENTAGE FOR ALL SEISMIC ZONES IN INDIA

This paper investigates the effect of different thickness and corresponding reinforcement percentages required for shear walls on multi-storied buildings. Building models with shear walls are developed using ETABS. The location of the shear walls are kept same and a comparative study is done for different thickness of the shear wall for different height of the building (5 storied, 10 storied and 15 storied). In each of the cases corresponding reinforcement percentages required are found out. It is observed that for a constant thickness of shear wall, reinforcement percentage increases with increase of both seismicity and number of stories. It is also observed that for all zones, the reinforcement percentage increases if the shear wall thickness increases for a certain range of thickness and then decreases for a certain range of thickness. Thus the results indicate that increase of shear wall thickness is not always effective for earthquake resistant design.

Mechanical Behavior Analysis of Reinforced Concrete Column Strengthening with Shear Wall

This paper studies the influences of factors such as axial compressive ratio and shear wall thickness on the mechanical performance of the reinforced concrete column strengthening with shear wall under low-cyclic reversed loading. Considering the secondary stress characteristics of the strengthening column, a numerical analysis was made on the load displacement hysteretic curve and skeleton curve. The results show that, with the increasing of axial compression ratio, the bearing capacity and stiffness of reinforced concrete column increased, but the ductility of reinforced column reduced; the bearing capacity and rigidity of reinforced column strengthening with shear wall increase while the ductile was lower; the change of shear wall thickness has a little effect on the bearing capacity, but improves the energy dissipation capacity of reinforced concrete columns.

Parametric Study of Exterior Shear Wall–Floor Slab Connections

AbstractExperimental investigation on the effect of geometric parameters on the performance of exterior shear wall–floor slab joints subjected to cyclic loading is presented. A prototype building situated at Chennai, India was analyzed and estimated the force components in the exterior shear wall–slab joint. The force components and the dimensions were scaled down for 1/4th model following Cauchy’s law of similitude. Experimental investigations were carried out on eight numbers of 1/4th scaled models. The loading was applied at the end of the slab. The parameters considered are (1) ratio of height of shear wall and the effective width of the slab (H/We), (2) ratio of thickness of slab to shear wall (ts/tw), and (3) development length of reinforcing bars. The experimental observations were analyzed to arrive at optimum values of the height of shear wall (H), effective width of slab (We), thickness of shear wall (tw), thickness of slab (ts), and development length (Ld). Numerical investigations were employe...

Research on the Stiffness Optimization of the Reinforced Concrete’s Shear Wall Structure Based on the Earthquake Response Spectrum

Optimization design is the significant development in the structure design which could adopt the better from several plans in the same task. This paper build the finite element model of sixteen-floors shear wall structures, which control the deformation as the restraint condition, to make the thickness of shear wall as the design variable and to take the light structure as the objective function in order to execute the optimization. After the optimization, the bottom and internal stress become higher, whereas the centralized stress will occur in the corner and the middle of the rooftop and the opening of the shear wall. The horizontal earthquake of the various floors presents the curve like S with the increasing of the floors. And the floor which occur earthquake effect and the biggest displacement angle is in the middle of the structure and the whip tip effect will emerge in the top of the structure.

Structural Design Optimization for a Case of a High-Rise Comprehensive Building

Framework-shearwall structure is a dual resistive system to lateral force, which should have reasonable arrangement of shear wall thickness and quantity. The thickness should be decreased successively along the height of a building so as to adjust the internal force and deformation of the framework and the shear wall, and give full play to each of their advantages under stresses and finally achieve the purpose of safety and economy.

Frequency optimization of a wind turbine blade in pitching motion

This article presents a mathematical model for optimizing frequencies of a wind turbine blade in pitching motion. Related design problems include the excessive blade torsional vibrations induced by continuous pitching, which is necessary to limit the power output and protect generator from damages in severe wind conditions. This, in turn, can have adverse effects on the fatigue life of the blades and might cause catastrophic failures near the resonant frequencies. The study considers a blade tapered linearly towards the tip representing the effective aerodynamical surface for producing the needed power. The blade inboard portion is modelled by an equivalent torsional spring simulating the torsional stiffness near the root. The model provides exact solutions of the resulting governing differential equation by utilizing analytical Bessel's functions of the first kind, where the functional behaviour of the torsional frequency has been thoroughly examined. The associated optimization problem is formulated by considering two forms of the objective function. The first one is represented by a direct maximization of the fundamental frequency, while the second one considers minimization of the square of the difference between the fundamental frequency and its target or desired value. In both strategies, an equality constraint is imposed on the total structural mass in order not to violate other economic and performance requirements. Design variables encompass the blade tapering ratio, chord, and shear wall thickness distributions, which are expressed in dimensionless form, making the formulation valid for a variety of blade configurations. In fact, the mathematical procedure implemented can be regarded as a beneficial design tool, in which significant increase in the overall stiffness/mass ratio level of the blade structure combined with full separation of the frequency from the undesired range that resonates with the pitching frequencies can be achieved.

Design optimization of 3D reinforced concrete structures having shear walls

This paper presents a computer-based method for the optimal design of three-dimensional Reinforced Concrete (RC) structures having beams subjected to shear force and bending moment, columns subjected to biaxial moments, biaxial shears and axial loads, and shear walls subjected to pure shear. Regarding the beams and columns, the design variables are the width, depth and area of longitudinal reinforcement of member sections. The design variables for the shear walls are the thickness of the wall, the area of vertical reinforcement, horizontal distance between the vertical stirrups, the area of horizontal reinforcement, vertical space between the horizontal stirrups, and the area of vertical flexural reinforcement. The Optimality Criteria (OC) method is applied to minimize the cost of the concrete, steel and formwork for the structure. ACI code [1] provisions concerning the strength and ductility of beams, columns and shear walls are taken as constraints. The constraints also impose upper and lower bounds on the dimensions of beams and columns, and on shear wall thickness, reinforcement area and the maximum and minimum vertical and horizontal spaces between the stirrups of the shear walls. Sensitivity analysis is conducted for both internal forces and the capacities of the sections of the beams, columns and shear walls. The features of the design method are illustrated by a solved example.