Comparison of equivalent seismic load and response spectrum methods according to TSC 2018 and TSC 2007

2019 ◽  
Vol 5 (4) ◽  
pp. 141
Author(s):  
İbrahim Hakkı Erkan ◽  
Talha Polat Doğan
Keyword(s):  
Response Spectrum ◽  
Seismic Load ◽  
Structural Systems ◽  
Seismic Loads ◽  
Analysis Method ◽  
Base Shear ◽  
Response Spectrum Method ◽  
Shear Forces ◽  
Linear Dynamic ◽  
Spectrum Method

In this study, two different analysis methods were compared; the first is a linear static analysis method and the second is a linear dynamic analysis method. First one is the Equivalent Seismic Load Method, which is a linear static method where seismic loads can be obtained by applying a simple calculation. The second method, the Response Spectrum method, is a linear dynamic analysis method which obtains the seismic loads using more complex statistical calculations. For this analysis study, 18 structural models with 3 different building heights were analyzed according to the conditions of Equivalent Seismic Load Method and Response Spectrum Method specified in both TSC 2007 and TSC 2018 and base shear forces obtained as a result of these analyzes were compared. As a result of analysis; compared to the results obtained from TSC 2007, due to the effective stiffness coefficients specified in TSC 2018, it was observed that the base shear forces obtained for both methods were lower and the modal period values were longer in the analyzes applied according to TSC 2018. This means that the structural systems created with the designs according to TSC 2018 are more ductile than the structural systems created with the designs made according to TSC 2007. Base shear forces obtained by 2 different analysis methods applied according to regulations stated in both TSC 2018 and TSC 2007; it was observed that the base shear forces obtained by the Equivalent Seismic Load Method were higher than the results of the Response Spectrum Method.

An investigation on determining optimum wall ratio–cost relationship of shear walled reinforced concrete buildings

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
İbrahim Hakkı Erkan ◽  
Talha Polat Doğan ◽  
Musa Hakan Arslan
Keyword(s):  
Reinforced Concrete ◽  
Response Spectrum ◽  
Construction Cost ◽  
Frame Structures ◽  
Structural Systems ◽  
Analysis Method ◽  
Base Shear ◽  
Shear Forces ◽  
Concrete Wall ◽  
Wall Structures

Reinforced concrete walls are very efficient structural elements in terms of carrying the lateral loads that are expected to affect the structures during the service of the buildings. These elements, which are not used for economic reasons in buildings designed in areas with low seismic hazard, can actually provide a significant increase in performance with a very small increase in construction cost. In this study, a total of 9 building models have been created and the relationship between optimum reinforced concrete wall ratio and cost on these buildings has been investigated. The design and analysis of the models were carried out according to the criteria specified in TSC 2018. Three different structural systems specified in TSC 2018 were used in the designed models. These structural systems used; RC frame structures, RC wall-frame structures and RC wall structures. These structures were analyzed by Response Spectrum Method which is linear analysis method and base shear forces were obtained. Then, push-over analysis, which is a nonlinear analysis method, was applied to obtain the base shear forces that the structure can actually carry. After the analysis, the quantities of materials to be used for the construction of the structural systems of the models were calculated and current manufacturing prices and rough costs were calculated. In order to compare the obtained costs with the structural performances, nonlinear shear forces and linear shear forces ratios were calculated and the over strength factors were calculated for each model. In the light of the data obtained from the studies in the literature, when the over strength factors and cost values are examined together, it is concluded that the optimum design for the conditions specified in TSC 2018 will be provided with the RC wall ratio between 0.001 - 0.0016. It is concluded that lateral load carrying capacity of construction increases up to 650% by increasing the construction cost by 17% for the designed models.

Research on the Seismic Analysis and Optimization of High Flux Reactor Nuclear Power Piping System Based on Multi-Point Response Spectrum Method

2020 ◽  
Author(s):  
Xuan Huang ◽  
Pingchuan Shen ◽  
Shuai Liu ◽  
Jian Liu ◽  
Xiaozhou Jiang ◽  
...  
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
High Flux ◽  
Analysis Method ◽  
Response Spectrum Method ◽  
High Flux Reactor ◽  
Reactor Coolant ◽  
Spectrum Method ◽  
Flux Reactor ◽  
Coolant System

Abstract High flux reactor is an important engineering test reactor, which can be used in irradiation research of materials, chemistry, isotopes, medicine and other fields. In the high flux reactor coolant system, there are a large number of nuclear pipes and the layout is complex. The optimization of seismic analysis method for reactor coolant system is an important part in the design process to ensure the nuclear pipes meet the design specifications. The traditional single point response spectrum method needs to envelope the response spectrum of different floors as the analysis input. This method is difficult to give the reasonable seismic load to the numerous nuclear pipes and it will increase the design cost and the difficulty of safety analysis about nuclear pipe. In this paper, an optimized seismic analysis method of reactor coolant system is proposed. By using the multi-point response spectrum method, the optimization of different excitation loading modes for different constrained support points is realized. The analysis results show that the multi-point response spectrum method can solve the problem that different support points are located at different elevation floors in the reactor coolant system, which makes the calculation results more accurate and reasonable. Compared with the traditional method, it can make the design more efficient and practical.

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 Seismic Behaviour of Offshore Steel Jacket Platform Braced in Horizontal and Vertical Planes

2019 ◽  
Vol 8 (12) ◽  
pp. 1947-1953
Keyword(s):  
Seismic Analysis ◽  
Response Spectrum ◽  
Vertical Plane ◽  
Static Method ◽  
Base Shear ◽  
Response Spectrum Method ◽  
Seismic Behaviour ◽  
Jacket Platform ◽  
Spectrum Method ◽  
Time Period

The offshore jacket platforms are primarily installed in the large oceans mainly for drilling the crude oil, carbohydrates and production of electricity. The current studies emphasize on the structural performance of offshore deck jacket platform with different bracing systems. Earthquake analysis has been performed to calculate the seismic responses, with the help of bracings to control the seismic induced vibrations of the jacket platforms. For this study, a jacket platform made up of steel members has been modeled and then analyzed under earthquake and wave loadings. This paper mainly deals to compute and compare the seismic behavior of offshore steel deck platform using SAP 2000 v20 software with bracing in the horizontal plane and bracing in both horizontal and vertical planes. The total number of 8 models has been analyzed in the SAP2000 software with bracing i.e. X, V, Inverted V and K in the vertical plane and bracing i.e. X, V, Inverted V and K in both horizontal and vertical plane. A relative study has been carried out in Time period, deck displacement and base shear. Seismic analysis using linear static, i.e. Equivalent static method (ESA) and linear dynamic, i.e. Response spectrum method (RSA) has been performed. Further deck displacement, time period and base shear are determined by Equivalent static method and Response spectrum method for various types of bracing models in both horizontal and vertical planes. Among the all various types of bracing models, Inverted V bracing in the vertical plane is found to be the optimum model among all other models.

scholarly journals A study on earthquake performances of reinforced concrete buildings with various number of stories

2021 ◽  
Vol 4 (2) ◽  
pp. 83-98
Author(s):  
Yuşa Uğur Çapa ◽  
Ali Ruzi Özuygur ◽  
Zekai Celep
Keyword(s):  
Load Capacity ◽  
Response Spectrum ◽  
Lateral Load ◽  
Seismic Load ◽  
Implicit Assumption ◽  
Response Spectrum Method ◽  
Nonlinear Load ◽  
Seismic Codes ◽  
Spectrum Method ◽  
Modal Response

Seismic codes generally require that the Equivalent Seismic Load Method or the Modal Response Spectrum Method is adopted in the design of buildings. In the equivalent seismic load method, the equivalent seismic static force applied to the building is determined depending on the seismicity of the region where the building is located, the usage class of the building, the fundamental period of the building and the building mass. Later, this equivalent seismic load is reduced by the seismic load reduction factor to take into account the increase in the capacity of the system and the decrease in the seismic demand due to the nonlinear and inelastic behavior of the system, i.e., by accepting limited inelastic deformations in the building subjected to the design earthquake. Then, structural system of the building is analyzed under the reduced seismic forces in addition to the vertical loads by using the load combinations given in the design codes. The process is completed by designing the sections and the structural elements of the building. Similar processes can be implemented by using the modal response spectrum method. The difference between these two methods is consideration of the higher modes of the building instead of the first mode only and the use of the modal masses of the building for each mode, instead of the total mass of the building. In the latter method, the contributions of the higher mode are combined by using specific superposition rules. The codes assume that the structural systems designed in this way will exhibit the almost same level of inelastic deformation, i.e., the controlled damage state, regardless of the building parameters, such as the number of stories. In this study, an attempt is made to investigate the validity of this implicit acceptance. For this purpose, the buildings with a various number of stories are designed by satisfying the bare minimum requirements of the code only, as much as possible. The seismic behavior and the lateral load capacity of these buildings are examined by the static and dynamic nonlinear analyses. The ratio of the nonlinear load capacity to the reduced equivalent seismic load is evaluated depending on the number of the stories of the buildings. The results which are presented in detail yield that the buildings with a low number of stories have relatively larger nonlinear lateral load capacity-to-the reduced elastic seismic load ratio, which is not compatible with the general implicit assumption made in the seismic codes.

Vertical seismic response analysis of long-span composite open-web grid floor

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qizhu Yang ◽  
Kejian Ma ◽  
Huagang Zhang ◽  
Yanhui Wei ◽  
Ze Xiang
Keyword(s):  
Seismic Performance ◽  
Response Spectrum ◽  
Time History ◽  
Grid Floor ◽  
Time History Analysis ◽  
Analysis Method ◽  
Response Spectrum Method ◽  
Content Type ◽  
Spectrum Method ◽  
History Analysis

PurposeThe purpose of this paper is to study the dynamic characteristics and seismic performance of the composite open-web grid floor structure.Design/methodology/approachStudied by using mode-superposition response spectrum method and time history analysis method.FindingsThe results show that the vertical mode-superposition response spectrum method is close to the time history analysis method. The floor has strong seismic performance, and the deflection and internal force are not large under vertical seism. The vertical seismic action suggested that 10% of the representative value of gravity load should be used to ensure the safety of the structure.Originality/valueIn the design, the mid-span section should be properly strengthened or the variable section design should be adopted.

Research on Analysis Method of Seismic Response of Long Span Cable-Stayed Bridge

2013 ◽  
Vol 353-356 ◽  
pp. 2228-2232
Author(s):  
Xu Li ◽  
Sheng Ping Wu ◽  
Zhen Zheng Fang
Keyword(s):  
Seismic Wave ◽  
Response Spectrum ◽  
Time History ◽  
Time History Analysis ◽  
Seismic Load ◽  
Analysis Method ◽  
Cable Stayed Bridge ◽  
Spectrum Method ◽  
Long Span ◽  
History Analysis

The response of the long-span cable-stayed bridges under seismic load is complex. Reasonable methods is very important to analyze the seismic performance. In this paper, a practical project is taken as research background which is double pylon cable-stayed bridge with main span of 416m. Two artificial seismic waves and two seismic records were selected to analyze the seismic behaviors by the response spectrum method, time history analysis method and power spectrum method. The result shows that seismic responses of the girder and main tower are basically identical under the effect of artificial seismic wave. The response spectrum analysis results of them are between the other two methods under the effect of the natural seismic wave. For stay cable, time history analysis results has great difference compared with results of other two methods. Therefore, different methods should be choosed base on specific circumstances to analyse the earthquake response of this structure.

scholarly journals Performannce Base Analysis of Multy Storied Building

2021 ◽  
Vol 9 (8) ◽  
pp. 2053-2062
Author(s):  
Kunwer Fahmed Alam Ariyana
Keyword(s):  
Response Spectrum ◽  
Pushover Analysis ◽  
Horizontal Load ◽  
Base Shear ◽  
Response Spectrum Method ◽  
Spectrum Method ◽  
Linear Approach ◽  
Time Period ◽  
Non Linear ◽  
Pushover Curve

Abstract: In India multistoried buildings are widely designed with the method suggested by Indian Standard IS1893: Part-1:2016, Criteria for the Earthquake resistance design of the structures: General Provision and Buildings for the calculation of equivalent horizontal load generated during earthquake. Response Spectrum method is widely used for the multistoried buildings with base shear scaled to get the equal value as calculated with the time period obtained by the empirical formula of time period of the buildings. The approach of the dynamic analysis is basically a linear approach. In this scenario we are totally relying on ductility of the structure. The concept for performing the Pushover Analysis is to analyze a structure with non linear approach and to find the behavior of structure beyond its ductile limit. Pushover analysis can help to demonstrate how progressive failure in building really occurs and to identify the mode of final failure of the buildings. Pushover analysis is commonly used to evaluate the seismic capacity of existing structures and appears in several recent guidelines for retrofit seismic design. It can also be useful for performance-based design of new buildings that rely on ductility or redundancies to resist earthquake forces. So basically Pushover analysis is non linear approach to estimate the strength capacity of the structure beyond Limit State. In this analysis we can predicts the weak areas in the building and keeping track of the sequence of damages of each and every member in the building/structure, thus can be performed for existing structure and also for performance base design, similarly for progressive collapse analysis. The approach is easy to understand, when we designed or analyze a moment resisting frame as per IS 1893:2016 by Response Spectrum method with response spectrum method with the response reduction factor 5 i.e. R=5, we are basically designing the structure with 1/5th horizontal load (calculated with the empirical formula given in IS 1893:2016), the rest 4/5th load is basically taken care by the ductile behavior of the building. The ductile detailing suggested by the 13920:2016 will resist the full impact of seismic load without collapse. The distribution and impact of the full horizontal load can be analyzed with the non linear approach, and pushover analysis is one of them. METHODLOGY: A pushover analysis is performed by subjecting a structure to a monotonically increasing pattern of lateral loads, representing the inertial forces which would be experienced by the structure when subjected to ground shaking. Under incrementally increasing loads various structural elements may yield sequentially. Consequently, at each event, the structure experiences a loss in stiffness. Using a pushover analysis, a characteristic non linear force displacement relationship can be determined. Key elements of the pushover analysis 1) Definition of plastic hinges, it includes hinges for uncoupled moment, hinges for uncoupled axial load, hinges for uncoupled shear force, hinges for coupled axial force and hinges for biaxial bending moment. 2) Definition for control node, the node used to monitor the displacement of the structures. Pushover curve is obtained from the displacement verses base shear. 3) Developing the pushover curve which includes the elevation of the forces distribution 4) Estimation of the displacement demand. 5) Evaluation of performance level for the structure

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