scholarly journals Behavioural Study of Infill’s Walls on Soft Story Building

Author(s):  
Shilpa S and Navith K B

Open ground storey or soft storey is a typical feature in multistory structures in urban areas. This open storey is provided to accommodate parking, reception lobbies, office, communication hall etc. Many of structure having soft storey suffered major damage and collapsed in recent earthquakes. During an earthquake, because of variation in stiffness in soft story and its adjacent floors the inter story drift can occur and the lateral forces cannot be well distributed along the height of building. Lateral forces concentrate on soft story causes large displacement. In this work, an attempt has been made to observe the behavior of gradual decrease in stiffness of building, by using different types of infill material. This work discusses Optimum Earthquake response of tall buildings by response spectrum method as per IS 1893:2002 (Part- I) in ETAB’S software. Seismic parameters like storey stiffness and storey displacement are checked out.

Author(s):  
Ashutosh Shrivastava ◽  
Rajesh Chaturvedi

Nowadays, as in the urban areas the space available for the construction of buildings is limited. So in limited space we have to construct such type of buildings which can be used for multiple purposes such as lobbies, car parking etc. To fulfill this demand, high rise buildings is the only option available. The performance of a high rise building during strong earthquake motion depends on the distribution of stiffness, strength and mass along both the vertical and horizontal directions. If there is discontinuity in stiffness, strength and mass between adjoining storeys of a building then such a building is known as irregular building. The present study focuses on the seismic performance of regular and vertical irregular building with and without masonary infills. In the present study G+11 building is considered for the analysis with modelling and analysis done on ETABS software v17.0.1. The earthquake forces are calculated as per IS 1893 (part 1): 2016 for seismic zone III. The width of strut is calculated by using equivalent diagonal strut method. Total five models are considered for the analysis i.e. regular building with bare frame, regular building with masonary infill, soft storey building with open ground storey, mass irregular building with masonary infill and vertical geometric irregular building with masonary infill. The non-linear static analysis (pushover analysis) and linear dynamic analysis (response spectrum analysis) are performed for all the models and thereby compare their results. From analysis, the parameters like performance point, time period, maximum storey displacement, maximum storey drifts, storey shears and overturning moments are determined and also comparative study is done for all the models. From the comparison, it is observed that the vertical geometric irregular building shows better performance under seismic loading and bare frame building shows inferior performance. Moreover, the performance of masonary infilled frame building is f


Present scenario growth of Multistory building is incredibly high attributable to fast growth everywhere around the globe. Open first story is usually provided for congested parking space, reception lobbies, party areas or any purpose in multistory building. However just in case of multistory building with soft story provides reduced performance. There are numerous aspects that effects on the behavior of multistory building like irregular plan within the structure. In the present work, study of various locations of weak stories is being considered for the analysis. To study of various locations on the seismic behavior of multistory building, linear static analysis (ESA) and linear dynamic analysis (RSA) in ETABs 2016 version is applied. Some seismic constraints like time period, story shear, story displacement, story drift and base shear are tried. The seismic behaviors of multistorey building with soft stories are administered.


2021 ◽  
Vol 933 (1) ◽  
pp. 012008
Author(s):  
A H Prathama ◽  
M Teguh ◽  
F Saleh

Abstract The growing growth of human activities has led to changes in housing patterns in urban areas. The land crisis in urban areas has made land prices uneconomical, so buildings are designed vertically. One solution to resist earthquakes in multi-story buildings is to add a shear wall structure with the proper profile and layout. Shear wall designs with variations influence the base shear, drift ratio, lateral deflection, and story drift patterns. This study presents the structural response comparison of buildings against variations in the profile and layout of shear walls subjected to earthquake loads. Force Based Design method utilizing the response spectrum approach was adopted in the analysis and carried out using SAP200. Six structural models comprise a frame without shear walls, three L-profile shear walls, two I-profile (straight) shear walls. The simulation results of the overall structural models show that the profile and layout configuration of shear walls in the frame structure of a multi-story building correlates directly to the performance of base shear, drift ratio, and story drift with relatively comparative conditions.


Nowadays highly increases in the high rise building with architectural requirement in modern city. The purpose of the study is to understand the response of the building due to vertical irregularities. In this paper the incorporated irregularities are as per IS1893 (Part )1:2016 and study response of 12 story building frame 13 models with mass irregular, stiffness irregular and vertical geometric irregularities are analyze in ETABS 2017 by linear dynamic analysis i.e. Response spectrum Analysis. The various structural response parameters such as maximum storey displacement, inter story drift and storey shear are taken to compare the result. Mass irregularity is placed in fourth story, stiffness irregularity is provided in first storey and vertical geometric irregularity is provided in different upper floor. It is concluded that the soft story at bottom highly increases the lateral displacement of that floor, mass irregular at fourth story highly increases the storey shear below that storey and vertical geometric irregularity effect on the relative displacement of building. Combined irregularity highly effect performance of the building therefore chance of collapse also increases as increases in irregularities. All the comparison are represented graphically.


2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Dian Yuristia ◽  
Ririt Aprilin S ◽  
R. Eka Murtinugraha

The purpose of this research was to analyze soft second  story bulding behavior due to the earthquake load by applying column height variation. The building case has a vertical irregularity soft story on the second level so the behavior during the earthquake was analyzed by heighten the columns at the second level of the building. The behavior of building structure results the response such as internal forces in columns and beams, base shear, fundamental period, displacement and story drift. The seismic analysis is using dynamic analysis response spectrum based on SNI 1726:2012 and carried out using software ETABS version 9.7.4. The results of this research indicates that the increase of column height in soft second  story building reduces the building stiffness. So it decreases the building forces, extending the fundamental period, decreasing the base shear, increasing the displacement and the story drift. It can be concluded that the soft second  story building reduces the building resistance of earthquake load by produces the behavior approaches the collapse.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 657
Author(s):  
Aoki Takanose ◽  
Yoshiki Atsumi ◽  
Kanamu Takikawa ◽  
Junichi Meguro

Autonomous driving support systems and self-driving cars require the determination of reliable vehicle positions with high accuracy. The real time kinematic (RTK) algorithm with global navigation satellite system (GNSS) is generally employed to obtain highly accurate position information. Because RTK can estimate the fix solution, which is a centimeter-level positioning solution, it is also used as an indicator of the position reliability. However, in urban areas, the degradation of the GNSS signal environment poses a challenge. Multipath noise caused by surrounding tall buildings degrades the positioning accuracy. This leads to large errors in the fix solution, which is used as a measure of reliability. We propose a novel position reliability estimation method by considering two factors; one is that GNSS errors are more likely to occur in the height than in the plane direction; the other is that the height variation of the actual vehicle travel path is small compared to the amount of movement in the horizontal directions. Based on these considerations, we proposed a method to detect a reliable fix solution by estimating the height variation during driving. To verify the effectiveness of the proposed method, an evaluation test was conducted in an urban area of Tokyo. According to the evaluation test, a reliability judgment rate of 99% was achieved in an urban environment, and a plane accuracy of less than 0.3 m in RMS was achieved. The results indicate that the accuracy of the proposed method is higher than that of the conventional fix solution, demonstratingits effectiveness.


2021 ◽  
Vol 11 (3) ◽  
pp. 1290
Author(s):  
Santiago Mota-Páez ◽  
David Escolano-Margarit ◽  
Amadeo Benavent-Climent

Reinforced concrete (RC) frame structures with open first stories and masonry infill walls at the upper stories are very common in seismic areas. Under strong earthquakes, most of the energy dissipation demand imposed by the earthquake concentrates in the first story, and this eventually leads the building to collapse. A very efficient and cost-effective solution for the seismic upgrading of this type of structure consists of installing hysteretic dampers in the first story. This paper investigates the response of RC soft-story frames retrofitted with hysteretic dampers subjected to near-fault ground motions in terms of maximum displacements and lateral seismic forces and compares them with those obtained by far-field earthquakes. It is found that for similar levels of total seismic input energy, the maximum displacements in the first story caused by near-fault earthquakes are about 1.3 times larger than those under far-field earthquakes, while the maximum inter-story drift in the upper stories and the distribution and values of the lateral forces are scarcely affected. It is concluded that the maximum displacements can be easily predicted from the energy balance of the structure by using appropriate values for the parameter that reflects the influence of the impulsivity of the ground motion: the so-called equivalent number of cycles.


2013 ◽  
Vol 353-356 ◽  
pp. 2301-2304
Author(s):  
Fan Wu ◽  
Ming Wang ◽  
Xin Yuan Yang

High-rise buildings, as a result of rapid urbanization in China, become one of popular structure kind. However, there have been few seismic vulnerability studies on high-rise buildings, and few fragility curves have been developed for the buildings. Based on the published data of more than 50 high rises and super high rises, the structural information such as building heights, mode periods, locations and sites, the maximum design story drift ratios, are collected and analyzed. The vulnerability analysis for high rises uses response spectrum displacement as seismic ground motion input, since the structures have comparatively long natural period. Using statistics and regression analysis, the relationship between the maximum story drift ratio and response spectrum displacement is established. Based on height groups and earthquake design codes, the fragility curves of different performance levels can be developed. These curves can provide good loss estimation of high rise structural damage under earthquake ground motion.


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