scholarly journals Study on the Effect of Extra Pole Support on Seismic Resistance for Low-Rise RC Structures

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Pengjie Lu ◽  
Guoxin Wang

There is a common way to enhance the collapse safety of residential houses using extra tilted poles supporting poor structures from the outside before and/or after earthquakes in seismic regions, especially in rural areas. But, almost all of these supporting measures are still weak and lack of scientific design and evaluation. This study takes a poorly designed two-bay and three-story RC frame building as an object to explore the effect of this kind of support measures on structural seismic resistance by comparing with a standard-designed RC frame structure model as a contrastive case. The results obtained by performance-based methods indicate that extra poles can improve the seismic collapse safety and reduce structural seismic damage of the poorly designed structure (PDS) effectively. The median collapse capacity parameter θ increases from 1.31 g to the range of 1.92∼2.39 g, and SaT1;10% (spectral acceleration at the first-mode period which causes 10% probability of structural collapse) also increases from 0.57 g to the range of 0.75∼1.08 g. Study of dynamic structural damage shows a great damage reduction of PDS under seismic loads, especially SaT1 = 0.2 g. This study proves that this simple measure can improve the seismic resistance of PDS into an acceptable level by taking our suggested practical and efficient supporting schemes.

2012 ◽  
Vol 204-208 ◽  
pp. 1286-1289
Author(s):  
Soo Yeon Seo ◽  
Jeong Hun Kim ◽  
Jae Yeong Yeon ◽  
Hyung Joo Park ◽  
Ki Bong Choi

In this study, a push down analysis was performed for reinforced concrete (RC) frame building with collapsed column at lower floor by shock due to abnormal load in order to find progressive collapse process of building. The nonlinear flexural behavior of each structural element was defined from sectional analysis by using X-tract program. For push-down analysis of frame structure, Zeus-NL program was used. Main parameters in the analysis are location of damaged column and story of building. As a result, the deflection at the time of collapse of internal column was lower than one at the time of collapse of external column. In the frame structure with severely damaged column at lower floor, the higher the story was, the smaller the change of moment in beams at upper floors was. And, deflections of beams were found to appear evenly. This can be judged to be caused by a beam's suspension action.


Author(s):  
Pham Thai Hoan ◽  
Nguyen Minh Tuan

This study presents an investigation on the design of long reinforced concrete (RC) structures subjected to uniform temperature load by considering three RC frame building models with different lengths of 45 m, 135 m, and 270 m using Etabs. The uniform temperature load is considered being the change from the annual average highest to lowest air temperature at the construction site in the case of unavailable temperature data of concrete. The analysis results indicate that the uniform temperature load mainly influences on the internal forces of RC members at storey 1 and slightly effects on the internal forces of RC members at storey 2. For short-length RC structures, the effect of temperature load can be ignored in the design of RC elements, whereas it must be taken into account in design of slab, beams and some column positions at storey 1 of medium-length and long RC structures without expansion joints. For the present RC frame building models, the required slab reinforcement in long direction increases about 33.4% for medium-length RC structures (135 m) and about 48.2% for long RC structures (270 m) without expansion joints. The required reinforcement for positive moment at mid-span increases from 33.7 to 39.4%, whereas the total required reinforcement for negative moment at the supports of beams increases from 19.4 to 34.9% in long direction of 270 m long RC structures without expansion joints due to uniform temperature load. Column design of long RC structures without expansion joints under uniform temperature load must be concerned, especially for columns in the corners.


2012 ◽  
Vol 568 ◽  
pp. 85-88
Author(s):  
Ming Gao

In 5·12 Wenchuan earthquake, most of the buildings were damaged at different degrees in Mianyang. To analysis seismic damage of RC frame structure building, and investigate its reinforcement situation,the results show that: For destruction of frame column or bottom frame structure column, enlarge section method is used mostly for reinforcement in civil engineering;To serious damage of affiliated structure such as filler wall and Parapet, most of them will be demolished and built again, and add constructional column; To the situation of concrete bottom plate with crack, paste carbon fiber sheet or bottom plant steel was used depending on the structural damage degree, and jet concrete for strengthening.


2011 ◽  
Vol 255-260 ◽  
pp. 644-648
Author(s):  
Yan Xia Ye ◽  
Hua Huang ◽  
Dong Wei Li

Comparative analyses of twenty-eight finite element structures with filler walls were established to study dynamic characteristics of RC frame structures under seismic waves. The results of these analyses show that filler walls have little influence on vibration modes of the structure. But as a result of soft storey in the bottom of building caused by reduction of the filler walls, vibration modes have a great influence. As the stiffness of filler wall decrease, the stiffness of soft storey decrease shapely, vibration mode curve becomes much smoother. Considering the filler wall has influence on the vibration periods of framework, the reduction factor of 0.7 should be taken. The influence of filler wall to the value of lateral drift and storey displacement angle of frame can not be ignored. The main effect factors to the dynamic characteristics of framework are included quantity, location, material of the fill wall and the selection of seismic waves.


2014 ◽  
Vol 556-562 ◽  
pp. 712-715
Author(s):  
Jing Zhao ◽  
Jing Zhao ◽  
Xing Wang Liu

In collapse-resistant design of a structure under accidental local action, it is important to understand the failure mechanism and alternative load paths. In this paper, a pseudo-static experimental method is proposed. Based on which, the collapse of frame structure was simulated with testing a 1/3 scale; 4-bay and 3-story plane reinforced concrete frame. In the experience, the middle column of the bottom floor was replaced by mechanical jacks to simulate its failure, and the simulated superstructure’s gravity load acted on the column of the top floor by adopting a servo-hydraulic actuator with force –controlled mode.


Author(s):  
Kugan K ◽  
Mr. Nandha Kumar P ◽  
Premalath J

In this study, four geometrically similar frames having different configurations of masonry infills, has been investigated. In this article attempts are made to explain the factors that impact the soft storey failure in a building are compared with different type of infill. That is Four models like RC bare frame, RC frame with brick mansonry infill, RC frame with brick infill in all the storeys exept the firstsoft storey, RC frame with inverted V bracing in the soft storey. Time history analysis has been carried out for a G+8 multistoried building to study the soft storey effect at different floor levels using E tabs software. The behavior of RC framed building with soft storey under seismic loading has been observed in terms of maximum displacement ,maximum storey drift, base shear and storey stiffness as considered structure.


2010 ◽  
Vol 97 (28) ◽  
pp. 25-32
Author(s):  
Marin Lupoae ◽  
Carmen Bucur ◽  
Cătălin Baciu

2019 ◽  
Vol 2019 ◽  
pp. 1-18
Author(s):  
Guang Yang ◽  
Erfeng Zhao ◽  
Xiaoya Li ◽  
Emad Norouzzadeh Tochaei ◽  
Kan Kan ◽  
...  

The reinforced concrete (RC) frame with masonry infill wall is one of the most common structural systems in many countries. It has been widely recognized that the infill wall has significant effects on the seismic performance of RC frame structure. During the Wenchuan earthquake (China 2008), a lot of infilled RC frame structures suffered serious damages due to the detrimental effects brought about by the infill wall rigidly connected to the surrounding frame. In order to solve this problem, flexible connection, introduced by Chinese designers, is recommended by the updated Chinese seismic design code, because of its effect to reduce the unfavorable interaction between infill wall and frame. Although infilled RC frame structure with flexible connection has a lot of advantages, but because of the lack of research, this structure type is seldom used in practical engineering. Therefore, it is of great significance to scientifically investigate and analyze the effects of flexible connection on structure behaviors of infilled RC frame. In this study, a macrofinite element numerical simulation method for infilled RC frame with flexible connection was investigated. Firstly, the effects of connection between infill wall and surrounding frame on in-plane behaviors of infilled RC frame were discussed. Secondly, based on deeply studying the equivalent diagonal strut models for infilled RC frame with rigid connection, an improved equivalent diagonal strut model for infilled RC frame with flexible connection was proposed. Employed with inversion analysis theory, the parameter in the proposed model was estimated through artificial fish swarm algorithm. Finally, applied with the existing experiment results, a case study was conducted to verify the effectiveness and feasibility of the proposed model.


2011 ◽  
Vol 255-260 ◽  
pp. 2632-2636
Author(s):  
Zhong Wei Liu ◽  
Yu Bai ◽  
Xiang Hui Xiong ◽  
Jun Ting Li

Based on the appraisal reports of primary and secondary school in Kunming and the statistical analysis of RC frame structure buildings, evaluation of earthquake resistance capacity was given. Problems affecting functions of the RC frame structure were analyzed to facilitate the reconstruction and fetrofit of this sort of RC frame structure.


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