Buildings Subjected to Recurring Earthquakes: A Tale of Three Cities

2011 ◽  
Vol 27 (3) ◽  
pp. 635-659 ◽  
Author(s):  
Beyhan Bayhan ◽  
Polat Gülkan

Three different buildings built according to the same design have experienced three different near-field strong ground motions over a period of 11 years in three different cities in Turkey. The input motion was known for each because strong-motion sensors were located adjacent or close to the buildings. We examine the performance of the five-story, reinforced concrete-frame buildings. Bidirectional nonlinear time history and nonlinear static analyses on 3-D analytical models are performed. The principal focus is to assess whether the analytical model of the buildings could indicate column-beam damage consistent with that observed at the sites after the earthquakes. Results illustrate that nonlinear time history analyses are capable of indicating the occurrence of shear failure in captive columns; however, they overestimate the global damage. The overestimation is greater where the building sustained a pulse-type motion without significant distress. It appears that difference between visual observations and analytical results persists.

Author(s):  
Hye-min Shin ◽  
Kyung-jae Shin ◽  
Su-woong Lee ◽  
Dae-geun Kim ◽  
Min-ki Lee ◽  
...  

On November 15, 2017, the second strongest earthquake occurred in Korea, which was 5.4 in size on the Richter Scale. The duration of the earthquake was short, but the damage was serious. Two recent earthquakes have shown that our country is no longer safe from earthquakes. However, to date, Korean structures are showing a low earthquake resistance, and seismic retrofitting is necessary in preparation for a large-scale earthquake. In this study, reinforcing effect of steel slit damper was analyzed based on the dynamic test results of the previously studied reinforced concrete frame. After that, push over analysis and nonlinear time history analysis using OpenSees were selected for the residential piloti-type building as the target building. In the above Korean earthquake, the damage to the piloti-type building was conspicuous. Through analysis, the vulnerable part of the piloti-type building was identified and the seismic strengthening with the steel slit damper was carried out.


2014 ◽  
Vol 580-583 ◽  
pp. 1458-1462
Author(s):  
Min Sheng Guan ◽  
Hong Biao Du ◽  
Wei Chen ◽  
Yu Hua Wu

Using the three-strut model, five types of frame structures, i.e., without infilled walls, with full infilled walls, without bottom-storey infilled walls, without middle-storey infilled walls and without top-storey infilled walls, were studied. The mode analysis and nonlinear time-history analysis were carried out on each model. In order to investigate the effects of infilled walls with different configurations on the seismic behavior of reinforced concrete frame structures, the structural periods, the ratio of Tt to T1 and the maximum interstorey drifts were analyzed. The results indicate that the infilled walls enhance the lateral stiffness of frames, and the configuration of infilled walls has little influence on the calculation of structural periods. It also shows that the weaker storey is formed due to the unreasonable layout of infilled walls, thus leading to the collapse of the whole structures under the seismic action.


2012 ◽  
Vol 594-597 ◽  
pp. 1734-1739
Author(s):  
Min Yao ◽  
Tie Ying Li

This paper introduces the concept and design method of the base isolation structure, through the SAP2000 software to analyze 6-story reinforced concrete frame for nonlinear time-history analysis, comparison of isolated and non-isolated structure's maximum displacement, acceleration under frequent earthquake and the maximum displacement, acceleration of isolation structure under rare earthquake. The results show that the isolated structure have a much better seismic responding than the traditional structures.


Author(s):  
Shuichi Fujikura ◽  
Yuji Sakakibara ◽  
Minh Hai Nguyen ◽  
Akinori Nakajima

<p>The 2016 Kumamoto Earthquake occurred in central Kyushu, Japan, on April 14th with Mw 6.2 followed by the Mw 7.0 mainshock on April 16th. These earthquakes were mainly caused by the Futagawa fault and Hinagu fault where surface ruptures extended about 34 km long. Some of the bridges located in mountain area and close to the fault were damaged due to these near‐field earthquakes. Oginosaka Bridge is one of them and is a horizontally curved bridge with longitudinal and transverse slope, which is a feature of the bridges located in mountain area. The superstructure was rotated on plan and displaced transversely at both abutments to the opposite side, and there was an evidence of the deck‐abutment pounding in longitudinal direction. In order to investigate the seismic behavior of the curved bridge, nonlinear time‐history analyses including a deck‐abutment pounding interaction were carried out. The deck‐abutment pounding interaction considered in the analyses could capture the post‐impact response of the superstructure. The near‐field ground motions were used for the analyses. The analytical results showed that the curved bridge is susceptible to the deck rotation caused by pounding in longitudinal direction at the deck end under earthquake loading.</p>


2012 ◽  
Vol 166-169 ◽  
pp. 2138-2142
Author(s):  
Hui Min Wang ◽  
Liang Cao ◽  
Ji Yao ◽  
Zhi Liang Wang

For the complex features in the form of a flat L-shaped reinforced concrete frame structure, the three dimensional FEM model of the structure was established in this paper, and the dynamic characteristics of the structure was analyzed, the participation equivalent mass of every mode’s order was obtained. Seismic response analysis for the structure was carried out with modal decomposition spectrum method and time history analysis method, the weak layer of the structure was pointed out and the reference for the structural design was provided.


2016 ◽  
Vol 16 (02) ◽  
pp. 1450094 ◽  
Author(s):  
Seyed Morteza Zinati Yazdi ◽  
Mohammad Taghi Kazemi

Heavy damages on structures caused by near field earthquakes in recent years has brought serious attention to this problem. An examination of previous records has shown significant differences for near field earthquakes, including a large energy pulse, unlike far field earthquakes. But as a general rule, the effects of near field earthquakes have been ignored in most building codes. The purpose of this paper is to investigate the effect of near field earthquakes on reinforced concrete (RC) moment frames. To achieve this goal, the Erduran damage index, an efficient way to calculate damage, was employed to analyze two 4- and 8-story RC moment frame buildings. The buildings with moderate and high ductility were designed by the strength criteria. Seven pairs of near field and far field earthquakes were scaled and used for dynamic nonlinear time history analysis. Using Erduran’s beam and column damage index, respectively, based on rotation and drift, the results from both near and far field earthquakes were compared. Moreover, for better assessment, 4-story buildings were evaluated from the performance based viewpoint of design. We observe from the results that most of the components of the structures under near field earthquakes sustained severe damages and in some cases even component failure. Components of the structures under near field earthquakes suffered from 30% more of damage, on average, than that under far field earthquakes.


2013 ◽  
Vol 671-674 ◽  
pp. 782-785
Author(s):  
Bin He ◽  
Jin Lai Pang ◽  
Cheng Qing Liu

For the lack of research in the longitudinal frame of prefabricated structure for its weak lateral stiffness, pushover analysis is conducted to evaluate the seismic performance of a fabricated concrete frame. Based on case study, the strengthening strategies with viscous dampers are analyzed. In view of the undesirable drift distribution and failure mode in the existing building, it is believed that arrangement of dampers should be designed to attain a uniform drift distribution. Based on the nonlinear time history analysis method, the strategy of damper allocation in vertical direction of the structure is investigated .Results indicate that a proper design might be attained based on the property of existing system, leading to a uniform drift distribution and better seismic performance.


2016 ◽  
Vol 20 (7) ◽  
pp. 1125-1138 ◽  
Author(s):  
Jing Yu ◽  
Xiaojun Liu ◽  
Xingwen Liang

A new model that can simulate the behavior of construction joint subjected to seismic forces was proposed. Nonlinear time-history analysis was carried out for reinforced concrete regular frame structures designed in different seismic intensity regions as well as with different height-to-width ratios. Two kinds of numerical models are adopted to simulate the seismic behavior of each frame, one with construction joint using the new proposed model and the other without construction joint using the conventional model. Results show that the influence of construction joint on the seismic behavior of reinforced concrete frame is strongly related to structural nonlinearity. It may increase the top displacement and the inter-story drift, change the inter-story drift distributions, and exacerbated the local reaction of key members. The influence of construction joint cannot be ignored for structures with low emergency capacity against major earthquake. Seismic design suggestions are proposed from the aspect of calculation analysis method.


2010 ◽  
Vol 163-167 ◽  
pp. 4301-4308
Author(s):  
Min Sheng Guan ◽  
Da Jian Han ◽  
Hong Biao Du ◽  
Xin Wang

Earthquake input energy and structural energy dissipation are key indicators to assess the seismic performance of structures. To study the rules of distribution of hysteretic energy within structures, a 6-storey regular reinforced concrete frame structure model is analyzed through elasto-plastic time-history dynamic analysis using the El Centro and Northridge accelerograms. Based on the comparison between numerical results for the earthquake input energy and structural hysteretic energy under the minor, moderate and major earthquakes of Grade 8 and 9, the distribution of the ratio of the storey hysteretic energy to the total hysteretic energy through the height was further studied. It shows that the computed results corresponding to the two earthquake records are in good agreement under different ground motion severity. And the percentage of structural hysteretic energy to input energy is basically stable. The distribution pattern of storey hysteretic energy through the height is that the value of the upper stories is smaller than the value of the lower stories. And the ground motion severity has a minor influence on the distribution pattern when the plasticity of structure develops more sufficiently.


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