scholarly journals Experimental Study on the Behavior of Existing Reinforced Concrete Multi-Column Piers under Earthquake Loading

2021 ◽  
Vol 11 (6) ◽  
pp. 2652
Author(s):  
Jung Han Kim ◽  
Ick-Hyun Kim ◽  
Jin Ho Lee

When a seismic force acts on bridges, the pier can be damaged by the horizontal inertia force of the superstructure. To prevent this failure, criteria for seismic reinforcement details have been developed in many design codes. However, in moderate seismicity regions, many existing bridges were constructed without considering seismic detail because the detailed seismic design code was only applied recently. These existing structures should be retrofitted by evaluating their seismic performance. Even if the seismic design criteria are not applied, it cannot be concluded that the structure does not have adequate seismic performance. In particular, the performance of a lap-spliced reinforcement bar at a construction joint applied by past practices cannot be easily evaluated analytically. Therefore, experimental tests on the bridge piers considering a non-seismic detail of existing structures need to be performed to evaluate the seismic performance. For this reason, six small scale specimens according to existing bridge piers were constructed and seismic performances were evaluated experimentally. The three types of reinforcement detail were adjusted, including a lap-splice for construction joints. Quasi-static loading tests were performed for three types of scale model with two-column piers in both the longitudinal and transverse directions. From the test results, the effect on the failure mechanism of the lap-splice and transverse reinforcement ratio were investigated. The difference in failure characteristics according to the loading direction was investigated by the location of plastic hinges. Finally, the seismic capacity related to the displacement ductility factor and the absorbed energy by hysteresis behavior for each test were obtained and discussed.

Author(s):  
Satoru Kai ◽  
Akihito Otani

An inertia force resulting from excitation of a structure exposed to ground motion due to an earthquake excites the structure excited and generates a seismic force on the structure. The handling of seismic forces has been being discussed in terms of how the seismic force on a piping controls the deformation of the piping, load-controlled or displacement-controlled. A seismic design code for nuclear facilities applied in Japan qualifies this kind of seismic forces as primary stress components which shall be limited to prevent any plastic collapse, on the assumption that the seismic force mainly consists of load-controlled loads and the deformation due to earthquakes is caused by the loads. On the other hand, theoretically, an inertia force generated from response acceleration under harmonic vibration condition of a structure tends to oppose a response displacement of the structure. Since the inertia force produced from the response acceleration counteracts the response displacement, it is assumed that unstable failures represented by plastic collapse are hardly broken out on such a condition. To figure out the tendency between those forces, several time history analysis using simplified piping models, the vibration characteristic of which were arranged to have various specified natural frequency and specified damping ratio, were performed and the relationship between the element forces which result from response displacements and the inertia forces due to response accelerations have been investigated. The result of this investigation is expected to be useful to improve current seismic design methodology in the future.


2012 ◽  
Vol 166-169 ◽  
pp. 730-733 ◽  
Author(s):  
Fei Zhu ◽  
Feng Lai Wang ◽  
Xu Jie Sun ◽  
Y. Zhao

Unreinforced stone masonry pagodas have great cultural value and should be detailed investigation its mechanical properties. These buildings were not designed to resist earthquakes in ancient China, at least not in the way of current methods. The objectives of this research were to understand the dynamic behavior of unreinforced stone masonry pagoda and its seismic performance. To accomplish these, a 1/12 scale model of China Dinosaurs Pagoda was constructed and tested on shaking table. The octangle model height is 3.96m, with aspect ratio of height to width is 2.93, both parameters exceed the stipulated limit of Code for Seismic Design of Building. The model built with the stones and motars similar to the prototype materials and the arrangements. Its dynamic behavior and seismic performance were tested on the shaking table towards the free vibration and three earthquake waves. The experimental program adopted in the research is explained in this paper.


2020 ◽  
Vol 23 (13) ◽  
pp. 2928-2941
Author(s):  
Qunyi Huang ◽  
John Orr ◽  
Yanxia Huang ◽  
Feng Xiong ◽  
Hongyu Jia

To improve both seismic performance and thermal insulation of low-rise housing in rural areas of China, this study proposes a load-bearing prefabricated composite wall panel structure that achieves appropriate seismic performance and energy efficiency using field-assembled load-bearing prefabricated composite wall panels. A 1:2 scale prototype built using load-bearing prefabricated composite wall panel is subjected to quasi-static testing so as to obtain damage characteristics, load-bearing capacity and load–displacement curves in response to a simulated earthquake. As a result, seismic performance indicators of load-bearing capacity, deformation and energy-dissipating characteristics, are assessed against the corresponding seismic design requirements for rural building structures of China. Experimental results indicate that the earthquake-resistant capacity of the prototype is 68% higher than the design value. The sample has a ductility factor of 4.7, which meets the seismic performance requirement mandating that the ductility factor of such concrete structures should exceed 3. The design can be further optimized to save the consumption of material. This shows that the load-bearing prefabricated composite wall panel structure developed here has decent load-bearing capacity, ductility and energy dissipation abilities, a combination of which is in line with the seismic design code. A new construction process proposed here based on factory prefabrication and field assembly leads to a considerable reduction of energy consumption.


2018 ◽  
Vol 34 (1) ◽  
pp. 55-76 ◽  
Author(s):  
Sang Whan Han ◽  
Tae O Kim ◽  
Seong Jin Baek

Steel ordinary moment frames (OMF) are seismic force-resisting systems that can be used in buildings. In current seismic design and detailing provisions, such as the American Society of Civil Engineers ASCE/SEI 7-10 (2010) , American Institute of Steel Construction ANSI/AISC 341-10 (2010), and ANSI/AISC 358-10 (2010) , less stringent design and detailing requirements are specified for steel OMFs compared with those for steel special- and intermediate-moment frames. The strong-column weak-beam (SC/WB) requirement is not enforced for steel OMF connections. In the present study, the seismic performance evaluation is conducted for steel OMFs designed according to current seismic design and detailing provisions considering different combinations of gravity, seismic, and wind loads, as well as wind drift limits. Based on the results of seismic performance evaluation, permissible structural heights for steel OMFs are also proposed.


2019 ◽  
Vol 13 (03n04) ◽  
pp. 1940005 ◽  
Author(s):  
Zijian Cao ◽  
Quanwang Li

The quality of precast concrete (PC) component connections is one of the main factors that affect the seismic reliability of PC structures. China is developing PC structures in high seismic regions, and it is important to assess the effect of connection deficiency on seismic performance of PC structures. This paper presents a comprehensive method to assess the seismic reliability of PC shear wall-frame structure whose wall panels are assembled through grouted sleeve connections which are susceptible to insufficient grouting. Considering the uncertainties associated with the number, locations and loading behavior of defected sleeve connections, the probabilistic behavior of PC shear wall with defected connections is estimated through point estimate method using simulation results of the experiment-validated finite element model. Then, a simple shear wall-frame building, designed for the seismic intensity of 8 according to China’s seismic design code, is modeled on platform of OpenSees. Static pushover analyses and seismic fragility analyses are performed on the structure with different degrees of connection deficiency, to investigate the effect of deficiency occurrence rate on seismic performance. The seismic performance is significantly affected by connection deficiencies; it no longer meets the requirement of seismic design as the deficiency occurrence rate exceeds 25%, so the occurrence rate of defected connections should be controlled carefully in construction site.


2011 ◽  
Vol 250-253 ◽  
pp. 2371-2375
Author(s):  
Hua Wei Zhao ◽  
Xiu Qin Cui ◽  
Tong Hao

Four constructional columns with concrete porous brick walls were constructed for low cyclic loading test. The damage on the characteristics and strength of the wall, hysteresis curve, ductility and other seismic performance were analyzed. Setting constructional columns in the wall at both ends increase the ultimate strength and improve its deformation, ductility and other properties. Meanwhile the height-wide-ratio of wall, axial pressure and other factors on the shear bearing capacity on the wall have been studied. Based on the shear capacity formula of wall in the Structural Seismic Design Code, considering the contribution of the constructional columns on the shear strength, according to the results, the shear capacity formula of constructional columns with concrete brick walls is presented.


2000 ◽  
Vol 16 (1) ◽  
pp. 127-140
Author(s):  
Harold O. Sprague ◽  
Nicholas A. Legatos

The building code development process has traditionally given little effort to developing the seismic design process of nonbuilding structures. This has created some unique problems and challenges for the structural engineers that design these types of structures. The intended seismic performance requirements for “building” design are based on life safety and collapse prevention. Structural elements in buildings are allowed to yield as a method of seismic energy dissipation. The seismic performance of nonbuilding structures varies depending on the specific type of nonbuilding structure. Nonlinear behavior in some nonbuilding structures is unacceptable while other nonbuilding structures may be allowed to yield during an earthquake. Nonbuilding structures comprise a vast myriad of structures constructed of all types of materials, with markedly different dynamic characteristics, and with a wide range of performance requirements. This paper discusses the development of codes, design practices, and future of the seismic design criteria for nonbuilding structures.


Author(s):  
Masami Oshima ◽  
Takashi Kase

After Hyogo South Area earthquake, a new seismic design method considering non-elastic deformation behavior is established against Level 2 earthquake (Safety Shutdown Earthquake) in the Seismic Design Code of High-pressure Gas Facilities in Japan. In this paper, this method is applied for an evaluation of existing structures supporting loading-arms in LNG Receiving Terminal. A procedure of pre-earthquake seismic upgrading and modification of the structures that are supported by platforms and supporting loading-arms is introduced. In this evaluation, the seismic loads taking into account of interaction among platforms, structures, and loading-arms are analyzed as total systems. And yield strength design method is applied. Then for the seismic design of loading-arms, floor response spectrums on the installation level are presented. After upgrading the platforms in this case, seismic evaluation of loading-arms based on this study will be performed. So the effect of changing its stiffness is studied. Also to evaluate the dynamic loads subjected to the loading-arms, they are compared with seismic loads that are derived from modified static coefficient method of the seismic design code. Thus with studies of vibration characteristics as total systems, it is possible to make effective and economical countermeasures for pre-earthquake seismic upgrading and modification of the structures and loading-arms.


2010 ◽  
Vol 163-167 ◽  
pp. 3952-3957
Author(s):  
Xiao Song Ren ◽  
Yu Fei Tao

The main seismic objective in China is defined as “no failure under minor earthquake, repairable damage under moderate earthquake and no collapse under major earthquake”. Both strength and deformation are important to evaluate the seismic performance. For masonry building, only the shear strength check under minor earthquake is stipulated in the current Chinese seismic design code. Due to the poor ductility of masonry building, the seismic design analysis method may not guarantee the collapse-resistant capacity under major earthquake. For the achievement of the seismic objective, the demand of ductility is discussed. A typical severely damaged masonry building by the 5.12 Wenchuan Earthquake of 2008 is presented for the analysis of the through X-shape crack on the load-bearing wall. In order to enhance the collapse-resistant capacity, the authors suggest more shear strength margin to take the influence of structural ductility into consideration. The feasible way can be easily realized as a target to raise the limitation for the shear strength check parameter under minor earthquake and to keep uniform seismic capacity in two directions. The investigated building is also illustrated here as an example to process the shear strength check for better seismic performance by the authors’ suggestion.


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