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CONTENTS
Volume 21, Number 2, August 2021
 


Abstract
Developments in performance-based earthquake engineering have emphasized the importance of evaluation of structural collapse resistance. Several collapse criteria were proposed to define structural collapse in various perspective. In this paper, collapse resistant capacity of ductile reinforced concrete (RC) frame was evaluated using different collapse criteria. Since most of the criteria focus on overall structural response, a component deformation-based method was adopted to describe the damage in component level. Incremental dynamic analysis (IDA) of a 6-story ductile RC frame conforms to current codes was conducted in OpenSEES. The collapse resistant capacity under different collapse criteria was compared. Moreover, relationship between overall structural response and the distribution of damaged components were discussed through the component deformation-based method. It was indicated that the story of maximum inter-story drift ratio is neither consistent with the one which is most seriously damaged nor with the story of maximum residual inter-story drift ratio. Furthermore, the component deformation-based method can depict structural damaged state and formation of collapse mechanism more reasonably. The analysis result evidences that structure conforms to current code have the good ductility and hardly reaches physical collapse under rare earthquake, however, the structure is more likely to be demolished due to unacceptable residual deformation.

Key Words
collapse criterion; collapse resistant capacity; component deformation; performance-based earthquake engineering; residual deformation

Address
Difang Huang:School of Civil Engineering and Transportation, South China University of Technology, Tianhe, Guangzhou, 510641, China

Xiaolei Han:School of Civil Engineering and Transportation, South China University of Technology, Tianhe, Guangzhou, 510641, China/ State Key Laboratory of Subtropical Building Science, South China University of Technology, Tianhe, Guangzhou, 510641, China

Shengfang Qiao: Guangzhou Institute of Building Science Co., Ltd., Guangzhou, 510080, China

Jing Ji:School of Civil Engineering and Transportation, South China University of Technology, Tianhe, Guangzhou, 510641, China/ State Key Laboratory of Subtropical Building Science, South China University of Technology, Tianhe, Guangzhou, 510641, China

Jidong Cui:RBS Architectural Engineering Design Associates, Guangzhou, 510030, China

Abstract
In this study, it is aimed to investigation the performance of historical arch bridge under near fault earthquakes with the finite element method (FEM) and to demonstrate the capability and performance estimation. For this purpose, Konjic Bridge constructed in the Bosnia and Herzegovina is selected. To investigated the behaviour of near fault earthquakes on Konjic Bridge, first, FEM of the Konjic Bridge is built and analyzed under various near fault using the program ANSYS. To build FEM, 647894 nodes and 215464 elements are used in ANSYS. Then, near-fault earthquakes are taken into accounted (Chi-Chi 1999, Imperial Valley 1979, Superstation Hill 1987, NorthRidge 1994, Cape Mend 1992, Kobe 1995). The maximum displacement values, principal stresses and elastic strain values are compared with the help of contour diagrams. As a result of these analyzes, it is seen that the arch of the historical masonry arch bridge has more effect on the structural behavior of the historical masonry arch bridge. Furthermore, it is obviously seen that under the near fault earthquakes, the tensile stresses, especially on the top, bottom and side of the large belt, reached the allowable tensile strength of the wall under the near fault earthquakes. There may also be a risk of damage due to these stresses.

Key Words
ansys; finite element method; historical masonry arch bridge; near fault earthquakes; static and dynamic analysis

Address
Memduh Karalar:Zonguldak Bülent Ecevit Üniversity, Department of Civil Engineering, Zonguldak, Turkey

Mustafa Yeşil:Zonguldak Bülent Ecevit Üniversity, Department of Civil Engineering, Zonguldak, Turkey

Abstract
The equivalent lateral force method is one of the commonly used methods for the seismic design of building structures. The assumptions included an equivalent coefficient of 0.85 when determining the equivalent total weight of the structure, and the horizontal seismic action distributed as an inverted triangle pattern is used in the existing formula in relevant Chinese codes. And the two assumptions make a big difference between the calculation results of the equivalent lateral force method and the mode-superposition response spectrum method in Chinese code. The dynamic structural parameters of the designed six reinforced concrete frame structures and the calculated case structure, which were designed according to Chinese codes, are extracted in this paper. The six structures are analyzed using the mode-superposition response spectrum method and the equivalent lateral force method in Chinese code, respectively. The comparative analysis results show that shear forces at the bottom of structures calculated by the equivalent lateral force method in Chinese code is smaller, but the horizontal displacement of each storey of the structure is larger. Aiming at the shortcomings of the equivalent lateral force method in Chinese codes, combining with the calculation results of the mode-superposition response spectrum method, a modified calculation formula of the equivalent lateral force method is proposed. The calculation results of the modified equivalent lateral force method established in this paper are superior to the calculation results of the equivalent lateral force method in Chinese codes through examples verifications.

Key Words
equivalent lateral force method; response spectrum method; seismic design; displacement checking

Address
Mingzhen Wang:College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China/ College of Civil Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China

Zailin Yang:College of Aerospace and Civil Engineering, Harbin Engineering University, Harbin 150001, China

Lin Gao:College of Civil Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China

Abstract
In this study, the performance of rotational-friction slip dampers in steel structures with different heights is investigated by the use of fragility curves. The use of dampers is one of the methods for vibration control of structures by simultaneously increasing both the structural stiffness and damping. Rotational-friction slip dampers are among the passive control devices that dampen the earthquake energy through their stable cyclic behavior. To study the performance of these devices in steel structures, 3, 6 and 9-story steel moment frame structures are designed, and the mentioned dampers are attached to the structure by Chevron braces. To account for the earthquake uncertainty, with the aid of incremental dynamic analysis (IDA), the damper-equipped structure is subjected to both near-field and far-field ground motion records. The acceleration and drift engineering demand parameters are selected as the functions to quantify the damage states, and the design, modeling and material properties uncertainties are considered in accordance with FEMA P-695. Evaluation of statistical results and comparison of the fragility curves, shows that the probability of failure at different damage states decreases when the dampers are added to the structure. This decrease is more remarkable in low-rise structures and near-fault ground motions.

Key Words
acceleration; drift; far-field; fragility curve; Incremental Dynamic Analysis (IDA); near-field; rotational-friction damper

Address
Sahar Borhan:Civil Engineering Department, Science and Arts University, Yazd, Iran

Hamed Tajammolian:Department of Civil Engineering, Yazd University, Yazd, Iran

Mehdi Yazdian:Civil Engineering Department, Science and Arts University, Yazd, Iran

Abstract
Cultures and lifestyles of past communities can be transferred to the next generations through historical structures. Accordingly, these structures should be carefully preserved against devastating events i.e. earthquakes, wind, and fire. Seismic performances of historical structures can be determined with destructive and nondestructive methods. As destructive methods are quite difficult and complex, easier and reliable methods should be used to determine the seismic behaviors of these structures. In this study, the seismic behavior of the historical Lala Mehmet Pasha minaret is investigated by considering Soil-Structure Interaction (SSI). Dynamical properties of the minaret are experimentally obtained with the operational modal analysis (OMA) method and the initial finite element (FE) model is updated. Embedded and SSI models are generated by Abaqus, then linear (LTH) and nonlinear time history (NLTH) analyses are performed. As a result of analyses, displacements, damage, and stress distributions are obtained and interpreted. These analyses show that SSI is quite effective on the structural behavior and results obtained from the nonlinear analysis are more realistic than that of linear analysis.

Key Words
CDP; historical structure; masonry; OMA; soil-structure interaction; time history analysis

Address
Taha Yasin Altiok:Department of Civil Engineering, Manisa Celal Bayar University, Manisa, P.O.45140, Turkey

Ali Demir:Department of Civil Engineering, Manisa Celal Bayar University, Manisa, P.O.45140, Turkey

Abstract
This study mainly focuses on experimental and numerical investigation of the isolation mechanism and seismic performance of a self-centering railway bridge pier. To begin, a 1/25 scale typical self-centering railway pier model was designed and constructed, which consisted of a gravity pier, a spread foundation and a pedestal. The gravity pier was rigidly connected to the spread foundation, which was then directly seated at the top of the pile cap to allow the uplift of the pier during strong earthquakes. The model was tested in a pseudo-static manner under constant axial load and cyclic lateral load to characterize its seismic performance. It was found that the lateral load, the bending moment at the pier bottom, and the width of compression zone at the bottom of pier remained essentially constant when the uplift reached a certain extent. The hysteretic curves were in inverse 'Z' shape with narrow loops indicating good self-centering effect but poor energy dissipation. This means that the lateral force-displacement relationship of this type of piers can be simplified as an elasto-plastic curve and they should be used along with additional energy-dissipation devices. Upon the test results, a two-spring model was proposed and developed in the OpenSees platform to represent the test model, which was analyzed using the test load history. The results indicate that the two-spring model can simulate the pseudo-static test with high precision. This modeling technique hence can be employed to analyze seismic response of this type of bridge piers.

Key Words
gravity pier; hysteretic curve; numerical simulation; pseudo-static test; railway bridge; self-centering

Address
Xiushen Xia:School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China

Suiwen Wu:Department of Civil and Environmental Engineering, University of Nevada, Reno, 89557, U.S.A.

Xinghan Wei:Gansu Provincial Highway Aviation Tourism Investment Group Co., Ltd, Lanzhou 730070, China

Chiyu Jiao:Beijing Advanced Innovation Center for Future Urban Design,Beijing University of Civil Engineering and Architecture, Beijing, 100044, China/ Engineering Structure and New Materials Research Center of Beijing Higher Education Institutions, Beijing University of Civil Engineering and Architecture, Beijing, 100044, China

Xingchong Chen:School of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China

Abstract
This paper presents some advanced finite element FE analyses conducted on one of the most historic structures in the world. The Church of Nativity located in Bethlehem (Palestine). To ensure the model quality, a 3D FE model was created using two different commercial software, DIANA FEA and SAP2000, one of the expected behaviors for this kind of masonry structure "low modal period" was found. The seismic behavior of the church was studied using pushover analyses, which were conducted using DIANA FEA as well as a dynamic analysis using SAP2000 is carried out using the accelerogram (1940 El Centro earthquake) to simulate a complete progressive collapse process. The first unidirectional mass proportional load pattern was created in both directions, X direction as a longitudinal direction and Y direction as the transversal direction. An incremental iterative procedure was used with monotonically increasing horizontal loads, using constant gravity loads. The results showed that the transversal direction is the most vulnerable and the damage concentrates at the main lateral (longitudinal) walls, mainly at the south and north alignment walls, and also at the vaults and at the connections of the vaults to the apse. A more accurate nonlinear dynamic analysis is recommended in the near future, which takes into account the material nonlinearity for good seismic behavior, anticipation for such an important monument, and heritage.

Key Words
DIANA FEA; FE model; masonry; non-linear analysis; SAP 2000; seismic assessment

Address
Belal M. Almassri:Civil and Architectural Engineering Department, Palestine Polytechnic University, Hebron, Palestine

Ali A. Safiyeh:Civil Engineering Department, An-Najah National University, Nablus, Palestine

Abstract
The paper presents a few case studies on the seismic response behavior of liquid storage tanks (LSTs), for which not much literature is available. They include (i) the comparison between responses obtained by the 2D-FE analysis and analysis performed according to the procedure recommended by ACI 350.3 for different PGA levels of ground motions; (ii) the comparison between the variations of sloshing heights, base shear, and overturning moment with the PGA obtained by the 2D- and 3D-FE analyses; (iii) the effect of bi- and tri-directional earthquake interactions on different responses; and (iv) the effect of angle of incidence of the earthquake on those responses. The numerical study is conducted with a square tank of size 6 m

Key Words
angle of incidence; FEM; FSI; liquid storage tank; near-fault earthquake; vertical component

Address
Sourabh Vern:National Centre for Disaster Mitigation and Management, Malaviya National Institute of Technology Jaipur,Jawahar Lal Nehru Marg, Jaipur, Rajasthan 302017, India

Mahendra K. Shrimalia:National Centre for Disaster Mitigation and Management, Malaviya National Institute of Technology Jaipur,Jawahar Lal Nehru Marg, Jaipur, Rajasthan 302017, India

Shiv D. Bharti:National Centre for Disaster Mitigation and Management, Malaviya National Institute of Technology Jaipur,Jawahar Lal Nehru Marg, Jaipur, Rajasthan 302017, India

Tushar K. Datta:National Centre for Disaster Mitigation and Management, Malaviya National Institute of Technology Jaipur,Jawahar Lal Nehru Marg, Jaipur, Rajasthan 302017, India


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