• Structural Engineering and Mechanics
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• v.51 no.3
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• pp.503-518
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• 2014

On October 23, 2011, an earthquake of magnitude 7.0 struck Van, Turkey. This powerful earthquake caused the deaths of 604 people, more than 2,000 injuries, and a considerable loss of property. After this devastating earthquake, on November 9, 2011, another earthquake of magnitude 5.7 occurred. This moderate earthquake caused the deaths of 40 people. Partial and total collapse of the masonry and adobe buildings occurred in the rural areas of Van. In this paper, the acceleration records and response spectrums of the earthquakes were given and the structural deficiencies and reasons of the failures of the rural buildings were evaluated according to the Turkish Seismic Code. The observed failures showed that low quality of structural materials, poor workmanship, lack of engineering services and insufficient detailing of the structural elements are the main reasons of damages.

• Smart Structures and Systems
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• v.15 no.3
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• pp.913-929
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• 2015

Hybrid simulation is increasingly being recognized as a powerful technique for laboratory testing. It offers the opportunity for global system evaluation of civil infrastructure systems subject to extreme dynamic loading, often with a significant reduction in time and cost. In this approach, a reference structure/system is partitioned into two or more substructures. The portion of the structural system designated as 'physical' or 'experimental' is tested in the laboratory, while other portions are replaced with a computational model. Many researchers have quite effectively used hybrid simulation (HS) and real-time hybrid simulation (RTHS) methods for examination and verification of existing and new design concepts and proposed structural systems or devices. This paper provides a detailed perspective of the enabling role that HS and RTHS methods have played in advancing the practice of earthquake engineering. Herein, our focus is on investigations related to earthquake engineering, those with CURATED data available in their entirety in the NEES Data Repository.

• Geomechanics and Engineering
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• v.22 no.5
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• pp.433-439
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• 2020

Tunnels are one of the most important constructions in civil engineering. The damage to these structures caused enormous costs. Therefore, the safe and economic design of these structures has long been considered. However, both applied loads on the tunnels as well as the resistance of the structural members are naturally uncertain parameters, hence, the design of these structures requires considering the probabilistic approaches. This study aims to determine the load and resistant factors of lining tunnels concerning the earthquake extreme events limit state function. For this purpose, tunnels that have been designed according to the previous design codes (AASHTO Tunnel LRFD 2017) and using reliability analysis, the optimum reliability of these structures for different loading scenarios is determined. In this paper, the tunnel is considered circular. Finally, the proper load and resistance factors are calculated corresponding to the obtained target reliability. Based on the performed calibration earthquake extreme events limit state function, the result of this study can be recommended to AASHTO Tunnel LRFD 2017.

• Structural Engineering and Mechanics
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• v.59 no.5
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• pp.795-802
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• 2016

Gas pipelines are types of structures that are highly susceptible to corrosion. Sometimes, the pipes are subjected to a thinning of the wall thickness at the inside or outside wall due to erosion/corrosion. Therefore, it is important to evaluate the strength of the pipes undergoing corrosion to maintain the integrity of the piping systems. The main purpose of this study is to understand failure aspects caused by degradation of metal due to corrosion through. The ASME standard offers a relationship for the yielding pressure of the corroded pipes which was compared with the finite element results. The results demonstrate to obtain accurate results, the ASME relationship is unreliable. Moreover, pitting corrosion must be considered critical more than of other types.

• Structural Engineering and Mechanics
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• v.71 no.5
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• pp.503-513
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• 2019

Genetic Algorithms (GAs) have found the best design for reinforced concrete frames. The design of the optimum beam sections by GAs has been unified. The process of the optimum-design sections has satisfied axial, flexural, shear and torsion necessities based on the designing code. The frames' function has contained the function of both concrete and reinforced steel besides the function of the frames' formwork. The results have revealed that limiting the dimension of frame-beam with the dimension of frame-column have increased the optimum function of the structure, thereby reducing the reanalysis requirement for checking the optimum-designed structures through GAs.

• Earthquakes and Structures
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• v.17 no.3
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• pp.317-327
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• 2019

High-speed railway bridge piers in seismically active area may be subjected to multiple earthquakes and then produce cumulative residual deformation. To study the cumulative residual deformation of high-speed railway bridge piers under multiple earthquakes, a nonlinear numerical analytical model with multi-DOF (MDOF) system is presented and validated against two shaking table tests in this paper. Based on the presented model, a simple supported beam bridge pier model of high-speed railway is established and used to investigate the cumulative residual deformation of high-speed railway bridge pier under mainshock-aftershock sequences and swarm type seismic sequences. The results show that the cumulative residual deformation of the bridge pier increases with earthquake number, and the increasing rates are different under different earthquake number. The residual deformation of bridge pier subjected to multiple earthquakes is accumulated and may exceed the limit of code.

• International Journal of Concrete Structures and Materials
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• v.18 no.1E
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• pp.11-16
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• 2006

The use of the current ACI 318 stress block parameters has been reported to provide unconservative estimations of the moment capacities for high-strength concrete columns. Accordingly, several concrete stress block parameters have been recently proposed. This paper discusses various concrete stress block parameters for high-strength concrete and their influences on the code provisions. In order to adopt the proposed stress block parameters to the design code, it is necessary to understand the impact of the change of the stress block parameters on various aspects of the code provisions. For this purpose, the influence of using of different stress block parameters on the location of the neutral axis and the tensile strain in extreme tension steel as well as the axial and moment capacities are investigated. In addition, the influence on the prestressed concrete members is also elucididated.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.2
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• pp.153-168
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• 2016

Sloshing phenomenon is a complicated free surface flow problem that increases the dynamic pressure on the sidewalls and the bottom of the storage tanks. When the storage tanks are partially filled, it is essential to be able to evaluate the fluid dynamic loads on the tank's perimeter. In this paper, a numerical code was developed to determine the pressure distribution on the rectangular and trapezoidal storage tanks' perimeters due to liquid sloshing phenomenon. Assuming the fluid to be inviscid, the Laplace equation and the nonlinear free surface boundary conditions were solved using coupled boundary element - finite element method. The code performance for sloshing modeling was validated using Nakayama and Washizu's results. Finally, this code was used for partially filled rectangular and trapezoidal storage tanks and free surface displacement, pressure distribution and horizontal and vertical forces exerted on the tanks' perimeters due to liquid sloshing phenomenon were estimated and discussed.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.8
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• pp.765-772
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• 2006

The L2 Civil Signal (L2CS) will be transmitted by modernized IIR(IIR-M), IIF and all subsequent GPS satellites. It contains two codes of different length; CM code contains 10,230chips, repeats every 20milliseconds and is modulated with message data, and CL code contains 767,250chips, repeats every 1.5second Z-count and has no data modulation. And the message data is encoded for Forward Error Correction(FEC). The long code length is useful for weak signal, but it also requires very long acquisition time. Therefore, the structure of GPS Ll/L2C Correlator and the fast acquisition scheme are proposed in this paper.

• Structural Engineering and Mechanics
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• v.54 no.6
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• pp.1175-1200
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• 2015

This paper investigates the fundamental period of vibration of RC buildings by means of finite element macro-modelling and modal eigenvalue analysis. As a base study, a number of 14-storey RC buildings have been considered "according to code designed" and "according to code non-designed". Several parameters have been studied including the number of spans; the span length in the direction of motion; the stiffness of the infills; the percentage openings of the infills and; the location of the soft storeys. The computed values of the fundamental period are compared against those obtained from seismic code and equations proposed by various researchers in the literature. From the analysis of the results it has been found that the span length, the stiffness of the infill wall panels and the location of the soft storeys are crucial parameters influencing the fundamental period of RC buildings.