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CONTENTS
Volume 22, Number 4, April 2022
 


Abstract
Masonry structures are the most common structural systems that have been used almost all over the world from the earliest ages of history to the present day. These structural systems are often unfavorably affected by natural disasters such as earthquakes. The main reason for this is that they are built without sufficient engineering knowledge. On January 24, 2020, a severe earthquake occurred near the Sivrice District of Elazig in eastern Turkey. According to the Turkish Directorate of Disaster and Emergency Management (AFAD), the magnitude of the earthquake was 6.8 and the focal depth 8 km. This earthquake caused damage and destruction to the masonry structures used extensively in the region. The Haci Yusuf Tas (new) mosque in the Malatya city center, located about 64 km from the epicenter of the earthquake, was among the buildings affected by the earthquake. The mosque has smooth-cut stone walls and domes made of brick units. The main dome of the structure was severely damaged during the earthquake. In this study, information about the earthquake is first provided, and the damage to the mosque is then interpreted via photographs. In addition, two separate finite element models were produced, where the current state of mosque and solution suggestions are presented, and response spectrum analyses were carried out. According to these analyses and field observations, a buttress system to the main walls of the structure should be constructed in the direction which has little lateral rigidity.

Key Words
masonry structures; restoration; Sivrice earthquake; strengthening; strong ground motions

Address
Fatih K. Firat, Ali Ural and Mehmet E. Kara:Aksaray University, Department of Civil Engineering, 68100, Aksaray, Turkey

Abstract
The configuration of an open ground floor (pilotis) is a common and very critical irregularity observed in multistory reinforced concrete frame structures. The characteristics and the geometrical formation of the beams of the first story proved to be a critical parameter for the overall seismic behavior of this type of Reinforced Concrete (RC) structures. In this work the combination of open ground floor (pilotis) morphology with very strong perimetrical beams at the level of the first story is studied. The observation of the seismic damages and the in situ measurements of the fundamental period of four buildings with this morphology and Π-shaped plan view are presented herein. Further analytical results of a pilotis type Π-shaped RC structure are also included in the study. From the measurements and the analytical results yield that the open ground floor configuration greatly influences the fundamental period whereas this morphology in combination with strong beams can lead to severe local shear damages in the columns of the ground floor. The structural damage was limited in the columns of the ground floor and yet based on the changes of the in situ measured fundamental period the damaged level is assessed as DI=88%. Furthermore, due to the Π-shape of the plan view the tendency of the parts of the building to move independently strongly influences the distribution of the damages over the ground floor vertical elements.

Key Words
in situ measurement of period; irregular buildings; open ground floor; seismic behavior; Π-shaped building

Address
Martha A. Karabini, Athanasios J. Karabinis and Chris G. Karayannis:Civil Engineering Department, Democritus University of Thrace, Xanthi 67100, Greece

Abstract
The study is part of an experimental program on full-scale Un-Reinforced Masonry (URM) wall panels strengthened with Textile reinforced mortars (TRM). Eight brick walls (two with and five without central opening), were tested under the diagonal tension (shear) test method in order to investigate the strengthening system effectiveness on the in-plane behaviour of the walls. All the URM panels consist of the innovative components, named "Orthoblock K300 bricks" with vertical holes and a thin layer mortar. Both of them have great capacity and easy application and can be constructed much more rapidly than the traditional bricks and mortars, increasing productivity, as well as the compressive strength of the masonry walls. Several parameters pertaining to the in-plane shear behaviour of the retrofitted panels were investigated, including shear capacity, failure modes, the number of layers of the external TRM jacket, and the existence of the central opening of the wall. For both the control and retrofitted panels, the experimental shear capacity and failure mode were compared with the predictions of existing prediction models (ACI 2013, TA 2000, Triantafillou 1998, Triantafillou 2016, CNR 2018, CNR 2013, Eurocode 6, Eurocode 8, Thomoglou et al. 2020). The experimental work allowed an evaluation of the shear performance in the case of the bidirectional textile (TRM) system applied on the URM walls. The results have shown that some analytical models present a better accuracy in predicting the shear resistance of all the strengthened masonry walls with TRM systems which can be used in design guidelines for reliable predictions.

Key Words
brick URM; diagonal compression test; in-plane performance; masonry wall's opening; seismic strengthening; shear prediction; TRM

Address
Athanasia K. Thomoglou and Athanasios I. Karabinis:Civil Engineering Department, Democritus University of Thrace (DUTh), Kimmeria, 67100 Xanthi, Greece

Abstract
The development of performance-based design methodologies requires a reasonable definition of a displacement response spectrum. Although ground motions are known to be significantly affected by the resonant-like amplification behavior caused by multiple wave reflections within the surface soil, such a soil-resonance effect is seldom explicitly considered in current-displacement spectral models. In this study, an analytical approach is developed for the construction of displacement response spectra by considering the soil-resonance effect. For this purpose, a simple and rational equation is proposed for the response spectral ratio at the site fundamental period (SRTg) to represent the soil-resonance effect based on wave multiple reflection theory. In addition, a bilinear model is adopted to construct the soil displacement-response spectra. The proposed model is verified by comparing its results with those obtained from actual observations and SHAKE analyses. The results show that the proposed model can lead to very good estimations of SRTg for harmonic incident seismic waves and lead to reasonable estimations of SRTg and soil displacement-response spectra for earthquakes with a relatively large magnitude, which are generally considered for seismic design, particularly in high-seismicity regions.

Key Words
displacement; response spectral ratio; response spectrum; site fundamental period; soil-resonance effect

Address
Haizhong Zhang and Yan-Gang Zhao:Department of Architecture, Kanagawa University, Yokohama, Japan

Abstract
To study the seismic damage of masonry structures and understand the characteristics of the multi-intensity region, according to the Dujiang weir urbanization of China Wenchuan earthquake, the deterioration of 3991 masonry structures was summarized and statistically analysed. First, the seismic damage of multistory masonry structures in this area was investigated. The primary seismic damage of components was as follows: Damage of walls, openings, joints of longitudinal and transverse walls, windows (lower) walls, and tie columns. Many masonry structures with seismic designs were basically intact. Second, according to the main factors of construction, seismic intensity code levels survey, and influence on the seismic capacity, a vulnerability matrix calculation model was proposed to establish a vulnerability prediction matrix, and a comparative analysis was made based on the empirical seismic damage investigation matrix. The vulnerability prediction matrix was established using the proposed vulnerability matrix calculation model. The fitting relationship between the vulnerability prediction matrix and the actual seismic damage investigation matrix was compared and analysed. The relationship curves of the mean damage index for macrointensity and ground motion parameters were drawn through calculation and analysis, respectively. The numerical analysis was performed based on actual ground motion observation records, and fitting models of PGA, PGV, and MSDI were proposed.

Key Words
empirical damage vulnerability; field reconnaissance observation; Masonry structure (MS); parameter matrix model of mean damage index (MDI); statistical and regression vulnerability model

Address
Si-Qi Li:1)Longjian Road and Bridge Co., Ltd., No. 109, Songshan Road, Harbin City, China 2)School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin City, China 3)School of Civil Engineering, Heilongjiang University, No.74, Xuefu Road, Harbin City, China

Yong-Sheng Chen:Institute of Engineering Mechanics, China Earthquake Administration, No.29, Xuefu Road, Harbin City, China

Hong-Bo Liu:1)School of Civil Engineering, Heilongjiang University, No.74, Xuefu Road, Harbin City, China 2)Key Laboratory of Functional Inorganic Material Chemistry (Heilongjiang University), Ministry of Education

Ke Du:School of Civil Engineering, Heilongjiang University, No.74, Xuefu Road, Harbin City, China

Bo Chi:Longjian Road and Bridge Co., Ltd., No. 109, Songshan Road, Harbin City, China

Abstract
A novel hybrid extreme machine learning-multiverse optimizer (ELM-MVO) framework is proposed to predict the liquefaction phenomenon in seismically excited tunnel lining inside the sand lens. The MVO is applied to optimize the input weights and biases of the ELM algorithm to improve its efficiency. The tunnel located inside the liquefied sand lens is also evaluated under various near- and far-field earthquakes. The results demonstrate the superiority of the proposed method to predict the liquefaction event against the conventional extreme machine learning (ELM) and artificial neural network (ANN) algorithms. The outcomes also indicate that the possibility of liquefaction in sand lenses under far-field seismic excitations is much less than the near-field excitations, even with a small magnitude. Hence, tunnels designed in geographical areas where seismic excitations are more likely to be generated in the near area should be specially prepared. The sand lens around the tunnel also has larger settlements due to liquefaction.

Key Words
Extreme Machine Learning (ELM); Multi-Verse Optimizer (MVO); sand lens; tunnel; liquefaction; near and far-field earthquake

Address
Payam Shafiei, Mohammad Azadi and Mehran Seyed Razzaghi:Department of Civil Engineering, Qazvin Branch, Islamic Azad University, Qazvin, Iran

Abstract
This paper addresses the stochastic control problem of robots within the framework of parameter uncertainty and uncertain noise covariance. First of all, an open circle deterministic trajectory optimization issue is explained without knowing the unequivocal type of the dynamical framework. Then, a Linear Quadratic Gaussian (LQG) controller is intended for the ostensible trajectory-dependent linearized framework, to such an extent that robust hereditary NN robotic controller made out of the Kalman filter and the fuzzy controller is blended to ensure the asymptotic stability of the non-continuous controlled frameworks. Applicability and performance of the proposed algorithm shown through simulation results in the complex systems which are demonstrate the feasible to improve the performance by the proposed approach.

Key Words
earthquake engineering; genetic algorithm; modified adaptive law; reinforced concrete frame structures

Address
ZY Chen:Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, Peoples R China

Rong Jiang:Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, Peoples R China

Ruei-Yuan Wang:Guangdong University of Petrochem Technol, Sch Sci, Maoming 525000, Peoples R China

Timothy Chen:Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125

Abstract
One of the best choice for transportation of oil and gas at the end of rivers or seas is concrete pipelines. In this article, a concrete pipe at the end of river is assumed under the earthquake load. The Classic shell theory is applied for the modelling and the corresponding motion equations are derived by energy method. An external force induced by fluid around the pipe is asssumed in the final motion equations. For the solution of motion equations, the differential quadrature method (DQM) and Newmark method are applied for deriving the dynamic deflection of the pipe. The effects of various parameters including boundary conditions, fluid and length to thickness ratio are presented on the seismic response of the concrete pipe. The outcomes show that the clamped pipe has lower dynamic deflection with respect to simply pipe. In addition, with the effect of fluid, the dynamic defelction is increased significantly.

Key Words
concrete pipe; dynamic analysis; earthquake load; fluid force; numerical method

Address
Yanbing Liu:Beijing Earthquake Agency, Beijing 100080, China

Mohamed Amine Khadimallah:1)Prince Sattam Bin Abdulaziz University, College of Engineering, Civil Engineering Department, Al-Kharj, 16273, Saudi Arabia
2)Laboratory of Systems and Applied Mechanics, Polytechnic School of Tunisia, University of Carthage, Tunis, Tunisia

Amir Behshad:Faculty of Technology and Mining, Yasouj University, Choram 75761-59836, Iran


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