scholarly journals Performance of RC and Masonry Structures During 2019 Durrës Earthquake

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Marsed Leti
Keyword(s):  
Structural Damage ◽  
Structural Response ◽  
Poor Performance ◽  
Past Century ◽  
Masonry Structures ◽  
System Quality ◽  
Building Stock ◽  
Damage Level ◽  
Rc Building

Albania has suffered from major earthquakes in the past century that have caused varying levels of damage to buildings. As a result of the number of damaged buildings and loss of life, attention has focused mostly on the poor performance of reinforced concrete and masonry structures in low and mid-rise buildings. This paper presents the results of a reconnaissance visits to the disaster-stricken area in the Durrës region in Albania and covers many zones in the region where historical and modern buildings suffered serious structural damage or collapses during the November 26, 2019, Durrës Earthquake. Special emphasis was placed on masonry and RC buildings, since the damage level was high in these buildings. The consequences of the Durrës earthquake are important for similar masonry and RC building stock in other seismically vulnerable European cities. Regularity of the structural system, quality of the material utilized, the distribution of mass and stiffness through the building, the ratio of openings on masonry walls and diaphragm stiffness have a crucial influence on the structural response. Inappropriate interventions led to serious damage or collapses, resulting in casualties. Examples of numerous damage types, as witnessed during the site visits to the affected region are presented, along with technically explanation of causes for the damages.

Behavior of multidirectional friction dampers

2020 ◽  
Vol 26 (21-22) ◽  
pp. 1969-1979
Author(s):  
Recep Suk ◽  
Gökhan Altintaș
Keyword(s):  
Structural Damage ◽  
Load Capacity ◽  
Spherical Surface ◽  
Poor Performance ◽  
Surface Friction ◽  
Building Stock ◽  
Seismic Damper ◽  
Earthquake Performance ◽  
Production Techniques ◽  
Property Losses

Earthquakes are catastrophic events causing loss of lives, injuries, and extensive losses in properties. Majority of the life and property losses of earthquakes are dependent on the incapabilities of the building stock to resist earthquakes. Although unsuitable design, analyses, and production techniques play a major role as the main reasons for the poor performance of buildings against earthquakes, buildings constructed in accordance with building codes also suffer from the devastating impact of earthquakes. In this context, the lack of proper management and adequate damping of the energy caused by earthquakes is a major cause of structural damage in earthquakes. The efficiency of conventional basic elements in structures with energy damping is very limited and may not be sufficient for the damping of a large amount of earthquake-induced energy. Thanks to the rapid advances in technology and associated engineering techniques, numerous new products, and production and calculation techniques are underway to mitigate the devastating effects of earthquakes on buildings. In this study, it was aimed to theoretically and experimentally investigate the performance of a versatile friction-type seismic damper that eliminates earthquake energy. The damper is designed using a spherical surface friction joint to respond to all loads regardless of the loading direction. The damper can be easily adjusted to the desired capacity by means of bolt tensioning elements. Experiments have been carried out for various shear loads and damping parameters. Furthermore, numerical analysis of the model was carried out by use of the finite element method. The results of this study revealed that the shear load capacity of the device did not change at different frequencies. Analyzing the effect of the equipment on a structure, it was understood that it reduces roof displacement and periods of the structure. The analysis revealed that the damper significantly improved the earthquake performance of the structure.

scholarly journals Methods for the Assessment of Critical Properties in Existing Masonry Structures under Seismic Loads—The ARES Project

2020 ◽  
Vol 10 (5) ◽  
pp. 1576 ◽  
Author(s):  
Mislav Stepinac ◽  
Tomislav Kisicek ◽  
Tvrtko Renić ◽  
Ivan Hafner ◽  
Chiara Bedon
Keyword(s):  
Current Knowledge ◽  
Structural Response ◽  
General Tendency ◽  
Masonry Buildings ◽  
Masonry Structures ◽  
Building Stock ◽  
Existing Structures ◽  
Critical Issues ◽  
Reliable Design ◽  
Basic Features

Masonry structures are notoriously vulnerable to horizontal actions caused by earthquakes. Given the high seismicity of the European region, and that the European building stock comprises a lot of masonry buildings, knowledge about their structural response to seismic excitation is particularly important, but at the same time difficult to determine, due to the heterogenous nature of materials and/or constructional techniques in use. An additional issue is represented by the current methods for mechanical properties assessment, that do not provide a reliable framework for accurate structural estimations of existing buildings characterized by different typological properties. Every structure, in other words, should be separately inspected in regard to its mechanical behaviour, based on dedicated approaches able to capture potential critical issues. In this review paper, an insight on the Croatian ARES project is presented (Assessment and Rehabilitation of Existing Structures), including a state-of-the-art of the actual building stock and giving evidence of major difficulties concerning the assessment of existing structures. The most commonly used techniques and tools are compared, with a focus on their basic features and field of application. A brief overview of prevailing structural behaviours and Finite Element numerical modelling issues are also mentioned. As shown, the general tendency is to ensure “sustainable” and energy-efficient building systems. The latter, however, seem in disagreement with basic principles of structural maintenance and renovation. The aim of the ongoing ARES project, in this context, is to improve the current knowledge regarding the assessment and strengthening of structures, with a focus on a more reliable design and maintenance process for existing masonry buildings.

scholarly journals Suitability of Current Assessment Techniques to Retrodict the Seismic Damage of Buildings: A Case Study in Van, Turkey

2015 ◽  
Vol 9 (1) ◽  
pp. 330-343
Author(s):  
Viorel Popa ◽  
Radu Văcăreanu ◽  
Vasile Oprisoreanu ◽  
Emil Albotă ◽  
Dietlinde Köber
Keyword(s):  
Structural Damage ◽  
Local Community ◽  
Structural Characteristics ◽  
Rapid Assessment ◽  
Seismic Damage ◽  
Seismic Assessment ◽  
Damage State ◽  
Building Stock ◽  
Damage Level ◽  
Assessment Techniques

Two strong earthquakes hit the region of Van (Turkey) in 2012, generating major losses. A large part of the building stock was damaged causing the evacuation of the residents. A post-earthquake investigation team dispatched by the UNESCO through the IPRED platform, six month after the earthquakes, observed the damage state in some still standing buildings. Ten buildings having different structural characteristics were observed. Slight structural damage and severe non-structural damage were observed in three multi-storey apartment buildings, being evacuated at the time of the investigation. Despite the slight structural damage, two multi-storey reinforced concrete shear wall buildings were listed for demolition based on the results of the post-earthquake rapid assessment. These two buildings were recently built based on modern seismic design regulations. The design blueprints were available to the investigation team with the support of the local community of Van. Various rapid post-earthquake investigation techniques applied by the investigation team generated contradictory results. A comprehensive seismic assessment was carried out to retrodict the observed seismic damage. Various methods were applied starting from simple rapid assessment techniques to more elaborated structural analysis based on nonlinear dynamic procedure. In the latter case, strength and stiffness degrading hysteretic models were applied and the non-structural masonry walls were considered in the analytical model. This paper presents the results of these structural analyses in comparison with the observed damage on site. Conclusions regarding the suitability of the applied seismic assessment techniques to retrodict the damage level of the investigated structures are drawn. Some findings of the post-earthquake investigation team are presented as well.

scholarly journals PREDICTION OF HIGH-PERFORMANCE FIBERREINFORCED POLYMER CONCRETE USING FUZZY NEURAL NETWORK PROTOTYPES

YMER Digital ◽  
2022 ◽  
Vol 21 (01) ◽  
pp. 192-205
Author(s):  
N Raghuraman ◽  
Keyword(s):  
Neural Network ◽  
High Performance ◽  
Fuzzy Neural Network ◽  
Structural Response ◽  
Polymer Concrete ◽  
Model Parameters ◽  
Maintenance Time ◽  
Fuzzy Neural ◽  
Rc Building

RC building elements of Reinforcing and upgrading is essential to extend its maintenance time, to overcome first structural limitations, and to control the consequence of building construction or design flaws. The RC constructions are reinforced by using the FRP-fiber reinforced polymer. This study utilizes the FRP in concrete structures for instance a Jute, coir, and Sisal is explored for its reliability in improving ductility and strength related structural performance. FRP structural response of the model parameters is studied by measuring the numerical and experimental terms, for instance, Ductility, Deflection, Tensile-Strength, and Compression-Strength. The quality of the sample specimens is tested by using the Fuzzy Neural Network (FNN) system. At this time, compared with existing jobs, the propounded Fuzzy Neural Network model accomplishes the best presentation regarding all boundaries for the fiberreinforced specimen over different stacked conditions

Improvement in Gate Dielectric Quality of Ultra Thin a: SiN:H MNS Capacitor by Hydrogen Etching of the Substrate

2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao
Keyword(s):  
Silicon Nitride ◽  
Gate Dielectric ◽  
Substrate Surface ◽  
Scaling Limit ◽  
Tunneling Current ◽  
Chemical Vapor ◽  
Poor Performance ◽  
State Density ◽  
Direct Tunneling Current

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.

Effect of Resource Factors and Quality of Instruction on Performance in Mathematics of Nigeria Secondary School Students

2020 ◽  
Vol 5 (1) ◽  
pp. 61-69
Author(s):  
Umar Abdullahi ◽  
Musa Sirajo
Keyword(s):  
Secondary School ◽  
Secondary School Students ◽  
Poor Performance ◽  
Secondary School Student ◽  
Teaching Staff ◽  
Ministry Of Education ◽  
School Students ◽  
Quality Of Instruction ◽  
The Public

It seems that educational system in Nigeria has undergone only quantitative improvement in terms of number of schools and students’ enrolment. However, there has been little effort in respect to the capacity to manage them through provisions of adequate financial, human, material and physical resources. Physical and material resources in secondary schools were discovered to be inadequate and poorly equipped. Some of the secondary school buildings were dilapidated, also the allocated financial resource, teaching and non-teaching staff are grossly inadequate compared with the students’ enrolment. The public, the Ministry of Education and other stakeholders in education are expressing serious concern about the consistency of the poor performance of secondary school students especially in mathematics. Increase in population and the government’s free education programs make people want to take advantage of the education provided. Provision of both professionally qualified and non-qualified teachers by government and non-state providers of education also appear not to ameliorate the problem of declining performances in mathematics. The effect of all these on the public secondary school student academic performance in mathematics concern the researchers of this study. It is against this background that the study sought to empirically investigates effect of resource factors and quality of instruction on performance in mathematics of Nigeria secondary school students.

scholarly journals Evaluating the success of the tele-pathology system in governmental hospitals in Kuwait: an explanatory sequential mixed methods design

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ali Jasem Buabbas ◽  
Tareq Mohammad ◽  
Adel K. Ayed ◽  
Hawraa Mallah ◽  
Hamza Al-Shawaf ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Mixed Methods ◽  
Support Services ◽  
User Satisfaction ◽  
Technical Support ◽  
Successful Implementation ◽  
System Quality ◽  
Mixed Methods Design ◽  
Telepathology System

Abstract Background Telepathology is the practice of reviewing and exchanging pathological images through telecommunication systems to obtain diagnoses remotely. Studying the factors that make such a system successful and favourable is important to ensure the merits of its implementation in clinical practice. Objective This study aims to evaluate the success of a telepathology system from the users’ perspectives, using specific evaluation criteria, namely: system quality, information quality, technical service quality, user satisfaction, and benefits. Methods A sequential explanatory mixed methods design was adopted in this study, which consists of two phases. Initially, a questionnaire was distributed via WhatsApp to all of the pathologists (total: 45) working at governmental hospitals in Kuwait. Followed by, semi-structured interviews with ten senior pathologists. Results Forty pathologists responded to the questionnaire, giving an 89% response rate. There were 42.5% of the respondents aged between 35–44 years old, and 52.5% were male. The quantitative results reveal that most of the respondents were satisfied with the quality of the telepathology system with a mean of 2.6025 (Standard Deviation (SD) = 0.47176), whereas they were dissatisfied with the quality of the information with a mean of 2.4100 (SD = 1.580) and the technical support services with a mean of 2.2750 (SD = 0.99535). In addition, there was disagreement on the benefits of telepathology in clinical practice among the pathologists with a mean of 2.4667 (SD = 0.77552). The qualitative results indicate that the lack of interest in and little experience with using the system were behind the general dissatisfaction of most of the respondents. All of the interviewees were satisfied with the performance of the telepathology system and considered it successful; however, the quality of the technical support services, including training workshops, was deemed deficient. Conclusion This study concluded that telepathology system in Kuwait is functioning well and has been successful in its implementation; however, pathologists are dissatisfied with it, mainly due to the deficient quality of the technical support services provided. In addition, the successful implementation of such advanced technologies requires careful steps to be taken on multiple levels: technical, organisational, and managerial. Recommendations were suggested.

scholarly journals System Quality of Human Physiological Signal Based Medical Auxiliary Diagnosis

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 27130-27139
Author(s):  
Zhiyuan Liu ◽  
Linghui Wu ◽  
Weina Fu
Keyword(s):  
System Quality ◽  
Physiological Signal
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