• Steel and Composite Structures
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• v.5 no.2_3
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• pp.169-180
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• 2005

Current codes of practice do not exist in isolation, and rules that have been developed assume certain material properties and minimum workmanship in fabrication and erection. These are either in separate documents or different parts of the code. This paper explains the main requirements for materials and workmanship and how they can be related to design and construction in general. The use of very high strength steels is also considered and the measures that may be needed to allow their use with modern codes are also presented.

• Structural Engineering and Mechanics
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• v.58 no.1
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• pp.121-142
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• 2016

The national standard being used in Turkey for suspended ceiling systems (SCS) regulates material and dimensional properties but does not contain regulations regarding installation instructions which cause substandard applications of SCSs in practice. The lack of installation instructions would potentially affect the dynamic performance of these systems. Also, the vast majority of these systems are manufactured using substandard low-quality materials, and this will inevitably increase SCS related damages during earthquakes. The experimental work presented here focuses on the issue of dynamic performance of SCSs with different types of carrier systems (lay-on and clip-in systems), different weight conditions, and material-workmanship qualities. Moreover, the effects of auxiliary fastening elements, so called seismic perimeter clips, in improving the dynamic performance of SCSs were experimentally investigated. Results show that clip-in ceiling system performs better than lay-on system regardless of material and workmanship qualities. On the other hand, the quality aspect becomes the most important parameter in affecting the dynamic performance of lay-on type systems as opposed to tile weights and usage of perimeter clips. When high quality system is used, tile weight does not change the performance of lay-on system, however in poor quality system, tile weight becomes an important factor where heavier tiles considerably decrease the performance level. Perimeter clips marginally increase the dynamic performance of lay-on ceiling system, but it has no effect on the clip-in ceiling system under the shaking levels considered.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.10a
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• pp.29-32
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• 1991

It is well known that the fatigue damage process in composite materials is very complicated due to complex failure mechanisms that comprise debounding, matrix cracking, delamination and fiber splitting of laminates. Therefore, the residual strength, instead of a single dominant crack length, is chosen to describe the criticality of the damage accumulated in the sublaminate. In this study, two models for residual strength degradation established by Yang-Liu and Tanimoto-Ishikawa that are capable of predicting the statistical distribution of both fatigue life and residual strength have been investigated and compared. Statistical methodologies for fatigue life prediction of composite materials have frequently been adopted. However, these are usually based on a simplified probabilistic approach considering only the variation of fatigue test data. The main object of this work is to propose a fatigue reliability analysis model which accounts for the effect of all sources of variation such as fabrication and workmanship, error in the fatigue model, load itself, etc. The proposed model is examined using the previous experimental data of GFRP and it is shown that it can be practically applied for fatigue problems in composite materials.

• 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.

• Earthquakes and Structures
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• v.5 no.3
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• pp.343-357
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• 2013

On May 19, 2011 an earthquake struck Simav district of K$\ddot{u}$tahya which located west of Turkey. According to Disaster and Emergency Management Agency (DEMA), magnitude of this earthquake was $M_L$ = 5.7. In this earthquake 2 people lost their lives and considerably damages occurred in the city center and surrounding villages. Damaged structures in the earthquake area did not have adequate earthquake resistance since low quality materials, poor workmanship and improper selection of the structural system. In this study, reasons of damages and failure mechanism of reinforced concrete and masonry buildings were evaluated.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.459-467
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• 2011

Construction errors can have significant effects on project performance. Yet, any attempt to tackle error should be driven by the ability to understand its archetypal nature. This study aims to analyze a variety of construction errors at the execution stage, in order to develop a comprehensive set of categories that shall provide insights about the effect of different error types on the industry. We investigate a database provided by an authoritative source, which includes a number of 256 construction errors that occurred in the year 2009 in Dubai construction industry. Results from this study reveal that the most common error arose from 'poor workmanship' which accounted for 21% of the total encountered faults. The next most common types arose from the 'usage of impaired materials', followed by the 'deviation from an intended dimension'. These observations infer that the majority of construction errors are driven by workers' lack of skill or competence. Moreover, it suggests that execution-oriented errors are the major cause of faults and accidents rather than design errors.

• Earthquakes and Structures
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• v.5 no.5
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• pp.571-588
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• 2013

Many of the current buildings in Algeria were built in the past without any consideration to the requirements of the seismic code. Among these buildings, there are a large number of individual houses built in the 1980's by their owners. They are Reinforced Concrete (RC) frame structures with unreinforced hollow masonry infill walls. This buildings type experienced major damage in the 2003 (Algeria) earthquake, generated by deficiencies in the structural system. In the present study, special attention is placed upon examining the vulnerability of RC frame houses. Their situation and their general features are investigated. Observing their seismic behavior, structural deficiencies are identified. The seismic vulnerability of this type of buildings depends on several factors, such as; structural system, plan and vertical configuration, materials and workmanship. The results of the vulnerability assessment of a group of RC frame houses are presented. Using a method based on the European Macroseismic Scale EMS-98 definitions, presented in previous studies, distribution of damage is obtained.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.04a
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• pp.391-396
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• 1998

The concrete structures are hardly ever built under ideal conditions. So many defects may occur for a various reasons such as unsuitable and defective materials, construction methods, poor workmanship, particular structural form and prevailing weather conditions. Some structural form can greatly increase the risk of occurrence of defects. Therefore we investigated the actual condition of the deterioration factors for reinforced concrete apartment, which was composed of 85 apartments with various building ages in different regions with five evaluation the deterioration factors of apartment building to establish the overall evaluation system of deterioration degree for reinforced concrete apartment in Korea.

• Earthquakes and Structures
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• v.25 no.3
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• pp.209-221
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• 2023

The Mw=7.7 (Pazarcık-Kahramanmaraş) and Mw=7.6 (Elbistan-Kahramanmaraş) earthquakes that occurred in Türkiye on 06.02.2023 with 9 hours' intervals, caused great losses of life and property as the biggest catastrophe in the instrumental period. The earthquakes affecting an area of 14% of the country were enormous and caused a great deal of loss of life and damage. Numerous buildings have collapsed or damaged at different levels, both in the city centers and in rural areas. Within the scope of this study, masonry structure damage built from different types of materials in the earthquake region was taken into consideration. In this study, the damage and causes of such masonry structures that do not generally receive engineering services were examined and explained in detail. Insufficient interlocking between wall-wall and wall-roof, inadequate masonry, lack of horizontal and vertical bond beams, usage of low-strength materials, poor workmanship, and heavy earthen roof are commonly caused to structural damages. Separation at the corner point and out-of-plane mechanism in structural walls, and heavy earthen roof damages are common types of damage in masonry structures.

• Computers and Concrete
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• v.11 no.4
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• pp.337-350
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• 2013

The sensitivity of compressive strength of no-slump concrete to its ingredient materials and proportions, necessitate the use of robust models to guarantee both estimation and generalization features. It was known that the problem of compressive strength prediction owes high degree of complexity and uncertainty due to the variable nature of materials, workmanship quality, etc. Moreover, using the chemical and mineral additives, superimposes the problem's complexity. Traditionally this property of concrete is predicted by conventional linear or nonlinear regression models. In general, these models comprise lower accuracy and in most cases they fail to meet the extrapolation accuracy and generalization requirements. Recently, artificial intelligence-based robust systems have been successfully implemented in this area. In this regard, this paper aims to investigate the use of optimized support vector machine (SVM) to predict the compressive strength of no-slump concrete and compare with optimized neural network (ANN). The results showed that after optimization process, both models are applicable for prediction purposes with similar high-qualities of estimation and generalization norms; however, it was indicated that optimization and modeling with SVM is very rapid than ANN models.