Scheduling of Construction Projects under Resource-Constrained Conditions with a Specifically Developed Software using Genetic Algorithms

The purpose of this study is to develop a genetic algorithm (GA) based software that can perform resource allocation close to optimum and that can determine the critical path by minimizing the project duration according to the resource profile for a present work schedule and resource pool using a programmable objective function. In this context, the methodology of GAs was presented, the software was developed and the performance of this software was tested with a sample project. With the developed software, by minimizing the activity durations in both constrained and unconstrained resource conditions, projects can be scheduled, total duration and the critical path of the projects can be determined. With this software, any construction company will be able to determine how much time would be required to complete a project at the bidding stage by considering its resources and constraints and can take the required precautions. The main difference of this present study is that the developed code performs minimization of schedule duration integrated with resource allocation and levelling. It also determines the critical path of the final solutions. Both renewable and non-renewable resources are included in the code which is not often considered in the literature. By minimizing project duration and optimizing resource allocation, construction projects can become more sustainable, and the environmental impact of the construction process could be minimized

OKUL BİNALARININ GÜÇLENDİRİLMESİNDE ÖRNEK BİR UYGULAMA

Bu çalışmada, Konya ili sınırları içerisinde, 1. Derece deprem bölgesinde yer alan ve deprem güvenliği açısından incelenerek güçlendirilmesine karar verilen Akşehir ilçesi Akşehir Kız Meslek Lisesi (AKML) binasının, betonarme perde duvar ilavesi ve kolon mantolama yöntemiyle güçlendirilmesinin maliyeti incelenmiştir. Bunun için AKML binasının 2007 birim fiyatları ile birim imalat yöntemine göre yapım maliyeti hesaplanmıştır. Binanın statik analizleri için gerekli veriler oluşturulmuş, analizler yapılmış, ilave edilecek betonarme perde duvarlar ile mantolanacak kolonlar belirlenmiştir. Güçlendirme için gerekli perde ilavesi ve mantolamanın birim imalat yöntemine göre 2007 yılı fiyatları ile yapım maliyetleri hesaplanmıştır. Sonuç olarak, AKML binasının 2007 fiyatlarıyla yapım maliyetinin 1.392.016.00 YTL, güçlendirme maliyetinin 693.708.93 YTL. olduğu ve güçlendirme maliyetinin yapım maliyetinin yaklaşık %50’ye ulaştığı görülmüştür

BAĞLAYICI ÖZELLİĞİ ARTIRILAN HARÇLA OLUŞTURULAN YIĞMA DUVARLARIN MEKANİKSEL DAVRANIŞLARI

Bu çalışmada,  normal harçla hazırlanan bir yığma duvar numunesiyle, katkı maddesi kullanılarak bağlayıcı özelliği artırılmış harçla hazırlanan bir yığma duvar numunesinin mekaniksel davranışları araştırılmış ve sonuçları karşılaştırılmıştır. Yapılan deneysel çalışmada, ASTM 1391-81’de önerilen, yığma duvar numuneleri için standart kayma gerilmesi deney tekniği kullanılmıştır. Bunun için ilk önce en uygun yapışma oranını verecek katkı maddesinin miktarını belirlemek amacıyla 6 adet aynı boyutlarda duvar numunesi değişik katkı miktarları kullanılarak örülmüştür. Daha sonra bu duvar numuneleri deneye tabi tutulmuş ve en uygun katkı maddesi miktarı belirlenmiştir. Katkı maddesi miktarı belirlendikten sonra,  normal harçla örülmüş numune ile katkı maddesinin en iyi sonuç verdiği numune arasındaki farklar araştırılmıştır. Deney numunelerinde gözlenen davranışlar ve deney sonucu oluşan çatlaklar incelenmiş,  τ   (kayma gerilmesi) değerleri ile yük-deplasman grafikleri karşılaştırılmıştır

YIĞMA BİR OKUL BİNASININ DEPREM PERFORMANS ANALİZİ

Türkiye’de yığma binalar, yerleşim yerlerindeki yapıların önemli bir kısmını oluşturmaktadır. Yönetmeliklere göre inşa edilmeyen yığma yapıların olası bir depremde hasar görmesi kaçınılmazdır. 2007 yılında yürürlüğe giren Deprem Bölgelerinde Yapılacak Binalar Hakkında Yönetmelik kapsamında yapıların güçlendirilmesine karar vermek için performans değerlendirilmesi yapmak gerekmektedir. Bu makalede 1. Derece deprem bölgesinde yer alan, Sivas’ın Suşehri ilçesinde, yığma yapı olarak inşa edilmiş Aşağısarıca İlköğretim Okulu’nun, 2007 Deprem Yönetmeliği esaslarına göre hem analitik yöntem ile hem de StatiCAD-Yığma paket programı ile performans analizi yapılmıştır. Program ile analitik yöntem sonuçları karşılaştırılmış ve her iki yöntem ile elde edilen sonuçlarda bina göçme sınırında bulunmuştur

Investigating the Effectiveness of Certain Priority Rules on Resource Scheduling of Housing Estate Projects

The heuristic method is one of the methods used for the scheduling of resource-constrained projects. This method is commonly used in programming the projects with high number of activities and resources such as construction investments. This paper investigates the effectiveness of three heuristic method priority rules applied in the resource scheduling of ten Turkish housing estate projects which were scheduled according to three preselected priority rules [maximum remaining path length (MRPL), latest finish time (LFT), and minimum slack time (MNSLCK)] in resource-constrained conditions. The performance of each priority rule was evaluated in relation to the duration of the project. The results revealed that MRPL priority reduced the project duration to minimum in six projects, whereas LFT priority yielded the best duration results in three projects and MNSLCK priority in only one project

Cost effect of earthquake region and soil type for office buildings in Turkey

WOS: 000248145600019In this study, the change in the load-bearing system cost of a reinforced concrete office building has been investigated in relation to the earthquake regions and soil types. Three different office projects each with five stories were investigated. The structural design calculations have been made according to four different soil types and four different earthquake regions. According to each combination, concrete, steel and formwork adopted approximations were calculated to reach the rough cost of each office building. The changes in the cost of projects according to the soil type and earthquake region were examined with multiple regression analysis and analysis of variance. In general, the change in cost has been observed around 22% between first and fourth soil type and 14% between first and fourth earthquake region. (C) 2006 Elsevier Ltd. All rights reserved

DETERMINATION OF DRINK AND POTABLE WATER DEMAND IN KAHRAMANMARAŞ PROVINCE

In this research, the need of drinking water and its usage by people lived in the city of Kahramanmaraş have been examined. In a study previously done, it was understood that 80 % of water was consumed by housing. For this purpose to determine the amount of the water consumption the questionnaries have been applied. Therefore, in this study as well as general factors affecting water consumption in residential centers, the determination of the other factors affecting housing water consumption in the city was also decided. In these questionnarie works, the results of water consumption were obtained by taking the values of l / man / day and l / family / day as dependent variable and the factors affecting water consumption as independent variables. In addition, the factors affecting water consumption in the city were individually undertaken, and the water consumed in the last years was examined by using regression method. And then, the water to be needed 40 years later was tried to be calculated. Furthermore, suggestions were given as to which sources this need of water could be supplied from as well

ÖRNEK HAZIRLAMA YÖNTEMİNİN KONİ BATMA LİKİT LİMİT DEĞERİNE ETKİSİ

Bu çalışmada, ASTM D 4318’de tarif edilen ıslak hazırlama ve ülkemizde uygulandığı şekliyle kuru hazırlama yöntemlerinin likit limit değerini hangi düzeyde etkilediği belirlenmeye çalışılmıştır. Bu amaçla, değişik bölgelerden alınmış 10 farklı doğal zemin numunesi üzerinde koni batma yöntemiyle likit limit deneyleri yapılmıştır. Yapılan deneyler sonucunda ıslak eleme yöntemiyle hazırlanan numunelerin likit limit değerlerinin kuru eleme yöntemiyle hazırlanan numunelerden % 1.2 – 14.9 arasında değişmek üzere daha büyük olduğu saptanmıştır

Cost assessment of concrete and steel types for office buildings: An exploratory study

WOS: 000246650600028This paper presents a set of regression models which incorporates concrete and steel types in modeling the costs of office buildings. To these ends, three typical office buildings with seven and 15 stories have been designed by the help of a commercial software taking into account the Turkish practice. In each project C-16, C-20, C-25, C-30 and C-35 concrete classes and S-220 and S-420 steel types were used for dimensioning purposes. Rough construction costs were then calculated for different combinations of concrete classes and steel types. The findings of the study revealed that column dimensions decrease following an increase in a particular concrete class. However, this decrease stops after C-30. Furthermore, an average cost difference of 16% was observed between the steel types S-220 and S-420. (c) 2006 Elsevier Ltd. All rights reserved

Effects of project size and resource constraints on project duration through priority rule-base heuristics

Priority rules are one of the frequently used methods in project programming with resource-constraints. In this paper, the effects of project size and number of resource constraints on project duration are compared to the performances of pre-selected priority rules. Ten projects in different sizes have been programmed with 3, 5, 7, 9, and 11 limited-resource conditions by means of MRPL (Maximum Remaining Path Length), LFT (Latest Finish Time), MNSLCK (Minimum Slack Time), EFT (Earliest Finish Time), and LST (Latest Start Time) priority rules. When the number of resource constraints is low, the performance of MRPL is generally observed to be higher. As the number of resource constraints increases, a decrease in the performance of MRPL is observed in contrast with an increase in the performance of LFT