S. Ümit Dikmen

An Artificial Neural Networks Model for the Estimation of Formwork Labour

Abstract Artificial Neural Networks (ANN) is a problem solving technique imitating the basic working principles of the human brain. The formwork labour cost constitutes an important part within the costs of the reinforced concrete frame buildings. This study suggests a method based on artificial neural networks developed for estimating the required manhours for the formwork activity of such buildings. The introduced method has been verified in the study with reference to the test conducted involving two case studies. In all cases, the model produced results reasonably close to actual field measurements. The model is a simple and quick tool for the estimators and planners to aid them in their work.

A PRODUCTIVITY FACTOR IN HIGH RISE CONSTRUCTION: WIND

When the human comfort is considered, especially the pedestrian comfort, it is a well-known fact that wind has serious effects. In the past, valuable research has been conducted and numerous publications have been made on the subject. In similar respect, wind has negative effects both on the operation of equipment like cranes and on the productivity of labor at construction sites. On the other hand, in Istanbul especially due to the shortage of available land the construction of high rise buildings have accelerated. The objective of this study is the analytical investigation of the effects of wind on the construction at high rise building sites and under the climatic conditions of Istanbul.

COST ESTIMATION TECHNIQUES USED IN THE OTTOMAN ERA

There is no doubt that throughout all the ages, cost estimations have formed the foundations of the construction planning process. At every age the cost estimate was very important and as it is now budget preparations were made. In the Ottoman times the estimations of new and repair works were determined beforehand. For this purpose quantity survey based or design prepared on graph paper were used by taking unit prices into consideration. In this respect during the Ottoman era no construction work was permitted without the prior determination of the costs. The reason for this is to guarantee the completion of the investment, as well as the assurance of transparency and avoidance of misconduct. In this study, the cost calculation methods and cost estimation methods used in the Ottoman era will be presented and a comparison of these methods with those of the methods used to day will be made.

OSMANLI DÖNEMİNDE KULLANILAN YAKLAŞIK MALİYET TAHMİN YÖNTEMLERİ

Hic kusku yok ki, tum caglar boyunca yapi uretim surecinin planlamasinin temelini yapi maliyetleri olusturmustur. Yapinin kaca mal olacaginin onceden bilinmesi her donem onemli olmus, buna gore de gunumuzde oldugu gibi oncelikli olarak butce organizasyonlari yapilmistir. Osmanli`da da onarim ve yeni yapi calismalarinda yapi maliyetleri yine onceden belirlenmis, metraja dayali yaklasik maliyet hesaplari ile kareli kagitlara cizilen projeler uzerinden birim fiyatlar esas alinarak yapilan maliyet tahmin (Karname) yontemleri kullanilmistir. Bu baglamda, Osmanli doneminde maliyeti onceden bilinmeyen hic bir yapim isine izin verilmemekteydi. Bunun nedeni yatirimin garanti altina alinmasi oldugu gibi, olasi suistimallerin onune gecilerek seffafligin saglanmasidir. Bu calismada, ozellikle Osmanli doneminde onarim ve yeni yapim calismalarinda kullanilan yaklasik maliyet hesaplamalari ile maliyet tahmin yontemleri incelenecek olup gunumuzde kullanilan yontemlerle karsilastirilacaktir.

Effect of Depth of Ground Water on the Seismic Response of Frame Type Buildings on Sand Deposits. Part I: Soil Response

Earthquake codes often times classify the subsoil based on their shear wave velocities which are mostly calculated based on the situ static conditions. However, it has been shown by various researchers that saturated sands exhibit a softening behavior under cyclic conditions. As a result of this behavior the surface response may be significantly affected by the existence of ground water. In this study, the effect of depth of water table on the seismic response of sand deposits is investigated.