Sedat Sert

Kazıklı İksa Sistemi ile Şev Duraylılığının Sağlanması

Bu makalede stabilitesi her asiri yagis sonrasinda bozulan, uzerinde devamli kullanilan bir yol ile evler bulunan bir yamacin guvenliginin saglanmasi icin kullanilan kazikli iksa sistemi aciklanmistir. Kazikli iksa sistemi Sakarya ili, Karapurcek Ilcesi, Kanlicay Mevkii guney bati yamacinda bulunan yol uzerinde gerceklesmis heyelani onlemek icin kullanilmistir. Yaklasik olarak 35-40 metre genislik ve 60-65 metre uzunluga sahip olan zemin kitlesinde hareketin farkli zamanlarda gerceklestigi, ozellikle yagan yagmurlar sonucunda hareketin siddetinin arttigi beyan edilmektedir. Calisma alaninda toplam derinligi 29.5 metre olan 3 adet donel sondaj gerceklestirilmistir. Sondajlardan alinan numuneler uzerinde heyelan incelemesine yonelik olarak fiziksel ve mekanik deneyler gerceklestirilmistir. Yapilan incelemeler sonucunda alanda meydana gelen harekete zemin ortaminda bosluk suyu basinclarinin yukselmesinin neden oldugu anlasilmistir. Yurutulen heyelan analizleri sonucunda hasar goren yolun kazikli sistem uzerine oturtulacak konsol duvar ile cozumlenebilecegi kanisina varilmis ve imalat gerceklestirilmistir.

Yerel zemin özelliklerinin deprem hasarı üzerindeki etkisinin CBS ile değerlendirilmesi

Moderate magnitude earthquakes hit the Sakarya region, Turkey, in the range of 10-30 years. The 1999 earthquakes, which occurred in the study area, gave different damage patterns due to the variation of soil properties. In-situ and laboratory investigations were performed by Sakarya University in the centres of two townships in the Sakarya region: Arifiye and Geyve, which are known to possess different soil properties. Borings and cone penetration soundings were performed around the selected towns and data were entered into a database, which is connected to a Geographical Information System (GIS) software. Some thematic maps have been prepared for depths up to 15 m and an evaluation of damage patterns has been performed from points of view including: geology, geomorphology and geotechnical engineering in the investigation area. By evaluating the maps prepared in GIS, local soil properties affected the earthquake destruction of buildings. The number of heavily damaged buildings decreased with increasing bearing capacity. It was also proven that the liquefaction phonomena has not occurred in clayey areas.

Koni Penetrasyon Deneyi ile Zeminlerin Karakterizasyonu

Determination of the physical, mechanical and hydraulic properties of soils is one of the most important tasks in geotechnical engineering. The conventional approach of drilling a borehole and attempting to procure undisturbed samples often present difficulties due to sample disturbance, in addition SPT procedures still have human and equipment based problems. So, some other alternative in-situ tests started to being widely used. The use of the cone penetration test for the determination of soil properties is a novel approach to soil investigation because of its speed and requiring minimum human intervention on the readouts. Today, the standard penetration test, a long time favourite is full of pitfalls in implementation and interpretation whereas the CPT with pore pressure measurements has been used increasingly in respect to improving technology to determine some other parameters (ie: chemical properties of water, electrical resistivity, pH, temperature) in addition to geotechnical properties of soils and detecting soil stratigraphy. This paper describes the advantages of the CPT through the results obtained in the city of and Adapazarı during the past fourteen years.

Evaluation of the liquefaction potential through dissipation measurement in PCPT

This paper discusses the interpretation of the pore water dissipation curves obtained during a piezocone test with the prime objective of determining the seismic behaviour of fine-grained soil. The pore pressure dissipation approach was attempted to perform a faster diagnosis of liquefiability of fine-grained soils where the ground water table is almost at the surface. Furthermore, because non-plastic silts are very difficult to sample for laboratory testing, such an in situ measurement appears to be the only realistic method for the purpose. Most of the dissipation tests were conducted by using the u2 filter on the neck of the probe, and the others were performed by using the u1 filter where the piezometer is located on the cone tip. Penetration was arrested at depths where the presence of silts had been detected by previous sounding and drilling, and t50, t90 and t100 were determined analytically. The results indicate that t90 values have a notable potential for diagnosing a potential for liquefaction. This was demonstrated by a t90 of 300 s or less for liquefiable layers, whereas considerably longer periods are required for non-liquefiable silts similar to clays. This feature is illustrated by the presentation of several types of dissipation curves.