Nokta Yükleme Deneyi ile İlgili Uygulamada Karşılaşılan Problemler

Yıl 2000, Cilt: 24 Sayı: 1, 73 - 86, 15.12.2000

Tamer Topal

Öz

Nokta yükleme deneyi, iki konik uç arasına yerleştirilen kayaç örneğinin kırılması esasına dayanmaktadır. Yenilme yükü ve örnek boyutları kullanılarak bulunan nokta yükleme dayanım indeksi çeşitli amaçlarla mühendislik jeolojisi çalışmalarında kullanılmaktadır. Bu makalede, nokta yükleme deneyi ile ilgili uygulamada karşılaşılan aletsel ve kullanıcıyı ilgilendiren problemler tartışılmıştır. Yazarın uygulamada elde ettiği deneyimleri sonucu, standart deney formuna kayacın "D”' boyutu, kırılma zamanı ve yüzde olarak yenilme yüzeyindeki süreksizliğin ve kayaç dokusunun kontrolü hakkındaki bilgilerin eklenmesi önerilmiştir. Tek eksenli sıkışma dayanımı (σc)- nokta yükleme dayanım indeksi (Is(50)) oranının (k) değişik kayaçlar için çok geniş bir aralıkta değişmesi nedeniyle, mühendislik projelerinde bu oran ayrıca belirlenmelidir. Bu çalışmada, tüfler için kullanılabilecek yüksek korelasyon katsayısı veren (<σc)-(Is(50)) ilişkisi sunulmuştur.

Anahtar Kelimeler

K-Değeri, Mühendislik Jeolojisi, Nokta Yükleme Dayanim Indeksi, Tek Eksenli Sikişma Dayanimi, Tüf

Problems Faced in The Applications of The Point Load Index Test

Öz

The point load index test is based on the principle that rock sample is broken between two conical platens. Failure load and specimen dimensions are used to calculate the point load strength index and this index is used in engineering geological studies. In this paper, the problems related to the point load testing device and the common mistakes of the users are discussed. Based on the experience of the author, a proposal for including "D’ " dimension of the rock, failure time, and textural and structural information of the failure surface of rock in the point load test form is given, k-value, defining the ratio between the uniaxial compressive strength (soc) and the point load strength index (Is50), varies significantly for different rocks. Therefore, k-values for different rocks should be assessed for engineering projects. In this study, a linear relationship with high correlation coefficient between (σc) and (Is(50)) is given for tuff's.

Anahtar Kelimeler

Engineering Geology, K-Value, Point Load Strength Index, Tuff, Uniaxial Compressive Strength.

Kaynakça

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