A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies

SÖNMEZ, Harun; ULUSAY, Reşat

A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies

Harun SÖNMEZ, (Hacettepe Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Ankara, Türkiye)

Reşat ULUSAY (Girilmedi)

Yerbilimleri

13 0

Yıl: 2002 Cilt: 0 Sayı: 26 Sayfa Aralığı: 77 - 99 Metin Dili: Türkçe İndeks Tarihi: 29-07-2022

A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies

Öz:

Yakın aralıklı eklemlerle bölünmüş kaya kütlelerinin mekanik davranışının tahmini, laboratuvar deneyleri için gerekli olan örnek boyutlarının büyük olması nedeniyle kaya mekaniğinin temel sorunlarından biridir. Kaya malzemeleri ve kaya kütleleri için önerilmiş olan görgül (ampirik) yenilme ölçütleri arasında yer alan Hoek-Brown ölçütü oldukça popüler olmuştur. Ölçüt, özellikle zayıf kaya kütlelerine uygulanmasıyla ilgili bazı sınırlamaları nedeniyle, ilk kez önerildiği 1980'den bu yana farklı zamanlarda tekrar düzenlenmiş ve genişletilmiştir. 1997 yılında Jeolojik Dayanım İndeksi (GSI), kaya kütlesinde ölçek etkisini dikkate alan bir parametre olarak geliştiricileri tarafından ölçüte dahil edilmiştir. Ayrıca GSI'nın daha niceliksel şekilde belirlenebilmesi ve GSI ile ilgili girdi parametrelerinin tahmininde kullanılabilecek yöntemler konusunda 1999 yılında bu makalenin yazarları tarafından mevcut GSI Sistemi'ne yönelik bazı değişiklikler önerilmiştir. Bununla birlikte yazarlar, GSI değeri 25 ve 26 olan kaya kütlelerinin yenilme zarfları arasında ortaya çıkan bir dayanım boşluğu, belirli bir normal gerilme düzeyinde yüksek ve düşük dayanımlı kaya kütielerinin yenilme zarflarının birbirlerini kesmesi ve GSI<25 koşulunda s=0 olduğu zaman tek eksenli sıkışma dayanımının sıfır olarak elde edilmesi gibi sorunların giderilmesi gerektiğini düşünmüşlerdir. Bu çalışmada, yenilme ölçütünde 's' ve 'a' gibi kaya kütlesi parametrelerinin belirlendiği eşitliklerle ilgili bazı değişiklik önerileri yapılmıştır. Ayrıca, yazarların daha önce orijinal GSI Sistemi'nden adapte ederek geliştirdikleri niceliksel GSI Sistemi de masif kaya kütlesi kavramı da dikkate alınarak yeniden düzenlenmiştir. Önerilen değişikliklerin geçerliliği; ölçüt, kuramsal bir şeve, yenilmiş açık işletme ve döküm harmanı şevlerine uygulanarak sınamıştır. Sonuçlar; özellikle zayıf ve iyi kaliteli kaya kütleleri arasındaki 25 olan sınır GSI değerinin 30 olarak alınmasının ve zayıf kaya kütleleri için 's' parametresinin sıfır olarak kabul edilmemesinin gerektiğini göstermiştir. Ayrıca, önerilen değişiklikler, şev duraysızlığı vakaları esas alınarak, bu çalışmanın tamamlanmasından sonra Hoek ve çalışma grubunca yayımlanan ve ölçütün 2002 yılına ait son versiyonuda önerilen eşitliklerle karşılaştırılmıştır.

Anahtar Kelime:

Konular: Jeoloji

Hoek-Brown yenilme ölçütü üzerine bir tartışma ve şev duraylılığı vakaları ile sınanmış ölçüte ilişkin değişiklik önerileri

Öz:

Estimation of the mechanical behavior of closely jointed rock masses is one of the fundamental problems in rock mechanics since the size of representative specimens is too large for laboratory testing. Among the empirical strength criteria suggested for intact rocks and rock masses, the Hoek-Brown criterion has become highly popular. Since its introduction in 1980, the criterion has been refined and expanded over the years, particularly due to some limitations in its application to poor-very poor quality rock masses. In 199,7 the Geological Strength Index (GSI) was introduced into the criterion by its originators as a scaling parameter. In addition, some modifications to the GSI System to provide a more quantitative estimate of GSI and methods of parameter estimation have also been previously suggested by the authors,of this paper in 1999. However, the authors considered that some improvements seem to be necessary in order to avoid the gap between failure envelopes of the rock masses with the GSI values between 25 and 26, intersection between failure envelopes of the rock masses of high and low strengths at a certain-normal stress level, and a uniaxial compressive strength of zero when s=0 for GSI<25. In this study, some improvements to the equations providing the rock mass parameters 's' and 'a' for the criterion were proposed. Further, a modification to the quantitative GSI chart, which was adopted from the original GSI chart by the authors, was also suggested by considering intact or massive rock mass. The validity of the proposed improvements was verified by applying the criterion to a hypothetical slope and to failed open pit mine and spoil pile slope case studies. The results particularly indicated that the switch GSI value of 25 between poor and good to reasonable quality rock masses in the criterion should be replaced by 30 and the parameter 's' should not be assumed as zero for poor quality rock masses. In addition, the improvements suggested in this study were also compared with the new equations in the 2002 version of the criterion, which was published by Hoek and his co-workers after this study has been completed, in conjunction with the use of case history examples.

Anahtar Kelime:

Konular: Jeoloji

Belge Türü: Makale Makale Türü: Diğer Erişim Türü: Erişime Açık

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APA	SÖNMEZ H, ULUSAY R (2002). A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. , 77 - 99.
Chicago	SÖNMEZ Harun,ULUSAY Reşat A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. (2002): 77 - 99.
MLA	SÖNMEZ Harun,ULUSAY Reşat A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. , 2002, ss.77 - 99.
AMA	SÖNMEZ H,ULUSAY R A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. . 2002; 77 - 99.
Vancouver	SÖNMEZ H,ULUSAY R A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. . 2002; 77 - 99.
IEEE	SÖNMEZ H,ULUSAY R "A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies." , ss.77 - 99, 2002.
ISNAD	SÖNMEZ, Harun - ULUSAY, Reşat. "A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies". (2002), 77-99.

APA	SÖNMEZ H, ULUSAY R (2002). A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri, 0(26), 77 - 99.
Chicago	SÖNMEZ Harun,ULUSAY Reşat A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri 0, no.26 (2002): 77 - 99.
MLA	SÖNMEZ Harun,ULUSAY Reşat A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri, vol.0, no.26, 2002, ss.77 - 99.
AMA	SÖNMEZ H,ULUSAY R A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri. 2002; 0(26): 77 - 99.
Vancouver	SÖNMEZ H,ULUSAY R A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies. Yerbilimleri. 2002; 0(26): 77 - 99.
IEEE	SÖNMEZ H,ULUSAY R "A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies." Yerbilimleri, 0, ss.77 - 99, 2002.
ISNAD	SÖNMEZ, Harun - ULUSAY, Reşat. "A discussion on the Hoek-Brown failure criterion and suggested modifications to the criterion verified by slope stability case studies". Yerbilimleri 26 (2002), 77-99.