Determination of the Deformability, Modulus Ratios and Anisotrophic Behavior of the Micaschists; A Case Study From Burgaz Dam Site, Izmir-Turkey

Öz

Base rock of the Burgaz dam in the eastern part of the city of İzmir consists of micaschists having different physical and mechanical properties due to weathering and fracturing. The first aim is to compute the amount of settlement and ultimate bearing capacity value of micaschist both in and beneath the cutoff zone by using the results of pressuremeter tests. In addition, data from in-situ and some laboratory tests, which were used in the establishment of the relations between elastic modulus of the micaschist rock mass (EM) and uniaxial compressive strength (σc), EM/Eintact ratios and RQD values. Comparison of in-situ and estimated rock mass deformation moduli by considering the RQD values was also performed. Pressuremeter tests indicate that for a dam with 115 m height and a base width of 58 m, the settlement will vary between 2.13 and 2.26 mm. The second aim of this work is to measure compression and shear wave velocities in order to obtain both the ratio of dynamic elastic modulus to Poisson′s ratio (E/v) dynamic and to compare (E/v)dynamic to (E/v)static. Test results reveal a positive linear relation of (E/v) dynamic =(E/v) static0.968. The sonic wave velocity of the micaschist is highly related to the testing direction. This study not only discusses the relationships between Estatic and sonic wave velocity (Vp) and Edynamic, but also the anisotropy effect arisen due to the schistosity planes with different orientations.

Anahtar Kelimeler

• Dam structure
• micaschist
• pressuremeter test
• settlement
• rock material classification
• anisotropy

Mikaşistlerin deformabilite, modül oranı ve anizotropik davranışlarının belirlenmesi; Burgaz baraj sahasından (İzmir-Türkiye) örnek bir çalışma

Öz

İzmir′in doğusunda yeralan Burgaz barajının temel kayacını ayrışma ve kırıklanma nedeniyle farklı fiziksel ve mekanik özelliklere sahip mikaşistler oluşturur. Bu çalışmanın birinci amacı, presiyometre deneylerinin sonuçlarını kullanarak hem cutoff zonunda hem de altında yeralan mikaşistlerin nihai taşıma güçlerini ve oturma miktarlarını hesaplamaktır. Buna ek olarak, bazı laboratuvar ve yerinde deneylerden elde edilen veriler, mikaşist kayaç kütlesinin elastisite modülü (EM) ve sağlam kayanın tek eksenli sıkışma dayanımı (σc), Em Ei oranları ve RQD değerleri arasındaki ilişkilerin kurulmasında kullanılmıştır. Mikaşist kayaç kütlesinin yerinde ölçülmüş elastisite modülü değerleriyle, RQD değerlerini dikkate alan tahmin edilmiş elastisite modülü değerleri karşılaştırılmıştır. Presiyometre deney sonuçları, 58 m taban genişliğine ve 115 m yüksekliğe sahip bir baraj için oluşacak oturmaların 2.13 mm ile 2.26 mm arasında değişeceğine işaret etmektedir. Bu çalışmanın ikinci amacı; ultrasonik dalga hızlarından (Vp ve

Anahtar Kelimeler

• Baraj yapısı
• mikaşist
• Presiyometre deneyi
• oturma
• kaya materyali sınıflaması
• anizotropi

Kaynakça

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