Sille Hamurda Kayasının Bozunma Davranışının Araştırılması

Year 2021, , 179 - 198, 20.08.2021

Elif Avşar

https://doi.org/10.17824/yerbilimleri.910036

Abstract

Bilindiği gibi hamurda kayalar blok ve matriks olmak üzere iki bileşenden oluşmaktadırlar. Bu kayaların dayanım, deformasyon ve bozunma davranışının araştırılmasında hamurda kaya ile birlikte blok ve matriksin jeo-mekanik özelliklerinin ve bozunma karakteristiklerinin belirlenmesi oldukça önemlidir. Bu çalışmada hamurda kayanın donma-çözünme ve suda dağılmaya karşı duraylılık olmak üzere iki süreç açısından fiziksel bozunma davranışı araştırılmıştır. Buna ek olarak, bu tür bir kayanın yerinde ve dolayısıyla zaman açısından doğal sürecinde bozunması sonucu dayanımındaki azalma gözlenmiştir. Bu amaçla bozunmaya bağlı olarak dayanım azalmasının yerinde tayin edilmesi için Sille Antik Kenti’ndeki (Konya) kaya oyma yapılarının duvarlarında Schmidt çekici deneyleri uygulanmıştır. Laboratuvar ve arazi çalışmalarının tümünde hamurda kayayı oluşturan matriks ve blok bileşenleri ve hamurda kayanın kendisi ayrı ayrı incelenmiştir. Ayrıca, laboratuvar ve arazi ölçeğinde bozunma sonucu hamurda kayada ve hamurda kaya kütlesinde gerçekleşen fiziksel değişimler birbiriyle ve diğer volkanik/volkanoklastik kayalarla karşılaştırılmıştır. Sonuçlara göre, hamurda kaya ve matriksin suda dağılmaya karşı duraylılığının düşük olduğu belirlenmiştir. Buna karşın, blokların suda dağılmaya karşı duraylılık indeksinin matriks ve hamurda kayanın suda dağılma indeks değerlerine oranla oldukça yüksek olduğu belirlenmiştir. Donma-çözünme çevrimleri sonunda hem hamurda kayada hem de blok ve matrikste tek eksenli sıkışma dayanımının kritik biçimde azaldığı belirlenmiştir. Blokların Schmidt geri sıçrama değerlerinin matrikse ait değerlerden daha yüksek olduğu ve kaya yapılarının dış duvarlarındaki geri sıçrama değerlerinin iç odaların duvarlarında ölçülenlerden belirgin biçimde düşük olduğu ortaya konmuştur.

Keywords

Bozunma, donma-çözünme, hamurda kaya, antik kaya yapıları

Supporting Institution

Selçuk Üniversitesi

Project Number

17401137

Thanks

Bu çalışma, Selçuk Üniversitesi (Konya) Bilimsel Araştırma Projeleri (BAP) birimi (Proje no. 17401137) tarafından mali olarak desteklenmiştir. Schmidt çekici deneylerinin uygulanması ve örneklerin derlenmesi aşamalarındaki desteklerinden dolayı Araş. Gör. Dr. Ali Bozdağ’a (Konya Teknik Üniversitesi) teşekkür ederim.

Investigation of Weathering Behaviour of Sille Bimrock

Abstract

As is known, bimrocks are composed of two constituents, blocks and matrix. It is crucial to determine the geo-mechanical properties and weathering characteristics of bimrock, blocks and matrix, individually, while studying on the strength, deformation and weathering behaviour of these rocks. In this study, physical weathering behaviour of bimrock was investigated in terms of two processes such as freezing-thawing and slake durability. In addition, strength reduction because of weathering of such rock has been observed in situ and therefore in its natural process in terms of time. For this purpose, Schmidt hammer tests were applied on the walls of the rock-hewn structures in Sille Antique City (Konya) in order to determine the strength reduction due to the in-situ weathering. The matrix and block constituents that compose the bimrock and the bimrock itself were separately examined in all of the laboratory and field studies. In addition, physical changes in the bimrock and bimrock mass because of weathering were compared both for laboratory and field scale and with the weathering behaviour of other volcanic/volcanoclastic rocks. The results suggested that the bimrock and matrix have very low slake stability. On the other hand, it was determined that the slake durability index of the blocks is quite higher than the durability index of the matrix and the bimrock. It was revealed that the uniaxial compressive strength of the bimrock, block and matrix decrease critically when subjected to the freezing-thawing cycles. The Schmidt rebound values of the blocks are higher than values of matrix, and the rebound values on the outer walls of the rock structures are significantly lower than determined on the walls of the inner chambers.

Keywords

Antique rock-hewn structures, bimrock, freezing-thawing, weathering

Project Number

17401137

References

• Afifipour, M., and Moarefvand, P., 2014. Mechanical behavior of bimrocks having high rock block proportion. International Journal of Rock Mechanics and Mining Sciences, 65, 40-48.
• ASTM., 2014. Annual Book of ASTM Standards-Soil and Rock, Building Stones, Section-4, Construction vol. 04.08. ASTM Publications. Philadelphia.
• Avşar E., 2019. Piroklastik Kayaçların (Sille, Konya) Tek Eksenli Sıkışma Dayanımlarının Tahmini. MÜHJEO’2019: Ulusal Mühendislik Jeolojisi ve Jeoteknik Sempozyumu, 03-05 Ekim 2019, PAÜ, Denizli.
• Avşar, E., 2020. Contribution of fractal dimension theory into the uniaxial compressive strength prediction of volcanic welded bimrock. Bulletin of Engineering Geology and the Environment, 79, 3605-3619.
• Aydan, Ö., and Ulusay, R., 2003. Geotechnical and environmental characteristics of man-made underground structures in Cappadocia, Turkey. Engineering Geology, 69 (3/4), 245-272.
• Barbero, M., Bonini, M., Borri-Brunetto, M., 2008. Three-dimensional finite element simulations of compression tests on bimrock. In Proceedings of the 12th Int. Conference of International Association for Computer Methods and Advances in Geomechanics IACMAG, Goa, India. 631–637.
• Boving, T.B., and Grathwohl, P., 2001. Tracer diffusion coefficients in sedimentary rocks: correlation to porosity and hydraulic conductivity. Journal of Contaminant Hydrology, 53, 85-100.
• Coli, N., Berry, P., Boldini, D., 2011. In situ non-conventional shear tests for the mechanical characterisation of a bimrock (BimTest). International Journal of Rock Mechanics and Mining Sciences, 48, 95–102.
• Coli, N,, Berry, P., Boldini, D., Bruno, R., 2012. The contribution of geostatistics to the characterisation of some bimrock properties. Engineering Geology, 137-138, 53–63.
• Deniz, B.E., and Topal, T., 2021. A new durability assessment method of the tuffs used in some historical buildings of Cappadocia (Turkey). Environmental Earth Sciences, 80:266.
• Ergüler, Z.A., 2009. Field-based experimental determination of the weathering rates of the Cappadocian tuffs. Engineering Geology, 105, 186–199.
• Erguler, Z.A., and Ulusay, R., 2009. Water-induced variations in mechanical properties of clay-bearing rocks. International Journal of Rock Mechanics and Mining Sciences, 46, 355–370.
• Fener, M., and Ince, İ., 2015. Effects of the freeze-thaw (F-T) cycle on the andesitic rocks (Sille-Konya/Turkey) used in construction building. Journal of African Earth Sciences, 109, 96-106.
• Franklin, J.A., and Chandra, A., 1972. The slake-durability test. International Journal of Rock Mechanics and Mining Sciences, 9, 325–341.
• Garcia-Vallés, M., Topal, T., Vendrell-Saz, M., 2003. Lithenic growth as a factor in the physical deterioration or protection of Cappadocia monuments. Environmental Geology, 43, 776–781.
• Gökçeoğlu, C., Ulusay, R., and Sönmez, H., 2000. Factors affecting the durability of selected weak and clay bearing rocks from Turkey, with particular emphasis on the influence of the number of drying and wetting cycles. Engineering Geology, 57, 215-237.
• Haneberg, W,C., 2004. Simulation of 3D block populations to characterize outcrop sampling bias in bimrocks. Felsbau Rock and Soil Engineering - Journal of Engineering Geology, Geomechanics and Tunnelling, 22(5), 19–26.
• ISRM (International Society for Rock Mechanics), 1981. In:Brown, E.T. (Ed.), Rock Characterization Testing and Monitoring: ISRM Suggested Methods. Pergamon. 211 pp.
• ISRM., 2007. Suggested methods prepared by the commission on testing methods. In:Ulusay R, Hudson JA, eds. The Complete ISRM Suggested Methods for Rock Characterization, Testing and Monitoring. International Society for Rock Mechanics, Compilation Arranged by the ISRM Turkish National Group, Kozan Ofset; 628.
• Kahraman, S., and Alber, M., 2006. Estimating unconfined compressive strength and elastic modulus of a fault breccia mixture of weak blocks and strong matrix. International Journal of Rock Mechanics and Mining Sciences, 43(8), 1277–1287.
• Kahraman, S., Alber, M., Günaydın, O. 2008. Evaluating the geomechanical properties of Misis fault breccia (Turkey). International Journal of Rock Mechanics and Mining Sciences, 45, 1469-1479.
• Kaşmer, Ö., and Ulusay, R. 2013. Effects of geo-engineering characteristics of the soft tuffs and environmental conditions on the rock-hewn historical structures at Zelve Open Air Museum (Cappadocia, Turkey). Environmental and Engineering Geoscience, 19 (2), 149-171.
• Kaşmer, Ö., Ulusay, R., Geniş, M. 2013. Assessments on the stability of natural slopes prone to toe erosion, and man-made historical semi-underground openings carved in soft tuffs at Zelve Open-Air Museum (Cappadocia, Turkey). Engineering Geology, 158, 135-158.
• Koncagul, E.C., and Santi, P.M., 1999. Predicting the unconfined compressive strength of the Breathitt shale using slake durability, Shore hardness and rock structural properties. International Journal of Rock Mechanics and Mining Sciences, 36, 139-153.
• Koca, Y. M., and Kıncal, C., 2016. The relationships between the rock material properties and weathering grades of andesitic rocks around İzmir, Turkey. Bulletin of Engineering Geology and the Environment, 75, 709–734.
• Özkan, M.A., 2017. Küçükmuhsine-Sulutaş (Konya batısı, Türkiye) Çevresindeki Karasal Neojen Çökellerinin (Geç Miyosen-Erken Pliyosen) Stratigrafisi. El-Cezerî Journal of Science and Engineering, 4(3), 382–410 (In Turkish).
• Sönmez, H., Ercanoğlu, M., Kalender, A., Dağdelenler, G., Tunusluoglu, C., 2016. Predicting uniaxial compressive strength and deformation modulus of volcanic bimrock considering engineering dimension. International Journal of Rock Mechanics and Mining Sciences, 86, 91–103.
• Sönmez, H., Tuncay, E., Gökçeoğlu, C., Nefeslioğlu, H., 2005. Matriks içinde blok içeren kayaçların deformasyon modülünün saptanabilmesine yönelik fotoanaliz destekli yaklaşımların geliştirilmesi. TÜBİTAK Yer, Deniz, Atmosfer Bilimleri ve Çevre Araştırma Grubu, Proje no.102Y033.
• Topal, T., and Doyuran, V., 1997. Engineering geological properties and durability assessment of the Cappadocian tuff. Engineering Geology 47, 175–187.
• Topal, T., and Doyuran, V., 1998. Analyses of deterioration of the Cappadocian tuff, Turkey. Environmental Geology, 34 (1), 5–20.
• Ulusay, R., Özkan, I., Ünal, E., 1995. Characterization of weak stratified and clay-bearing rock masses for engineering Geology and some engineering properties applications. In: Myer, L.R., et al., (Eds.), Fractured and Jointed Rock Masses Conference, June 3-5, 1992, Lake Tahoe, CA. A.A. Balkema, Rotterdam, pp. 229-235.
• Wang, Y., Li, X., Zheng, B., Mao, T.Q., Hu, R.L., 2016. Investigation of the effect of soil matrix on flow characteristics for soil and rock mixture. Geotechnical Letters, 6, 1-8.
• Xu, W.J., Xu, Q., Hu, R.L., 2011. Study on the shear strength of soil-rock mixture by large scale direct shear test. International Journal of Rock Mechanics and Mining Sciences, 48(8),1235-1247.
• Zhang, H.Y., Xv, W.J., Yu, Y.Z., 2016. Triaxial tests of soil-rock mixtures with different rock block distributions. Soils Foundation, 56(1), 44–56.
• Zorlu, K., 2008. Description of the weathering states of building stones by fractal geometry and fuzzy inference system in the Olba ancient city (Southern Turkey). Engineering Geology, 101 (3-4), 124-133.