Development of Tehran alluvium classification based on geological characteristics and geotechnical parameters

Document Type : Original Article

Authors

1 Structural and engineering geology department, School of geology, College of science, University of Tehran

2 Engineer

3 Faculty of Civil Engineering, College of Engineering, Tehran University

Abstract

The proposed classification based on the combination of geological variables and geotechnical parameters provides the possibility of using geological knowledge in estimating the geotechnical parameters. The city of Tehran is one of the metropolises that founded on Quaternary alluvium. The alluvium is divided into four groups, A, B, C, and D, based on age and formation conditions. Some researchers have proposed a new classification using the combination of geological variables and geotechnical parameters for A and C Tehran's alluvia. The aim of this study is to sub-classification of unit B of Tehran alluvia based on combination of geological variables and geotechnical parameters. In this research, based on geological findings in 66 locations of Tehran's alluvia, the geological variables affecting the geotechnical parameters of the coarse-grained B alluvia including grain size, grain form, grain contact, cement between grain, homogeneity and layering were identified and based on these variables, unit B was divided into four units of Bn1, Bn2, Bn3 and Bn4. Using the results of 27 performed direct shear test and 70 plate loading tests in specified units, the geotechnical parameters of these four units, including the internal friction angle, cohesion, and modulus of deformability were determined. With combination of geological variables and geotechnical parameters, new classification of unite B was proposed that make it is possible to estimate the geotechnical parameters based on the geological variables for this alluvium.

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چشمی،ا.، فاخر، ع.، خامه­چیان، م.، ا.،1387، زمین­شناسی آبرفت­های تهران و ارزیابی طبقه­بندی ریبن جهت مطالعات زمین­شناسی مهندسی، مجله علوم دانشگاه تهران، جلد 34، شماره 1، صفحات 47-61.
Arnous, M.O., 2011. Geotechnical site investigations for possible urban extensions at Suez city, Egypt using GIS. Arab. J. Geosci. 6, 1349–1369.
ASTM D4554-12, 2012. Standard Test Method for In Situ Determination of Direct Shear Strength of Rock Discontinuities.
ASTM D1194-94, 1994. Standard Test Method for Bearing Capacity of Soil for Static Load and Spread Footings.
Barton, M.E. 1993. Cohesive sands: the natural transition from sand to sandstone. In: Anagnostopoulose, I.G. et al., (ed.) Proceedings of Geotechnical Engineering of Soft Rocks–Hard Soil. Balkema, Rotterdam, 367–374.
Berberian, M., King, G.C.P., 1981. Towards a paleogeography and tectonic evolution of Iran. Can. J. Earth Sci. 18, 210–265.
Cheshomi, A., Fakher, A., Jones, C.J.F.P., 2011. A correlation between friction angle and particle shape metrics in Quaternary coarse alluvia. Q. J. Eng. Geol. Hydrogeol. 42, 145–155.145–155.
Dobkins, J.E., and Folk, Rl., 1970, Shape development on Tahiti-Nui: jour. Sed. Petrol., V.40, p.1167-1203.
El May, M., Dlala, M., Chenini, I., 2010. Urban geological mapping: geotechnical data analysis for rational development planning. Eng. Geol. 116, 129–138. 
Fakher, A., Cheshomi, A., Khamechian,M., 2007. The addition of geotechnical properties to a geological classification of coarse grain alluvium a pediment zone. Q. J. Hydrogeol. 40, 163–174Eng. Geol.
Fuchu, D., Yuhai, L., Sijing, D., 1994. Urban geology: a case study of Tong Chuan city, Shaanxi Province, China. Eng. Geol. 38, 165–175.
Jannuzzi, G.M.F., Danziger, F.A.B., Martins, I.S.M., 2015. Geological–geotechnical characterization of Sarapuí II clay. Eng. Geol. 190, 77–86.
Maharaj, R.J., 1995. Engineering–geological mapping of tropical soils for land-use planning and geotechnical purposes: a case study from Jamaica, West Indies. Eng. Geol. 40, 243–286.
Raspa, G., Moscatelli, M., Stigliano, F., Patera, A., Marconi, F., Folle, D., Vallone, R., Mancini, M., Cavinato, G.P., Milli, S., Costa, J.F.C.L., 2008. Geotechnical characterization of the upper Pleistocene–Holocene alluvial deposits of Roma (Italy) by means of multivariate geostatistics: cross-validation results. Eng. Geol. 101, 251–268.
Rieben, E.H., 1966. Geological observation on alluvial deposits in Northern Iran. Geol. Organ. Iran Rep. 9 (in French).
Samadian, B., Fakher, A.,2016. Proposing a framework to combine geological and geotechnical information for city planning in Sanandaj (Iran). Engineering Geology 209 (2016) 1–11.
Sitar, N. 1983. Slope stability in coarse sediment. In: Yong R.N. (ed.) Proceedings on Geotechnical Environment and Soil Properties, Houston, TX. American Society of Civil Engineers, New York, 82–98.
 Skipper, J., Follett, B., Menkiti, C.O., Long, M., Clark-Hughes, J., 2005. The engineering geology and characterization of Dublin Boulder Clay. Q. J. Eng. Geol. Hydrogeol. 38, 171–187.
Tucker, M. E., 1981. Sedimentary petrology: An introduction: Blackwell Science Pub., London. 252 P.
Touch, S., Likitlersuang, S., Pipatpongsa, T., 2014. 3D geological modelling and geotechnical characteristics of Phnom Penh subsoils in Cambodi. Eng. Geol. 178, 58–69.
Wadel, H., 1932, volum, shape, and roundness of rock particles. Journal of Geology, 40:443-51.