A laboratory study of anisotropy in engineering properties of Ankara clay

Download
2011
İspir, Mustafa Erdem
Anisotropy in engineering properties of soils occurs due to the depositional process forming the soil fabric and/or different directional stresses in soil history. This study investigates the anisotropy in undrained shear strength and drained compressibility of preconsolidated, stiff and fissured Ankara Clay. The compressibility behavior is determined using standard oedometer testing while the shear strength anisotropy is investigated through large diameter unconsolidated-undrained triaxial testing on undisturbed samples taken in vertical and horizontal directions from several deep excavation sites along the Konya Road in Çukurambar-Balgat Area, Ankara. According to the results achieved, Ankara Clay is slightly anisotropic in compressibility, with an anisotropy ratio between 0.72 and 1.17 in terms of coefficient of volume compressibility for several pressure ranges between 50 kPa and 1600 kPa. On the other hand, while a slight anisotropy in undrained shear strength at a ratio ranging between 0.87 and 1.19 in terms of deviator stress can be observed in Ankara Clay, considering the great variation in the test results of samples in same direction which mostly overlaps with the range of results obtained in the other direction, it has been concluded that the Ankara Clay located in this area can be regarded as isotropic in terms of shear strength for practical purposes.

Suggestions

Determination of soil hydraulic properties using pedotransfer functions in a semi-arid basin, Turkey
TOMBUL, MUSTAFA; Akyürek, Sevda Zuhal; ŞORMAN, ALİ ÜNAL (2004-12-01)
Spatial and temporal variations in soil hydraulic properties such as soil moisture 0(h) and hydraulic conductivity K(theta) or K(h), may affect the performance of hydrological models. Moreover. the cost of determining soil hydraulic properties by field or laboratory methods makes alternative indirect methods desirable. In this paper, various pedotransfer functions (PTFs) arc used to estimate soil hydraulic properties for a small semi-arid basin (Kurukavak) in the north-west of Turkey. The field measurements...
A Preliminary study on construction of a high capacity tensiometer and its use in measurement of matrik suction in unsaturated soils
Köksalan, Ali Okan; Toker, Nabi Kartal; Department of Civil Engineering (2013)
Soil suction is one of the main state parameters that governs unsaturated soil behaviour. Tensiometers are the only type of probe that can measure soil suction directly, but only up to 90 kPa. In the past two decades, a new type of tensiometer with much greater measurement range (up to 2 MPa) has appeared in the literature. The measurement range (i.e. capacity) of a tensiometer is limited by (i) how well it is saturated, and (ii) the air entry value of its porous interface. In this study, the first high cap...
A new technique for rapid measurement of continuous soil moisture characteristic curves
Toker, Nabi Kartal; Sjoblom, K.J.; Culligan, P.J. (2004-01-01)
The soil moisture characteristic (SMC) curve of a soil describes the relationship between the soil suction (tension in the soil pore water) and its water content. The majority of traditional methods used to obtain SMC curves involve gathering individual point measurements of soil water content over a range of applied soil suctions, and then fitting a curve through these points. Each point measurement requires at least a day of testing to gather, leading to a total testing time of weeks to assemble the whole...
An analysis of deformation behaviorof Muratlı asphalt faced rockfill dam
Ünsever, Yeşim Sema; Özkan, M. Yener; Department of Civil Engineering (2007)
In this study, settlement and seepage behavior of Muratlı Dam, which is the first asphalt faced rockfill dam in Turkey, is investigated for the “end of construction” and “reservoir impoundment” loading conditions. Two dimensional plane strain finite element analyses are carried out in order to determine the total stresses, displacements and pore water pressures. Hardening soil model is used in order to represent the non-linear, inelastic and stress dependent behavior of rockfill material. Material model par...
Engineering geological and geotechnical site characterization and determination of the seismic hazards of Upper Pliocene and Quaternary deposits situated towars the west of Ankara
Koçkar, Mustafa Kerem; Akgün, Haluk; Department of Geological Engineering (2006)
The purpose of this study is to assess the engineering geological and geotechnical characteristics and to perform seismic hazard studies of the Upper Pliocene and Quaternary deposits located towards the west of Ankara. Based on a general engineering geological and seismic characterization of the site, site classification systems are assigned for seismic hazard assessment studies. The objective of the research is to determine the regional and local seismic soil conditions, predominant periods and ground ampl...
Citation Formats
M. E. İspir, “A laboratory study of anisotropy in engineering properties of Ankara clay,” M.S. - Master of Science, Middle East Technical University, 2011.