Sıkıştırılmış Şişen Killerin Mikroyapısal Değişiminde Şişme-Büzülme Çevrimin Etkisi

Year 2009, Volume: 22 Issue: 1, 77 - 91, 30.06.2009

Murat Türköz

Abstract

Şişen zeminler üzerinde inşa edilen temellerin zeminin şişme-büzülme çevrimiyle ilişkili

olarak yukarı ve aşağı hareketi, yapıda yorgunluğa ve çatlamaya sebep olmaktadır. Konu

üzerinde yapılan çalışmalar, özellikle ıslanma ve kuruma çevrimlerinin şişen zeminlerin şişme

yeteneğinde büyük oranda etkiye sahip olduğunu göstermektedir. Buna karşın ulaşılan sonuçlar

arasında bir farklılık vardır. Bu olayı açıklamak için, bu çalışmada, sıkıştırılmış kil zeminlerin

şişme davranışı üzerinde çevrimin etkisini ve buna bağlı mikro yapıdaki değişim incelenmiştir.

Bu amaçla, Eskişehir bölgesinden elde edilen zemin numunesi kullanılmıştır. Örnek numuneler;

kuru ağırlığının yüzdesi olarak sıra ile %0-5-10-15 katkı oranlarında eklenen bentonit katkı

ilavesiyle hazırlanmıştır. Hazırlanan kil numunelerinin tekrarlı olarak şişmesi ve büzülme limiti

su muhtevasına gelecek şekilde kurumaya maruz bırakılmaları durumunda mikro yapıdaki

değişim gözlenerek, şişen killerin şişme davranışı üzerindeki etkisi çevrim açısından

değerlendirilmiştir.

Keywords

Şişen kil, mikroyapı, büzülme

Effect Of Cyclic Swell-Shrink On Microstructural Changes Of Compacted Swelling Clays

Abstract

Cyclic swelling and shrinkage of clays and associated movements of foundations

may result in cracking and fatigue to structures. Recent studies on this subject suggest that

wetting and drying cycles have greatly influenced the swelling abilities of expansive soils.

However, there is a discrepancy among the archived results. In order to explicit this

phenomenon, the basic objective of this study was to investigate the microstructural changes on

the basis of the effect of cyclic swelling on behavior of compacted swelling soils. For this

purpose, soil sample obtained from Eskisehir city was used, and specimens were prepared by

considering bentonite mixture at different percentage (0, 5, 10 and 15 percent of dry soil

weight). The effect of cyclic swelling on clays was addressed on the basis of microstructural

changes of clay specimens subjected to fully shrunk to their shrinkage limits.

Keywords

Swelling clay, microstructure

References

• [1] W.S. Abdullah, K.A. Alshibli, M.S. Al-Zou’bi, “Influence of pore water chemistry on the swelling behavior of compacted clays,” Applied Clay Science, Vol. 15, pp.447-462, 1999.
• [2] A.A. Al-Rawas, R. Taha, J.D., Nelson, T.B. Al-Shap, and H. Al-Siyabi, “A comparative evaluation of various additives used in the stabilization of expansive soils”, Geotechnical Testing Journal, GTJODJ, Vol. 25, No. 2, pp. 199-209, 2002.
• [3] A.A. Basma, A.S., Al-Hamoud, and A. Husein, “Laboratory assessment of swelling pressure of expansive soils”, Applied Clay Science, Vol. 9, pp.355-365, 1995.
• [4] F.H. Chen, “Foundation on Expansive Soils”, American Elsevier Science Publication, NewYork, 1988.
• [5] Y. Du, S. Li, and S. Hayashi, “Swell –shrinkage properties and soil improvement of compacted expansive soil, Ning-Liang Highway, China”, Engineering Geology, Vol. 53, pp. 351-358, 1999.
• [6] C. Parker, D.F. Amos and D.L. Kaster, “An evaluation of several methods of estimating soil volume change”, Soil Science Society of America Journal, Vol. 41, pp.1059-1064, 1977.
• [7] B. Shi, H. Jianh, Z. Liu, H.Y. Fang, “Engineering Geological Characteristics of expansive soils in China”, Engineering Geology, Vol. 67, pp. 63 – 71, 2002.
• [8] F.H. Chen and G. S. Ma, “ Swelling and shrinkage behavior of expansive clays.” 6th Int. Conference on Expansive Soils, Vol.1, New Delhi, India, pp.127-129, 1987.
• [9] K. S., Subba Rao, and G. G., Satyadas, “Swelling potential with cycled of swelling and partial shrinkage.” 6th Int. Conf. On Expansive Soils, Vol. 1, New Delhi, India, pp.137- 142, 1987.
• [10] A.E. Dif, and W.F. Bluemel, “Expansive soils under cyclic drying and wetting.” Geotech. Testing J., Vol. 14, No. 1, pp.96-102, 1991.
• [11] A.S. Al-Homoud, A.A. Basma, A.I. Husein Malkawi, M.A. Al Bashabsheh, “Cyclic swelling behavior of clays.” J. Geotech. Eng. Div., ASCE, Vol. 121, No. 7, pp. 562-565, 1995.
• [12] M. Popesco, “Behavior of expansive soils with crumb structure.” 4th Int. Conf. On Expansive Soils, Vol.1, ASCE, New York, N.Y., pp. 158-171, 1980.
• [13] R.W. Day, “Swell-shrink behavior of compacted clay.” J. Geotech. Eng. Div., ASCE, Vol. 120, No. 3, pp.618-623, 1994.
• [14] M.M. Allam and S. Sridharan, “Effect of wetting and drying on shear strength” J. Goetechnical Engineering Div., ASCE, Vol. 107, No. 4, pp. 421-438, 1981.
• [15] K. Collins, “Characterization of expansive soil microfabric.” In Proceedings of the5th International Conference on Expansive Soils, Adelaide, South Australia, May 1984, pp. 37-41, 1984.
• [16] R. Push, “Unfrozen water as a function of clay microstructure”, Engineering Geology, Vol. 13, pp. 157-162, 1979.
• [17] J.K. Mitchell, Fundamentals of Soil Behavior, 2nd edn. Wiley, New York, 1993.
• [18] BSI, 1990. British Standart Methots of Test for Engineering Purposes: Compaction Related Test, BS 1377: Part 4. British Standarts Institution, London.