An Experimental Study on Stress Relaxation of a Silt-type Soil

Yıl 2021, Cilt: 42 Sayı: 1, 70 - 84, 22.04.2021

Eren Kömürlü

https://doi.org/10.17824/yerbilimleri.774533

Öz

In this study, stress relaxation tests were carried out by keeping specimens of a silt type soil under different strain levels. Decreases in the stress values with time data was collected to better understand the effect of the strain level on the relaxation properties of soil specimens. In addition, the stress relaxation effect on the uniaxial compressive strength (UCS) values of the specimens was investigated with a series of tests. According to the results obtained from this study, the UCS values of the silt specimens significantly vary as a result of the stress relaxation effect. The UCS values were determined to increase with an increase of relaxation strain level to a threshold value. On the other hand, the UCS values were found to be affected adversely in case of high stress levels at the initiation of the relaxation, which are close to the peak level.

Anahtar Kelimeler

Stress relaxation, time-dependent effect, compressive strength of silts, stress drop

Silt türü bir Zeminin Gerilme Rahatlaması üzerine Deneysel bir Çalışma

Öz

Bu çalışmada, farklı birim deformasyon seviyelerine tabi tutulan silt türü zemin numuneleri üzerine gerilme rahatlaması testleri gerçekleştirilmiştir. Gerilme değerlerinin zamana bağlı değişimleri ile farklı birim deformasyon değerlerinin gerilme rahatlaması üzerine etkileri incelenmiştir. Ayrıca, gerilme rahatlamasının tek eksenli sıkışma dayanımı (serbest basınç mukavemeti) değerleri üzerindeki etkileri bir dizi deneysel çalışma ile belirlenmiştir. Elde edilen bulgular, gerilme rahatlamasının tek eksenli sıkışma dayanımı (TESD) değerleri üzerinde önemli etkisi olduğunu göstermektedir. TESD değerleri belirli bir seviyeye kadar gerilme rahatlaması yaşanan birim deformasyon miktarı arttıkça yükselmiştir. Ancak, dayanım değerlerine yakın yüksek gerilme seviyelerinde başlayan rahatlamaların TESD değerlerini olumsuz etkilediği görülmüştür.

Anahtar Kelimeler

Gerilme rahatlaması, Zamana bağlı davranış, Siltlerin sıkışma dayanımı, Gerilme düşüşü

Kaynakça

• ASTM International, 2010. ASTM D4318-10: Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils. 2010 Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA
• Augustesen, A., Liingaard, M. and Lade P.V., 2004. Evaluation of Time-Dependent Behavior of Soils. International Journal of Geomechanics, 4(3), 137-156.
• Bagheri, M., Rezania, M. and Nezhad, M.M., 2019. Rate Dependency and Stress Relaxation of Unsaturated Clays. International Journal of Geomechanics, 19(12), 04019128. Bock, R.G., Puri, V.M. and Manbeck, H.B., 1991. Triaxial test sample size effect on stress relaxation of wheat en masse. Transactions of the ASAE, 34(3), 966-971.
• Chegenizadeh, A., Keramatikerman, M., Nikraz, H., 2020. Effect of loading strain rate on creep and stress-relaxation characteristics of sandy silt. Results in Engineering, 7, 100143.
• Dijkstra, J., Andò, E. and Dano, C., 2019. Grain kinematics during stress relaxation in sand: not a problem for X-ray imaging. E3S Web of Conferences, 92, 01001.
• Dob, H., Messast, S., Boulon, M. and Flavigny, E., 2016. Treatment of the High Number of Cycles as a Pseudo-Cyclic Creep by Analogy with the Soft Soil Creep Model. Geotechnical and Geological Engineering, 34, 1985–1993.
• Hanley, K.J., O'Sullivan, C., Wadee, M.A. and Huang, X., 2015. Use of elastic stability analysis to explain the stress-dependent nature of soil strength. Royal Society Open Science, 2(4), 150038.
• Kamao, S., 2016. Creep And Relaxation Behavior of Highly Organic Soil. International Journal of Geomate, 11(25), 2506-2511
• Komurlu, E. and Kesimal, A., 2015. Experimental study of polyurethane foam reinforced soil used as a rock-like material. Journal of Rock Mechanics and Geotechnical Engineering, 7(5), 566-572.
• Kutergin, V.N., Kalbergenov, R.G., Karpenko, F.S., Leonov, A.R. and Merzlyakov, V.P., 2013. Determination of Rheological Properties of Clayey Soils by the Relaxation Method. Soil Mechanics and Foundation Engineering, 50, 1–6.
• Kwok, C.Y. and Bolton, M.D., 2013. DEM simulations of soil creep due to particle crushing. Géotechnique, 63(16), 1365-1376.
• Lade, P.V., Nam, J. and Liggio, C.D.J., 2010. Effects of Particle Crushing in Stress Drop-Relaxation Experiments on Crushed Coral Sand. Journal of Geotechnical and Geoenvironmental Engineering, 136(3), 500-509.
• Lade, P.V. and Karimpour, H., 2015. Stress relaxation behavior in Virginia Beach sand. Canadian Geotechnical Journal, 52(7), 813-835.
• Lade, P.V. and Karimpour, H., 2016. Stress drop effects in time dependent behavior of quartz sand. International Journal of Solids and Structures, 87(1), 167-182.
• Levin, F., Vogt, S. and Cudmani, R., 2019. Time-dependent behaviour of sand with different fine contents under oedometric loading. Canadian Geotechnical Journal, 56(1), 102-115.
• Li, G., Ni, C., Pei, H., Wan-ming, G. and Ng, C.W.W., 2013. Stress relaxation of grouted entirely large diameter B-GFRP soil nail. China Ocean Engineering, 27, 495–508.
• Liingaard, M., Augustesen, A. and Lade, P.V., 2004. Characterization of Models for Time-Dependent Behavior of Soils. International Journal of Geomechanics, 4(3), 157-177.
• Miksic, A. and Alava, M.C., 2013. Evolution of grain contacts in a granular sample under creep and stress relaxation. Physical Review E, 88, 032207.
• Sabir, M.A., Umar, M., Farooq, M. and Faridullah, F., 2016. Computing soil creep velocity using dendrochronology. Bulletin of Engineering Geology and the Environment, 75, 1761–1768.
• Sanchez-Giron, V., Andreu, E. and Hernanz, J.L., 2001. Stress relaxation of five different soil samples when uniaxially compacted at different water contents. Soil and Tillage Research, 62(3–4), 85-99.
• Sheahan, T., Ladd, C. and Germaine, J., 1994. Time-Dependent Triaxial Relaxation Behavior of a Resedimented Clay. Geotechnical Testing Journal, 17(4), 444-452.
• Staszewska, K. and Cudny, M., 2020. Modelling the time-dependent behaviour of soft soils. Studia Geotechnica et Mechanica, 42(2), 97–110.
• Tong, F. and Yin, J.H., 2013. Experimental and Constitutive Modeling of Relaxation Behaviors of Three Clayey Soils. Journal of Geotechnical and Geoenvironmental Engineering, 139(11), 1973-1981.
• Tran, T.T.T., Hazarika, H., Indrawan, I.G.B. and Karnawati, D., 2018. Prediction of Time to Soil Failure Based on Creep Strength Reduction Approach. Geotechnical and Geological Engineering, 36, 2749–2760.
• Wang, Y.F., Zhou, Z.G. and Cai, Z.Y., 2014. Studies about Creep Characteristic of Silty Clay on Triaxial Drained Creep Test. Applied Mechanics and Materials, 580–583, 355–358.
• Xu, M., Hong, J. and Song, E., 2018. DEM study on the macro- and micro-responses of granular materials subjected to creep and stress relaxation. Computers and Geotechnics, 102, 111-124.
• Yin, Z.Y., Zhu, Q.Y., Yin, J.H. and Ni, Q., 2014. Stress relaxation coefficient and formulation for soft soils. Geotechnique Letters, 4(1), 45-51.