Effect of Dynamic Earth Vibration on the Behavior of Laterally Loaded Single Pile Embedded within Unsaturated Soil

Abood, Maha H.; Mahmood, Mahmood R.; Salim, Nahla M.

doi:10.30684/etj.v39i12.508

	Effect of Dynamic Earth Vibration on the Behavior of Laterally Loaded Single Pile Embedded within Unsaturated Soil
Engineering and Technology Journal
Article 2, Volume 39, Issue 12, December 2021, Pages 1748-1752 PDF (947.18 K)
Document Type: Research Paper
DOI: 10.30684/etj.v39i12.508
Authors
Maha H. Abood^* ; Mahmood R. Mahmood; Nahla M. Salim
Civil Engineering Department, University of Technology-Iraq, Alsina’a street, 10066 Baghdad, Iraq.
Abstract
Most of the studies of laterally loaded piles focused on the behavior for piles subjected to static or cyclic lateral loading embedded within dry or saturated soils, few studies investigate the behavior of piles embedded within partially saturated soils and subjected to dynamic loads. In this research, an experimental study presents an aluminum pile model embedded within dry, fully saturated and partially saturated soils, subjected to dynamic load with the El Centro 1940 NS acceleration data (0.05g, 0.15g, and 0.32g) accelerations. Three different lowering levels of the water table for fully saturated soils model is achieved to get partially saturated soils of three different values of matrix suction. During an earthquake model, a liquefaction phenomenon is observed by boiling of sand and completed collapse in the soil as shown in the results. It is concluded that the resisting to the bending moment reduced by 22%, 50%, and 57% after 1st, 2nd and 3rd lowering of water level respectively, than that of the saturated condition. This reduction approaches to 28% for completely dry soil. It is worth to mention, that, the deflection of the pile reduced as the lowering of water level increased. The soil resistance increases with the increasing of dynamic load acceleration. The soil resistance increases about 35% when the acceleration increase from 0.05g to 0.15g and an increase of about 22% when the acceleration increases from 0.15g to 0.32g.
Highlights
A single pile embedded in the unsaturated soil and subjected to lateral shaking load (earthquake) The bending moment and deflection will decrease with increasing of the matric suction. Bending moment in unsaturated condition reduced 57% with matric suction (10kPa). Bending moment in dry condition reduces about 28% than those of the saturated condition. In saturated soil, liquefaction occur after about (12sec) of shaking time for 0.32 g acceleration.
Keywords
Unsaturated soil; Laterally Dynamic loading; Bending moment; deflection; Soil resistance

References
[1] M. K., Al-Recaby, A Comparison between Static and Dynamic Load Tests on Bored Piles, Eng. &Tech. Journal, 34 (2016) 2993-3004. [2] Q. S. M. Shafiqu, M. M. Ahmed, Consolidation Behavior of Two-Pile Group System under Different Loading Condition Using the, Eng. &Tech. Journal, 31 (2013) 185-202. [3] I.C.howdhury & S. P., Dasgupta, Dynamics of Structure and Foundation – A Unified Approach: 2. Applications,Taylor & Francis, UK, (2009). [4] M. Y. Fattah, M. A. Al-Neami, N. H. Jajjawi, Implementation of Finite Element Method for Prediction of Soil Liquefaction Around Undergroud Structure, Eng. &Tech. Journal, 31 (2013) 703-714. [5] L. C. Reese and W. F. Van Impe, (2011), Single Piles and Pile Groups under Lateral Loading, 2nd edition, Taylor & Francis, UK. [6] M. Ghayoomi, JS. McCartney, Measurement of small-strain shear moduli of partially saturated sand during infiltration in a geotechnical centrifuge, ASTM, Geotechnical Testing Journal, 34 (2013) 1-11. [7] M. Ghayoomi, M. Mirshekari, Equivalent linear site response analysis of partially saturated sand layers,” UNSAT2014 conference, Sydney, Australia (2014) 1–6. [8] M. Ghayoomi, S. Ghadirianniari, A. Khosravi and M. Mirshekari, Seismic behavior of pile-supported systems in unsaturated sand, Soil Dynamics and Earthquake Engineering, Elsevier, 112 (2018) 162–173. [9] D. G. Fredlund, A. E. Xing, Equations for the soil-water characteristic curve, Canadian. Geotechnical Journal, 31 (1994) 521-532. [10] D.G. Fredlund, H. Rahardjo and M.D. Fredlund, Understanding the family of soil-water characteristic curves, Proceedings of the Canadian Geotechnical Conference, Geo- Edmonton, Edmonton, September (2018) 23-26. [11] Q. Zhai, H. Rahardjo, and A. Satyanga, Uncertainty in the estimation of hysteresis of soil-water characteristic curve, Environmental Geotechnics (2017) (Published online) DOI: 10.1680/JENGE.17.00008. [12] H. K. Dash and T. G. Sitharam, Effect of frequency of cyclic loading on liquefaction and dynamic properties of saturated sand, International Journal of Geotechnical Engineering, 10, issue 5, (2016) 487-492, Tylor& Francis, DOI: 10.1080/19386362.2016.1171951.
Statistics Article View: 416 PDF Download: 279