Assessment of Changes in Shear Strength Parameters for Soils below Circular Machine Foundation

Document Type : Original Article

Authors

1 Department of Civil Engineering, University of Technology, Baghdad, Iraq

2 Department of Civil Engineering, Al-Nahrain University, Baghdad, Iraq

Abstract

This paper focuses on the response of circular machine foundation resting on different soils (sand and clay) through studying the variation of soil shear strength parameters and strain with the number of cycles. The objective of the current study is to explore the results related to the parameters of the dynamic load (number of loading cycles and frequency of load) related to the circular footing of a machine on the dynamic shear strength parameters (for sand soil (ϕ˚dyn) and for clay soil (Cudyn)) in addition to the amplitude strain foundation. A special setup was designed and manufactured to simulate the vertical vibration of a circular machine foundation. A steel circular machine foundation with a diameter of 150 mm was used to represent the footing. A total of 6 cases were examined to take into account the effects of different parameters including different frequencies (0.5, 1, and 2 Hz); state of sand (medium and dense) which corresponded to relative densities of (50 and 80%), while the state of clay (medium and stiff) corresponded to undrained shear strengths (50 and 70 kPa).  All tests were carried out under load amplitude of 2.5 kN. It was found that the rate of increase in shear strength parameters for the soil under a circular machine foundation decreases remarkably when increasing the frequency for both types of soil under the footing. While little change in the shear strength parameters, or even no change was observed under the effect of other locations. Moreover, the amplitude strain decreased when increasing the frequency for both types of soil.

Keywords

References

1.     Tripathy, S., and Desai, A. K. “Seismic analysis of turbo machinery foundation: Shaking table test and computational modeling.” Earthquake and Structures, Vol. 12, No. 6, (2017), 629–641. https://doi.org/10.12989/eas.2017.12.6.629
2.     Richart, F. E., and Whitman, R. V. “Comparison of Footing Vibration Tests with Theory.” Journal of the Soil Mechanics and Foundations Division, Vol. 93, No. 6, (1967), 143–168. Retrieved from https://trid.trb.org/view/126866
3.     Vesic, A. S. “Analysis of Ultimate Loads of Shallow Foundations.” Journal of the Soil Mechanics and Foundations Division, Vol. 99, No. 1, (1973), 45–73. Retrieved from https://trid.trb.org/view/125905
4.     Carroll, W. “Dynamic Bearing Capacity of Soils: Vertical Displacements of Spread Footings on Clay: Static and Impulsive Loadings.” Technical Report No. 3-599, Report 5, U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, Mississippi, (1963).
5.     Baidya, D. K., Muralikrishna, G., and Pradhan, P. K. “Investigation of Foundation Vibrations Resting on a Layered Soil System.” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 132, No. 1, (2006), 116–123. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:1(116)
6.     Fattah, M. Y., Karim, H. H., and Al-Qazzaz, H. H. “Cyclic Behavior of Footings on Dry Sand under Different Rates of Loading.” International Journal of Construction Engineering and Management, Vol. 6, No. 6, (2017), 240–253. https://doi.org/10.5923/j.ijcem.20170606.03
7.     Kirar, B., Krishana, A. M., and Rangwala, H. M. “Dynamic properties of soils for the design of machine foundations.” In Proceedings of Indian Geotechnical Conference, (2016), 1–4. Retrieved from http://www.igs.org.in:8080/portal/igc-proceedings/igc-2016-chennai-proceedings/theme5/IGC_2016_paper_265.pdf
8.     Cabalar, A. F., Khalaf, M. M., and Karabash, Z. “Shear modulus of clay-sand mixtures using bender element test.” Acta Geotechnica Slovenica, Vol. 15, No. 1, (2018), 3–15. https://doi.org/10.18690/actageotechslov.15.1.3-15.2018
9.     Venkateswarlu, A., and Hegde, A. “Numerical Analysis of Machine Foundation Resting on the Geocell Reinforced Soil Beds.” Geotechnical Engineering Journal of the SEAGS & AGSSEA, Vol. 49, No. 4, (2018), 55–62. Retrieved from https://www.researchgate.net/publication/329451307
10.   Fattah, M. Y., Salim, N. M., and Alwan, K. K. “Contact pressure distribution under circular shallow foundation subjected to vertical and rocking vibration modes.” Journal of Building Engineering, Vol. 26, (2019), 100908. https://doi.org/10.1016/j.jobe.2019.100908
11.   American Society for Testing and Materials. Annual Book of ASTM Standards, (2007).
12.   Ranjan, G. and Rao, A.S.R., Basic and applied soil mechanics. New Age International, (2007).
13.   O’reilly, M. P., and Brown, S. F. “Observations on the resilient shear stiffness of granular materials.” Geotechnique, Vol. 42, No. 4, (1992), 631–633. https://doi.org/10.1680/geot.1992.42.4.631
14.   Tutunchian, M. A., Shahnazari, H., Salehzadeh, H., and Asadi, M. “Study on Dynamic Behavior of Shallow Foundations on Liquefiable Sand, Using Video Processing Technique.” Electronic Journal of Geotechnical Engineering, Vol. 16, (2011), 945–960. Retrieved from https://www.researchgate.net/publication/265119640
15.   Fattah, M. Y., Al-Mosawi, M. J., and Al-Americ, A. F. I. “Stresses and pore water pressure induced by machine foundation on saturated sand.” Ocean Engineering, Vol. 146, (2017), 268–281. https://doi.org/10.1016/j.oceaneng.2017.09.055
International Journal of Engineering
Volume 33, Issue 8
TRANSACTIONS B: Applications
August 2020
Pages 1491-1498

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