Impact of Tamper Shape on the Efficiency and Vibrations Induced During Dynamic Compaction of Dry Sands by 3D Finite Element Modeling

Document Type : Research Papers

Authors

1 School of Engineering, Kharazmi university, Tehran, Iran.

2 School of Engineering, Kharazmi University, Tehran, Iran

Abstract

Dynamic compaction is a soil improvement method which has been widely used for the increase of bearing capacity through stress wave propagation during heavy tamping. The cost and time of project implementation can be effectively curtailed by developing a model that can be used in the design of dynamic compaction operations. The numerical models offered so far are mostly one or two-dimensional, incapable of examining the total effect of wave emission in the soil. This paper involved the three-dimensional finite element program ABAQUS employing Mohr-Coulomb failure criterion for the analysis of dynamic compaction operation. Modeling of impact on soil surface involved an initial velocity applied to the tamper nodes. Flat section and conical shape tampers with various cone angles were modeled and their effects on the efficiency of dynamic compaction for soils with different initial relative densities were investigated. Moreover, variations of peak particle velocity (PPV) induced by flat or conical tamper at different radial distances and soil densities were evaluated. The analyses were done individually for each mode over five consecutive blow counts. Comparison of the results of PPV, crater depth and crater volume for different tampers revealed the effect of tamper shape on efficiency and vibrations induced during dynamic compaction. Increasing the cone angle of conical tampers increased improvement depth and velocity of particles in all radial directions.

Keywords

Main Subjects

References

Ardeshir Behrestaghi, A., Eskandari Ghadi, M. and Vaseghi-Amiri, J. (2013). “Analytical solution for a two-layer transversely isotropic half-space affected by an arbitrary shape dynamic surface load”, Civil Engineering Infrastructures Journal, 46(1), 1-14.
Arslan, H., Baykal, G. and Ertas, O. (2007). “Influence of tamper weight shape on dynamic compaction”, Ground Improvement, 11(2), 61-66.
Bement, R.A.P. and Selby, A.R. (1997). “Compaction of granular soils by uniform vibration equivalent to vibro driving of piles”, Geotechnical and Geological Engineering Journal, 15(2), 121-43.
Feng, T.W., Cheng, K.H., Su, Y.T. and Shi, Y.C. (2000). “Laboratory investigation of efficiency of conical-based pounders for dynamic compaction”, Geotechnique, 50(6), 667-674.
Ghanbari, E. and Hamidi, A. (2014). “Numerical modelling of rapid impact compaction in loose sands”, Geomechanics and Engineering, 6(5), 487-502.
Ghassemi, A., Pak, A. and Shahir, H. (2009). “A numerical tool for design of dynamic compaction treatment in dry and moist sand”, Iranian Journal of Science and Technology, 33(B4), 313-326.
Hwang, J.H. and Tu, T.Y. (2006). “Ground vibration due to dynamic compaction”, Soil Dynamics and Earthquake Engineering, 26(5), 337-346.
Li, W., Gu, Q., Su, L. and Yang, B. (2011). “Finite element analysis of dynamic compaction in soft foundation”, Procedia Engineering, 12, 224-228.
Lukas, R.G. (1986). “Dynamic compaction for highway construction”, Report No. FHWA/RD-86/133. Washington D.C., Federal Highway Administration, Department of Transportation, USA.
Luongo, V. (1992). “Dynamic compaction: Predicting depth of improvement”, Geotechnical Special Publication, 2(30), 927-939.
Mayne, P.W., Jones, J.S. and Dumas, J.C. (1984). “Ground response to dynamic compaction”, Journal of Geotechnical Engineering, ASCE, 110(GT6), 757-773.
Menard, L. and Broise Y. (1975). “Theoretical and practical aspects of dynamic consolidation”, Geotechnique, 25(1), 3-18.
Merrifield, C.M. and Davis, M.C.R. (2000). “A study of low-energy dynamic compaction: Field trials and centrifuge modeling”, Geotechnique, 50(6), 675-681.
Pan, J.L. and Selby, A.R. (2002). “Simulation of dynamic compaction of loose granular soil”, Advances in Engineering Software, 33(7-10), 631-640.
Pourjenabi, M., Ghanbari Alamouti, E. and Hamidi, A. (2013). “Numerical modeling of dynamic compaction in dry sand using different constitutive models”, 4th International Conference on Computational Methods in Structural dynamics and Earthquake Engineering, Greece.
Pourjenabi, M. and Hamidi, A. (2015). “Numerical modeling of dynamic compaction process in dry sands considering critical distance from adjacent structures”, Structural Engineering and Mechanics, 56(1), 49-56.
Qiao, J. and Li, L. (2011). “Model test study on vibration transferring of dynamic compaction of hydraulic filling foundation reinforcement”, Systems Engineering Procedia, 1, 61-68.
Raoofian Naeeni, M. and Eskandari Ghadi, M. (2016). “A potential method for body and surface wave propagation in transversely isotropic half and full spaces”, Civil Engineering Infrastructures Journal, 49(2), 263-288.
Rezaei, M., Hamidi, A. and Farshi Homayoun Rooz, A. (2016). “Investigation of peak particle velocity variations during impact pile driving process”, Civil Engineering Infrastructures Journal, 49(1), 59-69.
Shafiei, M. and Khaji, N. (2015). “An adaptive physics-based method for the solution of one-dimensional wave motion problems”, Civil Engineering Infrastructures Journal, 48(2), 217-234.
Smoltczyk, U. (1983). “Deep compaction”, 8th European Conference on Soil Mechanics and Foundation Engineering, Finland.
van Impe, W.F. (1989). Soil improvement techniques and their evolution, A.A. Balkema, Rotterdam.

Files

History

  • Receive Date: 29 September 2016
  • Revise Date: 23 December 2016
  • Accept Date: 25 December 2016

Share

How to cite

Statistics