Densification of Pond Ash by Blasting
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 125, Issue 10
Abstract
Fly ash from thermal power plants is disposed, in huge quantities in ash ponds, which occupy large land areas otherwise useful for agriculture, housing, or other development. For effective rehabilitation of ash ponds, densification of the slurry deposit is essential to increase the bearing capacity and to improve its resistance to liquefaction. Extensive field trials were carried out to evaluate the effectiveness of deep blasting for densification of deposited fly ash. Ninety explosions comprising 15 single blasts, with varying depths and quantities of charges, and 3 group blasts, each having 25 charges placed at various spacings, were carried out. The compaction achieved in terms of an increase in relative density was evaluated from surface settlement measurements. Extensive field monitoring was undertaken through pore-water pressure measurements, vibration measurements, penetration tests, and block vibration tests. For the average charge of 2–4 g of explosive per cubic meter of untreated deposit, the average relative density was found to improve from 50% to 56–58%. Analysis of the test results indicates that deep blasting may be an effective technique for modest compaction of loose fly ash deposits. The field testing program presented in this paper provides valuable information that can be used for planning blast densification of fly ash deposits.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Charlie, W. A., Jacobs, P. J., and Doehring, D. O. (1992). “Blast-induced liquefaction of an alluvial sand deposit.” Geotech. Testing J., 15(1), 14–23.
2.
Drake, J. L., and Little, C. D. ( 1983). “Ground shock from penetrating conventional weapons.” Proc., Symp. on the Interaction of Non-Nuclear Munitions with Struct., U.S. Air Force Academy, Colorado Springs, Colo., Part I, 1–6.
3.
Gandhi, S. R., Raju, V. S., and Vimal Kumar. (1997). “Densification of deposited ash slurry.” Proc., 13th Int. Conf. on Solid Waste Technol. and Mgmt., Vol. 1, 4C, 1–8.
4.
Hall, C. E. (1962). “Compacting a dam foundation by blasting.”J. Soil Mech. and Found. Div., ASCE, 88(3), 33–51.
5.
Hryciw, R. D. ( 1986). “A study of the physical and chemical aspects of blast-densification of sand,” PhD thesis, Northwestern University, Evanston, Ill.
6.
Ivanov, P. L. (1983). “Prediction and control techniques to compact loose soils by explosions.” Proc., 8th Eur. Conf. on Soil Mech. and Found. Engrg., Vol. 1, 253–254.
7.
Jenkins, D. V., Kilian, A. P., and Hachey, J. E. (1994). “Use of deep blast densification for bridge foundation improvement on SR-504.” Transp. Res. Rec. 1447, Transportation Research Board, Washington, D.C. 102–109.
8.
Kate, S. R., and Vinod Kumar. (1997). “New generation explosives for faster and economic tunnelling.” Indian Concrete J., Bombay, Nov., 627–632.
9.
Kramer, S. L. (1996). Geotechnical earthquake engineering. Prentice-Hall, Upper Saddle River, N.J.
10.
Lyakhov, G. M. (1961). “Shock waves in the ground and the dilatancy of water saturated sand.” Zhurnal Prikladony Mekhanik i Tekhnicheskoy Fiziki, Moscow, 1, 38–46.
11.
Narin Van Court, W. A., and Mitchell, J. K. ( 1995). “New insights into compaction of loose, saturated, cohesionless soils.” Soil improvement for earthquake hazard mitigation, ASCE Geotech. Spec. Publ. No. 49, 51–65.
12.
Prugh, B. J. (1963). “Densification of soil by explosive vibrations.”J. Constr. Div., ASCE, 89(1), 79–100.
13.
Raju, V. R., and Gudehus, G. (1994). “Compaction of loose sand deposits using blasting.” Proc., 13th ICSMFE, 1145–1150.
14.
Sharma, S. ( 1998). “Field monitoring of ash densification by blasting.” M. Tech. thesis, Indian Institute of Technology, Madras, India.
15.
Solymar, Z. V. (1984). “Compaction of alluvial sands by deep blasting.” Can. Geotech. J., Ottawa, 21, 305–321.
16.
Solymar, Z, V., and Mitchell, J. K. (1986). “Blasting densifies sand.” Civ. Engrg., ASCE, 56(3), 46–48.
17.
Van Impe, W. E. (1989). Soil Improvement techniques and their evaluation. Balkema, Rotterdam, The Netherlands.
18.
Wild, P. A. ( 1961). “Tower foundations compacted with explosives.” Electr. World, Jan. 9, 36–38, 66.
Information & Authors
Information
Published In
History
Received: May 12, 1998
Published online: Oct 1, 1999
Published in print: Oct 1999
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.