Abstract:
On floors of hydraulic structres resting on permeable soils, the water seeping undernearth due to the cutoff head causes uplift pressure, reducing in intensity along the seepage path. Residual heads have been measured by the first author in laboratory for the cases of one, two and three pilelines fixed to flush and depressed floors. Head loss gradients are computed for vertical and horizontal reaches of the creep path, as well as the ratio R of the two gradients. Incorporating the values of R formulae for relative residual head have been established, and compared with existing ones. The research reveals that :(1) R is different for vertical paths along the three pilelines. (2)In the case of three pilelines, the intermediate pilelines is of indirect benefit only, in that its presence increases the effectiveness of the two end pilelines, particularly the downstream one. (3) In the case of double pilelines Ru > Rd, i. e. the upstream pilelines is more effective in reducing uplift pressure than the downstream pileline. On the other hand, in the case of triple pilelines Ru>Rd.
Page(s):
10-19
DOI:
DOI not available
Published:
Journal: Mehran University Research Journal of Engineering and Technology, Volume: 11, Issue: 2, Year: 1992