Publication Abstract

Proceedings - Fourth International Conference - Piling and Deep Foundations, 1991, Stresa, Italy, (DFI)

15 Large Diameter, Rock Socket, Base Grouted Piles in Bristol
M.S. Mojabi & M.J. Duffin; Ove Arup & Partners, Bristol, UK

The Galleries is a retail development in the center of Bristol. The site presented a number of unusual and challenging problems in the design and construction of the 10,000m^2 by 6m deep basement. Site conditions were unfavorable being in the alluvial flood plane of the river Frome that crosses the site in a masonry culvert. Fill and Estuarine Alluvium overlie Keuper Sandstone with high groundwater levels. Before construction work could commence, over 100 existing piles, which obstructed the line of perimeter wall and the basement piles, had to be removed. To save about six-months construction time the 'top-down' method of basement construction was adopted. This meant that within the basement one hundred and twenty base grouted piles with cast-in steel stanchions were required to carry loads of up to 11,300kN into the Keuper Sandstone. This paper considers the design and construction steps involved in building the piles.

 article #455; publication #37 (IC-1991-IT)