A building company has been awarded the contract to undertakethe construction works for a multi-storey office project in a citycentre location. A deep basement is to be installed under one halfof the building, within a layer of dense gravel.
The site is surrounded by public roads and buildings on allsides and it is expected that the water table is extremely close tothe ground surface on a year-round basis.
You have been asked by the contractor to advise their companywith regard to a number of issues on the project, in advance of theconstruction works.
(a) What details would you provide to the contractor in relationto the options and methods available to dewater the soil on theproject, to facilitate both the basement construction and trenchexcavations for utility ducting installation on the site? How wouldthe range of dewatering methods be combined to produce a suitablesolution?
(b) Given the basic information available in relation to thelocation and ground conditions on this site, describe theparticular options that you would recommend to the contractor foruse on this specific site to assist in supporting the sides of thedeep excavations during the basement construction.
