Ultralightweight foundation system for peaty ground

Abstract

Construction on peat deposits represents a major challenge for the geotechnical community. Waterlogged peat deposits have great potential for buoyancy generation. The premise of the present investigation is that this can be beneficially incorporated in foundation design practice, thereby reducing the net bearing pressure and hence resulting settlements. A novel foundation system, comprising a bamboo frame (BF) structure incorporating recycled plastic block (RPB) inclusions, is presented for supporting lightweight structures bearing on peaty ground. The buoyancy effect is produced by the lower bulk density of the foundation construction materials combined with the waterlogged condition of the peat deposit. A programme of reduced-scale 1g physical modelling was conducted to investigate the performance of BF- and BF–RPB-type footing bearing on remoulded peat with different water content and fibre content (FC) values. The mobilised undrained bearing capacity (qf) increased for lower-water- content and higher-FC peat materials. Deeper BF footings and the inclusion of the RPBs within their cavities significantly improved the mobilised qf value. Advantages of the presented foundation system over conventional solutions for peaty ground include its simple technology, reduced earthworks in construction, reduced settlement due to the buoyancy contribution and being more sustainable and economically viable.