A case study of soft ground improvement by dynamic consolidation approach

• Published in: IOP conference series. Materials Science and Engineering 2019-04, Vol.512 (1), p.12052
• Main Authors: Choy, Lee Eng, Rusli, Qusanssori Noor bin, Razali, Muhammad Khudrie, Andy, Ramu
• Format: Article
• Language: English
• Subjects: Case studies; Clay; Consolidation; Pore water pressure; Soft clay; Soft ground; Soil compaction; Soil conditions; Soil permeability
• ISSN: 1757-8981; 1757-899X; 1757-899X
• DOI: 10.1088/1757-899X/512/1/012052

There are several ground improvement approaches which can be utilised to deliver results which are sought after in when constructing over poor ground conditions. Where soft grounds, such as soft saturated clays, are encountered, ground improvement utilising consolidation approaches such as, surcharge with PVD, are commonly adopted. It is known that surcharge fill is required to pressurise the porewater within the soft clay, hence creating an excess pore pressure within the pores of the clay matrix. This excess pore pressure drives the pore water towards the PVD and upwards towards the drainage blanket. An alternative method to pressurise the pore water is by applying impact energy such as HIEDYC dynamic compaction. This approach has proven to be capable of developing excess porewater pressures in soft saturated clays. The excess porewater pressure is 'locked-in' due to the low permeability of the clay. The magnitude of this excess pore pressure has been measured as up to 30kPa which is equivalent to the placement of 1.5m surcharge fill height. Hence, this method is coined 'DYCON' or Dynamic Consolidation. This method will require installation of PVD but with reduced surcharge requirements. A case study of application of this approach in ground improvement in soft ground is described in this paper. The case study illustrated that Dycon can effectively improve soft ground and the procedure is recommended for sites with similar soft soil condition.