- About Us
- Civil Engineering
Customer: Horncastle Group
VHE were appointed to undertake earthworks on a site adjacent to the former runway of BAE Systems.
Following a competitive tender VHE were appointed to undertake the earthworks for a proposed housing development. The works are the first phase of a multi-phase extension to the Brough development masterplan.
Owing to the geotechnical properties of the underlying strata an area of the housing development platform of approximately 19,000m2 required the construction of a 70,000 m3 surcharge plateau. Constructed into the plateau were a series of columns containing monitoring equipment consisting of vertical wire piezometers, magnetic extensometers and settlement monitoring plates these were monitored to ensure that the induced settlement was within design parameters before relocating the surcharge materials for use into public open space areas and extending the development zone to the designed levels. The surcharge remained in situ for 13 weeks.
A total earth move of over 234,000m3 was undertaken, including topsoil excavation; the creation of a surface water storage lagoon with bunds and planted wetland areas including the daylighting of a sewer with outfall and headwalls.
As soils were variable materials were managed on site throughout the project based on geotechnical properties and their suitability for engineering this included site won clays, sands and gravels from the storage lagoon excavations, reduced level dig in future phase areas and importation using tipper wagons from an off-site source.
Where within range of geotechnical improvement soils which were above suitable moisture content were modified using VHE’s in house lime stabilisation team. Over 12,000 meters of materials were modified for incorporation into the development area.
This became increasing challenging following an extended tender period. Despite losing approximately 1 months programme to the exceptionally wet spring VHE delivered the earthworks within the original planned programme period of 50 weeks.
Throughout the project the earthworks required geotechnical validation through a grid of plate testing, CBR, Dynamic cone penetration and mexicone testing on each layer of placement together with sand replacement testing and nuclear density testing for compaction compliance. Constant close volumetric calculations were required by our surveyors and engineers to ensure a balancing of materials on site between processed site soils, reworked post surcharge volumes, stockpiling and recovery of natural materials from the borrow pits and off site imports.
Due to the location of surrounding residential areas, main line railway and River Humber works required careful management of water during heavy rain and dust mitigation and monitoring during dry periods.