Construction of major new relief road connecting the A29 with the A259 to the north of Bognor, being built in conjunction with the new housing development north of Felpham in an area covering 20 hectares (49 acres) which will provide around 700 new residential homes, new community facilities, sports pitches, play parks and public spaces.
The relief road itself consists of a bridge over the railway and a viaduct structure over the floodplain with the road on either side, raised on embankments, with several culverts and water alleviation ponds.
The viaduct structure over the flood plain is made up of 16 equal spans, 30.3m in length.
The spans are supported by columns atop piled foundations up to 30m into the ground. The precast beams across the spans are 30m in length and can weigh up to 60 tonnes, they will be delivered and installed on-site at night. The width of the Relief Road is 15.6m.
With such major works across a floodplain and crossing a railway, the project has many constraints which have been integrated into the design and planning phases to reduce the risk involved during the construction phase. These include:
CDM Co-ordinator &
Sensitivity to surrounding area and local community
Working in close proximity to and over the railway
Working in close proximity to and over a major watercourse
Significant groundwater & prevailing weather conditions associated with floodplain
Stability of ground & inadequate bearing capacity of soils
Aggressive soil & groundwater chemistry
Managing the safety of local footpaths crossing construction area which have to remain open during works
Major live services in an around works area
Transporting large pre-cast beams to site
Lifting & piling restrictions due to ground conditions
Managing a range of environmental restrictions
Potential for unexploded ordnance
Barratt Development plc
Hochtief (UK) Construction
GHPC Group Ltd
approx £26 million