Design and Supply of Reinforced Earth Abutment Wall at Prince of Wales Hospital (PWH)

Background

To meet the increasing services demand of the New Territories East Cluster and the need of the future medical development, the Hospital Authority has planned to redevelop the Prince of Wales Hospital (PWH) in phases to provide additional space to meet operational needs and service developments, and promote integrated research, teaching and education. 

A vehicular ramp was proposed to replace the existing elevated road (which has been planned for demolition in Phase 2 Stage 1 in 2021 to facilitate the PWH Redevelopment) connecting the vehicular entry point with existing vehicular deck of the Hospital Old Building Group (Old Blocks).

Solution

In the original design, socket H-piles with pile cap and reinforced concrete wall would be constructed as the abutment of the replacement ramp to support the steel girder.  In order to minimize the construction time and to fit in the tight construction schedule, a Reinforced Earth® Wall was proposed to replace the reinforced concrete abutment and ramp wall supported by the socket H-piles.  By using the Reinforced Earth® wall, the socket H-piles could be eliminated.  Therefore, there was not only a saving in the construction time, but also a saving in the cost of the socket H-piles (around 27 nos. with 40m depth). In addition, the pile cap was also reduced.  This Reinforced Earth® Wall was designed as a True Abutment which means that there was no piling to support the steel girder.  The steel girder is supported by a reinforced concrete beam seating which is located directly on the backfill of the Reinforced Earth® Wall.  This vehicular ramp was designed as a permanent structure and will be used as a temporary access to replace the existing elevated road and will last for around 10 years.  It will be much easier to demolish in comparison with the original design of socket H-piles and reinforced concrete wall. It will also reduce significantly the construction wastage.