Reinforced Earth Wall system works at Pak Shek Kok Development

Background

To mitigate the traffic impact to the Toto Highway and MTR East Rail Line, an approximately 250m long elevated vehicular bridge spanning over Tolo Highway and MTR East Rail Line tracks was built.  Due to the site constrain and construction difficulties, the main contractor initiated an alternative scheme of Reinforced Earth wall to replace the original 3-cell RC Box structure which was founded on 2m dia. Bored Pile Deep Foundation.

Solution

Due to the site condition (relative weak soil layer of marine deposit and alluvium were located underneath the RE wall), relatively large consolidation settlement was anticipated.  This might cause significant deformation and distortion.  Also, there might have adverse impact on the structural integrity and the performance of the Reinforced Earth wall.  In order to solve this problem, preloading ground treatment was proposed to accelerate the consolidation process.  Moreover, 2-stage Reinforced Earth Wall system was proposed to minimize the impact of differential settlement.