Laying solid foundations
ICC is located above a major fault zone with difficult geological conditions, which makes normal end-bearing piling system unviable. Following a series of detailed studies and comparison of various foundation types, shaft grouted friction barrettes were chosen as the foundation system.
ICC is the first private development in Hong Kong that has adopted this special system to enhance the friction capacity of the piles. A designed volume of cement grout was injected into the soil-pile interface to improve the contact between the barrettes and the surrounding soil. The lateral pressure, due to this injection grouting, compacted the surrounding soil at the interface, which was softened or loosened during trench excavation. With this enhancement in the lateral pressure, the frictional capacity of the barrettes has been significantly increased.
Since shaft grounding is a new technique in Hong Kong for barrettes construction, five trial piles and four working barrettes were constructed for testing. The results turned out to be satisfactory in load carrying capacity as well as settlement performance.