This project involved construction of a 148-metre-high, 25-storey, Grade A office building with a four-storey basement of RC structure. It comprised design and construction of an underground tunnel using horizontal pipe piling and in-situ reinforced concrete lining. An opening for the tunnel portal was created in the diaphragm wall of the existing basement diaphragm. It also incorporated installation and maintenance of flood enclosures and pumps for waterproofing and tunnel drainage systems and the design and construction of the new passage opening connecting the MTR Central Station.