Reconstruction of Tai Wai Bridge
281. Tai Wai Bridge is situated in the New Territories some 8 miles from Kowloon on the Tai Po Road near Sha Tin. The new bridge was constructed 100 ft. downstream from the original narrow, single carriageway bridge, which was left in position to provide access to the small villages now by-passed by the main road.
282. For the new bridge a reinforced concrete continuous beam and slab construction was selected as this provided the necessary area of water-way and also the most economical formation for the bridge approaches. It consists of three equal 40'-0" spans with a skew angle of 14°11', and was designed to the Ministry of Transport recommended loadings for Highway bridges. It carries a 22'-0" wide carriageway and two 9'-0" footways. Provision is made for cable ducts and pipes underneath the footways. The foundations to the abutments and piers were formed of 14" × 14" reinforced concrete piles varying in length from 10'-0" to 14'-0", each capable of sustaining a load of 80 tons. The superstructure consists of seven continuous beams varying in depth from 3'-0" at the outside to 3'-4½" at the centre of the bridge to provide the correct road camber for the 9" deck slab. In longitudinal section the beams were constructed to a shallow parabolic curve which formed the connecting vertical curve between the two bridge approaches. Contraction and expansion is provided for by sliding plates at one pier, and cast steel rollers at the abutments.
283. Consideration was given to aesthetic values and, in keeping with the rural surroundings, the exposed sections of the substructure were faced with coursed granite rubble whilst the bridge parapets were designed as four equally spaced pilasters connected by a single 15" high plinth course all of dressed granite. A light section of framed and welded wrought iron railings 3'-0" high was then set into the pilasters and gave the bridge elevation the desired appearance of lightness.
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