X - HKU Libraries

V.4.2Amendment No. V-l/91 (Jan.)4.2 LOADSBritish Standard Institute Committee has reviewedBS 5400 : Part 2 : 1978 and has agreed to a series of majoramendments.In August 1989, the United Kingdom Department ofTransport issued a Departmental Standard BD 37/88, Loads forHighway Bridges. This Standard contains a full compositeversion of BS 5400 : Part 2 incorporating all the agreedrevisions and intended to be applicable to traffic andenvironmental conditions in the United Kingdom and is notnecessarily appropriate for Hong Kong.In April 1990, Hong Kong Government employed Flint& Neill Partnership as consultants to undertake an overallreview of the Highway loading in Hong Kong taking intoaccount BD 37/88. The consultants recommendations within theframe work of BD 37/88 are now incorporated in this manual.4.2.1 GeneralHighway structures and railway bridges should bedesigned for the loads and forces, and combinations of loadsand forces, specified in BS 5400 : Part 2, published asAppendix A to the United Kingdom Department of TransportDepartmental Standard BD 37/88, except where modified by thischapter. Where Hong Kong conditions differ from theconditions described in BS 5400 : Part 2, loads and forcesappropriate to Hong Kong as described in this chapter shouldbe used instead.For superimposed dead load, the following valuesof YfL should be substituted for the values recommended inBS 5400 : Part 2 : 5.2.2.ULSSLSdeck surfacing 1.75 1.20other loads 1.50 1.00The value of y fL for dead load imposed by decksurfacing may be reduced to 1.5 for the ULS if it isabsolutely certain that the thickness (and hence the weight)of the surfacing will not be increased during the life of thebridge, e.g. where open texture friction course is alwaysmilled off before retreatment. Further reduction of thesevalues will not be permitted.The recommendations of BS 5400 : Part 2 clauses3.2.9.1 and 3.2.9.3.1 should be replaced by the followingclauses 4.2.1.1 and 4,2.1.2 respectively to suit carriagewaysin Hong Kong.