有一段好难懂的英文，谁能翻呢？
The design and detailing of this bridge employed imaginateve uses of steel.For a typical three-span bridge,the end spans would usually be about 80% of the main span length(or about 30m[98~]for this bridge ).It was felt that long end spans would have a negative aesthetic impact on the bridge.Several end span lengths and counterweight size combinations were considered in order to achieve shorter end spans.Perliminary end span length was estimated to be 12m based on a 2:1 ground line slope along the end span enclousure wall.The counterweight for that span length would have been 4,5m to 5m(approximately 15`),or 40%of the end span length .A decision was made to lengthen the end spans and uses a smaller counterweight.A“middle lf the road “combination was chosen.Using end spans of 15,7m(51,5),the required counterweight was 1,5 meters long(4,9),approximately 10% of the end span length .The ground line slope than shown on the preliminary plan.This 3:1 slope provided a more aesthetically pleasing ground line along the “wing wall“.The counterweight were designed to eliminate uplift due to dead load plus live load .AASHTO standard specification requires no uplift for dead plus twice the service live load with impact (sec3,17,1)
The beams are haunched in the center span and constant depth in the end spans.The end span web depth is 1350mm(4~-5~~).The center span web depth is 800mm(2~-7,5~~)with haunches near the piers.The span composite beams is about 40:1 .AASHTO LRFD suggests about 30:1 for continuous steel composite beams.The span-to-depth ratio of the beams alone is about 47:1,giving the main span a slender appearance .The minimum vertical clearance is 16~-4~~at the edge of the shoulder .the beams were designed as three span continuous using Merlin Dash line girder analysis .The beams wer designed for HS25 live load.HS20 live load was used to compute live load deflections .
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