EA Box Girder System

Abstract

A precast concrete girder including a substantially planar web extending longitudinally between ends of the girder; a pair of flanges formed integrally with the web, each flange extending laterally from an elongate edge of the web and extending longitudinally between the ends of the girder so as to define a structure engaging surface of the girder; and a plurality of diaphragms formed integrally with the web and the flanges, each diaphragm spanning laterally between a side of the web and one of the flanges, wherein the diaphragms are spaced apart along the girder to thereby support the flanges.

What is claimed is: 
     
         1 . A girder for use in construction of a long span bridge structure comprising:
 a generally vertical web extending longitudinally between a first terminus and a second terminus;   a generally horizontal planar support formed integrally with the web at an upper terminus and extending cantilever to form a pair of opposing flanges;   an enlarged bulb formed integrally with the web at a lower terminus and opposing the upper terminus, said bulb further having a horizontal lower edge, a pair of vertical opposed side edges, and tapering angularly upward from the side edges to the web;   a plurality of diaphragms formed integrally with the web and spaced apart along the girder supporting the flanges, each diaphragm spanning laterally between a side of the web and one of the flanges and the angularly upward taper of the bulb; and   a plurality of reinforcing members extending longitudinally between the first terminus and the second terminus through at least one of the group consisting of: the bulb; the web; and the horizontal planar support;   
       wherein the reinforcing members are prestressed and the girder is cast from concrete as a unitary body. 
     
     
         2 . The girder of  claim 1 , further comprising an end block formed at the first terminus and the second terminus, each end block formed as a vertical extension of the vertical opposed side edges between the bulb to the flanges;
 wherein the end block is cast from concrete as part of the unitary body.   
     
     
         3 . The girder of  claim 1 , wherein said plurality of diaphragms are formed as pairs between respective sides of the web and respective flanges at the same longitudinal position along the girder. 
     
     
         4 . The girder of  claim 3 , wherein said pairs of diaphragms are spaced apart by a spacing distance, and wherein the spacing distance sufficient such that a load applied to an outer portion of one of the flanges will be transmitted to the web via one of the diaphragms. 
     
     
         5 . The girder of  claim 4 , wherein the spacing distance is less than 30 times a flange thickness of the flanges. 
     
     
         6 . The girder of  claim 1 , further comprising laterally extending internal reinforcements at least at longitudinal positions coinciding with the diaphragms. 
     
     
         7 . The girder of  claim 3 , further comprising laterally extending internal reinforcements at least at longitudinal positions coinciding with the diaphragms. 
     
     
         8 . The girder of  claim 2 , wherein said plurality of diaphragms are formed as pairs between respective sides of the web and respective flanges at the same longitudinal position along the girder. 
     
     
         9 . The girder of  claim 8 , wherein said pairs of diaphragms are spaced apart by a spacing distance, and wherein the spacing distance sufficient such that a load applied to an outer portion of one of the flanges will be transmitted to the web via one of the diaphragms. 
     
     
         10 . The girder of  claim 9 , wherein the spacing distance is less than 30 times a flange thickness of the flanges. 
     
     
         11 . The girder of  claim 8 , further comprising laterally extending internal reinforcements at least at longitudinal positions coinciding with the diaphragms. 
     
     
         12 . A long span vehicle bridge structure including a plurality of girders according to  claim 1 . 
     
     
         13 . A long span vehicle bridge structure including a plurality of girders according to  claim 2 . 
     
     
         14 . A long span vehicle bridge structure including a plurality of girders according to  claim 3 . 
     
     
         15 . A long span vehicle bridge structure including a plurality of girders according to  claim 4 . 
     
     
         15 . A long span vehicle bridge structure including a plurality of girders according to  claim 5 . 
     
     
         16 . A long span vehicle bridge structure including a plurality of girders according to  claim 6 . 
     
     
         17 . A long span vehicle bridge structure including a plurality of girders according to  claim 7 .