EA Box Girder System

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 .