Bridge System and Method Including Four Sided Concrete Bridge Units Adapted for Promoting Sedimentation

Abstract

A method of providing an environmentally appealing region for water flow along an surrounded pathway tunnel involves providing a plurality of four-sided concrete bridge units in abutting relationship to create a surrounded pathway tunnel, one end of the tunnel located upstream along a water path and an opposite end of the tunnel located downstream along the water path; allowing water to flow through the surrounded pathway tunnel during a rain or other flow event; and providing a multiplicity of the four-sided bridge units with a corresponding bottom wall structure that interacts with the flowing water and earthen material in the flowing water such that capture and settling of the earthen material at locations along the tunnel occurs to produce a more natural water flow pathway along the tunnel.

What is claimed is: 
     
         1 . A method of providing an environmentally appealing region for water flow along a surrounded pathway tunnel, the method comprising:
 providing a plurality of four-sided concrete bridge units in abutting relationship to create a surrounded pathway tunnel, one end of the tunnel located upstream along a water path and an opposite end of the tunnel located downstream along the water path;   allowing water to flow through the surrounded pathway tunnel during a rain or other flow event; and   providing a multiplicity of the four-sided bridge units with a corresponding bottom wall structure that interacts with the flowing water and earthen material in the flowing water such that capture and settling of the earthen material at locations along the tunnel occurs to produce a more natural water flow pathway along the tunnel.   
     
     
         2 . The method of  claim 1 , further comprising providing the bottom wall structure of each of the multiplicity of the four-sided bridge units with a plurality of through openings such that at least forty percent of the bottom wall structure is open. 
     
     
         3 . The method of  claim 2 , wherein at least fifty percent of the bottom wall structure of each of the multiplicity of the four-sided bridge units is open. 
     
     
         4 . The method of  claim 2 , further comprising providing a lip structure at a top portion of at least some of the through openings, the lip structure facing upstream. 
     
     
         5 . The method of  claim 2 , further comprising arranging the plurality of openings of each bottom wall structure in rows that extend along a span of the respective four-sided bridge unit. 
     
     
         6 . The method of  claim 5 , further comprising providing the plurality of openings in the shape of elongated slots, each elongated slot defining a row, such that multiple beams are formed in the bottom wall structure and also extend along the span. 
     
     
         7 . The method of  claim 6 , further comprising providing at least one beam with a height that is greater than a height of another beam, the higher beam interacting with the flowing water and earthen material to reduce flow velocity and thereby enhance settling out of earthen material. 
     
     
         8 . The method of  claim 7 , further comprising providing a lip structure along at least one beam, the lip structure extending in an upstream direction into an adjacent elongated slot and acting to limit wash out of earthen material that has settled in the adjacent elongated slot. 
     
     
         9 . The method of  claim 5 , further comprising providing the plurality of openings as multiple series of openings, each series of openings forming a respective row. 
     
     
         10 . The method of  claim 9 , further comprising staggering openings of adjacent rows to provide nesting of the openings. 
     
     
         11 . The method of  claim 10 , further comprising providing upper lip structure along one or more edges of at least some of the openings, the lip structure extending into its respective opening. 
     
     
         12 . The method of  claim 2 , wherein in each of the multiplicity of the four-sided bridge units haunch sections connect the bottom wall structure with side walls of the respective four-sided bridge unit. 
     
     
         13 . The method of  claim 1 , further comprising providing the bottom wall structure of each of the multiplicity of the four-sided bridge units with a recessed portion to create a low flow channel through which marine life can travel. 
     
     
         14 . An overfilled bridge system, comprising:
 a plurality of four-sided concrete bridge units arranged in abutting relationship to create a surrounded pathway tunnel, one end of the tunnel located upstream along a water path and an opposite end of the tunnel located downstream along the water path;   wherein each of a multiplicity of the four-sided bridge units includes a corresponding bottom wall structure that is configured to interact with the flowing water and earthen material in the flowing water such that capture and settling of the earthen material at multiple locations along the tunnel occurs to produce a more natural water flow pathway along the tunnel.   
     
     
         15 . The system of  claim 14 , further comprising:
 earthen material, deposited from flowing water, settled at the multiple locations.   
     
     
         16 . The system of  claim 14 , wherein the bottom wall structure of each of the multiplicity of the four-sided bridge units includes a plurality of through openings such that at least forty percent of the bottom wall structure is open. 
     
     
         17 . The system of  claim 16 , wherein at least fifty percent of the bottom wall structure of each of the multiplicity of the four-sided bridge units is open. 
     
     
         18 . The system of  claim 16 , wherein at least some of the through openings include an upper lip structure at least part of which faces upstream. 
     
     
         19 . The system of  claim 16 , wherein the plurality of openings of each bottom wall structure are arranged in rows that extend along a span of the respective four-sided bridge unit. 
     
     
         20 . The system of  claim 19 , wherein the plurality of openings are configured as elongated slots, each elongated slot defining a row, such that multiple beams are formed in the bottom wall structure and also extend along the span. 
     
     
         21 . The system of  claim 20 , wherein at least a first beam of each of the multiplicity of four-sided bridged units has a height that is greater than a height of another beam, the first beam configured to interact with the flowing water and earthen material to reduce flow velocity and thereby enhance settling out of earthen material. 
     
     
         22 . The system of  claim 21 , wherein the first beam includes an upper lip structure extending in an upstream direction into an adjacent elongated slot and is configured to limit wash out of earthen material that has settled in the adjacent elongated slot. 
     
     
         23 . The system of  claim 19 , wherein the plurality of openings are arranged as multiple series of openings, each series of openings forming a respective row. 
     
     
         24 . The system of  claim 23 , wherein the openings of adjacent rows are staggered to provide nesting of the openings. 
     
     
         25 . The system of  claim 24 , wherein multiple openings of each of the multiplicity of four-sided bridge units includes an upper lip structure along one or more edges, the lip structure extending into its respective opening. 
     
     
         26 . The system of  claim 16 , wherein the bottom wall structure of each of the multiplicity of the four-sided bridge units includes a recessed portion to create a low flow channel through which marine life can travel. 
     
     
         27 . A structure, comprising:
 a four-sided concrete unit buried in earthen material, the four sided bridge unit having a top wall, a bottom wall and first and second side walls connecting the top wall to the bottom wall, wherein the bottom wall includes multiple openings therein for allowing water to infiltrate through the bottom wall into the earthen material.   
     
     
         28 . The structure of  claim 27 , wherein the plurality of openings of the bottom wall are arranged in rows that extend along a span of the four-sided bridge unit. 
     
     
         29 . The structure of  claim 28 , wherein the plurality of openings are in the shape of elongated slots, each elongated slot defining a row, such that multiple beams are formed in the bottom wall structure and also extend along the span and act to transfer load to the ground below the unit.