>>CONVENTIONALLY, REINFORCED CONCRETE PIERS
HAVE BEEN THE SUPPORT STRUCTURE OF CHOICE FOR MODERN-DAY BRIDGE CONSTRUCTION. HOWEVER,
AS TECHNOLOGY ADVANCES, CONVENTION SEEMS TO BE SHIFTING. THERE'S A NEW KID ON THE BLOCK
CALLED GEOSYNTHETIC REINFORCED SOIL, OR G-R-S; AND IT'S CHANGING THE FOOTPRINT OF
MANY MODERN-DAY STRUCTURES. ALTHOUGH GEOSYNTHETIC REINFORCED SOIL HAS BEEN AROUND AWHILE, ITS
USE AS PART OF AN INTEGRATED BRIDGE SYSTEM, OR I-B-S, IS FAIRLY NEW.<<
>>"THE CONCEPT OF GEOSYNTHETIC REINFORCED
SOIL CAME ABOUT IN THE EARLY 1970s WHEN THE U.S. FOREST SERVICE USED NON-WOVEN
GEOTEXTILES TO BUILD BURRITO WALLS, WRAPPED FACED WALLS IN THE STEEP MOUNTAIN TERRAIN
FOR LOGGING ROADS. THE COLORADO D-O-T, DURING THAT TIME, TOOK NOTICE OF WHAT THE U.S. FOREST
SERVICE WAS DOING AND REFINED THE TECHNOLOGY.
IN ABOUT THE MID-1990s WE ACTUALLY BUILT A FULL-SCALE EXPERIMENT HERE AT TURNER-FAIRBANK
HIGHWAY RESEARCH CENTER IN MCLEAN, VIRGINIA TO DEMONSTRATE THE LOAD BEARING CAPACITY OF
REINFORCED SOIL. WE DETERMINED THAT IT IS EXTREMELY PREDICTABLE WHEN YOU BUILD IT
IN A CLOSELY SPACED FASHION AS WE DO TODAY IN THE I-B-S. A COUPLE OF YEARS LATER WE WERE
GIVEN THE OPPORTUNITY HERE AT TURNER-FAIRBANK TO BUILD THE PROTOTYPE I-B-S. AND AFTER THE
SUCCESS OF THAT PROJECT, IN THE EARLY 2000s THE F-H-W-A INTRODUCED THE
BRIDGE OF THE FUTURE INITIATIVE AND WE PIGGY-BACKED ON THAT CONCEPT AND WE CONTINUED TO WORK WITH
THE D-O-Ts AND WITH THE LOCALS TO SEEK OUT PROJECTS TO BUILD G-R-S ABUTMENTS AND THE
I-B-S."<<
>>IN 2005, DEFIANCE COUNTY,
OHIO, BUILT THE FIRST PRODUCTION I-B-S SYSTEM, THE BOWMAN ROAD BRIDGE. TODAY, THAT BRIDGE
IS PERFORMING VERY WELL, AND AS A RESULT, THE COUNTY HAS BUILT 23 OTHER BRIDGES USING
THE G-R-S I-B-S SYSTEM. IN 2010, SAINT LAWRENCE COUNTY IN NEW
YORK TOOK NOTICE OF THE SUCCESSES IN DEFIANCE COUNTY AND ARE NOW USING THE TECHNOLOGY TO
REPLACE MANY OF THEIR OWN BRIDGES. HOW DOES THE G-R-S I-B-S SYSTEM
WORK? THE G-R-S I-B-S IS SUPPORTED BY A REINFORCED SOIL FOUNDATION, OR R-S-F. THE R-S-F IS AN
ECONOMICAL, SHALLOW FOUNDATION CONSISTING OF LAYERS OF GEOTEXTILE
AND COMPACTED FILL. THE G-R-S ABUTMENT AND INTEGRATED APPROACH IS ENGINEERED TO ACCOMMODATE
SETTLEMENT, ALLOWING FOR A SMOOTH TRANSITION FROM THE BRIDGE ONTO THE ROADWAY; THUS ALLEVIATING
THE "BUMP AT THE BRIDGE" NORMALLY CAUSED BY UNEVEN SETTLEMENT.
CONSTRUCTING A G-R-S ABUTMENT IS OFTEN DESCRIBED AS BEING AS EASY AS 1-2-3.
IT REQUIRES PLACING A ROW OF FACING BLOCK, A LAYER OF GRANULAR FILL, AND A SHEET OF GEOSYNTHETIC
REINFORCEMENT AND REPEATING THE PROCESS UP TO
THE SPECIFIED HEIGHT OF THE ABUTMENT. THIS METHOD HAS BEEN PROVEN IN THE FIELD TO FACILITATE
QUICK AND EFFICIENT CONSTRUCTION WITH IMPRESSIVE RESULTS.<<
>>"IT'S FAIRLY SIMPLE ONCE YOU UNDERSTAND THE CONCEPT, THAT BY PUTTING
THE SHEETS OF GEOTEXTILE IN THE COMPACTED STONE THAT IT BEHAVES AS A COMPOSITE AND HAS
ENGINEERING PROPERTIES. IT HAS A STRESS-STRAIN CURVE THAT IS FAIRLY PREDICTABLE. YOU'RE
REALLY DESIGNING THESE ABUTMENTS AS A GRAVITY WALL."<<
>>TO FULLY BENEFIT FROM THE RAPID CONSTRUCTION AVAILABLE USING
G-R-S TECHNOLOGY, IT IS IMPORTANT TO FOLLOW GUIDELINES FOR G-R-S ABUTMENT CONSTRUCTION.
FIRST, SINCE ALL OTHER COURSES OF BLOCK ARE BUILT OFF THE FIRST ROW, MAKE SURE THAT THE
BOTTOM ROW IS LEVEL AND EVEN. SECOND, FOR OPTIMAL PRODUCTIVITY, USE ONLY THE CREW
AND EQUIPMENT NECESSARY. DIVIDE THE LABOR INTO THREE BASIC STEPS --
STEP 1: LAYING THE BLOCK; STEP 2: PLACING AND COMPACTING THE BACKFILL; AND STEP 3: LAYING
A SHEET OF GEOSYNTHETIC REINFORCEMENT. FINALLY, LIMIT THE MOVEMENT OF THE EXCAVATOR TOWARDS
THE BACK OF THE ABUTMENT WHERE IT CAN REACH AND
PLACE MATERIAL WITHOUT HAVING TO BE MOVED.<< >>"THE WHOLE PROCESS IS FAIRLY RHYTHMATIC;
FAIRLY ROUTINE IN TERMS OF ONCE YOU GET THE CONCEPT DOWN OF STACK AND COMPACT, IT IS A
VERY REPETITIOUS PROCESS. THAT ONCE THAT IDEA IS LEARNED THE REST OF IT JUST BECOMES KIND
OF A RHYTHM THAT THE WALL JUST CONSTRUCTS."<< >>BECAUSE OF THE SIMPLE PROCESS,
A LARGE CREW IS NOT NECESSARY TO SUCCESSFULLY CONSTRUCT A G-R-S ABUTMENT. A TYPICAL CONSTRUCTION
CREW CONSISTS OF LABORERS AND THE EQUIPMENT OPERATOR.<<
>>"IN COMPARISON TO A TRADITIONAL BRIDGE, THE G-R-S I-B-S SYSTEM, I'M
GOING TO TELL YOU, IS TEN TIMES MORE SIMPLE FOR YOUR AVERAGE LAYMAN TO BUILD. LIKE I SAID,
YOU CAN TAKE MOST LOW CONSTRUCTION PEOPLE, THEY DON'T
EVEN HAVE TO BE BRIDGE PEOPLE, YOU CAN START AT THE BOTTOM AND WITHIN A FEW WEEKS YOU CAN
HAVE A BRIDGE STANDING."<< >>SPECIALIZED EQUIPMENT IS NOT REQUIRED
TO CONSTRUCT A G-R-S ABUTMENT. READILY AVAILABLE TOOLS LIKE HAND TOOLS AND MEASURING DEVICES
ARE ALL THAT'S NECESSARY. HEAVY EQUIPMENT, SUCH AS A TRACK HOE EXCAVATOR AND
A WALK BEHIND VIBRATORY PLATE TAMPER, WILL ALSO BE NEEDED.
THE FIRST STEP IN CONSTRUCTING THE G-R-S I-B-S IS SITE PREPARATION. SINCE
G-R-S TECHNOLOGY REQUIRES BUILDING FROM THE BOTTOM UP, STAGING, AND DELIVERY OF
THE MATERIAL SHOULD NOT HAMPER CONTINUOUS CONSTRUCTION. IT IS IMPORTANT THAT DIVERSION
TRENCHES BE PLACED AROUND THE PERIMETER OF THE SITE TO DIVERT ANY WATER. AS WITH CONSTRUCTION
OF THE G-R-S ABUTMENTS, SITE PREPARATION IS ALSO FAIRLY STRAIGHTFORWARD.<<
>>"IT'S A FAIRLY SIMPLE PROCESS OF DIGGING DOWN TO A KNOWN ELEVATION FOR THE
FOUNDATION TO BEGIN AND ONCE YOU REACH THAT ELEVATION TO START BUILDING OR CONSTRUCTING
THE WALL FROM THE BOTTOM-UP UNTIL YOU REACH THE DESIRED ELEVATION AT THE TOP."<<
>>ONCE THE SITE LAYOUT AND EXCAVATION ARE COMPLETE, IT'S TIME
TO BEGIN CONSTRUCTING THE REINFORCED SOIL FOUNDATION. THE BASE SHOULD BE CUT SMOOTH,
SLOPED TO DRAIN, AND EXCAVATED TO A UNIFORM DEPTH. ALL LOOSE, UNSTABLE MATERIAL SHOULD
BE REMOVED, BACKFILLED, AND COMPACTED TO PROVIDE A GOOD FOUNDATION. LAYING THE REINFORCED
SOIL BASE CAN TYPICALLY BE COMPLETED IN 1 DAY.
THE NEXT STEP IN BUILDING THE G-R-S I-B-S IS TO ENCAPSULATE THE SOIL FOUNDATION
WITH GEOTEXTILE TO PREVENT EROSION. TYPICAL SPACING IN THE REINFORCED SOIL FOUNDATION
IS 12 INCHES. ONCE THE SOIL FOUNDATION HAS BEEN
FULLY ENCAPSULATED, COMPACTION BEGINS. PLACE THE FILL FROM THE BACK TO THE EDGE OF THE
R-S-F AND ROLL OUT ANY FOLDS OR WRINKLES TO THE FREE END OF THE LAYER. THE SOIL FOUNDATION
SHOULD BE BACKFILLED IN COMPACTED LIFTS NOT TO EXCEED 6 INCHES.
THE FINAL STEP IN THIS PHASE IS BUILDING THE G-R-S BASE. THE TYPICAL BASE IS CONSTRUCTED
WITH SPLIT-FACED CONCRETE MASONRY UNITS AND COMPACTED BACKFILL.
PROPERLY COMPACTED BACKFILL IS CRUCIAL TO G-R-S I-B-S PERFORMANCE.
COMPACT ALL AREAS BEHIND THE SPLIT-FACED CONCRETE MASONRY UNITS SO THAT NO VOIDS EXIST
BELOW THE GEOSYNTHETIC REINFORCEMENT. A THIN LEVELING LAYER OF FINE AGGREGATE CAN HELP
SET THE C-M-U BLOCKS TO GRADE, AND PREVENT THEM FROM ROCKING. THE LEVELING
LAYER SHOULD BE KEPT TO A MINIMUM THICKNESS OF NO MORE THAN 0.5 INCHES.
BEFORE PLACING THE GEOSYNTHETIC REINFORCEMENT, IT IS IMPORTANT TO SWEEP OFF ANY GRANULAR
FILL FROM THE TOP OF THE BLOCK. THIS WILL PREVENT CRACKING OF THE FACING BLOCKS.
THE G-R-S PROJECT WILL DETERMINE THE NUMBER OF REINFORCEMENT
ZONES NEEDED. REINFORCEMENT ZONES REPRESENT DIFFERENT LENGTHS OF REINFORCEMENT AWAY FROM
THE WALL. ROLL OUT THE GEOTEXTILES SO THAT THE GREATEST REINFORCEMENT STRENGTH IS PERPENDICULAR
TO THE WALL FACE.
WHERE ONE ROLL ENDS, THE NEXT ROLL SHOULD BEGIN. OVERLAPPING BETWEEN THE SHEETS OF REINFORCEMENT
IS NOT REQUIRED. ANY EXCESS REINFORCEMENT MATERIAL SHOULD BE REMOVED WITH A RAZOR KNIFE
OR A PROPANE TORCH. PREVENTING WRINKLES IN THE REINFORCEMENT MATERIAL
IS CRUCIAL. THEREFORE, PLACE THE FILL FROM
THE WALL FACE BACKWARD SO THAT ANY WRINKLES THAT DO FORM CAN BE REMOVED. CONSTRUCTION
OF THE G-R-S ABUTMENT CONTINUES WITH ALTERNATING LAYERS OF COMPACTED GRANULAR FILL AND GEOSYNTHETIC
REINFORCEMENT ACCORDING TO THE DESIGN PLANS.
AS THE ABUTMENT WALL IS BEING CONSTRUCTED, IT IS CRUCIAL TO MAINTAIN THE PROPER WALL
FACE ALIGNMENT. CHECK THE VERTICAL G-R-S WALL FOR PLUMBNESS AT EVERY OTHER LAYER. ANY DEVIATIONS
GREATER THAN 0.25 INCHES MUST BE CORRECTED. AS THE UPPER
LAYERS OF THE G-R-S WALL ARE CONSTRUCTED, A BEARING REINFORCEMENT BED IS CONSTRUCTED
TO PROVIDE ADDITIONAL STRENGTH TO SUPPORT THE INCREASED LOADS DUE TO THE BRIDGE. THE
BEARING BED REINFORCEMENT SERVES AS AN EMBEDDED FOOTING WITHIN THE G-R-S ABUTMENT.
THE SPACING OF THE REINFORCEMENT IN THIS LOCATION IS HALF THE PRIMARY SPACING, OR TWO LAYERS
PER COURSE OF BLOCK. THE DEPTH OF THE BEARING REINFORCEMENT ZONE IS DETERMINED BASED ON
THE INTERNAL STABILITY DESIGN FOR REQUIRED REINFORCEMENT STRENGTH. AT A MINIMUM,
THERE SHOULD BE FIVE BEARING BED REINFORCEMENT
LAYERS. FOR A BRIDGE WITH SUPER ELEVATION, IT IS IMPORTANT TO ENSURE THAT THE MINIMUM
NUMBER OF BEARING BED REINFORCEMENT LAYERS BENEATH THE BEAM SEAT IS INSTALLED ACROSS
THE LENGTH OF THE ABUTMENT FACE.
AT THIS POINT THE REINFORCEMENT LAYERS BECOME STAIR STEPPED WITH REINFORCEMENT TERMINATING
ALONG THE ANGLED SURFACE OF THE ELEVATION. PINNING AND GROUTING THE UPPER THREE COURSES
OF BLOCK COMPLETES CONSTRUCTION OF THE FACING WALL. IT IS IMPORTANT TO SUSPEND
ANY CONSTRUCTION ACTIVITY NEAR THE FACE ONCE THE TOP OF THE WALL HAS BEEN PINNED AND
GROUTED TO AVOID WALL DISPLACEMENT. ONCE THE ABUTMENT WALL IS COMPLETED,
THE BEAM SEAT IS CONSTRUCTED DIRECTLY ABOVE THE BEARING BED REINFORCEMENT ZONE. THE SUPERSTRUCTURE
WILL BE POSITIONED ON TOP OF THE BEAM SEAT. PROPER BEAM SEAT CONSTRUCTION BEGINS
BY PLACING 4 INCHES OF PRE-CUT FOAM BOARD ON TOP OF THE BEARING BED REINFORCEMENT. IT IS IMPORTANT
TO MAKE SURE THE FOAM BOARD IS BUTTED AGAINST THE BACK FACE OF THE BLOCK.
NEXT, PLACE A SOLID CONCRETE BLOCK ON TOP OF THE FOAM BOARD ACROSS THE ENTIRE
LENGTH OF THE BEARING AREA. THE FINAL STEP IS WRAPPING THE
LAYERS OF COMPACTED FILL. THE THICKNESS OF THE WRAPPED LAYERS IS ESSENTIAL TO MAINTAINING
THE FINAL BEAM ELEVATION. THE FILL THICKNESS OF THE FIRST 4-INCH WRAPPED
LAYER SHOULD BE COMPACTED TO THE TOP OF THE FOAM BOARD. THE FILL THICKNESS OF THE SECOND
WRAPPED LAYER SHOULD BE COMPACTED TO THE TOP OF THE SOLID BLOCK. THE TOP OF THIS SECOND
LAYER CONTROLS THE BEAM ELEVATION; THEREFORE IT SHOULD BE CAREFULLY COMPACTED
AND GRADED. AS AN OPTION, ALUMINUM FLASHING
CAN BE INSTALLED AFTER CONSTRUCTION OF THE BEAM SEAT AND PRIOR TO SETTING THE BRIDGE
BEAMS. IF USED, THE FLASHING SERVES AS BOTH A DRIP EDGE AND A CLEAR SPACE FILLER.
PLACE THE FLASHING BETWEEN THE BOTTOM OF THE BEAMS AND THE FOAM BOARD. MAKE SURE THE LENGTH
OF THE FLASHING EXTENDS BEYOND THE OUTSIDE OF THE BRIDGE BEAMS. FINALLY, TRIM THE FLASHING
SO THAT IT FITS AGAINST THE PARAPETS. PLACEMENT OF THE SUPERSTRUCTURE
OCCURS FOLLOWING CONSTRUCTION OF THE BEAM SEAT AND FLASHING INSTALLATION. MAKE SURE
TO SET THE BEAMS SO THEY ARE SQUARE AND LEVEL. NEVER DRAG THE BEAMS OVER THE BEAM SEAT SURFACE.
THE WINGWALLS AND PARAPET ARE CONSTRUCTED FOLLOWING PLACEMENT OF THE SUPERSTRUCTURE.
FIRST, TRIM THE SPLIT-FACED CONCRETE MASONRY UNIT IN THE PARAPET WALL FOR A CUSTOM
FIT AGAINST THE BEAM EDGE. NEXT, FILL THE SPACE BETWEEN THE SUPERSTRUCTURE AND THE FACING
BLOCK WITH THIN LAYERS OF CUT BLOCK OR MORTAR MIX. FOLLOWING COMPLETION OF
THIS PHASE, APPROACH CONSTRUCTION CAN BEGIN. THE G-R-S INTEGRATED APPROACH IS
CONSTRUCTED OF AGGREGATE LAYERS, REINFORCED AND WRAPPED WITH GEOTEXTILE THAT BLENDS THE
APPROACH WAY TO THE BRIDGE DECK TO CREATE A SMOOTH TRANSITION. IT IS IMPORTANT TO USE
WELL GRADED MATERIAL THROUGHOUT THIS PHASE AND
TO TRIM THE GEOTEXTILE REINFORCEMENT TO THE PRESCRIBED LENGTH AFTER IT IS WRAPPED. REPEAT
THIS PROCESS UNTIL REACHING A HEIGHT APPROXIMATELY 2 INCHES FROM THE TOP OF THE BEAM GRADE. THE
WRAPPED LAYERS ARE THEN PLACED BEHIND THE BEAM END.
THERE ARE A FEW GUIDELINES TO FOLLOW FOR PAVEMENT OF A G-R-S PROJECT. FIRST, DURING
PAVING, IT IS IMPORTANT TO KEEP THE TOP LAYER OF REINFORCEMENT APPROXIMATELY 2 INCHES BELOW
THE BEAM GRADE. THIS WILL ALLOW A LAYER OF AGGREGATE
COVER TO BE PLACED TO PROTECT THE GEOTEXTILE REINFORCEMENT FROM CONTACT WITH HOT MIX ASPHALT.
ALSO, THE PAVING FABRIC SHOULD EXTEND 3 FEET OVER THE BRIDGE DECK ONTO THE APPROACH. FINALLY,
IF GUARD RAIL INSTALLATION IS PART OF THE PROJECT DESIGN, IT IS RECOMMENDED
TO USE STEEL "H" POSTS FOR ANY RAILING THAT IS DRIVEN THROUGH THE REINFORCEMENT.
IT IS ALSO POSSIBLE TO DRILL THROUGH G-R-S WITH AN AUGER TO SET OTHER TYPES OF POSTS.
THESE PROCEDURES FOR CONSTRUCTING A G-R-S I-B-S HAVE BEEN PROVEN IN THE FIELD
TO FACILITATE QUICK AND EFFICIENT CONSTRUCTION.
ADDITIONALLY, G-R-S I-B-S PROVIDES FASTER PROJECT COMPLETION AT A REDUCED COST BECAUSE
THE DESIGN IS FLEXIBLE AND THEREFORE EASILY MODIFIED IN THE FIELD.<<
>>"THE BIGGEST BENEFIT TO THE G-R-S I-B-S SYSTEM IS THE ADAPTABILITY
TO THE DIFFERENT SITES AND THEN THE OVER EXCAVATION THAT IS NOT REQUIRED AS
PART OF THIS. WE CAN PUT IT ON UNSUITABLE SOILS; WE CAN PUT IT IN WATER ENVIRONMENTS
WHERE WE WOULD NORMALLY HAVE TO HAVE PILES FOR STANDING CONCRETE. OBVIOUSLY,
IT'S CHEAPER, IT'S FASTER AND IN THESE ECONOMIC TIMES THAT WE'RE
IN NOW, CHEAPER AND FASTER IS OBVIOUSLY A BIG FACTOR."<<
>>"IT'S NOT TRADITIONAL, SO TO LOOK AT IT FROM THE OUTSIDE, YOU MIGHT
QUESTION IT. BUT ONCE THE CONSTRUCTION PROCESS STARTS, YOU CAN QUICKLY SEE HOW
EASY THE CONCEPT IS AND HOW FLEXIBLE YOU CAN BE IN TIMES OF CONSTRUCTION, WITH RAIN,
WEATHER; IT DOESN'T REALLY SHUT ANYTHING DOWN IN TERMS OF MOVING THE CONSTRUCTION PROCESS
ALONG."<< >>THERE ARE THREE PRIMARY ADVANTAGES
FOR USING THE G-R-S I-B-S. IT'S FASTER, MORE ECONOMICAL, AND EASIER TO BUILD
THAN TRADITIONAL BRIDGE STRUCTURES. ADDITIONALLY, RESEARCH INDICATES THAT ITS LONG-TERM DURABILITY
WILL BE BETTER BECAUSE IT HAS FEWER PARTS AND BECAUSE THE SUBSTRUCTURE AND SUPERSTRUCTURE
ARE BLENDED WITH THE APPROACH WAY TO CREATE A JOINTLESS BRIDGE SYSTEM.
THE G-R-S I-B-S SYSTEM DOESN'T HAVE MANY OF THE COMMON ELEMENTS ASSOCIATED WITH A TRADITIONAL
BRIDGE, PARTICULARLY THOSE LEADING FROM THE ROADWAY TO THE BRIDGE. FOR EXAMPLE, IT DOESN'T
HAVE AN APPROACH SLAB OR A SLEEPER SLAB, AND IT ELIMINATES THE BRIDGE
BEARINGS. G-R-S I-B-S IS NOT FOR EVERY BRIDGE
BUILDING ASSIGNMENT. IT IS, HOWEVER, A PERFECT SOLUTION FOR SMALLER, SINGLE-SPAN BRIDGES.
THE SYSTEM IS CURRENTLY TAILORED FOR SINGLE-SPAN BRIDGES UP TO 140 FEET.
THE LONGEST BRIDGE CONSTRUCTED TO DATE IS A 140 FOOT STEEL GIRDER BRIDGE. THAT BRIDGE
IS PERFORMING VERY WELL. EVEN THROUGHOUT ITS THERMAL CYCLES, THERE HAVE BEEN NO ADVERSE
EFFECTS SEEN ON THE APPROACH WAY. G-R-S I-B-S IS GREAT FOR GRADE SEPARATIONS,
ALTHOUGH THE BRIDGES COMPLETED TO DATE ARE BUILT
OVER STREAMS WITH NON-SCOUR CONDITIONS. IT IS A SHALLOW FOUNDATION SYSTEM AND THUS NOT
SUITABLE FOR SCOUR CRITICAL AREAS. HOWEVER, THE TECHNOLOGY WORKS VERY WELL FOR BOTH STEEL
AND CONCRETE SUPERSTRUCTURES.
IN DEFIANCE COUNTY, THE FIRST BRIDGES BUILT
USING THE G-R-S I-B-S PROVIDED THEM WITH A 21 PERCENT COST SAVINGS. TODAY, DEFIANCE COUNTY
IS SAVING UP TO 40 PERCENT ON THEIR BRIDGES BECAUSE OF THEIR ABILITY TO RAPIDLY CONSTRUCT
THE SUBSTRUCTURE. THEY UNDERSTAND HOW THE TECHNOLOGY WORKS AND THE LABOR
CREW IS WELL-TRAINED. IN SAINT LAWRENCE COUNTY, THEIR SAVINGS
ARE EVEN GREATER BECAUSE IN THEIR PREVIOUS DESIGN METHODOLOGY THEY INCLUDE MANY OF THE
DETAILS ASSOCIATED WITH A TRADITIONAL BRIDGE, SUCH AS THE APPROACH
SLAB, THE SLEEPER SLAB, THE BRIDGE BEARINGS, AND THE PARAPETS. WITH THE G-R-S I-B-S YOU DON'T
NEED THESE TRADITIONAL ELEMENTS. SAINT LAWRENCE COUNTY HAS REALIZED A SAVINGS OF BETWEEN
50 TO 60 PERCENT ON ALL THE BRIDGES THEY ARE CURRENTLY BUILDING.
RECENTLY, THE INTERIM IMPLEMENTATION GUIDE FOR THE GRS-IBS
WAS COMPLETED. THIS GUIDE IS THE RESULT OF ABOUT 40 YEARS OF RESEARCH. IT CONSISTS OF
TWO VOLUMES. ONE SPECIFICALLY FOR THE DESIGN AND CONSTRUCTION OF THE G-R-S I-B-S; THE OTHER
VOLUME CONTAINS A CENSUS REPORT OF ALL THE AVAILABLE RESEARCH SUPPORTING
THE DESIGN AND CONSTRUCTION OF THE G-R-S I-B-S.<< >>"FOR OTHERS THINKING ABOUT G-R-S,
THE THING TO DO FIRST IS KIND OF GET COMFORTABLE WITH IT IN TERMS OF HOW IT WORKS. UNDERSTAND
THE FACT THAT THERE IS A LOT OF DATA THAT SHOWS THAT YOU CAN TRUST IT. IF YOU PUT IT
TOGETHER THIS WAY, YOU'LL GET THE KIND OF PERFORMANCE THAT WE'VE SEEN.
AND THEN TO GET COMFORTABLE WITH THE ACTUAL CONSTRUCTION. IT'S BEEN
A GOOD FIT FOR US."<< >>"I CAN QUITE SINCERELY SAY THAT
FROM THE BEGINNING OF RESEARCHING THIS TECHNOLOGY IT HAS AMAZED
ME WITH EACH EXPERIMENT. IT HAS FAR EXCEEDED OUR EXPECTATIONS, AND WHEN WE BUILT THE I-B-S,
DESIGNED THE I-B-S, WE REDESIGNED THE BRIDGE WHERE WE GOT RID OF ALL THE COMMON ELEMENTS
ASSOCIATED WITH THE BRIDGE AND REDESIGNED
IT FROM THE BOTTOM-UP. I THINK IT CAN BE USED ON THE INTERSTATE SYSTEM, ONCE
PEOPLE TAKE MORE NOTICE OF ITS LONG-TERM PERFORMANCE ON THESE LOCAL ROAD SYSTEMS. I TRULY BELIEVE
THAT THE TECHNOLOGY HAS A HOME IN ALL FACETS OF EARTHWORK, NOT JUST IN
BRIDGE SUPPORT APPLICATIONS."<< >>THE MANY ADVANTAGES G-R-S I-B-S
TECHNOLOGY OFFERS MAKE IT A VIABLE CHOICE FOR MANY BRIDGE PROJECTS.<<