5. 5
GEOGRIDS ARE NOTHING BUT THE OPEN
STRUCTURES FORMED BY BONDING
POLYMER STRIPS AT THEIR CROSS POINT
OR PUNCHING
6. 6
HISTORICAL DEVELOPMENT
1) FIRST USED FOR ROAD CONSTRUCTION
IN SOUTH CAROLINA IN 1930
2) FOR EROSION CONTROL IN 1960 IN
EUROPE AS WELL AS U.S.A IN 1969
3) IN GREAT WALL OF CHINA ALSO USED
IN THE FORM OF TREE BRANCHES.
22. 22
APPLICATIONS OF GEOGRID:
1. RETAINING WALLS
2. BRIDGE / RAILWAY ABUTMENTS
3.REINFORCED SOIL SLOPES
4. REINFORCED FOUNDATION OVER PILES
5. REINFORCED EMBANKMENTS OVER SOFT
FOUNDATION
23. 23
GEOGRID COMPARED WITH OTHER
SOLUTIONS
1. IT IS COST SAVING MATERIAL
2. IT INCREASES CONSTRUCTION SPEED
3. PROPER REINF OR CEMENT IS ACHIEVED
4. IMPROVED QUALITY
24. 24
DRAW BACKS:
1. POSSIBLE DAMAGE TO GEOGRID
2. IRREGULAR GEOMETRY
3. INCOMPLETE CODES AND
STANDARDISATION
25. 25
SITE VISIT:
CONSTRUCTION OF KRANTI CHOWK
FLYOVER in Aurangabad.
1. FOR MAKING THE LOAD TRANSFER
PLATFORM
2. FOR SEPRATION OF SOIL MASS
3. FOR RETAINING WALL
USE:
29. 29
CONCLUSION:
1. TO EFFECTIVELY SOLVE SOME PROBLEMS OF SOIL MASS
LIKE, BEARING CAPACITY, FAILURE OF SLOPES,
EROSION CONTROL, LAND SLIP REPAIR, ROADS, QUICK
CONSTRUCTION AND ALL OTHER, GEOGRID IS BETTER
SOLUTION .
2. GEOGRIDS ARE MAGIC MATERIALS TO YIELD
EXCELLENT RESULTS .
Lou and I are not Professors Barely made it through College Learned through trial and error Mostly Error Benefit of our Mistakes Not a Technical Session Practical Session Like the Medical Doctors, We Practice Geosynthetics
I need to give you a little history How things were done way back when Sometimes knowing how it was done before can help you with what to do now Chances are the original grade is still there hiding under your road today
Many road constructed Called “Mucker” roads, Or the floating dredge Anybody know what I’m talking about
Anyone here know what a mucker road is? Many roads in NW minnesota constructed this method Their called State Highways
Common fix was using corduroy. or logs placed end to end With the price of timber, this would be very expensive today Civil War story, minnesota regiment
Lou and I are going to show you many applications where geosynthetics have worked extremely well, But first, I want to show you some situations where geotextiles may not Make the Grade
Probably need to get more drainage first.
Lou, Isn’t that your truck? Need better drainage!
A bridge would of helped.
Most of our applications in Northern Minnesota, or more appropriately, Northwest Corner Glacial Lake Aggazziz Lake deposits of silt clay lots of peat Gravel is mostly poor from beaches Haul distance are long, sometime 30 to 50 miles Crying out for geosythetics
Most used type for reconstruction with rural section, ie ditches, was type VI woven Road 2-3 feet above natural ground Well drained ditches Explain Type V and VI
Experience some strange problems and tried the non-woven to allow more moisture movement -Trapped moisture under fabric during period of maximum spring thaw. Frozen deeper, water could not go down, warmer pavement (sun), woven trapped water from evaporating out, Called evaporation potential.
Most basic properties to think about Hands on feel for some of these properties. Pull- apart, bi-directional strength Stretch- during construction and stress related movement Water-the big factor Stiffness-think of the Contractor Cost--the deciding factor
There is nothing easier to lay down than grid It’s tough, water goes through it, But it’s expensive fines can still migrate use it for patching…. Failed or utility
We tried them all I will let Lou tell you about using Geocells, He has a great story later on
I started in about 1990, so we are looking at cases that are twelve years old. When some of these projects have been around this long, we started noticing some strange things Crack filling crew story
This is our recommendation to you This is what our presentation is all about We are not the industry, we are just road engineers that have seen this stuff work. Less than the cost of turf establishment
It was not an industry call that got me started using geotextiles, It was PETE
Remember the old road core County was widening the road for future blacktop Typically would core out each side along the old grade and push into the swamp. Along came the CORPS. Something about deposits in a wetland. REMOTE Area
The CORPS shut the project down, no more excavation unless we hauled it away. Too expensive. Small town, word gets around in the coffee shops, project was shut down by some guy from the cities (minn/st paul) named PETE. Called into the County Commissioners meeting, wanted to know who was pete
This is what we came up with, that was OK with the CORPS And it worked pretty darn good
I call the northwest angle the mistake on the lake. It is actually part of the united states, only because of a surveying error. Seems the french gave the english a bad map. The line was to follow the normal water course (canoe route) from Superior to the NORTHWEST CORNER OF LAKE OF THE WOODS Determined by a good map and ruler One of the last border lines 1922
100 miles from the county seat, about 50 miles through Canada fantastic fishing for walleye, northern, and muskie, along with small mouth bass Many drive from as far away as Chicago to fish the opening season, when fish are concentrated
Imagine driving all the way from Chicago, 600 miles, only to be turned back when you are only a few miles to the resorts Because the road, even in summer, was so rough, Many of the locals considered this road a good area to find spare trailer parts
For some of the most hearty of tourists, where no was not acceptable, The county provided a dozer and chained up the vehicle and dragged them through the mud. The best part of the road was actually almost in the ditch. The center was so soft you could stick a 4 ft. lath up to your armpit into the grade
We had some experience with one project, but this was different. We could not shut down the road, heck we could not even delay vehicles too long. We’re talking 200-300 vehicles a day in and out We tried to come up with a method that could be done, fast, cheap, no traffic delay, and oh yeah, get gravel from a foreign country
We first looked at some ways that did not work out so good. Oh Yeah, Reminder, you might want to write this down. Fabric is delivered in big rolls, with a black plastic covering, like a giant hefty garbage bag. The semi drops them off along the job. Been there for a week. You line up 20 trucks and equipment, ready to roll, you open the bags and find out it’s the wrong stuff.
Geotextiles are a great tool, but you have to use it the right way. What’s wrong with this picture?
