About Us

Federally funded research shows that generic Geosynthetically Confined Soil (GCS®) structures can have bearing capacities and safety factors more than 10 times those of Mechanically Stabilized Earth (MSE) walls. NCHRP research demonstrated that GRS/GCS® walls and abutments can withstand any credible earthquake. State of the art GCS® technology translates into better, safer, quicker, easier and cheaper retaining walls, bridge abutments, box culverts, foundations, rockfall barriers, avalanche and debris flow deflectors, and more. Facing options include natural vegetation, wire mesh, natural stone, concrete block, or sculpted shotcrete. You are the designer – use your imagination.

GCS® structures behave as GeoMonoliths or Unique Composites. Unique Composite behavior exceeds the sum of its components. As with concrete, which is a Unique Composite, testing is done after combining the elements. We erred in the 1970’s by attributing the stellar performance of “fabric walls” to the contribution of the two elements, fabric and soil as simple composite behavior where performance is a predictable sum of the two elements. We called this Mechanically Stabilized Earth (MSE).

We then set out to “improve” the design with stronger, stiffer elements. And with all this added cost, we had to open the spacing for economy of material cost and the illusion of economy in construction. That was as wrong as wrong gets, and we have had chaos since. MSE has a failure rate, and with the certainty that many standing MSE walls are just marginally stable.

The key to GCS® performance, as demonstrated in the very first “fabric walls” in the 70’s, is close (8 inch/200mm) spacing of geosynthetic sheets in compacted granular backfill. These inclusions provide measureable confining effects in granular backfilll up to about four inches (100mm) from each sheet. Proximal confinement induces interparticle failure modes as with concrete and bedrock, and explains why Unique Composite GCS® structures even with the lightest fabrics can be designed to withstand loads over 20 tons per square foot (2.2 MPa). Simple composite, quasi-tieback MSE structures rely on intraparticle shear and can fail under self weight.

The world of opportunity in the true science of GeoMonlithic behavior is lost on our generation and probably the next. Our professors, engineers and associations have yet to recognize the grievous error of our day one decision to use Rankine methods to describe this Unique Composite or GeoMonolithic behavior. The world would be a different place had we understood in the 1970’s to test after construction….we would have recognized and quantified the non linear relationships of spacing. We would not have thrown the light, inexpensive fabrics under the bus in favor of wide spaced grids.

Herein are reports, papers and essays that add illumination to these topics. It is our goal, our hope, that this site will provide insight and incentive to our next generation of engineers to escape our current bondage to vendors, AASHTO, FHWA, NCMA, peer review, risk aversity and all the related trappings whose goal is immortalizing existing practice. Real engineering is fun. Just ask me and Al. One of the unexpected pleasures is finding out how little the establishment really knows. You will be disappointed to find how low the confining fence around your corral really is. It is an easy step out.

I am always available to comment, assist, even visit sites at no cost.

Bob Barrett
Participant in MSE development and Co-Founder of GCS® Wall Technology

ESSAYS

TYPE	CLICK FILE NAME TO VIEW ESSAYS	FILE SIZE
	GCS® GeoMonolith Theory, Design and Construction | PDF	191kb
	Geomonolith APPENDIX 1 Revisting Research | PDF	805kb
	Geomonolith APPENDIX 2 History of GCS® Research | PDF	414kb
	Geomonolith APPENDIX 3 Practical Design Considerations | PDF	158kb
	Geomonolith APPENDIX 4 Construction and Inspection | PDF	881kb
	Geomonolith APPENDIX 5 Bridges on GRS CGS Geomonoliths | PDF	1.39MB
	Geomonolith APPENDIX 6 Why we do what we do | PDF	154kb
	Letters to the Editor | PDF	104kb

PRESENTATIONS

TYPE	CLICK FILE NAME TO VIEW PRESENTATION IN NEW WINDOW	FILE SIZE
	Geosynthetically Confined Soil™ Presentation | Flash	online
	Rockfall, Mudflow and Avalanche Protection with GCS® | Flash	online
	Bob Holtz Symposium Presentation, GeoAmericas 2008, Cancun, Mexico	online

TECHNICAL PAPERS

TYPE	CLICK FILE NAME TO VIEW TECHNICAL PAPER	FILE SIZE
	Adoption & implementation of GRS design concepts: A consultant’s perspective	461kb
	MSE Retaining Wall Cost DOUBLES with AASHTO's new LRFD guidelines!	300kb
	Open Letter to FHWA and AASHTO on MSE and GCS® Walls	50kb
	Durability of Retaining Wall Facing Blocks	2MB

Free Workshops and Brownbags Presenters

This presentation/workshop is a summary of 40 years of research by the Colorado DOT, Federal Highway Administration, U. S. Forest Service and several universities in the U. S. and beyond. Topics will include the history of reinforced soil, the evolution of Mechanically Stabilized Earth (MSE) and the next generation of technologies based on the phenomenon of confined soil, Geosynthetically Confined Soil (GCS). Retaining walls to 300 feet high are possible. Bridges that last longer, cost less and are much faster to build are now mainstream in some parts of the U. S. These bridges and box culverts can be built in less than 24 hours in some cases. The presentation concludes with innovations in rockfall mitigation and landslide and erosion control - there are tools and technologies that can cut costs in half. These include the Soil Nail Launcher, SuperNails, SuperMicropiles, GCS retaining walls, GCS Rockfall Impact Barriers and more. Some discussion will be presented on newer technologies for rockfall mitigation and for scour remediation.

• Robert K. Barrett

Bob is the founder and former owner of Soil Nail Launcher, Inc., a company that provides design/build solutions for landslides and erosion problems. Co-Founder of LandslideSolutions, Inc. of California and GeoStabilization, Inc. of Colorado. Past Chairman of NCHRP Project 12-59, charged with preparing Design and Construction Guidelines For Bridge Abutments on Geosynthetically Reinforced Soil. Past Chair of the TRB Committee on Geosynthetics, and the NCHRP project that developed proper closure methods for geotechnical borings. Recipient of 1991 Colorado Governor’s Award for creativity and innovation. Ruckman and Barrett were recipients of the IFAI International Design Award in 1997 for design and construction of a 55-foot-high GRS retaining wall. Co-Recipient of the international 2009 NOVA award from the Construction Innovation Forum for development of GCS bridge abutments. Partner Al Ruckman and Mr. Barrett have been awarded 7 patents, on retaining wall design, on rockfall fences, on earthquake resistant abutments on fiberglass nails, on shotcrete alternatives and on scour micropiles. Co-inventor of the Colorado Rockfall Simulation Program, a program that predicts the behavior of a rock in motion. We have presented GRS, landslide mitigation and rockfall technology transfer programs all over the U. S. and on all continents except Africa. Constructed GRS abutment and wall demonstration projects in several countries.

• Colby Barrett

Co-owner and President of SNL, Inc., Colby has worked for Bob and Al for over 10 years, managing projects throughout the continental United States, Puerto Rico, and Jamaica. Mr. Barrett studied Chemistry and Chemical Engineering at the University of California at Berkeley and Oxford University on an NROTC scholarship. He served as a Captain in the United States Marine Corps, leading both infantry and Scout/Sniper platoons throughout the Pacific Rim and the Middle East. Mr. Barrett holds Juris Doctor from the Yale Law School and is licensed in Colorado. He is currently wrapping up the requirements for his Professional Engineer License.