October 10, 2008 - EarthTec MSE Walls Selected for Final Phase of Wilson Bridge Project
EarthTec, a specialist in mechanically stabilized earth (MSE) structures and subsidiary to GeoStructures, has completed the design work and begun delivering wall components needed for improvements to the I-495 highway at Telegraph Road. Part of the $2.52 billion effort to build the new Woodrow Wilson Bridge span across the Potomac River, this project features a grade-separated interchange and widening of I-495 for about two miles, which will keep traffic moving more smoothly through the often-congested area.
Under an agreement with general contractor CK Constructors, EarthTec’s MSE wall system will be used for retaining walls and bridge abutments, including several pile-supported integral bridge abutments. When the project is completed in late 2009, it will have 29 EarthTec structures totaling 130,000 square feet for 11 ramps and bridges. Other structures on the project include five box culvert extensions, drainage improvements, CIP retaining walls and noise walls.
“Widening roads within highly populated areas like Northern Virginia creates significant challenges in terms of wall design, aesthetics and stability because walls generally need to be taller in those environments,” says Michael Cowell, P.E., president of EarthTec. “Solutions such as the Telegraph Road interchange make better use of vertical space with walls and ramps, so they minimize bottlenecks and are a key part of overall transportation planning.”
The unique challenges at Telegraph Road led CK to adopt EarthTec’s 5’ x 10’ pre-cast concrete panel MSE system because its ribbed steel strips can be positioned to avoid obstructions such as drainage structures and bridge-support piles. EarthTec uses the widest and thickest galvanized, ribbed-steel strip in the industry, so it can reinforce the earth with fewer strips and allow for larger spans between strips to accommodate obstructions. In addition, since the strips are wider at the point where they are bolted to the precast panels, tensile capacity is maximized, and corrosion is minimized at the most critical location of the bolt hole, all of which contribute to better wall performance.
These benefits are partly what led the Virginia Department of Transportation to approve EarthTec’s MSE system last year as “Category A,” thus pre-approving its use in all typical bridge abutments and retaining wall applications.
April 22, 2008 - EarthTec’s Highway Wall System Gets Green Light in Virginia
EarthTec, a specialist in the design and supply of mechanically stabilized earth (MSE) retaining walls, has achieved approval from the Virginia Department of Transportation (VDOT) to use its EarthTrac™ HA system on highway and transportation infrastructure projects. VDOT classifies the EarthTrac system in “Category A,” thus pre-approving its use in all typical bridge abutment and retaining wall applications.
EarthTrac HA has been on VDOT’s probationary systems list since August 2007. Since then the company has carried out two VDOT-related projects to widen Spriggs Road (Phase II with Branch Highways), and to build a bridge abutment on Route 28 for Shirley Contracting.
EarthTrac HA also received approval in 2007 from Maryland’s State Highway Administration under both the Load and Resistance Factor Design (LRFD) Specifications and the Standard (Allowable Stress) Bridge Design Specifications. Since then contractors have used the system on projects at the Greenbelt Metro redevelopment and at Prince Frederick Boulevard.
MSE has been the preferred technique for constructing earth retaining structures on publicly funded infrastructure projects since its introduction in the U.S. in 1972. EarthTrac HA represents an up-to-date embodiment of the MSE system partly because its galvanized, ribbed-steel strips that reinforce the soil are unusually wide at the point where they are bolted to the precast concrete facing panels. This maximizes strip capacity, minimizes corrosion effects, reduces the amount of steel lost to the bolt hole, and contributes to better wall performance.
“EarthTrac HA combines the best elements of traditional MSE structures and new technologies so that walls have higher factors of safety, durability, and longevity,” says Michael Cowell, P.E., president of EarthTec. “Because of this we expect to see other departments of transportation follow the lead of Maryland and Virginia.”
EarthTec provides a wide range of earth retaining solutions.
In addition to EarthTrac HA, the firm also has a wire-faced MSE wall for temporary works and permanent industrial structures, which can be adapted to construct steep slopes with a stone vegetated facing.
About EarthTec
A subsidiary of GeoStructures (www.geostructures.com), EarthTec (www.earthteccorp.com) designs and supplies a range of steel- and geosynthetic-based MSE structures, primarily for use in transportation infrastructure, and commercial development projects. EarthTec solutions cover the full range of site and soil conditions, with greater flexibility of backfills, resulting in savings of both time and money.
September 19, 2007
EarthTec’s Highway Wall System Gets Approval in Maryland EarthTec, a design/supply specialist for retaining walls used in transportation and commercial applications, has received approval from the Maryland State Highway Administration (SHA) for EarthTrac™ HA, a mechanically stabilized earth (MSE) wall system. Maryland has approved Earthtrac™ for MSE walls up to 50 feet in height, which is the highest on the approved list.
EarthTrac HA was the first product to gain SHA approval for use under both the Load and Resistance Factor Design (LRFD) Specifications and the Standard (Allowable Stress) Bridge Design Specifications. Under the Federal highway aid program, October 2007 is the deadline for all states to adopt LRFD for bridge design.
MSE is the preferred retaining wall construction technique on publicly funded infrastructure projects throughout the United States. EarthTrac HA, which uses galvanized, ribbed-steel soil reinforcements bolted to precast concrete facing panels, represents an up-to-date embodiment of the MSE system that SHA first used more than 25 years ago.
“The EarthTrac HA system employs materials that have long history of successful use on department of transportation projects, so for authorities like SHA it is an easy choice to approve us,” says co-founder and managing director David P McKittrick.
EarthTec provides a wide range of earth retaining solutions. In addition to EarthTrac HA, the firm also offers EarthTrac geosynthetic strip reinforcement, a precast panel faced geosynthetic strap system for use in chemically aggressive soil environments, EarthTrac Wire, a wire-faced MSE wall for temporary works and permanent industrial structures, and EcoForm, an economical wall and steep slope system employing vegetated or stone facings.
July 30, 2007 GeoStructures Spins Off Subsidiary for MSE Wall Construction
To meet the demand among contractors and state departments of transportation (DOTs) for mechanically stabilized earth (MSE) systems, GeoStructures has established and launched EarthTec, a new enterprise providing design, supply, and turnkey construction of MSE structures.
Led by co-founders Mike Cowell and David McKittrick, the new company is a response to the market’s demand for an alternative supplier of MSE systems, the reinforced soil structures used to provide grade separations and support of sound walls, bridge abutments, dams, and seawalls. A merger between two national MSE suppliers in 2006 left the market with one dominant, national supplier of steel-reinforced MSE structures, which are built by embedding layers of steel reinforcement in granular soils. Among DOTs, galvanized, ribbed-steel strips and precast concrete-facing panels have been the product of choice for MSE structures, and EarthTec is offering these in its EarthTracHATM system. The name derives from the track-like appearance of the ribbed steel strip.
EarthTec also is offering two new MSE systems incorporating geosynthetic straps for soil reinforcement. Known as EarthTrac PETTM and EarthTrac UltraTM, the polymer-based straps are durable in acidic or alkaline soils where steel reinforcements are susceptible to corrosion. The EarthTrac UltraTM system has been designed for use with highly alkaline backfill such as recycled concrete, which helps contractors and owners achieve project environmental targets while saving up to 30 percent of the total structure cost when compared with use of virgin quarried aggregates.
“The U.S. and the east coast in particular has a lot of varying soils, so we have deliberately established a broad product line to ensure that contractors and owners have the right product for their particular soil conditions,” according to co-founder and Managing Director David McKittrick.
Developed by McKittrick during his tenure at Europe-based VE Geostructures, the geosynthetic strap systems were initially designed for use in the Middle East where aggressive, chloride-rich soils preclude the use steel soil reinforcing strips. EarthTec is the only U.S. supplier for these geosynthetic straps and has a patent pending for the way they connect to MSE facings.
Adds co-founder and President Mike Cowell, “The systems we offer are in place on more than five million square feet of MSE structures around the world. And the geosynthetic systems give us an opportunity to lead the U.S. industry and resolve, in a new way, some of the unmet needs facing our customers.”
EarthTec has already employed the galvanized steel strip system on two projects in Virginia, and the April 2007 groundbreaking for the Holiday Inn Express in Alexandria, Va. will represent EarthTec’s first project in the U.S. to use the new geosynthetic straps.
About EarthTec
EarthTec (www.earthteccorp.com) provides a range of steel- and geosynthetic-based MSE structures, primarily for use in transportation infrastructure projects. The company’s product suite installs in a variety of conditions and soils, with greater flexibility of backfills, resulting in savings of both time and money.
About GeoStructures
GeoStructures (www.geostructures.com) is a ground-stabilization company that helps customers achieve significant savings in site preparation prior to construction. The only provider of Geopier technology in the Mid-Atlantic region, the company has a variety of soil improvement systems that stiffen soil to support multi-story structures, eliminate the need for costly, deep foundations, and enable rapid scheduling for year-round construction
