Monthly Archives: February 2022

GEOBLOCK Grass Pavers: Fire Lane Access System

GEOBLOCK® POROUS PAVEMENT SYSTEM Environmental regulations that control and limit stormwater runoff, reduce impervious surfaces, and increase green space have resulted in the growth of permeable pavements for traffic areas. The GEOBLOCK Porous Pavement System offers support for all vehicular loadings and protects the grass from the  damaging effects of traffic while allowing natural groundwater replenishment. Examples of the GEOBLOCK system providing solutions for fire access lane requirements are illustrated in this case study summaries below. Test 1: The City of Kentwood (1994) Kentwood, Michigan GEOBLOCK System Put to the Test The City of Kentwood, Michigan put the GEOBLOCK system through a worst-case scenario field test to measure performance and prove the system’s capabilities. Prior to testing, a series of less-than-ideal installation conditions were established: Five inches of sand subbase was installed, developing a base support capacity of only 2.8% CBR. GEOBLOCK units were laid parallel (rather than perpendicular) to the direction of traffic. Edge restraints, typically used to help prevent block shifting until vegetation, were omitted—both of which help anchor the system. The test area was not proof-rolled prior to load applications. The fire marshal directed a 60,000 lb (22,400 kg) ladder/pumper to drive onto the unfilled 13 ft… Read more »

GEOWEB Geocells Combined with a Turf Reinforcement Mat (TRM)

GEOWEB® System – Research Synopsis Research Objective Measure the performance of the GEOWEB (GW) material combined with a turf reinforcement mat (TRM) (integrated system) with topsoil infill and vegetation under varying shear stresses and flow rates to quantify both hydraulic forces and corresponding soil loss. The test consisted of a series of continuous one-hour flows over the GW-TRM system at incrementally increasing discharges. The performance threshold was defined as the point at which 0.5 inches (13 mm) of soil loss occurred. Research Scenario The Research Facility Steep-Gradient Overtopping Facility (SGOF) at the Hydraulics Laboratory of the Engineering Research Center (ERCD) at Colorado State University (CSU), Ft. Collins, Colorado Test Timeframe April 2005-August 2006 Test Materials GEOWEB Soil Stabilization System North American Green C350 Turf Reinforcement Mat Scope of Test Hydraulic performance testing was conducted on an integrated system comprising the GW30V textured/perforated GEOWEB System and the North American Green C350 composite turf reinforcement mat. The C350 TRM was chosen for its known performance in the test apparatus. Six tests were conducted under the research program to measure the performance of the integrated system, identify stability threshold conditions, and quantify both hydraulic forces and soil loss. Assembling the Test Components The… Read more »

Solar Installations on Closed Landfills: Using Geosynthetics to Overcome Redevelopment Challenges

Written by: Michael Dickey, P.E. (WI, FL, GA, NC), Director Redevelopment of closed landfills and capped solid waste sites represent a unique opportunity for landfill owners, solar developers, and communities to work together to put underutilized properties back into productive use. Moreover, many such sites are conveniently located near existing transmission infrastructure and may be easier and more economical from an interconnection standpoint than rural greenfield sites. However, building over a closed landfill poses unique challenges because most landfills are covered by an engineered cap not typically designed to support loads from permanent foundations or heavy equipment. Additionally, state and federal regulations generally prohibit any activity that could potentially breach or damage the cap. Therefore, retrofitting a closed landfill for utility-scale or community solar projects requires careful planning. Ultimately, the project must not jeopardize the intent of the original cap design; that is, to protect human health and the environment. Selecting a Suitable Foundation Concrete slabs and pre-cast ballast footings are both foundation options for solar system installations on landfill caps. In general, concrete slab foundations are heavier than ballast footings and pose a higher risk of creating landfill settlement and side-slope stability issues. Ballasted footings are a lighter-weight option… Read more »