By: William G. Handlos, P.E. Research shows that GEOTERRA® and GEOTERRA® GTO structural mats provide a ground-surface reinforcement layer to support heavy loads over soft subgrades. More cost-effective than other reinforcement mat systems, the GEOTERRA mats can be utilized for either temporary or permanent applications and are reusable. Offering high crush and flexural strength, the GEOTERRA mats have demonstrated the ability to handle the forces from some of the heaviest wheeled and tracked vehicles under severe conditions. Scope of Test: Performance testing of the GEOTERRA and GEOTERRA GTO mat systems was conducted at the University of Kansas Geotechnical Laboratory over weak to intermediate subgrades with CBR values ranging from 1% to 4%. A total of twelve tests were conducted to identify threshold and limit conditions, to create a data-set for modeling, and to determine the equivalent crushed aggregate base. Testing Procedure: All of the test sections were subjected to 40 kN (9 kip) cyclic loading on a 300 mm (12 in) diameter plate. Earth pressure cells were placed over of the subgrade to measure vertical interface stress distribution. Loading plate displacements were measured by the displacement transducer inside the actuator. Test Observations: The following conclusions were determined for the GEOTERRA… Read more »
Posts Categorized: Construction Mats (GEOTERRA & GEORUNNER)
Written by: William G. Handlos, P.E. How long does it take to install? It is a question we hear every day. When it comes to cost and installation rates for geosynthetic construction products, there are no simple answers to what seems like simple questions. In fact, beware of those who try to simplify determination of installation costs for their products with quick answers or charts and tables to determine construction rates. Experienced project managers and site supervisors of the crews charged with installation are in the best position to estimate productivity rates. They know best their crew’s capability and the characteristics of the site involved. The variables that need to be considered include: Crew size, talent, work ethic and workday length Temperature, precipitation and length of day (sunlight) Experience with product class Size of the project Site Access Site Conditions (see weather) Crew The optimum crew size is important. Too small and you may lose the benefits of assembly line productivity. Too large and you will find that you fall over each other and pay for extra “inspectors”. All crews are not created equally. The familiarity with tools and techniques vary greatly as does the work ethic both between crews and… Read more »
Written by William G. Handlos, P.E. Lightweight Construction Mats Construction access in soft soils present a common challenge engineers and project managers face while attempting to complete a project on-time and within budget while avoiding scheduling delays and associated costs. These soft soil sites may also be located in remote, difficult to access areas making construction impossible without a good site access system. Popular construction mat systems are made out of a range of materials including timber, laminate, steel and composite mats. They can be effective, but are also costly. They can also put laborers at risk as they require heavy equipment to install. The ideal mat system for access road construction would be designed to have a high utility-to-weight ratio and would deliver an eco-friendly alternative to current technology. A lightweight construction mat system made from high density polyethylene (HDPE), GEOTERRA®, was created by Presto Products in 2003 to meet the needs of major oil and gas companies working in remote areas of the Amazon jungle. Transporting materials to these sites by helicopter precipitated the need for light, yet strong mats for work platforms and roadways. As the first of its kind, the mats capitalize on the sustainable characteristics of… Read more »
Written by William G. Handlos, P.E.