“All the good sites are gone.” Have you heard that one before? I think we all have. Well, there are still a lot of good sites remaining; they just take a little more creativity to develop. At least that’s what I like to think. One issue with many sites is the presence of soft soils. These sites typically require fill to raise them out of flood plains or up to the surrounding grades. This amount of fill as well as building loads often leads to significant settlements. In the past, these sites would have just been passed over for a better one, now these are prime locations. Many times pre-loading and/or post-grading waiting periods are recommended to allow the natural soils to settle; therefore reducing post-construction settlements. The waiting periods for some sites can be measured in weeks, months, or sometimes years. Maybe you don’t have time to pre-load or maybe there is an existing structure on site that wasn’t designed to handle the settlement of the adjacent soils or the added lateral load of new fill.
Whatever the case, lightweight fill may be an option. By reducing the weight of the fill material, you can significantly reduce the load applied to the natural soils. One form of lightweight fill is EPS (Extruded Poly Styrene) also commonly referred to as geofoam. Geofoam is extremely lightweight, as little as 5 percent the weight of typical soils. It is designed and manufactured based on project requirements and per ASTM and can be installed during inclement weather. It is delivered in various block sizes and is easily cut to required sizes in the field and extremely efficient to install. Other forms of lightweight fill that are typically used include foamed concrete, waste material from local industrial and process facilities, and wood chips or fiber. Each of these has unique characteristics and may also be applicable to your project. If you have any questions regarding lightweight fill or have a project in mind you would like to discuss, please call anytime.
