August 24, 2010 - EarthFax Completes Civil Engineering Designs at a Pozzolan Mine in Central Utah

EarthFax recently completed civil engineering designs for a central Utah pozzolan mine located adjacent to U.S. Interstate Highway 70 ("I-70").  Project work included roadway design for an un-surfaced haul road from the mine to I-70 and hydraulic design for reduction of storm water flow beneath I-70.  The design distance of the haul road was approximately 0.33 miles and included grade, width, geometric improvements, drainage ditch and culvert locations, and slope stability analysis for cut and fill locations.  The road design was engineered to accommodate ore trucks that would travel to and from the mine.  EarthFax completed design work for deceleration and acceleration lanes onto I-70 according to Utah Department of Transportation standards, although this aspect of the project was not implemented.

Given the costs and safety hazards of trucking ore across I-70, design studies were conducted to evaluate the feasibility of crushing ore on the east side of I-70 and conveying it through a storm water box culvert to the west side of I-70 for processing and shipping.  EarthFax evaluated the hydraulic capacity of the culvert without the conveyor and, in consultation with UDOT, determined that additional free board would be needed during peak runoff events.  To meet this need, we designed a detention pond upstream from the box culvert to reduce the peak flow entering the culvert from both the 100-year, 24-hour storm and the 500-year, 24-hour storm. The detention pond was sized to ensure that the depth of storm water flow through the culvert box would leave a freeboard of at least 2.5 feet during the 100-year storm and 1.5 feet during the 500-year storm.  This ensured that flow through the culvert would occupy approximately 33% and 50% of the capacity of the culvert during these peak events, respectively, and provide enough room for the conveyor system without threatening the integrity of the highway or the functionality of the conveyor system.  The detention pond design included a settling basin to prevent debris from entering the culvert box.  The pond was located in a former borrow pit created during construction of the freeway, providing a significant construction cost savings to the client.

EarthFax Engineering, Inc. is a consulting engineering firm that was founded in 1982, with offices in Midvale, Utah.  The firm provides services in the areas of civil engineering, environmental engineering, geotechnical engineering, hydrology, geology, land reclamation, and environmental planning.  Additional information regarding EarthFax can be found at www.earthfax.com.