By: Lynn Stocker
Continental Gold, an exploration and development company, established a mining operation in the mountains of Antioquia, Colombia. Situated 940 m (3,084 ft) above sea level, the very complex and steep terrain rendered the area nearly inaccessible for construction equipment that was required to build a stable storage and work area. In fact, mules had to be used to access the location and bring building materials to the jobsite. Continental Gold needed a stable, level platform that could handle high loads from heavy equipment while being cost-effective and able to use the in-situ soils.
After an engineering analysis, Stratagrid was selected as the soil reinforcement for the construction of a mechanically stabilized earth-retaining structure. Stratagrid was chosen not only because of the quality products provided, but also for Strata’s technical expertise in support of Syntex, Strata’s distributor in Colombia. Advantages of Stratagrid include excellent long-term design strength derived from high resistance to creep and low installation reduction factors, plus convenient roll sizes. Local workers layered SG500 as the primary geogrid, with SG200 as the secondary geogrid. They then hand-filled polypropylene bags with material from the mountainside to act as construction form and final facing for the proposed 9.4-m (31-ft) near-vertical structure. The platform will remain unpaved, and the facing will be planted with natural vegetation, creating not only a long-term stable structure, but also one that is in visual harmony with its surroundings.
The plan successfully resulted in a 35% cost savings due to the ability to use onsite fill. This created an environmentally friendly project that took less time and required less freight transport. Excavation machines and other heavy construction equipment now have ease of access and a safe work platform. The mountainside structure will require little maintenance over its lifetime.
