Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/301563
Good Barriers Improve Safety OPERAT A berm is defi ned as a mound or bank of earth used as a barrier or to provide insula- tion. is is especially true at aggregate operations. A good berm keeps mobile equipment safely on the haul road and away from the edge of drop-off s, stockpiles, se ling ponds, and dump points. It also serves as a buff er zone between the operation and the surrounding area, providing a noise break and something nice for neighbors to look at rather than a processing plant. According to the Mine Safety and Health Administration (MSHA), berms must be maintained on the outside edge of all haul roads where a drop-off exists of suffi cient grade or depth to cause a vehicle to overturn or endanger persons in equipment, and at dump points where there's a danger of equipment overturning or going over the edge. MSHA provides many rules, regulations, and best practices about where to put berms and how high they should be. How to build the berm, as well as what material to use, is le up to each individual operation, but there's more to constructing a good berm than just piling up dirt. A well-constructed berm, once put into place, should only require occasional maintenance to keep it in good shape. However, it must be con- structed with a material that resists se ling and provides drainage for the roadways. "In our sand and gravel operation, we have ideal materials for building berms," says Jim Tweedy, plant super- intendent at CalPortland's Pioneer Aggregates Plant in DuPont, Wash. "Our sand and gravel deposit is a very good mix of coarse aggregate and sand that's very stable and well-draining." ough berms off er some resis- tance, they should never be relied on to stop a vehicle. ey should only serve as a guide to warn the operator that the vehicle is too close to a drop- off or edge. "I always felt like, if you have a berm that's at least half the height of the axle of your largest machine, it would take a pre y big machine to plow through it," says Bill Page, project manager at Huntsville, Ohio- based Duff Quarry. "But, according to MSHA's reports online, a berm like that can be pierced by a runaway machine fairly easily." To help operations understand proper berm construction, MSHA off ers a 15-minute video, Good Berms Save Lives, on its website, www.msha. org. e video shows the results of one mining company's study on berms using various materials and diff erent heights. It shows how the size and speed of mining equipment, weather conditions, and grades all play a role in proper berm construction. AGGREGATES MANAGER When constructing a berm, be sure to choose a material that allows for drainage and won't compact too much or support weed growth. A well-constructed earthen berm can be as much as three times wider than it is high. When planning for a new roadway, be sure to allow enough room for the berm in addition to the space necessary for traffi c. Drainage can be an issue for some quarries, so proper drain- age must be engineered into the berms when they are built. Some put a break in the berm, but it must be located in such a manner that it doesn't create a hazard for vehicles driving on the roadway. Others create an area in the berm that has larger aggregate to allow water to drain through easily. 1 Use a stable material 4 Allow for drainage