Page 40

2013SprShotcreteEMag

Safety Shooter Shotcrete Work in Confined Space Areas Smaterials in storage bins, hoppers, culverts, of entry or exit and are not designed for continuousof a confined space have a limited or restricted meansan excellent method of installing concrete By Ted Sofis hotcrete work, by its very nature, provides exit from the space. Such areas fitting the definition inlets, vaults, tanks, and other areas, where it is employee occupancy. Confined spaces may include difficult to transport and efficiently install inlets or manholes, vaults, process vessels, tanks, materials by conventional casting methods. The excavations or pits, boiler dead air spaces, or a shotcrete equipment and materials can be staged multitude of other areas where the configurations outside the enclosed area and the gunning hose and entry issues meet the defined criteria. can be fed in through an access hatch, a manhole, Permit-required confined spaces are spaces that or any other small opening to convey the shotcrete OSHA describes as having one or more of the material into the internal enclosed area and onto following characteristics: contains or has the the receiving surface. Many of these tight or potential to contain a hazardous atmosphere, restricted areas are regarded as confined spaces. contains a material that has the potential to engulf When working in confined spaces, it is of utmost the entrant, has walls that could converge or collapse importance to ensure the safety of those working inward, a sloping floor or bottom that slopes into a in the enclosed area and to follow all OSHA safety taper or smaller area that could trap or asphyxiate requirements (refer to Fig. 1 through 3). the entrant, or contains ANY OTHER RECOG- OSHA defines a confined space as a space that NIZED SAFETY HAZARD. These may include has a restricted or confined area that hinders the unguarded machinery, exposed live wires, or high- activities of employees who must enter, work in, and temperature areas that can cause heat stress. When dealing with permit-required confined spaces, it is mandatory to have an attendant at an opening into the confined space at all times while entrants are in the space. There are specific OSHA Fig. 1: Worker entering a manhole opening into a confined space along the side of a ventilation tube Fig. 2: In confined areas like this steel mill Fig. 3: In this confined space area in a power smokestack and ductwork, a refractory lining is plant ash pit, dry-process shotcrete is being being gunned in place using the dry process gunned in place 38 Shotcrete • Spring 2013


2013SprShotcreteEMag
To see the actual publication please follow the link above