Excavation and Earthwork Safety

Earthwork in engineering is simply the process of moving or displacing parts of the earth’s surface involving quantities of soil, dirt, or unformed rock. The earth may be moved to another location and formed into a desired shape for the purpose of preparing for new construction of roads, railways, causeways, dams, levees, canals, and berms. Typical earthwork in engineering normally consists of excavation and fill or backfill of the area needed. Excavation may be classified by either type of material or purpose or, oftentimes, both.

excavation-safety

Excavation By Material Types:

  • Topsoil excavation

  • Earth excavation

  • Rock excavation

  • Muck excavation – this usually contains excess water and unsuitable soil

  • Unclassified excavation – this is any combination of material types

Excavation By Purpose:

  • Stripping

  • Roadway excavation

  • Drainage or structure excavation

  • Bridge excavation

  • Channel excavation

  • Footing excavation

  • Borrow excavation

  • Dredge excavation

  • Underground excavation

Most often what people think of when the word excavation comes up is heavy equipment digging trenches for whatever reason. It might be your local municipality preparing to add drainage at the side of an existing road or your neighbor digging out a new pond for either livestock or personal use.

pond-excavation

The safety issues involved in any excavation job cannot be stressed enough. Safety is such an important aspect to any excavation project that an entire website is devoted to just this one aspect of excavation and earthwork. In one 2015 article written by Allen Powell in the site’s magazine “Before You Dig,” there is an extraordinary list of the 10 best practices that every excavation contractor should put in place for their next excavation and site preparation job. These 10 things are:

  1. Training of all field employees should be comprehensive and mandatory.

  2. Pre-survey. White line all proposed paths of excavation before the start of any project.

  3. Community Outreach. Have your crew knock on every door on a route, explaining the upcoming work to be done.

  4. Homeowner Association (HOA) Meetings.

  5. Fully staff a 24-hour hotline that alerts location managers each night with a phone call and e-mail regarding unresolved issues.

  6. Daily tailgate meetings at the beginning of each workday.

  7. Air Knives & Vacuum Excavation. Companies that take potholing seriously take the extra time to use tools like air knives that limit the chances of damaging a utility or tracer wire.

  8. When constructing potholes with air knives and vacuums, require the drill foreman to document the depth at which a utility is found in order to guarantee the legal separation distance between the utility being placed and the utility already in place.

  9. After the project is complete, again go door-to-door, leaving behind customer door hangers with contact info for questions or complaints.

  10. Require a damage prevention team to show up on unannounced occasions for real-time audits and post inspections.

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Along the lines of general safety issues in an excavation project, the number one person to be considered “at risk” is the single worker. The challenges of connecting more closely with any single worker can be numerous and frustrating. In this context, we define single workers as those that are self-directed, not part of your normal cohesive crew, do not regularly interact with co-workers and supervisors, and often on the job in a remote area. These employees generally leave home in the morning and go straight to the work site and return straight home in the evening, and have little – if any – interaction with other team members within their company.

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Most single workers like the fact of their independence and the autonomy that their job provides, and really enjoy working “under the radar.” They make their own decisions each day that ultimately determines their own safety and well-being on the job site. So what, if any, steps can your business take to make sure that the needs and safety of any single worker are addressed? What can you do to ensure the health and safety program and all policies and procedures are being made available to this worker? What tools can you use to engage this worker in order to lessen his or her chances of injuries?

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Premier Utility Services, LLC, recently shared the program they have in place in order to assist the single worker in remaining safe throughout his employment with the company. Their program requires all employees to attend both on the job and in classroom training which covers a three-step process of hazard recognition, hazard analysis, and following through on your plan made in the previous two steps.  The company’s full outline of their training program is:

1) Assess hazards associated with their work. Hazard recognition is the first step, whether the tasks involved driving, working in or near excavations, working near electrical equipment, working over water, using a drill or a hammer, lifting manhole covers, or any other associated work tasks.

2) Analyze the hazard in relation to the work being performed and develop a plan to eliminate or mitigate the hazard, e.g. if the task involved walking through high grass and deciding what to do to avoid hazards such as holes in the ground, uneven terrain, poison ivy and ticks? Most of the information needed to mitigate hazards is found in the Incident Prevention Manual, risk assessments, best practices and policies or tailgate bulletins and alerts, all located on the Premier safety website.

3) Act according to the plan by making the right decisions and avoiding shortcuts or alterations to the plan unless conditions change.

excavation-box

So, as you can see, safety is not to be taken lightly in any excavation project. The available resources are plentiful and easily located. When in doubt about any portion of your company’s policies regarding health and safety issues in the excavation and earthwork job environment, you should always defer to OSHA standards and rules. Please feel free to share this information with any excavation contractors you know.

Removing or Backfilling a Swimming Pool

You can’t just start dumping a bunch of dirt into your old swimming pool and expect that to be the end of it. First, you should hire a reputable demolition and excavation expert to do the job for you. Then you must make sure your demolition contractor has pulled all the proper permits from your city or county, whichever is required. You must make sure to do your part in advance of the day of demolition or removal of your old swimming pool. Ask your contractor what needs to be clear out of the way and what can stay.

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You can choose to either have the entire pool removed before filling in the hole, or you can have just part of the pool removed. In either case, the demolition crew starts with making sure all water is completely drained from the pool. After using a powerful pump to get out 90% of the water, the demolition team will punch holes through the concrete bottom of your old pool to make sure the final water is drained out. This also ensures that if you are only removing the first few feet of concrete before backfilling, there will be proper and efficient drainage in the future.

Whether removing all or part of the concrete that makes up your in-ground swimming pool, you should be certain that the contractor you’ve chosen will be recycling the old concrete and not dumping it in the landfill.

pool-excavation

Once the pool is completely drained, an underground utility locator will go work locating any water, electric and gas lines for proper disconnection prior to the actual demolition. Depending on your location, you and the contractor will have to decide whether to dig out all of the plumbing first or if it is better to just disconnect the supply and cap and bury the pipes. This is mostly dependent on building code in your specific location.

If you have decided to use the “abandonment” method of pool removal, here is what will happen once the are is readied as outlined above. Using a skid loader or Bobcat, the demolition contractor will open up one end of the pool and then uses some of the available dirt to build a ramp for access in and out of the swimming pool cavity. At that point, the skid loader begins punching holes in the bottom of the pool to allow future drainage as mentioned above.  Once the holes are in place then the pool deck area is pushed into the bottom of the abandoned pool cavity.  The skid loader then hammers and removes the top 2 to 3 feet of the pool and pushes that into the cavity.  Once the primary concrete is smashed up and pushed to the center of the vacant pool,  dirt is placed into the pool using a stepping process which consists of placing about 2 feet of dirt  into the pool cavity and then machine compacting. This process is repeated until the hole is filled.

pool-removal3

If you have chosen the “exhumation” method to have your swimming pool removed,  this means the crew will not only break up all of the concrete inside the pool as well as the decking, they will also cart it out and haul it to a recycle plant. This method is, for obvious reasons, the more costly of the two so you should confer with your demolition and excavation professional before making your decision. It usually depends on what you want to do in the area once the pool is removed and backfilled as to which method you would want to use.

 

Residential Demolition Basics

So, in a nutshell, the process of taking down and cleaning up the mess of old buildings, old swimming pools, falling down barns, etc, etc, is demolition. Your guy comes on to your residential property, assesses your need and decides the best way to tear down and take away your little problem. The first thing they need to do to make sure everyone is safe is to make sure that the electric and water, cable line and phones are all disconnected and moved completely out of the way of any equipment they might be bringing in.

demolition-before

So then your highly qualified demolition contractor needs to be sure that the equipment he is bringing in matches the needs of your job. Because, using my old barn as the example, there would be no need to bring in a giant wrecking ball to knock that building over …right? Also, they want to be paying close attention to nearby structures (if there are any), trees or other landscaping. You don’t want them coming in and wrecking the whole property! Along those lines, if they do need to bring in heavy equipment like bulldozers and such, they will need to plan out the route to take well before they get there so they don’t run over and mash up your septic system. Wouldn’t that be a hoot?!?!? LOL – no.

demolition-services

Make sure you talk to your prospective demo guy at length before anything gets started. You want to make sure they know what they are doing. If the building you need torn down and taken away is like mine, or is an old chicken coop or other skanky outbuilding, you probably don’t need them to bring in the “A” team tools like diesel powered rams, excavators, bobcats, bulldozers and cranes. They can use manual demolition on an old building like that, and get it down and cleaned away no problem. But if you do need them to demolish the old homestead so you can build anew, manual demolition more than likely won’t be enough and they will definitely bring in the big power tools and do a nice, safe mechanical demolition for you.

land-clearing

Okay, so let’s just say that you are needing to tear down your house and clear the land so you can build a new, safe, shiny house on the same residential property. And your house is 10,000 square feet with multiple floors, a basement, a 10 car garage, and the attached mother-in-law bunk for those special visits. In this case, both manual and mechanical demolition may not be enough. Before your contractor starts swinging around his wrecking ball, he may want to discuss another type of demolition which is called undermining. The most well-known method of undermining demolition is an implosion. Wait, wait, before you go getting all excited about blowing up your stuff, let me point out a few things.

  1. Implosion demolition is super expensive

  2. implosion demolition is dangerous

  3. the prep for an implosion takes 6 times as long as prep for a mechanical demolition

  4. the cleanup after the implosion takes up to 10 times as long as mechanical demolition

So instead of insisting on implosion demolition of your old house, just watch this video and let your guy bring in his wrecking ball and not explosives.

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One last thing to touch on here is the green method of demolition called deconstruction. It means exactly what it sounds like! The crew takes apart your building, fence or brick wall piece by piece and saves all of those pieces for a future project. This is actually very nice for several reasons:

  • no noisy equipment on your property

  • no diesel fumes gunking up the atmosphere

  • no large safety issues to watch for

  • easier to get local permits

  • materials at hand for your new project

This method of demolition is the slowest. Your demolition contractor will most likely bring in an experienced tree service to either protect your 50-year-old oak trees or move them to a safe location that is aesthetically pleasing and fits in with your new building project. Many contractors charge more for it if you are keeping the materials yourself. You can try to strike a better bargain by offering to let the demo guy take the materials for himself and see if you can get a better rate for your residential demolition project.