Hydro Excavation Overview
Hydro Excavation is the general term for any excavation job that uses hydraulic power to move earth or rock by use of a water pump and a power shovel. A hydraulic Excavator or vacuum Excavator is a construction machine that either removes material from a hole in the ground, or extracts heavy materials from the ground. The excavators, also called hydro diggers are designed to be used in very tough circumstances such as making trenches, breaking up huge rocks, excavating ditches for pipes or cables, grading land, dredging large holes etc. Some other types of excavators include tunneling excavators, sluice gates, screen door excavators, front-end loaders, boom trucks, wire rope excavators, belt excavators and more.
Usually the process of hydro excavation begins with the drilling of a large hole in the ground, and then using a bulldozer or pump to pump the excavated material into the new hole. The pumped material will usually have to travel through small tunnels which are lined with drains and pipelines to an underground facility. There will be a series of pipe lines, ductwork, and electrical cables throughout the underground facility to connect the various pieces.
The next step in hydro excavation work is to lay a series of drain pipes, pipelines, ductwork, and other utility systems to route the excavated material through. Once the utilities have been placed backfill is required to keep water out of the excavation site. This is done by a plowing out of the excavated soil and the placing of a layer of gravel or soil backing up to the front of the excavated area. This level of backfill is dependent upon the amount of space that is available in the area. Most excavation jobs require more than just the plowing out of the soil, this step is often called “backfilling”. Backfilling is done so that if water comes up through the digging, it will have a better chance of being directed away from the main dig and utility lines.
After the backfill has been placed and landscaping has been completed the actual hydro excavation project begins. A hydro digger is used to dig large holes for sewer and utility line excavation projects. The contractor will usually rent an air compressor to help with the digging process, this way the air can be pumped at a faster rate. The digger is equipped with an auger which is able to use a larger auger hole than what would be possible with a shovel.
Once the air excavating equipment has been placed in the hole it is time to move the excavated dirt safely and quickly to the new location. The hydro excavation project crew will either dig the pipes one by one or group all pipes together. This group of pipes is known as a line crew. This is the crew that lines each individual pipes with rocks and soil so that no debris is left behind. This method saves time because there is not a lot of room to move the heavy excavated dirt around.
After the pipes have been dug all the dirt is removed, the area is leveled and then the topside is painted with an anti-slip solution. This paint acts as a shield from the high-pressure water. After the painting is complete and the area is dry, the Hydro Excavation contractor will then secure the area with high-pressure water and concrete mixers. The Hydro Excavation contractor then turns off the water and the Hydro Excavation team leaves the site.