A Quick Guide On How The Excavation Process Is Carried Out
Excavation involves moving earth, rock and other materials on or below the ground. It is widely used in construction during the preparation of foundations and basements. In the construction of houses, building contractors sub contract the excavation works to excavation contractors. These contractors specialize in site preparation, grading, dredging, trenching, and digging. They have the proper equipment to carry out all of these tasks.
You are probably on this site looking for professional excavation contractors. But before we tell you how to find them, wouldn’t you like to know what they do? Here is a quick guide on how the excavation process is carried out.
Site preparation is the next step after your land has been surveyed, and the project drawings approved. This stage is the right time to hire an excavation contractor. The contractor will clear trees, shrubbery, boulders and even existing construction on the project site. Before the digging begins, they have to consult with land surveyors to establish project boundaries. Also, they have to consult with utility providers so that gas and water lines can be taken into account during the excavation. The contractor has to plan and prepare the excavation carefully to ascertain the safety of surrounding building and structures.
If the structure is small, digging is done using hand tools such as pick axes and crow bars. But if the design requires a basement or deep foundation, deep excavation is required. The depth of the excavation is determined by structural engineers. They take into account the nature of the soil, the design, and the purpose of the building.
The back hoe is the machine most contractors use to dig. Some excavation jobs may need a bull dozer. It has a wider blade than a back hoe. An excavator is also used. It is the machine with a long arm with a bucket at the end.
In the small structures, if the site has hard soils, and the trenches do not go deeper than 1.5 meters, there is no need to support the sides. But in the case of soft soils and deep excavations, the sides of the excavation have to be supported for the safety of the equipment and those working in the excavation. This process is called shoring. The shoring system most excavators use is the timber shoring. The system consists of posts, struts, and sheeting.
One of the potential challenges to face during excavation is hitting a rock bed. Rocks locations on a project site can be determined during a geotechnical test. Knowing the location of the rock helps the building contractor prepare for rock excavation.
Excavation contractors extract rocks using two methods – blasting and ripping. Ripping is the mechanical splitting of the rock by slipping a steel point into a crevice on the rock and exerting force. Ripping is done by a bulldozer. Blasting involves placing explosives in pre-drilled holes in the rock. Blasting requires permits and a licensed blaster.
Dewatering the excavation
Most excavations go below the subsoil water level. Therefore, the foundation hole and trenches become waterlogged. In the foundation, there is masonry work and concrete. The water in the foundation will compromise the strength of the structure. Therefore, it is important that the foundation is dewatered. There are several dewatering methods. Among them is using the bucket of the excavator to scoop and dump the water elsewhere.
After dewatering, the bottom of the excavation is compacted. Excavation contractors use a machine called a compactor. The soil is compacted to 90% maximum dry density. This process strengthens the base of the foundation. Also, this process decreases the probability of differential settlement, which has the potential to fail the whole structure.
The building contractor handles the concreting work and the masonry work in the foundation. After finishing building the foundation, it is waterproofed. The building contractor does this too. However, some excavating contractors specialize in foundation water proofing.
After water proofing, the next step is backfilling. The excavation contractor will use the bull dozers for the backfilling process. After backfilling the site is rough graded to ensure proper drainage. The excavation contractor handles the excess soil, which could involve transporting it off site.
How to find excavation contractors
Contractors Today is the best place to find excavation contractors. We are committed to helping you find excavation contractors near you. We have listings of licensed and certified excavation contractors in all states in the US. All you have to do is select your state then click on your county. It’s that simple. Stop delaying your project and start searching now.