Types and Methods of Excavation
1st Apr 2020
When it comes to excavating a site it can be hard to decide which method is the best for you.
Selecting the wrong excavation method could make it impossible to complete the project or even result in damaging underground utilities and cost you in the process. The average cost for damage to underground utilities is around £30,000 and can even run into the millions.
A company was charged £210,000 when a worker was killed after striking an underground utility.
There are many different situations where you may need excavation work done, and the choice of tools and vehicles can become overwhelming.
VAC UK have dug up the dirt to provide you with all the information you need to know about your excavation project.
We’ll help give you peace of mind when deciding which excavation technique is the best for you.
14 Different Excavation Situations
Excavation is a broad term meaning to move or remove earth or other materials with tools or equipment. Excavation can be utilised in a number of different situations, such as the construction of buildings & bridges, installing underground utilities, and even building tunnels.
Depending on the situation, the material being moved, the most efficient method of removing it may vary. We have split the situations into 2 categories, the material and the purpose, to help you decide what equipment and method matches your requirements.
Some excavation techniques will be much more efficient than others. Because of this, we have listed the main types of materials and how you should approach your project.
- Sand and Fine Soils Excavation
Sand and fine soil excavation is one of the most basic excavation methods. This involves the removal of fine materials, such as sand, from an area. Sometimes, this excavation method is used to package and move the material. Other times it is just used to remove the material from the area.
Almost every method for excavation works with sand and fine soil except drilling. It is important you take into account the size of the operation and whether or not you plan on reusing the material you are excavating when considering your different options.
- Topsoil Excavation
Topsoil excavation is the method of excavating that is defined by the material: the top level of soil including vegetation and its rootzone. This method is used to remove anything that would be unsuitable to bear structural loads. This includes vegetation, soil, and any other decaying material.
Topsoil excavation is one of the most common excavation methods.
- Rock Excavation
Rock excavation, one of the more difficult excavation types, is the method of clearing rocky terrain and surfaces to prepare for a construction project. Due to the scale and hardness of the rocks, more conventional equipment such as diggers, excavators and picks aren’t efficient in breaking up and removing this material.
Depending on the size of the rocks, you will have to use drills or even explosives to penetrate and break up the rock making it small enough to excavate.
- Muck Excavation
Muck excavation is the combination of liquid (usually water) with dirt, creating a sloppy unpleasant material. This can be undesirable, and often have a negative impact on nearby rivers, lakes or ponds.
Using large excavation vehicles such as diggers, excavators or vacuum excavators you can collect the material and spread it out allowing it to dry up or you can relocate it.
- Earth Excavation
Earth excavation is the method of removing the soil located underneath the topsoil. Usually, a method used to lay out a structural foundation, it can also be utilised for creating drainage ditches and other projects.
With most earth excavation projects being fairly large, they will normally be performed by excavation vehicles such as suction excavators, diggers and dump trucks.
Not to be confused with muck excavation, liquid excavation is the relocation, and usually disposal, of liquid from an area. This is usually performed on small ponds, lakes or silos, as well as removing liquid from projects which has accumulated as a result of bad weather.
This is usually conducted by machines such as suction excavators and vacuum trucks.
Depending on the job at hand, the method of excavation will change. A form of excavation which may be perfect for one environment could be completely ineffective in another.
- Cut and Fill
Cut and fill excavation is sometimes known as stripping excavation and is the method construction companies use to clear and prepare large areas. This method involves removing all of the material such as rock, sand, and topsoil that would be unstable to work on.
Due to the scale of these operations, this method usually requires large excavation vehicles such as excavators and back-hoes.
A trench is an excavation where the length exceeds the depth. Typically this method is used to prepare for or replace underground utilities, foundations, and sewer systems.
The method of conducting trench excavation is dependent upon many different factors including its size, the likelihood of underground utilities and materials. This means that the most effective method of excavation changes from project to project, and should always be treated with caution.
If there is a likelihood of encountering underground utilities, we would recommend first conducting an underground utility survey to help locate these utilities. If utilities are found lower risk techniques such as vacuum excavation and manual digging are recommended depending on the size of the project.
If there is nothing to watch out for, and the project is a larger one, then we would recommend a large excavation vehicle.
Dredging is the removal of built-up underwater sediment which can make it difficult for boats to navigate or construction to get underway. Over time, debris and other sediments can build up in an area which can make it dangerous for vehicles and can impede construction.
Depending on the scale of dredging, it can either be performed from land by vehicles such as vacuum excavators and grab dredgers, or by water using naval excavators.
Basement excavation is the excavation of the area beneath a property. This can be a very complicated procedure. It is important the equipment used for this is both accurate and well equipped for the situation.
The best equipment for this excavation changes from project to project, and depends on the opening size, property size and basement size.
When constructed, bridges require very solid foundations to make certain that they don’t become a hazard in the future. It’s therefore important that the area is correctly excavated and reviewed before construction begins.
Certain materials and objects that may have negative impacts on the bridge’s stability and efficiency of construction will need to be removed to keep the project running smoothly. Choosing the right method depends on the size and the location of the bridge.
Most bridges require large construction vehicles such as excavators, and diggers to ensure the construction is as cost-effective as possible.
Borrow excavation is different to most excavation types as the goal is to not remove the material but instead to relocate it to be used for a separate project. This type of excavation is most commonly used for sand, gravel and soil, with plans to mix it with construction materials such as concrete.
Borrowing not only requires a method for the initial excavation, but often requires sorting and grading later on. The most efficient equipment for this excavation type can range from suction excavators to dump trucks, depending on the end-use of the borrowed material.
Channels and bodies of flowing water can quickly get a buildup of sediments and other materials. The goal of channel excavation is to remove the built-up sediment and other materials to help control the flow of water and decrease the likelihood of flooding. The size of the channel can vary between jobs meaning the volume of sediment to remove, and the most cost-effective method of removing it, can also vary.
Drainage systems are used to carry water and other liquids from one location to another. To avoid blockages and flooding it is important that they remain clear and unblocked.
This excavation type is used for drainage ditches, storm drains, and draining waste around structures. Due to drainage systems usually being small and hard to get to, precision forms of excavation are required. This can include manual methods such as handheld tools, and powered equipment like suction trucks and vacuum excavator trucks.
When hiring a vacuum excavator from VAC UK Ltd you will not only receive a top of the range excavation truck, but you will also be provided with one of our highly trained operators. All of our operators have years of experience dealing with all types of excavation.
This means that no matter what your excavation needs are, we are here for you, allowing you to focus on the rest of your project, safe in the knowledge that your excavation needs will be completed as efficiently and effectively as possible.
At Vac UK Ltd, we can ensure the use of our vacuum excavation units meet the current requirement with regards to the new social distancing rules implemented by HM Government.
All of our crews will carry out work on-site, adhering to the 2-metre rule whilst operating the Vac Ex. We manage this through on-site control measures using a Social Distancing checklist before the start of the shift. We have risk assessed the hazards with regards to COVID-19 and set control measures in place before and during the work activity.
If you are working on critical essential infrastructure on the water, gas, power, telecoms, airport, highways, rail and want to know how Vac UK can help you comply with the two-metre rule then feel free to contact us.
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