backfilling methods

4 Trench Backfill Methods You Should Know

Is your current construction project due for a trench backfill? Special considerations should be taken when compacting and filling trenches to accommodate utility lines.

If you’re comparing possible trench backfilling options, there are a few different methods that might be a good fit for your project. 

First, what is a trench backfill?

Backfilling is the process of placing back soil into a trench or foundation as soon as the excavation or other related work is accomplished. Trench backfilling requires heavy equipment as well as skills and knowledge of the specifications, soil conditions, and contract requirements. 

Each area of the soil has certain distinct characteristics that require different construction methods to achieve the desired results.

How does the backfill process work?

Backfill material is processed with proper compaction and there are backfill methods for fine material and other soil types. Filling and compacting trenches for utility lines involves unique considerations.

The soil type necessarily determines the type of backfilling method. Backfilling stone compacts are different from backfilling clay or plastic soils. Everything, however, is done by mechanical means. 

Backfill crews need to observe proper care to avoid any impact loading of shafts, pipelines, cabling, structures, or any buried elements when compacting and placing backfill. 

You might sometimes need to consider the presence of a pipe or how you will create a pavement. A different backfill technique should be considered if there is an installation involved.  

The 4 Trench Backfill Methods You Should Know

Here are 4 common trench backfill methods:

trench backfilling methods

1. Jetting

This practice is also known as “water jetting”, and involves the application of pressurized water through a long, metal device into the trench.

Water Dissipation reduces trench volume. This method is recommended for granular soil types. Clay, for example, is not the best soil type to conduct jetting. The pavement around the trench may become uneven or fall, creating a depression in the roadway.

[Read: The Truth About Digging A Trench To Drain Water]

2. Filling (flowable fill)

Flowable fill uses a cement mixture that is transported directly to the site. 

While the flowable fill technique is generally effective, it can cause problems if the flowable material covers any pipes too tightly. Protective material should be used to cover pipes before filling. It is also a good idea not to fill the trench with the same fill in more than one batch. If it spreads to other areas, the fill won’t be as even or level.

3. Dumping

This involves filing a trench with granular material without compaction. This method has some drawbacks. Granular aggregates are naturally porous, which means fine material could enter. Contractors prefer this method over others because it does not require additional trench compaction.

4. Compacting

Compacting is the process of using existing soil and organic materials to dig a trench. 

The process of compacting backfill trenches requires solid knowledge of the soil. When backfilling trenches using this method, find out the soil mechanics for the area first. 

Tamping rammers are more effective in cohesive materials, such as clay, because they have lower frequencies. For granular materials, such as sand, vibratory plates are the best option because of their higher frequencies.

Compaction is more expensive than other methods, but it will be worth it when the project is complete.

[Read: Digging A Drainage Trench 101: An Expert’s Guide]

Contact Specialty Grading Today!

backfilling with heavy equipment

Most building owners overlook trench backfill methods, even though it is an important phase in the construction process. 

While the costs and procedures differ, several activities must be completed to prepare the foundations of your building or your home.

Contact Specialty Grading in Yavapai County if you need tree service, heavy equipment, construction equipment, and trench backfilling. We know exactly what you need; therefore, we focus on providing efficient services and excellent value!

Call us now to get started!

If you have questions or stories to share about home construction, we’d love to hear from you! Leave us a comment below!

About the Author
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Specialty Grading

We are a family-owned and operated business in different areas of Yavapai County such as Prescott, Prescott Valley, Dewey, and Chino Valley for over 20 years since 1995. With the help of our certified and licensed excavating and grading contractors, we take pride in providing our customers with efficient services and excellent value.

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