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What Kinds of Excavation Methods Are Used During Construction?
August 13, 2023 at 7:00 AM

Excavation is one of the most fundamental and critical phases of nearly any construction project. The excavation process lays the literal groundwork for buildings, roads, bridges, landscaping, and more by removing soil, rocks, and other materials. Construction companies use different excavation techniques, equipment, and approaches based on the specifics of the project and site. Here is an overview of some of the most common excavation methods used during construction excavation in the Pacific Northwest and beyond.

Mechanical excavation

Many large-scale construction excavation projects in the Pacific Northwest rely primarily on mechanical excavation. This involves using heavy construction equipment and machinery such as excavators, backhoes, bulldozers, and frontend loaders to dig up and remove earth, clay, gravel, and other materials efficiently. Mechanical excavation is ideal for digging large areas like basement foundations.

Hydraulic excavation

Hydraulic excavation introduces pressurized water to break up densely packed soil and gravel. This technique is faster and less disruptive than traditional mechanical digging. It uses specialized hydraulic excavators that blast water into the ground through a nozzle at up to 2,500 PSI while simultaneously vacuuming up the loosened soil. Hydraulic excavation is common in the Pacific Northwest when working near underground utilities to dig safer, neater trenches.

Pneumatic excavation

Pneumatic excavators work similarly to hydraulic excavators but use highly compressed air instead of water. The air loosens soil and simultaneously vacuums it up through a specialized probe inserted into the ground. Pneumatic excavation is extremely precise, making it well-suited to safely exposing underground utilities. This popular technique enables excavation near utilities without damage.

Trench excavation

Trench excavation means digging a long, narrow hole to access and install utilities like piping, electrical lines, or cables. These linear trenches are then backfilled once utilities are in place. Trenchers have a specialized boom and bucket that can dig continuous trenches with clean vertical walls, unlike wider excavation pits. Trenching efficiently accesses linear areas like pipeline routes.

Slope excavation

Sloped or benched excavation angles back the sides of deeper pits and trenches for stability and safety. This prevents collapse in loose or wet soils. Earthmoving equipment like backhoes slope the walls by incremental cutting and gradual stepping in toward the center. Proper slope grading based on soil and site conditions is standard in the Pacific Northwest.

Underground excavation

For construction projects like underground parking garages, specialized excavation like the cut-and-cover method is used to create open spaces below grade. This involves excavating down from the surface then reinforcing and covering the space. Temporary shoring walls stabilize the earth throughout the underground excavation process.

Selective excavation

Unlike mass excavation of entire sites, selective excavation surgically targets only the necessary areas. This precision technique carefully exposes specific points of interest, archaeological artifacts, or samples for testing. Selective excavation is done manually with small tools. It conserves time, costs, and environmental impact.

Environmental excavation

Excavating contaminated soils requires special environmental excavation methods. This isolated excavation contains pollution, limits exposure, and disposes of hazardous soils properly. Strict protocols minimize risks to workers, the public, and the surrounding environment when digging into contaminated ground.

Underwater excavation

Underwater excavation uses barges, small dredges, or remotely-operated vehicles (ROVs) to dig below ponds, rivers, or the ocean. Dredging creates channels and harbors. ROVs excavate precise seabed areas. Excavation underwater demands specialized skills and equipment. Proper sediment control prevents environmental impacts.

The excavation techniques used in the Pacific Northwest depend on factors like soil conditions, project scale, site accessibility, and proximity to utilities and structures. Skilled construction companies use the right methods and tools to dig foundations, trenches, slopes, and more in preparation for building projects safely, efficiently, and responsibly.

Get in touch with Christensen Contracting for dedicated construction excavation in the Pacific Northwest!

Excavation is a foundational process on nearly all construction projects, but not all digging is equal. Construction companies utilize a wide range of excavation techniques tailored to the needs and conditions of each unique site. From mass mechanical digging to targeted hydraulic blasting to underwater dredging, specialized equipment and methods allow successful, efficient excavation.

Choosing the right excavation approach makes complex projects feasible, while minimizing time, costs, and environmental impact. With their arsenal of excavation capabilities, experienced construction companies like Christensen Contracting provide the ideal foundation for their clients’ projects throughout the Pacific Northwest. By leveraging the appropriate methods for each site, excavation lays the groundwork for building and infrastructure to take shape. The techniques may vary, but meticulous excavation remains paramount to construction success.

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