3 Excavation Shoring Buy-out Pitfalls

By Jeffrey W. Coonse, PE / May 31, 2023

General Contractors have a huge responsibility when buying out the many trades. Excavation shoring can be difficult as some GCs may only hire this trade once a year. Buy-out gets more tricky in a tough economy. Unscrupulous subcontractors are tempted to push hidden risks onto the GC in hopes of having the low number. Honest…

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5 Mistakes Contractors Make with Deep Excavations

By Jeffrey W. Coonse, PE / February 26, 2023

Deep Excavation Mistake #1.  You get 4′ for free. OSHA tricked us.  It’s really not our fault.  Everywhere I go, in every deep excavation I visit, most contractors think they get 4 feet for free?  Right?  Don’t we?  Unfortunately, no.  Where did this get started?  I believe it’s from the OSHA benching sketch. It sure…

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Limited Access Micropiles, 180′ Deep

By Jeffrey W. Coonse, PE / March 28, 2022

Limited Access Micropiles, Company Record 180′ Depth As the 17-story Virginia General Assembly Building (VAGA) neared completion, it was determined that a pedestrian tunnel would be built across the Capital Grounds and enter the building’s basement. The proposed tunnel would enter the VAGA basement by first going through a preserved historic façade; however, the tunnel…

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Drilling Anchors for Soldier Pile Wall

Anchors

By Jeffrey W. Coonse, PE / August 27, 2021

Anchor design and installation for excavation support systems Definition FHWA defines anchors as cement grouted prestressed steel tendons that are installed in soil or rock. Benefits Open Excavations: Anchors are used to provide the horizontal force necessary retain temporary or permanent shoring systems for deep excavations.  They provide an open site, as opposed to internal…

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photo of internally braced soldier pile wall

Soldier Pile Wall Safety

By Jeffrey W. Coonse, PE / April 28, 2021

What are some safety considerations when constructing soldier pile walls? Soldier pile wall safety is about taking care of people first. Here’s how we do it. Drill Rig Stability Drill rigs must have a stable base to prevent overturning.  The bearing capacity of the soil must be sufficient to support the rig weight and the…

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Soldier Pile Wall Construction

By Jeffrey W. Coonse, PE / April 15, 2021

How are soldier pile walls constructed? Soldier Pile Installation Soldier piles are typically steel H-piles or W sections.  The piles may be driven, vibrated, or drilled into place.  Piles are typically driven or vibrated into the ground where soil profiles do not prevent driving and were vibrations can be tolerated by adjacent structures.  On newer…

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Duke University Bed Tower Anchored Soldier Pile Walls

Soldier Pile Wall Advantages

By Jeffrey W. Coonse, PE / March 31, 2021

What are the advantages of a soldier pile wall? Flexibility Soldier Pile Walls are the go-to excavation shoring solution in densely populated urban areas such as city centers, hospital campuses, and universities.  Soldier piles allow for flexibility when working around existing buildings and existing utilities.  For taller walls, anchors can be installed 10′ below existing…

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Micropile Drilling

Quality Control for Micropiles

By Jeffrey W. Coonse, PE / March 22, 2021

Micropile Foundation Quality Control Using some basic micropile foundation quality control measures will help your project move forward with fewer mistakes and will avoid dreaded rework.  With that in mind, here are some basic QC steps for micropiles. Receipt of Materials Ensure that the threaded steel bars and casing pipes are the correct size and…

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photos of micropiles for supporting a tower crane

Micropile Design

By Jeffrey W. Coonse, PE / February 25, 2021

Micropile Design Micropile design includes structural and geotechnical design. Let’s discuss the importance of these two types of design for your next commercial construction project. Structural Design Design CriteriaMicropiles are designed by two standards, the Federal Highway Administration (FHWA) and the 2015 International Building Code (IBC).  Of course, the FHWA standard applies to highway projects…

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photo of a small drill rig installing micropoiles

Micropile Advantages

By Jeffrey W. Coonse, PE / February 21, 2021

What are the advantages of micropiles? Overcoming Difficult Ground Conditions The first advantage of micropiles has to do with the natural ground conditions at a project site. Micropiles can overcome difficult ground conditions such as debris fill, natural boulders, and karst. Other foundations systems such as auger cast piles and driven piles are not suitable…

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