QA Test for Deep Foundations

 

Crosshole Sonic Logging (CSL) is the most accurate and reliable technique for assessing the integrity of deep foundation elements constructed on-site from concrete or grout. The crosshole sonic logging method is normally applied as a quality assurance (QA) technique for newly placed drilled shafts and auger cast piles, but can also be applied to slurry walls, mat foundations, and mass concrete pours.

CSL testing provides assurance that the foundation concrete is sound and contains no defects, such as soil intrusions, necking, sand lenses, voids, etc. The extent, nature, depth, and approximate lateral location of defects can be determined with the CSL method. The CSL method is typically performed in access tubes (steel or PVC) of 1.5 inch I.D. or greater which are tied to the rebar cage and cast into the shaft at the time of construction.

The test can also be performed using coreholes, if available. A variation of this method, called Single-Hole Sonic Logging (SSL) can also be used on smaller diameter drilled mini-piles and auger cast piles. The single hole sonic logging method is used in cases where only a single access tube can be placed in a shaft, and tests the concrete quality in the region around the single access tube.

In cases where a defect or other anomaly is located with the CSL method but more information is needed about the defect size, shape and nature, we can perform Crosshole Tomography (CT) testing. The Crosshole Tomography method is used to create a 2D or 3D image of the interior of the foundation element in the area of the defect to determine defect size, shape, and location.

Applicable On:

Drilled Shafts (Bored Piles)

Slurry Walls & Diaphram Walls

Pressure Injected Footings

Auger Cast Concrete Piles

Grout

Water Saturated Media

Cemented Radioactive Wastes

Test For:

Cracks

Voids

Soil Intrusions

Sand Lenses

Uncured

Weak Concrete

Necking

Crosshole Sonic Logging CSL, Olson Engineering
Crosshole Sonic Logging CSL, Olson Engineering
Crosshole Sonic Logging CSL, Olson Engineering

The CSL System

Diagnose Accurately

The CSL system is the most accurate and reliable technique for assessing the integrity of deep foundation elements

Quality Assurance

CSL testing is the go-to QA technique for newly cast concrete structures

Crosshole Sonic Logging CSL, Olson Engineering
Method Variation

CSL testing can be used as Single-Hole Sonic Logging (SSL) when access is limited to one tube or in conjunction with Crosshole Tomography (CT) to find out more information about defects

Variety of Applications

Test newly placed drilled shafts, auger cast piles, slurry walls, mat foundations, and mass concrete pours

Locate Defects

Locate the extent, nature, depth, and approximate lateral location of defects