Geotechs & Engineers

Listing helical piles as an acceptable deep foundation option opens the door for your client to save money and consider all the alternatives available to them.  Helical piles are no longer just a high cost choice when nothing else will work.   Helical piles are now cost effective for practically any application where a deep foundation is needed.  Helical piles can often be more cost effective than shallow foundations when excavation, back fill and compaction is required.

Can we help with the engineering & design?

Yes.  Based on the geotechnical investigation report we can provide a recommended helix configuration and installation depth.

Soil Testing:

Of the standard test methods; Standard Penetration Test (SPT), ASTM D-1586: provide the best data for determining helical pile requirements. Accurate SPT blow counts (N Values) can be useful for estimating helical pile or tension anchor depth.  It is important to continue the testing to the anticipated depth of the pile.

Helical piles and helical tension anchors can be installed into almost any soil.  For soils with SPT values between 0 & 4, the shaft is considered unsupported and buckling strength needs to be considered.  With SPT values of 5 or high the helical pile has adequate lateral support for it’s full capacity.

Low SPT value soils require more and larger helices on the lead section to develop the  needed axial capacity.  Where blow counts exceed 15 to 25, typical structural loads are typically supported with single, double, or triple helix lead sections. As the blow counts increase smaller helix can be used to achieve the required capacity.  It is difficult to install helical piles or tension anchors where SPT blow counts are greater than 100.

 Other Soil Test Methods: can also be used.  But final installed depths are more likely to  vary from the predicted helical pile design.

Helical Screw Test Probe: A helical pile can be installed to determine depth, capacity, and cost of a helical pile or tension anchor.  A small helix configuration is deliberately used so that it can be installed to a depth deeper than the anticipated pile depth.  Torque is measured at regular intervals to get a complete profile.  From this data the helix configuration can be determined for the targeted installation depth.  The test pile is then removed since they screw out as easily as they screw in.  Therefore, performing a helical screw test probe is fast and relatively inexpensive because all helical steel is removed and there is no permanent site impact.

Contact us and let us help you with your deep foundation design.
Southern Industrial Piling
El Dorado, Arkansas
info@SIPiling.com
870-866-9002

Installers of Helical Foundation & Soil Anchors Systems
Service: Helical piles; helical piers; steel piles; deep foundations;
Areas: Served: Arkansas, Louisiana, Mississippi, Tennessee, Texas, Missouri, Oklahoma
Advantages: Quick service; low mobilization cost; Tight access; Low Clearance
key words:  helical pile; helical piles; Arkansas