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ICC-ES Approves Significant Changes to AC358
by Moncef Souissi
HPW Technical Advisor
On June 6th at their meeting held in Los Angeles, the International Code Council Evaluation Services (ICC-ES) approved some significant changes to AC358 – the acceptance criteria for helical piles, systems and devices. The changes had been formerly requested by the Ad Hoc Committee of Helical Pile Manufacturers after many months of meetings and conference calls required to work through differences of opinions and the infinite amount of detail that is required.
The most noticeable changes include:
- Axial capacity verification tests - the axial capacity verification section has now been integrated into the torque correlation section of the AC.
- Multiple helices are now permitted on piles for both the axial capacity compression and tension verification tests.
- Ultimate pile capacity can be determined by the maximum test load instead of the 10% net deflection used previously in the torque correlation tests.
- 12D (12 times the diameter of the largest helix bearing plate) is the minimum depth required for the tension tests. All ESR certifications will require a registered design professional to sign off on any helical pile tension installations that are less than 12D.
The revised AC358 text will be available in about a month according to ICC-ES officials.