Ala. Admin. Code r. 535-X-13-.05 – Soil Classification

The Commission hereby adopts the following soil classifications for the purpose of determining design loads, specifications and holding power of anchors and tiedown devices.

SOIL CLASS	TYPES OF SOILS	BLOW COUNT (ASTM)	TEST PROBE (1) TORQUE VALUE (2)
I	Sound hard rock Very dense and/or cemented........	NA	NA
II	Sands, coarse gravel and cobbles, preloaded silts, clays, and corals..........	40-up	More than 550 lbs.-in.
III	Medium-dense coarse, sands, sandy gravels, very stiff silts and clays.......	24-39	350-549 lbs.-in.
IV	Loose to medium dense sands, firm to stiff clays and silts, alluvian fill...	(3) 14-23	(3) 200-349 lbs.-in.
V	Peat, organic silt, inundate silts, loose fine sand, alluvium, loess, varied clays, fill, fly ash.............	0-14	0-200 lbs.-in.

(1) The test probe is a device for measuring the torque of soils to assist in evaluating the holding capability of the soils in which the anchor is placed. The test probe has a helix on it. The overall length of the helical section is 10.75 in.; the major diameter is 1.25 in.; the minor diameter is 0.81 in.; the pitch is 1.75 in. The shaft must be of suitable length for anchor depth.
(2) A measure synonymous with moment of a force when distributed around the shaft of the test probe.
(3) Below these values a registered professional engineer should be consulted.
(4) A C4 or C5 anchors that has been approved by the Commission must be used unless the soil is tested with a soil test probe or another Commission approved method.

Author: Jim Sloan

Statutory Authority: Code of Ala. 1975, §§24-4A-3, 24-5-31, 24-5-32, 24-6-4.

History: New Rule: Filed June 24, 1993; effective July 29, 1993. Amended: Filed July 27, 2000; effective August 31, 2000; operative October 1, 2000.