TIMBER PILING (INCLUDING TIMBER SHEET PILING)
953-1 General.
Piles shall be of timber which will stand the driving for which they are intended. They shall be sound and solid. Piling cut from southern pine shall contain at least 30% of summer wood. Cypress piles used for purposes other than as foundation piling shall have, at the butt, a diameter of red or black heart of at least 12 inches. Douglas fir used for timber piling shall be Pacific Coast Douglas Fir. Piles shall be cut above the ground swell, shall have a form taper, and shall not vary more than plus or minus 6 inches from the specified length. Specific requirements for timber sheet piles are contained in 953 -6.
953-2 Diameter of Butt and Tip.
For round piles the minimum bu tt diameter shall be 12 inches, measured at a section 3 feet from the end. For piles up to 50 feet in length , the minimum tip diameter shall be 8 inches. For lengths in excess of 50 feet, a graduated reduction in tip diameter at the rate of 1 inch for eac h 10 feet of length in excess of 50 feet will be permitted. This reduction will correspond to 7 inch tips for 60 foot piles and 6 inch tips for 70 foot pile; at which length these allowable reductions shall cease. As an exception to the above, when so show n in the Plans, 7 inch diameter tips on timber piles less than 60 feet in length will be accepted. No piles shall have tips less than 6 inches in diameter. The maximum diameter at the cut -offs shall be 20 inches.
953-3 Straightness Requirements.
A straight line drawn from the center of the butt to the center of the tip shall not, at any point, fall further away from the center of the pile than a distance equal to 1% of the length of the pile. The surface of the pile shall not contain kinks greater than 1 inch in 5 feet, as measured by a straightedge.
953-4 Peeling and Trimming.
The pile shall be peeled soon after cutting. In the operation of removing the bark from the pile, not more than three annual rings of the solid wood shall be removed. All knots sha ll be trimmed close to the body of the pile.
953-5 Permissible Knots and Other Defects.
The diameter of sound knots shall not exceed one -third of the diameter of the pile at the point where the knot occurs. In these Specifications , a sound knot shall be defined as a knot which is solid across its face, is as hard as the surrounding wood and shows no indication of decay. It may vary in color from red to black and may contain a pith hole not more than 1/4 inch in diameter. An unsound knot may or may not be as hard as the surrounding wood, but contains decay, and will be allowed only in accordance with the restrictions in ASTM D25. FY 2023-24 Return to Table of Contents Any defect, or combination of defects, which would be more injurious than the maximum allowable knot will not be acceptable. Turpentine cuts will be allowed on all timber piles provided that no single cut shall exceed one -half of the circumference of the pile, and that the length of the cut shall not be more than 15% of the length of the pile. Piles to be used as outside piles in timber bents shall not have more than one turpentine cut.
953-6 Timber Sheet Piles.
Unless a particular species of timber is called for in the Plans, timber sheet piles may consist of any species which will satisfactorily stand driving. They shall be saw n square and shall be free from worm holes, loose knots, wind shakes, decayed or unsound portions, and other defects which might impair the strength or tightness The piles shall be of the dimensions shown in the Plans and shall be treated in accordance with Section 955. FY 2023-24 Return to Table of Contents SECTION 954 TIMBER FENCE POSTS AND BRACES
954-1 Types of Timber and Treating Requirements.
Timber fence posts and braces shall be of southern yellow pine and shall be treated in accordance with Section 955. Prior to the treatment, all knots on the posts shall be trimmed close to the body of the post.
954-2 Requirements for Cutting.
Round or sawn posts will be permitted but all posts on a single project shall be the same. Sawn post shall comply with AASHTO M 168, have a minimum Fb of 1,350 psi, be grade- stamped by an inspection agency accredited by the American Lumber Standards Committee (ALSC), and shall meet the requirements of 954 -6. Round posts shall be cut from sound and solid trees and shall contain no unsound knots. The butt shall be cut at a sufficient distance above the ground swell of the tree that there will be no abrupt change in cross -section of the post. The butts shall be sawn square. The post tops shall be sawn neatly and at right angles to the vertical axis of the post.
954-3 Knots, etc.
Sound knots will be permitted provided the diameter of the knot does not exceed one- third of the diameter of the piece at the point where it occurs. Peck (in cypress posts) shall be limited as provided for knots; the area of permissible peck not exc eeding the area occupied by permissible knots, and a combination of peck and knots not exceeding the aggregate of knots allowed. The posts shall be free from decayed wood, rot, and red heart, and of ring shake or season checks which penetrate at any point more than one fourth the diameter of the piece, or are greater than 1/4 inch wide.
954-4 Peeling.
All posts shall be peeled for their full length, and all inner and outer bark removed, except that isolated strips of inner bark which do not exceed 1/2 inch in width or 3 inches in length will be permitted.
954-5 Straightness.
The straightness of the post shall be such that for any 8 foot post (or for any 8 feet of length, for longer posts) a straight line from the center of the tip to the center of the but t (or from center of the cross sections at the extremes of the 8 foot lengths) shall not fall outside the center of the mid -section of the 8 foot length by more than 2 inches.
954-6 Dimensions.
954-6.1 Minimum Lengths Allowable :
Line posts - 8 feet. Corner and pull posts - 8 feet, 6 inches. Braces - As required by the Plans. (A tolerance of minus 1 inch to plus 2 inches will be allowed in the lengths shown for the posts.) FY 2023-24 Return to Table of Contents