ASTM D2899-12(2017)

Standard Practice for Establishing Allowable Stresses for Round Timber Piles

SIGNIFICANCE AND USE
4.1 This practice is intended for use by associations, technical societies and other groups that develop national design standards and use recommendations for round timber piles.  
4.2 In using allowable stresses established under this practice, factors specific to each end use which may affect the performance of the pile system shall be considered. Such factors include the location of the critical section, the bearing capacity of the soil, the ability of the pile to withstand driving forces and conditions of service.
SCOPE
1.1 This practice contains procedures for establishing allowable stresses for round timber piles starting with clear wood strength properties.  
1.2 Stresses established under this practice are applicable to piles conforming to the quality, straightness, spiral grain, knot, check, shake, and split provisions of Specification D25.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Sep-2017
• ICS: 79.080 - Semi-manufactures of timber
• Technical Committee: D07 - Wood
• Drafting Committee: D07.04 - Pole and Pile Products

Relations

• Replaces: ASTM D2899-12 - Standard Practice for Establishing Allowable Stresses for Round Timber Piles
• Effective Date: 01-Oct-2017
• Refers: ASTM D2555-17a(2024)e1 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Feb-2024
• Refers: ASTM D2555-17a(2024) - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Feb-2024
• Refers: ASTM D2555-17a - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Aug-2017
• Refers: ASTM D2555-17 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 15-Apr-2017
• Refers: ASTM D2555-16 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Aug-2016
• Refers: ASTM D2555-15 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Sep-2015
• Refers: ASTM D25-12 - Standard Specification for Round Timber Piles
• Effective Date: 01-May-2012
• Refers: ASTM D245-06(2011) - Standard Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber
• Effective Date: 01-Oct-2011
• Refers: ASTM D2555-06(2011) - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Oct-2011
• Refers: ASTM D2555-06 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Mar-2006
• Refers: ASTM D245-06 - Standard Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber
• Effective Date: 01-Mar-2006
• Refers: ASTM D25-99(2005) - Standard Specification for Round Timber Piles
• Effective Date: 01-Oct-2005
• Refers: ASTM D2555-05a - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-Oct-2005
• Refers: ASTM D2555-05 - Standard Practice for Establishing Clear Wood Strength Values
• Effective Date: 01-May-2005

Overview

ASTM D2899-12(2017): Standard Practice for Establishing Allowable Stresses for Round Timber Piles sets forth procedures for determining allowable stress values for round timber piles based on the clear wood strength properties of the species in question. This practice is an essential reference for associations, technical societies, and engineering professionals involved in developing national design standards or recommendations for timber piling systems. It outlines a comprehensive approach to adjust base strength values to reflect the practical realities of pile quality, material variability, service conditions, treatment processes, and end-use factors.

Key Topics

• Establishing Allowable Stresses: The standard describes methods to derive allowable stress values from clear wood properties, considering factors such as duration of load, grade characteristics, density, form, and size adjustments.
• Species and Quality Considerations: Applies to any timber species with established clear wood values under ASTM D2555, and requires conformity to quality and grading specifications as per ASTM D25.
• Adjustment Factors: Key adjustment factors are used for:
  • Duration of load and safety factor
  • Grade characteristics (knots, checks, splits, shakes)
  • Density (especially for Douglas fir and southern pine)
  • Pile diameter and cross-sectional form
  • Service conditions (wet or exposed environments)
• Load Sharing in Pile Groups: Recognizes the increased reliability achieved when piles act as a group, requiring further adjustments to stress values.
• Moisture and Treatment Effects: Specifies that allowable stresses account for piles in wet or weather-exposed conditions, with adjustments for certain treatments or conditioning.

Applications

The standard is primarily applied in the design, assessment, and specification of round timber piles used for load-bearing foundations in civil engineering projects. Key applications include:

• Bridge and Wharf Construction: Ensures adequate load-carrying capacities for piles supporting heavy structures.
• Marine and Coastal Works: Accommodates the demands of consistently wet service environments.
• Building Foundations: Provides a robust basis for engineers specifying timber foundation systems in various climatic regions.
• Pile Replacement or Rehabilitation Projects: Used to verify the suitability of in-situ piles or to specify replacements that meet performance expectations.
• Engineering Calculations: Supports structural analysis through defined allowable stresses for bending, shear, compression, and modulus of elasticity.

Related Standards

• ASTM D25 – Specification for Round Timber Piles: Specifies requirements for quality, straightness, grain orientation, and permissible defects in pile timber.
• ASTM D245 – Practice for Establishing Structural Grades and Related Allowable Properties for Visually Graded Lumber: References methods for determining grading and property adjustments for timber.
• ASTM D2555 – Practice for Establishing Clear Wood Strength Values: Provides baseline strength properties of wood species used in pile stress determination.

Practical Value

ASTM D2899-12(2017) is a cornerstone for projects employing timber piles by ensuring that designs account for material variability, service environment, and load demands, improving both safety and reliability. It assists engineers and organizations in harmonizing design practices with recognized international principles and addressing critical factors such as soil bearing capacity, driving stresses, timber grading, and long-term durability.

By following this standard, practitioners can confidently establish allowable stresses for round timber piles, facilitating compliance with broader building codes and quality assurance requirements on foundation design projects worldwide.

Keywords: ASTM D2899, allowable stresses, round timber piles, wood strength, pile design, foundation engineering, wood treatment, timber grading, civil engineering standards.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D2899 − 12 (Reapproved 2017)
Standard Practice for
Establishing Allowable Stresses for Round Timber Piles
This standard is issued under the fixed designation D2899; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.3 load sharing—the distribution of load in proportion to
pile stiffness. This results in piles that perform as a group
1.1 Thispracticecontainsproceduresforestablishingallow-
reducing effects of between-pile variability and increasing
able stresses for round timber piles starting with clear wood
system reliability over that of piles which perform indepen-
strength properties.
dently.
1.2 Stresses established under this practice are applicable to
3.1.4 skin friction—the interaction between the pile surface
piles conforming to the quality, straightness, spiral grain, knot,
and the soil which serves to distribute load either away from or
check, shake, and split provisions of Specification D25.
into a pile. A positive skin friction refers to pile loads
1.3 This standard does not purport to address all of the
distributed to the soil. Negative skin friction distributes load to
safety concerns, if any, associated with its use. It is the
the pile when soil strata subside or consolidate.
responsibility of the user of this standard to establish appro-
3.2 Symbols: C = adjustment for small clear compression
cp
priate safety, health, and environmental practices and deter-
perp for annual ring orientation (1/1.67)
mine the applicability of regulatory limitations prior to use.
C = conditioning factor
ct
1.4 This international standard was developed in accor-
C = adjustment for duration of load and factor of safety
dance with internationally recognized principles on standard- dol
C = adjustment for density applied for Douglas fir and
ization established in the Decision on Principles for the d
Southern pine only
Development of International Standards, Guides and Recom-
C = combined adjustment for form and size (= 0.97)
mendations issued by the World Trade Organization Technical fs
C = adjustment for grade characteristics applied to all
Barriers to Trade (TBT) Committee.
g
species including bending (0.75), compression (0.93), and
shear (0.50)
2. Referenced Documents
2 C = adjustment for height in the tree (= 0.96 if softwoods
h
2.1 ASTM Standards:
and = 1.0 for hardwoods)
D25 Specification for Round Timber Piles
C = adjustment for height and for reduced variability
hv
D245 Practice for Establishing Structural Grades and Re-
(MOR = 0.91forsoftwoods,1.05forhardwoods, C// = 0.91for
lated Allowable Properties for Visually Graded Lumber
softwoods, 1.05 for hardwoods, Shear = 0.99 for softwoods,
D2555 PracticeforEstablishingClearWoodStrengthValues
1.03 for hardwoods)
C = load sharing adjustment (structural engineers option)
ls
3. Terminology
C = size adjustment
s
3.1 Definitions:
C = adjustment for shear deflection in calculation for bend-
v
3.1.1 allowable stress—the numeric value of pile strength
ing modulus of elasticity (= 1.06)
that is appropriate for use in structural analysis.
D = diameter of a round timber pile
3.1.2 end-bearing—compression-parallel-to-the-grain stress
E = clear wood unseasoned average modulus of elasticity
resulting when pile load is not carried to the soil through skin
from Test Methods D2555
friction.
MOE = modulus of elasticity (average)
F = allowable stress for stress designated by the subscript β
β
F = allowable compression stress for pile tips
c
This practice is under the jurisdiction of ASTM Committee D07 on Wood and
f = small clear lower 5 % exclusion compression strength
c05
is the direct responsibility of Subcommittee D07.04 on Pole and Pile Products.
in accordance with Test Methods D2555
Current edition approved Oct. 1, 2017. Published October 2017. Originally
f = lower 5 % exclusion value for stress “x” determined
approved in 1970 as D2899 – 70 T. Last previous edition approved in 2012 as
i05
D2899 – 12. DOI: 10.1520/D2899-12R17.
using the green, small clear strength and standard deviation
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
values reported in Test Methods D2555
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
β = stress value subscripts, c = compression parallel,
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. cp = compression perpendicular, b = bending, v = shear
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2899 − 12 (2017)
4. Significance and Use 7.2 For round timber piles, only the between tree compo-
nent of variance is applicable. Clear wood 5 % exclusion
4.1 This practice is intended for use by associations, tech-
values applied to piles are adjusted to account for this reduced
nical societies and other groups that develop national design
variability.
standards and use recommendations for round timber piles.
4.2 In using allowable stresses established under this
8. Minimum Tip and Critical Section Properties
practice, factors specific to each end use which may affect the
8.1 Average clear wood properties given in Test Methods
performance of the pile system shall be considered. Such
D2555 represent volume weighted average whole tree values
factors include the location of the critical section, the bearing
where the average property is that associated with material
capacity of the soil, the ability of the pile to withstand driving
occurringbetweenheightsof8and16ft.Forsoftwoodspecies,
forces and conditions of service.
clear wood strength properties generally decrease as the height
PRINCIPLES INVOLVED IN ESTABLISHING
location in the tree increases.
ALLOWABLE STRESSES
8.2 Forcompressionparalleltograin,theminimumstrength
of the pile occurs at the pile tip, or at a minimum diameter of
5. Species
5 in. For bending and shear strengths, the critical section of the
5.1 This practice applies to any species of piles for which
pile is assumed to occur at a point 10 ft above the pile tip. In
clear wood strength values are given in Test Methods D2555.
terms of location in the tree, both of these sections occur at
heights in the tree which are appreciably greater than the
5.2 Where pile allowable stress is to be established for a
heights associated with the whole tree average property values.
combination of species and or regions, clear wood values
Therefore clear wood average properties obtained from Test
assigned to such combinations are based on the grouping
Methods D2555 must be reduced to account for this height
criteria given in Section 5 of Test Methods D2555.
effect when establishing compression parallel to grain,
bending, shear and modulus of elasticity design stresses for
6. Clear Wood Properties
piles made with softwood species.
6.1 Information on average properties and their variation
given in Test Methods D2555 apply to small, clear, straight-
9. Density
grained wood in the green condition under short-term loading.
9.1 Specification D25 requires the outer 50 % of the radius
6.2 Round timber piles having minimum tip diameters of 5
at the pile tip to have an average rate of growth of at least 6
in. or larger are considered by this practice to be comparable to
rings per inch and an average summerwood content of not less
sawn timbers: General adjustment factors used to establish
than33.3 %.Pileswithlessthan6ringsperinchareacceptable
allowable stress for such timbers under Practice D245 also are
if the average summerwood content in the outer 50 % of the
applied to piles.
pile tip radius is 50 % or more.
6.3 For the properties of bending strength (modulus of
9.2 Practice D245 provides for the classification of Douglas
rupture), compression strength parallel to the grain and hori-
fir and southern pine sawn lumber meeting growth rate and
zontal shear strength, clear-wood 5 % -exclusion values calcu-
summerwood content requirements similar to those in Speci-
lated from Test Methods D2555 are divided by the adjustment
fication D25 as dense material. The properties of such lumber,
factors given in Table 10 of Practice D245 to obtain basic
exceptshear,areincreasedtoaccountfortheincreasedstrength
values for these properties from which pile allowable stress is
and stiffness associated with limiting the occurrence of low
established. The adjustment factors for the three strength
density material.
properties include a reduction for normal duration of load and
a factor of safety.
9.3 Increases for density applicable to Douglas fir and
southern pine lumber also are applicable to piles of the same
6.4 For the properties of modulus of elasticity and compres-
species. The increase for density in compression parallel to
sion perpendicular to grain at 0.04-in. deformation, clear wood
grain applicable to lumber must be adjusted when applied to
average values from Test Methods D2555 are divided by the
piles to account for the inner core of the pile tip that is not
adjustment factors for these properties given in Table 10 of
required to meet the density provisions.
PracticeD245toobtainbasicvaluesfromwhichpileallowable
stress for these properties also are established. The modulus of
10. Form and Size
elasticity factor is a shear deflection adjustment. The compres-
sion perpendicular to grain factor is an adjustment to account
10.1 The average bending strength of round wood sections
for limiting ring position.
based on standard beam formulas is greater than that of
matchedrectangularsections.However,thesectionmodulusof
7. Pile Variability
a round beam is less (1/1.18) than that of a square beam of
7.1 Standard deviations given in Test Methods D2555 and equivalent area by approximately the same ratio as the strength
used to calculate 5 % exclusion values include both variability of the round member is greater than that of the rectangular
in properties between trees and variability in properties occur- member.Roundmembersthereforeareassigned aunitstrength
ring within the cross section and along the length of an equal to 1.18 times that based on rectangular sections when the
individual tree. section modulus of the circular cross section is used.
D2899 − 12 (2017)
10.2 Clear wood bending stresses in Test Methods D2555 for round timber piles established under this practice are
are based on tests of 2-in. deep rectangular sections. Under short-term test values reduced to a normal load duration basis.
Practice D245, such values are adjusted for depth (d) by the Normal load duration represents application of a load that fully
1/9
factor (2/d) when applied to sawn lumber members. Based stresses a member to its design stress for a cumulative duration
on a circular section having an area equal to that of a square of approximately 10 years.
section, the equivalent depth adjustment for a round member is
12.2 When the cumulative duration of the full maximum
1/9
(2.2568/D) .
load is less than or more than ten years, pile allowable stress
10.3 Under standard practice, bending allowable stress for for bending, compression parallel to grain and horizontal shear
beams and stringers and post and timbers are given for a 12-in. shall be modified in accordance with the duration of load
beam depth. Values for beams exceeding 12 in. are reduced adjustments shown in Fig. 6 of Practice D245. Load duration
using the 1/9 power equation. The same practice is employed adjustments greater than 1.6 shall not apply to piles preserva-
with round timber piles. Pile bending stresses are indexed to tively treated with water-borne salts.
the diameter of a circular section having an area equal to that
12.3 Duration of load adjustments are not applied to pile
of a 12-in. square, or 13.5 in. Clear wood bending values are
allowable stress for modulus of elasticity and compression
adjusted to a 13.5-in. pile diameter by the factor 0.82.
perpendicular to grain based on a deformation limit.
11. Grade
13. Moisture Content
11.1 Knots in round piles reduce compression parallel to
13.1 Allowable stress established by this practice applies to
grain and bending strength properties. Limits on allowable size
piles that are continuously wet or are continuously exposed to
and spacing of knots along the pile length are given in
the weather.
Specification D25.
13.2 No increase in proper
...