1、Designation: D7989 15Standard Practice forDemonstrating Equivalent In-Plane Lateral SeismicPerformance to Wood-Frame Shear Walls Sheathed withWood Structural Panels1This standard is issued under the fixed designation D7989; the number immediately following the designation indicates the year oforigin
2、al adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice establishes a method for alternative shearwall syst
3、ems to compare seismic equivalency parameters(SEP) derived from cyclic in-plane racking tests to perfor-mance targets derived from tests of light-frame shear wallsconstructed with wood structural panel (WSP) sheathing at-tached to dimension lumber framing using nails.1.2 This practice considers only
4、 the performance of shearwalls subject to cyclic lateral loading, parallel to the plane ofthe shear wall. Design of walls with openings and performancefor other wall functions, such as out-of-plane bending, com-bined shear and uplift, etc. are not considered.1.3 This practice is applicable only to s
5、hear walls where allvertical-load-supporting elements are intact at the end of thein-plane lateral load test and remain capable of supportinggravity loads. Wall assemblies whose vertical-load-supportingelements buckle or otherwise become incapable of supportinggravity loads during the lateral load t
6、est are outside the scopeof this practice. In addition, for bearing wall systems, thispractice assumes that the shear wall system under evaluationhas documented design procedures to ensure that vertical-load-supporting elements have adequate resistance to the combinedeffect of compression loads caus
7、ed by overturning and gravityloads.1.4 This practice does not address height limitations, detail-ing requirements, wall openings, derivation of design valuesfor strength and stiffness, or other requirements and limitationsthat may be necessary for an alternative shear wall system.These requirements
8、shall be provided elsewhere, such as by asuitable product standard for the alternative shear wall system.1.5 This practice assumes that the stiffness or deformationof the alternative shear wall system can be estimated, and thatdesign loads within a structure will be distributed amongseismically equi
9、valent wall systems based on their relativestiffness.1.6 This practice is not intended to preclude other rationalmeans of evaluating seismic performance.1.7 This practice assumes that the alternative shear wallsystem may be used alone or in combination with wood-frameshear walls sheathed with wood s
10、tructural panels.1.8 UnitsThe values stated in inch-pound units are to beregarded as standard. The values given in parentheses aremathematical conversions to SI units that are provided forinformation only and are not considered standard.1.9 This standard does not purport to address all of thesafety
11、concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E2126 Test Methods for Cyclic (Reve
12、rsed) Load Test forShear Resistance of Vertical Elements of the Lateral ForceResisting Systems for BuildingsF1667 Specification for Driven Fasteners: Nails, Spikes, andStaples2.2 Other Documents:PS1-09 Structural Plywood, U.S. Department of CommerceVoluntary Product StandardPS2-10 Performance Standa
13、rd for Wood-Based StructuralUse Panels, U.S. Department of Commerce VoluntaryProduct Standard3. Terminology3.1 DefinitionsThe definitions in Test Methods E2126also apply to this practice.3.2 Definitions Specific to this Practice:3.2.1 aspect ratio, nratio of a shear walls height dividedby its length
14、.1This test method is under the jurisdiction of ASTM Committee D07 on Woodand is the direct responsibility of Subcommittee D07.05 on Wood Assemblies.Current edition approved Dec. 1, 2015. Published February 2016. DOI: 10.1520/D7989-15.2For referenced ASTM standards, visit the ASTM website, www.astm.
15、org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.2.2 allowa
16、ble design load, nmaximum in-plane rackingresistance assigned to a tested shear wall configuration forseismic design using an allowable stress design methodology.3.2.3 alternative shear wall system, nshear wall systemseeking to establish seismic equivalence to the reference shearwall system.3.2.3.1
17、DiscussionThe alternative shear wall system mayrepresent a range of possibilities including pre-fabricated orfield-fabricated wall assemblies that do not resemble thereference shear wall system or assemblies with minor modifi-cations to the reference system, such as the use of alternativefasteners,
18、framing, or sheathing.3.2.4 component overstrength, nratio of peak load dividedby allowable design load.3.2.5 drift capacity, nultimate cyclic displacement on theaverage envelope curve defined in Test Methods E2126 corre-sponding to the failure limit state.3.2.6 ductility, nratio of drift capacity d
19、ivided by thedisplacement on the average envelope curve defined in TestMethods E2126 corresponding to the allowable design load.3.2.7 peak load, nmaximum load on the average envelopecurve defined in Test Methods E2126.3.2.8 reference shear wall system, nwood-frame shearwall system used for the equiv
20、alence benchmark, consisting ofwood structural panel sheathing attached to dimension lumberframing using 6d, 8d, or 10d common or box nails, with fullround heads, complying with Specification F1667, Section S1,Table S1.1, and Specification F1667, Table 6 or Table 15.3.2.8.1 DiscussionTable X1.1 prov
21、ides summary informa-tion for the walls evaluated to represent the reference shearwall system.3.2.9 seismic equivalence parameters (SEP), nkey param-eters representing seismic performance of shear walls, specifi-cally drift capacity, component overstrength, ductility, andmaintenance of vertical-load
22、-supporting capability.3.2.10 shear wall, nwall designed to resist lateral rackingshear forces parallel to the plane of the wall.3.2.11 shear wall configuration, nshear wall of a specificheight and length representing one possible case of a shear wallsystem and consisting of a specific arrangement o
23、fcomponents, such as framing, fasteners, sheathing, and anchor-age.3.2.12 wood structural panel (WSP)panel manufacturedin accordance with PS1 or PS2 from veneers; wood strands orwafers; or a combination of veneer and wood strands or wafers;bonded together with waterproof resins or other suitablebond
24、ing systems.4. Summary of Practice4.1 Shear walls are tested in accordance with Test MethodsE2126, and the average envelope curve is generated for eachspecimen as defined in 3.2.4 of Test Methods E2126.4.2 SEPs are determined from the average envelope curvefor each specimen, and the average SEPs for
25、 each tested shearwall configuration are compared to the benchmark parameters.4.3 Seismic equivalency is established if each of the SEPsfor the alternative shear wall system meets specified require-ments and the vertical-load-supporting elements are intact andcapable of supporting gravity loads.5. S
26、ignificance and Use5.1 This practice documents cyclic performance bench-marks for shear walls constructed with wood structural panel(WSP) sheathing attached to dimension lumber framing usingcommon or box nails as defined in 3.2.8.5.2 Procedures described in this practice provide a methodto evaluate
27、an alternative shear wall systems SEPs to demon-strate equivalent in-plane lateral seismic performance to thereference shear wall system.5.3 The procedures described in this practice do not addressall factors to be considered for recognition of an alternativeshear wall system. Such factors, as descr
28、ibed in 1.4, vary by theend-use application and shall be addressed outside the scope ofthis standard through an evaluation of the acceptability of thealternative shear wall system in accordance with requirementsof building codes and standards, as applicable.6. Testing Requirements6.1 Test Program De
29、signThe test program used to evalu-ate the alternative shear wall system shall be based onconsideration of the range of intended applications and vari-ables that have a potential impact on the seismic performance.Variables may include, but are not limited to, allowable designloads, configuration opt
30、ions, material variations, fastenerspacings, and aspect ratios.6.2 Number of TestsFor each tested shear wallconfiguration, the number of replicates shall be as required in8.1 of Test Methods E2126 or as required by the applicableproduct standard.6.3 LoadingCyclic lateral load tests shall be conducte
31、dusing Method C from Test Methods E2126.6.3.1 Load BeamThe load beam used to apply load to thetest assembly shall comply with 7.3 of Test Methods E2126.6.4 Rigid BaseTesting shall be conducted on a rigid base,such that the performance of the test specimens is not influ-enced by deformation of the ba
32、se structure. The specimensshall be anchored directly to the base and shall be in fullcontact with the base.6.5 Test Specimen ConstructionSpecimens shall be con-structed using details consistent with the intended application.Sheathing, if present, shall not bear on any portion of the testfixture or
33、the loading beam during the tests, except where thespecified end-use installation requires the sheathing to bear onsupporting elements, such as foundations or sill plates. Ifbearing on a wood sill plate is specified in application, a similarwood sill plate shall be included in the tested assembly.6.
34、5.1 Aspect RatiosAspect ratios and wall dimensionsshall be consistent with the intended application.6.5.1.1 Alternative shear wall systems that are similar to thereference system (i.e., repetitive vertical stud framing spaced at24 in. on center or less with structural sheathing nailed toD7989 152fra
35、ming), except for variations in framing materials, sheathingmaterials, or fasteners, shall be evaluated using an aspect ratioof 1:1 and a minimum wall height of 8 ft (2.4 m).6.5.1.2 Alternative shear wall systems that vary more sig-nificantly from the reference system described in 6.5.1.1 shallbe ev
36、aluated using the range of aspect ratios for the intendedapplication.6.5.2 Sheathing JointsAlternative shear wall systems thatwill include discrete sheathing panels shall include at least onevertical sheathing joint if such joints will occur in application.Test specimens may include horizontal sheat
37、hing joints asnecessary, such as where specimen heights exceed panel heightor where sheathing is intended to be installed with the longdimension perpendicular to the longitudinal axis of the studs.6.5.3 FramingWhere applicable, the stud and platematerial, species, grade, size, and spacing shall be r
38、epresenta-tive of that used in application. Framing shall meet therequirements of 6.3 in Test Methods E2126.6.5.3.1 For alternative systems described in 6.5.1.1, framingwith the smallest standard stud and plate cross sectionsexpected in application shall be used, and the smallest numberof end post s
39、tuds that can practically be employed in accor-dance with standard design provisions shall be used.6.5.4 Anchorage and Framing ConnectionsShearanchorage, overturning restraint, and framing connections,including connections between individual plies of built-upposts, shall be representative of connect
40、ions used in applicationand shall be designed and detailed to balance the designresistance of the connections to the design load of the shearwall.6.5.5 Sheathing ConnectionsWhere sheathing attached toframing is used to resist lateral loads, the sheathing fastenersshall be installed using the minimum
41、 edge distance recom-mended by the sheathing manufacturer along all four sheathingedges. The number of fasteners installed along each edge shallbe equal to the length of the sheathing edge divided by thespecified fastener spacing, plus one. Spacing between thesheathing corner fastener and the next a
42、djacent fastener ispermitted to be less than the recommended spacing to accom-modate the required edge distance. Sheathing fasteners placedin the field of the panel, if any, shall be positioned as requiredby the design. Sheathing fasteners shall be driven so that thehead of the fastener contacts the
43、 surface of the sheathing, butnot so deep as to crush the surface, unless specified differentlyby the manufacturer.7. Evaluation of Cyclic Response7.1 Average Envelope CurveThe average envelope curveshall be generated for each test specimen as defined in 3.2.4 ofTest Methods E2126.7.2 SEP Determinat
44、ionThe component overstrength, driftcapacity, and ductility shall be determined for each specimenas defined in 3.2. The average values calculated for allreplicates of a tested shear wall configuration shall be the SEPsfor the alternative shear wall configuration. The results ofmultiple shear wall co
45、nfigurations shall not be averaged orotherwise combined for the evaluation.7.3 Assessment of Vertical-Load-Supporting ElementsThecondition of the vertical-load-supporting elements shall bevisually assessed to qualitatively determine whether the capa-bility to support gravity loads is retained.NOTE 1
46、Visual assessment of vertical-load-supporting elements relieson examination during and after the test for observation of occurrence ofbuckling of the vertical-load-supporting elements. For wood-frame wallsthat comprise the reference shear wall system, the lack of observedbuckling of the studs and en
47、d posts has been used as visual confirmationof retained ability to support gravity loads.8. Requirements for Equivalency8.1 Table 1 provides the SEP performance targets based ontests of the reference shear wall system conducted in accor-dance with Method C of Test Methods E2126.8.2 Seismic equivalen
48、cy is established if the SEPs for thealternative shear wall system meet requirements specified inTable 1 and if the vertical-load-supporting elements are judgedto retain capability to support gravity loads.9. Keywords9.1 cyclic loads; earthquake, shear wall; lateral force; seis-mic; wood structural
49、panel;D7989 153APPENDIX(Nonmandatory Information)X1. COMMENTARYX1.1 IntroductionX1.1.1 Shear walls constructed with wood structural panels(WSP) fastened to sawn lumber framing with common or boxnails are widely used in construction. This system serves as thereference shear wall construction for this practice. Whensubjected to cyclic loads, this reference system demonstratesdesirable ductile yield modes with significant drift capacity,ductility, and overstrength. The seismic design provisions forengineered light-frame wood construction in North Americ
