1、Designation: D4015 151Standard Test Methods forModulus and Damping of Soils by Fixed-Base ResonantColumn Devices1This standard is issued under the fixed designation D4015; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、 last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEEditorially corrected Eq 28 in February 2017.1. Scope*1.1 These test methods cover the determination of shearmodulus and she
3、ar damping as a function of shear strainamplitude for solid cylindrical specimens of soil in intact andremolded conditions by vibration using resonant column de-vices. The vibration of the specimen may be superposed on acontrolled static state of stress in the specimen. The vibrationapparatus and sp
4、ecimen may be enclosed in a triaxial chamberand subjected to an all-around pressure and axial load. Inaddition, the specimen may be subjected to other controlledconditions (for example, pore-water pressure, degree ofsaturation, temperature). These test methods of modulus anddamping determination are
5、 considered nondestructive when theshear strain amplitudes of vibration are less than 102%(104in. in.), and many measurements may be made on thesame specimen and with various states of static stress.1.2 Two device configurations are covered by these testmethods: Device Type 1 where a known torque is
6、 applied to thetop of the specimen and the resulting rotational motion ismeasured at the top of the specimen, and Device Type 2 wherean uncalibrated torque is applied to the top of the specimen andthe torque transmitted through the specimen is measured by atorque transducer at the base of the specim
7、en. For both devices,the torque is applied to the active end (usually top) of thespecimen and the rotational motion also is measured at theactive end of the specimen.1.3 These test methods are limited to the determination ofthe shear modulus and shear damping, the necessary vibration,and specimen pr
8、eparation procedures related to the vibration,etc., and do not cover the application, measurement, or controlof the axial and lateral static normal stresses. The latterprocedures may be covered by, but are not limited to, TestMethod D2850, D3999/D3999M, D4767, D5311/D5311M,orD7181.1.4 Significant Di
9、gitsAll recorded and calculated valuesshall conform to the guide for significant digits and roundingestablished in Practice D6026.1.4.1 The procedures used to specify how data are collected/recorded and calculated in this standard are regarded as theindustry standard. In addition, they are represent
10、ative of thesignificant digits that should generally be retained. The proce-dures used do not consider material variation, purpose forobtaining the data, special purpose studies, or any consider-ations for the users objectives; and it is common practice toincrease or reduce significant digits of rep
11、orted data to becommensurate with these considerations. It is beyond the scopeof this standard to consider significant digits used in analysismethods for engineering design.1.4.2 Measurements made to more significant digits orbetter sensitivity than specified in this standard shall not beregarded a
12、nonconformance with this standard.1.5 UnitsThe values stated in SI units are to be regardedas standard. The values given in parentheses are mathematicalconversions to inch-pound units, which are provided forinformation only and are not considered standard. Reporting oftest results in units other tha
13、n SI shall not be regarded asnonconformance with these test methods.1.5.1 The converted inch-pound units use the gravitationalsystem of units. In this system, the pound (lbf) represents a unitof force (weight), while the unit for mass is slugs. Theconverted slug unit is not given, unless dynamic (F
14、= ma)calculations are involved.1.5.2 It is common practice in the engineering/constructionprofession to concurrently use pounds to represent both a unitof mass (lbm) and of force (lbf). This implicitly combines twoseparate systems of units; that is, the absolute system and thegravitational system. I
15、t is scientifically undesirable to combinethe use of two separate sets of inch-pound units within a singlestandard. As stated, this standard includes the gravitationalsystem of inch-pound units and does not use/present the slugunit for mass. However, the use of balances or scales recordingpounds of
16、mass (lbm) or recording density in lbm/ft3shall notbe regarded as nonconformance with this standard.1These test methods are under the jurisdiction of ASTM Committee D18 on Soiland Rock and are the direct responsibility of Subcommittee D18.09 on Cyclic andDynamic Properties of Soils.Current edition a
17、pproved Oct. 1, 2015. Published November 2015. Originallyapproved in 1981. Last previous edition approved in 2007 as D4015 07. DOI:10.1520/D4015-15E01.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
18、 PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organizatio
19、n Technical Barriers to Trade (TBT) Committee.11.6 This standard does not purport to address all of thesafety 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 regu
20、latory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD2166/D2166M Test Method for Unconfined CompressiveStrength of Cohesive SoilD2216 Test Methods for Laboratory Determination of Water(Moisture) Content of Soil and Ro
21、ck by MassD2850 Test Method for Unconsolidated-Undrained TriaxialCompression Test on Cohesive SoilsD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD3999/D3999M Test Methods for the Determination of
22、 theModulus and Damping Properties of Soils Using theCyclic Triaxial ApparatusD4753 Guide for Evaluating, Selecting, and Specifying Bal-ances and Standard Masses for Use in Soil, Rock, andConstruction Materials TestingD4767 Test Method for Consolidated Undrained TriaxialCompression Test for Cohesive
23、 SoilsD5311/D5311M Test Method for Load Controlled CyclicTriaxial Strength of SoilD6026 Practice for Using Significant Digits in GeotechnicalDataD7181 Test Method for Consolidated Drained Triaxial Com-pression Test for Soils3. Terminology3.1 DefinitionsFor definitions of other terms used in thesetes
24、t methods, see Terminology D653.3.2 Definitions of Terms Specific to This Standard:3.2.1 damping capacity D unitless, typically expressed in%, nin resonant column systems, is related to the componentof the dynamic shear modulus that lags the applied shear stressby 90 degrees.3.2.2 Device Type 1, DT1
25、, nin resonant column systems,aresonant column system as shown in Fig. 1 where the passiveend platen is directly connected to the Fixed Base (no torquetransducer), a calibrated vibratory torque is applied to theactive end, and rotation is measured at the active end.3.2.2.1 DiscussionThe vibration ex
26、citation device mayincorporate springs and dashpots connected to the active-endplaten, where the spring constants and viscous damping coef-ficients must be known. The rotational inertia of the active-endplaten and portions of the vibration excitation device movingwith it must be known.3.2.3 Device T
27、ype 2, DT2, nin resonant column systems,aresonant column system as shown in Fig. 1 where the passiveend platen is connected to a torque transducer, an uncalibrated2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book
28、 of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.For Device Type 1, no torque transducer is needed and the Passive End Platen is connected to the Fixed Base.FIG. 1 Resonant-Column Schematic for Both Device Types 1 and 2D4015 1512torque is applied
29、to the active end, torque is measured by thetorque transducer at the passive end, and rotation is measuredat the active end.3.2.3.1 DiscussionThe vibration excitation device mayincorporate springs and dashpots connected to the active-endplaten, but the spring constants and viscous damping coeffi-cie
30、nts are not needed. The rotational inertia of the active-endplaten and portions of the vibration excitation device movingwith it also are not needed.3.2.4 dynamic shear modulus, G* FL-2, nin resonantcolumn systems, is the ratio of shear stress to shear strain undervibratory conditions (also known as
31、 complex shear modulus).3.2.5 equivalent elastic shear modulus G FL-2, ninresonant column systems, is the component of the dynamicshear modulus that is in-phase with the applied shear stress.3.2.6 resonant-column system, na system as shown in Fig.1 consisting of a cylindrical specimen or column of s
32、oilenclosed with a flexible membrane that has platens attached toeach end and where a sinusoidal vibration excitation device isattached to the active-end platen and where the other end is thepassive-end platen that is rigidly fixed.3.2.7 specimen shear strain , unitless, frequently ex-pressed as %,n
33、in resonant column systems, is the averageshear strain in the specimen where the shear strain in each crosssection varies from zero along the axis of rotation to amaximum at the perimeter of the specimen.3.2.7.1 DiscussionThe radius for calculating averageshear strains vary depending on soil type, s
34、train level, confin-ing stress, etc. The default value of the radius for calculatingaverage strain is 0.4*diameter but values in the range of 0.33to 0.40*diameter may be used if the value is documented in thereport.3.2.8 system resonant frequency frs-1, nin resonant col-umn systems, for Device Type
35、1 is the lowest frequency atwhich the rotational velocity at the active end is in phase withthe sinusoidal excitation torque and for Device Type 2, is thelowest frequency at which the rotational motion at the activeend is a maximum.4. Summary of Test Method4.1 The resonant column device is shown sch
36、ematically inFig. 1. In the resonant column test, a cylindrical soil specimen,usually enclosed with a thin membrane, is subjected to animposed static axial and lateral stress condition. Torsionalsinusoidal vibrations are applied at the top of the soil specimenand the rotational response is measured.
37、 The frequency ofexcitation is varied until the system resonant frequency isachieved as described in 3.2.8. Given the geometry, mass andsystem parameters, the equivalent elastic shear modulus anddamping capacity can be determined at a measured level ofexcitation vibration. The amplitude of vibration
38、 (which isrelated to shear strain) is typically varied to measure thevariation of modulus and damping as a function of shear strain.The test is usually conducted at levels of shear strain between0.00001 % and 0.2 %. (The upper limit of shear strain isdependent on the specimen stiffness and the maxim
39、um torquecapability of the excitation system.) For specimens where themaximum shear strain measured is of the order of 0.01 %, thetest is often conducted at several different sets of static axialand lateral stress conditions to measure the variation of moduliand damping with static stress states. Th
40、e test results aredependent on sample quality/specimen disturbance which arebeyond the scope of this standard.5. Significance and Use5.1 The equivalent elastic shear modulus and dampingcapacity of a given soil, as measured by the resonant columntechnique herein described, depend upon the strain ampl
41、itudeof vibration, the state of effective stress, and the void ratio ofthe soil, temperature, time, etc. Since the application andcontrol of the static axial and lateral stresses and the void ratioare not prescribed in these methods, the applicability of theresults to field conditions will depend on
42、 the degree to whichthe application and control of the static axial and lateralstresses and the void ratio, as well as other parameters such assoil structure, duplicate field conditions. The techniques usedto simulate field conditions depend on many factors and it is upto the engineer to decide on w
43、hich techniques apply to a givensituation and soil type. The results of these tests are useful forcalculations involving soil-structure interaction and seismicresponse of soil deposits.NOTE 1The quality of the results produced by this standard isdependent on the competence of the personnel performin
44、g it, and thesuitability of the equipment and facilities. Agencies that meet the criteriaof Practice D3740 are generally considered capable of competent andobjective testing/sampling/inspection/etc. Users of this standard are cau-tioned that compliance with Practice D3740 does not in itself assurere
45、liable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.6. Apparatus6.1 GeneralThe complete test apparatus is shown sche-matically in Fig. 1 and includes the platens for holding thespecimen in the pressure cell, the vibration excita
46、tion device(torque motor) , transducers for measuring the response, thecontrol and readout instrumentation, and auxiliary equipmentfor specimen preparation. The theory for the resonant columnis provided in Annex A1. The entire apparatus is generallyenclosed within a pressure chamber (commonly referr
47、ed to asa triaxial cell). For some apparatus that can apply an axial loadto the specimen, the pressure chamber lid may be fitted with apiston passing through the top.6.2 Specimen PlatensBoth the active-end and passive-endplatens shall be constructed of noncorrosive material having amodulus at least
48、ten times the modulus of the material to betested. Each platen shall have a circular cross section and aplane surface of contact with the specimen, except that theplane surface of contact may be roughened to provide for moreefficient coupling with the ends of the specimen. Rougheningand flow of flui
49、ds into or from the specimen may be accom-plished by rigidly fastening porous disks to the platens. Thediameter of platens shall be equal to or greater than thediameter of the specimen. The construction of the platens shallbe such that their stiffness is at least ten times the stiffness ofthe specimen.D4015 15136.2.1 The active-end platen may have a portion of theexcitation device, transducers, springs, and dashpots connectedto it. The transducers and moving portions of the excitationdevice must be connected to the platen in such a fashion tha
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1