1、Designation: D 1195 93 (Reapproved 2004)Standard Test Method forRepetitive Static Plate Load Tests of Soils and FlexiblePavement Components, for Use in Evaluation and Design ofAirport and Highway Pavements1This standard is issued under the fixed designation D 1195; the number immediately following t
2、he designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method cover
3、s a procedure for making repeti-tive static plate load tests on subgrade soils and compactedpavement components, in either the compact condition or thenatural state, and provides data for use in the evaluation anddesign of rigid and flexible-type airport and highway pave-ments.1.2 The values stated
4、in inch-pound units are to be regardedas the standard.1.3 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
5、of regulatory limitations prior to use.2. Terminology2.1 Definitions:2.1.1 deflectionthe amount of downward vertical move-ment of a surface due to the application of a load to the surface.2.1.2 rebound deflectionthe amount of vertical rebound ofa surface that occurs when a load is removed from the s
6、urface.2.1.3 residual deflectionthe difference between originaland final elevations of a surface resulting from the applicationand removal of one or more loads to and from the surface.3. Significance and Use3.1 Field, in-place repetitive static plate load tests are usedfor the evaluation and design
7、of pavement structures. Repetivestatic plate load tests are performed on soils and unbound baseand subbase materials to determine a measure of the shearstrength of pavement components.4. Apparatus4.1 Loading DeviceA truck or trailer or a combination ofboth a tractor-trailer, an anchored frame, or ot
8、her structureloaded with sufficient weight to produce the desired reaction onthe surface under test. The supporting points (wheels in thecase of a truck or trailer) shall be at least 8 ft (2.4 m) from thecircumference of the largest diameter bearing plate being used.4.2 Hydraulic Jack Assembly, with
9、 a spherical bearingattachment, capable of applying and releasing the load inincrements. The jack shall have sufficient capacity for applyingthe maximum load required, and shall be equipped with anaccurately calibrated gage that will indicate the magnitude ofthe applied load.4.3 Bearing PlatesA set
10、of circular steel bearing platesnot less than 1 in. (25.4 mm) in thickness, machined so thatthey can be arranged in pyramid fashion to ensure rigidity, andhaving diameters ranging from 6 to 30 in. (152 to 762 mm).The diameters of adjacent plates in the pyramid arrangementshall not differ by more tha
11、n 6 in.NOTE 1A minimum of four different plate sizes is recommended forpavement design or evaluation purposes. For evaluation purposes alone, asingle plate may be used, provided that its area is equal to the tire-contactarea corresponding to what may be considered as the most criticalcombination of
12、conditions of wheel load and tire pressure. For the purposeof providing data indicative of bearing index (for example, the determi-nation of relative subgrade support throughout a period of a year), a singleplate of any selected size may be used.4.4 Dial Gages, two or more, graduated in units of 0.0
13、01 in.(0.03 mm) and capable of recording a maximum deflection of1 in. (25 mm) or other equivalent deflection-measuring de-vices.4.5 Deflection BeamA beam upon which the dial gagesshall be mounted. The beam shall be a 212-in. standard blackpipe ora3by3by14-in. (76 by 76 by 6-mm) steel angle, orequiva
14、lent. It shall be at least 18 ft (5.5 m) long and shall reston supports located at least 8 ft (2.4 m) from the circumferenceof the bearing plate or nearest wheel or supporting leg. Theentire deflection measuring system shall be adequately shadedfrom direct rays of the sun.4.6 Miscellaneous Tools, in
15、cluding a spirit level, for prepa-ration of the surface to be tested and for operation of theequipment.1This test method is under the jurisdiction of ASTM Committee E17 onVehicle-Pavement Systems and is the direct responsibility of Subcommittee E17.41on Pavement Management.Current edition approved D
16、ec. 1, 2004. Published December 2004. Originallyapproved in 1952. Replaces D 1195 57. Last previous edition approved in 1997 asD 1195 93 (1997).1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5. Procedure5.1 Carefully center a bearin
17、g plate, of the selected diam-eter, under the jack assembly. Set the remaining plates ofsmaller diameter concentric with, and on top of, the bearingplate. Set the bearing plate level in a thin bed of a mixture ofsand and plaster of Paris, of plaster of Paris alone, or of finesand, using the least qu
18、antity of materials required for uniformbearing. To prevent loss of moisture from the subgrade duringthe load test, cover the exposed subgrade to a distance of 6 ft(1.8 m) from the circumference of the bearing plate with atarpaulin or waterproof paper.5.2 Where unconfined load tests are to be made a
19、t a depthbelow the surface, remove the surrounding material to providea clearance equal to one and one-half plate diameters from theedge of the bearing plate. For confined tests, the diameter of theexcavated circular area shall be just sufficient to accommodatethe selected bearing plate.5.3 Use a su
20、fficient number of dial gages, so located andfixed in position as to indicate the average vertical movementof the bearing plate. When using two dial gages, they shall beset near each extremity of a diameter of the bearing plate, 1 in.(25.4 mm) from the circumference. When three gages areemployed, th
21、ey shall be set at an angle of 120 from each other,and equidistant from the circumference of the bearing plate.Each individual set of readings shall be averaged, and thisvalue is recorded as the average settlement reading.5.4 After the equipment has been properly arranged, andwith all of the dead lo
22、ad (jack, plates, etc.) acting, seat andbearing plate and assembly by the quick application and releaseof a load sufficient to produce a deflection of not less than 0.01in. (0.25 mm) nor more than 0.02 in. (0.51 mm) as indicated bythe dial gages. When the dial needles come to rest followingthe relea
23、se of this load, reseat the plate by applying one half ofthe recorded load producing the 0.01 to 0.02-in. deflection.When the dial needles have again come to rest, set each dialaccurately at its zero mark.NOTE 2The use of additional dial gages, placed on the surface of thematerial being tested at on
24、e half, one, and one and one-half, and so forth,bearing-plate diameters from the edge of the bearing plate, is optional.5.5 Apply a load giving a deflection of about 0.04 in. (1.0mm), start a stop watch, and maintain the same load constantlyuntil the rate of deflection is 0.001 in. (0.03 mm) per min
25、 orless for three successive minutes. Then completely release theload, and observe the rebound until the rate of recovery is0.001 in. per min or less, for three successive minutes. Applyand release the same load in this manner six times. Record thereadings of the dial gages resting on the bearing pl
26、ate at the endof each minute; record the readings of the dial gages set beyondthe perimeter of the bearing plate just before the application,and just before the release of load, for each repetition. Toensure good contact between the gages and the bearing plate orother surface on which they are resti
27、ng, briefly buzz an electricbell attached to the deflection beam, 10 s before the dial gagesare to be read.5.6 Increase the load to give a deflection of about 0.2 in. (5.1mm), and proceed as directed in 4.5.5.7 Increase the load to give a deflection of about 0.4 in.(10.2 mm), and proceed as directed
28、 in 4.5.5.8 In all cases the standard end point shall be a rate of0.001 in. (0.03 mm)/min or less for three successive minutes.5.9 From a thermometer suspended near the bearing plate,read and record the air temperature at half-hour intervals.6. Record of Tests6.1 In addition to the continuous listin
29、g of all load, deflec-tion, and temperature data, as prescribed in Section 4, a recordshall also be made of all associated conditions and observationspertaining to the test, including the following:6.1.1 Date,6.1.2 Time of beginning and completion of test,6.1.3 List of personnel,6.1.4 Weather condit
30、ions,6.1.5 Any irregularity in routine procedure,6.1.6 Any unusual conditions observed at the test site, and6.1.7 Any unusual observations made during the test.7. Calculation and Plotting of Load-DeflectionRelationships7.1 For each repetition of each load, determine the deflec-tion at which the rate
31、 of deflection is exactly 0.001 in. (0.03mm)/min. This is termed end point deflection and can bedetermined with sufficient accuracy from visual inspection ofthe deflection data for each repetition of load recorded.7.2 Correct the recorded loads, as read from the pressuregage of each hydraulic jack e
32、mployed, by means of thecalibration curve for each jack and pressure gage used.7.3 Determine graphically the zero point corrections forboth applied load and deflection. This requires taking intoaccount the weight of the hydraulic jack, that of the pyramid ofbearing plates, etc., and that of the corr
33、ected jack loads atwhich the dial gages were set to zero at the beginning of thetest.7.4 Plot the corrected deflection at which the rate ofdeflection is exactly 0.001 in. (0.03 mm)/min versus thenumber of repetitions of each corrected load. Similar graphsmay be prepared in which corrected residual d
34、eflection andrebound deflection are plotted versus the number of repetitionsof each corrected load.8. Precision and Bias8.1 The precision and bias of this test method for makingrepetitive static plate load tests on subgrade soils and flexiblepavement components has not been determined. Soils andflex
35、ible pavement components at the same location may exhibitsignificantly different load-deflection relationships. No methodpresently exists to evaluate the precision of a group ofrepetitive plate load tests on soils and flexible pavementcomponents due to the variability of these materials. Thesubcommi
36、ttee is seeking pertinent data from users of thismethod which may be used to develop meaningful statementsof precision and bias.9. Keywords9.1 bearing plate; deflection; pavementsD 1195 93 (2004)2ASTM International takes no position respecting the validity of any patent rights asserted in connection
37、 with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible t
38、echnical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful conside
39、ration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr
40、 Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D 1195 93 (2004)3
