1、Designation: D 4506 02 (Reapproved 2006)Standard Test Method forDetermining the In Situ Modulus of Deformation of RockMass Using a Radial Jacking Test1This standard is issued under the fixed designation D 4506; the number immediately following the designation indicates the year oforiginal adoption o
2、r, 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. Scope*1.1 This test method is used to determine the in situmodulus of deformation of r
3、ock mass by subjecting a testchamber of circular cross section to uniformly distributedradial loading; the consequent rock displacements are mea-sured, from which elastic or deformation moduli may becalculated. The anisotropic deformability of the rock can alsobe measured and information on time-dep
4、endent deformationmay be obtained.1.2 This test method is based upon the procedures devel-oped by the U.S. Bureau of Reclamation featuring longextensometers (1)2. An alternative procedure is also availableand is based on a reference bar (2).1.3 Application of the test results is beyond the scope of
5、thistest method, but may be an integral part of some testingprograms.1.4 The values stated in inch-pound units are to be regardedas the standard.1.5 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 stand
6、ard 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:3D 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 3740 Practice for Minimum Requirements for AgenciesEngaged in th
7、e Testing and/or Inspection of Soil and Rockas Used in Engineering Design and ConstructionD 4403 Practice for Extensometers Used in Rock3. Terminology3.1 Definitions: See Terminology D 653 for general defini-tions.3.2 Definitions of Terms Specific to This Standard:3.2.1 deformationthe change in the
8、diameter of the exca-vation in rock (test chamber).4. Summary of Test Method4.1 A circular test chamber is excavated and a uniformlydistributed pressure is applied to the chamber surfaces bymeans of flat jacks positioned on a reaction frame. Rockdeformation is measured by extensometers placed in bor
9、eholesperpendicular to the chamber surfaces. Pressure is measuredwith a standard hydraulic transducer. During the test, thepressure is cycled incrementally and deformation is read ateach increment. The modulus is then calculated. To determinetime-dependent behavior, the pressure is held constant and
10、deformation is observed over time.5. Significance and Use5.1 Using this test method, a volume of rock large enough totake into account the influence of discontinuities on theproperties of the rock mass is loaded. The test should be usedwhen values are required which represent the true rock massprope
11、rties more closely than can be obtained through lessexpensive uniaxial jacking tests or other procedures.NOTE 1The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet
12、 thecriteria of Practice D 3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D 3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D 3740prov
13、ides a means of evaluating some of those factors.6. Apparatus6.1 Chamber Excavation EquipmentThis includes drillingand “smooth wall” blasting equipment or mechanical excava-tion equipment capable of producing typically a 9-ft (3-m)diameter tunnel with a length about three times that dimension.1This
14、test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct responsibility of Subcommittee D18.12 on Rock Mechanics.Current edition approved May 1, 2006. Published June 2006. Originallyapproved in 1985. Last previous edition approved in 2002 as D 4506 02.2The boldfac
15、e numbers in parentheses refer to the list of references appended tothis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary pag
16、e onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.2 Concreting EquipmentConcreting materials andequipment for lining the tunnel, together with str
17、ips of weakjointing materials for segmenting the lining.6.3 Reaction FrameThe reaction frame shall be com-prised of steel rings of sufficient strength and rigidity to resistthe force applied by flat jacks, as depicted in Fig. 1. For loadapplication by flat jacks, the frame must be provided withsmoot
18、h surfaces; hardwood planks are usually inserted be-tween the flat jacks and the metal rings.6.4 Loading Equipment, to apply a uniformly distributedradial pressure to the inner face of the concrete lining,including:6.4.1 Hydraulic Pump, with all necessary hoses, connectors,and fluid, capable of appl
19、ying the required pressure and ofholding this pressure constant to within 5 % over a period of atleast 24 h.6.4.2 Flat Jacks, used for load application (Fig. 1), of apracticable width and of a length equal at least to the diameterof the tunnel (9 ft (3m). The jacks should be designed to loadthe maxi
20、mum of the full circumference of the lining withsufficient separation to allow displacement measurements, andshould have a bursting pressure and travel consistent with theanticipated loads and displacements. Stainless steel flat jacks ineffective contact with 90 % of the area are recommended, withth
21、e maximum pressure capacity twice the design pressure.6.5 Load Measuring EquipmentLoad measuring equip-ment shall consist of one or more hydraulic pressure gages ortransducers of suitable range, capable of measuring the appliedpressure with an accuracy better than 62 %. Measurements areusually made
22、by means of mechanical gages. Particular care isrequired to guarantee the reliability of electric transducers andrecording equipment, when used.6.6 Displacement Measuring Equipment Displacementmeasuring equipment to monitor rock movements radial to thetunnel must have a precision better than 0.01 mm
23、. Multiple-position (six anchor points) extensometers in accordance withPractice D 4403 should be used. The directions of measure-ment should be normal to the axis of the tunnel. Measurements1. Measuring profile. 2. Distance equal to the length of active loading. 3. Control extensometer. 4. Pressure
24、 gage. 5. Reference beam. 6. Hydraulic pump. 7. Flat jack.8. Hardwood lagging. 9. Shotcrete. 10. Excavation diameter. 11. Measuring diameter. 12. Extensometer drillholes. 13. Dial gage extensometer. 14. Steel rod. 15. Expansionwedges. 16. Excavation radius. 18. Inscribed Circle. 19. Rockbolt anchor.
25、 20. Steel ring.FIG. 1 Radial Jacking TestD 4506 02 (2006)2of movement should be related to reference anchors rigidlysecured in rock, well away from the influence of the loadedzone. The multiple-position extensometers should have thedeepest anchor as a reference situated at least 3 test-chamberdiame
26、ters from the chamber lining.7. Personnel Qualification and Equipment Calibration7.1 All personnel involved in performing the test, includingthe technicians and test supervisor, shall be formally prequali-fied under the quality assurance procedures established as partof the overall testing program.7
27、.2 The compliance of all equipment and apparatus with theperformance specifications in Section 6 shall be verified.Performance verification is generally done by calibrating theequipment and measurement systems. Calibration and docu-mentation shall be accomplished in accordance with standardquality a
28、ssurance procedures.8. Procedure8.1 Test Chamber:8.1.1 Select the test chamber location taking into consider-ation the rock conditions, particularly the orientation of therock mass elements such as joints, bedding, and foliation inrelation to the orientation of the proposed tunnel or opening forwhic
29、h results are required.8.1.2 Excavate the test chamber by smooth (presplit) blast-ing to the required diameter of 9 ft (3 m), with a length equalto at least three diameters.8.1.3 Record the geology of the chamber and specimenstaken for index testing, as required. Core and log all instru-mentation ho
30、les as follows:8.1.3.1 Cored BoreholesDrill the boreholes using dia-mond core techniques. Continuous core shall be obtained.8.1.3.2 Core LoggedCompletely log the recovered core,with emphasis on fractures and other mechanical nonhomoge-neities.8.1.4 Accurately mark out and drill the extensometer hole
31、s,ensuring no interference between loading and measuring sys-tems. Install six-point extensometers and check the equipment.Place two anchors deep beyond the tunnel influence, appropri-ately spacing the other four anchors as close to the surface ofthe tunnel as possible.8.1.5 Assemble the reaction fr
32、ame and loading equipment.8.1.6 Line the chamber with concrete to fill the spacebetween the frame and the rock.8.2 Loading:8.2.1 Perform the test with at least three loading andunloading cycles, a higher maximum pressure being applied ateach cycle. Typically, the maximum pressure applied is 1000psi
33、(7 MPa), depending on expected loads.8.2.2 For each cycle, increase the pressure at an average rateof 100 psi/min (0.7 MPa/min) to the maximum for the cycle,taking not less than 10 intermediate sets of load-displacementreadings in order to define a set of pressure-displacementcurves (see Fig. 2). Th
34、e automation of data recording isrecommended.8.2.3 On reaching the maximum pressure for the cycle, holdthe pressure constant for 10 min. Complete each cycle byreducing the pressure to near zero at the same average rate,taking a further three sets of pressure-displacement readings.8.2.4 For the final
35、 cycle, hold the maximum pressureconstant for 24 h to evaluate creep. Complete the cycle byunloading in stages, taking readings of pressure and corre-sponding displacements similar to the loading cycle.9. Calculation9.1 Correct the applied load values to give an equivalentdistributed pressure, p1, o
36、n the test chamber lining, as follows:p15(b2pr1pm(1)where:p1= distributed pressure on the lining at r1, psi (MPa),r1= radius, ft (m),pm= pressure in the flat jacks, psi (MPa), andb = flat jack width (see Fig. 3), ft (m).9.1.1 Calculate the equivalent pressure p2at a “measuringradius” r2just beneath
37、the lining; this radius being outside thezone of irregular stresses beneath the flat jacks and the liningand loose rock (see Fig. 3).P25r1r2P15(b2p r2Pm(2)Pm(b 5 P12r1 pP15Pm(b2p r1P25 P1r1r29.2 Superposition is only strictly valid for elastic deforma-tions but also gives a good approximation if the
38、 rock ismoderately plastic in its behavior. Superposition of displace-ments for two fictitious loaded lengths is used to give theequivalent displacements for an “infinitely long test chamber.”This superposition is made necessary by the comparativelyshort length of the test chamber in relation to its
39、 diameter.9.3 Plot the result of the long duration test, Ddundermaximum pressure, max P2, on the displacement graph (Fig.4). Proportionally correct test data for each cycle to give thecomplete long-term pressure-displacement curve. The elasticFIG. 2 Typical Graph of Applied Pressure Versus Displacem
40、entD 4506 02 (2006)3component, De, and the plastic component, Dp, of the totaldeformation, Dt, are obtained from the deformation at the finalunloading:Dt5Dp1Desee Fig.4! (3)9.4 The elastic modulus, E, and the deformation modulus,D, are obtained from the pressure-displacement graph (Fig. 2)using the
41、following formulae based on the theory of elasticity:E 5p2r2De1 1n!n(4)D 5p2r2Dt1 1n!nwhere:p2= maximum test pressure, andn = estimated value for Poissons Ratio.9.4.1 As an alternative to 9.4, the moduli of undisturbedrock may be obtained, taking into account the effect of afissured and loosened reg
42、ion, by using the following formulae:E 5p2r2DeSn11n1 lnr3r2D(5)D 5p2r2DtSn11n1 lnr3r2Dwhere:r3= radius to the limit of the assumed fissured andloosened zone, ft (m), andln = natural logarithm.9.4.2 AssumptionsThis solution is given for the case of asingle measuring circle with extensometer anchors i
43、mmedi-ately behind the lining. The solution assumes linear-elasticbehavior for the rock and is usually adequate in practice,although it is possible to analyze more complex test configu-rations (using, for example, a finite element analysis).10. Report10.1 The purpose of this section is to establish
44、the minimumrequirements for a complete and usable report. Further detailsmay be added as appropriate, and the order of items may bechanged. If application of the test results is part of the testingprogram, an application section compatible with the formatdescribed below should be included. The repor
45、t shall includethe following:10.1.1 Introductory SectionThe introductory section isintended to present the scope and purpose of the testingprogram and the characteristics of the material tested, asfollows:10.1.1.1 ScopeThis shall include (1) the location andorientation of the test boreholes (a graph
46、ic presentation isrecommended), (2) the reasons for selecting the test locations,and (3) in general terms, a discussion of the limitations of thetesting program, that is, the areas of interest not covered by thetesting program and the limitations of the data within the areasof application.10.1.2 Bri
47、ef Description of the Test Site GeologyDescribethe rock type macroscopically from both field inspection andfrom the core logs of the test boreholes. Discuss structuralfeatures affecting the testing, as appropriate. Include a listing ofthe types of data available on properties of the rock corescontai
48、ning such property data as may aid interpretation of thetest data (for example, rock quality designation (RQD), labo-ratory tests of strength and deformation).10.1.3 Test Method Section:10.1.3.1 Equipment and ApparatusInclude a detailed list-ing of the equipment actually used for the test. The name,
49、model number, and basic specifications of each major pieceshall be presented in the report.10.1.3.2 ProcedureList in detailed steps the procedureactually used for the test.10.1.3.3 VariationsIf the actual equipment or procedurehas varied from the requirements contained in this test method,note each variation and the reasons for such variation. Discussthe effect of the variation upon the test results.FIG. 3 Scheme of Loading Showing Symbols Used in theCalculationsFIG. 4 Typical Graph Showing Total and Plastic Displacements asa Function of Di
