1、Designation: D6230 98 (Reapproved 2005)D6230 13Standard Test Method forMonitoring Ground Movement Using Probe-TypeInclinometers1This standard is issued under the fixed designation D6230; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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. Scope Scope*1.1 This test method covers the use of inclinometers to monitor the internal movement of ground. Th
3、e test method covers typesof instruments, installation procedures, operating procedures, and maintenance requirements. It also provides formulae for datareduction.1.2 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in PracticeD6026 u
4、nless superseded by this test method.1.2.1 The procedures used to specify how data are collected, recorded or calculated in this test method are regarded as theindustry standard. In addition, they are representative of the significant digits that generally should be retained. The proceduresused do n
5、ot consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the usersobjectives; it is common practice to increase or reduce significant digits of reported data to be commensurate with theseconsiderations. It is beyond the scope of this test met
6、hod to consider significant digits used in analytical methods for engineeringdesign.1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are forinformation only.1.4 This standard does not purport to address all of the safety concerns, if any
7、, associated with its use. It is the responsibilityof the user of this standard to establish appropriate health and safety practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and Contained
8、 FluidsD4622D3740 Test Method for Rock Mass Monitoring Using InclinometersPractice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction (Withdrawn 2000)D6026 Practice for Using Significant Digits in Geotechnical Dat
9、aD7299 Practice for Verifying Performance of a Vertical Inclinometer Probe3. Terminology3.1 Definitions:3.1.1 For definitions of general terms, see Terminology D653.3.1.2 Definitions of terms specific to this test method are included in Section 5.4. Significance and Use4.1 An inclinometer is a devic
10、e for measuring deformation normal to the axis of a pipe by passing a probe along the pipe andmeasuring the inclination of the probe with respect to the line of gravity. Measurements are converted to distances usingtrigonometric functions. Distances are summed to find the position of the pipe. Succe
11、ssive measurements give differences in1 This test method is under the jurisdiction of ASTM Committee D18 on Soil and Rock and is the direct responsibility of Subcommittee D18.23 on Field Instrumentation.Current edition approved Nov. 1, 2005Jan. 15, 2013. Published December 2005 February 2013. Origin
12、ally approved in 1998. Last previous edition approved in 19982005as D6230 98.D6230 98 (2005). DOI: 10.1520/D6230-98R05.10.1520/D6230-13.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume inf
13、ormation, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately
14、depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM Interna
15、tional, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1position of the pipe and indicate deformation normal to the axis of the pipe. In most cases the pipe is installed in a near-verticalhole. Measurements indicate subsurface horizontal deformation. In some cases
16、 the pipe is installed horizontally and themeasurements indicate vertical deformation.4.2 Inclinometers are also called slope inclinometers or slope indicators. Typical applications include measuring the rate oflandslide movement and locating the zone of shearing, monitoring the magnitude and rate o
17、f horizontal movements forembankments and excavations, monitoring the settlement and lateral spread beneath tanks and embankments, and monitoring thedeflection of bulkheads, piles or structural walls.NOTE 1Notwithstanding the statements on precision and bias contained in this test method, the precis
18、ion of this test method is dependent on thecompetence of the personnel performing it and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 aregenerally considered capable of competent and objective testing. Users of these test methods are caution
19、ed that compliance with Practice D3740 doesnot in itself ensure reliable results. Reliable testing depends on many factors; Practice D3740 provides a means of evaluating some of those factors.5. Apparatus5.1 The probe type inclinometer uses sensors inside a probe to indicate the orientation of the p
20、robe relative to the pull of gravity.The complete system consists of:5.1.1 A permanently installed pipe, called casing, with test method grooves. The casing is made of plastic, aluminum alloy, orfiberglass.5.1.2 The ProbeMost probes use force balance accelerometers which give a voltage output that i
21、s proportional to inclinationof the probe. Biaxial probes contain two sensors oriented 90 apart to permit readings in orthogonal directions at the same time.5.1.3 A portable readout unit with power supply for the sensors and display to indicate probe inclination. The readout unit mayhave internal me
22、mory to record data.5.1.4 An electrical cable connecting the probe and readout unit with distance markings. Fig. 1 shows a typical set ofcomponents.6. Procedure6.1 Installation of Casing in a Borehole:6.1.1 Select casing materials that are compatible with the environmental conditions at the installa
23、tion. Select casing sizeconsistent with the specific measurement requirements and conditions for the job. Store casing materials in a safe, secure place toprevent damage. Sunlight may damage plastic casing. High and low pH may damage metal casing. Note that a special probe maybe required for non-ver
24、tical boreholes.6.1.2 Assemble all components required for the casing, including casing, joints, connectors, and end cap. Examine eachcomponent for defects. Do not use defective components since they may later cause problems with readings that are difficult todiagnose and impossible to correct. Keep
25、 all components clean and free of foreign matter during assembly. Follow themanufacturers instructions for assembly of the casing. If required, use sealing mastic and tape to seal all couplings to prevent laterflow of soil particles into the casing. This is especially important when using grout to s
26、eal the casing in the hole. Exercise careto keep the casing grooves free of obstructions. When assembling couplings, use procedures to prevent spiraling of the casinggrooves. Twist adjacent couplings in alternate directions before fixing to minimize spiraling. Examine the casing during assemblyto co
27、nfirm that spiraling is not occurring. Place a cap on the bottom end and seal it to prevent inflow.FIG. 1 Typical Components of Inclinometer SystemD6230 1326.1.3 Create the borehole using procedures to keep it aligned within the range of the readout equipment. Extend the boreholeat least 5 m (16 ft)
28、 beyond the zone of expected movement. It may be necessary to use casing, hollow-stem augers, or drilling mudto keep the hole open and stable. Flush the hole until clear of drilling cuttings.6.1.4 Insert the casing into the borehole. Establish the reference orientation for the casing and align one s
29、et of groves with thisreference. This orientation is commonly referred to as the A direction. It should align with the direction of greatest anticipatedmovement. movement (see Note 2). Add clean water to the casing if necessary to help overcome buoyancy. Use of water alonewill not overcome buoyancy
30、created by fresh cement grout. See following section for guidance. Use care to minimize any twistof the casing during installation. Care should be exercised to maintain orientation without twisting from the first piece of casingto the last. Twisting the top of the casing may cause spiraling of casin
31、g at depth.NOTE 2This recommendation has legacy to the past where the sensor in the B axis was not as precise as the sensor aligned with the main axis. Forprobes produced in the past two decades, both sensors give good quality readings if the carriage wheels are in good condition. If the A grooves a
32、re notaligned with the actual maximum movement, both sensors detect the movement corroborating what the other is reading. Most commercially availablesoftware for reducing inclinometer readings will report the maximum movement and the direction.6.1.5 Backfill the annular space between the borehole wa
33、ll and the inclinometer casing with a suitable filling material. Boreholecan be pre-grouted or post-grouted. If post-grouted, grouting can be through a tremie placed in the annulus of the inclinometercasing and the boreholes walls or via an internal tremie connected to a one-way bottom grout valve.
34、Options include cement grout,sand (see Note 3), and pea gravel. A lean cement grout backfill is preferable unless the surrounding ground is too pervious to holdthe grout. Place grout with a tremie. Buoyancy must be overcome with grout backfills.Add a weight or earth anchor to the bottomof the inclin
35、ometer casing, temporarily place clean drill pipe inside the casing, or place the first 3 m (10 ft) of grout around thebottom of the casing and let it set, then complete the grouting. Place sand and gravel backfills slowly and with techniques to preventleaving large voids in the backfill. Such voids
36、 can later lead to erratic readings. Place backfill and withdraw drill casing or augersin sequence to prevent any squeezing off of the borehole. Withdraw drill casing and hollow-stem augers without rotation to preventdamage to the inclinometer casing. Use measures to prevent backfill from spilling i
37、nto the inclinometer casing.NOTE 3Many practitioners contend that sand should never be used as backfill especially for installations in excess of 30 m (100 ft) in depth. Sandplaced by tremie often results in open voids as the sand bridges between the casing and borehole walls. In addition, the sand
38、may settle resulting in dragon the casing that may deform or damage the casing.6.2 Installation on The Ground Surface of Horizontal Casing:NOTE 4A practical limit for installing horizontal casing is about 100 m. Beyond 100 m cable friction makes it difficult to pull the inclinometer probethrough the
39、 casing. Special TFE-fluorocarbon inserts on the cable alleviate the problem to some degree.6.2.1 Select casing materials that are compatible with the environmental conditions at the installation. Select casing sizeconsistent with the specific measurement requirements and conditions for the job. Sto
40、re casing materials in a safe, secure place toprevent damage. Sunlight may damage plastic casing. High and low pH may damage metal casing. Note that a special probe isrequired for horizontal casing. If one end of the casing is to be buried then the end cap contains a pulley to carry a wire that isus
41、ed to pull the probe into the inclinometer casing. Special care must be taken to insure that the pulley is correctly assembled, freeto turn and has the wire in place. Take precautions at all times during installation to keep the wire clean.6.2.2 Create a near-level surface over the length where the
42、casing is to be installed. Cover with a bed of at least 50-mm (2-in.)deep and 300-mm (12-in.) wide of clean sand, pea gravel or a lean grout.6.2.3 Assemble all components required for the casing, including casing joints, connectors, and end cap. Examine eachcomponent for defects. Do not use defectiv
43、e components since they may later cause problems with readings that are difficult todiagnose and impossible to correct. Keep all components clean and free of foreign matter during assembly. Follow themanufacturers instructions for assembly of the casing. If required use sealing mastic and tape to se
44、al all couplings to prevent laterflow of soil particles into the casing. This is especially important when using grout to seal the casing in the borehole. Exercise careto keep the casing grooves free of obstructions. When assembling couplings, use procedures to prevent spiraling of the casinggrooves
45、. Twist adjacent couplings in alternate directions before fixing to minimize spiraling. Examine the casing during assemblyto confirm that spiraling is not occurring.6.2.4 Place the casing onto the bed and adjust its position until it is within the tolerances required by the readout device.Establish
46、the reference orientation for the casing and align one set of groves with this reference. This orientation is commonlyreferred to as the A direction. It aligns with the direction of greatest anticipated movement. Visually check for and remove anyspiraling. Determine that the pull cable is in positio
47、n and moves freely through the inclinometer casing.6.2.5 Use hand tools or light construction equipment to place clean sand, pea gravel or lean grout evenly, at least 150-mm (6-in.)wide, on both sides of the casing. Cover the inclinometer casing with at least 50 mm (2 in.) of clean sand, pea gravel
48、or lean grout.Place fill over casing in 150-mm (6-in.) lifts. Fill for the first lift should not contain any particles larger than 25 mm (1 in.). Ifcompaction is required, use hand compactors for the first two lifts.6.3 Calibration: Equipment Verification:6.3.1 Inclinometers are factory calibrated a
49、nd supplied with a calibration factor, K, that is specific to the probe and the readoutunit. Some manufacturers provide standardized readout units that can be used with multiple probes. However it should be notedthat electronic variations in the readout equipment may cause conditions where different probes will give different readings. It isD6230 133recommended that a calibrationverification check be performed any time a probe and readout unit combination is changed. Forapplications involving small but important changes over several years, recalibrate the instrument
