sonda suspendida_boring geophysical logging field measurement procedures-geovision & oyo (2007)

MACTEC Engineering and Consulting, Inc.North Anna COL Geotechnical Report Attachment E

APPENDIX F

Project 6468-06-1472January 17, 2007

BORING GEOPHYSICAL LOGGING

FIELD MEASUREMENT PROCEDURES

GEOVision Report 6410-01 vol 1 of 2 North Anna COL Boring Geophysical Logging rev A 1/17/2007 Page 302 of 359


Project 6468-06-1472January 17, 2007

PROCEDURE FOR

OYO P-S SUSPENSION SEISMIC VELOCITY LOGGING

Background

This procedure describes a method for measuring shear and compressional wavevelocities in soil and rock. The OYO P-S Suspension Method is applied by generatingshear and compressional waves in a borehole using the OYO P-S Suspension Loggerborehole tool and measuring the travel time between two receiver geophones orhydrophones located in the same tool.

Objective

The outcome of this procedure is a plot and table of P and SH wave velocity versusdepth for each borehole. Standard analysis is performed on receiver to receiver data.Data is presented in report format, with ASCII data files and digital records transmittedon diskette.

Instrumentation

1. OYO Model 170 Digital Logging Recorder or equivalent

2. OYO P-S Suspension Logger probe or equivalent, including two setshorizontal and vertical geophones, seismic source, and power supply for thesource and receivers

3. Winch and winch controller, with logging cable

4. Batteries to operate P-S Logger and winch

The Suspension P-S Logger system, manufactured by OYO Corporation, or theRobertson Digital P-S Suspension Probe with the Robertson Micrologger2 are currentlythe only commercially available suspension logging systems. As shown in Figure 1,these systems consists of a borehole probe suspended by a cable and arecording/control electronics package on the surface.

The suspension system probe consists of a combined reversible polarity solenoidhorizontal shear-wave generator (SH) and compressional-wave generator (P), joined to

GE (!JUSlOn Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 1



Project 6468-06-1472January 17, 2007

two biaxial geophones by a flexible isolation cylinder. The separation of the twogeophones is one meter, allowing average wave velocity in the region between thegeophones to be determined by inversion of the wave travel time between the twogeophones. The total length of the probe is approximately 7 meters; the center point ofthe geophones is approximately 5 meters above the bottom end of the probe.

The probe receives control signals from, and sends the amplified geophone signals to,the instrumentation package on the surface via an armored 4 or 7 conductor cable. Thecable is wound onto the drum of a winch and is used to support the probe. Cable travelis measured by a rotary encoder to provide probe depth data.

The entire probe is suspended by the cable and may be centered in the borehole bynylon "whiskers." Therefore, source motion is not coupled directly to the borehole walls;rather, the source motion creates a horizontally propagating pressure wave in the fluidfilling the borehole and surrounding the source. This pressure wave produces ahorizontal displacement of the soil forming the wall of the borehole. This displacementpropagates up and down the borehole wall, in turn causing a pressure wave to begenerated in the fluid surrounding the geophones as the soil displacement wave passestheir location.

Environmental Conditions

The OYO P-S Suspension Logging Method can be used in either cased or uncasedboreholes. For best results, the uncased borehole must be between 10 and 20 em indiameter, or 4 to 8 inches. A cased borehole may be as small as 3 inches, if properlygrouted (see below) and the grout annulus does not exceed 1 inch.

Uncased boreholes are preferred because the effects of the casing and grouting areremoved. It is recommended that the borehole be drilled using the rotary mud method.This method does little damage to the borehole wall, and the drilling fluid coats andseals the borehole wall reducing fluid loss and wall collapse. The borehole fluid isrequired for the logging, and must be well circulated prior to logging.

If the borehole must be cased, the casing must be PVC and properly installed andgrouted. Any voids in the grout will cause problems with the data. Likewise, large groutbulbs used to fill cavities will also cause problems. The grout must be set beforetesting. This means the grouting must take place at least 48 hours before testing.

For borehole casing, applicable preparation procedures are presented in ASTMStandard D4428/D4428M-91 Section 4.1 (see ASTM website for copy).

Calibration

Calibration of the digital recorder is required. Calibration is limited to the timingaccuracy of the recorder. GEOVision's Seismograph Calibration Procedure orequivalent should be used. Calibration must be performed on an annual basis.

GE(fJUszon Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 2

GEOVision Report 6410-01 vol 1 of 2 North Anna COL Boring Geophysical Logging rev A 1/1712007 04 of 359


Measurement Procedure

Project 6468-06-1472January 17, 2007

The entire probe is lowered into the borehole to a specific measurement depth by thewinch. A measurement sequence is then initiated by the operator from theinstrumentation package control panel. No further operator intervention is then neededto complete the measurement sequence described below.

The system electronics activates the SH-wave source in one direction and records theoutput of the two horizontally oriented geophone axes which are situated parallel to theaxis of motion of the source. The source is then activated in the opposite direction, andthe horizontal output signals are again recorded, producing a SH-wave record of polarityopposite to the previous record. The source is finally actuated in the first directionagain, and the responses of the vertical geophone axes to the resultant P-wave arerecorded during this sampling.

The data from each geophone during each source activation is recorded as a differentchannel on the recording system. The seismograph has at least six channels (twosimultaneous recording channels), each with at least a 12 bit 1024 sample record.Newer seismographs may have longer record lengths. The recorded data is displayedon a CRT or LCD display and possibly on paper tape output as six channels with acommon time scale. Data is stored on digital media for further processing. Up to 8sampling sequences can be stacked (averaged) to improve the signal to noise ratio ofthe signals.

Review of the data on the display or paper tape allows the operator to set the gains,filters, delay time, pulse length (energy), sample rate, and stacking number in order tooptimize the quality of the data before recording. In the case of the Model 170, printeddata is verified by the operator prior to moving the probe. In the case of the RobertsonMicrologger2, storage on the hard disk should be verified from time-to-time, certainlybefore exiting the borehole.

Typical depth spacing for measurements is 1.0 meters, or 3.3 feet. Alternative spacingis 0.5 meter, or 1.6 feet.

Required Field Records

1) Field log for each borehole showing

a) Borehole identification

b) Date of test

c) Tester or data recorder

GE(fJUslon Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 3



d) Description of measurement

e) Any deviations from test plan and action taken as a result

f) QA Review

Project 6468-06-1472January 17, 2007

2) Paper output records are no longer required, since the Micrologger2 cannotgenerate them. However, data must be stored in at least 2 places prior to leavingthe site

3) List of record 10 numbers (for data on digital media) and corresponding depth

4) Diskettes, CDRom, or USB flash drives with backup copies of data on hard disk,labeled with borehole designation, record 10 numbers, date, and tester name.

An example Field Log is attached to this procedure.

Analysis

Following completion of field work, the recorded digital records are processed bycomputer using the OYO Corporation software program PSLOG and interactivelyanalyzed by an experienced geophysicist to produce plots and tables of P and SH wavevelocity versus depth.

The digital time series records from each depth are transferred to a personal computerfor analysis. Figure 2 shows a sample of the data from a single depth. These digitalrecords are analyzed to locate the first minima on the vertical axis records, indicatingthe arrival of P-wave energy. The difference in travel time between these arrivals isused to calculate the P-wave velocity for that 1-meter interval. When observable, Pwave arrivals on the horizontal axis records are used to verify the velocities determinedfrom the vertical axis data. In addition, the soil velocity calculated from the travel timefrom source to first receiver is compared to the velocity derived from the travel timebetween receivers.

The digital records are studied to establish the presence of clear SH-wave pulses, asindicated by the presence of opposite polarity pulses on each pair of horizontal records.Ideally, the SH-wave signals from the 'normal' and 'reverse' source pulses are verynearly inverted images of each other. Digital FFT - IFFT lowpass filtering are used toremove the higher frequency P-wave signal from the SH-wave signal.

The first maxima are picked for the 'normal' signals and the first minima are picked forthe 'reverse' signals. The absolute arrival time of the 'normal' and 'reverse' signals mayvary by +/- 0.2 milliseconds, due to differences in actuation time of the solenoid sourcecaused by constant mechanical bias in the source or by borehole inclination. Thisvariation does not affect the velocity determinations, as the differential time is measuredbetween arrivals of waves created by the same source actuation. The final velocity

GE(!JUSlon Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 4



Project 6468-06-1472January 17, 2007

value is the average of the values obtained from the 'normal' and 'reverse' sourceactuations.

In Figure 2, the time difference over the 1-meter interval of 1.70 millisecond isequivalent to a SH-wave velocity of 588 m/sec. Whenever possible, time differencesare determined from several phase points on the SH -wave pulse trains to verify the dataobtained from the first arrival of the SH -wave pulse. In addition, the soil velocitycalculated from the travel time from source to first receiver is compared to the velocityderived from the travel time between receivers.

Figure 3 is a sample composite plot of the far normal horizontal geophone records for arange of depths. This plot shows the waveforms at each depth, clearly showing the Swave arrivals. This display format is used during analysis to observe trends in velocitywith changing depth.

Once the proper picks are entered in PSLOG, the picks are transferred to an Excelspreadsheet where Vs and Vp are calculated. The spreadsheet allows output forpresentation in charts and tables.

Standard analysis is performed on receiver 1 to receiver 2 data, with separate analysisperformed on source to receiver data as a quality assurance procedure.

Date 4/10/06

References:

QA Review__'\-'~---f4I '-"..-_---==------__Date 4/1 0/06

1. "In Situ P and S Wave Velocity Measurement", Ohya, S. 1986. Proceedings of InSitu '86, Use of In-Situ Tests In Geotechnical Engineering~ an ASCE SpecialtyConference sponsored by the Geotechnical Engineering Division of ASCE andco-sponsored by the Civil Engineering Dept of Virginia Tech.

2. Guidelines for Determining Design Basis Ground Motions, Report TR-102293,Electric Power Research Institute, Palo Alto, California, November 1993,Sections 7 and 8.

3. "Standard test Methods for Crosshole Seismic Testing", ASTM StandardD4428/D4428M-91, July 1991, Philadelphia, PA

GE(fJUston Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 5



Project 6468-06-1472January 17, 2007

OYO SUSPENSION P-S VELOCITY LOGGING SETUP

DisketteCDR, or USBFlash drivewith Data

OYO PS-170 orMicrologger2Logger/Recorder

Overall Length - 25 ft

i---- Weight

4 or 7-Conductor cable

M---+~"""'--- Filter Tube

l4----+~N--- Lower Geophone

~~~~---- Upper Geophone

+-----ifi'l<'\i!"-"i--- Source

+------jfN\O!lN--- Source Driver

Cable Head ---11--+1

Head Reducer--1+--+1

Or TelemetryUnit

Figure 1. Suspension PS logging method setup

GE (!JUSlOn Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 6



Far HN9 .960 t----+--;--.......;-~+_____;...~~,,--,..---,~.,

Far HR9 .960 1---+------j---r---t-------------'1''-.

Far lJ5 .470 f--+--+---f" J

Near HNB .260 r----..--...----...----t~._;_...~----..

Near HRB .260 I--->---;--..-+---I--+--!----~~

Near lJ4 .9B0 1----'----+

Project 6468-06-1472January 17, 2007

Figure 2. Sample suspension method waveform data showing horizontal normal andreversed (HR and HN), and vertical (V) waveforms received at the near(bottom 3 channels) and far (top 3 channels) geophones. The arrivals inmilliseconds for each pick are shown on the left. The box in the upper rightcorner shows the depth in the borehole and the velocities calculated basedon the picks.

GE(fJUston Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 7



Project 6468-06-1472January 17, 2007

: : :-!'-"--~---I~ ; -i......,...

~~!--L-j.-; ! i i----

! i

~+H+!-~+-

"-""-""!'-~:-.-r--r-~,j..~"""'!------io-

........!

Dopth . .88,

6.6fL 12.291 --+a .2ft 12 .491 1----;.-'-;;--r--+_-,,;---;-."i"""!'-9 .8ft 11.'1a81----;-~;-...

11.!lf+' 11.~!iA

1'3 .1t' L 18.89114.8ft 18.841 ~~""';"'---i'--__--J-_.

15.'1ft 18.251 t----............._"'-

10 .Aft. !I.ro!iA19.?fL 9.791 21.3ft 9 .4911-----+--+~........._+_l-..~~ .Uft !.I.:-:Il:tll .......--...-.;-?4 . rlft. !I.?RA26.3fL 11.19127.9ft 18 .221 t---+-----+-"!---+---1~

~l.J .!:rft 111 .U.II 1------:--.;-_;..-~1 .?ft. 111.A4A32.8fL 11.54131.Sft 11.'1a81---!----T,~;-_l,-~_+_...~:-:I, .!:rft 11.liltll 1----;.;- +-r+--~fI. Ht. 12.AflA -;.... -; ~ -;- -37.?fL 13.861 -+- ~." i-ii !!"'!'I. "1ft 15 .Sfll1 I-_ _+-~_+_~--+-_+----''-...i.-_+__+"I!-

41 .Uft lli . ~ltll t--....-;--r---+--+--+--i-----if--+--+----i-t""..'-i'12.7ft 16.859 t---+-+-.--t,--!.~-+--_t:,-t-+--t--t--t!"'...,..44.:Jft 14 .~~8 + L! --L -

4~.~1. n.4~A :-+! i !

'17.6ft 12 .821 t-----T-r--T-"""""i"---r--+---i'~

4l.J.~t 11.~l:t1l f------........-_~--" ...._!lR.Oft. 11.!I!=lA52.SfL 12.941151. 1ft 12 .228 t-------'--:---'!--~-~+-.........._~J..." ......~......

~~::~ }; :~~: t--~_+j-_-;...:---1---!---~-;i-~'~),59.1ft 12.6411 , : .lilt :(n 12.4l:t1l ,,1-: .Ii~.:lr+_ 12.fifiA ----i--t -j- - - 1

54.8fL 12.5411 - ~-r~i - i65.6ft 11.918 t-----!-'~;-_r___r_---?---1"-.l

Ii,( .::Ift 11 .Ultll t---i---r--+-t----+-----1~ron. !Ut. 11.ronA - i- :79. Sft 11.9411 t---.................-!-'-T-------?--.'n .~t 12 .:-:1111 t--......;..~~-+---+-.---+--'-.._...

?J.Ort 12.~ao - j- r- T._75 .Sf L 13 .3811 " -:77 . 1ft 1.1."Ifll1 t---+..........,!---+-_+--+-~---!-+"!'--

.(l:t :(-ft lJ . HII t---+---![----r!.--;-----;--+-__+"'~88. 4t' L 12.9411 T i-- !

Figure 3. Sample composite waveform plot for normal shear waves receivedat the near geophone in a single borehole

GE(!JUston Procedure for OYO P-S Suspension Seismic Velocity LoggingRev 1.3 4/06/06 Page 8



P-S SUSPENSION VELOCITY FIELD LOG

Project 6468-06-1472January 17, 2007

SITE: DATE: _

CLIENT: JOB: _

AUTHOR: PAGE 1 OF

CONTACT: _

CONTACT: _

CONTACT: _

CONTACT: _

DRILLER: _

COMPANY: _

OFFICE PHONE: _

_ PHONE:. _

OFFICE PHONE: __ PHONE: _

____ PHONE: _

_ PHONE: _

____ PHONE: _

_ PHONE: _

____ PHONE: _

_ PHONE: _

NO__

TIME SINCE LAST CIRCULATION: _

DIRECTIONS TO SITE: _

GENERAL SITE CONDITIONS/LOCATION: _

EA#: _

BOREHOLE DESIGNATION: LOCATION: _

COUNTY: RANGE: TOWNSHIP: SECTION:__

BOREHOLE CONSTRUCTION: CASED UNCASED__

DIAMETERS AND DEPTH RANGES: aTO ,__, TO _

BOREHOLE TOTAL DEPTH AS DRILLED: _

CONDUCTOR CASING?: YES__ DEPTH TO BOTTOM OF CASING _

DEPTH TO BEDROCK: DEPTH TO WATER TABLE: _

BOREHOLE FLUID: WATER__; FRESH WATER MUD__; SALT WATER MUD __:OTHER: _

DEPTH TO BOREHOLE FLUID: _

GEOVision Geophysical Services 1151 Pomona Road, Suite P, Corona, CA 92882 Ph (951) 549-1234 Fx (951) 549-1236



Project 6468-06-1472January 17, 2007

SITE: DATE: _CLIENT: JOB: _AUTHOR: PAGE 2 OF

LOGGING CREW: _

VEHICLE(S) USED AND MILEAGE: _

MOBILIZED FROM: DEPARTURE TIME: _

ARRIVED ON SITE: _

STANDBY TIME: CAUSE: _

LOGGING STARTED: LOGGING COMPLETED: _STANDBY TIME: CAUSE: _

LOGGING STARTED: LOGGING COMPLETED: _

DEMOBILIZED TO: ARRIVAL TIME: _

ADDITIONAL DEMOB TIME: REASON: _

BATTERIES CHANGED BEFORE LOGGING: YES__; NO__; STORED WITH NEW__

WINCH COMPROBE 0 GREYO OYO 0 RGO OTH 0INSTRUMENT OYO 120040 150140 190290 RG 1600230 160024 0

RECEIVER SIN 120080 200420 260660 11001 0 23053 0

MAINTENANCE PERFORMED ON SITE: _

EQUIPMENT PROBLEMS OR FAILURES: _

SUGGESTIONS, ADDITIONS, CHANGES:. _

COMMENTS:. _

GEOVision Geophysical Services 1151 Pomona Road, Suite P, Corona, CA 92882 Ph (951) 549-1234 Fx (951) 549-1236



Project 6468-06-1472January 17, 2007

GEOVISION SUSPENSION LOGGING FIELD NOTESSITE: DATE: _

CLIENT: JOB:-------------------AUTHOR: PAGE O.::..:...-F _

DEPTH DEPTH UNFILTERED FILTERED COMMENTSMETERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

0.5 1.641.0 3.281.5 4.922.0 6.562.5 8.203.0 9.843.5 11.484.0 13.124.5 14.765.0 16.405.5 18.046.0 19.696.5 21.337.0 22.977.5 24.618.0 26.258.5 27.899.0 29.539.5 31.1710.0 32.8110.5 34.4511.0 36.0911.5 37.7312.0 39.3712.5 41.0113.0 42.6513.5 44.2914.0 45.9314.5 47.5715.0 49.2115.5 50.8516.0 52.4916.5 54.1317.0 55.7717.5 57.4118.0 59.06



Project 6468-06-1472January 17, 2007

GEOVISION SUSPENSION LOGGING FIELD NOTESSITE: DATE:------------------- ----------CLIENT: JOB:-------------------AUTHOR: PAGE OF------------------- ------'------DEPTH DEPTH UNFILTERED FILTERED COMMENTSMETERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

18.5 60.7019.0 62.3419.5 63.9820.0 65.6220.5 67.2621.0 68.9021.5 70.5422.0 72.1822.5 73.8223.0 75.4623.5 77.1024.0 78.7424.5 80.3825.0 82.0225.5 83.6626.0 85.3026.5 86.9427.0 88.5827.5 90.2228.0 91.8628.5 93.5029.0 95.1429.5 96.7830.0 98.4330.5 100.0731.0 101.7131.5 103.3532.0 104.9932.5 106.6333.0 108.2733.5 109.9134.0 111.5534.5 113.1935.0 114.8335.5 116.4736.0 118.11



Project 6468-06-1472January 17, 2007


CLIENT: JOB:-------------------AUTHOR: PAGE OF------------------- ----~:...--_--

DEPTH DEPTH UNFILTERED FILTERED COMMENTSMETERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

36.5 119.7537.0 121.3937.5 123.0338.0 124.6738.5 126.3139.0 127.9539.5 129.5940.0 131.2340.5 132.8741.0 134.5141.5 136.1542.0 137.8042.5 139.4443.0 141.0843.5 142.7244.0 144.3644.5 146.0045.0 147.6445.5 149.2846.0 150.9246.5 152.5647.0 154.2047.5 155.8448.0 157.4848.5 159.1249.0 160.7649.5 162.4050.0 164.0450.5 165.6851.0 167.3251.5 168.9652.0 170.6052.5 172.2453.0 173.8853.5 175.5254.0 177.17



Project 6468-06-1472January 17, 2007


CLIENT: JOB:-------------------AUTHOR: PAGE O..:;:",;"...F _

DEPTH DEPTH UNFILTERED FILTERED COMMENTS

METERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

54.5 178.8155.0 180.4555.5 182.0956.0 183.7356.5 185.3757.0 187.0157.5 188.6558.0 190.2958.5 191.9359.0 193.5759.5 195.2160.0 196.8560.5 198.4961.0 200.1361.5 201.7762.0 203.4162.5 205.0563.0 206.6963.5 208.3364.0 209.9764.5 211.6165.0 213.2565.5 214.9066.0 216.5466.5 218.1867.0 219.8267.5 221.4668.0 223.1068.5 224.7469.0 226.3869.5 228.0270.0 229.6670.5 231.3071.0 232.9471.5 234.5872.0 236.22



Project 6468-06-1472January 17, 2007


CLIENT: JOB:-------------------AUTHOR: PAGE O..::...:....F _

DEPTH DEPTH UNFILTERED FILTERED COMMENTS

METERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

72.5 237.86

73.0 239.50

73.5 241.14

74.0 242.78

74.5 244.42

75.0 246.06

75.5 247.70

76.0 249.34

76.5 250.98

77.0 252.62

77.5 254.27

78.0 255.91

78.5 257.55

79.0 259.19

79.5 260.83

80.0 262.47

80.5 264.11

81.0 265.75

81.5 267.39

82.0 269.03

82.5 270.67

83.0 272.31

83.5 273.95

84.0 275.59

84.5 277.23

85.0 278.87

85.5 280.5186.0 282.15

86.5 283.79

87.0 285.43

87.5 287.07

88.0 288.71

88.5 290.35

89.0 291.99

89.5 293.64

90.0 295.28



Project 6468-06-1472January 17, 2007

GEOVISION SUSPENSION LOGGING FIELD NOTESSITE: DATE:------------------- ---------CLIENT: JOB:-------------------AUTHOR: PAGE OF------------------- ---------DEPTH DEPTH UNFILTERED FILTERED COMMENTSMETERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

90.5 296.92

91.0 298.56

91.5 300.20

92.0 301.84

92.5 303.48

93.0 305.12

93.5 306.76

94.0 308.40

94.5 310.04

95.0 311.68

95.5 313.32

96.0 314.9696.5 316.60

97.0 318.2497.5 319.88

98.0 321.52

98.5 323.1699.0 324.80

99.5 326.44100.0 328.08100.5 329.72

101.0 331.36

101.5 333.01102.0 334.65

102.5 336.29

103.0 337.93103.5 339.57104.0 341.21104.5 342.85

105.0 344.49105.5 346.13106.0 347.77

106.5 349.41107.0 351.05107.5 352.69

108.0 354.33



Project 6468-06-1472January 17, 2007

GEOVISION SUSPENSION LOGGING FIELD NOTESSITE: DATE: ---------CLIENT: JOB:

AUTHOR: PAGE OF------------------- -------'-----DEPTH DEPTH UNFILTERED FILTERED COMMENTSMETERS FEET FILE NO. FILE NO. CASING, WATER, ROCK, ETC

108.5 355.97109.0 357.61109.5 359.25110.0 360.89110.5 362.53111.0 364.17111.5 365.81112.0 367.45112.5 369.09113.0 370.73113.5 372.38114.0 374.02114.5 375.66115.0 377.30115.5 378.94116.0 380.58116.5 382.22117.0 383.86117.5 385.50118.0 387.14118.5 388.78119.0 390.42119.5 392.06120.0 393.70120.5 395.34121.0 396.98121.5 398.62122.0 400.26122.5 401.90123.0 403.54123.5 405.18124.0 406.82124.5 408.46125.0 410.10125.5 411.75126.0 413.39


sonda suspendida_boring geophysical logging field measurement procedures-geovision & oyo (2007)

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