ML032721615
| ML032721615 | |
| Person / Time | |
|---|---|
| Site: | Clinton, 05200007, PROJ0718  |
| Issue date: | 09/25/2003 |
| From: | Exelon Generation Co, Exelon Nuclear |
| To: | Office of New Reactors |
| Shared Package | |
| ML032721596 | List:
|
| References | |
| +ReviewedClintonESP, +reviewednvg DEL-096-REV0 | |
| Download: ML032721615 (48) | |
Text
Attachment A-5 GeoVision Suspension Logging Report
P-S SUSPENSION LOGGING BOREHOLE B-2 CLINTON NUCLEAR POWER PLANT CLINTON, ILLINOIS October 10, 2002
P-S SUSPENSION LOGGING BOREHOLE B-2 CLINTON NUCLEAR POWER PLANT CLINTON, ILLINOIS Prepared by GEOVision Geophysical Services 1151 Pomona Road, Unit P Corona, California 92882 (909) 549-1234 Report 2495-01
TABLE OF CONTENTS TABLE OF CONTENTS............................................................................................................................................ I TABLE OF FIGURES...............................................................................................................................................II TABLE OF TABLES.................................................................................................................................................II INTRODUCTION.......................................................................................................................................................1 INSTRUMENTATION AND PROCEDURES.........................................................................................................2 INSTRUMENTATION........................................................................................................................................................2 FIELD MEASUREMENT PROCEDURES..............................................................................................................................4 DATA ANALYSIS.......................................................................................................................................................5 P-WAVE ANALYSIS........................................................................................................................................................6 SH-WAVE ANALYSIS......................................................................................................................................................6 RESULTS.....................................................................................................................................................................8 DATA RELIABILITY.........................................................................................................................................................8 QUALITY ASSURANCE....................................................................................................................................................8 EXHIBIT A PROCEDURE FOR OYO P-S SUSPENSION SEISMIC VELOCITY LOGGING EXHIBIT B OYO 170 VELOCITY LOGGING SYSTEM - NIST TRACEABLE CALIBRATION PROCEDURE AND CALIBRATION RECORDS
ii Table of Figures Figure 1: Concept illustration of P-S logging system............................................................ 9 Figure 2: Unfiltered Record for a Depth of 126.3 ft.............................................................. 10 Figure 3: Filtered Record for a Depth of 126.3 ft................................................................. 10 Figure 4: Borehole B-2, Suspension P-and SH-wave Velocities..................................... 11 Figure 5: Borehole B-2, Suspension P and SH-Wave R1-R2 and S-R1 Velocities........ 17 Table of Tables Table 1: Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP......................................................................................................................... 12 Table 2: Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP......................................................................................................................... 18
1 INTRODUCTION Borehole geophysical measurements were performed in one borehole at the Clinton Nuclear Power Plant, Clinton, Illinois for the purpose of measuring in-situ soil velocities, both shear wave (SH-wave) and compressional wave (P-wave). OYO P-S Suspension logging data acquisition was performed on August 8, 2002 by Antony Martin of GEOVision. Analysis was subsequently completed by Antony Martin and Quality Assurance review was completed by Rob Steller.
The OYO Model 170 Suspension Logging Recorder and Suspension Logging Probe were used to obtain in-situ horizontal shear and compressional wave velocity measurements at 1.64 ft intervals in borehole B-2, which was drilled to a depth of 323 ft. The acquired data was analyzed and a profile of velocity versus depth was produced for both compressional and horizontally polarized shear waves, where possible.
A detailed reference for the velocity measurement techniques used in this study is:
Guidelines for Determining Design Basis Ground Motions, Report TR-102293, Electric Power Research Institute, Palo Alto, California, November 1993, Sections 7 and 8.
2 INSTRUMENTATION AND PROCEDURES The GEO Vision Procedure for Oyo P-S Suspension Seismic Velocity Logging (Exhibit A) was followed during this investigation. This procedure was supplied and approved in advance of the field work. Following is a summary.
Instrumentation Suspension soil velocity measurements were performed using the Model 170 Suspension Logging system, manufactured by OYO Corporation. This system consisted of the following components: Model 3331A recorder (S/N 19029), Model 3348A head reducer (S/N 28063),
Model 3385 receiver (S/N 23053), Model 3387 1 meter isolation tube (S/N 24053), Model 3304 source (S/N 37113), Model 3386A source driver (S/N 27073), Model 3302W weight (S/N 12007) and Model 3828A winch/depth encoder (S/N 18020). Calibration records for the recorder are presented in Exhibit B. The suspension logging system directly determines the average velocity of a segment of the soil column surrounding the borehole of interest by measuring the elapsed time between arrivals of a wave propagating upward through the soil column. The receivers that detect the wave, and the source that generates the wave, are moved as a unit in the borehole producing relatively constant amplitude signals at all depths.
The suspension system probe consists of a combined reversible polarity solenoid horizontal shear-wave source (SH) and compressional-wave source (P), joined to two biaxial receivers by a flexible isolation cylinder, as shown in Figure 1. The separation of the two receivers is approximately 1 meter or 3.3 ft, allowing average wave velocity in the region between the receivers to be determined by inversion of the wave travel time between the two receivers. The total length of the probe as used in this survey is 19 ft, with the center point of the receiver pair 12.1 ft above the bottom end of the probe. The probe receives control signals from, and sends the amplified receiver signals to, instrumentation on the surface via an armored 7 or 4 conductor cable. The cable is wound onto the drum of a winch and is used to support the probe. Cable travel is measured to provide probe depth data.
The entire probe is suspended by the cable and centered in the borehole by nylon "whiskers",
therefore, source motion is not coupled directly to the borehole walls; rather, the source motion creates a horizontally propagating impulsive pressure wave in the fluid filling the borehole and
3 surrounding the source. This pressure wave is converted to P and SH-waves in the surrounding soil and rock as it impinges upon the borehole wall. These waves propagate through the soil and rock surrounding the borehole, in turn causing a pressure wave to be generated in the fluid surrounding the receivers as the soil waves pass their location. Separation of the P and SH-waves at the receivers is performed using the following steps:
- 1. Orientation of the horizontal receivers is maintained parallel to the axis of the source, maximizing the amplitude of the recorded SH-wave signals.
- 2. At each depth, SH-wave signals are recorded with the source actuated in opposite directions, producing SH-wave signals of opposite polarity, providing a characteristic SH-wave signature distinct from the P-wave signal.
- 3. The approximate 7 ft separation of source and first receiver permits the P-wave signal to pass and damp significantly before the slower SH-wave signal arrives at the receiver. In faster soils or rock, the isolation cylinder is extended to allow greater separation of the P-and SH-wave signals.
- 4. In saturated soils, the received P-wave signal is typically of much higher frequency than the received SH-wave signal, permitting additional separation of the two signals by low pass filtering.
- 5. Direct arrival of the original pressure pulse in the fluid is not detected at the receivers because the wavelength of the pressure pulse in fluid is significantly greater than the dimension of the fluid annulus surrounding the probe (meter versus centimeter scale),
preventing significant energy transmission through the fluid medium.
In operation, a distinct, repeatable pattern of impulses is generated at each depth as follows:
- 1. The source is fired in one direction producing dominantly horizontal shear with some vertical compression, and the signals from the horizontal receivers situated parallel to the axis of motion of the source are recorded.
- 2. The source is fired again in the opposite direction and the horizontal receiver signals are recorded.
- 3. The source is fired again and the vertical receiver signals are recorded. The repeated source pattern facilitates the picking of the P and SH-wave arrivals; reversal of the source changes the polarity of the SH-wave pattern but not the P-wave pattern.
4 The data from each receiver during each source activation is recorded as a different channel on the recording system. The Model 170 has six channels (two simultaneous recording channels),
each with a 12 bit, 1024 sample record. The recorded data is displayed on a CRT display and on paper tape output as six channels with a common time scale. Data is stored on 3.5 inch floppy diskettes for further processing. Up to 8 sampling sequences can be summed to improve the signal to noise ratio of the signals.
Review of the displayed data on the CRT or paper tape allows the operator to set the gains, filters, delay time, pulse length (energy), sample rate, and summing number to optimize the quality of the data before recording. Verification of the calibration of the Model 170 digital recorder is performed every twelve months using a NIST traceable frequency source and counter.
Field Measurement Procedures The borehole was logged as a 6-inch diameter open hole filled with drilling mud. The borehole probe was positioned with the mid-point of the receiver spacing at ground surface, and the mechanical and electronic depth counters were set to zero. The probe was lowered to the bottom of the 323-ft deep borehole and then returned to the surface, stopping at 1.64 ft intervals to collect data, as summarized below.
At each measurement depth the measurement sequence of two opposite horizontal records and one vertical record was performed, and the gains were adjusted as required. The data from each depth was printed on paper tape, checked, and recorded on diskette before moving to the next depth.
Upon completion of the measurements, the probe zero depth indication at grade was verified prior to removal from the borehole.
5 DATA ANALYSIS The OYO Model 170 P-S Suspension Logger system offers the opportunity to measure ground velocity in two ways using the same data. The standard method is to measure the velocity from the travel time between the two receivers, as described under Instrumentation above. A second method is to use the travel time from the source to the first receiver. The difference between these methods is summarized as follows:
- 1. The receiver-to-receiver (R1-R2) method is normally more accurate, because the picks are made from the peak of the arrival waveform. The analyst picks the arrival waveform, and software is used to find the peaks. Travel time is then from peak-to-peak.
- 2. R1-R2 data has higher resolution, because the travel time is averaged over the nominal 1m or 3.3ft between receivers. The greater scatter in velocities is attributed to the changes in material from one measurement location to another. These measurements are very repeatable.
- 3. Averaging the normal and reverse travel times eliminates errors due to hysteresis of the source (difference in actuation pulses).
- 4. Source-to-receiver (S-R1) measurements are subject to a source delay, nominally 4 milliseconds for the 7-conductor systems and 3 milliseconds for the 4-conductor systems.
This source delay is independently verifiable, but subject at times to change due to loss of source springs during the measurement program.
- 5. The S-R1 results are more subject to picking errors, since the picks are based on the analysts choice of first motion rather than software peak detection. These errors are less significant, however, since the total travel time is more than twice as long.
- 6. The S-R1 results exhibit less scatter, since the velocity is averaged over the greater distance from the source to the first receiver, approximately 7ft compared to 3.3ft.
(NOTE: actual measured separations used in the analysis varied from 7.11 to 7.17ft))
- 7. The S-R1 results are less subject to possible effects of dispersion, if present.
- 8. The S-R1 data set extends about 5ft deeper than the R1-R2 data set. The reason is that the depth reference location between the source and the first receiver is about 5.1ft below
6 the depth reference between R1 and R2. On the other hand, for the same reason, R1-R2 data will extend closer to the surface by about 5.1ft.
For the above reasons, normally R1-R2 results are considered the primary results, and S-R1 results are used only for quality assurance purposes, to check the validity of the R1-R2 results.
P-Wave Analysis The recorded digital records were analyzed to locate the first minima or first arrival on the vertical axis records, indicating the arrival of P-wave energy. The difference in travel time between receiver 1 and receiver 2 (R1-R2) arrivals was used to calculate the P-wave velocity for that 3.3 ft segment of the soil column. When observable, P-wave arrivals on the horizontal axis records were used to verify the velocities determined from the vertical axis data. P-wave arrival data was of excellent quality in this borehole, except to the upper 20 ft which was of fair quality.
The P-wave velocity calculated from the travel time over the approximately 7 ft interval from source to receiver 1 (S-R1) was calculated and plotted for quality assurance of the velocity derived from the travel time between receivers. In this analysis, the depth values as recorded were increased by 5.1 ft to correspond to the mid-point of the approximately 7 ft S-R1 interval, as illustrated in Figure 1. Travel times were obtained by picking the first break of the P-wave signal at receiver 1 and subtracting the source delay; approximately 3 milliseconds, the calculated and experimentally verified delay from source trigger pulse (beginning of record) to source impact. This delay corresponds to the duration of acceleration of the solenoid before impact.
SH-Wave Analysis The recorded digital records were studied to establish the presence of clear SH-wave pulses, as indicated 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 very nearly inverted images of each other. Digital FFT - IFFT low-pass filtering was used to remove the higher frequency P-wave signal from the SH-wave signal. Different filter cutoffs were used to separate P-and SH-waves at different depths.
7 Generally, the first minima was picked for the 'normal' signals and the first maxima for the
'reverse' signals, although other points on the waveform were used if the first pulse was distorted.
The absolute arrival time of the 'normal' and 'reverse' signals may vary by +/- 0.2 milliseconds, due to differences in the actuation time of the solenoid source caused by constant mechanical bias in the source or by borehole inclination. This variation does not affect the R1-R2 velocity determinations, as the differential time is measured between arrivals of waves created by the same source actuation. The final velocity value is the average of the values obtained from the
'normal' and 'reverse' source actuations.
The SH-wave velocity calculated from the travel time over the approximate 7 ft interval from source to receiver 1 (S-R1) was calculated and plotted for verification of the velocity derived from the travel time between receivers. In this analysis, the depth values were increased by 5.1 ft to correspond to the mid-point of the 7 ft S-R1 interval, as illustrated in Figure 1. Travel times were obtained by picking the first break of the SH-wave signal at the near receiver and subtracting 3.0 milliseconds, the calculated and experimentally verified delay from the source trigger pulse (beginning of the record) to source impact.
Figure 2 shows an example of R1 - R2 measurements on the unfiltered record for a depth of 126.3 ft in borehole B-2. Figure 3 displays the same record after filtering of the SH-waveform record with a 1,000 Hz FFT - IFFT digital lowpass filter, illustrating the presence of higher frequency P-wave energy at the beginning of the record.
8 RESULTS Suspension R1-R2 P-and SH-wave velocities for borehole B-2 are plotted in Figure 4. The suspension velocity data presented in this figure is presented in Tables 1. P and SH-wave velocity data from R1-R2 analysis and quality assurance analysis of S-R1 data are plotted together in Figures 5 to aid in visual comparison. It must be noted that R1-R2 data is an average velocity over a 3.3 ft segment of the soil column whereas S-R1 data is an average over 7 ft. S-R1 data is, therefore somewhat smoother. S-R1 data are presented in tabular format in Table 2.
Good correspondence between the shape of the P-and SH-wave velocity curves is observed for this data set. The velocities derived from S-R1 and R1-R2 data are in good agreement, providing verification of the higher resolution R1-R2 data.
Data Reliability P-and SH-wave velocity measurement using the Suspension Method gives average velocities over a 3.3 ft interval of depth. This high resolution results in the scatter of values shown in the graphs. Individual measurements are very reliable with estimated precision of +/- 5%.
Standardized field procedures (Exhibit A) and quality assurance checks add to the reliability of these data.
Quality Assurance These velocity measurements were performed using industry-standard or better methods for both measurements and analyses. All work was performed under GEOVision quality assurance procedures, which include:
- Use of NIST-traceable calibrations, where applicable, for field and laboratory instrumentation
- Use of standard field data logs
- Use of independent verification of data by comparison of receiver-to-receiver and source-to-receiver velocities
- Independent review of calculations and results by a registered professional engineer, geologist, or geophysicist.
9 Figure 1: Concept illustration of P-S logging system
Cable Head Head Reducer Upper (R2)
Receiver Lower (R1)
Receiver 3.28 ft flexible Isolation Cylinder Combined Sh and P-wave Source (S)
Source Driver Weight
Winch Armored 7-Conductor cable Diskette with Data OYO PS-170 Logger/Recorder Overall Length ~ 19 ft Depth reference location for R1-R2 analysis:
mid-point of Receivers 1.64 ft 1.64 ft Joint Joint Tip 7.02 ft 12.1 ft Depth reference location for S-R1 analysis : mid point of 7.02 ft S-R1 spacing 5.15 ft 3.44 ft 3.51 ft 3.51 ft Not to Scale
10 Figure 2: Unfiltered Record for a Depth of 126.3 ft.
Figure 3: Filtered Record for a Depth of 126.3 ft.
11 CLINTON NUCLEAR POWER PLANT, BOREHOLE B-2 Receiver to Receiver Vs and Vp Analysis 0
50 100 150 200 250 300 0
2000 4000 6000 8000 10000 VELOCITY (ft/s)
DEPTH (ft)
Near-Far Receivers, Vs Near-Far Receivers, Vp Figure 4: Borehole B-2, Suspension P-and SH-wave Velocities
12 Table 1: Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Velocity Depth at Velocity Midpoint Between Receivers Vs Vp Poisson's Ratio Midpoint Between Receivers Vs Vp Poisson's Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 1.6 830 1720 0.35 0.5 250 520 0.35 3.3 830 1680 0.34 1.0 250 510 0.34 4.9 890 2410 0.42 1.5 270 730 0.42 6.6 850 3630 0.47 2.0 260 1110 0.47 8.2 990 4560 0.48 2.5 300 1390 0.48 9.8 960 4960 0.48 3.0 290 1510 0.48 11.5 940 5630 0.49 3.5 290 1710 0.49 13.1 1270 4500 0.46 4.0 390 1370 0.46 14.8 1340 4380 0.45 4.5 410 1340 0.45 16.4 1040 4620 0.47 5.0 320 1410 0.47 18.0 1010 5360 0.48 5.5 310 1630 0.48 19.7 1000 4560 0.47 6.0 310 1390 0.47 21.3 1030 4890 0.48 6.5 310 1490 0.48 23.0 920 5040 0.48 7.0 280 1540 0.48 24.6 910 5110 0.48 7.5 280 1560 0.48 26.3 1110 5920 0.48 8.0 340 1800 0.48 27.9 1040 5820 0.48 8.5 320 1770 0.48 29.5 1100 5920 0.48 9.0 340 1800 0.48 31.2 1140 6030 0.48 9.5 350 1840 0.48 32.8 880 5190 0.49 10.0 270 1580 0.49 34.5 930 5190 0.48 10.5 280 1580 0.48 36.1 830 5400 0.49 11.0 250 1650 0.49 37.7 820 5820 0.49 11.5 250 1770 0.49 39.4 860 5920 0.49 12.0 260 1800 0.49 41.0 840 5440 0.49 12.5 260 1660 0.49 42.7 860 5970 0.49 13.0 260 1820 0.49 44.3 950 5720 0.49 13.5 290 1740 0.49 45.9 1050 6030 0.48 14.0 320 1840 0.48 47.6 1100 5770 0.48 14.5 340 1760 0.48 49.2 1100 6140 0.48 15.0 340 1870 0.48 50.9 1090 6430 0.49 15.5 330 1960 0.49 52.5 1310 6430 0.48 16.0 400 1960 0.48 54.1 1760 7500 0.47 16.5 540 2290 0.47 55.8 1970 7260 0.46 17.0 600 2210 0.46 57.4 1930 7180 0.46 17.5 590 2190 0.46 59.1 1650 6680 0.47 18.0 500 2040 0.47 60.7 1690 7030 0.47 18.5 510 2140 0.47 62.3 1880 7030 0.46 19.0 570 2140 0.46 64.0 1860 7110 0.46 19.5 570 2170 0.46
13 TABLE 1 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Velocity Depth at Velocity Midpoint Between Receivers Vs Vp Poisson's Ratio Midpoint Between Receivers Vs Vp Poisson's Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 65.6 2400 6960 0.43 20.0 730 2120 0.43 67.3 2060 6620 0.45 20.5 630 2020 0.45 68.9 1350 5720 0.47 21.0 410 1740 0.47 70.5 1290 6190 0.48 21.5 390 1890 0.48 72.2 1250 6030 0.48 22.0 380 1840 0.48 73.8 1100 5820 0.48 22.5 330 1770 0.48 75.5 1280 6190 0.48 23.0 390 1890 0.48 77.1 1570 6750 0.47 23.5 480 2060 0.47 78.7 1710 7030 0.47 24.0 520 2140 0.47 80.4 1860 7580 0.47 24.5 570 2310 0.47 82.0 2110 7420 0.46 25.0 640 2260 0.46 83.7 2020 7420 0.46 25.5 620 2260 0.46 85.3 1990 7500 0.46 26.0 610 2290 0.46 85.3 1990 7670 0.46 26.0 610 2340 0.46 85.3 1980 7580 0.46 26.0 600 2310 0.46 86.9 2260 7760 0.45 26.5 690 2360 0.45 88.6 2250 7500 0.45 27.0 690 2290 0.45 90.2 2280 7940 0.46 27.5 700 2420 0.46 91.9 2360 8040 0.45 28.0 720 2450 0.45 93.5 2340 8330 0.46 28.5 710 2540 0.46 95.1 2580 8540 0.45 29.0 790 2600 0.45 96.8 3130 8880 0.43 29.5 950 2710 0.43 98.4 3250 8770 0.42 30.0 990 2670 0.42 100.1 2860 8540 0.44 30.5 870 2600 0.44 101.7 2850 8230 0.43 31.0 870 2510 0.43 103.4 2630 8330 0.44 31.5 800 2540 0.44 105.0 2660 8330 0.44 32.0 810 2540 0.44 106.6 2590 8230 0.45 32.5 790 2510 0.45 108.3 2530 7850 0.44 33.0 770 2390 0.44 109.9 2590 7940 0.44 33.5 790 2420 0.44 111.6 2250 8040 0.46 34.0 690 2450 0.46 113.2 2470 7850 0.44 34.5 750 2390 0.44 114.8 2390 7580 0.44 35.0 730 2310 0.44 116.5 2240 7940 0.46 35.5 680 2420 0.46 118.1 2120 7180 0.45 36.0 640 2190 0.45 119.8 2210 7580 0.45 36.5 670 2310 0.45 121.4 2250 7500 0.45 37.0 690 2290 0.45 123.0 2210 7580 0.45 37.5 670 2310 0.45 124.7 2150 7500 0.46 38.0 660 2290 0.46
14 TABLE 1 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Velocity Depth at Velocity Midpoint Between Receivers Vs Vp Poisson's Ratio Midpoint Between Receivers Vs Vp Poisson's Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 126.3 2210 7420 0.45 38.5 670 2260 0.45 128.0 2220 7260 0.45 39.0 680 2210 0.45 129.6 2060 7420 0.46 39.5 630 2260 0.46 131.2 2060 7340 0.46 40.0 630 2240 0.46 132.9 2140 7670 0.46 40.5 650 2340 0.46 134.5 2100 7260 0.45 41.0 640 2210 0.45 136.2 2160 7500 0.45 41.5 660 2290 0.45 137.8 2240 7180 0.45 42.0 680 2190 0.45 139.4 2140 7500 0.46 42.5 650 2290 0.46 141.1 2180 7760 0.46 43.0 660 2360 0.46 142.7 2370 8130 0.45 43.5 720 2480 0.45 144.4 2490 7760 0.44 44.0 760 2360 0.44 146.0 2450 7760 0.44 44.5 750 2360 0.44 147.6 2360 7760 0.45 45.0 720 2360 0.45 149.3 2350 7760 0.45 45.5 720 2360 0.45 150.9 2380 8230 0.45 46.0 720 2510 0.45 152.6 2430 7940 0.45 46.5 740 2420 0.45 154.2 2200 7760 0.46 47.0 670 2360 0.46 155.8 2280 7850 0.45 47.5 700 2390 0.45 157.5 2280 8130 0.46 48.0 700 2480 0.46 159.1 2350 7500 0.45 48.5 720 2290 0.45 160.8 2250 7670 0.45 49.0 690 2340 0.45 162.4 2200 7760 0.46 49.5 670 2360 0.46 164.0 1820 6620 0.46 50.0 560 2020 0.46 165.7 1420 6680 0.48 50.5 430 2040 0.48 167.3 1390 6250 0.47 51.0 420 1910 0.47 169.0 1450 6080 0.47 51.5 440 1850 0.47 170.6 1470 6140 0.47 52.0 450 1870 0.47 172.2 1650 6890 0.47 52.5 500 2100 0.47 173.9 1740 7260 0.47 53.0 530 2210 0.47 175.5 1630 7030 0.47 53.5 500 2140 0.47 177.2 1530 6680 0.47 54.0 470 2040 0.47 178.8 1540 6490 0.47 54.5 470 1980 0.47 180.5 1610 6680 0.47 55.0 490 2040 0.47 182.1 1790 6960 0.46 55.5 540 2120 0.46 183.7 2120 7420 0.46 56.0 650 2260 0.46 185.4 2470 8040 0.45 56.5 750 2450 0.45 187.0 2590 7940 0.44 57.0 790 2420 0.44 188.7 2670 7580 0.43 57.5 810 2310 0.43
15 TABLE 1 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Velocity Depth at Velocity Midpoint Between Receivers Vs Vp Poisson's Ratio Midpoint Between Receivers Vs Vp Poisson's Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 190.3 2800 7940 0.43 58.0 850 2420 0.43 191.9 2790 8230 0.44 58.5 850 2510 0.44 193.6 2520 7500 0.44 59.0 770 2290 0.44 195.2 2410 7580 0.44 59.5 730 2310 0.44 196.9 2390 7940 0.45 60.0 730 2420 0.45 198.5 2400 7850 0.45 60.5 730 2390 0.45 200.1 2470 7850 0.44 61.0 750 2390 0.44 201.8 2630 7760 0.44 61.5 800 2360 0.44 203.4 2380 7420 0.44 62.0 720 2260 0.44 205.1 2210 7500 0.45 62.5 670 2290 0.45 206.7 2010 6960 0.45 63.0 610 2120 0.45 208.3 1860 6890 0.46 63.5 570 2100 0.46 210.0 1890 6960 0.46 64.0 580 2120 0.46 211.6 1700 7420 0.47 64.5 520 2260 0.47 213.3 1880 7180 0.46 65.0 570 2190 0.46 214.9 2210 6820 0.44 65.5 670 2080 0.44 216.5 2190 6890 0.44 66.0 670 2100 0.44 218.2 2300 6620 0.43 66.5 700 2020 0.43 219.8 2000 6430 0.45 67.0 610 1960 0.45 221.5 1830 6430 0.46 67.5 560 1960 0.46 223.1 1870 6490 0.45 68.0 570 1980 0.45 224.7 1850 6750 0.46 68.5 560 2060 0.46 226.4 1800 6550 0.46 69.0 550 2000 0.46 228.0 1890 6750 0.46 69.5 570 2060 0.46 229.7 1860 6680 0.46 70.0 570 2040 0.46 231.3 1900 6820 0.46 70.5 580 2080 0.46 232.9 1890 6890 0.46 71.0 580 2100 0.46 234.6 1930 7340 0.46 71.5 590 2240 0.46 236.2 2180 7110 0.45 72.0 670 2170 0.45 237.9 2210 6430 0.43 72.5 670 1960 0.43 239.5 1920 6620 0.45 73.0 590 2020 0.45 241.1 1760 6030 0.45 73.5 540 1840 0.45 242.8 1720 6030 0.46 74.0 520 1840 0.46 244.4 1830 6820 0.46 74.5 560 2080 0.46 246.1 2140 7420 0.45 75.0 650 2260 0.45 247.7 2120 6820 0.45 75.5 650 2080 0.45 249.3 1970 6430 0.45 76.0 600 1960 0.45 251.0 1990 6820 0.45 76.5 610 2080 0.45 252.6 2480 7260 0.43 77.0 760 2210 0.43
16 TABLE 1 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Receiver-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Velocity Depth at Velocity Midpoint Between Receivers Vs Vp Poisson's Ratio Midpoint Between Receivers Vs Vp Poisson's Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 254.3 2400 7180 0.44 77.5 730 2190 0.44 255.9 2210 6960 0.44 78.0 670 2120 0.44 257.6 2160 6820 0.44 78.5 660 2080 0.44 259.2 1790 6310 0.46 79.0 550 1920 0.46 260.8 1780 6250 0.46 79.5 540 1910 0.46 262.5 1890 6750 0.46 80.0 580 2060 0.46 264.1 1890 7180 0.46 80.5 570 2190 0.46 265.8 1830 6890 0.46 81.0 560 2100 0.46 267.4 1690 5490 0.45 81.5 520 1670 0.45 269.0 1560 5270 0.45 82.0 480 1610 0.45 270.7 1510 5720 0.46 82.5 460 1740 0.46 272.3 1470 5490 0.46 83.0 450 1670 0.46 274.0 1470 5970 0.47 83.5 450 1820 0.47 275.6 1360 5870 0.47 84.0 410 1790 0.47 277.2 1190 6370 0.48 84.5 360 1940 0.48 278.9 1300 6680 0.48 85.0 400 2040 0.48 280.5 1650 6680 0.47 85.5 500 2040 0.47 282.2 1750 6680 0.46 86.0 530 2040 0.46 283.8 2580 7180 0.43 86.5 790 2190 0.43 285.4 2780 7110 0.41 87.0 850 2170 0.41 287.1 2920 7580 0.41 87.5 890 2310 0.41 288.7 2780 7110 0.41 88.0 850 2170 0.41 290.4 3040 7030 0.38 88.5 930 2140 0.38 292.0 3310 7940 0.39 89.0 1010 2420 0.39 293.6 3250 8130 0.41 89.5 990 2480 0.41 295.3 3280 8130 0.40 90.0 1000 2480 0.40 296.9 3260 8130 0.40 90.5 990 2480 0.40 298.6 3410 8440 0.40 91.0 1040 2570 0.40 300.2 3390 8230 0.40 91.5 1030 2510 0.40 301.8 3440 8130 0.39 92.0 1050 2480 0.39 303.5 3390 8040 0.39 92.5 1030 2450 0.39 305.1 3590 7850 0.37 93.0 1090 2390 0.37 306.8 3880 7940 0.34 93.5 1180 2420 0.34 308.4 3990 7670 0.31 94.0 1220 2340 0.31 310.0 4220 7940 0.30 94.5 1290 2420 0.30
17 CLINTON NUCLEAR POWER PLANT, BOREHOLE B-2 Source to Receiver and Receiver to Receiver Analysis 0
50 100 150 200 250 300 0
2000 4000 6000 8000 10000 VELOCITY (ft/s)
DEPTH (ft)
Near-Far Receivers, Vs Source-Near Receiver, Vs Near-Far Receivers, Vp Source-Near Receiver, Vp Figure 5: Borehole B-2, Suspension P and SH-Wave R1-R2 and S-R1 Velocities
18 Table 2: Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Midpoint Velocity Depth at Midpoint Velocity Between Source and Near Receiver Vs Vp Poisson' s Ratio Between Source and Near Receiver Vs Vp Poisson' s Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 6.9 920 4270 0.48 2.1 280 1300 0.48 8.6 890 3960 0.47 2.6 270 1210 0.47 10.2 900 3220 0.46 3.1 270 980 0.46 11.8 880 4430 0.48 3.6 270 1350 0.48 13.5 970 4370 0.47 4.1 290 1330 0.47 15.1 960 3940 0.47 4.6 290 1200 0.47 16.8 950 4270 0.47 5.1 290 1300 0.47 18.4 890 4270 0.48 5.6 270 1300 0.48 20.0 900 4570 0.48 6.1 280 1390 0.48 21.7 990 4600 0.48 6.6 300 1400 0.48 23.3 1040 4980 0.48 7.1 320 1520 0.48 25.0 990 4570 0.48 7.6 300 1390 0.48 26.6 1040 4810 0.48 8.1 320 1470 0.48 28.2 1090 5090 0.48 8.6 330 1550 0.48 29.9 1030 5050 0.48 9.1 310 1540 0.48 31.5 1050 4720 0.47 9.6 320 1440 0.47 33.2 1070 4570 0.47 10.1 330 1390 0.47 34.8 990 4660 0.48 10.6 300 1420 0.48 36.4 950 4810 0.48 11.1 290 1470 0.48 38.1 960 4940 0.48 11.6 290 1510 0.48 39.7 900 5200 0.48 12.1 270 1580 0.48 41.4 950 5050 0.48 12.6 290 1540 0.48 43.0 1010 5160 0.48 13.1 310 1570 0.48 44.6 1050 5600 0.48 13.6 320 1710 0.48 46.3 1100 5740 0.48 14.1 340 1750 0.48 47.9 1140 5760 0.48 14.6 350 1760 0.48 49.6 1170 6100 0.48 15.1 360 1860 0.48 51.2 1280 6460 0.48 15.6 390 1970 0.48 52.8 1380 6610 0.48 16.1 420 2010 0.48 54.5 1620 6760 0.47 16.6 490 2060 0.47 56.1 1900 6830 0.46 17.1 580 2080 0.46 57.8 1870 6890 0.46 17.6 570 2100 0.46 59.4 1870 6700 0.46 18.1 570 2040 0.46 61.0 1850 6760 0.46 18.6 560 2060 0.46 62.7 1870 6830 0.46 19.1 570 2080 0.46 64.3 1820 6830 0.46 19.6 560 2080 0.46 66.0 1590 6580 0.47 20.1 480 2000 0.47 67.6 1620 6610 0.47 20.6 490 2010 0.47 69.3 1560 6460 0.47 21.1 480 1970 0.47
19 TABLE 2 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Midpoint Velocity Depth at Midpoint Velocity Between Source and Near Receiver Vs Vp Poisson' s Ratio Between Source and Near Receiver Vs Vp Poisson' s Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 70.9 1290 6350 0.48 21.6 390 1930 0.48 72.5 1190 6460 0.48 22.1 360 1970 0.48 74.2 1310 6370 0.48 22.6 400 1940 0.48 75.8 1360 6520 0.48 23.1 420 1990 0.48 77.5 1570 6800 0.47 23.6 480 2070 0.47 79.1 1820 7030 0.46 24.1 550 2140 0.46 80.7 1910 7510 0.47 24.6 580 2290 0.47 82.4 1950 7510 0.46 25.1 590 2290 0.46 84.0 2120 7630 0.46 25.6 650 2320 0.46 85.7 2280 7630 0.45 26.1 700 2320 0.45 87.3 2270 7840 0.45 26.6 690 2390 0.45 88.9 2410 7840 0.45 27.1 730 2390 0.45 90.6 2400 7970 0.45 27.6 730 2430 0.45 90.6 2410 8010 0.45 27.6 730 2440 0.45 90.6 2400 7920 0.45 27.6 730 2410 0.45 92.2 2480 7970 0.45 28.1 760 2430 0.45 93.9 2710 8240 0.44 28.6 820 2510 0.44 95.5 2850 8340 0.43 29.1 870 2540 0.43 97.1 3030 8490 0.43 29.6 920 2590 0.43 98.8 2980 8690 0.43 30.1 910 2650 0.43 100.4 3050 8960 0.43 30.6 930 2730 0.43 102.1 2810 8290 0.43 31.1 860 2530 0.43 103.7 2800 8340 0.44 31.6 850 2540 0.44 105.3 2670 8100 0.44 32.1 810 2470 0.44 107.0 2640 7920 0.44 32.6 800 2410 0.44 108.6 2710 8010 0.44 33.1 820 2440 0.44 110.3 2550 8010 0.44 33.6 780 2440 0.44 111.9 2540 7790 0.44 34.1 770 2380 0.44 113.5 2480 7970 0.45 34.6 760 2430 0.45 115.2 2360 7840 0.45 35.1 720 2390 0.45 116.8 2490 7710 0.44 35.6 760 2350 0.44 118.5 2360 7670 0.45 36.1 720 2340 0.45 120.1 2310 7710 0.45 36.6 700 2350 0.45 121.7 2370 7550 0.45 37.1 720 2300 0.45 123.4 2410 7630 0.44 37.6 740 2320 0.44 125.0 2360 7350 0.44 38.1 720 2240 0.44 126.7 2340 7240 0.44 38.6 710 2210 0.44 128.3 2310 7350 0.45 39.1 700 2240 0.45 129.9 2280 7350 0.45 39.6 700 2240 0.45
20 TABLE 2 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Midpoint Velocity Depth at Midpoint Velocity Between Source and Near Receiver Vs Vp Poisson' s Ratio Between Source and Near Receiver Vs Vp Poisson' s Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 131.6 2310 7430 0.45 40.1 700 2260 0.45 133.2 2310 7390 0.45 40.6 700 2250 0.45 134.9 2310 7390 0.45 41.1 700 2250 0.45 136.5 2280 7630 0.45 41.6 700 2320 0.45 138.1 2170 7280 0.45 42.1 660 2220 0.45 139.8 2310 7240 0.44 42.6 700 2210 0.44 141.4 2410 7510 0.44 43.1 730 2290 0.44 143.1 2370 7710 0.45 43.6 720 2350 0.45 144.7 2400 7670 0.45 44.1 730 2340 0.45 146.4 2390 7670 0.45 44.6 730 2340 0.45 148.0 2430 7670 0.44 45.1 740 2340 0.44 149.6 2430 7630 0.44 45.6 740 2320 0.44 151.3 2440 7710 0.44 46.1 740 2350 0.44 152.9 2410 8010 0.45 46.6 730 2440 0.45 154.6 2440 7550 0.44 47.1 740 2300 0.44 156.2 2450 7710 0.44 47.6 750 2350 0.44 157.8 2430 7630 0.44 48.1 740 2320 0.44 159.5 2400 7510 0.44 48.6 730 2290 0.44 161.1 2080 7510 0.46 49.1 630 2290 0.46 162.8 1910 6930 0.46 49.6 580 2110 0.46 164.4 1640 6670 0.47 50.1 500 2030 0.47 166.0 1550 6290 0.47 50.6 470 1920 0.47 167.7 1420 6290 0.47 51.1 430 1920 0.47 169.3 1420 6290 0.47 51.6 430 1920 0.47 171.0 1530 6400 0.47 52.1 470 1950 0.47 172.6 1570 6580 0.47 52.6 480 2000 0.47 174.2 1600 6670 0.47 53.1 490 2030 0.47 175.9 1600 6760 0.47 53.6 490 2060 0.47 177.5 1580 6490 0.47 54.1 480 1980 0.47 179.2 1610 6460 0.47 54.6 490 1970 0.47 180.8 1730 6760 0.47 55.1 530 2060 0.47 182.4 1960 7000 0.46 55.6 600 2130 0.46 184.1 2140 7170 0.45 56.1 650 2190 0.45 185.7 2420 7550 0.44 56.6 740 2300 0.44 187.4 2700 7670 0.43 57.1 820 2340 0.43 189.0 2660 7970 0.44 57.6 810 2430 0.44 190.6 2720 7670 0.43 58.1 830 2340 0.43 192.3 2630 7710 0.43 58.6 800 2350 0.43 193.9 2520 7510 0.44 59.1 770 2290 0.44
21 TABLE 2 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Midpoint Velocity Depth at Midpoint Velocity Between Source and Near Receiver Vs Vp Poisson' s Ratio Between Source and Near Receiver Vs Vp Poisson' s Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 195.6 2410 7630 0.44 59.6 730 2320 0.44 197.2 2410 7510 0.44 60.1 730 2290 0.44 198.8 2460 7510 0.44 60.6 750 2290 0.44 200.5 2480 7630 0.44 61.1 760 2320 0.44 202.1 2500 7430 0.44 61.6 760 2260 0.44 203.8 2280 7130 0.44 62.1 690 2170 0.44 205.4 2120 7030 0.45 62.6 650 2140 0.45 207.0 2040 7030 0.45 63.1 620 2140 0.45 208.7 2010 6930 0.45 63.6 610 2110 0.45 210.3 2010 6930 0.45 64.1 610 2110 0.45 212.0 2150 7030 0.45 64.6 660 2140 0.45 213.6 2240 7130 0.45 65.1 680 2170 0.45 215.2 2290 6930 0.44 65.6 700 2110 0.44 216.9 2220 6930 0.44 66.1 680 2110 0.44 218.5 2120 6800 0.45 66.6 650 2070 0.45 220.2 2080 6610 0.44 67.1 630 2010 0.44 221.8 2000 6490 0.45 67.6 610 1980 0.45 223.5 1940 6700 0.45 68.1 590 2040 0.45 225.1 1880 6610 0.46 68.6 570 2010 0.46 226.7 1930 6700 0.45 69.1 590 2040 0.45 228.4 1950 6700 0.45 69.6 590 2040 0.45 230.0 1960 6670 0.45 70.1 600 2030 0.45 231.7 1930 6610 0.45 70.6 590 2010 0.45 233.3 2010 6800 0.45 71.1 610 2070 0.45 234.9 2050 6800 0.45 71.6 620 2070 0.45 236.6 2010 6700 0.45 72.1 610 2040 0.45 238.2 1980 6610 0.45 72.6 600 2010 0.45 239.9 1900 6490 0.45 73.1 580 1980 0.45 241.5 1770 6290 0.46 73.6 540 1920 0.46 243.1 1790 6290 0.46 74.1 550 1920 0.46 244.8 1880 6370 0.45 74.6 570 1940 0.45 246.4 1760 6520 0.46 75.1 540 1990 0.46 248.1 1900 6490 0.45 75.6 580 1980 0.45 249.7 2030 6610 0.45 76.1 620 2010 0.45 251.3 2100 6700 0.45 76.6 640 2040 0.45 253.0 2270 7100 0.44 77.1 690 2160 0.44 254.6 2490 7430 0.44 77.6 760 2260 0.44 256.3 2210 7170 0.45 78.1 670 2190 0.45 257.9 1990 6760 0.45 78.6 610 2060 0.45
22 TABLE 2 (cont.)
Summary of Compressional Wave Velocity, Shear Wave Velocity, and Poisson's Ratio Based on Source-to-Receiver Travel Time Data - Borehole B-2, Clinton NPP American Units Metric Units Depth at Midpoint Velocity Depth at Midpoint Velocity Between Source and Near Receiver Vs Vp Poisson' s Ratio Between Source and Near Receiver Vs Vp Poisson' s Ratio (ft)
(ft/s)
(ft/s)
(m)
(m/s)
(m/s) 259.5 2030 6800 0.45 79.1 620 2070 0.45 261.2 1860 6490 0.45 79.6 570 1980 0.45 262.8 1890 6830 0.46 80.1 580 2080 0.46 264.5 1870 6760 0.46 80.6 570 2060 0.46 266.1 1780 6700 0.46 81.1 540 2040 0.46 267.7 1720 6460 0.46 81.6 520 1970 0.46 269.4 1640 6000 0.46 82.1 500 1830 0.46 271.0 1610 5830 0.46 82.6 490 1780 0.46 272.7 1560 5690 0.46 83.1 470 1730 0.46 274.3 1440 5670 0.47 83.6 440 1730 0.47 275.9 1390 5980 0.47 84.1 420 1820 0.47 277.6 1420 6180 0.47 84.6 430 1880 0.47 279.2 1450 6400 0.47 85.1 440 1950 0.47 280.9 1680 6830 0.47 85.6 510 2080 0.47 282.5 2040 6930 0.45 86.1 620 2110 0.45 284.1 2290 6930 0.44 86.6 700 2110 0.44 285.8 2540 7350 0.43 87.1 770 2240 0.43 287.4 2820 7350 0.41 87.6 860 2240 0.41 289.1 2910 7630 0.41 88.1 890 2320 0.41 290.7 2910 7590 0.41 88.6 890 2310 0.41 292.3 2980 7750 0.41 89.1 910 2360 0.41 294.0 3060 8390 0.42 89.6 930 2560 0.42 295.6 3160 8540 0.42 90.1 960 2600 0.42 297.3 3400 8490 0.40 90.6 1040 2590 0.40 298.9 3430 8640 0.41 91.1 1050 2630 0.41 300.6 3480 8490 0.40 91.6 1060 2590 0.40 302.2 3730 8390 0.38 92.1 1140 2560 0.38 303.8 3640 7970 0.37 92.6 1110 2430 0.37 305.5 3660 8190 0.38 93.1 1120 2500 0.38 307.1 3940 8060 0.34 93.6 1200 2460 0.34 308.8 3900 8100 0.35 94.1 1190 2470 0.35 310.4 3850 8190 0.36 94.6 1170 2500 0.36 312.0 3920 8290 0.36 95.1 1190 2530 0.36 313.7 3960 8290 0.35 95.6 1210 2530 0.35 315.3 3590 8190 0.38 96.1 1090 2500 0.38
EXHIBIT A PROCEDURE FOR OYO P-S SUSPENSION SEISMIC VELOCITY LOGGING
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 1 GE PROCEDURE FOR OYO P-S SUSPENSION SEISMIC VELOCITY LOGGING
Background
This procedure describes a method for measuring shear and compressional wave velocities in soil and rock. The OYO P-S Suspension Method is applied by generating shear and compressional waves in a borehole using the OYO P-S Suspension Logger borehole tool and measuring the travel time between two receiver geophones or hydrophones located in the same tool.
Objective The outcome of this procedure is a plot and table of P and SH wave velocity versus depth 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 transmitted on diskette.
Instrumentation
- 1. OYO Model 170 Digital Logging Recorder or equivalent
- 2. OYO P-S Suspension Logger probe, including two sets horizontal and vertical geophones, seismic source, and power supply for the source and receivers
- 3. Winch and winch controller, with logging cable
- 4. Batteries to operate OYO 170 and winch The Model 170 Suspension P-S Logging system, manufactured by OYO Corporation, is currently the only commercially available suspension system. As shown in Figure 1, the System consists of a borehole probe suspended by a cable and a recording/control electronics package on the surface.
The suspension system probe consists of a combined reversible polarity solenoid horizontal shear-wave generator (SH ) and compressional-wave generator (P), joined to two biaxial geophones by a flexible isolation cylinder. The separation of the two geophones is one meter, allowing average wave velocity in the region between the
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 2 GE geophones to be determined by inversion of the wave travel time between the two geophones. The total length of the probe is approximately 7 meters; the center point of the 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 7 conductor cable. The cable is wound onto the drum of a winch and is used to support the probe. Cable travel is measured by a rotary encoder to provide probe depth data.
The entire probe is suspended by the cable and centered in the borehole by nylon whiskers. Therefore, source motion is not coupled directly to the borehole walls; rather, the source motion creates a horizontally propagating pressure wave in the fluid filling the borehole and surrounding the source. This pressure wave produces a horizontal displacement of the soil forming the wall of the borehole. This displacement propagates up and down the borehole wall, in turn causing a pressure wave to be generated in the fluid surrounding the geophones as the soil displacement wave passes their location.
Environmental Conditions The OYO P-S Suspension Logging Method can be used in either cased or uncased boreholes. For best results, the borehole must be between 10 and 20 cm in diameter, or 4 to 8 inches.
Uncased boreholes are preferred because the effects of the casing and grouting are removed. 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 and seals the borehole wall reducing fluid loss and wall collapse. The borehole fluid is required 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 and grouted. Any voids in the grout will cause problems with the data. Likewise, large grout bulbs used to fill cavities will also cause problems. The grout must be set before testing. This means the grouting must take place at least 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> before testing.
For borehole casing, applicable preparation procedures are presented in ASTM Standard D4428/D4428M-91 Section 4.1 (see ASTM website for copy).
Calibration Calibration of the Model 170 digital recorder is required. Calibration is limited to the timing accuracy of the recorder. GEOVisions Seismograph Calibration Procedure or equivalent should be used. Calibration must be performed on an annual basis.
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 3 GE Measurement Procedure The entire probe is lowered into the borehole to a specific measurement depth by the winch. A measurement sequence is then initiated by the operator from the instrumentation package control panel. No further operator intervention is then needed to complete the measurement sequence described below.
The system electronics activates the SH-wave source in one direction and records the output of the two horizontally oriented geophone axes which are situated parallel to the axis of motion of the source. The source is then activated in the opposite direction, and the horizontal output signals are again recorded, producing a SH-wave record of polarity opposite to the previous record. The source is finally actuated in the first direction again, and the responses of the vertical geophone axes to the resultant P-wave are recorded during this sampling.
The data from each geophone during each source activation is recorded as a different channel on the recording system. The Model 170 has six channels (two simultaneous recording channels), each with a 12 bit 1024 sample record. The recorded data is displayed on a CRT display and on paper tape output as six channels with a common time scale. Data is stored on 3.5-inch floppy diskettes for further processing. Up to 8 sampling sequences can be stacked (averaged) to improve the signal to noise ratio of the signals.
Review of the displayed data on the CRT or paper tape allows the operator to set the gains, filters, delay time, pulse length (energy), sample rate, and stacking number in order to optimize the quality of the data before recording. Final printed data is verified by the operator prior to moving the probe.
Typical depth spacing for measurements is 1.0 meters, or 3.3 feet. Alternative spacing is 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 d) Description of measurement e) Any deviations from test plan and action taken as a result f) QA Review
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 4 GE
- 2) Paper output records for each measurement as backup showing depth and ID number
- 3) List of record ID numbers (for data on diskette) and corresponding depth
- 4) Diskettes with backup copies of data on hard disk, labeled with borehole designation, record ID 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 by computer using the OYO Corporation software program PSLOG and interactively analyzed by an experienced geophysicist to produce plots and tables of P and SH wave velocity versus depth.
The digital time series records from each depth are transferred to a personal computer for analysis. Figure 2 shows a sample of the data from a single depth. These digital records are analyzed to locate the first minima on the vertical axis records, indicating the arrival of P-wave energy. The difference in travel time between these arrivals is used to calculate the P-wave velocity for that 1-meter interval. When observable, P-wave arrivals on the horizontal axis records are used to verify the velocities determined from the vertical axis data. In addition, the soil velocity calculated from the travel time from source to first receiver is compared to the velocity derived from the travel time between receivers.
The digital records are studied to establish the presence of clear SH-wave pulses, as indicated 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 very nearly inverted images of each other. Digital FFT - IFFT lowpass filtering are used to remove 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 for the 'reverse' signals. The absolute arrival time of the normal and reverse signals may vary by +/- 0.2 milliseconds, due to differences in actuation time of the solenoid source caused by constant mechanical bias in the source or by borehole inclination. This variation does not affect the velocity determinations, as the differential time is measured between arrivals of waves created by the same source actuation. The final velocity value is the average of the values obtained from the normal and reverse source actuations.
In Figure 2, the time difference over the 1-meter interval of 1.70 millisecond is equivalent to a SH-wave velocity of 588 m/sec. Whenever possible, time differences are determined from several phase points on the SH -wave pulse trains to verify the data obtained from the first arrival of the SH -wave pulse. In addition, the soil velocity
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 5 GE calculated from the travel time from source to first receiver is compared to the velocity derived from the travel time between receivers.
Figure 3 is a sample composite plot of the far normal horizontal geophone records for a range of depths. This plot shows the waveforms at each depth, clearly showing the S-wave arrivals. This display format is used during analysis to observe trends in velocity with changing depth.
Once the proper picks are entered, PSLOG automatically calculates both Vs and Vp for each depth. The program allows spreadsheet output for presentation in either charts or tables or both.
Standard analysis is performed on receiver 1 to receiver 2 data, with separate analysis performed on source to receiver data as a quality assurance procedure.
Registered Geophysicist____________________________Date__6/20/00______
QA Review____________________________Date__6/20/00______
References:
- 1. Guidelines for Determining Design Basis Ground Motions, Report TR-102293, Electric Power Research Institute, Palo Alto, California, November 1993, Sections 7 and 8.
- 2. The P-S Velocity Logging Method, R.L. Nigbor and T. Imai, XIII ICSMFE, 1994, New Delhi, India / XIII CIMSTF, 1994, New Delhi, India
- 3. Standard test Methods for Crosshole Seismic Testing, ASTM Standard D4428/D4428M-91, July 1991, Philadelphia, PA
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 6 GE OYO SUSPENSION P-S VELOCITY LOGGING SETUP Figure 1. Suspension PS logging method setup Cable Head Head Reducer Upper Geophone Lower Geophone Filter Tube Source Source Driver Weight Winch 7-Conductor cable Diskette with Data OYO PS-160 Logger/Recorder Overall Length ~ 20 ft Borehole Fluid
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 7 GE Figure 2. Sample suspension method waveform data showing horizontal normal and reversed (HR and HN), and vertical (V) waveforms received at the near (bottom 3 channels) and far (top 3 channels) geophones. The arrivals in milliseconds for each pick are shown on the left. The box in the upper right corner shows the depth in the borehole and the velocities calculated based on the picks.
Procedure for OYO P-S Suspension Seismic Velocity Logging Rev 1.2 6/20/00 Page 8 GE Figure 3. Sample composite waveform plot for normal shear waves received at the near geophone in a single borehole
EXHIBIT B OYO 170 VELOCITY LOGGING SYSTEM NIST TRACEABLE CALIBRATION PROCEDURE AND CALIBRATION RECORDS