technical memorandum
TECHNICAL MEMORANDUM Project No. E07175.004 7 September 2007 To:
Smith Flat Engineering, Attn: Nate Stong, P.E. Email: [email protected]
From:
Keith E. Millard, C.E.G.
Reviewed by: Brandon K. Shimizu, P.E., G.E.
Subject:
GATEWAY HOTEL & GAS STATION Smith Flat Road, Placerville, California SUBSURFACE EVALUATION FOR TUNNEL BORING
References:
1. Geotechnical Study for the Point View Gas Station, prepared by Carlton Engineering, Inc., dated February 2000 (Project No. 99-537). 2. Geotechnical Engineering Study for Gateway Hotel and Service Station, prepared by Carlton Engineering, Inc., dated January 2004 (Project No. 3008-08-03). 3. Geotechnical Engineering Study Update for Gateway Hotel and Service Station, prepared by Youngdahl Consulting Group, Inc., dated 31 May 2007 (Project No. E07175.001) 4. Preliminary Sketch (Plan and Profile) of Proposed Tunnel Boring – Gateway Hotel & Service Station, prepared by Smith Flat Engineering, dated 7 August 2007.
As requested, Youngdahl Consulting Group, Inc. has performed a Subsurface Evaluation for the proposed tunnel boring beneath Smith Flat Road. The tunnel boring is proposed to cross Smith Flat Road at Station 19+30, and is currently oriented at approximately N04°W, with depths ranging from 4 to 15 feet below the existing ground surface (Reference No. 4). Based on the Reference No. 4 sketch, we advanced 2 vertical borings in the vicinity of the proposed alignment to evaluate subsurface conditions as they pertain to construction of the proposed tunnel boring. Subsurface Conditions We performed our exploration using a high torque CME-75 drill rig equipped with 8 inch diameter hollow stem auger. Both borings encountered phyllite schist (slatey) bedrock with varying amounts of hard quartz and varying degrees of weathering. Boring B-1, drilled in Smith Flat Road, encountered easy drilling in intensely weathered bedrock with isolated small quartz zones from immediately beneath the 6 inch roadway section to a depth of approximately 8 feet. Standard Penetration Test (SPT) values in this interval ranged from 15 to 20 blows per foot. From 8 feet to approximately 10.5 feet, the bedrock graded to highly weathered and indurated with auger down pressures on the order of 1,000 to 1,500 psi. SPT values in this interval were on the order of 60 blows per foot. From 10.5 feet to the maximum depth explored of 20 feet, drilling resistance increased along with SPT values which reached approximately 50 blows per 2 to 6 inches. Proposed tunnel depth at this location is approximately 15 feet. No auger refusal or groundwater was encountered. Boring B-2 was drilled at the north edge of the recreation trail, north of Smith Flat Road. Within the 4 to 8 foot bedrock cut for the recreation trail, drilling progressed relatively easily through intensely weathered bedrock with occasional quartz zones to a depth of approximately 5.5 feet. SPT values were on the order of 40 blows per foot. From 5.5 to 8.5 feet SPT values increased to approximately 50 blows per 2 to 4 inches, bedrock weathering decreased to moderate, and auger down pressures
Gateway Hotel & Gas Station Page 2
Project No. E07175.004 7 September 2007
increased to 1,200 psi. At 8.5 feet, very “crunchy” drilling conditions resulted from a further decrease in weathering and an increase in quartz content. At 10 feet, an 18 inch zone of intense weathering with SPT values of 28 blows per foot was encountered, followed by very hard drilling which lifted the drill rig’s outriggers off the ground to achieve sufficient down pressure. From 12.5 feet to the maximum depth explored in B-2 of 20 feet, moderately weathered bedrock with alternating zones of intense weathering and quartz were encountered. SPT values in this interval were on the order of 50 blows per 2 to 4 inches. Proposed tunnel depth at this location is approximately 4 feet. No auger refusal or groundwater was encountered. A more detailed description of the subsurface conditions encountered is presented graphically on the “Exploratory Boring Logs”, Figures A-3 and A-4, attached. These logs show a graphic interpretation of the subsurface profile, and the location and depths at which SPT blow counts were recorded. Conclusions Following our drilling operations, our engineering geologist made measurements of exposed bedrock in the vicinity of the proposed boring. Those measurements indicate a strike of bedrock foliation (“layering”) of approximately N40°W (azimuth 320°). The layers dip (stand) nearly vertically. Conditions in layered metamorphic bedrock are typically less variable along the strike, and most variable perpendicular to the strike. Advancing the tunnel boring at an angle to the strike may result in deflection of the drill bit as it encounters more resistant layers at an acute angle. Vertical deflection is also possible due to bedrock variations with depth. The proposed tunnel boring is currently oriented at approximately 36° to the strike. In summary, the proposed alignment of the tunnel boring is anticipated to encounter highly variable bedrock conditions. Where less weathered bedrock and/or quartz is encountered, the tunnel boring may be deflected off of its proposed alignment and/or may be incapable of being advanced along the proposed alignment with the drilling equipment typically used by the utility contractor. Based on our geologic interpretations, advancing the tunnel boring in an orientation parallel to the foliation is anticipated to encounter less variable drilling conditions, but will require a longer drilling path. If there are any questions regarding these recommendations, please feel free to contact our office at your convenience. Attachments: Figure A-1, Vicinity Map Figure A-2, Site Plan Figure A-3 and A-4, Exploratory Boring Logs Figure A-5, Soil Classification Chart and Boring Log Legend
Approximate Site Location
N
Base Map Reference: The Thomas Guide For Sacramento & Solano Counties, Street Guide, 2006, Page 246 Project No.: E07175.004 September 2007
VICINITY MAP
FIGURE
Gateway Hotel And Gas Station
A-1
Placerville, California
B-2
N
B-1
= Approximate Boring Location 0
25
50
100
Approximate Scale: 1" = 50'
B-2
B-1
Project No.: E07175.004 EXCERPT FROM: Site Plan Provided By Client
September 2007
SITE PLAN
FIGURE
Gateway Hotel And Gas Station
A-2
Placerville, California
Logged By: KEM
Date: 24 August 2007
Boring No.
Elevation: unknown
B-1
1 2
Moisture Content (%)
Dry Density (pcf)
Blow Count
Geotechnical Description & Unified Soil Classification
Sample
Ground Water
Graphic Log
Depth (Feet)
Equipment: CME-75 With 8" Hollow Stem Auger
Tests & Comments
2" AC, 4" BASE Microcrystalline quartz ROCK, very hard
Grades to intensely weathered phyllite schist, some hard pieces, soft drilling
3
15
4 5 6 7 8 9 10
18 Isolated hard spot, few inches thick
Grades highly weathered, indurated, moderate drilling 1,000 - 1,500 psi down pressure
11
50/2"
Cutting Warm
50/6"
(Tunnel Depth) Cuttings Very Warm / Hot
12 13 14 15 16 17
50/5"
18 19 20
Boring terminated at 20.5' No groundwater encountered
50/5"
Note: The boring log indicates subsurface conditions only at the specific location and time noted. Subsurface conditions, including groundwater levels, at other locations of the subject site may differ significantly from conditions which, in the opinion of Youngdahl Consulting Group, Inc., exist at the sampling locations. Note, too, that the passage of time may affect conditions at the sampling locations.
Project No.: E07175.004 September 2007
EXPLORATORY BORING LOG
FIGURE
Gateway Hotel And Gas Station
A-3
Placerville, California
Logged By: KEM
Date: 24 August 2007
Boring No.
Elevation: unknown
B-2
1
Moisture Content (%)
Dry Density (pcf)
Blow Count
Geotechnical Description & Unified Soil Classification
Sample
Ground Water
Graphic Log
Depth (Feet)
Equipment: CME-75 With 8" Hollow Stem Auger
Tests & Comments
Phyllite schist ROCK, completely weathered, weakly to moderately indurated, easy drilling
2 3 4
41
Tunnel Depth
50/5"
Cuttings Hot
5 6 7 8
Grades moderately weathered, indurated, moderate to firm drilling, 1200 psi down pressure
9
Grades slightly weathered, hard, crunchy drilling
10
Grades intensely weathered, moderate drilling
11 12 13
28 Very hard spot, slightly weathered, lifting the outriggers Grades less hard, but still crunchy, intermittent hard and soft zones (about 1' intervals)
14 15 50/2"
16 17 18 19 20
Boring terminated at 20.5' No groundwater encountered
50/4"
Note: The boring log indicates subsurface conditions only at the specific location and time noted. Subsurface conditions, including groundwater levels, at other locations of the subject site may differ significantly from conditions which, in the opinion of Youngdahl Consulting Group, Inc., exist at the sampling locations. Note, too, that the passage of time may affect conditions at the sampling locations.
Project No.: E07175.004 September 2007
EXPLORATORY BORING LOG
FIGURE
Gateway Hotel And Gas Station
A-4
Placerville, California
UNIFIED SOIL CLASSIFICATION SYSTEMS Clean GRAVELS With Little Or No Fines
SYMBOLS
PLASTICITY CHART
TYPICAL NAMES
USED FOR CLASSIFICATION OF FINE GRAINED SOILS
GW
Well graded GRAVELS, GRAVEL-SAND mixtures
GP
Poorly graded GRAVELS, GRAVEL-SAND mixtures
GM
Silty GRAVELS, poorly graded GRAVEL-SANDSILT mixtures
GC
Clayey GRAVELS, poorly graded GRAVEL-SANDCLAY mixtures
SW
Well graded SANDS, gravelly SANDS
GRAVELS With Over 12% Fines
Clean SANDS With Little Or No Fines
SANDS With Over 12% Fines
SILTS & CLAYS Liquid Limit < 50
SILTS & CLAYS Liquid Limit > 50
HIGHLY ORGANIC CLAYS
80
SP
Poorly graded SANDS, gravelly SANDS
SM
Silty SANDS, poorly graded SAND-SILT mixtures
SC
Clayey SANDS, poorly graded SAND-CLAY mixtures
ML
Inorganic SILTS, silty or clayey fine SANDS, or clayey SILTS with plasticity
CL
Inorganic CLAYS of low to medium plasticity, gravelly, sandy, or silty CLAYS, lean CLAYS
PLASTICITY INDEX
GRAVELS Over 50% > #4 sieve SANDS Over 50% < #4 sieve
FINE GRAINED SOILS Over 50% < #200 sieve
COARSE GRAINED SOILS Over 50% > #200 sieve
MAJOR DIVISION
60 CH
A-LINE
40 CL MH & OH 20
ML & OL 0
20
60
40
80
100
LIQUID LIMIT
SAMPLE DRIVING RECORD
OL
Organic CLAYS and organic silty CLAYS of low plasticity
MH
Inorganic SILTS, micaceous or diamacious fine sandy or silty soils, elastic SILTS
CH
Inorganic CLAYS of high plasticity, fat CLAYS
OH
Organic CLAYS of medium to high plasticity, organic SILTS
PT
PEAT & other highly organic soils
BLOWS PER FOOT
DESCRIPTION
25
25 Blows drove sampler 12 inches, after initial 6 inches of seating 50/7" 50 Blows drove sampler 7 inches, after initial 6 inches of seating 50/3" 50 Blows drove sampler 3 inches during or after initial 6 inches of seating Note: To avoid damage to sampling tools, driving is limited to 50 blows per 6 inches during or after seating interval.
SOIL GRAIN SIZE U.S. STANDARD SIEVE
6"
3"
¾"
4
10
GRAVEL BOULDER
200
COBBLE
SILT COARSE
SOIL GRAIN SIZE IN MILLIMETERS
40 SAND
150
75
FINE 19
COARSE 4.75
MEDIUM 2.0
CLAY
FINE .425
0.075
0.002
KEY TO PIT & BORING SYMBOLS
KEY TO PIT & BORING SYMBOLS
Joint
Standard Penetration test
Foliation
2.5" O.D. Modified California Sampler NFWE FWE REF DD MC LL PI PP UCC TVS EI Su
3" O.D. Modified California Sampler Shelby Tube Sampler 2.5" Hand Driven Liner Bulk Sample Water Level At Time Of Drilling Water Level After Time Of Drilling P
Perched Water
Project No.: E07175.004 September 2007
Water Seepage No Free Water Encountered Free Water Encountered Sampling Refusal Dry Density (pcf) Moisture Content (%) Liquid Limit Plasticity Index Pocket Penetrometer Unconfined Compression (ASTM D2166) Pocket Torvane Shear Expansion Index (ASTM D4829) Undrained Shear Strength
SOIL CLASSIFICATION CHART & LOG EXPLANATION Gateway Hotel And Gas Station Placerville, California
FIGURE
A-5
Smith Flat Engineering, Attn: Nate Stong, P.E. Email: [email protected]
From:
Keith E. Millard, C.E.G.
Reviewed by: Brandon K. Shimizu, P.E., G.E.
Subject:
GATEWAY HOTEL & GAS STATION Smith Flat Road, Placerville, California SUBSURFACE EVALUATION FOR TUNNEL BORING
References:
1. Geotechnical Study for the Point View Gas Station, prepared by Carlton Engineering, Inc., dated February 2000 (Project No. 99-537). 2. Geotechnical Engineering Study for Gateway Hotel and Service Station, prepared by Carlton Engineering, Inc., dated January 2004 (Project No. 3008-08-03). 3. Geotechnical Engineering Study Update for Gateway Hotel and Service Station, prepared by Youngdahl Consulting Group, Inc., dated 31 May 2007 (Project No. E07175.001) 4. Preliminary Sketch (Plan and Profile) of Proposed Tunnel Boring – Gateway Hotel & Service Station, prepared by Smith Flat Engineering, dated 7 August 2007.
As requested, Youngdahl Consulting Group, Inc. has performed a Subsurface Evaluation for the proposed tunnel boring beneath Smith Flat Road. The tunnel boring is proposed to cross Smith Flat Road at Station 19+30, and is currently oriented at approximately N04°W, with depths ranging from 4 to 15 feet below the existing ground surface (Reference No. 4). Based on the Reference No. 4 sketch, we advanced 2 vertical borings in the vicinity of the proposed alignment to evaluate subsurface conditions as they pertain to construction of the proposed tunnel boring. Subsurface Conditions We performed our exploration using a high torque CME-75 drill rig equipped with 8 inch diameter hollow stem auger. Both borings encountered phyllite schist (slatey) bedrock with varying amounts of hard quartz and varying degrees of weathering. Boring B-1, drilled in Smith Flat Road, encountered easy drilling in intensely weathered bedrock with isolated small quartz zones from immediately beneath the 6 inch roadway section to a depth of approximately 8 feet. Standard Penetration Test (SPT) values in this interval ranged from 15 to 20 blows per foot. From 8 feet to approximately 10.5 feet, the bedrock graded to highly weathered and indurated with auger down pressures on the order of 1,000 to 1,500 psi. SPT values in this interval were on the order of 60 blows per foot. From 10.5 feet to the maximum depth explored of 20 feet, drilling resistance increased along with SPT values which reached approximately 50 blows per 2 to 6 inches. Proposed tunnel depth at this location is approximately 15 feet. No auger refusal or groundwater was encountered. Boring B-2 was drilled at the north edge of the recreation trail, north of Smith Flat Road. Within the 4 to 8 foot bedrock cut for the recreation trail, drilling progressed relatively easily through intensely weathered bedrock with occasional quartz zones to a depth of approximately 5.5 feet. SPT values were on the order of 40 blows per foot. From 5.5 to 8.5 feet SPT values increased to approximately 50 blows per 2 to 4 inches, bedrock weathering decreased to moderate, and auger down pressures
Gateway Hotel & Gas Station Page 2
Project No. E07175.004 7 September 2007
increased to 1,200 psi. At 8.5 feet, very “crunchy” drilling conditions resulted from a further decrease in weathering and an increase in quartz content. At 10 feet, an 18 inch zone of intense weathering with SPT values of 28 blows per foot was encountered, followed by very hard drilling which lifted the drill rig’s outriggers off the ground to achieve sufficient down pressure. From 12.5 feet to the maximum depth explored in B-2 of 20 feet, moderately weathered bedrock with alternating zones of intense weathering and quartz were encountered. SPT values in this interval were on the order of 50 blows per 2 to 4 inches. Proposed tunnel depth at this location is approximately 4 feet. No auger refusal or groundwater was encountered. A more detailed description of the subsurface conditions encountered is presented graphically on the “Exploratory Boring Logs”, Figures A-3 and A-4, attached. These logs show a graphic interpretation of the subsurface profile, and the location and depths at which SPT blow counts were recorded. Conclusions Following our drilling operations, our engineering geologist made measurements of exposed bedrock in the vicinity of the proposed boring. Those measurements indicate a strike of bedrock foliation (“layering”) of approximately N40°W (azimuth 320°). The layers dip (stand) nearly vertically. Conditions in layered metamorphic bedrock are typically less variable along the strike, and most variable perpendicular to the strike. Advancing the tunnel boring at an angle to the strike may result in deflection of the drill bit as it encounters more resistant layers at an acute angle. Vertical deflection is also possible due to bedrock variations with depth. The proposed tunnel boring is currently oriented at approximately 36° to the strike. In summary, the proposed alignment of the tunnel boring is anticipated to encounter highly variable bedrock conditions. Where less weathered bedrock and/or quartz is encountered, the tunnel boring may be deflected off of its proposed alignment and/or may be incapable of being advanced along the proposed alignment with the drilling equipment typically used by the utility contractor. Based on our geologic interpretations, advancing the tunnel boring in an orientation parallel to the foliation is anticipated to encounter less variable drilling conditions, but will require a longer drilling path. If there are any questions regarding these recommendations, please feel free to contact our office at your convenience. Attachments: Figure A-1, Vicinity Map Figure A-2, Site Plan Figure A-3 and A-4, Exploratory Boring Logs Figure A-5, Soil Classification Chart and Boring Log Legend
Approximate Site Location
N
Base Map Reference: The Thomas Guide For Sacramento & Solano Counties, Street Guide, 2006, Page 246 Project No.: E07175.004 September 2007
VICINITY MAP
FIGURE
Gateway Hotel And Gas Station
A-1
Placerville, California
B-2
N
B-1
= Approximate Boring Location 0
25
50
100
Approximate Scale: 1" = 50'
B-2
B-1
Project No.: E07175.004 EXCERPT FROM: Site Plan Provided By Client
September 2007
SITE PLAN
FIGURE
Gateway Hotel And Gas Station
A-2
Placerville, California
Logged By: KEM
Date: 24 August 2007
Boring No.
Elevation: unknown
B-1
1 2
Moisture Content (%)
Dry Density (pcf)
Blow Count
Geotechnical Description & Unified Soil Classification
Sample
Ground Water
Graphic Log
Depth (Feet)
Equipment: CME-75 With 8" Hollow Stem Auger
Tests & Comments
2" AC, 4" BASE Microcrystalline quartz ROCK, very hard
Grades to intensely weathered phyllite schist, some hard pieces, soft drilling
3
15
4 5 6 7 8 9 10
18 Isolated hard spot, few inches thick
Grades highly weathered, indurated, moderate drilling 1,000 - 1,500 psi down pressure
11
50/2"
Cutting Warm
50/6"
(Tunnel Depth) Cuttings Very Warm / Hot
12 13 14 15 16 17
50/5"
18 19 20
Boring terminated at 20.5' No groundwater encountered
50/5"
Note: The boring log indicates subsurface conditions only at the specific location and time noted. Subsurface conditions, including groundwater levels, at other locations of the subject site may differ significantly from conditions which, in the opinion of Youngdahl Consulting Group, Inc., exist at the sampling locations. Note, too, that the passage of time may affect conditions at the sampling locations.
Project No.: E07175.004 September 2007
EXPLORATORY BORING LOG
FIGURE
Gateway Hotel And Gas Station
A-3
Placerville, California
Logged By: KEM
Date: 24 August 2007
Boring No.
Elevation: unknown
B-2
1
Moisture Content (%)
Dry Density (pcf)
Blow Count
Geotechnical Description & Unified Soil Classification
Sample
Ground Water
Graphic Log
Depth (Feet)
Equipment: CME-75 With 8" Hollow Stem Auger
Tests & Comments
Phyllite schist ROCK, completely weathered, weakly to moderately indurated, easy drilling
2 3 4
41
Tunnel Depth
50/5"
Cuttings Hot
5 6 7 8
Grades moderately weathered, indurated, moderate to firm drilling, 1200 psi down pressure
9
Grades slightly weathered, hard, crunchy drilling
10
Grades intensely weathered, moderate drilling
11 12 13
28 Very hard spot, slightly weathered, lifting the outriggers Grades less hard, but still crunchy, intermittent hard and soft zones (about 1' intervals)
14 15 50/2"
16 17 18 19 20
Boring terminated at 20.5' No groundwater encountered
50/4"
Note: The boring log indicates subsurface conditions only at the specific location and time noted. Subsurface conditions, including groundwater levels, at other locations of the subject site may differ significantly from conditions which, in the opinion of Youngdahl Consulting Group, Inc., exist at the sampling locations. Note, too, that the passage of time may affect conditions at the sampling locations.
Project No.: E07175.004 September 2007
EXPLORATORY BORING LOG
FIGURE
Gateway Hotel And Gas Station
A-4
Placerville, California
UNIFIED SOIL CLASSIFICATION SYSTEMS Clean GRAVELS With Little Or No Fines
SYMBOLS
PLASTICITY CHART
TYPICAL NAMES
USED FOR CLASSIFICATION OF FINE GRAINED SOILS
GW
Well graded GRAVELS, GRAVEL-SAND mixtures
GP
Poorly graded GRAVELS, GRAVEL-SAND mixtures
GM
Silty GRAVELS, poorly graded GRAVEL-SANDSILT mixtures
GC
Clayey GRAVELS, poorly graded GRAVEL-SANDCLAY mixtures
SW
Well graded SANDS, gravelly SANDS
GRAVELS With Over 12% Fines
Clean SANDS With Little Or No Fines
SANDS With Over 12% Fines
SILTS & CLAYS Liquid Limit < 50
SILTS & CLAYS Liquid Limit > 50
HIGHLY ORGANIC CLAYS
80
SP
Poorly graded SANDS, gravelly SANDS
SM
Silty SANDS, poorly graded SAND-SILT mixtures
SC
Clayey SANDS, poorly graded SAND-CLAY mixtures
ML
Inorganic SILTS, silty or clayey fine SANDS, or clayey SILTS with plasticity
CL
Inorganic CLAYS of low to medium plasticity, gravelly, sandy, or silty CLAYS, lean CLAYS
PLASTICITY INDEX
GRAVELS Over 50% > #4 sieve SANDS Over 50% < #4 sieve
FINE GRAINED SOILS Over 50% < #200 sieve
COARSE GRAINED SOILS Over 50% > #200 sieve
MAJOR DIVISION
60 CH
A-LINE
40 CL MH & OH 20
ML & OL 0
20
60
40
80
100
LIQUID LIMIT
SAMPLE DRIVING RECORD
OL
Organic CLAYS and organic silty CLAYS of low plasticity
MH
Inorganic SILTS, micaceous or diamacious fine sandy or silty soils, elastic SILTS
CH
Inorganic CLAYS of high plasticity, fat CLAYS
OH
Organic CLAYS of medium to high plasticity, organic SILTS
PT
PEAT & other highly organic soils
BLOWS PER FOOT
DESCRIPTION
25
25 Blows drove sampler 12 inches, after initial 6 inches of seating 50/7" 50 Blows drove sampler 7 inches, after initial 6 inches of seating 50/3" 50 Blows drove sampler 3 inches during or after initial 6 inches of seating Note: To avoid damage to sampling tools, driving is limited to 50 blows per 6 inches during or after seating interval.
SOIL GRAIN SIZE U.S. STANDARD SIEVE
6"
3"
¾"
4
10
GRAVEL BOULDER
200
COBBLE
SILT COARSE
SOIL GRAIN SIZE IN MILLIMETERS
40 SAND
150
75
FINE 19
COARSE 4.75
MEDIUM 2.0
CLAY
FINE .425
0.075
0.002
KEY TO PIT & BORING SYMBOLS
KEY TO PIT & BORING SYMBOLS
Joint
Standard Penetration test
Foliation
2.5" O.D. Modified California Sampler NFWE FWE REF DD MC LL PI PP UCC TVS EI Su
3" O.D. Modified California Sampler Shelby Tube Sampler 2.5" Hand Driven Liner Bulk Sample Water Level At Time Of Drilling Water Level After Time Of Drilling P
Perched Water
Project No.: E07175.004 September 2007
Water Seepage No Free Water Encountered Free Water Encountered Sampling Refusal Dry Density (pcf) Moisture Content (%) Liquid Limit Plasticity Index Pocket Penetrometer Unconfined Compression (ASTM D2166) Pocket Torvane Shear Expansion Index (ASTM D4829) Undrained Shear Strength
SOIL CLASSIFICATION CHART & LOG EXPLANATION Gateway Hotel And Gas Station Placerville, California
FIGURE
A-5
