BIP_Report_3450-008P_Boulder_Bridge.pdf

BRIDGE INSPECTION REPORT

BOULDER BRIDGE

BEACH DRIVE OVER ROCK CREEK

ROCK CREEK PARK

LS

STRUCTURE NO. 3450-008P

INSPECTION TYPE: ROUTINE

INSPECTION DATE: 6/12/13

Federal Highway Administration

Report prepared by: ED

MILE POINT:

KILOMETER POINT:

2.65 4.27

Federal Lands Bridge Office Bridge Inspection and Management Program 21400 Ridgetop Circle Sterling, Virginia 20166 http://www.efl.fhwa.dot.gov/FLHBO/BIP

STRUCTURE SUMMARY STRUCTURE NO. 3450-008P

BOULDER BRIDGE INSPECTION DATE: 6/12/13

BRIDGE IDENTIFICATION AND DESCRIPTION

MAIN SPAN MATERIAL: ....... CONCRETE NO. OF MAIN SPANS:

MAIN SPAN TYPE: ............... ARCH - DECK NO. OF APPR. SPANS:

# OF BEAMS, MAIN SPAN: .. 1 STRUCT. TOTAL LENGTH: .. 79.5 FT (24.2 M)

DECK TYPE: ......................... NOT APPLICABLE MAX. SPAN LENGTH: .......... 79.5 FT (24.2 M) WEARING SURFACE: .......... NOT APPLICABLE DECK WIDTH: ...................... 29.3 FT (8.9 M)

ABUT. FOUNDATIONS: ........ UNKNOWN CURB TO CURB WIDTH: ..... 22.3 FT (6.8 M)

PIER FOUNDATION(S): ........ N/A YEAR BUILT:

ABUTMENT / PIER MAT'L: ... CONCRETE YEAR RECONSTRUCTED: .. N/A

PROJ./PLAN REF. NO: ......... 000000000000 / NONE SKEW ANGLE: ..................... 0 °

NPS ROAD CLASS: .............. 1 - PRINCIPAL PARK ROAD FRACTURE CRITICAL: ........ N/A

STRUCTURE HISTORY: ...... 2008-ASPHALT PATCHING.

LOCATION

ROCK CREEK PARK MILE POINT: ..................... 2.65 (KM PT 4.27)

STATE: ................................. DISTRICT OF COLUMBIA LOCATION: 1.5 MILES FROM JOYCE ROAD

FACILITY CARRIED: ............ BEACH DRIVE

FEATURE INTERSECTED: .. ROCK CREEK

STRUCTURE EVALUATION SUMMARY

This concrete deck arch bridge is fair condition overall. Problems include minor to moderate deterioration and longitudinal cracking of the asphalt pavement over the structure and at the approaches, and minor to moderate efflorescence and water leakage at the construction joints on the arch underside. The pavement cracking should be sealed to limit further water infiltration and help extend the useful life of the pavement.

Additional problems include moderate scour at the south abutment and minor slope failure on the north upstream channel bank at the structure. Engineered riprap should be placed at the downstream end of the south abutment and on the north upstream channel bank at the structure to prevent further scour and erosion.

INSPECTION TEAM: E. DUES, C. MARBURGER (GANNETT FLEMING)

CONDITION ASSESSMENT:

ERIC DUES, PE, FIELD TEAM LEADER

REPORT REVIEW :

MARCUS MILLER, P.E., SENIOR INSPECTION ENGINEER 703-404-6252

REPORT APPROVAL: DATE: 10/31/13

JORGOMAI CEESAY, PH.D., P.E., BIP SUPERVISORY ENGINEER 703-404-6244

RECOMMENDATIONS AND ESTIMATED COSTS STRUCTURE NO. 3450-008P

A (Critical) - Structure is closed, in imminent danger of collapse, or presents a critical safety hazard.

B (Major) - Structure is seriously deficient or presents a safety hazard, but can remain in service at reduced loads or with frequent inspections.

C (Moderate) - Structure is deficient, functionally obsolete, or requires substantial repairs to prevent a serious deficiency or unsafe condition.

D (Minor) - Structure is generally in good condition. Preventative maintenance may be required.

E (Special) - Structure is under construction or reconstruction.

D226 PRIORITY OF IMPROVEMENT

ITEM

NO.

MAINTENANCE RECOMMENDATIONS

(GENERALLY NOT FLHP ELIGIBLE)

QTY. UNIT COST

UNIT

ESTIMATE

COST

PRELIM.

PRELIM. MAINTENANCE TOTAL :

ITEM

NO.

REHABILITATION/RECONSTRUCTION

(TYPICALLY NEEDED WITHIN 5 YEARS)

QTY. UNIT

UNIT

COST ESTIMATES

PRELIM. COST

REHAB. RECONSTR.

PRELIM. REHABILITATION/RECONSTRUCTION TOTAL :

COST ESTIMATE SUMMARY

PRELIM. MAINTENANCE TOTAL:

PRELIM. REHABILITATION TOTAL:

PRELIM. RECONSTRUCTION TOTAL:

TOTAL ITEMIZED COSTS:

PRELIMINARY ESTIMATE TOTAL* :

(*Includes typical contract costs for mobilization, traffic control, and design/construction engineering; but does not include detour bridges, work beyond the bridge limits, or work not listed above. Estimates are approximate and are for preliminary planning purposes only; they should not be used as a complete or final engineers estimate.)

REMARKS:

FIELD INSPECTION REPORT STRUCTURE NO. 3450-008P

CONDITION RATING CODES FOR ITEMS 58 - 62, 222, 223

N NOT APPLICABLE 3 SERIOUS CONDITION - loss of section, deterioration, spalling, or scour have seriously affected primary structural components. Local failures are possible.

9 EXCELLENT CONDITION Fatigue cracks in steel or shear cracks in concrete may be present.

8 VERY GOOD CONDITION - no problems noted. 2 CRITICAL CONDITION - advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present

7 GOOD CONDITION - some minor problems. or scour may have removed substructure support. Unless closely monitored it may be necessary to close the structure until corrective action can be taken.

6 SATISFACTORY CONDITION - structural elements show some minor deterioration. 1 “IMMINENT” FAILURE CONDITION - major deterioration or section loss present in critical structural components or obvious vertical or horizontal

5 FAIR CONDITION - all primary structural elements are sound but may have movement affecting structure stability. Structure is closed to traffic but minor section loss, cracking, spalling, or scour. corrective action may return structure to light service.

4 POOR CONDITION - advanced section loss, deterioration, spalling, or scour. 0 FAILED CONDITION - out of service; beyond corrective action.

CONDITION RATING CODE EQUIVALENTS FOR SUB-ELEMENTS

G = GOOD (CODES 7 - 9) F = FAIR (CODES 5 - 6) P = POOR (CODES 0 - 4)

58. DECK N ITEM REFERENCE AND REMARKS

N1. DECK SLAB

N2. EXPANSION JOINTS

P3. WEARING SURFACE

F4. RIDEABILITY

F5. CURBS, SIDEWALKS, AND MEDIAN

G6. PARAPETS AND/OR RAILINGS

G7. DRAINS AND DRAINAGE

N8. UTILITIES

N9. DEFLECTION AND/OR VIBRATION

N10. OTHER

59. SUPERSTRUCTURE 6

N1. BEARING DEVICES

N2. GIRDERS OR BEAMS

F3. ARCH(ES) OR SLAB(S)

N4. FLOOR BEAMS AND STRINGERS

N5. TRUSSES

N6. DIAPHRAGMS AND BRACING

N7. PAINT

G8. FASCIA(E)

G9. DEFLECTION AND/OR VIBRATION

G10. ALIGNMENT

N11. OTHER

60. SUBSTRUCTURE 7

58.3,4, 222.4 MINOR TO MODERATE DETERIORATION AND LONGITUDINAL

CRACKING OF ASPHALT PAVEMENT OVER STRUCTURE AND ON

APPROACHES; MINOR RANDOM CRACKING ALONG CENTERLINE.

MAP CRACKING AND RUTTING UP TO 1-1/2"D IN WHEEL PATHS WITH

DETERIORATION OF PATCHING AT MIDSPAN IN NORTHBOUND

LANE. MINOR TRANSVERSE CRACKING OF PAVEMENT AT SOUTH

APPROACH.

58.5 MODERATE TRANSVERSE CRACKING AND MINOR SPALLING OF

BOTH CURBS AND GUTTERS.

58.6 MINOR SPALLING AND CRACKING OF STONE AT SOUTH END OF

WEST PARAPET.

59.3,8 MINOR TO MODERATE EFFLORESCENCE AND WATER LEAKAGE AT

LONGITUDINAL CONSTRUCTION JOINTS IN ARCH UNDERSIDE.

MINOR RANDOM CRACKING OF ARCH UNDERSIDE AT ISOLATED

LOCATIONS WITH EFFLORESCENCE. TWO SMALL AREAS OF

DELAMINATION AT CENTERLINE OF ARCH UNDERSIDE NEAR

MIDSPAN.

MINOR EFFLORESCENCE ON MASONRY SPANDREL WALLS AND

RING STONES. MINOR VEGETATION GROWTH IN SPANDREL WALL

MASONRY MORTAR JOINTS.

60.6 MINOR EFFLORESCENCE FROM WINGWALL MASONRY MORTAR

JOINTS. MINOR VEGETATION GROWTH ON WINGWALLS.

60.9, 61.1,2,3 CHANNEL UNDER NORMAL FLOW CONDITIONS CENTERED UNDER

SOUTH HALF OF STRUCTURE CAUSING MINOR SCOUR UP TO 1'D AT

SOUTH ABUTMENT, DOWNSTREAM END.

MINOR SLOPE FAILURE OF NORTH UPSTREAM CHANNEL BANK AT

STRUCTURE; AREA IS WELL VEGETATED WITH RIPRAP IN PLACE

ON CHANNEL BANK UPSTREAM OF STRUCTURE.

ABUTMENTS

BREASTWALLS OR COLUMNS1. G

PILE BENTS2. N

CAPS AND/OR BEARING SEATS3. N

BACKWALLS AND/OR BULKHEADS4. N

FOUNDATIONS5. N

WINGWALLS6. G

WEEP HOLES7. N

EXPANSION JOINTS8. N

EROSION AND/OR SCOUR9. F

SETTLEMENT OR DEFLECTION10. G

SLOPE PROTECTION11. N

OTHER 12. N

PIER(S)

WALLS AND/OR COLUMNS 13. N

PILE BENTS14. N

CAPS AND/OR BEARING SEATS15. N

FOUNDATIONS16. N

EROSION AND/OR SCOUR17. N

SETTLEMENT OR DEFLECTION18. N

OTHER 19. N

FIELD INSPECTION REPORT STRUCTURE NO. 3450-008P

ITEM REFERENCE AND REMARKS

STREAM BED COMPOSITION : 9.

AVERAGE CLEAR OPENING 8.

NORMAL VELOCITY 7.

ADEQUACY OF OPENING 6.

OTHER 5.

WATERWAY OBSTRUCTIONS 4.

CHANNEL PROTECTION3.

EROSION AND/OR SCOUR2.

ALIGNMENT1.

61. CHANNEL 6

F F G G N

MED

SUFF

15 FT.

SAND, ROCK

222. APPROACHES 6

OTHER 9.

ALIGNMENT 8.

SIGNS7.

SETTLEMENT 6.

EROSION5.

SURFACING4.

APPROACH GUARDRAIL 3.

2. RELIEF JOINTS

APPROACH SLABS1.

(VEGETATION)

N N N F G G G P F

223. RETAINING WALL N

OTHER 6.

SETTLEMENT OR DEFLECTION5.

EROSION AND/OR SCOUR4.

FOUNDATION3.

WEEP HOLES2.

1. WALL

36. TRAFFIC AND SAFETY FEATURES

APPROACH GUARDRAIL ENDSD.

APPROACH GUARDRAILSC.

TRANSITIONSB.

BRIDGE RAILINGSA. 0

N N N

222.5 MINOR EROSION OF SOUTH APPROACH SHOULDERS WITH UP TO 6"

DROP-OFF FROM CURBS.

222.7 YELLOW OBJECT MARKER AT NORTHWEST AND SOUTHEAST

CORNERS OF BRIDGE.

222.8 STRUCTURE IS LOCATED ON STEEP VERTICAL CURVE. SHARP

HORIZONTAL CURVE AT SOUTH APPROACH WITH RESTRICTED

SIGHT DISTANCE.

222.9 TREES OVERHANG STRUCTURE AT SOUTH APPROACH.

36.A PARAPET STONES ARE ROUGH AND UNEVEN; PARAPET IS NOT

CAPABLE OF SAFELY REDIRECTING AN ERRANT VEHICLE.

ROADWAY WIDTH IS VERY NARROW. MINIMUM PARAPET HEIGHT

OF 1'-6" DOES NOT MEET AASHTO MINIMUM HEIGHT SPECIFICATION

OF 2'-3" FOR TRAFFIC BARRIERS.

TRAFFIC SAFETY RATING CODES

N

Does not meet standards or a safety feature is required and none is provided.

Meets currently acceptable standards.

Not applicable or a safety feature is not required.

STRUCTURE LOAD RATING STRUCTURE NO. 3450-008P

TRUCK TYPE

INVENTORY RATING (NORMAL TRAFFIC) OPERATING RATING (MAXIMUM LOAD)

TONS METRIC TONS TONS METRIC TONS

H 15 14 25 23

HS 20 18 33 30

TYPE 3 19 17 31 28

TYPE 3S2 24 22 40 37

TYPE 3-3 28 25 47 42

DESIGN LOADING: UNKNOWN (H15 EQUIVALENT ASSUMED - SEE REMARKS)

X CAPACITY MEETS OR EXCEEDS DESIGN LOAD

CAPACITY IS LESS THAN DESIGN LOAD

ORIGINAL LOAD RATING CALCULATION APPLICABLE

ORIGINAL LOAD RATING CALCULATION REVISED

DATE OF LOAD RATING CALCULATION:

LOAD RATING CONTROLLED BY:

REMARKS: DESIGN LOADING IS UNKNOWN; ASSUMPTION IS BASED ON STRUCTURE TYPE, LOCATION, AGE, AND

CONDITION.

A

A

STRUCTURE INVENTORY AND APPRAISAL STRUCTURE NO. 3450-008P

BOULDER BRIDGE INSPECTION DATE: 6/12/13

STRUCTURE IDENTIFICATION

(201) PARK: ROCK CREEK PARK (1) STATE: ....................................... 113 - DISTRICT OF COLUMBI

(202) STRUCTURE NAME: .......... BOULDER BRIDGE (2) STATE HWY. AGENCY DIST:

(203) STRUCTURE KIND: ............ 1 - BRIDGE (3) COUNTY CODE: ........................ 001 - DISTRICT OF COLUMBI

(204) STRUCTURE NUMBER: ..... 3450-008P (4) CITY/PLACE CODE:

(205) NPS REGION: .................... 2 - NATIONAL CAPITAL (5) INVENTORY ROUTE:

(206) ROUTE CODE NUMBER: ... 10 (6) FEATURES INTERSECTED:....... ROCK CREEK

(207) ROAD SECTION NO: .......... 008P (7) FACILITY CARRIED: .................. BEACH DRIVE

(208) NPS ROAD CLASS: ............ 1 - PRINCIPAL PARK ROAD (8) STATE STRUCTURE NO: .......... 3450008P0000000

(209) WITHIN NPS BNDRY?: ....... YES (9) LOCATION: ................................ 1.5 MILES FROM JOYCE ROA

(210) OPERATING UNIT: ............. PARK (10) INV. RTE. - MIN. VERT. CLR: .. 99.99 FT (99.99 M)

(211) PROJECT NO(S): ................ 000000000000 (11) MILE POINT: ............................. 2.65 (KM PT 4.27)

(212) DRAWING NUMBERS: ....... NONE (27) YEAR BUILT:

(21) MAINTAINED BY: ................. 66 - NATIONAL PARK SERVICE (106) YEAR RECONSTRUCTED: .... N/A

(22) OWNER: ............................... 66 - NATIONAL PARK SERVICE (20) TOLL: ........................................ 3 - FREE ROAD

(37) HISTORICAL DESIGNATION: .. 2 - ELIGIBLE FOR REGISTER

STRUCTURE DESCRIPTION, FOUNDATION, AND DECK TYPE

(43A) MAIN STR. MATERIAL: ..

(43B) MAIN STR. TYPE:

(45) NO. OF MAIN SPANS:

(48) MAX. SPAN LENGTH:

(49) STRUCTURE LENGTH:

(216A) ABUTMENT #1 FDN:

(216B) ABUTMENT #2 FDN:

(217A) PREDOM. PIER FDN.: ..

(217B) SECOND. PIER FDN: ...

(107) DECK TYPE:

1 - CONCRETE

11 - ARCH - DECK

79.5 FT (24.2 M)

79.5 FT (24.2 M)

0 - UNKNOWN

0 - UNKNOWN

6 - N/A

6 - N/A

N - NOT APPLICABLE

(44A) APPR. STR. MATERIAL: ........ 0 - OTHER

(44B) APPR. STR. TYPE: ................ 00 - OTHER

(46) NO. OF APPROACH SPANS: .. 0

(108) WEAR SURFACE/PROTECT SYSTEM:

A) TYPE WEARING SURFACE: .. N - NOT APPLICABLE

B) TYPE MEMBRANE: ................. N - NOT APPLICABLE

C) TYPE PROTECTION: .............. N - NOT APPLICABLE

(218) IS SALT USED?: ..................... YES

LOAD RATING AND POSTING

(31) DESIGN LOAD: ................. 0 - UNKNOWN (41) LOAD RESTRICTION: ......... R - POSTED (OTHER)

(66) INVENTORY RATING: ...... 20.0 TONS (18.0 METRIC TONS) (70) BRIDGE POSTING: .............. 4 - POSTING REQUIRED

(64) OPERATING RATING: ...... 33.0 TONS (30.0 METRIC TONS)

INSPECTION DATES

(90) INSPECTION DATE: 6/13 (91) FREQ. OF INSP: 24 MONTHS (92 / 93) CRITICAL FEATURE INSPECTION (CFI):

(219) ADD. STUDIES NEEDED: N - 0 - NONE (A) FRACTURE CRITICAL: ... NO

INSP. EVERY: MONTHS - LAST INSP. : (220) SPECIAL STUDY TYPE: 0 - NONE

(B) UNDERWATER: .............. NO

(221) SPECIAL STUDY DATE: INSP. EVERY: MONTHS - LAST INSP. :

(C) SPECIAL INSPECTION: .. NO

INSP. EVERY: MONTHS - LAST INSP. :

STRUCTURE INVENTORY AND APPRAISAL STRUCTURE NO. 3450-008P

GEOMETRY, TRAFFIC, AND NAVIGATIONAL DATA

(16) LATITUDE: ............................. 38°56'54.90" (51) CURB TO CURB WIDTH: ........... 22.3 FT (6.8 M)

(17) LONGITUDE: ......................... 77°02'41.40" (52) DECK WIDTH: ............................ 29.3 FT (8.9 M)

(19) DETOUR LENGTH: ............... 3 MI (5 KM) (32) APPR. ROADWAY WIDTH: ........ 22.3 FT (6.8 M)

(28A) LANES ON STRUCT: .......... 02 (213) APPR. PAVEMENT WIDTH: ..... 22.3 FT (6.8 M)

(28B) LANES UNDER STRUCT: ... 00 LEFT SHOULDER: .................. 0.0 FT (0.0 M)

(42A) SERVICE ON: ..................... 1 - HIGHWAY RIGHT SHOULDER: ................ 0.0 FT (0.0 M)

(42B) SERVICE UNDER: .............. 5 - WATERWAY (33) BRIDGE MEDIAN: ....................... 0 - NO MEDIAN

(29) AVG. DAILY TRAFFIC: .......... 13774 (34) SKEW ANGLE: ............................ 0 °

(30) YEAR OF ADT: ...................... 2007 (35) DECK FLARE?: ........................... NO

(114) FUTURE ADT: ..................... 15118 (47) TOTAL HORIZ. CLEARANCE: .... 22.3 FT (6.8 M)

(115) YEAR OF FUTURE ADT: ..... 2027 (50) SIDEWALKS:

(101) PARALLEL STRUCTURE: ... N - NONE LEFT : ...................................... 0.0 FT (0.0 M)

(38) NAVIGATION CONTROL?: ... 0 RIGHT : ................................... 0.0 FT (0.0 M)

(39) VERTICAL CLEARANCE: ...... 0.0 FT (0.0 M) (214) BRIDGE RAIL TYPE:

(40) HORIZ. CLEARANCE: ........... 0.0 FT (0.0 M) RAIL CONFIGURATION: ......... 3 - PARAPET ONLY

(111) ABUT. OR PIER PROT: ....... MATERIAL: .............................. 9 - OTHER

DESIGN TYPE: ........................ 1 - CONTINUOUS RAIL LATERAL UNDERCLEARANCE:

(55) RIGHT: ....................... 0.0 FT (0.0 M) (215) BRIDGE RAIL HEIGHT: ............ 1.50 FT (0.46 M)

(56) LEFT: ......................... 0.0 FT (0.0 M) (53) MIN. VRT. CLEAR. OVER DECK: 99.99 FT (99.99 M)

(54) MIN. VRT. UNDERCLEARANCE: 0.00 FT (0.00 M)

CONDITION AND APPRAISAL DATA, PROPOSED IMPROVEMENTS, AND COST

(58) DECK: ................................. N

(59) SUPERSTRUCTURE:

(60) SUBSTRUCTURE:

(61) CHANNEL:

(62) CULVERT: ........................... N

(222) APPROACHES:

(223) RETAINING WALL: ........... N

(36) TRAFFIC SAFETY FEAT: ... 0NNN

(75A) TYPE OF WORK:

(75B) WORK DONE BY:

(76) IMPROVEMENT LENGTH: ..

(67) STRUCTURAL EVALUATION:

(68) DECK GEOMETRY:

(69) UNDERCLEARANCES:

(71) WATERWAY ADEQUACY:

(72) APPROACH ALIGNMENT:

(113) SCOUR CRITICAL:

(225) PURPOSE OF IMPROVEMENT:

(226) PRIORITY OF IMPROVEMENT:

(227) MAINTENANCE COST:

(228) REHAB./RECONSTR. COST: ...

(229) CONSTRUCTION COST:

N

U - Unknown foundation. Not yet

1 - MAINTENANCE

D - MINOR

ADDITIONAL INFORMATION

(230) STRUCTURE HISTORY:

2008-ASPHALT PATCHING.

(231) ADDITIONAL CONSIDERATIONS:

(330) ADDITIONAL CONFIG. INFO.:

http:77�02'41.40 http:38�56'54.90

APPENDIX STRUCTURE NO. 3450-008P

PHOTOGRAPHS STRUCTURE NO. 3450-008P

PHOTO #1 - LOOKING NORTH TOWARD JOYCE ROAD

FLOW

PHOTO #2 - WEST (UPSTREAM) SIDE

PHOTO #3 - GENERAL TOPSIDE VIEW

LOOKING SOUTH

PHOTO #4 - TYPICAL LONGITUDINAL AND MAP

CRACKING AND RUTTING OF ASPHALT

PAVEMENT IN WHEEL PATHS; EAST LANE

SHOWN

PHOTO #5 - TRANSVERSE CRACKING OF

ASPHALT PAVEMENT AT SOUTH APPROACH

PHOTO #6 - TYPICAL SPALLING OF CURBS

AND GUTTERS; WEST SIDE NEAR SOUTH END

SHOWN

PHOTO #7 - EROSION OF SOUTH APPROACH SHOULDER ON WEST

SIDE WITH DROP-OFF FROM CURB

PHOTO #8 - GENERAL UNDERSIDE VIEW LOOKING SOUTH

PHOTO #9 - TYPICAL WATER LEAKAGE AT

LONGITUDINAL CONSTRUCTION JOINTS IN

ARCH UNDERSIDE; WEST LONGITUDINAL

CONSTRUCTION JOINT AT NORTH ABUTMENT

SHOWN

PHOTO #10 - TYPICAL RANDOM CRACKING OF

ARCH UNDERSIDE WITH EFFLORESCENCE;

WEST SIDE NEAR MIDSPAN SHOWN

PHOTO #11 - AREAS OF DELAMINATION AT

CENTERLINE OF ARCH UNDERSIDE NEAR

MIDSPAN

PHOTO #12 - TYPICAL EFFLORESCENCE ON

RING STONES; WEST SIDE AT NORTH

ABUTMENT SHOWN

PHOTO #13 - GENERAL VIEW OF NORTH ABUTMENT

PHOTO #14 - SCOUR AT SOUTH ABUTMENT, DOWNSTREAM END

PHOTO #15 - SLOPE FAILURE OF NORTH UPSTREAM CHANNEL BANK

AT STRUCTURE, AREA WELL VEGETATED

PHOTO #16 - LOOKING UPSTREAM THROUGH STRUCTURE

PHOTO #17 - LOOKING DOWNSTREAM THROUGH STRUCTURE