2018_-_Pohono_Bridge_Inspection_Report.pdf

STRUCTURE SUMMARY STRUCTURE NO. 8800-001P

POHONO BRIDGE INSPECTION DATE: 7/12/18

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: .. 80.0 FT (24.4 M)

DECK TYPE: ......................... NOT APPLICABLE MAX. SPAN LENGTH: .......... 80.0 FT (24.4 M)

WEARING SURFACE: .......... NOT APPLICABLE DECK WIDTH: ...................... 35.8 FT (10.9 M)

ABUT. FOUNDATIONS: ........ SPREAD FTG ON BEARING MAT'L CURB TO CURB WIDTH: ..... 26.4 FT (8.0 M)

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

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

PROJ./PLAN REF. NO: ......... 1B2 / 00000 SKEW ANGLE: ..................... 0 °

NPS ROAD CLASS: .............. 1 - PRINCIPAL PARK ROAD FRACTURE CRITICAL: ........ NO

STRUCTURE HISTORY: ...... 2006-STRUCTURE AND SOUTH APPROACH REPAVED. 2008-STRUCTURE AND APPROACHES

REPAVED. 2015-ADDITIONAL SCOUR ANALYSIS PERFORMED.

LOCATION

YOSEMITE NATIONAL PARK MILE POINT: ..................... 0.02 (KM PT 0.03)

STATE: ................................. CALIFORNIA LOCATION: 7.9 miles east from El Portal boundary line on CA Route 140 (El Portal Road). Bridge is atFACILITY CARRIED: ............ VALLEY LOOP ROAD beginning of one way loop road.

FEATURE INTERSECTED: .. MERCED RIVER

STRUCTURE EVALUATION SUMMARY

This concrete arch bridge is in fair structural condition, but has some issues with scour and undermining, the extent of which is further described below. Other problems with the bridge include minor cracking of the arch underside, with efflorescence leaching from the cracks; and missing object markers at the north approach.

Please note that this structure had previously been assigned an Improvement Category of “B” (Major) due to concerns about scour and possible undermining of the north abutment footing. However, an underwater inspection performed in July 2018 confirmed that the undermining is limited to a protective concrete apron adjacent to the north abutment, and that the abutment footing itself is not undermined. As a result, this structure has been reassigned an Improvement Category of “C” (Moderate).

It should also be noted that this structure has been deemed "scour critical", i.e. calculations from a 1998 scour study indicate the bridge foundations may be susceptible to undermining and instability during a major flood event. An additional scour evaluation was performed in 2015, and further hydraulic analyses are in progress. Please be advised that the scour countermeasure recommendations in this report may be revised based on the results of these analyses.

INSPECTION TEAM: J. ANDERSON, D. CHRISTENSEN

CONDITION ASSESSMENT:

JEFFREY ANDERSON, P.E., FIELD TEAM LEADER 720-963-3384

REPORT REVIEW:

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

REPORT APPROVAL: DATE: 12/4/18

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

RECOMMENDATIONS AND ESTIMATED COSTS STRUCTURE NO. 8800-001P

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

B (Major) - Structure exhibits severe deterioration, presents a safety hazard, or is designated a high priority due to age and/or condition.

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.

C226 PRIORITY OF IMPROVEMENT

ITEM

NO.

ROUTINE MAINTENANCE QTY. UNIT UNIT

COST

PRELIM.

COST

ESTIMATE

ITEM

NO.

REHABILITATION/RECONSTRUCTION

(TYPICALLY NEEDED WITHIN 5 YEARS)

QTY. UNIT

UNIT

COST

PRELIM. COST

ESTIMATES

REHAB. RECONSTR.

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: It is recommended that bridge foundations be monitored for scour following major flood events.

Cost estimates assume that recommended actions will be combined with similar work being performed on other structures.

FIELD INSPECTION REPORT STRUCTURE NO. 8800-001P

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

CONDITION RATING CODE EQUIVALENTS FOR SUB-ELEMENTS

SERIOUS CONDITION - loss of section, deterioration, spalling, or scour have seriously affected primary structural components. Local failures are possible.

Fatigue cracks in steel or shear cracks in concrete may be present.

CRITICAL CONDITION - advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless closely monitored it may be necessary to close the structure until corrective action can be taken.

“IMMINENT” FAILURE CONDITION - major deterioration or sec ion loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Structure is closed to traffic but corrective action may return structure to light service.

FAILED CONDITION - out of service; beyond corrective action.

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

NOT APPLICABLE

EXCELLENT CONDITION

VERY GOOD CONDITION - no problems noted.

GOOD CONDITION - some minor problems.

SATISFACTORY CONDITION - structural elements show some minor deterioration.

FAIR CONDITION - all primary structural elements are sound but may have minor section loss, cracking, spalling, or scour.

POOR CONDITION - advanced section loss, deterioration, spalling, or scour.

N

58. DECK ITEM REFERENCE AND REMARKS

OTHER

ALIGNMENT

DEFLECTION AND/OR VIBRATION

FASCIA(E)

DIAPHRAGMS AND BRACING

TRUSSES

FLOOR BEAMS AND STRINGERS

ARCH(ES) OR SLAB(S)

GIRDERS OR BEAMS

BEARING DEVICES

59. SUPERSTRUCTURE

OTHER

DEFLECTION AND/OR VIBRATION

UTILITIES

DRAINS AND DRAINAGE

PARAPETS AND/OR RAILINGS

CURBS, SIDEWALKS, AND MEDIAN

RIDEABILITY

WEARING SURFACE

EXPANSION JOINTS

DECK SLAB

ABUTMENTS

60. SUBSTRUCTURE

1.

10.

2.

3.

4.

5.

6.

7.

8.

9.

10.

9.

8.

7.

6.

5.

4.

3.

2.

1.

PAINT

11.

N

N N F N N N N G G

N G

G G G G G N

N

N

N

N

58.5 SURVEY MARKER ON SOUTHWEST CURB.

58.6 GAP IN TOP OF STONE PARAPET ON EAST SIDE NEAR SOUTH

ABUTMENT.

58.7 MINOR PONDING AT NORTHEAST CORNER OF BRIDGE (NOT VISIBLE

DUE TO DRY CONDITIONS AT TIME OF INSPECTION).

59.3 MINOR EFFLORESCENCE FROM MORTAR JOINTS THROUGHOUT

RING STONES AND SPANDREL WALLS. MODERATE

EFFLORESCENCE BETWEEN MASONRY RING STONES AND

CONCRETE ARCH ALONG BOTH SIDES.

MINOR TRANSVERSE CRACKING ON ARCH UNDERSIDE, ESPECIALLY

NEAR ABUTMENTS. SMALL VOIDS (UP TO 12" DEEP) IN BASE OF

ARCH ON BOTH SIDES, BOTH ENDS OF ARCH. MINOR DIAGONAL

CRACK WITH EFFLORESCENCE ON ARCH UNDERSIDE NEAR EAST

SIDE, APPROXIMATELY 1/3 OF SPAN FROM NORTH ABUTMENT.

MINOR EFFLORESCENCE ALONG COLD JOINTS. LOCAL HEAVY

EFFLORESCENCE 10' FROM NORTH ABUTMENT, EAST SIDE. 1. BREASTWALLS OR COLUMNS N

2. PILE BENTS N

3. CAPS AND/OR BEARING SEATS N

4. BACKWALLS AND/OR BULKHEADS N

5. FOUNDATIONS F

6. WINGWALLS G

7. WEEP HOLES N

8. EXPANSION JOINTS N

9. EROSION AND/OR SCOUR F

10. SETTLEMENT OR DEFLECTION G

11. SLOPE PROTECTION N

12. OTHER N

PIER(S)

13. WALLS AND/OR COLUMNS N

14. PILE BENTS N

15. CAPS AND/OR BEARING SEATS N

16. FOUNDATIONS N

17. EROSION AND/OR SCOUR N

18. SETTLEMENT OR DEFLECTION N

19. OTHER N

FIELD INSPECTION REPORT STRUCTURE NO. 8800-001P

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 PROTECTION 3.

EROSION AND/OR SCOUR 2.

ALIGNMENT 1.

61. CHANNEL 6

G F N G N

HIGH

SUFF

9 FT.

SANDY, BOULDERS

222. APPROACHES 7

1. APPROACH SLABS

2. RELIEF JOINTS

3. APPROACH GUARDRAIL

4. SURFACING

5. EROSION

6. SETTLEMENT

7. SIGNS

8. ALIGNMENT

9. OTHER

N N N G G G F F N

223. RETAINING WALL N

1. WALL

2. WEEP HOLES

3. FOUNDATION

4. EROSION AND/OR SCOUR

5. SETTLEMENT OR DEFLECTION

6. OTHER

36. TRAFFIC AND SAFETY FEATURES

A. BRIDGE RAILINGS

B. TRANSITIONS

C. APPROACH GUARDRAILS

D. APPROACH GUARDRAIL ENDS

TRAFFIC SAFETY RATING CODES

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

1 - Meets currently acceptable standards.

N - Not applicable or a safety feature is not required.

60.5,9 UNDERWATER INSPECTION PERFORMED IN AUGUST 2018 NOTED

UNDERMINING OF PROTECTIVE CONCRETE APRON ADJACENT TO

NORTH ABUTMENT, HOWEVER NO UNDERMINING OF ABUTMENT

FOOTING ITSELF WAS OBSERVED.

MINOR HONEYCOMBING AND VOIDS IN ENDS OF NORTH ABUTMENT

CONCRETE AT JUNCTION WITH ROCK. GROUTED RIPRAP ON TOP

OF 6' DEEP X 7' HORIZONTAL CONCRETE APRON AT EAST SIDE OF

NORTH ABUTMENT IS UNDERMINED. OVERRUN OF GROUT POUR

ALSO PRESENT; CONCRETE APRON EXTENDS TO STREAM BED.

REMAINDER OF APRON CAST ON 3' DIAMETER OR LARGER

BOULDERS.

MODERATE SCOUR ALONG SOUTH ABUTMENT EXPOSING TIMBER

FORMING AT CENTER, NO UNDERMINING NOTED. HEAVY SCALING

AT WATERLINE WITH VOIDS; 3"L X 4"D VOID IN BOTTOM OF SOUTH

ABUTMENT AT WEST END. WATER ACTION HAS ALSO WASHED OUT

RING STONE MORTAR ALONG BOTTOM OF ARCH AT BOTH SIDES OF

SOUTH ABUTMENT.

SEE AUGUST 2018 UNDERWATER INSPECTION REPORT FOR

ADDITIONAL INFORMATION.

60.6 MINOR MORTAR JOINT DETERIORATION WITH EFFLORESCENCE

FROM MORTAR, AND MOSS GROWTH THROUGHOUT WINGWALLS;

MOSS GROWTH NOT NOTED DURING THIS INSPECTION.

61.2 SEE BRIDGE FILE FOR SCOUR EVALUATION.

61.4 MEDIUM SIZE TREE IN CHANNEL AT UPSTREAM END OF SOUTH

ABUTMENT, NOT NOTED DURING THIS INSPECTION.

222.5 FILL AND RIPRAP HAVE BEEN PLACED IN DITCH ON WEST SIDE OF

SOUTH APPROACH TO CORRECT EROSION, SETTLEMENT, AND

UNDERMINING OF TREES.

222.7 "POHONO BRIDGE" SIGNS ATTACHED TO ENDS OF NORTHWEST AND

SOUTHEAST PARAPET ENDS.

OBJECT MARKERS NOT PRESENT AT NORTH APPROACH.

222.8, 36.B,C,D

SIGHT DISTANCE IS FAIR. CURVES AT BOTH ENDS OF BRIDGE;

MINOR SPEED REDUCTION IS REQUIRED.

36.B,C,D NO APPROACH GUARDRAILS PRESENT.

STRUCTURE LOAD RATING STRUCTURE NO. 8800-001P

TRUCK TYPE

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

TONS METRIC TONS TONS METRIC TONS

H 30 27 50 45

HS 41 37 68 62

TYPE 3 34 31 57 52

TYPE 3S2 59 54 99 90

TYPE 3-3 70 64 117 106

DESIGN LOADING: UNKNOWN

X CAPACITY MEETS OR EXCEEDS DESIGN LOAD

CAPACITY IS LESS THAN DESIGN LOAD

ORIGINAL LOAD RATING CALCULATION APPLICABLE

X ORIGINAL LOAD RATING CALCULATION REVISED

DATE OF LOAD RATING CALCULATION: 5/16

LOAD RATING CONTROLLED BY: MOMENT

REMARKS: LOAD RATING HAS BEEN REVISED BASED ON FINDINGS FROM 8/19/18 UNDERWATER INSPECTION. SEE

BRIDGE FILE FOR LOAD RATING CALCULATIONS.

STRUCTURE INVENTORY AND APPRAISAL STRUCTURE NO. 8800-001P

STRUCTURE IDENTIFICATION

(201) PARK: YOSEMITE NATIONAL PARK

(202) STRUCTURE NAME: .......... POHONO BRIDGE

(203) STRUCTURE KIND: ............1 - BRIDGE

(204) STRUCTURE NUMBER: ..... 8800-001P

(205) NPS REGION: .................... 6 - PACIFIC WEST

(206) ROUTE CODE NUMBER: ... 500

(207) ROAD SECTION NO: ..........001P

(208) NPS ROAD CLASS: ............ 1 - PRINCIPAL PARK ROAD

(209) WITHIN NPS BNDRY?: .......YES

(210) OPERATING UNIT: ............. PARK

(211) PROJECT NO(S): ................1B2

(212) DRAWING NUMBERS:

(21) MAINTAINED BY: ................. 66 - NATIONAL PARK SERVICE

(22) OWNER: ............................... 66 - NATIONAL PARK SERVICE

(1) STATE:

(2) STATE HWY. AGENCY DIST:

(3) COUNTY CODE:

(4) CITY/PLACE CODE:

(5) INVENTORY ROUTE:

(6) FEATURES INTERSECTED:

(7) FACILITY CARRIED:

(8) STATE STRUCTURE NO:

(9) LOCATION:

(10) INV. RTE. - MIN. VERT. CLR: ..

(11) MILE POINT:

(27) YEAR BUILT:

(106) YEAR RECONSTRUCTED:

(20) TOLL:

(37) HISTORICAL DESIGNATION: ..

069 - CALIFORNIA (CA)

043 - MARIPOSA

161005000

MERCED RIVER

VALLEY LOOP ROAD

8800001P0000000

7.9 miles east from El Po

99.99 FT (99.99 M)

0.02 (KM PT 0.03)

N/A

3 - FREE ROAD

5 - NOT ELIGIBLE

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

80.0 FT (24.4 M)

80.0 FT (24.4 M)

2 - SPREAD FTG ON BEARING MAT'L

2 - SPREAD FTG ON BEARING MAT'L

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?: ..................... NO

LOAD RATING AND POSTING

(31) DESIGN LOAD: ................. 0 - UNKNOWN (41) LOAD RESTRICTION: ......... A - OPEN, NO RESTRICTION

(66) INVENTORY RATING: ...... 41.0 TONS (37.2 METRIC TONS) (70) BRIDGE POSTING: .............. 5 - NO POSTING REQUIRED

(64) OPERATING RATING: ...... 68.0 TONS (61.7 METRIC TONS)

INSPECTION DATES

(90) INSPECTION DATE: 7/18 (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: 5 - SCOUR

(B) UNDERWATER: .............. YES

(221) SPECIAL STUDY DATE: 9/98 INSP. EVERY: 24 MONTHS - LAST INSP. : 8/18

(C) SPECIAL INSPECTION: .. NO

INSP. EVERY: MONTHS - LAST INSP. :

STRUCTURE INVENTORY AND APPRAISAL STRUCTURE NO. 8800-001P

GEOMETRY, TRAFFIC, AND NAVIGATIONAL DATA

(16) LATITUDE: ............................. 37°42'59.90"

(17) LONGITUDE: ......................... 119°39'58.50"

(19) DETOUR LENGTH: ............... 199 MI (199 KM)

(28A) LANES ON STRUCT:

(28B) LANES UNDER STRUCT: ... 00

(42A) SERVICE ON: ..................... 5 - HIGHWAY-PEDESTRIAN

(42B) SERVICE UNDER: .............. 5 - WATERWAY

(29) AVG. DAILY TRAFFIC:

(30) YEAR OF ADT:

(114) FUTURE ADT:

(115) YEAR OF FUTURE ADT:

(101) PARALLEL STRUCTURE: ... N - NONE

(38) NAVIGATION CONTROL?: ... 0

(39) VERTICAL CLEARANCE: ...... 0.0 FT (0.0 M)

(40) HORIZ. CLEARANCE: ........... 0.0 FT (0.0 M)

(111) ABUT. OR PIER PROT:

LATERAL UNDERCLEARANCE:

(55) RIGHT: ....................... 0.0 FT (0.0 M)

(56) LEFT: ......................... 0.0 FT (0.0 M)

(51) CURB TO CURB WIDTH:

(52) DECK WIDTH:

(32) APPR. ROADWAY WIDTH:

(213) APPR. PAVEMENT WIDTH:

LEFT SHOULDER:

RIGHT SHOULDER:

(33) BRIDGE MEDIAN:

(34) SKEW ANGLE:

(35) DECK FLARE?:

(47) TOTAL HORIZ. CLEARANCE:

(50) SIDEWALKS:

LEFT :

RIGHT :

(214) BRIDGE RAIL TYPE:

RAIL CONFIGURATION:

MATERIAL:

DESIGN TYPE:

(215) BRIDGE RAIL HEIGHT:

(53) MIN. VRT. CLEAR. OVER DECK:

(54) MIN. VRT. UNDERCLEARANCE:

26.4 FT (8.0 M)

35.8 FT (10.9 M)

23.0 FT (7.0 M)

21.0 FT (6.4 M)

1.0 FT (0.3 M)

1.0 FT (0.3 M)

0 - NO MEDIAN

0 °

NO

26.4 FT (8.0 M)

0.0 FT (0.0 M)

5.1 FT (1.6 M)

3 - PARAPET ONLY

9 - OTHER

1 - CONTINUOUS RAIL

3.50 FT (1.07 M)

99.99 FT (99.99 M)

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: ... 1000

(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

3 - Scour critical; foundations un

2 - REHAB/RECONSTRUCTION

C - MODERATE

$500

$390,000

$0

ADDITIONAL INFORMATION

(230) STRUCTURE HISTORY:

2006-STRUCTURE AND SOUTH APPROACH REPAVED. 2008-STRUCTURE AND APPROACHES REPAVED. 2015-ADDITIONAL SCOUR

ANALYSIS PERFORMED.

(231) ADDITIONAL CONSIDERATIONS:

(330) ADDITIONAL CONFIG. INFO.:

Span #1 - Length 80'; Type 111 (R/C Spandrel Filled Arch) https://119�39'58.50 https://37�42'59.90

APPENDIX STRUCTURE NO. 8800-001P

PHOTOGRAPHS STRUCTURE NO. 8800-001P

PHOTO #1 - LOOKING SOUTH TOWARD SOUTHSIDE DRIVE

FLOW

PHOTO #2 - WEST (DOWNSTREAM) SIDE

PHOTO #3 - LACK OF OBJECT MARKERS AT NORTH APPROACH

CORNERS, NORTHWEST CORNER SHOWN

PHOTO #4 - GENERAL TOPSIDE VIEW LOOKING SOUTH

PHOTO #5 - TYPICAL STONE MASONRY PARAPETS

PHOTO #6 - GAP IN TOP OF PARAPET ON EAST SIDE NEAR SOUTH

ABUTMENT

PHOTO #7 - GENERAL UNDERSIDE VIEW LOOKING TOWARD NORTH

ABUTMENT

PHOTO #8 - GENERAL UNDERSIDE VIEW LOOKING TOWARD SOUTH

PHOTO #9 - TRANSVERSE CRACK ALONG CONSTRUCTION JOINT AT

BOTTOM OF ARCH TOWARD NORTH ABUTMENT AT CENTER OF

STRUCTURE

PHOTO #10 - EFFLORESCENCE FROM MORTAR AT BOTTOM OF RING

STONES, EAST SIDE SHOWN

PHOTO #11 - LOSS OF MORTAR BETWEEN STONE RING AND

CONCRETE, WEST SIDE AT NORTH ABUTMENT SHOWN

PHOTO #12 - EFFLORESCENCE FROM MORTAR ON BOTTOM OF STONE

RING, BOTH SIDES

PHOTO #13 - 4"H X 20"W GAP IN MORTAR AT BOTTOM OF STONE RING

AT SOUTHEAST CORNER

PHOTO #14 - UNREPAIRED SCOUR HOLE IN FRONT OF NORTH

PHOTO #15 - ABRASION OF CONCRETE AT NORTH ABUTMENT WITH

VOIDS AT EAST END

PHOTO #16 - 18"L X 3"D VOID AT EAST END OF NORTH ABUTMENT

PHOTO #17 - 18"L X 6"D VOID AT EAST END OF NORTH ABUTMENT

PHOTO #18 - 16"L X 3"T X 11"D VOID IN WEST END OF NORTH

PHOTO #19 - EXPOSED TIMBER FORMING AT CENTER OF SOUTH

ABUTMENT

PHOTO #20 - EFFLORESCENCE FROM MORTAR JOINTS IN WINGWALLS,

SOUTHEAST WINGWALL SHOWN

PHOTO #21 - LOOKING UPSTREAM

PHOTO #22 - LOOKING DOWNSTREAM