Report_Tunnel_Inspection_Tanbark_Ridge_Tunnel.pdf

TUNNEL INSPECTION REPORT

TANBARK RIDGE TUNNEL

BLUE RIDGE PARKWAY THROUGH TANBARK RIDGE MOUNTAIN

BLUE RIDGE PARKWAY

NP

STRUCTURE NO. 5140-141P

INSPECTION TYPE: ROUTINE

INSPECTION DATE: 6/25/13

Report prepared by: SP

MILE POINT: 374.24

Federal Highway Administration KILOMETER POINT: 602.26 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. 5140-141P

TANBARK RIDGE TUNNEL INSPECTION DATE: 6/25/13

TUNNEL IDENTIFICATION AND DESCRIPTION

LINING MATERIAL: ............... UNLINED / CONCRETE MINIMUM VERTICAL CLR: .... 14.5 FT (4.4 M)

SPRINGLINE LENGTH: ........ 30.2 FT (9.2 M) STRUCT. TOTAL LENGTH: ... 843.0 FT (256.9 M)

CURB TO CURB WIDTH: ..... 30.2 FT (9.2 M) YEAR BUILT:

PROJ./PLAN REF. NO: ......... 2P5,2P8,2M17 / YEAR RECONSTRUCTED:

NPS ROAD CLASS: .............. 1 - PRINCIPAL PARK ROAD

STRUCTURE HISTORY: ...... 1961-TUNNEL LININGS AND PORTALS; 1990-MAJOR RECONSTRUCTION/SUPERSTRUCTURE, ROCKBOLTS AND SCREENING.

LOCATION

BLUE RIDGE PARKWAY MILE POINT: ..................... 374.24 (KM PT 602.26)

STATE: .................................. NORTH CAROLINA LOCATION: 19.1 MILES TO NC ROUTE 128

FACILITY CARRIED: ............. BLUE RIDGE PARKWAY

FEATURE INTERSECTED: ... TANBARK RIDGE MOUNTAIN

STRUCTURE EVALUATION SUMMARY

This tunnel is in poor condition due to severe cracking and spalling of the south concrete lining. Voids are present in the rock at areas of spalled lining near the south portal with active water leakage. This condition is causing leakage on the roadway which could cause ice to form when the temperature drops below freezing, thus causing hazardous driving conditions.

Other problems include loose rock in the crown of the unlined portion of the tunnel, missing and damaged reflectors inside the tunnel, and minor spalling with exposed rebar on the north lining.

Corrective action should be taken as outlined in this report to prevent the possible development of more serious or costly problems in the future.

INSPECTION TEAM: J. ALLEN, J. BEREZNIAK (GANNETT FLEMING)

CONDITION ASSESSMENT:

JEFFREY ALLEN, 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. 5140-141P

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.

B226 PRIORITY OF IMPROVEMENT

ITEM

NO.

MAINTENANCE RECOMMENDATIONS

(GENERALLY NOT FLHP ELIGIBLE)

QTY. UNIT COST

UNIT

ESTIMATE

COST

PRELIM.

59.1 SCALE/REMOVE LOOSE ROCK FROM UNLINED SECTION APPROXIMATELY 293'

AND 302' FROM NORTH PORTAL.

1 LS

59.8, 222.7 REPLACE MISSING AND DAMAGED REFLECTORS. REPLACE VERTICAL

CLEARANCE SIGN AT NORTH APPROACH. POST VERTICAL CLEARANCE SIGN AT

SOUTH APPROACH.

22 EA

59.1 CLEAN EXPOSED REBAR AND SEAL WITH APPROVED PROTECTIVE COATING ON

NORTH LINING.

6 SF

PRELIM. MAINTENANCE TOTAL :

ITEM

NO.

REHABILITATION/RECONSTRUCTION

(TYPICALLY NEEDED WITHIN 5 YEARS) QTY. UNIT UNIT

COST ESTIMATES

PRELIM. COST

REHAB. RECONSTR.

59.1,4 REHABILITATE SOUTH LINING. REPLACE DRAIN CHASE IN SOUTH

LINING APPROXIMATELY 540' FROM NORTH PORTAL.

350 LF

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

FIELD INSPECTION REPORT STRUCTURE NO. 5140-141P

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

N

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.

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 section 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 CODE EQUIVALENTS FOR SUB-ELEMENTS

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

59. TUNNEL 4

P1. LINING

G2. PORTALS

N3. CURBS AND SIDEWALKS

P4. DRAINS AND DRAINAGE

G5. WEARING SURFACE

G6. RIDEABILITY

N7. LIGHTING

P8. OTHER (REFLECTORS)

9. ADEQUACY OF OPENING SUFF

222. APPROACHES 7

N1. APPROACH SLABS

N2. RELIEF JOINTS

N3. APPROACH GUARDRAIL

G4. SURFACING

G5. EROSION

G6. SETTLEMENT

F7. SIGNS

G8. ALIGNMENT

N9. OTHER

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

NA. BRIDGE RAILINGS

NB. TRANSITIONS

NC. APPROACH GUARDRAILS

ND. 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.

ITEM REFERENCE AND REMARKS

59.1,4 CONCRETE LINING AT EACH END WITH UNLINED SECTION

BETWEEN THEM.

MODERATE SPALLING (36"H X 24"W X 1.5"D) WITH EXPOSED REBAR

ON EAST SIDE OF NORTH LINING NEAR PORTAL. MINOR CRACKING

WITH EFFLORESCENCE ON WEST SIDE OF NORTH LINING.

MODERATE LEAKAGE AT WEST SIDE BETWEEN NORTH LINING AND

UNLINED SECTION.

METAL SCREENING AND ROCKBOLTING IN UNLINED SECTION WITH

MINOR RUSTING OF EXPOSED PORTIONS OF ROCKBOLTS; SCREEN

DAMAGED ALONG EAST SIDE APPROXIMATELY 405' FROM NORTH

PORTAL. AREAS OF POTENTIALLY LOOSE ROCK IN CROWN OF

UNLINED SECTION BEHIND SCREEN APPROXIMATELY 293' AND 302'

FROM NORTH PORTAL.

PREVIOUS SPALLING HAS LEFT VOIDS WITH EXPOSED REBAR IN

SOUTH LINING: ON WEST SIDE APPROXIMATELY 508' FROM NORTH

PORTAL, AND NEAR SOUTH PORTAL (6.5'W X 5'H X 1'D) WITH VOIDS

BEHIND CONCRETE; ON CROWN APPROXIMATELY 555' FROM

NORTH PORTAL. MINOR SPALLING WITH EXPOSED REBAR ON EAST

SIDE OF SOUTH LINING APPROXIMATELY 697' FROM NORTH

PORTAL; ON WEST SIDE APPROXIMATELY 805' FROM NORTH

PORTAL; ON CROWN APPROXIMATELY 555', 612', AND 753' FROM

NORTH PORTAL. ONE AREA OF LOOSE CONCRETE ON CROWN

APPROXIMATELY 753' FROM NORTH PORTAL. MODERATE SPALLING

WITH EFFLORESCENCE AND EXPOSED REBAR AND DRAIN CHASE

ON WEST SIDE APPROXIMATELY 540' FROM NORTH PORTAL.

SEVERE DELAMINATION, SPALLING, AND CRACKING WITH

EFFLORESCENCE ON EAST SIDE NEAR SOUTH PORTAL. SEVERE

SPALLING (10'H X 2'W X 6"D) WITH EXPOSED REBAR ON EAST SIDE

AT SOUTH PORTAL. SIGNIFICANT LEAKAGE ALONG JUNCTION WITH

RING STONES. METAL SCREEN ATTACHED TO LINING IN SEVERAL

AREAS OF DETERIORATION.

59.2 MODERATE EFFLORESCENCE FROM MASONRY JOINTS AT BOTH

PORTALS. MINOR LEAKAGE FROM BOTH PORTAL STONES. MINOR

VEGETATION ON BOTH PORTALS.

59.5, 222.4 TWO CORE LOCATIONS WITH PATCHES AT NORTHBOUND LANE

BELOW SOUTH PORTAL AND TWO AT SOUTHBOUND LANE OF

SOUTH APPROACH.

FIELD INSPECTION REPORT STRUCTURE NO. 5140-141P

ADDITIONAL ITEM REFERENCE AND REMARKS

59.8 SEVERAL REFLECTORS ARE DAMAGED OR MISSING; NUMEROUS MISALIGNED. REFLECTORS AT PORTAL HAVE

FADED.

222.7 13'-11" VERTICAL CLEARANCE SIGN AT NORTH APPROACH; MISSING FROM SOUTH APPROACH; ACTUAL CLEARANCE IS 14'-6". "TURN LIGHTS ON" AND "TANBARK RIDGE TUNNEL" SIGNS AT BOTH APPROACHES.

STRUCTURE INVENTORY AND APPRAISAL STRUCTURE NO. 5140-141P

STRUCTURE IDENTIFICATION

(201) PARK: BLUE RIDGE PARKWAY (1) STATE: ....................................... 374 - NORTH CAROLINA (NC)

(202) STRUCTURE NAME: .......... TANBARK RIDGE TUNNEL (2) STATE HWY. AGENCY DIST:

(203) STRUCTURE KIND: ............3 - TUNNEL (3) COUNTY CODE: ........................ 021 - BUNCOMBE

(204) STRUCTURE NUMBER: ..... 5140-141P (4) CITY/PLACE CODE:

(205) NPS REGION: .................... 4 - SOUTHEAST (5) INVENTORY ROUTE:

(206) ROUTE CODE NUMBER: ... 1 (6) FEATURES INTERSECTED:....... TANBARK RIDGE MOUNTAIN

(207) ROAD SECTION NO: ..........141P (7) FACILITY CARRIED: .................. BLUE RIDGE PARKWAY

(208) NPS ROAD CLASS: ............ 1 - PRINCIPAL PARK ROAD (8) STATE STRUCTURE NO: .......... 5140141P0000000

(209) WITHIN NPS BNDRY?: .......YES (9) LOCATION: ................................ 19.1 MILES TO NC ROUTE 12

(210) OPERATING UNIT: .............GILLESPE (10) INV. RTE. - MIN. VERT. CLR: .. 14.25 FT (4.34 M)

(211) PROJECT NO(S): ................2P5,2P8,2M17 (11) MILE POINT: ............................. 374.24 (KM PT 602.26)

(212) DRAWING NUMBERS: ....... (27) YEAR BUILT:

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

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

(37) HISTORICAL DESIGNATION: .. 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:

0 - OTHER

18 - TUNNEL

30.2 FT (9.2 M)

843.0 FT (256.9 M)

6 - N/A

6 - N/A

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: .. 2 - INTEGRAL CONCRETE

B) TYPE MEMBRANE: ................. 0 - NONE

C) TYPE PROTECTION: .............. 0 - NONE

(218) IS SALT USED?: ..................... NO

LOAD RATING AND POSTING

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

(66) INVENTORY RATING: ...... 0.0 TONS (0.0 METRIC TONS) (70) BRIDGE POSTING: .............. 5 - NO POSTING REQUIRED

(64) OPERATING RATING: ...... 0.0 TONS (0.0 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. 5140-141P

GEOMETRY, TRAFFIC, AND NAVIGATIONAL DATA

(16) LATITUDE: ............................. 35°39'45.80" (51) CURB TO CURB WIDTH: ........... 30.2 FT (9.2 M)

(17) LONGITUDE: ......................... 82°27'39.30" (52) DECK WIDTH: ............................ 0.0 FT (0.0 M)

(19) DETOUR LENGTH: ............... 40 MI (64 KM) (32) APPR. ROADWAY WIDTH: ........ 38.0 FT (11.6 M)

(28A) LANES ON STRUCT: .......... 00 (213) APPR. PAVEMENT WIDTH: ..... 22.0 FT (6.7 M)

(28B) LANES UNDER STRUCT: ... 02 LEFT SHOULDER: .................. 8.0 FT (2.4 M)

(42A) SERVICE ON: ..................... 1 - HIGHWAY RIGHT SHOULDER: ................ 8.0 FT (2.4 M)

(42B) SERVICE UNDER: .............. 1 - HIGHWAY (33) BRIDGE MEDIAN: ....................... 0 - NO MEDIAN

(29) AVG. DAILY TRAFFIC: .......... 5007 (34) SKEW ANGLE: ............................ 0 °

(30) YEAR OF ADT: ...................... 2013 (35) DECK FLARE?: ........................... NO

(114) FUTURE ADT: ..................... 5507 (47) TOTAL HORIZ. CLEARANCE: .... 21.6 FT (6.6 M)

(115) YEAR OF FUTURE ADT: ..... 2033 (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: ......... 0 - N/A

(111) ABUT. OR PIER PROT: ....... MATERIAL: .............................. 0 - N/A

DESIGN TYPE: ........................ 0 - N/A LATERAL UNDERCLEARANCE:

(55) RIGHT: ....................... 0.0 FT (0.0 M) (215) BRIDGE RAIL HEIGHT: ............ 0.00 FT (0.00 M)

(56) LEFT: ......................... 0.0 FT (0.0 M) (53) MIN. VRT. CLEAR. OVER DECK: 14.50 FT (4.42 M)

(54) MIN. VRT. UNDERCLEARANCE: 14.50 FT (4.42 M)

CONDITION AND APPRAISAL DATA, PROPOSED IMPROVEMENTS, AND COST

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

(59) SUPERSTRUCTURE: .........N

(60) SUBSTRUCTURE: ..............N

(61) CHANNEL: .......................... N

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

(222) APPROACHES:

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

(36) TRAFFIC SAFETY FEAT: ... NNNN

(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

N

N

N - Not over waterway.

2 - REHAB/RECONSTRUCTION

B - MAJOR

$0

ADDITIONAL INFORMATION

(230) STRUCTURE HISTORY:

1961-TUNNEL LININGS AND PORTALS; 1990-MAJOR RECONSTRUCTION/SUPERSTRUCTURE, ROCKBOLTS AND SCREENING.

(231) ADDITIONAL CONSIDERATIONS:

(330) ADDITIONAL CONFIG. INFO.:

APPENDIX STRUCTURE NO. 5140-141P

PHOTOGRAPHS STRUCTURE NO. 5140-141P

PHOTO #1 - NORTH PORTAL

PHOTO #2 - SOUTH PORTAL

PHOTO #3 - GENERAL UNDERSIDE VIEW OF NORTH LINING LOOKING

SOUTH

PHOTO #4 - GENERAL ROADWAY VIEW LOOKING SOUTH

PHOTO #5 - SIGNAGE AT NORTH APPROACH

PHOTO #6 - LEAKAGE ON WEST SIDE OF NORTH PORTAL; NOTE

VEGETATION GROWTH

PHOTO #7 - TYPICAL FADED REFLECTOR AT NORTH PORTAL, WEST

SIDE SHOWN

PHOTO #8 - SPALLING WITH EXPOSED REBAR ON EAST SIDE OF

NORTH LINING NEAR PORTAL

PHOTO #9 - CRACKING WITH EFFLORESCENCE ON WEST SIDE OF

NORTH LINING NEAR PORTAL

PHOTO #10 - LEAKAGE AT WEST SIDE BETWEEN NORTH LINING AND

UNLINED SECTION

PHOTO #11 - GENERAL UNDERSIDE VIEW OF UNLINED SECTION

LOOKING NORTH

PHOTO #12 - TYPICAL MISALIGNMENT OF REFLECTOR ON UNLINED

SECTION, WEST SIDE SHOWN

PHOTO #13 - AREA OF POTENTIALLY LOOSE ROCK AT CROWN,

APPROXIMATELY 293' FROM NORTH PORTAL

PHOTO #14 - AREA OF POTENTIALLY LOOSE ROCK AT EAST SIDE OF

CROWN, APPROXIMATELY 302' FROM NORTH PORTAL

PHOTO #15 - DAMAGE TO SCREEN ALONG EAST SIDE OF UNLINED

SECTION APPROXIMATELY 405' FROM NORTH PORTAL

PHOTO #16 - GENERAL UNDERSIDE VIEW OF SOUTH LINING LOOKING

NORTH

PHOTO #17 - CRACKING WITH

EFFLORESCENCE ON EAST SIDE OF SOUTH

LINING NEAR UNLINED SECTION

PHOTO #18 - GENERAL VIEW OF VOID WITH

EXPOSED REBAR AT WEST SIDE OF SOUTH

LINING APPROXIMATELY 508' FROM NORTH

PORTAL

PHOTO #19 - GENERAL VIEW OF SPALLING

WITH EXPOSED REBAR AND DRAIN CHASE AT

WEST SIDE OF SOUTH LINING

APPROXIMATELY 540' FROM NORTH PORTAL

PHOTO #20 - SPALLING WITH EXPOSED

REBAR AND DRAIN CHASE AT WEST SIDE OF

SOUTH LINING APPROXIMATELY 540' FROM

NORTH PORTAL; NOTE EFFLORESCENCE

PHOTO #21 - GENERAL VIEW OF SPALLING WITH EXPOSED REBAR

AND VOID WITH EXPOSED REBAR AT CROWN OF SOUTH LINING

APPROXIMATELY 555' FROM NORTH PORTAL

PHOTO #22 - SPALLING WITH EXPOSED REBAR AND VOID WITH

EXPOSED REBAR AT CROWN OF SOUTH LINING APPROXIMATELY 555'

FROM NORTH PORTAL

PHOTO #23 - VOID WITH EXPOSED REBAR AT CROWN OF SOUTH

LINING APPROXIMATELY 555' FROM NORTH PORTAL

PHOTO #24 - SPALLING WITH EXPOSED REBAR AT CROWN OF SOUTH

LINING APPROXIMATELY 555' FROM NORTH PORTAL

PHOTO #25 - SPALLING WITH EXPOSED

REBAR AT CROWN OF SOUTH LINING

APPROXIMATELY 612' FROM NORTH PORTAL

PHOTO #26 - SPALLING WITH EXPOSED

REBAR ON EAST SIDE OF SOUTH LINING

APPROXIMATELY 697' FROM NORTH PORTAL

PHOTO #27 - GENERAL VIEW OF SPALLING WITH EXPOSED REBAR AT

CROWN OF SOUTH LINING APPROXIMATELY 753' FROM NORTH

PORTAL; NOTE LOOSE CONCRETE

PHOTO #28 - SPALLING WITH EXPOSED REBAR AT CROWN, SOUTH

LINING APPROXIMATELY 753' FROM NORTH PORTAL; NOTE LOOSE

CONCRETE

PHOTO #29 - SPALLING WITH EXPOSED REBAR AT CROWN OF SOUTH

LINING APPROXIMATELY 753' FROM NORTH PORTAL; NOTE LOOSE

CONCRETE

PHOTO #30 - SPALLING WITH EXPOSED REBAR ON WEST SIDE OF

SOUTH LINING APPROXIMATELY 805' FROM NORTH PORTAL

PHOTO #31 - GENERAL VIEW OF SPALLING AND VOID WITH EXPOSED

REBAR ON WEST SIDE OF SOUTH LINING NEAR SOUTH PORTAL

PHOTO #32 - VOID WITH EXPOSED REBAR ON WEST SIDE OF SOUTH

LINING NEAR SOUTH PORTAL

PHOTO #33 - SPALLING WITH EXPOSED

REBAR ON WEST SIDE OF SOUTH LINING

NEAR SOUTH PORTAL; NOTE LEAKAGE ALONG

RING STONES

PHOTO #34 - DELAMINATION AND SPALLING

OF EAST SIDE OF SOUTH LINING NEAR SOUTH

PORTAL

PHOTO #35 - SPALLING WITH EXPOSED

REBAR ON EAST SIDE OF SOUTH LINING NEAR

SOUTH PORTAL

PHOTO #36 - SPALLING WITH EXPOSED

REBAR ON EAST SIDE OF SOUTH LINING AT

SOUTH PORTAL; NOTE EFFLORESCENCE AND

LEAKAGE

PHOTO #37 - EFFLORESCENCE AND LEAKAGE

ON RING STONES AT SOUTH PORTAL

PHOTO #38 - DAMAGE AND MISALIGNMENT OF

REFLECTORS ALONG EAST SIDE