UNDERWATER INSPECTION OF

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29 Νοε 2013 (πριν από 3 χρόνια και 6 μήνες)

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UNDERWATER INSPECTION OF
BRIDGES ILLUSTRATED WITH
CASE STUDY

BY


Shri.
K.Simon
, Dy.CE/C/SCR


Shri
Mohd. Bakhsh
, Dy.CE/W/WR

Shri .
A.Raj Kumar
, DEN/SR

WHY UNDER
-
WATER INSPECTION?



TO ENSURE SAFE CONDITION


OF SUB
-
STRUCTURE DURING


THE COURSE OF ITS LIFE.


TO DETECT ANY DISTRESSED


CONDITION OF SUB
-
STRUCTURE


OUT LIVED OR PRE
-
MATURE


TO PREVENT ANY POSSIBLE

MISHAP DUE TO STRUCTURE

FAILURE BY TIMELY ACTION

WHERE UNDER
-
WATER INSPECTION IS ESSENTIAL?


IT IS REQUIRED TO CHECK THE SUBSTRUCTURE OF ALL


BRIDGES OVER PERENNIAL RIVERS &BACKWATERS.



ON BRIDGES WHERE SUBSTRUCTURE CANNOT BE


INSPECTED DUE TO SUBMERGING UNDER WATER

WHAT SHALL BE INSPECTED IN UW INSPECTION?


CAVITY IN MASONRY /CONCRETE


JOINTS IN MASONRY /CONCRETE


LOOSE/ MISSING STONE/BRICKS IN MASONRY


WEATHERING OF MASONRY


EXPOSURE OF REINFORCEMENT






RUST STAINING, CRACKING, SPALLING,
ABRASION, DISINTEGRATION IN CONCRETE
STRUCTURES


BULGING IN SUB STRUCTURE


STEEL WORKS



--
CI PIPES



--

STEEL CAISSONS



--

SCREW PILES


CORRECT LOCATION AND IDENTIFICATION OF
DEFECTS IS IMPORTANT






WHAT SHALL BE INSPECTED IN UW INSPECTION?







(
CONTD)

Anerobic Bacterial Growth

Scaling of concrete

Spalling of concrete

Disintegration of concrete

Deep Cavitation

WHO WILL DO UNDER
-
WATER INSPECTION?



ONLY WELL TRAINED PERSONNEL


PRACTICAL PROBLEM IS THAT IN MAJORITY OF THE


CASES ONLY EXPERT DIVERS ARE USED BUT THEY


WILL NOT HAVE ANY EXPERTISE IN CIVIL/ BRIDGE ENGG.

WHAT IS LAID DOWN IN OUR CODES ON THIS TOPIC?


CODES INCLUDING IRBM’98 IS SILENT ABOUT THIS ASPECT


AFTER TRAGIC KADALUNDI ACCIDENT, BASED ON CCRS


RECOMMENDATIONS, RDSO HAS BROUGHT OUT BS
-
40


GUIDE LINES FOR UNDERWATER INSPECTION OF BRIDGES


DURING THE YEAR 2001.

CE’S CIRCULAR No.3/2002 OF Srly PRESCRIBED 2 YEARS FERQUENCY

WHEN TO CONDUCT UNDERWATER INSPECTION?


BS
-
40 SUGGESTS DURING THE PERIOD OF LOW WATER


OR LOW POLLUTION LEVELS OR GOOD VISIBILITY (UNDER)



20% OF UNDERWATER UNITS FOR EACH BRIDGE
SELECTED RANDOMLY SHOULD BE INSPECTED. THE
RANDOM INSPECTION SHOULD BE MADE IN SUCH A
WAY THAT ENTIRE STRUCTURE IS COVERED IN 5 YEARS




METHODS OF PERFORMING UNDER
-
WATER
INSPECTION


2.SCUBA
-
SELF CONTAINED UNDERWATER BREATHING APPRATUS


3. SURFACE SUPPLIED AIR DIVING OR MIXED GAS DIVING

4.DEEP SEA DIVING


NOT USED FOR BRIDGE INSPECTION

SCUBA DIVING


SCUBA DIVER IS PROVIDED WITH PORTABLE AIR SUPPLY


& IS CONNECTED TO SURFACE THROUGH AN UMBILICAL


CABLE


MIN.EQUIPMENT ARE SCUBA, LIFE PRESERVER,WEIGHT


BELT, KNIFE,FACE MASK AND SWIM FINS

1.WADING INSPECTION


BASIC, REGULAR METHID OF
INSPECTION


PROBING/SOUNDING ROD



……. CONTD SCUBA DIVING)


IS SUITED WHEN MANY DIVES OF SHORT DURATION


ARE NEEDED & MOBILITY IS THE PRIME CONSIDERATION


MERITS ARE RAPID DEPLOYMENT, PORTABILITY, MIN.


SUPPORT AND EXCELLENT MOBILITY


DEMERITS ARE DEPTH LIMITATION, MIN.AIR SUPPLY


LACK OF VOICE COMMUNICATION FROM SURFACE


MAX. SUSTAINED TIME AND DEPTH IS ONE HOUR @18 M


DIVING TEAM SHOULD HAVE 3 MEN & BOAT IS REQUIRED

SURFACE SUPPLIED AIR DIVING




AIR IS SUPPLIED TO THE DIVER THROUGH
UMBILICIL HOSES, CONNECTED TO THE SURFACE
AIR COMPRESSOR TANK



COMMUNICATION CABLE, LIFE LINE,
PNEUMATIC FATHOMETER ARE ATTACHED TO
THE DIVER


SUITED FOR IN ADVERSE CONDITION


HIGH
STREAM VELOCITY, POLLUTED/TURBID WATER
AND LONG DURATION/DETAILED INSPECTION


UNLIMITED AIR SUPPLY


SUSTAINED TIME


60 MINUTES AT 18m DEPTH


IS 10291
-
1982 LAID DOWN


QUALIFICATION OF DIVERS AND SUPERVISORS


SAFEGUARDS FOR THEIR WORKING


MINIMUM AGE 18 YEARS


FITNESS BY DOCTOR IN LAST SIX MONTHS


FITNESS TESTED FOR WORK AT REQUIRED DEPTH
OR EQUIVALENT PRESSURE IN COMPRESSION
CHAMBER


KNOWLEDGE OF DIVING SIGNALS



TRAINED FOR WORK IN NO VISIBILITY
CONDITIONS AND 0.6M DEPTH OF MUD AND
CONDUCT SEARCH ETC.

SAFEGUARDS FOR THEIR WORKING


GOOD PHISIQUE,CAPABLE OF SUSTAINING STRAIN


FREE FROM CARDIAC PROBLEM


FREE FROM MID EAR PROBLEM ETC


NOT ADDICTED TO ALCOHOL AND EXCESS SMOKING


MORE THAN 45 YEARS NOT BE EMPLOYED FOR DEEP
DIVING


SELECT AGE >30YEARS FOR TRAINING


DIVERS DRESS,HELMET,COMPRESSED AIR AND
ACCESSORIES


STANDARD EQUIPMENTS

……. CONTD SCUBA DIVING & SAFE GUARDS FOR DIVERS)


VIDEO CAMERAS /CLOSE CIRCUIT TV CAMERAS AND TV
MONITOR


TELEMETRY LINK TO OPERATE CAMERA


COMMUNICATION SYSTEM WITH AMPLIFIER AND LOUD
SPEAKERS ETC


UNDERWATER LAMP/HEAD LAMP

TOOLS REQUIRED

TYPES OF INSPECTION AND INTENSITY
LEVELS



LEVEL I
-
VISUAL,TACTILE INSPECTION(ROUTINE
INSPECTION)


LEVEL II
-
DETAILED INSPECTION WITH PARTIAL CLEANING


LEVEL III
-
HIGHLY DETAILED INSPECTION WITH NDT


LEVEL I
-
INSPECTION


GENERAL VISUAL ROUTINE INSPECTION


COVERED OVER EXTERIOR SURFACE


PROBING OVER SUBSTRUCTURE AND STREAMBED


TO DETERMINE THE NEED FOR LEVEL II/III INSPECTION

TYPES OF INSPECTION (Contd..)


LEVEL II INSPECTION


TO BE CONDUCTED BASED ON REPORT OF LEVEL I
INSPECTION


NEEDS CLEANING OF STRUCTURAL ELEMENT


DETAILED INVESTIGATION OF SELECTED COMPONENTS


ATLEAST 20% OF ALL UNDERWATER ELEMENTS TO BE
COVERED


SIMPLE INSTRUMENTS

CALIPPERSE AND SCALE TO
IDENTIFY EXTENT AND SEVERITY OF DAMAGE





TYPES OF INSPECTION (Contd..)


LEVEL III INSPECTION


HIGHLY DETAILED INSPECTION OF A CRITICAL
STRUCTURE OF STRUCTURAL ELEMENT


INCLUDES EXTENSIVE CLEANING, DETAILED
MEASUREMENTS


SELECTED NDT/PARTIALLY DISTRUCTIVE
TESTING SUCH AS ULTRASONIC, SAMPLE
CORING, IN
-
SITU HARDNESS TESTING Etc..


REQUIRES MORE EXPERINCE AND TRAINING


UNDERWATER INSPECTION PROCEDURE


INTIAL INSPECTION REQUIRES CAREFUL PLANNING


PRIOR SITE SURVEY FOR SELECTION OF INSPECTION
METHODS, TYPE AND INTENSITY LEVEL, EQUIPEMENT
REQUIRED


REVIEW OF AVAILABLE RECORDS AND PAST HISTORY


AVAILABILITY OF TOOLS AND PLANTS


ABILITY/QUALIFICATION OF DIVING TEAM


SCOUR INVESTIGATION


INSPECTION OF SUB STRUCTURE


UNDERWATER INSPECTION PROCEDURE
(Contd..)


UNDERWATER NDT INSPECTION



SOUNDING/SENSING DEVICE
-

FOR CHECKING
SCOUR IN THE STREAM BED


REBOUND HAMMER
-

SURFACE HARDNESS
TESTER


TO OBTAIN GENERAL CONDITION OF
CONCRETE


MAGNETIC REBAR LOCATION
-

TO DETERMINE
THE LOCATION AND ORIENTATION OFREBAR


ULTRASONIC SYSTEM FOR CONCRETE
-

TO
CHECK UNIFORMITY OF CONCRETE FROM ONE
LOCATION TO THE OTHER

UNDERWATER
NDT

INSPECTION
(Contd..)


ULTRASONIC THICKNESS METRES


TO MEASURE
THE THICKNESS OF THE STEEL


UW MAGNETIC PARTICLE TESTING


TO DETECT
SURFACE CRACKS


RADIOGRAPHY


TO DETECT INTERNAL
DEFECTS/FLAWS



PROCEDURE

OF UNDER
-
WATER INSPECTION BY DIVERS

LIST &CHECK THE WORKING OF ALL TOOLS &EQUIPMENT


BOATS & LIFE PRESERVERS AS REQUIRED


CAMERAS


INSPECTION DOCUMENTS, PAPER,CLIP BOARD &PENCILS


CONCRETE OR STEEL TOOL KIT AS APPLICABLE


SOUNDING EQUIPMENT &MARKING PENCILS(FOR SCOUR)


SAFETY EQUIPMENT(ROPES, BUOYS&
MANNED SAFETY

BOAT)

PROCEDURE FOR CHECKING PIERS FORMED OF PILES


TWO DIVERS TO INSPECT SAME PILE.


IF VISIBILITY IS POOR, PUT LIGHT CLOSE AND INSPECT


DIFFERENT FACES AND TURN LATER TO UNINSPECTED SIDE

PROCEDURE FOR CONCRETE PIERS


INSPECT CONDITION OF CONCRETE. TAKE PHOTOS AS REQD


MEASURE DIMENSIONS OF SPALLS &RECORD LOCATION


INSPECT CRACKS AND MEASURE SIZE, LENGTH&LOCATION

DOCUMENTAION OF THE RESULTS OF U/W INSPECTION


RECORD THE RESULTS OF UNDER
-
WATER INSPECTION


IN THE PROFORMA PRESCIBED IN ANNEXURE
-
II,III&IV OF


BS
-
40 “GUIDE LINES FOR U/W INSPECTION ISSUED BY RDSO

ACTION TO BE TAKEN ON RESULTS OF U/W INSPECTION


MINOR DEFECTS


SUCH AS CRACKS

-
AQUA RESINS FOR GROUTING REPLACING WATER


CRACK >6mm sand with grouting resins


SPECIAL GROUTING EQUIPMENTS


PREPARATION OF SURFACE BY WATER JET AT
HIGH PRESSURE


APPLYING THICK COAT OF EPOXY RESIN ON THE
PREPARED SURFACE FOR BONDING


EPOXY MORTAR

SPALLING OF CONCRETE


JACKETING BY SHOTCRETE/GUNITE LAYER OF
75MM THICKNESS OR SO


SHOTCRETE RING IS PREPARED ABOVE LOW
WATER LEVEL AND LOWERED UPTO BOTTOM


ANNULAR SPACE IS SUBSEQUENTLY GROUTED
WITH MORTAR DISPLACING WATER

REPAIR TECHNIQUES

FOR CONCRETE PILES


TREMIE CONCRETE


BOTTOM OPENING SKIP BOX


BAGGED CONCRETE


GROUT INJECTION OF PREPLACED AGGREGATE

REPAIR BY UNDERWATER CONCRETING


DESIGNED FOR LOW STREGTH UPTO M20


SLUMP 150
-
200mm


COHESIVE AND SHOULD NOT SEGREGATE
DURING TRANSPORT OR PLACEMENT


W/C RATIO =<0.5


CEMENT CONTENT HIGH 400 KG/CUM

TREMIE CONCRETE


PLASTICISERS FOR WORKABILITY


TREMIE PIPE DIA 20MM AGRT
-
150MM



40MM 200MM


BOTTOM OF PIPE 300
-
400 MM IMMERSED IN CONCRETE


MORE THAN 30 SQM AREA MORE THAN ONE PIPE


IF MORE THAN ONE LIFT DIVERS TO PREPARE
SURFACE BY REMOVING LAITANCE

CASE STUDY OF Br. No.1201 ON SRR
-
MAQ SECTION ON S.Rly

BRIDGE No.1201 AT Km.837/100
-
500 ON DOWN LINE

ON RIVER PYSAVALI WITH SPAN 3 x 30.48+ 18 x 15.24


1
ST

3 SPANS ARE 100’ON RIVETTED UNDERSLUNG GIRDERS

SUPER STRUCTURE


RIVETTED STEEL PLATE GIRDERS



NEXT 18 SPANS ARE 40’ RIVETTTED PLATE GIRDERS

BEARINGS
-

1
ST

3 SPANS


ROCKER & ROLLER TYPE


REST ALL


CENTRALLY ARTICULATED

SUB
-
STRUCTURE

PIERS 1,2,3, 5,7,9,11,13,15,17,19 & A1 AND A2 ON CR MASONRY

PIERS REST 4,6,8,10,12,14,16,18 AND 20 ARE MASS CONCRETE

FOUNDATION

WELL FOUNDATION WITH TWIN CIRCULAR MASONRY WELL

HISTORY OF THE BRIDGE

1.BRIDGE WAS BUILT IN 1906 AS 12 X 30.48 M UNDER SLUNG


RIVETTED PLATE STEEL GIRDER BRIDGE ON ROCKER AND


ROLLER BEARINGS, ON CRS MASONRY PIERS WITH STONE


MASONRY TWIN CIRCULAR WELLS

2. DURING 1960
-
1970, THOUGH CLEAR RECORDS ARE NOT


AVAILABLE, 9 SPANS FROM 4
TH

TO 12
TH

ARE DIVIDED AS


2 EACH MAKING BRIDGE AS 3x 30.48+18x 15.24 WITH 18


SPANS WITH RIVETTED PLATE GIRDERS BY


PROVIDING 9 ADDITIONAL MASS CONCRETE PIERS ON


CR MASONRY TWIN CIRCULAR WELL FOUNDATION


REASONS FOR SUCH CHANGE IS NOT DOCUMENTED

OBSERVATIONS PRIOR TO IDENTIFICATION OF PROBLEM ON Br1201


FREQUENT ATTENTION TO CROSS
-
LEVEL NEAR P4


(Right Rail low)



FREQUENT MIS
-
ALIGNMENT ON
-
TO ONE SIDE



NON
-
RETENTION OF RECTIFIED CROSS
-
LEVEL & ALIGNMENT

ACTION TAKEN ON THE OBSERVATIONS



INITIALLY FORTNIGHTLY THEN WEEKLY RECORDING OF


PARAMETERS DONE. ON GETTING PROGRESSIVE CHANGE


UNDER
-

WATER INSPECTION WAS ORDERED



ON 20.02.2002 DIVERS INSPECTED THE SUB
-
STRUCTURE


& REPORTED THAT RH WELL STEINING OF P4 HAS A CAVITY


1.25 x 0.75 x 0.50 SIZE ON EAST SIDE JUST BELOW WELL CAP

CONFIRMATION OF PROBLEM (IN MARCH
-
APRIL2002)


SUBSEQUENT TO THE REPORT BY DEPARTMENTAL DIVERS


EXPERT FROM CBE/O/MAS, SSE/BR &DIVER WAS CALLED


AND CAVITY AND ITS SIZE WAS GOT CONFIRMED.

PROGRAM FOR RECTIFICATION OF THE CAVITY


BASED ON INSTRUCTIONS FROM CBE (HQ), DIVISION HAS


CALLED TENDER FOR MICRO CONCRETING WORK UNDER


WATER AND FIXED UP AN AGENCY BY 12.03.2003


M/S DYANSOURE TREATMENT, MUMBAI IS THE AGENCY


MICRO CONCERETING WITH ANTI
-
WAHSABLE, ANTI
-
SHRINKABLE PROPERTY USING RENDEROC UW OF FOSROC
MAKE WAS ORDERED IN THE AGREEMENT ALONG WITH
VIDEOGRAPHY OF UNDER WATER WORK

TECHNICAL DETAILS OF MICRO
-
CONCRETING


RENDEROC UW(UW STANDS FOR UNDER WATER) OF
FOSROC MAKE IS A READY TO USE DRY POWDER, A
MIXTURE OF PROCESSED CEMENT WITH ADDITIVES AND
FINE AGGREGATES, WHICH IMPART IT CONTOLLED
EXPANSION,WATER REDUCTION AND NON
-
WASHABLE
PROPERTIES. THIS IS PACKED IN25 kg BAGS AND DOSAGE
PER YIELD IS 14.5 LITRES PER 25 KG AT W/P 0.22


MICRO CONCRETE IS EXPECTED TO GIVE A CRUSHING


STRENGTH OF 30 N/MM2 AFTER 7 DAYS

RENDEROC UW CAN BE USED IN ONE POUR FOR THICKNESS
UPTO 150 MM. FOR MORE, STONE AGGREGATE OF 2 TO 10 MM
GRADED SHALL BE USED AT 1:1 RATIO


5.5 LITRES OF WATER IS TO BE ADDED FOR 25 KG BAG OF


RENDEROC UW.& CONCRETE MIXER TO BE USED FOR MIX


RENDEROC PLUG IS THE PRODUCT USED TO SEAL JOINTS

AGENCY’S INPUTS FOR MICRO CONCRETING

MANPOWER FROM CONTRACTOR’S SIDE


ONE CIVIL ENGINERING GRADUATE AS SITE ENGINEER


ONE DIVER MATE (EX
-
NAVY) FOR MONITORING DIVING


ONE EXPERT DIVER, 2 DIVERS & 1 ASST. DIVER


APART FROM ABOVE, 1 BOAT AND 12 MEN ENGAGED AS


AND WHEN NEEDED FOR CONCRETING LOCALLY

TOOLS & EQUIPMENT USED BY CONTRACTOR


AIR COMPRESSOR & DIESEL GENERATOR ALOGN WITH


3 DIVING EQUIPMENT


VIDEO CAMERA FOR USING UNDER WATER, RECORDER


WITH DISPLAY UNIT

MATERIALS USED FOR THE WORK

160 NO.S OF 25 KG RENDEROC UW BAGS, 20 NO.S OF PLUG

IN 5 KG BAGS, 200 No.S 25 KG 6MM AGGREGATE BAGS ETC

MODUS OPERANDI OF MICRO CONCRETING


PHASE
-
1
-
INITIAL INSPECTION AND VIDEO RECORDING


PHASE
-
2
-
CLEANING AND PREPARATION OF SURFACE


PHASE
-
3


ASSESSMENT OF QUANTITY


PHASE
-
4


SHUTTERING / FIXATION OF FORM WORK


PHASE


5


MICRO CONCRETING


SAND BAGS WERE USED TO SUPPORT SHUTTERING


MS ANGLES AND TIES WERE USED TO SUPPORT GI SHUTTER


JOINT BETWEEN SHUTTER SHEET AND STRUCTURE WAS


SEALED WITH RENDEROC PLUG


TREMIE WAS MANUFACTURED WITH PLASTIC HOSE PIPE


FOR POURING CONCRETE INTO CAVITY. COMPACTION WAS


DONE USING RODS. DIVERS ENSURED PROPER PLACEMENT



CONCRETING COMPLETED IN 3 DAYS

EXPERIENCES AND SUGGESTIONS


RENDEROC UW IS GOOD FOR UNDERWATER CONCRETING


DIVERS WERE GOOD IN DIVING JOB BUT THEY HAVE VERY


LITTLE KNOWLEDGE OF CIVIL/BRIDGE ENGINEERING


SHUTTERING /POURING TECHNIQUES USED BY THE FIRM


ARE NOT VERY SATISFACTORY & TO BE UPGRADED


VIDEO RECORDING IS NOT ABLE TO THROW LIGHT FOR


THE PURPOE, IT IS INTENDED. LOCATIONS SHALL BE


GIVEN WITH METAL STRIP LIKE IDENTIFICATION MARKS


AN ACTUAL 7 DAY CRUSHING STRENGTH OF 44 M/MM2


WAS ACTUALLY ACHIEVED AGAINST ANTICIPATED 30 N


COST CAN BE BROUGHT DOWN WITH WIDE USE OF THESE

PRODUCTS.


PERFORMANCE TILL DATE IS SATISFACTORY.

CONCLUSIONS


SYSTEMATIC AND SCIENTIFIC UNDERWARTER
BRIDGE INSPECTION ARE VERY IMPORTANT IN
BRIDGE MAINTENANCE AND MANAGEMENT


THE SIGNIFICINT DAMAGE ENCOUNTER TO THE
BRIDGE CAN BE AVOIDED BY CARRYING OUT
UNDERWATER INSPECTION IN TIME

Thank you
Thank you
Thank you