Finnish Transport Agency Guidelines for the inspection of ... PIANC 2017/170927 1400... · Finnish Transport Agency Guidelines for the inspection of underwater engineering structures

Finnish Transport Agency

Guidelines for the inspection

of underwater engineering

structures

+ case study

Nord PIANC

27.-28.9.2017

Stockholm

Kari Pohjola

a brand of

WHO?• Work was ordered by Finnish Transport Agency• FTA takes care of public fairway infrastructure in

Finland, like bridges, canals, ferry harbours and AtoNs

• FTA orders inspections and maintenance worksfor these structures

• FTA is leading property owner to developespecifications and standards in this field

• Work was done by group of consultants workingwith these inspections

Nord PIANC, 27.-28.9.2017, Kari Pohjola

WHY?

• FTA is leading maritime infrastructure propertyowner to develope specifications and standardsin this field in Finland

• New techniques has been developed with new advantages

• Existing specifications and standards includesalmost only diving inspections

• Property owners are rather concervative and don’t have experience about ecoustic methodswhen they choose inspection method


UNDERWATER ENGINEERING STRUCTURES

• Bridges• Canal structures• Piers, ferry berths and shore structures• Fixed navigation aids


Examples of structures


DAMAGES TO STRUCTURES

• Weather and environmental impacts• Use-related impacts• Damages to materials


Examples of damages 1


Examples of damages 2


INSPECTION OF UNDERWATER ENGINEERING STRUCTURES

• Inspection system– General inspection– Special inspection– Continuous monitoring

• Qualifications of inspectors• Safety planning

– Regulations and guidelines– Different parties tasks


Inspection periods and intervall


Explanations for stress classes• Based on environmental effects or use of structure

• Examples :• Bridge:

– Exeptional environmental stress (strong stream, floating ice, recognised risks)– High environmental stress (stream, sea, probable erosion risks)– Small environmental stress (not stream)

• Quays:– High environmental stress and use (ferry quays with regular traffic and similar in

sea conditions)– Ordinary environmental stress (deep draught fairway quays in lake area, ordinary

sea conditions)– Small environmental stress (no regular traffic , inland waters)

• Fixed AtoNs– Important structures in sea conditions, risk for erosion– Important structures in sea conditions (light houses and other big marks)– Ordinar AtoNs


UNDERWATER ENGINEERING STRUCTURES, INSPECTION METHODS

• Sector Scanning echo sounding• Multibeam echo sounding• Documentation of echo sounding• Diving inspection• Comparison of inspection methods (suitability)• Other survey methods


Inspection methods


Suitability for inspection methods

XX= good, X= moderate, 0= not suitable


Results, visualization


DAMAGE REPAIRS

• Concrete structures• Steel structures• Wood structures• Stone structures• Erosion protection


SUMMARY• FTA has taken leading role to adopt new underwater

inspection methods• These guidelines are a part of present practise

when FTA orders underwater inspections• As a first published guidelines these instructions are

supposed to effect to the practices adopted by otherseafront structure owners too

• Methods have advantages and limitationsdepending the characteristics of the project

• Combination of methods can give best results• Underwater inspections reaches the new level


Saimaa canala case study


Saimaa canal, a case study 1/5Basic information:• Saimaa canal connects lake Saimaa district to the Gulf of Finland• It is partially in Russian side (land area is rented by Finnish government)• Total length of canal route is 43 km and it contains 8 locks and 7 movable bridges.• Difference with water levels in lake Saimaa and Gulf of Finland is 75,7 m.• Ship dimensions at the moment: length/width/draft – 82/12,2/4,35 m• Construction years (infra) 1963-1968 and most of the length is artificial open canal


Saimaa canal, a case study 2/5• Work was ordered by Finnish Transport Agency• Survey, analyze and reporting by Meritaito 2015 -2017• Survey was conducted with small 6 m long survey launch Keila 1• Survey included multibeam survey and laser scanning• Equipment: 400 kHz Reson Seabat 7125 and Riegel laser scanner• Motivation for survey: Canal is almost 50 years old and Finland and Russian have

negociated 50 years extention for the renting of canal and it’s land area.• To document present situation of canal for infrastructure and risk management

purposes: Water depths, scouring, canal slopes, structures, fixed AtoN: maintananceand future development


Saimaa canal, a case study 3/5FINDIGS• Scouring, sedimentation, slope conditions


Saimaa canal, a case study 4/5FINDIGS• Structural damages, fixed AtoNs, Hazardous objects


Saimaa canal, a case study 5/5

POSSIBILITIES TO UTILIZE RESULTS PRODUCTIVELY:

• Challange: To store gathered data in usable format at least 30 years• Base material for most of future activities related to canal infrastructure• Risk anlyze: where and when can you expect damages• Maintenance planning, future development of canal• Programming and targeting forthcoming underwater inspection needs• Excellent material to understand what happens and why under the water in

working canal system• Lock operations, ship traffic impacts, slope conditions, collisions with

structures• Modelling for different purpoces f.ex. Intelligent Fairway


Thank you for your attention!Questions?


Documents

Finnish Transport Agency Guidelines for the inspection of ... PIANC 2017/170927 1400... · Finnish Transport Agency Guidelines for the inspection of underwater engineering structures