bANANA ALLEY landing is a timber structure situated on the RIGHt bank of the river yarra in MELBOURNE, victoria. it WAS A PROPOSED SITE FOR A NEW FACILITY RENTING BOATS. ADVICE WAS BEING SOUGHT FROM SURESIDE AS TO WHETHER THE LANDING WAS SUITABLE FOR TYING INTO TO SUPPORT A BOAT HIRE FACILITY. THE ASSESSMENT WAS ALSO TO BE USED TO FULFIL PARKS VICTORIA’S OWN MONITORING ACTIVITIES IN ACCORDANCE WITH ITS ASSET MANAGEMENT SYSTEM.

THE STRUCTURE WAS FOUND TO HAVE WELL PROGRESSED THROUGH ITS LIFECYCLE WITH DETERIORATION BEING EVIDENT AT VULNERABLE LOCATIONS AND SOME BEAMS SHOWING EXTREME LEVELS OF DISTRESS. THE REMAINDER OF BEAMS SHOWED EVIDENCE OF DETERIORATION, WITH THERE BEING A RISK OF DETERIORATION THAT COULD BE MORE PRONOUNCED THAN COULD BE ESTABLISHED FROM VISUAL CONDITION ASSESSMENT ALONE.

DETERIORATION AT VULNERABLE LOCATIONS MEANT THAT AUGMENTATION OF THE STRUCTURE WOULD BE NECESSARY TO TIE THE STRUCTURE TOGETHER IN ORDER TO MAKE THE STRUCTURE SUITABLY ROBUST TO CONNECT TO.

THERE WAS ALSO A RISK OF MARINE BORER DETERIORATION IN PILES THAT COULD NOT BE DIAGNOSED BY VISUAL CONDITION ASSESSMENT AND THAT A DIVERS INSPECTION MAY HAVE BEEN INCONCLUSIVE GIVEN VISIBILITY CONSTRAINTS. THE PILES WERE AT A LATER TIME REMOVED AND REVIEWED BY SURESIDE IN DETAIL. THE INSPECTION SHOWED THAT PILES WERE COMMONLY HEAVILY DETERIORATED INTERNALLY. WHILST THE BRACKISH ENVIRONMENT WAS ANTICIPATED TO LIMIT POTENTIAL DETERIORATION, LATER OBSERVATION SHOWED LITTLE SIGN OF MARINE BORER DETERIORATION HAVING BEEN ABATED. THERE WERE SIGNS THAT A LARGE NUMBER OF TEREDINID DID NOT PERSIST TO MATURITY. BUT FOR ALL INTENTS AND PURPOSES, TEH MARINE BORER DETERIORATION WAS SUBSTANTIATED TO BE PROLIFIC ENOUGH TO BE OF STRUCTURAL CONCERN.

sureside’s capability and attention to detail meant that the issues the structure was facing were identified. OF IMPORTANCE TO CONSIDER IN FUTURE IS THAT DETERIORATION BY MARINE BORER IN BRACKISH WATER IN THE RIVER YARRA IS POTENTIALLY PROLIFIC. ASSESSING THE RIVER YARRA AS LOWER RISK THAN NON-BRACKISH WATER IS POTENTIALLY MISLEADING. NORMAL APPROACHES TO ASSESSING MARINE BORERS SHOULD BE APPLIED TO ASSETS IN THE RIVER YARRA PLUS RECOGNITION THAT MORE CHALLENGING ASSESSMENT IS ALSO A FACTOR (given low visibility). ASSESSMENTS NEED TO TAKE INTO CONSIDERATION THE AGE AND SPECIES OF PILES. PILES SHOULD BE DESIGNED TO MEET HAZARD REQUIREMENTS THAT ARE EQUIVALENT TO THE DOWNSTREAM PORT PHILLIP.

project client: parks victoria

sureside client: parks victoria

services: diagnostic analysis & condition Assessment

time period: 2021