InCom WG 137
Navigation Structures
Resilience to Overloading
Terms of Reference
Background

Care of the waterways, as well as the protection of harbours and the environment is ahistoric concern of PIANC. However, the emerging trend within PIANC is to consider
more than inland navigation, but to develop an Integrated Water Basin perspective which
also includes flood protection whether performed by the navigation authority or otherorganizations.
EnviCom Working Group 12, Sustainable Waterways Within the Context of Navigation
and Flood Management was formed to investigate and quantify possible relationshipsbetween waterway development and maintenance measures for navigation and floodmanagement. Also InCom WG26, Design of movable weirs and storm surge barriers
addresses recent designs for these structures; however the concept of resilience tooverloading was not included.
In many instances, navigation structures also serve as flood defence structures or become
inundated during major floods. A significant issue associated with these systems is how
they will behave when they have been loaded beyond their designed capacity.
The requirement for resilience is to ensure the system does not fail catastrophically if theflood is higher then the design flood A small amount of cosmetic damage is acceptable,
but the system should still be capable of withstanding the design loads after the flood
event passes and is capable of being returned to navigational duty as soon as reasonablypossible.
Design guidance for the incorporation of features to ensure resilience to overloading forflooding is limited. Comprehensive “lessons learnt” and the incorporation of features toensure resilience will help facilitate preparation of design guidance and the design of new
construction or rehabilitation of existing structures.

Objective of the Working Group
Establish a flood resilience Working Group to assemble lessons learned, determine theresilience of navigational structures, and to provide guidelines for the updating ofexisting structures and the design of new ones when used on inland waterways.
Final ProductThe intent will be to provide a comprehensive summary of “lessons learnt” and bestpractices that can be incorporated into future navigational system designs. The intent of
this Working Group is to provide advice for the structural, mechanical ,electrical andoperational design for navigational structures to assure performance during and after aflood event. One important issue is to incorporate the concept of resilience tooverloading which happens to a navigation system if it is overtopped.
This WG would identify methods for ensuring resilience to the system by requiring it tosurvive this overload without catastrophic failure, endure only cosmetic damage, becapable of withstanding the design loads after the flood event passes and returning tonormal service.
The report will include a summary of relevant guidance documents from variouscountries. The Working Group will provide guidance on the choice of features and/orsystems to use in future designs to ensure system resilience and consider the cost/benefit
implications of the adoption of these guidelines.
Matters to be Investigated
The report will use Case Studies to identify and compile “lessons learnt” on theperformance of navigation systems and whether or not they behaved in a resilient fashion.
Resilience means gradual failure modes rather than sudden failure modes, not increased
capacity. Some of the issues to be investigated include:a. Performance of storm surge barriers.
b. Performance of banks, lock and flood walls
c. Performance of gate closures and risks from overtopping.
d. Performance of pumping stations and outlet works.
e. Features added to the navigation system to minimize risk of catastrophic failureand consequential liabilities if system capacity is exceeded.

Desirable Background or Experience of Working Group Members
The background and experience may include the following:a. Civil, Mechanical, Geotechnical, Hydraulic, Hydrologic and Structural Design
engineers.
b. Personnel responsible for daily maintenance and emergency operation of flood
protection systems.
c. Academic personnel familiar with flood protection systems
d. Representative from RecCom
RELEVANCE TO COUNTRIES IN TRANSITION
This working group can be useful for all countries where river navigations are subject toflooding and inundation and where navigation authorities wish to improve theirnavigational structures and increase their resilience in extreme conditions.