INTRODUCTION
Harbors construction and management in locations highly exposed locations (i.e. to ssevere met-ocean conditions ) areis a very challenging issue. Met-ocean conditions highly affect the normal development of construction activities, seriously jeopardizing every task at the surroundings of the water-land threshold. Construction managers demand, not only the information about wave and wind conditions during construction, but also their influence and interference with daily construction activities, first, to reduce accidents, and second, to improve the management of the construction agenda along its different stages.
Once Ones the construction of the port has been completed, it is necessary to manage the exploitation and planning of port activities through a, reliable met-ocean forecasts are necessary, in order to to optimize the available resources.
This work study presents an integrated early -warning system to support construction and managemente the harbor infrastructures, providing an answer to such demands exposed at different construction stages. The system is designed to help and manage the daily schedule tasks in harbor under construction stage or the final stage, with the aim of being ais designed as a flexible tool to be relocatable in any location. The system is oriented to obtain the short and mid-term (within 180-hour prediction) characteristics of met-ocean conditions (waves, water level and wind) at the harbor surroundings in the site, as well as, the wave-structure interaction characteristics for any stage of the construction phase. The system goes beyond the classical met-ocean alert system, because integrates the use and coupling of: different numerical models,; downscaling techniques;, and met-ocean databases. ,Coupled with construction protocols related with any specific activities at any location along the harbor and under different construction stages.. One of the main objectives is to help the construction managers to improve and establish human safety threshold,s r. Related with the different tasksjobs along the harbor, exposed to the met-ocean variables, and interacting with the unfinished harbor structures.
The system allow to saveoptimize exploitation and construction costs and to achieve the individual deadlines of every task or activity. Note that some construction operations are very expensive, because use resources very specialized, and conditioned to be used only during specific met-ocean conditions along enough time-windows.
METHODOLOGY
The early warning system presented in this work contains different modules, which can be adapted according to the harbor location, the construction procedures and the met-ocean complexity.
First, deep water a met-ocean module (as the main core of the system) should be defined, covering two main tasks: a) the wind, wave and sea-level hindcast analysis, based on high-accurate and validated global datasets; and b) the 7-days hourly prediction for wind, wave and sea-level forecasting system, such as NOMADS system (provided by NOAA).
Second, the downscaling module designed to propagate the met-ocean variables from deep to coastal zone and to any location near, in front and/or inside the harbor.
Third, the met-ocean-structure interaction module that contains high-resolution analysis for one or more of the following processes: harbor agitation and resonance due infragravity waves (mild slope and Boussinesq modelling); wave run-up and overtopping (laboratory data, analytical formulations and CFD modelling); scour and silting (analytical approximations and CDF modelling); moored ship response (CFD, Boussinesq and potential theory approximation); dredging (measurements and dredge protocols); and wake waves (Boussinesq modelling), considering any construction stage for any bathymetric characteristics and any unfinished harbor structure geometries.
It is important to note that the information provided by this third module is relevant because is combined with the construction activities, recommendations and protocols along the breakwaters, basins, and berthing zones, as well as, the crucial importance in the use of CFD numerical modelling to cover the lack of semi-empirical formulations in literature for unfinished breakwater cross-sections. In particular wave overtopping information (i.e.: mean discharge, maximum volume) is considered as a crucial product to be crossed with secure thresholds related with the different construction works to determine its viability and safety.
Finally, the system can include a fourth module dedicated for the assimilation of real-time measurements provided by met-ocean data (nowcast), as a quick quality control module for each variable predicted.
The robustness of the early warning system makes it suitable for the construction stages, as well as for the optimization of the operation of these infrastructures once the works are finished.
RESULTS
All the modules are integrated in a friendly web-based interface, available 24/7 service for the managers. The web gives a quick understanding about the daily activities at the different areas of the port. Information is daily updated and if required, sent also by e-mail to the managers.
One example will be shown during the presentation for the development and adaptation of an early warning system for the construction of Açu TX-1 terminal in Brazil.
In 2013, the company FCC Citizen Services within the Joint Venture FCC Tarrio TX-1 Construção LTDA started the construction of the TX-1 terminal of Açu Superport in São João da Barra, 315 kilometers north of Rio de Janeiro (Brazil). The works include the construction of a breakwater, composed by a 600 m long rubble-mound breakwater 600 m long (Core-loc 10T) and a 2.100 m long vertical breakwater (47 reinforced concrete caissons), with a crest at +10 m elevation.
To support the construction of Açu Port, a high-resolution operational system in the port was developed, ad-hoc for the FCC constructive resources and techniques.
This operational system allows planning the operations in advance (more than a week forecast) and realistic (assimilating in-situ instrumental information), from the numerical prediction of wind, sea level, waves, long-waves, agitation and overtopping, taking into account the geometric evolution of the works in each construction stage. The system produces daily safe working conditions (1) to transport the caissons from Río de Janeiro to the port of Açu, (2) to construct the caissons, (3) to anchor the caissons and (4) to construct the crest.