375
1 INTRODUCTION
Santos Port, in São Paulo State Coastline (Fig.1),
throughputsapproximately15%ofBrazilianmaritime
cargo,morethan110milliontonsperyearandisthe
most important maritime cargo transfer terminal in
theSouthernHemisphere.Therequirementtoenlarge
and deepen the Santos Port Outer Access Channel
(depth,
width and radius) to receive Post Panamax
Plus and New Panamax, typically vessels of 12,000
TEUs(LOA=398m,B=56.4m,Tfullload=15.0m)
trainingwallscrossingtheOffshore Bar are the best
cost‐benefit solution to avoid huge dredging rates.
Thisconceptwasalready
presentedinthefirstMaster
PlanofSantosPort,proposedinthesixties,anditis
thePhase1 oftheSeawardConceptualPlanningfor
the Offshore Port (Alfredini, Arasaki & Moreira,
2015).
Furthermore,thesealevelriseoccurredinthelast
century (IPCC, 2014) and the increasing rates of
extreme
events of storm surges require different
alternatives concerning sea defenses structures in
Santosbeaches,mainlyinPontadaPraialocation.
AccordingtoAlfredini,Arasaki&Moreira(2015),
the construction of two training walls, with a total
length of 9 km, is an engineering solution for the
reducing Santos Port dredging
rates in the Offshore
Bar. Indeed, this solution would provide a
significantly reducing the maintenance dredging
OPEXcosts,re‐designingthechanneldimensionsina
suitablewayforthelargervessels.
Otherwise,duetothestormsurgeattackinPonta
daPraiaarea(Fig.1),itisalsoimportanttoprovidea
shoreprotectionstructure.
For Port and Municipality Authorities decision
support, the Hydraulic Laboratory of Engineering
Alternative study for the Nautical and Shore Protection
Structures in the Estuary of Santos, Brazil
P.Alfredini,E.Arasaki&J.C.M.Bernardino
UniversityofSaoPaulo,SaoPaulo,Brazil
G.daSilva
HydraulicTechnologicalCenterFoundation,SaoPaulo,Brazil
ABSTRACT: For the enlargement of the nautical dimensions of Santos Port Outer Access Channel (Brazil),
trainingwallscrossingtheOffshoreBarareneeded. Thetrainingwallschoicetoreduce dredgingratesalso
inducestoconsideracouplingplanningbetweennauticalpurposesandshoreprotection
measures,asSantos
Municipalityhaveseriouserosionproblemsnowadaysduetotheurbangrowthinthebackshoreandsealevel
rise. For decision support, the Hydraulic Laboratory of Engineering School of University of Sao Paulo was
commissionedtostudyinacompositemathematicalandscalemodel.Resultsincludechangesin
waveheight
anddirectionand currentspeedanalysisto conditionswithtrainingwallsandsegmentedbreakwaters.The
water renewal was also analyzed to the condition with segmented breakwater and compared to current
situation,basedonhydrodynamicsresultsandconsideringthatthisstructurecanreducewaterqualityinthis
area.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 12
Number 2
June 2018
DOI:10.12716/1001.12.02.19
376
SchoolofUniversityofSaoPaulowascommissioned
to evaluate, in a composite mathematical and scale
model (Fig. 2), the morphological impacts of the
trainingwalls,consideringthenauticalpurposesand
a compatible solution for the shore protection
structures.
Thegoalinthispaperistopresentthefirstresults
of two conceptual projects solution, considering the
nautical purposes as mandatory, but also trying to
find a compatible solution for the shore protection
structures.
2 MATERIALANDMETHODS
2.1 StudyArea
SantosCityislocatedintheSouthernBrazilianlittoral
and constantly faces negative impacts with storm
surge events and
consequent inundation of coastal
areaanderosionduetowaveactionandsealevelrise.
ThemostcriticalareainthisbeachiscalledPontada
Praia,locatedintheeasternendofthisbeach.Itisa
residentialareawhereislocatedtheAvenueSaldanha
da Gama, and is near
the maritime entrance to the
PortofSantos(Fig.1).Atechnicalanalysishasbeen
developedbyAlfredinietal.(2013)whodiscussesthe
possible causes of this event and explains the
situationagainstsealevelrise.
Figure1.Locationmapofstudyareaandobservationpoints
P1,P2,P3andP4(dots).
The data set was obtained with an ADCP gauge
fromSantosPilot(2016),locatedinpointP2(seeFig.
1). Two conceptual projects solutions were studied:
the construction of training walls and a segmented
breakwaterstructure(Fig.3).
2.2 NumericalModellingDescription
Theeffectivenessandefficiencyofthecitedstructures
were analyzed
using numerical modeling. Delft3D
numericalmodel(DELTARES,2014),FlowandWave
modules, was used in the present study with the
application of complete formulations for shallow
water equation finite‐difference calculation, the
hydrostatic hypothesis and the Boussinesq
approximation. The Boussinesqapproximationstates
that,ifdensityvariationsaresmall, the density
may
be assumed constant in all terms except the
gravitationalterm(Broomans,2003).
AccordingtoChatzirodou&Karunarathna(2014),
Delft3D is a finite difference code that solves the
Navier‐Stokes equations under the Boussinesq and
shallowwaterassumptions,in2Dor3Ddimensions.
For a 3D flow simulation, the system of
equations
thenreads:

dU dV
S
tx y


 
