Costa Rica divides two oceans, the Atlantic and the Pacific, and is renowned for its rich wild life, volcanoes and undisturbed natural areas. Besides the export of coffee, tourism is one of the major economic pillars of the country. The Pacific Coast is the preferred destination for fishermen, but until recently it lacked adequate port infrastructure for private fisher boats. During the rainy season with heavy storms, no protective harbour was available along the coast.


In 2007 a group of local investors decided to start working on a project that would benefit locals as well as tourists. Marina "Pez Vela" had been planned for years and started to become reality. The 308 slip marina will feature one of the most sophisticated breakwaters ever built for a recreational marina, providing a safe harbour and hurricane protection. The extra-wide, modern, concrete floating docks, allow safe loading of passengers and equipment, and secure moorage. The first phase of construction includes 100 slips accommodating yachts up to 61 m in length. Being built with an emphasis towards environmental protection which includes the use of recycled steel and the installation of a water treatment system, the marina will fully meet American and Costa Rican building codes and standards.
 

The design considered the needs of the boat owners and the necessary infrastructure to host the future landing point. The governing design factor in this case was the standard wave height of 2.5 m. During the first discussions this was assumed as too big, but actual experience proved it was a good assumption.


To achieve adequate shelter for the boats, a strong and reliable breakwater had to be built. Different gravity structures were analysed, including rock dam, rectangular 'double wall' sheet pile cofferdam, concrete caissons and circular cells cofferdam.
 

The limited availability of aggregates in the area made the rock dam solution very difficult and expensive. At the same time, concrete caissons would have required too much construction time.


Consequently the final choice for the 540 m long breakwater was a circular cell cofferdam with AS 500 straight web steel sheet piles which offers multiple advantages:

• once the crew acquires the necessary training, installation is quick. Time required to finish one cell is only 7-8 working days,
• after the cell is closed and backfilled, the system is auto-stable and can resist wave loads, and support the crane, thus ensuring safety. The temporary template, and later the backfill, stabilizes the structure, hence no tie-back system is needed,
• the use of 'mariner' steel grade according to ASTM A 690, with additional alloy content (copper,…), provides higher resistance against corrosion in the splash zone,
• the cell diameters of 12.2 m and 18.6 m offer significant space for development along the top of the wall,
• the flexible structure's performance under seismic loading is good.

The whole project will be implemented by a local contractor with the help of an experienced pile driving crew. Additional technical support was provided during the design stage and execution phase by the sheet pile manufacturer's technical department.




After site installation and construction of the first 12 m diameter template, pile installation started with one crew. It became clear to the project owner during the early days itself that the circular cell solution was the correct decision. The rough weather and waves of more than 2.5 m gave the crew a hard time. Even the crane was hit by a wave that overtopped the dam. Nevertheless, execution of the circular cells progressed as planned.


Later on the fabrication of the second template with a diameter of 18 m was completed, and work started on the opposite side of the breakwater with a second crane. The same conditions for the design were imposed - resistance against horizontal impact of the waves and vertical bearing capacity for a 150 t crane.

 

The backfill of the first cells was brought in from a local sand pit. Shortly after, a dredger was used to draw out sand from within the marina and dump it into the cells. Compaction of the sand fill is done by gravity and is accelerated by vertical drains. In areas with high vertical loads on the cells, additional foundation piles will be installed.


After completion of the breakwater in November 2008, prefabricated 'tetrapodes' will be placed on the outside of the marina. In a next stage all other shipbuilding facilities, housing and even a waste water treatment plant will be built.


Since the design took into account seismic loads, a recent earthquake with a magnitude of 6.4 did not cause any damage to the steel structure.


In the future the marina will give shelter not only to the tourist boats, but also to the local fisherman - a dramatic improvement over the situation that existed before its construction.
 

Costa Rica divides two oceans, the Atlantic and the Pacific, and is renowned for its rich wild life, volcanoes and undisturbed natural areas. Besides the export of coffee, tourism is one of the major economic pillars of the country. The Pacific Coast is the preferred destination for fishermen, but until recently it lacked adequate port infrastructure for private fisher boats. During the rainy season with heavy storms, no protective harbour was available along the coast.


In 2007 a group of local investors decided to start working on a project that would benefit locals as well as tourists. Marina "Pez Vela" had been planned for years and started to become reality. The 308 slip marina will feature one of the most sophisticated breakwaters ever built for a recreational marina, providing a safe harbour and hurricane protection. The extra-wide, modern, concrete floating docks, allow safe loading of passengers and equipment, and secure moorage. The first phase of construction includes 100 slips accommodating yachts up to 61 m in length. Being built with an emphasis towards environmental protection which includes the use of recycled steel and the installation of a water treatment system, the marina will fully meet American and Costa Rican building codes and standards.
 

The design considered the needs of the boat owners and the necessary infrastructure to host the future landing point. The governing design factor in this case was the standard wave height of 2.5 m. During the first discussions this was assumed as too big, but actual experience proved it was a good assumption.


To achieve adequate shelter for the boats, a strong and reliable breakwater had to be built. Different gravity structures were analysed, including rock dam, rectangular 'double wall' sheet pile cofferdam, concrete caissons and circular cells cofferdam.
 

The limited availability of aggregates in the area made the rock dam solution very difficult and expensive. At the same time, concrete caissons would have required too much construction time.


Consequently the final choice for the 540 m long breakwater was a circular cell cofferdam with AS 500 straight web steel sheet piles which offers multiple advantages:

• once the crew acquires the necessary training, installation is quick. Time required to finish one cell is only 7-8 working days,
• after the cell is closed and backfilled, the system is auto-stable and can resist wave loads, and support the crane, thus ensuring safety. The temporary template, and later the backfill, stabilizes the structure, hence no tie-back system is needed,
• the use of 'mariner' steel grade according to ASTM A 690, with additional alloy content (copper,…), provides higher resistance against corrosion in the splash zone,
• the cell diameters of 12.2 m and 18.6 m offer significant space for development along the top of the wall,
• the flexible structure's performance under seismic loading is good.

The whole project will be implemented by a local contractor with the help of an experienced pile driving crew. Additional technical support was provided during the design stage and execution phase by the sheet pile manufacturer's technical department.




After site installation and construction of the first 12 m diameter template, pile installation started with one crew. It became clear to the project owner during the early days itself that the circular cell solution was the correct decision. The rough weather and waves of more than 2.5 m gave the crew a hard time. Even the crane was hit by a wave that overtopped the dam. Nevertheless, execution of the circular cells progressed as planned.


Later on the fabrication of the second template with a diameter of 18 m was completed, and work started on the opposite side of the breakwater with a second crane. The same conditions for the design were imposed - resistance against horizontal impact of the waves and vertical bearing capacity for a 150 t crane.

 

The backfill of the first cells was brought in from a local sand pit. Shortly after, a dredger was used to draw out sand from within the marina and dump it into the cells. Compaction of the sand fill is done by gravity and is accelerated by vertical drains. In areas with high vertical loads on the cells, additional foundation piles will be installed.


After completion of the breakwater in November 2008, prefabricated 'tetrapodes' will be placed on the outside of the marina. In a next stage all other shipbuilding facilities, housing and even a waste water treatment plant will be built.


Since the design took into account seismic loads, a recent earthquake with a magnitude of 6.4 did not cause any damage to the steel structure.


In the future the marina will give shelter not only to the tourist boats, but also to the local fisherman - a dramatic improvement over the situation that existed before its construction.
 

Costa Rica divides two oceans, the Atlantic and the Pacific, and is renowned for its rich wild life, volcanoes and undisturbed natural areas. Besides the export of coffee, tourism is one of the major economic pillars of the country. The Pacific Coast is the preferred destination for fishermen, but until recently it lacked adequate port infrastructure for private fisher boats. During the rainy season with heavy storms, no protective harbour was available along the coast.


In 2007 a group of local investors decided to start working on a project that would benefit locals as well as tourists. Marina "Pez Vela" had been planned for years and started to become reality. The 308 slip marina will feature one of the most sophisticated breakwaters ever built for a recreational marina, providing a safe harbour and hurricane protection. The extra-wide, modern, concrete floating docks, allow safe loading of passengers and equipment, and secure moorage. The first phase of construction includes 100 slips accommodating yachts up to 61 m in length. Being built with an emphasis towards environmental protection which includes the use of recycled steel and the installation of a water treatment system, the marina will fully meet American and Costa Rican building codes and standards.
 

The design considered the needs of the boat owners and the necessary infrastructure to host the future landing point. The governing design factor in this case was the standard wave height of 2.5 m. During the first discussions this was assumed as too big, but actual experience proved it was a good assumption.


To achieve adequate shelter for the boats, a strong and reliable breakwater had to be built. Different gravity structures were analysed, including rock dam, rectangular 'double wall' sheet pile cofferdam, concrete caissons and circular cells cofferdam.
 

The limited availability of aggregates in the area made the rock dam solution very difficult and expensive. At the same time, concrete caissons would have required too much construction time.


Consequently the final choice for the 540 m long breakwater was a circular cell cofferdam with AS 500 straight web steel sheet piles which offers multiple advantages:

• once the crew acquires the necessary training, installation is quick. Time required to finish one cell is only 7-8 working days,
• after the cell is closed and backfilled, the system is auto-stable and can resist wave loads, and support the crane, thus ensuring safety. The temporary template, and later the backfill, stabilizes the structure, hence no tie-back system is needed,
• the use of 'mariner' steel grade according to ASTM A 690, with additional alloy content (copper,…), provides higher resistance against corrosion in the splash zone,
• the cell diameters of 12.2 m and 18.6 m offer significant space for development along the top of the wall,
• the flexible structure's performance under seismic loading is good.

The whole project will be implemented by a local contractor with the help of an experienced pile driving crew. Additional technical support was provided during the design stage and execution phase by the sheet pile manufacturer's technical department.




After site installation and construction of the first 12 m diameter template, pile installation started with one crew. It became clear to the project owner during the early days itself that the circular cell solution was the correct decision. The rough weather and waves of more than 2.5 m gave the crew a hard time. Even the crane was hit by a wave that overtopped the dam. Nevertheless, execution of the circular cells progressed as planned.


Later on the fabrication of the second template with a diameter of 18 m was completed, and work started on the opposite side of the breakwater with a second crane. The same conditions for the design were imposed - resistance against horizontal impact of the waves and vertical bearing capacity for a 150 t crane.

 

The backfill of the first cells was brought in from a local sand pit. Shortly after, a dredger was used to draw out sand from within the marina and dump it into the cells. Compaction of the sand fill is done by gravity and is accelerated by vertical drains. In areas with high vertical loads on the cells, additional foundation piles will be installed.


After completion of the breakwater in November 2008, prefabricated 'tetrapodes' will be placed on the outside of the marina. In a next stage all other shipbuilding facilities, housing and even a waste water treatment plant will be built.


Since the design took into account seismic loads, a recent earthquake with a magnitude of 6.4 did not cause any damage to the steel structure.


In the future the marina will give shelter not only to the tourist boats, but also to the local fisherman - a dramatic improvement over the situation that existed before its construction.
 

Costa Rica divide due oceani, l’Atlantico e il Pacifico, ed è rinomata per la sua natura selvaggia, i suoi vulcani e le sue inalterate aree naturali. Oltre alle esportazioni di caffé, il turismo é uno dei principali pilastri economici del paese. La Costa del Pacifico è la meta preferita dai pescatori, ma fino a poco tempo fa mancavano adeguate infrastrutture portuali capaci di ospitare le barche private dei pescatori, ed inoltre, durante la stagione delle pioggie non vi era alcun approdo lungo la costa in grado di offrire protezione dalle forti tempeste.


Nel 2007 un gruppo di investitori locali decisoro di iniziare a lavorare su un progetto di cui avrebbero potuto trarre beneficio sia gli abitanti che i turisti. Marina “Pez Vela” progettata da anni, finalmente iniziava a diventare realtà. I 308 porticcioli di attracco caratterizzeranno una delle più sofisticate dighe mai costruita per un lido turistico, fornendo un porto sicuro e una protezione contro gli uragani. Degli enormi e moderni bacini galleggianti di cemento armato offrono un trasporto sicuro ai passeggeri ed alle attrezzature, ed un ormeggio stabile. La prima fase di costruzione include 100 attracchi capaci di accogliere imbarcazioni fino a 61 m di lunghezza. Il porticciolo è stato realizzato con una particolare attenzione verso la tutela ambientale, utilizzando acciaio riciclato e installando un sistema di trattamento delle acque si riscontra inoltre il pieno rispetto degli standards degli edifici Americani e del Costa Rica.
 

Il progetto prendeva in considerazione le esigenze dei proprietari di imbarcazioni e le infrastrutture necessarie per ospitare il futuro punto di sbarco. Il fattore determinante per il progetto, era rappresentato dai 2,5 m di altezza standard dell’onda.Nonostante fosse inizialmente considerato esagerato, l’esperienza attuale ha dimostrato essere un buon presupposto.


Per realizzare un adeguato riparo per le barche, era necessaria una diga forte ed affidabile. Sono state analizzate diverse strutture di gravità come una diga a scogliera, un cofferdam rettangolare realizzato in palancole, cassoni di cemento armato e celle circolari realizzate con l’ausilio delle palancole piatte.
 

La limitata disponibilità di aggregati nella zona ha reso la soluzione della diga a scogliera estremamente difficile ed onerosa. Mentre i cassoni in cemento armato avrebbero richiesto troppo tempo per la loro realizzazione.


La scelta finale per i 540 m di lunghezza della diga è dunque caduta sulle celle circolari realizzate con palancole AS 500 capaci di offrire molteplici vantaggi:

• Acquisita la necessaria formazione, l’installazione è veloce. Il tempo necessario per terminare una cella è di solo 7-8 giorni lavorativi,
• Chiuso e riempito di terra, il sistema è auto-stabile e in grado di garantire la sicurezza, resistendo alle azioni delle onde, e sostenendo la gru. La stabilità del sistema è garantita della dima durante la fase d’infissione e dal riempimento nelle fasi successive, rendendo superfluo l’utilizzo dei tiranti,
• L’uso di acciaio “marittimo” secondo ASTM A 690 in lega con altri contenuti (rame, ...), offre maggior resistenza contro la corrosione nella “splash zone”,
• I diametri della cella da 12,2 m e 18,6 m offrono un notevole spazio lungo la sommità del muro,
• the Buone risposte del sistema asseggiato a carichi sismici.

L’intero progetto sarà realizzato da un impresa locale con l’aiuto di una esperta squadra di infissore. Un supporto tecnico supplementare è stato fornito durante la fase di progettazione ed esecuzione da parte del nostro dipartimento tecnico.




Dopo l’installazione in loco del cantiere e la costruzione della prima dima, avente diametro di 12 m, una squadra ha iniziato l’infissione delle palancole. I primi giorni di lavoro hanno confermato che la soluzione della cella circolare era la decisione corretta. Il mal tempo e le onde alte più di 2,5 m hanno creato notevoli difficoltà alla squadra. Anche la gru è stata colpita da un onda che ha superato la diga. Tuttavia, l’esecuzione delle celle circolari avanzava come previsto.


Successivamente la fabbricazione della seconda dima con un diametro di 18 m è stata completata, consentendo l’inizio dei lavori sul lato opposto della diga con una seconda gru.Anche su questo versante si sono applicate le stesse condizioni di progetto: la resistenza contro l’impatto orizzontale delle onde e una capacità portante verticale per una gru di 150 t.

 

Le prime celle sono state riempite con sabbia di una cava locale. Poco dopo, una draga é stata utilizzata per estrarre la sabbia dall’interno del porticciolo e scaricarla nelle celle. La compattazione del terrapieno sabbioso avviene per gravità ed è accelerata da dreni verticali. Nelle aree dove erano previsit elevati carichi verticali sono stati installati pali di fondazione supplementare.


Dopo il completamento della diga nel novembre 2008, “tetrapodi” prefabbricati sono stati posti sulla parte esterna del porticciolo. Gli altri impianti erlativi a cantieri navali, abitazioni e trattamento delle acque di scarto sono stati realizzati in una fase successiva.


Dato che il progetto teneva conto dei carichi sismici, un recente terremoto con magnitudine pari a 6,4 non ha causato alcun danno alla struttura in acciaio.


In futuro il porticciolo accoglierà non solo imbarcazioni turistiche, ma anche di pescatori locali offrendo un notevole miglioramento rispetto alla situazione che esisteva prima della sua costruzione.