The port is the brainchild of entrepreneur Eike Batista, the Brazilian billionaire. His company LLX Logistica has provided the basic detailing, engineering and management of the project. Tecton Engineering submitted the design while Logos Engineering was responsible for monitoring construction and quality control. Eventually the port will include an industrial complex incorporating a steel plant, two cement plants, a power plant, an oil refinery and at least four mills for iron ore pelletising and is estimated to create 50,000 jobs. The most important part in the port’s development programme at this point was completed last March. This is the access jetty to the berthing piers, a huge structure of concrete and steel nearly three kilometers long and 26.6 meters wide, linking the coast to 10 berths for mooring vessels and complete with offshore loading and unloading facilities. A joint venture comprising two Rio de Janeiro-based contractors, ARG and Civil Port, was awarded the access jetty contract. ARG is the main contractor with an 80% share while Civil Port has expertise in port development projects.
Driving force
To form the jetty foundations and to drive the steel and concrete piles required, a CG300 hydraulic piling hammer fitted with a 20t ram weight was purchased from manufacturer BSP International Foundations (BSP) based at Ipswich in England. Following the hammer’s commissioning by BSP field engineers, the CG300, suspended from a Manitowoc 300 crane fitted with a 60m boom, began driving concrete piles in August 2008. Approximately 1200 concrete piles 47m long and 800mm in diameter were driven 10m to 15m into the sea bed through sand and layered clay over a 19 month period. In addition, tubular steel piles were driven in areas with thick layers of soft clay. The longest of these were up to 96m and filled with concrete. Piling was carried out in three shifts, 24 hours a day, every day of the week over a stretch of water 14m deep. At the same time dredging was carried out to deepen the access channel and berthing basin to 18.5m with further dredging planned to 21m allowing the port to receive large ships such as bulk carriers up 220,000t. The piling grid for the structure consisted of rows of four to six piles driven to create a pier. Altogether 163 piers were built and were spaced 20m apart with each pier linked together by four parallel concrete beams 20m long and weighing 38t each to form the base of jetty deck. To ensure accuracy and enhance production the contractors used a purpose built 1100t steel gantry frame for the piling work with opening gates and mounted on two railway tracks. The gantry was supported on previously driven piles which allowed up to six piles to be held in place and positioned in rows. Piles were then driven to a predetermined level and when the gantry gates were opened the hammer was able to pass through and drive the piles to the required depth. For every five piles driven two further inclined piles were driven at the end of each pier to avoid side swing of the structure and to contain pitching. As each pier was completed and capped the gantry was then moved forward together with the crane and hammer thus moving the pile gates to the next position ready for a new batch of piles to be loaded. This system allowed the jetty to move seaward at a rate of 20m per week. Throughout the project the contractors have s achieved excellent results with the CG300 hammer enabling the company to keep ahead of the construction programme. The crane suspended CG300 is just one of BSP’s heavy-duty CG range of piling hammers with ram weights from 12t up to 25t. The company’s larger CGL range offers ram weights from 25t up to 40t. Maximum impact energies extend from 185kNm to 400kNm. All have been designed for driving a variety of bearing piles including steel, combi piles, ‘H’ sections and reinforced/pre-stressed concrete piles and can be operated from piling rig leaders or, as in the Porto do Acu project, crane suspended. Also included are hinged type back guides to allow quicker installation onto the leader. Some important features include: total control of hammer stroke and blow rate, precise matching of energy to suit the particular pile driving requirements and the ability to drive piles with an ultimate load bearing up to 14,500kN. Fitted with a BSP remote control panel, the CG range is capable of delivering an infinitely variable stroke and blow rate enabling precise delivery of energy to the pile thereby allowing the contractor to maximise production, avoid pile damage and problems of pile runaway. A major feature of the CG hammers is the design of the hydraulic actuator which, for a given blow rate and energy transference, results in less fuel consumption and reduced exhaust emissions Piling helmets are also available to efficiently transfer the hammer’s impact to the pile. Using a BSP manifold control valve the CG range can be connected into existing power supply from a hydraulic piling rig or crawler crane base. All the concrete used for the manufacture of the pre-cast piles and capping beams was produced in a purpose build facility on the onshore site. Construction of the jetty is estimated to have consumed 100,000m3 of concrete and 16,000t of steel. It is forecast that the port will eventually handle over 63 million tonnes of iron ore, 10 million of steel products, 15 million of coal, five million of dry bulk and 7.5 million of general cargo.