FISH MARKET IN VENICE – False ceiling in pultruded profiles in the trading area
A suspended GFRP frame for the construction of an ultra-lightweight false ceiling in a large area characterised by a main vaulted roof structure.
Located near the island of Tronchetto in the same area now occupied by the Port of Venice, the wholesale fish market of Venice (Mercato Ittico all’ingrosso – MIT) is situated in a strategic position in the Venice lagoon, which can easily be reached via sea or land. A large number of fish species from all over the world arrive at the Venice market and it is precisely this variety, along with the high quality, which determines its success, earning it a place as one of the top wholesale markets in Italy. A recent intervention was carried out by VERITAS, subject to public capital controlled by the council to whom Venice assigned the task of managing the fish market, and which involved the trading area warehouse.
On request of the local health authority, Veritas was asked to tackle the problem concerning the lack of a cooling system in the wholesale trading area. Indeed, even though most of the wholesale market’s work takes place at night and in the early hours of the morning, and the fish is transported and stored in ice-filled containers or refrigerators, in the summer period, higher temperatures represent a significant element/variable in keeping the fish fresh.
The creation of a cooling system, however, was significantly hindered by the vaulted ceiling of the building which occupied a large area. The project phase, therefore, called for the development of a solution to create a false ceiling which would reduce dispersion of such a large area, in addition to the structural modifications and integrations required.
The market, which was built in 1952, occupies an area of 6,900 square metres of which 4,900 is covered and used as offices, warehouses and market hall.
The market hall trading area occupies 1,700 square metres (measuring approx. 80m x 21m) where the so-called sales stands are located.
The building consists of a structure with perimeter columns in reinforced concrete and divisory walls in solid bricks. The vaulted roof consists of a concrete and masonry ceiling supported by truss arches in cast-in-place standard reinforced concrete, placed at distances of approx. 5 metres (starting height of the arches approx. 5.5 m and maximum height approx. 10.5 m). There are no central pillars and the trading area is free from any element that could represent an obstacle.
INTERVENTION WITH FIBRE NET SYSTEM
The installation of a cooling system called for the modification of existing structural elements (lighting, ventilation, etc.) and the need to install a false ceiling to reduce the volume to be cooled in the trading area which would, otherwise, have been too dispersive.
The client also imposed a ban on installing internal pillars and any other element which would interrupt the free flow of the surface (during work execution as well) given that the area was fully occupied during trading hours and constantly accessed by transport vehicles, such as forklift trucks.
The false ceiling, therefore, needed to be supported by an aerial frame that covered the entire trading area and was in turn suspended from the main vaulted roof structures.
Given that any suspended metal element would have been too heavy for the existing structures, it was decided to use GFRP pultruded profiles with steel cables/ropes which could meet the structural verifications of the existing elements.
The false ceiling, whose main feature is its lightweight, was, therefore, created with a two-directional frame of pultruded profiles made of G.F.R.P. (Glass Fiber Reinforced Polymer FBPROFILE) consisting of chemically resistant glass fibre and thermosetting polyester resins, characteristic tensile strength in the longitudinal direction 395 MPa, average modulus elasticity to traction in the longitudinal direction 32600 MPa.
Procurement of the material called for the drafting of a detailed plan, production diagrams, custom-cut and machining of the profiles, pre-drilling of holes and preparation of all the joins. The company also supplied the bolts, connection plates between the profiles and the eyebolts for attaching the bracing and support cables. Composite material was used for some joints while metal parts required were made of steel.
The work was carried out without interrupting the activity in the fish market which continued as normal while the false ceiling and systems were being installed. The work was divided between two shifts when the market closed and in the early hours of the evening. The installation work involved the use of an aerial platform which advanced gradually on a daily basis.
WORK SITE DIAGRAM
SUBJECT_False ceiling project for the installation of a cooling and ventilation system in the market hall
LOCATION_Tronchetto Fish Market, Venice
DESIGNER_Mr. Pierluigi Moro (engineer) and Mr. Riccardo Tommasi (engineer), Studio Moro, Venice
MAIN SUPPLY COMPANY_CO.EDIL COSTRUZIONI SRL