Sfoglia altre lingue

A discutere di sicurezza, associata al mondo dei ponteggi, gli argomenti corrono parallelamente all’attività di ancoraggio che, solitamente, avviene con i tasselli.

Ai sensi del D.Lgs 81/2008 articolo 125 comma 6, gli ancoraggi vanno realizzati almeno ogni due piani di ponteggio e ogni due impalcati. In presenza di ponteggi con campate standard da 1,8 m, occorre almeno realizzare un ancoraggio con tassello ogni 14,4 mq secondo le modalità previste dal libretto di autorizzazione ministeriale.

I DPI richiedono la realizzazione di ancoraggi specifici, conformi alla norma UNI EN 795 e dotati delle caratteristiche di resistenza indicate nelle istruzioni d’uso. La conformità alla norma europea, in fatto di ponteggi, non è solo una questione di forma, peraltro importante ai fini dell’attribuzione delle responsabilità, ma anche di sostanza: infatti, gli ancoraggi per ponteggi vengono solitamente progettati per resistere a carichi di trazione perfettamente perpendicolari ai tasselli di fissaggio.

Per ancorare un ponteggio in maniera idonea, è fondamentale conoscere il materiale di supporto perché, per identità e consistenza, condiziona in fase preliminare, la scelta dell’opzione di ancoraggio e la sua collocazione.

In commercio, attualmente esistono diversi tipi di tasselli ancoranti:

• meccanici ad espansione forzata, ideali per i materiali compatti ed uniformi

• meccanici a variazione di forma

• chimici a variazione di forma, ideali per i materiali forati, alleggeriti e porosi

• chimici per adesione, la resina costituisce un corpo unico con le pareti del foro, con il materiale di supporto trattenendo l’elemento metallico che normalmente è una barra filettata

• Ancoraggi chimici a fiala

• Ancoraggi chimici ad iniezione

L’azienda produttrice, nella scheda tecnica, deve specificare la portata teorica tenendo conto della resistenza del materiale.

Per questo, gli ancoraggi per ponteggi sono di diversi tipi e rigorosamente descritti nei libretti delle Autorizzazioni Ministeriali compresi dove viene indicata portata teorica e resistenza ai materiali eventualmente impiegati. Sono così classificati:

·         Ancoraggio ad anello

·         Ancoraggio con tubi e giunti a cravatta

·         Ancoraggio a tubi e giunti a contrasto

·         Ancoraggio a barre filettanti passanti dotate di piastre di contrasto

·         Ancoraggio con barra munita di gancio

Quindi, per operare sull’ ancoraggio di un ponteggio, è necessario provare la resistenza dei muri con vari test dopo uno studio preliminare.

Dopo aver provato le condizioni con l’ausilio di alcuni strumenti come il dinamometro, è necessario, infine, confrontare i risultati con un tecnico qualificato al fine di certificarne l’idoneità, numero e collocazioni necessarie a garantire l’adeguata portata del ponteggio.

In questa maniera, si può procedere finalmente al montaggio del ponteggio rispettando le procedure in sicurezza ed evitando di ancorarlo al muro nei punti in cui sono state effettuate le precedenti prove di tenuta.

Quando si parla di questo tipo di lavorazioni, si ragiona con esperienza ed il primo nome che balza alla mente è Euroedile. Con più di 35 anni di servizio, Euroedile guida la classifica dei partner affidabili per la progettazione ed installazione di allestimenti di ponteggi. Non esistono ancoraggi difficili per Euroedile ma solo soluzioni per introdurre nuovi sistemi.

The presence of scaffolding on the construction site must guarantee not only the safety of the people working on it but also that of all the workers involved in the work. It is of fundamental importance that it is built and used in compliance with all the precautions and specific structural standards established by the regulations in force.

When you decide to erect a scaffolding, you start a mission that starts, essentially, from ananalysis of the safety of the geographical area in which the grass yard will then flourish.

Several factors are under the magnifying glass on the aspect of security so that episodes like those of last October 9 in Borgaro Torinese (where a seven-storey facade scaffolding collapsed right in the centre) remain only a distant memory.

Starting from the physical area that delimits the necessary space, the first rule is the word "order": an orderly building site, where each space is dedicated to a specific function, an advantageous part compared to a sequence left to chaos.

For all other aspects, the real bible of the coordination of the use of scaffolding and the regulations associated with it, is certainly the Legislative Decree no. 81 of 9 April 2008, or better known as "Legislative Decree 81/08": it contains the correct behaviours to be adopted or the possible reactions to be adopted on site and in case of need. Because this condition could be found around every corner and cannot leave room for imagination, one must be ready for the correct reaction when needed.

Beginning to analyze the decree, Article 133 of the same lays the foundations by speaking clearly and highlighting a fundamental aspect of the site: the project.

Because this is the starting point and it clearly states: "Scaffolding of more than 20 metres in height and those for which the specific structural configurations used with the relevant diagrams of use are not available in the calculation report must be erected according to a design including: a) strength and stability calculation carried out in accordance with the instructions approved in the ministerial authorisation; b) executive design".

The project, therefore, must be signed and validated by a qualified engineer or architect and must be accompanied by a copy of the ministerial authorisation and executive drawings illustrating the correct manufacture of the structures: it must always be made available and shown to the supervisory bodies with a copy of the assembly and disassembly plan, the so-called Pi.M.U.S. (Plan for Assembly, Use and Disassembly).

So, the safety mechanism starts, basically, in the office where, after detailed inspections on the field, a professional designs and calculates the correct conformation of the structure. The calculations are the basis of everything because the rules of physics are not an opinion: the accounts must come back, there must not be even a crumb of doubt. For this reason, the competent supervisory bodies are in constant control, institutionally everything must square without smudging.

The decree also imposes very precise indications on the physical laying of the scaffolding by defining anti-slip plans with fixing surfaces and laying surfaces with a well-defined load-bearing capacity.

Syllogism is a creed to be printed in block letters: the scaffolding must be stable. Stability is the secret ingredient of a good scaffolding recipe, the cornerstone of a safe scaffolding. Everything must be adapted to the loads to be carried and the safe circulation within the structure. The elements must be firmly connected to each other and there must be no dangerous gaps between decks and vertical fall protection devices.

Scaffolding parts that are not ready for use, during assembly and disassembly operations, must be indicated by appropriate signs to warn of the danger of a possible collision, perhaps delimiting the material storage area and signalling it promptly.

Hence the importance of the figure of the person in charge, a person who has the function of enforcing the rules meticulously.

Another element of fundamental importance are the protection systems suitable for the specific use composed of different elements, not necessarily present at the same time and complying with technical standards, such as:

a) energy absorbers;
b) connectors;
c) anchoring device;
d) lanyards;
e) retractable devices;
f) flexible guides or lifelines;
g) rigid guides or lifelines;
h) harnesses.

The protection systems must be secured, directly or by means of a connector, along a guide or life line, to stable parts of fixed or temporary works. 

If there is no constant monitoring or updating of these devices, there is no history. Or rather, it will not have a happy ending.

From a legal point of view, from the moment the construction site is opened, the contractor is responsible for the custody not only of what is necessary for the execution of the work, but also of all those common parties involved in the work. And so the contractor who awarded the contract for the works is directly responsible for any damage that may be caused to the structure or third parties as a result of the execution of the works: the responsibility for the fall of the scaffolding can only lie with the person who placed it and who had the obligation to check its anchorage during the execution of the works. The choice of the contractor must therefore be extremely scrupulous and fall on companies in possession of those certain requirements that meet particular safety standards required by law (Legislative Decree no. 494/96) on the observance of which the contractor must monitor.

Let us conclude, therefore, by reaffirming that safety is a serious matter: if there is no respect for all the rules, we do not improvise scaffolding. Scaffolding is study, reflection, reflection and respect for the rules. None of these characteristics must be allowed to fail: everything is part of a circle, a perfect ritual.

"The sense of one's own safety is more often born of habit": getting used to safety is an obligation that every building site must have. Safe scaffolding is the starting point for a successful construction site.