Category: Projects

The project involved the construction of three steel-framed fire escape staircases at the Andrea Doria school, located in Via Lepanto-Via Andrea Doria, Naples.

The tallest staircase rises approximately 9.70 m above ground. The columns are made of HE200B steel sections, while the beams consist of HE200B and UPN180 steel sections.

Steps and landings are made of prefabricated anti-slip galvanised steel panels.

The rest landings were given a curved profile for a more refined architectural appearance.

The steel structure was hot-dip galvanised beforehand, and on-site erection was carried out simply by assembling it with high-strength grade 8.8 bolts.

The foundation consists of a reinforced concrete raft on four piles; the raft is 60 cm thick.

The foundation piles are bored piles with a diameter of 50 cm and a length of no less than 12.00 m.

The piles were placed directly beneath the load-bearing columns. Four 60×60 cm tie beams embedded in the raft directly connect the columns and the pile heads.

Because of the shallow water table (1–2 m below ground level), the 50 cm diameter piles were built as cased piles.

The three staircases were analysed using the finite element software SAP2000 by CSI, Berkeley (USA).

Staircase A layout

Staircase B layout

Staircase C layout

Staircase A view

Staircase C view

Column-to-column joint detail

Column-to-beam connection detail

Column-to-beams connection detail

Column-to-beams connection detail

Column-to-foundation pile base plate detail

The building stands in the historic centre of Finale Emilia and has a load-bearing structure of solid brick masonry, steel and timber floors, and masonry staircases. It rises three storeys above ground and is used for residential purposes. The structure suffered very severe damage in the May 2012 earthquakes and was declared unfit for use following a technical inspection. The main structural works carried out were: new reinforced concrete foundations beneath the additional masonry walls; reinforced concrete ring beams at the existing masonry foundations, anchoring the reinforced plaster meshes and limiting differential settlement; consolidation of the existing masonry through stitch-and-repair (“cuci e scuci”) and reinforced plaster; replacement of the existing timber and steel floors; steel and reinforced concrete frames around the largest openings. The seismic upgrade raised the building’s seismic safety level from 15% to 61%, in compliance with the Emilia-Romagna Region ordinances for works on buildings damaged by the earthquakes of 20 and 29 May 2012. The structural design was based on non-linear static analyses using a finite element model.

3D analysis model in virtual reality

Object-based analysis model

Finite element analysis model

Damage diagram from seismic assessment with non-linear static analysis

Steel floors

Timber floors

Timber floors

Steel beam connectors

Connections between brick and clay-block masonry

Reinforced concrete ring beams

Timber floors

Timber floors

Timber floors

Timber floors

The project involves the repair of a barn with a load-bearing structure of solid brick masonry, located in the Municipality of Dosso (FE) and damaged by the earthquakes of 20 and 29 May 2012.

The existing load-bearing structure consisted of 60×60 brick columns with heights ranging from 6.80 to 8.60 m.

The central body was a single-storey brick masonry cowshed with a timber roof.

Because of the very severe damage to the columns, they had to be demolished together with the timber roof, while the central cowshed was retained at the owner’s request.

The demolished structural elements were replaced by a steel and timber structure.

The columns were rebuilt in steel and clad with plastered panels; the roof was rebuilt in timber.

To reduce column slenderness, a grid of steel beams and bracing was installed at the first level (ground-floor roof).

The horizontal bracing created a semi-rigid diaphragm, greatly improving dynamic regularity (modes of vibration).

The steel frame system is independent of the cowshed to avoid dynamic interference.

Displacements of the steel structure at the level of the cowshed roof are in the order of 1–1.5 cm.

To limit displacements without unduly compromising the building’s appearance, two vertical bracings were installed in one direction only, set against the cowshed walls.

The HE300A steel columns are oriented with their weak axis along the direction of the bracing.

The foundation consists of two reinforced concrete rafts, 50 cm thick plus 10 cm of lean concrete, connected in the central area by reinforced concrete beams to eliminate the effects of any horizontal displacement at the column bases.

The reinforced concrete beams were built so as not to interfere with the cowshed masonry.

The structure was analysed using finite element software.

Axonometric views and elevations are shown below for a better understanding of the structure described in this report.

Original structure

Original structure

Completed structure

3D virtual reality model

Front view of the object-based structural model

Rear view of the object-based structural model

Finite element structural model

Vertical bracing layout

Elevation

Elevation

Top view

First-level framing plan

Timber roof layout

Horizontal floor bracing

Roof detail

Roof detail

Steel-timber connection detail

Horizontal bracing details

Horizontal and vertical bracing details

Horizontal bracing connection detail

Vertical bracing detail

Timber beam installation

Timber beam installation

Foundation base plate detail

The repair and seismic upgrade of the former National Guard building was particularly challenging, as one perimeter wall was shared with the structure of Finale Emilia Cathedral.

A study of the seismic deformed shapes was needed so as not to disturb the Cathedral’s natural modes of vibration. To this end, works were also required on the Cathedral itself, calibrating all interventions on the building aggregate to obtain neutral seismic deformed shapes, i.e. unaffected by the mutual interaction between the Cathedral and the former National Guard building.

The stiffness distribution was optimised through the following works:

• Stiffening of the Cathedral roof pitches with steel bracing and ring beams.
• Stiffening of the roof pitches and floors of the former National Guard building with steel bracing.
• Framing of the ground-floor openings of the former National Guard building on the façade opposite the Cathedral.
• Strengthening of the existing masonry with reinforced plaster.

Structural rendering

Object-based structural model

Finite element structural model

Longitudinal seismic displacements with optimised behaviour, free from structural interaction between the two buildings

Floor stiffening details with steel bracing and ring beams

Floor stiffening details with steel bracing and ring beams, and masonry consolidation

Steel frame around an internal opening – steel ring beams and bracing

Steel frame around an internal opening – steel ring beams and bracing

Steel frames around internal and external openings

Reinforced concrete frame around an internal opening – reuse of the existing roof

Roof rebuilt reusing the existing main beams

Roof pitch stiffening with steel straps

1. Access ramp to the Temple of Serapis – Pozzuoli

The project involves the construction of a steel-framed pedestrian ramp.

The structure was designed using finite element analysis software.

Architectural design rendering

Structural design rendering

Object-based structural model

Finite element structural model

2. Seismic upgrade of the masonry walkway within the Stadium of Antoninus Pius site – Pozzuoli

Transverse and longitudinal ties between the masonry arches are planned so that they behave like a frame, significantly reducing horizontal displacements caused by seismic actions.

Laser scanner survey of the existing structure

Structural design rendering

Object-based structural model

Finite element structural model

3. Masseria del Gigante – Cumae

The seismic upgrade project provides for the stiffening of some floors using steel bracing and ring beams.

Structural checks were carried out using finite element software.

Structural rendering

Object-based structural model

Finite element structural model

Structural rendering

Object-based structural model

Finite element structural model

Pad foundations and tie beams

Positioning of templates for foundation base plates

Erection of the superstructure

Erection of the superstructure

Erection of the superstructure

Foundation base plate