La SIA S.p.A., by assignment received from the Interregional Superintendency for Public Works, was awarded the verification of the building’s structural safety and seismic vulnerability on the outcome of which was conformed to the technical and economic feasibility project for the extraordinary maintenance and energy efficiency interventions of the Palace of Justice, located in Bari.
Our efforts were aimed at identifying and resolving potential structural hazards while ensuring the full functioning of the activities carried out within the building during the improvement process. The courthouse, located in a densely urbanized area of Bari, was subjected to a detailed analysis to ensure its optimal safety and operation.
Among the main goals of the project was to significantly improve the building’s energy efficiency. In accordance with national directives, we have committed to reducing primary energy consumption by 20 percent and meeting the minimum parameters specified by Law no. 90/2013.
Our integrated approach made it possible to effectively coordinate structural verification and energy improvement work under the same direction, ensuring optimization of time and resources used.
In pursuing the goal of environmental sustainability and structural safety, La SIA is committed to meeting the minimum environmental requirements and achieving the goals set by the Action Plan for Environmental Sustainability of Consumption in the Public Administration Sector. This included the reuse of 70 percent of waste materials in order to minimize the environmental impact of the interventions.
The design activity was divided into several stages. Initially, a detailed analysis of the courthouse was conducted, including its condition, structural and plant features, and a study of the surrounding urban context. Subsequently, extensive investigations were carried out, including structural safety and seismic vulnerability verification of the building.
Based on the results of these investigations, interventions needed for the regulatory and functional upgrading of the Bari Palace of Justice, as well as its energy improvement, were identified.
Civil works included replacement of window frames, insulation of solar slabs, and other complementary building works.
From a systems point of view, several actions were planned, including the replacement of Air Handling Units (AHUs), the installation of high-efficiency heat pumps, and the installation of a rooftop photovoltaic system.
Regarding structural works, following the seismic vulnerability assessment, structural reinforcement works were planned, including the use of steel tubular bracing, reinforcing and stiffening frames at the boundary with the existing building, and contrasting frames at the basement level.
Laser scanner survey and point cloud processing
The survey involved the exterior facades, those of the interior cloisters, roofs, and accessible terraces.
The end result was a colorful point cloud with almost no “noise” therefore sharper and higher quality, rich in detail. The cloud was needed to provide a certain basis for the next stage of BIM modeling of the building and its georeferencing.
For the purpose of designing the energy efficiency measures, an analysis was carried out to determine the energy profile of the building in terms of both consumption and energy performance indices. The previous facilities, were unable to provide the necessary air exchange, nor to maintain thermo-hygrometric comfort conditions in winter and summer. Therefore, the proposed interventions aimed not only to reduce energy consumption by 20% as required, but also to make the plant fit for the required needs. With regard to lighting electricity consumption, the previously installed lamps, which were old linear fluorescent tubes, were considered.
The post-operam energy model was obtained on the basis of the ante-operam model, considering the following substitutions and additions:
– The replacement of windows and doors with others of the best thermal and solar characteristics, in line with the characteristics required by the DM of 25/06/2015 (the so-called “Decree of minimums”) for major second-level renovations.
– Renovation of the roof insulation to meet the transmittance characteristics required by the DM of 25/06/2015 for major renovations of the second level.
– Replacements of previous AHUs (not equipped with any heat recovery) with others with the same primary air flow rate produced in the previous state, but equipped with total recovery enthalpy wheel heat recovery, a technology that achieves the highest efficiency values by being able to recover both part of the sensible and latent heat of the exhaust air.
– Integration of the heat generator consisting of No. 2 existing heat pumps with No. 2 others of the same rated cooling capacity but capable of providing the necessary heating and cooling capacity at very high efficiencies
– Installation of LED lamps instead of fluorescent lamps
– Installing a photovoltaic system of ca. 113 kW peak with flat mono crystalline panels oriented south and tilted ca. 30° from the horizontal plane.
The energy class of the building, going from the actual state to the design state, went from D to B, that is, it improved by 2 of classes. The total global energy performance index by moving from the actual state to the design state was reduced from 364.7 kW/m2year to 214.6 kW/m2year, with a percentage reduction in overall energy consumed in one year of 41.2%.
Thus, the overall savings achieved in percentage terms was greater than the minimum value required for incentives (20%).
With regard to building works, these are related to the first of the two objectives identified within the Design Guidance Document, namely to make significant improvements to the building’s energy management in technical, economic and consumption terms. Therefore, as made explicit within the DIP, the intervention included the replacement of existing window and door frames and the thermal insulation of the solar slabs without, however, going to intervene on the facades without stone cladding by means of thermal insulation. All complementary building works deemed necessary were added to these interventions. Preliminary to the choice of these interventions, was the in-depth analysis of the fire executive project aimed at the regulatory and functional adaptation of the Palace of Justice in order to bring it into compliance with the provisions within this PFTE. In this regard, it should be noted that the interventions arranged within the EP with regard to construction works were as follows:
– Masonry work: demolition and reconstruction of existing partitions in order to reconfigure or create fire compartmentalization of the building
– False ceilings and plasterboard works: installation of different types of false ceilings in the building’s distribution corridors, in places where it was necessary to mask the passage of plant networks and inside the smoke filters
– Indoor and outdoor flooring
– Coatings and finishes: installation of interior lime and paint on the interior partitions being reconstructed, and installation of full-height cladding on the newly built walls inside the Courtroom on the second floor and the Great Hall on the third floor
– Interior fixtures: installation of single- and double-leaf fire doors for configuring fire compartments and creating escape routes
– Exterior fixtures: replacement of only some of the existing fixtures with PVC profiles and double glazing safety glass consisting of float glass with polyvinyl butyral (PVB) film in between
– Replacement of railings and balustrades
– Re-functionalization of elevators
– Restroom renovation
The design and construction of the building dates back to the early 1960s, it consists of several bodies in adjacency separated by non-seismic construction joints. At these joints, the vertical and implacate load-bearing structures (beams and columns) doubled, and the buildings were practically adhered to each other. A central block, in which there is the main access to the courthouse, which in turn is constructively divided into 3 joined and adjacent bodies named “C,” “D,” and “E,” respectively; to the west is block “A” and block “B” (also formed by joining individual joined bodies); and to the northeast is the block named “F.”
The load-bearing structures made of reinforced concrete, having frames arranged in the two orthogonal directions and beams almost always at slab thickness.
Dating back to 2019 is the project for the renovation of the structural elements (beams, pillars, and floors) of the basement, in the area below the uncovered forecourt of the main entrance, elements found to be affected by degradation phenomena such as the detachment of the iron cover as a result of oxidation of the reinforcements and the breaking apart of the floors, phenomena related to environmental factors such as humidity and water infiltration from the levels above, which are no longer efficient from the point of view of waterproofing.
Regarding the structural aspect, the structural safety assessment of the building was conducted in accordance with paragraph 8.3 of Ministerial Decree 17.01.2018 (Update of “Technical Standards for Construction”). Evaluating the safety of an existing structure is a quantitative procedure designed to determine the extent of actions that the structure is capable of sustaining with the minimum level of safety required by the aforementioned regulations. It was conducted with reference:
– to the combinations of actions that normally affect the structure and, in particular, with reference to gravitational loads;
– To seismic combinations.
In both cases, the safety level of the construction expressed respectively by:
– zV = Rd / Ed (ratio of performance capacity to performance demand under static conditions);
– zE = Rd / Ed (ratio of performance capacity to performance demand under seismic conditions);
The following table summarizes these ratios:
From it, it was found that the structure was adequate with reference to gravity loads while seismic upgrades were needed to raise the zE safety level from 0.73 to 1. In order to achieve this objective, interventions have been designed to reduce the structural displacements induced by the design seismic action to values compatible with the performance capabilities of the structure, thereby reducing its stresses to values acceptable to the structure. This was achieved by designing additive stiffnesses, by means of nondissipative metal bracing that possessed the aforementioned function. Such bracing, made of X-shaped metal tubing, will be to be installed at precise locations within certain structural meshes. An additional type of intervention to be installed in the basement, within the crawl spaces, a contrast system capable of blocking movement of the buried portion of the building against the perimeter retaining wall.
Structural upgrades
The types of interventions provided PFTE drafted by La SIA are listed below:
