Influence of Short Segments in the Trabeation With Opposing Inclined Edges on the Seismic Vulnerability of the Marble Blocks Colonnade in the Archaeological Site of Pompeii

This study presents the vulnerability analysis of a masterpiece of the architectural heritage of the ancient city of Pompeii in Italy. First, a historical analysis of the structure is proposed; then finite element analyses are discussed to evaluate the seismic vulnerability of the colonnade today, including the effect of water leakage and pollutants in between the marble blocks of the structure. Pompeii, in fact, is a partially buried Roman town-city; after suffering many earthquakes in the past it was destroyed during a long catastrophic eruption of the Vesuvius volcano in 79 ad and remained covered until its accidental rediscovery in 1749. After excavations, the ruins of the ancient town present many partially collapsed buildings, not only due to other earthquakes during the past three centuries, but also due to rapid degradation of the archaeological material. Temples and public places mainly present slender columns and typical shapes of discrete marble overlaying blocks. In the case of the colonnade of the Forum, residing in the main square of the town, an “innovative solution” was adopted for the trabeation. To avoid long span beams over the columns, short segments were built up providing opposing inclined patterned edges. Numerical analyses show the seismic vulnerability of a colonnade, in order to understand how a UNESCO World cultural heritage site can be preserved. The beam segmentation was an “innovative solution” for that period aiming to simplify the constructability of those structures. This solution did not substantially alter the colonnade current seismic vulnerability. Nevertheless any contemporary alteration between blocks could potentially increase the colonnade’s seismic vulnerability, potentially putting at risk cultural heritage and human life.