Safety assessment of the foundations of the Basilica of Maxentius in Rome

摘要

The construction of Massenzio's Basilica was begun in 306 A.D. by Marcus Aurelius Valerius Maxentius (278-312) and was ended in 313 by Costantine. Originally it covered an area of almost 6000 m~2 and was composed by three naves; two of them collapsed, probably after an earthquake, in the very early middle age. Today we can see only one of the naves composed by three big arches, 25 meters high and 20 meters wide, running for 80 meters parallel to the present day Via dei Fori Imperiali. The behaviour of the soil has a determinant role on the present condition of the Basilica, which resulted from various morphological modifications from the construction time to the last century. Thus a deep knowledge of the nature of the foundation soil and of its mechanical behaviour are elements of primary importance for understanding the static conditions of the Basilica and designing a conservative restoration. Many studies have been carried out on the Basilica foundations: three campaigns of borings in the subsoil, the definition of the mechanical characteristics of the soil layers; a campaign of borings into the masonry and the measurements of its mechanical characteristics. The recent studies on the building behaviour have been focused on the Carinae pier. Here new excavations are being made to reopen the Arco del Latrone passage, presently occluded by soil and demolition materials. This project is particularly delicate because of the seven-meter ground drop between the inner and the outer sides of the pier that impairs the whole structure stability. Therefore a numerical F.E. model of the behaviour of the structure was done, taking account of soil behaviour and of the building history. Studies and archaeological excavations are still going on in order to gather further elements on the behaviour of the equilibrium conditions of the Basilica, in the area close to the Arco del Latrone.