Escavations

O presente trabalho aborda um estudo sobre deslocamentos do maciço devido às escavações de túneis, com ênfase nos deslocamentos verticais superficiais do maciço e na instrumentação geotécnica, destacando sua importância no acompanhamento da execução, visando a segurança da obra e regiões lindeiras. Primeiramente é apresentada uma revisão bibliográfica dos métodos de previsão dos deslocamentos, sendo estes métodos classificados em analíticos, empíricos e semi-empíricos, em seguida, apresenta-se uma relação de instrumentos utilizados para a medição das grandezas físicas relacionadas às obras geotécnicas (deslocamentos, tensões, poropressão etc.); são indicados os principais tipos, suas características e sua aplicação em obras de túneis. Por fim, é apresentado um estudo de caso de uma obra pertencente a um sistema de transporte urbano.

The Roman archaeological site of Podšilo is located in southern part of the Lopar Peninsula (Lopar Municipality, island of Rab, County of Primorje and Gorski Kotar). It is situated in a bay, encompassing the entire coastal area (between the bays of Dubec and Sahare) as well as a part of the immediate hinterland towards the south-west, all the way to the next antiquity site called “Beli Grad”. Since 2007 the Institute of Archaeology has conducted field survey of the territory of this site within the project “Northern Croatian Coastland within the Context of the Classical Antiquity Defense System”, led by Goranka Lipovac Vrkljan, PhD. At the Podšilo site a partly preserved Roman kiln was identified. Since its architectural elements are directly endangered, from 27th April until 17th May 2009 the Zagreb Institute of Archaeology conducted archaeological rescue excavations. The Roman kiln lays in the north-eastern peripheral part of the Podšilo Bay (opposite Goli Otok) and it seems that an elevated earthen hill was chosen for its position above the sea. But the fact that this hill is elevated compared to the surrounding landscape is a consequence of the disappearance of the surrounding soil due to erosion. Above the earthen cover its bow was visible, and it was not possible to identify whether it belonged to the bottom parts of the architecture or to the kiln’s roofing. In the last survey of this structure, conducted near the end of the year 2008, a devastation of the bow was stated, which in fact set off the kiln’s rescue excavation at the very beginning of the year 2009. After the preparatory stage of the site’s arrangement and documenting the existing status of the finds, the humus part SU 001 (only 0.5 m thick) was removed. The first surface stratigraphic data enabled an immediate identification of the important spatial determinant for the location of the Lopar Roman kiln. The Romans decided to locate it on the hilly elevation (which was out of reach of sea), and the kiln’s entire structure – apart from the entrance part of the firing channel and its final coverings – was sunken into the ground. The method of burying the kiln is most evident from the height differences of sterile soil, and thus between the entrance to the kiln and its gable. At the entrance to the baking chamber the sterile soil ranged from ▼273 m above sea level to ▼3.57 m above sea level. At the gable part of the kiln it is ▼5.20 m above sea level. In addition to choosing a hilly elevation for burying the kiln, its constructors used another natural characteristic of the terrain: the presence of schist rocks, SU 013. Although schist is not as firm as other rock types, in this region it is an extraordinarily valuable construction element, used for kiln foundations and for reinforcement of its construction elements on a tremor flysch terrain. The kiln was buried in line with the ramp system: from the lowest point at the entrance into the praefurnium towards the highest point at the end of the kiln i.e. the gable wall. The Lopari Roman kiln was built as a standard Roman kiln type with a rectangular chamber, type II b (according to Cuomo di Caprio). The kiln consists of two basic parts: the firing channel – praefurnium (SU 021) and a combustion chamber (SU 087). The firing channel is 0.70 m / 0.80 m wide. The praefurnium floor (SU 048 and SU 079) is ▼3.370 m above sea level. The firing channel walls were built of tiles and arch vaulted. No visible remains of the vault were preserved. The larger part of the channel was sunken (praefurnium SU 022 buried in sterile soil), with the exception of the entrance part. The preserved remains suggest that the firing channel length is 2.20 m. The firing channel leads to the baking chamber and its smoke channel, SU 028. The baking chamber is of a rectangular shape 3.00 m x 2.90 m. Only the bottom layers of the chamber’s walls, SU 020, were preserved. Within the chamber there is a smoke channel SU 028, which had an arch vault with three opposite pairs of pilasters (diagonal compartments) followed by bows. As the fill of the kiln’s chamber was emptied, numerous contemporary materials were found pointing to a recent attempt at devastating this archaeological site. It was identified that the layers of almost the entire fill are upside-down. At the point where the firing channel turned to the chamber’s smoke channel, beneath the flooring of this preserved kiln, an extraordinarily thick layer of collapsed material, SU 080, was found, consisting of construction ceramic fragments. The collapsed layer is part of an earlier kiln that used to be at the same spot. Thus our assumption was confirmed that the remains of the Lopari kiln are not an isolated antiquity find at this site, but part of a pottery workshop belonging to a nearby Roman villa rustica. According to the first analyses, the Lopar kiln can be dated approximately in the first two centuries BC. Parallel with the archaeological digs, field survey was conducted of the wider area near the Podšilo site, and of the Lopar area. Thanks to information provided by the local population, numerous antiquity sites were identified, which testify to a very intensive life in the Lopar area during Roman antiquity.