Welcome to the Domus Aurea worksite blog!
The last few days have been cold and rainy. The size and solidity of the large hangar covering about 800 m2 of the Park on the Oppian Hill are striking: it looks like a place untouched by the bad weather. … Continue reading
The new year began with a novelty for the Domus Aurea and for our team: our Director, Fedora Filippi, is now enjoying her well-earned pension! Fedora, widely known for her enormous scholarly competence, has also been for us an example … Continue reading
At present, the Domus Aurea consists of a complex underground structure above which lies the Oppian Hill park with the visible remains of the Baths of Trajan.
The rooms that previously belonged to Nero’s vast palace, originally designed as an overground complex, are now concealed by the park and have thus become subterranean structures, though they were not intended to be so.
Holes in the vaults and apertures in the vaults have formed preferential paths for the percolation of water and caused the structures to become far weaker than they originally were.
Examples of these situations, widespread throughout the monument, can be found in Room 33, where rebuilding and conservation work has already taken place, in Gallery 20E and Room 94.
Numerous attempts have been made to waterproof the ancient structures to intercept rainwater and prevent it seeping into the underground monument, though these have covered limited areas.
We have recently completed the Definitive Project for the rehabilitation of the area above the Domus Aurea.
It is obvious that water infiltration, resulting from increasingly frequent heavy rains, continues to cause damage to the monument, even in areas where the conservation of internal surfaces is underway and where work has already been completed.
Considering the importance and urgency of limiting the percolation of water into the monument, in order to reduce the risk of compromising the conservation work already undertaken, the continuation of planned interventions and the potential opening of a limited area of the monument to visitors, we are in the process of laying a drainage layer on the surface of the park above the Domus Aurea.
The aim of this intervention is to significantly reduce the intensity of surface water percolation rapidly and at modest expense before the autumn rains that usually affect Rome in the first third of November.
We aim to achieve this objective by draining the surface waters in a way that does not hinder or endanger the work underway in the park.
We believe that draining 50% of rainwater is sufficient to re-establish a degree of security, or at least to slow down the decay of structures and paintings sufficiently for the definitive project, in the form of the Integrated Protection System, to be “in time”.
Drainage will be achieved by laying a geocomposite in a channel just over 4 metres wide, at the centre of which will be a drainage tube supported by gravel, with a gradient of 0.5%. The drainage geocomposite and the tube will be buried by the earth dug out, so as to ensure that the surface is passable as at present, allowing spontaneous plants to grow.
The depth of the geocomposite varies from a minimum of 20 cm to a maximum of 80 cm, whilst that of the drainage tube ranges from a minimum of 0.50 to a maximum of 1.20 metres. The tube will have a diameter of 160 mm for the first 20 metres and subsequently of 200 mm; it will flow into the park’s sewer system.
The purpose of the geocomposite is to drain and filter rainwater. It consists of a three-dimensional polyamide core, heat-treated to give it a v-shape configuration, particularly suited to resisting the confining pressures exerted by the surrounding soil, enclosed in two non-woven heat-sealed filters integral with the drainage core. The geocomposite chosen has a vertical transmissivity (hydraulic gradient i = 1) at 20 kPa of no less than 2.5 l/s m (equal to 9000 l/hm).
Rainwater seeps into the ground vertically. When it meets the drainage geocomposite it will tend to flow into it, as the resistance to motion is several degrees of magnitude lower than the surrounding soil, where a small quantity of water will nonetheless remain. The water will thus drain away inside the geocomposite until it reaches the drainage pipe that channels the water towards the sewer system. The route of the drainage pipe may run through highly permeable soils or soils with voids or fractures, where the water collected may percolate downwards, thus compromising drainage and making the concentration of water created by the drainage process dangerous. To avoid this, a geosynthetic liner with an impermeable outer membrane will be laid next to and underneath the drainage pipe, so as to form a waterproof channel through which water can pass only in the direction of the pipe before being discharged into the sewer. Building this system over the 16,000 m2 of the Oppian Hill above the Domus has a high cost in terms of time and expenditure. We have thus opted for a compromise, implementing these drainage systems over about 20% of the surface. However, the system can be extended to complement the work already carried out without compromising its effectiveness.
Drainage far exceeding 20% of surface water can be achieved by adopting some expedients such as digging a dense network of small drainage channels about 7 metres long, with a slope of 1%, a depth of 20 cm and a very low side gradient of 1/3 (18°). These small channels, which will not hinder movements on the surface, will run into the main drainage system; where the two systems meet small drainage pipes will be placed crosswise in the main channel to facilitate the capture of the waters collected on the surface.
These expedients will allow us to capture more rainwater, especially during very heavy and prolonged rains.
We should also consider that when large quantities of water are not captured by these systems, soaking the soil and thus creating a suspended water table, when the latter comes into contact with the underneath of the geocomposite it will be drained away. In this case, the system behaves like a drainage ditch.
All these considerations allow us to estimate that over 50% of rainwater will be drained away, especially during heavy and prolonged rains, which represent the greatest danger.
Finally, we should stress that not using waterproof sheaths helps transpiration and prevents the soil rotting, since it remains naturally aerated as before the implementation of the system; the capillary fringe is not significantly affected.
The drainage system is subdivided into 14 drainage channels positioned so that progress in building the 22 drainage basins belonging to the Definitive Project does not compromise the effectiveness of the channels not directly affected by this work.
The quantity of water drained by each channel will be measured to evaluate the efficiency of the drainage system.
Work has already begun and is scheduled for completion by the end of this October.
- Press Kit for Conference on 18 June 2014
- Press Conference in the Octagonal Room
- Operations in the Pilot Worksite
- The Pilot Worksite
In September-November 2012, we carried out an archaeological sounding in the sector of the Oppian Hill park above the outer surface of Trajanic Galleries 20A and 20B. The study was aimed at understanding the external layout and construction features of the ancient vaults, with a view both to reconstructing the missing parts and to defining the new external protection system for the monument. Below we publish the preliminary results of the archaeological study.
- The test pits on the Colle Oppio
- Research on the lower storey of the Domus Aurea
- Topographical and archaeological recordings
- Interventions in the “Little Barracks” – Update November 2013
- The conservation of room 34
- An inspection of the great Cryptoporticus and Vasari’s account
- Coordinating health and safety in the Domus Aurea
It is of real importance for all those who, like us, are concerned for the Domus Aurea and its vegetation, respectively a unique and irreplaceable archaeological heritage and a magnificent natural heritage, to discuss the difficult relationship between these two features in the park on the Oppian Hill.
Recently the Domus Aurea has gained significant visibility with a series of public events at which it was present.
18 November saw the Domus Aurea Project Workshop, organized by us in collaboration with the German Archaeological Institute in Rome: large numbers of people participated in both the morning and the afternoon sessions.
During the morning session, presided by Prof. Fulvio Cairoli Giuliani, Fedora Filippi, Director of the monument, gave a paper on the overall rehabilitation project, an appraisal of 5 years of hard work. A brief survey of the monument’s institutional history highlighted the fact that on several occasions during the past century and the start of this century rehabilitation projects were begun, aimed particularly at resolving the problems of decay caused by the percolation of water from the park above, without ever succeeding in achieving this objective. This time, noted Fedora Filippi after outlining the data on the works and the choices made, we have a definitive project to replace the current park with an integrated protection system, to be completed in four years… the Domus can make it, it is surrounded by experts who have studied its behaviour and structural peculiarities in depth, developed a plan for intervention and a uniform methodology; this is an asset that must be preserved, enhanced and extended. If this work is not completed the benefits of the investments in consolidating the interior of the structure will soon be lost. The paper ended with the hope that this monument, that gave something of itself to the Italian Renaissance, will itself be reborn. We have a duty to give the Domus Aurea back the light it needs if it is to continue to produce cultural value (this, and no other, is its lofty mission), but above all to give it back the dignity of its historical authenticity.
Heinz Beste, an architect from the German Archaeological Institute in Rome who has collaborated with the project since 2006 with a research convention, discussed the graphic documentation, essential if work to rehabilitate the ancient architecture is to be carried out correctly. He demonstrated the recording techniques adopted, exploiting the new potential offered by instrumental recordings in parallel with traditional recordings based on the crucial direct observation of the structure. Over the past few years, we have worked hard to define correctly the topographical layout of both the interior and exterior of the monument, both in the known ancient levels and in relation to the current urban context. All these activities were necessary both to define individual consolidation projects inside the monument, on both its structures and the decorations on its surfaces, and to design the new Integrated Protection System. Naturally, a new and increasingly detailed understanding of the monument is of fundamental importance from a purely academic point of view as well. This demonstrates, once again, that processes of safeguard and conservation are inextricably linked to our understanding of ancient monuments and that both are connected to enhancement.
During the morning, we also presented a technical report on the Project for the Integrated Protection System and the New Sustainable Park.
Sandro Massa, responsible for the physical design process, illustrated the thermo-hygrometric study and the results of the various tests carried out. Vincenzo Angeloro dealt with the technological, hydrological and hydraulic problems of the System whilst Gabriella Strano illustrated the methodological, historical and landscaping choices governing the project for the new park: on the one hand it completes the Integrated Protection System and on the other restores public perception of the connections between the two ancient monuments, the Domus Aurea and the Baths of Trajan through its design.
During the afternoon, the workshop tackled the more general issue of the conservation problems of underground monuments. This discussion was of enormous interest, in part for the large amount of information shared and the experience brought to the table by the directors of monumental complexes dealing with the difficulties deriving from their underground condition and the presence of decorations.
Sandro Massa introduced the topic from a general methodological point of view with a series of examples and experiences, including negative ones, in funerary contexts in Italy, Egypt and the East.
Gisella Capponi, Director of the Istituto superiore per il restauro illustrated, on behalf of the group of specialists who participated, the conservation work on two rooms in the Domus Aurea, started in the 1980s to test the effects of hermetic closure from the outside.
Rita Volpe, Sovraintendenza Capitolina per i Beni Culturali, discussed the problems, very similar to those of the Domus Aurea, in the sector underneath the large exhedra in the Baths of Trajan where extremely important remains of decorated rooms have come to light with both frescoed surfaces and walls covered with mosaics.
Ida Sciortino presented the conservation work completed by SSBAR in the Underground Basilica at Porta Maggiore, an extraordinary complex with 1st-century stucco decorations, where serious problems caused by outdoor pollution, the presence of the railway and radon, a gas that develops in underground spaces and whose levels most be controlled, were resolved.
Barbara Mazzei, Pontifical Commission for Sacred Archaeology, gave an interesting general paper on the conservation problems of Christian catacombs and on the various solutions adopted, with special reference both to climate issues and the consolidation of the tufa rock into which the underground rooms were dug.
Marian Magnani Cianetti, SSBAR Architect, illustrated the rehabilitation and enhancement project for the Jewish catacombs at Villa Torlonia, with reference both to issues specific to consolidation and to the problems concerning the insertion of the complex inside a historic park.
Pietro Zander, Archaeologist at the Fabbrica di San Pietro in the Vatican, concluded with an interesting paper on the Vatican necropolis, focusing on the conservation problems of this extraordinary complex, located beneath various structural layers covering thousands of years that make up St Peter’s Basilica, one of the world’s most visited and frequented places.