Title of the article: Even today part of a roman aqueduct dating back to the 2nd century bc. supplies the city of Rome with water (our proposal to give it still a long life) by LAMANNA Luigi Franco (*)
Photo 01 - The great beauties of the eternal city
Premise It is my duty to make a premise. How does the old Roman aqueduct look like in Rome? He's really in a bad way. In fact, out of the 5,400 kilometers of pipelines present (of which 499 km, still in use, date back to ancient Rome), the dispersion on the territory of Rome is 44.1%, against a national average of 39%. This means that almost half of the water taken from the five aqueducts in the Lazio region is lost, the main one, the Peschiera-Capore, alone provides 70% of Rome's daily needs. Potenza (Italy) is at the top of the ranking of wasteful cities (68.8 %%) while Milan (Italy) is the most virtuous capital: here only 6.6% of drinking water leaks from the broken pipes of the aqueduct. In other words, that's 55 liters per person per day. In Naples (Italy) 35.7% is wasted, 54.6% in Palermo (Italy) and almost 60% in Cagliari (Italy). Things are not going well even in Trieste (Italy) 46.8%, Trento (Italy) 32.6% and Aosta (Italy) 24.5%.
Construction type of the aqueducts of ancient Rome An aqueduct is an infrastructure built to transport water from springs to an inhabited place. It is basically a conduit made in square work or in concrete and lined internally with “coccio pesto" to waterproof it; this conduit is always fully covered to protect the water it carries from external contamination (earth, animals); the internal cavity in which the water flows is called "speco". The "speco" had such dimensions as to allow the comfortable passage of a man, in order to allow the maintenance of the same by removing the limestone that over the years deposited on the walls over the years and the bottom.
Photos 02 - old Roman aqueduct
The Roman aqueduct conduit was built with a slight constant slope (about one meter of difference in height for each kilometer) in order to exploit the force of gravity to make the water flow free from the source to the place of distribution; therefore it was necessary that the springs were located at a higher sea level than that in which the water was withdrawn to be consumed; its path was rather tortuous as it had to follow the orography of the land in order to maintain the right altitude and speed for the flow of water and not to lose height as the higher the “Castello Terminale” (Terminal Castle) was, the greater the area served.
Speco underground Normally most of the route of all the aqueducts proceeded underground; if the galleries were dug directly into the "tufo" this was then simply covered with "signino" to make the walls waterproof; if the conduit proceeded where the ground was inconsistent, a square or reticulated wall or brickwork was built depending on the period with a double sloping or flat roof in the oldest (anio vecchio, appio) or vaulted roof.
Photo 03 - Path of the aqueduct of the Acqua Vergine – «Aqua Virgo» (still in operation) _____
Aqua Virgo (still today called: "New Virgin Aqueduct") The underground conduit of virgin water was built at the time of Agrippa in 19 BC. to feed the Baths of Agrippa and under Caligula it was also extended to supply the Campo Marzio; in De Aquis I.10 we read that the source is located at the 8th mile of the «Collatina» [near today's "Salone" inside the "Parco dell'Acqua Vergine"] in a
marshy spot, surrounded by concrete masonry Roman with the aim of confining the gushing waters and then conveying them into the conduit; this masonry still exists underground. Pliny places the spring two miles from the eighth mile of the Prenestina, on the left, which corresponds to the same place. This locality was called «Agro Lucullano» (Ager Lucullanus) and singularly the aqueduct ends at the "Horti Lucullani" in via Capo le Case, also owned by Lucullus. Today from the springs, in addition to the water that feeds the ancient Virgin, the drinking water of the "New Virgin Aqueduct" is taken into which part of the aqueduct of "Peschiera-Capore" and the nearby springs of
Photo 5 - Entrance of the inspection duct to the acqua vergine aqueduct in via del Nazareno
Photo 04 - The fountain in vicolo della Spada in Orlando
"Colle Mentuccia" converge.
"Frontino" writes that the path of the ancient Virgo water is 14,105 steps long, of which 12,865 are in the underground channel, 700 steps on arches and 540 on structures above ground; tributaries enter the duct whose length is 1,405 steps. "Lanciani" in the "Commentarii" reports that the 540 steps of structures above ground refer to the 4 short sections in which it emerges from the ground during the journey towards "Campo Marzio": • to "Bocca di Leone" locality situated where the "Collatina Antica" road intersects the "via Palmiro Togliatti" and where there are few spring veins; • on the final stretch of "via di Pietralata" where this runs along the "Aniene river", at the confluence of the "Marranella" ditch with the "Aniene river"; • on the eastern side of the "Marranella valley" where the aqueduct abruptly changes direction heading north; • in the valley between "via Salaria" and "via Nomentana" under the «Basilica of Santa Agnese». These references are better described in the "map of the Virgin" (photo 3) relating to the Renaissance period; the first two sections are clearly visible today, while the last two, I believe, are now both buried by the stratifications of the ground.
These references are better described in the "map of the Virgin" relating to the Renaissance period; the first two sections are clearly visible today, while the last two, I believe, are now both buried by the stratifications of the ground. The 700 steps on arches related to its final stretch. Underground it also proceeds at a depth of 30 meters reaching a maximum depth of over 40 meters near "Piazza Ungheria" and "Viale Romania" and during the 20 kilometers of its journey it suffers a difference in height of only 6 meters; it was on arches above ground only starting from the "Orti Luculliani" (near the intersection between "Via due Macelli" and "via Capo le Case") from which it reached "Campo Marzio" (to the Pantheon). The "Vergine" was provided with a total of "18 distribution castles" located in Regions IV, VII and XIV; the "Castello a S. Macuto" is the one of which we have more certain information, having found numerous inscriptions referring to Hadrian, Antonino Pio, the "Temple of Matidia", Narcisso, Traiano, Cecilio Capitone; an enormous "hiatus" was also found which, through a long siphon, fed the "Terme di Agrippa" located just behind the "Pantheon". It should be noted that even today this aqueduct, despite some water leaks along its path, has been in operation for over two thousand years and there is no intention of making it stop.
Aqueduct name
Year built
Length
Original daily flow rate “Quinarie
Original daily flow in m3
Definitive daily flow in “Quinarie”
Definitive daily flow in m3
Liters for second
Anio Novus
38 d.C.
87 km
4738 q.
196627 m³
4738 q.
196627 m³
2274
Anio Vetus
270 a.C.
63,5 km
4398 q.
182517 m³
4398 q.
182517 m³
2111
Aqua Alexandrina
226 d.C.
22 km
521 q.
21632 m³
521 q.
21632 m³
250
Aqua Alsietina
2 a.C.
33 km
392 q.
16257 m³
392 q.
16257 m³
188
Aqua Appia
312 a.C.
16,5 km
841 q.
34000 m³
1825 q.
75737 m³
876
Aqua Claudia
38 d.C.
68 km
4607 q.
191190 m³
4607 q.
191190 m³
2211
Aqua Iulia
33 a.C.
23 km
1206 q.
50043 m³
1651 q.
68516 m³
792,5
Aqua Marcia
144 a.C.
91 km
4690 q.
194365 m³
4339 q.
180068 m³
2083
Aqua Tepula
125 a.C.
18 km
190 q.
7885 m³
1651 q.
68516 m³
792,5
Aqua Traiana
109 d.C.
57 km
2848 q.
118200 m³
2848 q.
118000 m³
1367
Aqua Virgo
19 a.C.
20 km
2504 q.
103916 m³
2504 q.
103916 m³
1202
Table 01 - Summary table of the aqueducts of ancient Rome
Even today the Acqua Vergine aqueduct (AQUA VIRGO) feeds large and small fountains between the Trevi, Colonna and Campo Marzio districts: the Trevi fountain and the Barcaccia fountain in Piazza di Spagna (with
the supply pipes that give the name in via dei Condotti), the fountain of the Four Rivers in Piazza Navona, but also the fountain in vicolo della Spada in Orlando.
BELOW A TYPICAL EXAMPLE OF REPAIR AND CONSOLIDATION OF A HYDRAULIC TUNNEL WITHOUT OBSTRUCTING THE FLOW OF DRINKING WATER OBJECT OF THIS POST. [ The waterproofing and consolidation resin is certified for use in the presence of water for human use ]
Step 1)
Step 4)
State of fact.
Injection and consolidation of the subsurface (2st
Loss of water to the subsurface
filling)
Step 2)
Step 5)
Drilling
Preparation for the consolidation of the wall structure. All this can be done without locking the
Step 3)
flow of water (in this case potable water)
Injection and consolidation of the subsurface (1st filling)
Step 6) Consolidation of the wall structure. Injection “RESIN”
PU-8402-Foam
Silex-330-Foam
This type of products have blowing properties (e.g. SILEX-330-FOAM (1), PU-8408-FOAM (2), PU-8408-FRFOAM (3), PU-8402-FOAM (4), while others they only form compact masses (eg. SILEX-304-STONE (5) ). Others react only in the presence of water (eg. PU-8402-FOAM), while still others react both in the presence of water, expanding up to 20 - 40 times the initial volume (free expansion), and both in the absence of the same, forming compact masses (eg PU-8408-FOAM, PU8408-FR-FOAM), still others are totally insensitive to the presence, or not, of water that react the same (e.g. SILEX-330-FOAM, SILEX-304-STONE):
1). - SILEX-330-FOAM - resin for filling voids (stoves) and cavities in advance, with high foam expansion capacity up to 40 times, used for the consolidation of sandy / gravelly soils and fractured rocks. It can also be used in the presence of water 2). - PU-8408-FOAM - two-component polyurethane resin with high expansion capacity, up to 25 times, for filling voids and cavities, consolidation of sandy / gravelly soils and fractured or loose rocks even in the presence of large 'water. The product in the presence or absence of water reacts in any case, giving rise to a hard and compact resin. 3). - PU-8408-FR-FOAM - two-component polyurethane resin with high expansion capacity, up to 25 times, for filling voids and cavities, consolidation of sandy / gravelly soils and fractured or loose rocks even in the presence of large coming of water. The product in the presence or absence of water reacts in any case, giving rise to a hard and compact resin. Non flammable product. 4). - PU-8402-FOAM - single-component polyurethane resin indicated for the consolidation, waterproofing and filling of voids clogged by large flows of water. Reacts (swells) only in the presence of water. 5). - SILEX-304-STONE - non-expansive, consolidating and waterproofing resin with a mechanical support effect, strong water and gas resistance. Able to restore the monolithic nature of rock layers and repair cracked concrete. For applications where structural strength and great flexibility are required. All the formulations indicated above are characterized by a low reaction exotherm that allows their use even in dangerous areas (a typical example is coal mines and large underground cavities in the presence of large quantities of water, also drinkable because this type of foams do not pollute). The wide range of formulations, in particular those non-polluting and based on polyurethane resins, allows the structural consolidation of most of the soils, but the use of one or other product must be evaluated directly on site by the geologist, according to the geological characteristics. - morphological ones that meet. I remember that the term polyurethane is very generic and does not reflect the technical changes that have taken place in the last 30/40 years. In fact, for many people polyurethane resin (PU or PUR) is considered a liquid that foams and in some cases blocks water leaks. This statement is simplistic, as it does not reveal some of the key properties of a water reactive resin. Isocyanate polyurethanes (aromatic or aliphatic) are polyols. To fill a void and prevent the ingress of water, the following properties are required: - 1) - expansion of the material in contact with water; - 2) - formation of a dense and stable foam; - 3) - no shrinkage after foam formation; - 4) - have a closed cell structure to prevent water permeation. Achieving all these properties with a one-component water-reactive resin is impossible under any conditions. The density of the foam will depend on the amount of water and the reaction time. Furthermore, the expansion will vary according to the specific environmental conditions of each project. ….oo0oo…. (*) Luigi Franco, LAMANNA INDEPENDENT TECHNICAL CONSULTANT Consultant Specialized in Mechanized Tunnelling with Hard Rock TBM and Soft Soil EPB Shields. Expert and Consultant in structural reinforcement of concrete and / or masonry structures, tunneling, mining and engineering.