Rome+Line+C

By: Steven Tuttle =Introduction=

toc An effective and efficient transportation system is critical to facilitating commerce in an urban environment. A major building block of this system is a high-quality public transportation system that serves citizens reliably and frequently. Additionally, multiple studies have found access to transportation to be the single largest contributor to escaping poverty (Bouchard, 2015). This is because good public transportation allows those in poverty to travel to locations with better economic opportunity than their current location. There is simply not enough space in a Rome, especially the dense historic district, for everyone to drive their personal vehicles. There have been attempts to remedy this challenge by implementing a Zona Traffico Limitato (Limited Traffic Zone) around 20 years ago which charges or prohibits certain vehicles from entering highly congested areas. This has forced citizens onto public transportation which mainly relies on busses and a severely lacking subway system. Unfortunately, these busses are extremely unreliable as they have an insufficient amount of dedicated right of way and no schedule to follow. Based on personal experience the bus system in Rome is terrible with multiple experiences waiting more than half an hour only for the bus to never arrive or be so full they cannot be boarded. The subway system in Rome is reliable since it is fully grade separated but prior to November 2014 only consisted of 2 lines (Wikipedia, n.d.). Additionally, the subway system has a gaping hole in it as it does not serve the historic dense downtown core where tourists would likely use it. For this reason, Line C was designed to both expand the reach of the system while creating more connections between the lines while also serving the dense and high ridership area in the city center. This project looked great in the planning stages but upon construction, archeological discoveries have proved to be a nightmare for keeping the project on schedule and on budget.

=Existing System Prior to Line C=

Before line C was opened in 2014 there were only 2 metro lines in Rome which made an X across the city with the midpoint being Termini Station. Lines B and A were opened in 1955 and 1980 respectively and while there have been moderate extensions since then, they still do not serve entire neighborhoods of the city (Wikipedia, n.d.). These two lines only totaled a measly 25.82 miles meaning Rome had a metro line with a length similar in length to Sofia, Bulgaria but has around three times the population. By another comparison, Paris has about the same population as Rome (2.5 million vs 2.8 million) but its subway system is 133 miles long making Rome’s system look depressing.





Line B
Construction on Line B began shortly after World War II in 1948 and allowed the area originally reserved for the Universal Exposition to be redeveloped into a commercial district Esposizione Universale Roma (EUR) (Wikipedia, Linea B). This line only went from Termini to Laurentenia while serving the EUR at its southern terminus. The project was completed at a time with less on a focus on archeological discoveries and more on getting the project done as quickly as possible (Morabito, 2017). This can also be exemplified by the picture below of the Colosseum station being built directly next to the monument. Even today if you pay close attention you can feel the metro passing under your feet which is likely not the best for the longevity of the Colosseum. This line carries an impressive 345,000 people every day even though it is only about 11.5 miles long (ATAC, 2013). There are currently studies for extensions to the split which occurs to extend it further into the suburbs however this has been overshadowed by the Line C problems and delays (La Repubblica, 2012). Another interesting observation about Line B, which improves its connectivity to the rest of the is that it interlines with the Roma Lido Urban Railway at 3 of its stops ( Piramde, Baslica S. Paolo, and EUR Magliana). This not only improves the ability to transfer between them, but also the Roma Lido Line uses the same trainsets as Line B allowing for the cars to be used interchangeably and a single maintenance base to be used. 

Line A
Line A is the second metro line in Rome but is called A for seemingly unknown and arbitrary reasons. This line runs from Batitstini to Anaginina and the original section from Ottaviano to Anaginia was opened in 1980. This was the extent of this line until the second phase of construction was completed in 2000 which extended line A northwest to its current terminus in Batitstini. The construction of this line was more closely watched by archeologists and the city as to the artifacts discovered during excavation. The result of this was increased conflicts with the preservation office and engineers and which necessitated changes of the project scope (Morabito, 2017). The problems became so bad that workers would actively destroy or cover archeological discoveries in order to prevent the project from being delayed further (Morabito, 2017). This line carries the most passengers of the two metro lines with an estimated 450,000 boardings per day on only an 11.5-mile line (Chiusolo et al, 2013). This means these cars are generally packed which is why it runs every 2 minutes 45 seconds during peak and every 4 minutes off peak for an impressive 617 trips per day (Chiusolo et al, 2013). This crowding has been the catalyst for studies to automate the line similar to Line C to decrease dwell and reverse times in order to improve efficiency (Chiusolo et al, 2013).

=Line C=

Line C has been planned and discussed In Rome since 1994 with a planned completion in 2000 but due to a variety of funding, archeological and engineering challenges, construction on this line did not begin until 2007 (Squires, 2014). This line was made to not only connect the eastern suburbs to central Rome but more importantly to serve, in close proximity, the Centro Storico or Old Town including tourist attractions such as Campo di Fiori, the Pantheon, and Piazza Veniza. The current estimated cost of the project is €3.5 billion which is near twice the €2.0 billion which was originally budgeted (Squires, 2014). Upon this project’s completion, it will have the capacity to transport a staggering 24,000 people per hour with 1,200 people per train and 3-minute headways (Daniele, 2017). This capacity will be the largest in Europe and which is about twice the most optimistic capacity for Sound Transit’s Link Light Rail (Sorge, Moretti & Tripoli, 2012).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">

=Subway Tunnel Construction=

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Subway tunnel construction is a routine civil engineering activity with thousands of miles excavated with similar methods and tunnel boring machines (TBM). Rome’s Line C has required special attention to ensure <range type="comment" id="618922993_4">minimal ground settling as ancient monuments are present above tunnel route</range id="618922993_4">. There were four of these TBM’s used for the and the nearly complete section from San Giovanni to Pantano which includes more than 14 kilometers of tunnels. Two of the machines will continue the project and be launched from the San Giovanni work site in early 2018 while the other two were sent to Millan where they will work on another metro tunneling project (Danielle, 2017). The TBMs used for this project were Earth Pressure Balance Shield (EPB) type produced by Herrenknecht (Daniele, 2017). This type of machine was used because it turns the excavated material into a soil paste which is used as the support, making it possible to balance the pressure conditions at the tunnel face and avoiding uncontrolled inflow of soil into the machine, creating the conditions for rapid tunneling with minimum settlement (Herrenknecht, n.d.). As the TBM moves forward, the soil paste is removed through a screw conveyor whose rate must be finely adjusted. This ensures the support pressure from the TBM is exactly the same as the earth and water pressure on pushing in the opposite direction (Herrenknecht, n.d.). The minimal ground settling is critical to the success of the project because if monuments had any chance of being damaged, work would not be allowed to continue. The rapid tunneling has been particularly beneficial to this project with an impressive 30 meters of the tunnel built in one day (Daniele, 2017). <range type="comment" id="618922993_5">Two other ways the project has limited and monitored the amount of ground settling is through a two-component backfill grout along with an extensive remote monitoring network.</range id="618922993_5">

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">



Two-Component Backfill Grouting
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Tunnel boring machines have specific routines as they move forward along their route. First the machine pushes off the ring previously laid approximately 1 meter where it will stop (Herrenknecht, n.d.). Precast concrete pieces, which in the case of Line C are produced very close to Rome, are then aligned with the walls and set in place (Daniele, 2017). There are six pieces which are put around the diameter along with one smaller piece called the “key” which is about 1/3 size and comes in 19 different geometries to follow the shape direction of the tunnel (Daniele, 2017). The unique technology used in this step of the tunnel is the grout used to secure the concrete rings. This method of backfill grout was first used in Singapore around 10 years ago, for a similar project and has received almost exclusively positive reactions since then (Pelizza, Peila, Sorge & Cignitti, 2012). The most common and traditional backfill system used in Europe has been a cementitious grout (Negro et al, 2010). The new system’s first component is “a super-fluid grout, comprising cement, water, and bentonite with a retarding agent to guarantee workability and ability to pump over a long distance and periods” (Negro et al, 2010). The second part is an accelerator mixture which is added right before injection to get immediate <range type="comment" id="618922993_6">jellification </range id="618922993_6">of the mixture (Negro et al, 2010). These components must also be stored nearby the TBM and transported to the front of the cutting head. As shown in Figure 5, the two mixtures were stored in silos on the worksite until they were needed. Specifically, with Line C, different methods of transporting the grout<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> were used on depending on the tunnel section, using a mortar car and pumping directly to the TBM (Negro et al, 2010). The most important benefit of this method is the complete filling of the voids between the existing soil and concrete rings or annulus which results in decreased settling (Pelizza et al, 2012). Another benefit of this system is the quick development of mechanical strength once injected meaning it will not be compressed once it is injected (Pelizza et al, 2012). The two-component mixture resulted in no clogged pipes for the extent of the initial tunneling, a large challenge with the traditional cementitious grout which leads to construction delays and costs due to lost working time (Peila et al, 2011). Finally, the raw materials used for this method of grouting, including cement, bentonite, retardants, and accelerants are industrialized meaning their origin can easily be controlled (Negro et al, 2010).

** Remote Monitoring **

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Due to the various archeological sites present both above the tunnel route and near the construction sites, a complex remote monitoring system was put in place for this project. This system consists of over 20,000 instruments including strain gauges, inclinometers, robotized total station, and load cells (Sorge, Moretti & Tripoli, 2012). This is in place for several reasons, most importantly “verifying the compliance between the actual behavior of the land, facilities, and environment and what was expected” (Sorge et al, 2012). The system is also used to ensure the safety of the buildings and citizens while construction is being completed. At sites of specific and higher historic significance, the monitoring system is used to keep a long record of the natural movement and behavior of the building (Daniele, 2017). For example, at Piazza Venezia, where construction has not even begun for the station nor tunnel, there have been monitoring sites in place since 2009 (Sorge et al, 2012). This means there will be extensive data about what kinds of movement are experienced, both before and during construction, in case there was to be a deterioration of the monument. Citizens and municipalities are n<range type="comment" id="618922993_7">aturally leery of Tunnel Boring Machines</range id="618922993_7"> so might be quick to blame and potentially file lawsuits if cracks or other irregularities to form. The monitoring means that Metro C S.p.c.A can prove it is not responsible for the damage. Especially since they know a bus rumbling by Piazza Veniza will cause much more damage and movement than a tunnel boring machine 30 meters below the ground (Danielle, 2017).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">

Archeological Preservation
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">The main challenge with Line C construction is not the tunneling itself, as that is done at 18-30 meters, well below archeological layers, but the stations, launch, and ventilation shafts. With Rome being inhabited continuously since 753 B.C it is not surprising that excavations lead to the discovery of previously unknown structures. Depending on how historically significant and extensive the structures are, they can either be excavated and moved or the entire station may need to be scrapped. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">An example of large and significant ruins is present at Largo di Torre Argentina. This location sits on the original Pompey’s theater where Julis Caesar was killed meaning it is of extreme cultural significance. During the initial Line C plan, a station was planned here but had to be scrapped after ruins of the theater were found to be much more extensive than originally anticipated (Adraino, 2017). <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">A location where archeological finds could be worked around is a ventilation shaft in between the future Amba Aradam and Fori Imperiali Stations. Here, an ancient aqueduct was located right in the center of the shaft which would be impossible to locate prior to excavation with carrot samples (Adriano, 2017). Aqueduct discoveries are relatively common since there are several hundred miles of them and we were even able to crawl through one as part of this project. For this reason, the Metro C S.c.p.A was able to remove this obstacle with careful documentation for future reconstruction if the city decides to (Adriano, 2017). <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Above ground monuments which are particularly sensitive to small ground shaking have also been reinforced to ensure there are no unexpected damages. This occurred in segment T3 shown in figure X after monument interaction studies showed it would be necessary to reinforce these monuments prior to construction (Metro C S.c.p.A, 2017). These reinforcements range from temporary shoring to compensation grouting or permanent shoring. These actions are forward thinking because the project is financing improvements to the monuments not only to the bare minimum for construction to be completed but for the increased resilience of the structures in the future. =Line Currently In Service= <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">The first section of line to open on November 9, 2014, was the section from the eastern terminus in Monte Compatri/Pantano to Parco di Centrocelle. This section includes a tunneled portion as well as 11 above ground stations which made use of the existing Rome-Pantano Railway and simply upgraded the stations to subway standards (Sorge, Moretti & Tripoli, 2012). This line was of relatively little use to most residents and completely useless to tourists as it only barely gets you inside the Grande Raccordo Anulare (GRA) which encompasses Rome’s city limits. I believe this section was opened to have something to show after countless years of delays. It seemed to be a publicity deal with a grand opening celebration rather than to open a fully functioning line. This was further exemplified by the line opening to chaos with the trains stopping short of their destination and doors getting stuck with dignitaries including the mayor of Rome onboard (Squires, 2014).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">A further section of underground line opened less than a year later which extends it to its current western terminus of Lodi. This makes the line somewhat more useful but since it does not connect to the rest of the metro system, still has very low ridership. The daily ridership of the entire line is only 50,000 which pales in comparison to either of the other lines (Corriere Della Sera, 2015). This makes sense as it travels well outside the city limits too<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> much less dense areas but is also the product of a bus transfer being required to the urban center or other lines. I traveled on this line during rush hour times on a weekday and found many open seats even with the open gangway cars used which have few seats, to begin with. By the end of the line, there were around ten people on the entire train with the parking areas built at the stations being 90% empty. The line also only runs with 12-minute headways even at peak times showing that there is not very high demand on this line without a connection to the rest of the system.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">An interesting factor about these recently opened stations is that at the Teano station, the tunnels are stacked rather than side by side. Per Ricci Daniele, one of the Metro C S.c.p.A supervisors, that configuration is to allow future branches of the line to easily be built (2017). There is an identical station configuration at the Bologna station where the B line splits into the B1 and B2 lines (Daniele, 2017). No branches of line C are planned but it is exciting that this project was designed to allow for easy growth of the system for the future rather than just preparing for current demands.

=Future Stations Under Construction=

San Giovanni
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">This is easily the most important station to be completed on this project as it provides a direct link to Line A and the entirety of the metro, train, and bus network. The reason this station has taken so long to become operational is also because has the greatest engineering challenges because it goes right under line A. This has required the use of innovative techniques like ground freezing to permit the tunneling operation go on along with uninterrupted operation of Line A. The freezing allows for waterproofing along with stabilizing the ground without any negative environmental effects as the coolant is completely contained in pipes directly next to the tunneling site (Metro C S.p.c.A, 2017). The ground is frozen over 16 days with the liquid nitrogen mixture injected into the pipes shown in figure X (Rotndi & Sorge, n.d.). The tunnels can then be excavated with a temporary shotcrete coating for increased stabilization of the ground. This was done with minimal disruption to line A, although there was a one-month closure during August 2017, replaced by a bus bridge, while I was here to complete the integration of the two lines.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Another reason this station is particularly interesting is it is one of two museum stations being built as part of this line, the other being Amba Aradam. There were more than 40,000 artifacts found during construction of the line and the most interesting are displayed in the museum (Squires, 2017). The artifacts increase in age as passengers descend into the station which provides an immersive experience and shows this project while hindered by archeological discoveries, wants to share the history with the public.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Upon this writing the general public was told this station would be opened in Fall 2017 around October but based on the history of keeping deadlines, that seems unlikely. Additionally, on our tour, the guide hinted that it would be open in early 2018 (Daniele, 2017). Whenever it opens, this station will be an important block in completing a comprehensive metro system for the city of Rome.



<span style="font-family: Arial,Helvetica,sans-serif;">Amba Aradam
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">This is the next station after San Giovanni and has also been wrought with challenges from archeological discoveries. Here, barracks from the first half of the second century AD built under Emperor Hadrian were discovered about 9 meters or 30 feet beneath the surface (Squires, 2016). This caused a delay of 10 to 12 months per Andrea Sciott<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> the manager for Metro C in the Capitol building. This station is said to continue its construction even with this discovery and they hope to incorporate the discoveries into the museum which will also be housed in the station (Squires, 2016).

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">The tunnel from San Giovanni has interesting characteristics with regards to how it is being constructed. Approximately 200 meters west of the San Giovanni station a 30-meter-deep shaft was built to relaunch the TBMs and for a ventilation shaft upon completion (Daniele, 2017). Those 200 meters were excavated<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> without a TBM by a different method called micro-tunneling. Here excavation has been completed, by hand or with small machines, on a 3-meter<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> diameter tunnel (the full diameter needed is 6.7 meters). With this smaller tunnel<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">, there can be mixtures injected into the soil to produce improved permeability and condition of the ground surrounding it (Daniele, 2017). After this, the tunnel will soon be destroyed and enlarged to the proper final size. While this sounds unconventional, it works best in this situation since the distance being tunneled is so short (Daniele, 2017). Logistically it was not reasonable to reposition a 200-meter<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> long machine to tunnel such a short distance meaning that time could be saved if both the short and longer tunnels were constructed simultaneously.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"><range type="comment" id="618922993_8">A fact I found fascinating about this construction project was that cross passages are not built between the tunnels for evacuation purposes. Twelve ventilation shafts were used in the current<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;"> operational section to Lodi and two more are being built from San Giovanni to Fiori Imperiali (Rotndi & Sorge, n.d.). These, along with the stations are the emergency evacuation routes which is much different than construction in the United States. This is because Italian building codes are very stringent and concerned about the spread of fires with the use of cross passages (Daniele, 2017). By comparison, the Northgate Link Light Rail project in Seattle was required to build many of these connectors for access between the tunnels (Sound Transit, n.d.)</range id="618922993_8">. <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 1.3em;">**Fiori Imperiali/Colosseo**
<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">This station, under construction and expected to open with the 3km section from (but not including) San Giovanni Station. It will be another critical station as it provides direct connections to Line B and will bring the number of transfer stations from one with the current system to three. This location faces similar challenges as at San Giovanni because it passes under another line whose service cannot be interrupted. This station was originally planned to be a museum station but due to cost overruns on the rest of the line that was canceled. Instead of a museum, there will be a large glass window installed to allow the public to see ruins of barracks located next to the station (Wikipedia, n.d.). <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">This section of line is still quite far from opening with expected completion dates ranging from 2020 to 2022 with Metro C S.p.c.A saying 2021. Personally, I am skeptical of this estimation since tunneling has not even begun from San Giovanni. Northgate Link had tunneling completed in 2016 and yet the line will still not be operational until 2021 so I find it hard to believe this segment will open by then. =<span style="font-family: Arial,Helvetica,sans-serif;">Future Planned Stations = <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">Piazza Venezia is the only other station currently funded for construction thanks to $300 million in funding from the Italian government for infrastructure projects (Wanted in Rome, 2014). Only station design has been completed with construction still not scheduled to begin. This is due to a 900 seat arts center built by Emperor Hadrian being discovered during preliminary excavations (Kington, 2012). This discovery has been hailed as one of the biggest discoveries since the discovery of the Roman Forum according to archaeologists working the site (Kington, 2012). This places serious doubts upon whether the station will move forward which is difficult to hear considering this station would bring metro service much further into the Centro Storico. Metro C S.c.p.A has assured the public that this station will still be completed and have released plans with rough station drawings to coexist with the ruins (Metro C S.c.p.A, 2017). <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">After Piazza Veniza there was originally planned a station at Largo di Torre Argentina but was canceled due to extensive archeological remains. It is unfortunate that this station had to be canceled since it would provide direct access, within five minutes walking, to Campo di Fiori. This leaves a one-kilometer gap between stations through the densest part of the city where close station spacing improves walkability and increases ridership. Unfortunately, this gap may be increased due to problems currently being faced at the next station, Chuisa Navona.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">This station is not only unfunded at this time but also has the very likely possibility of being canceled altogether. This is due to the extensive historical buildings surrounding the planned construction site which may be impossible to work around (Morabito, 2017). There is a current talk of canceling that station and using the savings to improve the rest of the line, such as ensuring remaining stations are built (Morabito, 2017). A lack of station here would defeat the whole purpose of Linea C as it would either tremendously underserve Centro Storico or not serve it at all, failing to solve the problem it was built for. The San Pietro station is next on the line but unlike the others will almost certainly be built. Preliminary examinations have shown the site suitable for construction and it will provide a crucial link to areas across the Tiber River and near Vatican City. There are plans for another connection to Line A at Ottaviano and one additional station to the north. This section after Fiori Imperiali is part of section T2 of the project and will begin more extensive designs and construction as the three stations currently under construction near completion (Daniele, 2017). This is because Metro C S.c.p.A opens smaller sections of the line while working on future extensions to improve project deliveries to the public (Daniele, 2017).

= Integration Into Transportation Network and Personal Outlook = <span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">During my time in Rome, I was able to ride Linea C from beginning to end. I marveled at how high quality the metro line was, being fully automated, grade-separated, and with high capacity. This is what Rome desperately needs more of rather than buses and trams which run in mixed traffic or partial grade separation. Upon connection to San Giovanni, the network will become so much more efficient, useful, and reliable since more transfer points allow for faster travel throughout the city.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">As these stations come online, ATAC, the operator of the bus and tram network can restructure its lines to provide frequent service to a larger portion of the city’s population. A great example of this is when University Link Light Rail was put into service. Upon that line’s inauguration, King County Metro was able to do a complete system restructure to avoid redundancies and reinvest service hours into surrounding neighborhoods all while creating robust transfer opportunities at the stations. It is my hope that a process similar to this will occur in Rome to improve the public transportation system by taking advantage of new metro service.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 12pt;">With regards to the construction of Line C, I think it is one of the most important infrastructure projects to be completed and think it is unfortunate that so many delays have occurred due to archeological discoveries. While I understand the deep cultural and historical significance of these monuments I also think it is important to construct infrastructure which will increase the quality of life for citizens. I am hopeful that all of the currently planned stations will be completed and can coexist with existing sites. A great example working with archeological discoveries is at Amba Aradam where they are taking the site and incorporating it into the station. Unless Rome is able to keep this precedent of working with ancient ruins rather than around, they will continue to be stuck in the past and be swallowed by traffic and other disasters in the future.

=References=

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Bouchard, M., (7 May 2015). Transportation Emerges as Crucial to Escaping Poverty. Retrieved September 29, 2017, from [|https://www.nytimes.com/2015/05/07/upshot/transportation-emerges-as-crucial-to-escaping-poverty.html? mcubz=0] <span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Buselli, F., Logarzo, A. & Miliziano, S., 2010. Class A prediction of the effects induced by the Metro C construction on a preexisting building, in Rome. , pp.767–772.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Corriere Della Sera. (11 November 2015). Metro C runs one year: 326 races per day and 50,000 passengers. Retrieved September 17, 2017, from [|http://roma.corriere.it/notizie/cronaca/15_novembre_11/metro-c-compie-anno-326- corse-giorno-50mila-passeggeri-999a0f74-886f-11e5-a995-c9048b83b4c2.shtml]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">D’Albergo L., (5 August 2016). Metro C Roma, sledging<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> again by 2022 the delivery of Amba Aradam and Fori stations. Retrieved September 17, 2017, from [|http://roma.repubblica.it/cronaca/2016/08/05/news/metro_c_roma_slitta_ancora_al_2022_la_consegna_delle_stazioni_amba_aradan_e_fori-145433183/?refresh_ce#gallery-slider=139911817]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Daniele, R., (13 September 2017) Metro Line C Tour at San Giovanni TBM Launch Pit. Oral Presentation and Tour

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Herrenknecht. (n.d.). EPB Shield. Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Kington, T., (26 December 2012). Hadrian's hall: archaeologists finish excavation of Roman arts centre. Retrieved September 17, 2017, from [|https://www.theguardian.com/world/2012/dec/26/hadrians-hall-roman-emperor-arts- centre]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">La Repubblica Roma. (18 February 2012). Metro B1, ok to the Ionian-Bufalotta section the councilor: "Call for tender in 3-4 months". Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Morabito, A., “Underground Rome.” University of Washington Rome Center. Rome. 8 September<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> 2017. Powerpoint Presentation.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Peila, D., Borio, L. & Pelizza, S., 2011. THE BEHAVIOUR OF A TWO-COMPONENT BACKFILLING GROUT USED IN A TUNNEL-BORING MACHINE.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Romani, E. & Miniero<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">, N., 2013. Construction of the Line C San Giovanni station in Rome. Taylor & Francis Group, (Geotechnical Engineering<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> for the Preservation of Monuments and Historic Sites), pp.627–632.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Rotundi, F.M. et al., Rome Metro Line C under Historical Centre 3 Colosseo / Fori Imperiali Station. , pp.1–17.

Sisego<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">. (n.d.). Rome Underground-Line C-Italy. Retrieved September 17, 2017, from [|https://www.sisgeo.com/projects/tunnels-and-underground-works/item/rome- underground-line-c.html]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Sorge, R., 2012. Line C in Rome:<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> Remote monitoring system. Taylor & Francis Group, ( Geotechnical<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> Aspects of Underground<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> Construction in Soft Ground), pp.309–317.

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Squires N., (10 November<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> 2015) Rome’s New Metro Opens to Chaos. Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Squires, N., (17 May 2016). Human skeletons and 2,000-year-old barracks found during construction of metro<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> line in Rome. Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Squires, N., (5 May 2017). Rome unveils 'museum' metro station packed with hundreds of ancient artifacts<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;"> found during construction. Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Sound Transit. (n.d.). Cross Passages and Tunnels. Retrieved September 17, 2017, from [|https://www.soundtransit.org/Projects-and-Plans/Northgate-Link- Extension/Location-and-stations-Northgate/cross-passages-tunnels]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">The Colosseum. (n.d.). Chronology. Retrieved September 17, 2017, from []

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Wanted in Rome. (18 September 2014). Decision time for Rome’s Metro C. Retrieved September 17, 2017, from [|http://www.wantedinrome.com/news/decision-time-for- romes-metro-c.html]

<span style="font-family: Arial,Helvetica,sans-serif; font-size: 10pt;">Wikipedia. (n.d.). Transport in Rome. Retrieved September 17, 2017, from [] <span style="display: block; height: 1px; left: 0px; overflow: hidden; position: absolute; top: 5581.5px; width: 1px;"> Bouchard, M., (7 May 2015). Transportation Emerges as Crucial to Escaping Poverty. Retrieved September 29, 2017, from [|https://www.nytimes.com/2015/05/07/upshot/transportation-emerges-as-crucial-to- escaping-poverty.html?mcubz=0]

<span style="font-family: Calibri,sans-serif; margin: 0in;">Buselli, F., Logarzo, A. & Miliziano, S., 2010. Class A prediction of the effects induced by the Metro C construction on a preexisting building, in Rome. , pp.767–772. Corriere Della Sera. (11 November 2015). Metro C runs one year: 326 races per day and 50,000 passengers. Retrieved September 17, 2017, from [|http://roma.corriere.it/notizie/cronaca/15_novembre_11/metro-c-compie-anno-326- corse-giorno-50mila-passeggeri-999a0f74-886f-11e5-a995-c9048b83b4c2.shtml] D’Albergo L., (5 August 2016). Metro C Roma, sledging again by 2022 the delivery of Amba Aradam and Fori stations. Retrieved September 17, 2017, from [|http://roma.repubblica.it/cronaca/2016/08/05/news/metro_c_roma_slitta_ancora_al_ 2022_la_consegna_delle_stazioni_amba_aradan_e_fori- 145433183/?refresh_ce#gallery-slider=139911817] Daniele, R., (13 September 2017) Metro Line C Tour at San Giovanni TBM Launch Pit. Oral Presentation and Tour Herrenknecht. (n.d.). EPB Shield. Retrieved September 17, 2017, from [] Kington, T., (26 December 2012). Hadrian's hall: archaeologists finish excavation of Roman arts centre. Retrieived September 17, 2017, from [|https://www.theguardian.com/world/2012/dec/26/hadrians-hall-roman-emperor-arts- centre] La Repubblica Roma. (18 February 2012). Metro B1, ok to the Ionian-Bufalotta section the councilor: "Call for tender in 3-4 months". Retrieved September 17, 2017, from [|http://roma.repubblica.it/cronaca/2012/02/18/news/metro_b1_ok_a_tratta_ionio- bufalotta_aurigemma_bando_entro_3-4_mesi-30097090/] Morabito, A., “Underground Rome.” University of Washington Rome Center. Rome. 8 Septermber 2017. Powerpoint Presentation. <span style="font-family: Calibri,sans-serif; margin: 0in;">Peila, D., Borio, L. & Pelizza, S., 2011. THE BEHAVIOUR OF A TWO-COMPONENT BACKFILLING GROUT USED IN A TUNNEL-BORING MACHINE. <span style="font-family: Calibri,sans-serif; margin: 0in 0in 0.0001pt;">Romani, E. & Miniero, N., 2013. Construction of the Line C San Giovanni station in Rome. Taylor & Francis Group, (Geotechnical Enineeering for the Preservation of Monuments and Historic Sites), pp.627–632. Rotundi, F.M. et al., Rome Metro Line C under Historical Centre 3 Colosseo / Fori Imperiali Station. , pp.1–17. Sisego. (n.d.). Rome Underground-Line C-Italy. Retrieved September 17, 2017, from [|https://www.sisgeo.com/projects/tunnels-and-underground-works/item/rome- underground-line-c.html] <span style="font-family: Calibri,sans-serif; margin: 0in;">Sorge, R., 2012. Line C in Rome : Remote monitoring system. Taylor & Francis Group, (Geotechnucal Aspects of Undergroun Construction in Soft Ground), pp.309–317. <span style="font-family: Calibri,sans-serif; margin: 0in 0in 0.0001pt;">Squires N., (10 Novemver 2015) Rome’s New Metro Opens to Chaos. Retrieved September 17, 2017, from [|http://www.telegraph.co.uk/news/worldnews/europe/italy/11221379/Romes- new-metro-opens-to-chaos.html] Squires, N., (17 May 2016). Human skeletons and 2,000-year-old barracks found during construction of metro line in Rome. Retrieved September 17, 2017, from [|http://www.telegraph.co.uk/news/2016/05/17/human-skeletons-and-2000-year-old- barracks-found-during-construc/] Squires, N., (5 May 2017). Rome unveils 'museum' metro station packed with hundreds of ancient artefacts found during construction. Retrieved September 17, 2017, from [|http://www.telegraph.co.uk/news/2017/05/05/rome-unveils-museum-metro-station- packed-hundreds-ancient-artifacts/] <span style="font-family: Calibri,sans-serif; margin: 0in 0in 0.0001pt;">Sound Transit. (n.d.). Cross Passages and Tunnels. Retrieved September 17, 2017, from [|https://www.soundtransit.org/Projects-and-Plans/Northgate-Link- Extension/Location-and-stations-Northgate/cross-passages-tunnels] The Colosseum. (n.d.). Chronology. Retrieved September 17, 2017, from [|http://www.the- colosseum.net/history/chronology.htm] <span style="font-family: Calibri,sans-serif; margin: 0in;">Wanted in Rome. (18 September 2014). Decision time for Rome’s Metro C. Retrieved September 17, 2017, from [|http://www.wantedinrome.com/news/decision-time-for- romes-metro-c.html] Wikipedia. (n.d.). Transport in Rome. Retrieved September 17, 2017, from [] <span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;">Yazwinski, T., (8 December 2014). WSDOT denies report of 'uneven settling' near Alaskan Way Viaduct, work on Bertha access tunnel remains stopped Retrieved December 4,2017<span style="font-family: Arial,Helvetica,sans-serif; font-size: 11pt;"> From http://q13fox.com/2014/12/08/report-uneven-settling-near-popular-viaduct-bridge/