This document summarizes a presentation given by Giuseppe Lunardi on the Rome Metro B1 project. Some of the key challenges of the project included excavating in soft ground with a high water level and interference with existing buildings. Innovative solutions used included special jet grouting and diaphragm walls for the stations. Monitoring systems were also implemented during the jet grouting process to measure deformation and send alerts if thresholds were exceeded.

1. NHAZCA OPEN DAY
ROMA
31 – 01 – 2013
Roma MetroB1: problems and solutions
for a deep underground excavation in urban context
in soft ground and with high water level
G. Lunardi
Rocksoil s.p.a
Roma 31 – 01 – 2013 NHAZCA OPEN DAY GIUSEPPE LUNARDI

2. METRO B1 DESIGN FEATURES:
Excavation in ground with low geotechnical properties;
Deep excavation with high water level;
Heavy interference with buildings;
GEOTECHNICAL ASPECTS
• Hexcavation = 40 m
• HW= 35 m
Roma 31 – 01 – 2013 NHAZCA OPEN DAY GIUSEPPE LUNARDI

3. INNOVATIVE SOLUTIONS:
Special jet grouting and Hydromill Diaphragm walls (stations);
H jet= 12 m
Diaphragm
•Pressione miscela 400 - 420 bar
•Portata miscela 325 - 345 l/min wall
•Pressione aria 6 -10 bar
Deflection for
•Portata aria 6500 – 8000 l/min
•Densità miscela 1,51 kg/dm3 jet grouting
•Velocità di rotazione 3 – 5 giri/min
•Velocità di risalita 18 – 22 cm/min
Roma 31 – 01 – 2013 NHAZCA OPEN DAY GIUSEPPE LUNARDI

4. Monitoring systems adopted during the jet grouting phase
Monitoring Sh=101 mm
instrumentation in
Gondar Station
CONTROL OF JET-
GROUTING
PARAMETERS
L’acquisizione ravvicinata del dato, la trasmissione in
tempi brevissimi e la procedura di allarme tramite sms
preimpostati, se si fosse superata una determinata soglia
di deformazione, hanno permesso di portare a termine le
lavorazioni monitorate senza ulteriori movimenti.
Roma 31 – 01 – 2013 NHAZCA OPEN DAY GIUSEPPE LUNARDI