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09:30-09:50 Ground Treatment for Risk Mitigation During Tunnelling at the Port of Miami R. Storry, Dragages Hong Kong Ltd; D. Bruce, Geosystems, L.P and A. Hochart, Bouygues TP The Port of Miami Tunnel (POMT), designed and constructed by Bouygues Civil Works Florida (BCWF) between 2009 and 2014, was a Public Private Partnership between the Miami Access Tunnel Concessionaire (MAT), Florida Department of Transport (FDOT), Miami-Dade County and the City of Miami. The project comprises dual 11.3m internal diameter, 1.27km long, twin lane road tunnels running between Watson and Dodge islands and under the main shipping channel in Biscayne Bay 09:50-10:10 Measurement of Grout Injection Pressure in Situ L. Tunbridge, A. Aaset and E. Tønnesen, Norwegian Geotechnical Institute Injection grouting in rock around tunnels is used to reduce or stop water inﬂow. Little is known about the distribution of pressure within the rock mass during and after grouting. Instrumentation was developed to record pressure at the back of the packers inside the rock mass during injection grouting in order to improve our understanding of the process. Using this equipment measurements inside multiple injection holes during injection pumping have been made during several rounds of injection grouting in a tunnel. The data has been compared to the data recorded on the grout pumping rig and analysed to gain an understanding of the behaviour of grout injection process in the rock mass.
10:10-10:40 Break 22 – 28 APRIL | MOSCONE CENTER | WTC2016 10:40-11:00 Breaking Through: Shaft Design and Construction Considerations from Miami’s Norris Cut Project B. Caro Vargas, Nicholson Construction Company and R. Giffen and T. Carroll, Arup This paper, presented by Arup and Nicholson Construction, takes an in-depth look at the $72 million design-build Norris Cut project, which includes the replacement of an existing 54-inch waste water sewer main to Fisher Island under the Norris Cut Channel.
Tunneling through one of the country’s most unpredictable geologies created unique challenges in both the design and construction phases of the project. The paper presents the geotechnical and structural design considerations for the 100-foot deep secant piled TBM launch shaft in the highly permeable Fort Thompson formation limestone and sands. The structural design effort also included the design of the tremie slab, thrust wall and design of the largely unreinforced launch shaft to resist asymmetric loading from partial ground freezing. The retrieval shaft was designed as a deep soil mixed shaft and is thought to be the deepest soil-mixed shaft in Miami. From a construction perspective, this paper discusses the unique challenges of building two shafts with two different techniques and will compare some of the constructability aspects, costs and equipment schedule-considerations related to the use of two separate techniques.
11:00-11:20 Ground Freezing to Repair Leaks in a Slurry Wall Shaft S. P. Coughlin, Moretrench American Corporation; J. Leonardo Tello del Pino, Odebrecht Infraestructura and M. A. Schimmenti, Moretrench American Corporation In Buenos Aires Province, Argentina, a potable water project included a 3.6 m diameter tunnel and 5 access shafts constructed with slurry wall panels. Access Shaft #3 experienced persistent soil and water inﬂows through panel joints during excavation. The contractor failed to stop the leaks using various methods, including jet grouting and dewatering. With a TBM waiting upstream of the shaft but the leaks continuing, the contractor ﬁlled in the shaft to above the tunnel crown to allow the TBM to pass through. To complete the shaft, the contractor consulted a specialty geotechnical subcontractor to design and install a ground freezing system to isolate the shaft from the surrounding soil. Steel pipes were drilled around the shaft and tunnel to circulate cooled brine and create an impermeable barrier of frozen soil. After the frozen wall was formed, the shaft was excavated without incident and the ﬁnal liner was successfully installed.
11:20-11:40 Ground Freezing for Construction at the Port of Miami Tunnel R. Storry, Dragages Hong Kong; O. Martin, Bouygues Travaux Publics; D. Harris, D I Harris Geotechnics and A. Hochart, Bouygues Travaux Publics The Port of Miami Tunnel (POMT), designed and constructed by Bouygues Civil Works Florida between 2009 and 2014, was a Public Private Partnership between the Miami Access Tunnel
11:40-12:00 Conventional Excavation of Connecting Tunnels in C13 Metro Station (Poland-Warsaw – Line 2) The Complex History of the Construction of Three Connecting Tunnels M. Bringiotti, F. De Angelis, and M. Aurelio Piangatelli, CIPA S.p.A.
The construction of the three connecting tunnels between the east side and the west side of station C13, adjacent to the Vistula river, has a long and complex history, as they cross beneath one of Warsaw’s main road arteries (Wisłostrada). After the attempt to excavate the ﬁrst tunnel, the face of the tunnel collapsed on the night of 13 August 2012, and a volume of about 10,000 cubic meters of liquid mass (water, silty soil and sand) entered and ﬂooded the west side of the station, which was ﬁlled up to more than seven meters from the bottom. Fortunately, the workers managed to escape, but machines and equipment were lost. This is the story of how the tunnels were completed, by adopting soil improvement, jet grouting, GRP bars, ground freezing and a careful choice of work steps.
12:00-12:20 Combined Ground Freezing Application for the Excavation of Connection Tunnels for Centrum Nauki Kopernik Station – Warsaw Underground Line II A. Balossi Restelli, Studio ingegneria Balossi Restelli e Associati; A. Pettinaroli, Studio Ing. Andrea Pettinaroli s.r.l.,. and E.
Rovetto, Studio ingegneria Balossi Restelli e Associati, The Underground Station, 10m below the water table in crown and close to Vistula river, required the excavation of three connection tunnels, underpassing a six-lanes road tunnel in service, working from two lateral shafts. After the collapse and ﬂooding occurred while digging the ﬁrst tunnel, the use of artiﬁcial ground freezing was chosen to ensure the excavation under safety conditions. A complex freezing pipes geometry and excavation stages sequences were necessary because of the interferences with road
diaphragm walls foundations, shafts internal structures and previous grouting activities. Combined freezing method was used:
nitrogen for freezing tunnels arches and brine for freezing the intermediate wall and for maintenance stages. Sandy and silty sandy layers where frozen around the crowns and sides. No treatment was necessary for the inverts, lying in clay. Non-stop monitoring system of ground temperatures and structure movements allowed to manage successfully the completion of works in 8 months.
22 – 28 APRIL | MOSCONE CENTER | WTC2016 Posters (On display in the exhibit hall during exhibit hours. Authors will be at their poster from 13:00-14:00 for discussion.) Metro Rome line “C” – Artiﬁcial Ground Freezing Application for the Underpass of the Existing Metro Station San Giovanni-line “A” A. Bertero, F. Cribari, A. Tanzi, S. Fancello, and T. Gondolini, Trevi Spa and F. Giannelli, M. Lodico, M. D’Angelo, E. Romani, Metro C Spa The new metro line “C” entails the construction and rehabilitation of 24 stations and 21,5 km of metro line, 13 of which carried out underground; the new metro line will improve the transportation system of a congested city such as Rome. The new line “C” of San Giovanni metro station will be constructed adjacent to the existing line “A” of San Giovanni station; the new metro line “C” is deeper than line “A” and will underpass the existing station. The underpass project envisages an Artiﬁcial Ground Freezing in order to excavate two new tunnels, while keeping trains running in the safest possible condition. In order to allow trains to regularly run to and from the existing station’s line “A”, a temporary structure for rail support, during excavation of the under-crossing tunnels, was installed and a real-time monitoring system was devised in order to control both soil temperature during freezing activities and the existing station’s behavior. The excavation of tunnels under the water table, with a hydraulic head of over 10 m in not homogeneous soils having different mechanical properties and permeability and below existing sensitive structures, involves special ground freezing sequences and methods, as well as peculiar drilling systems and operations, such as TDDT (Trevi Directional Drilling Technology).
The Design of Deep Rock Shafts of the Rondout – West Branch Bypass Tunnel C. E. Dianora, and M. Sorrell, New York City Department of Environmental Protection and E. Test, McMillen Jacobs Associates Constructed between 1939 and 1945, the Rondout -West Branch Tunnel (RWBT) portion of the Delaware Aqueduct is 45 miles (72 km) long. The New York City Department of Environmental Protection (NYCDEP) ﬁrst identiﬁed suspected areas of leakage from the RWBT in the 1990s. A $1 billion project is underway to mitigate the leakage through the construction of a bypass tunnel around the area of most severe deterioration, a 2.5 -mile ( 4 km) section located beneath the Hudson River. Two shafts, 800 and 900 feet (244 and 274 m) below the ground surface, are being sunk to support the tunnel construction. The deep shafts will be subjected to high groundwater pressures and have been designed to accommodate multiple tunnel portals. This paper discusses the engineering decisions and analyses leading up to the ﬁnal design.
WTC2016 | SAN FRANCISCO CALIFORNIA, USA WEDNESDAY 27 APRIL Modelling of Tunnel Settlement Induced by Train Vibration Considering Different Boundary Permeability Conditions Q. Huang, H. Huang, D. Zhang, and B. Ye, Tongji Univerisity and F. Zhang, Nagoya Institute Of Technology Nowadays, many cities around the world have constructed metro tunnels to alleviate transportation pressure from rapid urbanization. In soft soil areas, metro tunnels are usually constructed by shield-tunneling method due to its high efﬁciency and little disturbance to environment. However, the tunnels may show signiﬁcant post-construction settlement after several years of operation. Take Shanghai Metro line 2 for example, the maximum longitudinal settlement reached 160mm after ten years of operation, shown in Figure 1. When analyzing varying factors that contribute to the long-term settlement of tunnels, the effect of cyclic loading from train vibration is rarely taken into consideration for most researches only focus on the inﬂuence of leakage problems in the tunnel while neglecting train vibration induced leakage and resulting settlement. It’s true that metro tunnels from shield-tunneling method are prone to have leakage problems due to the special structural conﬁguration. Furthermore, trains move hundreds of times inside the tunnel every day, which inevitably will cause accumulation and dissipation of excess pore pressure. When the excess pore pressure dissipates, tunnel settlement induced by train vibration occurs(Deng F H, 2007). Although researchers (Zheng et al., 2005;
Wongsaroj et al., 2007; Mair, 2008; Shin et al., 2012; Zhang et al., 2012, 2015) conducted extensive numerical analysis on the relationship between tunnel settlement and relative permeability of tunnel to surrounding soil by treating tunnels as permeable media, their attention was only paid to the tunnel settlement from reduction of hydrostatic pressure in the ground, rather than from the dissipation of excess pore pressure generated by train vibration.
Therefore, the inﬂuence of train vibration on the long-term settlements of metro tunnels is still not clear.
Sprayed Concrete for Frozen Ground in Hong Kong K. Lo, BASF Construction Chemicals For more than a century, ground freezing has been a construction technique used in stabilization of ground by means of lowering the temperature of surrounding soil strata. This technique is used in circumstances where conventional grouting method is unable to achieve the degree of consolidation required to prevent settlement and water ingress during the execution of underground excavation. Whilst ground freezing is effective in imparting self
-supporting characteristics to the excavation proﬁle, it poses signiﬁcant challenges when it comes to the New Austrian Tunneling Method (NATM) where sprayed concrete is used to support the freshly excavated ground. Sprayed concrete, if used in an appropriate manner, provides a fast, efﬁcient and structurally - reliable means of supporting the structure, especially in underground construction.
22 – 28 APRIL | MOSCONE CENTER | WTC2016 Posters (Continued) Performance Beneﬁts of Colloidally Mixed Two-Component Grouts P. Antunes and A.E. Reschke, Team Mixing Technologies Inc Tunnel Boring Machine (TBM) operations require the injection of material into the annular tail voids as the machine advances ahead of the segmental concrete lining. This annular gap is created because the cutting diameter of the TBM has to be larger than the outer diameter of the concrete segments of the tunnel lining. Fundamentally, the two basic types of annular grout are thick, concrete like mortars and thin, mobile, two-component grouts. While some European countries seem to still favor the concrete like mortars, from a global perspective it is now the two-component type grouts that dominate the industry.
Two-component type grouts are comprised of an “A” component grout (typically cement, ﬂyash, bentonite and a retarder/stabilizer) and a “B” component accelerator (sodium silicate or water glass as it is sometimes known). They are thus sometimes referred to as A/B type or bi-component grouts and were pioneered by the Japanese over 30 years ago.