NATM

Exchange Place is a key station on the PATH commuter rail service between New York and New Jersey. After the World Trade Center collapse, the station and river crossing running tunnels were closed. Precautions were taken to prevent flooding of the subway system from broken water mains and sewer lines. Turning existing elements into a terminus and extending the platform tunnels by 45m involved excavating new crossovers, modifying the 5 existing tunnels, raising the invert and crown up to 3m and back filling unneeded tunnel spaces to create the ground in which new spaces could be excavated.

The station is located in central London between Tottenham Court Road and Liverpool Street Crossrail (CRL) Stations. Constructed in the geologically most complex area in the whole of CRL, an optimised geotechnical and SCL tunnel design was implemented, which resulted in significant time and cost benefits for the project. Using a dynamic 3D geological model in conjunction with SCL tunnelling represented a key element of the geotechnical risk management framework.

The Pajares Rail Tunnel is part of the new Leon-Asturias High Speed Rail Line, and with a length of 25.7km one of the longest tunnels in the world. The project encompasses twin 10m dia. TBM hard rock tunnels, bifurcation chambers, cross passages, and emergency stops. The tunnel is lined with a pre-cast segmental lining made from high-strength with a thickness from 50 to 60cm. The connection between the access tunnel and the main tunnel requires the construction of a large-span Bifurcation Chamber and a short mined tunnel.

High Speed 2 (HS2) is a high-speed railway between London Euston, the English Midlands, North West England, Yorkshire, and there are plans to extend the line to North East England and the Central Belt of Scotland. The project is currently split to two phases, namely a first phase between London and Birmingham, then a second branched phase to Manchester Piccadilly via Crewe and Manchester Airport, furthe to Leeds via the East Midlands Hu and Sheffield. 

Devil's Slide is located south of the City of Pacifica in California along the coastal road of Highway 1. Landslides and grade subsidence in the Devil's Slide area along Route 1 have led to the road being closed for extended periods causing significant economic loss to the surrounding communities. The solution: Construct a tunnel through the mountain to bypass the dangers and reoccurring problems. Construction of 1250m twin tunnels, 9m wide, 6.8m high using Sequential Excavation Method (SEM). Additionally, drill and blast and roadheader excavation through weathered rock utilised.

Beacon Hill Station is part of the 22.5 km initial segment of Sound Transit's Central Link Light Rail. It is located 49 m below the ground surface in complex glacial soils with multiple groundwater horizons. The project comprises deep mined station tunnels and two 1.5 km long running tunnels excavated using a tunnel boring machine. The mined station was excavated through compressible glacial soils with multiple groundwater horizons using conventional mining techniques. The access shafts and station headhouses were constructed using slurry walls and cut-and-cover techniques.

Green Park tube station is a LU station situated on the north side of Green Park in central London. The station serves as an interchange between the Piccadilly, Victoria and Jubilee lines. As part of Transport for London's (TfL) investment programme, LU is implementing capacity enhancement and step‐free access (SFA) works to various stations. Dr. Sauer & Partners was responsible for the design of the primary support, i.e. sprayed concrete lining (SCL) and for providing construction support services including supervision of the excavation works and installation of the primary lining.

Bond Street tube station is a major gateway to London's West End served by both the Central and Jubilee lines. As part of the LU tube upgrade plan, the station is undergoing a major upgrade to increase capacity, improve accessibility and create interchange with the new Crossrail station. The project provides two additional escalators from the interchange level to the Jubilee line, low-level interchange route between the Central and Jubilee lines, a new step-free entrance, ticket hall and new lifts. The majority of the tunnelling works will be mechanically excavated and lined with sprayed concrete.