A new state-of-the-art Cancer Centre, 14 storeys high, is being constructed at Guy’s Hospital which will act as a hub for south east London and will provide specialist cancer services, training, development and research.
The initial phase required two existing buildings to be demolished followed by an extensive piling program with piles being installed up to 42 metres deep.
A retaining wall around the excavation has been constructed using secant piles with internal ground force props used for support during the 4.5 metre excavation to complete the concrete base.
During preliminary excavation several artefacts were discovered including pottery, coins and wine bottles from both pre-medieval and post-medieval eras which will be held by the Museum of London Archaeology (MOLA).
Due to the deep basement being excavated adjacent to an existing wing of the hospital it was necessary to monitor tilt of the existing structures, together with the excavation itself.
- Guy’s Hospital
- London, UK
- Guy’s & St Thomas’ NHS Foundation Trust
- Laing O’Rourke
- Instrumentation Specialist
- Select Plant Ltd
Tilt Meters with built-in data logging capability (Tilt Loggers) were installed on several walls where access was possible to download data via a USB connection to a PC or PDA.
Some Tilt Meters were required on the roof of the existing building adjacent to the excavation. Due to restrictions in access to the roof, data retrieval posed a major problem. Geosense therefore proposed a Wi-SOS 100 D2W (direct to web) wireless system which meant that once the Tilt Meters were installed no further access to the roof would be required. Each node has an integral SIM card allowing data from the Tilt Meter to be sent directly to the Wi-SOS Webcentre where the data can be viewed in real time and downloaded.
Should the logging interval require changing due to site conditions, it can be adjusted through the Wi-SOS Webcentre so that access to the sensor is not required.
To allow measurement of deflection on the wall during excavation, inclinometer casing was installed at 5 locations within the secant pile wall and measurements taken using inclinometers. Additional monitoring of the capping beam and surrounding structures was undertaken using traditional survey methods with targets and BRE sockets.