Geosense Instrumentation Used At New Cancer Centre At Guys Hospital

A new state-of-the-art Cancer Centre, 14 storeys high, is being constructed at Guy’s Hospital as a hub for south east London and will provide specialist cancer services, training, development and research.

Tilt Meters were required on the roof of the existing building adjacent to the excavation but 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 that meant 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 Web Centre where 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 Web Centre so that access to the sensor is not required.

Geosense General Manager Grant Taylor said: “There is growing interest in wireless data logging and particularly in projects such as this where there is restricted access once the sensors are installed.

“Reliability is crucial with wireless systems and a great deal of research and development has gone into our Wi-SOS range. We believe they are some of the best on the market.”

The initial phase of the project 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 was constructed using secant piles with internal ground force props used for support during the 4.5 metre excavation to complete the concrete base.

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. Geosense 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.

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.