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GEOCISA UK LIMITED CHESTER HOUSE 1-3 Road. SW9 6DE INFO: [email protected] www.geocisa.com

INSTRUMENTATION & MONITORING C305 EASTER RUNNING TUNNELS. LONDON

Client: CROSSRAIL DRAGADOS SISK DSJV Site Location: LONDON

The Crossrail C305 Project “Eastern weave their way between existing Running Tunnels”, is part of the largest underground lines, sewers, tunnels and Crossrail east-west route across and below building foundations from station to station at . depths of up to 36m. The whole Crossrail project comprises of Geocisa UK monitored the stakeholder’s 118 Km from which 42km are underground assets above the tunnel footprint at ground tunnels. The Eastern Running Tunnels level during the advancing of the tunnelling encompasses construction of part of the sub- works. surface section of the Crossrail route. Within this footprint Geocisa encountered a The scope of the project comprises of variety of challenges: monitor several live 12km of 6.2m diameter twin bore tunnels with services tunnels (EDF, BT, Post Office tunnels), concrete segment lining across this sections: numerous Network Rail and London underground live lines. → Drive Y : 8.3km, Limmo Peninsula to Far-ringdon . Description system implemented: → Drive Z : 2.72km, Green to The monitoring and data mining of the Pudding Mill Lane stakeholder assets, the control of the works and the control of settlement within the zone →Drive G : 0.9km, Limmo Peninsula to of influence was achieved by installing and Royal Victoria Dock monitoring the following devices and systems: The route itself has a “Y” shape, bifurcating → Over 20nr Automated Total Stations itself at Stepney Green, with the southeast (ATS), Leica TM30 spur running underground to and then onto Abbey Wood via the and the north east spur running underground to Pudding Mill and then onto Shenfield in Essex. The 42km of bored tunnels forming the Eastern running tunnels are located below the busy streets of London where the tunnels will Figure 1: ATS in operation

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GEOCISA UK LIMITED CHESTER HOUSE 1-3 Brixton Road. London SW9 6DE INFO: [email protected] www.geocisa.com

→ Over 225 Boreholes drilled for web which was developed for the project. installation of Inclinometers, Piezometers, Extensometers, Deep Datum and Shallow Datum. → Over 1,800m In-Place Inclinometers for monitoring of diaphragm walls. → Over 10,000 Studs/Monitoring Points for precise ground levelling. → Over 1500 Sockets for monitoring of Buildings and Assets. → Over 1,000 3D Geodetic Prisms for ATS. Figure 2: Flow Diagram data collection and storage → Over 225 Strain Gauges to monitor The progress of the tunneling is clearly temporal propping during shaft excavation visible in a graphical way defining the zone of → 10 Lasers to monitor convergences and influence of the works at any time and 10 Vibration systems at sensitive places and therefore, fully informed decisions can be times. made by the client. → 30 Tilmeters. Reporting → 4 Crack meters. Every 12 hours a report is produced and presented to the client and the main third → Over 1,000m Electrolevel system parties representatives in the Shift Review installed for settlement control including power Group meeting. Also weekly reports are and communication. produced.

Figure 3: Electrolevels beam in Gas Main Database system (SAI) Figure 3: Liverpool Street Station Crossrail tunnel underpasses The impact of the works was evaluated by several utilities tunnels and LUL Lines. SAI software analysing a large amount of data that was managed by our Monitoring team who processed reported and analysed the data. If the values are in exceedance of the predefined trigger levels the system automatically raised an alarm which would be communicated via email and mobile SMS to the subscribed users. The in-house developed specialist software is capable of displaying the data in real time fed by the automatic systems and also of doing calculations. All this results were accessible to the client via a password protected Internet

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