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Instrumentation & Monitoring Project Gallery

Real-time monitoring of expansion joints of a bridge

March 2006, Singapore

Nine linear variable displacement transducers (LVDT) were used to monitor the change of expansion joint widths of an expressway flyover.

The system made use of GPRS to retrieve data wirelessly. GPRS data retrieval and monitoring enables zero site manpower, zero human error and editing error. The system monitored the flyover for duration of a week to cover day time, night time and raining days, all of which affect movement of expansion joints.

Ground penetration radar (GPR) investigation of
locations of tendons & rebars of a bridge

Jan ~ Apr 2006, Singapore

Strengthening of an expressway flyover required drilling through-holes on the bridge beams. GPR was used to detect locations of tendons and rebars so as for site team not to drill on the rebar or tendons

Residual strain measurement of welding of mega steel transfer beams

Apr ~ May 2006, Singapore

Mega transfer beams (50m x 6m) were used at a shopping centre project. Extensive welding was used to erect and fix the mega beams on steel columns.

Spot weldable strain gauges (VWSG) in form of rosette were used to measure residual strain of the beam due to welding. The measured results before and after the welding were analysed with the design expectation to ensure there was no excess residual strain and stress due to welding so as to proceed to next construction stages.

Real-time vibration monitoring of a hotel during an excavation with explosive

2002, Monaco

The Hermitage is a building of the beautiful time period which is among the luxury hotels of the principality of Monaco. An important extension project, including an excavation of 35m deep at the right of the building was launched in 2002. This real-time monitoring is ensured thanks to a GORGONE vibration connected by cable and radio to tri-axial sensors of low frequency (4Hz). The system records in real-time the overtaking of thresholds. The transmission of the measurements is automatically made by radio. The data are immediately available in the site offices.

Monitoring of cut & cover station and tunnels built on reclaimed land
adjacent to an elevated highway structure

2003, Hong Kong

Three total stations continuously measured the small movements on 300 prisms fixed on the bypass of the elevated highway to be built. A secondary monitoring system consisting of tilt meters and survey points was also installed. The site itself was monitored with 25 in-place inclinometers installed in the diaphragm walls. Deck deflections of more than 20mm due to traffic loading were observed. The total stations were themselves subject to daily movements automatically corrected by fixed reference prisms.

Monitoring of buildings and metro stations
during excavation of a new ticket hall

On-going, Kings Cross Station, London Underground, UK

Eight total stations were installed on surface to monitor tracks and several buildings listed by the English Heritage. Another eight total stations were then installed in the three underground stations. Additional monitoring systems like vibration, strain gauges and tile meters were spread out over the site.

Automatic monitoring of city buildings during realisation of a new subway line

On-going, Amsterdam, Holland

The scope of monitoring work includes: design of manual and automatic instrumentation, installation of instruments and automatic acquisition system in the town centre of Amsterdam, installation and maintenance of the system during seven years, and frequent transmission of the data to Noord-Zuid Lijn.

FOSTA Pte Ltd | FOSTA (Malaysia) Sdn Bhd
BBR Building, 50 Changi South Street 1, SINGAPORE 486126
Tel: +65 6561 9885 Fax: +65 6561 3766 info@fos-ta.com

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