BRIDGE MONITORING. Picture 1: Benjamin Sheares Bridge

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1 BRIDGE MONITORING Opened in 1981, the Benjamin Sheares Bridge is the longest bridge in Singapore, spanning 1.8 km, and the tallest, at 20 m. It is named after Dr Benjamin Henry Sheares, the 2nd president of the Republic. The bridge is part of the East Coast Parkway. The cost of construction was S$177 million. Built over reclaimed land, the bridge is made of pre-stressed concrete and links East Coast Parkway on the east coast to Marina Bay on the west coast. Picture 1: Benjamin Sheares Bridge The Marina Bay Bridge across Marina Bay was officially opened on 24 April There are two components to the new bridge a six-lane vehicular connection and a six-metre wide curved pedestrian connection that embraces Marina Bay. The Helix, at 280m long, was chosen for the spiral-shaped pedestrian bridge while the Bayfront Bridge, spanning 303m, was picked for the parallel bridge for vehicles. Picture 2: Helix Bridge Protecting Your Future with Monitoring Solution 1 of 11 Bridge Monitoring

2 The Bayfront Bridge is a vehicular bridge part of the Bayfront Avenue which links the Marina Bay Sands Integrated Resort to Raffles Avenue at the junction with Temasek Avenue. Its simple design blends in with the existing Benjamin Sheares Bridge to form a backdrop to The Helix Bridge. The bridge provides a direct connection between Marina Centre and Marina South. The opening of this new road network will provide road access to the upcoming developments in the Marina Bay area, such as the Marina Bay Sands Integrated Resort (MBSIR), Gardens by the Bay and the Marina Bay Financial Centre (MBFC). Picture 3: Bayfront Bridge Monitoring Solution Providers Pte Ltd was involved in monitoring the movement of the Benjamin Sheares Bridge and later, the Bayfront Bridge under Land Transport Authority Contract 905. Proposed C905 Tunnel Zone of Monitoring Contract 905 is for the design, construction and completion of tunnels between Promenade Protecting Your Future with Monitoring Solution 2 of 11 Bridge Monitoring

3 Station and Marina Bay. It includes two pairs of stacked bored tunnels between the Marina Bay Sands Integrated Resort (MBSIR) development and Promenade interchange station for the Circle Line (CCL) and DTL Stage 1. DESIGN CRITERIA Protecting Your Future with Monitoring Solution 3 of 11 Bridge Monitoring

4 Distance of the monitoring points to the total station to be kept below 250 m to achieve the required accuracy when monitoring under harsh environment. eg (Hot afternoon sun and the shimmering effects of the water body at sea). The Measurement Station deployed must have 1 accuracy in angular measure and 1+1pmm accuracy for distance measurement. Equipment/Measurement Station to be used must also have high ratings in dust and water protection. Power consumption of all equipment used must be kept to the minimum due to the lack of constant power supply. The proposed Downtown Line MRT construction C905 is in close vicinity of the existing Benjamin Sheares Bridge and an Automated Deformation Monitoring System (ADMS) was deployed for structural deformation and displacement monitoring of the bridge during the construction of the project. The installation and monitoring of this system will progress in two (2) phases to accommodate the construction sequence of the civil contractors. Phase 1 Pier 1A to Pier 8A (installed on 28 March 2008) Phase 2 Pier 9A to Pier 22 (to be installed in late April 2008) The system configuration for phases 1 & 2 is such that phase 1 is a standalone system with its own stable reference points. On the other hand, phase 2 being introduced on a later date will be linked to phase 1, for transferring its reference points to stable areas. PROPOSAL The instruments used for phase 1 & 2 automated monitoring are: Protecting Your Future with Monitoring Solution 4 of 11 Bridge Monitoring

5 Phase 1: 1 nos. of Sokkia NET1-m total station; 29 nos. of monitoring prism; 2 nos. of 360 o prisms for monitoring and future connection to phase 2 monitoring system Phase 2: 2 nos of Sokkia NET1-m total station X nos of monitoring prism INSTRUMENT SETUP (STN1) was installed on the bridge column that is within the C905 site office (STN2 & STN3) were installed on the pile caps of the bridge column that is within the Marina Bay channel MONITORING PRISM Protecting Your Future with Monitoring Solution 5 of 11 Bridge Monitoring

6 RAPID INTELLIGENT UNIT Protecting Your Future with Monitoring Solution 6 of 11 Bridge Monitoring

7 Station 1 Rapid IU (Type 2) Rapid IU with Power and Data control system, housing the PC with installed RAPID-PC software dictating the monitoring process of the NET1-m and sending the monitoring data to Office for processing. Station 2 & 3 Rapid IU (Type 1) Rapid IU with Power and Data control system, housing the Ruggedized PDA (built-in GSM) with installed RAPID-WM software, dictating the monitoring process of the Station 2 & 3 NET1-m. Upon completion of each monitoring cycle, the RAPID_WM automatically activate its GPRS connection to transmit the data to the HQ Server for processing C905 PROCESSED DATA Processed data from the monitoring site can slso be viewed and downloaded from the Internet Protecting Your Future with Monitoring Solution 7 of 11 Bridge Monitoring

8 via MSP WebPro. Changes in Height Coordinates at Office (STN1) Changes in Height Coordinates (mm R12-dRL(mm) 22-May-03 Date and Time 23-May-03 The Automated Deformation Monitoring System (ADMS) was officially commissioned 23 rd April Protecting Your Future with Monitoring Solution 8 of 11 Bridge Monitoring

9 MONITORING SOLUTION PROVIDERS PTE LTD C905 SITE PHOTO Protecting Your Future with Monitoring Solution 9 of 11 Bridge Monitoring

10 MONITORING SOLUTION PROVIDERS PTE LTD C905 SITE PHOTO. Protecting Your Future with Monitoring Solution 10 of 11 Bridge Monitoring

11 MONITORING SOLUTION PROVIDERS PTE LTD C905 SITE PHOTO MONITORING SOLUTION PROVIDERS PTE LTD 33 Ubi Avenue 3, #05-31, VERTEX Singapore Tel: Fax: Website: Co. Reg No: W Protecting Your Future with Monitoring Solution 11 of 11 Bridge Monitoring