NDRC Micro-tunneling work for Mediclinic City Hospital
The project comprised the construction of an underground crossroad as part of NDRC (Non-Disruptive Road Crossings) works in the eastern area of Dubai near Wafi mall in Umm Hurair District.
The project included the construction of micro-tunnel with two shafts on either end of the tunnel. The construction works were quite adjacent to the existing Mediclinic City Hospital building and also nearby Dubai Health Care city metro station’s footbridge foundation pile.
As the project required the construction of shaft just adjacent to Mediclinic City Hospital building and tunneling below existing Dubai Health Care City Metro Station footbridge (close to foundation piles), instrumentation was planned for safety monitoring of structures, as well as for the risk management of construction works.
Encardio-rite’s sister concern Encardio-rite Geosystems LLC in UAE was instructed by Road and Transport Authority (RTA-Owner of Metro structure) and Kele Contracting LLC to provide instrumentation and monitoring program during NDRC to assess the impact on adjacent structures including Dubai Green Line metro pier as per M/s RTA code of practice.
Scope of works included:
- Pre-construction building condition survey of metro piers and its viaduct.
- Supply of geotechnical instruments, precise survey instruments, and targets
- Installation of geotechnical instruments including the drilling works for subsurface instruments and survey targets
- Manual and automatic monitoring
- Optical Surveying-precise levelling & 3D deformation monitoring
- Programming and commissioning of data acquisition systems
- Setting up an online web-based data management system (WDMS) and maintenance during the contract period
Daily & weekly reporting with evaluation & interpretation
The instrument used included:
- Instruments for Metro Pier monitoring
- Tilt meters Installed on metro piers to monitor any deflection caused by nearby construction works
- Building settlement points Installed on metro piers to monitor any settlement caused by nearby construction works
Instruments for surface/sub-surface monitoring near construction works
- Inclinometer Installed to monitor lateral movements in the ground around the deep excavation for shafts
- Standpipe piezometer Installed to monitor groundwater level around the deep excavation for shafts
- Borehole extensometer Installed to monitor settlement in the ground around the deep excavation for shafts
- Surface settlement points Installed in the soil to monitor surface settlement around the deep excavation for shafts
- Automatic compact data logger For automatic monitoring of tiltmeters, which required monitoring at every 4 hours.
Installation and monitoring of the above-mentioned instruments were executed successfully by experienced and proficient I&M team of Encardio-rite. The NDRC works started after the installation of the above instruments and recording their base readings.