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 the Umm Hurair District.

The project included the construction of a micro-tunnel with two shafts on either end of the tunnel. The construction works were adjacent to the Mediclinic City Hospital building and the Dubai Health Care City metro station’s footbridge foundation pile. 

As the project required the construction of a shaft just adjacent to the Mediclinic City Hospital building and tunneling below the existing Dubai Health Care City Metro Station footbridge (close to foundation piles), instrumentation was planned for the safety monitoring of structures and the risk management of construction works.

Encardio-rite’s sister concern, Encardio-rite Geosystems LLC in UAE, was instructed by the Road and Transport Authority (RTA-Owner of Metro structure) and Kele Contracting LLC to provide an instrumentation and monitoring program during NDRC to assess the impact on adjacent structures, including the Dubai Green Line metro pier, as per the 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 leveling & 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 instruments used included:

• Instruments for Metro Pier monitoring
• Tilt meters were 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

• An 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.

The experienced and proficient Encardio-rite I&M team successfully installed and monitored the above mentioned instruments. After installing them and recording their base readings, the NDRC works started.