Near the city of Cambridge in Great Britain, the trunk road between Girton and Histon is being widened by one lane per direction. The A14 is an important national highway that connects the Port of Felixstowe on the east coast with the British road network.

Several steep sidehill cuts have to be comprehensively stabilized within the scope of the A14 widening. Self-drilling soil nail is a good helper for stabilizing slopes. Soil nails are installed top-down by the sidehill cuts that are carried out in individual stages, and the cut face is secured immediately as construction progressed.

To install the R25 9-15m long soil nail support system, the boreholes are drilled with two rigs working concurrently to maintain progress consistent with the tight time frame. Afterward, the soil nail system is installed using spacers to centralize the bars within the holes and then grouted via a tremie pipe from the bottom to the mouth of the borehole. It ensures the full column bonding of the soil nail to the ground.

The soil nail system is ideal for top-down construction in this project because they provide a permanent, safe, and economic reinforcement of slopes without the requirement for additional support. The soil nail system installs featured galvanized protection, which provides comprehensive corrosion protection for soil nailing applications. This application of the soil nail system has great benefits, not only economically, but also technically.