Strain monitoring of soil nails installed for a slope stability ground improvement scheme.
The project
Ongoing slope stability issues adjacent to a Transport for London rail line required a soil nailing system to strengthen the slope and improve ground conditions.
The challenge
The soil nails required monitoring to provide the client with the accurate measurements of the applied load and stresses within the nails.
The monitoring scheme needed a data acquisition system that would collect and transmit data for all instrumentation unattended, as there would be minimal access to site after the installation works.
The solution
Strain gauges were installed on the top and bottom of the single strand bars to show the changes in strain in multiple directions. Sensors were installed at multiple points along the strand. This is similar in principle to the installation of a strain gauges within a pile. Load cells were also installed at the top of the monitored anchors to measure applied stress.
GEO-Instruments’ QuickView visualisation software was provided for visualisation and management of the project data. GEO-Instruments worked with the client to develop new software features to assist with reporting requirements.