Deep Braced Monuments

GeoNet is an integrated monitoring system that facilitates the collection, processing and archiving of geophysical data to inform research into geological hazards and support the response to major events.

An important part of the construction of this system is the installation of a network of braced GPS monuments across the country.

The monument sites are spread across the length and breadth of New Zealand. Their design and function mean that installation is generally carried out in rugged terrain and, more often than not, on the tops of isolated hills and ranges.

The monuments are based on a standard international “UNAVCO” design, which requires four accurately drilled and grouted stainless steel legs, incorporating isolation foam, to meet a central stainless steel post.

The budget for this work was also limited year-on-year for our client, requiring GNS and Webster Drilling to work together for more than 15 years, installing the currently 97 sites as funding allowed.

Webster Drilling designed a package of equipment and an installation process that allowed the monument network to be installed at the lowest possible cost to the client.

Our custom rig design allowed us to access and install the entire network using either a single 4WD truck or, when necessary, a locally sourced helicopter operator. No expensive or time-consuming track cutting is required.

The monuments can be installed in almost any location imaginable, without requiring changes to the equipment or additional costs.