Nelson Tasman Site Classification Study: Defining the dynamic site characteristics of the Nelson-Tasman region subsoil materials

Abstract

The project objective is to determine and map dynamic site characteristics across the Nelson‐Tasman region and therefore assess the potential seismic site response including soft‐soil amplification effects. A combination of geotechnical and geophysical methods are to be used in a region‐wide study of the developed urban areas of Nelson‐Tasman. Collection and reference to existing sub‐surface information will be utilised to identify geological trends across the region that can then be used to better define and interpret the collected geophysical testing information. To achieve this, the following goals were set: 1. Collect existing geotechnical subsurface information from around the region, understand the geological and geomorphological features of the area. 2. Estimate the site period over a grid of sites across Nelson‐Tasman focus using horizontal‐to‐vertical spectral ratio (HVSR). 3. Undertake Multi‐Channel Analysis of Surface Waves (MASW) testing to define the shear wave velocity profile for selected sites across the region.