Portarlington Flood Relief Scheme - Site Investigation works

Description

The purpose of this investigation is • to provide geotechnical information on the prevailing ground conditions underlying the site, • to determine the composition of any existing embankments, • to investigate possible sources of any embankment fill material, • to determine groundwater levels • to install instrumentation necessary to capture the long-term behaviour and seasonal variations to the groundwater at key areas across the site and also • to determine the engineering properties of the soils encountered in order to assist in progressing the design. The works will also investigate the presence and details of existing foundations. The site investigation shall comprise the following investigation methods: • 20No. cable percussive boring to a maximum depth of 10m, • construction of groundwater monitoring installations, • 12No. windowless samples with adjacent super heavy dynamic proving to a maximum depth of 5m, • 39No. machine (or hand) excavated trial pits to a maximum depth of 3.0m, • 12No. Observation pits (machine and hand excavated) to investigate existing foundation conditions to a maximum depth of 1.5m, • In situ variable head permeability testing within boreholes and infiltration testing within selected trial pits, • In-situ SPT and hand vane testing, • Installation and retrieval of 5No. groundwater dataloggers, • Geotechnical and geoenvironmental sampling of soil and groundwater, • Geotechnical and geo-environmental laboratory testing, • Groundwater monitoring and • Preparation of a Factual and Interpretive Report, incl. monitoring