Ireland - N4 Carrick-on-Shannon to Dromod Project - Phase 2 Ground Investigation

Description

The N4 Carrick-on-Shannon to Dromod Project aims to identify, evaluate, and
resolve the transportation issues in the Carrick-on-Shannon / Cortober area, its
environs, and the broader national road network – in particular the N4 corridor, as
appropriate.
The ground investigation comprises a combined geotechnical, geo-environmental
and hydrogeological investigation, as part of Phase 2 for the N4 Carrick-on-
Shannon to Dromod Project. In total, the ground investigation will comprise 31
No. cable percussive boreholes with rotary core follow-on to various depths, 11
No. rotary percussive boreholes to various depths, 29 No. groundwater monitoring
installations and 1 No. combined groundwater and gas monitoring installation, 3
No. push in vibrating wire groundwater piezometers, 42 No. trial pits to a
maximum depth of 4.5mBGL, 208 No. dynamic probes to a refusal, 6 No.
window samples to refusal, 19.0km of electrical resistivity tomography profiles
and 10.0km of 2D MASW survey.
Soil, rock and groundwater samples are required from the trial pits, boreholes and
monitoring wells for geotechnical and chemical testing and classification.
The ground investigation scope shall be completed in stages to ensure reusability
and other critical laboratory testing is completed within the required timeframe.
To allow for this, boreholes at potential cut locations and all trial pits have been
scheduled to be completed within the first 2 weeks of the field works. The
locations to be completed as part of each stage is provided in Schedule 2 and must be adhered to.
A number of proposed exploratory locations sit within the flood plains of the
River Shannon and its associated tributaries and also in peat bog areas. Soft
ground conditions that may be difficult to traverse will be encountered in these
areas. The Contractor shall allow for appropriate measures to overcome difficult
access due to soft or wet ground in the tender return.

Opportunity closing date

11 December 2020

Value of contract

to be confirmed