Location

Cork Institute of Technology, Cork, Ireland

Event Website

https://event.ceri2020.exordo.com/

Start Date

27-8-2020 4:15 PM

End Date

27-8-2020 5:30 PM

Description

This paper describes Caha Tunnel, a 180m long rock tunnel of siltstone and sandstone formation located along the N71 between Kenmare, Co. Kerry and Glengarriff Co. Cork. The tunnel was formed in the mid-19th century through blasting methods, thus giving it its inhomogeneous cross-sectional shape throughout and exposing the natural face of the rock. In recent years there has been numerous reports of rock falls within the tunnel which is causing uncertainty of the safety of the tunnel amongst road users. Calls for rehabilitation works are sought amongst the public to ensure the long-term safety of the tunnel is provided as well as significantly reducing the possibility of any tunnel related road closure. This paper provides an overview of the recent short-term repair works by means of rock removal methods, and non-destructive testing (NDT) of the rock tunnel which provides an indication of the most suitable solution for ensuring long-term structural validity of the tunnel. The short-term repair works initially provides details of a hammer tap-survey, a geological mapping survey, a visual inspection as well as known historical rock fall locations which all give an indication of where immediate rock removal works were required. Following on from this, details of the rock removal operation works as well as associated site constraints are described. The non-destructive testing describes the various methods such as ground penetrating radar (GPR), electrical resistivity tomography (ERT) and seismic refraction which were all undertaken at the tunnel to determine any weak underlying layers/zones. An interpretation of these results as well as the most suitable long-term strengthening measures required within the tunnel are also described.

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Aug 27th, 4:15 PM Aug 27th, 5:30 PM

Caha Tunnel Rock Repairs and Improvements including Non-Destructive Testing

Cork Institute of Technology, Cork, Ireland

This paper describes Caha Tunnel, a 180m long rock tunnel of siltstone and sandstone formation located along the N71 between Kenmare, Co. Kerry and Glengarriff Co. Cork. The tunnel was formed in the mid-19th century through blasting methods, thus giving it its inhomogeneous cross-sectional shape throughout and exposing the natural face of the rock. In recent years there has been numerous reports of rock falls within the tunnel which is causing uncertainty of the safety of the tunnel amongst road users. Calls for rehabilitation works are sought amongst the public to ensure the long-term safety of the tunnel is provided as well as significantly reducing the possibility of any tunnel related road closure. This paper provides an overview of the recent short-term repair works by means of rock removal methods, and non-destructive testing (NDT) of the rock tunnel which provides an indication of the most suitable solution for ensuring long-term structural validity of the tunnel. The short-term repair works initially provides details of a hammer tap-survey, a geological mapping survey, a visual inspection as well as known historical rock fall locations which all give an indication of where immediate rock removal works were required. Following on from this, details of the rock removal operation works as well as associated site constraints are described. The non-destructive testing describes the various methods such as ground penetrating radar (GPR), electrical resistivity tomography (ERT) and seismic refraction which were all undertaken at the tunnel to determine any weak underlying layers/zones. An interpretation of these results as well as the most suitable long-term strengthening measures required within the tunnel are also described.

https://sword.cit.ie/ceri/2020/3/4