Just before the torrential rains of last weekend, work on the Crib Walling of Rath Lugh National Monument finally began amidst much speculation as to the long delay. This was contrary to the recommendations made in the Technical Report of Golder Associates.
Extracts from the Technical Memorandum Golder Assiciates Ltd.
Review of Slope Stability of the Rath Lugh National Monument, Lismullin, Co. Meath.
NOTE: This review is dated 11th Feb 08 following a ground inspection which was carried out on 18th Dec 07.
It is now Aug 08.
The factor of safety obtained from the slope stability analysis is adequate for a short
term situation. A generally conservative approach has been taken in the assumptions
and in the selection of design criteria.
There is silt exposed extensively on one of the slope faces. Silt by its nature is highly
susceptible to erosion and degradation with exposure to weather. Therefore its
condition can deteriorate fairly quickly with time. It is therefore recommended that
the completion works in this area be undertaken as quickly as possible so that the
exposed slope can be regarded, stabilised and protected. If final completion works
are to be delayed, then temporary protection measures should be instituted. Such
temporary protection works could comprise gravel sheeting over a suitable geotextile
In addition, due to the presence of silt soils within the slope, there is a potential for
liquefaction of these silts as a result of vibrations from adjacent construction works.
This is not thought to be a major factor since the slope appears reasonably dry and
provided reasonable precautions are exercised to avoid extended use of heavy
equipment near the toe of the slope.
Photographs courtesy of Mars.