December 2013
CONSTRUCTION WORLD
52
Specialist Contractors or Suppliers
B
SPECIAL MENTION
Sir Lowry’s Pass slope stabilisation
Project information
• Project name: Sir Lowry’s Pass slope stabilisation
• Company entering: Maccaferri SA
• Project start date: 14 November 2012
• Project end date: 5 July 2013
• Client: SANRAL
• Main contractor: Guncrete
• Project manager: SANRAL
• Consulting engineer: Melis & Du Plessis Consulting
Engineers
• Project value: R9,8-million
F
ollowing heavy rains in July 2012, there was a rockfall event on
Sir Lowry’s Pass. The Sir Lowry’s Pass Stabilisation Project was
fast-tracked by SANRAL, as a resultof the emergency nature
with the aim of getting the road opened for traffic along this busy
and important section of the N2 routeas soon as possible as well as
trying to minimise the effect on the traffic during the rehabilitation
and construction phase.
The design for all the rockfall mitigation measures, as well as the
full-time on site supervision, was done by Melis & Du Plessis Consult-
ing Engineers. Following a competitive tendering process, Guncrete
were awarded the contract and construction started on 14 November
2012. The main focus of the emergency work to be carried out on the
most severe areas, was to ensure that all four lanes of the road could
safely be opened for the December holiday season.
The work for the first phase for the stabilisation of the slopes was
completed in time, with the contractor burning the candle at both
ends so that the work for this first emergency phase was completed
before the Christmas shutdown on 7 December 2012, and thus allow-
ing all four lanes to be opened during this high traffic volume period.
After the Christmas break, works on site restarted mid January 2013.
The contractor also had to programme his construction so as to allow
for the reopening the full four road lanes for the Easter Weekend.
Inclement weather (especially wind) was one of the biggest
concerns and resulted in construction delays. Cherry pickers were
used on site to gain access to the work areas that were several metres
above the road level. Where wind speeds were in excess of 45 km/h,
the cherry pickers could not operate due to the extreme danger
during thesesevere weather conditions. The result of this was that
the completion date was then extended from the original date of
14 June to the 5 July.
Guncrete was innovative in the execution of the project. High
rise access platforms are used for drilling large diameter holes up to
heights of 34 m. Guncrete developed a safe work procedure which
resulted in zero possible harm to human life – even at excessive
heights. This work procedure reduced costs significantly as no crane
was required.
Traffic accommodation on this project was a major concern from
the start of the planning. The main criterion was to allow the safe
flowof traffic during construction.Two lanes remained open to traffic
during the construction phase. These lanes were kept open until the
end of the contract. There were numerous reasons for the concerns
for the traffic accommodation.
At the start of the project, the engineers, Melis & Du Plessis
took the decision to make use of the concrete barriers instead
of the conventional delineators. So as to ensure the safety of all,
it was decided to make use of increased signage and flashing lights.
This proved to work well throughout the contract, protecting both
workers and motorists.
