Construction World January 2023

ROADS & BRIDGES

Risk Management The project risks were addressed prior to commencement with a full risk assessment and determination of mitigation measures developed. A risk register was prepared and the risks to achieving the required milestones and standards, health, safety, environment and the achievement of the employer’s considered by the site team. With a pre-construction ADT of 14 566 vehicles per day the disruption to and safety of road users was a major risk and the provision of concrete NJ barriers ensured the live lanes were kept clear and vehicles were not at risk of being struck by boulders. Rock falls and debris coming off the slope and endangering the safety of workers and road users or causing damage to vehicles and construction plant. The stability of the existing slopes was a risk uppermost in the site team’s assessment of risks and the Engineers had identified problem areas in three of the five construction zones. With the N2 to remain open to traffic at all times, albeit with occasional lane closures, the possibility of slips and rock falls from the slopes was a significant hazard and the risk to passing traffic was monitored throughout the project. Working space, particularly for the telehandlers, MEWPs and the soil nailing rig, was a concern however SANRAL permitted a lane drop to provide working space for this particular activity. This caused some traffic delays but these were well managed by the specialist traffic control subcontractor. The varying nature of the in situ material in the cut slopes also meant that runoff due to heavy rainfall had to be closely managed. This was achieved by cutting temporary interceptor drains along the top of the two cut slopes in the position of proposed permanent concrete and stone-pitched cut-off drains. The team was lucky with the weather and this risk was not fully realised. Strong winds were a constant issue for the site teams and protocols were enforced to ensure site staff exercised care at all times, especially in exposed positions on the slopes. Working at heights, particularly when barring down loose material was a significant risk but the installation of life lines and the rope access teammeant the risks were mitigated to acceptable levels. 

C2KMPI JV appointed a project Designated Environmental Officer (DEO) from Civils 2000 to monitor environmental impacts and ensure implementation of the requirements of the EMP. The DEO prepared environmental method statements addressing environmental aspects and impacts of the construction work and developed impact prevention or mitigation measures to apply to the construction activities. The DEO then ensured controls were in place for waste generated by the construction activities and site offices, use of construction water, the impacts of vehicles and construction plant, erosion following site clearance and excavation, water pollution from runoff, preparation of an emergency procedure for controlling spills, maintenance of spill containment kits, and monitoring noise and dust from the drilling rigs. Health & Safety The risks from rock falls, falls from elevated positions and live traffic were well managed on site. Ultimately only one medical injury case was recorded and 20 motor vehicle accidents -17 inside road closure, 3 outside lane closure and of the 20 recorded as MVA, 3 of these were in fact truck breakdowns. Time, Cost and Quality The initial contract duration was extended due to additional work required towards the end of the contract. The critical path for this project initially flowed through the soil nailing operations and subsequently the construction of the gabion buttresses. Projected completion of 29/07/2022 was pushed out slightly to 02/08/2022 due to physical site constraints and the road was fully open by 12/08/2022. The Civils 2000 quality management system was adopted by the JV teams and applied to the site works and construction management processes for the project. A Quality Plan was developed for the project and approved by the Engineer. The basic approach involved development of detailed method statements for each activity. Quality control inspections were undertaken and the completed work inspected by the RE for acceptance on behalf of the client.

28 CONSTRUCTION WORLD JANUARY 2023