CLIENT: DM Roads
TYPE OF PROJECT: Civil Excavation/Replace Stormwater
When: November, 2018
DM Roads engaged Pipe Management Australia to assist with an emergency event in the suburb of Riverstone, NSW. This specific location was experiencing critical surface failure with pot holes, an unstable sub base and blocked stormwater drains. The cause of this sudden event was uncertain and needed urgent attention.
This location in Riverstone is potentially the busiest intersection in the suburb. The intersection experienced heavy traffic day and night from local bus services, local transport companies and general high flow of traffic due to the local train station. Without knowing the cause of this failure from the beginning a plan needed to be formulated and followed until resolved.
Due to the location of these works, all works were required to be undertaken after hours. This minimised the impact to local traffic and increased the safety for all workers. Although, working within these timeframes required all activities onsite to be planned and executed with out fault to have the road open each morning for the morning influx of traffic.
PMA commenced a methodical approach to identifying the cause of this issue. Drain cleaning and CCTV were undertaken of the stormwater network in this intersection to identify the network and to identify all the outlet positions. Through this process PMA identified that a poorly constructed outlet point had collapsed and was the cause of this issue. Non Destructive Excavation was then undertaken to confirm the exact location of the collapse and identify any deviations in the alignment passed this point.
Having the issue identified, rehabilitation options were then discussed. Due to the collapse and poor condition of the existing pipe the decision was made to excavate the existing stormwater asset to replace with a new Class 4 asset and also re-establish the outlet by casting a new junction pit to ensure no future failures.
Considering the multitude of elements with this project the excavate and replace methodology proved to be the best outcome possible for the client. This option provided reinstatement to flow instantly, gave the client critical information on the ground conditions for their stage 2 of rectification works (stabilising the sub grade) and installing the junction pit has now safeguarded the client and asset owner from future failures by giving the option for maintenance access.
This project was finished in an efficient time frame, with zero injury’s/incidents and enabled DM Roads to re-open this busy intersection to full capacity reducing impact to the local community.