While much of Australia was forced into shutdown at the height of the coronavirus pandemic, the infrastructure construction industry carried on as the Government acknowledged the sector as an essential service.
Infrastructure projects are booming across Australia with progress continuing at levels unseen in decades, supported by a new $1.5 billion stimulus announced by the Federal Government. The works include major tunneling, road and rail projects across the country, including civil infrastructure and asset rejuvenation work. However, as the economy dips into recession, keeping construction projects on track and within budget will be critically important.
Mainmark is helping engineers and contractors to maintain productivity by using site-specific asset remediation and water stop solutions that are cost-effective, fast-acting and non-invasive. Its range of specialized resins, gels and coatings are designed to revitalize, seal, protect and structurally reinforce a wide range of assets, including many that have been impacted by water ingress. Water ingress can occur due to geotechnical conditions that are either encountered during construction or have appeared over time due to factors including corrosion and weakened ground.
This blog (the first of a three-part series) takes a closer look at common issues that can occur during the construction phase of large infrastructure projects, and how innovative solutions now available in Australia from Mainmark can help engineers and construction professionals approach complex geotechnical issues when excavating and tunneling. These solutions ensure infrastructure is not only safer and more structurally sound, they are also delivered more efficiently and cost-effectively due to their unique properties and application methods.
Using specialized resins, gels and coatings to restore structural integrity to underground assets
Underground road and tunneling projects may unearth ground issues that contractors have historically addressed using concrete. In addition, water control treatments may be needed in areas with a low lying watertable, as is the case in many inner suburbs of Sydney. Deep excavation in these areas is susceptible to groundwater inflow which can significantly impact the cost and duration of a construction project.
Equally, weaker soil conditions and fractured and jointed rock strata can contribute to subsidence problems and considerable remediation costs in the future. Hard-wearing solutions including specialized resins, gels and coatings can help to stop water leaks, seal joints and cracks, solidify soil and protect against premature structure breakdown. Mainmark’s specialized range of water control, chemical injection and cementitious grouting products are suitable for application in both wet and dry conditions making them particularly beneficial for large infrastructure projects with complex ground issues. The engineered solutions are typically non-invasive technologies that have been used to rectify and preserve all types of structures, including commercial buildings, industrial sites, residential and heritage properties as well as major civil infrastructure and mining projects.
Tunneling and drilling projects where deep excavation is required can present unique geological and environmental challenges due to differing soil structures that can range from large fissures, clay seams, soft shale, and wet sandstone to cracked and fractured rock stratum. These varying soil substrates can cause serious issues requiring an innovative approach to help limit or eradicate water seepage, address ground stability and improve the structural integrity of the tunnel or cavity.
Existing geological conditions, either identified prior to commencement or discovered during the project, can also impact the construction phase of infrastructure works. For instance, geological anomalies like paleochannels (deep soil sediments), which are prevalent in some parts of inner Sydney, are ancient rivers filled with alluvium, soft sediment which water easily passes through, located up to 50 meters below the ground; these can be a catalyst acting as a conduit for water ingress into a new sub-surface infrastructure tunnel excavation or ventilation shaft.
Addressing these types of complex environments requires specialized expertise and tailored solutions specific to the ground conditions in and around the site, such as the major transport and urban renewal infrastructure that is currently under construction in Sydney and Melbourne. Mainmark’s innovative water stop and control solutions, including rock and substrate injection treatments, include specially formulated products such as cementitious grout, structural resin, silica, and acrylic polymers. Each solution has high compressive strength properties for underground use, and some feature fast setting times to control water flows that can be as fast as 250 liters per minute. These proven high-performance water control treatments can be critical in emergency situations where fast-flowing water needs to be addressed quickly, delivering both safety and longer-term asset preservation.
The right help at the right time
Major infrastructure projects, including tunneling, commonly face obstacles throughout their long construction project timeframe and also in their service asset lifespan. While there are solutions to aid projects as unforeseen problems arise, most ground issues can be prepared for in advance using geotechnical data acquired during the planning phase. Having experienced ground engineering and asset preservation specialists on board before projects commence can help to design a better, site-specific approach to benefit the speed of delivery and the overall budget of the project, and the structural integrity of the completed works.