{"id":10111,"date":"2024-06-11T02:21:47","date_gmt":"2024-06-11T02:21:47","guid":{"rendered":"https:\/\/www.reco.com.au\/?p=10111"},"modified":"2024-06-27T08:02:02","modified_gmt":"2024-06-27T08:02:02","slug":"precast-concrete-arches-revolutionising-infrastructure-with-efficiency-and-durability","status":"publish","type":"post","link":"https:\/\/www.reco.com.au\/precast-concrete-arches-revolutionising-infrastructure-with-efficiency-and-durability\/","title":{"rendered":"Precast concrete arches: Revolutionising infrastructure with efficiency and durability"},"content":{"rendered":"
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Technical Paper:<\/strong> Precast concrete arches in geotechnical engineering and infrastructure projects will be discussed in this technical paper, analysing their application, benefits and arch design methods.<\/p>\n

The arches are becoming a preferred structural solution in major infrastructure projects throughout Australia, encompassing roadways, railways, and mining sectors. These precast concrete arch solutions are meticulously engineered to deliver substantial support and enduring durability for applications such as bridge underpasses, culverts, overpasses, and covered tunnels. Their advanced design and construction methods confer numerous advantages.<\/p>\n

What Are Precast Concrete Arches and Their Benefits?<\/strong><\/h1>\n

Precast concrete arches are structural solutions increasingly utilised in large infrastructure projects across Australia, including roadways, railways and mining. These arches are engineered to provide robust support and long-lasting durability for bridge underpasses, overpasses and covered tunnels, and offer a range of benefits due to their innovative design and construction methodology. A notable example of this innovation is the TechSpan\u00ae arch, offered by Reinforced Earth.<\/p>\n

Advantages of Concrete Arches for Engineering Projects<\/strong><\/h2>\n

High Load-Bearing Capacity<\/strong><\/h3>\n

Accommodate Heavy Loads:<\/strong> Concrete arches are engineered to support substantial loads, including high fills and significant live loads. They are adept at handling both static and dynamic forces, making them ideal for high-traffic and demanding environments.<\/p>\n

Alternating Loading Conditions:<\/strong> These structures are capable of withstanding alternating loads during both installation and service, ensuring stability and safety throughout their lifecycle.<\/p>\n

Efficiency and Speed of Construction<\/strong><\/h3>\n

Reduced Onsite Time:<\/strong> Precast elements, such as TechSpan\u00ae arches, significantly reduce the duration of onsite construction, leading to faster project completion and lower costs.<\/p>\n

Minimal Wastage:<\/strong> The controlled factory environment for precasting minimises material waste, enhancing the sustainability and cost-effectiveness of the construction process.<\/p>\n

Rapid Installation:<\/strong> TechSpan\u00ae arches can achieve erection rates of 10 to 20 linear meters per shift with a single crane. The process can be expedited further with two cranes, facilitated by a straightforward and predictable installation procedure that requires only a small crew and conventional equipment.<\/p>\n

Design Flexibility and Precision<\/strong><\/h3>\n

Custom Design:<\/strong> Each precast concrete arch is tailored to meet specific project requirements. The use of finite element model (FEM) analysis, as seen in TechSpan\u00ae designs, ensures optimal curvature and minimal bending moments, resulting in slender yet robust structures.<\/p>\n

Optimised Reinforcement:<\/strong> FEM analysis allows for optimised reinforcement, enhancing the safety and durability of the arches while keeping costs low for builders and end-users.<\/p>\n

Free Design Tools:<\/strong> Reinforced Earth provides an online design tool at www.precastarches.com<\/a>, enabling designers, project managers, and coordinators to draft their required TechSpan\u00ae arch and download CAD drawings.<\/p>\n

Durability and Longevity<\/strong><\/h3>\n

Long Service Life:<\/strong> Precast concrete arches, such as TechSpan\u00ae, are designed for a 100-year service life, in accordance with Australian Standard for bridge design. This ensures long-term safety and functionality.<\/p>\n

Resilience to Environmental Factors:<\/strong> Concrete arches are highly resistant to weathering, aggressive environments, and erosion, contributing to their longevity and reliability in various conditions.<\/p>\n

Space Efficiency<\/strong><\/h3>\n

Narrow Footprint:<\/strong> The installation of TechSpan\u00ae arches requires a narrow footprint, allowing for efficient use of space, which is particularly beneficial in constrained project sites or urban environments.<\/p>\n

The above outlines precast concrete arch benefits, read on to learn more about precast concrete arch technology, design and construction.<\/em><\/p>\n<\/div>

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Technical Details and Design of Segmental Precast Arches – TechSpan\u00ae<\/h2>\n

TechSpan\u00ae bridge arches and culverts consist of segmental precast units forming a three-hinged arch structure, utlising the concept of a funicular curve. The term funicular is defined as “imitating a rope and its tension”. While sophisticated in terms of design, the precast arch is simple for planners and builders to incorporate into their bridge and tunnel projects across Australia, offering a span of 8m to 22m<\/a>, and heights up to 10m at 1m in width.<\/p>\n

Optimised precast arch construction and manufacturing, using Reinforced Earth\u2019s unique flexible concrete precast formwork and quality-controlled casting process, results in finished elements that conform to any and all geometric and material quality specifications. The TechSpan\u00ae design and material supply package of concrete arches often includes materials required to construct the necessary retaining structures for wing walls and spandrels, and also other precast solutions including footings, copings, barriers and slip joints.<\/p>\n

The TechSpan\u00ae solution minimises site needs and minimises disruptions, eliminating the need for intensive onsite formwork, scaffolding, joints or bearings. Installation of the precast concrete TechSpan\u00ae arches over active roadways, railways, waterways and conveyance systems is possible without disruption to the ongoing activity.<\/p>\n

The three-hinged TechSpan\u00ae system consists of precast concrete half arch units that meet at the crown, supported by precast or cast-in-place footings sized for site specific conditions. MSE walls are easily customised and built at the ends of the arch tunnel, forming a standalone bridge, concrete tunnel, or hydraulic structure. The arch units are typically 200 to 300 mm thick, and are custom designed for the application to minimise materials.<\/p>\n

TechSpan\u00ae precast concrete arch construction starts with the installation of cast-in-place or precast footings on both sides. The arch units are set and grouted along the footing keyway. Geotextile or geomembrane is applied to the joints as designed. The crown beam is cast along the top of the arch, locking both sides together. MSE headwalls or wing walls are then installed as designed.<\/p>\n

The abbreviated installation procedure consists of the following steps:<\/p>\n