Satt Singh Basra’s Post

I am still in love with tunnelling work, despite the risks in almost all aspects. The heat and smoke almost everywhere that I have been through.    

Almost 900 women have applied to join this groundbreaking initiative, showcasing the immense interest in construction careers among women. ACCIONA, as part of the Suburban Connect consortium, have received an unprecedented number of applicants for the world's first all-women Tunnel Boring Machine (TBM) crew for the Suburban Rail Loop (SRL) East project in Melbourne. 🔍- About the New Crew The all-women TBM crew will be one of several teams tasked with excavating the SRL East’s 16km twin tunnels between Cheltenham and Glen Waverley. This pioneering team will comprise approximately 25 highly skilled positions, including TBM operators, gantry and segment crane operators, grouters, and various support roles. Successful candidates will undergo comprehensive training and gain hands-on experience to equip them with the necessary skills for their roles. The strong response means that even applicants not selected for the TBM crew may be considered for other suitable positions within the project. ACCIONA, alongside our consortium partners CPB Contractors and Ghella, are committed to ensuring that at least 10% of total labour hours on the Tunnels South works will be performed by women. 🔍- About the Project SRL East Tunnels South will also deliver 55 safety cross passages between the tunnels, station boxes at Clayton and Monash and the construction of portals – the entrances and exits to the tunnels – at the stabling facility. The SRL East project, spanning from Cheltenham to Box Hill, will feature six new underground stations. Construction activities are already in progress at each site, with crews preparing TBM launch sites, relocating underground services, and setting the stage for major construction efforts. Tunnelling operations are set to commence in 2026, with the all-women crew anticipated to be operational by 2027. This initiative not only marks a significant milestone in the construction industry but also aligns perfectly with ACCIONA's commitment to diversity, inclusion, and sustainable infrastructure development. The SRL East project is expected to create up to 8,000 jobs, with over 1,400 individuals already contributing to its progress. We’re proud to be part of this transformative project to significantly reduce travel times, alleviate congestion, and open up more housing options near essential services in Melbourne's east and southeast. #SustainableInfrastructure #InvestInThePlanet #ACCIONAteam

Second Chilterns TBM breaks through The second tunnel boring machine (TBM) building #HS2 under the Chiltern Hills broke through at the twin tunnels’ northern portal on Thursday 21st March 2024. Having set off from near Maple Cross in June 2021, TBM Cecilia has now completed her 10-mile drive and reunited with her twin sister machine, Florence, who reached the site near Wendover on 27th February after completing her adjacent tunnel drive. Between them, the two 2,000-tonne machines have built the twin bore tunnel at depths of up to 80 metres and excavated three million cubic metres of chalk. They have each installed 56,000 pre-cast concrete tunnel segments, grouting them into place and moving forward at an average speed of 16 metres per day. HS2 Ltd’s head of civil works for this section of the route, Mark Clapp, said: “Cecilia’s arrival completes excavation of HS2’s 10-mile twin-bore tunnel, but it’s only the end of the first chapter in the story of building Britain’s high-speed railway under the Chiltern Hills. Several years of intensive, world class engineering lie ahead of us to complete the tunnels’ four ventilation shafts plus headhouses; install the mechanical and electrical plant and machinery, slab track and overhead electrical wires before trains begin passing through at 200mph.” The #Herrenknecht TBMs were operated by HS2’s main works contractor, Align – a joint venture of Bouygues Construction, Sir Robert McAlpine, and VolkerFitzpatrick Ltd. Align’s underground construction director, Didier Jacques, said: “Ten miles is a long drive for a TBM, with a typical average being around three miles. The complexity and technically challenges of completing such a long drive for both our TBMs has been significant. However, I am delighted that as a team, we have risen to the challenge. “Both TBMs were designed in partnership with Herrenknecht and incorporate innovations and technologies that have been introduced on TBMs in the UK for the first time, to enhance performance and safety. This includes ‘semi-continuous boring’, allowing our TBMs to build the rings that line the tunnels without pausing.” https://lnkd.in/efmg6kpU

 A new #tunnel boring machine (#TBM) from Herrenknecht AG in #Germany will be used to drive the new bore for the Gotthard Tunnel in #Switzerland. The driving work will be carried out by the #construction company Marti Group while the client is the Swiss Federal Roads Office (ASTRA).  The new tube is needed due to the growth in #traffic since the original bore was built. Around 16,000 vehicle/days pass through the 16.9km Gotthard #road tunnel. It is a key link for European north-south traffic through the Alps. It runs between Göschenen in the Swiss canton of Uri and Airolo in the canton of Ticino. The Swiss Federal Roads Office (ASTRA) is tackling the necessary age-related repairs after long-term and careful planning.  ASTRA has commissioned the #construction of a second, parallel tube to ensure that traffic can continue to flow during the #renovation and the necessary closure of the tunnel. Once all the work on both tubes has been completed, one tunnel with one lane (plus emergency lane) will be available for southbound and one for northbound traffic, an improvement in safety compared to the previous operation with two-way traffic in one tube.  The diameter of the Single Shield TBM is 12.31m and the cutterhead is driven by 16 electric motors, which have a total output of 5,600kW. As a Single Shield TBM, the machine is a specialist for driving through the hard rock of the Alps. Granite, gneiss and slate are the main types of rock to be expected on the 7.755km-long southern #tunnelling section.  Following its #technical acceptance, the #machine will now be dismantled and the components transported to the construction site in Airolo (Ticino). There, the TBM will be reassembled so that the personnel from Marti Tunnel can start driving the main tunnel from the south as planned from March 2025. According to preliminary #geological investigations, the tunnel builders expect a geological fault zone in both the north and south of the planned route for the main tunnel. Due to the rock characteristics, the decision was made to #excavate the two fault zone sections using conventional blasting before starting the mechanised main tunnel drive. In order to reach the fault zones in the mountain, access tunnels were driven through the rock. For the access tunnels, mechanized tunnelling #technology was also used. Marti Tunnel successfully completed the excavation of the southern access tunnel with a Herrenknecht Single Shield TBM in August 2023. The machines for the main tunnel will later be pulled through the two fault zones that have already been excavated.  A joint venture partnership, ARGE secondo tubo, is carrying out the project and comprises Implenia Schweiz, Frutiger Gruppe; Los 243 with Webuild and CSC construzioni. 

The precise erection and fixing of a TBM ensure efficient and accurate tunneling operations. The erection and fixing of a Tunnel Boring Machine (TBM) involve several critical steps to ensure efficient tunneling operations. First, the TBM is transported in sections to the construction site, where a specialized team assembles it in a launch shaft. This process requires precise alignment and the use of cranes or gantries to position the machine's various components, including the cutter head, shield, and backup systems. After assembly, the TBM is anchored securely to the launch site’s framework to prevent shifting during operation. Hydraulic jacks then push the machine forward to begin the tunneling process. Throughout this process, engineers continuously monitor and adjust the machine’s alignment to maintain optimal performance and tunnel accuracy. video rights : Tunnel Engineering (IG) #tunnel #tunnelling #engineering #construction #civilengineering #civilconstruction #engenhariacivil #engenharia #engenheiro #engenheirocivil #ingeniero #ingenierocivil

Exploring the Powerhouses of Tunneling: Types of TBM Tunnel Boring Machines (TBMs) are engineering marvels, each unique #designed to #conquer the #subterranean world. Let’s delve into the five principal types of #TBMs that facilitate our ambitious #underground #projects. 1.0 Main Beam TBM: The stalwart of hard rock excavation, the Main Beam TBM is your go-to machine for rapid penetration through the toughest terrains. Its full-face cutter-head carves out tunnels with precision, making it an indispensable asset for swift progress. 2.0 Double Shield TBM: When traversing fractured rock zones, the Double Shield TBM is the best choice. Its ingenious design allows for simultaneous drilling and casing, ensuring safety and efficiency even in the most challenging conditions. 3.0 Single Shield TBM: The Single Shield TBM offers a sanctuary for projects plagued by unstable grounds. It provides a protective shell for workers while the tunnel lining is securely installed, mitigating the risks associated with broken strata. 4.0 Crossover TBM: The chameleon of TBMs, the Crossover, adapts to mixed geological landscapes. Whether it’s hard rock, soft ground, or boulder fields, this TBM can switch components to tackle diverse tunneling scenarios, exemplifying versatility. 5.0 Earth Pressure Balance (EPB) TBM: Tailored for soft, waterlogged soils, the EPB TBM maintains equilibrium between earth pressures. Its articulated shield counters water ingress, while the controlled pressure environment facilitates safe and steady excavation. Selecting the appropriate type of Tunnel Boring Machine (TBM) is crucial for the success of a #tunneling project. The decision is typically based on a thorough analysis of several key factors: **Tunnel Length**: Longer tunnels may require TBMs with higher endurance and advanced systems for muck removal and segment installation. **Tunnel Cross Section**: The tunnel's size and shape influence the TBM's design and size. **Tunnel Depth**: Deeper tunnels face higher pressures and temperatures, necessitating robust TBMs capable of withstanding such conditions. **Geotechnical Conditions**: The type of soil or rock dictates the cutting tools and shield type. For instance, hard rock TBMs are equipped with disc cutters, while soft ground TBMs may use an earth pressure balance system. **Water Table**: The presence of water requires TBMs that can handle inflows, such as Slurry TBMs or EPBs with face pressure control to prevent flooding. A comprehensive geotechnical report analysis is essential to understanding the ground conditions. This includes assessing the stability and face support requirements, soil and rock excavation challenges such as clogging and wear, and the percentage of fines at the tunnel excavation profile. The permeability and hydraulic head also play a role in determining whether an Earth Pressure Balance (EPB) or Slurry machine is more suitable.

"According to a report FBA and Cartesian put together, the median cost for underground deployments is $16.25 per foot, more than twice the median cost of aerial deployments ($6.49 per foot)." ..... "Respondents said labor made up around 73% of the cost of underground deployments and 67% of aerial construction costs. Labor’s share of cost was roughly twice that of construction materials." ..... "The median underground deployment cost in urban areas (with more than 50 homes per mile) is $23.25 per foot, whereas the median aerial cost is $6.54 per foot." ..... "Cartesian found trenching was the cheapest construction method for underground deployments, with a median cost of $12 per foot. Plowing was the most expensive at $17 per foot. Directional boring was the most frequent method respondents cited ($15.10 per foot median cost)" #Fiber #FTTX #FTTH #BEAD #FBA

CHILTERN TUNNEL TBMS DISMANTLED Dismantling of the two TBMs that built HS2 (High Speed Two) Ltd’s Chiltern Tunnel has been completed. TBM Florence broke through on HS2 (High Speed Two) Ltd’s longest tunnel on February 27, followed by TBM Cecilia on March 21. The two Herrenknecht AG machines were 170m long and weighed 2,000 tonnes. Mammoet, which supported Align JV with the assembly of the two TBMs at the south portal, also dismantled them at the north portal after they each completed their 16.1km journey. Mammoet senior commercial manager Simon Crawley said the restrictions at the north portal meant the equipment used to build the TBMs wasn’t necessarily what was needed for their dismantling. “There were different limitations at the two sites. Because there were obstructions in the way, a 600t crawler crane was needed at the construction stage. We believed that a 400t crawler crane would be adequate to perform the dismantling,” he said. The 400t capacity crawler crane was used to remove the biggest components from the TBMs. To remove the cutterhead, an LR1300SX crawler crane was also used to perform a tandem lift. The components were lowered onto Mammoet self-propelled modular transporters (SPMTs) before being taken to one of two laydown areas. Read more online: https://lnkd.in/gP43XJJ6 Follow the British Tunnelling Society for the latest insight on tunnel-related matters To learn about the benefits of joining the British Tunnelling Society click here: https://bit.ly/3r0MPoU #BritishTunnellingSociety #civilengineering #undergroundconstruction #tunnelling

First cross-border TBM unveiled for Mont Cenis base tunnel The TBM that will build the tunnel across the French-Italian border for the new Lyon-Turin railway has been unveiled at Herrenknecht’s factory in Germany. The 10.4m, 334m-long machine is the fourth of seven TBMs delivered to excavate the tunnels of the Lyon-Turin line, and the first for the twin tunnels that will cross the border. The ELYOT group of companies, comprising Eiffage Génie civil, Spie batignolles génie civil, Ghella and Cogéis, will deploy the gripper TBM to excavate 18km of one of the two tubes of the Mont Cenis base tunnel, between the Villarodin/Bourget-Modane access adit in France and the Clarea underground safety site in Italy. A gripper TBM was chosen because of the geology of relatively compact, uniform and stable formations; the depth of the tunnels, with more than 2,200m of overburden; and geotechnical considerations, such as detachments and convergence. There are also the high temperatures present at such depths, which were highlighted by the exploratory tunnel of La Maddalena in Chiomonte, which was used to establish the TBM’s specification. While excavation is under way, shotcrete support will be applied to the walls, along with bolts and ribs. Behind the TBM, a 650m-long machine called the Würm (worm) will fix the final concrete lining. CO5 construction site on the Mont Cenis base tunnel crosses the border between Italy and France. It starts from the Villarodin-Bourget-Modane access adit, passes through the Ambin massif, and reaches the underground safety site of Clarea. At the same time as the 18km-long twin tunnels are excavated, 7.8km of tunnels will be dug using conventional methods. In addition to these works, all connected and logistical works will be carried out. In total, around 15km of tunnels will be built using the conventional method, including the underground safety area at Modane. Maurizio Bufalini, general director of Tunnel Euralpin Lyon-Turin (TELT), said: “It is the fourth TBM that we have come here to receive in Schwanau and, as ever, it is always a great thrill. Its twin will be ready in February, and then it will be the turn of the two Italian TBMs. We will then have no fewer than seven of them digging to complete the 57.5km tunnel, the longest railway tunnel in the world.” CO5 project director Salah Ghozyel said the job site was exceptional “in terms of size, logistics, simultaneous excavation using both conventional and mechanised methods, along with the technical and human resources mobilised, all of which are constrained by the single access point provided by the Villarodin-Bourget/Modane access adit”. “All this means that the group of companies and all those involved will need to be truly adaptable,” he said. https://lnkd.in/eTG6vwGD

The precise erection and fixing of a TBM ensure efficient and accurate tunneling operations. The erection and fixing of a Tunnel Boring Machine (TBM) involve several critical steps to ensure efficient tunneling operations. First, the TBM is transported in sections to the construction site, where a specialized team assembles it in a launch shaft. This process requires precise alignment and the use of cranes or gantries to position the machine's various components, including the cutter head, shield, and backup systems. After assembly, the TBM is anchored securely to the launch site’s framework to prevent shifting during operation. Hydraulic jacks then push the machine forward to begin the tunneling process. Throughout this process, engineers continuously monitor and adjust the machine’s alignment to maintain optimal performance and tunnel accuracy. video rights : Tunnel Engineering (IG) #tunnel #tunnelling #engineering #construction #civilengineering #civilconstruction #engenhariacivil #engenharia #engenheiro #engenheirocivil #ingeniero #ingenierocivil