Category: 白皮书论文

长距离隧道掘进机：印第安纳州印第安纳波利斯市DigIndy隧道系统中翻新主梁式掘进机的应用

在妥善维护的情况下，隧道掘进机（TBM）的使用寿命可达数十年，且能在一个又一个项目中经过翻新后继续使用。翻新后的隧道掘进机能有多出色？在美国印第安纳州印第安纳波利斯的DigIndy隧道系统项目中，一台翻新后的隧道掘进机就发挥了显著作用。这台直径6.2米的主梁式隧道掘进机最初制造于1980年，经翻新后掘进了40多公里的隧道，并在6至7米直径级别中创下三项世界纪录，其中单月最佳掘进成绩为1754米。在本文中，作者对该隧道掘进机的翻新过程、性能表现以及经验教训进行了分析，为未来计划在长距离工程中使用翻新隧道掘进机的项目提供建议。

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相隔 30 年的隧道掘进机设计与性能评估：莱索托高地输水隧道一期与二期工程

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Use of a Tunnel Boring Machine on Nepal’s First and Second TBM-Driven Tunnels

Nepal’s mountainous terrain has historically been a challenge to tunnel through. That very terrain also holds great promise for hydropower – a resource that the country is now beginning to tap into. Launched in October 2022, a 6.4 m Double Shield TBM is making Nepal’s hydropower plans into a reality as it bores the 13.1 km headrace tunnel for the Sunkoshi Marin Diversion Multipurpose Project (SMDMP). The tunnel is connected to a 28.6 MW surface powerhouse on the Marin River.

The SMDMP is the machine’s second tunnel: on its 12.2km first tunnel (the Bheri Babai Diversion Multipurpose Project/BBDMP), the TBM finished nearly one year early and achieved 1,202 m advance in one month. It was the first instance of TBM use in the country.

In this paper, we examine the successes and lessons learned in Nepal’s mountainous conditions during excavation of both the SMDMP and BBDMP.

 

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Record-Setting Large Diameter Mixed Ground Tunneling in Turkey: The Eşme-Salihli Railway Tunnel

Large diameter tunneling has historically been seen as a challenge. Add into the equation mixed ground conditions, and it becomes a task that may seem insurmountable. How-ever, a recently completed tunnel in Turkey is a flagbearer for changing the mindset towards these challenging tunneling scenarios that are becoming more frequent. A 13.77 m diameter mixed ground Rock/EPB TBM bored the Eşme-Salihli Railway Tunnel at rates of up to 721.8 m in one month, making it the fastest TBM ever recorded over 13 m in diameter. The machine began its bore in altered gneiss, then passed through mélange consisting of gneiss, sandstone, claystone, mudstone, quartz, and silt. By the end of the bore the machine was excavating in mainly mudstone. Core drillings were taken every 200 m prior to boring.

In this paper, we detail the project as well as analyze factors contributing to the fast advance rates. The factors include TBM choice and system design, ground conditions, TBM utilization rates and downtimes, as well as maintenance practices, crew expertise and technical support, all of which have a part to play in the overall advance rates and successful outcome. Recommendations are made as to best practices in order to achieve good advance rates on similar large diameter, mixed ground tunnels.

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Lessons Learned During Excavation of the Incredibly Challenging Yin Han Ji Wei Water Diversion Tunnel

The 2022 breakthrough of an 8 m diameter Main Beam TBM at China’s Yin Han Ji Wei project was a triumph of technology and perseverance – crews at the 17.5 km long tunnel encountered over 14,000 rock bursts, some with energy as high as 4,080 kJ. The rock, consisting of mainly quartzite and granite, was estimated to have a rock hardness of between 107 and 309 MPa UCS, with high abrasivity and a maximum quartz content of 92.6%. The incredibly challenging tunnel also experienced at times severe water inflows, with one particular event exceeding 20,000 m3 of water in one day from a single point. In-tunnel ambient temperatures peaked at 40 degrees Celsius and 90% humidity. Throughout the challenges, the crew and support teams found ways to persevere – whether through unique ground support, or increased monitoring and analysis. In this paper, we will examine the successes and lessons learned in the incredibly challenging ground conditions, determining what worked best to confront each condition as it came up. Recommendations will be made towards what could be used successfully on future projects that en-counter these geological features.

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Record-Setting Tunnel Boring Below Lake Ontario at the Ashbridges Bay Outfall Tunnel

The 3.5 km long Ashbridges Bay Outfall in Toronto, Ontario, Canada was a challenging drive set below Lake Ontario. After a remote machine acceptance due to the global pandemic, an 8 m diameter Single Shield machine launched in March 2021 from an 85 m deep shaft and began its bore in shale with limestone, siltstone and sandstone. During excavation, the TBM and its crew bored a city-wide record of 30 rings in one day, or 47 m of advance. This paper will cover the unique project, from TBM acceptance through to launch, tunneling in difficult conditions, and completion in 2022.

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Enhanced Probe Drilling & Pre-Grouting on Hard Rock TBMs

While probe drills are not strictly necessary for all projects, the incorporation and use of probe drills and pre-grouting adds capability and insurance to boring operations. Water ingress and unstable ground can be resolved before becoming a problem and resulting in costly delays through the use of enhanced, 360-degree probe drilling setups. To do this, proper design of the array of drill ports in the shield, matched to the possible ground conditions, is critical. For ground with exceptional water and instabilities expected, additional probing locations are low-cost additions that can lower risk and increase efficiency. In this paper we will look at recent and ongoing projects including the Lower Meramec Tunnel and Jefferson Barracks Phase 2. We will detail the design of those probe drill arrangements, and our overall recommendations for probing/grouting systems that best suit challenging ground conditions and keep projects running smoothly.

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A Clean Solution for Renewable Energy: Small Diameter Hydro Tunnels

Small hydroelectric power projects, with installed capacity up to 10 MW, are a relatively untapped but potentially game-changing source of renewable energy worldwide. In Norway, hydro projects are pioneering the use of small diameter TBMs in hard rock. Compared with drill and blast, TBMs offer increased production rates and reduction in cross section, as well as lowered rock support requirements and reduced project schedules.

The uniquely designed machines are engineered to take on steep gradients, up to a 45-degree angle in some cases. Both shielded and open-type TBM designs have been developed that utilize safety grippers and customized mucking systems to operate at steep grades. This paper will discuss the specialized TBMs and their performance at several projects in Norway, as well as the potential to use this technology throughout Europe and internationally.

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Non-Circular Tunnel Boring for Underground Mine Development

TBMs have been used in mining in decades past, but their use has been limited and sporadic. This has changed in recent years, with TBMs being used at Stillwater Mine, Grosvenor Coal Mine Slopes, and Sirius Minerals potash mine. These machines are all full face, circular TBMs. With their circular bores, these machines have thus far been unable to tackle a larger issue for mines—the need for a flat floor. While the mining industry excavates many more kilometers of tunnel each year than the civil construction industry, typically a flat floor is needed for mining vehicles to traverse.

A novel type of non-circular boring machine is now answering that need with its ability to cut a rectangular profile in hard rock. This cross section allows for use of typical mine trucks and other rubber-tired mine vehicles. It provides more useable space, compared to a circular profile, and minimizes the amount of excavated rock that must be hoisted out of the mine. This machine uses typical disc cutters to cut the rock and has a support structure similar to an open type TBM; however, the cutting geometry is entirely different. The machine is currently cutting an access tunnel at a silver mine.

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Unprecedented In-Tunnel Diameter Conversion of the Largest Hard Rock TBM in the U.S.

The largest hard rock TBM ever to bore in the USA, an 11.6 m diameter Robbins Main Beam TBM, recently underwent a planned in-tunnel diameter change to a more compact 9.9 meters. The first-of-its-kind conversion process for the Main Beam TBM was undertaken 2.8 km into the bore and was not done inside a shaft or pre-excavated portal. This paper will detail the unique dual-diameter machine designed for the Mill Creek Drainage Relief Tunnel in Dallas, Texas, USA, machine performance, and successful size conversion process that took place in early 2021—a process that utilized the four C’s of construction to enormous benefit: Communication, Cooperation, Collaboration and Coordination.

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