Analysis of the examination and maintenance of the Jakarta MRT Tunnel Wall

Tunnel boring machines (TBM) excavate tunnels with a circular cross section through a variety of rock strata. They can be used to bore through hard rock or sand and almost anything in between. Tunnel diameters can range from a metre (done with micro-TBMs) to 19 metres. Tunnel boring machines are used as an alternative to drilling and blasting (D&B) methods. A TBM has the advantages of not disturbing surrounding soil and producing a smooth tunnel wall. This significantly reduces the cost of lining the tunnel, and makes them suitable to use in built-up areas. The key disadvantage is cost. TBMs are expensive to construct, difficult to transport and require significant infrastructure. A tunnel boring machine (TBM) typically consists of one or two shields (large metal cylinders) and trailing support mechanisms. At the front end of the shield a rotating cutting wheel is located. The cutting wheel will typically rotate at 1 to 10 rpm (depending on size and stratum), cutting the rock face into chips or excavating soil (muck). A TBM can cut through rock at up to one kilometre a month. Powerful hydraulic rams force the machine’s cutting head forwards as the rock is cut away called the feed. The action here is very much like an earthworm. The rear section of the TBM is braced against the tunnel walls and used to push the TBM head forward. At maximum extension the TBM head is then braced against the tunnel walls and the TBM rear is dragged forward. As tunnels has become one of the most important source of underground transportation like metro rail and other projects, this TBM can be utilized as an easy and effective machine for more better results. Because of their demonstrated capabilities in attaining high rates of advance in civil tunnel construction, the hard rock mining industry has always shown a major interest in the use of TBMs for mine developments. The successful application of TBM technology to mining depends on the selection of most suitable equipment and cutting tools for the rock and ground conditions to be encountered.

Imaging ahead of a tunnel boring machine with DC resistivity: A laboratory and numerical study

With recent technological advancements, tunnel boring machines (TBM) have developed and exhibited high performance in large diameters and weak ground conditions. Tunnels are crucial structures that significantly influence the timelines of highway and railway projects. Therefore, the construction of tunnels with TBMs becomes a preferred option. In this study, a comparative analysis between TBM and the New Austrian Tunneling Method (NATM) for tunnel construction is performed in the construction of the T1 tunnel with a diameter of 13 m, which is the longest tunnel in the Eşme‐Salihli section of Ankara‐İzmir High‐Speed Railway Project (Türkiye). The selection of TBM type, measures taken in problematic sections, and application issues of TBM are discussed. The impact of correct description of geological and geotechnical conditions on both selection and performance of TBM is presented. An earth pressure balanced type TBM is chosen for the construction of the T1 tunnel. Because of the additional engineering measures taken before excavation in problematic areas, the tunnel was completed with great success within the initially planned timeframe. From this point of view, this study is an important case and may contribute to worldwide tunneling literature.

The purpose of this study is to establish a smart safety management system during deep-seated Shield TBM(Tunnel Boring Machine)tunnel construction. During this work, the site is continuously managed and controlled audio-visually to identify and discover unexpected situations in advance. This study aims to contribute to preventing accidents during TBM (Tunnel Boring Machine) construction while performing efficient work by responding accurately. The system is composed of turn gates and vascular recognizers that can control workers'access, smart tags for tracking workers' location in real-time, emergency call systems, Workers motion sensor to detecting workers who are not moving, monitoring through CCTV cameras, PTZ (Pan Tilt Zoom), DOME, sensing systems detecting four major gases (02, CO, H2S, CH4) that can cause serious accident, loudspeakers, amplifiers, and two-way interphones, etc.
 As a result of this study, the IoT Smart Safety Management System for the Shield TBM Tunnel Construction in the deep underground construction site has been materialized to establish the Safety Management Control Center, safety management system for TBM Construction Machinery, tunnel internal safety management system, network system, and can make immediate response in case of emergency. This system can guarantee safety of workers who provide labor within the poor working environment of deep underground spaces. The IoT-based smart safety management system established in this study is expected to contribute a IoT to preventing industrial accidents at the site of underground deep-seated TBM tunnel construction (earth pressure type and Slurry shield TBM or Open TBM) over 40m in the future.

This paper describes the advanced concepts used for the underground construction of tunnels i.e., the New Austrian Tunneling Method (NATM) in Indian Metro Rail. Many areas of Indian cities are highly congested and populated. Hence, elevated metro rail construction is not always feasible. Therefore, the Metro Rail system in India is elevated as well as underground also. Underground tunnel construction below highly congested urban area is another challenge in itself. It was constructed by using various tunneling methods. Some most popular methods used for tunnel construction in urban areas are Tunnel Boring machines (TBM), Cut & Cover Method, NATM, etc. The construction of a complete tunnel by using a single method does not only consume more time but also results in uneconomical construction. NATM is commonly adopted on both sides of underground stations for providing a safe opening for TBM launching and outbreaks. It is also used for providing cross-passage between up-line and down-line tunnels. In this paper, the methodology of applications of NATM in Indian Metro Rail is explained. The NATM method has been used to construct all underground metro tunnels in India. A comparative aspect of the construction of an underground tunnel by using NATM in Pune Metro and Mumbai Metro is also discussed in this paper. In addition, challenges like heavy groundwater seepage, application of NATM in soft ground, etc. are presented here.KeywordsNew Austrian Tunneling Method (NATM)Cut & Cover MethodTunnel Boring Machine (TBM)Metro stationsCross passage

The world of underground engineering and construction has acquired a wide‐ranging and high‐level experience on tunnel construction with Tunnel Boring Machines (TBM) and nowadays remarkable progresses are traceable in the number of tunnels that are becoming longer, going deeper, and growing larger in diameter and in other words becoming more difficult to realize. Tabriz‐one of the big cities in northern west of Iran has four subway lines which are under construction or investigation. The phase1 design of Tabriz urban railway line 2 (TURL2) has completely been done. Method statement of this line in the length of about 20 km and much interference due to tunneling in urban area dictates the application of TBM. Two kinds of TBM such as EPB (earth pressure balance) and SS (slurry shield) are usually used for urban areas. In this paper, the process of choosing TBM for TURL2 using MCA method (Multi Criteria Analysis) is expressed. Generally in this method some technical, economical and environmental parameters affected the TBM type are identified and taken into account by assigned weights related to the case study. Finally the results show that EPB‐TBM will be more appropriate choice for TURL2 excavation. Santrauka Potemine intinerija ir statyba labai išplito bei igijo aukšto lygmens patirti tuneliu statyboje emus naudoti tuneliu gretimo mašinas (TGM). Šis statybos būdas taikytas statant daug tuneliu, kurie vis ilgeja, gileja ir plateja pagal skersmeni, t. y. statyba realizuojama sunkiau. Tabrize – viename iš didtiausiu šiaures vakaru Irano miestu – yra keturios statomos arba planuojamos statyti metro linijos. Tabrizo miesto geletinkelio 2‐os linijos (TMG2L) pirmoji projektavimo faze yra baigta. Jos ilgis – 20 km, daug jos atkarpu eina po teme. Poteminems atkarpoms pastatyti gali būti naudojamos dvieju tipu TGM. Tai temes slegines pusiausvyros mašina (TSPM) arba suspensijos skydo mašinos (SSM). Šiame straipsnyje nagrinejamas TGM pasirinkimas tarp TSPM ir SSM taikant daugiatiksli sprendimu priemimo metoda (DSPM). Šiam metodui pritaikyti apibretiami tam tikri techniniai, ekonominiai ir aplinkos rodikliai, darantys itaka TGM tipui. Rodikliams priskiriami svoriai. DSPM taikymo rezultatai parode, kad TSPM yra tinkamesne TMG2L kasti.

Construction of large-diameter drainage tunnels requires stringent line and grade tunnel alignment control in order to carry sewer and storm water in municipal areas. Tunnel boring machine (TBM) has been extensively applied to improve tunneling productivity and safety performances on drainage tunnel projects. The current practice for TBM guidance largely relies on the traditional laser system, which however falls short of accuracy and reliability. The proposed research aims to develop an automation solution to facilitate TBM guidance and as-built tunnel alignment survey in drainage tunnel construction. In contrast with our previous application of automating TBM guidance in microtunneling and pipe jacking for installing small-diameter utility pipelines, this research will address a related but more challenging problem defined in the context of drainage tunnel construction due to different construction methods and particular site constraints. An automation system is proposed, in which a robotic total station is employed to automate the continuous process of TBM tracking and positioning in the 3D underground space. ZigBee-based wireless sensor networks are applied for wireless data communication inside the tunnel. Real-time survey data are thus acquired and processed on the fly, resulting in: (1) TBM's precise coordinates in the underground space; (2) three-axis body rotations of the TBM; (3) tunneling chainage progress; and (4) line and grade deviations of the tunnel alignment. A prototype of the automation system was developed in-house and the lab testing carried out.

The uncertainty of rockmass conditions will be an important factor causing TBM construction risks and inefficient tunnelling. Currently, prediction of rockmass classification based on TBM operation data and machine learning models has been proved feasible by many researchers. However, due to the sample imbalance problem in the previous studies, the prediction accuracy of minority rockmass class is relatively poor. To overcome the above problem, this study proposed a rockmass classification advance prediction method based on cost-sensitive learning (CSL), which using 10 key TBM operation parameters as model inputs. First, through the data preprocessing, the dataset consists of 7538 TBM tunnelling cycles and corresponding rockmass classification information is obtained. And the sample set was divided into training set and test set by stratified sampling. Then, eight classifiers, i.e., support vector machine (SVM), decision tree (DT), random forest (RF), k-nearest neighbors (KNN) and their cost-sensitive version are established to construct the mapping relationship between key TBM operation parameters and rockmass classes. The case study results show that AdaBoost classifier presents the best prediction performance, with the accuracy and F1-score more than 0.9. And CSL can improve the prediction accuracy of minority class samples to some extent to achieve more reasonable prediction results. INTRODUCTION With the continuous improvement of construction mechanization level, tunnel boring machine (TBM) plays an increasingly important role in tunnel construction. Especially for long tunnels, the efficiency and economic advantages of TBM will be more obvious (Liu et al., 2020a; Hou et al., 2022b). TBM is sensitive to the change of rockmass condition, and depends on the empirical adjustment of TBM driver to achieve adaptive tunnelling (Hamidi et al., 2010). However, the geological exploration boreholes before the construction of the long tunnel are relatively sparse, which cannot effectively describe the rockmass conditions of the whole tunnel. Therefore, it is urgent to propose an advanced prediction method of rockmass classification during TBM construction.

NATM is a design philosophy as well as a construction process. The idea is to reinforce the tunnel construction as much as possible by utilizing the strength of the surrounding earth. Put another way, the tunneling process is dictated by the ground conditions. Constant monitoring is also encouraged by the NATM ideology. The study investigates the structural behavior of concrete linings in Mumbai Metro Line-3’s Sahar Road crossover, focusing on comparing the New Austrian Tunneling Method (NATM) and Tunnel Boring Machine (TBM) utilization. The research aims to understand these methods’ effectiveness in ensuring tunnel constructions’ integrity and stability. The research compares various load combinations at different sections and parts of the crossover. Stress resultants, including axial force, moments, and shear forces, are analyzed using STAAD Pro software to understand the concrete tunnel lining’s structural behavior accurately. Additionally, Von Mises stresses are used to predict the behaviors of SCL under the complex loading. Principal minor and major resultant stresses are scrutinized. The design of the final lining in underground works through NATM (New Austrian Tunneling Method) incorporates a comprehensive approach, encompassing software analysis, conventional concrete lining principles, and the implementation of Steel Fiber Reinforced Sprayed Concrete Lining (SCL). This multi-faceted design methodology ensures the structural integrity and safety of the final lining in underground constructions.

Design according to MC2010 of a fibre‐reinforced concrete tunnel in Monte Lirio, Panama

Tunnel Boring Machine (TBM) constructed tunnels are widespread, and can deliver significant environmental and cost benefits. However, as noted in the noteworthy examples of TBM traffic tunnels presented in this book, there are still important challenges associated with them, linked in particular to structural safety in the event of earthquakes, as well as cost and safety issues during operation. To face these challenges, Innovation in TBM Traffic Tunnels presents three innovative concepts in the field of construction of TBM rail and road tunnels: the TISB concept that improves the structural safety of those built on soft soil in seismic areas, and the TMG and TMF concepts, for rail and road tunnels, respectively, that allow for significant reduction of their cost and the improvement of safety during operation. Examples of the application of these new concepts in the conceptual design of specific tunnel cases are presented and compared with solutions based on common approaches, demonstrating the additional benefits of these concepts. The book also draws attention to other innovations in TBM tunnelling that may improve the construction of tunnels in the future, especially when using the concepts mentioned above. Innovation in TBM Traffic Tunnels is aimed at professionals involved in the planning, design, and construction of tunnels for transport infrastructure, including authorities, consultants and construction companies, worldwide.

Tunnel construction method using a tunnel boring machine (TBM) is commonly adopted for building underground infrastructure, such as railways, roads, sewers, or utility pipelines. TBM tunnelling entails precise guidance of the machine in the underground space, as well as effective construction management and project control. The research aims to address critical engineering and management problems during the course of tunnel excavation, including TBM guidance, automated asbuilt data acquisition, real-time data processing and 3D visualization. In this paper, we propose an integrated TBM guidance and operations monitoring solution for tunneling applications. A robotic total station is employed to automate the continuous processes of TBM tracking and guidance inside the tunnel. Wireless sensor networks are particularly implemented for on-site data communication. The results of TBM's position state, tunnel alignment and construction progress are processed and presented in straightforward, user-friendly interfaces on the fly. Working with the City of Edmonton, Alberta, Canada, the integrated system has been implemented in the construction of a 2.4-meterdiameter and 1-km-long sewage tunnel project and undergone seven-month field testing in 2013. The solution lends substantial support to TBM operators and project managers in making critical decisions on a near real-time basis.

Tunnel Boring Machine (TBM) is widely utilized in tunnel construction. Effective fault diagnosis of TBM is vital for the safety of tunnel boring since the failure of TBM might cause harm for the workers accompanying with the loss of time and economy. A Web Service-Based Remote Diagnosis System (WSRDS) with Bayesian network (BN) as the faults analysis model is proposed in this paper. BN is a concise, practical and intuitive method to determine the exact cause for failure. The WSRDS enables an easy access for the diagnosis system of TBM and highlights an enhancement to the ubiquitous information processing. Taken the thrusting system of TBM as an example, the architecture of the WSRDS is formulated and the function of every module is described. The key system modules including general diagnostic procedure and integrated design of the diagnostic database are elaborated. The WSRDS could effectively realize the data integration among distributed enterprises of heterogeneous systems and greatly improves system reusability. The proposed WSRDS might have a promising wide application in the maintenance of TBM.

The launching of a tunnel boring machine (TBM) is very important in the tunnel construction procedure, but it also has great risk. Water and slurry may burst into the shield work well in the case of an inappropriate launching process, resulting in the collapse of the work well. Generally, one work well of a tunnel station is uniquely designed for one TBM. The condition where two tunnels or more share one shield work well is rare. Based on the tunnel construction project of metro line 1 in Hangzhou, the special problem of TBM launching from one work well that had three tunnels in parallel was studied. The minimum spacing between tunnels was 1.83 m, which was only approximately one-third of the diameter of the tunnel. The most dangerous situation of middle TBM launching was studied, which had great influence on the two existing side tunnels. A finite element (FE) program was adopted to simulate the grouting reinforcement around the side tunnels. The stresses and displacements of the two side tunnels during the middle tunnel launching progress were studied. The effects of grouting reinforcement and different reinforcement regions were compared to guide the reinforcement construction. By real-time monitoring of the displacement of side tunnels and ground settlement, the grouting reinforcement and TBM operation measures were modified and adjusted, ensuring the successful launching of the TBM.

The NeTTUN (New Technologies for Tunnelling and Underground Works) Project involves a consortium of 23 industrial, research & development laboratories and small and medium enterprise organizations across 9 countries in Europe; the ultimate goal is to enable groundbreaking change in the construction and maintenance of tunnels. Most existing ground prediction methods require the stopping of excavation work for several hours, which relegates them to a once per week activity. This generally far exceeds the available nominal idle time required for the construction of a ring in a segmental lined tunnel. NeTTUN aims to develop a fully automated system, that when installed on a tunnel boring machine (TBM), provides identification of large obstacles that can obstruct digging (e.g. other tunnels, cavities, boulders, foundations, archaeological remains, etc.) as well as soil changes (e.g. from gravel to fractured rock). Current methods for predicting geological variations mainly exploit seismic sources and receivers, deployed during pauses in drilling. In contrast, NeTTUN proposes the combined use of a seismic system and a ground prediction radar. The design has to fulfil two conflicting requirements of a large inspection operating range (which requires low frequency sensors) and detection of rock fractures that can be just a few centimeters in length (requiring high frequency sensors), while also dealing with the main issue of the interaction between the metallic TBM cutter head and the sensors.