scholarly journals Use of saturation diving technique for tunnel boring machine cutterhead intervention in the Tuen Mun–Chek Lap Kok Link Sub-sea Tunnel Project, Hong Kong

2021 ◽  
Vol 28 (1) ◽  
pp. 31-38
Author(s):  
A W Y Chan ◽  
Charles H C Yeung ◽  
A J Westmoreland ◽  
S W Fok ◽  
Conrad C W Ng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Cutting Tools ◽  
Tunnel Boring Machine ◽  
Tunnel Boring ◽  
Tunnel Section ◽  
Decomposed Granite ◽  
Boring Machines ◽  
Mixed Ground ◽  
Tunnel Alignment ◽  
Ground Condition

The entire Tuen Mun–Chek Lap Kok Link (TM-CLKL) was commissioned on 27 December 2020 and it comprises a 9km-long dual 2-lane carriageway between Tuen Mun and North Lantau, Hong Kong. Construction of the 5km-long sub-sea tunnels was carried out by two 14m diameter Tunnel Boring Machines (TBMs). The tunnel alignment for the TM-CLKL sub-sea tunnel section is in mixed ground condition with the first 500 m in mixed geology of slightly to moderately decomposed granite and completely decomposed granite (CDG), followed by soft ground condition with CDG, alluvial sand, alluvial clay and marine deposit. This mixed ground geology requires regular TBM cutterhead interventions to change the worn-out cutting tools during the tunnelling operation. As the tunnel alignment is up to 55 m below the sea level with the deepest seabed level at -21 mPD, in order to maintain the cutting face stability during the intervention, the intervention pressure could be up to 6 bars. This paper describes different techniques used for TBM interventions under the sea such as trimix bounce mode and saturation mode that appears first time in Hong Kong under a high hyperbaric pressure to change the worn-out cutting tools at the TBM cutterhead.

Geotechnical risks, mitigation measures and performance of tunnel boring machine (TBM) tunnels for the Tuen Mun – Chek Lap Kok Link Project, Hong Kong

2019 ◽  
Vol 26 (4) ◽  
pp. 175-189
Author(s):  
Lucas Kwan Lok Chan ◽  
Alan Kwok Lun Kwong
Keyword(s):  
Hong Kong ◽  
Ground Improvement ◽  
Tunnel Boring Machine ◽  
Mitigation Measures ◽  
Face Stability ◽  
Tunnel Boring Machines ◽  
Tunnel Boring ◽  
Overall Performance ◽  
Boring Machines ◽  
And Performance

The Tuen Mun – Chek Lap Kok Link (TM-CLKL) project implemented latest innovation designs and ground improvement techniques in large slurry tunnel boring machines (TBM) tunnelling for constructing the sub-sea TBM tunnel in Hong Kong. Face stability, ground settlement, blow out, water ingress and ovalisation are always the major geotechnical risks for TBM tunnelling in the industry. This paper summarises the design considerations in terms of ground improvement and special arrangements of TBM tunnelling to mitigate the geotechnical risks and the improvement of the overall performance of TBM tunnelling under the TM-CLKL project. Field monitoring data such as surface settlement, ovalisation of segmental lining and ground improvement technique such as barrettes are presented.

scholarly journals Prediction of load on the cutting tools in tunnel boring machines

2020 ◽  
pp. 444-452
Keyword(s):  
Neural Network ◽  
Cutting Tools ◽  
Circular Cross Section ◽  
Tunnel Boring Machine ◽  
Correct Identification ◽  
Tunnel Boring Machines ◽  
Tunnel Boring ◽  
Cutting Insert ◽  
Boring Machines ◽  
Network Type

A tunnel boring machine (TBM) is a machine that is used to excavate tunnels with a circular cross-section. TBMs can bore through a variety of ground conditions. Tunnel boring machines are used as an alternative to drilling methods. TBMs have the advantages of limiting the disturbance to the surrounding ground. Predicting the load on cutting tools in tunnel boring machines is important for the mining process. The article presents a proposal for a method of forecasting the load on mining machinery tools. This paper presents current trends in hard rock tunnelling, including the directions of research on automated excavation processes. Particular emphasis is put on the aspects of predicting load variations in the cutterhead tools, which is of vital importance for machine power selection and mining process control, among others. The problem of predicting the load and wear of excavation tools plays an important role in designing and maintaining cutterheads. The effective monitoring of the operation of multi-tool cutterhead knives and their replacement time depend on correct identification of the type and condition of the excavating tool cutting insert. A neural network with a multilayer perceptron structure was used as a prediction tool. The concept of this network type is based on the arrangement of neurons in successive layers. This neural network type is treated as an input-output model. Its parameters include weights and threshold values.

scholarly journals A perspective of pipejacking works by tunnel boring machines in Hong Kong: part I – development, selection of design, operations and types of techniques

2021 ◽  
pp. 108-118
Author(s):  
Wilson W S Mok ◽  
Andrew S W Ng
Keyword(s):  
Hong Kong ◽  
Design Method ◽  
Tunnel Boring Machine ◽  
Tunnel Boring Machines ◽  
Tunnel Boring ◽  
Ground Conditions ◽  
History Of ◽  
Boring Machines ◽  
And Performance ◽  
Selection Of

In this paper, the history of pipejacking works by tunnel boring machines in Hong Kong, their development, selection of design method and tunnel boring machine (TBM), operations, length and alignment of a pipeline, types of techniques to suit different site constraints and ground conditions, and performance of the works are discussed. This paper should be read together with part II, which covers applications, problems encountered, cost and prospects.

scholarly journals Construction of the Tuen Mun–Chek Lap Kok Link Sub-sea Tunnels in Hong Kong

2021 ◽  
pp. 139-153
Author(s):  
Albert W Y Chan Chan ◽  
Charles H C Yeung ◽  
Andy J Westmoreland ◽  
S W Fok ◽  
Conrad C W Ng ◽  
...  
Keyword(s):  
Hong Kong ◽  
Sea Water ◽  
Cutting Tools ◽  
Tunnel Boring Machine ◽  
Successful Implementation ◽  
Reclaimed Land ◽  
Hyperbaric Pressure ◽  
Ground Freezing ◽  
Ground Conditions ◽  
Mixed Ground

The entire Tuen Mun–Chek Lap Kok Link (TM-CLKL) was commissioned on 27 December 2020 and comprises a 9 km dual twolane carriageway between Tuen Mun and North Lantau, Hong Kong. The challenges for the construction of the TM-CLKL tunnels included sub-sea tunnelling up to 55 m below sea level in mixed ground geology that required replacement of tunnel boring machine (TBM) cutting tools at hyperbaric pressure up to 5.8 bars; replacement of worn TBM cutting tools in complicated ground conditions; construction of approach tunnels in newly reclaimed land subject to long-term consolidation; and construction of cross passages at 100-metre intervals between the two sub-sea tunnels with a risk of sea water ingress at 5.5 bars. This project has deployed sophisticated techniques to surmount the challenges encountered during construction of the five-kilometre-long sub-sea tunnels. These included the use of the world’s largest slurry-type Mixshield TBM, 17.63 m in diameter, for the construction of the northern approach tunnel, followed by two 14 m diameter slurry-type Mixshield TBMs for the construction of the sub-sea tunnels; use of saturation diving techniques for TBM cutterhead interventions up to 5.8 bars which was the first such works in Hong Kong and one of only a few uses of saturation diving in tunnelling worldwide; use of ground freezing techniques in complicated ground conditions for TBM interventions to change worn cutting tools at the TBM cutterhead; TBM tunnelling in newly reclaimed land at the northern landfall and the southern landfall; and the construction of cross passages by mini-TBM using pipe jacking methods between the two main tunnel tubes which was the first such works ever undertaken anywhere in the world. This paper introduces the successful implementation of these techniques for the satisfactory completion of the TM-CLKL sub-sea tunnels.

scholarly journals 3D MODELLING OF TUNNEL EXCAVATION USING PRESSURIZED TUNNEL BORING MACHINE IN OVERCONSOLIDATED SOILS

2013 ◽  
Vol 35 (2) ◽  
pp. 3-17 ◽  
Author(s):  
Rafik Demagh ◽  
Fabrice Emeriault
Keyword(s):  
Numerical Simulation ◽  
Urban Areas ◽  
Three Dimensional ◽  
Ground Surface ◽  
Tunnel Boring Machine ◽  
Confining Pressure ◽  
Soil Mass ◽  
Shield Tunnel ◽  
Tunnel Boring ◽  
Boring Machines

Abstract The construction of shallow tunnels in urban areas requires a prior assessment of their effects on the existing structures. In the case of shield tunnel boring machines (TBM), the various construction stages carried out constitute a highly three-dimensional problem of soil/structure interaction and are not easy to represent in a complete numerical simulation. Consequently, the tunnelling- induced soil movements are quite difficult to evaluate. A 3D simulation procedure, using a finite differences code, namely FLAC3D, taking into account, in an explicit manner, the main sources of movements in the soil mass is proposed in this paper. It is illustrated by the particular case of Toulouse Subway Line B for which experimental data are available and where the soil is saturated and highly overconsolidated. A comparison made between the numerical simulation results and the insitu measurements shows that the 3D procedure of simulation proposed is relevant, in particular regarding the adopted representation of the different operations performed by the tunnel boring machine (excavation, confining pressure, shield advancement, installation of the tunnel lining, grouting of the annular void, etc). Furthermore, a parametric study enabled a better understanding of the singular behaviour origin observed on the ground surface and within the solid soil mass, till now not mentioned in the literature.

SEGMENT CRACKS AND ALIGNMENT ISSUES FOR TUNNELING CONSTRUCTION

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Arulampalam Paul Suyanthiran
Keyword(s):  
Tunnel Boring Machine ◽  
Shield Tunnel ◽  
Proper Selection ◽  
Tunnel Boring ◽  
Twin Tunnel ◽  
Shield Tunnelling ◽  
Tunnel Alignment ◽  
Selection Of ◽  
Left Lead

This study describes the causes of shield tunnel segment cracks and alignment issues during shield tunnelling. The study was conducted in Down Town Line 3 (DTL3) contracts 926 and 927 twin tunnel projects in Singapore. It is revealed that these issues arose when Tunnel Boring Machine (TBM) shoving on curve alignment though TBM is designed with articulation, which allows the machines to handle tight curves with ease. The study focused on how construction methodology affects the quality of tunnelling in terms of alignment and segment cracks. It was found that the clearance between the tail shield and tunnel lining was not maintained during mining. As a result, the tail shield exerts stress on the segments and causes cracks. In addition, the tunnel alignment deviated from pre-designed alignment, which directly affects the safety and durability of the shield tunnel. This study concludes that a proper selection of ring type “right lead” or “left lead” and the appropriate key selection, along with the skill of the workers, significantly solve segment cracks and alignment issues.

scholarly journals Influence of geology on tunnel boring machine performance: A review

2020 ◽  
Vol 56 (1) ◽  
pp. 1-14
Author(s):  
P.K. Pandey ◽  
A.K. Raina ◽  
S. Deshmukh ◽  
R. Trivedi ◽  
R. Vajre ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Circular Cross Section ◽  
Tunnel Boring Machine ◽  
Intact Rock ◽  
Joint Spacing ◽  
Tunnel Boring Machines ◽  
Tunnel Boring ◽  
Machine Performance ◽  
Geological Conditions ◽  
Boring Machines

Tunnel boring machines are used for excavating a variety of soils and rocks for circular cross-section tunnels. Several published studies examined the role of rockmass in determining the cutting and advance rate of tunnel boring machines. A comprehensive review of literature was conducted to ascertain the influence of geological conditions on the performance of tunnel boring machines and revealed that different rock characteristics were used to define the tunnel boring machine performance. The progress of the tunnel boring machine was ascribed to the inherent properties of the rockmass, intact rock properties, and surrounding geological conditions. Several authors found that extreme geological conditions strongly influence the advance of the machine. The review revealed that joint spacing, angle between plane of weakness and tunnel axis, rock quality designation, and number of joint sets were the most important variables that influenced the advance rates of the tunnel boring machine. At least 12 intact rock variables were used to define tunnel boring machine performance with one to seven such variables used in combination. The compressive strength, tensile strength, and brittleness index emerged as most crucial intact properties. Rockmass classifications or indices of tunnel boring machine performance were used by different authors to predict their performance and even to define their selection methodology. Use of dynamic properties of rock/rockmass was identified as a grey area for future research by scientists.

scholarly journals Assessment of rate of penetration of a tunnel boring machine in the longest railway tunnel of Turkey

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Candan Gokceoglu
Keyword(s):  
Multiple Regression ◽  
Prediction Models ◽  
Tunnel Boring Machine ◽  
Regression Equations ◽  
Railway Tunnel ◽  
Tunnel Boring Machines ◽  
Rate Of Penetration ◽  
Tunnel Boring ◽  
Ann Models ◽  
Boring Machines

AbstractOne of the most important issues in tunnels to be constructed with tunnel boring machines (TBMs) is to predict the excavation time. Excavation time directly affects tunnel costs and feasibility. For this reason, studies on the prediction of TBM performance have always been interesting for tunnel engineers. Therefore, the purpose of the study is to develop models to predict the rate of penetration (ROP) of TBMs. In accordance with the purpose of the study, a new database including 5334 cases is obtained from the longest railway tunnel of Turkey. Each case includes uniaxial compressive strength, Cerchar Abrasivity Index, α angle, weathering degree and water conditions as input or independent variables. Two multiple regression models and two ANN models are developed in the study. The performances of the ANN models are considerably better than those of the multiple regression equations. Before deep tunnel construction in a metamorphic rock medium, the ANN models developed in the study are reliable and can be used. In contrast, the performances of the multiple regression equations are promising, but they predict lower ROP values than the measured ROP values. Consequently, the prediction models for ROP are open to development depending on the new data and new prediction algorithms.

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