Underground Tunnelling Research Articles

Clogging potential of tunnel boring machine (TBM): a review

Tunnel boring machines excavating through soft soils face different challenges, one of which occurs when the soil sticks to the cutter face or the conveyor band and obstructs the machine. This phenomenon, commonly referred to as clogging, leads to wearing of the cutting wheel and transportation system, delays in the time schedule and economic loss. Although several laboratory devices can evaluate the adhesion mechanism of soil to metal, the method to measure adhesion has not been standardised. As clogging is also directly related to the construction phase, engineers are more concerned with methods to avoid this problem during construction. In this regard, the application of soil conditioners has become useful, the benefits of which include torque reduction, easier soil manageability and clogging reduction. However, the effectiveness of the soil conditioners is difficult to evaluate. To provide some insight into the topic, this paper describes the basic mechanism of clogging, the key parameters for its evaluation, the laboratory tests conducted up to date, the classification diagrams developed to assess clogging risk and mitigation of this risk in underground tunnelling. This paper also describes some of the additives and their functions, the ratios used for measurement and application, and the current tests to evaluate their performance. Finally, the conclusions summarise the current findings in the issue of clogging, pointing to the advantages and shortcomings of previous research, as well as some lines of investigation to improve identification and mitigation of this problem.

Stability assessment of tunnel face in a layered soil using upper bound theorem of limit analysis

Underground tunnelling is one of the sustainable construction methods which can facilitate the increasing passenger transportation in the urban areas and benefit the community in the long term. Tunnelling in various ground conditions requires careful consideration of the stability factor. This paper investigates three dimensional stability of a shallow circular tunnel in a layered soil. Upper bound theorem of limit analysis was utilised to solve the tunnel face stability problem. A three dimensional kinematic admissible failure mechanism was improved to model a layered soil and limiting assumptions of the previous studies were resolved. The study includes calculation of the minimum support pressure acting on the face of the excavation in closed-face excavations. The effects of the characteristics of the layers on the minimum support pressure were examined. It was found that the ratio of the thickness of cover layers particularly when a weak layer is overlying a stronger layer, has the most significant influence on the minimum tunnel support pressure. Comparisons have been made with the results of the numerical modelling using FLAC3D software. Results of the current study were in a remarkable agreement with those of numerical modelling.

The use and application of pumpable resin grouts for rock anchoring

AbstractMinova is one of the world's leading suppliers of injection and bolting chemicals for use in underground mining, tunnelling and civil engineering. Developed from the range of silicate resins, Carbothix is a thixotropic resin system that can be used for the placement of rock bolts in underground mines. This paper describes the use of Carbothix in the underground environment and describes the cost benefits and advantages of using Carbothix for the anchoring of rock bolts.

Landtunnel Utrecht at Leidsche Rijn: The conceptualisation of the Dutch multifunctional tunnel

The Landtunnel Utrecht at Leidsche Rijn has become a milestone in Dutch tunnelling because it signifies a remarkable leap forwards in the conceptualisation, awareness and insight into the use of underground space technology and tunnelling for environmental purposes. At the beginning of the 21st century, all motorway tunnels in the Netherlands (with the exception of the Schiphol road tunnel) were subsurface constructions that were built to pass waterways. The Landtunnel Utrecht at Leidsche Rijn is the first aboveground motorway tunnel built to minimise the environmental impact of the road, and it allows development of the largest residential area in the Netherlands: Leidsche Rijn, Utrecht. Implementing the project highlights the difficulties decision makers face when they have to balance safety issues, high costs, multiple environmental issues, complex financing and urban development objectives. With no effective regulation in place and no similar practice to fall back on, the Landtunnel Utrecht (together with Sijtwende and the Green Link A15) breaks ground to allow the use of motorway tunnels for a new and promising application: environmental and spatial integration of motorways in urban areas.

The effects of mine fog and vibration sources on an experimental ground convergence monitor

Falls of ground are a leading source of worker injury and fatality indicating a persistent need for advances in ground monitoring technology. The high-resolution target movement monitor (HRTMM) is an experimental convergence monitor utilising a digital camera and custom software to track the position of one or more lasers across a target. The potential uses of the HRTMM include convergence monitoring in underground mining or tunnelling applications. For this article, the HRTMM was installed in an underground lead mine near active operations to test its response to three aspects of the mining environment: the ability of the monitor to survive intense blasting vibrations; error from the vibrations of close-proximity heavy equipment; and mine fog error. Improvements to the monitor design are identified from the mine blast test, the measurement error from light fog is determined, and vibrations from nearby equipment are shown to be inconsequential to convergence monitoring activities with the HRTMM.

Research on the effect of underground tunnelling on the settlement of the building and the ground surfaces

The construction of underground tunnel plays a more and more important role on the development of big cities. One of the most important problems caused by the construction of tunnel is that underground excavation will cause large settlements of ground buildings. And it heavily affects the safety of the building. The depth of underground tunnel and the horizontal distance between the tunnel and the building are two important factors which have great influence on the settlements of ground buildings. During the designing of tunnels these two factors must be taken into account. It is necessary to find out the regulations between the settlements of buildings and those two factors. On the other hand, the loess plateau in the west of China has a vast territory, integrated strata and large depth, which is rare in the world. Currently in big cities located in the loess areas, such as Xi'an, underground tunnel is preferred to be adopted to solve the traffic problem. So it is of great importance for the construction of underground project to research the relationship between the building subsidence and the excavation of underground cavity or the construction of underground tunnel in western China. This paper will aim to find out the quantity rules that how the underground tunnels affect the settlements of ground buildings in the loess areas. According to the mechanical characteristic of loess, the Duncan-Chang non-linear elastic constitutive model will be adopted; through the simulation in term of the FEA program- GeoFBA, the regulation that how the depth of underground tunnel and the horizontal distance between the tunnel and the buildings influence the settlements of ground buildings, will be obtained. And this result can be used as theoretic reference to the construction of the underground engineering in loess areas. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.

The future of civil and mining tunnelling and underground space in Australia

Underground construction in Australia has surged over the past decade, in particular projects involving inner city road and rail infrastructure. By 2004, tunnel construction in the nation's capital cities will be proceeding at unprecedented levels. Civil tunnelling and tunnelling associated with metalliferous mining in Australia accounts for an annual tunnelling advance of approximately 625 km for a population of approximately 20 million people. Approximately 4% of this (25 km/a) is civil tunnelling in our capital cities. Because of the large annual tunnelling advance, by world standards, Australia has considerable expertise in tunnelling in a large variety of ground conditions. The development of the infrastructure of our major capital cities will require increased tunnelling in the future. In these cities, as surface ring road systems are reaching their peak capacity, they are being paralleled by underground tunnel systems. In Brisbane, an underground rail system is being proposed to reach suburbs currently not serviced by rail and to service the inner CBD area better. Underground space commercial development is the next area of development that needs assessing by the urban planners and this has application in all of the capital cities in Australia. Sydney and Brisbane are ideally suited to this type of development because of their good ground conditions and it is necessary that planning allows for future underground space developments. Australia should sustain an annual tunnel advance, for civil purposes, of approximately 20 km/a from 2006 onwards. Projected tunnelling in Australia from 2004 to 2007 is summarised in Table 1. Australia is a world leader in underground tunnelling technology and application of tunnelling techniques. City planners have identified the benefits of tunnels in the design of infrastructure for our expanding cities. These benefits include improved amenity for urban dwellers, improved commuter travel times and reduced impact on the city landscape. The quality of air emitted from exhaust stacks on long tunnels remains the greatest community concern in regards to tunnel projects and this needs to be addressed in tunnel design. Underground space commercial development is an untapped use of tunnels in Australia which will advance over the next decade. (A). Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.

Applications of numerical modelling in underground mining and construction

Numerical modelling has been used to investigate a variety of problems in underground mining and tunnelling: subsidence induced by longwall coal mining; stresses generated when an open stope is filled cemented backfill and the stability of exposures created during subsequent mining of adjacent stopes; the interaction of two tunnels; and the effects of under-mining a pre-existing tunnel and shaft. In each case, results from nonlinear stress analyses can be used to guide the design of excavations and rock support mechanisms.

地下トンネルを掘るシールド掘進機と土砂粒度組成

地下トンネルを掘るシールド掘進機と土砂粒度組成

Use of underground mining and tunnelling techniques for in situ oil recovery : Stephenson, H G; Luhning, R W Proc tunnelling '88, London, 18–21 April 1988P333–345. Publ London: IMM, 1988

Use of underground mining and tunnelling techniques for in situ oil recovery : Stephenson, H G; Luhning, R W Proc tunnelling '88, London, 18–21 April 1988P333–345. Publ London: IMM, 1988

Underground mining and tunnelling techniques for in-situ oil recovery

Underground mining and tunnelling techniques for in-situ oil recovery