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World Tunnelling Congress
Abstract: Prognosis on surface settlements above tunnels in urban areas are usually based on the empirical green field approach. The parameters necessary for estimating tunnel induced settlements are highly dependent on experiences with previous projects carried out with similar methods and under similar geological conditions. For the prediction of settlements of a new Stormwater tunnel in Copenhagen, a...
Abstract: The traditional construction method of the sprayed concrete lining (SCL) in soft ground tunnelling comprises a temporary primary lining of sprayed concrete, a permanent cast-in-situ or sprayed secondary lining and a sheet waterproofing membrane interface between them. This design philosophy has changed in the last two decades. It is wasteful in terms of material and financial resources...
Abstract: For rapid construction system of lining concrete for tunnel structures, the development of a long span tunnel formwork carriage system that extends one construction span to 18 m or more has been worked on. In order to reduce the risk of the occurrence of cracks at unspecified locations, a method to form crack-inducing joints was proposed by installing metal plates at the mid-span of the tunnel...
Abstract: This report discusses tunneling in an unconsolidated shallow overburden ground with measuring displacement of support and ground. The mechanism of displacement is analyzed by measured data of final converged displacement. In this study, the concept of ‘initial displacement rate’ is defined to clarify plastic and elastic behavior of the ground. Based on this concept, effectiveness of auxiliary...
Abstract: The Evouettes Tunnel is a bidirectional, single-tube, 657 m long road tunnel under construction in Wallis, Switzerland. The encountered ground conditions, comprising loose material, makes the implementation of a classical pipe umbrella stabilization method very difficult. The decision was taken to design and specify a sub horizontal jet-grouting umbrella, which allows for full-face excavation,...
Abstract: This paper describes the passage of the Birkavägen fracture zone during the excavation of an access tunnel for the expansion of the Stockholm metro to Nacka. The projects main challenges included requirements to limit ground water inflow and passing the fracture zone area, with a combination of low rock cover and densely fractured rock mass. The tunnel was excavated using drill and blast...
Abstract: The Actuated disc cutting (ADC) is one of the most state-of-art technologies in the fields of rock cutting mechanics. The ADC is based on the undercutting mechanism, while many cutting parameters are involved in a complex rock cutting process. This paper introduces the new concept of a lab-scaled rock cutting system which can facilitate cutting experiments implemented undercutting concept based...
Abstract: This paper presents the experimental study and numerical simulation of Paris plastic clay in a case study of Grand Paris Express project. Paris plastic clay is a highly plastic clay from the Sparnacian age (Lower Eocene) and forms the first tertiary deposits of Paris sedimentary basin, it has a very low permeability, is normally consolidated or overconsolidated, and is swollen in outcrops. To...
Abstract: After the operation of joint sealant, a certain amount of water pressure is applied to the sealant body, so as to test the water pressure resistance of high and low modulus sealants, and get the quantitative limit values of water pressure resistance. The results show that the back water surface of low modulus polyurethane sealant can sustain 0.3 MPa water pressure continuously, and the back...
Abstract: This paper presents an implementation of Bayesian network (BN) and structure learning algorithm to explore the interactions and causal relationships among excavation features of an earth pressure balance tunnel boring machine (EPBM). This study was performed on a data set from the State Route 99 (SR99) tunnel construction in Seattle, WA. A score-based structure learning algorithm was used to...
Abstract: Directional core drilling (DCD) affords design engineers accurate imaging of the geology along the tunnel’s trajectory. The collected core as well as the borehole can be examined and provide a verified account of the rock formation, recording position, dimension and properties of weakness zones, and geological anomalies. Before initiating a directional borehole, careful planning is needed....
Abstract: A number of large tunnels have already been built around the world with Fibre Reinforced Concrete (FRC) precast segment linings.In accordance with fib bulletin 83, Model Code 2010, the structural design of FRC elements is based on the post-crack residual tensile strength provided by the steel fibers. Nominal values of the material properties can be determined by performing a flexural bending test.
Abstract: In the present paper, the effect of face instability on the surface settlements of a shallow tunnel driven in cohesive- frictional soils, under seepage flow conditions was studied numerically. A three-dimensional finite element model was created, and several coupled analyses were performed employing elastic-perfectly plastic soil material. A parametric study was also done to investigate the...
Abstract: Strength anisotropy is characteristic to sedimentary and metamorphic rocks and is often markedly directional in their strengt h behaviour under triaxial stress regime. Mohr-Coulomb criterion and most conventional analyses of rock failure have ignored the influence of intermediate principal stress, σ2 (σ1 ≥ σ2 ≥ σ3) by assuming σ2=σ3, which tends to underestimate the strength of such rocks, as...
Abstract: ABSTRACT: In France, the MINnD Project aims at extending Building Information Modeling (BIM) capacities to describe infrastructures such as roads, bridges, railways, tunnels and geotechnics. The MINnD working group GT1-5 is dedicated to Geotechnics, especially in an underground infrastructure construction context. Such activity leads to the proposal of a conceptual data model and appropriate...
Abstract: The FIDIC Emerald Book has been drafted with the aim of providing fair and balanced contracts for the underground industry. The excavation and lining works of a tunnel depend on the geological/geotechnical situation, which will be encountered during the execution. It is not possible to estimate the required quantities for the support beforehand and remuneration of the Contractor needs to be...