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Papers from WTC and ITA conferences have been made available as PDF documents.
List of endorsed conferences
World Tunnelling Congress
Abstract: One of the main concerns regarding the performance of radial joints in segmental tunnel lining has not well studied in spite of many researches and experiences. The radial (longitudinal) joint of segmental lining, i.e. the contact joint between segment to segment in a segmental ring, is chosen and designed in the form of either flat or curved shape. From technical and economical points of view,...
Abstract: Resistance to ram thrust pressure in pre-cast concrete tunnel segments is an important consideration in the design of both the concrete mix and reinforcement comprising tunnel segments. Duration of loading is known to affect the apparent strength of concrete in compression, flexure, and direct tension, but its effect on bursting resistance is poorly understood. The capacity of plain and fibre...
Abstract: During the excavation of the underground powerhouse complex a shear/fracture zone of approximate 8m thickness, intersecting both the caverns was encountered. Presence of the shear zone necessitated detailed rock mechanics studies for re-evaluation of excavation methodology and support system. To ensure the stability of the caverns and efficacy of the revised support system numerical modeling...
Abstract: The construction of a relatively shallow mining tunnel in Brasilia was done under challenging ground conditions. After the end of the construction phase, numerical simulations were performed to compare the real settlements occurred on the tunnel entrances with the predicted settlements of the numerical analysis. These analyses were three-dimensional. The adjustment of the on-site...
Abstract: Cutterhead type and cutting tools configuration are two important considerations for the design of a shield machine. A comprehensive analysis of the cutterhead selection and cutting tools configuration of a shield machine in a sandy cobble stratum indicates that cutterhead selection more significantly impacts shield machine operation than cutting configuration. A spoke-type cutterhead and a...
Abstract: As the rapid expansion of urban area, the demand of infrastructure projects has increased continuously, while land area is limited. Therefore, the underground construction has become one alternative. Consequently, shield tunnelling method has become the major construction method in urban area, since this method can minimize ground disturbance and also influence to neighboring structures. This...
Abstract: Recent development and application of composite sprayed concrete lining (SCL) in major tunnelling projects have raised concerns on its short- and long-term flexural performance. Little literature has been found on the short-term crack development and the long-term ageing effect on composite SCL. Understanding of these issues will facilitate the efficient design of composite SCL. Four-point...
Abstract: The No.15 bid project of Beijing subway Line 14 includes 3 stations and 3 running tunnels about 2507.9 m in length. Instead of two running tunnels, one double-track tunnel was arranged to connect the neighboring stations due to the limited underground space. To reduce the project duration, the construction plan employed is innovative of first completing the continued 3151.6 m long tunnel...
Abstract: Effect of conditioning parameters on workability of sands was investigated by using flow table and newly suggested mini slump tests. The soil conditioning tests were performed on standard mortar sand at two foam types and different Foam Expansion Ratio () and Foam Injection Ratio () values. The foams were characterized by measurements of stability (half-life), density and bubble size. The...
Abstract: This paper reports the construction of an underground structure by underpinning where the Tokyo Gaikaku Expressway crosses under the railway viaduct of the JR-Sobu Line without affecting train operation. A large-scale box culvert was immersed on both sides of the existing railway viaduct by pneumatic caisson method. In addition, the box culverts were used as foundations for piers which...
Abstract: In estimating the effect of tunnelling on existing buildings, the value of volume loss, which is often determined by experience, is an important input parameter. This paper proposes a method to predict the volume loss for various cover-to-diameter C/D ratios in case of shallow tunnelling. By applying a number of (empirical) relation, such as the stability number of O’Reilly(1988) and an...
Abstract: When creating an opening in a sidewall of an existing cut-and-cover tunnel, safety verification should be carried out for fear of decrease in rigidity of the node connecting the upper slab and the sidewall. The decrease in the rigidity of the node connecting the upper slab and the sidewall results in an increase in vertical displacement along the upper slab span, and for this reason, the inner...
Abstract: With the hydroelectricity development booming in China, the number of underground caverns increases dramatically. In this paper, the large underground caverns of three representative projects in southwestern China (the 6300 MW Longtan hydroelectricity project, the 6400 MW Xiangjiaba hydroelectricity project, and the 3600 MW Jinping I hydroelectricity project) are introduced. Different failure...
Abstract: 3D laser scanners can make detailed measurements of the configuration of objects such as structures and may be used to measure two-dimensionally the surface configuration of a tunnel wall, and technology to apply this equipment to measure displacement of tunnels has recently been developed. However, measurements using a 3D laser scanner can obtain only the surface configurations at the moment...
Abstract: Rockbursts in the tight confines of a TBM tunnel can be highly hazardous events given the proximity of vital equipment and workers to the rockburst source, and the space constraints that severely limit employment of countermeasures. Consequently, the ability to predict rockbursts with some measure of confidence as excavation proceeds (i.e. in the ‘short-term’) is critical to the safety of both...
Abstract: This paper presents a detailed evaluation of airport runway settlement behavior during construction of passenger terminal connecting railway twin tunnels (1,150 m long) by 7.9 m diameter EPB shield TBM in soft ground. The instrumented settlement data are analyzed to evaluate the surface settlement trough occurred by TBM tunneling. The maximum settlement is controlled within about 25 mm at the...