Muir Wood Research Articles

Numerical and artificial neural network analysis of tunnel liner design parameters – a comparative study

ABSTRACT This paper proposes the development of an analytical-based Artificial Neural Network (ANN) model for predicting the concrete segmental lining parameters and comparing it with the finite element method, Rocscience tool. To achieve this aim, the dataset was prepared for twelve different loading conditions using the analytical equations by Muir Wood and Curtis. Using this dataset, an ANN model was developed for predicting the segmental lining parameters, viz. displacement, bending moment, axial and shear force. Furthermore, the Rocscience tool was used to analyse the aforementioned design parameters, and the results of these two methods were compared and summarised. It is found that the developed ANN model shows reasonable results of liner design parameters with the Rocscience program. The efficiency of both techniques was evaluated using the statistical measures viz. Mean Absolute Error, Root Mean Square Error, and Coefficient of Efficiency. It is observed that the ANN model is best fitted for the prediction of liner shear and axial force, while it could not find the optimised solution for liner displacement and bending moment. The finding of this study showed that the developed ANN model can be applied to predict the tunnel liner design parameters instead of the alternative complicated and time-consuming techniques.

Projected Effects of a Deep Excavation Pit on the Existing Metro Tunnel and Findings of Geotechnical Monitoring: A Comparative Analysis

With the evolution of modern cosmopolitan cities, subterranean spaces have developed in dense urban environments. Hence, new metro tunnels often intersect with those in operation. The top-priority task of designers is to evaluate the effect of new construction projects. The experience accumulated in this field should contribute to the design of a realistic geotechnical model to simulate long-term displacements in the future. This paper includes a backward analysis of a design scheme developed for a tunnel construction area above an existing tunnel with a 10.3 m diameter, according to the results of geotechnical monitoring performed in PLAXIS 2D. The authors identified the optimum combination of the distance from the tunnel bottom to the lower boundary of the design model, the soil model, and tunnel lining stiffness. The authors derived regression equations describing vertical and horizontal displacements of the tunnel at the stage of excavation to the elevation datum as the excavation pit bottom. These equations can be applied to preliminarily predict the displacements of the tunnel depending on geometrical parameters at the initial design stage. Geometrical parameters include the distance from the tunnel to the excavation pit, the depth of the tunnel from the surface to the crown, the depth of the designed excavation pit, and the distance from the bottom of the excavation pit to the bottom of the tunnel. In addition, the effect of the Muir–Wood coefficient on the vertical displacements of the tunnel was investigated. This work found a reduction in the stiffness of the bearing structure of the tunnel and an increase of 4.8% in deformations on average when this coefficient was considered.

Circular lining behaviour due to earthquake load in MRT Jakarta underground tunnel area CP-106

One solution to traffic congestion in Jakarta is to build a mass transportation system in the form of Mass Rapid Transit (MRT), especially the application of underground tunnel structures. This study examines the modeling of tunnel behavior on the effect of earthquake loads. This study calculates circular tunnel behavior in static and dynamic conditions due to earthquake effects. Static condition analysis using Muir Wood’s theory and dynamic conditions using the theories of Wang (1993) and Panzien (2000) as well as supported by empiric and numeric calculations. The depth of the MRT tunnel in the CP-106 area is at a depth of 11 meters by diverting by clay with NSPT 3-20. The results show that in static condition has tunnel deformation that works at 8.06 mm in empiric and 15.12 mm in numeric. In the dynamic analysis with earthquake acceleration in 300 cm/s2 produces oval deformation at 15.95 mm in empiric and 15.20 mm in numeric. The maximum deformation limit given is 20 mm with a maximum earthquake acceleration value of 400 cm/s2. In conclusion, MRT Jakarta area CP-106 in static condition has a lower deformation than dynamic conditions, but both conditions fulfill the deformation tunnel requirements.

Ultimate capacity of a segmental grey cast iron tunnel lining ring subjected to large deformations

Understanding the behaviour of existing tunnels subjected to in-service deformations, as a result of the construction of underground works (e.g. new tunnels) in their proximity, is of importance in order to safeguard infrastructure within the urban environment. The associated deformations that take place during tunnelling have to be carefully assessed and their impact on the existing tunnels needs to be considered. A half-scale segmental grey cast iron (GCI) tunnel lining ring was tested as part of an extensive research project investigating the impact of new tunnel excavations on existing tunnels conducted at Imperial College London. A sophisticated experimental arrangement was developed to deform the ring in a variety of modes under combined displacement and load control. This paper reports on experiments carried out to assess its structural response when subjected to large deformations. The tests reported are the first to be conducted on a realistic scale model under carefully controlled conditions, and provide valuable insight into the behaviour of a GCI segmental ring during distortions commonly observed in reality. Details of the experiments, including the adopted test set-up and the instrumentation employed, are presented. The measured bending moments around the ring, as a result of the applied deformations, are determined and compared with those predicted using the well-known equations given by Morgan (1961) and Muir Wood (1975), often used in industry, as well as those obtained assuming an elastic continuous ring.

Buch: Civil engineering in context. By A. Muir Wood

Buch: Civil engineering in context. By A. Muir Wood

Geotechnical Modelling by Professor David Muir Wood (University of Bristol), Spon Press (London & New York), 2004, Applied Geotechnics Volume 1, ISBN 0-415 34306-6 (hbk), £80.00, ISBN 0-419-23730-5 (pbk), £25.00

Professor Muir Wood puts an interesting slant on soil mechanics theory: all theoretical solutions are just models. This proposition allows him to write a book on geotechnical modelling which is populated by many of the simple, classical, solutions that are the stock in trade of the undergraduate (or maybe Masters’) course in soil mechanics. However, the central idea means that some of the solutions that are lumped together are a rather eclectic collection: for example, under ‘empirical models’ we find the vane test, the pressuremeter, cone tests and their correlation with settlement of footings on sand, and Skempton & Bjerrum's slant on consolidation settlement. However, the idea is exhausted by the end of …

A New Species Polynema muirii on Fagus grandifolia

Polynema muirii sp. nov. is described and illustrated from Fagus grandifolia collected in the Muir's Wood, Québec, Canada. It is compared with known Polynema species. This is the second report of a species of Polynema from North America.

A new species Polynema muirii on Fagus grandifolia

Polynema muirii sp. nov. is described and illustrated from Fagus grandifolia collected in the Muir's Wood, Québec, Canada. It is compared with known Polynema species. This is the second report of a species of Polynema from North America.

Zussmanite in ferruginous metasediments from Southern Central Chile

AbstractZussmanite KFe13[AlSi17O42](OH)14, a modulated 2:1 layer silicate, has so far been found only in iron-rich metasediments from Laytonville, California (Agrell et al.), 1965). A new occurrence is reported here from Punta Nihue north of Valdivia, Chile, in banded stilpnomelane-schists. These are intercalated in the ‘Western Series’, a complex of low-grade metamorphic rocks with local high-pressure, low-temperature overprint (e.g. blueschists).The rock contains conspicuous porphyroblasts of zussmanite of mm size and is composed of chemically distinct bands with the subsequent assemblages: (1) zussmanite-stilpnomelane-quartz, (2) siderite-quartz±stilpnomelane (3) apatite-stilpnomelane-quartz±siderite. The chemical composition of zussmanite, (K0.80Na0.05Ba0.01)(Fe11.292+Mg1.11Mn0.25Fe0.143+Cr0.01Al0.19Ti0.01)[Al1.23Si16.77O42](OH)14, its optical properties and X-ray data correlate well with the Californian occurrence. Additionally, we present new IR data. In type (2) bands of fine-grained crystals of a K,Al poor mineral formed from siderite and quartz. Its chemical composition is close to that of zussmanite. A similar phase was also reported from Laytonville, California (Muir Wood, 1980).The rarity of rock-forming zussmanite can be explained by its occurrence in strongly Fe-rich and reduced rocks, as well as, by a possibly narrow P-T stability field.

Diarimella laurentidae anam.: sp.nov. from Quebec

Diarimella laurentidae, a new species occurring on dead bark and decorticated twigs of American beech (Fagus grandifolia Ehrh.), is reported from the Muir's Wood ecological reserve, located in the centre of the Haut-Saint-Laurent region in the province of Quebec. Diarimella laurentidae is characterized by stromatic, pulvinate, black, setose fructifications composed of a basal stroma of textura angularis, a brown peripheral wall of textura porrecta, conidiomatal setae of two types, and unicellular multisetulate conidia. Its relationships with described Diarimella species is discussed. This is the first report of a species of Diarimella from North America.Key words: Diarimella laurentidae, new fungus species, coelomycete, Fagus grandifolia.

Porosity waves in a fluidized sand–column test

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Vardoulakis I., Stavropoulou M. and Skjaerstein A. 1998Porosity waves in a fluidized sand–column testPhil. Trans. R. Soc. A.3562591–2608http://doi.org/10.1098/rsta.1998.0288SectionRestricted accessPorosity waves in a fluidized sand–column test I. Vardoulakis I. Vardoulakis Department of Engineering Science, National Technical University of Athens, 5 Heroes of Polytechniou Avenue, GR–15773 Athens, Greece Google Scholar Find this author on PubMed Search for more papers by this author , M. Stavropoulou M. Stavropoulou Department of Engineering Science, National Technical University of Athens, 5 Heroes of Polytechniou Avenue, GR–15773 Athens, Greece Google Scholar Find this author on PubMed Search for more papers by this author and A. Skjaerstein A. Skjaerstein IKU, Norsk Hydro ASA, PB 200, 1321 Stabekk, Vaekero, Oslo, Norway Google Scholar Find this author on PubMed Search for more papers by this author I. Vardoulakis I. Vardoulakis Department of Engineering Science, National Technical University of Athens, 5 Heroes of Polytechniou Avenue, GR–15773 Athens, Greece Google Scholar Find this author on PubMed Search for more papers by this author , M. Stavropoulou M. Stavropoulou Department of Engineering Science, National Technical University of Athens, 5 Heroes of Polytechniou Avenue, GR–15773 Athens, Greece Google Scholar Find this author on PubMed Search for more papers by this author and A. Skjaerstein A. Skjaerstein IKU, Norsk Hydro ASA, PB 200, 1321 Stabekk, Vaekero, Oslo, Norway Google Scholar Find this author on PubMed Search for more papers by this author Published:15 November 1998https://doi.org/10.1098/rsta.1998.0288AbstractFluidized–sand column experiments performed at the IKU provided insight into the mechanism of density adjustment to the conditions of flow against the direction of gravity, and for hydraulic gradients around and past the critical value corresponding to the ‘quick’ condition. X–ray computer–tomography scan images obtained during these tests show a process which could be described as a kinematic density or porosity–wave motion. Forchheimer's flow law, holding in the post–critical regime, is calibrated by using the storage equation and the data concerning the propagation velocity of the observed porosity waves. Finally, the observed rarefaction waves are simulated mathematically and experimental results are back–analysed. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Rossi G, Fabris P and Zuliani D (2017) Overpressure and Fluid Diffusion Causing Non-hydrological Transient GNSS Displacements, Pure and Applied Geophysics, 10.1007/s00024-017-1712-x, 175:5, (1869-1888), Online publication date: 1-May-2018. Omlin S, Malvoisin B and Podladchikov Y (2017) Pore Fluid Extraction by Reactive Solitary Waves in 3-D, Geophysical Research Letters, 10.1002/2017GL074293, 44:18, (9267-9275), Online publication date: 28-Sep-2017. Rossi G, Zuliani D and Fabris P (2016) Long-term GNSS measurements from the northern Adria microplate reveal fault-induced fluid mobilization, Tectonophysics, 10.1016/j.tecto.2016.04.031, 690, (142-159), Online publication date: 1-Oct-2016. Philippe P and Badiane M (2013) Localized fluidization in a granular medium, Physical Review E, 10.1103/PhysRevE.87.042206, 87:4 Philippe P and Badiane M (2011) Chimney of Fluidization and “Sandboil” in a Granular Soil Advances in Bifurcation and Degradation in Geomaterials, 10.1007/978-94-007-1421-2_16, (125-129), . Vardoulakis I (2004) Fluidisation in artesian flow conditions: Hydromechanically stable granular media, Géotechnique, 10.1680/geot.2004.54.2.117, 54:2, (117-130), Online publication date: 1-Mar-2004. di Prisco C and Imposimato S (2002) Static liquefaction of a saturated loose sand stratum, International Journal of Solids and Structures, 10.1016/S0020-7683(02)00164-6, 39:13-14, (3523-3541), Online publication date: 1-Jun-2002. This Issue15 November 1998Volume 356Issue 1747Discussion Meeting Issue ‘Mechanics of granular materials in engineering and Earth sciences’ organized by D. Muir Wood, G. S. Boulton and J. M. Rotter Article InformationDOI:https://doi.org/10.1098/rsta.1998.0288Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online15/11/1998Published in print15/11/1998 License: Citations and impact Keywordsfluidized sandsfluid flowporosity wavesporous media

Preface to Mechanics of granular materials in engineering and Earth sciences. A Discussion Meeting held at the Royal Society on 28 and 29 January 1998.

Preface to Mechanics of granular materials in engineering and Earth sciences. A Discussion Meeting held at the Royal Society on 28 and 29 January 1998. Organized and edited by D. Muir Wood.

Some aspects of flow in granular materials in hoppers

The main part of the paper is devoted to the description of the localized deformation zones in plane (slow) flow of granular materials from hoppers. Specifically, two types of zones are discussed i...

Pressures from flowing granular solids in silos

Large displacement flows in granular solids occur whenever silos are discharged. Measurements of pressures during flow, combined with visual observations of flow patterns and control tests on the e...

Earthquakes, strain-cycling and the mobilization of fluids : R. Muir Wood, in: Geofluids: origin, migration and evolution of fluids in sedimentary basins, ed J. Parnell, (Geological Society, London; Special Publication, 78), 1994, pp 85–98

Earthquakes, strain-cycling and the mobilization of fluids : R. Muir Wood, in: Geofluids: origin, migration and evolution of fluids in sedimentary basins, ed J. Parnell, (Geological Society, London; Special Publication, 78), 1994, pp 85–98

Absolute dating of fault movements

The papers in this thematic set arise from a meeting jointly organized by the Tectonic Studies Group and the Stratigraphy Committee of the Geological Society and held at Burlington House on 28 November 1990. About 80 people heard oral presentations of 15 papers of which seven are published in this thematic set. Abstracts of most of the papers presented at the meeting were given in the Geological Society Newsletter for September 1990. In a recent essay criticizing the way in which scientists apply the term absolute, Wendell Duffield (1990, p. 1774) wrote ‘Still more liberty is taken with the ‘A-word’ [absolute] by people concerned with ages of geologic materials’. In choosing the title for this meeting, the convenor quite purposefully took such liberty in an attempt to attract presentations on dating fault movements using a diversity of absolute, comparative, direct and high-resolution relative age dating techniques. More accurate and more precise dating of fault movements has relevance not only to academic studies of the dynamics and kinematics of fault movements but also engineering seismic hazard assessment, radwaste disposal, the timing of hydrocarbon migration and entrapment, and the economic mineralization of fault zones. This relevance was made apparent at the meeting by an audience which included representatives of a number of sectors of industry, regulatory bodies and academia. Commencing the meeting with an amusingly titled presentation (‘Doctor-is my fault active?’), R. Muir Wood (Principid Yard Limited) examined the taxing geological and regulatory questions of how to classify faults as seismically ‘active’

Discussion

A. Whittaker writes: My comments on the paper presented by Muir Wood and Mallard are partly about the scientific concepts and arguments advanced, but also about semantics. I find the concept of the ‘current tectonic regime’ to be useful. It is certainly to be preferred, in the consideration of whether or not a fault is active, to criteria based simply upon some arbitrarily-decided, extrinsic time period. However, I wonder whether the term ‘current tectonic regime’ is the most appropriate. The authors concede that the ‘current tectonic regime’ can only be described by its manifestations, i.e. observation of the stresses and strains within the Earth’s crust. Would it not be more informative to the non-specialist to make it explicit and clear that, essentially, it is crustal stress that is being referred to? A similar concept was advanced at the Society’s meeting on neotectonics held in 1984 (Hancock & Williams 1986). At this meeting Hancock, in discussion of the temporal scope of neo- tectonics, suggested that the selection of an arbitrary Neogene or Quaternary date to be applied globally for the beginning of the period during which neotectonic structures form, is unhelpful. He brought forward the alternative notion that for a given region the neotectonic phase could be thought of as having begun when the present day disposition of relevant plate boundaries (and their associated motions) was estab- lished. A suggestion to modify this proposal was made by Blen- kinsop (Hancock & Williams 1986). It was to the effect that the neotectonic

Geophysical studies of the West Antarctic Rift System

Geophysical studies of the West Antarctic Rift System

Strain-dependent moduli and pressuremeter tests. Technical note : Muir Wood, D GeotechniqueV30, N3, Sept 1990, P509–512

Strain-dependent moduli and pressuremeter tests. Technical note : Muir Wood, D GeotechniqueV30, N3, Sept 1990, P509–512

Anisotropic elasticity and yielding of a natural plastic clay : Muir Wood, D; Graham, J Int J PlasticityV6, N4, 1990, P377–388

Anisotropic elasticity and yielding of a natural plastic clay : Muir Wood, D; Graham, J Int J PlasticityV6, N4, 1990, P377–388