No abstract is provided for this article.
The York Durham Sewage System (YDSS) Interceptor Sewer construction spanned a total length of 5.5 km, which included a 1.4-km stretch of open cut construction and tunnelled stretch of 4.1 km, with four access shafts. Two of the tunnel access shafts were located in an environmentally sensitive area with water bearing cohesionless soils and considered as a potential geotechnical hazard for tunnel break-ins/break- outs. A combination of slurry wall and jet grouting was used to stabilize the ground and control groundwater flow at shafts #2 and #3 during break-in/break-out of the tunnel boring machine (TBM). This paper presents a case study, addressing the application of double fluid jet grouting technique to mitigate a significant geotechnical hazard at shafts #2 and #3 for the YDSS Interceptor Sewer Project.
An incremental and piecewise linear finite element theory is developed for the large displacement, large strain regime with particular reference to elastic-plastic behavior in metals. The resulting equations, though more complex, are in a similar form to those previously developed for large displacement, small strain problems, the only additional term being an initial load stiffness matrix which is dependent on current loads. This similarity in form means that existing nonlinear general purpose programs may easily be extended to include finite strains. A large displacement, small strain formulation (as applicable to problems of structural stability) is obtained from this theory by assuming that changes in length of line elements and relative rotation of orthogonal line elements are negligible compared to unity. The simplified equations are in essential agreement with previous formulations in the literature. The only difference which is observed is the persistence of the initial load stiffness matrix, which may be significant in some cases.
Gemusterte selbstorganisierte Monoschichten (SAMs), die durch Mikrokontakt-Drucken hergestellt wurden, erleichtern die Synthese von dünnen Polymerfilmen mit wohldefinierten zweidimensionalen Anordnungen und Zusammensetzungen senkrecht zur Filmebene. Nach der Trennung von der Oberfläche behalten die nur 5 – 10 nm dicken Polymerfilme ihre Form bei, die ihnen durch das Muster der SAM aufgezwungen wurde, wenngleich eine gewisse Neigung zur Faltung und zum Aufrollen besteht.
Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) have been used to characterize the surface structure and electronic properties of Tl2Ba2CaCu2O8 and Tl2Ba2Ca2Cu3O10 single crystals. Atomic resolution STM images show that 90%–95% of the surface has a near-trigonal structure with a=b=0.24 nm and an a–b angle of 65°. The remaining 5%–10% of the surface consists of a new orthorhombic structure with a=b=0.40 nm. Spatially resolved STS measurements further demonstrate that regions with the 0.24 nm period structure are metallic, while areas with the 0.40 nm period structure are semiconducting.
