A methodology for designing a tunnel support system according to the actual ground conditions and the critical behaviour types is analysed in this paper. The methodology is justified with the principles of the New Austrian Tunnelling Method that incorporates the top heading and bench method. The role of the geological material and its implication in tunnel design, reinforced with advances in site investigation methods, cannot be based solely on the development of the geotechnical classification systems and the consequent quantification of the rock masses. Support requirements for rock masses with equal classification ratings can be different. The procedure presented in this study cannot bypass the geological and/or in situ characteristics dictating or influencing the tunnel behaviour compared with a standardised classification that could miss the specifics and particularities of and around a tunnel section. The step-by-step procedure is applied in a tunnel excavated in tectonically disturbed heterogeneous flysch sediments in Serbia. The complex structure of these materials, resulting from their depositional and tectonic history that includes severe faulting and folding, presents a challenge to geologists and engineers. The possible ground types are evaluated, and then, combined with the factors of the tunnel geometry, the primary stress condition, and the water conditions, several behaviour types are considered. These classified behaviour types, followed by the suitable mechanical properties that are required for effective tunnel engineering design, are the basis for the numerical design of the appropriate primary support measures to achieve stable tunnel conditions. The twin-tube, two-lane highway tunnel was successfully constructed without significant problems.
The paper estimates the anticipated changes in the seepage conditions towards the karstic aquifer, the recharge of the aquifer
from the combined rainfall, seepage and exploitation as well as the potential alteration in the quality of the aquifer due
to the creation of a nearby reservoir. It is shown that despite the somewhat increased seepage of polluted river water towards
the aquifer, the quality of the groundwater in the karstic aquifer is not expected to degrade appreciably. However, since
the water of the aquifer is used for the supply of neighbouring communities, it is proposed that in the areas where the thickness
of the intervening semi-permeable alluvia is small, artificial sealing is installed using either compacted clay or plastic
membranes.
Conséquences sur l'environnement des fuites d'un réser voir de barrage vers un aquifère karstique
Résumé L'article traite le problème des fuites du réservoir d'un barrage qui pourraient se produire vers un aquifère karstique proche
et les modifications du régime des eaux souterraines qui en résulteraient, tout en tenant compte des conditions d'alimentation
et d'exploitation de cet aquifère. L'analyse montre que malgré l'augmentation des fuites des eaux du fleuve, les quantités
concernées ne peuvent aggraver la qualité des eaux souterraines d'une manière notable. Néanmoins, comme les eaux sont utilisées
en même temps pour les adductions d'eau potable, il est proposé, dans certains secteurs, où l'épaisseur des alluvions interposées
est faible, d'imperméabiliser les berges.
Hepatocellular carcinoma (HCC) remains one of the most common malignancies and the third cause of cancer-related death worldwide, with surgery being the best prognostic tool. Among the well-known causative factors of HCC are chronic liver virus infections, chronic virus hepatitis B (HBV) and chronic hepatitis virus C (HCV), aflatoxins, tobacco consumption, and non-alcoholic liver disease (NAFLD). There is a need for the development of efficient molecular markers and alternative therapeutic targets of great significance. In this review, we describe the general characteristics of HCC and present a variety of targeted therapies that resulted in progress in HCC therapy. 相似文献
The adoption of information systems in healthcare is no less significant than in any other commercial or caring organisation. The literature on IS adoption in healthcare, makes it clear that the actors involved in the adoption process are almost universally seen as crucial, which matches our research results too. However, how such actors should be identified remains a topic for investigatory work since these are early days in achieving this. We derive and propose a structured method to model how actors might be identified: structured because such a rationale is explicable and such a method is more readily usable when transferred to others. Our structured method, named IGOHcaps, uses a static and then a dynamic step to pull out the individual, group, organisational and human determinants of the critical actors. In this process, the individual actors' differing views emerge which could enable decision-making bodies to produce more robust proposals if they incorporated some of the appropriate views. We discuss the application of IGOHcaps through a hospital case study. While a single case study cannot be a proof, the engagement of the actors was encouraging. 相似文献
This paper refers to the proposed western extension of the Athens Metro to Piraeus city. The railway consists of a 9.45 m
diameter, 8.2 km long tunnel and seven stations. Tunnelling works are expected to be undertaken within a variety of lithological
formations ranging from very strong alpine limestones to recent soft littoral deposits. The tunnel alignment was divided into
12 areas with respect to the geological and geotechnical conditions that may be encountered during construction. In many of
these zones, the geotechnical conditions together with the presence of sensitive surface and/or subsurface structures led
to the selection of a closed-face TBM (Earth Pressure Balance Machine or Slurry Tunnel Boring Machine) as the appropriate
tunnelling technique. The Piraeus extension is a project where in places both types of commonly used closed-face tunnelling
machines will encounter ‘text book’ application areas, but not always. The applicability of each type of TBM is discussed
using the available data obtained from an extensive site investigation.
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The geological strength index (GSI) is a system of rock-mass characterization that has been developed in engineering rock mechanics to meet the need for reliable input data, particularly those related to rock-mass properties required as inputs into numerical analysis or closed form solutions for designing tunnels, slopes or foundations in rocks. The geological character of rock material, together with the visual assessment of the mass it forms, is used as a direct input to the selection of parameters relevant for the prediction of rock-mass strength and deformability. This approach enables a rock mass to be considered as a mechanical continuum without losing the influence geology has on its mechanical properties. It also provides a field method for characterizing difficult-to-describe rock masses. After a decade of application of the GSI and its variations in quantitative characterization of rock mass, this paper attempts to answer questions that have been raised by the users about the appropriate selection of the index for a range of rock masses under various conditions. Recommendations on the use of GSI are given and, in addition, cases where the GSI is not applicable are discussed. More particularly, a discussion and suggestions are presented on issues such as the size of the rock mass to be considered, its anisotropy, the influence of great depth, the presence of ground water, the aperture and the infilling of discontinuities and the properties of weathered rock masses and soft rocks. 相似文献
Interleukin-12, a cytokine with an important role against intracellular pathogens, promotes Th1 cell development, cellmediated cytotoxicity, and interferon-gamma production. We investigated the immunoregulatory role of IL-12 in 72 chronic hepatitis B virus (HBV) carriers, 33 of whom were monitored longitudinally during interferon-alpha treatment. Serum levels of IL-12 heterodimer, IL-12 p40 subunit, IL-4, and Th1 cytokines were determined by specific ELISAs, and hepatitis B core antigen-specific T cell response by a proliferation assay. Chronic HBV carriers had higher serum levels of IL-12 and IL-12 p40 in comparison with controls (P < 0.01), suggesting that IL-12 production is not impaired. The longitudinal analysis revealed a further substantial increase (> 2.5x baseline level) of bioactive IL-12 and Th1 cytokines in patients who cleared HBV and seroconverted to anti- hepatitis B e, unlike the 23 nonresponders with persistent HBV replication (P < 0.01). The IL-12 peak followed the peak of hepatocytolysis by 9.8+/-2.8 wk and occurred either before or simultaneously with hepatitis B e seroconversion. Hepatitis B core antigen-specific T cell proliferation closely correlated with hepatocytolysis and increased significantly in all patients (8 responders and 15 nonresponders) who developed hepatitis flare, irrespective of the virological outcome. These results provide in vivo evidence that IL-12 may have an important role for viral clearance in chronic HBV infection. 相似文献
By using either NH2-functionalized linear/4-arm star poly(ethylene oxide) or NH2-TEMPO initiator, the following novel polymer/polypeptide hybrids (macromolecular chimeras) of poly(ethylene oxide), PEO and poly(N-vinyl pyrrolidone), PNVP, were synthesized: PEO-b-(PBLG or PBLL), PEO-b-PBLL-b-PBLG, 4-arm star copolymer (PEO-b-PBLG)4, PNVP-b-PBLG-b-PBLL, where PBLG is poly(γ-benzyl-l-glutamate) and PBLL, poly(tert-butyloxycarbonyl-l-lysine). The amino-groups are used for the ring opening polymerization (ROP) of α-amino acid carboxyanhydrides (NCAs), while TEMPO was employed for the polymerization of NVP. Molecular characterization revealed the high molecular weight and compositional homogeneity of the macromolecular chimeras prepared. The success of the synthesis was based on the recently developed living ROP of NCAs and controlled/living TEMPO polymerization, using high vacuum techniques. 相似文献