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Wpływ drogowych nawierzchni betonowych na bezpieczeństwo i zużycie energii w tunelach

Krispel S., Peyerl M., Maier G.

Cement Wapno Beton

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2018

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R. 21/83, nr 5

379--395

PL

W przeprowadzonych badaniach zastosowano różne modelowe rozwiązania oświetlenia tunelu oraz je oceniono. Oszacowano, że korzystny wpływ drogowej nawierzchni betonowej na fotometryczną charakterystykę tunelu ma podstawowe znaczenie. Betonowa nawierzchnia zapewnia odpowiednie oświetlenie drogi przy znacznie mniejszej wydajności lamp, niezależnie od ich rodzaju. Równocześnie moc lamp może być zmniejszona o dwie trzecie w porównaniu z nawierzchnią asfaltową. Natomiast wpływ dodatku tlenku tytanu do betonu nie ma znaczenia. Ogólnie, obecność pieszych na drodze może być dostrzeżona znacznie wcześniej i wyraźniej w związku z większą jasnością luminancją i odbiciem światła nawierzchni betonowej. Beton ma większą zdolność odbicia światła, co przyczynia się do lepszego pośredniego oświetlenia strefy ruchu.

EN

In the course of the research project a variety of different lighting situations were simulated and subsequently evaluated. The positive impact of a concrete road on the photometric characteristics of a tunnel can be assessed as substantial. In order to guarantee the necessary luminance on the road, concrete roads require significantly lower lamp performance independent from the lamp type. At the same time, the lamp power can theoretically be decreased by two thirds compared to asphalt roads. The influence on the necessary lamp wattage between common concrete pavements and concrete pavements, that have been supplemented with titanium oxide, is negligible. In general, objects, such as a pedestrian for example, can be detected significantly earlier and better due to increased brightness and the better reflectivity of the concrete. The concrete reflects a higher proportion of the light and therefore ensures a better indirect lighting of the traffic area.

2

Fundamentals of direct methods in poroplasticity

Maier G., Cocchetti G.

Foundations of Civil and Environmental Engineering

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2002

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No. 1

11-136

EN

A nonlinear initial-boundary-value coupled problem, central to poroplasticity, is formulated under the hypotheses of small deformations, quasi-static regime, full saturation, linear Darcy diffusion law and piecewise-linearized stable and hardening poroplastic material model. After a preliminary nonconventional multifield (mixed) finite element modelling, shakedown and upper bound theorems are presented and discussed, numeri-cally tested and applied to dam engineering situations using commercial linear and quadratic programming solvers. Limitations of the presented methodology and future prospects are discussed in the conclusions.

3

Extremum and saddle-point theorems for elastic solids with dissipative displacement discontinuities

Carini A., Maier G.

Archives of Mechanics

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2000

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Vol. 52, nr 4-5

523-545

EN

In a number of engineering situations concerning structures made of quasi-brittle, concrete-like materials, all nonlinearities can be reasonably confined to a locus of possible displacement discontinuities. This locus has a lower dimensionality (by one) with respect to the problem domain; it encompasses joints, cracks, fracture process zones (described by cohesive crack models) and their possible propagation paths. Linear elasticity is assumed everywhere else for overall analysis purposes. With reference to a very broad class of interface models, i.e. of (holonomic or nonholonomic, inviscid or time-dependent) relationships between displacement jumps and tractions across that locus, the (possibly multiple, if any) solutions of the initial-boundary-value problem of structural analysis are shown herein to be characterized by duality pairs of extremum and min-max properties.