Wyniki wyszukiwania - BazTech

1

Materiałowe aspekty równości nawierzchni betonowej

Glinicki Michał A.

Drogownictwo

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2020

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nr 4

99--108

PL

Zgodnie z definicją podaną w MEPDG 2020, równość nawierzchni odzwierciedla profil nawierzchni w śladach kół. W artykule przestawiono przegląd materiałowych i technologicznych czynników wpływających na równość nawierzchni drogowej z betonu cementowego, dyblowanej i kotwionej, przeznaczonej do kategorii ruchu KR5-KR7. Omówiono specyfikę metody ślizgowej, która jest procesem ekstruzji betonu, pozwalającym na monolityczne ułożenie warstwy przy jednym przejeździe układarki. Omówiono właściwości reologiczne mieszanki betonowej oraz jej praktyczne cechy techniczne, mające decydujące znaczenie przy formowaniu powierzchni jezdni. Utrzymanie stałego profilu nawierzchni w projektowanym 30-letnim okresie eksploatacji jest możliwe dzięki wysokiej odporności betonu na silne oddziaływania mechaniczne, termiczne i agresję środowiska.

EN

According to the definition given in MEPDG 2020, the evenness of pavement reflects the surface profile in the wheel tracks. A review of material and technological factors influencing the evenness of the road pavement made of cement concrete, doweled and anchored, designed for traffic category KR5-KR7 is presented. The specificity of the slip-formmethod, which is a process of concrete extrusion, allowing for monolithic paving at one pass of the paver is discussed. Rheological properties of the concrete mixture and its practical technical features, which are decisive for the formation of roadway surface, are discussed. Maintaining a constant surface profile over the designed 30-year service life is possible due to the high resistance of concrete to strong mechanical, thermal and environmental influences.

2

Równość nierówności drogi, czyli co warto (po)wiedzieć o IRI

Godlewski D., Szpinek S.

Drogownictwo

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2016

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nr 5

155--164

PL

W artykule przedstawiono wybrane zagadnienia dotyczące procedury wyznaczania ocen równości nawierzchni drogowych wyrażonych poprzez wielkość IRI, w tym założenia metody badawczej, równania ruchu oraz przykłady ich rozwiązania dla urządzeń bezpieczeństwa ruchu. W analizie oddziaływania „dużych nierówności” na jadące pojazdy, oprócz ocen równości, posłużono się współczynnikiem dynamiczności do kontroli siły nacisku koła na nawierzchnię i współczynnikiem niedogodności do określenia wielkości wstrząsu nadwozia. Uzyskane wyniki badań symulacyjnych i wnioski mogą być odniesione również do oceny innego typu nierówności nawierzchni jezdni.

EN

Selected issues related to procedure of road pavement evenness evaluation expressed by IRI value are presented in the paper. In the above, assumptions to test method, traffic equations and examples of their solving for road safety devices are included. Dynamic coefficient for control of wheel loading force on the pavement and coefficient of inconvenience for evaluation of vehicle body shock are used in analysis of impact of “large unevenness” on moving vehicles. The results of simulation tests and conclusions may be referred also to evaluation of other types of unevenness.

3

Prediction of Blended Yarn Evenness and Tensile Properties by Using Artificial Neural Network and Multiple Linear Regression

Malik S. A., Farooq A., Gereke T., Cherif C.

Autex Research Journal

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2016

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Vol. 16, no. 2

43--50

EN

The present research work was carried out to develop the prediction models for blended ring spun yarn evenness and tensile parameters using artificial neural networks (ANNs) and multiple linear regression (MLR). Polyester/cotton blend ratio, twist multiplier, back roller hardness and break draft ratio were used as input parameters to predict yarn evenness in terms of CVm% and yarn tensile properties in terms of tenacity and elongation. Feed forward neural networks with Bayesian regularisation support were successfully trained and tested using the available experimental data. The coefficients of determination of ANN and regression models indicate that there is a strong correlation between the measured and predicted yarn characteristics with an acceptable mean absolute error values. The comparative analysis of two modelling techniques shows that the ANNs perform better than the MLR models. The relative importance of input variables was determined using rank analysis through input saliency test on optimised ANN models and standardised coefficients of regression models. These models are suitable for yarn manufacturers and can be used within the investigated knowledge domain.

4

Metodyka przeliczania danych kształtu profilu powierzchni na normatywny parametr równości według metody łaty i klina

Kalinowski J.

Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo

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2015

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Z. 21 (171)

91--100

PL

W artykule zaprezentowano algorytmy przeliczania danych numerycznych profilu powierzchni zapisanego w postaci punktów 2D wg metodyki pomiarów równości za pomocą normatywnej metody łaty i klina. Dzięki wykorzystaniu techniki komputerowej zadanie to można rozwiązać w bardzo krótkim czasie, uzyskując maksymalną dokładność.

EN

This paper presents numerical data conversion algorithms of surface profile stored in the form of 2D points according to the methodology of measurements of evenness with the normative patches and wedge method. Through the use of computer technology this task can be solved in a very short time with the maximum accuracy.

5

Diagnostyka nawierzchni jezdni w miejscach zdarzeń drogowych

Godlewski D., Szpinek S.

Drogownictwo

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2015

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nr 11

362--371

PL

W artykule omówiono wybrane metody badań równości i poślizgowości nawierzchni jezdni, z jakich można korzystać w diagnostyce miejsc zdarzeń drogowych. Ogólnie opisano urządzenia i stosowane obecnie procedury pomiarowe w badaniach systemowych na sieci dróg. Na różnych przykładach pokazano niestandardowe sposoby przetwarzania zbiorów danych pomiarowych i opracowania wyników, które służą do rozpoznania miejsc osobliwych o skokowo zmiennych cechach nawierzchni jezdni, jakie mają znaczący wpływ na warunki i bezpieczeństwo ruchu pojazdów.

EN

The article descripts chosen measurement methods of roughness and (?) including currently used equipment and procedures, which can be used in road surface diagnosis in accidents zones, and presents examples of other non-standard methods of data acquisition and processing, which were collected both from places of expected discontinuously variable road surface features, as well as visually unrecognizable discontinuities, which affects the conditions and safety of the traffic.

6

Analiza oddziaływania między pojazdem a nawierzchnią dla celów klasyfikacji IRI w ramach słowackiego PMS

Celko J., Decky M., Kovac M.

Eksploatacja i Niezawodność

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2009

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nr 1

15-21

PL

Równość jest jednym z podstawowych czynników jakości nawierzchni. Stanowi ona charakterystykę stanu drogi, jak również bezpieczeństwa na drodze i komfortu jazdy. Nierówności podłużne powodują niedogodności w ruchu drogowym i niebezpieczeństwo zmniejszenia oddziaływania między kołami a nawierzchnią. Wymienione aspekty zostały wzięte pod uwagę w analizie poziomów klasyfikacji w ramach Słowackiego PMS. Symulacje różnych warunków brzegowych podczas diagnostyki nawierzchni miały na celu przede wszystkim zbadanie wpływu nierówności na pojazd, a co za tym idzie, na komfort jazdy. Z drugiej strony, wpływ nierówności na oddziaływanie między nawierzchnią a kołem stanowił podstawowe kryterium oceny z punktu widzenia bezpieczeństwa. Przedmiotem artykułu jest obserwacja i ocena opisanych parametrów podczas przeprowadzonych symulacji i pomiarów eksperymentalnych. Do symulacji użyto dynamicznych charakterystyk prawdziwych pojazdów.

EN

Road evenness is one from basic factors of the pavement quality. It represents the characteristic of the road serviceability but also road safety and comfortable. The longitudinal unevenness causes the traffi c discomfort and danger of the wheel-pavement interaction decreasing. Listed aspects were taken into account for analyze of classifi cation levels in frame of the Slovak PMS. The simulations of different boundary conditions during pavement surface diagnostics were oriented above all to the response of unevenness to the vehicle and to the ride comfort consequently. On the other hand an effect of unevenness to interaction between surface and wheel was the basic criteria of evaluation from safety point of view. The paper is oriented to the observation and evaluation described parameters during realized simulations and experimental measurements. For simulations were used dynamic characteristics of real vehicles.

7

Równość podłużna nawierzchni betonowej autostrady płatnej

Szpinek S.

Drogownictwo

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2004

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nr 11

339-346

PL

Oszacowano wpływ szczelin dylatacyjnych na równość nowej nawierzchni betonowej w wyniku badań dwóch odcinków nawierzchni na autostradzie A18 i drodze nr 8. Pomiary wykonano profilografem laserowym RSP a równość określono wskaźnikiem IRI. Na autostradzie A18 78% długości spełnia wymagania stawiane dla autostrad płatnych a na drodze nr 8 tylko 20%. Analizowane widma amplitudowe nierówności podłużnej również istotnie różnią się dla obu dróg. Na autostradzie wpływ szczelin dylatacyjnych na równość jest niezauważalny a na drodze nr 8 jest istotny, co świadczy o niestarannym wykonaniu.

EN

Influence of joints on the evenness of new concrete pavement has been evaluated in the result of testing of the two sections of the pavement of motorway A18 and road No 8. Tests were made by Road Surface Profiler and the evenness was determined by International Roughness Index. On the motorway A18 78% of the length fulfilled requirements for toll motorways but on the road No 8 20% only. Analysed amplitude spectrum of longitudinal evenness are significantly various for both roads. Influence of joints on the motorway may be neglected while it is significant on the road No 8. This is the result of careless construction.

8

Relative abundance distributions of species : the need to have a new look at them

Ulrich W.

Polish Journal of Ecology

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2001

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Vol. 49, nr 4

391-405

EN

This paper shows that recent models of relative abundances (RADs) like the log-normal model or sequential breakage or nich apportionment models are not able to describe and explain RADs found in natural communities because they are derived from a classical niche concept and assume strong past or present interspecific competition. None of them refers especially to temporal variability and functional niche dimensions. The present paper identifie three basic features of natural communities (unimodal species-weight distributions, abundance-weight distributions with more or less marked upper boundaries, and species density fluctuations that can be modelled by four different random processes). Modelling communities with these basic features resulted in RADs that only in part could be described by classical models but that had shapes often found in sampling from larger natural communities. No single distribution like the canonical log-normal appeared that may serve as a general null-model but RAD and evolutionary strategy (r- or K selection) seem to be related. The shape of relative abundance distributions was found to depend on the number of species even if all parameter setting of the generating distributions were identical. This indicates that classical evenness indices (that assume independence of species number) might not be appropriate to compare communities with different numbers of species. It appeared that RAD and body weight related community patterns have to be studied together.

9

On the scale dependence of evenness

Ulrich W.

Polish Journal of Ecology

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2001

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Vol. 49, nr 1

91-94

EN

A recently reported (Wilson et al. 1999) effect of spatial scale on evenness is studied and it is shown that such a pattern is not necessarily an effect of changes in community structure at different scales but may simply result as a byproduct from constrains introduced by maximum and minimum allowed densities due to the sampling procedure. Evenness is found to be constant only if the species area relationship of the community under study has exactly the parameter values that are given by the parameter values of the relative abundance distribution of the community. Because such a situation will seldom occur under natural circumstances scale dependence of the evenness (and of related descriptors of structure) is expected to be a general feature.

10

Models of relative abundance distributions. 2, Diversity and evenness statistics

Ulrich W.

Polish Journal of Ecology

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2001

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Vol. 49, nr 2

159-175

EN

The recent concepts of diversity and evenness and their definitions are discussed. It is shown that especially the ambiguities in defining evenness has led to confusion about evenness measures and their applicability. Definitions of diversity and evenness from parameters of relative abundance distributions avoid such ambiguities. In this paper diversity is defined as the negative inverse of the slope of the relative abundance distribution in a semilogarithmic plot and evenness as the arcus tangens transformed shaping parameter. Diversity and evenness depend therefore on the type of relative abundance distribution and diversities from communities of different types of relative abundance distributions (power, fraction, random assortment or Zipf-Mandelbrot type) cannot be compared directly. The properties of these newly defined diversity and evenness indices and their behavior in samples are discussed. It is shown that Tokeshi's newly developed power fraction model may serve as a universal basis for defining diversity and evenness indices.

11

On species-area relationships. 2, Slope and factor values of power function and exponential model

Ulrich W.

Polish Journal of Ecology

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2000

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Vol. 48, nr 1

21-35

EN

Using model assemblages generated by a FORTRAN program the parameter values of the slope of the power function and the factor of the exponential model of species-area relationships have been studied. It appeared that the slope value is not a constant independent of area and sampling method but depends strongly on grain, sampling method and model fit. The fraction of singletons in the sample proofed to be of major importance. A plot of slope against assemblage structure (estimated by the standard deviation of log2 (densities) was bell shaped with the highest slope values at intermediate SD values. A comparison of this plot with SD values from theoretical relative abundance distributions showed that log-normal distributed assemblages should have slope values that are higher than previously reported in the literature. Although it was impossible to predict the slope from the relative abundance distribution, the opposite was possible. At any given slope value there are two linked relative abundance distributions. The factor of the exponential model was more independent of sampling methods but linearily connected with sampling efficacy. A high non-linear correlation between factor and Shannon diversity was detected and a general function of this relationship developed and tested. The factor of the exponential species-area relationship may serve as an estimate of regional diversity.

12

On species-area relationships. 1, fit of power function and exponential model

Ulrich W.

Polish Journal of Ecology

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2000

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Vol. 48, nr 1

3-20

EN

A FORTRAN program is developed that generates model assemblages on the basis of three basic features of animal communities: the species-weight relationship, the density-weightrelationship, and the minimal density. Samplings from random placed individuals of such assemblages revealed the influence of the sampling method (sequential adding, nested and non-nested), the scale, and the underlying relative abundance distribution on resulting species-area relationships (SPARs). It is concluded that the type of the species-area relationship is not an intrinsic factor of an assemblage but depends especially on the sampling method and the unit of area. The fraction of species found only once in the sample (singletons) was the major factor influencing the model that fitted the SPAR best (at low fractions the exponential, at higher fractions the power function model). All sampling and structural factors that influence the fraction of singletons also influence the fit of the SPAR model. A mathematical derivation showed that at a certain fraction of singletons in the sample a shift from the power function to the exponential model is expected independent of assemblage type. This shift will occur between 20 and 30% singletons.

13

On species-area relationship. 3, The intercept of the power function and the exponential model

Ulrich W.

Polish Journal of Ecology

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2000

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Vol. 48, nr 1

37-48

EN

Using model assemblages the dependence of the intercept of the power function and the exponential model of species-area relationships on slope and factor value were studied. It is shown that the quotient of intercept and total species number in the assemblage (A[unit]/S[a]) can be interpreted as a relation between local and regional diversity and linked with species-area relations. Two general relations are derived and tested combining both concepts: z=a/ln[area] [...] with z being the slope of the power function model, H the Shannon diversity, Beta, Beta[1] and Beta[2] constants, and a the constant of the relation between S[unit]/S[a] and z. It is concluded that with the above functions species-area relationships can be used to infer the relation between local and regional species numbers and to compute regional diversities.