20 research outputs found
Human perception of vibrations according different assessment methods
Human perception of vibration could be the basic parameter in designing new buildings subjected to different type of transport vibrations. Humans are more sensitive for vibrations then building structure. In an increasingly urbanized city centres people are exposed to vibrations from different transport sources such as: tramways, railways, heavy truck traffic or subway especially when considered shallow underground. The aim of this paper is to investigate the use of two different evaluation methods of human perception of vibrations. Methods chosen for evaluation are: the basic root mean squared (RMS) method and the additional method of evaluation vibration dose value (VDV). The building chosen for analysis is subjected to three different vibration sources: tram, heavy truck and subway passages. It is located in Warsaw where is a shallow underground which could have significant influence on human response to vibrations because vibrations from this kind of source is more perceptible on lower floors. That is why measurement points were located in the middle of the floor on the ground floor and on the top floor. The registered signal from the three different sources of vibration was analysed according to RMS and VDV procedure included in ISO standard. RMS and VDV methods were compared with each other
Influence of crest factor on evaluation of human perception of traffic vibration
In this article many vibrational signals of different value of crest factor are investigated. Evaluation of human perception of vibration is made with use of two different method of evaluation: basic RMS method and vibration dose value method (VDV), which is one of additional method mostly used for peak signals. Analysis of influence of crest factor value on evaluation of human response to vibration is made
Analysis of acoustic insulation in traditional wooden architecture hotel building
This paper presents evaluation of vibroacoustical requirements in the context of impact and airborne sound insulation in hotel building. This building represents traditional wooden architecture present in southern Poland. Similar structures can be found all around Europe in mountainous areas. Due to fact that there are little information about acoustic conditions of such buildings, this paper gives measured values of sound insulation of typical solutions used in this architecture. In order to define if requirements of current polish standard PN-B-02151-03:2015 for hotel buildings are met, impact sound level and airborne sound insulation of representative partitions were measured. Measurement conducted in presented building shows issues connected with non-sufficient airborne sound insulation of internal partitions – timber log walls. Due to its low mass and, in simplification, homogenous structure, its sound insulation is far from meeting requirements. Considering timber structural ceiling and reinforced concrete floor present in hotel building requirements of impact sound level and airborne sound insulation are met. The solution of weak acoustic conditions of walls is proposed as plasterboard pre-wall with mineral wool inside
Vibration induced by railway traffic-zones of influence on buildings and humans
The article presents selected results of evaluation of the harmfulness of buildings vibrations and influence on humans in buildings caused by railway traffic. The results presented in the paper were part of larger group of in field test which gather, were the basis of creation the zones of influence of railway vibrations. The paper presents the methodology of field test as well as some selected results. The discussion of the results leads to conclusions which are presented, as mentioned above, zones of influence of railway vibrations on building construction as well as on human in the buildings. The proposed zones are different for cargo and passenger trains. The ranges of zones are also different in case of building structure and human perception. All analyzes are compatible with polish codes PN-B-02170:2016 [1] and PN-B-02171:2017 [2] and executed by accredited laboratory with significant participation of the authors. The proposed zones were assumed by manager of the national railway network PKP PLK S.A
Analiza skuteczności rozwiązań obniżających poziom drgań młynów węglowych w elektrowni – studium przypadku
W referacie, rozważając przypadek elektrowni, w której stwierdzono znaczący wzrost przemieszczeń fundamentów budynku głównego jednego z bloków energetycznych, przedstawiono przykładowy sposób rozwiązywania tego typu zagadnień. Problem dotyczył zarówno osiadań statycznych, jak i dynamicznych. Ze względu na fakt, iż praca urządzeń (młyna węglowego) powoduje ruch trudny do ustalenia metodami analitycznymi, należało wstępnie wykonać pomiary drgań. Dzięki temu uzyskano czasowe przebiegi przyśpieszeń drgań fundamentów oraz wybranych punktów konstrukcji. Model obliczeniowy (MES) został poddany zarejestrowanemu na fundamencie wymuszeniu, zaś przebiegi czasowe przyśpieszeń drgań uzyskane w warunkach rzeczywistych posłużyły do walidacji jego parametrów (stałych materiałowych konstrukcji oraz gruntu i sztywności połączeń). Po uzyskaniu zadowalającej różnicy pomiędzy przyśpieszeniami (model MES – rzeczywista konstrukcja) zasymulowano trzy warianty naprawcze. W dwóch z nich drogę propagacji przecięto barierą antywibracyjną, zaś w jednym zwiększono sztywność gruntu pod fundamentami. Każde z rozważanych rozwiązań powodowało obniżenie drgań konstrukcji młynów węglowych. Jednak w przypadku „otulenia” fundamentów matą antywibracyjną uzyskano znaczne wzrosty przyśpieszeń drgań młynów. Zwrócono też uwagę, iż zwiększenie sztywności gruntu pod fundamentami pomimo ograniczenia poziomu amplitud drgań w całym obiekcie może ze względów technologicznych okazać się kłopotliwe.The paper presents case of selected power plant, where substantial increase of displacements of the foundations of the main power unit were observed and an exemplary method of solving such type of problem. The problem concerned both static settlements as well as vibrations. Since the operation of the equipment (coal mill) causes movement difficult to be determined using analytical methods, initially vibration measurements had to be made. As a result, time courses of foundations as well as selected points onto investigated structure accelerations were obtained. The computational model (FEM) was loaded with excitation registered on the foundation, while acceleration time courses obtained in real conditions were used to validate its parameters (material constants of structure and soil) and joints rigidity. After obtaining a satisfactory difference between accelerations (FEM model – real construction), three repair variants were simulated. In two of them the propagation path was separated with an anti-vibration barrier, while in one the stiffness of the soil below foundation was increased. Each of the mentioned solutions reduced the vibration level of the structure in the vicinity of coal mills. Nevertheless, in the case of "covering" foundations with anti-vibration mat, significant increases in vibration acceleration of mills were observed. It was also pointed out that increasing the soil stiffness below foundations, despite limiting the level of vibration amplitudes in the entire facility, may prove to be troublesome for technological reasons
Application of vibration measurements and forecasting calculations in the framework of protection of neighborhood buildings against railway vibrations
Praca dotyczy zagadnień związanych z wpływem drgań wywołanych ruchem kolejowym na konstrukcję budynków i na ludzi w tych budynkach. Nawiązując do norm PN-B-02170:2016-12 i PN-B-02171:2017-06 omówiono zasady stosowania pomiarów drgań celem oceny tych wpływów. Podano zasięgi stref tych wpływów. Przedstawiono zasady stosowania pomiarów drgań i prognozowania wpływów drgań na postawie obliczeń symulacyjnych z wykorzystaniem modeli do analiz propagacji drgań w gruncie i modeli budynków do obliczeń dynamicznych. Wskazano algorytm projektowania rozwiązań wibroizolacyjnych z wykorzystaniem obliczeń symulacyjnych. Zasady te odniesiono do dwu sytuacji: budowy lub przebudowy linii kolejowej (wpływ na istniejącą zabudowę) oraz projektowania nowego budynku w sąsiedztwie linii kolejowej.The work concerns the impact of railroad vibration on the construction of buildings and people in them. Referring to the PN-B-02170: 2016-12 and PN-B-02171: 2017-06 standards, the principles of using vibration measurements to assess these impacts were discussed. The ranges of these influence zones are given. The principles of using vibration measurements and forecasting of vibration effects based on simulation calculations using models for soil vibration propagation analysis and building models are presented. The algorithm for designing vibration isolation solutions is indicated. These principles are referred for two situations: construction or reconstruction of the railway line (impact on existing buildings) and design of a new building in the vicinity of the railway line
Wybrane problemy ochrony zabudowy powierzchniowej przed drganiami generowanymi przez komunikację podziemną
Tyt. z nagłówka.Bibliografia s. [362].Dostępny również w formie drukowanej.ABSTRACT: Chosen problems of the influence of vibrations generated by underground transport to buildings and to people in buildings are presented in the paper. Diagnostics of these influences is also discussed. Algorithm of analysis of these influences in the case of transport investments is given. The exemplary applications of the vibroinsulation in a construction of rail track in train tunnel in Warsaw and in Warsaw metro are presented with examples of the vibration influence prediction and former verification of it. KEYWORDS: metro, building vibrations, transport vibrations. STRESZCZENIE: W pracy przedstawiono wybrane problemy wpływu drgań generowanych przez komunikację podziemną na budynki i ludzi w budynkach. Omówiono krótko diagnostykę tych wpływów. Podano algorytm analizy tych wpływów w przypadku realizacji inwestycji komunikacyjnych. Zaprezentowano przykładowe zastosowania wibroizolacji w konstrukcji nawierzchni szynowej w kolejowym tunelu średnicowym w Warszawie oraz na bielańskim odcinku warszawskiego metra, podając przykłady prognoz wpływów drgań wraz z ich późniejszą weryfikacją doświadczalną. SŁOWA KLUCZOWE: metro, drgania budynku, drgania komunikacyjne
Protection of historic buildings against environmental pollution of vibrations
Historic buildings in Poland are largely neglected objects that small percentage is preserved in its original form. Unrelenting in the case of historic buildings is a time that brings with it the natural processes of aging of buildings, but also the history of the object which is often marked by military conflicts, fires or even incompetently carried out reconstruction. Nowadays historic buildings are also destroyed by the rapid development of infrastructure and residential construction. This development could lead to changes of water in the soil, make changes in the geologic al structure or cause exposure of the historic building to the new influences (eg. traffic vibrations), to which building has not been subjected so far. Vibrations are often omitted in environmental issues, although the protection against noise and vibration has its place in the Law on Environmental Protection. This article presents the methodology for the measurement and interpretation of vibration influence on historic buildings and the assessment methods of technical condition of historic building on the example of dynamic measurements made on St. Nicholas Church in Krakow. The importance of well-done crack-by-crack documentation and characterization of damages based on damage index is shown. Difficulties that can be encountered when determining the causes of technical condition of historic buildings are also shown. Based on the example of the Church in the article are also given the possible protection solutions of historic structures from vibrations
Vibrations of free-field and building caused by passages of the Pendolino train
The objective of the paper was to conduct dynamic measurements of free-field vibrations in three profiles and establish decay relations of propagating vibrations. The sources of vibrations were passages of the Pendolino train with dedicated speeds from 40 to 293 km/h. In each profile, soil properties tests were carried out. Based on the data for a few selected speeds of the Pendolino train’s passages, the Vibration Reduction Coefficients (VRC) were determined at selected points. The paper is also focused on the analysis of vibrations of the selected one-storey masonry residential building located in the vicinity of one of the profiles and their evaluation of the harmfulness on the building structure using standard scales of dynamic influence
Drgania mechaniczne przegród ograniczających pomieszczenie w kontekście dopuszczalnych poziomów hałasu
Drgania mechaniczne stropów w budynkach przeznaczonych na stały pobyt ludzi (np. biura, mieszkania) jak i poziom hałasu panujący w pomieszczeniu mają znaczący wpływ na subiektywne odczucie komfortu osoby eksponowanej na te zjawiska. W polskich przepisach dopuszczalne wartości dla prędkości zarówno drgań, jak i poziomu ciśnienia akustycznego A-ważonego są podawane przez osobne dokumenty i stanowią osobny przedmiot oceny. Niniejszy artykuł stanowi analizę, przy użyciu metod uproszczonych, sprzężenia mechano-akustycznego, jakim jest generowanie hałasu w pomieszczeniu przez drgające przegrody ograniczające to pomieszczenie z wykorzystaniem wartości progowych odczuwania drgań