Marius Mickaitis

Statistical assessment of environmental noise generated by road traffic

Abstract The necessity to check requirements for sound insulation of new building facades against outdoor noise and for estimating noise pollution of the residential area comprise the assessment of environmental noise taking in situ measurements that are mainly carried out under the standardized method presented in the EU directives and Lithuanian legislation. For these estimations, annual composite daily equivalent sound pressure level Ldеn becomes obligatory. When the value of this descriptor is determined from measurements, it is relevant to reasonably reduce a time interval of the performed measurement. The possibilities of determining the noise level Ld ,12h of the day (12h) undertaking annual Lden assessment making short-term (15÷60 min.) measurements is dealt in this work. In this way, the sensitivity of the set of statistical descriptors to variations in sound pressure levels was investigated. The paper proposes that the obtained instantaneous A-weighted sound pressure levels with F (fast) time we...

Vibration attenuation at asymmetric cross‐form joints of buildings

Abstract The aim of the work is to estimate sound energy transmission through asymmetrical cross‐junctions in buildings. Several kinds of these joints have been investigated. Theoretical calculation model to obtain transmission loss was developed and a system of equations established. The equations were solved and expressions were obtained for predicting transmission loss. Using this procedure for different structural connections, the simplified calculation formulas were received for different cases of asymmetrical cross‐joint. The influence of geometrical parameters and material properties were determined for the sound energy attenuation in the joints of buildings. The obtained results may be applied for evaluation of influence flanking noise transmission through different asymmetric cross‐junctions in buildings.

Features of sound classification scheme designated to label buildings in Lithuania

AbstractIn Lithuania’s case, the legal requirements for the building acoustic quality since the year 2004 has been expressed through the sound classification scheme (SCS). The relationship of the subjective indoor acoustic comfort with the value of objective sound insulation was considered as a core for the classification scheme. SCS was designed to provide at least one sound class as a request for the newly erected building, other lower classes for reconstructed buildings and higher classes for premises with enhanced acoustic comfort. The adopted scheme contains five sound classes with various steps between them and is based on rating by two different sound insulation descriptors both having the same limit value. A request to protect against noise for newly erected and reconstructed buildings was enforced via the mandatory pre-completion acoustical testing. The database collected during testing allowed for the analysis of about 2000 in situ measurements of sound insulation properties of building partitio...

Experience obtained during the ten years of the sound classification practical use for regulation building acoustics in Lithuania

Advantages of application the sound classification schemes were foreseen in the two applications. In the legal regulation, the scheme expresses in the users friendly and easy understandable form protection against noise requirements for the buildings. The scheme is also a tool for designer to advice criteria of the suitable acoustic comfort in premises and also to label buildings according acoustic quality. Classification scheme implemented in Lithuania comprise five acoustic comfort classes—A, B, C, D, and E. Acoustical requirements expressed by the C sound class limit values correspond to the at least acceptable acoustic comfort level. The lowest (worst) sound class is E and comprise limit values corresponding to the acoustical comfort level in old buildings erected under sound insulation requirements existed before. By this reason, the step in limit values between different classes cannot be permanent and depends from the changes in acoustical demands during the time. For enforcement, legal requirement...

Angaro rekonstrukcija įgyvendinant inovatyvius darnios architektūros sprendimus

Santrauka Siekiant pagerinti studijų infrastruktūrą ir pritaikyti siuolaikinius mokymosi metodus, grupinio darbo vietų sukūrimas dažnai tampa aktuali problema. Vienas is galimų jos sprendimo būdų yra rekonstruoti apleistą angarą ar kitą panasų statinį. Planuojant ir įgyvendinant rekonstrukcijos sprendimus, taikytini aktualūs darnios ir tvarios architektūros principai. Taikant tarptautiniu ir nacionaliniu lygiu veikiancias skirtingas darnias pastatų sertifikavimo sistemas sukaupta nemažai patirties ir istobulintos siūlomos schemos. Jų reikalavimų kriterijų optimizavimas konkreciam objekto tipui leistų pasiekti subalansuotus ir inovatyvius darnios architektūros sprendimus naujos statybos arba renovacijos atvejais. Sio darbo tikslas yra įvertinti inovatyvių darnios ir tvarios architektūros principų taikymo galimybes rekonstruojant angarą į neformalų studijų ar panasios paskirties pastatą.

Vibration transmission through joints of walls and columns in framed buildings

Abstract Constructional practice has shown that structure‐borne sound transmission through joints can signally reduce airborne sound insulation in buildings. Vibration transmission coefficient evaluates this reduction in design calculations. In this article sound transmission through joints in framed buildings is investigated. Rooms in framed buildings are shaped by walls and ceilings connected to columns. Several walls could be connected to each column in a building plan. Such joints are modelled like idealised plate–beam–plate junctions. Examining vibration transmission through these junctions, the influence of a column must be estimated. The column will resist forces and moments applied by the connected walls. The aim of the paper is to evaluate how various properties of walls and columns influence the vibration transmission loss at joints of buildings. The results are compared with the results of similar junctions without columns.