This report addresses serviceability issues of tall wood buildings focusing on vibration and sound insulation performance. The sound insulation and vibration performance may not affect building's safety, but affects occupants' comfort and proper operation of the buildings and the funciton of sensitive equipment, consequently the acceptance of midrise and tall wood buildings in market place. Lack of data, knowledge and experience of sound and vibration performance of tall wood buildings is one of the issues related to design and construction of tall wood buildings.
This report addresses serviceability issues of tall wood buildings focusing on their vibration and sound insulation performance. The sound insulation and vibration performance may not affect the building’s safety, but affects the occupants’ comfort and the proper operation of the buildings and the function of sensitive equipment, consequently the acceptance of the midrise and tall wood buildings in market place. Lack of data, knowledge and experience of sound and vibration performance of tall wood buildings is one of the issues related to design and construction of tall wood buildings.
The measured and estimated values should also be correlated with actual experiences of the occupants in the building if such information is obtained, for example, through a survey.
Serviceability performance studied covers three different performance attributes of a building. These attributes are 1) vibration of the whole building structure, 2) vibration of the floor system, typically in regards to motions in a localized area within the entire floor plate, and 3) sound insulation performance of the wall and floor assemblies. Serviceability performance of a building is important as it affects the comfort of its occupants and the functionality of sensitive equipment as well. Many physical factors influence these performances. Designers use various parameters to account for them in their designs and different criteria to manage these performances. Lack of data, knowledge and experience of sound and vibration performance of tall wood buildings is one of the issues related to design and construction of tall wood buildings.
For wood floor systems, their vibration performance is significantly dependent on the conditions of their supports, specifically the rigidity of the support. Detrimental effects could result if the floor supports do not have sufficient rigidity. This is special ture for floor supporting beams. The problem of vibrating floor due to flexible supporting beams can be solved through proper design of the supporting beams. However, there is currently no criterion set for the minimum requirement for floor supporting beam stiffness to ensure the beam is rigid enough. Designers’ current practice is to use the uniform load deflection criteria specified in the code for designing the supporting beams. This criterion is based on certain ratios of the floor span (e.g. L/360, L/480 etc.). The disadvantage of this approach is that it allows larger deflections for longer-span beams than for shorter beams. This means that engineers have to use their experience and judgement to select a proper ratio, particularly for the long-span beams. Therefore, a better vibration-controlled design criterion for supporting beams is needed.
It is recommended to further verify the ruggedness of the proposed stiffness criterion for floor supporting beams using new field supporting beam data whenever they become available.
Les opérateurs d'équipement de préparation de terrain sont exposée à des niveaux élevés de vibration globale du corps, à caise des impératifs du cycle de travail selon lesquels la machine doit se déplacer de façon continue et couvrir entièrement la surperficie à traiter. La présente étude détermine l'ordre de grandeur de ces niveaux de vibration, pour un échantillon de machines travaillant dans des conditions variées de site, et elle montre comment les caractéristiques des machines et les paramètres opétationnels peuvent influencer les niveaux de vibration globale du corts. L'échantillon de mahcines comprend des véhicules à chemilles et à roues, qui poussent les accessoires de préparation de terrain ou les tirent.
Dans le but de permettre à l'industrie de mieux saisir la relation entre le déplacement hors-route d'une machine et le confort de l'opérateur, FERIC a évalué les niveaux de vibrations dûs au transport, générés par des débusqueurs à roues dans diverses conditions de fonctionnement. Ces vibrations ont été mesurées pour un échantillon de débusqueurs à pince et à câble, dotés de sièges à suspension et de sièges rigides, durant des opérations réelles en Ontario et au Québec. Les vibrations globales du corps enregistrées ont été analysées en termes de valeur efficace, de valeur crète et de facteur de crète. Les résultats ont montré que les opérateurs étaient dans tous les cas exposés à une vibration quotidienne égale ou supérieure aux limites "acceptables" reconnandées par la norme 2631 de l'ISO.
The operators of site preparation equipment are subjected to high levels of whole-body vibration (W-BV) because of the prerequisite for a continuous travel work cycle and for full coverage of the area to be treated. This study defines the magnitude of these levels for a sample of machines working in various site conditions, and shows how machine and operating characteristics can influence W-BV levels. The machine sample encompasses both tracked and wheeled prime movers, with these either pulling or pushing their site preparation implement.
To further the industry's understanding of the relationship between off-road travel and machine operator well-being, FERIC evaluated the motion induced vibration levels generated by wheeled skidders working in a variety of operating conditions. Ride-induced vibration was measured for a sample of grapple and cable skidders, both with and without suspension seats, during actual operations in Ontario and Quebec. The whole-body vibration (WBV) recorded was analysed in terms of RMS, peak, and crest factor levels. The operator's daily vibration exposure was found to equal or exceed the "acceptable" limits as defined by the ISO 2631 standard in all cases. In addition, the report presents a discussion of WBV theory and issues of potential interest.
The classic ride model CR48 air-cushioned suspension for fifth-wheels was studied to determine its effects on fuel consumption saving, motion-induced vibrations, and load sway (trailer roll) when used on logging trucks in their actual working environment. Comparison of trips made by a tractor-trailer, on various road surfaces, both loaded and empty, with the air cushion inflated and deflated, shows overall improvements of 1 to 2% in the fuel consumption rate when inflated. Some positive effects on vibration levels were found on the tractor and trailer when loaded. Little improvement was found when empty. No detrimental effect on load sway was observed.