Vibration control solutions are used to support buildings and building structures in order to provide protection from low frequency ground-borne noise and vibration generated from external sources such as underground railways for the entire life of the building. As a proud British manufacturer, Farrat design and manufacture a comprehensive range of ever improving standard and bespoke products; ranging from individual Acoustic Bearings through to complete Building Isolation Systems [BIS] (see Fig 1.0).
Vertical Support Bearings (see Fig 1.1)
Elastomeric bearings or full area mats used to support the vertical loads of the building whilst acting as a low natural frequency spring to eliminate the disturbance associated with ground-borne vibration and re-radiated noise. Bearings can be designed to support:
- Project specific connection details
- New and retained facades
- Cores (stair and lift)
- Floor slab edges
Bearing Assembly (see Fig 1.2)
CE marked, galvanised steel assemblies which may include some or all of the following features: • Levelling plates to assist a fast and accurate installation • Fail-safes • Lateral restraints • Load spreading to ensure the load from the structure is evenly spread over the entire area of the isolation bearings • Disproportionate collapse measures such as acoustically isolated vertical ties and lateral restraints • Bearing replacement features
High Capacity Acoustic Shear Keys to Isolate Cores and Shear Walls (see Fig 1.3)
Shear keys within cores and shear walls can either be designed into the structure by the structural engineer or as a simpler alternative we have a range of Acoustic Shear Keys that can be cast directly into the structure. They have been designed to provide: • High vertical load capacity which facilitates an efficient design that usually eradicates tension in the walls • High shear loads to minimise the number of assemblies required We are happy to work with the design team to develop the most suitable solution for particular constraints of buildings.
Lateral Perimeter Isolation (see Fig 1.4)
Full area elastomeric materials used to acoustically separate the isolated structure from surrounding rigid elements.
Acoustic Floating Floors (see Fig 1.5)
Used typically to isolate the base of isolated cores and ground floor slabs.
- VFT System
- Isomat Floating Floor System
Fig 1.1 Lateral Bearing Application
Fig. 1.2 Anatomy of a Bearing Assembly
Fig 1.3 Shear Key Assembly
Fig 1.4 Perimeter Isolation
Fig 1.5 Acoustic Floating Floor
Low and precise natural frequency performance
Our range covers natural frequencies from 6 to 12Hz, providing highly effective attenuation of noise and vibration.
*Disturbing frequencies <12Hz.
Minimal deflection to achieve low natural frequencies
Typical deflection required of bearings to achieve natural frequency of 10Hz is ~4-5mm, as opposed to synthetic or harder grade rubber that needs to deflect upto 20mm.
*To achieve the same performance & will demonstrate slightly higher levels of creep.
Very low Creep
Our building isolation bearings have a tested creep rate of ~2% p/logarithmic decade, meaning additional deflection from creep after 60 years will be ~8%.
*E.g. for a 10Hz bearing with working deflection 4.5mm, after 60 years this will have increased to less than 0.5mm.
Our elastomeric compounds have been externally certified based on the most stringent and appropriate test requirements.
*Meeting BS EN 1337-3:2005 and BS 6177:1982 criteria.
Bespoke compound design
We design our own elastomeric compounds to optimise their performance for building isolation. Farrat natural rubbers have enhanced ozone resistance & low temperature performance.
*Min. working temperature -10oC.
Long service life
Farrat bearings require no maintenance, do not require regular inspections and are not designed to need to be replaced; 15 year warranty/60 year design life.
Contact us for a copy of our Technical Paper on the Long Term Performance of Farrat’s Laminated Natural Rubber (LNR) Bearings.
Our ISO 9001 certified manufacturing processes are developed to control quality, provide traceability and maximise capacity. Every bearing is tested and inspected under full factored load to demonstrate performance is within set limits.
*Developed in line with BS EN 1337-3:2005 to ensure no defects.
Farrat understand the complexity of the construction process tand aim to work with clients to best meet project programs. We can hold assemblies to dispatch against these & provide dedicated and timed deliveries.
*To maximise crane availability.
- Building Isolation
- Concert Halls/Theatres
- Residential & Office Buildings
- Laboratories & Test Facilities
- TV/Recording Studios
Protecting Buildings from:
- Railway/Tram Lines
- Underground Rail
- Industrial Facilities
- Structure Borne Noise
- Test Facilities
- Power Presses
- Turbine Foundations
- Data Centres
- Oil/Gas extraction
- Power Generation
- Anechoic Chambers
- Reverberation Rooms
- CMM Facilities & Medical Imaging
Queen Mary University Type: Acoustic Structural Bearings
Warwick University Building Type: Acoustic Structural Bearings
Wembley Central B2 Type: Acoustic Structural Bearings
Cartwright Gardens Type: Acoustic Structural Bearings
Grosvenor Square Type: Floating Floors
Farrat Design Support Farrat’s design principles and products provide an adaptable and flexible way of incorporating vibration control into building structures, with the aim to achieve the best combined system performance of load bearing capacity, structural integrity, vibration control and buildability. The success of a building isolation project is not just reliant on the performance of the isolation bearings but requires consideration of the entire building design including:
- Structural modelling to achieve an integrated design between the structure and the isolation bearings
- Robust structural design to take disproportionate collapse and column effective length into account
- Effective structural and architectural detailing of all interfaces between isolated and non-isolated elements which may be structural internal fit out or services
- A construction methodology that minimises risk, time and cost
Contractor Support All Farrat products are designed for maximum performance whilst at the same time being practical and quick to install. Our aim is to provide a service to the contractor that includes:
- Guidance on overall building design and construction
- Delivering the right products to site at the right time
- Planning and co-ordination with the contractor to ensure products can be unloaded from the delivery wagon and efficiently transported to the work area
- Clear installation schedules and product labelling and to ensure the correct products are placed in the correct locations
- Well thought through installation methodologies that take into account location specific constraints
- Clear and comprehensive installation instructions and drawings
- Installation briefings, on-site support and inspections
In order to start the process, please send us the following information:
- Acoustic/Vibration Specification
- Relevant Structural and Architectual Drawings
- Column and Core Vertical Loadings*/**
*ideally in Excel format, provided as Dead Load, Super-imposed dead Load and Live Load with location plan drawings. **We will consider horizontal loadings, but only once the vertical bearings have been designed.
Oliver Farrell CEng MEng FIMechE CEO & Technical Director
Structural Vibration and Building Isolation Systems
Oliver is a Chartered Mechanical Engineer with over 12 years experience in mechanical and structural engineering. He is Farrat’s 3rd generation CEO and Technical Director for Structural Vibration and Building Isolation systems.