Carrington Street Case Study

The Carrington Street project is a mixed-use residential development located in the narrow backstreets of Mayfair. This seven-storey building features 28 apartments, a gym, a spa, a pool and space allocated for retail units.

With a focus on high specifications, noise limitations in the residential spaces were a key consideration. The target was to meet an upper noise limit of 35 dB LAmax, while aiming for a lower target of 30 dB LAmax. Train passes from nearby underground lines, such as the Piccadilly and Jubilee Lines, posed a risk of exceeding these noise limits unless properly addressed.

To meet these requirements, the structural bearings supporting the main lift core, columns, and walls below the isolation line were designed to have a maximum natural frequency of 8 Hz. This corresponds to a rubber bearing with a thickness of 111 mm. The bearing design also includes a built-in ±20% load variation, allowing for comfortable building tolerances without compromising the isolation criteria.

The isolation line begins at the base of the lift core. It is standard practice to isolate the entire lift core from base to top due to its open void and multiple lift rail connections, which are difficult to decouple. Consequently, wherever the core interacts with an un-isolated (or noisy) slab, an isolation detail is necessary. Once the core reaches the horizontal isolation line—specifically, the upper ground floor slab—it can be rigidly tied into the building structure, and conventional construction methods can then be applied.

Given the acoustic separation line runs across various building levels, any structures crossing this line required design modifications to maintain the acoustic standards. The south-facing façade, a key component of the project, was to be supported at ground level (noisy) but needed to be connected to the building above. To address this, an isolated concrete beam was designed and constructed to support the façade, accommodating both vertical and horizontal load conditions.

Mason UK would like to extend its thanks to Ardmore Construction and Toureen Contractors for their careful attention and diligence during the bearing installation phase of the project.

Installation Photos

Please see additional installation photos below:

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