Technical Specifications
Technique 1 :
Mass Concrete Underpinning
- Site S2 - Warehouse 1927
- 2.5m deep
- Underpinning, breaking out of existing foundations and temporary propping to an existing facade retention scheme
Technique 2 :
Mass Concrete Underpinning & Stem Base Underpinning
- Site S1C & S2 - Warehouse 1887
- 3m deep
- Internal and external mass concrete underpinning works to an existing warehouse unit. All internal underpinning works were completed from inside the existing basement area. We also removed an existing concrete foundation as part of our underpinning works.
Technique 3 :
Mass Concrete Underpinning
- Site S1 - 12-13 Blossom Street
- 2.4 - 4m deep
- Internal and external mass concrete underpinning works to an existing warehouse unit.
The Challenge
We were approached by the client to complete a series of underpinning to various areas of the site using different underpinning techniques. We provided temporary shoring designs for both mass concrete underpinning and stem base underpinning techniques.
The site was constrained with a lot of other works being completed including demolition, piling and groundworks at the same time as our underpinning works which made access and egress from the site very challenging. The underpinning works enabled the construction of a series of RC frames to be erected on site due to the shallow depth of the existing foundations and basements were also installed following the installation of the underpinning works to continue the foundation depth to the formation level of the proposed basement areas.
One of the most difficult parts of the project was underpinning an existing façade to Warehouse 1927 and this was maintained safely throughout the underpinning process using a detailed sequence of underpinning and installing a series of structural steel props which were also installed during the underpinning process along with removing an existing concrete foundation to allow us to install the underpinning to the proposed depth of the formation level.
All underpinning works were completed on site within budget and all works were completed in 23 weeks. Works were also completed during Covid 19 and therefore the works were stopped and restarted once lockdown restrictions were lifted in central London.
The Solution
A series of underpinning to various areas of the site were installed using different underpinning techniques and temporary shoring designs were completed to enable the underpinning to be constructed safely and efficiently.
