Case Study: Access SFA Piling and Foundation Slab for Residential Extension

Location: 20 Park Avenue South, Harpingdon

Project Scope: Foundation extension for a larger residential entertainment area

Ground Conditions: Clay line over chalk

Timeline: 3 Weeks

Background

This project involved a foundation extension for a residential property in Harpingdon to accommodate a new, larger entertainment area. The client is a returning customer, having previously engaged our piling services for the main house construction four to five years prior. Ground conditions at the site—characterized by a clay line over chalk—dictated a piled foundation approach.

Site Context & Logistical Blockers

The primary constraints on this site were spatial and structural rather than environmental. While the water table presented no issues, the logistical setup was heavily restricted:

Severe Access Limitations: The site featured only a single access point restricted to a 1-meter width.

Structural Proximity: The pre-existing house is constructed from high-end materials including sandstone, requiring rigorous protection protocols during heavy machinery operation to prevent vibration damage or surface impact.

The Fallon Piling Solution

To navigate the 1-meter access bottleneck and operate safely adjacent to the structure, the engineering plan required ultra-compact machinery and low-vibration methods.

Methodology: Sectional Flight Auger (SFA) open bore piling was selected as the optimal technical response. This method allows for effective penetration through the clay into the chalk bearing stratum without generating the severe vibrations associated with driven piles.

Specifications: Installation of 300mm diameter SFA piles.

Machinery: Deployment of a "Super Kitten" piling rig. This specialized, highly maneuverable rig is specifically designed for restricted-access environments and easily navigated the 1-meter entry point.

Protection Protocols: Protective measures were implemented to shield the existing high-end masonry from spoil and operational contact

The Result

The project was completed within the planned 3-week timeframe. Utilizing the Super Kitten rig successfully bypassed the primary logistical blocker of the 1-meter access path. The SFA open bore method, combined with strict protective measures, ensured zero damage to the existing structure while successfully installing the necessary 300mm piles through the clay and into the chalk.

Following the piling phase, the scope advanced to the necessary groundworks. The existing drainage systems were systematically rerouted to clear the new footprint, followed by the installation of the new underground drainage network. Finally, a 300mm structural raft slab, reinforced to the engineer's exact designs, was constructed and cast directly onto the piling. To overcome the 1-meter access restriction during this final phase, the concrete was pumped directly from the street. This comprehensive sequence delivered a complete, finished foundation, clearing the path for the client to commence the above-ground build phases.

SPEAK TO OUR PILING EXPERTS TODAY

Have a project in mind? Get a quote or more information from one of our team.