Dark Lane, Cheshunt
Project Overview
SPEEDECK contributed to the development of 50 low-rise housing units in Cheshunt for a main contractor, delivering a complete foundation scheme over a swift 10-week span.
This presented a unique opportunity to implement foundations that are also tailor-made to specific requirements of the housing development, increasing time-efficiency, design and cost effectiveness.
SPEEDECK’s commitment to efficiency was evident with the successful handover of all plots at Structural Slab Level (including underslab drainage) over the ten weeks. Despite the ground challenges, SPEEDECK delivered sustainable solutions and unparalleled value to the client with intricate technical knowledge and targeted site investigations.
- 40% concepting
- 10% detailed design
- 50% duration on site.
Concept Design
SPEEDECK’s involvement commenced with a review of the existing ground information for the site, which identified a significant challenge: a high water table. Trying to build below the water table introduces additional costs, which are best mitigated by trying to keep construction above this level.
Acknowledging the challenges, SPEEDECK was tasked to carry out a thorough site investigation and designed a foundation solution bespoke to the site’s unique challenges. The proposed design encompassed:
Piled Raft Foundation: A strategic decision to avoid excavating below the water table. This method bypassed potential pitfalls such as ground instability and the costly dewatering process. With our construction techniques, the project was set to progress quickly, safely, and with fewer complications.
CFA Piling: Given the site’s high water table, conventional piling could have resulted in problems like borehole collapses. By choosing CFA piles, which are effective even below the water table, we guaranteed a foundation that was not only more stable and reliable but also sped up construction timelines whilst minimising disturbances to the surroundings.
Cost-Efficiency: Our design decisions reduced the need for constructing piling mats below the water table, which led to significant cost savings. Our approach was particularly cost-effective compared to the traditional pile and ground beam methods.
Despite the cost challenges, we committed to and provided a fixed price for the entire scheme, offering solutions with value for the project with our client-focused approach.
Design Engineering
With great attention to detail, SPEEDECK’s comprehensive site investigation from the previous Concept Design stage informed the design process:
Heave Report: A detailed heave report was submitted to address potential ground movements and to guarantee foundation stability. This proactive step meant that heave precautions were eliminated, simplifying the entire construction process.
Temporary Works Calculations: Essential in evaluating the stability and safety during the initial construction stages, these calculations enabled SPEEDECK to forego the need for an engineered piling platform. This decision reduced the consumption of resources and transportation, as well as optimising both construction pace and cost efficiency.
Pile Design Refinement: The pile design was refined to ensure it provided robust structural support while also withstanding environmental challenges.
Standardised Design Pack: Our consolidated design pack streamlined the approval process and successfully obtained full sign-off from the NHBC (National House Building Council). This recognition underscores the compliance and quality of our design approach.
Construction
Over 10 weeks SPEEDECK adeptly laid the foundation for all 50 housing units, from commencement of piling works, handing slabs back at their structural slab level, ready for bricklayers.
Construction was simplified by keeping all construction above the water table.
Project Conclusion
The Dark Lane, Cheshunt housing development stands as a testament to SPEEDECK Foundations adaptive capabilities, particularly in addressing unique challenges like the high water table in this project.
Our innovative approach, epitomised by the strategic choice of a piled raft foundation and CFA piles, ensured a robust foundation whilst demonstrating cost-effectiveness, faster construction and environmental consideration. This commitment to efficient and sustainable solutions was further echoed in our streamlined approvals, with the creation of a standardised design pack that swiftly secured a full endorsement from the NHBC.
Our commitment extends beyond the construction phase; we aim to foster lasting relationships with our clients, ensuring a legacy of trust and excellence. Contact Us today to discuss our range of solutions, tailored to the unique challenges of each site.
