Pinhoe Quarry

Harrington Lane, Pinhoe, Exeter

Pinhoe Quarry
Client
Pinhoe Quarry LLP
Site
Harrington Lane
Location
Exeter
Date
2012
Related service
Land Quality Service

Summary

Our Land Quality Service was delivered for this site in two stages:

We initially worked with the client to review the remediation and earthworks proposals prior to outline planning consent being granted in 2012. The bulk of the earthworks were completed between 2014 and 2016, with the final works and geotechnical and environmental monitoring being completed in 2017.

Facts and Figures

27m
deep clay pit which formerly serviced a local brick-making factory
380
new homes plus community facilities included in planning consent
6 years
for remediation planning and earthworks

Challenges

Environmental Hazards

Due to the site's previous use as a brick clay pit, there was potential for Made Ground and elevated ground gases.

Geotechnical Hazards

In addition to the presence of some existing fill, there was a potential for self-weight settlement of the new fill on this site with a resulting risk of differential settlement issues. This risk was managed by a stringent earthworks specification, which required a minimum relative compaction to 98% of the maximum dry density with maximum air voids of 5% together with surcharging of the fill thereafter.

The potential for collapse settlement arising from water inundation into the engineered fill was assessed by inundation plate tests as well as inundation of large scale load tests in-situ.

Solution

Remediation Strategy

NHBC and the client agreed a strategy for creation of a development platform using site-won and imported materials placed to an engineered-specification with the maximum depth fill material of 27m.

A programme of ongoing environmental and geotechnical monitoring and assessment was agreed and was conducted throughout the earthworks.

Development

Up to 380 residential units and associated community facilities will be constructed on site in the future. In addition, the site has a feature listed as a ‘Regional Important Geological Site’ (RIGS). This geological feature will be preserved within a ‘Geopark’ which will be incorporated into the future development.

Talk to us

Our Land Quality Service removes the uncertainty about whether a site is suitable for future housing development. Get in touch to find out how we can help your project.

a photo depicting the plan for the northern gateway Land Quality Service

Northern Gateway

At the end of summer 2022 NHBC’s Land Quality Service (LQS) team was commissioned by Bellway Homes North West to undertake a review of the proposals for the redevelopment of former farmland in Deeside, Wales into residential dwellings.

Read more
a 3D render of a modern, sleek, attic bedroom conversion NHBC Accepts

Ultrapanel Building Technologies

The Ultrapanel ‘room in the roof’ System is a brand new precision engineered system that was created to meet the demands of volume residential housebuilders.

Read more
a modern, white house with grey roof and wooden pagoda NHBC Accepts

Porotherm

Building with Porotherm clay blocks is an innovative method of construction with the reassuringly traditional values of clay material; it delivers versatile, high performance and sustainable walls.

Read more