Case Study: Tesco Extra, Cumbernauld – Ground Investigation
Client: Uplands Retail
Services: Rotary coring, ground investigation, geotechnical laboratory testing, groundwater observations, foundation recommendations, soil-nailing design support
Location: Cumbernauld, Glasgow
Project summary & client purpose:
To support the proposed construction of a new wall adjacent to Tesco Extra in Cumbernauld, Earth Environmental & Geotechnical carried out a targeted ground investigation for Uplands Retail.
The purpose of the works was to establish the ground and rock conditions beneath the site and provide the geotechnical information required to support foundation and soil-nailing design. Understanding the depth, strength and variability of the underlying strata was important to developing a practical and appropriate engineering solution.
Our services:
Our team completed a 10.5m rotary cored borehole using a tracked dual-purpose drilling rig. Continuous core samples were recovered through the superficial deposits and underlying rock, with Standard Penetration Tests undertaken at regular intervals to assess ground strength.
The investigation was supported by geotechnical laboratory testing, including moisture content, plasticity, pH, sulphate and uniaxial compressive strength testing. The findings were brought together in an interpretative report, providing design parameters and practical recommendations for the proposed wall and associated foundations.
The challenges:
The site was positioned within a constrained area close to an operational retail development, delivery access and existing utility infrastructure. This required careful planning of the exploratory location and preliminary service clearance before drilling could begin.
Ground conditions also changed significantly with depth. Made ground and natural clay were encountered above weathered siltstone, with groundwater recorded within the deeper borehole. Accurately defining the transition between these materials was essential because each stratum offered different strength, settlement and construction characteristics.
Results:
The investigation established a clear ground profile across the full depth of the borehole, identifying made ground to approximately 1.1m, natural clay to around 3.9m and siltstone below this level.
The recovered core and laboratory results provided the design team with reliable information on soil and rock strength, groundwater and ground chemistry. This enabled appropriate foundation and soil-nailing options to be assessed using site-specific evidence rather than assumptions. By identifying the engineering characteristics of the ground before construction, the investigation helped reduce uncertainty, inform design decisions and manage the risk of unexpected conditions during the wall works.
