Trial pit
A trial pit (also known as a test pit) is a type of intrusive ground investigation that is used as a means of determining the condition of the ground, typically before beginning construction works.
Trial pits are commonly used to investigate shallow ground conditions to develop an understanding of the profile of soils within the ground. They can be particularly useful where buried structures, variable conditions or contamination is suspected or needs further investigation.
They can be excavated by hand or using a backhoe excavator, generally to a depth of up to 3.5-4.5 m. If a trial pit is deeper than 1.2 m and is intended to be entered by people, it should be made secure against the possibility of structural collapse.
Trial pits (or trenches) can be more cost-effective than boreholes but they cannot reach the same depth. Trial pits can also excavated relatively quickly. However, they can cause significant surface disturbance and it can be difficult to properly fill excavations when the pit is no longer needed.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Download your free guide.
Four new types of prior approval for solar developments
Online Planning Portal application types from 5 September.
Election fails to spark construction industry revival
Contract awards and planning; post election.
Making diversity and inclusion easy for SMEs
The CIOB tool for companies with limited resources.
Sustainable Futures: Redefining Retrofit for Net Zero Living
BSRIA Briefing 2024, initial speakers announced.
Looking back at the UK's first Passivhaus leisure centre
Reflections on St Sidwell’s Point with CIAT.
A-Level results and electrical apprenticeships
Electrical Skills Index highlights areas with skills shortages.
One of the world's more unusual drive-throughs.
A quick introduction.
Hadrian's Wall Path and the national trails
The trails are heritage assets in their own right.
Articles on timely advice and hydraulic lime.
Building Designers Association of Australia
CIAT and BDAA sign Memorandum of Understanding.
Built Environment Inclusive partners issue statement committed to inclusion.
Building regulation requirements can have unintended consequences.
CIOB announces 2024/25 vice president
Sustainability champion Professor Saul Humphrey.
Accelerating towards a net-zero built environment.