Events & Courses

A geological hazard (geohazard) is the consequence of an adverse combination of geological processes and ground conditions, sometimes precipitated by anthropogenic activity. The term implies that the event is unexpected and likely to cause significant loss or harm. To understand geohazards and mitigate their effects, expertise is required in the key areas of engineering geology, hydrogeology, geotechnical engineering, risk management, communication and planning, supported by appropriate specialist knowledge of subjects such as seismology and volcanology. There is a temptation for geoscientists involved in geohazards to get too focused on the 'science' and lose sight of the purpose of the work, which is to facilitate the effective management and mitigation of the consequences of geohazards within society.

The study and assessment of geohazards into the wider social context, helping the engineering geologist to better communicate the issues concerning geohazards in the UK to the client and the wider public.

Module Overview

Problematic soils – Swell/shrink soils

Shrink-swell soils and rocks constitute some of the most costly and widespread geological hazards globally, with costs estimated to run into several billion pounds annually. These engineering materials present significant geotechnical and structural challenges to anyone wishing to build on, or within, them. Shrink-swell occurs as a result of changes in the water content of soils (and rocks) containing clay minerals. This is reflected in a change in volume of the ground through shrinking or swelling. Swelling pressures can cause heave, or lifting, of structures on the surface and excavations below ground, whilst volume changes due to shrinkage can cause differential settlement at or near the surface.

Many major towns and cities worldwide are founded on clay-rich soils and rocks, upon and within which their infrastructure, buildings and underground services are constructed. In the UK, the effects of shrinkage and swelling of clay soils and rocks, with respect to foundation and building damage, were first recognised by geotechnical specialists following the dry summer of 1947. After the drought of 1975–76, insurance claims in the UK came to over £50 million, and since then the cost of this has risen dramatically. In 1991, after a preceding drought, claims peaked at over £500 million. Over the past 10 years, the adverse effects of shrink-swell behaviour has cost the economy an estimated £3 billion, making it the most damaging geohazard in Britain today, with as many as one in five homes in England and Wales at risk from ground that swells when it gets wet and shrinks as it dries out, despite the UK’s temperate climate resulting in reduced risk compared with many other countries.

This lecture aims to present the viewer with a basic understanding of shrink-swell soils. To do this, we will review their nature and distribution and describe the basic processes of swelling and shrinkage. Finally, we will discuss how these soils are sampled and tested in the laboratory, relationships with Atterberg Limits and what strategies are available for their management in an engineering environment.

Speaker

Dr Colin Serridge

Dr Colin Serridge FGS CGeol EurGeol – Ground Improvement Practitioner with over 30 years' industrial experience in the design and project management of Ground Improvement projects both in the UK and overseas. Colin also currently works in academia.

Time and date

This module will take place virtually via Zoom on Thursday 4 July at 16:00 BST and will run until approximately 17:30 BST, depending on audience participation.

Fees

If you are not a Fellow of the Society, save money for this course and much more by applying for Fellowship. Find out more.

Concessions 

We offer students a generous discount. Please verify your student status by either registering with your student email address, or uploading a photograph of your student identification/acceptance letter. 

The Society offers a limited number of concessionary rates for those in financial hardship. Contact [email protected] (Please note you may be required to provide details/evidence to support your application for this.)

Registration

If you require an invoice to register for this course, please email [email protected] 

Registration will close 24 hours before the event takes place. 

We can offer bespoke discounts on group registrations of five or more. Please email [email protected] to enquire.