Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Particle pressure

I agree with Professor Andrew Schofield that the scree in his photo of the Grand Canyon may have remained stable for six million years but this does not mean that creep strain has never occurred at some of the contacts between the scree particles.

When the scree particles were deposited, the weight of the particles would have resulted in interparticle forces at the contacts.

Initially these forces may have resulted in contact stresses exceeding the yield stress of the scree material thus promoting viscous flow at some of the interparticle contacts.

One effect of the viscous flow would be shear strain at the interparticle contacts but this would be accompanied by merging of adjacent particles at their points of contact due to the compressive effect of the normal component of the interparticle forces.

With the passage of time, such merging would progressively reduce the interparticle stresses and consequently the creep strain rate. Ultimately, the interparticle stresses would be reduced to a value less than the yield stress of the scree material and creep strain would cease.

I very much welcome Arthur Penman's comment on the need for more research to develop reliable methods for predicting ground movements and I believe that to achieve that goal it is necessary to recognise the time dependent nature of the deformation behaviour of geotechnical materials.

Mike Keedwell

Honorary Research Fellow

Coventry University

Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Please note comments made online may also be published in the print edition of New Civil Engineer. Links may be included in your comments but HTML is not permitted.