Hi Akshay,

If you've not come across it already, a good starting point would be the review paper by Lavrov (2003) on this topic, focusing on the Kaiser effect in differing lithotypes and under varying test conditions. A citation list for this paper from Google Scholar will give you a good idea of the latest research.

Hope this helps,

Graham

Lavrov, A. "The Kaiser effect in rocks: principles and stress estimation techniques." International Journal of Rock Mechanics and Mining Sciences 40.2 (2003): 151-171.

Hi Graham,

Thank you.

I came across this publication. I will go through the references.

However, I am working on stress anisotropy in shale using ultrasonic velocities.

Akshay

The pressure memory of rock is actually the result of the plasticity and rigidity of rock. This has a certain relationship with the composition of the rock. For example, rocks with high shale content are sensitive to pressure and will remember the characteristics of the stresses, while rocks with high quartz content may return to their original state when the pressure disappears (this depends on At the time the stress is applied). But more importantly, the depth of the crust where the rock is located, generally the rock within 3Km is generally a rigid body, which will return to its original shape after stress deformation, while the deeper position of the rock is generally plastomer, stressed and deformed. Obviously, it will not be restored.

Best wishes,

Liu Chenming

Sorry, the problem with the network.

Liu Chenming

Hi Liu,

Thank you.

Yes, I am getting similar results with shale rock as you explained above. I am working on stress anisotropy in shales.

Akshay

I would add is related to the hardness of the rocks some requires more stress than others to have an imprint so memory...same as applying a small force on a diamante will not do anything but the same force applied to a sandstone or marl will have a great effect also will have a memory of the force(stress) applied

There is no simple answer to the question. Essentially, most (if not all) rocks exhibit varying amounts of all three mechanical properties, i.e. elastic, viscous, and plastic properties. Rocks at depth are compressed so that upon coring, the core material will respond to some degree depending on rock type to an elastic response, which will decrease the amount of measurable "stored stress." Similarly, rocks can lose stored stress over time due to their viscous properties. Examples would include warping of rock slabs after quarrying several years after removal form the quarry. Plastic behavior is a time independent, irrecoverable strain. It is unlikely that you could observe plastic behavior of any rock removed from any depth.

Thank you David Weinberg.

I agree, the stored stress is not the same as before. It might not be as reflective as sub-surface and it can be different with different rock composition, is that right?

It depends on the rocks rheology witch itself depends on mineralogical and of course geochemical compostion. Of course, the area characteristics are olso important as temperature, and water contents.

I recommend Graham's answer

Best Regards

Interesting

also relates to the elasticity and plasticity of the rocks

Interesting point,following