Deriving soil hardening model parameters - drained vs undrained tests

Hi,

I'm scheduling triaxial tests on silty sand (SM) and while I understand that consolidated drained (CD) test is required to obtain the soil hardening parameters, the test may take a long time due to the fine content in the soil sample. Therefore, I have a few questions:

1. What if I use consolidated undrained (CU) test instead? I know it is not ideal but otherwise how do people come across this long testing time issue? Especially for clay?

2. Is there any guidance on fine content % vs CD test time?

3. Due to the difficulty to obtain quality undisturbed sample for SM, I'm planning to remold the sample to the insitu dry density and natural moisture content, then perform a multistage triaxial test. Again I understand that a multistage triaxial test is not ideal, but I think it is still possible to use it to derive soil hardening parameters. Any thoughts on this approach would be much appreciated.

Thanks!