Hi,
The client wants to use a MH (USCS classification) type material for an embankment. 99% of the material is silt/clay. LL is 78%, PL is 54%. MDD for modified proctor test is only 1.22g/cm3 with a OMC = 41%. The embankment is going to be constructed on soft soils, so there will be wick drains...
I'm designing a near-vertical temporary reinforced soil wall, to be designed to settle by using prefabricated vertical drains. The temporary FOS against slip surface failure is designed to be around 1.3. Using finite element analysis, the lateral displacements at the wall toe are about 40% of my...
Hi,
I'm currently looking for an flexible, inert and electrically conductive material that can be mass produced. Cost would be the largest issue here.
I'm thinking of either electrically conductive plastics or graphite strips. Would like some advice on this. Thank you!
Hi all,
For some reason, the client is unwilling to use cohesionless backfill for a temporary reinforced earth wall (using wraparounds) for the edge of an embankment fill. So far, they are proposing the use of MH type soils. I'm concerned about the problems that using cohesive fill might cause...
From what I know, there's two distinct methods of designing for earthquake resistance, one for underground structures and one for above-ground structures.
For underground structures you look at the soil displacement during the earthquake and assume that the soil "imposes" the displacement on...
Has anyone tried to correlate clay undrained shear strength with basic index properties such as water content, LL, PL, overburden stress, etc...? How successful would that be?
Has anyone compared the results of CU testing vs SHANSEP parameters using other methods?
With the consolidated undrained testing, you can get a set of effective stress parameters and a set of total stress parameters, which relates shear strength to consolidation pressure (similar to SHANSEP...
I am calculating rebound settlements along the recompression line. Just wondering, how fast does rebound occur after the removal of surcharge? I understand that the soil will swell slightly once the surcharge is removed. If the rebound is not instantaneous, will it help to counteract the...
I'm designing some piles for a building with a soft compressible top layer that is currently undergoing consolidation and will be filled about 2m. Now the whole area is going to undergo ground improvement (PVD and surcharge) before the piles are done. Am I able to ignore negative skin friction...
Hi all,
I'm calculating post-PVD secondary consolidation for a soil that is going to be improved using prefabricated vertical drains. Now the secondary consolidation equation goes like this: s = Ca/(1+e0) X log (t2/t1). The log (t2/t1) is bothering me a lot now, because I am using prefabricated...
I have seen quite a bit of samples with overconsolidation ratio (OCR) less than 1 (from oedometer tests). Some have told me that it is a testing artefact due to disturbance of the soil, they say technically OCR cannot be less than 1. Some others say that this is due to the fact that the samples...
Hi,
I'm performing a liquefaction (for sands) /cyclic softening analysis (for clays) based on the Simplified method which uses CSR and CRR (based on the Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils and Idriss and Boulanger...
Hi,
I am designing foundations for a structure using bored micropiles which extend to the rock about 30m deep. The borehole log showed hard residual soils right at the top with significant softening at around 10m depth (from N>100 blows to N=5) which continued up to the rock. We suspected that...
