Check the file attached,it will explain.http://files.engineering.com/getfile.aspx?folder=c7afcefa-17a8-49bf-b39b-e119ffcd2992&file=Force_at_a_point_in_the_semi-infinite_solid.pdf
From my knowledge, the results will be equivalent to the results from Cassagrande's apparatus.
As the shear strength is close to zero at liquid limit from both methods.
Is it reasonable to calculate consolidation coeffcient for unloading phase in oedometer test? Is it possible to use it to estimate the unloading behaviour? Please give some advice?
You should know something about consolidation.
In the normal consolidation test,with the rise of load pressure the void ratio will decrease, thus the moisture content will decreas also.
I am a little confused about your post.
Thanks fattdad!
One of the samples is described according to BS as "Firm, grey, slightly sandy CLAY ",just check with ASTM it could be classified as lean clay. Others mostly could be classfied as clay or just sandy clay.
What I concern is that reason why half or more consolidation is finished...
Our lab contractor is doing some consolidation tests on silty clay.
Step 1 load the sample to in-situ stress to reduce some disturbance.
Step 2unload to 5kpa then reload to 3200kpa.
They encountered some problem on reporting t50 and cv.
In some cases the deformation happens very...
Please check “the "d" is half of the height H”, I don't think it is right.H/D should be less than 0.4. Also normally you should check Part 5 instead of Part 6 for the conventional oedometer test even the formula is the same to some extent.
For such problem,it is not so relevent for the geotechnical bearing capacity as it goes into the rock. With larger settlement/displacement, obviously the pile will have a larger bearing capacity. So only the settlement/displacement matters other the bearing capacity.
For the similar situation...
And do remember the preconsolidation stress the sample experienced.It could cause different behaviour for the sample. A obvious overconsolidated sample commonly will show a higher C' and lower Phi' compared to its normal consolidated peer.
Suggest do an oedometer test before carry out any...
It is very pity most of these references are only with Japanese. But one file is attached, you guys can have a look of the construction procedure. http://files.engineering.com/getfile.aspx?folder=5232f063-a3f6-4e9d-a420-105e7540b930&file=gaiyo.pdf
The word "caisson" comes from the French,which means "box".
For the caisson in the early age, it only refers to the pneumatic caisson as you mentioned. In the enclosed shaft,excavation is carried out with high air pressue to balance the water pressure below the excavation surface below and the...
Pacheco Silva’s method from south america is also convenient to use and also independent of the graph scale.
Pacheco Silva, F. 1970. A new graphical construction for determination of the pre-consolidation stress of a soil sample. In Proceedings of the 4th Brazilian Conference on Soil Mechanics...
The principal is that the shear strength determined by the consolidation state.
I think the aim you want to carry out SHANSEP analysis is that want to get preoconsolidation stress from this concept. Or maybe you have already make a lot of CPTU test,and want to get some correlation with the...
For lab test, you can refer to the method proposed in BS1377-6:1990. See the chapter "Procedure for consolidation test with drainage radially",I think it is more reliable.
For in-situ test,CPTU with dissipation test is a good and convenient way to do that.The interpretation approach could refer...
From Guide to Cone Penetration Testing for Geotechnical Engineering by Robertson, it mentions that "Calibrations should be carried out at regular intervals (approximately every 3 months)".
However for the contractor,it is commonly 1.5 years.
I would consider the 1st factor you mention.
As FixedEarth described, it is a deep seated settlement.It could be caused by the loss of deep soil. From your reference,"The subsoil is characteristically high in exchangeable sodium - i.e. sodic." It is easy to be corroded.And as a fine grained...
I agree with BigH.
It might caused by disturbance.
Another reason might be the stress history of the soil. Is it highly overconsolidated? The test must be carried out properly.
