I am looking for different treatment methods to densify silt soils up to 10-15 m. I assume vibrofloation methods are only applicable to sands. but not for silt.
Offshore methods would also be helpful.
Thank you.
Can someone explain the difference between Modified Unified and Unified soil classification systems. What are the pros and cons of one against the other.
Why some used the A line on Casagrande Chart and others use A and U line with little differences near the PI less than 4?
My search did...
Hi - I am analyzing boreholes with 200-250 ft depths in predominantly silt, clayey silt or sandy silt. No Shelby but only SPT. Correlations are often through N-values, which I assume is the raw SPT obtained in the field. For example
Beta= (N//15)* (1.2 - 0.11 sqrt(Z). or Phi= 0.3N + 27 or...
I am employing the beta method to calculate the ultimate load capacity of relatively long piles (35-40m). The soils encountered are predominantly clayey sandy silts, as well as sand. The Standard Penetration Tests (SPTs) conducted in the field often exceed 30 or are reported as refusal before...
Hi, I have three 250ft boreholes with only SPTs every 5ft for a heavy foundation of 1000 m2. The soils are predominantly silt, some clayey silt and (silty) sand in a till context. The silts to me err on the sand type rather than clay. I will have some Atterberg limit tests to verify.
Grain...
Albert Atterberg invented the test apparatus for liquid limit with a porcelain bowl in 1900 that was then upgraded to a metal bowl in 1932. These two great engineers still remain pioneers. The attached picture may indicate the state of the art of industry during Atterberg-Casagrande marvelous...
Hi
I understand well the concept and application of FoS. However, having gone through the Canadian Foundation Manual, I have a difficulty to understand the geotechnical resistance factor. For example, a resistance factor of 0.5 is recommended for vertical bearing resistance of shallow...
The fine soil materials classifications are unusually made based on A-line in Casagrande Chart. I have seen some engineers classify the fine soil based on the result of hydrometer test only and call it silty clay if the percentage of clay from hydrometer test is more than silt or clayey silt if...
I am working on ground investigation for a 28 floor high building on predominantly dense clayey sandy silt soils. I would like to know how deep others have gone down for boreholes. If it was a dam site, one would expect a borehole depth equal to the dam height. I do not think there would be a...
Hi - I am looking for typical hydraulic conductivity values for shales in Texas and still looking for a convincing range. I would appreciate your feedback if you may have used it for GeoStudio analysis.
Also for the sake of argument let's assume two laboratory tests showed K1= 1E-5 m/sec and...
I have gone through few rather difficult references for drain/filter design but still uncertain about what a practical method of toe drain design for an old embankment made from clay would be. Do designers usually apply Terzaghi (or USBR) filter design criteria for the toe drain design or do...
The stress distribution under a footing is generally calculated with a slope of 2V:1H. It seems this angle should increase for a structural fill soil that is compacted to 95% proctor? I could not find a reference and would like to hear from soil experts here if there is any relationship between...
RDD anaylses are conducted on an old 15 m high embankment dam made of one zone fat clay with 2.3:1 slopes. The factor of safety for 2.5 days drawdown is ~ 0.25, using soil parameters obtained from a recent site investigation. This low fos seems to be very critical for a dam that has been there...
There is a gas pipeline overpassing a canal having an approx. span of ~ 80'. The pipeline is bowed upwards. Would this relate to the internal operating gas pressure or due to external geotechnical and support reaction A pic is attached for a better visualization.
I am a soil engineer but recently involved in stress calculations for gas pipelines. Could someone introduces to me a classical method of calculation? Going through some calculations by others has not been conclusive to me. In particular:
What factor of sefaty is used in oil&gas projects to...
Online searches show DCP is usually driven to 1 m (3-4 ft. DCP results up to 8 ft was seen in an engineering report
In practice to what depth can reliable results be obtained with DCP, assuming sufficient manpower available - working mainly on clay soils). Thanks for your advice in advance.
The SPT values in muddy clay soils are about 1-3 or sometimes WOH. The clay soils in the area is known to be over-consolidated. A pre-consolidation pressure of 4 tsf can be constructed on the oedometer test curves.
Question: How could a very soft muddy clay soil have been under a...
After going through a number of references I found ambiguities on the dimensional equations. While ks = p/y should be in kN/m3 form, sometimes it is stated as kN/m2. In some references it is given as Ks =ks.x which makes a good sense but this is not consistent. Also modulus of subgrade reaction...
There is a little confusion in literatures about the difference between coefficient of sunbgrade reaction (ks) and modulus of subgrade reaction (Ks). Both have been shown with F/L3 dimensions while some literature mention that k=K/B. Could someone help to understand. Thanks
