Uncertainty of measurement and variability of direct shear parameters

Abstract ID: 3.13446 | Accepted as Talk | Talk | TBA | TBA

Gerald Innocent Otim (1)
Giulio Barbato (2), Irene Rocchi (1), Gianmario Sorrentino (1), Stefan Trapp (1), Alena Zhelezova (1)
(1) Technical University of Denmark, Building 118, Brovej, 2800 Lyngby, DK
(2) Politecnico di Torino University, Torino, 10129, Italy

Categories: Soil-Hazards
Keywords: uncertainty of measurement, variability, numerical analyses, shear strength, expanded uncertainty

Categories: Soil-Hazards
Keywords: uncertainty of measurement, variability, numerical analyses, shear strength, expanded uncertainty

The diverse and variable nature of ground conditions and soil properties presents a challenge when it comes to determining design parameters for a soil model. In these numerical analyses, one of the key properties to focus on is shear strength. It’s important to balance the number of data sets to achieve an accurate linear Mohr-Coulomb failure surface within budget and time constraints. Careful consideration of important parameters such as normal stress is necessary, and it’s recommended to use a set of three data sets in practice. However, this approach may still result in a notable amount of data variability. To evaluate this, the direct shear test was performed in accordance with ASTM D3080/D3080M-23 on loose sand of size 0.3-0.5 mm on a set of 6 normal loads (0 – 100 kPa) each with 10 repetitions. This sand was a simplified material that could be compared to alluvial fans in mountainous subsoils but equally cohesionless. By leveraging the Mohr-coulomb shear strength equation and applying an area correction to the data sets, the uncertainty in this measurement was determined using the guide to the expression of uncertainty in measurement approach. The relative expanded uncertainty obtained from normal stress ranged between 3.2 – 3.5 % while that from the shear stress was 3.9 %. When applying the shear strength equation, a combined relative expanded uncertainty of 5.3 % was observed. Furthermore, the uncertainty measurements for the angle of internal friction and cohesion were determined as 33 ± 10 and 7.5 ± 1.1 kPa respectively, with residuals exhibiting randomness. The three primary factors influencing the uncertainty in both the normal and shear stresses included reproducibility and bias on the measuring forces, and bias on the diameter of the specimen. Combinations within the data set were derived to investigate the variability in shear strength parameters. The variability in the angle of internal friction and cohesion were 34 ± 1.80 and 3.6 ± 2.0 kPa respectively. The exploration of the variability in shear strength parameters with sand demonstrated the impact on the long-term stability of a natural homogeneous slope when simulated in plaxis software.

N/A
NAME:
TBA
BUILDING:
TBA
FLOOR:
TBA
TYPE:
TBA
CAPACITY:
TBA
ACCESS:
TBA
ADDITIONAL:
TBA
FIND ME:
>> Google Maps

Choose the session you want to submit an abstract. Please be assured that similar sessions will either be scheduled consecutively or merged once the abstract submission phase is completed.

Select your preferred presentation mode
Please visit the session format page to get a detailed view on the presentation timings
The final decision on oral/poster is made by the (Co-)Conveners and will be communicated via your My#IMC dashboard

Please add here your abstract meeting the following requirements:
NO REFERNCES/KEYWORDS/ACKNOWEDGEMENTS IN AN ABSTRACT!
Limits: min 100 words, max 350 words or 2500 characters incl. tabs
Criteria: use only UTF-8 HTML character set, no equations/special characters/coding
Copy/Paste from an external editor is possible but check/reformat your text before submitting (e.g. bullet points, returns, aso)

Add here affiliations (max. 30) for you and your co-author(s). Use the row number to assign the affiliation to you and your co-author(s).
When you hover over the row number you are able to change the order of the affiliation list.

1
2
1

Add here co-author(s) (max. 30) to your abstract. Please assign the affiliation(s) of each co-author in the "Assigned Aff. No" by using the corresponding numbers from the "Affiliation List" (e.g.: 1,2,...)
When you hover over the row number you are able to change the order of the co-author list.

1
2
3
4
5
1
1
2
3
4
5
1
Close