Experiment to Evaluate the Impulse Plate Compaction in a Test Embankment Section

Author(s):  
Chavdar Kolev
Keyword(s):  
2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Rafał Wróżyński ◽  
Krzysztof Pyszny ◽  
Mariusz Sojka ◽  
Czesław Przybyła ◽  
Sadżide Murat-Błażejewska

AbstractThe article describes how the Structure-from-Motion (SfM) method can be used to calculate the volume of anthropogenic microtopography. In the proposed workflow, data is obtained using mass-market devices such as a compact camera (Canon G9) and a smartphone (iPhone5). The volume is computed using free open source software (VisualSFMv0.5.23, CMPMVSv0.6.0., MeshLab) on a PCclass computer. The input data is acquired from video frames. To verify the method laboratory tests on the embankment of a known volume has been carried out. Models of the test embankment were built using two independent measurements made with those two devices. No significant differences were found between the models in a comparative analysis. The volumes of the models differed from the actual volume just by 0.7‰ and 2‰. After a successful laboratory verification, field measurements were carried out in the same way. While building the model from the data acquired with a smartphone, it was observed that a series of frames, approximately 14% of all the frames, was rejected. The missing frames caused the point cloud to be less dense in the place where they had been rejected. This affected the model’s volume differed from the volume acquired with a camera by 7%. In order to improve the homogeneity, the frame extraction frequency was increased in the place where frames have been previously missing. A uniform model was thereby obtained with point cloud density evenly distributed. There was a 1.5% difference between the embankment’s volume and the volume calculated from the camera-recorded video. The presented method permits the number of input frames to be increased and the model’s accuracy to be enhanced without making an additional measurement, which may not be possible in the case of temporary features.


1990 ◽  
Vol 27 (5) ◽  
pp. 531-545 ◽  
Author(s):  
D. T. Bergado ◽  
K. C. Chong ◽  
P. A. M. Daria ◽  
M. C. Alfaro

This study centred on the performance of the screw plate test (SPLT) to determine the deformability and consolidation characteristics of soft Bangkok clay. For comparison, a series of stress-path-controlled triaxial consolidation tests (tri) were carried out on good quality samples of Bangkok clay taken from the same testing sites and imposed with the same loading conditions as the screw plate tests. Undrained and drained moduli and coefficients of consolidation were obtained from the stress-path-controlled triaxial consolidation tests and were compared with the corresponding values of the screw plate test. In addition, the ultimate bearing capacity was derived from the pressure–deformation relationships of the screw plate test results. A graphical method was used to compute the coefficient of consolidation from the screw plate tests and from stress-path-controlled triaxial consolidation test results. The compressibility data were also obtained from conventional oedometer tests (oed). Both cv (SPLT)/cv (tri) and cv (SPLT)/cv(oed) ratios compared favorably with the cv (field)/cv (laboratory) ratio obtained from past investigations. The data from pressure–settlement–time relationships of the screw plate tests were used to successfully predict values that compared favorably with the measured values at each stress level. The pressure–deformation–time relationship from stress-path-controlled triaxial consolidation tests were also evaluated, and they indicated behaviour similar to that of the screw plate test results. Soil parameters obtained from screw plate tests were subsequently used to predict the settlement of two test embankments, giving fairly close agreement with the observed values. Key words: soft clay, settlement, deformation, consolidation, screw plate test, triaxial test, embankment, prediction, stress path.


2007 ◽  
Vol 44 (5) ◽  
pp. 545-563 ◽  
Author(s):  
Tien H Wu ◽  
Steven Z Zhou ◽  
Stephan M Gale

The case history of an embankment built over soft water-treatment sludge is presented. To assure that the sludge would consolidate and gain strength as predicted, a test embankment was built. The observed performance of the test embankment was compared with the predicted performance to verify and modify design assumptions. The results were used to design and construct the full-scale embankment. The finite element method and the critical state model were used to predict the performances of the test embankment and the full-scale embankment. Bayesian updating and system identification were used to update the material properties used in the prediction for the test embankment. The updated properties were then used to update the prediction for the test embankment and to predict the performance of the full-scale embankment. These predictions were compared with the observed performances to evaluate the accuracies of the predictions with different input data. Efforts were made to identify factors that cause differences between predicted and measured performances.Key words: Bayesian updating, consolidation, finite-element prediction, shear strength, stability, water-treatment sludge.


2012 ◽  
pp. 722-727
Author(s):  
L Korkiala-Tanttu ◽  
M Juvankoski ◽  
H Kivikoski

1995 ◽  
Vol 32 (3) ◽  
pp. 512-534 ◽  
Author(s):  
R. Kerry Rowe ◽  
C.T. Gnanendran ◽  
A.O. Landva ◽  
A.J. Valsangkar

The instrumentation, construction, and field performance of a full-scale geotextile reinforced test embankment constructed on a soft compressible soil is presented. A relatively high-strength polyester woven geotextile was used as reinforcement. The construction sequence, the observed pore pressure response, and the vertical and horizontal displacements are reported. The development and propagation of cracks in relation to the construction sequence and the manner in which the embankment failed are described. The field data suggest that the shear strength of the foundation soil was mobilized at a fill thickness between 5 and 5.7 m. However, due to the stabilizing effect of the geotextile reinforcement, the embankment did not fail until the geotextile reached its ultimate tensile strength and tore when the fill thickness reached 8.2 m. The failure of the embankment was of a viscoplastic nature and although additional fill could be placed after failure of the geotextile and embankment at 8.2 m, no additional gain in the net height (i.e., relative to the surrounding area) could be maintained above the maximum of 6.6 m recorded when the fill thickness reached 8.2 m. Key words : embankment, geotextile reinforcement, field behaviour, stability, deformations, pore pressures.


2018 ◽  
Vol 93 ◽  
pp. 178-190 ◽  
Author(s):  
Yibin Gong ◽  
Yun Hang Chok
Keyword(s):  

Geosciences ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 42
Author(s):  
Jemal Jibril Muhammed ◽  
Priyantha W. Jayawickrama ◽  
Stephen Ekwaro-Osire

This paper presents the quantification of uncertainties in the prediction of settlements of embankments built on prefabricated vertical drains (PVDs) improved soft soil deposits based on data collected from two well-documented projects, located in Karakore, Ethiopia, and Ballina, Australia. For this purpose, settlement prediction biases and settlement distributions were statistically computed based on analyses conducted on two Class A and Class C numerical predictions made using PLAXIS 2D finite element modelling. From the results of prediction bias, Class C predictions agreed well with the field measured settlements at both sites. In Class C predictions, the computed settlements were biased to the measured values. For Class A predictions, the calculated settlement values were in the range of mean and mean minus 3SD (standard deviations) for Karakore clay, and they were within mean and mean minus 2SD limit for the Ballina soil. The contributing factors to the settlement uncertainties of the Karakore site may include variability within the soil profile of the alluvial deposit, particularly the presence of interbedded granular layer within the soft layers, and the high embankment fills, and the limited number of samples available for laboratory testing. At the Ballina test embankment site, the uncertainties may have been associated with the presence of transitional layers at the bottom of estuarine clay and sensitivity of soft soil to sample disturbances and limitations in representing all the site conditions.


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