Discussion of “Settlement of Building on Deep Compressible Soil”

1970 ◽  
Vol 96 (2) ◽  
pp. 768-774
Author(s):  
Jeanpierre P. Giroud ◽  
J. M. Runacher ◽  
Clyde N. Baker ◽  
M. Anandakrishnan ◽  
T. Kuppusamy ◽  
...  
Keyword(s):  
1969 ◽  
Vol 95 (3) ◽  
pp. 769-790
Author(s):  
Peter J. Moore ◽  
Graham K. Spencer
Keyword(s):  

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.


1996 ◽  
Vol 33 (2) ◽  
pp. 324-338 ◽  
Author(s):  
R Kerry Rowe ◽  
C T Gnanendran ◽  
A O Landva ◽  
A J Valsangkar

The finite element analysis of an instrumented geotextile-reinforced test embankment is described and the results are compared with the field measurements. The embankment was constructed to failure on a soft compressible organic clayey silt deposit at Sackville, New Brunswick. The analysis adopts a fully coupled large-strain elasto-plastic Biot consolidation model with modified Cam-clay material behaviour. It is shown that the analysis captured many features of the embankment behaviour. However, it is concluded that the elasto-plastic modified Cam-clay formulation is not adequate for accurately and simultaneously predicting the multiple characteristics (e.g., vertical and horizontal deformations, pore pressures, and geotextile strains) of the embankment behaviour, primarily because of the rate sensitive nature, and the consequent progressive failure of the foundation soil. Key words: embankment, geotextile, reinforcement, analysis, field behaviour, deformations.


1994 ◽  
Vol 31 (2) ◽  
pp. 285-298 ◽  
Author(s):  
J.-M. Konrad ◽  
J.T.C. Seto

Undisturbed Champlain Sea clay samples were subjected to laboratory freezing tests with pore-pressure measurements in order to determine the freezing characteristics of a structured compressible soil. Step-freezing and ramped-freezing tests with applied back pressure were conducted on 10 cm high samples in open-system conditions. Significant pore-pressure reductions in the unfrozen soil induce important frost-induced consolidation and destructuration of the clay. It was found that the freezing characteristics of Saint-Alban clay are best defined by the segregation potential at the active ice lens, SPℓ, which includes water fluxes generated within the frozen fringe and within the unfrozen soil as excess water is expelled during consolidation, and finally water from an external source. For the Saint-Alban clay, SPℓ values of the intact clay ranged between 450 and 600 × 10−5 mm2/(s °C), whereas those of destructured clay at a lower void ratio were significantly smaller. Back-calculating the segregation potential solely from surface heave measurements in laboratory tests may underestimate considerably the frost susceptibility of compressible structured clays. Segregation potential inferred from instrumented field sites was 430 × 10−5 mm2/(s °C) and is consistent with the laboratory tests results. Key words : freezing, frost heave, structured clay, undisturbed, consolidation.


2018 ◽  
Vol 149 ◽  
pp. 02008
Author(s):  
Ramdane Bahar ◽  
Omar Sadaoui ◽  
Fatma Zohra Yagoub

2020 ◽  
Vol 10 (3) ◽  
pp. 36-53
Author(s):  
Dr. Zaid Hameed Majeed ◽  
Eng. Kadhim Jawad Aubais ◽  
Dr. Mohd Raihan Taha

The design foundations  of storage tanks for oil industry experiences significant problems due to the widespread occurrence of weak and compressible soil which resulted in foundation failure. In this study, soft soils were taken from two locations and mixed with three types of nanoparticles which were nano-alumina (nano Al2O3), nano-copper (nano CuO), and nano-magnesium (nano MgO). Nanomaterials were incorporated in small percentage (less than 1%) by dry weight of soil. The tested geotechnical characteristics included the water content, dry density, and the unconfined compressive strength. The results showed significant enhancements in the maximum dry density and unconfined compressive strength. The level of enhancement depended on the type of nanomaterials and the contents. Improved strength and hardening properties were shown with the utilization of nano CuO material in comparison to the soil samples with the other nanomaterials additions, with its optimum addition of 0.7% provided an increment rate of 662.7% while the optimum nano CuO which is about 1% showed a 532% increasing rate in the compressive strength of S1 soil. It was noted that the maximum dry density and unconfined compressive strength enhanced with the increase in the nanoparticles content until reaching a percentage in which the strength decreased. The optimum content of the nano MgO was 0.3% while the optimum nano Al2O3 content was about 0.3% for soil S1 and was about 0.1% for soil S2. The presence of nanomaterials in excessive contents caused agglomeration of particles which had negative influences on mechanical characteristics of the soils. Generally, the incorporation of finer particles like nanoparticles even with low amount would improve the geotechnical characteristics of soils with the consideration of the potential environmental benefits, these combined admixtures are intended to lower the cost and become a more sustainable and environmental alternative for soil stabilization


2003 ◽  
Author(s):  
Kuang-Hsiang Chen ◽  
Tzung-Hsun Hsieh ◽  
I.-Fan Lin

Radial consolidation equations for vertical prefabricated drain which considers the effects of drain spacing, well resistance, extension of drain above the compressible soil layer, well peripheral smear effect, and differential vertical strain between smear zone and undisturbed zone at finite strain condition are derived. Particularly, the effects of smear as well as differential vertical strain between smear zone and undisturbed zone at finite strain condition are studied for the first time. Result indicating the time required for consolidation is increased by the effect of well peripheral smear. The effect of differential vertical strain can be ignored.


2020 ◽  
Vol 57 (3) ◽  
pp. 377-390
Author(s):  
Dongli Zhu ◽  
Buddhima Indraratna ◽  
Harry Poulos ◽  
Cholachat Rujikiatkamjorn

Piles and prefabricated vertical drains (PVDs) are two well-established inclusions used by geotechnical practitioners when dealing with soft compressible foundations. Induced movements in highly compressible soil can adversely influence the pile response by inducing additional movements and stresses in the piles. Especially, undesirable soil–pile interaction often leads to the development of excess pore-water pressure during pile installation and negative skin friction caused by the settlement of compressible soil surrounding the piles. Additional drainage by PVDs prior to the installation of a pile could reduce excess pore-water pressure, lateral soil movement, and negative skin friction on the pile. In this paper, full-scale field testing on two trial embankments built on soft soil is reported and the relative behaviour of these two embankments is compared and discussed. Soft soil underneath both embankments was consolidated before one pile was installed at the centre of each embankment. The pore-water pressure, lateral soil movement, surface settlement, and associated strain at the pile shaft were recorded. The pile capacity was tested immediately and 3 h after pile installation. The monitoring and testing results indicated that preconsolidation with PVDs before piling can effectively reduce the excess pore-water pressure, lateral soil movement, and downdrag on the pile.


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