Effects of random heterogeneity of soil properties on bearing capacity

2005 ◽  
Vol 20 (4) ◽  
pp. 324-341 ◽  
Author(s):  
Radu Popescu ◽  
George Deodatis ◽  
Arash Nobahar
2021 ◽  
Vol 7 ◽  
Author(s):  
Kouseya Choudhuri ◽  
Debarghya Chakraborty

This paper intends to examine the influence of spatial variability of soil properties on the probabilistic bearing capacity of a pavement located on the crest of a fibre reinforced embankment. An anisotropic random field, in combination with the finite difference method, is used to carry out the probabilistic analyses. The cohesion and internal friction angle of the soil are assumed to be lognormally distributed. The Monte Carlo simulations are carried out to obtain the mean and coefficient of variation of the pavement bearing capacity. The mean bearing capacity of the pavement is found to decrease with the increase in horizontal scale of fluctuation for a constant vertical scale of fluctuation; whereas, the coefficient of variation of the bearing capacity increases with the increase in horizontal scale of fluctuation. However, both the mean and coefficient of variation of bearing capacity of the pavement are observed to be increasing with the increase in vertical scale of fluctuation for a constant horizontal scale of fluctuation. Apart from the different scales of fluctuation, the effects of out of the plane length of the embankment and randomness in soil properties on the probabilistic bearing capacity are also investigated in the present study.


2017 ◽  
Vol 36 (3) ◽  
pp. 663-670
Author(s):  
AB Salahudeen ◽  
JA Sadeeq

This study investigated the soil bearing capacity and foundation settlement characteristics of Minna City Centre development site using standard penetration test (SPT) data obtained from10 SPT boreholes at 0.6, 2.1 and 3.6 m depths to correlate soil properties. Evaluation of foundation bearing capacity and settlement characteristics for geotechnical preliminary design of foundations was carried out using some conventional empirical/analytical models and numerical modelling. The aim was to investigate and determine the geotechnical parameters required for adequate design of Physical structures of the proposed Minna City Centre, at Minna the capital of Niger state. The SPT N-values were corrected to the standard average energy of 60% (N60) before the soil properties were evaluated. Using the corrected N-values, allowable bearing pressure and elastic settlement of shallow foundations were predicted at 50 kN/m2 applied foundation pressure. The numerical analysis results using Plaxis 2D, a finite element code, shows the analytical/empirical methods of estimating the allowable bearing pressure and settlements of shallow foundations that provided acceptable results. Results obtained show that an average bearing capacity value of 100 – 250 kN/m2 can be used for shallow foundations with embedment of 0.6 to 3.6 m on the site.  http://dx.doi.org/10.4314/njt.v36i3.1


2013 ◽  
Vol 477-478 ◽  
pp. 485-491 ◽  
Author(s):  
Feng Sun ◽  
Rong Pan ◽  
Xiu Yun Zhu ◽  
Tie Lin Chen

Due to the complication of grouting process in soil, design of fracture grouting works is still mainly based on empirical considerations and experiences from past projects. Based on the theory of particle flow, the domain of flow is defined by using Fish language implemented in PFC and the formulas for flow and pressure are put forward respectively. Combined with above study, the process of fracture grouting in soil is simulated with particle flow code (PFC2D) from micro-viewpoint under coupling environment. In addition, the emergence and development of crack and grouting pressure in soil is analyzed under different grouting pressure and soil properties. The research results show that pressure plays a key role in consolidating the soil by fracture grouting, but in fact it should be kept in a reasonable value in order to forming grouting slurry net entirely. Filed test indicates that fracture grouting greatly increases the bearing capacity of weathered rock in Xiamen Xiangan subsea tunneling and the conclusions of numerical simulation agrees well with the field test and grouting theory.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Tarun Kumar Lohani ◽  
Melkamu Teshome Ayana ◽  
Abdella Kemal Mohammed ◽  
Jyotiranjan Pattanaik

Borehole samples drilled up to a depth of 10 m provide a clear understanding whether a foundation is safe for any structure. The main objective of the present study reconnoitered the soil bearing capacity and foundation settlement characteristics using the standard penetration test (SPT) data obtained from 3 boreholes at 1 m, 2 m, and 3 m depths to correlate soil properties and deterrents, if any, created by groundwater. The methodology of the research is to collect soil samples, and ensuing subsoil analysis was performed in order to obtain concrete information to optimize the foundation system within the safe bearing capacity of soil and its allowable settlement. The scope of the work encompasses conducting detailed soil investigation from drilling logs, laboratory testing, and conducting and estimating safe bearing capacity. The result of the research aims at providing safety to the foundation from the investigations of conclusive recommendation to be adopted which would be economically feasible and structurally secured.


2020 ◽  
Vol 156 ◽  
pp. 02015
Author(s):  
Rina Yuliet ◽  
Syahril Rahmat ◽  
Elsa Eka Putri ◽  
Hendri Gusti Putra

Common problems that are often found on embankments are soil instability and low soil bearing capacity. To prevent landslides, consideration of the embankment stability and ways to improvement it is essential. This study investigates the use of quicklime as a stabilising material and a number of fill layers on the safety factor of the slope of the embankment in order to find the optimal combination. The type failure or deformation and extreme stresses that occurred in these soil embankments was also studied. Laboratory testing is used to determine soil properties. Three types of soil were analysed; subgrade, fill from original soil and fill from soil mixed with 15% quicklime. This quicklime mix was used as a 40 cm reinforcement layer on the slope surface of the embankment.


1969 ◽  
Vol 6 (2) ◽  
pp. 197-208
Author(s):  
A. Baracos

Case histories are given to illustrate bearing capacity, settlement, and volume changing characteristics of Winnipeg clays. These clays are of glacial lake origin, highly plastic, and generally irregularly varved. I have endeavored to show by calculation the relationship between soil properties determined by tests, and the behavior of the supported structure.


Strength characteristics of foundation soils in the six geo-political zones of Nigeria were evaluated based on standard penetration test (SPT) results using some conventional empirical/analytical models and the bearing capacity was predicted by numerical analysis using Plaxis 3D, a finite element application package. The SPT N-values were first corrected to the standard average energy of 60% (N60) before they were used to correlate soil properties. Evaluation of the soil properties were done at foundation embedment depths of 0.6, 2.1, 3.6, 5.1, 6.6, 8.1, 9.6, 11.1 and 12.6 m. The results of overconsolidation ratio, rigidity index, relative density, angle of internal resistance, undrained shear strength and unconfined compressive strength show that the strength characteristics of Nigerian soils is lowest on the average in the South South (SS) geo-political zone, followed by South West (SW), South East (SE), North East (NE), North West (NW) and the North Central (NC) geo-political zone has the highest prediction of strength characteristics. Bearing capacity generally increased with boring depth and having its lowest values in the SS geo-political zone and increased for the remaining zones in the order of SW, SE, NE, NW and the NC geopolitical zone.


2021 ◽  
Vol 8 (1) ◽  
pp. 14
Author(s):  
Tahar Ayadat

The undrained shear strength is a paramount parameter in determining the consistency and the ultimate bearing capacity of a clay layer. This resistance can be determined by in-situ tests, such as the field vane test or by laboratory tests, including the portable vane test, the triaxial, the simple compression test, and the consistency penetrometer test (i.e. the Swedish cone). However, the field vane test and the Swedish cone are the most commonly test used by geotechnical experts. In this paper, relationships between the field undrained shear strength of sensitive clay and some laboratory soil properties were developed. The soil properties consisted of the percentage of fine particles (less than 2 µm), the moisture content and the Atterberg limits. Furthermore, a correlation was proposed associating between the undrained shear strength of sensitive clay as obtained by the field vane test and the laboratory cone penetration test (Swedish cone). In addition, some applications of the proposed correlation on some geotechnical problems were included, such as the determination of the consistency and the bearing capacity of a clay layer. Comparison of the results of the developed correlations with the experimental results of the present investigation and the results reported in the literature show acceptable agreement.


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