Design parameters of granular soils from in situ tests

2020 ◽  
pp. 65-94
Author(s):  
Michele Jamiolkowski ◽  
Diego C.F. Lo Presti ◽  
Francesco Froio
1996 ◽  
Vol 33 (1) ◽  
pp. 189-198 ◽  
Author(s):  
J A.R Ortigao ◽  
R P Cunha ◽  
L S Alves

An in situ testing programme was carried out in 1992 aimed at obtaining design parameters for the construction of the Brasília Underground line, Brazil. The top layer of soil consisted of an unsaturated and collapsible soft porous clay layer 5–30 m thick followed by residual soils from slate and interlayered metasiltsones and quartzites. A series of Marchetti dilatometer (DMT) logging tests results were comapred with Ménard pressuremeter (PMT) and horizontal plate loading (PLH) tests, as well as laboratory tests on block samples. In situ stresses, strength, and deformation parameters were obtained for the porous clay. The DMT yielded very good results: excellent repeatability, low cost, and results that agree with other in situ tests and laboratory data. Key words: porous clay, in situ testing, dilatometer, pressuremeter.


2018 ◽  
Vol 64 (4) ◽  
pp. 285-307
Author(s):  
T. Godlewski

AbstractIncreasingly complex design systems require an individual approach when determining the necessary design parameters. As soils are characterized by strong strain-dependent nonlinearity, test methods used to characterize the subsoil should be carefully selected, in terms of their “sensitivity” as well as suitability for the analyzed type of problem. When direct measurements are not available, while design calculation models require specific parameters, indirect parameter estimation may be used. This approach requires calibration and validation of empirical correlations, based on well documented database of tests and case studies. One of the parameters often used, when analyzing soil-structure interaction problems, is the shear stiffness of the soil and its strain-dependent degradation. The aim of the article is to present the procedure for description and evaluation of soil stiffness based on field tests (CPTU, DMT and SDMT) and a large number of reference curves obtained from laboratory tests (TRX) for selected soil types. On the basis of the given algorithm, it is possible to obtain a stiffness module G0 value at any level of deformation, based on in-situ tests.


1990 ◽  
Vol 27 (2) ◽  
pp. 167-176
Author(s):  
R. G. Campanella ◽  
R. Hitchman ◽  
W. E. Hodge

An in situ densification probe that employs the novel technique of simultaneous vibration and dewatering has been developed by Phoenix Engineering Ltd. to compact deep, loose, granular soils. It is believed that pumping water out of the soil during the densification process offers improved densification capability over systems operating with vibration alone. An independent study was undertaken by the In-Situ Testing Group at the University of British Columbia to evaluate the performance of the Phoenix system.A field testing programme was conducted at a site in Vancouver where hydraulic sand fill overlies a natural silt and then medium Fraser River sand. Characterization of the site and evaluation of the densification treatment process were achieved using in situ tests. Changes to soil parameters due to densification treatment were examined, taking into account the modification of stresses brought about by the vibro-drainage process. The study investigated the degree of densification achieved, the value of concurrent drainage, the zone of influence of a single compaction probe, and group effects. The study also compares the performance of the Phoenix machine with that of other vibrocompaction equipment. Key words: in situ, densification, soils, granular, probe, vibratory, drainage, compaction, R&D.


1985 ◽  
pp. 269-292
Author(s):  
T. Lunne ◽  
S. Lacasse ◽  
G. Aas ◽  
C. Madshus

2010 ◽  
Vol 8 (2) ◽  
pp. 135-143
Author(s):  
Nebojsa Davidovic ◽  
Zoran Bonic ◽  
Verka Prolovic ◽  
Biljana Mladenovic ◽  
Dragoslav Stojic

The paper presents a brief description of experiment within the research project 'Theoretical and experimental analysis of interaction of shallow reinforced concrete foundations and soil for the purpose of improvement of national regulations and implementaation of Eurocode system' where in situ tests of a series of reinforced concrete foundation footing were performed, by loading until failure. As a rule, methods for calculation of shallow foundations settlement on granular soils overestimate the expected settlement, and underestimate soil bearing capacity, which results in a conservative foundation design. In order to test accuracy and reliability of the different settlements prediction methods, a comparative analysis of settlements calculated using these methods and those measured during experiment, was performed.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Shuai Luan ◽  
Fenglai Wang ◽  
Tiehong Wang ◽  
Zhao Lu ◽  
Weihou Shui

Granite residual soil is widely distributed in south China and is treated as a special soil. Its design parameters in rotary drilling bored piles are a matter of debate due to lack of in-situ pile load tests. Back-analysis of test piles is a reliable means of studying the geotechnical capacity of granite residual soil for pile design. In this study, a series of in situ tests was conducted comprising six full-scale instrumented test piles in gravelly granite residual soil in Shenzhen to consider the effects of different construction methods. The six piles were constructed with three different rotary drilling methods. Two commonly used design methods were investigated in the back-analysis: the SPT and effective stress methods. The results of the loading tests and strain gauges were used to obtain the back-analyzed parameters of the ultimate shaft resistance and ultimate base resistance for gravelly granite residual soil with these two design methods.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4743
Author(s):  
Tomasz Janoszek ◽  
Zbigniew Lubosik ◽  
Lucjan Świerczek ◽  
Andrzej Walentek ◽  
Jerzy Jaroszewicz

The paper presents the results of experimental and model tests of transport of dispersed fluid droplets forming a cloud of aerosol in a stream of air ventilating a selected section of the underground excavation. The excavation selected for testing is part of the ventilation network of the Experimental Mine Barbara of the Central Mining Institute. For given environmental conditions, such as temperature, pressure, relative humidity, and velocity of air, the distribution of aerosol droplet changes in the mixture of air and water vapor along the excavation at a distance was measured at 10 m, 25 m, and 50 m from the source of its emission. The source of aerosol emission in the excavation space was a water nozzle that was located 25 m from the inlet (inlet) of the excavation. The obtained results of in situ tests were related to the results of numerical calculations using computational fluid dynamics (CFD). Numerical calculations were performed using Ansys-Fluent and Ansys-CFX software. The dimensions and geometry of the excavation under investigation are presented. The authors describe the adopted assumptions and conditions for the numerical model and discuss the results of the numerical solution.


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