scholarly journals Experimental and numerical analysis of foundation pilings partially embedded in rock

2013 ◽  
Vol 66 (4) ◽  
pp. 439-446
Author(s):  
Jean Rodrigo Garcia ◽  
Paulo José Rocha de Albuquerque ◽  
Rodrigo Álvares de Araújo Melo
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Field Tests ◽  
Soil Surface ◽  
Residual Soil ◽  
Geotechnical Parameters ◽  
Weathered Rock ◽  
Load Tests ◽  
Geotechnical Design ◽  
Transfer Method

The behaviours of four foundation pilings (ϕ=0.41 m) constructed in Foz do Iguaçu, Paraná (PR), Brazil and subjected to slow loading tests were analysed. The results were compared with results from three-dimensional numerical modelling using the finite element method, which facilitates simulation of the elasto-plastic behaviour of soil. The local subsoil comprises varied stratigraphies; it is composed of a residual soil surface layer followed by weathered rock and bedrock, which are a few meters deep. The massif geotechnical parameters were determined through correlations obtained from field tests, whereby the values for cohesion, angle of friction, modulus of deformability and uniaxial compressive strength in the different subsoil layers were estimated. The load tests were interrupted at 3000 kN and displaced by less than 5 mm in the working load (1500 kN). The pilings were subjected to lateral friction work with an average stress of approximately 70 kPa for the surface portion (residual soil) and greater than 150 kPa for the weathered rock portions. The estimated geotechnical parameters provided values that were an exact match with the numerical analyses. Thus, given the analyses and load transfer method, the piling lengths can be reduced, which will facilitate the optimisation of the geotechnical design.

Design of bored piles in residual soils based on field-performance data

1991 ◽  
Vol 28 (2) ◽  
pp. 200-209 ◽  
Author(s):  
M. F. Chang ◽  
B. B. Broms
Keyword(s):  
Load Transfer ◽  
Large Diameter ◽  
Design Procedure ◽  
Field Performance ◽  
Residual Soil ◽  
Residual Soils ◽  
Weak Rocks ◽  
Load Tests ◽  
Bored Piles ◽  
Load Displacement

The current practice for the design of large-diameter bored piles in residual soils in Singapore is based on the calculated static capacity of the piles. Insufficient consideration of the load-transfer mechanism and overreliance on pile load tests have led to conservative designs. A better alternative is to adopt a load–displacement analysis method that provides information on the load distribution along the pile and the complete load–displacement relationship. Results of full-scale load tests on instrumented piles indicate that bored piles in residual soils in Singapore behave in the same way as in stiff clay and weak rocks elsewhere in that the load transfer at the working load is dominated by shaft friction. Simple correlations exist between the standard penetration resistance and the load-transfer parameters. An example illustrates that the proposed design procedure that uses these simple correlations and the load-transfer method is an improvement over present design methods. Key words: bored piles, cast-in-place piles, design, drilled piers, field test, load transfer, residual soil, shaft resistance.

scholarly journals BACK ANALYSIS OF OSTERBERG-CELL PILE LOAD TEST BY MEANS OF THREE-DIMENSIONAL GEOTECHNICAL MODELING

2021 ◽  
Vol 30 (3) ◽  
Author(s):  
Szilárd Kanizsár
Keyword(s):  
Construction Projects ◽  
Three Dimensional ◽  
Back Analysis ◽  
Field Tests ◽  
Small Strain ◽  
Load Test ◽  
Soil Behavior ◽  
Load Tests ◽  
Pile Load Test ◽  
Pile Load Tests

In 3D geotechnical modelling it is essential for the realistic simulation of soil behavior that the parameters of the hardening soil with small strain constitutive model are specified appropriately. The possibility of deriving these parameters for very stiff cohesive soils similar to the so called Kiscell clay that has a significant role in deep construction projects in Budapest, from laboratory and field tests is rather limited. The results of the pile load test completed for the MOL Campus high-rise building project proved to be useful data source. The article presents the circumstances of the quoted Osterberg-cell pile load tests and the modelling of the pile performed by the above-mentioned soil model. The parameters specified on the basis of laboratory tests - and in absence of those based on literature - data can be fine-tuned by approaching the load test results.

scholarly journals The Use of Geotechnical Methods to Determine the Deformation Parameters of the Ground in Terms of Operation and Safety of Mortar Use

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7237
Author(s):  
Grzegorz Bartnik ◽  
Kazimierz Józefiak ◽  
Małgorzata Superczyńska ◽  
Magdalena Czerwińska ◽  
Witold Krajewski ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Field Tests ◽  
Research Problem ◽  
Measurement Methods ◽  
Geotechnical Parameters ◽  
Firing Test ◽  
Deformation Parameters ◽  
Different Types ◽  
Load Tests ◽  
Clear Description

During firing from a mortar, an important issue is the parameters of compressibility of the ground on which the mortar is placed. This affects the operation of the mortar (including safety). During the qualification tests of the mortar, the influence of different types of terrains on its strength and work during shooting should be examined. Until now, in the Polish standardization documents there was no clear description of the ground parameters used for these kinds of tests. Analysis of the literature also did not allow to determine the dependence of the mortars displacement in the function of the type of ground and its geotechnical parameters. In view of the above, it has become important to draw up a research problem in the form of determining the types of soil with parameters, enabling the mortar tests to be carried out in conditions as close as possible to combat conditions. Therefore, the authors carried out the theoretical calculations and field tests with the use of geotechnical methods such as static and dynamic load tests to determine the parameters of the ground for mortar testing. Preliminary tests were conducted using the prescribed measurement methods and a comparative mortar firing test. Subsequently, an analysis of the results was carried out and the possibilities of using the tested methods of measuring the parameters of soil compressibility were determined.

scholarly journals THE LOAD-DISPLACEMENT BEHAVIOUR OF GROUND ANCHORS IN FINE GRAINED SOILS

2018 ◽  
Vol 16 ◽  
pp. 18
Author(s):  
Juraj Chalmovský ◽  
Lumír Míča
Keyword(s):  
Load Transfer ◽  
Progressive Failure ◽  
Back Analysis ◽  
Material Model ◽  
Experimental Program ◽  
Structural Element ◽  
Fine Grained ◽  
Ground Anchors ◽  
Load Tests ◽  
Transfer Method

Ground anchors represent an important structural element in the area of geotechnical engineering. Despite their extensive usage, a design process of these elements is usually performed using simple empirical and semi-empirical methods, neglecting several important influencing factors. This paper gives an analysis of the factor of non-uniform distribution of skin friction resulting in a progressive failure of ground anchors. First, the finite element method in combination with a material model involving regularized strain softening is utilized. Next, an experimental program, including several investigation anchor load tests, was carried out. The goal of this program was to confirm preliminary conclusions drawn from numerical studies and to obtain relevant data for further back analysis. After, there is then described a newly developed application based on the load transfer method, in which all the findings from numerical computations and experimental measurements are incorporated.

Deep Excavations for the Manufacturers Life Centre, Toronto

1972 ◽  
Vol 9 (2) ◽  
pp. 137-144
Author(s):  
G. D. Prasad ◽  
C.F. Freeman ◽  
D. Klajnerman
Keyword(s):  
Field Tests ◽  
Full Scale ◽  
Triaxial Tests ◽  
Design Parameters ◽  
Loading Test ◽  
Deep Excavations ◽  
Design Procedures ◽  
Load Tests ◽  
Geotechnical Design ◽  
Soldier Pile

Geotechnical considerations associated with deep excavations for the Manufacturers Life Centre in Toronto are discussed. The depth to shale bedrock and the necessity to obtain maximum access to the foundation grade resulted in selecting the use of tie backs into the overburden with or without rakers for supporting the soldier pile lagging system. Full scale load tests were carried out to prove the recommended geotechnical design parameters for the shoring system. Adhesion values obtained from full scale field tests on tie backs agreed closely with the shear strength obtained from laboratory quick triaxial tests. However a full scale loading test on an inclined raker footing gave a higher bearing value compared with conventional design procedures.

Definition of load transfer curves of piles in granitic residual soil

Geotecnia ◽  
2014 ◽  
Vol 130 ◽  
pp. 79-99
Author(s):  
David Jorge Pereira Fernandes ◽  
◽  
<br>António Viana da Fonseca ◽  
Keyword(s):  
Load Transfer ◽  
Residual Soil ◽  
Definition Of

EFFECT OF CANOPY AND INCORPORATION ON METRIBUZIN PERSISTENCE IN SOILS

1989 ◽  
Vol 69 (3) ◽  
pp. 711-714 ◽  
Author(s):  
K. I. N. JENSEN ◽  
E. R. KIMBALL ◽  
J. A. IVANY
Keyword(s):  
Key Words ◽  
Half Life ◽  
Field Tests ◽  
Soil Surface ◽  
Bare Soil ◽  
Field Conditions ◽  
Row Width ◽  
Sampling Zone

The half-life of metribuzin applied to a bare soil surface was calculated to be 3–7 d over four field tests. An artificial cover erected after application or a shallow incorporation increased the half-life of metribuzin approximately 2.5- to 3-fold. Leaching out of the 0- to 5-cm-deep sampling zone could not account for loss of metribuzin. It was concluded that metribuzin persistence may be affected by volatility and/or photodecomposition losses under field conditions, especially shortly after application. Key words: Metribuzin half-life, volatility, photodecomposition, row width

Uplift behaviour of tapered piles established from model tests

2000 ◽  
Vol 37 (1) ◽  
pp. 56-74 ◽  
Author(s):  
M Hesham El Naggar ◽  
Jin Qi Wei
Keyword(s):  
Load Transfer ◽  
Compressive Loading ◽  
Compressive Load ◽  
Tensile Load ◽  
Confining Pressure ◽  
Cohesionless Soil ◽  
Uplift Capacity ◽  
Experimental Modelling ◽  
Confining Pressures ◽  
Load Tests

Tapered piles have a substantial advantage with regard to their load-carrying capacity in the downward frictional mode. The uplift performance of tapered piles, however, has not been fully understood. This paper describes the results of an experimental investigation into the characteristics of the uplift performance of tapered piles. Three instrumented steel piles with different degrees of taper were installed in cohesionless soil and subjected to compressive and tensile load tests. The soil was contained in a steel soil chamber and pressurized using an air bladder to facilitate modelling the confining pressures pertinent to larger embedment depths. The results of this study indicated that the pile axial uplift capacity increased with an increase in the confining pressure for all piles examined in this study. The ratios of uplift to compressive load for tapered piles were less than those for straight piles of the same length and average embedded diameter. The uplift capacity of tapered piles was found to be comparable to that of straight-sided wall piles at higher confining pressure values, suggesting that the performance of actual tapered piles (with greater length) would be comparable to that of straight-sided wall piles. Also, the results indicated that residual stresses developed during the compressive loading phase and their effect were more significant on the initial uplift capacity of piles, and this effect was more pronounced for tapered piles in medium-dense sand.Key words: tapered piles, uplift, axial response, load transfer, experimental modelling.

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