scholarly journals Bearing Capacity Study for Small-Scale Testing of Rotary Pile with Helix Plate

2016 ◽  
Vol 15 (1) ◽  
pp. 37-46
Author(s):  
Eun-Chul Shin ◽  
Kyeong-Sig Kim ◽  
Hyeong-Rok Moon
Keyword(s):  
Bearing Capacity ◽  
Small Scale

scholarly journals Pile Model Tests Using Strain Gauge Technology

2015 ◽  
Vol 37 (3) ◽  
pp. 49-52 ◽  
Author(s):  
Adam Krasiński ◽  
Tomasz Kusio
Keyword(s):  
Bearing Capacity ◽  
Axial Force ◽  
Strain Gauge ◽  
Force Measurement ◽  
Ground Level ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Pile Head ◽  
Pile Model

Abstract Ordinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine the total bearing capacity of the pile, without the knowledge of its distribution into the shaft and base resistances. Much more information can be obtained by carrying out a test of instrumented pile equipped with a system for measuring the distribution of axial force along its core. In the case of pile model tests the use of such measurement is difficult due to small scale of the model. To find a suitable solution for axial force measurement, which could be applied to small scale model piles, we had to take into account the following requirements: - a linear and stable relationship between measured and physical values, - the force measurement accuracy of about 0.1 kN, - the range of measured forces up to 30 kN, - resistance of measuring gauges against aggressive counteraction of concrete mortar and against moisture, - insensitivity to pile bending, - economical factor. These requirements can be fulfilled by strain gauge sensors if an appropriate methodology is used for test preparation (Hoffmann [1]). In this paper, we focus on some aspects of the application of strain gauge sensors for model pile tests. The efficiency of the method is proved on the examples of static load tests carried out on SDP model piles acting as single piles and in a group.

Laterally Loaded Piles With Bulge

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Jan Dührkop ◽  
Jürgen Grabe
Keyword(s):  
Bearing Capacity ◽  
Ground Surface ◽  
Steel Plates ◽  
Small Scale ◽  
Calculation Methods ◽  
Laterally Loaded Piles ◽  
Standard Methods ◽  
Theoretical Investigations ◽  
Innovative System ◽  
Laterally Loaded

This paper contains several investigations on the behavior of bulged piles. Bulge means the application of vertical steel plates somewhere near the ground surface to improve the lateral bearing capacity. The results of small scale tests in sand are illustrated, which demonstrate the effectiveness of such bulge. Some theoretical investigations are presented trying to apply standard methods like the p‐y-curve procedure to the design of bulged piles. An outline of possible calculation methods is given. Investigations on two different exemplary pile systems demonstrate the behavior of the bulged structure and give an idea of the advantages of this innovative system.

Laterally Loaded Piles With Bulge

2007 ◽  
Author(s):  
Ju¨rgen Grabe ◽  
Jan Du¨hrkop
Keyword(s):  
Bearing Capacity ◽  
Ground Surface ◽  
Steel Plates ◽  
Small Scale ◽  
Calculation Methods ◽  
Laterally Loaded Piles ◽  
Standard Methods ◽  
Theoretical Investigations ◽  
Innovative System ◽  
Laterally Loaded

This paper contains several investigations on the behaviour of bulged piles. Bulge means the application of vertical steel plates somewhere near ground surface to improve the lateral bearing capacity. The results of small scale tests in sand are illustrated, which demonstrate the effectiveness of such bulge. Some theoretical investigations are presented trying to apply standard methods like the p-y-curve procedure to the design of bulged piles. An outline of possible calculation methods is given. Investigations on two different exemplary pile systems demonstrate the behaviour of the bulged structure and give an idea of the advantages of this innovative system.

scholarly journals Experimental bearing capacity of eccentrically loaded foundation near a slope

2019 ◽  
Vol 41 (1) ◽  
pp. 33-41
Author(s):  
Tarek Mansouri ◽  
Khelifa Abbeche
Keyword(s):  
Bearing Capacity ◽  
Scale Model ◽  
Small Scale ◽  
Test Results ◽  
Square Footing ◽  
Proportional Relation ◽  
Core Boundary ◽  
Relationship Of ◽  
Small Scale Model ◽  
Increasing Load

AbstractBased on the response of small-scale model square footing, the present paper shows the results of an experimental bearing capacity of eccentrically loaded square footing, near a slope sand bed. To reach this aim, a steel model square footing of (150 mm × 150 mm) and a varied sand relative density of 30%, 50% and 70% are used. The bearing capacity-settlement relationship of footing located at the edge of a slope and the effect of various parameters such as eccentricity (e) and dimensions report (b/B) were studied. Test results indicate that ultimate bearing capacity decreases with increasing load eccentricity to the core boundary of footing and that as far as the footing is distant from the crest, the bearing capacity increases. Furthermore, the results also prove that there is a clear proportional relation between relative densities –bearing capacity. The model test provides qualitative information on parameters influencing the bearing capacity of square footing. These tests can be used to check the bearing capacity estimated by the conventional methods.

scholarly journals Effect of the Drum Height on the Seismic Behaviour of a Free-Standing Multidrum Column

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Ante Buzov ◽  
Jure Radnić ◽  
Nikola Grgić ◽  
Goran Baloević
Keyword(s):  
Bearing Capacity ◽  
Numerical Models ◽  
Small Scale ◽  
Seismic Behaviour ◽  
Free Standing ◽  
Maximum Acceleration ◽  
Experimental Database ◽  
Scale Free ◽  
Additional Weight ◽  
Equal Height

The results of a shake-table study on the effect of the drum height on the seismic behaviour and bearing capacity of small-scale free-standing multidrum columns are presented. Columns of equal height with one, three, and six drums through their height were considered for the case of their self-weight only and for the case with an additional weight on the top of the column. The columns were exposed to a horizontal base acceleration of three accelerograms by successively increasing the maximum acceleration to their failure. The characteristic displacements and accelerations of the column were measured. It was concluded that an increase in the number of blocks in the column can significantly increase or decrease its ultimate bearing capacity, depending on the type of the applied accelerogram. It is expected that the experimental database can be useful in the validation of nonlinear numerical models for the dynamic analysis of multidrum columns.

scholarly journals Bearing Capacity Model of Corroded RC Eccentric Compression Columns Based on Hermite Interpolation and Fourier Fitting

2018 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Jingzhou Xin ◽  
Jianting Zhou ◽  
Fengbin Zhou ◽  
Simon Yang ◽  
Yi Zhou
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Hermite Interpolation ◽  
Measured Data ◽  
Small Scale ◽  
Pure Bending ◽  
Eccentric Compression ◽  
Starting Point ◽  
Hermite Interpolating Polynomial ◽  
Fourier Function

With an extension in service years, bridges inevitably suffer from performance deterioration. Columns are the main components of bridge structures, which support the superstructure. The damage of pier columns is often more harmful to bridges than that of other components. To accurately evaluate the time-varying characteristics of corroded columns, this paper proposes a new model for the bearing capacity evaluation of deteriorated reinforced concrete (RC) eccentric compression columns based on the Hermite interpolation and Fourier function. Firstly, the axial compression point, the pure bending point and the balanced failure point were selected as the basic points, and the deteriorated strength of these basic points was calculated by considering factors such as concrete cracking, reduction of reinforcement area, buckling of the steel bar, bond slip and strength reduction of confined concrete. After that, the interpolation points were generated by a piecewise cubic Hermite interpolating polynomial, and the explicit expression of the interpolation points fitting function was realized by the trigonometric Fourier series model. Finally, comparison studies based on measured data from forty-five corroded RC eccentric compression columns were conducted to investigate the accuracy and efficiency of the proposed method. The results show that: (1) the prediction results for bearing capacity of corroded RC columns are in good agreement with the measured data, with the average ratio of predicted results to test results at 1.06 and the standard deviation at 0.14; (2) the proposed model unifies the three stress states of axial compression, eccentric compression and pure bending, and is consistent with the continuum mechanics characteristics; (3) the decrements of axial load carrying capacity for 10% and 50% of the corrosion rate are 31.4% and 45.2%, while in flexure they are 25.4% and 77.4%, respectively; and (4) the test data of small-scale specimens may overestimate the negative effect of corrosion on the bearing capacity of actual structures. The findings in this paper could lay a solid starting point for structural life prediction technologies based on nondestructive testing.

scholarly journals Small Scale Experiments to Assess the Bearing Capacity of Footings on the Sloped Surface

Eng ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 240-248
Author(s):  
Mohammad Nurul Islam
Keyword(s):  
Bearing Capacity ◽  
Carrying Capacity ◽  
Maximum Load ◽  
Scale Model ◽  
Small Scale ◽  
Load Carrying Capacity ◽  
Engineering Structures ◽  
Load Carrying ◽  
Limiting Condition ◽  
The Impact

Construction of civil engineering structures on or next to a slope requires special attention to meet the bearing capacity requirements of soils. In this paper, to address such a challenge, we present laboratory-scale model tests to investigate the effect of footing shape on the sloped surface. The model comprised of a well stiffened mild steel box with three sides fixed and one side open. We considered both with and without reinforcement to assess the effectiveness of reinforcement on the sloped surface. Also, we used three types of footing (i.e., square, rectangular, and circular) to measure the footing shape effects. We considered three different slope angles to evaluate the impact of the sloped face corresponding to the applied load and the reinforcement application. We obtained that the maximum load carrying capacity in the square footing was higher than the rectangular and the circular footing for both the reinforced and the unreinforced soil. With the increase of geo-reinforcement in all three footing shapes and three sloped angles, the load carrying capacity increased. We also noticed a limiting condition in geo-reinforcement placement effectiveness. And we found that with the increase of slope, the load bearing capacity decreased. For a steep slope, the geo-reinforcement placement and the footing shape selection is crucial in achieving the external load sustainability, which we addressed herein.

scholarly journals Bearing Capacities of Different-Diameter Concrete-Filled Steel Tubes under Axial Compression

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Wenjing Wang ◽  
Zhenyun Tang ◽  
Zhenbao Li ◽  
Hua Ma
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Peak Load ◽  
Steel Tube ◽  
Specimen Size ◽  
Small Scale ◽  
Strengthening Effect ◽  
Steel Tubes ◽  
Specimen Diameter ◽  
Concrete Filled Steel Tubes

The bearing capacities of concrete-filled steel tubes are normally derived through experiments with small-scale specimens, but it is uncertain whether such derivations are appropriate for the much larger components used in practical engineering. This study therefore investigates the effect of different diameters (219, 426, 630, and 820 mm) on the axial compression of short concrete columns in steel (Q235) tubes. It is found that the peak nominal stress decreases with increasing specimen size and that the axial bearing capacity is determined by three separate components: the cylinder compressive strength of the concrete, the improvement in strength due to the confining effect of the steel tube, and the longitudinal strength of the steel tube. At peak load, increases in the specimen diameter reduce the hoop stresses in the steel tube, thereby reducing the strengthening effect of confinement. Vertical stress in the steel tube is increased with diameter; therefore, the axial bearing capacity of the steel tube is directly related to the specimen size. Size effect coefficients for these three aspects of bearing capacity are defined and used to develop a size-dependent model for predicting the axial bearing capacity of large, concrete-filled steel tubes. The model is then validated against experimental data.

United States sea ice physics project, 1954–59

Polar Record ◽  
1959 ◽  
Vol 9 (63) ◽  
pp. 553-555 ◽  
Author(s):  
W. F. Weeks
Keyword(s):  
United States ◽  
Sea Ice ◽  
Physical Properties ◽  
Bearing Capacity ◽  
Air Force ◽  
Field Tests ◽  
Small Scale ◽  
Army Corps ◽  
Army Corps Of Engineers ◽  
General Physical

In 1954 the Geophysics Research Directorate of the Air Force Cambridge Research Center (AFCRC), at the request of Northeast Air Command, United States Air Force, organized a study of the physical properties, growth, and bearing capacity of sea ice. The object of the study was to gain information about the conditions under which various aircraft and vehicles could operate on sea ice, for supply and rescue purposes. The Navy Hydrographic Office (NHO) and the Snow, Ice and Permafrost Research Establishment (SIPRE) of the Army Corps of Engineers also took part in the project. The spheres of interest of each organization were as follows: AFCRC, the application of geophysical and crystallographic methods to the study of sea ice; NHO, the details of the relations between meteorological conditions and the growth rate and general physical properties of sea ice; and SIPRE, the variation of the strength of sea ice as determined by small-scale field tests, and the application of this information toward an analysis of the bearing capacity of sea ice.

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