Analysis of Bored Piles' Field Test Results

2019 ◽  
Vol 828 ◽  
pp. 194-201
Author(s):  
Lidia Kondratieva ◽  
Vladimir Konyushkov ◽  
Le Van Trong ◽  
Vladimir Kirillov
Keyword(s):  
Bearing Capacity ◽  
Deformation Modulus ◽  
Field Tests ◽  
Side Surface ◽  
Geometrical Parameters ◽  
Foundation Design ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Geological Conditions ◽  
Bored Piles

The purpose of the study is to establish accuracy of determining the load-bearing capacity of bored piles according to the method specified in Regulations 24.13330.2011 "Pile foundations". Relevance of the topic is determined by the following: the load-bearing capacity of a pile is a fundamental indicator affecting all subsequent activities related to foundation design, and accuracy of analytical solutions for complex engineering and geological conditions is highly questionable. Field tests of bored piles were carried out in engineering and geological conditions of Saint Petersburg with deformation modulus from 10 to 40 MPa at a load in the range from 1,000 to 6,300 kN, at achievement of absolute settlement of 40 mm. Piles with a diameter from 0.15 to 0.88 m and a length from 10 to 47 m were made using various technologies: using casing, using slurry, using a flight auger. Following the results of field tests, diagrams of load-bearing capacity of piles according to the material, depending on geometrical parameters and manufacturing techniques, diagrams of actual and designed load-bearing capacity of piles were plotted. Approximating functions to describe the dependences were obtained. According to the analysis of the results, it is possible to conclude that the load-bearing capacity of the bored pile during field tests is 1.4–1.7 times higher than the load-bearing capacity of the pile designed according to Regulations 24.13330.2011; the average share of the load-bearing capacity along the side surface of the pile was 65% and under the pile toe — 35%.

scholarly journals DEVELOPMENT OF A METHOD FOR CALCULATING THE BEARING CAPACITY OF BORED CONICAL PILES

2021 ◽  
Vol 6 (9) ◽  
pp. 28-36
Author(s):  
I. Rybnikova ◽  
A. Rybnikov
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Side Surface ◽  
Strength Properties ◽  
Empirical Method ◽  
Full Scale ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Static Tests ◽  
Ground Resistance

Three methods for determining the load-bearing capacity of bored conical piles are presented, considering the additional forces of the ground rebound along their inclined side surface under vertical load. It is proposed to determine the bearing capacity according to the results of field tests using the coefficient of transition from the maximum permissible settlement of the building foundation to the settlement of the pile obtained during static tests. Its value varies from 0.1 to 0.3 depending on the angle of the pile taper. To determine the bearing capacity of the empirical method, tabular data of the ground rebound forces on the side surface of the piles are developed. It depends on the strength properties of the base soil, the angle of the pile taper and the depth of the location of the changing cross-section of the pile along the length. The process of compressing the soil in a drilled well with an elastic cylindrical pressiometer is close to the occurrence of a ground rebound when it is pushed apart by the side surface of a conical pile during sediment under load. It is proposed to determine the ground resistance on the side surface of conical piles according to the same dependence as when processing the results of pressiometric tests of soils, taking into account the introduction of a correction factor depending on the parameters of the pile. The calculated load-bearing capacity of the piles, determined by the proposed methods, differs from the actual load-bearing capacity, determined by the results of static tests of full-scale piles, within 10 %. However, these methods need to be improved with the accumulation of statistical data for testing full-scale piles in different ground conditions.

scholarly journals ANALYSIS OF THE FIELD TESTS RESULTS OF BORED CONICAL PILES UNDER THE ACTION OF VARIOUS TYPES OF LOADS

2018 ◽  
Vol 3 (3) ◽  
pp. 24-29
Author(s):  
Ирина Рыбникова ◽  
Irina Rybnikova ◽  
Александр Рыбников ◽  
Aleksandr Rybnikov
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Normal Component ◽  
Cone Angle ◽  
Field Tests ◽  
Side Surface ◽  
Test Results ◽  
Head Diameter ◽  
Cylindrical Piles ◽  
Bored Piles

One of the methods of improving the bearing capacity of bored piles is giving them a taper. The feature of these (wedge-type) piles is that under load they work "as a thrust" and transfer part of the load due to the normal component to the inclined side surface. Three sizes of tapered bored piles were tested, with the length of 4.5 m, head diameter 0.4; 0.5; 0.6 m and with cone angle 1o and 2,5o. The test results were compared with the test results of cylindrical piles, 4.5 m long, with head diameter 0.4 m and 0.6 m. It has been discovered that with the increasing cone angle, the bearing capacity of piles against the pressing load, especially the specific load capacity for 1 m3 of material, as compared to cylindrical piles, increases significantly. It has been determined that the larger is the diameter of the head of the pile, the higher is the bearing capacity against the horizontal load, and the bearing capacity against the pullout load is equal to the breakout force of a pile from the soil.

scholarly journals A concrete prefabricated slab as a technology for reconstructing damaged, local air-field pavements

2018 ◽  
Vol 2018 (12) ◽  
pp. 51-64
Author(s):  
Mariusz Wesołowski ◽  
Bartosz Świerzewski
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Working Life ◽  
Concrete Slabs ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
The Real ◽  
International Airport ◽  
Fast Reconstruction

The age of currently operated concrete airfield pavements in Poland exceeds 30 years opera-tion period many times. Such a long working life of airfield pavements forced to search for the efficient and fast technologies of their reconstruction. The article described in detail the technologies of fast reconstruction of airfield concrete slabs using prefabricated slabs. The addressed technology guarantees the reconstruction and even the improvement of the condi-tion of load-bearing capacity of mentioned airfield slabs which was confirmed during labora-tory tests, field tests and practically verified in the real operation in the International Airport Kraków-Balice.

scholarly journals Reconstructing the Load-Bearing Capacity of Deteriorated, Concrete Airfield Pavements Using Prefabricated Slabs

2018 ◽  
Vol 41 (1) ◽  
pp. 31-61
Author(s):  
Mariusz Wesołowski ◽  
Agata Kowalewska ◽  
Bartosz Świerzewski
Keyword(s):  
Bearing Capacity ◽  
Laboratory Tests ◽  
Field Tests ◽  
Working Life ◽  
Concrete Slabs ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Operation Period ◽  
Fast Reconstruction ◽  
Loadbearing Capacity

Abstract The age of currently operated concrete airfield pavements in Poland exceeds 30 years operation period many times. Such a long working life of airfield pavements forced to search for the efficient and fast technologies of their reconstruction. The article described in detail the technologies of fast reconstruction of airfield concrete slabs using prefabricated slabs. The addressed technology guarantees the reconstruction and even the improvement of the condition of loadbearing capacity of mentioned airfield slabs which was confirmed during laboratory tests, field tests and practically verified in the real operation in the International Airport Kraków-Balice.

CALCULATION OF THE BEARING CAPACITY OF A TWO-SLOT STRIP FOUNDATION

2021 ◽  
Vol 12 (1) ◽  
pp. 57-71
Author(s):  
O. A Bogomolova
Keyword(s):  
Bearing Capacity ◽  
Poisson’S Ratio ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Side Surface ◽  
Poisson's Ratio ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Lateral Pressure Coefficient ◽  
Double Slit

The results of computer modeling of the process of formation and development of areas of plastic deformations in the connected base of a double-slit ribbon foundation are presented. All calculations are performed using computer programs developed with the participation of the author. These programs allow you to take into account all the variety of physical and mechanical properties of the foundation soil (volume weight, internal friction angle, specific adhesion, lateral pressure coefficient and deformation modulus) and the foundation material (elastic modulus and Poisson's ratio). In the calculations, it is assumed that the value of the lateral pressure coefficient of the soil is 0.75, as is typical for cohesive clay soils, and the same value for the foundation material is assumed to be 0.43 (converted through the Poisson's ratio). Based on the results of calculations, it was possible to determine the features of the stress state of the base of the double-slit foundation and the process of development of plastic areas in the core of the foundation. First of all, the part of the bearing capacity of the base of the double-slit foundation that contacts its side surface is realized, and the inclusion of the side surface of the slit foundation in the work occurs from the bottom up. Then the part of the base that is located directly under the soles of the walls in the ground (cracks) is included in the work. It is established that the smaller the distance between the slits, the greater the bearing capacity of the base and the greater its part falls on the side surface. The bearing capacity of the base of a double-slit foundation is directly proportional to the depth of its foundation (the height of the cracks). The part of the load-bearing capacity realized on the side surface of the foundation can reach 60 % or more of its full value. An engineering method for calculating the load-bearing capacity of the base of a double-slit foundation, including simple formulas and graphs, is proposed. The method is formalized in a calculator program. The verification calculations showed a high degree of accuracy in approximating the results of the numerical experiment.

The Load-Bearing Capacity of Aluminum Alloy T-Stub Joints

2011 ◽  
Vol 261-263 ◽  
pp. 765-769 ◽  
Author(s):  
Han Xu ◽  
Xiao Nong Guo ◽  
Yong Feng Luo
Keyword(s):  
Aluminum Alloy ◽  
Bearing Capacity ◽  
Parametric Analysis ◽  
Failure Modes ◽  
Ultimate Load ◽  
Numerical Results ◽  
Effective Length ◽  
Geometrical Parameters ◽  
Load Bearing Capacity ◽  
Load Bearing

The application of Aluminum alloy T-stub joints has been found widely in China recently, while the research achievements of the joint are far from adequate for design. This paper is focused on the ultimate load-bearing capacity of aluminum alloy T-stub joints. On the basis of Kulak prying model, formulas for calculating ultimate load-bearing capacity, considering four types of failure modes, are derived. The numerical simulation is carried out by means of ABAQUS FEA. Numerical results are verified by comparing with previous results obtained from experimental analysis. A parametric analysis is performed to investigate the influence of several geometrical parameters on the behavior of aluminum alloy T-stub joints including failure modes, ultimate load-bearing capacity and effective length of flanges. These numerical results are also compared with those calculated by relevant formulas in EC9.

scholarly journals Bearing capacity of deep bored piles

2020 ◽  
Vol 17 (3) ◽  
pp. 116-126
Author(s):  
Van Trong Le ◽  
Keyword(s):  
Statistical Processing ◽  
Field Tests ◽  
Side Surface ◽  
Soil Resistance ◽  
Underground Structures ◽  
Saint Petersburg ◽  
High Rise ◽  
Geological Conditions ◽  
Bored Piles ◽  
Technical Regulations

Modern technical regulations and design principles are limited by soil resistance on the side surface and under the point of bored piles up to 40 m. Meanwhile, the construction of high-rise buildings and underground structures requires the use of deeper bored piles. The author has set the task to determine the soil resistance for deep-bored piles by statistical processing of numerous results of field tests of bored piles and nonlinear extrapolation of soil resistance to a depth of 100 m in the geological conditions of Saint Petersburg.

scholarly journals Deformation behaviour of granular column reinforced by geosynthetic encasement

2021 ◽  
Vol 4 (2) ◽  
pp. first
Author(s):  
Lê Quân ◽  
Võ Đại Nhật ◽  
Nguyễn Việt Kỳ ◽  
Phạm Tiến Bách
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Thermal Power ◽  
Soil Improvement ◽  
Soft Ground ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Geological Conditions ◽  
Consolidation Settlement ◽  
Granular Column

In Vietnam, the overpopulation and strong economic development require the synchronous development of infrastructure such as roads, urban areas, industrial parks, export processing zones, etc. With such requirements, the development of land fund for infrastructure construction is an indispensable need. Meanwhile, the appropriate land fund is very limited. Therefore, the land fund must be developed for areas with little value for agriculture, such as swamps, estuaries, and coastal areas, etc. These areas often have weak geological conditions; hence, to meet the requirements of infrastructure construction on the soft ground, it is necessary to carry out soil improvement to ensure load bearing capacity, total settlement, and consolidation settlement but still ensuring economic effectiveness. Beside several conventional methods widely used for soft soil improvement in order to increase bearing capacity and accelerate consolidation settlement of the ground, geosynthetic reinforced granular column is one of the new methods that has been applied to improving soft ground in designing practice in the recent years due to the many advantages of this method compared with other methods. In this paper, based on the unit cell model, the authors research on deformation behavior of granular column reinforced by geosynthetic encasement through the analytical analysis by varying external loadings corresponding to column diameter, stiffness of geosynthetic encasement. The settlements of a single geosynthetic encased granular column and load bearing capacity of the composite foundation are calculated on geological conditions of Ash Pond Area of Song Hau 1 Thermal Power Plant located in Hau Giang Province. The relationship between settlement and load bearing capacity with external loadings for different column diameters and geosynthetic stiffnesses are shown schematically. Other considerations related to factor of safety are also presented. The future researches are also proposed.

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