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.

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 Geotechnical Properties of Anthropogenic Soils in Road Engineering

2020 ◽  
Vol 12 (12) ◽  
pp. 4843
Author(s):  
Andrzej Głuchowski ◽  
Katarzyna Gabryś ◽  
Emil Soból ◽  
Raimondas Šadzevičius ◽  
Wojciech Sas
Keyword(s):  
Cyclic Loading ◽  
Bearing Capacity ◽  
Construction Material ◽  
Bottom Ash ◽  
Field Tests ◽  
Recycled Concrete ◽  
Concrete Aggregate ◽  
Test Results ◽  
Anthropogenic Soils ◽  
Road Engineering

The construction of a roads network consumes high amounts of materials. The road materials are required to fulfill high standards like bearing capacity and low settlement susceptibility due to cyclic loading. Therefore, crushed aggregates are the primary subbase construction material. The material-intensity of road engineering leads to depletion of natural resources, and to avoid it, the alternative recycled materials are required to be applied to achieve sustainable development. The anthropogenic soils (AS), which are defined as man-made unbound aggregates, are the response to these requirements. For the successful application of the AS, a series of geotechnical laboratory and field tests were conducted. In this article, we present the set of 58 test results, including California Bearing Ratio (CBR) bearing capacity tests, oedometric tests, and cyclic CBR tests, to characterize the behavior of three AS types and to compare its reaction with natural aggregate (NA). The AS tested in this study are recycled concrete aggregate (RCA), fly ash and bottom ash mix (BS), and blast furnace slag (BFS). The results of the tests show that the AS has similar characteristics to NA, and in some cases, like compression characteristic, RCA and BFS behave a stiffer response to cyclic loading. The test results and analysis presented here extend the knowledge about AS compressibility and AS response to cyclic loading.

Model Test Studies of the Vertical Bearing Behavior of Bored Piles with Breakage Defects

2012 ◽  
Vol 256-259 ◽  
pp. 65-70
Author(s):  
Cheng Hua Wang ◽  
Juan Su ◽  
Gan Wang
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Great Influence ◽  
Test Results ◽  
Sudden Drop ◽  
Bored Piles ◽  
Vertical Bearing ◽  
Vertical Bearing Capacity ◽  
Bearing Behavior

In order to study the vertical bearing behavior of bored piles with breakage defects, a series of methods for simulation of normal piles and broken piles in laboratory was developed and used to investigate the vertical bearing behavior of these piles. The load-settlement curves of normal piles and broken piles were measured and analyzed. The tests revealed that the upper part of a broken pile works alone as a short pile before it contact with the lower part of the pile at the end of the first sudden drop stage.The analysis of the test results showed that the position of the breakage defect has a great influence on the lost in vertical bearing capacity of the pile.

scholarly journals ANALYSIS OF THE RESULTS OF TENSOMETRIC STUDIES OF NATURAL BORED CONICAL PILES

2020 ◽  
pp. 44-55 ◽  
Author(s):  
I. Rybnikova ◽  
A. Rybnikov
Keyword(s):  
Bearing Capacity ◽  
Lateral Surface ◽  
Sandy Loam ◽  
Side Surface ◽  
Contact Stresses ◽  
Strain Gauges ◽  
Soil Resistance ◽  
Taper Angle ◽  
Different Types ◽  
Bored Piles

Four bored piles of two standard sizes with a length of 4,5 m, a diameter of heads of 0,4 and 0,6 m, a diameter of the lower end of 0,2 m with a taper angle of 1o20ʹ and 2o40ʹ, respectively, are studied. Two different types of piles are equipped with a height of four strain gauges, and two-ten bulldozers of five on each of the diagonal opposite sides. The soils on the experimental ground are composed of solid sandy loam. According to the measurements of strain gauges and load cell, plots of the distribution of forces and stresses in sections along the pile trunk, as well as plots of contact stresses along their lateral surface are constructed. The results of the research revealed that additional forces of soil repulsion along the inclined lateral surface during its sedimentation under load are significantly involved in the bearing capacity of bored conical piles. The proportion of soil resistance, depending on the angle of taper, is 34-49 % of the total bearing capacity, the resistance of the lower end – 17-23 %, friction on the side surface of the trunk-34-43 %. These data indicate the effectiveness of giving the trunks of bored piles up to 5 m even a slight taper in the range of 1,5 o ... 3,0 o.

Test study on the characteristics of mudcakes and in situ soils around bored piles

2009 ◽  
Vol 46 (3) ◽  
pp. 241-255 ◽  
Author(s):  
Zhong-Miao Zhang ◽  
Jun Yu ◽  
Guang-Xing Zhang ◽  
Xin-Min Zhou
Keyword(s):  
Bearing Capacity ◽  
Void Ratio ◽  
Cement Grout ◽  
Test Results ◽  
Lower Shear ◽  
Bored Pile ◽  
Test Study ◽  
Disturbed Zone ◽  
Bored Piles

Constructing a bored pile produces a disturbed zone of soil adjacent to the pile, referred to as a “mudcake.” The physical properties of the mudcake are different from those of the surrounding soil. This paper reports research on bored piles in silt, clay, and sandy silt layers in Hangzhou, China. Laboratory tests were performed on samples of in situ soil, mudcake, and mudcake mixed with cement grout. The test results showed that mudcakes have a higher water content, higher void ratio, higher compressibility, lower friction, and lower shear strength than in situ soils. They also showed that mudcake properties could be improved by the addition of cement grout. Mudcakes form a weak, thin layer between a pile and a borehole wall, which can lead to a decrease in bearing capacity and an increase in settlement of the pile. Grouting improves the characteristics of mudcakes remarkably, thereby increasing the bearing capacity of piles, which is demonstrated by the case history in this paper.

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 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 Assessment of the bearing capacity of piles during static load test

2020 ◽  
Vol 8 (4) ◽  
pp. 22-27
Author(s):  
Pavel Gavrilov ◽  
Vyacheslav Glukhov
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Field Tests ◽  
Load Test ◽  
Static Load Test ◽  
Static Tests ◽  
Standard Values ◽  
Bored Piles ◽  
The Moment ◽  
Experimental Researches

The purpose of this research is to estimate the bearing capacity of bored piles with broadening, formed by stone rolling. A series of static tests of the existing piles was performed in accordance with the requirements of the current regulatory documentation, the analysis of the obtained results was carried out. According to this experimental researches, was made a conclusion about the advisable to take into account the standard values of settlements at the determining of the bearing capacity of piles by ground. The results of field tests were compared with the calculated values, determined by calculation with the recommendations of SP 24.13330.2011. Noted, that the value of load, corresponding to the moment of the pile «failure», should be taken as a criterion of the factual bearing capacity.

Comparison of field loading test results of bored piles with bearing capacity analysis based on various standards

ce/papers ◽  
2018 ◽  
Vol 2 (2-3) ◽  
pp. 93-112
Author(s):  
Ahmet SAGLAMER ◽  
Hüsnü Korhan OZALP ◽  
Bahadir KARGIOGLU
Keyword(s):  
Bearing Capacity ◽  
Capacity Analysis ◽  
Test Results ◽  
Loading Test ◽  
Bored Piles

scholarly journals Economic efficiency of vibroreinforced soil-cement piles implemented in construction

2018 ◽  
Vol 2 (51) ◽  
pp. 97-101
Author(s):  
Oleksandr Novytskyi ◽  
Tetіana Nesterenko
Keyword(s):  
Bearing Capacity ◽  
Economic Efficiency ◽  
Economic Effect ◽  
Field Tests ◽  
Residential Building ◽  
Reinforced Soil ◽  
Implementation Effectiveness ◽  
Soil Cement ◽  
Bored Piles ◽  
Economic Comparison

The results of the executed economic comparison of foil-cement piles reinforcement use by vibroreinforced - vibroreinforced soil-cement piles are presented. The comparison is based on the results of piles bearing capacity by field tests. Considering the results of field tests two variants of piles foundation have been designed for residential building. Economical comparison is made for implementation effectiveness of reinforced and non-reinforced soil-cement piles at the piles calculated bearing capacity on the soil that is greater than the calculated bearing capacity by the material. .Economical comparison is made for implementation effectiveness of vibrated vibroreinforced soil-cement piles and bored piles at their calculated bearing capacity by the material at times greater than that on the soil. The obtained results and the determined economic effect are analyzed. The results of comparison are used for design and implemented in construction.

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