scholarly journals LABORATORY EXPERIMENTAL RESEARCH OF LOADING FORCES DEVELOPMENT ACTING ON THE SIDE SURFACE OF THE PILES

2018 ◽  
Vol 1 (50) ◽  
pp. 174-180
Author(s):  
V. E. Naydenova
Keyword(s):  
Experimental Research ◽  
Lateral Surface ◽  
Side Surface ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Ground Resistance ◽  
Theoretical Statement ◽  
Torque Load ◽  
Negative Friction ◽  
Resistance Forces

The forces of negative friction or loading forces of friction on the piles develop due to additional deformations of near pile array and they cannot be more force of resistance on the side of pile in rest, that is formed due to own weight of the ground founding. The paper presents the results of laboratory experimental research of loading forces of friction acting on the lateral surface of the piles without taking into account the vertical load (being relatively at rest) and provided an analysis of methods for detection of negative friction forces (loading forces) acting on the lateral surface of the pile, with the appointment of their load-bearing capacity. The researches have confirmed the theoretical statement about the equality of the loading forces of friction to ground resistance forces under the action of the torque load but not the pulling load, as it is suggested in the modern standards.

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 New design of a tapered bored pile For installation in structurally unstable soils

2018 ◽  
Vol 2 (51) ◽  
pp. 102-107
Author(s):  
Oleksandr Samorodov ◽  
Artem Ubyivovk ◽  
Anna Kupreichyk ◽  
Victoria Naydenova
Keyword(s):  
Surface Area ◽  
Experimental Research ◽  
Slope Angle ◽  
Friction Forces ◽  
Additional Load ◽  
Bored Pile ◽  
Bored Piles ◽  
Potential Impact ◽  
Negative Friction ◽  
The Impact

New designs of bored piles with a tapered shaft shape are proposed. To confirm reduction or absence of the potential impact of additional load (negative) friction forces effectiveness on piles lateral surfaces in structurally unstable soils (fill-up grounds etc.) due to a change in the edge slope angle, laboratory experimental research on models of tapered piles have been conducted; the confirming results have been provided and described in detail in the laboratory experimental research. The impact of the changed slope angle of the edge on the effect of additional load friction forces on the lateral surfaces of experimental piles was demonstrated; the correlation between the change in taper of piles and the decrease in their surface area has been proven.

scholarly journals SINGLE PILES SETTLEMENT UNDER THE ACTION OF NEGATIVE FRICTION FORCES

2017 ◽  
Vol 2 (49) ◽  
pp. 171-176
Author(s):  
O. V. Samorodov ◽  
D. L. Muliar ◽  
S. V. Tabachnikov
Keyword(s):  
Experimental Data ◽  
Pile Foundation ◽  
Reliable Method ◽  
Field Testing ◽  
Load Bearing Capacity ◽  
Friction Forces ◽  
Actual Load ◽  
Single Piles ◽  
Negative Friction ◽  
Full Scale Tests

Nowadays, the use of pile-plate foundations has received extensive development, which takes into account the soil inclusion in the work under its plate part. We proposed a new design of a plate-pile foundation and an engineering method for determining the main parameters of such a foundation, where one of the parameters is the piles settlement under the action of the negative friction forces Pn. As far as is known, field testing of production piles using pressing-in loads is the most reliable method for determining their actual load-bearing capacity. We carried out full-scale tests of a multi-section pile with the loading at depth, on the basis of which a comparative analysis of the settlement of single piles from the action of the negative friction forces, obtained with the help of adapted and existing methods and experimental data

Improvement of Stamping by Rolling Processes of Pipe and Cylindrical Blades on Experimental Research

2020 ◽  
Vol 844 ◽  
pp. 168-181
Author(s):  
Andrii Shtuts ◽  
Mykola Kolisnyk ◽  
Andrii Vydmysh ◽  
Oleksandr Voznyak ◽  
Serhii Baraban ◽  
...  
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Mathematical Models ◽  
Experimental Research ◽  
Lateral Surface ◽  
Side Surface

During the experimental study, a pronounced beating and sealing of the side surface of the tubular, cylindrical blanks was recorded. It is established that cracks appear and develop in the central part of the lateral surface, i.e., it are destroyed. This fact confirms the claim that the destruction of tubular, cylindrical blanks of some materials begins on the side surface. It is established that the bases of analytical dependencies between the components of deformations describe the obtained results of the experimental study of SR tubular, cylindrical blanks within the error of the experimental data, which made it possible to construct a number of mathematical models for the purpose of further study of the SDS and the method of their determination.

Experimental Research on Load-Bearing Capacity of Frame Columns with Construction Joint under Low-Cyclic Reversed Loading

2013 ◽  
Vol 351-352 ◽  
pp. 363-366
Author(s):  
Xi Kang Yan ◽  
Cheng Dong ◽  
Pei Chen ◽  
Kang Ma
Keyword(s):  
Bearing Capacity ◽  
Experimental Research ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Construction Joint ◽  
Axial Compression Ratio ◽  
The Third ◽  
Simple Processing ◽  
Reversed Loading ◽  
Crack Position

In this paper,in order to study the load-bearing capacity of frame columns with construction joint under low-cyclic reversed loading, nine specimens were made, divided into three groups.Every group had three specimens, the first were made without construction joint, the second had fine processing construction joint, the third had simple processing construction joint. The three groups were loaded in axial compression ratio of 0.23,0.34,0.46 respectively.The results show that the influence of different processing with construction joint to crack position ultimate bearing capacity,skeleton curves.

scholarly journals Free oscillations of steel beams prestressed by wall stretching

2020 ◽  
Vol 17 (6) ◽  
pp. 97-103
Author(s):  
V. A. Kravchuk ◽  
Keyword(s):  
Free Oscillation ◽  
Forced Oscillations ◽  
Steel Beams ◽  
Load Bearing Capacity ◽  
Study Results ◽  
Oscillation Process ◽  
Circular Frequency ◽  
The Impact ◽  
Resistance Forces ◽  
Prestressed Beams

The article presents the study results of the impact of steel beam prestressing by wall stretching on changes in the circular frequency, frequency, period, and number of oscillations per minute for free oscillation, and for oscillation taking into account the resistance forces. The forced oscillations of the beam under impulse loading are investigated. There has been carried out a comparative analysis of the dynamic parameters of prestressed beams and conventional beams of equal cross-section with the same load-bearing capacity parameters. The analysis results of the influence of resistance forces on the oscillation process in prestressed beams and conventional beams are submitted. There has been established the time of oscillations damping in the compared beams at free oscillation, taking into account the resistance forces.

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.

scholarly journals Interaction of the pile with the sagging loess soil

2018 ◽  
Vol 196 ◽  
pp. 03020
Author(s):  
Zaven Ter-Martirosyan ◽  
Ivan Luzin
Keyword(s):  
Lateral Surface ◽  
Moisture Transfer ◽  
Lower Layer ◽  
Loess Soil ◽  
Darcy's Law ◽  
Geomechanical Model ◽  
Deformation Properties ◽  
Negative Friction ◽  
Slab Foundation ◽  
Surrounding Soil

The article presents the formulation and solution of the problem in the interaction of a pile with a two-layered base, the upper layer of which settles due to the moistening by the filtrational flow (Darcy's law) or moisture transfer (Fick's law), and the lower layer is bearing, possesses relatively strong and deformation properties, which pushes against. It is shown that due to subsidence of the surrounding soil, negative friction occurs on the lateral surface of the pile, which causes additional draft and force at the level of the heel of the pile. As a calculation, the geomechanical model of the ground cylinder, containing the pile and perceiving the load from the grillage as part of the pile-slab foundation, is considered.

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