Field investigations of negative friction forces in thawing soils

1978 ◽  
Vol 15 (4) ◽  
pp. 241-245
Author(s):  
V. D. Ponomarev ◽  
Yu. G. Fedoseev
Keyword(s):  
Friction Forces ◽  
Field Investigations ◽  
Negative Friction

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 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

Field Investigations in Surf Zones

1974 ◽  
Author(s):  
Hans Henning Dette ◽  
Alfred Führböter
Keyword(s):  
Field Investigations

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

Discharge-pulse Geotechnical Electro Discharge Technology of Bases Strengthening

2020 ◽  
Vol 787 (12) ◽  
pp. 63-65
Author(s):  
N.S. Sokolov
Keyword(s):  
Bearing Capacity ◽  
Mechanical Characteristics ◽  
Discharge Pulse ◽  
Zero Values ◽  
Traditional Technologies ◽  
Negative Friction ◽  
Geotechnical Problems ◽  
Physical And Mechanical Characteristics

The problem of increasing the bearing capacity of the base is an relevant problem in modern geotechnical construction. When significant loads are transmitted to the base, the use of traditional technologies is not always justified. Often there is an urgent need to use non-standard ways to strengthen the bases. In many cases, the geotechnical situation is aggravated by the presence of weak underlying layers with unstable physical and mechanical characteristics in engineering-geological sections. When strengthening such bases with the help of traditional piles, the latter can get negative friction, which significantly reduces their bearing capacity on the ground, sometimes reaching zero values. This may lead to additional precipitations of the objects being constructed and constructed in the zone of geotechnical influence. The use of ERT piles in most cases successfully solves many complex geotechnical problems.

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