scholarly journals EXPERIMENTAL TESTS OF A BEARING CAPACITY OF «FUNDEX» PILES AFTER THE LONG “RELAXATION” IN CLAY SOILS THE DEAD PRESSING AND PULLING-OUT LOADS

2019 ◽  
Vol 10 (2) ◽  
pp. 13-29
Author(s):  
A. V Savinov ◽  
V. E Frolov ◽  
Y. N Brovikov ◽  
M. P Kozhinskiy
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Experimental Tests ◽  
Soil Conditions ◽  
Field Methods ◽  
Technical Science ◽  
Pull Out ◽  
Geological Conditions ◽  
Wide Range ◽  
The Dead

In the article analyzes the results of experimental tests of new “Fundex” piles for The City of Saratov. Сlassification of piles based on their interplay with the pile base has been devised by Doctor of Technical Science, Professor F.K. Lapshin. Changes introduced in 2016 into SP 24.13330.2011 “Pile foundations” concerning calculation of the displacing stuffed concrete piles. The short analysis of history of creation of tables SP 24.13330 by determination of rated resistance on a lateral area and under the lower end of piles is carried out. It is shown that these sizes are not the limit resistances at exhaustion of a carrying capacity of a soil at “failure”, and are accepted with some stock at achievement by a pile of “predetermined” settling. There has been noted the existence of a large number of piles testing methods by means of incrementally increasing load different from methodology GOST 5686-2012 “Soils. Methods of field trials of piles” by various assessment criteria of the ultimate pile bearing capacity. Two identical piles have been manufactured in identical soils and after a long (3 months) “relaxation” without load tests have been conducted under GOST 5686 with static indenting and pull out loads. Engineering-geological conditions of the platform and distance between piles excluded their interference at manufacture and tests. the dead pressing and pulling-out loads. Comparison of results of field tests of “Fundex” piles to design values of a bearing capacity of the displacing piles determined by the recommendations of SP 24.13330 is carried out. The essential divergence of the experimental and estimated values at assessment of a bearing capacity of a heel of a pile is noted. Conclusions are drawn on need of additional experimental research of the basis of “Fundex” piles for the wide range of soil conditions by laboratory and field methods with parallel tests static indenting and pull out loads.

scholarly journals EXPERIMENTAL TESTS OF THE BASIS OF “FUNDEX” PILES AFTER THE LONG “RELAXATION” IN CLAY SOILS

2020 ◽  
Vol 11 (1) ◽  
pp. 5-19
Author(s):  
A. V Savinov ◽  
V. E Frolov ◽  
Y. N Brovikov ◽  
M. P Kozhinskiy
Keyword(s):  
Field Tests ◽  
Experimental Tests ◽  
Soil Conditions ◽  
Field Methods ◽  
Pilot Studies ◽  
Physical Strength ◽  
Physicomechanical Characteristics ◽  
Pull Out ◽  
Wide Range ◽  
Lateral Area

In the soil conditions, typical for the city of Saratov, piles on Fundex technology with a loss screw tip of DPOS-4E are executed. After the long «relaxation» of piles without loading guaranteeing completion generally of processes of compaction, consolidation, restitution of the water and colloid communications additional engineering-geological researches are executed and the complex of laboratory researches of parameters of the near pile array of a soil is conducted. Physicomechanical characteristics of the basis immediately at a lateral area and at the lower end of a pile, apart by 1 m are received from its side and in a soil of natural addition. Results are compared in a tabular and graphic form. Conclusions are drawn on the nature of changes of physical, strength and deformation characteristics of the near pile array of a soil at various distance from a lateral area of a pile. The essential differences in formation of the condensed soil zones around Fundex piles from the traditional displacing drive and pressed piles influencing a carrying capacity (the extreme resistance) of the basis of stuffed piles are noted. Comparison of the obtained datas of laboratory with results of field tests of similar piles in identical soil conditions after long “relaxation” (3 months) in accordance with static indenting and pull out loads. Conclusions are drawn on need of additional pilot studies of the basis of Fundex piles for the wide range of soil conditions by laboratory and field methods with parallel tests by the dead pressing and pulling-out loads.

Experimental and large-scale field tests of grid-anchor system performance in increasing the ultimate bearing capacity of granular soils

2016 ◽  
Vol 53 (7) ◽  
pp. 1047-1058 ◽  
Author(s):  
M. Mosallanezhad ◽  
N. Hataf ◽  
S.H. Sadat Taghavi
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Field Tests ◽  
Experimental Tests ◽  
Ultimate Bearing Capacity ◽  
Soil Reinforcement ◽  
Granular Soils ◽  
Anchor System ◽  
Scale Field ◽  
Large Scale Field

Soil reinforcement by means of geogrid is an effective method of increasing the ultimate bearing capacity (UBC) of granular soils. In this study a new system, created by adding cubic anchors to ordinary geogrids, is introduced to increase the UBC of granular soils. This system is called “grid-anchor” (G-A). To analyse the performance of the G-A system in increasing the UBC of granular soils, 45 experimental tests and 9 field tests were performed, the results of which show that the G-A system is 1.8 times more capable than ordinary geogrids in increasing the UBC in square foundations. Furthermore, the failure of soil reinforced by the ordinary geogrid takes place at a settlement of 9% of the foundation width, while the same value for the G-A system is almost 13%.

scholarly journals EVALUATION AND ANALYSIS OF BEARING CAPACITY OF BORED PILES AND DEEP-LAID PILE-BARRETTE FOR A HIGH-RISE BUILDING ON LOOSE GROUNDS BASED ON CALCULATIONS AND FIELD TESTS

2018 ◽  
Vol 14 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Rashid A. Mangushev ◽  
Nadezda S. Nikitina
Keyword(s):  
Bearing Capacity ◽  
Rectangular Cross Section ◽  
Standard Procedure ◽  
Field Tests ◽  
Thick Layer ◽  
Top Down ◽  
Field Methods ◽  
Static Tests ◽  
High Rise ◽  
High Rise Building

The study describes the standard procedure of the assessment of the bearing capacity of piles by field methods used in the Russian Federation. Basing on the example of an experimental deep-laid foundation pile (length L = 65 m, diameter D = 1.2 m) intended for a high-rise building designed for a thick layer of loose ground the study demonstrates the structure of a loading system on site and the results of static tests of piles in comparison with the results of analytical and numerical calculations. On the same construction site an experimental barrette-pile of rectangular cross-section measuring 3.3 x 1.1 with a length of 65 m was installed with the base in solid Protero­zoic clays. The pile test was carried out using Osterberg cells. For this purpose in the process of the installation of the pile strain gauges were mounted in its reinforcing cage at 9 levels. The test barrette-pile was carried out in two stages. On the first stage a standard test of the whole pile in the top-down direction was performed (Top - Down). On the second stage, after reaching the maximum possible load, the “O - cell” element test was performed trans­mitting the load in two directions (up and down). “O - cell” was located at a depth of 50 m in the layer of blue- stone. The article contains the graphs of the movements of pile from under the load applied on the first and second stages of the tests and the general assessment of the load-bearing capacity of the barrette-piles by different methods

scholarly journals Experimental justification of the stability of the floating unit

2021 ◽  
Vol 264 ◽  
pp. 01054
Author(s):  
Vladimir Zimnyukov ◽  
Marina Zborovskaya ◽  
Vasiliy Fartukov ◽  
Anton Zaitsev
Keyword(s):  
Bearing Capacity ◽  
Power Unit ◽  
Hydroelectric Power ◽  
Static Loads ◽  
Geological Conditions ◽  
Wide Range ◽  
Vertical Displacements ◽  
Shear Characteristics ◽  
Experimental Justification ◽  
The Stability

One of the main tasks arising when installing a floating hydroelectric power unit on a foundation without preliminary excavation is a thorough justification of the shear stability and bearing capacity of the "floating hydroelectric power unit - foundation" system on a complex geological massif. Failure to take into account these factors can lead to serious consequences during the landing of the structure in the target and further operation. It should be emphasized that this problem still includes a number of difficulties and does not always allow obtaining exact solutions in a volumetric setting. Based on the selection of a wide range of model materials, bases of various capacities were modelled for four models. In this case, the shear real characteristics of alluvial soils and their change after reinforcing cementation were taken into account. The studies were carried out on 4 models under static loads with bringing them to destruction. The models reproduced the real geological conditions at the base of the block, simulated deformation, and shear characteristics. Indicator diagrams of displacements, damage patterns, and generalized safety factors for bearing capacity were obtained. Model tests have shown that reinforcing cementation reduces not only the values of horizontal and vertical displacements of structures but also leads to a significant increase in the safety factor.

scholarly journals Development of a New Inflatable Controlled Anchor System and Experimental Study of pull-out Capacity

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Xuexiang Yang ◽  
Shanpo Jia ◽  
Caoxuan Wen ◽  
Yuanjie Liu
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Ultimate Bearing Capacity ◽  
Inflation Pressure ◽  
Working Mechanism ◽  
Anchor System ◽  
System A ◽  
Pull Out ◽  
New Type ◽  
Soil Interface

Considering the deficiency of traditional anchors, we propose a new type of inflatable controlled anchor system in this paper. The working mechanism and its structural composition of newly designed inflatable controlled device are discussed in detail. To investigate the performance and pull-out capacity of this new anchor system, a series of field tests were carried out under different inflation pressure conditions. By comparing these test results with those of traditional grouting anchors, a full-process constitutive model of anchor-soil interface is proposed to depict the pull-out characteristics of the inflatable controlled anchor. The results show that the ultimate bearing capacity of the inflatable controlled anchor is greater than that of the traditional grouting anchor when the inflation pressure is greater than 0.2 MPa and the ultimate bearing capacity of this new anchor improves obviously with the increase of inflation pressure. When the inflation pressure reaches 0.4 MPa, the ultimate bearing capacity of the inflatable controlled anchor is 2.08 times that of the traditional grouting anchor. Through comparison with the experimental curves, the results of model calculation indicate that the proposed anchor-soil interface constitutive equation can describe the pull-out characteristics of the inflatable controlled anchor. The designed controlled anchor has the advantages of no grouting, recyclability, rapid formation of anchoring force, and adjustable anchoring force.

A Comparison of Pull-Out Capacity of Suction Anchors in Clay and Sand

2014 ◽  
Vol 614 ◽  
pp. 613-617
Author(s):  
Jia Qing Du ◽  
Shou Ji Du ◽  
Zhi Wang
Keyword(s):  
Aspect Ratio ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Extreme Environment ◽  
Soil Conditions ◽  
Analysis Method ◽  
Comparison Analysis ◽  
Pull Out ◽  
Rise Rate ◽  
Geological Conditions

With the oil and gas exploitation develop to the deep sea; offshore platform under extreme environment load needs more stable anchorage foundation. Based on the slender suction anchor of SPAR, three-dimensional numerical analysis method was presented to study the ultimate pull-out capacity. Based on the geological conditions from South China Sea, clay and sand was selected as soil conditions to make a comparison analysis. The effects of soil type, load positions, load angles and aspect ratio on the ultimate bearing pull-out resistance of the suction foundation were studied. The comparison analysis results indicated that the ultimate pull-out resistance of suction anchors in sand has a greater rise rate and achieve ultimate pull-out capacity need smaller displacement than in clay; load point and load angles have a great impact on the resistance and there is a critical aspect ratio under inclined loading in sand.

scholarly journals Investigation of Bearing Capacity of the Drill-Impact Micropiles with Enlarged Toe in the Soils of Different Type

2021 ◽  
Vol 1203 (3) ◽  
pp. 032054
Author(s):  
Adam Podhorecki ◽  
Oleksandr Hnatiuk ◽  
Mykola Lapchuk ◽  
Oleksandr Mazepa
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Field Tests ◽  
Soil Conditions ◽  
Quantitative Correlation ◽  
Real Work ◽  
Different Types ◽  
Circular Bar ◽  
Flow Consistency

Abstract The reinforced concrete micropiles with enlarged toe is the effective construction for the arranging of new and reinforcing of existing foundations which a drill-impact method are made as a circular bar with a diameter to 250 mm from the flow consistency concrete with prefabricated reinforcement cage and enlarged to two diameters toe cone-shaped form. For research of them real work by the authors of the article and engineers of PP BKF “Osnova” were conducted them field tests on the objects of building in the different soil conditions and the analysis of them calculation and experimental bearing capacity is given. The analysis of quantitative correlation of experimental and theoretical bearing capacity for the different types of soils is the task of researches.

scholarly journals Pulsars as probes of gravity and fundamental physics

2016 ◽  
Vol 25 (14) ◽  
pp. 1630029 ◽  
Author(s):  
Michael Kramer
Keyword(s):  
Strong Field ◽  
Direct Detection ◽  
Field Tests ◽  
Dense Matter ◽  
Experimental Tests ◽  
Fundamental Physics ◽  
Tests Of General Relativity ◽  
Pulsar Timing ◽  
Wide Range ◽  
Tests Of Gravity

Radio-loud neutron stars known as pulsars allow a wide range of experimental tests for fundamental physics, ranging from the study of super-dense matter to tests of General Relativity (GR) and its alternatives. As a result, pulsars provide strong-field tests of gravity, they allow for the direct detection of gravitational waves in a “pulsar timing array” (PTA), and they promise the future study of black hole properties. This contribution gives an overview of the on-going experiments and recent results.

Improving the test methodology of design piles on a construction site

2020 ◽  
pp. 9-13
Author(s):  
Igor Boyko ◽  
Tetiana Dyptan
Keyword(s):  
Bearing Capacity ◽  
Tall Buildings ◽  
Side Surface ◽  
Soil Conditions ◽  
Special Technique ◽  
Technical Object ◽  
Static Tests ◽  
Pull Out ◽  
Real Objects ◽  
Test Schedule

Reliable solutions for the design of tall buildings with pile foundations depend on the correctness of the load-bearing capacity. In some cases, you need to know that it is impossible to determine the ability on the side surface and under the sole. To do this, it is proposed to develop a special technique that combines tests to remove and pull out and educate the nature of the downloads (static or  kinematic).Тhe publication proposes a method of testing piles in the field, which simulates the processes that accompany the interaction of the pile with the soil base in real situations of operation of the technical object: for example, emergency soaking of soils when there is no time for stabilization deformations under load from a building or structure. It is shown that the value of friction on the side surface of the piles significantly depends on the nature of the loads. The analyzed results of the test schedule allow to separate these two components in the case when unloading is carried out continuously and the beginning of the pile movement in the opposite direction gives the value of soil resistance on the side floor. This simulates the real behavior of the pile at the base of the building, because in real objects there is no time for stabilization.It is offered to carry out tests of piles before loading which causes continuous indentation of piles, and division into components - bearing capacity on lateral surface Fdf and bearing capacity under the sole of the pile FdR will allow to accumulate the calculated soil supports in the respective zones, which makes it possible to create tables «R» and «f» for soil conditions of Ukraine.Taking into account the peculiarities of the construction of the pile test schedule and the proposed approaches will allow to correctly determine the components used in determining the bearing capacity of the pile. The accumulation of test results in the future will clarify the calculated soil supports of Ukraine. Reliable values of the calculated resistances will reduce the amount of static tests, which are time consuming and expensive.

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%.

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