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.

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%.

Analysis of Bearing Capacity of New-Type Formwork Support Frame

2013 ◽  
Vol 341-342 ◽  
pp. 1449-1452
Author(s):  
Qing Dun Zeng ◽  
Fang Liu
Keyword(s):  
Bearing Capacity ◽  
Structural Stability ◽  
Failure Process ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Solid Model ◽  
Finite Element Software ◽  
Support Frame ◽  
New Type ◽  
Security And Reliability

Various new type scaffolds have been introduced and developed in China. They are novel in structure and economic in material, but their security and reliability can not be ignored. This paper introduced a new chained formwork support frame with nine upright tubes and many cross-braced connections. Firstly, the load test of the support frame was performed in order to observe the failure process and to determine the ultimate bearing capacity. Then, the strength and stability of both single upright tube and a cross-braced rod were checked according to the existing specifications on scaffolds. Finally, a finite element software ANSYS was used to establish a solid model for the support frame. The structural stability was analyzed and the ultimate bearing capacity was calculated. The comparison between the computational and experiment results was carried out. The results show that the ultimate bearing capacity of the new chained formwork support frame is controlled by the structural stability.

Experimental Investigation on Anchorage Mechanisms of Self-Locked Anchor under Combined Tension and Shear

2010 ◽  
Vol 163-167 ◽  
pp. 3600-3603
Author(s):  
Ying Li ◽  
Dong Zi Pan ◽  
Lian Zhang
Keyword(s):  
Experimental Investigation ◽  
Bearing Capacity ◽  
Fracture Pattern ◽  
Ultimate Bearing Capacity ◽  
Design Codes ◽  
Design Recommendations ◽  
Experimental Parameters ◽  
Current Design ◽  
New Construction ◽  
New Type

Self-locked anchor is a new type of underreamed anchor, and which is more and more frequently used in both new construction and structural retrofitting or strengthening projects. Nevertheless, current design codes do not contain suitable design recommendations for these anchors. This study investigates the anchorage mechanisms of self-locked anchor under combined tension and shear loadings. The experimental parameters mainly include anchor diameters (Φ16 and Φ20) and loading angles (0°, 30°, 45°, and 60°). The present results indicate the characters of axial and transverse deformations, the ultimate bearing capacity, the fracture pattern of anchor, and the breakout model of concrete.

Investigation of the Axial Bearing Capacity of the Discontinuous-Tube-in-Core Concrete Filled Steel Tubular Column-Slab Joint

2008 ◽  
Vol 400-402 ◽  
pp. 901-910 ◽  
Author(s):  
Fu Jun Liu ◽  
Jian Cai
Keyword(s):  
Mechanical Properties ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Steel Tube ◽  
Working Mechanism ◽  
Engineering Applications ◽  
New Type ◽  
Cfst Columns ◽  
The Cost ◽  
Core Concrete

Based on the principle of restrained concrete, this paper presents a new-type concrete filled steel tubular column-slab joint. This new-type joint is characterized by keeping the concrete floor slab continuous while breaking the steel tube of the column for the joint, thus joining the slab and the concrete filled steel tubular(CFST) columns at the top and the bottom of the slab. The joint has the advantage of transferring loads dependably, constructing conveniently and saving on the cost. Three groups of experiments (21 specimens contained) were performed to test the safety of the joint and investigate its axial bearing capacity. The results show that the joint is dependable and feasible in engineering applications. In addition, this paper studies the working mechanism and mechanical properties of the joint under axial compression, discusses the factors to influence its axial bearing capacity, and finally brings out the formula of the joint’s bearing capacity under axial compression that adapts to engineering applications, which conservatively evaluate the result of the experiments.

Experimental Research on Seismic Response of Heat-Insulating Perforated Brick Full-Scale Walls with Openings

2013 ◽  
Vol 353-356 ◽  
pp. 1896-1900
Author(s):  
Chuan Qing Liu ◽  
Ming Hai Li ◽  
Guang Chun Zhou ◽  
Zuo Yun Mei
Keyword(s):  
Bearing Capacity ◽  
Seismic Response ◽  
Axial Force ◽  
Masonry Wall ◽  
Ultimate Bearing Capacity ◽  
Full Scale ◽  
Window Opening ◽  
New Type ◽  
The One ◽  
Ultimate Displacement

Heat-insulating perforated brick is a new type energy-saving masonry material. In order to investigate seismic response of masonry wall with this new-type brick, a set of quasi-static full-scale cyclic tests are performed. The test results show that this brick owns a good cooperative work system between bearing layer and insulation layer, and vertical axial force is an obvious factor which affects seismic response of heat-insulating perforated brick walls. With the increase of vertical axial force, ultimate bearing capacity increases, however, ultimate displacement can be decreased. In the case of the same axial force, ultimate bearing capacity of the specimen wall with door opening is less than the one with window opening, and the ultimate displacement also is less than the one with window opening.

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.

Computation of Jacked Pipe Pile Side Resistance Based on Time Effect

2011 ◽  
Vol 368-373 ◽  
pp. 2657-2660
Author(s):  
Jia Tao Wang
Keyword(s):  
Bearing Capacity ◽  
Early Period ◽  
Field Tests ◽  
Frictional Resistance ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Soil Resistance ◽  
Computing Model ◽  
Logarithmic Curve ◽  
Side Resistance

In the re-pressed tests of jacked pipe piles in soft clay, it was observed that the re-pressed starting pressure can reach to more than 2.5 times of the final pressure for 25 days after finishing the installation; and it increased more rapidly in early period than later. Through the study of the time effect mechanism, it is found that the increment of ultimate bearing capacity of the single pile is mainly caused by side soil resistance. The end resistance has little influence on the time effect of bearing capacity of pile. According to the simulation result of the test data, the relationship between pile side resistance and time can be described with logarithmic curve. By this new computing model, the side frictional resistance in different resting time can be obtained, and then the ultimate bearing capacity. It is proved that this method is feasible because the values of side soil resistance calculated by the computing model with software are well consistent with the field tests results.

A Field Study on Bearing Capacity of Al-Najaf Sandy Gypseous Soil

2020 ◽  
Vol 857 ◽  
pp. 179-187
Author(s):  
Mohammed Kadum Fakhraldin
Keyword(s):  
Bearing Capacity ◽  
Field Study ◽  
Field Tests ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Water Infiltration ◽  
Infiltration Process ◽  
Plate Load Test ◽  
Angle Of Internal Friction ◽  
Gypseous Soil

Gypseous considered as problematic soils also gypseous soils are distributed all over the world, as well as in large areas of Iraq, including Al- Najaf city. Gypseous soils are characterized by high strength in dry conditions, but they collapse due to water infiltration process under constant head conditions. In this research, a field study investigates gypseous soils and the effect of soaked state on the bearing capacity and settlement of the gypseous soils are investigated. A site with a high percentage of gypsum (about 25%) was selected to perform plate load tests. The test was carried out in a natural and soaked state on the gypseous soils by plate load test with time-dependent. The results show the ultimate bearing capacity of gypseous soil from plate load test are decrease under the soaking condition and maximum settlement increase. The angle of internal friction (ø) of gypseous soil we obtained from the direct shear test is 47.620 for natural soil. The ultimate bearing capacity of gypseous soil was calculated from the Terzaqhi’s equation and the high difference between field tests and theoretical results.

scholarly journals Synergistic Bond Properties of Different Deformed Steel Fibers Embedded in Mortars Wet-Sieved from Self-Compacting SFRC

2021 ◽  
Vol 11 (21) ◽  
pp. 10144
Author(s):  
Xinxin Ding ◽  
Haibin Geng ◽  
Minglei Zhao ◽  
Zhen Chen ◽  
Jie Li
Keyword(s):  
Bearing Capacity ◽  
Cross Sections ◽  
Steel Fiber ◽  
Concrete Strength ◽  
Ultimate Bearing Capacity ◽  
Steel Fibers ◽  
Unit Weight ◽  
Bond Properties ◽  
Pull Out ◽  
Concrete Matrix

Reliable bond of steel fiber in concrete is a key problem relating to the reinforcing effect of steel fiber on concrete matrix and for the guide in significance for the optimal design of the geometry and mechanical properties of steel fiber. In this paper, on the basis of multi-indices of evaluation for the bond properties of single hooked-end steel fiber, the indices for the evaluation of synergistic bond properties of different deformed steel fibers are proposed. The pull-out tests were carried out for different deformed steel fibers embedded in mortar wet-sieved from self-compacting SFRC with manufactured sand. Fourteen types of steel fibers were used, including six hooked-end, two crimped, four indentation, one milling, and one large-end. The bond strength, bond energy, and bond toughness of single and per unit weight steel fiber were evaluated with the correspondence to the loading status of cracking resistance, normal serviceability, and ultimate bearing capacity of concrete. Results show that the deformed steel fibers presented different bond behaviors, hooked-end, and crimped steel fibers with circular cross-sections and a tensile strength of higher than 1150 MPa have excellent effects of strengthening, energy dissipation, and toughening capacity on self-compacting concrete with a cubic compressive strength of 60 MPa at normal serviceability and ultimate bearing capacity. Indentation, milling, and large-end steel fibers are more suitable for reinforcing the concrete strength due to the rigid bond before concrete cracking. The synergistic working of steel fibers with concrete matrix should be concerned to realize the effects of only or simultaneously reinforcing the strength and toughness of concrete.

scholarly journals Numerical Investigation of the Undrained Compression and Pull-Out Capacity of Suction Foundations in Clay

2015 ◽  
Vol 22 (s1) ◽  
pp. 126-135 ◽  
Author(s):  
Jiaqing Du ◽  
Shouji Du ◽  
Shuilong Shen ◽  
Zhenyu Yin
Keyword(s):  
Bearing Capacity ◽  
Three Dimensional ◽  
Ultimate Bearing Capacity ◽  
Capacity Factor ◽  
Embedment Depth ◽  
Pull Out ◽  
Effective Depth ◽  
Undrained Conditions ◽  
Tresca Criterion ◽  
Bearing Capacity Factor

Abstract This paper presents the results of three-dimensional finite difference analysis of suction foundations in uniform and non-uniform clays under undrained conditions. The Tresca criterion was used to simulate the stress-strain response. The bearing capacity of the foundations was investigated, with the degree of nonhomogeneity (kD/sum) of soil varying from 0 to 5, and the embedment depth being up to four times the foundation diameter. The end bearing capacity factor in compression and the reverse bearing capacity factor in tension were both calculated and were compared with each other under different foundation displacements. Numerical results showed that the ultimate bearing capacity factor can have the same value in cases of both compression and tension. The recommended ultimate bearing capacity factor is determined on the basis of the embedment ratio and displacement magnitude, and the displacement is not more than 30% of the foundation diameter. Finally, two equations are proposed to evaluate both the bearing capacity factor and the effective depth factor.

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