Studies on Soil Resistance to Pipelines Buried in Sand

2011 ◽  
Vol 243-249 ◽  
pp. 3151-3156 ◽  
Author(s):  
Run Liu ◽  
Lin Ping Guo ◽  
Shu Wang Yan ◽  
Yu Xu
Keyword(s):  
Failure Modes ◽  
Model Tests ◽  
Soil Resistance ◽  
Test Results ◽  
Buried Pipe ◽  
Pull Out ◽  
Soil Failure ◽  
Pipe Segment ◽  
Force Displacement ◽  
Peak Value

A series of model tests were carried out to investigate the soil resistance when the buried pipe segment moved in the sand. In the tests, the pipe segments were pulled out in vertical, lateral and axial directions and the pipe segments movement and soil resistance were recorded. Observed data show that the soil resistance depends on the pipe diameters and the depth of cover. According to the uplift test results, the force-displacement relationships with smaller depth of cover are greatly different from those with larger depth of cover. The results of the lateral sliding and axial pull out tests show that the soil resistance initially increases before a peak value is reached and then keeps the same level. For the same covered depth, the lateral soil resistance is more than twice that for uplift. According to the uplift test results, the soil failure modes with smaller depth of cover are greatly different from those with larger covered depth.

PULL OUT STRENGTH FOR DIFFERENT SIZE OF DOWEL AND GRAIN DIRECTION OF GLULAM

2016 ◽  
Vol 78 (5-4) ◽  
Author(s):  
Tengku Anita Raja Hussin ◽  
Mohamad Iswandi Jinne ◽  
Rohana Hassan
Keyword(s):  
Failure Modes ◽  
Maximum Load ◽  
Experimental Program ◽  
Drilling Process ◽  
Test Results ◽  
Bond Behaviour ◽  
Pull Out ◽  
Timber Joints ◽  
Different Thickness ◽  
Pull Out Strength

This paper presents an experimental program for testing glued-in dowel glulam timber joints. Hundred thirty glulam specimens, each with a single glued-in rebar parallel to the grain and perpendicular to grain with different size of dowels 12mm, 16mm and 20mm were tested to evaluate the effects of anchorage length and different dowel diameter for parallel and perpendicular to the grain on pull-out strength and bond behaviour of glued-in rebar timber joints. The test results showed that the maximum load for specimen with dowel glued-in parallel to the grain given the higher maximum load than dowel glued-in perpendicular to the grain direction. Failure modes were characterized by pull out failure in the mode of adhesive-dowel, yet one sample failed in timber-adhesive mode. This might happened because the surface of the timber was burned by drilling machine during the drilling process. The pull-out was tested with different thickness grain direction with different dowel size with a rate of 2mm/min and the failure modes were observed after the testing of pull-out test. PRF is the adhesive used for the strengthening purposes. Resistance to the withdrawal of dowels glued-in perpendicularly was 44.2% to 53.5 % lower than that obtained for dowels glued-in parallel to the grain direction. The result shows that the dowel glued-in parallel to the grain given the higher maximum load than dowel glued-in perpendicular to the grain direction.

scholarly journals Experimental and Parametric Study on the Pull-Out Resistance of a Notched Perfobond Shear Connector

2019 ◽  
Vol 9 (4) ◽  
pp. 764 ◽  
Author(s):  
Shuangjie Zheng ◽  
Yuqing Liu ◽  
Yangqing Liu ◽  
Chen Zhao
Keyword(s):  
Failure Modes ◽  
Concrete Strength ◽  
Shear Connector ◽  
Test Results ◽  
Explicit Finite Element ◽  
Shear Connectors ◽  
Pull Out ◽  
Cutting Out ◽  
Circular Holes ◽  
Alternative Equation

To ease the installation of perforating rebars through multi-holes, an alternative notched perfobond shear connector was proposed by cutting out the hole edge. This paper presents the test results of six pull-out specimens with conventional and notched perfobond shear connectors. The objective was to compare the failure modes and pull-out behaviors of perfobond shear connectors using circular holes and notched holes. Furthermore, the explicit finite element method was introduced and validated to generate parametric results for pull-out tests of notched perfobond shear connectors. A total of 33 parametric simulations were performed to further study the influences of several variables, including the hole diameter, the cut width, the perfobond thickness, the concrete strength, the diameter and strength of the rebar, and the strength of the structural steel. The experimental and numerical results were used to evaluate the previous equations for perfobond shear connectors. Finally, an alternative equation was proposed to estimate the pull-out resistance of notched perfobond shear connectors.

Testing of URM wall-to-diaphragm through-bolt plate anchor connections

2020 ◽  
pp. 875529302094418
Author(s):  
Dmytro Dizhur ◽  
Shou Wei ◽  
Marta Giaretton ◽  
Arturo E. Schultz ◽  
Jason M. Ingham ◽  
...  
Keyword(s):  
Failure Modes ◽  
Phase 1 ◽  
Current Strength ◽  
Design Standards ◽  
Pull Out ◽  
Test Parameters ◽  
Standards And Guidelines ◽  
Plate Anchor ◽  
Two Phases ◽  
Force Displacement

The presence of effective wall-to-diaphragm connections has been shown to significantly improve the global seismic behavior of unreinforced masonry (URM) buildings. However, despite the importance of such connections, there remains a paucity of experimental research to provide physical validation of current recommendations in design standards and guidelines. The experimental study reported herein included a total of 18 tests which were undertaken in two phases, with Phase 1 testing being undertaken on existing vintage plate anchor connections in an existing URM building and Phase 2 testing involving newly installed plate anchor connections in two additional existing URM buildings. The tested buildings offered variation in material properties, levels of axial load, and wall thickness as test parameters. Attained failure modes and corresponding force-displacement curves are presented herein, as well as comparisons regarding the influence of varying test parameters on the ultimate pull-out capacity. Prediction of plate anchor capacity was undertaken using a basic mechanics approach, and comparisons to current strength recommendations in standards and guidelines are provided.

Seepage Induced Soil Failure and its Mitigation During Suction Caisson Installation in Silt

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Lizhong Wang ◽  
Luqing Yu ◽  
Zhen Guo ◽  
Zhenyu Wang
Keyword(s):  
Pressure Effects ◽  
Offshore Wind ◽  
Soil Resistance ◽  
Clayey Soils ◽  
Test Results ◽  
Filtration Method ◽  
Suction Caisson ◽  
Soil Failure ◽  
Tip Resistance ◽  
Internal Side

Suction caisson is an advantaged foundation option for offshore wind turbines in sandy and clayey soils. In this work, a series of model tests were conducted to investigate the installation behavior of a suction caisson in silty soils. The test results showed that the total soil resistance to the caisson increased steadily with penetration depth in the beginning of the suction-assisted penetration (SP) process, but rose slowly or remained constant after reaching a certain depth with excessive soil heave. This failure mechanism, which was quite different from that identified in sandy or clayey soils, was caused by the seepage induced silt soil failure in the caisson, such as erosion, liquefaction or piping, with reducing internal side friction and tip resistance. To suppress this type of failure, a special filtration method was introduced to help caisson penetration. The test results showed that such filtration technique had the advantage of reducing the height of soil heave and prevent seepage induced soil failure in the silt, but also suppress the under pressure effects on reducing the soil resistance. Numerical simulations were also performed to aid in understanding the observed test results and mitigation mechanisms.

scholarly journals Design Recommendations for Bonded Anchors under Fire Conditions Using the Resistance Integration Method

2021 ◽  
Vol 11 (17) ◽  
pp. 7810
Author(s):  
Omar Al-Mansouri ◽  
Romain Mège ◽  
Nicolas Pinoteau ◽  
Thierry Guillet ◽  
Roberto Piccinin ◽  
...  
Keyword(s):  
Failure Modes ◽  
Integration Method ◽  
Temperature Profiles ◽  
Test Results ◽  
Pull Out ◽  
Epoxy Adhesives ◽  
Assessment Procedures ◽  
Adhesive Anchors ◽  
Recommendations For Assessment ◽  
Fire Conditions

Fire design of cast-in place and post-installed anchors in concrete under fire is covered by EN 1992-4, Annex D, allowing steel- and concrete-related failure modes of anchors to be calculated. This informative annex of EN 1992-4 is limited to cast-in place or mechanical anchors, whereas post-installed adhesive anchors remain out of its scope. This paper presents a study of the applicability of the more flexible resistance integration method (RIM), proposed originally for the design of the pull-out resistance of post-installed reinforcement (PIR) by Pinoteau, on bonded anchors in uncracked concrete. This method is validated from a comparison of test results obtained from two research projects conducted at CSTB and TU Kaiserslautern on bonded anchors in uncracked concrete under ISO 834-1 fire conditions. The data considered include tests conducted on anchor sizes from M8-M30 using three different adhesives (two epoxy adhesives and one cementitious mortar). Design of the pull-out resistance under fire using RIM requires numerical calculation of temperature profiles considering models of concrete and steel elements; different assumptions about modeling these elements can produce vastly different end results. Finally, recommendations for assessment procedures for bonded anchors under fire conditions are provided as entry data for design.

Paper 11. Yaw Motion Stability; Twin-Screw, Twin-Rudder Ships—Some Model and Ship Results

1972 ◽  
Vol 14 (7) ◽  
pp. 75-79
Author(s):  
G. D. Thurman
Keyword(s):  
Model Test ◽  
Model Tests ◽  
Full Scale ◽  
Test Results ◽  
Motion Stability ◽  
Ship Model ◽  
Pull Out ◽  
Twin Screw ◽  
Model Correlation ◽  
Stability Results

This paper describes the pull-out manoeuvre as an indication of yaw motion stability. Results of model tests at the Admiralty Experiment Works and full-scale trials data are presented as a demonstration of ship/model correlation; additional model test results are given to illustrate use of the manoeuvre for detecting changes in stability due to alterations in ship configuration.

On Utilization of Material Failure Criterion in Modeling Pull-Out Failure of Spot-Welded Joints

2013 ◽  
Author(s):  
Long Zeng ◽  
Yong Xia ◽  
He Zhao ◽  
Qing Zhou
Keyword(s):  
Test Data ◽  
Failure Criterion ◽  
Welded Joints ◽  
Failure Modes ◽  
Failure Criteria ◽  
Spot Weld ◽  
Test Results ◽  
Pull Out ◽  
Metal Sheets ◽  
Spot Welded

Two distinct failure modes of spot welds, interfacial and pull-out failure, are observed in impact of spot-welded structures. Automotive industries prefer pull-out as the predominant failure mode since it makes more use of load-bearing capacity of a joint. For the time being, finite element models for predicting pull-out failure of spot weld have not been well developed. The dependence of failure on the stress state, i.e., a locus in the space of failure strain and stress triaxiality, needs to be known for base metal sheets when modeling spot weld pull-out. Existing failure criteria, with or without physical base, were formulated to provide an effective way to utilize a limited number of tests to reconstruct the failure locus. This paper is aimed to evaluate influence of failure criterion form for identifying failure parameters on modeling spot weld pull-out. As for material tests, various specimen configurations of metal sheets were designed to obtain stress states around a number of typical stress triaxialities. These test results constructed a set of test data for calibrating failure criterion. The spot-welded joints were also tested two different coupon configurations. The force-displacement curves were obtained, and the deformation fields around the spot weld nugget were achieved with DIC. These test results of joints were utilized to validate the model of spot weld pull-out. Two prevailing failure criteria, shear-modified Gurson model and Modified Mohr-Coulomb model, were selected to predict the complicated spot weld pull-out failure. Parameters in each of the two failure criteria were identified with material test data. Various simulation results were thereafter obtained based on different failure criteria. The two criteria were evaluated in terms of their predictive capabilities for spot weld pull-out failure.

scholarly journals Pull-Out Resistance Capacity of a New Perfobond Shear Connector for Steel Pile Cap Strengthening

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Young-Ho Kim ◽  
Jae-Yoon Kang ◽  
Hyun-Bon Koo ◽  
Dae-Jin Kim
Keyword(s):  
Failure Modes ◽  
Shear Connector ◽  
Test Results ◽  
Pull Out ◽  
Dowel Action ◽  
Test Parameters ◽  
Pile Cap ◽  
New Type ◽  
Embedment Length ◽  
The One

This study proposes a new type of the perfobond shear connector, which can be used to strengthen the steel pile cap embedded into the structure foundation, and evaluates its pull-out resistance capacity by performing a test on ten specimens. Test parameters include the embedment length of the shear connector, existence of transverse rebars passing through holes in the shear connector, and their shape, size, and number. The pull-out load versus slip curve is plotted for all specimens, and their failure modes are identified. The effects of the test parameters on the peak pull-out load are examined in this work. The test results show that the perfobond shear connector proposed in this study can retain the peak pull-out load up to 6 times higher than the one without any holes. This indicates that the existence of holes in the shear connector enables the dowel action of concrete inside the hole, resulting in the improvement of the shear resistance capacity of the connector.

Study on shear performance of the connection with external stiffening ring between square steel tubular column and unequal-depth steel beams

2020 ◽  
pp. 136943322098166
Author(s):  
Shuhao Yin ◽  
Bin Rong ◽  
Lei Wang ◽  
Yiliang Sun ◽  
Wuchen Zhang ◽  
...  
Keyword(s):  
Failure Modes ◽  
Plastic Hinge ◽  
Steel Tube ◽  
Nonlinear Finite Element ◽  
Steel Beams ◽  
Finite Element Models ◽  
Test Results ◽  
Panel Zone ◽  
Load Paths ◽  
Shear Performance

This paper studies the shear performance of the connection with the external stiffening ring between the square steel tubular column and unequal-depth steel beams. Two specimens of interior column connections were tested under low cyclic loading. The deformation characteristics and failure modes exhibited by the test phenomena can be summarized as: (1) two specimens all exhibited shear deformation in steel tube web of the panel zone and (2) weld fracture in the panel zone and plastic hinge failure at beam end were observed. Besides, load-displacement behaviors and strain distributions have been also discussed. The nonlinear finite element models were developed to verify the test results. Comparative analyses of the bearing capacity, failure mode, and load-paths between the equal-depth and unequal-depth beam models have been carried out.

scholarly journals Microstructure and Mechanical Performance of Resistance Spot Welded Martensitic Advanced High Strength Steel

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Yunzhao Li ◽  
Huaping Tang ◽  
Ruilin Lai
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Strong Dependence ◽  
High Strength ◽  
Weld Nugget ◽  
Resistance Spot ◽  
Pull Out ◽  
Cross Tension ◽  
Spot Welded

Resistance spot welded 1.2 mm (t)-thick 1400 MPa martensitic steel (MS1400) samples are fabricated and their microstructure, mechanical properties are investigated thoroughly. The mechanical performance and failure modes exhibit a strong dependence on weld-nugget size. The pull-out failure mode for MS1400 steel resistance spot welds does not follow the conventional weld-nugget size recommendation criteria of 4t0.5. Significant softening was observed due to dual phase microstructure of ferrite and martensite in the inter-critical heat affected zone (HAZ) and tempered martensite (TM) structure in sub-critical HAZ. However, the upper-critical HAZ exhibits obvious higher hardness than the nugget zone (NZ). In addition, the mechanical properties show that the cross-tension strength (CTS) is about one quarter of the tension-shear strength (TSS) of MS1400 weld joints, whilst the absorbed energy of cross-tension and tension-shear are almost identical.

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