Field Study on the Effects of Impact Frequency on the Axial and Lateral Capacity of Driven Pipe Piles in Sand

2018 ◽  
Author(s):  
Ivana Anusic ◽  
Barry M. Lehane ◽  
Gudmund R. Eiksund ◽  
Morten A. Liingaard
Keyword(s):  
Test Site ◽  
Driven Piles ◽  
Impact Frequency ◽  
Static Tests ◽  
Lateral Capacity ◽  
Load Tests ◽  
Loading Tests ◽  
Set Up ◽  
Lateral Behavior ◽  
The Impact

With pile installation being an important part of the total project cost, improving the efficiency of the offshore operations would require resolving the uncertainties in how different installation methods influence pile capacity. This paper describes a programme of testing involving static loading tests on eight 165 mm diameter open-ended steel tubes driven into medium dense siliceous sand at a well-characterized test site in Perth, Western Australia. Six piles were installed by impact driving under two different driving frequencies, and two piles were installed by vibration with the aim of identifying the effects of impact frequency on the response of driven piles to static axial and lateral loading. It was found that the tension capacity of piles measured 1 week after installation was not significantly dependent on the impact frequency and that these piles had approximately the same capacity as the piles installed by vibration. First time load tests performed 4 months after the initial tests indicated that all pile types had a similar set-up characteristic. Inspection of static tests on lateral behavior of vibrated and impact driven piles suggests that installation method has no impact on the lateral capacity.

scholarly journals Improving the design of piles driven in chalk through the ALPACA research project

2019 ◽  
pp. 2 ◽  
Author(s):  
Richard James Jardine ◽  
Róisín Marie Buckley ◽  
Byron Walter Byrne ◽  
Stavroula Kontoe ◽  
Ross Alexander McAdam ◽  
...  
Keyword(s):  
Field Experiments ◽  
Field Testing ◽  
Field Work ◽  
Test Site ◽  
Offshore Wind ◽  
Driven Piles ◽  
Lateral Resistance ◽  
Large Numbers ◽  
Port Facilities ◽  
Set Up

Chalk is present under large areas of NW Europe as a low-density, porous, weak carbonate rock. Large numbers of offshore wind turbines, bridges and port facilities rely on piles driven in chalk. Current European practice assumes ultimate shaft resistances that appear low in comparison with the Chalk’s unconfined compression strength and CPT cone resistance ranges and can impact very significantly on project economics. Little guidance is available on pile driveability, set-up or lateral resistance in chalk, or on how piles driven in chalk can sustain axial or lateral cyclic loading. This paper describes the ALPACA (Axial-Lateral Pile Analysis for Chalk Applying multi-scale field and laboratory testing) project funded by EPSRC and Industry that is developing new design guidance through comprehensive field testing at a well-characterised low-to-medium density test site, supported by analysis of other tests. Field experiments on 36 driven piles, sixteen of which employ high resolution fibre-optic strain gauges, is supported by advanced laboratory and in situ testing, as well as theoretical analysis. The field work commenced in October 2017 and was largely complete in May 2019.

Effect of Skirt-Tip Geometry on Set-Up Outside Suction Anchors in Soft Clay

2004 ◽  
Author(s):  
Knut H. Andersen ◽  
Lars Andresen ◽  
Hans Petter Jostad ◽  
Edward C. Clukey
Keyword(s):  
Shear Strength ◽  
Skin Friction ◽  
Soft Clay ◽  
Wall Roughness ◽  
Driven Piles ◽  
The Mean ◽  
Set Up ◽  
Anchor Design ◽  
The Impact

An important part of suction anchor design is the determination of the shear strength along the outside skirt wall. Previous work has suggested that when a suction anchor in clay is installed by applying underpressure inside the anchor, the external skin friction may be reduced compared to the skin friction expected for driven piles. The primary reason for this reduction is that the movement of soil at and beneath the caisson tip during installation will be influenced by whether the anchor is penetrated by weight or by underpressure. To further investigate the impact of installation by underpressure, additional finite element analyses have been performed where the skirt installation process has been better followed than in the previous analyses. The movement of soil around the caisson wall was studied for both a flat caisson tip and a tip with a tapered edge of 45° towards the outside of the anchor. The tapering was made to see if it would cause more of the displaced soil to move outside the anchor and thereby increase the mean total stresses and the shear strength along the outside anchor wall. The analyses were made with two separate wall roughness factors for a typical anchor in soft clay.

FIBRE OPTIC INSTRUMENTATION OF VIBRO CONCRETE COLUMNS AND SURROUNDING GROUND FOR STATIC AND DYNAMIC LOAD TESTS

2020 ◽  
Author(s):  
Maximilian Lerch ◽  
Thomas Neidhart ◽  
Michal Bubenicek
Keyword(s):  
Dynamic Load ◽  
Pore Water Pressure ◽  
Axial Strain ◽  
Water Pressure ◽  
Concrete Columns ◽  
Test Site ◽  
Special Procedure ◽  
Load Tests ◽  
Loading Tests ◽  
Effective Design

Instrumentation of full displacement pile like elements – at Keller called as vibro concrete columns (VCC) – is practically impossible due to utilisation of heavy deep vibro technique during the production and absence of any steel reinforcement. Thanks to cooperation between Keller and Faculty of Civil Engineering of OTH Regensburg a special procedure for post-instrumentation was developed that allows for the axial strain measurement in VCC during the loading tests. The instrumentation comprises among others optical fibre components. The procedure has been deployed on a test site during static as well as dynamic load tests. There were two different types of instrumentation implemented according to art of the load tests. Further there were robust piezometers installed in the soil in advance next to the VCC that allowed for continuous pore water pressure measurements during the load tests. Purpose of the instrumentation deployed is above all to obtain data for effective design of VCC.

Effects of Coupler Height Mismatch on Tank Car Stub Sills

2000 ◽  
Author(s):  
Anand Prabhakaran ◽  
Vinaya Sharma ◽  
Jose S. Peña
Keyword(s):  
Structural Integrity ◽  
Longitudinal Force ◽  
Operating Conditions ◽  
Vertical Force ◽  
Static Tests ◽  
Critical Areas ◽  
Significant Damage ◽  
Load Tests ◽  
Static Conditions ◽  
The Impact

Abstract Revenue service tests of tank cars conducted by the Association of American Railroads (AAR) as part of the ‘Freight Equipment Environmental Sampling Tests’ (FEEST) program have measured high coupler vertical loads. It is believed that such high vertical loads can cause significant damage to the structural integrity of tank car stubsills, thereby seriously affecting operational safety. Also, it is suspected that coupler height mismatches are a major source of these vertical forces, and thereby contribute to stubsill failures. The focus of this paper is the study of the effect of coupler height mismatches on stub sill integrity. As part of this study a tank car loaded to 266,200 lb. was instrumented and tested, in static conditions and during impact. The static tests consisted of a series of longitudinal load (squeeze) tests conducted at three different coupler heights, and vertical load tests with forces being applied at the coupler shank. The impact tests consisted of a series of impacts at speeds ranging from 2 mph to 8.5 mph for the following coupler mismatch levels: a) Struck and striking car at the same level, b) Struck car 2″ higher, and c) Struck car 2″ lower. In addition to the testing, finite element models were developed to help in studying additional operating conditions. These models were validated using the test results. The results from the testing indicate that coupler height mismatches have a significant effect on the vertical force levels and the stress levels seen at critical car locations. The stresses in critical areas are generally higher when the struck car is lower. Differences over 50% (compared to when the cars are level) were noted at the head brace, when the struck car was 2″ lower than the hammer car. The tests also established the criticality of vertical forces on the structural integrity of the stubsill. On average, a 50,000 lb. vertical force can generate as much stress as a 680,000 lb. longitudinal force. This work is being funded by the Office of Research & Development of the Federal Railroad Administration (FRA).

scholarly journals Dynamic and static tests of the safety foil for windows for composite glass interaction

2020 ◽  
Vol 313 ◽  
pp. 00029
Author(s):  
Daniel Papán ◽  
Zuzana Papánová ◽  
Lucia Figuli
Keyword(s):  
Experimental Investigation ◽  
Composite System ◽  
Glass Plate ◽  
Mechanical Resistance ◽  
Dynamic Resistance ◽  
Main Task ◽  
Static Tests ◽  
Composite Glass ◽  
Load Tests ◽  
The Impact

The standard windows can be enhanced with safety foil. This types of foils are usually used for car windows. The paper shows how can the composite system created from glass plate and safety foil improve the mechanical resistance. The main task is to determinate affecting parameters for the impact or dynamic resistance. The various methods are showed in the paper. All results are based on the experimental investigation and load tests.

Tank Car Load Environment Under Impact Conditions

2001 ◽  
Author(s):  
Anand Prabhakaran ◽  
Vinaya Sharma ◽  
Jose S. Peńa
Keyword(s):  
Research Effort ◽  
Impact Testing ◽  
Test Sequence ◽  
Vertical Force ◽  
Vertical Load ◽  
Static Tests ◽  
Critical Areas ◽  
Load Tests ◽  
Scale Test ◽  
The Impact

Abstract High coupler vertical loads have been measured in revenue service tests conducted by the Association of American Railroads (AAR) as part of the ‘Freight Equipment Environmental Sampling Tests’ (FEEST) program. These high loads can induce cracks and/or accelerate crack propagation rates, causing premature tank car stub sill separation, leading to compromised safety of operation. This project was initiated to study the vertical load environment experienced by tank cars. A full scale test sequence with static and impact testing of a tank car was conducted, followed by test data analysis. A tank car loaded to 266,200 lb gross rail load (GRL) was instrumented and used as the test car. The static tests consisted of vertical load tests with forces being applied at the coupler head and squeeze tests with loads applied at the rear draft lugs. The impact tests consisted of 2 series of impacts at speeds ranging from 2 mph to 8.5 mph for three coupler mismatch levels. The results showed that significant vertical forces are generated during an impact event, even in the absence of any coupler height mismatch between impacting cars. On average, vertical force peaks of about 45,000 lb were observed at an impact speed of 7.5 mph even when the impacting cars were at the same level. It was also noted that under impact conditions, vertical forces induce 50% of the maximum stress seen at the tank head. Therefore, ignoring the effects of vertical force will lead to an under-estimation of stress levels and fatigue levels in tank cars. In addition, the vertical forces and stresses in critical areas of the stub sill-tank car interface are generally higher when the struck car is lower. Differences (in stress level) over 50% (compared to when the cars are level) were noted when the struck car was 2 in lower than the hammer car. In light of this, it seems prudent to minimize coupler height mismatch whenever and wherever feasible. This research effort was funded by the Office of Research and Development of the Federal Railroad Administration (FRA).

MOTIF DAN DAMPAK PERNIKAHAN DINI DI INDARUNG NGALAU BATU GADANG

2018 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Murisal Murisal
Keyword(s):  
Young Men ◽  
Early Marriage ◽  
Marriage Law ◽  
Men And Women ◽  
Home Life ◽  
Family Household ◽  
Set Up ◽  
The Impact ◽  
Husband And Wife

Motif and Impact of Early Marriage in Indarung Ngalau Batu Gadang.Penelitian is motivated by teenagers who married early on. Today, young men and women have a tendency to be less prepared to enter the home life, they are only ready to marry (ready here can be interpreted, maturity in terms of financial, understand what the meaning of marriage according to marriage law) is the bond of inner birth between a man and a woman as husband and wife for the purpose of forming a happy and eternal family (household) based on the Supreme Godhead while they are not ready to set up a home, whereas to build a household requires preparation both physically and spiritually . The purpose of this study to determine the motives underlying adolescents to make early marriage and the impact caused in the household as a result of the marriage.

Dissent and Education

2018 ◽  
Author(s):  
Mark Burden
Keyword(s):  
Eighteenth Century ◽  
Seventeenth Century ◽  
Educational Activity ◽  
Educational Institutions ◽  
Higher Educational Institutions ◽  
Legal Restrictions ◽  
Higher Educational ◽  
Set Up ◽  
The Impact ◽  
Dissenting Academies

Much eighteenth-century Dissenting educational activity was built on an older tradition of Puritan endeavour. In the middle of the seventeenth century, the godly had seen education as an important tool in spreading their ideas but, in the aftermath of the Restoration, had found themselves increasingly excluded from universities and schools. Consequently, Dissenters began to develop their own higher educational institutions (in the shape of Dissenting academies) and also began to set up their own schools. While the enforcement of some of the legal restrictions that made it difficult for Dissenting institutions diminished across the eighteenth century, the restrictions did not disappear entirely. While there has been considerable focus on Dissenting academies and their contribution to debates about doctrinal orthodoxy, the impact of Dissenting schools was also considerable.

scholarly journals Deterministic approach for multiple-source tsunami hazard assessment for Sines, Portugal

2015 ◽  
Vol 15 (11) ◽  
pp. 2557-2568 ◽  
Author(s):  
M. Wronna ◽  
R. Omira ◽  
M. A. Baptista
Keyword(s):  
Sea Level ◽  
Wave Height ◽  
Hazard Assessment ◽  
Test Site ◽  
Tsunami Hazard ◽  
Deterministic Approach ◽  
Flow Depth ◽  
Mean Sea Level ◽  
Tsunami Hazard Assessment ◽  
The Impact

Abstract. In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.

scholarly journals On Kaufmann's theory of the impact of the pianoforte hammer

1920 ◽  
Vol 97 (682) ◽  
pp. 99-110 ◽  
Keyword(s):  
Initial Conditions ◽  
Practical Importance ◽  
Prima Facie ◽  
Point Of View ◽  
Infinite Length ◽  
Modes Of Vibration ◽  
Rigorous Treatment ◽  
The Subject ◽  
Set Up ◽  
The Impact

The theory of the vibrations of the pianoforte string put forward by Kaufmann in a well-known paper has figured prominently in recent discussions on the acoustics of this instrument. It proceeds on lines radically different from those adopted by Helmholtz in his classical treatment of the subject. While recognising that the elasticity of the pianoforte hammer is not a negligible factor, Kaufmann set out to simplify the mathematical analysis by ignoring its effect altogether, and treating the hammer as a particle possessing only inertia without spring. The motion of the string following the impact of the hammer is found from the initial conditions and from the functional solutions of the equation of wave-propagation on the string. On this basis he gave a rigorous treatment of two cases: (1) a particle impinging on a stretched string of infinite length, and (2) a particle impinging on the centre of a finite string, neither of which cases is of much interest from an acoustical point of view. The case of practical importance treated by him is that in which a particle impinges on the string near one end. For this case, he gave only an approximate theory from which the duration of contact, the motion of the point struck, and the form of the vibration-curves for various points of the string could be found. There can be no doubt of the importance of Kaufmann’s work, and it naturally becomes necessary to extend and revise his theory in various directions. In several respects, the theory awaits fuller development, especially as regards the harmonic analysis of the modes of vibration set up by impact, and the detailed discussion of the influence of the elasticity of the hammer and of varying velocities of impact. Apart from these points, the question arises whether the approximate method used by Kaufmann is sufficiently accurate for practical purposes, and whether it may be regarded as applicable when, as in the pianoforte, the point struck is distant one-eighth or one-ninth of the length of the string from one end. Kaufmann’s treatment is practically based on the assumption that the part of the string between the end and the point struck remains straight as long as the hammer and string remain in contact. Primâ facie , it is clear that this assumption would introduce error when the part of the string under reference is an appreciable fraction of the whole. For the effect of the impact would obviously be to excite the vibrations of this portion of the string, which continue so long as the hammer is in contact, and would also influence the mode of vibration of the string as a whole when the hammer loses contact. A mathematical theory which is not subject to this error, and which is applicable for any position of the striking point, thus seems called for.

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