scholarly journals Static pile capacity from the rapid test via the unloading-point method

2021 ◽  
Vol 63 (2) ◽  
Author(s):  
I Luker
Keyword(s):  
Rapid Test ◽  
Liquid Limit ◽  
Point Method ◽  
Load Test ◽  
Shear Stresses ◽  
Test Results ◽  
Pile Capacity ◽  
Static Test ◽  
Rapid Tests ◽  
Load Tests

ABSTRACT Laboratory measurements were done of the end-bearing and side-shear stresses on small piles subjected to "static" and rapid load tests. Interpretation, by the unloading-point method, of the results of rapid tests were done to estimate what the behaviour under a static test would have been if it had been done instead. Comparisons were made of the estimated static test behaviour to the actual static test behaviour to determine empirical values of a factor to adjust estimates closer to actual static test results. The dependence of the empirical factor on soil type, the liquid limit of plastic soils and water content is shown. Keywords: piles, load test, clays, dynamics, empiricism

Driven cast-in-situ pile capacity: insights from dynamic and static load testing

2021 ◽  
Author(s):  
Kevin N. Flynn ◽  
Bryan A. McCabe
Keyword(s):  
Dynamic Load ◽  
Shear Stresses ◽  
Load Testing ◽  
Pile Capacity ◽  
Compression Load ◽  
Shaft Resistance ◽  
Pile Installation ◽  
Cast Concrete ◽  
Load Tests

Driven cast-in-situ (DCIS) piles are classified as large displacement piles. However, the use of an oversized driving shoe introduces additional complexities influencing shaft resistance mobilisation, over and above those applicable to preformed displacement piles. Therefore, several design codes restrict the magnitude of shaft resistance in DCIS pile design. In this paper, a series of dynamic load tests was performed on the temporary steel driving tubes during DCIS pile installation at three UK sites. The instrumented piles were subsequently subjected to maintained compression load tests to failure. The mobilised shear stresses inferred from the dynamic tests during driving were two to five times smaller than those on the as-constructed piles during maintained load testing. This was attributed to soil loosening along the tube shaft arising from the oversized base shoe. Nevertheless, the radial stress reductions appear to be reversible by the freshly-cast concrete fluid pressures which provide lower-bound estimates of radial total stress inferred from the measured shear stresses during static loading. This recovery in shaft resistance is not recognised in some European design practices, resulting in conservative design lengths. Whilst the shaft resistance of DCIS piles was underpredicted by the dynamic load tests, reasonable estimates of base resistance were obtained.

Predicting the Ultimate Bearing Capacity of Single Piles Based on CPTU

2011 ◽  
Vol 243-249 ◽  
pp. 4402-4407
Author(s):  
Yong Hong Miao ◽  
Guo Jun Cai ◽  
Song Yu Liu
Keyword(s):  
Load Test ◽  
Load Testing ◽  
Pile Capacity ◽  
Piezocone Penetration Test ◽  
Load Carrying ◽  
Load Tests ◽  
Pile Load Test ◽  
Single Piles ◽  
Pile Load Tests ◽  
Best Fit

Six methods to determine axial pile capacity directly based on piezocone penetration test (CPTU) data are presented and evaluated. Analyses and evaluation were conducted on three types piles that were failed during pile load testing. The CPT methods, as well as the CPTU methods, were used to estimate the load carrying capacities of the investigated piles (Qp ). Pile load test were used to determine the measured load carrying capacities (Qm). The pile capacities determined using the different methods were compared with the measured pile capacities obtained from the pile load tests. Two criteria were selected as bases of evaluation: the best fit line for Qp versus Qm and the arithmetic mean and standard deviation for the ratio Qp /Qm. Results of the analyses showed that the best methods for determining pile capacity are the CPTU methods.

scholarly journals Numerical and Experimental UAV Structure Investigation by Pre-Flight Load Test

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3014 ◽  
Author(s):  
Artur Kurnyta ◽  
Wojciech Zielinski ◽  
Piotr Reymer ◽  
Krzysztof Dragan ◽  
Michal Dziendzikowski
Keyword(s):  
Computer Aided Design ◽  
Flight Test ◽  
Load Test ◽  
Load Spectrum ◽  
Static Test ◽  
Multi Stage ◽  
Post Test ◽  
Cad Modelling ◽  
Ground Test ◽  
Load Tests

This paper presents the preparation and execution of on-ground static and engine load tests for the composite unmanned aerial vehicle (UAV). The test was conducted for pre-flight structural strength verification of the remotely piloted aerial target named HORNET, after introducing some structural modifications. The ground tests were performed before the flight test campaign, to ensure the strength and operational safety of the modified structure. The panel method and Computer Aided Design (CAD) modelling were adopted for numerical evaluation of aerodynamic and inertial forces’ distribution to simulate loading scenarios for launch, flight and parachute deploying conditions during the static test. Then, the multi-stage airframe static test was prepared and executed with the use of a designed modular test rig, artificial masses, as well as a wireless strain measurement system to perform structure verification. The UAV was investigated with 150% of the typical load spectrum. Furthermore, an engine test was also conducted on a ground test stand to verify strain and vibration levels in correspondence to engine speed, as well as the reliability of data link and the lack of its interferences with wireless control and telemetry. In the article, data achieved from the numerical and experimental parts of the test are discussed, as well as post-test remarks are given.

scholarly journals Static and Dynamic Load Tests of Shaft and Base Grouted Concrete Piles

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Jialin Zhou ◽  
Xin Zhang ◽  
Hongsheng Jiang ◽  
Chunhao Lyu ◽  
Erwin Oh
Keyword(s):  
Dynamic Load ◽  
Static Load ◽  
Test Results ◽  
Pile Capacity ◽  
Friction Resistance ◽  
Concrete Piles ◽  
Double Tangent ◽  
Load Tests ◽  
Bored Piles ◽  
Comparison Of The Results

This paper examines shaft and base grouted concrete piles by conducting vertical static load tests (SLTs) and dynamic load tests. Three concrete piles with shaft and base grouting, with base grouting only, and without grouting techniques were selected, and compressive SLTs were conducted. Two piles with grouting were also assessed with dynamic load tests. Another two uplift SLTs were conducted to one shaft and base grouted pile and one pile without grouting. Traditional presentations were provided to check whether the bored piles reached the design requirement. Interpretations of test results were also provided to determine the ultimate pile capacity. Results from these 5 SLT programs indicated that double-tangent and DeBeer's methods are close to each other, and Chin's method overestimates the pile capacity. Comparison of the results from the SLTs and dynamic load tests shows that the results from Chin's method are close to dynamic results, and Mazurkiewicz's method overestimates for friction resistance. The results also demonstrate that base and shaft grouted pile and base grouted pile increase by 9.82% and 2.89% in compressive capacity, respectively, and compared to the uplift SLTs; there is a 15.7% increment in pile capacity after using base and shaft grouting technology.

The Effect of Specimen's Height on the Point Load Test

2013 ◽  
Vol 848 ◽  
pp. 108-111 ◽  
Author(s):  
Jin Kui Li ◽  
Fei Fei Li ◽  
Xian Ke Wei
Keyword(s):  
Point Load ◽  
Load Test ◽  
Test Results ◽  
Strength Index ◽  
Underground Engineering ◽  
Point Load Strength ◽  
Size And Shape ◽  
Point Load Test ◽  
Specimen Height ◽  
Load Tests

In order to use different size of the rock in the site point load tests, select the same site at the scene of specimen do load test research. Through the statistical analysis of 9 groups of the point load strength index data, demonstrates the influence of the test specimen size and shape sample size and shape to rock point load test results, and draws the influence rule of the specimen height to the point load test. The research has the vital significance for underground engineering design and construction.

scholarly journals Large-diameter helical pile capacity – torque correlations

2017 ◽  
Vol 54 (7) ◽  
pp. 968-986 ◽  
Author(s):  
Jared Harnish ◽  
M. Hesham El Naggar
Keyword(s):  
Large Diameter ◽  
Failure Criteria ◽  
Load Test ◽  
Ultimate Capacity ◽  
Pile Capacity ◽  
Shearing Resistance ◽  
Helical Piles ◽  
Torque Capacity ◽  
Load Tests ◽  
Pile Load Tests

Large-diameter helical piles are utilized increasingly to support heavy structures. Both the magnitude of the required installation torque and the pile capacity can be directly attributed to the soil shearing resistance developed over the embedded area of the pile including the shaft and helical plates. Hence, the pile capacity can be correlated to installation torque. Such correlations are widely used in the helical pile industry as a means for quality control and quality assurance. In the current study, a total of 10 test piles were installed while monitoring the installation torque continuously with depth. The recorded installation torque profiles were demonstrated to be accurate and repeatable. Field pile load tests were conducted and their results were analyzed to determine the interpreted ultimate capacity of the test piles. The results demonstrate that the ultimate capacity of large-diameter helical piles can be interpreted from pile load test data employing the failure criteria proposed by Elkasabgy and El Naggar in 2015 and Fuller and Hoy in 1970. The measured installation torque and corresponding ultimate capacity values were employed to define torque–capacity correlation (Kt) based on embedded pile area. It was demonstrated that the proposed Kt is suitable for large-diameter helical piles.

scholarly journals ANALYSIS OF STATIC AND DYNAMIC DEFORMATION MODULUS

2016 ◽  
Vol 8 (2) ◽  
pp. 79-84 ◽  
Author(s):  
Mindaugas Mikolainis ◽  
Marijus Ustinovičius ◽  
Danutė Sližytė ◽  
Tatyana Zhilkina
Keyword(s):  
Soil Compaction ◽  
Dynamic Deformation ◽  
Deformation Modulus ◽  
Load Test ◽  
Test Results ◽  
Plate Load Test ◽  
Test Execution ◽  
Load Tests ◽  
Different Depths ◽  
Result Interpretation

This article summarises dynamic deformation modulus correlation with second reload of static plate load test results for an even thickness soil strata layer. An analysis of execution and result interpretation of both static deformation modulus and dynamic deformation modulus is provided also. Different correlations between the two modulus according to different authors are provided. Since dynamic plate load test is not regulated in Lithuania as a soil compaction contron method, a few dynamic plate load tests and static plate load tests were executed in order to compare compaction results. The additional experiments for dynamic plate load tests in different depths were executed which showed that deformation modulus is dependant on depth of test execution, thus it is worthwile to mention to be cautious on compaction results in trenches.

scholarly journals Within-site variability and reliability of foundation designs based on load tests

2019 ◽  
Author(s):  
◽  
Andrew Z. Boeckmann
Keyword(s):  
Load Test ◽  
Test Results ◽  
Considerable Variability ◽  
Specific Load ◽  
Primary Input ◽  
Bayesian Techniques ◽  
Test Information ◽  
Load Tests ◽  
A Site ◽  
Site Variability

Probabilistic evaluations of the reliability of foundation designs based on site-specific load test information are somewhat limited in number. Published evaluations have generally relied on Bayesian techniques. A primary input for Bayesian analysis is within-site variability, which describes the variability of foundation resistance across a site. Within-site variability is attributed to geologic variation across a site and to differences in construction outcomes among foundation elements. Published evaluations have generally used a deterministic value of within-site variability wherein within-site variability is treated as a known parameter and is not subject to updating based on load test results. In contrast, probabilistic within-site variability treats within-site variability as an uncertain parameter with its own probability distribution that is updated based on load test results. Probabilistic within-site variability has not been applied commonly. This research examines differences in reliability outcomes between deterministic and probabilistic within-site variability. Analysis of micropile load test results from five different sites was used to develop a distribution of within-site variability. The resulting distribution is relatively variable (i.e. the value of within-site variability is, itself, variable), which demonstrates that there is, in fact, considerable variability and uncertainty in the value of within-site variability.

scholarly journals Rapid Tests for the Diagnosis of Viral Infections

2021 ◽  
Vol 96 (5) ◽  
pp. 415-420
Author(s):  
Hyun Soo Kim
Keyword(s):  
Nucleic Acid ◽  
Diagnostic Tests ◽  
Viral Infections ◽  
Rapid Test ◽  
Test Results ◽  
Test Items ◽  
Rapid Tests ◽  
Antigen Tests ◽  
Antibody Tests ◽  
Rapid Antibody

Rapid and accurate diagnostic tests for viral infections are essential for diagnosis, treatment, and patient isolation. Various rapid nucleic acid tests, rapid antigen tests, and rapid antibody tests have been developed and used to diagnose viral infections. In this paper, the types and characteristics of various rapid viral tests currently used in Korea, test items, and considerations when interpreting rapid test results are described.

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