Experimental Study on Bearing Behavior of Long Rock Socked Pile with O-Cell Test Method

2014 ◽  
Vol 501-504 ◽  
pp. 137-140
Author(s):  
You Yuan Wang ◽  
Zhan Wang ◽  
Deng Feng Sang ◽  
Lin Wang Su
Keyword(s):  
Load Transfer ◽  
Test Method ◽  
Offshore Structure ◽  
Test Technique ◽  
Cell Method ◽  
Testing Method ◽  
Pile Testing ◽  
Cell Test ◽  
Bearing Behavior ◽  
Shaft Friction

The O-cell method which was applied on the pile testing was introduced, including the basic principle, test device and test technique. The advantages of O-cell method compared to traditional pile testing method were also illustrated. Based on the project of offshore structure in Mozambique, the O-cell test was performed on the long drilled rock socked pile. The results were converted to the traditional load-settlement curve to analyze the bearing behavior and load transfer characteristics. The regularity of axial force and shaft friction of rock socked pile were also revealed.

Experimental Study on O-Cell Test of Long Rock Socket Bored Pile

2013 ◽  
Vol 477-478 ◽  
pp. 509-513
Author(s):  
Li Zhang Yao ◽  
Deng Feng Sang ◽  
Lin Wang Su ◽  
De Yin Tan
Keyword(s):  
Load Transfer ◽  
Test Method ◽  
Load Testing ◽  
Offshore Structure ◽  
Test Device ◽  
Test Technique ◽  
Bored Pile ◽  
Cell Test ◽  
Bearing Behavior ◽  
Shaft Friction

The O-cell test method which was applied on the pile load testing was introduced, including the basic principle, test device and test technique. Based on the project of offshore structure in Malaysia, the O-cell test was performed on the long rock socket bored pile. The bearing behavior and load transfer characteristics were analyzed. The shaft friction in the rock played an important role in the pile shaft friction. In some long rock socket pile, The O-cell method cant test the ultimate capacity of some long rock socket pile.

scholarly journals In Situ Test Research on Friction Resistance of Self-Anchored Test Pile

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Chi Chen ◽  
Hailong Ma ◽  
Bilian Yang
Keyword(s):  
Transfer Process ◽  
Load Transfer ◽  
Test Method ◽  
Hyperbolic Function ◽  
Function Model ◽  
In Situ Test ◽  
Testing Method ◽  
Pile Testing ◽  
Test Pile

The traditional static load test method has been considered as the most direct and reliable method to determine the bearing capacity of single pile, but it has some disadvantages, such as inconvenient operation, laborious test, high cost, and being time-consuming. In this paper, a new type of pile testing method, self-anchored pile testing method, was proposed, and the in situ test was carried out for the first time. This method allows the upper and lower piles to provide force to each other and does not occupy other construction spaces. It had the advantages of simple operation and being economical and practical. Based on the Q-w curve, axial force distribution curve, and hyperbolic function model of load transfer, this paper studied the evolution law of friction of self-anchored test pile and the load transfer process of self-anchored test pile. The results show that the load transfer process of self-anchored pile-soil interface can be divided into three stages: elastic, elastic-plastic, and limit state. The friction of the upper and lower piles starts from the bottom of each pile and then gradually increases. The soil around the upper and lower piles gradually undergoes nonlinear deformation and shear failure, and the pile soil reaches the yield state. By analyzing the hyperbolic function model of load transfer, it shows that the hyperbolic function model can be better applied to the self-anchored test pile, which has reference value for the selection of the function model of self-anchored test pile in the future.

Comparison of the Bidirectional Load Test with the Top-Down Load Test

2005 ◽  
Vol 1936 (1) ◽  
pp. 108-116 ◽  
Author(s):  
Oh Sung Kwon ◽  
Yongkyu Choi ◽  
Ohkyun Kwon ◽  
Myoung Mo Kim
Keyword(s):  
Load Transfer ◽  
Measurement Data ◽  
Load Test ◽  
Load Testing ◽  
Pile Head ◽  
Top Down ◽  
Simple Method ◽  
Testing Method ◽  
Settlement Behavior ◽  
Cell Test

For the past decade, the Osterberg testing method (O-cell test) has been proved advantageous over the conventional pile load testing method in many aspects. However, because the O-cell test uses a loading mechanism entirely different from that of the conventional pile loading testing method, many investigators and practicing engineers have been concerned that the O-cell test would give inaccurate results, especially about the pile head settlement behavior. Therefore, a bidirectional load test using the Osterberg method and the conventional top-down load test were executed on 1.5-m diameter cast-in-place concrete piles at the same time and site. Strain gauges were placed on the piles. The two tests gave similar load transfer curves at various depth of piles. However, the top-down equivalent curve constructed from the bidirectional load test results predicted the pile head settlement under the pile design load to be approximately one half of that predicted by the conventional top-down load test. To improve the prediction accuracy of the top-down equivalent curve, a simple method that accounts for the pile compression was proposed. It was also shown that the strain gauge measurement data from the bidirectional load test could reproduce almost the same top-down curve.

Semiquantitative Test Method for Degradation Ratio of Vacuum Degree of Vacuum Glazing by Photoelastic Method

2016 ◽  
Vol 680 ◽  
pp. 44-47
Author(s):  
Xiao Gen Liu ◽  
Hai Feng Xu ◽  
Zhan Jing Wang ◽  
Yi Wang Bao
Keyword(s):  
Spot Size ◽  
Test Method ◽  
Photoelastic Method ◽  
Test Technique ◽  
Vacuum Degree ◽  
Degradation Ratio ◽  
Proportional Relationship ◽  
Vacuum Glazing ◽  
Bearing Behavior

Vacuum failure will lead to insulation function failure and increasing huge potential security problems for vacuum glazing, it is necessary to inspect the vacuum degree value of the vacuum glazing in service. In this work, the relationship between the bearing behavior and vacuum degree value of the vacuum glazing was studied by experiment, the experiment results show that the bearing behavior of vacuum glazing showed a greater than 50% reduction after the vacuum degree lose completely in vacuum cavity of the vacuum glazing. One test technique for degradation ratio of vacuum degree of vacuum glazing by photoelastic method was developed in this study. Through linear proportional relationship between support stress spot size and degradation ratio of vacuum degree observed via photoelastic method, vacuum degree completely disappear and stress spot size is 0. So, the ratio R(less than or equal to 1) represent the relative differential pressure between the support stress spot size tested in-situ and the support stress spot size measured in vacuum degree intact environment. The degradation ratio of vacuum degree is (1-R) %. Obtaining qualitative or semi-quantitative assessment of vacuum degree degradation ratio of vacuum glazing through observe support stress spot size with photoelastic apparatus.

A Single Specimen CTOA Test Method for Evaluating the Crack Tip Opening Angle in Gas Pipeline Steels

2004 ◽  
Author(s):  
Sayyed H. Hashemi ◽  
Ian C. Howard ◽  
John R. Yates ◽  
Robert M. Andrews ◽  
Alan M. Edwards
Keyword(s):  
Steady State ◽  
Crack Growth ◽  
Crack Tip ◽  
Gas Pipeline ◽  
Test Method ◽  
Opening Angle ◽  
Single Specimen ◽  
Data Set ◽  
Test Technique ◽  
Pipeline Steels

Failure information from recent full-scale burst experiments on modern TMCP gas pipeline steels having a yield strength level of 690MPa and higher has shown that the CTOA fracture criterion can be effectively used to predict the arrest/propagation behaviour of the pipe against possible axial ductile fractures. The use of CTOA as an alternative or an addition to the Charpy V-notch and DWTT fracture energy in pipelines is currently under review. A significant difficulty currently limiting the more extensive use of CTOA in pipeline assessment is its practical evaluation either in the real structure or in a laboratory scale test. Different combinations of experimental and finite element analyses have been proposed for the measurement of the CTOA of a material. Although most of these models are able to predict the CTOA effectively, their implementation requires extensive calibration processes using the test load-deflection data. The authors have recently developed a novel test technique for direct measurement of the steady state CTOA using a modified double cantilever beam geometry. The technique uses optical imaging to register the uniform deformation of a fine square grid scored on the sides of the specimen. The slope of the deformed gridlines near the crack tip is measured during crack growth from captured images. Its value is a representative of the material CTOA. This paper presents recent results from the implementation of the technique to determine the steady state CTOA (steady state in this work refers to regions of ductile crack growth where CTOA values are constant and independent of crack length) of API X80 and X100 grade gas pipeline steels. In each case the approach was able to produce large amounts of highly consistent CTOA data from both sides of the test sample even from a single specimen. This extensive data set allowed an evaluation of the variance of the stable CTOA as the crack grew through the microstructure. The test method generated a steady CTOA value of 11.1° for X80 and 8.5° for X100 steels tested, respectively.

The importance of aerodynamics for prosthetic limb design used by competitive cyclists with an amputation: An introduction

2014 ◽  
Vol 39 (3) ◽  
pp. 232-237 ◽  
Author(s):  
Bryce Dyer
Keyword(s):  
Field Test ◽  
Aerodynamic Drag ◽  
Field Tests ◽  
Field Testing ◽  
Test Method ◽  
Limb Amputation ◽  
Small Scale ◽  
Prosthetic Limb ◽  
Testing Method ◽  
Competitive Cyclists

Background/Objectives: This study introduces the importance of the aerodynamics to prosthetic limb design for athletes with either a lower-limb or upper-limb amputation. Study design: The study comprises two elements: 1) An initial experiment investigating the stability of outdoor velodrome-based field tests, and 2) An experiment evaluating the application of outdoor velodrome aerodynamic field tests to detect small-scale changes in aerodynamic drag respective of prosthetic limb componentry changes. Methods: An outdoor field-testing method is used to detect small and repeatable changes in the aerodynamic drag of an able-bodied cyclist. These changes were made at levels typical of alterations in prosthetic componentry. The field-based test method of assessment is used at a smaller level of resolution than previously reported. Results: With a carefully applied protocol, the field test method proved to be statistically stable. The results of the field test experiments demonstrate a noticeable change in overall athlete performance. Aerodynamic refinement of artificial limbs is worthwhile for athletes looking to maximise their competitive performance. Conclusion: A field-testing method illustrates the importance of the aerodynamic optimisation of prosthetic limb components. The field-testing protocol undertaken in this study gives an accessible and affordable means of doing so by prosthetists and sports engineers. Clinical relevance Using simple and accessible field-testing methods, this exploratory experiment demonstrates how small changes to riders’ equipment, consummate of the scale of a small change in prosthetics componentry, can affect the performance of an athlete. Prosthetists should consider such opportunities for performance enhancement when possible.

Test Method for Electronic Device on Condition of Small Sampling

2013 ◽  
Vol 347-350 ◽  
pp. 525-528
Author(s):  
Ze Cheng ◽  
Zhao Long Xuan ◽  
Wei Wang ◽  
Mao Sen Hao
Keyword(s):  
Experimental Data ◽  
Quality Assessment ◽  
Prior Information ◽  
Electronic Device ◽  
Electronic Devices ◽  
Test Sample ◽  
Test Method ◽  
Bayes Method ◽  
Testing Method ◽  
Quality Testing

The traditional quality testing method does not apply for the new electronic device which have characters that high-value and small-count, take advantage of the small sampling theory, we can reduce the number of test sample significantly by using the Bayes method. In the processing of the experimental data, we can improve the accuracy of the quality assessment of electronic devices by using of the Bayes method and make full use the prior information.

scholarly journals Load Transfer of Offshore Open-Ended Pipe Piles Considering the Effect of Soil Plugging

2019 ◽  
Vol 7 (9) ◽  
pp. 313 ◽  
Author(s):  
Liu ◽  
Guo ◽  
Han
Keyword(s):  
Load Transfer ◽  
Earth Pressure ◽  
Offshore Structures ◽  
Rigid Plastic ◽  
Soil Plug ◽  
Centrifuge Testing ◽  
Trilinear Model ◽  
Method Model ◽  
Transfer Properties ◽  
Shaft Friction

Open-ended pipe piles have been increasingly used as the foundations for offshore structures. Considering the soil plugging effect, a novel analytical model is proposed in this paper to study the load transfer mechanism of open-ended pipe piles. A trilinear model for the external shaft friction was introduced, while a rigid plastic model was adopted to describe the load transfer at the pile-plug interface. Furthermore, an equilibrium equation of the soil plug was proposed, based on the hypothesis of a trilinear distribution of lateral earth pressure. The pile end resistance was analyzed by dividing it into two parts, i.e., the soil plug and pile annulus, the behaviors of which were described by the double broken line model. A calculation example was carried out to analyze the load transfer properties of the open-ended pipe piles. As a validation, similar load transfer processes of the open-ended pile were also captured in a newly built discrete element method model, mimicking the 100g centrifuge testing conditions.

High-Temperature Interlaminar Tension Test Method Development for Ceramic Matrix Composites

2013 ◽  
Author(s):  
Todd Engel
Keyword(s):  
High Temperature ◽  
Method Development ◽  
Standardized Test ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Test Method ◽  
Test Technique ◽  
Structural Applications

Ceramic Matrix Composite (CMC) materials are an attractive design option for various high-temperature structural applications. In particular, the use of CMC materials as a replacement for state-of-the-art nickel-based superalloys in hot gas path turbomachinery components offers the potential for significant increases in turbine system efficiencies, due largely to reductions in cooling requirements afforded by the increased temperature capabilities inherent to the ceramic material. However, two-dimensional fabric-laminated CMCs typically exhibit low tensile strengths in the thru-thickness (interlaminar) direction, and interply delamination is a concern for some targeted applications. Currently, standardized test methods only address the characterization of interlaminar tensile strengths at ambient temperatures; this is problematic given that nearly all CMCs are slated for service in high-temperature operating environments. This work addresses the development of a new test technique for the high-temperature measurement of interlaminar tensile properties in CMCs, allowing for the characterization of material properties under conditions more analogous to anticipated service environments in order to yield more robust component designs.

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