Field experiments for slope stability of embankment reinforced by small-diameter steel pipes with blades

Austenitic stainless steels are widely used in the key components of major equipment and the welds can be the weakest parts of equipment made with these materials. Ultrasonic waves propagate in austenitic stainless steel welds with multiple paths and modes. This study employed a multi-view total focusing method using an ultrasonic phased array for defect detection in the welds of small-diameter austenitic stainless steel pipes. The detection capability of four different direct wave modes and eight different half-skip wave modes for typical defects were compared and analysed through numerical simulation. A fusion imaging method was developed using the preferred direct and half-skip wave modes. The process was further verified with a weld defect detection experiment carried out on small-diameter austenitic stainless steel pipes. The results show that the multi-view total focusing method can efficiently detect the defects in the welds of small-diameter tubes. Compared with the single-mode imaging method, the fusion total focusing imaging approach can not only improve the signal-to-noise ratio but can also reduce the number of image artefacts.

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Experimental Study of Replacement the Tension Reinforcing Bars in Concrete Beams by Steel Pipes

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.20.25931 ◽

2018 ◽

Vol 7 (4.20) ◽

pp. 229

Author(s):

Labeeb Saadoon Al-Yassri ◽

Alaa Mahdi Al-Khekany ◽

Hajer Satea Abbas

Keyword(s):

Reinforced Concrete ◽

Construction Projects ◽

Concrete Beams ◽

Small Diameter ◽

Reinforced Concrete Beams ◽

Steel Pipe ◽

Steel Pipes ◽

Steel Bar ◽

Steel Bars ◽

The Difference

Structures designed with reinforced concrete beams are used extensively in construction projects because of their functional and economic features. In this research, tested concrete beams were cast and reinforced with small diameter steel pipes and /or steel bars as flexural reinforcement to study the effect of this configuration of reinforcement on the structural behavior of reinforced concrete beams. The idea of this research involves performing and testing of four reinforced concrete beams reinforced by small diameter steel pipes with different percentages of replacement with traditional steel bars (0%, 33%, 66% and 100%). The experimental results showed that using of steel pipes reduces the flexural capacity by (2.7, 18.3, 37.5%) if compared with traditional steel bar according to the replacement percentages of (33%, 66%, and 100%) respectively. Moreover, the stiffness of beams reinforced with steel pipes (fully or partially) decreased as a result of the difference in the mechanical properties between steel bar and the steel pipe and also, the bond strength reduction between the smooth steel pipe and surrounded concrete.

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Automatic Ultrasonic Testing System Designed For Small-Diameter Steel Pipes With Thick Wall

International Journal of Control and Automation ◽

10.14257/ijca.2017.10.1.27 ◽

2017 ◽

Vol 10 (1) ◽

pp. 301-314

Author(s):

Qi Zhang ◽

Li Hou ◽

Rui Tang

Keyword(s):

Ultrasonic Testing ◽

Small Diameter ◽

Thick Wall ◽

Testing System ◽

Steel Pipes

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IN-SEWER OXYGENATION OF WASTEWATER USING VENTURI SIDE-STREAM DISSOLVERS

Water Science & Technology ◽

10.2166/wst.1994.0020 ◽

1994 ◽

Vol 30 (1) ◽

pp. 185-194 ◽

Cited By ~ 2

Author(s):

G. A. Holder ◽

J. M. Leow

Keyword(s):

Field Experiments ◽

Operating Cost ◽

Small Diameter ◽

Oxygen Adsorption ◽

Absorption Efficiency ◽

Operating Conditions ◽

High Mass ◽

Oxygen Injection ◽

Power Cost ◽

Mixing Energy

The objective of the studies was to improve the efficiencies of venturi-nozzle oxygen-injection facilities installed for in-situ sewer oxygenation as part of an odour control strategy. A procedure which can be utilised to estimate cost-effective operation for oxygen injection at a given site is outlined. The procedure requires the experimental determination of oxygen-adsorption efficiency / nozzle-pres sure-loss plots for the range of operating conditions. Results from both laboratory and field experiments, together with theoretical studies are reported. The total operating cost for an installation consists of the oxygen cost plus the pumping power cost. As could be anticipated, there is a trade-off between oxygen costs and mixing energy efficiency. The total operating cost can be minimised by operating at high mass transfer efficiency. In these situations oxygen wastage is low. However this can only be accomplished when the system is supplied with adequate mixing energy. The studies showed that the best way to reduce the existing oxygen wastage problems was to operate at maximum absorption efficiency with a relatively small diameter nozzle (provided that precautions are taken to avoid nozzle plugging problems) and adequate nozzle pressure loss.

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Noise Reduction Using Wavelet Transform in Ultrasonic Flaw Detection of Small-Diameter Steel Pipe with Thick Wall

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.4755 ◽

2011 ◽

Vol 383-390 ◽

pp. 4755-4761

Author(s):

Shao Jiang Wang ◽

Li Hou ◽

Yu Lin Wang ◽

Jian Quan Zhang

Keyword(s):

Wavelet Transform ◽

Noise Reduction ◽

Flaw Detection ◽

Small Diameter ◽

Internal Noise ◽

Thick Wall ◽

Band Pass Filter ◽

Pass Filter ◽

Ultrasonic Signals ◽

Steel Pipes

In order to ensure that small diameter steel pipes with thick wall have high intensity and high quality, ultrasonic immersion method with focusing probe was used to detect the flaw of the small-diameter steel pipes with thick wall. In practice, the echoes are often corrupted with external noise or internal noise, therefore, it is necessary to reduce the noise and to enhance the SNR of ultrasonic signals. A technique for improving the SNR of ultrasonic signals using wavelet transform is presented. In this method, WT, consider as one band-pass filter, is used to remove the noises. The performance of this technique has been verified by experimental, which is done by using a series of flaw ultrasonic echoes obtained from a specimen of the small-diameter steel pipes with thick wall. In particular we have found the processing of the ultrasonic signals using wavelet transform extremely useful for noise reduction. After processing, the SNR of ultrasonic signals are enhanced substantially. All experimental results show that this technique is effective for removing the white noise from the ultrasonic signals.

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Fatigue Design Criteria for Small Super Duplex Steel Pipes

23rd International Conference on Offshore Mechanics and Arctic Engineering, Volume 2 ◽

10.1115/omae2004-51619 ◽

2004 ◽

Author(s):

Steinar Kristoffersen ◽

Per J. Haagensen

Keyword(s):

Stainless Steel ◽

Wall Thickness ◽

Large Diameter ◽

Small Diameter ◽

High Strength ◽

Gas Production ◽

Steel Pipes ◽

Fatigue Design ◽

Duplex Steel ◽

Design Guidance

Stainless steel pipes ranging in sizes from approximately 10 to 100 mm OD are used extensively in umbilicals for the control and monitoring of underwater installations for oil and gas production. Umbilicals are subjected to tensile loads as well as variable amplitude loading from wave and current actions. Fatigue is therefore a critical issue in the design of umbilical components. Sea water resistant high strength super duplex steel with ultimate strength of typically 800 to 900 MPa is used to save weight and reduce the wall thickness. Some umbilicals installed by Statoil have design pressure up to 1035 bar, which in combination with large dynamic loads from floating production units makes fatigue design of the umbilicals a challenging issue. While the fatigue performance of butt welded pipes for pipelines and risers are established and implemented in design guidance and codes, the experimental basis for design of small diameter piping made of high strength materials is not well documented in the open literature. However, unpublished data from in-house investigations indicate that small pipes in super duplex steel perform significantly better than larger diameter pipes in lower strength materials. It is therefore apparently scope for a “thinness effect”, i.e. a bonus effect that could be applied to the data for large diameter pipes in current codes to account for the higher S-N curves for small stainless steel pipes. This paper reviews some of the fatigue data for piping and compares these data with experimental evidence from a joint industry project. Tentative fatigue design guidance for small diameter super duplex steel piping is presented. Questions concerning special issues such as the possible influence of wall thickness, mean stress and pre-straining due to reeling are discussed.

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