Sonic echo and impulse response tests for length evaluation of soil nails in various bonding mediums

2008 ◽  
Vol 45 (7) ◽  
pp. 1025-1035 ◽  
Author(s):  
Shu-Tao Liao ◽  
Chin-Kuo Huang ◽  
Chung-Yue Wang
Keyword(s):  
Nondestructive Testing ◽  
Impulse Response ◽  
Field Tests ◽  
Drilled Shafts ◽  
Driven Piles ◽  
Soil Nails ◽  
Soil Nail ◽  
Testing Techniques ◽  
Nondestructive Testing Methods

The objective of this paper is to present the results of research for evaluating the installed lengths of soil nails with nondestructive testing methods. Two closely related methods, the sonic echo test and the impulse response test, both of which had been widely applied to assess the integrity of drilled shafts and driven piles, were evaluated to test their capabilities on soil nails. To carry out this study, soil nails of various lengths were embedded in different surrounding materials in the laboratory and then tested with both methods to predict their lengths. The surrounding materials studied in this research included soil and cement grout. Finally, field tests for in situ soil nails were carried out. The results indicated that the relative stiffness of the soil nail to the bond material plays a very important role in the success of testing. It is hoped that through this kind of study, the capability and limitation of using these nondestructive testing techniques to determine the installed lengths or to evaluate the bonding conditions of soil nails can be better understood.

Influence of soil nail orientations on stabilizing mechanisms of loose fill slopes

2013 ◽  
Vol 50 (12) ◽  
pp. 1236-1249 ◽  
Author(s):  
C.Y. Cheuk ◽  
K.K.S. Ho ◽  
A.Y.T. Lam
Keyword(s):  
Earth Pressure ◽  
Slope Movement ◽  
Numerical Analyses ◽  
Soil Nails ◽  
Soil Nail ◽  
Static Liquefaction ◽  
Liquefaction Failure ◽  
Loose Fill ◽  
Typical Design

Soil nailing has been used to upgrade substandard loose fill slopes in Hong Kong. Due to the possibility of static liquefaction failure, a typical design arrangement comprises a structural slope facing anchored by a grid of soil nails bonded into the in situ ground. Numerical analyses have been conducted to examine the influence of soil nail orientations on the behaviour of the ground nail–facing system. The results suggest that the use of steeply inclined nails throughout the entire slope could avoid global instability, but could lead to significant slope movement especially when sliding failure prevails, for instance, due to interface liquefaction. The numerical analyses also demonstrate that if only subhorizontal nails are used, the earth pressure exerted on the slope facing may cause uplift failure of the slope cover. To overcome the shortcomings of using soil nails at a single orientation, a hybrid nail arrangement comprising nails at two different orientations is proposed. The numerical analyses illustrate that the hybrid nail arrangement would limit slope movement and enhance the robustness of the system.

scholarly journals Investigation of Nondestructive Testing Methods for Friction Stir Welding

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 624 ◽  
Author(s):  
Hossein Taheri ◽  
Margaret Kilpatrick ◽  
Matthew Norvalls ◽  
Warren J. Harper ◽  
Lucas W. Koester ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Nondestructive Testing ◽  
Dissimilar Materials ◽  
Ex Situ ◽  
Testing Methods ◽  
Friction Stir ◽  
Weld Properties ◽  
Unique Approach ◽  
Nondestructive Testing Methods

Friction stir welding is a method of materials processing that enables the joining of similar and dissimilar materials. The process, as originally designed by The Welding Institute (TWI), provides a unique approach to manufacturing—where materials can be joined in many designs and still retain mechanical properties that are similar to, or greater than, other forms of welding. This process is not free of defects that can alter, limit, and occasionally render the resulting weld unusable. Most common amongst these defects are kissing bonds, wormholes and cracks that are often hidden from visual inspection. To identify these defects, various nondestructive testing methods are being used. This paper presents background to the process of friction stir welding and identifies major process parameters that affect the weld properties, the origin, and types of defects that can occur, and potential nondestructive methods for ex-situ detection and in-situ identification of these potential defects, which can then allow for corrective action to be taken.

scholarly journals Using the impulse response technique to estimate the length of in-situ soil nails

2003 ◽  
Author(s):  
Tareq Salloum
Keyword(s):  
Impulse Response ◽  
Soil Nails

Model Uncertainties in Foundation Design

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Naresh Samtani ◽  
Keyword(s):  
Drilled Shafts ◽  
Driven Piles ◽  
Mechanically Stabilized Earth ◽  
Model Uncertainties ◽  
Foundation Design ◽  
Soil Nail ◽  
Mse Walls ◽  
Braced Excavations ◽  
Helical Piles ◽  
Mechanically Stabilized

The book focuses on providing a foundation designer information on the model factor and its statistics for conventional foundation types such as shallow foundations, driven piles, and drilled shafts as well as special foundations such as spudcans and helical piles. Besides foundations, the book also provides information for other geostructures such as mechanically stabilized earth (MSE) walls, soil nail walls, pipes and anchors, slopes, and braced excavations.

Influence of Soil Dilatancy on Soil Nail Pull-Out Resistance in Completely Decomposed Granite Fill

2007 ◽  
Vol 340-341 ◽  
pp. 1237-1242
Author(s):  
Li Jun Su ◽  
Jian Hua Yin ◽  
Hong Jian Liao
Keyword(s):  
Field Tests ◽  
Soil Mass ◽  
Soil Nails ◽  
Soil Nail ◽  
Pull Out ◽  
Parametric Studies ◽  
Decomposed Granite ◽  
The Stability ◽  
Completely Decomposed Granite ◽  
Soil Dilatancy

Soil nailing, developed from the New Austrian Tunnelling Method, has been widely used in many countries and regions in the world since the 1970’s. This technique is used to stabilize in situ soil mass by installing a large number of closely spaced unstressed inclusions into the soil mass to increase its strength and stability. Since the mid 1970’s, several design methods have been proposed based on laboratory and field tests. Among the design criteria in these methods, the pull-out resistance of a soil nail is a key parameter that controls the stability assessment of soil nail structure. In the previous investigations, the soil dilatancy was found to be an important factor that influences the soil nail pull-out resistance especially for drill-and-grout soil nails. In order to study the influence of soil dilatancy on soil nail pull-out resistance, laboratory pull-out tests and numerical parametric studies have been carried out for soil nails in Completely Decomposed Granite (CDG) fill. The results show that the soil dilatancy has a significant influence on the soil nail pull-out resistance.

Experimental study on the pullout resistance of pressure-grouted soil nails in the field

2013 ◽  
Vol 50 (7) ◽  
pp. 693-704 ◽  
Author(s):  
Cheng-Yu Hong ◽  
Jian-Hua Yin ◽  
Hua-Fu Pei ◽  
Wan-Huan Zhou
Keyword(s):  
Water Content ◽  
Field Tests ◽  
Soil Samples ◽  
Soil Nails ◽  
Pullout Resistance ◽  
Soil Nail ◽  
Grouting Pressure ◽  
Overburden Stress ◽  
Drill Holes ◽  
Surrounding Soil

The pullout behaviour of cement-grouted soil nails, particularly in field conditions, is not yet fully understood. In this study, a series of tests was conducted to evaluate the pullout response of grouted soil nails in a field slope. A new innovative grouting packer system was developed to control the grouted length and maintain the cement grout pressure of the grouted part. By using the grouting packer system, a total of 10 soil nails placed at different soil depths were grouted with different pressures in the field. The pullout results of present field tests and a number of past laboratory tests indicate that the apparent coefficient of friction (ACF) decreases with the increase of overburden stress even though grouting pressure is applied. In addition, when the overburden stress is unchanged, the obtained ACF values in the field tests appear to increase almost linearly with the increase of grouting pressure. After the soil nails were completely pulled out of the ground, the surfaces of the soil nails and surrounding soil were examined. It is found that the water content of the soil samples at the soil–nail interfaces decrease substantially compared to the water content of soil samples in drill holes. Measurement results also show that the failure surfaces of soil nails shifted about 16 mm on average into the surrounding soil due to the application of grouting pressure.

scholarly journals Underwater Holographic Sensor for Plankton Studies In Situ Including Accompanying Measurements

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4863
Author(s):  
Victor Dyomin ◽  
Alexandra Davydova ◽  
Igor Polovtsev ◽  
Alexey Olshukov ◽  
Nikolay Kirillov ◽  
...  
Keyword(s):  
World Ocean ◽  
Field Tests ◽  
Field Measurements ◽  
Measuring Systems ◽  
Water Turbidity ◽  
Background Data ◽  
Average Size ◽  
Size Dispersion

The paper presents an underwater holographic sensor to study marine particles—a miniDHC digital holographic camera, which may be used as part of a hydrobiological probe for accompanying (background) measurements. The results of field measurements of plankton are given and interpreted, their verification is performed. Errors of measurements and classification of plankton particles are estimated. MiniDHC allows measurement of the following set of background data, which is confirmed by field tests: plankton concentration, average size and size dispersion of individuals, particle size distribution, including on major taxa, as well as water turbidity and suspension statistics. Version of constructing measuring systems based on modern carriers of operational oceanography for the purpose of ecological diagnostics of the world ocean using autochthonous plankton are discussed. The results of field measurements of plankton using miniDHC as part of a hydrobiological probe are presented and interpreted, and their verification is carried out. The results of comparing the data on the concentration of individual taxa obtained using miniDHC with the data obtained by the traditional method using plankton catching with a net showed a difference of no more than 23%. The article also contains recommendations for expanding the potential of miniDHC, its purpose indicators, and improving metrological characteristics.

Track Record of Nondestructive Testing Methods Applied to Steel Plate Quality Indexes at Magnitogorsk Iron and Steel Company

Metallurgist ◽  
2021 ◽  
Vol 64 (11-12) ◽  
pp. 1234-1238
Author(s):  
P. V. Shilyaev ◽  
V. L. Kornilov ◽  
L. S. Ivanova ◽  
A. A. Demidova ◽  
P. A. Stekanov ◽  
...  
Keyword(s):  
Nondestructive Testing ◽  
Steel Plate ◽  
Testing Methods ◽  
Steel Company ◽  
Iron And Steel ◽  
Track Record ◽  
Nondestructive Testing Methods ◽  
Plate Quality ◽  
Quality Indexes
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