Nondestructive Testing for Support Quality of Tunnel

2014 ◽  
Vol 501-504 ◽  
pp. 1815-1819
Author(s):  
Lan Qiao ◽  
Ming Cui ◽  
Qing Chi Cai
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Large Space ◽  
Tunnel Support ◽  
Impact Echo ◽  
Holding Power ◽  
Composite Lining ◽  
The Right ◽  
Non Destructive

A tunnel in Chengde collapsed several times and cracks existed in the second lining. Using non-destructive testing equipment, tunnel support was detected to find out the hidden trouble early. In the section of K16+890~K16+950, the quality of tunnel support was assessed, with GPR and anchor measuring apparatus. In the tunnel, the thickness of composite lining was 25cm, and the second lining was 38cm, both of which met the design requirements. Positive peak method was selected to locate on I beam. The average longitude space of I beam was 127cm, while the design value is 120cm. Many rock bolts was lacked at the right crown. Moreover, the bolts in the haunch did not kept in diamond layout, close to I beam. Through analyzing waveforms of impact-echo, the number of qualified bolts only made up 74 per cent of the total bolts. The large space of I beam led to the lack of holding power. Meanwhile, the disqualified bolts limit the coordination deformation between surrounding rock and support. All the support defects led to tunnel collapse. These tests results demonstrate that NDTcan be used to mitigate the risks of tunnel construction.

Detecting the Defects in Concrete Components with Impact-Echo Method

2014 ◽  
Vol 577 ◽  
pp. 1114-1118 ◽  
Author(s):  
Jing Liu ◽  
Jun Xie ◽  
Xiao Yu He ◽  
Yu Shan He ◽  
Jia Hui Zhong
Keyword(s):  
Prestressed Concrete ◽  
Large Scale ◽  
Concrete Block ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Impact Echo ◽  
The Impact ◽  
Non Destructive ◽  
Impact Echo Method

With the large-scale application of the prestressed concrete structure, the quality of the concrete component defects and pipeline grouting has increasingly become the focus of attention. The impact-echo scanner uses the nature of wave, which pass though different media at different velocities, to distinguish internal defects of concrete, pipe filling density and so on. In this paper, using the impact-echo method to detect the concrete block with prefabricated defects of shape, location, and size explores the effect of defect properties, parameter settings and detection environment to impact-echo preliminarily and also explores the relationship of pipeline filling status and impact-echo image. Based on this study, the article raised the problem met during this non-destructive testing methods applied to engineering, and accumulated a certain amount of available engineering data. The experiment results show that using the impact-echo method to identify the defects of concrete components and to test the quality of pipeline grouting is a more convenient and effective non-destructive testing method. Especially, with the radar method in the pipeline grouting quality inspection which complement each other to make up for the shortcomings the lightning wave in case of the metal medium total reflection phenomenon, cannot detect metal pipe grouting plumpness.

Estimation of Thickness of Concrete Slab Members Using Impact Echo Method

2014 ◽  
Vol 605 ◽  
pp. 139-142
Author(s):  
Seong Uk Hong ◽  
Yong Taeg Lee ◽  
Seung Hun Kim ◽  
J.H. Na
Keyword(s):  
Concrete Slab ◽  
Hardness Test ◽  
Pulse Velocity ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Impact Echo ◽  
Maintenance And Repair ◽  
Non Destructive ◽  
Impact Echo Method

Recently, the interest in maintenance and repair of existing concrete structures have increased, and it is typical to use non-destructive testing methods such as rebound hardness test or ultrasonic pulse velocity method to execute maintenance and repair of structures efficiently. Many non-destructive testing methods are being used in practice such as at construction sites, but verification for site applications are quite inadequate. Thus, this study intends to evaluate the applicability of Impact Echo Method which is one of the non-destructive testing methods using stress wave. Total of four specimens were planned and produced. The thickness of concrete slab members was estimated using I.E(OLSENs Freedom Data PC with Win.TFS Software Version 2.5.2). The estimated materials of concrete members by IE was found to be IE-1 specimen 178mm, IE-2 specimen 197mm, IE-3 specimen 191mm, and IE-4 specimen 263mm, and the error rate was found to be 4.22%~18.67% (average 9.6%), showing that they are relatively well in agreement. In this study, the experiments were executed with the objective of estimating the thickness of concrete slab members using Impact Echo Method. Through this study, the applicability of thickness estimation in concrete slab members using impact echo method could be confirmed.

scholarly journals Multi-Method END Study in the Search for 'Defects' in an Aeronautical Radar Element

2020 ◽  
Vol 14 (11) ◽  
pp. 19
Author(s):  
Gaston Sanglier ◽  
Jose Miguel ◽  
Jose Antonio Penaranda ◽  
y Gabriel Del Ojo
Keyword(s):  
Partial Information ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
The Past ◽  
New Methods ◽  
New Concepts ◽  
Indispensable Tool ◽  
Inspection Techniques ◽  
Non Destructive

Non-Destructive Testing (NDT) has gone from being a simple laboratory curiosity to an indispensable tool in the industry to determine the level of quality achieved in its products. The new concepts of Integrated Manufacturing (CIM) bring a more universal concept of quality compared to the past philosophy based on Quality Control as a group specialized in checking whether production works within certain specifications. Even so, NDTs have not lost interest, but have seen their interest increased due to automated inspection techniques. It has become a contribution to the structuring of quality as it allows to move from purely empirical criteria to other more objective and that constitute the link between design and evaluation (Ramirez et al, 1996). The work presented, although it does not propose new methods or techniques of NDT, has the interest of converging into a single object five conventional methods each of which provides partial information about their quality of manufacture and must synthesize the results in order to evaluate it. Furthermore, it shows a situation of the application of NDT in which these must be applied in the absence of reference standards, as they do not exist. This peculiar situation is completely different from the usual situation in the use of NDT in the industry, both in manufacturing processes and in maintenance inspections.

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