Scattering Attenuation of 2D Elastic Waves: Theory and Numerical Modeling Using a Wavelet-Based Method

2003 ◽  
Vol 93 (2) ◽  
pp. 922-938 ◽  
Author(s):  
T.-K. Hong
2021 ◽  
Author(s):  
Meng-quan Zhu ◽  
Zhi-yang Wang ◽  
Hong Liu ◽  
You-ming Li ◽  
Du-li Yu

Ultrasonics ◽  
2014 ◽  
Vol 54 (7) ◽  
pp. 1729-1736 ◽  
Author(s):  
Marie-Aude Ploix ◽  
Philippe Guy ◽  
Bertrand Chassignole ◽  
Joseph Moysan ◽  
Gilles Corneloup ◽  
...  

2006 ◽  
Vol 28 (1) ◽  
pp. 172-205 ◽  
Author(s):  
Bruno Lombard ◽  
Joël Piraux

Geophysics ◽  
1999 ◽  
Vol 64 (3) ◽  
pp. 963-966 ◽  
Author(s):  
Jianlin Zhu

In numerical modeling of wave motions, strong reflections from artificial model boundaries may contaminate or mask true reflections from the interior model interfaces. Hence, developing a kind of exterior model boundary transparent to the outgoing waves is of critical importance. Among proposed solutions, e.g., Smith (1974), Kausel and Tassoulas (1981), and Higdon (1991), the most widely used may be the Clayton and Engquist (1977) method of absorbing boundary conditions, based on paraxial approximations for acoustic and elastic‐wave equations. However, absorbing boundary conditions make the reflection coefficients zero only for normal incidence, and suppression of reflected S-waves (Clayton and Engquist, 1977) becomes poorer as the ratio of P- to S-wave velocity ([Formula: see text]) becomes larger.


2008 ◽  
Vol 22 (11) ◽  
pp. 899-904 ◽  
Author(s):  
JOOWON KIM ◽  
KI-IL SONG ◽  
GYE-CHUN CHO ◽  
SEOK-WON LEE

For a better evaluation of a grouted zone during and after tunnel construction involving weak soil layers, it is necessary to estimate the characteristics of grouted zone effectively. This study suggests a method that can be used for characterizing the time-dependent behavior of pre-reinforced zones around a large section of tunnel in soft ground using elastic waves. Experimental tests were performed to characterize the time-dependent behavior of the pre-reinforced zone. Experimental results show that shear strengths as well as elastic wave velocities increase with the curing time. Thus, shear strength or strength parameters can be uniquely correlated to elastic wave velocities. It is possible to characterize grouted soils around tunnel using elastic waves. Time-dependent strength and stiffness parameters in the experimental tests were applied in a numerical modeling of a large-section tunnel in soft ground, taking into account its construction sequence. According to the results of the numerical modeling, displacement results for fewer than 2~3 days of constant time boundary conditions are nearly identical to the analysis results of the time-dependent condition. The proposed analysis method, which combines experimental and numerical procedures while considering the time-dependent effect of the pre-reinforced zone on the tunnel behavior, will provide a reliable and practical design basis and a means of analysis for large-section tunnels in soft ground.


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