Peak surface motion due to scattering of plane harmonic P, SV, or Rayleigh waves by a rough cavity embedded in an elastic half-space

• Published in: Journal of seismology Vol. 15; no. 1; pp. 131 - 145
• Main Authors: Dravinski, Marijan, Yu, Michael C.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2011; Springer; Springer Nature B.V
• Subjects: Corrugating; Earth and Environmental Science; Earth Sciences; Earth, ocean, space; Earthquakes, seismology; Elastic scattering; Engineering and environment geology. Geothermics; Exact sciences and technology; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Half spaces; Holes; Hydrogeology; Incident waves; Internal geophysics; Mathematical models; Natural hazards: prediction, damages, etc; Original Article; Probability distribution; Roughness; Seismology; Structural Geology; Surface acoustic waves; Surface motion; Site effects; Elastic waves; Rough cavity; Computational seismology; models; Rayleigh waves; probability; seismology; elastic waves; BASIC; frequency; amplitude; harmonics; roughness; half-space; site effects; inclusions
• ISSN: 1383-4649; 1573-157X
• DOI: 10.1007/s10950-010-9213-8

Scattering of plane harmonic P, SV, or Rayleigh waves by a two-dimensional rough cavity completely embedded in an isotropic elastic half-space is investigated by using a direct boundary integral equation method. The cavity’s roughness is assumed to be in the form of periodic or random perturbations of arbitrary amplitude superimposed to a smooth elliptical shape. For the randomly corrugated cavities the normal or the uniform probability distribution functions are assumed. Based on multiple random cavity results, the corresponding average surface response is computed. These are compared with the corresponding periodically corrugated and smooth cavity responses. The surface response is evaluated for different cavity shapes and incident waves and for a range of frequencies. The surface motion results are used to determine the peak surface motion frequencies. They depend strongly upon the basic inclusion shape (the principal axes) and the nature of the incident wave. Strong similarity in the peak surface motion frequencies can be observed for the rough and smooth cavity models for both circular and elliptical shapes. In order to quantify the importance of the cavity corrugation upon the surface motion, a roughness influence factor is defined in terms of the rough and smooth cavity surface responses. This factor strongly depends upon the type of the incident wave, the nature of the cavity corrugation, the basic cavity shape, and the frequency. The factor clearly shows the effect of the cavity roughness upon the surface motion.