Near-Surface Salt Dissolution Void Identification Using Passive MASW

摘要: Near-surface voids occur in a variety of settings and from different sources ranging natural dissolution features to man-made illegal cross-border tunnels. The detection these typically air-filled using geophysical techniques is surprisingly difficult for an array factors, despite the drastic change mechanical properties rock. However, it vital efficiently accurately image surrounding rock due potential implications environment culture. Passive seismic surveys above known salt were conducted calculate overlying evaluate imminent collapse. multichannel analysis surface waves (MASW) recorded necessary low frequencies anomalous velocity zones as deep 90 meters below ground surface. Results this experiment correlate well with all data at site, identifying increased shear wave remaining solution mining early 1900’s.