In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM) involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations) and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstifica...

This article is mainly devoted to a review on fast BEMs for elastodynamics, with particular attention on time-harmonic fast multipole methods (FMMs). It also includes original results that complete a very recent study on the FMM for elastodynamic problems in semi-infinite media. The main concepts underlying fast elastodynamic BEMs and the kernel-dependent elastodynamic FM-BEM based on the diago...

Manuscript received November 5, 1998. Manuscript revised January 8, 1999. † The authors are with Niigata University, Niigata-shi, 9502181 Japan. †† The author is with University of Illinois at Chicago, IL, 60607-7018, USA. * Presently, with Fujitsu System Integration Laboratories Ltd. ** Presently, with NEC Saitama Corp. SUMMARY This paper discusses the classification of targets buried in the u...

Abstract The problem of registering underground cavities and caves is an older one at national level. With the advent several legislative initiatives regarding this type entity, term cadastre also appeared. case study represented by "Şuticoasa" Cave, which located in perimeter archaeological site, Şinteu Fortress "Piatra Şoimului", being integral part medieval monument pestis village, a village...

In a mature karstic system, the realisation of galleries using the methodology of railway tunnel boring machine (TBM) involves particular problems due to the high risk of interference with groundwater (often subject to remarkable level variations) and with cavities and/or thick fill deposits. In order to define groundwater features it is necessary to investigate both hydrodynamic and karstifica...

We present a novel method to detect underground cavities using cross-borehole ground-penetrating radar (GPR). model the propagation of GPR signal across cavity and find that spectrum will be distorted in specific low-pass manner. Comparing spectra received signals with predicted hypothesis-testing approach allows us high probability. The proposed is validated on both simulated real measurements...

In recent years, methane (CH4) has received increasing scientific attention because it is the most abundant non-CO2 atmospheric greenhouse gas (GHG) and controls numerous chemical reactions in the troposphere and stratosphere. However, there is much that is unknown about CH4 sources and sinks and their evolution over time. Here we show that near-surface cavities in the uppermost vadose zone are...