- Home
- About Us
- News/TAG Webinars
- Membership
- Annual Meeting/SAGEEP
- Publications & Merchandise
- What is Geophysics?
Just-Accepted Journal ArticlesJust-Accepted Articles are peer-reviewed, accepted manuscripts that have been assigned Digital Object Identifiers (DOIs) and undergo the normal publication process (copy editing, page composition, proofing by author, and finalization). A Just-Accepted article listing includes an abstract and the DOI (scroll). The article is removed when the final version of the manuscript is ready and assigned to a Journal of Environmental & Engineering Geophysics (JEEG) issue, becoming the official version of the article. The Just Accepted article has the same DOI that appears on the official version of the article; therefore, citations made to an article during the Just-Accepted stage will continue to link to the article's official version. EEGS Members can access the full, preliminary article via this "member-only" link: Just-Accepted Articles with full article PDF Shear Properties and Pore Characteristics of Soil-rock Mixture under Dry-wet cycling Authors: DOI: 10.32389/JEEG22-041 ABSTRACT: The mechanical properties of soil-rock mixtures can deform significantly under the influence of dry-wet cycles, affecting the safety of high-fill projects. A drying device was developed to perform direct shear tests on the soil-rock mixture (S-RM). Large-scale direct shear tests were carried out under the action of dry-wet cycling to study the effect of dry-wet cycling on the mechanical properties of S-RM. Image J software was used to identify the number and area of pores in the binary image, and the pore characteristics of S-RM under dry-wet cycles were analyzed. The results show that the section of post-peak in the shear stress-strain curve is softening under the natural state (no dry- wet cycles), but it is plasticizening under application of the dry-wet cycles. The cohesion of the S-RM particles is affected by the dry-wet cycling and decreases greatly under the first dry-wet cycle, and then decreases gradually for each successive cycle, after which it stabilizes during the fifth dry-wet cycle. The internal friction angle is not affected to a large degree. The effect of a dry wet cycle on pores with different areas is significantly different. The pores with initial sizes of 0.5–10 mm2 decrease, while pores with other initial sizes are hardly affected by the dry-wet cycling. This paper quantitatively analyzed the relationship between the surface two-dimensional porosity and the cohesion and peak strain of S-RM. Keywords: Soil-rock mixture (S-RM); Dry-wet cycle; Shear behavior; Porosity; Quantitative analysis Field evaluation of two impulsive downhole seismic sources in crosswell and reverse VSP geometries and high-resolution characterization of near-surface Texas Gulf Coast sediments Authors: ABSTRACT: Borehole seismic methods have been widely used for characterizing the shallow subsurface. Accurate analysis of their data is aided by a solid understanding of the borehole sources’ characteristics. This study presents a field evaluation of two impulsive borehole seismic sources, (Trident's Scorpion sparker and RT Clark's Ballard weight drop) in crosswell and reverse vertical seismic profile (RVSP) geometries at a Gulf of Mexico coastal site with two shallow vertical wells. The data is then utilized to characterize the near-surface coastal sediments. The Scorpion source generated P-wave dominant frequencies that were recorded as 650 Hz and 250 Hz in the crosswell and RVSP geometries respectively. For Ballard source in the two geometries, the P-wave dominant frequencies were 1100 Hz and 250 Hz. We were also able to pick direct S-wave arrivals with the Ballard source and their dominant frequencies were 100 Hz and 40 Hz for in situ and surface recordings respectively. The average signal-to-noise ratio (SNR) recorded with the Scorpion data for the crosswell geometry and RVSP respectively is 13 and 6, and for the Ballard source 62 and 30. We also investigated the source radiation patterns and signature wavelets. Seismic tomography was performed for the area between the two wells. Low P-wave and S-wave velocities correspond to three fresh water-saturated sand zones identified from drilling cuttings and previous well log data. A Vp-Vs plot also fits reasonably to the Mudrock Line. Both sources can excite repeatable seismic signals up to 150m away and be useful in many geotechnical settings. Validation and Potential Improvement of Soil Survey Maps Using Proximal Soil Sensing Authors: Felippe Hoffmann Silva Karp; Viacheslav I. Adamchuk; Alex Melnitchouck; Barry Allred; Pierre Dutilleul; Luis R. Martinez Influence of Radiative Components and Meteorological Conditions on Simulation of Slope-Specific Heat Balance Research on Time-domain Airborne EM Full-field Apparent Resistivity Imaging Method for Arbitrary Transmitting Waveform Authors: Jianbo Zheng; Yanfu Qi DOI: 10.32389/JEEG22-023 ABSTRACT: The time-domain airborne electromagnetic (AEM) system can do fast EM surveys over mountainous areas by carrying its detection equipment on an airplane. Due to the dense sampling of AEM method, it generates a huge amount of data. As a result, the resistivity imaging methods have become the first choice for data interpretation because they are fast. However, the traditional imaging methods do not fully consider the influence of the transmitting waveform. When they are used to deal with the AEM data with complex current waveform, the imaging results are seriously affected. Therefore, we develop a universal full-field apparent resistivity imaging method for AEM data with arbitrary transmitting waveform. Firstly, we calculate the convolution of time derivative of the current waveform and step response to obtain the time-domain AEM response of the arbitrary transmitting waveform. Then the full-field apparent resistivity imaging method based on the inverse function theorem is used to complete the rapid imaging of AEM data with complex waveform. Finally, we apply our imaging codes to both synthetic and field data to verify its correctness. Keywords: Time-domain; Airborne EM; Transmitting waveform; Full-field apparent resistivity. Noise Reduction of Aeromagnetic Data Using Artificial Neural Network Authors: Osama Elghrabawy DOI: 10.32389/JEEG22-013
|