Structural damage identification has recently become one of the most important topics for engineering structures due to its benefits in enhancing safety, reducing life-cycle cost and providing guidance for system construction and maintenance. This research investigates the accuracy of using displacement influence lines (DILs) and their derivatives (slope and curvature) for structural damage characteristics (location and severity). The method is based on static structure response, which can be measured using single or multi sensors. The study includes an analytical investigation of damage detection of single and multiple damages in a simply supported beam. The measuring point positions are also discussed in this paper. Furthermore, the advantages and disadvantages of using displacement influence lines in structural damage detection are also discussed.

Concrete-filled steel tube (CFST) beam-column joints are susceptible to brittle premature failure due to concentrated local stresses at the tips of the beam tension flange. In order to reduce the outward deformation of the steel tube wall, this paper addresses the influence of setting the steel beam at the corner of the CFST column on the connection performance. Therefore, two specimens represented the details of the common connection and the new proposed connection of exterior joint configuration were sub-assembled and examined experimentally under lateral monotonic loading. Compared with the flexible initial stiffness attained by the common connection, the results showed that the initial stiffness of the proposed connection was relatively rigid up to yielding of the middle region of the width of the beam compression flange under high bearing stresses. The connection strength also increased up to the expected design strength of the connecting beam, while the common connection strength was close to half of the beam design strength. Moreover, after the strength of the beam connection was achieved and at a total rotation of 0.025rad, the failure of the proposed connection was a significant buckling of the beam compression flange propagated to its web and associated with section warping.

Disposal of mining wastes (tailings) is one of the most severe issues related to groundwater contamination. Therefore, a properly selected disposal site helps to prevent the leakage of dissolved materials in the tailings to groundwater, especially in the karstic area. Where the karstic environment is one of the challenges facing groundwater environmental and engineering issues, for instance, groundwater exploration, vulnerability assessment, and hazard estimation. In this study, the resistivity method with a high-resolution surface data survey was carried out to investigate the pond location selection for mining tailings disposal at El Mochito mine site, northwest Honduras. The results of the two-dimensional (2-D) inversion for sixteen surveyed lines revealed that many low resistivity zones. These zones are related to water/clay-bearing zones that are structurally weak. From lines 8-12, the limestone underneath the surface is the most compact, and this is the best location in the survey area for tailings pond construction. The resistivity method has provided insight into the subsurface information and locating hydraulically conductive zones, so it can be useful for selecting the site of mining tailings.

To detect water seepage and ensure the safety of Pumped Storage Power Station (PSPS) facilities, we apply the electrical resistivity method to evaluate the leakage when the water level is on the rise. We check whether there is a leakage channel near the cavern group of the underground powerhouse. We conduct the field survey and integrate the results with regional geological data to determine the distribution of faults and large cracks. Granite intrusions generate a variation of high and low resistance phases, representing granite porphyry and tuff, respectively. The interface between the two lithologies is the location of the fault zone. In general, the apparent resistivity of two does not change much, indicating that the rock masses are relatively stable. The internal fractures of the rock masses are not developed, and there is no visible water content. However, from the location of the lithological contact interface, the rock mass is broken. Therefore, we recommend that before constructing the lower reservoir, anti-seepage treatment should be carried out.

Sulfide minerals are a group of compounds with the presence of sulfur. This group’s most abundant and economically members are pyrites, pyrrhotite, chalcocite, galena, sphalerite, and the group of copper sulfides minerals. Resistivity and Induced Polarization (IP) methods, which play an essential role in mineral exploration, showed great success in sulfide exploration. This paper started on reviewing sulfide formation by giving details which help to understand their genesis better. To make the reader understand the procedures and appropriate mineral exploration methods, we have briefly covered the theory, the basic principles of resistivity and IP methods, and different investigation techniques using one, two, and three-dimensional surveys. Based on many electrical surveys, we discussed with examples of resistivity and IP methods applied to the exploration of sulfide deposits: the data inversion and interpretation of the geophysical signatures of most of the sulfide deposits in various geological environments were analyzed and end by showing both successful surveys and limitations of the methods.

The geoelectrical tomography survey was carried out to explore and characterize a (Zn-Pb-Ag) sulphide deposit in Nash Creek (NC), New Brunswick province, Canada. The exploration strategy has been conducted by the 2-D survey for a well-cut grid consisting of twelve surface lines (profiles) each around 2 km long, and 300 m apart, for the total area around 9.5 km². The datasets (resistivity and induced polarization) were acquired using the Iris El-Rec Pro system with pole-dipole electrodes array spaced 50 m apart, and ten levels of data datum. The results of the 2-D inversion revealed that the underground resistivity and chargeability values in the exploration area have a range of (5 to 1300 Ωm) and (0-9.5 mV/V), respectively. The sulphide mineralization zones in the exploration area are characterized by moderate resistivity values (150-300 Ωm) and moderate to low chargeability values (>5.5 mV/V), with a depth of around (90140 m) from the surface. The 3-D visualization model clearly reveals that three main zones of sulphide mineralization are present in the exploration area. The predicted geological reserve of the sulphide ore in the exploration area was calculated. The inverted models revealed a good agreement with the existing geological features in the exploration area.

Mineral exploration in the Canadian shield is a major challenge nowadays. This is because of the thick overburden cover and complex geology. Borehole tomography using resistivity and induced polarization (BHDCIP) method has a big advantage here due to that the data is acquired underneath the cover and data quality, in general, is superior to that acquired at the surface. BHDCIP provides good resistivity and chargeability data, which can identify mineralization easily. In this study, the BHDCIP survey with high-resolution data was carried out to identify mineralization zones in the McCreedy West zone, north-western Sudbury, Ontario, Canada. Two and three-dimensional (2-D and 3-D) inversion results of three boreholes clearly revealed the mineralization zones and that harmonised with previous geological studies in the study area. The BHDCIP method provided insight and developed an informative subsurface map to identify the mineralization zones, thus proving it as a beneficial tool used for mineral exploration in complex geology with a minimal data survey and an irregular geometrical distribution.

The study aimed at investigating the geochemistry of a sandstone-type uranium deposit in Tarat formation for provenance, paleo-redox, tectonic setting in order to propose a geological model of uranium. X-Ray Fluorescence (XRF) and Induced Coupled Plasma Mass Spectrometry (ICP-MS) analyses were used to determine the sandstone composition. Major, trace and rare earth element compositions of the sandstones have been investigated to determine their provenance, tectonic setting and the influence of weathering conditions. Field studies of Tarat formation revealed that a major accident N30˚ that can be interpreted as an extension of the Austriche accident ensures the controls of Tarat sedimentation and mineralization deposits and the presence oxidized zone and reduced zone indicate the direction of circulation of the mineralized fluids from West to East. The uranium mineralization is disseminated as pitchblende that gives a yellow color to the sandstone while, molybdenum mineralization gives a blue color to the sandstone. Results of the Geochemical analysis indicate that the sandstone-type uranium deposit of Taratis classified into Protoquarzite (i.e. lithearenite and sublitharenite), arkose, subarkose, wacke and quartz arenite and varied in their maturity. Their Rare Earth Elements (REE) pattern displays high light REE over heavy REE, flat HREE and a significant negative Eu and Ce anomalies and in general correlated well with the NASC and PAAS average composition. The source area may have contained quartzose sedimentary rocks. The geochemical data support deposition in reducing environment of arid to humid climatic conditions rich in organic matter affected by passive margin (PM) tectonic setting and the sediments are derived from felsic and mafic source rocks. Trace and REE data as well as the high values of the weathering indices: Chemical Index of Alteration (CIA), Plagioclase Index of Alteration (PIA) and Chemical Index of Weathering (CIW) suggest intermediate to extreme weathering conditions in the source area or during transportation. The studied sandstones are inferred as highly mature sediments evidenced from their high SiO₂/Al₂O₃ > 1 and the presence of the ultra-stable clay minerals, smectite, kaolinite, chlorite and illite. Also the Th/U < 3 ratio suggests high uranium enrichment of Tarat sandstones over crust average composition. From the factor analysis of the analyzed sandstone, there is no direct relationship between organic carbon and uranium, indicating the absence of organo-uraniferous composite and a major source derived from felsic to the mafic rock of Air Massif. The mineralized fluids of circulating from west to east are usually capped and underlain by impermeable mudstone or clay-rich units and uranium mineralization occurs in the association U-Mo-Pb or U-Zn-Ni-Pb structurally controlled by the major fault in Azaoua lineament fault NS of Arlit in the West, the N70˚ Tin Adrar “faisceau” in the North, the N30˚ Mouron accident in the Southeast, N30 Autriche accident in the West and precipitated in areas of suitable reducing environment of arid to humid climatic conditions rich in organic matter affected by passive margin (PM) tectonic setting. The negative correlation of U-Th and U-Na in our samples indicates intense remobilization of uranium in Tarat formation.

Interpretation of the aeromagnetic and radiometric data over the Agbabu bitumen-belt reflects the litho-structural features affecting the area and its significance over bitumen mineralization. The orientations of lineaments from magnetic images are predominantly ENE-WSW/W-E. Magnetic sources from Euler and SPI depth estimations compare reasonably well and range from 76 m to 1395 m and 217 m–731 m respectively. The shallow depths coincide with the depth at which bitumen deposit was detected in geological boreholes within Agbabu and Ilubirin. This suggests that the bitumen mineralization is structurally controlled and hosted by shallow sources. Radiometric maps have been used to delineate the boundaries of lithologies, especially basement-sedimentary boundaries and the rise of the basement. It appears that the key factor influencing the distribution of bitumen deposits is the ENE-WSW/W-E trend corridor, lithological boundaries, and basement rise. These results will provide a valuable framework for guiding further research and bitumen mineral exploration within the study area.