Explore the vast range of titles available.

This study aimed to determine the surface deformation resulting from the earthquake on February 6, 2023, on the Turkish-Syrian border using Sentinel-1 SAR images and DInSAR techniques. The analysis was limited to pixels with a coherence value above 0.6 to reduce misinterpretations from phase decorrelation. Furthermore, the study aimed to map horizontal and vertical displacements within GIS environment, contributing to a processing methodology that reduces time and effort in detecting surface displacement over large spatial coverage. The results of this study revealed clear surface displacement patterns in northwest Syria and southern Turkey following the earthquake. These patterns encompass both westward and eastward horizontal shifts, as well as upward and downward vertical movements. Notably, the findings indicated significant upward and westward motion near Iskenderun, alongside eastward motion and complex vertical displacements in the Gaziantep/A’zaz/Zayzafun areas. To assess the precision of these displacements, they were compared to data from GPS stations within the study area, demonstrating good accuracy with Root Mean Square Errors (RMSE) of approximately ± 3.2 cm for Line-of-Sight (LOS) displacements and ± 3.7 cm for combined horizontal and vertical displacements. This research provides valuable insights into tectonic plate movements and carries implications for future seismic studies in the examined regions.

Terrestrial laser scanning (TLS) technology has become increasingly popular in investigating displacement and deformation of natural and anthropogenic objects. Regardless of the accuracy of deformation identification, TLS provides remote comprehensive information about the measured object in a short time. These features of TLS were why TLS measurement was used for a static load test of an old, steel railway bridge. The results of the measurement using the Z + F Imager 5010 scanner and traditional surveying methods (for improved georeferencing) were compared to results of precise reflectorless tacheometry and precise levelling. The analyses involved various procedures for the determination of displacement from 3D data (black & white target analysis, point cloud analysis, and mesh surface analysis) and the need to pre-process the· 3D data was considered (georeferencing, automated filtering). The results demonstrate that TLS measurement can identify vertical displacement in line with the results of traditional measurements down to ±1 mm.

We review here the gravitational effects on the temporal (time-lapse) gravity changes induced by the surface deformation (vertical displacements). We focus on two terms, one induced by the displacement of the benchmark (gravity station) in the ambient gravity field, and the other imposed by the attraction of the masses within the topographic deformation rind. The first term, coined often the Free Air Effect (FAE), is the product of the vertical gradient of gravity (VGG) and the vertical displacement of the benchmark. We examine the use of the vertical gradient of normal gravity, typically called the theoretical or normal Free Air Gradient (normal FAG), as a replacement for the true VGG in the FAE, as well as the contribution of the topography to the VGG. We compute a topographic correction to the normal FAG, to offer a better approximation of the VGG, and evaluate its size and shape (spatial behavior) for a volcanic study area selected as the Central Volcanic Complex (CVC) on Tenerife, where this correction reaches 77% of the normal FAG and varies rapidly with terrain. The second term, imposed by the attraction of the vertically displaced topo-masses, referred to here as the Topographic Deformation Effect (TDE) must be computed by numerical evaluation of the Newton volumetric integral. As the effect wanes off quickly with distance, a high resolution DEM is required for its evaluation. In practice this effect is often approximated by the planar or spherical Bouguer deformation effect (BDE). By a synthetic simulation at the CVC of Tenerife we show the difference between the rigorously evaluated TDE and its approximation by the planar BDE. The complete effect, coined here the Deformation Induced Topographic Effect (DITE) is the sum of FAE and TDE. Next we compare by means of synthetic simulations the DITE with two approximations of DITE typically used in practice: one amounting only to the first term in which the VGG is approximated by normal FAG, the other adopting a Bouguer corrected normal FAG (BCFAG).

Taking the construction project of a new bridge pile foundation above an in-service subway in Xi’an as an example, considering the influence of horizontal symmetrical construction of pile foundation hole forming on the deformation of different sections of asymmetric tunnels, a three-dimensional finite element geometric model of pile-tunnel-soil is established based on ABAQUS software. Through the numerical simulation analysis of the structural deformation behavior of the in-service subway tunnel under the two construction stages of pile foundation hole forming and concrete pouring, the horizontal and vertical deformation laws of the key points of the in-service subway tunnel caused by the construction of the adjacent new pile foundation are analyzed from different angles.The calculation results show that: the deformation of the interval tunnel is mainly caused by vertical displacement, resulting in overall settlement of the tunnel. However, the settlement value is within a controllable range and does not affect the normal operation of the in-service subway tunnel. The concrete pouring stage has a greater impact on subway tunnels. The research work has important reference value for the reasonable safety monitoring and control of similar construction projects.

Deep displacement monitoring of rock and soil mass is the focus of current geological hazard research. In the previous works, we proposed a geophysical deep displacement characteristic information detection method by implanting magneto-electric sensing arrays in boreholes, and preliminarily designed the sensor prototype and algorithm of deep displacement three-dimensional (3D) measurement. On this basis, we optimized the structure of the sensing unit through 3D printing and other technologies, and improved the shape and material parameters of the permanent magnet after extensive experiments. Through in-depth analysis of the experimental data, based on the data query algorithm and the polynomial least square curve fitting theory, a new mathematical model for 3D measurement of deep displacement has been proposed. By virtue of it, the output values of mutual inductance voltage, Hall voltage and tilt measuring voltage measured by the sensing units can be converted into the variations of relative horizontal displacement, vertical displacement and axial tilt angle between any two adjacent sensing units in real time, and the measuring errors of horizontal and vertical displacement are tested to be 0–1.5 mm. The combination of structural optimization and measurement method upgrading extends the measurement range of the sensing unit from 0–30 mm to 0–50 mm. It shows that our revised deep displacement 3D measuring sensor can better meet the needs of high-precision monitoring at the initial stage of rock and soil deformation and large deformation monitoring at the rapid change and imminent-sliding stage.

The right bank of the Kaniv Reservoir, which belongs to the Right Loess Plateau of the Dnipro River in Ukraine, is highly susceptible to landslides due to the geological features combined with climate change and human activities. Most landslides related complex morphostructure with central, characteristic elements was formed: a loess plateau with unstable slopes; the right-bank valley of the Dnipro River with erosive and accumulative terraces; ridge-beam, erosion and sliding. Human activities, namely clay mining, construction, and the expansion of agricultural lands induce landslides by altering slope stability. The current research aimed to assess landslide hazards by applying the DInSAR methodology, including the influence of slope, lithology, precipitation, and temperature regime. Optical sensors have known limitations due to their inability to capture Earth’s surface. The alternatives are radar sensors capable of seeing through the clouds and working independently of daylight. Integrating DInSAR technique data with classical geomorphological research helped define the kinematics and evolution of the landslides and establish their triggering factors in the Right Loess Plateau of the Dnipro River. Using measures in a seasonal change of temperature fluctuation and precipitation quantity can detect the outcrop, not overgrown vegetation areas, illustrating that radar data can detect landslide-prone areas.

The rapid growth of underground infrastructure in densely populated urban areas has increased the need for reliable design guidelines concerning the interaction of non-level crossing tunnels. The proximity of these tunnels often leads to complex soil–structure interactions, where excavation-induced stresses and deformations can significantly affect the safety and serviceability of existing tunnels. Despite the significance of this issue, few studies have comprehensively examined the combined impact of intersection angle, vertical spacing, and excavation sequence on the mechanical behavior of tunnels. This research aims to address this gap by performing a systematic three-dimensional finite element analysis using Plaxis 3D, focusing on the structural response of the lining and deformation patterns of the surrounding soil. A parametric study was conducted by varying three critical parameters: the intersection angle of the crossing tunnels, the vertical distance between tunnel axes, and the excavation sequence. The results included vertical displacements of the existing tunnel invert and crown, axial forces, bending and torsional moments in the lining, and soil failure indicators such as plastic point development and shear strain contours. Findings revealed that the intersection angle plays a dominant role, with mid-range angles (around 45°) producing the lowest settlements (up to 60% less than at acute angles) and minimizing lining forces. In contrast, near-orthogonal crossings (75°–90°) resulted in the most unfavorable conditions. Vertical spacing was also crucial: an intermediate spacing of 12.5 m resulted in nearly 30% lower settlements compared to 10 m, whereas a larger spacing (15 m) led to higher displacements due to stress redistribution. Additionally, the excavation sequence significantly influenced deformation patterns: shallow-first excavation caused more localized yet higher settlements, whereas deep-first excavation reduced peak displacements by roughly 10–12% but spread them over a broader zone. Overall, these findings emphasize the importance of carefully considering geometric and construction parameters in tunnel design. The results suggest that adopting intermediate intersection angles and moderate vertical spacing offer the best conditions. At the same time, the choice of excavation sequence should strike a balance between peak settlement and the extent of ground disturbance. These insights contribute to the development of safer and more effective design strategies for non-level crossing tunnels in complex urban environments.

Considering the future development trend of the airport pavement, a 3-D finite element model with 45m×20m×11.62m full-scale slabs is established to analyze the displacement response of asphalt concrete airport pavement under aircraft loads. Under different aircraft tire pressure levels, the vertical displacement and vertical displacement curve of the pavement in the region between 9 m and 13 m outside aircraft wheels is analyzed. The mechanical response of flexible pavement is studied, and the influence of various parameters on asphalt pavement.

Barometers are among the oldest engineered sensors. Historically, they have been primarily used either as environmental sensors to measure the atmospheric pressure for weather forecasts or as altimeters for aircrafts. With the advent of microelectromechanical system (MEMS)-based barometers and their systematic embedding in smartphones and wearable devices, a vast breadth of new applications for the use of barometers has emerged. For instance, it is now possible to use barometers in conjunction with other sensors to track and identify a wide range of human activity classes. However, the effectiveness of barometers in the growing field of human activity recognition critically hinges on our understanding of the numerous factors affecting the atmospheric pressure, as well as on the properties of the sensor itself—sensitivity, accuracy, variability, etc. This review article thoroughly details all these factors and presents a comprehensive report of the numerous studies dealing with one or more of these factors in the particular framework of human activity tracking and recognition. In addition, we specifically collected some experimental data to illustrate the effects of these factors, which we observed to be in good agreement with the findings in the literature. We conclude this review with some suggestions on some possible future uses of barometric sensors for the specific purpose of tracking human activities.

In regions susceptible to earthquakes, an increasing number of building structures are employing helical piles as their foundational system due to their commendable seismic performance. This paper investigates the vertical displacements of the helical pile-soil model, dynamic p-y curves, and seismic subsidence of helical piles in marine soft soil sites under seismic motions, considering the effects of various types of seismic waves, seismic intensity, angle of incidence, and the number of helical blades. The results demonstrate that the vertical displacement of double-blade helical piles is smaller than that of single-blade helical piles. Furthermore, the vertical displacement of helical pile-soil systems is influenced by the type of seismic wave, seismic intensity, and angle of incident. Moreover, the seismic subsidence of helical piles is significantly influenced by the peak ground acceleration and the frequency of the seismic wave, both of which are related to the angle of incident. Finally, this paper rectifies the p-y curve of soft soil in the API specification based on the angle of incidence. The conclusions of this study provide a basis for the seismic design of helical piles in marine soft soil sites.