Surface Deformation Research Articles

Deformation Monitoring Based on SBAS-InSAR and Leveling Measurement: A Case Study of the Jing-Mi Diversion Canal in China.

The Jing-Mi Diversion Canal is a large-scale water diversion project in Beijing. Routine monitoring is crucial for the reliability and stability of urban water supply. Compared with traditional monitoring methods, interferometric synthetic aperture radar (InSAR) has the advantages of large scale and high accuracy. Based on the small baseline subset InSAR, 187 ascending and 102 descending SAR images obtained from Sentinel-1 were used to detect the deformation along the diversion canal from 2017 to 2023. The results show that there was a sinking trend along the diversion canal. The subsidence was serious in the first half of the canal, and continued to sink from 2019 to 2020. The subsidence was alleviated in 2023. Combined with leveling measurements, the InSAR deformation monitoring results of important pumping station buildings were verified. The measurement accuracy of InSAR can reach the millimeter level. We extracted the groundwater level time series and subsidence for risky canal segments. Through pixel-by-pixel comparison, it was found that fluctuations in groundwater level would have some impact on surface deformation. Severe local subsidence or uplift deformation occasionally occurred. To ensure the safety of water diversion, the monitoring and maintenance of relevant pump station buildings in risky areas should be increased in the future.

InSAR-CTPIM-Based 3D Deformation Prediction in Coal Mining Areas of the Baisha Reservoir, China

Time series dynamic prediction of surface deformation in mining areas can provide reference data for coal mine safety and production, which has important impacts. The combination of interferometric synthetic aperture radar (InSAR) technology and the probability integral method (PIM) is commonly used for predicting deformation. However, most surface subsidence prediction in mining areas is based on the static PIM parameters, failing to achieve the three-dimensional (3D) dynamic deformation prediction. This paper proposed a 3D deformation dynamic prediction model (InSAR-3D-CTPIM) between InSAR deformation observations and dynamic coordinate-time PIM (CTPIM) parameters, which can realize the prediction of east–west, north–south, and vertical series deformation caused by mining. The method has been validated by simulation experiments and real experiments in the mining area of Jiansheng Coal Mine in Baisha Reservoir, Henan Province, China. The results showed that the modeling accuracy was improved by 34.3% compared to the traditional multi-rate model, and the accuracy was improved by 28.5% compared to the vertical deformation obtained by the traditional static PIM method. The InSAR-3D-CTPIM model can be used to predict the evolutionary history of basin-wide surface deformation dynamics in coal mining areas, and provide a reference for the early warning and prediction of geological hazards in coal mining areas.

Topographical Effects on Volcano Deformation Signal Intensity: Implications for GPS Network Configuration

AbstractVolcano GPS networks can capture vital information during volcanic unrest to aid with hazard assessment and eruption forecasting, but can be hindered by their discrete point locations and possibly miss key spatial information. We show how numerical models can reveal controls on spatial deformation signal intensity compared against GPS network design. Using the GPS network at Soufrière Hills Volcano (SHV), Montserrat, and a range of models, we explore expected surface deformation patterns. Peak horizontal deformation is located offshore, highlighting the difficulties with geodetic monitoring on small ocean‐island volcanoes. Onshore areas where the deformation signal is expected to be high are also identified. At SHV, topography plays a greater role in altering the relative distribution of surface displacement patterns than subsurface heterogeneity. Our method, which can be adapted for other volcanoes, highlights spatial areas that can be targeted for effective GPS station placement to help improve deformation monitoring efficiency.

In vivo effect of LATE-NC on integrity of white matter connections to the hippocampus.

TAR DNA-binding protein 43 (TDP-43) is a highly prevalent proteinopathy that is involved in neurodegenerative processes, including axonal damage. To date, no ante mortem biomarkers exist for TDP-43, and few studies have directly assessed its impact on neuroimaging measures utilizing pathologic quantification. Ante mortem diffusion-weighted images were obtained from community-dwelling older adults. Regression models calculated the relationship between post mortem TDP-43 burden and ante mortem fractional anisotropy (FA) within each voxel in connection with the hippocampus, controlling for coexisting Alzheimer's disease and demographics. Results revealed a significant negative relationship (false discovery rate [FDR] corrected p<.05) between post mortem TDP-43 and ante mortem FA in one cluster within the left medial temporal lobe connecting to the parahippocampal cortex, entorhinal cortex, and cingulate, aligning with the ventral subdivision of the cingulum. FA within this cluster was associated with cognition. Greater TDP-43 burden is associated with lower FA within the limbic system, which may contribute to impairment in learning and memory. Post mortem TDP-43 pathological burden is associated with reduced ante mortem fractional anisotropy. Reduced FA located in the parahippocampal portion of the cingulum. FA in this area was associated with reduced episodic and semantic memory. FA in this area was associated with increased inward hippocampal surface deformation.

Advanced Waterjet Technology for Machining Beveled Structures of High-Strength and Thick Material

The bevel cutting of large-thickness plates is a key process in modern industries. However, traditional processing method such as air-arc gouging bevel cutting or laser bevel cutting may cause serious deformation and rough surface quality due to the defects of the thermal cutting method. In order to improve the quality and efficiency of bevel processing, the abrasive waterjet cutting method is used in this research to overcome the challenge for bevel machining of high-strength DH40 steel plates with a large thickness. For different kinds of beveled structures, a 3D camera is used to measure the reference points defined on the workpiece and the SVD registration algorithm is adopted to transform the theoretical coordinate system to the actual coordinate system. Furthermore, the distance between the nozzle and the workpiece surface is also measured and compensated for to ensure the consistency of the bevel width. Finally, experiments are carried out for different kinds of bevels to verify the feasibility of the proposed method for high precision processing for beveled structures. The developed method has been effectively applied in the actual shipbuilding industry.

Three-Dimensional Surface Deformation of the 2022 Mw 6.6 Menyuan Earthquake from InSAR and GF-7 Stereo Satellite Images

Three-Dimensional Surface Deformation of the 2022 Mw 6.6 Menyuan Earthquake from InSAR and GF-7 Stereo Satellite Images

Structural inheritances, fault segmentation and seismogenic potential at the front of the eastern Southern Alps (central Carnic Prealps, NE Italy)

New geological and morphotectonic surface data coupled with the revision of the ENI-Exploration & Production seismic lines, made it possible to review the tectonic structure of the Pliocene-Quaternary front of the eastern Southern Alps in the area between the Cellina River and the Tagliamento River (central Carnic Prealps, NE Italy). The eastern Southern Alps are a SE-verging fold and thrust belt in activity from the middle Miocene to the Present. The presence of Paleogene structural inheritances influenced the current structural arrangement of the thrust-belt and the potential seismogenesis, supporting segmentation of the Neoalpine external front. In particular, the presence of the NW-SE trending Mt.Ciaurlec – Palmanova – Pozzuolo structural high, inherited from the W-ward propagation of the External Dinarides during Paleogene, generated lateral lithological facies change and influenced not only the undulation between the Neogene-Quaternary Maniago-Meduno and Toppo-Forgaria Thrusts, but also the segmentation of the outermost portion of the Neoalpine external front consisting into two segments with different geometric and structural characteristics: 1) the ENE-WSW striking Arba-Sequals segment that runs buried under the upper Pleistocene sequences of the piedmont Friuli plain; 2) the W-E Ragogna segment that shows widespread evidence of surface deformation of the Last Glacial Maximum (LGM) alluvial plain. In particular, the long-lasting activity of the Ragogna segment is testified by the late Miocene-Middle Pleistocene angular unconformities, forced drainage anomalies and tilted and uplifted Quaternary palaeosurfaces. A discussion on the seismogenic potential of the investigated structures is proposed.

Analyzing recent deformation in Wadi Hagul, Eastern Desert, Egypt, via advanced remote sensing and geodetic data processing

Abstract The Wadi Hagul region in the eastern desert of Egypt is facing seismic hazards and increased human activity. This study uses remote sensing and geodetic methods to monitor and analyze recent deformation in the area. Interferometric Synthetic Aperture Radar (InSAR) data from the Sentinel-1A satellite and Global Navigation Satellite System (GNSS) data were combined to track surface movements and deformations accurately. The study analyzed InSAR data from February 4, 2020, to February 07, 2024, and GNSS data from the Wadi Hagul geodetic network established in July 2022 and monitored until January 2024. Despite the relatively short GNSS monitoring period, it provided valuable insights into recent deformation trends. By integrating data from ten GNSS stations, including International Geodetic stations (IGS), and InSAR scenes from the Sentinel-1A mission, the study estimated recent ground deformation in the region. The main objectives were to analyze recent crustal movements by identifying spatial and temporal patterns of deformation and assess implications for geological processes. In Key Findings, horizontal movement fluctuates between 0.5 and 2.5 ± 0.1 mm annually across the geodetic network. The estimated velocity of the area was 1.5–2 ± 0.5 mm per year. Integrating GNSS and InSAR data helped calculate movement rates along fault lines and create a fault map. In conclusion, the results suggest that while current deformation rates are moderate, they could increase significantly due to human activity, leading to higher seismic activity and potential earthquakes. Limiting human activity in the region is advisable to prevent negative impacts on nearby populated areas.

Landslide Hazard Analysis Combining BGA-Net-Based Landslide Susceptibility Perception and Small Baseline Subset Interferometric Synthetic Aperture Radar in the Baige Section in the Upper Reaches of Jinsha River

The geological and topographic conditions in the upper reaches of the Jinsha River are intricate, with frequent occurrences of landslides. Landslide Susceptibility Prediction (LSP) in this area is a crucial aspect of geological disaster risk management. This study constructs an LSP model using a Convolutional Neural Network (CNN) based on a Bilateral Aggregation Guidance (BAG) strategy, termed BGA-Net. A comprehensive landslide hazard analysis, integrating static landslide susceptibility zonation with dynamic surface deformation monitoring, was therefore conducted. The study area selected was the upper reaches of the Jinsha River, particularly the site of the Baige landslide. The BGA-Net model was first proposed for LSP generation, achieving an accuracy exceeding 85%, while the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technology was jointly applied to comprehensively analyze the dynamic geological hazard risk at a regional scale. The final results were presented in a lookup table format and mapped to delineate and grade each risk level. The results show the method is practical, with high feasibility. Compared with traditional machine learning methods, the BGA-strategy-oriented CNN model more effectively differentiated the extremely low- and extremely high-susceptibility areas, enhancing decision-making processes.

Analysis of the impact of key strata failure on overlying strata and surface transport patterns

After mining the coal seam under the slope terrain in the southwestern mining area, it is difficult to predict the damage characteristics of the overlying strata and the surface movement and deformation law. To solve this problem, this paper comprehensively analyses the key strata by applying the theory, similarity simulation and the GDEM simulation software, and explores the influence of the change of the key strata’s height and thickness on the damage characteristics of the overlying strata and the surface movement and deformation. By analysing the key strata in the “inclined step” structure, the minimum support force for the key strata not to slip is obtained, and the minimum support force required for the key strata at different levels is deduced. The results of similar tests and numerical simulation analyses show that the vertical displacement of the overburden and surface will be smaller as the key layer is further away from the coal seam. AT the same time, the damage to the overlying strata and the surface is smaller when the key strata fails, and the location of the first subsidence of the slope surface due to mining is usually located in the area close to the bottom of the slope. In the stable structure from the key strata to the ground surface, once the key strata is unstable and broken, the damage and vertical displacement of the ground surface will increase dramatically, thus causing a series of geological disasters such as ground subsidence. Therefore, before the key strata are broken, grouting reinforcement measures are carried out for the rock fissures below the key strata to enhance the tensile strength of the key strata, which can effectively reduce the surface subsidence and deformation.

Engineering Visual Presentation E04: Predicting ground surface deformation induced from CO2 plume movement using machine learning

Engineering Visual Presentation E04: Predicting ground surface deformation induced from CO2 plume movement using machine learning

Advancing the Limits of InSAR to Detect Crustal Displacement from Low-Magnitude Earthquakes through Deep Learning

Detecting surface deformation associated with low-magnitude (Mw≤5) seismicity using interferometric synthetic aperture radar (InSAR) is challenging due to the subtlety of the signal and the often challenging imaging environments. However, low-magnitude earthquakes are potential precursors to larger seismic events, and thus characterizing the crustal displacement associated with them is crucial for regional seismic hazard assessment. We combine InSAR time-series techniques with a Deep Learning (DL) autoencoder denoiser to detect the magnitude and extent of crustal deformation from the Mw=3.4 Gallina, New Mexico earthquake that occurred on 30 July 2020. Although InSAR alone cannot detect event-related deformation from such a low-magnitude seismic event, application of the DL method reveals maximum displacements as small as (±2.5 mm) in the vicinity of both the fault and earthquake epicenter without prior knowledge of the fault system. This finding improves small-scale displacement discernment with InSAR by an order of magnitude relative to previous studies. We additionally estimate best-fitting fault parameters associated with the observed deformation. The application of the DL technique unlocks the potential for low-magnitude earthquake studies, providing new insights into local fault geometries and potential risks from higher-magnitude earthquakes. This technique also permits low-magnitude event monitoring in areas where seismic networks are sparse, allowing for the possibility of global fault deformation monitoring.

Mechanics of surface deformations in rigid bodies

Studying surface deformations in solids is crucial for advancing science and technology, informing material development, structural design and process enhancement. The purpose of study is to review and analyse the mechanics of surface deformations in rigid bodies in order to identify their features and develop new methods for describing and predicting such deformations. The study analysed theoretical models and experimental approaches to study surface deformation; among the methods used, the analytical method, classification method and synthesis method should be noted. In the study, the following parameters and aspects related to surface deformation in rigid bodies were investigated: material response to plastic deformation, mechanical properties, surface deformation characteristics, extent of deformation and behaviour under small deformations. The study investigates the impact of plastic deformation on the crystal structure of materials, focusing on grain boundary structure, dislocation motion and stacking faults. The main results of the study are the identification of the relationship between mechanical stress and surface deformation in rigid bodies. It was found that high mechanical stress leads to a change in the crystal structure of the material on the surface, which, in turn, affects its mechanical properties. Also, the results of the study are the establishment of relationships between the parameters of materials and the amount of surface deformation, as well as the identification of physical laws governing this process.

Factors influencing the effectiveness of SM-VCE method in solving 3D surface deformation

The recovery of coseismic 3-dimensional (3D) surface deformation field plays a crucial role in studying seismic source characteristics and earthquake hazards. As of now, there are two main types of methods for recovering coseismic 3D surface deformations: the first type is to solve the problem directly by using the least squares method based on observations from three or more viewpoints, and the second type solves the problem by combining ascending and descending InSAR line-of-sight (LOS) observations with constraint models. The former type is mainly applicable to surface rupture earthquakes, because when an earthquake ruptures to the surface, we can usually obtain surface deformation observations from three or more views. The latter type applies to earthquakes that do not cause surface ruptures and have extensive blind faults. Currently, most research focuses on improving the above types of methods. However, some key factors in the coseismic 3D surface deformation inversion are rarely mentioned, such as the influence of window size on the inversion results in the strain model and variance component estimation method (SM-VCE), and whether the outliers in the observational data are considered. So, we developed a new chain of integrating InSAR observation and SM-VCE model to systematically assess the impacts of window size and outliers on coseismic 3D surface deformation inversions. Through simulation experiments, we observed that the selection of window size significantly impacts the accuracy of the results. Specifically, larger window sizes lead to wider residuals ranges in the fault region, resulting in the loss of extreme solution values when using a window of 15 × 15 pixels (i.e., 7.5 km × 7.5 km). Hence, we recommend utilizing windows with 7 × 7 pixels or 9 × 9 pixels for optimal accuracy, as larger window sizes diminish the significance of the outcomes. The elimination of points displaying different deformation directions helps reduce residuals and preserves near-field deformation results. Furthermore, the residuals along the 3D direction can be reduced by 10%–30% when a small set of points is selected using a method based on Euclidean distances. However, when 441 points were selected, the vertical residuals increased by 22% compared to 81 points. Integration of the SM-VCE algorithm with robust estimation techniques effectively minimizes far-field deformation errors in data, thereby marginally enhancing the near-field deformation solution.

Three-point support analysis and optimization design under the change of gravity center of diamond lathe

The position of three-point support has an important impact on the stiffness and accuracy of the diamond lathe. To determine the position of the support, this paper commences by conducting static and dynamic analysis on the large-size platform machine tool whose base is 2340×1540 mm under the two support schemes. It determines the basic layout scheme of the support points of the machine tool under the change of gravity center. Subsequently, by combining the least squares fitting and particle swarm optimization algorithm with the optimization goal of minimum deformation of the machine tool base working surface, the position of the support points is optimized under the influence of the Change of Gravity center. The results indicate that the optimal solution of the design variable within the design interval can be obtained through limited sampling points and optimization iterations. The average and maximum deformation of the base working surface are 0.867 μm and 1.45 μm. They decreased by 11.17% and 26.02% compared with before optimization.

Investigation on algorithms for simulating large deformation and impact loads

It is a challenge to simulate the hydrodynamic problems covering the large deformation of the free surface arising in severe circumstances with intense flow. This paper investigates algorithms based on the moving particle semi-implicit method for simulating large deformation and impact loads. The algorithm discretizes the fluid domain into a series of particles, each representing a part of the fluid. The pressure field calculation is implicit, and the velocity field calculation is explicit. Three models, including the gradient model, source term, and free-surface detection, have been improved and compared to determine which improvement is the best to enhance the accuracy and stability. The enhanced pressure gradient guarantees that momentum conservation can be satisfied. Particle density and velocity divergence are incompressible conditions combined in the mixed source term approach. The arc approach is used in the free-surface judging process. The results show that the combination of three models is the most effective in exploring the problems of hydrodynamic pressure and dam break. The issue of liquid sloshing including roll and sway investigates the effect of the initial distance and time step. It is found that the simulation accuracy of impact pressure can be increased as the initial distance and the time step decrease. Finally, the free surface breaking and liquid splashing phenomena are easily observed, and the method can accurately simulate the massive deformation of the free surface. These findings are helpful for hazard assessments of the various fluid mechanics-related problems.

Ablation catheter–induced mechanical deformation in myocardium: computer modeling and ex vivo experiments

Cardiac catheter ablation requires an adequate contact between myocardium and catheter tip. Our aim was to quantify the relationship between the contact force (CF) and the resulting mechanical deformation induced by the catheter tip using an ex vivo model and computational modeling. The catheter tip was inserted perpendicularly into porcine heart samples. CF values ranged from 10 to 80 g. The computer model was built to simulate the same experimental conditions, and it considered a 3-parameter Mooney-Rivlin model based on hyper-elastic material. We found a strong correlation between the CF and insertion depth (ID) (R2 = 0.96, P < 0.001), from 0.7 ± 0.3 mm at 10 g to 6.9 ± 0.1 mm at 80 g. Since the surface deformation was asymmetrical, two transversal diameters (minor and major) were identified. Both diameters were strongly correlated with CF (R2 ≥ 0.95), from 4.0 ± 0.4 mm at 20 g to 10.3 ± 0.0 mm at 80 g (minor), and from 6.4 ± 0.7 mm at 20 g to 16.7 ± 0.1 mm at 80 g (major). An optimal fit between computer and experimental results was achieved, with a prediction error of 0.74 and 0.86 mm for insertion depth and mean surface diameter, respectively.Graphical

Deep Lithospheric Controls on Surface Deformation and Seismicity around the East Anatolian Fault Zone and A3 Triple Junction

Deep Lithospheric Controls on Surface Deformation and Seismicity around the East Anatolian Fault Zone and A3 Triple Junction

Research on the Wear Evolution Behavior of 20CrMnTi Alloy Steel under Different Loading Conditions

Abstract 20CrMnTi alloy steel has excellent surface hardness and good wear resistance, making it widely used in the preparation of key components of various high-speed and high-load gearboxes, such as gear, rack, and bearing. However, the existence of friction and wear behavior in service leads to various damage behaviors, which seriously affects its service stability and effective life. Based on experimental research and numerical simulation technology, this study reveals the damage evolution law of 20CrMnTi low carbon alloy steel under different wear load conditions. It is shown that the increase of wear load and time duration will obviously lead to the increase of contact stress and deformation of the material surface, and eventually lead to an increase in wear degree. The research findings provide experimental support and theoretical guidance for effectively predicting the damage law in actual service.

Large-scale laboratory investigation of pillar-support interaction

Underground mine pillars provide natural stability to the mine area, allowing safe operations for workers and machinery. Extensive prior research has been conducted to understand pillar failure mechanics and design safe pillar layouts. However, limited studies (mostly based on empirical field observation and small-scale laboratory tests) have considered pillar-support interactions under monotonic loading conditions for the design of pillar-support systems. This study used a series of large-scale laboratory compression tests on porous limestone blocks to analyze rock and support behavior at a sufficiently large scale (specimens with edge length of 0.5 m) for incorporation of actual support elements, with consideration of different w/h ratios. Both unsupported and supported (grouted rebar rockbolt and wire mesh) tests were conducted, and the surface deformations of the specimens were monitored using three-dimensional (3D) digital image correlation (DIC). Rockbolts instrumented with distributed fiber optic strain sensors were used to study rockbolt strain distribution, load mobilization, and localized deformation at different w/h ratios. Both axial and bending strains were observed in the rockbolts, which became more prominent in the post-peak region of the stress-strain curve.