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In order to clarify the key points of machine learning in surface deformation prediction of shield tunneling, the development background of machine learning was introduced, and the engineering application of machine learning was summarized from the aspects of database establishment, data preprocessing, model framework construction and model evaluation. It was pointed out that the shortcomings of the current relevant research were the lack of professional public database and the uneven quality of engineering data; for engineering with different stratum types, the model was prone to over fitting. At the same time, the further development direction of machine learning in shield tunneling surface deformation prediction was discussed, including the effective combination of algorithms could learn from each other; there was still a large research and application space for feature selection and super parameter optimization. [ABSTRACT FROM AUTHOR]

To address the problem that surface deformation causes in urban areas by affecting urban security and threatening human life and property, this study first measured the surface deformation in Shanghai from 2016 to 2020 using the time series InSAR method. Then, the spatial–temporal distribution and evolution characteristics of deformation were investigated in detail. The deformation mechanism is explained by factors including groundwater and rainfall. By introducing the seasonal changes of tides and sediment accumulation, the reason for the uplift in the Shanghai area is further explained. Finally, the surface deformation of the reclamation area is detected further. Meanwhile, the spatial–temporal variation characteristics of the surface in the reclamation area are explored. Through time series InSAR technology, the results of surface deformation in Shanghai demonstrate the following: (1) The deformation in the study area is uneven in time, and the subsidence is especially apparent during the 2016–2017 period. The maximum cumulative subsidence amounts to −131.1 mm, and the PS points with subsidence rates greater than −5 mm/y occupy 41.36% of all the subsidence points. In addition, PS points with uplift rates greater than 5 mm/y account for 39.55% of all the uplift points. The overall spatial distribution in the Shanghai area is characterized by the uplift in the north and subsidence in the south, whereas the cumulative subsidence in the time series presents a slowing trend; (2) Surface subsidence and groundwater, rainfall, and urban development in the Shanghai area are correlated. Seasonal changes in tides contribute to surface uplift in coastal areas. Coastal sediment accumulation and soil changes also make direct contributions to the occurrence of surface uplift; (3) The deformation of the reclamation area and the completion time are correlated, and the subsidence points of the reclamation area are mainly concentrated on the surrounding dikes from 2016 to 2020. The cumulative subsidence of the two years from 2016 to 2017 is up to −102.2 mm. The results of this study systematically explore the spatial–-temporal evolution and causes of surface deformation in Shanghai, providing scientific data which can support the development of Shanghai. [ABSTRACT FROM AUTHOR]

Due to the large cross-section design of large-diameter shield tunnels, most of the rocks and soils it crosses are composite strata with upper soft and lower hard. In order to reduce the construction cost of shield working shafts, large-diameter shield launching is usually buried at a shallow depth. Based on the typical large-diameter slurry shield tunnel, the following research results were obtained according to field monitoring and PLAXIS 3D finite element simulation. (1) The electronic level is used to monitor the surface settlement, and the field monitoring data were obtained; the surface settlement duration curve at the axis of the shield tunnel during the construction period can be divided into four stages: pre-deformation, shield passing, shield tail exit and shield moving away, of which the surface settlement accounts for the largest proportion during the shield passing. (2) In order to ensure the accuracy of the numerical simulation results, the linear shrinkage of the shield needs to be considered in the modeling. (3) The maximum surface settlement value at the center of the tunnel increases with the increase of the support pressure; when the support pressure exceeds 300 kPa, the surface uplift and the settlement caused by the formation loss will offset, and the surface settlement will decrease instead. The maximum surface settlement value is inversely proportional to the grouting pressure, but with the increase of the grouting pressure, the maximum uplift of the surface continues to increase. (4) With the numerical simulation of excavation step construction, the surface uplift increases with the increase of grouting pressure and shield radius, and decreases with the increase of shield buried depth. [ABSTRACT FROM AUTHOR]

Geological disasters caused by surface deformation are common, especially in urban areas, which seriously impede urbanization's sustainable development. Monitoring and analysis with high spatial and temporal resolution are particularly important to assess the risk of geological disasters caused by urban deformation. This study uses Sentinel-1A satellite imagery to obtain the surface deformation time series of Nanchang City based on SBAS-InSAR and PS-InSAR techniques and is combined with wavelet period analysis and gray correlation analysis to determine the correlation between deformation area and climate environment. This study shows that there was a large-scale subsidence trend in the central urban area of Nanchang in those two years, and an uplift trend in the agro-ecological areas in the southeast. A periodic analysis further shows that the areas with larger changes in surface deformation are more affected by changes in precipitation. This study, integrated with external data, examines the possibility of subsidence disasters occurring along subway lines in areas with large deformation magnitudes from multiple angles. [ABSTRACT FROM AUTHOR]

The development of urban underground space and traffic promotes the wide application of large section pipe jacking technology in urban tunnel construction.The functional requirements of parallel pipe jacking tunnel are different, so shapes and sizes of the section are also different.Based on the double-line parallel pipejacking tunnel with difference large section under through the main road in the city, a three-dimensional finite element calculation model is established for systematic analysis.At the same time, combined with the measured results of the field pipe jacking project, the characteristics and influencing factors of ground-surface deformation under different sections and different construction sequence of parallel pipe jacking are studied.The results show that the surface deformation curve caused by parallel differential section pipe jacking construction is Ⅴ-curve, and the peak point of the surface deformation curve gradually shifts from the large section rectangular pipe jacking axis to the two pipe centers.The surface settlement on the left side of the axis of the small section rectangular pipe jacking is larger than that on the right side of the axis.Construction of large section rectangular pipe jacking on the left line is more beneficial to control surface deformation.The influence of section size change on surface deformation is 30%, and the influence of process on surface deformation is 8%.The influence of section size difference on surface deformation is greater than that of process difference.The study on the influence of parallel differential section pipe jacking construction on surface deformation can provide theoretical basis and experience for future related parallel large section pipe jacking projects.

Underestimation of customized shortwall mining parameters of deep extra-thick coal seams (namely, mining height, mining width, and pillar width) may result in coal pillar instability, surface subsidence, and mining structure failure, while their overestimation would cause a waste of coal resources. This study proposes a new method for optimizing these parameters, whose main purpose is to achieve the maximum coal recovery rate while satisfying surface deformation and coal pillar stability requirements. A case study of an extra-thick coal seam in Eastern China with one km-overburden depth and a thickness of 10 m was analyzed. First, a new method for predicting surface deformation under deep customized shortwall mining based on surface deformation data from fully caving mining was proposed. The variation pattern of the extreme values of surface deformation parameters (including surface subsidence, tilt, curvature, and horizontal strain) versus the area-based recovery rate and mining width was analyzed. After that, the evolution law of the surface deformation with the changing mining height and area-based recovery rate was simulated using the FLAC3D software. The maximum recovery rate and the corresponding mining height, the area-based recovery rate were preliminarily determined, while the surface deformation fell within the allowable range. Simulations of evolutions of the plastic zone width, elastic core ratio, and vertical stress of coal pillars with varying coal pillar width under the maximum recovery rate were performed. The optimal mining scheme had a mining height of 10, a mining width of 100, a coal pillar width of 122 m. It ensured the coal pillar’s long-term stability with the surface deformation within the allowable range and achieved the maximum coal recovery rate of 45%. These findings are considered instrumental in the customized shortwall mining of extra-thick coal seams under buildings, in particular, under Eastern China mining and geological conditions.

In this paper, by applying theoretical method to the governing equations of compressible viscous flow, we derive the theoretical formula of the boundary dilatation flux (BDF) on a flexible wall, which generalizes the most recent work of Mao et al. (Acta Mechanica Sinica 38 (2022) 321583) for a stationary wall. Different boundary sources of dilatation are explicitly identified, revealing not only the boundary generation mechanisms of vortex sound and entropy sound, but also some additional sources due to the surface vorticity, surface angular velocity, surface acceleration and surface curvature. In particular, the generation mechanism of dilatation at boundary due to the coupled divergence terms is highlighted, namely, the product of the surface velocity divergence (∇∂B·U) and the vorticity-induced skin friction divergence (∇∂B·τω). The former is attributed to the surface flexibility while the latter characterizes the footprints of near-wall coherent structures. Therefore, by properly designing the surface velocity distribution, the dilatation generation at the boundary could be controlled for practical purpose in near-wall compressible viscous flows.

Soft soil has the characteristics of high compressibility, large void ratio, and strong structure. Therefore, it is more likely to cause surface subsidence or even surface cracking and collapse when laying oil and gas pipelines in soft soil areas through the pipe jacking method. In this study, test soil was pressurized using a flexible loading bladder, and variable formation losses brought on by pipe jacking were mimicked by varying the loading bladder’s water injection level. The surface deformation brought on by pipe jacking construction is related to the four parameters of stratum loss rate, overburden load, soil disturbance, soil tension fissures, and horizontal deformation. The findings demonstrate that the surface deformation brought on by the excavation gradually reduces and starts to stabilize after the thickness of the overlying soil layer on the pipe jacking surpasses 1.5 times the diameter of the pipe jacking. The constructed settling tank is broader the deeper the jacking pipe is submerged. Further ground surface settling will be exacerbated by the weight above the jacking pipe. The maximum ground surface deformation value will decrease with an increase in the overlying load when the overlying load is high (0.018 MPa).

Computer animation relies heavily on rigging setups that articulate character surfaces through a broad range of poses. Although many deformation strategies have been proposed over the years, constructing character rigs is still a cumbersome process that involves repetitive authoring of point weights and corrective sculpts with limited and indirect shaping controls. This paper presents a new approach for character articulation that produces detail-preserving deformations fully controlled by 3D curves that profile the deforming surface. Our method starts with a spline-based rigging system in which artists can draw and articulate sparse curvenets that describe surface profiles. By analyzing the layout of the rigged curvenets, we quantify the deformation along each curve side independent of the mesh connectivity, thus separating the articulation controllers from the underlying surface representation. To propagate the curvenet articulation over the character surface, we formulate a deformation optimization that reconstructs surface details while conforming to the rigged curvenets. In this process, we introduce a cut-cell algorithm that binds the curvenet to the surface mesh by cutting mesh elements into smaller polygons possibly with cracks, and then derive a cut-aware numerical discretization that provides harmonic interpolations with curve discontinuities. We demonstrate the expressiveness and flexibility of our method using a series of animation clips. [ABSTRACT FROM AUTHOR]

In order to study the influence of workpiece surface topography on deformation and residual stress during shot peening, the paper built a rough surface single-shot peening simulation model and designed a rough surface workpieces shot peening experiment to verify the correctness of the built simulation model, which differed from the smooth surface simulation model and was closer to the actual processing situation. Based on the W-M fractal dimension theory, the shot peening model of the target with a rough surface is established, and the simulation analysis is carried out by finite element software. The effect of different impact positions of the pellet on surface residual stress and surface displacement were also simulated. The simulation found that with the increase of surface complexity, the surface deformation and residual stress would both increase after shot peening. Through shot peening tests on workpieces with different surface roughness, it is found that the error between simulation and experiment results on surface deformation and residual stress are both less than 20%, which verifies the validity of the rough surface single-shot peening model and that the established model could provide a new method on shot peening simulation analysis. [ABSTRACT FROM AUTHOR]

Surface reconstruction is an essential operation in the evaluation of free-form surface form error. As a feasible technology in free-form surface sampling, touch-trigger probing has been widely used in on-machine measurement and coordinate measurement machine. However, surface reconstruction quality is influenced by limited sampling point size. This study proposes a surface reconstruction method based on surface position error and deformation error model. Surface form error is decomposed into surface position error and deformation error. Then, the design surface is taken as a rigid body, and a point-to-surface function-based iterative algorithm is conducted to adjust surface location and orientation to best match the sampling points. The advantage of this algorithm is that it considers the probe dimension, so further compensation of probe radius is not required. The geometry of the adjusted design surface is modified based on thin plate energy minimization and point-to-surface function. Due to the inherent feature of the proposed method, geometric features of the design surface are kept. Experiments are conducted to verify the effectiveness of the proposed method, and results show that the proposed method can achieve lower error compared with existing methods. • Surface location error and deformation error are defined and computed to evaluate the form error. • Geometry of the measured surface is modified based on thin plate energy minimization and point-to-surface function. • Experiment results show that the reconstruction accuracy is improved by 37.9%, compared with an existing method. [ABSTRACT FROM AUTHOR]

The historical Ukrainian rock-salt mining town of Solotvyno and its environmentally related problems are well-known. A complex monitoring system is needed to evaluate the current situation in order to revitalize the investigated area. In addition to other risks, surface deformation due to undermining is one of the major risks endangering building infrastructure in the inhabited area of the town. These processes are well-known in the area, and damages caused by the surface movement are often recognized. Measurement of the process's intensity and identification of the impacted area are crucial for any revitalization work. Information on these processes is the most important element of the hazard management and spatial-developmental planning of the town. This study aimed to characterize the long-term surface deformation processes and to identify the spatial and temporal trends and changes of these processes to assist spatial planning. The first step was to understand the surface deformation history from 1992. An InSAR-based assessment of the surface displacement of the undermined Solotvyno area was performed using data from three satellites, namely the ERS, Envisat, and the Sentinel-1, covering the time period between 1992 and 2021. The derived quantitative analysis indicated an intensive surface displacement and subsidence over the mining area. However, these displacements have not been even in the last 30 years of the investigation. The identification of the stabilized areas and recently started movements indicated the dislocation of the processes, which requires adequate actions for geohazard management and strategic planning. The demonstrated technology (InSAR) has the potential to set up an appropriate alarm system and provides an automated mechanism for continuous risk detection. A complex systems development is able to significantly reduce the geohazards over the unstable built-up zones. [ABSTRACT FROM AUTHOR]

Satellite radar interferometry is a powerful tool for measuring displacements of the Earth's surface. However, we recommend to extend the currently prevailing focus on ex-post analyses and monitoring towards ex-ante early warning applications. Underlying challenges and key requirements are discussed. [ABSTRACT FROM AUTHOR]

In order to better solve the problem of deformation in subway crossing construction, a new non-equal strength grouting method is proposed. The application effect of non-equal strength grouting is analyzed. The effects of grouting method, grouting strength and grouting thickness on surface settlement and differential settlement are studied. Non-equal strength grouting is applied to the actual production to analyze the displacement and differential settlement of bridge piles. The results show that non-equal strength grouting is more conducive to control the surface settlement and differential deformation, and make the settlement trough curve incline to be flat. The higher strength of the grouting structure, the larger width of the central grouting layer, the greater grouting thickness, and the more conducive to control the surface settlement. The non-equal strength grouting can be applied to the actual project to realize the coordinated deformation of stratum and existing structure. [ABSTRACT FROM AUTHOR]

The identification and early warning of potential landslides can effectively reduce the number of casualties and the amount of property loss. At present, interferometric synthetic aperture radar (InSAR) is considered one of the mainstream methods for the large-scale identification and detection of potential landslides, and it can obtain long-term time-series surface deformation data. However, the method of identifying anomalous deformation areas using InSAR data is still mainly manual delineation, which is time-consuming, labor-consuming, and has no generally accepted criterion. In this study, a two-stage detection deep learning network (InSARNet) is proposed and used to detect anomalous deformation areas in Maoxian County, Sichuan Province. Compared with the most commonly used detection models, it is demonstrated that the InSARNet has a better performance in the detection of anomalous deformation in mountainous areas, and all of the quantitative evaluation indexes are higher for InSARNet than for the other models. After the anomalous deformation areas are identified using the proposed model, the possible relationship between the anomalous deformation areas and potential landslides is investigated. Finally, the fact that the automatic and rapid identification of potential landslides is the inevitable trend of future development is discussed. [ABSTRACT FROM AUTHOR]

The excessive extraction and recharge of groundwater lead to long-time seasonal land subsidence in Los Angeles, USA, and especially in the Santa Ana basin. The rate of land subsidence in the Santa Ana basin has been rising, which could pose a danger to infrastructure and human lives. However, the most recent research on land surface deformation in the area was conducted using the traditional parameter estimation method, resulting in little understanding of the regional spatiotemporal characteristics. The parametric method consists of a least square linear inversion, using the pre-defined mathematical geometric or geophysical theoretical models to describe groundwater deformation, and it requires precise external environmental variables and accurate geophysical parameters, which are more difficult to implement. In this study, multitemporal InSAR-derived deformation time series are analyzed by using 69 descending C-band Sentinel-1A SAR scenes acquired from 2015 to 2018. A method based on independent component analysis (ICA) is applied to characterize the spatial pattern and temporal evolution of land subsidence in the Santa Ana basin. The results reveal two different spatial and temporal deformation patterns in the basin. First, a widespread seasonal deformation is identified by the first component, related to annual seasonal groundwater level changes, and the overall deformation shows a concentrated spatial pattern. The second component captures a long-term signal with a large-scale spatial pattern. For quantitative assessment, the obtained deformation time series are compared with the GNSS data, validating an accuracy of millimeters. We further calculate the cross-correlation coefficient and the elastic skeletal storage coefficient from the ICA-derived seasonal deformation and groundwater level, which reveals that the deformation responds quickly (i.e., a lag of 8 days) to the change in groundwater and the Santa Ana aquifer retains almost the same elasticity for at least 15 years. Quantifying the spatiotemporal characteristics of the deformation in the Santa Ana basin can provide a reference for the monitoring and managing of groundwater. [ABSTRACT FROM AUTHOR]

Shuicheng county is located in the west of Guizhou province. Under the comprehensive effect of natural environment and human activities，landslides occur frequently in Shuicheng county，which has the characteristics of strong concealment，high suddenness and strong destructiveness，which threatens the safety of local people′s life and property. It is urgent to identify potential landslides in Shuicheng county by effective means，so as to provide strong information support for disaster prevention and mitigation. In view of the fact that Shuicheng county is mostly mountainous and canyon areas，and traditional manual investigation methods are difficult to implement，this paper proposes an early landslide identification method based on interferometry synthetic aperture radar technology. In this method，the effective deformation points in the slope direction of Shuicheng county are obtained by the improved small baseline set interferometry technology. The spatial outliers of these deformation points are analyzed and clustered by Anselin Local Moran′s I index，and get the low value gathering area. Finally，combined with the surface features of Google Image，the potential landslide is identified.The results show that：the surface deformation rate of Shuicheng county is uneven，and there are multiple deformation centers，and the maximum deformation rate of slope direction reaches 142.3mm/a. Through the method of this paper，the potential landslides in Shuicheng county are identified，and combined with the field survey data，14 potential landslides are successfully identified， and 8 landslides are located in the invisible area of radar，so the identification is not successful [ABSTRACT FROM AUTHOR]

Landslides are a common type of disaster in Indonesia, especially in steepslope areas. The landslide process can be well understood by measuring the surface deformation. Currently, there are no practical solutions for measuring surface deformation at landslide locations other than field surveys in the Pacitan Regency. We apply LiCSBAS, to identify surface deformation in several landslide locations in a specific non-urban area with mixed topographical features. LiCSBAS is a module that utilizes data from the project of looking inside the continent from space (LiCS), using the new small baseline area subset (NSBAS) method. This study utilizes the leaf area index (LAI) to validate the ability of LiCSBAS to detect surface deformation values at landslide locations. The study succeeded in identifying surface deformations at 100 landslide locations, with deformation values ranging from 15.1 to 10.9 millimeters per year. Most of the landslide locations are closely related to volcanic rocks and volcanic sediments on slopes of 30-35°. The NSBAS method in the LiCSBAS module can reduce gaps error in the sentinel-1 image network. However, the utilization of the C-band at a pixel size of 100 meters made surface deformation only well detectable in a large open landslide area. [ABSTRACT FROM AUTHOR]

Aiming at the problems of natural disasters such as landslide and ground fissure caused by mining in loess gully area, based on the mining geological conditions of Hanjiawan Coal Mine, we sorted out the monitoring data of the surface observation points in the mining area. The surface monitoring results show that the working face generally experiences start-up period, active period and decline period from mining to stop. In the initial stage of mining, the surface movement and deformation of the mining area are not obvious; when the advancing distance of 12106 working face is between 13 m and 109 m, the surface movement and deformation change dramatically, and the maximum subsidence can reach 1 963 mm, which is easy to cause landslide disaster. At the same time, the physical and mechanical parameters of the rock mass of the slope of Hanjiawan Coal Mine were selected. The FLAC3D software was used to simulate the formation mechanism of surface landslide hazard under different slope angles. The overlying strata structure is destroyed due to the mining of working face, the whole subsidence basin is shifted to the center, and the slope is subjected to tensile and compression deformation, resulting in plastic failure. The results show that when the slope inclination angle is greater than 60°, the displacement of the slope is not uniform, and the rock layer with large displacement loses support, resulting in landslide disaster; when it is less than 30°, the slip surface of the bedrock surface develops to the surface, and the occurrence of landslide disaster is less likely.

In recent years, the economic factor has played an increasingly important role in the selection of technologies for manufacturing machine parts with specified values of normalized parameters of geometric accuracy and quality of working surfaces. As applied to surface plastic deformation processes, this is noticeably manifested in the search for effective friction control methods in the “tool – workpiece” pair, which ultimately determines the distribution pattern and the magnitude of stresses and strains in the workpiece and the tool. It is not possible to obtain a rigorous analytical solution to the problem of establishing a connection between surface conditions, friction, and the stress-strain state of the contacted bodies. In this regard, the construction of mathematical models comes to the fore, the solution of which is possible by numerical methods. The paper presents the results of a numerical study (computational experiment) of a finite-element model of workpiece deformation under various conditions of contact interaction and friction by one of the methods of surface plastic deformation – surface mandrel drilling. The friction coefficient has been chosen as the criterion for assessing the conditions of contact interaction and friction. It is shown that a change in the friction coefficient in the process of surface mandrel has no noticeable effect on the formation of a stress field in the deformable workpiece both in the axial, and in the radial and circumferential directions. At the same time, with an increase in the value of the friction coefficient in the “tool – workpiece” pair and with the associated increase in the force of mechanical resistance to deformation of the workpiece, their growth is observed. A computational experiment has confirmed the presence of non-contact deformations of the workpiece and tool during surface mandrel drilling, as well as as a decrease in the value of residual deformations in the workpiece with a decrease in the coefficient of friction. Balance assessment of contact surface displacements in the workpiece (the inner surface of the hole to be machined) and the tool (mandrel) has shown that the deformations of the tool in the elastic region can lead to a significant decrease in the real tightness of surface mandrel drilling.

Freezing method is used in the main shaft slotting repair project in Chensilou Coal Mine in China. According to the actual conditions of Chensilou Coal Mine, this paper established a numerical calculation model which included the following influence factors: thermodynamic parameters, borehole layout, original formation temperature, groundwater seepage, hot water circulation protection. The calculation results show that the reasonable brine temperature for the freezing project in Chensilou Coal Mine should be controlled between -30 °C and -25 °C and the reasonable freezing time should be 160 days. When the freezing time extends to 80–120 days, the freezing front has developed to the temperature-control hole. In this case, the hot water circulation of the temperature-control hole needs to be started and the hot water temperature is not lower than 20 °C. The freezing construction was implemented in accordance with the optimized brine temperature and freezing time, and the freezing of tower foundation has been successfully avoided. The measured results show that the tower tilts to the northeast as a whole during formation freezing and the tilt values are all less than the allowable value.

This paper proposes a general algorithm to reconstruct watertight 2-manifold 3D bone surface model from CT images based on visual hyper-spherical mapping. The reconstruction algorithm includes three main steps: two-step thresholding, initial watertight surface reconstruction and shape optimization. Firstly, volume sampling points of the target bone with given narrower threshold range are extracted by thresholding with combination of 3D morphology operation. Secondly, visible points near the bone's outer surface are extracted from its corresponding volume sampling points by hyper-spherical projection mapping method. Thirdly, implicit surface reconstruction algorithm is employed on the extracted visible surface points to obtain an initial watertight 3D bone surface model which is used as the deformation model in the following accurate bone surface model generation stage. Finally, the initial surface model is deformed according to the segmentation data with wider threshold range under given constraints in order to achieve an accurate watertight 3D bone surface model. Experiment and comparison results show that the proposed algorithm can reconstruct watertight 3D bone surface model from CT images, and local details of the bone surface can be restored accurately for the cases used in this paper.

Abstract The Gorkha earthquake 2015 was one of the largest disastrous events that occurred in the main Himalayan thrust (MHT) region with epicenter at Gorkha region and magnitude of 7.8 which caused severe causality to life as well as property. The spatial statistics on vertical displacement and extent of damage zone is still too scarce to provide strong evidences of its hazard potential. In the present study, quantitative assessment on surface deformation has been carried out to compare land displacement of two different regions of Nepal (the Central Nepal and the Eastern Nepal), which are located at different distances from the epicenter, using InSAR technique on post- and pre-earthquake images from Sentinel 1A SLC product. The Central Nepal experiences an upliftment of 1.1 m and land subsidence of − 0.61 m, whereas for the Eastern Nepal the estimated upliftment and subsidence were 1.0 m and − 0.33 m, respectively. Further a regional earthquake-prone zone map was generated using the historical earthquake epicenter data and geographic information system (GIS) to understand the major vulnerability zones in the area. A total of 564 earthquake events were reported by USGS in Nepal region during 2000–2019, of which 476 (84.39%) were of magnitude greater than 4 on Richter scale and 376 events (66%) occurred at depth greater than 15 km. The damage assessment was done using machine learning (artificial neural network) back-propagation model in which the satellite imagery retrieved from the optical satellite Landsat 8 OLI sensor and digital elevation model was used to map slope, aspect, relief, drainage and lineament to be used as input layers to generate damage proxy map. The result obtained from ANN illustrated that despite being located comparatively at more distance from epicenter, the Eastern Nepal exhibited more damage-prone area (587 sq. km) in comparison with Central Nepal with 457sq. km damage prone in similar zone. Central Nepal evidences more damage-prone areas over compact build-up in contrast to Eastern Nepal, making greater risk potential in urban areas of Central Nepal during earthquake activity.

The article deals with tribochemical influence of the surface activity of biosynthetic oils on the operational efficiency and reliability of lubricated friction nodes under the critical conditions. It is proved that the oil surface activity is caused by the structure and properties of their molecules and interactions with steel surfaces. Evaluating criteria of oil tribochemical activity influence on the steel surface modification has been studied. The significant influence of biooils on the steel surface nanolayer phase transformations, friction and steel wearing is claimed. It has been established that the effect of the steel crystal structure deformation and strengthening its surface depends on activity of composition of lubricant. It is proved that biooils lead to improved friction and wear indicators of lubricated samples. X-structural analysis of the steel surfaces showed that during friction the austenite is destroyed and ferrite is formed. Penetration in the lubricated steel nanolayers shows increasing the ferrite and decreasing the austenite content, that cases reducing the deformation degree of metal crystals, which leads to the strengthening of its surface under the plasticized layer and to decreasing the level of friction and wear due to the formed intersurface servitotribopolymer film, which is stable under critical friction.

The northern scenic area of Changbai Mountain is a high-incidence area of debris flow disasters, which seriously threaten the safety of tourist’s lives and property. Monitoring debris flow and providing early warning is critical for timely avoidance. Monitoring the change of debris flow source is an effective way to predict debris flow, and the change of source can be reflected in the settlement deformation of the study area. The offset tracking technique (OT) is insensitive to the coherence of SAR images and can resist the decoherence of D-InSAR and SBSA-InSAR to a certain extent. It is a technical means for monitoring large gradient deformation. It has been widely used in the field of seismic activity, glaciers and landslides in recent years, but few scholars have applied this technique in the field of debris flow. In this paper, we use OT techniques in combination with field surveys, Google imagery and Sentinel-1 data to monitor surface deformation in the northern scenic area of Changbai Mountain in 2017 and use D-InSAR techniques to compare and complement the OT monitoring results. The results of this study show that for monitoring surface deformation in the study area after a mudslide, it is better to use both methods to determine the surface deformation in the study area rather than one, and that both methods have their own advantages and disadvantages and yet can complement each other. Finally, we have predicted the development trend of mudflows in the study area by combining the calculated single mudflow solids washout, which will help to improve the long-term monitoring and warning capability of mudflows in the study area. The study also enriches the application of offset-tracking technology and D-InSAR in the field of geohazard monitoring and provides new ideas and methods for the study of mudflow material source changes.

Many volcanoes show continuous but variable deformation over timescales of years to decades. Variations in uplift rate are typically interpreted as changes in magma supply rate and/or a viscoelastic response of the host rock. Here we conduct analogue experiments in the laboratory to represent the inflation of a silicic magma body at a constant volumetric flux, and measure the chamber pressure and resulting surface displacement field. We observe that dyke intrusions radiating from the magma body cause a decrease in the peak uplift rate, but do not significantly affect the spatial pattern of deformation or spatially averaged uplift rate. We identify 4 distinct phases: 1) elastic inflation of the chamber, 2) a gradual decrease in the rate of uplift and pressurisation, associated with the formation of visible cracks 3) propagation of a dyke by mode 1 failure at the crack tip and 4) a pressure decrease within the chamber. Phase 2 can be explained by either a) crack damage, which reduces the elastic moduli of the surrounding rock or b) magma filling pre-existing cracks. Thus these experiments provide alternative mechanisms to explain observed variations in uplift rate, with important implications for the interpretation of deformation patterns at volcanoes around the world. • Analogue experiments represent an inflating magma chamber at constant volume flux • Radial dyke intrusions change the uplift rate but not the deformation pattern • Reduced uplift rate can be explained by damage zone or opening of pre-existing cracks • Key implications for the interpretation of deformation patterns at volcanoes [ABSTRACT FROM AUTHOR]

The eruption of Hunga-Tonga Volcano on January 15, 2022 has stimulated a wide spectrum of atmospheric waves globally. To probe the surface deformation pattern, Sentinel-1 Synthetic Aperture Radar (SAR) data has been analyzed. It has been approximated that an overall area of about 2.47 square kilometres experienced deformation in conjunction with this event. To characterize the atmospheric wave propagation, barometric pressure data from 1814 stations distributed all around the globe have been examined. This study encompassed with the propagation characteristics of the waves over four zones including Indian and Polar regions for the first time using barometric data. Time-series observations indicate that the waves propagated globally multiple times. Within the Indian region, three minor arc passages and one major arc passage were identified. In Japan, two minor arc passages and one major arc were present. Conversely, in North America, both minor and major arc passages were detected, occurring a minimum of three times. Moreover, the attributes of these waves, such as their propagation speed and periodicity, were compared across these four regions. The estimated phase speed and periodicity fall within the ranges of approximately 291–314 m/s and 10–180 min, respectively including Polar Regions. These speed and periodicity measurements of the observed waves suggest that the dominant mode of wave propagation generated during the Tonga volcanic eruption is that of Lamb waves. In addition, a slower propagation phase speed of about 226.6 m/s was identified in Japan which corresponds to Pekeris mode of waves. • Hunga-Tonga volcanic eruption triggered atmospheric waves that travelled globally in all direction multiple times. • Analysis of barometric data from India, Japan, North America and Polar Regions reveal the multi-wave characteristics of atmospheric waves. • The comparison of phase speed and periodicities are in the range ∼291–314 m/s and 45–50 min respectively. [ABSTRACT FROM AUTHOR]

Over the past several years, a metal mine by block caving method has experienced a long-term and progressive surface deformation and fracturing, and then we start our investigation based on this background. The location of surface rupture was based on a series of mapping activities and the deformation data was collected by GPS from 2013 to 2016. In this paper, emphasis was put on the analysis of the fissures, deformation and stress of surface subsidence. Results reveal the diversity magnitude and structural features of surface deformation and ground fissures. In addition, the time dependent behavior is comprehended and the subsidence zone reflects different types of time-displacement curve – regressive phase, steady phase and progressive phase, all these achievements indicate the complexity and diversity of the subsidence zone. On the other hand, stress calculation which inspired from the mechanical model of the cracking of hole wall is carried out, it is meaningful to understand the relation between fracture features, displacement vectors and horizontal stress. [ABSTRACT FROM AUTHOR]

The 22 August 1902 Mw 7.7 Atushi earthquake is the most disastrous seismic event in the southwestern Tian Shan. However, the spatial distribution of surface rupture zones as well as the geometric feature of surface deformation remain unclear, and the seismogenic fault is still controversial. Based on geologic and geomorphic interpretations of multiple remote sensing imaging data, high-resolution DEM data derived from UAV imaging complemented by field investigations, we mapped two sub-parallel NEE-trending surface rupture zones with a total length of 108 km. In addition, ~60 km and ~48 km surface rupture zones are distributed along the pre-existing Atushi fault (ATF) and the Keketamu fault (KTF), respectively. The surface deformations are mainly characterized as bedrock scarp, hanging wall collapse scarp, pressure ridge, and thrust-related fold scarps along the two south-dipping thrust faults, which are defined as the seismogenic structure of the 1902 Mw 7.7 Atushi earthquake. Thus, we proposed the cascading-rupture model to explain the multiple rupture zones generated by the 1902 Mw 7.7 Atushi earthquake. Moreover, the multiple advanced remote sensing mapping techniques can provide a promising approach to recover the geometric and geomorphic features of the surface deformation caused by large seismic events in the arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

In order to prevent landslide and collapse in the mining area, it is essential not only to gain a full understanding of the surface deformation information about the open-pit mining area and surrounding dumps, but also to closely monitor the development of surface deformation. Small baseline set (SBAS) technology can be applied to extract the high-resolution spatial-temporal deformation information from the mining areas. Due to decoherence, however, it is difficult to obtain the effective information on deformation from some areas where the results are monitored. This paper proposes a kriging interpolation method that performs better in filling the missing values in the InSAR monitored results by integrating GPS measured data with InSAR monitored data. In the experimental process, 69 Sentinel-1 image data were collected from July 2018 to November 2020. The SBAS-InSAR technology was applied to monitor the surface deformation caused to the Kunyang phosphate mining area and surrounding dumping sites. It was found out that all the mining areas across the Kunyang Phosphorus Mine and the surrounding dumps suffered severe surface deformation, with the maximum line of sight (LOS) deformation rate of −132 mm/yr located in the dump in the north of the second mining area. The verification result shows that InSAR measurement results are consistent with the deformation estimated from GPS measurements. The root mean square error of most points is maintained within ±10 mm. The Kriging interpolation results of fusion GPS data are in good agreement with the GPS results. The root mean square errors at the 4 verification points are ±6.2 mm, ±4.6 mm, ±6.4 mm, ±7.8 mm. The method proposed in this paper is effective in filling in the missing values in the incoherent area, and can be applied to mine surface deformation monitoring with high reliability. The results of this paper serve as a scientific basis for the prevention and control of landslides, collapses and other hidden risks of geological disasters posed by the mining operations conducted in the Kunyang Phosphorus Mine. [ABSTRACT FROM AUTHOR]

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İzmir, the third-largest city and economic center of Turkey, has been exposed to many natural disasters throughout its history. It is one of them in the 6.6 magnitude earthquake that last occurred on October 30, 2020. In this study, the PSInSAR technique was applied on 26 descending Sentinel-1 images between February 2020 and January 2021 to monitor the land change of the study area determined in Izmir. PSInSAR method was carried out with the SNAP-StaMPS integration, whose methodology is given below. The annual velocity values of the PS points produced in the study area in the direction of satellite view were found between – 68 and 32 mm/year. As a result of the study, it was observed that the most prominent surface change occurred in Çiğli and Karşıyaka districts. The points containing the speed information obtained from the PSInSAR result, PS points, and maps showing changes in the land were shared online to be used as auxiliary data in other studies. [ABSTRACT FROM AUTHOR]

After the mine is closed, the coal and rock mass undergoes weathering degradation and strength reduction under the action of various factors such as stress, groundwater and oxygen. Moreover, the stress and bearing capacity of the mining fractured rock mass is changed, which is likely to cause secondary deformation of the surface of the goaf. Most of the existing researches focus on the monitoring of surface deformation during the mining process, while there are few researches on the monitoring of surface deformation after mine closure. To investigate the surface deformation law of closed mines, 62 Sentinel-1A images from 2015-12-21 to 2019-12-24 and small baseline subset-interferometric synthetic aperture radar (SBAS-InSAR) technology are used to obtain the surface deformation results and deformation laws of the time series within 4 years of the closed mines in western Xuzhou (including Pangzhuang Mine, Jiahe Mine and Zhangxiaolou Mine). The research results show that the maximum surface subsidence rate in three mines is -48 mm/a, and the cumulative maximum subsidence in 4 years is 178 mm. The surface of the Jiahe Mine shows subsidence followed by uplift, while the surfaces of the Pangzhuang Mine and Zhangxiaolou Mine continue to sink. The maximum surface deformation of three coal mines within 4 years is 1.70 mm/m, and the maximum curvature deformation is -0.039 mm/m2. Through interpolation statistical calculations, the surface deformations which are greater than 10 mm of Pangzhuang Mine, Jiahe Mine and Zhangxiaolou Mine are 10.5, 13.7 and 11.6 km2 respectively, and they are increasing year by year.

Over the past decade, Chengdu has become one of the fastest growing urban centers in China. However, the massive expansion of the infrastructure and the transportation network has resulted in surface subsidence which typically presents as a hard to detect geological hazard. As an all-day, all-weather, high-precision, and wide-range surface deformation monitoring tool, interferometric synthetic aperture radar (InSAR) technology has unique advantages with respect to monitoring long-period surface subsidence. In this article, the Sentinel satellite data from March 2018 to March 2021 for the ascending and descending orbits are used to obtain the deformation fields of Chengdu's surface in two different satellite line of sight directions using the time-series InSAR technique. The results are then used to invert the surface deformation field in the vertical direction and analyze it via the Peck and Logistic models. In addition, wavelet transform technology was used to investigate the relationship between deformation and climate. The results show that the surface deformation in Chengdu is stable, and the rate of deformation in the center of the urban area is within 5 mm/year. The main reason for the emergence of ground settlement funnels is the construction of subways and real estate development. It was also observed that the deformation of the buildings shows a clear periodic pattern, which is closely related to the seasonal rainfall and temperature in Chengdu.

Existing studies on surface deformation prediction consider single soil layers and straight-line excavation when investigating deformation caused by metro shield construction. In this study, we provide a new prediction method for studying the soil deformation caused by curved shield tunnel construction in the upper soft and lower hard soil. The deformation equations are derived using the Mindlin solution and random medium theory and are verified using engineering examples and numerical simulation. The influencing factors and laws of the surface deformation caused by the excavation are also identified. The study found that the horizontal settlement trough on the ground surface was distributed asymmetrically during the curve construction, with maximum settlement on the inner side of the curve. The offset and settlement values were affected by the thrust difference coefficients α and β and the turning radius. When constructing in the upper soft and lower hard soil layers, the settlement trough tends to become wider and shallower. The results show that the derived equation is suitable for actual engineering calculations, and the measured data are in good agreement.

Changes in groundwater storage in California's Central Valley (CV) are considered partly responsible for vertical uplift surrounding the southern CV and for stress changes on nearby faults. Questions remain regarding the distribution of stress on the central San Andreas fault (CSAF) from recent and historical drawdown of the CV aquifer over the past 150 years (1860–2010). We combine groundwater storage change estimates for the 2006–2010 drought with a three‐dimensional finite element model to estimate Coulomb failure stress change (ΔCFS) on the CSAF. We combine a simple parameterization of historical hydraulic head change for 1860–1960 with a CV hydrological model (1961–2003) to estimate visco‐elastic effects on ΔCFS total and 2010 rate. We find that ΔCFS on the CSAF correlates positively with shallow seismicity and low frequency earthquakes for both short‐term and long term stressing. Unloading uplift rates surrounding the southern CV only partially account for the observed vertical GPS rates. Plain Language Summary: We investigate the spatial and temporal effects of groundwater removal in California's Central Valley on ground surface deformation and on stress changes on the nearby central San Andreas fault (CSAF). In particular, we focus on two outstanding questions: (a) What are the spatial distributions of Coulomb failure stress (ΔCFS) on the CSAF? (b) What are the effects of viscoelasticity on uplift and ΔCSF over time? We focus on the well studied 2006–2010 drought, estimating the change in groundwater storage and the resulting uplift and stress change through a numerical model for the Earth. Viscoelastic effects are examined through an estimate of historical groundwater change from 1860‐1961 and a hydrological model from 1961‐2003 added to the 2006–2010 drought estimates. Here we find that lower crust or upper mantle viscosity variations enhance uplift and stress changes and that CSAF stress changes may accumulate with time, especially with droughts and groundwater consumption. Key Points: We estimate Central Valley groundwater unloading viscoelastic effects on present‐day central San Andreas (CSAF) fault stressingCoulomb stress change for the CSAF during the 2006–2010 drought corresponds positively with seismicity and low frequency earthquakesCumulative Coulomb stress change on the CSAF for 1860–2010 is on the order of ∼0.01–0.02 MPa depending on the lower crustal viscosity [ABSTRACT FROM AUTHOR]

The Western European Alps display measurable surface deformation rates from leveling and GNSS data. Based on the time‐series analysis of 4 years of Sentinel‐1 data, we propose for the first time an InSAR‐based mapping of the uplift pattern affecting the Western Alps on a ∼350 × 175‐km‐wide area. This approach provides a denser spatial distribution of vertical motion despite the high noise level inherent to mountainous areas and the low expected deformation signal. Our results show consistency with other geodetic measurements at the regional scale, and reveal smaller‐scale spatial variations in the uplift pattern. Higher uplift rates are found within the external crystalline massifs compared to surrounding areas, in agreement with the variations expected from recent deglaciation and long‐term exhumation data. This work brings the first InSAR‐based geodetic clue of differential uplift within the Alpine belt in response to the surface and deep processes affecting the belt. Plain Language Summary: The surface of the Earth is constantly moving from about a few millimeters to a few centimeters per year in response to geological processes such as tectonic plate motions and gravitational re‐equilibrium. In the Western European Alps, where the mountain‐building phase of the belt is over, the processes at the origin of surface motions are under debate. Mapping surface displacements at the highest possible resolution is mandatory to better understand the evolution of the Alpine belt. Among other techniques, radar satellites can provide measurements of such displacements. Here, radar images from the recent Sentinel‐1 satellite allow us to improve the spatial resolution of vertical surface displacements in the Western Alps compared to previous techniques. Thanks to the unmatched frequency of acquisitions from this satellite, we are able for the first time in our study area to measure small‐scale spatial variations within the vertical motions. These variations appear correlated to distinct geological units. This brings new insights into the geological processes acting nowadays on the Western Alps. Key Points: We use four years of Sentinel‐1 radar acquisitions to derive interseismic line‐of‐sight velocities over the Western European AlpsInSAR‐derived velocities are consistent with other geodetic studies and provide increased spatial resolution of surface velocity patternsShort‐wavelength spatial variations show locally higher velocities localized on crystalline massifs, interpreted as higher uplift rates [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to reduce the experience dependence during the orthognathic surgical planning that involves virtually simulating the corrective procedure for jaw deformities. Methods: We introduce a geometric deep learning framework for generating reference facial bone shape models for objective guidance in surgical planning. First, we propose a surface deformation network to warp a patient's deformed bone to a set of normal bones for generating a dictionary of patient‐specific normal bony shapes. Subsequently, sparse representation learning is employed to estimate a reference shape model based on the dictionary. Results: We evaluated our method on a clinical dataset containing 24 patients, and compared it with a state‐of‐the‐art method that relies on landmark‐based sparse representation. Our method yields significantly higher accuracy than the competing method for estimating normal jaws and maintains the midfaces of patients' facial bones as well as the conventional way. Conclusions: Experimental results indicate that our method generates accurate shape models that meet clinical standards. [ABSTRACT FROM AUTHOR]

[Display omitted] When a laser beam induces surface tension gradient at the free surface of a liquid, a weak surface depression is expected and has been observed. Here we report giant depression and rupture in "optothermocapillary fluids" under the illumination of laser and sunlight. Computational fluid dynamics models were developed to understand the surface deformation and provided desirable physical parameters of the fluid for maximum deformation. New optothermocapillary fluids were created by mixing transparent lamp oil with different candle dyes. They can be cut open by sunlight and be patterned to different shapes and sizes using an ordinary laser show projector or a common laser pointer. Laser driving and elevation of optothermocapillary fluids, in addition to the manipulation of different droplets on their surface, were demonstrated as an efficient controlling method and platform for optofluidic operations. The fundamental understanding of light-induced giant depression and creation of new optothermocapillary fluids encourage the fundamental research and applications of optofluidics. [ABSTRACT FROM AUTHOR]

In order to solve the problem of surface deformation and movement caused by coal mining under buildings in the south wing of Maokhe Coal Mine. By means of theoretical analysis and numerical simulation, the inclined zoning, oblique slicing and filling mining method is adopted for the -80~ 0 m stage of V9b coal seam in the south wing area. The calculation parameters of surface movement are determined, and the numerical simulation model of surface movement law is established by using FLAC3D software. The surface deformation and movement law is analyzed when the filling rate is 0, 80%, 85% and 90%. The results show that when the filling rate is 0, the maximum horizontal deformation of the surface is 8.40 mm, the maximum inclination is 14.60 mm/m, and the maximum curvature is 0.86; when the filling rate is 80%, the maximum horizontal deformation of the surface is 2.40 mm, the maximum inclination is 4.30 mm/m, and the maximum curvature is 0.21; when the filling rate is 85%, the maximum horizontal deformation of the surface is 1.70 mm, the maximum inclination is 2.80 mm/m, and the maximum curvature is 0.14; when the filling rate is more than 85%, the surface buildings can be guaranteed to be within the level I damage, and effect of filling and mining is good. [ABSTRACT FROM AUTHOR]

Based on the emergency monitoring data of vertical deformation, horizontal displacement, and crack width change of Huaying village in Chongqing, and combined with the ground elevation data of the study area, this paper describes the characteristics of vertical deformation and horizontal displacement of the study area through spatial analysis and modeling technology, and reveals the spatial relationship between them and the characteristics of ground cracks. The main conclusions are as follows: (1) The terrain conditions play an important role in limiting the development of ground cracks; (2) deep underground space development activities lead to horizontal displacement of the surface to the underground vibration center; (3) ground fissures mainly develop in areas with a large differential settlement of steep slopes at the edge of the settlement funnel; and (4) the hard fixed infrastructure is more susceptible to ground fissures. It is suggested that we should pay attention to the influence of earthquake and underground vibration activities in the study of urban ground fissures, and pay attention to the construction of the “funnel” three-dimensional model of land subsidence to monitor the change of horizontal displacement field of the surface. [ABSTRACT FROM AUTHOR]

The radiation patterns of an active phased array antenna (APAA) will inevitably deteriorate in service, due to the physical deformation of the antenna surface. Therefore, it is crucial that the APAA has an adaptive correction capability for the deterioration of the radiation patterns. This paper investigated an adaptive correction method for the radiation patterns of a deformed APAA, according to a small amount of measured strains from fiber Bragg grating (FBG) sensors. In this method, two kinds of strain-electromagnetic coupling models, which can change the excitation currents of antenna elements, were established using the phase correction and fast Fourier transform, respectively. The strain-electromagnetic coupling models are applied to quickly calculate the adjustment values of excitation currents, and then the corrected excitation currents are sent to the beam control circuit for compensating the influences of the antenna surface deformations. An X-band APAA experimental platform was developed. Some experiments were carried out, and the advantages of two coupling models were also compared and analyzed. The experimental results demonstrated that the proposed method can effectively correct the deterioration of radiation patterns caused by various antenna surface deformations. This method is suitable for developing an adaptive correction system in some applications such as the wing-APAA of an aircraft or the space-based flexible APAA.

The environment management and land utilization of the abandoned mining region is critically dependent on precise monitoring and comprehensive understanding of mining subsidence. In order to overcome the shortcomings of the traditional distributed target phase optimization method in the space continuity constraints of adjacent pixels, an improved phase optimization algorithm was proposed, which combines region growing and time series interferometric synthetic aperture radar with distributed scatterers (DS-InSAR). By using 17 L-band and 51 C-band SAR images, the characteristics of temporal and spatial distribution in Peibei mining area of Xuzhou, China, were obtained during the period from 2007 to 2011 and the period from 2017 to 2020. With the long-term monitoring, the evolution of deformation in the mining area was carried out. The modified phase optimization technique has proven its ability in the density of measurement points and the influence of noise in space, which is promising for the detection of large gradient deformation and the accurate analysis of surface deformation in mining areas. The study has been concentrated toward detecting continuous subsidence in the mining region. Coal mines in operation are usually accompanied by unstable ground, and the uplift or second subsidence has sometime occurred in the closed mine region. Conclusively, the presented methodology is practically feasible for long-term deformation pattern analysis in coal-exhausted mining areas.

A method of ultrasonic surface plastic deformation is widely used to change the properties of the surface layers of metal products. Under the influence of this type of treatment, the structure of the material changes, microhardness increases, roughness decreases, internal tensile stresses are removed, and compressive stresses are created. Now many types of ultrasonic surface plastic deformation have been developed, which differ in the degree of impact on the material. The object of this paper is to study the change in the microgeometry of steel 45 (ASTM M1044; DIN C45; GB 45) under the action of ultrasonic plastic deformation by a free deforming element (indenter in the form of a surface rolling ball). During the study, factors that have the greatest influence on the change in the microgeometry of the sample during treatment were identified. These include the initial roughness of the sample, the number of passes of the indenter, the feed of the indenter, the force with which the indenter is pressed to the treated surface, and the amplitude of the oscillations of the ultrasonic horn. The paper presents the dependences of changes in the main roughness parameters on the above factors. The value of the initial roughness at which it is possible to obtain a uniform surface microrelief is determined. The optimization of treatment parameters providing a change in the height and step parameters of roughness was carried out. Recommendations for choosing the most effective technological modes of ultrasonic treatment of steel 45 with a surface rolling ball are given.

Abstract Interferometric synthetic aperture radar (InSAR) has become an essential technique to detect surface variations due to volcanoes, earthquakes, landslides, glaciers, and aquifers. However, Earth's ionosphere, atmosphere, vegetation, surface runoff, etc., introduce noise that requires post‐processing to separate its components. This work defines a generator to create interferograms that include each of those components. Our approach leverages deformation models with real data, either directly or through machine learning using geostatistical methods. These methods result from previous developments to more efficiently and better simulate spatial variables and could replace some statistical approaches used in InSAR processing. We illustrate the use of the generator to simulate an artificial interferogram based on the 2015 Illapel earthquake and discuss the improved performance offered by geostatistical approaches compared with classical statistical ones. The generator establishes a tool for multiple applications (1) to evaluate InSAR correction workflows in controlled scenarios with known ground truth; (2) to develop training sets and generative methods for machine learning algorithms; and (3) to educate on InSAR and its principles.

Climate warming has accelerated permafrost degradation over the Qinghai-Tibet Plateau (QTP) over the past several decades. The development of thermokarst landforms is a key indicator of permafrost degradation, while it lacks quantified measurements and comprehensive research over the QTP. The aim of this study is to investigate the development of thermokarst terrains through repeated ground-based elevation observations by using terrestrial laser scanning (TLS) in the northern QTP from April 11, 2016 through June 16, 2018. TLS Time series analysis reveals that the margin of the thermokarst landforms undergoes significant ground subsidence, side materials collapse, and/or uplift and deposit, especially in the southeastern, northwestern part of thermokarst landforms during the middle through the late thaw season. The vertical deformation and headwall retreat of thermokarst landforms reached −3.364 m and 10.66 m from April 11, 2016 to June 16, 2018, respectively. We also generated high-resolution orthophotos based on aerial photos acquired by the built-in 4 K RGB (red, green, blue) camera of DJI Phantom 3 Professional unmanned aerial vehicle (UAV) in April and October of 2016. The UAV images confirmed the TLS observations during the same period and presented the severely deformed area. This study reveals that the seasonal vertical deformation and headwall retreat of the thermokarst landforms in the study site are consistent with seasonal ground temperature change during the observed period. Extreme precipitation event as a key factor triggered the severe deforming of the case study thermokarst. Ground ice, peat layer, and human activity also contributed to the thermokarst landforms formation. The results also illustrate that TLS is an effective method for studying thermokarst development quantitatively.

Coal gangue, as a solid waste produced in the coal mining process, can be disposed by being prepared into backfill materials and then filled in underground goafs, thus controlling strata movement and surface subsidence. However, gangue backfill materials are non-continuous; therefore, research into the surface deformation induced by backfill mining should consider the creep compression behavior of gangue backfill materials. The research took a backfill panel in Tangshan Coal Mine (Tangshan City, Hebei Province, China) as the background. In addition, broken coal gangue was collected in the field to prepare specimens of gangue backfill materials, and their creep compression properties were measured. The corresponding constitutive equation of creep compression was then established and embedded in the numerical software, FLAC3D. By building the numerical model for surface deformation induced by backfill mining, the surface deformation above the backfill panel under conditions of different creep durations of backfill materials was simulated and evaluated. In addition, two measuring lines were arranged on the surface to monitor changes in surface subsidence. After surface subsidence stabilized, the maximum surface subsidence was 163.4 mm, which satisfied the fortification criterion of surface buildings. This means the backfill mining did not affect nearby buildings. The results provide a theoretical basis for predicting surface deformation induced by backfill mining and its effective control.