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AbstractThis study compares dip brazing and TIG welding operations carried out under optimal conditions on the parameters of strength, deformation, and ability to resist shocks for Al-64430 joints, which find extensive use in automobile and telecommunication industries. The fabricated samples were tested for bump test, surface deformation, microhardness and tensile strength, and the joint properties were studied through SEM, EDAX mapping and EDX. Compared to the dip-brazed samples, the TIG welded samples achieved 161% greater strength and 1000% greater elongation but subsequently 1330% higher surface deformation. Both joints were able to pass the bump test; however, some degree of cracks were observed post testing in both samples. Both samples achieved similar joint microhardness values, but notably, compared with the TIG welded sample, the brazed sample showed no HAZ zones in terms of microhardness variation, where a substantial decrease in microhardness was recorded. This absence of the HAZ region was also confirmed through the microstructure. Both primary and secondary silicon were observed in brazed samples, which had finer grain sizes than did the welded samples. Dendrite formation was observed for the brazed samples, whereas a uniform distribution of aluminium was observed for the welded samples. Fractographic analysis revealed brittle intergranular fracture with small dimples present at the fracture point for the brazed joints, while out-of-plane fracture with sharp edges indicated a more ductile nature for welded joints. [ABSTRACT FROM AUTHOR]

Comprehensive mechanical testing of steels provides important information about the possibilities of their use under different processing and operating conditions. Comparison of test methods with each other, taking into account the development of plastic deformation and fracture analysis, is an urgent task for materials certification. The present work is devoted to the study of the characteristics of the response to deformation of high-manganese steels (13 and 22 wt.% Mn steels) in comparison with the behavior of high-entropy Cantor alloy during scratching, tensile, and microhardness tests. The plasticity of the materials and the nature of their destruction were assessed by the surface deformation relief and fractography. Analysis of the structure during scratch testing made it possible to assess the degree of plasticity of the materials and relate it to the results of tensile tests and the nature of destruction. The steel with 13 wt.% Mn (Hadfield steel) the destruction of which occurs by the quasi-viscous mechanism has the lowest ductility. The highest ductility has the Cantor alloy characterized by the viscous fracture mechanism. The Hadfield steel has the highest hardness of all materials studied, while the Cantor alloy has the least hardness. The research results lay the basis for the possibility of recalculating the mechanical characteristics from different tests, taking into account the implemented stress state scheme and processes of structural changes during deformation. [ABSTRACT FROM AUTHOR]

In March and April 2021, buoys were deployed in the Beaufort Sea, Arctic Ocean, to measure sea‐ice horizontal deformation over spatial scales that had not been previously achieved. Geodetic‐quality position measurements allowed measurements of strain‐rate over lengths from about 200 m to 2 km. Conventional ice‐drifters extended spatial coverage up to about 100 km. Past studies find there is multi‐fractal behavior for horizontal sea‐ice deformation from 10 to 1,000 km. Our results demonstrate that such behavior does not hold when including spatial scales below 10 km. We find that sea‐ice deformation is not scale invariant between the scale of individual sea‐ice floes and aggregates of floes. Therefore, we cannot expect the same physical laws or forcing to describe sea‐ice kinematics over these regimes, nor can we assume log‐log linear behavior for mean deformation. Using this scaling behavior as a metric to validate models that resolve sea ice floes and their interactions is hence not recommended. Plain Language Summary: In March and April of 2021, a nested array of buoys was deployed around a drifting camp on sea ice 50 km off‐shore in the Beaufort Sea, Arctic Ocean. The inner buoys of the array measured their position with centimeter‐level accuracy allowing for measurements of sea ice deformation at a wide range of spatial scales. Sea ice deformation includes the opening and closing of the ice and shearing motion that occurs along cracks in the ice known as leads and ridges. This experiment was the first time that sea‐ice deformation has been analyzed over scales from 100s of meters to 100s of kilometers. Past studies over areas spanning more than 10 km suggest that the sea‐ice deformation has fractal behavior, a mathematical relationship where the rates of deformation increase as you measure over increasingly smaller regions. Past measurements of deformation over smaller areas found a different fractal behavior. In this study, we find that the mathematical relationship does not fit observations across any region larger than a kilometer square. We conclude that sea‐ice deformation is not fractal and caution against assuming that this relationship exists for climate and forecast modeling. Key Points: Results from the first field experiment measuring sea‐ice deformation across spatial scales ranging from 200 m to over 100 km are presentedPrevious studies indicate sea‐ice deformation is multi‐fractal for scales above 10 km, and we find this does not holdOver spatial scales from 1 to ∼100 km, deformation does not scale log‐log linearly with separation distance, and is not fractal [ABSTRACT FROM AUTHOR]

The Kumaun Himalaya is considered as the most active part of the Central Seismic gap in the Indian Sub-continent. In this paper, we presented active surface deformation rates of the Kumaun region from February 2017 to February 2021 using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSI) technique. The cumulative displacement that occurred during the span of 4 years is ±55 mm, whereas the Line of Sight (LOS) deformation velocity rate ranges is ±7 mm/yr. Apart from PSI, we also estimated the b-value of the Kumaun region from 1803 to 2021 (399 events) and its value is 0.54 ± 0.03. A distinct NE-SW trend of b-value is observed where earthquakes with M>6 occurred towards NE of this trend. The PSIderived deformation reveals that the central part of the Inner Lesser Himalaya along with the Main Central Thrust (MCT) zone is dominated by uplift. The zone between the Munsiari Thrust (MT) and MCT in the central region shows the maximum uplift ranging 5-7 mm/yr which exactly lies above the mid-crustal ramp of the Main Himalayan Thrust (MHT). Our results are well corroborated with available observations of geodetic strain and peak ground acceleration values. However, the deformation patterns and highvelocity rates in the central part of the study area between MT and MCT indicate the accumulation of high stress. [ABSTRACT FROM AUTHOR]

The study is aimed at understanding the extent of topographic deformation due to opencast coal mining projects in Salanpur Blocks, District Paschim Bardhaman, West Bengal, and suggests mitigation measures. Five major opencast mining projects namely Bonjemehari, Dabor, Sangramgarh, Mohanpur, and Dalmiya are covered in the case study. These coal mines featured large opencast quarries and associated spoil dump ridges. These coal mines have defaced the surface topography as the surface area covered by positive topography (spoil dump ridges) is less than the negative topography (opencast quarries). This paper shows that the deformation of surface topography is by far the most significant impact of mining among the various geo-environmental impacts. Land is our most important natural resource that needs to be tended carefully and requires proper conservation measures. In this study, various sources of secondary data and Primary data have been used to find out the extent of topographic deformation. The authors have used Remote sensing/Geographic Information System techniques for analyzing and interpreting Satellite data. The study suggests suitable mining dumping sites depending on multi-criteria analysis for disposal of mining spoil rather than dumping the material elsewhere. [ABSTRACT FROM AUTHOR]

The activation movement of overburden rock in mined-out areas can lead to surface movement and threaten the safety of surface buildings. To avoid such disasters, taking the mined-out areas (MOA) of Baiping in China as the engineering background, a site survey was conducted to analyze the overburden rock state of the shallow MOA. The surface movement and deformation characteristics were numerically simulated to investigate the stability of surface buildings above the MOA. Results show that, the uneven settlement of the MOA can be divided into neutral, compression and tension zones. The settlement boundary angle of the MOA is approximately 55-59°, and a larger range of the MOA corresponds to a greater impact of the surface settlement. The 100 mm settlement line on the surface of the MOA is approximately 100 m from the stop-mining line. In the range of 50-70 m from the stop-mining line, the settlement of the residential buildings is approximately 0.6-0.8 m, and the tilting deformation is approximately 1.0-1.5 mm/m. When the distance among the buildings and the stop-mining line exceeds 100 m, the uneven settlement of the surface will have less impact on the surface buildings. The obtained conclusions provide a significantly technical support to evaluate the stability of the surface buildings in MOA [ABSTRACT FROM AUTHOR]

We developed an open source, extensible Python‐based framework, that we call the Versatile Modeling Of Deformation (VMOD), for forward and inverse modeling of crustal deformation sources. VMOD abstracts from specific source model implementations, data types and inversion methods. We implement the most common geodetic source models which can be combined to model and analyze multi‐source deformation. VMOD supports Global Navigation Satellite System (GNSS), InSAR, electronic distance measurement, Leveling and tilt data. To infer source characteristics from observations, VMOD implements non‐linear least squares and Markov Chain Monte‐Carlo Bayesian inversions, including joint inversions using different sources of data. VMOD's structure allows for easy integration of new geodetic models, data types, and inversion strategies. We benchmark the forward models against other published results and the inversion approaches against other implementations. We apply VMOD to analyze deformation at Unimak Island, Alaska, observed with continuous and campaign GNSS, and ascending and descending InSAR time series generated from Sentinel‐1 satellite radar acquisitions. These data show an inflation pattern at Westdahl volcano and subsidence at Fisher Caldera. We use VMOD to test a range of source models by jointly inverting the GNSS and InSAR data sets. Our final model simultaneously constrains the parameters of two sources. Our results reveal a depressurizing spheroid under Fisher Caldera ∼4–6 km deep, contracting at a rate of ∼2–3 Mm3/yr, and a pressurizing spherical source underneath Westdahl volcano ∼6–8 km deep, inflating at ∼5 Mm3/yr. This and past applications of VMOD to volcanic unrest benefit from an extensible framework which supports jointly inversions of data sets for parameters of easily composable multi‐source models. Plain Language Summary: We developed a computational framework called the Versatile Modeling Of Deformation (VMOD) to calculate surface deformation created by buried pressure, tensile and shear sources, or find parameter values for a model that fits observed surface deformation. The framework has three main components. One component handles the model, one component handles the data, and the remaining component handles the algorithm that finds the most probable values for the parameters of a given model. Deformation can be observed using different techniques such as Global Navigation Satellite System (GNSS) or satellite images. The framework supports most of these techniques and allows users to add new techniques or deformation models. We validate our framework with literature results and contrast it with similar software used in the volcano deformation community. We apply the framework to analyze a deformation episode at Westdahl volcano and Fisher Caldera on Unimak Island, Alaska. The deformation is captured by GNSS and satellite radar images. Our results suggest a deflating spheroid ∼4–6 km deep with a rate of ∼2–3 Mm3/yr for Fisher Caldera and a inflating spherical source underneath Westdahl volcano ∼6–8 km deep, at a rate of ∼5 Mm3/yr. This and previous experiences highlight the advantages of multi‐source model deformation observations from different techniques. Key Points: We introduce a Python‐based object‐oriented modeling and inversion framework for geodetic data (Versatile Modeling Of Deformation (VMOD))VMOD's expandable framework design enables easy integration of new observation types, new deformation models, or inversion strategiesWe validate VMOD against literature and a community exercise, and use it to infer deformation sources at Fisher Caldera and Westdahl volcano [ABSTRACT FROM AUTHOR]

Spray cooling is an effective heat dissipation technology and is widely used in the heat dissipation of encapsulated structures, but most of the research has only focused on the heat transfer performance itself and has lacked the analysis of surface stress and deformation. In this paper, a thermal stress coupling model was established under spray conditions, and the influence of spray parameters such as the spray height, spray flow, and nozzle inclination on heat transfer, surface stress, and deformation were studied. The result indicated that the lower the surface temperature, the smaller the stress and deformation. What is more, there was an optimal spray height (15 mm) to achieve the best heat transfer, and the surface stress and deformation were also minimal at the same time which the values were 28.97 MPa and 4.24 × 10−3 mm, respectively. The larger the spray flow rate, the better the heat transfer effect and the smaller the surface stress and deformation. When the spray flow rate was 24.480 L/h, the minimum values of surface stress and deformation were 25.42 MPa and 3.89 × 10−3 mm, respectively. The uniformity of surface stress distribution could be effectively improved with the increase in flow rate. Compared to 10 and 15 degree nozzle inclination, when the nozzle was perpendicular to the cooling surface, the surface stress and deformation were minimal. [ABSTRACT FROM AUTHOR]

Slant range geometry plays a crucial role in interpreting synthetic aperture radar (SAR) observations, especially in converting line-of-sight (LOS) surface deformations to actual vertical subsidence. This paper proposes a new conversion model to retrieve vertical settlements of the embankment slopes using the geometrical parameters of the dam and the SAR sensor. The simulation results highlight the impact of slope foreshortening and heading direction of the satellite on deformation retrieval. Various SAR data with different resolutions and bands are used to analyze the model's performance, revealing a high conformity of the model with practical conversion parameters exceeding 80% for TerraSAR-X and Cosmo-SkyMed data. [ABSTRACT FROM AUTHOR]

During the production of components, manufacturers of structures are obliged to meet certain requirements and ensure appropriate quality characteristics. It is especially important during the manufacturing of thin-walled structures, which are subject to many errors during machining due to the reduced rigidity of the products, including the deformation of thin walls, which may be the result of the vibration of the system. The appearance of vibrations reduces the quality of the machined surface affecting the increase in the values of surface topography parameters—waviness and roughness. Thin-wall structures—titanium or nickel alloy, among others—play a key role in the aerospace industry, which constantly strives to reduce the weight of the entire structure while meeting requirements. The present work focuses on the evaluation of the parameters of surface topography, dimensional and shape accuracy during the milling of nickel alloy Inconel 625 samples containing a thin wall in a vertical orientation. The experiment was conducted under controlled cutting conditions using a constant material removal rate. As part of the surface topography section, the distribution of waviness, Wa and Wz, and roughness, Ra and Rz, was determined in selected measurement areas in the direction parallel to the direction of the feed motion. Dimensional deviations, measured with a 3D optical scanner, were determined in selected cross sections in the direction perpendicular and parallel to the bottom of the sample presenting the deflection of the thin-walled structure. The results provide information that the used parameter sets affect the measured quantities to varying degrees. [ABSTRACT FROM AUTHOR]

Landslides are common natural disasters that cause serious damage to ecosystems and human societies. To effectively prevent and mitigate these disasters, an accurate assessment of landslide hazards is necessary. However, most traditional landslide hazard assessment methods rely on static assessment factors while ignoring the dynamic changes in landslides, which may lead to false-positive errors in the assessment results. This paper presents a novel landslide hazard assessment method for the Zagunao River basin, China. In this study, an updated landslide inventory was obtained for the Zagunao River basin using data from interferometric synthetic aperture radar (InSAR) and optical images. Based on this inventory, a landslide susceptibility map was developed using a random forest algorithm. Finally, an evaluation matrix was created by combining the results of deformation rates from both ascending and descending data to establish a hazard level that considers surface deformation. The method presented in this study can reflect recent landslide hazards in the region and produce dynamic assessments of regional landslide hazards. It provides a basis for the government to identify and manage high-risk areas. [ABSTRACT FROM AUTHOR]

The results of experimental and theoretical studies of the characteristics of surface deformation and fragmentation of droplets of high-viscosity liquids (glycerol and melted Al2O3) moving in a gaseous medium are presented. Typical shapes of droplets, modes, and cycles of surface deformation, cycle durations and the amplitude have been established. Minimum relative velocities of the movement of droplets have been determined leading to fragmentation of droplets of high-viscosity liquids (glycerol and melted Al2O3). The influence of a group of factors on the characteristics of deformation of droplets has been established: flow velocity (0–100 m/s) and initial sizes of droplets (1–5 mm). Satisfactory agreement between experimental data and the results of theoretical calculations for high-viscosity liquids (using the example of glycerol droplets) was obtained. [ABSTRACT FROM AUTHOR]

Deposition path patterns play an important role in controlling residual stresses and deformation in direct energy deposition-arc (DED-arc) process. In this paper, the effects of various path patterns on the evolution of the temperature history, residual stress distribution, and substrate deformations are investigated through experiments and finite element analysis. The predicted results of temperature fields and substrate deformations are verified experimentally by the infrared thermal imager and the laser profile scanner, respectively. It is found that the path patterns have significant effects on the stress distribution in the first few layers, and the minimum substrate deformation is obtained by the zigzag path along the short edge of the block. The proposed finite element method and measuring method are confirmed to be effective and feasible, providing valuable insight into the residual stresses and deformations control in the DED-arc process. [ABSTRACT FROM AUTHOR]

The article describes the peculiarities of the formation of the geometry of the deformation zones and the structure of samples made of pure-iron in surface plastic deformation (SPD) by a multiradius roller (MR-roller). The SPD MR-roller leads to a complex kinematic introduction of a deforming tool into the surface layer of a blank and the appearance of a deformation hearth of a curvilinear shape. The results of X-ray structural analysis of pure-iron are presented. It is shown that processing of SPD MR-roller with maximum force results in a significant increase in the microdistortion of the crystal grid, which is characteristic of the nanoscale structure. [ABSTRACT FROM AUTHOR]

In recent years, additive-subtractive hybrid manufacturing (ASHM) technology has become a research hotspot. To realize high-precision manufacturing of complex parts and avoid machining interference, alternating additive manufacturing (AM) and subtractive manufacturing (SM) are valuable to be adopted. In this paper, a finite element numerical model was established to simulate the temperature history, stress distribution, and deformation trend of the thin-walled parts alternately fabricated by AM and milling process. Then, 316L stainless steel thin-walled samples were built by the alternating ASHM process. The molten pool temperature, the surface residual stress, and the surface contour of samples were measured and analyzed. The results show that high tensile stress is exhibited at the junction of the AM segment with the substrate or the previous SM segment. With the increase of deposition height, the tensile stress decreases first and then increases. After the subsequent milling, the surface residual stress level shows a decreasing trend, which is because the milling-induced compressive stress offsets the initial residual tensile stress. Moreover, the deformation of the two ends and the top of the AM segments is more significant than that of the bottom. After SM, the deformation in the top area of the SM segments is still slightly more extensive than the bottom area. The subsequent AM process results in a small increase in the residual stress of the milled segment, but had little effect on its surface deformation. Finally, the repeated cutting height between two segments was studied. Compared with the previous work, this strategy considers the effect of the alternating ASHM process on the residual stress and deformation of thin-walled parts. This study has certain guiding significance for the manufacture of thin-walled parts such as turbine blades and parts with internal structure by alternating ASHM process. [ABSTRACT FROM AUTHOR]

This study uses Unmanned Aerial Vehicles (UAVs) to investigate earthquake-induced deformation in Turkey's Hatay region after significant earthquakes in February 2023. The study employs UAV photogrammetry to get high-resolution 3D modeling and aerial imagery to analyze surface deformations and fractures in the bedrock. Results show extensive fractures and fragmentation, with 7 cracks ranging from 24.11 to 497.69 m in length. Two subsidence areas are identified, measuring 23,060.8 m² and 13,954.2 m² respectively, with elevation changes of up to 20 m. Profile analysis within the subsidence area reveals the extent of physical deformations. The accuracy and precision of the photogrammetric products are validated with a Root Mean Square Error (RMSE) of 4.6 cm, indicating high accuracy. The 3 Dimensional (3D) models and observed fractures provide insights into the spatial patterns and magnitudes of surface deformations. This study demonstrates the effectiveness of UAV-based data in analyzing earthquake-induced deformations and landscape changes, offering a foundation for future research. [ABSTRACT FROM AUTHOR]

Photothermal conversion of energy in plasmonic nanostructures brought a new fascinating field of plasmon‐induced optofluidics to life. Notably, the heat generation by plasmonic nanostructures and consequent fluid convection recently attracted wide attention; however, the possibility of controlling and manipulating liquid surfaces has been sparsely investigated. The plasmon heating and convective fluid flow lead to the emergence of the surface tension gradient on a free liquid surface interface with air, resulting in the Marangoni effect‐driven fluid flow observed as water deformation. Here, nanoscale asymmetric fluid deformation anchored on the chiral plasmon‐induced optofluidic effect is reported on. To understand the fluid dynamics of surface deformation, a theoretical model is developed. The results demonstrate that deformation at different depths can be obtained by adjusting structural parameters or incident light intensity. The fundamental understanding of light‐induced asymmetric deformation will contribute to expanding chirality‐related discipline and open new avenues for controlling fluid flow at the micro‐ or nano‐scale. The proposed method can encourage the research and applications of optofluidics, including integrated fluidic devices, biochemistry, and clinical biology. Moreover, the use of the asymmetric fluid deformation on thermal dewetting of thin films of polymer solutions can be employed for the fabrication of functional and nanopatterned metal/polymer metasurfaces. [ABSTRACT FROM AUTHOR]

Computer‐aided craniofacial reconstruction (CFR) is a process that aims to estimate facial impressions based on skull remains. It mimics the conventional method with a conceptual model‐based framework. The existing problems in CFR are that landmark annotation is expert‐dependent, landmark processing in the 3D domain has volumetric challenges, and a method based on a population's morphological characteristics (templates). A framework with three stages is proposed: Building a craniofacial model, automatic landmark detection, and surface deformation. Machine learning is deployed to draw local surface correlations as landmarks and automatically detects their position. The local surface context is extracted using the Surface Curvature Feature (SCF) as a 3D descriptor. Using a cluster‐based filter, the average distance (to the ground truth) of the top 20 points is 0.0326 units. Cluster‐based filters are better than mass‐radius‐based filters and consistently give better pinpoint accuracy, especially in multi‐cluster cases. Training data consists of 140,000 SCF for ten landmark classes. The third stage, surface deformation, fits the facial template to the cranial based on the corresponding facial‐cranial landmarks. Five experts from the Anthropology department stated that of the reconstruction results, 91.5% could retain the template details and are accepted as the natural shape of the human face. [ABSTRACT FROM AUTHOR]

Changes in the structure of amorphous alloys under deformation by high-pressure torsion, multiple-pass rolling, and pressure treatment have been studied using X-ray diffraction and scanning electron microscopy. It has been shown that under all types of deformation, shear bands are formed in amorphous alloys, which are regions of lower density compared to a surrounding undeformed amorphous matrix. Shear bands are regions of an increased free volume; the formation of bands results in steps occurring on the surface of samples. The number of shear bands and the surface morphology of deformed amorphous alloys are determined by the deformation type and physical properties of a material. [ABSTRACT FROM AUTHOR]

Landslides – natural disasters be caused by various factors - are frequent in the region surrounding Souk Ahras. Comprehensive fieldwork, such as geotechnical drilling investigations and soil excavations, is conducted to monitor ground movements and assess the feasibility of geological locations. Synthetic Aperture Radar (SAR) and other active satellite remote sensors are utilized in Earth Observation-based systems to identify and track ground deformation and landslides in the study area. This research aims to illustrate how open-source processing software, SNAP, provided by the European Space Agency, can be combined with freely available datasets from Copernicus to accomplish this goal. In the North Eastern part of Algeria, which includes Souk Ahras, there is a high risk of landslides Through the use of InSAR technology, the research provided satisfactory results in identifying the morphology of landslides and generating a largescale interferometric map covering several regions in the East of Algeria, revealing the extent of distortion and spacing caused by the landslide phenomenon. [ABSTRACT FROM AUTHOR]

Characterisation of surface deformation at stratovolcanoes is essential for a better understanding of the processes that can compromise edifice structural stability and potential for flank collapse. Spreading produced by the presence of a hydrothermal system or intrusion of a viscous magma body can produce similar deformation signatures, and both processes have implications for flank instability. In this work, we perform analogue models and consider examples from real volcanoes (Damavand, Ubinas, Semeru and Casita) so as to characterise and recognise surface deformation patterns produced by spreading due to the presence of a hydrothermal system and in response to magma intrusion. The experiments show that there are differences in the resulting surface deformation associated with each process. Magma intrusion results in a sharp transition between areas of subsidence and uplift, and is associated with faults with oblique strikes in the upper part of the edifice. Instead, asymmetric flank spreading is associated with hydrothermal system and results in flank bulging close to the base of the edifice. Although laboratory analogue models show different deformation responses that could be diagnostic of the associated processes, application in the field is difficult as often these diagnostic features are not preserved during evolution. However, basal bulging represents a potential diagnostic for the identification of asymmetric volcano flank spreading associated with hydrothermal activity, and the potential for instability. Remote sensing techniques can allow identification of such surface deformation features, providing a useful tool for hazard assessment and design of monitoring strategies at potentially unstable volcanoes. [ABSTRACT FROM AUTHOR]

Background: Polyetheretherketone (PEEK) has provided the option to fabricate RPDs with aesthetics unlike metal RPDs, but little attention has been paid to its suitability, especially towards the retentive forces and deformation of the clasp. This study aimed to examine the retentive forces and the fitting surface (inner surface) deformation of clasps made from PEEK and compare it with cobalt–chromium (Co-Cr) clasp. Methods: Forty-two circumferential clasps (14 Co-Cr and 28 PEEK) were fabricated and divided into two groups with clasp undercuts (0.25 mm and 0.5 mm) with thicknesses of 1 mm and 1.5 mm. Each was examined for retentive forces after cycle test on its abutment for 360 cycles. Initial and final retentive forces were recorded. The fitting surface deformation was determined using 3-Matic research analysis software. Results: The results revealed that highest mean initial retentive force was of Co-Cr clasps with 0.50 mm undercut 22.26 N (±10.15 N), and the lowest was the 1 mm PEEK clasps with 0.25 mm undercut 3.35 N (±0.72 N) and highest mean final retentive force was the Co-Cr clasps with 0.50 mm undercut 21.40 N (±9.66 N), and the lowest was the 1 mm PEEK clasps with 0.25 mm undercut 2.71 N (±0.47 N). PEEK clasps had a lower retentive force than Co-Cr clasps with 0.50 undercut. PEEK clasps (1.5 mm) at 0.25 mm undercut had the least deformation (35.3 µm). PEEK showed significantly less deformation (p ≤ 0.014) than Co-Cr. Conclusion: The deformation of PEEK clasps fitting surface was lower than Co-Cr clasps and retentive forces were close to the Co-Cr clasps, suggesting the use of PEEK as an aesthetic clasp option for RPD framework. [ABSTRACT FROM AUTHOR]

The deformation characteristics and instability patterns of rotational landslides are complicated. Such landslides are large and occur continuously, seriously threatening people's lives. We used interferometry synthetic aperture radar (InSAR), digital elevation models of difference (DODs), numerical simulations, and other techniques for analyzing the topographic changes, surface deformation and movement process before, during and after a landslide. Based on the high-resolution terrain data before and after the landslide, the topographic changes were analyzed, and the active zone of the landslide was identified. The areas of the topographic changes were mainly located on the main scarp, toe and secondary landslides. The topographic changes were influenced by rainfall and rill erosion. The geomorphologically-guided InSAR interpretation method was applied to explore the displacement pattern. The deformation area in the middle of the landslide coincided with the secondary landslides. A time-series InSAR analysis revealed the dynamic evolution of the deformation before and after the landslide. Based on its evolution, the simulated landslide process included the main landslide and three secondary landslides. Based on the displacement of the longitudinal ground surface profiles, the displacement characteristics and kinematic behavior were summarized and compared with those of a single rotational landslide and multiple rotational landslides. The single rotational landslide had obvious secondary and progressive characteristics, developing into multiple rotational landslides triggered by conditions such as rainfall. [ABSTRACT FROM AUTHOR]

The ancient Aniangzhai (ANZ) landslide in Danba County, Sichuan Province of southwest China was reactivated after a series of complex hazard events that occurred in June 2020. Since then, and until June 2021, emergency engineering work was carried out to prevent the further failure of the reactivated landslide. This study investigates the potential of joint use of time series Interferometric Synthetic Aperture Radar (InSAR) and optical pixel offset tracking (POT) to assess deformation characteristic and spatial-temporal evolution of the reactivated ANZ landslide during the post-failure stage. The relationships between sun illumination differences, temporal baseline of correlation pairs and the uncertainties were deeply explored. Surface deformation along the line-of-sight (LoS) direction was retrieved by the time series InSAR processing with the two Sentinel-1 datasets, revealing a maximum deformation rate up to 190 mm/year. The large horizontal displacements were also detected from the POT processing using 11 optical images acquired by the PlanetScope satellite (3 m spatial resolution), showing a significant increase of about 24 m between 24 June 2020 and 11 June 2021. The time series analysis from the InSAR and optical POT results revealed that the reactivated ANZ landslide body is gradually slowing down to a steady deformation status since its occurrence in August 2020, indicating the effectiveness of engineering work on the prevention of further landslide. A slight acceleration was detected from both InSAR and optical POT time series analysis between May 2021 and June 2021, which could be caused by the increased rainfall in May 2021. [ABSTRACT FROM AUTHOR]

Historically, the Kyrgyz Republic and neighboring countries have experienced numerous strong earthquakes. Our research focused on the investigation of surface deformations caused by 5 earthquake events which had occurred during 2014-2017. A Differential Interferometric Synthetic Aperture Radar (DInSAR) technique was applied for the Sentinel-1 Interferometric data acquired before and after earthquake events. The pairs of images were processed using the SNAP software to produce a coseismic interferogram, coherence and displacement maps. [ABSTRACT FROM AUTHOR]

Construction, processing, biomedical instruments, electronics, automobiles, and aerospace widely use thin-wall parts. Mostly, these thinwalled parts are machined using either a peripheral milling machine or an end milling machine with the help of fixtures. In this study, three different material thin-walled parts (i.e., Inconel 718, AISI 316L, and Al 6061) are machined in end milling using a newly designed fixture with cylindrical heads, and the surface roughness and deformation with different machining parameters are compared. The optimum values of the machining parameters feed, speed, and depth of cut have been found to improve the surface roughness of thin-walled plates by arresting the deformation using the proposed fixture. Analysis of variance (ANOVA) results show that the speed is the most influential parameter in the case of displacement for AISI 716L and Al 6061, feed is the most influential parameter in the case of surface roughness for Inconel 718 and AISI 716L, and speed is the most influential parameter in the case of displacement and surface roughness for Al 6061. The use of fixtures provides a significant reduction in the deformation and surface roughness during the machining in end milling machine. [ABSTRACT FROM AUTHOR]

Pre‐eruptive signals at the crater lake‐bearing Mt. Ruapehu (New Zealand) are either absent or hard to identify. Here, we report on geophysical anomalies arising from hydrothermal unrest (HTU) and magmatic unrest (MU) using multiphysics numerical modeling. Distinct spatio‐temporal anomalies are revealed when jointly solving for ground displacements and changes in gravitational and electrical potential fields for a set of subsurface disturbances including magma recharge and anomalous hydrothermal flow. Protracted hydrothermal injections induce measurable surface displacements (>0.5 cm) at Ruapehu's summit plateau, while magmatic pressurization (5–20 MPa) results in ground displacements below detection limits. Source density changes of 10 kg/m3 (MU simulations) and CO2 fluxes between 2,150 and 3,600 t/d (HTU simulations) induce resolvable residual gravity changes between +8 and −8 μGal at the plateau. Absolute self‐potential (SP) anomalies are predicted to vary between 0.3 and 2.5 mV for all unrest simulations and exceed the detection limit of conventional electric surveying. Parameter space exploration indicates that variations of up to 400% in the Biot‐Willis coefficient produce negligible differences in surface displacement in MU simulations, but strongly impact surface displacement in HTU simulations. Our interpretation of the findings is that monitoring of changes in SP and gravity should permit insights into MU at Ruapehu, while HTU is best characterized using ground displacements, residual gravity changes and SP anomalies. Our findings are useful to inform multiparameter monitoring strategies at Ruapehu and other volcanoes hosting crater lakes. Plain Language Summary: Eruptions at Mt. Ruapehu in New Zealand often occur without any warning amid an absence of what are called pre‐eruptive geophysical signals. In order to study the detectability of relevant geophysical signals, we use physics‐based models to simulate two distinct subsurface processes at Mt. Ruapehu: magma accumulation and flow of hydrothermal fluids. Both processes involve fluid flow, density variations and pressure changes in the ground and have the potential to trigger eruptive activity. Here we identify distinct measurable sets of geophysical signals from either subsurface process: changes in the electrical and gravitational potential fields, or surface deformation. Our study highlights the benefit of computer models to provide useful information on the link between subsurface processes and measurable geophysical signals prior to eruptive activity. Our findings may have implications for volcano monitoring efforts at Mt. Ruapehu and other crater lake volcanoes. Key Points: Multiphysics simulations to study unrest processes at Mt. RuapehuSpatio‐temporal variations in self‐potential and gravity changes identified as indicators of magmatic unrestHydrothermal unrest induces resolvable ground displacements, and changes in gravity and self‐potential [ABSTRACT FROM AUTHOR]

In the present study, the mechanical and wear behaviour of the surface-mechanically treated high-manganese (high-Mn) twinning-induced plasticity (TWIP) steel were investigated. The TWIP alloy was first designed and fabricated via surface-mechanical attrition treatment (SMAT) system and the mechanical properties including strength, wear behaviour as well as the microstructural evolution were thereafter determined. Transmission electron microscopy (TEM) characterization revealed a typical dislocation as a result of the surface treatment as well as the formation of twin layers with a reduced stacking fault energy (SFE). Due to the ultra-fine grain refinement caused by plastic deformation during surface treatment, a microhardness value of 489 HV can be obtained after treatment. Likewise, the yield strength of the high-Mn TWIP steel could be enhanced from 360 MPa to 813 MPa and a reduction in elongation to failure of about 20 % can be achieved. The wear test showed that the treated TWIP steel possessed a reduced friction coefficient and improved wear resistance at different testing loads, attributed to the nanoscale refinement of grains induced during treatment. The strength, hardness, and wear resistance of the fabricated TWIP alloy improves significantly, thanks to surface treatment by SMAT. [Display omitted] [ABSTRACT FROM AUTHOR]

Despite the profound roles of surface deformation monitoring techniques in observing permafrost surface stability, predetermining the approximate location and time of possibly occurring severe permafrost degradation before applying these techniques is extremely necessary, but has received little attention. Taking the oil tank collapse accident in the Norilsk region as a case, we explored this concern by analyzing the permafrost deformation mechanisms and determining early surface deformation signals. Regarding this case, we firstly applied the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to obtain its permafrost surface deformation rate, then utilized a sine model to decompose its interannual deformation and seasonal deformation, and finally compared the relationship between the topographic slope and deformation rate. Based on experimental results, we reveal that when the annual average temperature continuously increases at a rate of 2 ° C/year for 2∼3 consecutive years, permafrost areas with relatively large topographic slopes (>15 ° ) are more prone to severe surface deformation during the summer thaw period. Therefore, this paper suggests that permafrost areas with large topographic slopes (>15 ° ) should be taken as the key surveillance areas, and that the appropriate monitoring time for employing surface deformation monitoring techniques should be the summer thawing period after a continuous increase in annual average temperature at a rate of 2 ° C/year for 2∼3 years. [ABSTRACT FROM AUTHOR]

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The influence of ultrasonic impact treatment (UIT) on the microhardness, roughness and structural-phase state of the stainless steel AISI 420 surface is studied. Ultrasonic impact treatment is performed in an inert environment under the same conditions—the amplitude of the hub end was 25 µm, the duration of treatment—50 s. Samples of AISI 420 steel are used after softening heat treatment at annealing temperature of 800°C (initial state), after additional hardening from 980°C with oil cooling and after additional hardening from 980°C with subsequent annealing at 250°C for one hour. As established, that after UIT there is a significant decrease in the roughness of the modified surface and increase in microhardness for all cases compared to the initial state. Taking into account the data of x-ray diffraction analysis the main factors of stainless steel AISI 420 surface layers deformation hardening under different combinations of thermal and ultrasonic impact are discussed. [ABSTRACT FROM AUTHOR]

In this article, we study the deformations of Filippov algebroids. First, we define a differential graded Lie algebra for a Filippov algebroid by introducing the notion of Filippov multiderivations for a vector bundle. We then discuss deformations of a Filippov algebroid in terms of low-dimensional cohomology associated with this differential graded Lie algebra. We define Nijenhuis operators on Filippov algebroids and characterize trivial deformations of Filippov algebroids in terms of these operators. Finally, we define finite order deformations and discuss the problem of extending a given finite order deformation to a deformation of a higher order. [ABSTRACT FROM AUTHOR]

This article discusses the traceability problem of relative mechanical deformations and presents the relevance of the development of a mechanical deformation measurement technique to obtain measurement results without comparison with a standard unit of the same kind. A state primary reference method for measuring the surface deformation of an elastically deformed beam of a rectangular constant cross section loaded according to the pure bending scheme and the equipment for implementing the method was developed. The article presents the procedure for establishing methodological parameters (e.g., changes in the ambient air temperature during measurement, initial non-flatness of the beam, and non-parallelism of beam faces) in the development course of the state primary reference measurement technique. The estimation procedure for the uncertainties of deformation measurements is described, and the identified sources of uncertainties and their contribution to the total uncertainty of the measurement results are indicated. The metrological characteristics of the measurement technique are calculated. The proposed technique is expected to aid in determining the characteristics of the reference and working measurement techniques for the surface strain of an elastically deformed beam of a constant rectangular cross section loaded according to the pure bending scheme. [ABSTRACT FROM AUTHOR]

Influence of rare-earth (La, Ce) and thermo-mechanical treatment on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy are presented in this article. After casting, the alloy which was modified by La, Ce, the grain size of samples obtained around 40-50 µm compared to that of without about 65 µm; and after homogeneous, the grain sizes is about 30 µm. After the cold deformation process, the distance between plates is 10 µm. By EDS after casting, the samples have tended to more La, Ce elements at the grain boundary, after homogeneous, the uniformation distribution of rare-earths was presented by mapping of EDS's results. In addition, after rolling and heat treatment, the elements were found on the grain boundary and matrix. After recrystallization annealing, the grain size is around 10 µm with the modification sample. The grain size was reduced by two processes of modification as well as thermal-mechanical treatment is a condition for increasing the ductility of the studied alloy. Further, as a result of ability deformation from the tensile test, these results demonstrate that the tensile test obtained 140 % when adding La, Ce contents into the alloy combine with thermal-mechanical treatment. The combined used of La, Ce and thermal-mechanical treatment have increased the ductility of Al-Zn-Mg-Cu alloy. [ABSTRACT FROM AUTHOR]

Interferometric synthetic aperture radar is an effective means of measuring changes in the altitude of the Earth's surface. In this research, the areas of surface deformation associated with low- and medium-intensity seismic events in Central Chile were analyzed using SENTINEL 1 satellite radar interferograms and geographical information system (GIS) tools. The persistent scatterer method was used to reduce noise from conventional InSAR methods. The results revealed that the coastal zone of Central Chile has a high density of daily earthquakes with a prevalence (93.03%) of low- and medium-intensity earthquakes. Monthly deformation maps were developed for the coast of the Biobio region in Central Chile. A clear deformation pattern is defined along the coast, being greater in the Arauco, Lota and Lebu areas. It was also shown that there was a slight upward trend in the north and northeast zone (i.e., δup ~3 mm/year), while there was an obvious accentuated upward trend (i.e., δup ~24 mm/year) in the southern part. This movement increases as latitude increases. This pattern is related to the daily seismic activity, the product of the movement between plates, and the geological faults located in the area. The deformation and trend maps provide certainty in terms of where hotspots are located, e.g., the most hazardous areas in the study zone, which can be applied to urban planning and/or safety assessment. [ABSTRACT FROM AUTHOR]

Physical flaws and defects on glass surfaces are known to reduce the mechanical strength and chemical durability of glass. The formation of surface defects depends not only on the mechanical conditions of the physical contact but also on the environment in which the contact is made. In this study, the nanoscratch behavior of soda lime silica (SLS) glass was investigated in 10% and 60% relative humidity (RH) conditions. Based on the evolution of friction and scratch depth, the deformation of SLS glass surface could be divided into four regimes: elastic deformation and recovery (E), RH‐independent mild plastic deformation (P‐1), RH‐dependent intermediate plastic deformation (P‐2), and RH‐independent severe plastic formation (P‐3). It is quite surprising to observe that plastic deformation of the glass surface has dependence on RH of the environment (outside the glass) because plastic deformation is the process occurring below the surface (inside the glass) by the externally applied load. From this result, it can be inferred that frictional energy dissipation mode at the sliding interface, which is a function of adsorbed water molecules, influences the subsurface deformation mode. Although friction, wear, and subsurface deformation/damage are all coupled, there is no direct one‐on‐one correlation among them. [ABSTRACT FROM AUTHOR]

Crustal deformation occurs both as localized slip along faults and distributed deformation off of faults. While there are few robust estimates of off‐fault deformation in nature, scaled physical experiments simulating crustal strike‐slip faulting allow direct measurement of the ratio of fault slip to regional deformation, quantified as kinematic efficiency (KE). We offer an approach to predict KE using a 2D convolutional neural network (CNN) trained directly on fault maps produced by physical experiments. Experiments with different loading rates and basal boundary conditions generate the fault maps throughout the evolution of strike‐slip faults. Strain maps allow us to directly calculate KE and its uncertainty, utilized in the loss function and performance metric. The trained CNN achieves 91% custom accuracy in the KE prediction of an unseen data set. Although the CNN model is trained on scaled experiments, it can predict off‐fault deformation of crustal faults that matches available geologic estimates. Plain Language Summary: Where the earth deforms at the boundaries between tectonic plates, some of the deformation is taken up as localized slip along fault surfaces and some of the deformation is distributed around the faults. This distributed deformation is very hard to measure in the crust. To get around this challenge, we create faults in the laboratory and use the direct measurements of the distributed deformation off of faults to train a machine learning model. The trained model performs well at predicting distributed off‐fault deformation from the active fault geometry. Key Points: Proposed convolutional neural networks can predict off‐fault deformation directly from binary fault mapsAnalog models provide abundant and diverse fault map data and calculated deformation labels, an ideal labeled data set for machine learningThe trained model achieves 91% accuracy on experimental faults and shows promise in predicting the kinematic efficiency of crustal faults [ABSTRACT FROM AUTHOR]

The Lisbon Metropolitan Area, Portugal, has been affected by several destructive earthquakes nucleating both along the offshore Africa‐Eurasia plate boundary and on onshore inherited intraplate faults. Using a dense GNSS dataset coupled with PSInSAR analysis, we provide new evidence of sinistral simple shear driven by a NNE‐SSW first‐order tectonic lineament. PSInSAR vertical velocities corroborate qualitatively the GNSS strain‐rate field, showing uplift/subsidence where the GNSS data indicate contraction/extension. We propose the presence of a small block to the W of Lisbon moving independently toward the SW with a relative velocity of 0.96 ± 0.20 mm/yr, whose boundaries are part of a complex and as yet poorly constrained strike‐slip fault system, possibly rooting at depth into a simpler basement fault. Comparison between geodetic and seismic moment‐rates indicates a high seismic coupling. We show that the contribution of intraplate faults to the seismic hazard in the LMA is more important than currently assumed. Plain Language Summary: Satellite data allow for the detection and characterization of surface deformation when points at the Earth's surface move with velocities of the order of 1 mm per year or higher. Using 15‐year long series of GNSS observations and 6‐year long series of RADAR images from ESA's Sentinel‐1 satellites, we characterize the deformation of the Lisbon Metropolitan Area. We conclude that the crust is being stretched in a NE‐SW direction, and on top of this pattern we detect a local patch of contraction, near the Tagus river bar. We propose that two blocks of crust are sliding horizontally past each other along the Lower Tagus Valley, inducing a style of deformation in the sediment cover called simple shear, while a smaller block between Lisbon and Cascais moves independently. Our results indicate that the faults near Lisbon contribute more to the seismic hazard of the region then assumed in previous studies, with implications for the building regulations. Key Points: We present a GNSS velocity model for the southern Lusitanian Basin and Lower Tagus and Sado BasinWe complement those results with PSInSAR‐derived velocities for the Lisbon Metropolitan AreaThe area in under sinistral simple shear, with velocities and strain‐rates pointing to higher seismic hazard than previously estimated [ABSTRACT FROM AUTHOR]

A comprehensive surface displacement monitoring system installed in the recently deglaciated bedrock slopes of the Aletsch Valley shows systematic reversible motions at the annual scale. We explore potential drivers for this deformation signal and demonstrate that the main driver is pore pressure changes of groundwater in fractured granitic mountain slopes. The spatial pattern of these reversible annual deformations shows similar magnitudes and orientations for adjacent monitoring points, leading to the hypothesis that the annually reversible deformation is caused by slope‐scale groundwater elevation changes and rock mass properties. Conversely, we show that the ground reaction to infiltration from snowmelt and summer rainstorms can be highly heterogeneous at local scale, and that brittle‐ductile fault zones are key features for the groundwater pressure‐related rock mass deformations. We also observe irreversible long‐term trends (over the 6.5 years data set) of deformation in the Aletsch valley composed of a larger uplift than observed at our reference GNSS station in the Rhone valley, and horizontal displacements of the slopes towards the valley. These observations can be attributed respectively to the elastic bedrock rebound in response to current glacier mass downwasting of the Great Aletsch Glacier and gravitational slope deformations enabled by cyclic groundwater pressure‐related rock mass fatigue in the fractured rock slopes. Plain Language Summary: Mountain ranges are subject to deformation due to tectonic forces, orogenesis, erosion, and gravity. Other factors can deform the slopes, such as atmospheric‐driven thermal expansion and contraction, freeze‐thaw in open fractures, and pore pressure variations. Close to retreating glaciers, the mechanical unloading of the ice body, and rapidly changing thermal and hydrologic conditions lead to deformation of the slopes. The difficulty resides in identifying the different factors contributing to the total deformation. We track surface displacements of fractured crystalline rock slopes adjacent to the Great Aletsch Glacier (Switzerland) tongue for more than six years at unprecedentedly high spatial and temporal resolutions. Our results demonstrate that groundwater is a critical driver of deformation. Centimetric reversible outward displacements are observed after the snowmelt season each year, followed by a seasonal recession to which are superimposed displacements caused by heavy rainfall‐recharge events. Fault zones can be key features where most of the hydromechanical deformation occurs, and their geometry can control the direction of deformation. Glacier melting induces long‐term trends of deformation. In addition, annual pore‐pressure cycles lead to hydromechanical fatigue processes. This work opens a new vision on the spatial and temporal variability of processes responsible for bedrock deformation in paraglacial mountain slopes. Key Points: Seasonal pore pressure variations in fractured crystalline hillslope induce correlated reversible surface deformationsDecameter‐scale brittle‐ductile faults control local spatial variations of deformation patternsCyclic groundwater pressure‐related rock mass fatigue induces irreversible gravitationally driven displacements in valley slopes [ABSTRACT FROM AUTHOR]

Landslide is a natural phenomenon that frequently occurs on the Java Island of Indonesia, causing significant damage and casualties. Due to advances in remote sensing technology, radar imaging can detect and evaluate ground surface deformation. This study examines the ground surface deformation and displacement in each landslide location in terms of spatial and temporal and identifies the different types and characteristics of landslides in the Sukabumi area of West Java, Indonesia. The Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) methodology was used in this study, and the DinSAR method was applied. We combined the LiCSAR data product with the Python coding-based LiCSBAS processing package to derive a surface displacement value at each landslide location. The results show that the DinSAR approach can detect surface deformation by integrating the LiCSAR product with the Python coding-based LiCSBAS processing software. According to quantitative data, the research area experienced surface deformation with a surface displacement velocity of -36,297 mm/year to 58,837 mm/year. The ground surface displacement at each landslide location ranged from -9.79 mm/year to +33.69 mm/year, with most of the landslides occurring on moderate to steep slopes (160-350). These results are suitable to use for support regional development planning in reducing losses and casualties. [ABSTRACT FROM AUTHOR]

This paper numerically investigates deformation behavior of coarse‐grained granular materials with emphasis on the effect of grain size distribution (GSD). Biaxial compression tests are simulated in two dimensions using distinct element method (DEM) on a set of samples composed of uncrushable spheres following a wide variety of GSDs. The results prove that high‐order characteristics of gradation, such as the shape of the GSD curve, significantly affect deformation behavior of widely‐graded materials. Two grading indices are proposed to consider the combined effects of the spread and the shape of the GSD curve, and they are highly correlated with the parameters of the materials' internal fabric. Strong correlations are found between the proposed grading indices and deformation parameters, such as those of the normal compression line and the critical state line (CSL) in the e‐p space, and the deformation modulus. In contrast, using the more conventional coefficient of uniformity cannot reach effective gradation‐dependent relations for those deformation parameters due to the deficiency in characterizing high‐order features of gradation. This study suggests the need for incorporating high‐order characteristics of gradation into a refined measure of size polydispersity in order to establish gradation‐dependent relations of deformation parameters widely effective for polydisperse granular materials. [ABSTRACT FROM AUTHOR]

An in situ relationship between the deformation behavior characteristics and the spatial and temporal evolution of deformation field distributions is studied in flat samples of technically pure A7 aluminum under uniaxial tension. Using a VIC-3D digital optical system, the features of the deformation field evolution on the sample surfaces at a macroscopic scale level are revealed. It is found out that in the transient section of the stress – strain curve in the patterns of distributions of longitudinal strains εYY, in addition to the macrohomogenous deformation on the surface of the gaging section of the sample, randomly distributed centers of tension and compression are observed to form. The presence of a transient section from elastic to plastic deformation indicates a low-stability state of the material. In the case where the stresses become higher than the elastic limit during the transition to the stage of plastic deformation, small foci of deformation merge into larger areas in the distribution patterns of the longitudinal relative strains on the sample surface. The transition from one stage to another occurs through the low-stability state of the system and is manifested, in addition to other factors, in a changed deformation field distribution on the surface of the sample under tension. [ABSTRACT FROM AUTHOR]

Recent years have witnessed increasingly complex circumstances like shield passing buildings and underground structures at close range in urban tunnel design and construction. This paper has analyzed the short-distance side-crossing masonry structure engineering of the shield tunnel of Zhengzhou Metro Line 5. Using field measurement method, surface settlement, settlement and distortion of masonry structure during the construction process of double-line parallel shield tunnels successively superimposed and side-passed through the existing masonry structures, were studied. According to finding, when the construction of the double-line tunnel was completed, the maximum value of surface settlement still occurred near the centerline of the first tunnel. It was expected to make reasonable calculations and assessments for the safety of masonry structures after shield crossing construction and provide reference for similar projects in future. [ABSTRACT FROM AUTHOR]

On 18 January 2016, the Zhangjiazhuang high-speed railway tunnel in Ledu, Qinghai Province, China, underwent serious deformation and structural damage. A crack formed at the top of the tunnel and the concrete on the crown peeled off. As a result, the tunnel could not be operated for three months. In order to determine the types and spatial distribution of the landslides in the region and the surface deformation characteristics associated with the tunnel deformation, we used field geological and geomorphological surveys, unmanned aerial vehicle image interpretation and differential interferometric synthetic aperture radar (D-InSAR) surface deformation monitoring. Nine ancient and old landslides were identified and analysed in the study area. Surface deformation monitoring and investigation of buildings in several villages on the slope front showed that the tunnel deformation was not related to deep-seated gravitational slope deformation. However, surface deformation monitoring revealed an active NEE-SWW fault in the area intersecting the tunnel at the location of the tunnel rupture. This constitutes a plausible mechanism for the deformation of the tunnel. Our study highlights the need for detailed engineering geomorphological investigations to better predict the occurrence of tunnel deformation events in the future. [ABSTRACT FROM AUTHOR]

A detailed characterization of the crustal deformation in the Himalaya is important to understand the tectonic and non-tectonic deformation processes responsible for the strain build-up and transients in deformation. In the present work, we have characterised the present day tectonic and non-tectonic deformations in the Kumaun Garhwal Himalaya estimated from the continuous GPS measurements. We observed strong seasonal variations in the horizontal and vertical displacement components (i.e. North, East and Vertical). The transient surface deformation estimated from global hydrological models is found to explain ~40–60% of the observed seasonal variations at sites. Plate convergence rate, and variation of slip deficit on the Main Himalayan Thrust (MHT) are calculated using site velocity estimated after removal of seasonal variations from the GPS time series. We report an excessive compression with an average principal shortening rate of −0.09 μ strain/yr in the north-northeast direction. The derived plate convergence rate is 18 ± 1 mm/yr and the width of locked frontal part of MHT is 100 ± 15 km. The quiescence of major to great earthquakes in the region since at least past 200 years and high rate of strain build up make this region vulnerable for a potentially devastating earthquake of Mw ≥ 8 in near future. • Strong seasonal variations in the displacement components with large H/V of seasonal amplitude (>0.5) at sites situated in Higher Himalaya of the Kumaun Garhwal Himalaya have been observed. • The available global models of hydrological loads explain ~40–60% of the observed seasonal variations in the displacement components. • Large strain rate (-0.1 μ strain/yr) in the Kumaun Garhwal Himalaya since past 200 years has potential to produce a megathrust earthquake of Mw~8.2. [ABSTRACT FROM AUTHOR]

Fixed beam structures are widely used in engineering, and a common problem is determining the load conditions of these structures resulting from impact loads. In this study, a method for accurately identifying the location and magnitude of the load causing plastic deformation of a fixed beam using a backpropagation artificial neural network (BP-ANN). First, a load of known location and magnitude is applied to the finite element model of a fixed beam to create plastic deformation, and a polynomial expression is used to fit the resulting deformed shape. A basic data set was established through this method for a series of calculations, and it consists of the location and magnitude of the applied load and polynomial coefficients. Then, a BP-ANN model for expanding the sample data is established and the sample set is expanded to solve the common problem of insufficient samples. Finally, using the extended sample set as training data, the coefficients of the polynomial function describing the plastic deformation of the fixed beam are used as input data, the position and magnitude of the load are used as output data, a BP-ANN prediction model is established. The prediction results are compared with the results of finite element analysis to verify the effectiveness of the method. [ABSTRACT FROM AUTHOR]

In safety-critical applications, deformation monitoring systems are required to issue timely alerts when a deformation beyond a critical threshold occurs. Only a very small probability of failing to issue an alert when in fact one should have been given, is acceptable. This probability is referred to as integrity risk. In this contribution, we show how to evaluate this risk, thereby taking the intimate link between testing and estimation into account. Using a simple example, the basic integrity components of deformation monitoring are introduced and illustrated. The integrity risk is then formulated for the generalized case where multiple-hypothesis testing is involved. As monitoring systems, in addition to issuing timely alerts, are also required to provide deformation estimates, it is also crucial to assess their confidence levels. In doing so, the statistical testing, that preceded the estimation of the deformation parameters, needs to be accounted for. As this is not the customary procedure followed in practice, we show how the combined estimation and testing can be probabilistically accounted for, and thereby demonstrate that the customary practice can give a too optimistic outcome of the stated confidence levels. The presented methodology is worked out and numerically illustrated by means of two deformation examples. [ABSTRACT FROM AUTHOR]

Induced seismicity is one of the negative phenomena caused by anthropogenic activities that include mining of minerals. This phenomenon manifests itself as sudden and unpredictable shocks of rock mass, which can cause surface deformation and damage to ground infrastructure. Until the advent of satellite radar interferometry that enables analysis of historical events, the characteristics of these unexpected surface deformations were difficult to assess. The main aim of the research was the spatial analysis of the geometry of surface displacements caused by eight induced tremors in the Rudna copper mine (SW Poland) and the dependence of deformation characteristics (vertical displacements, extent) on the induced shock energy. For this purpose, Sentinel-1 satellite imagery, the differential radar satellite interferometry (DInSAR) method and geographic information systems (GIS) based spatial statistics were used. Vertical displacements were mapped on the basis of 37 calculated interferograms. Spatial statistics on the pixel-to-pixel level were performed in the GIS Map Algebra environment. In the result, descriptive and spatial statistics characterizing deformations caused by individual shocks were calculated. The average values of vertical displacements ranged from −44 to −119 mm. Strong, statistical correlation between the extent, maximum vertical displacement, and energy values was determined. In addition, geometries of the formed deformation areas were analyzed and presented graphically. The results obtained in this research constitute development of a knowledge base on surface displacements caused by induced tremors in underground copper mining. [ABSTRACT FROM AUTHOR]