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The Yushenfu mining area has special hosting conditions, and the high-intensity coal mining is likely to cause surface cracks and negative impacts on the ecological environment. To accurately predict the location and depth of surface cracks, this paper proposed a prediction method that uses horizontal deformation as the key parameter, incorporating the stress-deformation characteristics of the loose layer. In this paper, the Yushenfu mining area was selected as the study area, the prediction formula of horizontal deformation was optimized and the Active Phase of the subsidence process was classified into two stages. A mechanical model of the wedge-shaped loose layer was established, combining this with the mechanical properties of the surface loose layer in Yushenfu mining area, a prediction method for the location and depth of surface crack was provided. Using the 112201 working face as a case study, the influence of seasonal rainfall on soil strength properties was considered. The results demonstrate that the optimized horizontal deformation formula has better performance compared with traditional calculations, and the accuracy of the method was verified and validated through on-site observations. The research provides an effective approach for predicting the location and depth of mining-induced surface cracks in the Yushenfu mining area.

Coal seam mining in the gully area easily causes ground cracks and even induces landslides, which endanger the safety of mining areas. In this paper, combined with the mining conditions of a mining area in southern Shanxi Province, China, ground crack mapping, crack width dynamic monitoring, and the numerical simulation method are used to study the static and dynamic evolution law and the formation mechanism of ground cracks in the gully area. The research shows that ground cracks mainly include dynamic in-plane cracks and boundary cracks. The dynamic in-plane cracks show the characteristics of “opening first and closing later”. The boundary cracks show the characteristics of “only opening and not closing”. It is found that the closure of the dynamic in-plane cracks will decrease (compared with plain areas). The development of ground cracks experiences three stages: the initial formation stage, the dynamic development stage, and the gradually stable stage. The “goaf–surface” structure model and force chain arch structure model are established to more intuitively analyze the formation mechanism of ground cracks. The research results have a specific reference value for preventing ground disasters caused by underground coal mining and land ecological restoration.

As one of the largest coal-rich provinces in China, Shanxi has extensive underground coal-mining operations. These operations have caused numerous ground cracks and substantial environmental damage. To study the main geological and mining factors influencing mining-related ground cracks in Shanxi, a detailed investigation was conducted on 13 mining-induced surface cracks in Shanxi. Based on the results, the degrees of damage at the study sites were empirically classified into serious, moderate, and minor, and the influential geological and mining factors (e.g., proportions of loess and sandstone in the mining depth, ratio of rock thickness to mining thickness, and ground slope) were discussed. According to the analysis results, three factors (proportion of loess, ratio of rock thickness to mining thickness, and ground slope) play a decisive role in ground cracks and can be respectively considered as the critical material, mechanical, and geometric conditions for the occurrence of mining surface disasters. Together, these three factors have a strong influence on the occurrence of serious discontinuous ground deformation. The results can be applied to help prevent and control ground damage caused by coal mining. The findings also provide a direct reference for predicting and eliminating hidden ground hazards in mining areas.

In 2014, the Pāhoa lava flow at Kīlauea, on the Island of Hawaiʻi (USA), entered a string of pre-existing meter-width ground cracks in the volcano’s East Rift Zone. The ground cracks transported lava below the surface in a direction discordant to the slope of the landscape. The cracks, which were 100s of meters long and 10s to 100s of meters deep, also widened by up to several meters as they filled, probably in part at the expense of adjacent cracks, which likely closed. Widening of the cracks caused shallow crustal blocks on the volcano’s flank to shift—this deformation was captured by a nearby GPS station and a borehole tiltmeter. The GPS station moved away from the cracks in response, while the tiltmeter showed tilting toward the cracks, consistent with opening. Noting that the lava-filled cracks act as top-fed dikes, we adapt existing theory for the thermo-rheological evolution of dikes to analyze transport of lava captured by ground cracks and propose mechanisms for the exit of the lava back to the surface. This study shows that ground cracks as narrow as 50 cm wide can facilitate the transport of advancing lava flows and can carry lava in directions that differ from those expected based on surface topography, invalidating flow path projections based on the assumption of subaerial flow.

The western mining regions of China, known for shallow-buried and high-intensity mining activities, face significant ecological threats due to damage to loose strata and the surface. The evolution of fissures within the loose layer is a critical issue for surface ecological environment protection in coal mining areas. The study employed field measurements, mechanical experiments, numerical simulations, and theoretical analysis, using the ‘triaxial consolidation without drainage’ experiment to assess the physical and mechanical properties of various strata in the loose layer. Additionally, the PFC2D numerical simulation software was employed to construct a numerical model that elucidates the damage mechanisms and reveals the evolution of loose layer fissures and the development of ground cracks. The research findings indicate that during shallow-buried high-intensity mining loose layer fissures undergo a dynamic evolution process characterized by “vertical extension-continuous penetration-lateral expansion”. As the working face advances, these fissures eventually propagate to the surface, forming ground cracks. The strong force chains within the overlying rock (or soil) layers develop in the form of an “inverted catenary arch”. As the arch foot and the middle of the arch overlap, fissures propagate along these strong force chains to the surface, resulting in ground cracks. The study elucidates the surface damage patterns in shallow-buried, high-intensity mining, offering theoretical insights for harmonizing coal mining safety with ecological conservation in fragile regions.

According to the special geotechnical problems encountered in the excavation of deep foundation pit, how to optimize the water stop and deformation scheme needs to be further studied. Taking the deep foundation pit project of Huzhu Road in Beilin District, Xi’an city, as an example, the paper analyzes the groundwater seepage and surface displacement change of the anchor pile support in the deep foundation pit, and the support scheme of local rotary jet + anchor pull pile is put forward. The results show that the uneven settlement value shows the shape of “Z,” and the maximum deformation value is about 48.2% compared than the ground fracture condition. Under the supporting scheme of + anchor row pile with local rotating jet, the hydraulic connection between inside and outside the foundation pit is reduced, which effectively makes the effective stress increase of the soil in the ground fissure area is controlled. Compared with the original measures, the maximum subsidence value on the surface is reduced by about 13.4 mm. With the new measure of foundation pit excavation, the deformation of the maximum pile body is reduced by about 19.4% compared with the original working condition, and the overall stability of the supporting structure is improved. In the aspects of supporting structure deformation, groundwater seepage, and surrounding surface settlement under the special geological conditions, the local rotary pile is better than the traditional dewatering pile anchor scheme.

On 26 November 2019, an Mw = 6.4 earthquake struck the central-western part of Albania. Its impact comprises secondary earthquake environmental effects (EEE) and severe building damage within the Periadriatic and the Tirana Depressions. EEE comprised mainly liquefaction phenomena in coastal, riverine, and lagoonal sites of the earthquake-affected area. From the evaluation of all available earthquake-related data, it is concluded that liquefaction sites are not randomly distributed within the affected area but are structurally and lithologically controlled. The affected areas are distributed within NW–SE striking zones formed in graben-like syncline areas with NW–SE trending fold axes. These graben-like areas are bounded by NW–SE striking marginal thrust faults and are filled with geological formations of Neogene to Quaternary age. These NW–SE striking zones and structures coincide with the NW–SE striking seismogenic thrust fault of the November 2019 earthquake as it is derived from the provided fault plane solutions. An approach for liquefaction susceptibility assessment is applied based on geological and seismological data and on liquefaction inventory. From the comparison of the compiled liquefaction inventory and the susceptibility maps, it is concluded that the majority of the observed liquefaction has been generated in very high and high susceptible areas.

In this study, a comprehensive assessment of the distribution characteristics of ground cracks in the Chengchao Iron Mine was conducted by field investigation and monitoring. In general, ground cracks are initially distributed around collapse pits, and subsequently extend outwards centered on the mined-out area. Greater ground deformation leads to more developed ground cracks. Ground cracks can be divided into cut-through crack, deep crack and shallow crack based on their downward extension depths. Furthermore, the formation of ground cracks is controlled by both underground mining and geological structures. Ground cracks can be divided into mining-induced crack and tectonic crack based on their main influencing factors. Moreover, many types of ground cracks are caused by different failure modes including tensile failure, shear failure and mixed failure. Ground cracks can be divided into vertical-shear crack, vertical-shear and horizontal-tensile crack, horizontal-tensile crack, horizontal-shear crack and mixed crack based on their formation mechanisms. In particular, the movement line and the break line, defined as ε = 2 mm/m and 6 mm/m, respectively, can be reasonably regarded as disturbance boundary and crack boundary in a metal mine. The disturbance zone caused by underground mining can be divided into collapse zone, break zone and movement zone based on the size of ground deformation and the characteristics of ground cracks. Increases in ground crack width and length exert different degrees of stress release on the rock masses outside and inside the crack, thus increasing their deformation difference. In addition, the extension of ground cracks is related to the ground topography and the strength and integrity of the rock masses and soil. Cracks on hilltop are more developed than those on flat land, and cracks will initially appear in rock mass and soil rather than on a concrete structure due to the lower strain resistance of the rock mass and soil. However, concrete structures are more sensitive to cracking than rock mass and soil because of the better integrity of concrete structures.

Ground cracks occur in many parts of the globe due to various causes. In Burdur (Turkey), they have been observed on an old alluvial fan encompassing 9 km by 7 km in an area south of Lake Burdur. This 3 m deep crack system continues along a line extending to 850 m, with the largest segment being about 170 m long. Because the cracks are close to a populated area, where damaging earthquakes had occurred in the past, further anxiety is created among the general population as to their source mechanism(s)—particularly if they are related to an imminent earthquake. An accurate mechanism for their occurrence requires resolution of multitude of issues. One aspect not considered to date is the drop in the lake’s water level of about 15 m in the last 25 years. This study focuses on the role of this drop in the lake’s water level. Satellite remote sensing and slope stability analysis methods are used. The results demonstrate significant influence of rapid drop in water level on the occurrence of cracks. The results are also significant for general understanding of the mechanism of occurrence of ground cracks elsewhere in the world.

Ground cracks resulting from coal mining subsidence can pose significant risks to coal mine safety, production, and the surrounding ecological environment. The use of drone technology coupled with deep learning holds practical value for accurately identifying ground cracks in mining areas. This study introduces an enhanced target detection algorithm based on YOLOv8n for analyzing ground cracks in aerial images captured by unmanned aerial vehicles (UAVs) dealing with small targets and widely distributed in shrubland. The C2f module of the backbone network is improved by incorporating deformable convolution (DCN), enhancing the model’s ability to adapt to detected object shapes, focus on small targets, and reduce irrelevant background information. Subsequently, the global attention mechanism (GAM) is integrated into the neck network to minimize feature information loss during training. Finally, the wise IOU (WIOU) loss function replaces the complete IOU (CIOU) loss function to improve the model’s generalizability. Experimental results demonstrate that the algorithm enhanced in this study exhibits improvements in precision (P), recall (R), and mean average precision (mAP@0.5) of 3.5%, 4.8%, and 5.1%, respectively, compared to the original YOLOv8n model. Furthermore, compared to other prevalent algorithms, the enhanced algorithm notably reduces model parameters, floating point operations per second (FLOPs), and model size while maintaining high detection accuracy. In conclusion, the enhanced YOLOv8n-based algorithm offers practical benefits for detecting cracks in mining subsidence areas.