Slope Type Research Articles

Indication of Deep-Water Gravity Flow Types by Shelf-Edge Trajectory Migration Patterns: A Case Study of the Quaternary Qiongdongnan Basin, South China Sea

The shelf-edge trajectory is comprehensively controlled by tectonics, sediment supply, sea level, and climate fluctuations; its migration and evolution have a strong influence on what happens in the deep-water depositional system during the Quaternary. The shelf-edge trajectory pattern, sediment-budget partitioning into deep-water areas, and reservoir evaluations are focused topics in international geosciences. In this paper, the Qiongdongnan Basin (QDNB) in the northern South China Sea is taken as an example to study how shelf-edge trajectory migration patterns can influence the types of deep-water gravity flow which are triggered there. Through quantitatively delineating the Quaternary shelf-edge trajectory in the QDNB, four types of shelf-edge trajectory are identified, including low angle slow rising type, medium angle rising type, high angle sharp rising type, and retrogradation-slump type. A new sequence stratigraphic framework based on the migration pattern of shelf-edge trajectory is established. There are four (third-order) sequences in the Quaternary, and several systems tracts named lowstand systems tract (LST), transgressive systems tract (TST), and highstand system tract (HST) are identified. This study indicates that the type of deep-water gravity flow can be dominated by the shelf-edge trajectory migration patterns. When the shelf-edge trajectory angle (α) ranged between 0° and 4°, the continental canyons were mostly small-scaled and shallowly incised, with multiple large-scale sandy submarine fan deposits with few MTDs found in the deep-water area. When the angle (α) ranged from 4° < α < 35°, the size and incision depth of the continental slope canyons increased, relating to frequently interbedded sandy submarine fan deposits and MTDs. When angle (α) ranged from 35° < α < 90°, only a few deeply-incised canyons were present in the continental slope; in this condition, large-scaled and long-distance MTDs frequently developed, with fewer submarine fans deposits. When angle (α) ranged from 90° < α < 150°, the valley in the slope area was virtually undeveloped, sediments in the deep-sea plain area consisted mainly of large mass transport deposits, and submarine fan development was minimal. Since the Quaternary, the temperature has been decreasing, the sea level has shown a downward trend, and the East Asian winter monsoon has significantly enhanced, resulting in an overall increase in sediment supply in the study area. However, due to the numerous rivers and rich provenance systems in the west of Hainan Island, a growing continental shelf-edge slope has developed. In the eastern part of Hainan Island, due to fewer rivers, weak provenance sources, strong tectonic activity, and the subsidence center, a type of destructive shelf-edge slope has developed. The above results have certain theoretical significance for the study of shelf-edge systems and the prediction of deep-water gravity flow deposition type.

Assessment of rock slopes stability using stereographic projection along Wadi Shorshirin in Zurbatiya region/ east of Iraq

Wadi Shorsirin is located in the Wasit governorate east of Iraq, it is considered a promising tourist site for the people who live close to this area. The research aims to study the rocky slopes and assess their stability, along the two banks of Wadi Shorhirine, by choosing five stations distributed where the failure occurs and to determine the expected rock failure along this valley. In addition, determine the factors that affect stability, such as discontinuities, rock resistance, and weathering to take them into account when establishing engineering projects such as roads, and tourist complexes. The stereoscopic projection technique was used to analyze the stability of these rocky slopes and showed there are two types of slopes which are oblique lateral and orthogonal slopes. Toppling and rockfall were found within the study area, in addition to the rolling. Differential eroded in the foot slope was the main reason for the failure, moreover, the existence of joint sets. The rocks of the slopes were evaluated based on the unconfined compressive strength deduced from the point load test into the moderately strong and strong.

Application of the Lambert function in the analytical solution of ballistics problems for flat flight trajectories of a material body, taking into account the gaseous (air) medium

Annotation. The paper describes the use of a special Lambert function for solving problems of ballistics of a material body, when the resistance of a gaseous (air) medium is taken into account. A model of quadratic (based on the speed of movement of a body) resistance of the medium within the limits of an approaching flat trajectory is considered. Problem. Problems of ballistics of a material body are considered in courses of theoretical mechanics, as well as in specialized literature. But, in addition to the cited literature, this research, like, for unraveling the simplified level of the material body in the problems of ballistics for flat trajectories of the power of a special function Lambert, which allows us to essentially simplify the algorithm for developing the parameters of the trajectory of a gentle slope (floor) type. Goal. The goal of the work is based on a framed model of a material body for flat trajectories in problems of modern ballistics on this basis, using a special Lambert function, to be controlled by a visible decoupling Didion, the determination of the main parameters of these types of crash trajectories. Methodology. Physic, mechanical and mathematical models are constructed that adequately describe the parameters of the collapse of a material body/particle that collapses along a flat trajectory when the wind is not supported , which are proportional to the square of the fluidity of the particles. For a more manual description of the parameters of the trajectory of the motion, there is a special Lambert function, which is tabulated in [1], or can be expanded with the help of computer in the middle of “Maple 8”. Practical value. The results obtained in the work can be used to improve and clarify engineering methods of calculation in problems of external ballistics of a material body, taking into account the quadratic (in terms of movement speed) resistance of the air environment

Ore Elements and Minerals in The Elements of Alaid Volcano (Kuril Island Arc)

Sublimates tested in 2013–2020 were studied. in the near-crater zone and on the slopes of the Alaid volcano, located in the Kuril Island arc. It has been established that in the near-crater zone there are native metals confined to zones of acid leaching, within which the original lavas and tuffs have been transformed into opal-like formations or rocks sharply enriched in ferric hydroxides. In these zones, the presence of native gold, palladium, silver, chromium, copper, zinc and alloys of gold and palladium, copper and zinc, copper and tungsten has been established. On the slopes of the Alaid volcano, the range of minerals in sublimates is wider, while the temperature of their formation is lower. Of the ore minerals, copper-containing ones predominate, and sublimates with vanadium-containing minerals belonging to hydrous oxides and vanadate-silicates are established. Two genetic types of slope sublimates have been identified: 1) minerals crystallizing from hydrothermal or steam-hydrothermal solutions near the outcrops of near-surface fumaroles and 2) copper and ferruginous colomorphic formations formed as a result of sedimentation from colloidal solutions in the shallow waters of drying up reservoirs, including small and large puddles.

Assessment of sustainability of natural complexes of the Minyarsky physiographic region of the Western slope of the Southern Urals

The article considers the evaluation of sustainability of natural complexes of low-mountain sections of the western slope of the Southern Urals (Minyarsk physical and geographical area) on the basis of analysis of landscape profiles on the indicator of sustainability of natural complexes. Peculiarities of the study area are highlighted: specific climatic conditions, complex geological and geomorphological conditions with ongoing industrial development, as well as a variety of soil and hydrological conditions combined with anthropogenic transformation of the territory. In the course of landscape profiling, as well as the application of methods of assessment of anthropogenic transformation of landscapes (at the level of the terrain), a decrease of diversity in natural complexes on the studied slopes was established, Replacement of typical plant communities by secondary successional communities in lowland areas dominated by horsetail. It has also been established that the aggregate of conditions in natural complexes indicates anthropogenic transformation of slope landscapes, the aggregate leading factor of which is the geochemical position on the element of the slope, Low resistance to external influence of the soil with a rinsing type of water regime defining plant associations. The obtained materials can be used as a basis for analysis of ecological condition of landscapes of the western slope of the Southern Urals, as well as characteristics of slope types of locations. Materials allow to further assess the recreational attractiveness of landscapes and the choice of ways of natural use of the studied area.

Monitoring of the Icing Process and Simulation of Its Formation Mechanism in the Cut Slope of Beihei Highway

Icing in cut slopes is a serious risk to transportation safety in cold regions. Research on the occurrence process and mechanism of icing is a prerequisite for proposing effective management measures. We took the cut slopes of the K162 section of the Beihei Highway as the research object. We used a combination of field investigation, geological exploration, monitoring, and simulation to study and analyze the power source, occurrence process, and triggering mechanism of icing in cut slopes. The results show that the geologic type of this cut slope is a mudstone–sandstone interaction stratum. Abundant shallow groundwater is the source of water for icing. The excavation of cut slopes extends the effect of negative temperatures on groundwater flow during the winter period. The process of ice formation in cut slopes can be described as follows: As the environmental temperature drops, the surface soil begins to freeze, resulting in a gradual narrowing of the water channel; then, the groundwater flow is blocked, so that the internal pressure begins to rise. When the internal pressure of the pressurized groundwater exceeds the strength of the frozen soil, groundwater overflows from the sandstone layer to the surface, forming icing. The high pore water pressure inside the cut slope is the precursor for the occurrence of icing. The dynamic pressure of the pore water pressure is the main driving force for the formation of icing in cut slopes. The obstruction of the water channel due to ground freezing is the triggering condition for ice formation in cut slopes.

Evaluation of Various Deep Learning Algorithms for Landslide and Sinkhole Detection from UAV Imagery in a Semi-arid Environment

AbstractSinkholes and landslides occur due to soil collapse in different slope types, often triggered by heavy rainfall, presenting challenges in the semi-arid Golestan province, Iran. This study primarily focuses on the detection of these phenomena. Recent advancements in unmanned aerial vehicle (UAV) image acquisition and the incorporation of deep learning (DL) algorithms have enabled the creation of semi-automated methods for highly detailed soil landform detection across large areas. In this study, we explored the efficacy of six state-of-the-art deep learning segmentation algorithms—DeepLab-v3+, Link-Net, MA-Net, PSP-Net, ResU-Net, and SQ-Net—applied to UAV-derived datasets for mapping landslides and sinkholes. Our most promising outcomes demonstrated the successful mapping of landslides with an F1-Score of 0.95% and sinkholes with an F1-Score of 89% in a challenging environment. ResUNet exhibited an outstanding Precision of 0.97 and Recall of 0.92, culminating in the highest F1-Score of 0.95, indicating the best landslide detection model. MA-Net and SQ-Net resulted in the highest F1-Score for sinkhole detection. Our study underscores the significant impact of DL segmentation algorithm selection on the accuracy of landslide and sinkhole detection tasks. By leveraging DL segmentation algorithms, the accuracy of both landslide and sinkhole detection tasks can be significantly improved, promoting better hazard management and enhancing the safety of the affected areas.

Stability Grade Evaluation of Slope with Soft Rock Formation in Open-Pit Mine Based on Modified Cloud Model

In recent years, the frequent occurrence of slope failures has brought the issue of slope problems to the forefront of widespread public concern, which significantly impedes progress toward the secure and sustainable development of open-pit mines. And, high and steep slopes of weak rock strata, being a more complex type of slope, pose a greater potential for danger. In order to ensure the reliability of the safety evaluation results of the high and steep open-pit slope containing soft rocks, an evaluation index system with quantized grade intervals was created based on the thought of an analytic hierarchy process, and the MATLAB R2021a was used to calculate the numerical characteristic values of the cloud model. Then, a standard stability cloud model based on cloud theory was established. With the opening pit mine as an example, its slope stability practice cloud image was generated and the similarity between this image and the grades of the cloud model was calculated through the ECM algorithm to effectively identify the stability and verify the scientificity and validity of the model. The results show that the similarity between the practice cloud image and the standard stability cloud image for the total evaluation of the stability of an open-pit mine is 0.021, 0.279, 0.594, and 0.106, respectively. The slope stability is at grade C, which is basically consistent with the numerical simulation and the analysis results of the traditional limit equilibrium method, verifying that the model is scientific and effective to a certain extent. The method provides substantial guidance to ensure production safety in this specific open-pit mine. It provides ideas and means for other similar complex slope stability analysis and prevention. Meanwhile, it promotes the safe and sustainable development of open-pit mines.

Optimization technology of hydroelectric power plant unit speed control based on the constriction coefficient-based particle swarm gravitational search algorithm fusion model

In recent years, the integration of wind power into hydropower networks has become a trend. But after wind power is connected to the grid, its unstable power will have an impact on the stability of the power grid. In order to improve the impact of wind power grid connection on the stability of the power supply network, a water motor speed control fusion model considering wind power interference is proposed. Firstly, analyze the impact of wind power grid connection and construct a speed regulation model for grid connected units. Secondly, the gravity search algorithm is introduced to optimize the unit speed control parameters. Considering that the algorithm is prone to local convergence, the convergence factor particle swarm optimization algorithm is adopted to optimize the gravity search algorithm. In addition, considering the impact of wind power interference on unit regulation, the Hopf bifurcation theory is introduced to analyze the dynamic regulation parameter range of hydropower units, in order to meet the requirements of stable operation of the power grid. The research contribution is mainly reflected in suppressing wind power grid connection interference through the speed regulation of hydroelectric units. At the same time, considering the impact of multiple interferences on grid connection, an intelligent model is introduced to optimize the speed control parameters of the unit, thereby improving the stable impact of wind power grid connection on the water conservancy grid. In the simulation analysis of hydroelectric unit speed regulation, after adding 5 % disturbance signal, the proposed model under rigid water hammer disturbance could stabilize the unit's stable control within 15 s, which is superior to other models. In the simulation analysis of speed regulation under wind power disturbance, the proposed model could achieve the fastest and most stable speed regulation under rigid water hammer step wind power disturbance, with a duration of 60 s. The proposed model could respond quickly to small overshoot and overshoot in elastic water hammer slope type wind power disturbances. Therefore, the proposed speed regulation technology for hydropower units has excellent application effects in practical scenarios, which will provide effective technical references for wind power grid connection and hydropower unit regulation.

Paleo-geomorphic features of pre-Jurassic and its oil-controlling effect in Wuqi–Dingbian area

The Fuxian-Yan10 layers are the main oil-producing reservoirs of Jurassic in Wuqi–Dingbian area of Ordos Basin. However, due to the lack of understanding of the pattern and distribution characteristics of oil reservoirs, the benefits of exploration and development are restricted. In order to provide theoretical guidance for the study of similar geological features, based on the analysis of paleogeomorphic features and evolution, the analysis focuses on the influence of palaeo-geomorphology on oil reservoir distribution, and summarizes the main types of reservoir models in the study area. The results show that there are four types of palaeo-geomorphic units in the Wuding area: palaeo-river, slope, highland and interriver hill. In the study area, the Jurassic paleogeomorphology controls the sedimentary development and distribution from Fuxian Formation to Yan 9 Formation. The compacted structure and lithologic barrier provide good trapping conditions for the paleogeomorphic oil. Moreover, the swampy coal measures and mudstone at the top of Yan 9 play a sealing role for oil accumulation, and the bottom water was obviously driven. In addition, the pre-Jurassic deep valley was the main channels for oil migration. On this basis, it is concluded that there are four reservoir-forming models in Wuding area: slope type, river hill type, ancient river type and highland type.

Experimental Study on the Evolutionary Law of Transient Saturation Zones in a Red Mud Dam under Rainfall Conditions

Utilizing a laboratory model test, this study seeks to evaluate the distribution patterns of volumetric moisture content, soil pressure, and pore water pressure within the body of a red mud dam, given varying initial conditions of slope types and ratios, during continuous heavy rainfall. The objective is to investigate the failure mechanisms of a red mud dam under distinct operational conditions during rainfall, thereby offering insights for landslide prevention and ensuring dam construction quality. The results suggest that a stepped red mud dam acts as a buffer platform, altering the seepage direction within the dam and minimizing the water seepage path. When the slope ratio is 1:1, the transient saturated zone is located on the slope face of the dam’s body, near the top of the slope, with the saturation time at the first monitoring point occurring 300 s earlier than in a dam with a slope ratio of 1:2. Rainfall affects the distribution of internal forces in the red mud dam body. After rainfall, in the transient saturated zone of the stepped dam body, vertical soil pressure decreases 25% and horizontal soil pressure decreases 6.5%; in the transient saturated zone of the dam with a slope ratio of 1:1, vertical soil pressure decreases 14.8% and horizontal earth pressure decreases 29%; in the transient saturated zone of a dam with a slope ratio of 1:3, the change in soil pressure is small.

Complex Deposit Slope Excavation Deformation Mechanism and Seismic Reinforcement Effect Evaluation

Background To further investigate the excavation deformation mechanism and remedial strategies for slope reinforcement in the southwest mountain area, the Baihetan-Jiangsu (Zhejiang) UHV transmission project deposit slope deformation reinforcement was used as a case study. Methods Deep displacement monitoring, on-site testing, and FLAC3D numerical simulation techniques were employed. The assessment of the deposit slope excavation deformation mechanism and the effectiveness of seismic reinforcement for different design options and pile parameters are conducted while analyzing the seismic reinforcement mechanism. Results and Discussions The results showed that (1) The deposit slope composed of “multi-genetic type soil” in the converter station is prone to deformation, where the dominant instability mode is “traction creep and tension failure mode.” (2) Both circular and rectangular anti-slide piles significantly reduce the amount of slope body deformation; employing circular anti-slide piles for addressing this type of deposit slope provides enhanced anti-slide retention and economic benefits. (3) Under the influence of an earthquake, the shear force and bending moment of the anti-slide pile first increase and then decrease with the increase of seismic intensity. Conclusion The distribution law of shear force and bending moment in a pile should be considered comprehensively in slope support design.

Effects of modified organic material addition on soil and microbial communities in ecologically restored engineering slopes of the Qinghai-Tibetan plateau: A mesocosm study

Organic material plays an essential role in the ecological restoration of different types of surfaces with engineering damage in extremely fragile environments. An outdoor mesocosm experiment was conducted to explore the effects of modified organic material on chemical, physical properties and microbial communities of reconstructed soil in ecologically restored engineering slopes of the Qinghai-Tibetan plateau. The physical and chemical properties of the soil indicate that the addition of modified organic materials significantly improves soil nutrients. In this area, organic carbon increased by 1.87 g·kg−1 in the frame beam slopes compared with the control area, and the potassium content doubled. In addition, modified organic material effectively induced soil metabolism responses, mainly promoting the activities of soil enzymes like amylase, cellulase, urease, sucrase, and alkaline phosphatase. Moreover, addition of modified organic material noticeably changed the abundance and structure of microbial communities in soils. The enhanced concentrations of the signal molecules N-acylated-L-homoserine lactone and auto inductor peptide indicated that addition of modified organic materials significantly influenced quorum-sensing in soil microbial communities. There are differences in the soil improvement effects of different types of slopes, among which the frame grid beam has the best effect. These findings demonstrate the effect and underlying mechanisms of the addition of incorporating modified organic materials, primarily sodium carboxymethyl cellulose and anionic polyacrylamide, into the soil of engineering slopes. These results have extensive application prospects for ecological restoration in strict environments.

Waste Management: Landfill Selection Using Gis and Analytical Hierarchy Process

The widespread use of landfilling as a convenient waste management method has become unsustainable due to the rapid development causing a surge in waste generation, threatening the lifespan of existing landfills. The closure of landfills presents waste management challenges, necessitating more extensive garbage disposal facilities to accommodate the growing urban population. However, poor site selection methods can have a negative impact on both the environment and human health, which goes against the objectives of sustainable development goal (SDG). Methods like Geographic Information System (GIS) and Multi-Criteria Decision Analysis (MCDA) facilitate decision-making processes. This integration reduces analysis time and costs enhances accuracy and minimizes errors. The Analytical Hierarchy Process (AHP) provides a framework to validate judgments and derive measurable values in decision-making involving theories and concepts. In this study, several criteria were used to create a final suitability map which is the distance from the residential area, distance from the plantation area, distance from the main road, distance from waterways, type of soil, slope, and land cover. The results indicate that distance from residential has the highest weightage of importance, which is 27%. It also found that the highly suitable new landfill area is located at Batu in Kuala Langat, Pulau Carey, and Bukit Rotan in Kuala Selangor.

Morphological characteristics of gullies affected by the soil type of artificial slopes in the Dry‐hot Valley Region, Southwest China

AbstractGully erosion is widely recognized as a significant form of land degradation globally, posing threats to ecological security and human societal development because of its ability to generate substantial amount of sediment. Artificial slopes are commonly disturbed landforms that are susceptible to intensive gully erosion. Morphological characteristics play a crucial role in assessing the intensity of gully erosion and can be utilized to predict sediment yield. Notably, soil type has been identified as a key factor influencing the morphological characteristics of gullies. Consequently, a comprehensive analysis was conducted based on meticulous field investigations to examine the impact of soil type on the morphological characteristics of gullies on artificial slopes in the Dry‐hot Valley Region of Southwest China. The results showed that the gully cross‐sectional area (Ac), curvature (Cc), and shape index (Si) exhibited a decrease along the downslope direction of the artificial slopes for all three studied soil types, following power functions. Additionally, the soil type of the artificial slope significantly influenced the mean values of the gully cross‐sectional morphological characteristics. Regarding the longitudinal morphological characteristics of the gullies, the largest longitudinal concavity (Ca), longitudinal curvature (Cl), and length‐gradient index (Gl) values were observed for the Vertisol, Entisol, and Ferrasol, respectively. These findings suggested that gullies developed on different soil types exhibit significant variations, particularly in terms of longitudinal morphological characteristics. Furthermore, strong correlations were detected between the gully cross‐sectional and longitudinal profile morphological characteristics, and the gully cross‐sectional shape index (Si) was correlated with all the longitudinal profile morphological characteristics. This study offers valuable insights into the morphological characteristics of gullies on artificial slopes with different soil types. Such knowledge is of paramount importance for effectively preventing and controlling gully erosion in contemporary society.

Influence of the Slope and Gate Offset on Movement Variability and Performance in Slalom Skiing

Adaptability to all types of terrain changes, slopes, and course settings is a key aspect related to the coordinative ability that elite skiers possess. In recent years, several studies have analyzed coordinative aspects of different motor actions via the assessment of movement variability (MV), an indicator of the motor control that assesses movement regularity. The aims of this study were (a) to evaluate the influence of different slopes and slalom (SL) gate offsets on MV and performance and (b) to assess the relationship between MV and performance. Four SL courses were set: a flat-turned (FT), a steep-turned (ST), a flat-straighter (FS), and a steep-straighter (SS). Five elite alpine skiers (21.2 ± 3.3 years, 180.2 ± 5.6 cm, 72.8 ± 6.6 kg) completed several runs at maximum speed for each SL course. A total of 77 runs were obtained. The use of an IMU accelerometer attached to the lower back of skiers measured MV through entropy. The skiers’ performance was evaluated with the total time of each run. The one-way repeated measures analysis revealed that the steepness of the slope significantly increases skiers’ MV, concretely between FS and ST courses (p = 0.004). Differences at the 10% level have been found between FS and SS and FT and ST courses (p= 0.055 and p = 0.078, respectively). For a given slope, turned courses (FT and ST) tend to produce a higher MV. In addition, faster times correlate with lower MV (r = 0.587, p = 0.01). It has been observed that both steeper and turned courses produce greater MV and that the best performing skiers have lower MV. Determining MV through entropy can be used to assess skiers’ expertise regarding different types of slopes and gate offsets.

Stability Analysis of a Water‐Rich Slope Under Seismic Disturbance

Studying slope stability under different water contents and stress conditions is very important for the early warning and prevention of slope disasters. In this study, the stability of a side slope in Xingwen County was studied via field investigations, laboratory tests, and numerical simulations. The results show that a dry sample has a greater rockburst proneness than a water‐rich sample. Compared with that of the dry sample, the strength of the sample representing the water‐rich area of the slope decreased significantly, the peak strength decreases by 28.5% on average under the different confining pressure conditions tested, and the stress–strain curve has more jitter after the peak and shows more obvious plastic characteristics. The peak shear strain in the XZ direction on the lower slope under water‐rich conditions is 48.5% greater than that under dry conditions, and the range of the slope plastic zone is also significantly greater than that under dry conditions. This indicates that the stability of the slope under water‐rich conditions is much lower than that under dry conditions. The safety factors of the three types of slopes are calculated. The slope safety factors under the “water‐rich and deadweight” and “water‐rich and earthquake” conditions are 3.1% and 5.4% lower, respectively, than that under the “dry and deadweight” conditions. Therefore, it is necessary to strengthen the protection of water‐rich areas on slopes with frequent microearthquakes.

Significant Location Accuracy Changes Resulting from Lightning Detection Networks Deployed on Inclined Terrains

This study investigates the location accuracy distribution of the lightning detection networks (LDNs) deployed on inclined terrains, an aspect frequently encountered in complex terrains but hitherto disregarded in previous studies. By designing eight substation LDNs deployed on slope-type (ST), mountain-type (MT) and basin-type (BT) terrains, respectively, we employed Monte Carlo simulations to analyze their spatial location accuracy distribution based on time-of-arrival technology. Significant differences among the LDNs on inclined terrains and between them and the LDN on plain-type (PT) terrain were revealed. Compared to the PT LDN, LDNs on inclined terrains exhibited a reduction in high-precision location regions and a shift in the distribution pattern of location accuracy. The ST LDN showed marked deviations in the high-precision vertical location toward the lower slope side with increases in the elevation angle and consistently smaller high-precision vertical location areas compared to MT and BT LDNs. The variations in elevation angles of MT and BT LDNs had a substantial impact on the spatial distribution patterns of both horizontal and vertical location accuracy, with BT LDNs featuring larger vertical high-precision areas than MT LDNs. Our conclusions were further corroborated through an analysis of an actual LDN, which combined characteristics from both ST and MT terrain patterns.

Study on the influence of slope shape with numerical calculation models on slope safety during slope excavation.

Under the influence of natural weathering and excavation in human engineering, slopes in nature have various slope shapes. In human engineering activities, the stability of different types of slopes formed by manual excavation must be affected by multiple factors such as geologic setting, lithology and environment. Therefore, to understand the impact of slope shape, geologic setting, and other conditions on slope stability of artificial slopes, calculation models for straight slope, concave slope, and convex slope are constructed based on the three slope shape characteristics. By changing the angles of upward and downward slope angles and analysing the parameters of slope shape, joint spacing, and joint angle, discrete element software is used to calculate the slope safety factor. The calculation results show that the slope shape, joint spacing, and joint inclination affect the safety of slopes. In straight slopes with large joint spacing, the smaller the slope angle, the greater the safety factor. However, in the interval of small joint spacing, the safety coefficient of slopes with slight joint inclination has the opposite variation characteristics. When a<90°, the straight slope has a dominant joint inclination angle that minimises the slope safety factor. In concave slopes, the more concave the slope shape is, the smaller the safety factor is; For concave slopes with small joint spacing, the slope with slight joint inclination has a more significant safety factor; Under the condition of large joint spacing, there is a dominant joint inclination in the joint inclination range of 30° to 70° for concave slopes, which minimises the safety factor of the slope. In convex slopes, the smaller the joint inclination angle of the slope, the smaller the safety factor of the slope, and the smaller the upslope angle of the slope, the greater the safety factor of the slope.

Interplays between plants and environmental factors determine pullout resistance on different revegetated slopes in mining areas

Plant roots play a crucial role in enhancing soil stability and protecting slopes during ecological restoration, particularly in mining areas where external-soil spray seeding is employed. However, the relationship between plant root pullout resistance and environmental factors on different types of slopes remains unclear. In this study, we investigated the interactions between the pullout resistance of a dominant species, Artemisia gmelinii, and environmental factors on three slope types (rocky, geotechnical, and soil) using multi-group structural equation modeling. Our findings reveal that the pullout resistance of plant roots was strongly influenced by various factors, including but not limited to biological factors such as plant height and biomass. It showed a positive correlation between soil silt content and soil nutrient levels. Notably, the pullout resistance on soil slopes was significantly higher than on rocky slopes. Furthermore, the impact of soil nutrients and texture on pullout resistance was more pronounced on geotechnical and soil slopes compared to rocky slopes. Multi-group structural equation modeling highlighted that among all environmental factors, slope gradient and underground biomass had the most significant influence on pullout resistance across all slope types. Specifically, slope gradient had a greater effect on soil slopes, whereas underground biomass played a more prominent role on rocky and geotechnical slopes. Overall, our study suggests that when implementing external-soil spray seeding in mining areas, it is crucial to consider the interplay between plant roots and environmental factors, including slope properties. This holistic approach is crucial for maximizing the effectiveness of plants in slope protection during eco-engineering projects.