bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Fracture Characteristics of Asphalt Pavement with Longitudinal and Transverse Cracks under the Influence of Real Temperature Field
Authors: Zhao Kang , Yan Guannan , Li Jianfeng , Wang Linbing
Published: April 2021

In order to study the influence of the actual temperature field of asphalt pavement on the fracture characteristics of asphalt pavement structure, the finite element(FE) software ABAQUS is used to simulate the temperature field of asphalt pavement in summer and winter, and then the temperature field corresponding to specific time period is introduced into the thermal mechanical coupling analysis. The effects of different loading speeds (10, 20 m/s) and different loads sizes (0.7, 1.2 MPa) on the stress intensity factors (SIF) of top-down (longitudinal) and base reflective (transverse) cracks were studied, and the crack propagation characteristics were discussed. It is found that in summer, the top-down cracks in the surface layer mainly propagate in mode II, and the value increases with the increase of load. In winter, the low temperature promotes the propagation of mode I crack, and the sign of K? value in winter is opposite to that in summer. For the reflection crack of base course, the coupled field promotes the propagation of mode II crack at high temperature in summer. However, in winter, the base is prone to mode I expansion, and increases with the increase of load. When there is no coupling field, the speed has little effect on crack propagation, but the location of SIF peak value changes in time. In the coupled field, the SIF value increases with the decrease of speed. Therefore, considering the real temperature field, heavy load and slow speed have the greater damage to the pavement.
Force Characteristic Analysis of Different Steel Deck Pavement under Temperature Load Coupling Situation
Authors: Zhou Yan , Song Jun-chao , Meng Lingyue , Li Xiang
Published: April 2021

In order to investigate the force characteristic of different steel deck pavement under extreme temperature and load coupling situation, we established the three dimensional extreme high temperature and extreme low temperature field of simple supported beam bridge, the paving structure were double layered SMA, double layered epoxy concrete, SMA+GA, using material elastic modulus changing with temperature. Analysis indicated that the maximum value of high temperature normal stress occurred in the epoxy upper layer pavement, the maximum value of shear stress occurred in the epoxy lower layer pavement, the maximum value of high temperature strain occurred in the upper layer of double layered SMA pavement. The maximum value of low temperature stress occurred in the SMA+GA lower layer pavement, the maximum value of low temperature strain occurred in the SMA+GA upper layer pavement, the maximum value of shear strain occurred in the SMA lower layer pavement. The maximum value of high temperature stress usually occurred in the bottom of pavement layer, maximum strain usually occurred on top of pavement layer. The maximum value of low temperature shear stress and shear strain usually occurred in the bottom of pavement layer, normal strain occurred on top of pavement layer. The stress difference between the upper and lower layers in SMA+GA pavement structure is very large which adversely affected the structural force.
Analysis of the Influence of Underground Traffic Tunnels by the Explosion Seismic Effect of the Storage Yard
Authors: Hu Guangxia
Published: April 2021

The dynamic response of the existing deep underground traffic tunnel under the seismic effect of dangerous goods explosion is an important issue that should be actively considered before the construction of the container yard. In order to ensure the safety of the tunnel, this paper first introduces the goods to be stored in the newly built container yard of dangerous goods and their dangerous characteristics. Then, the vibration response of the tunnel wall under the explosion of 1 t, 2.6 t and 6 t TNT is simulated by using Midas GTS finite element analysis software. When the explosive equivalent is 2.6 t, the vibration speed of the tunnel wall is in a safety critical state. The simulation results provide reference suggestions for the types of engineering design stockpiles and limited stockpiles and control the influence of dangerous goods container yard on traffic tunnel from the source.
State -of -the -Art and Development of Seismic Analysis for Complex Bridges
Authors: Chen Yang , Wang Qiuliang
Published: April 2021

Due to the complexity of dynamic response characteristics of complex bridges, it is difficult to give uniform regulations to give comprehensive and complete guidance for its seismic analysis. In order to promote the development of seismic analysis of complex bridges, the research status and progress of complex bridge seismic analysis were discussed in detail. Firstly, the characteristics of the commonly used seismic analysis methods for bridges and their applicability to complex bridges were summarized. Secondly, the selection and synthesis methods of far-field and near-field seismic used for bridge seismic analysis were concluded. Meanwhile, the seismic input methods and the most unfavorable input direction of curved bridges were discussed. Then, the anti-seismic analysis model of the main components of bridges were summed up, and the medium-structure interaction (including pile-soil-structure interaction, abutment-soil-structure interaction and water-structure interaction, etc.) were investigated. Finally, on this basis, the unsolved problems and the future development directions in this research field were pointed out. It is concluded that the seismic analysis of complex bridges still has some shortcomings, which needs to be improved and developed.
Research on Maintenance Management of Flexible Pavement Based on C-LTPP
Authors: Cheng Chunru , Wang Linbing , Yang Hailu , Miao Yinghao
Published: April 2021

Based on the Canadian Long-Term Pavement Performance (C-LTPP) data, this paper chooses the road performance related data as variable factors. According to the Dipstick detection results, the characteristic values such as rut depth, wheel track width and cross section area are extracted to describe the rutting. This paper established the relationship between the pavement rutting and the cumulative service time, determined the rutting evaluation index, and proposed the pavement maintenance time threshold. Comparing the flexible layer overlay repair schemes used in various test points, it provides a reference for the pavement performance management decision-making and the road repair scheme design after repair.
Static Strain Analysis of CRTS I Bi-Block Ballastless Track
Authors: Zeng Zhiping , Ye Mengxuan , Wang Weidong , Guo Wuji , Meng Xiaobai
Published: April 2021

In this paper, relying on the National Engineering Laboratory of High-Speed Railway Construction Technology, a full-scale model of the double-block ballastless track structure is established, and the strain analysis of the layered track structure under different static loads is carried out, which has a certain practical significance for the design and maintenance of the high-speed railway ballastless track in our country. Research conclusion: (1) Under the action of static load, the sleeper directly under the rail is under compression; the four corners of the sleeper are tensile strain; (2) The strain at each measuring point on the surface of the track slab around the sleeper is compressive strain; the edge of the top surface of the track slab is compressive strain; The longitudinal strain at the bottom of the side of the track slab is tensile strain; (3) Under static load, the longitudinal strain measurement point on the top surface of the base plate is tensile strain at a distance of two sleepers from the static load position; the longitudinal strain at the bottom of the side of the base plate is tensile strain.
Analysis of the Influence of the Unsymmetrical Surface Surcharge on the Structure of the Subway Tunnel
Authors: Gu Xueying , Huang Tianrong , Shen Zhongyuan , Shi Gang , Wu Jianxun
Published: April 2021

Field case of staggered jointed lining of metro shield tunnel with an unexpected unsymmetrical surface surcharge is introduced in details at first. The finite element model of beam-spring is used to reproduce the surface surcharge process. Results show that the tunnel deviates from the surface surcharge under the action of unsymmetrical surface load. The displacement of adjacent rings A and B is different, which caused tunnel disease such as segment dislocation and water leakage. In the design state, the bending moment and axial force of A and B rings are close to each other, after unsymmetrical surface surcharge, the bending moment of ring B with key segment on the lower surface pressure side is larger than ring A. When the crack width is 0.2 mm, the corresponding horizontal expansion and vertical convergence are 33 mm (5.3D ‰) and 34 mm (5.5D ‰). When the horizontal expansion value is greater than 50 mm (8D ‰), ring B will enter into the stage of rapid development of cracks, which should be closely monitored and treatment measures should be taken when necessary. The bearing capacity of ring A and ring B is different after surface surcharge, which is suggested to be considered in the subsequent structural reinforcement.
Numerical Analysis for Earthquake Response of Polar Crane
Authors: Wang Zhiyun , Li Shouju , Yu Shen
Published: April 2021

To evaluate seismic properties of polar crane in nuclear power station, the earthquake responses of polar crane are analyzed. The first order frequency of polar crane fixed on containment wall is 2.44 Hz. The first order mode shape of polar crane is transverse horizontal deformation of two horizontal parallel main girders. El Centro earthquake loading and Los Angeles earthquake loading are used as input loadings on bottom the containment wall. The maximum accelerations of time histories of earthquake loading are normalized. The numerical simulation investigation shows that the maximum Mises stresses in mid-span of girder of polar crane under the action of El Centro earthquake loading and Los Angeles earthquake loading are 131 MPa and 133 MPa respectively, and they are less than permissible stress of material. The numerical simulations indicate that the wheels on polar crane don’t derail during earthquake process because the wheel pressure is always compressive state. Considering the El Centro earthquake loading, the maximum vertical acceleration on polar beam of containment wall is 3.3 m/s2 and less than gravity acceleration (9.8 m/s2).
Stability and Failure Analysis of Zhaoshuling Landslide under the Reservoir Water and Earthquake
Authors: Xie Biting , Zhang Xiuli , Wang Hao , Jiao Yuyong
Published: April 2021

Due to the reservoir impoundment, the geological environment in Three Gorges Reservoir area deteriorates, consequently inducing a series of geological hazards. Zhaoshuling landslide is one of the most important landslides in Three Gorges Reservoir area, and its safety seriously affects the planning and construction of the new-established Badong city. The unfavourable change of hydraulic condition, accompanied with earthquake, may cause landslide instability. In this paper, the stability and failure features of Zhaoshuling landslide under the reservoir water and earthquake are researched by discontinuous deformation analysis (DDA) method. The simulated results show that Zhaoshuling landslide is globally stable under the reservoir water and VII earthquake, while considering the degradation effect of rainfall and reservoir water on the strength of the sliding zone, the landslide may be damaged. The landslide damages more seriously at a low water level, the failure mode is creep and traction, and the failure mainly happens at the head and middle of landslide. Therefore, the head and middle of landslide is the key section of prevention and treatment.
Evaluation of Metro Fire Emergency Response Ability Based on WRSR
Authors: Jiang Xiaoshu , Dong Sihui
Published: April 2021

In order to clarify the status of subway fire emergency response capability, a comprehensive evaluation method based on the weighted rank-sum ratio method is proposed. Firstly, the factors affecting the emergency response capability of subway fire accidents was put forward on the basis of the current relevant laws and regulations, and a subway fire emergency response capability evaluation system was also built; secondly, the Analytic Network Process (ANP) was used to calculate the weight of each indicator in the system; then, the weighted rank sum ratio method (WRSR) is used to evaluate the overall status of the subway fire accident emergency response capability, and the sub-range of each subway emergency response capability is obtained; finally, model verification was conducted with 8 typical subways in Central China. The results show that C1, C3, C16, C20 and C29 constitute important indicators of subway fire emergency response capabilities; the constructed model can comprehensively evaluate the subway fire emergency response capabilities and facilitate its safety management.
Exploration into the Anti-Seismic Technologies in the Museum
Authors: Tian Jingneng , Song Maomao , Zhang Mansheng , Pan Jiao
Published: April 2021

The overall seismic isolation structure is adopted for Yunnan Provincial Museum. The paper explores anti-seismic technologies for both museum buildings and collections, offers seismic protection analysis and design for precious museum collections by taking into account seismic waves, buildings, exhibition facilities and collections as a whole. Based on the demand for protecting museum collections from earthquakes, the paper discusses proper anti-seismic technologies for the museum structure, exhibition facilities, showcases and collections; it offers the dynamic time-history analysis of seismic isolation structure in rare earthquakes, and gives anti-seismic analysis and design for collections based on the acceleration response of the floor on different levels. Conclusions: The seismic protection for museum collections shall take into consideration seismic transmission from the venue and structure to exhibition facilities, showcases and collections. Under seismic actions, the acceleration response of the floor of exhibition halls on different levels of the museum varies greatly, the seismic response of showcases reinforced with anti-seismic measures decreases significantly, which ensures the safety of museum collections in earthquakes. The paper focuses on the anti-seismic technical route, technical measures, assessment results and implementation suggestions, offering reference for the construction of new museums and the seismic preventive conservation of collections.
Simulation Analysis of Earthquake Resistance and Isolation of 220kV GIS Equipment in Tianjin
Authors: Li Shiyong , Tang Jipeng , Zhang Xiaoliang , Sun Nan , Zhang Fuheng
Published: April 2021

The anti-seismic and isolation simulation analysis of a 220 kV GIS equipment is carried out using finite element software. The response spectroscopy method is used to simulate the displacement and acceleration dynamic response of the whole structure under the two working conditions before and after the isolation device is installed, and to analyze the change of the natural frequency of the structure. The results show that the relative deformation of 220 kV GIS equipment is smaller than before isolation, and the vibration characteristics of the overall structure are close to the single-particle model, and the structure’s seismic performance is significantly enhanced for the maximum acceleration of the overall structure is reduced by 90%.
Application of Statistical Prediction Model to the Reservoir Induced Seismic Risk Analysis of Aqing Hydropower Station in Xizang
Authors: Zhou Chenghao , Zhang Lifen , Li Jinggang , Wang Yajie
Published: April 2021

Based on field seismic geological survey and previous research results, this paper analyzed tectonic background, seismicity and hydrogeological conditions of Aqing hydropower station in Xizang respectively, then calculated the probability of reservoir induced seismicity. The results showed that it is possible for the reservoir induced seismicity occurring, whose probability is 0.455. In detail, the probabilities of occurring moderate-strong, weak, and micro earthquake are 0.089, 0.070, and 0.296 respectively. Under these circumstances and based on the intensity attenuation relationship of reservoir induced seismicity, it can be deduced that the moderate-strong earthquake would occur with epicentral intensity VII, and the lengths of major axis and minor axis are 6.5 km and 3.3 km respectively.
Seismic Optimization Study of Substation Bus-Bar Connecting Circuit
Authors: Liu Zhenlin , Xue Yaodong , Zhang Xiaojun
Published: April 2021

Bus-bar is an important power transmission channel in substation. To improve the safety performance of bus under the action of earthquake, the finite element simulation calculation is carried out for the bus-bar circuit in UHV substation. And this study analyzes the influence of structural design parameters such as tube bus layout and bracket span on earthquake response of pillar insulator in the circuit. The results show that the seismic performance of the bus-bar connecting circuit can be optimized by using independent tubular bus layout for each span, increasing insulator support and reducing the span of single tubular bus.
Experience of Urban Solid Waste Management in Russia under the Concept of Smart City and Its Enlightenment to Shenyang
Authors: Wang Qiufei , Li Siyu
Published: April 2021

Using digital technology and artificial intelligence to improve the level of municipal solid waste management and to explore the new path orientation of urban management with Chinese characteristics is an important and key task of smart city construction. There are many similarities between Russia and China in urban construction, economic development and so on, so the experience of municipal solid waste management is of great significance to China’s urban construction. This paper analyzes the basic situation and reform process of Russian municipal solid waste, investigates the practice of Russian municipal solid waste management in the process of smart city construction, and sums up its successful experience on this basis, combined with the present situation of Shenyang, this paper puts forward some suggestions on the treatment of municipal solid waste under the background of the construction of smart city.
The Simulation and Optimization of Flow Field in the Low Temperature SCR Reactor
Authors: Wang Shuqin , Wang Jing , Wang Xin
Published: April 2021

The uniformity of flue gas velocity at the inlet of selective catalytic reduction denitrification reactor can improve the denitrification efficiency, and the reasonable layout of guide plate can improve the flue gas flow rate. Fluent is used to analyze the flow field in the inlet flue of denitrification reactor, and the flue gas velocity in the guide plate reactor arranged in different ways is simulated. The optimized layout mode is the form of radian plus straight plate, which is helpful to uniform flue gas velocity, improve denitrification efficiency, and help students to improve the understanding of reactor flow field uniformity.
Numerical Simulation of a Certain Engineering Vehicle Gearbox under Low Temperature Conditions
Authors: Feng Suli , Zhang Hongzhuang , Ma Changzheng
Published: April 2021

The gearbox is an important part of the reducer. Its components must have high bearing capacity and reliability. Cracks often appear in the gearbox body in the actual work, so it is necessary to carry on the structure analysis to the gearbox body performance. In this paper, a 3-D model of an engineering vehicle gearbox is established by using Solidworks software. Based on the model, the stress State and maximum displacement of the gearbox under low temperature conditions are analyzed. According to the calculation, the structure of the gearbox meets the design requirements. The analysis results provide a theoretical basis for the structural optimization of the gearbox.
Analysis of Landslides Stability Influenced by the Heavy Rainfall and Drawdown of Reservoir Water Level in Three Gorges Reservoir
Authors: Liu Yi , Zhao Binbin , Kong Xiaoang , Yang Zhi
Published: April 2021

Heavy rainfall and reservoir drawdown rate are primary factors when evaluating landslide stability. This paper intends to ensure the feasibility of increasing reservoir drawdown rate before flood season influenced by those two factors in the Three Gorges Reservoir (TGR) area. At first, a heavy rainfall was calculated by Pearson type ? distribution (PE3) using rainfall data of 20 counties from 1960 to 2010. Based on the reservoir operation, annual rainfall data was divided into four groups and calculated separately. The parameters of PE3 were estimated by curve fitting method and validated by Kolmogorov-Smirnov test. Then a reservoir drawdown model was proposed considering the actual regulation of reservoir. At last, a seepage-slope analysis was carried out using extreme rainfall and reservoir drawdown model on Sifangbai landslide. The extreme rainfall results show that the extreme rainfall during flood season was 2.5, 1.4 and 2.2 times greater than that in other three parts. Stability analysis showed that the landslide stability was mainly influenced by reservoir drawdown. Total time and elevation in rapid drawdown model would reduce with the increase of reservoir drawdown rate. With extreme rainfall data and reservoir drawdown model provided in this paper, similar partially submerged landslides in the TGR can be evaluated before increasing reservoir drawdown rate.
Perception Measurement of Interface Transparency on the Side of Living Commercial Streets in North China
Authors: Li Danyang , Fu Yao , Liu Yutong
Published: April 2021

Street space is a place where residents engage in daily activities, and its environmental design plays an important role in regulating the physical and mental comfort of people. However, the visual environment of street space is complex with many design elements, which is not conducive to grasping the design focus. Based on visual perception of comfort, the study deconstructs street space design into four basic elements: interface transparency, storefront density, interface colors and interface materials, and builds a virtual scene using SU software. The combination of human factors experiments and questionnaires is used to study the perception of street transparency, providing basic information and new research methods for the humanized design of the visual environment of street space.
Structural Characteristics and Properties of Polylactic Acid (PLA) and Cellulose Triacetate (CTA) Fibers for Heat-Not-Burn (HNB) Cigarettes
Authors: Ke Weichang , Miao Mengyu , Liu Bing , Wu Qiao , Liu Tong
Published: April 2021

In this work, two commonly used filter fibers for heat-not-burn (HNB) cigarettes, polylactic acid (PLA) and cellulose triacetate (CTA) fibers, have been extensively investigated by characterizing their morphologies, thermal and wetting properties. It is found that plenty of small pores can be observed in PLA fibers, which can provide more effective surface areas for the adsorption of mainstream smoke than CTA fibers with smooth surface. At the same time, thermal properties results including differential scanning calorimetry data, thermogravimetry data, and thermal conductivities of PLA and CTA fibers indicate that CTA fibers have an amorphous phase, while PLA fibers present a mixture of amorphous phase and crystalline phase with better thermal properties. Additionally, wetting properties demonstrate that PLA fibers have better adsorption properties than CTA fibers.
Fabrication of CdS/ZnS/g-C3N4 Composites for Enhanced Visible-Light Photocatalytic Degradation Performance
Authors: Liu Huan , Li Ping , Duo Shuwang
Published: April 2021

Constructing a heterojunction is an ideal way to modify the photocatalytic efficiency of semiconductor photocatalysts. In this paper, CdS/ZnS/g-C3N4 (CZG) ternary composites with different mass ratio of CdS (10%, 20%, 30%) were prepared by cation exchange method using as-synthesized ZnS/g-C3N4 and Cd(NO3)2·6 H2O as the starting materials. The composition and optical properties were investigated by XRD and photoluminescence spectra (PL). The results showed the ternary heterojunctions possessed faster photo-induced electrons/holes separation efficiency. The photocatalytic experiments exhibited that the obtained ternary composite materials exhibited enhanced visible-light photodegradation efficiency for the degradation of MO aqueous solution. Among the ternary composite materials, the CZG-10% composite displayed the highest photocatalytic performance of 68.52%. The enhanced photodegradation efficiency could be ascribed to the reasonable design of the heterojunction.
Electric Shock Analysis Based on AHP-DEMATEL Model in High-Voltage Switch Room
Authors: Gao Song , Jin Fuguo , Zhang Yuanbo , Yao Xiwen , Pei Xinyue
Published: April 2021

Electric shock accident in high-voltage switch room based on AHP-DEMATEL was anaylzed. In order to solve the problem that the AHP method is too subjective and lacks the consideration of the indirect influence between events, the AHP-DEMATEL method is constructed by introducing the comprehensive weight in combination with DEMATEL. Taking the electric shock accident in high-voltage distribution room as an example, 16 accident causing factors were identified firstly, then the weight of each factor was calculated by AHP method, and the interaction between the factors was analyzed by DEMATEL method. Finally, the AHP-DEMATEL method is used to obtain the causation factors, and the comprehensive weight under indirect influence is considered. It is concluded that leakage protection failure, operating tool insulation damage and illegal live working are the important causation factors of the accidents, which provide help for the distribution of high voltage electric shock accident prevention.
One-Dimensional Consolidation Analysis Considering Non-Darcian Flow and Self-Weight Based on Continuous Drainage Boundary
Authors: Zong Mengfan , Yang Xiaoyan , Wu Wenbin
Published: April 2021

The one-dimensional consolidation problem of soft soil with self-weight and non-Darcian flow is studied by introducing continuous drainage boundary. A numerical solution is derived by using finite difference method and its correctness is proved by comparing with existing analytical and numerical solutions. Based on the present solution, the consolidation behavior of soil is detailedly analyzed by adjusting the different parameters. The results show that, the soil consolidation rate increases with the increase of interface parameters or external loading rate. The difference between the average consolidation degree obtained by the solution with continuous drainage boundary and that with traditional boundary is mainly in the early stage of consolidation, but in the late stage of consolidation, the difference between these two solutions becomes smaller. Compared with the soil consolidation solution considers non-Darcian flow, the soil consolidation rate with Darcy flow is faster.
Laboratory Model Test on Moisture-Heat and Deformation Behaviour of Red Clay Slope under Action of Rainfall and Sunlight
Authors: Chen Ming , Liu Jian , Xie Zhengyong , Hu Xunjian , Li Bingyang , Cen Yue
Published: April 2021

Taking the red clay of Guizhou as the test material, the moisture-heat and deformation behaviour of red clay slope under action of rainfall and illumination were studied by constructing model slopes, observation systems, artificial rainfall systems and sunlight systems. The results showed that the volume moisture content decreased continuously during the sunlight period and decreased slowly after 5 days of sunlight, but it increased sharply during the rainfall period and the increments decreased with the increase in depth. The volume moisture content of the slope crest had almost the same increments after each rainfall; the volume moisture content of the slope surface increased slightly after the first rainfall, and then increased significantly thereafter; and the volume moisture content of the slope toe increased significantly after the first rainfall, and then increased slightly. The migration of water and heat in the soil showed a strong coupling. In other words, the temperature change could indirectly reflect the volume moisture content change, and the volume moisture content change would promote the redistribution of temperature. The depth effected by everyday sunlight and rainfall on temperature were both less than 42cm. Rainfall mainly affected the horizontal displacement of the shallow soil of the slope, and the horizontal displacement of slope toe is the largest, followed by slope surface and the smallest at the slope crest.
The Application of 3D Laser Scanning and Unmanned Ship Sounding in the Reexamination of Reservoir Storage Capacity
Authors: Pei Jiangrong , Yao Chenglin , Deng Zhongjun , Ren Zhiming , Yang Yubo
Published: April 2021

In order to accurately measure the reservoir capacity after siltation, this paper uses the ground 3D laser scanning system to obtain the topography above the water surface and the unmanned ship sounding system to obtain the topography below the water surface. then carry out the accurate review of the reservoir capacity through the combination model of water and underwater. The blind area of measurement is caused by the change of water level and detection conditions, which leads to measurement error. combined with the measured data of surface and underwater topography, the complete reservoir water level-area curve is obtained by water level-area fitting and contour interpolation fitting respectively, the error caused by blind area is minimized, and finally the reservoir capacity review is carried out according to the contour volume method. Practice has proved that the use of contour interpolation fitting method can greatly improve the credibility of the reservoir capacity review results, provide accurate and reliable basic data for reservoir management units, and provide support for reservoir flood control and operation.
Study on Difference of Permeability Coefficient Obtained by Hydrogeological Test in Ground Fissure Zone
Authors: Meng Hongte , Li Xinsheng , Liu Hanlu , Shen Zhengyang
Published: April 2021

In order to study the reason of different permeability coefficient obtained by pumping test and water injection test, based on the field test of ground fissures in Xi’an City, this paper analyzed the reasons that affect the results of the two tests by means of chart analysis and curve fitting. At the same time, the reasons for the different permeability coefficients of the upper and lower walls of ground fissures are analyzed. The results show that the permeability coefficient has a linear relationship with flow rate and drawdown. The permeability coefficient increases with the increase of discharge and decreases with the increase of drawdown. This phenomenon is related to the changes of capillary water and bound water. The difference of permeability coefficient between the upper and lower walls of ground fissures is also related to the content difference of bound water and capillary water.
Frost-Heave Deformation and Prevention Technology of Power Transmission and Transformation Foundation under Extreme Boundary Temperature
Authors: Wang Shijun , Jiang Mingjun , Xu Bo
Published: April 2021

Freezing and thawing disasters in seasonal frozen soil areas seriously affect the safety of power transmission and transformation projects. Studying the distribution of soil temperature and deformation under thermal insulation foundations is an important basis for the analysis of foundation stability in seasonal frozen soil areas. The thermal protection structure is closely related to the thickness of the insulation layer and the external thermal field. This dissertation takes the typical tower foundation of the 750 kV Hexi Power Grid Project and the geological conditions of the Shule River area in Gansu as the research objects. The theoretical analysis and numerical simulation methods are used to consider the impact of different thermal protection structures on the tower foundation and surrounding soil under extreme boundary temperatures. The influence of body deformation, stress, and temperature changes was analyzed. Through comparative analysis, it is found that the optimized structural form can effectively increase the temperature of the soil in extreme environments, avoid frost heave, and meet the design requirements for bearing capacity. In addition, the thermal-mechanical coupling analysis of the foundations of the initial temperature fields of different boundaries is carried out, and the applicability of the insulation foundation under different boundary conditions is discussed.
Feasibility Analysis of Freezing Method in Strong Permeability Strata
Authors: Zhang Chaochao , Li Dongwei , Wang Zecheng , Yang Jie , Liu Shengli
Published: April 2021

If the underground engineering meets the strong permeable strata, such as sand and pebble strata, it will face huge challenges. Effective sealing of water has become a prerequisite for determining the safety of the project. Freezing method is currently an effective method for dealing with complex permeable strata, however, the influence of the groundwater velocity on the freezing engineering is huge. If the groundwater flow rate is too high, the freezing cannot be completed normally. Therefore, for the freezing project of strong permeable formation, the speed and flow direction of groundwater is a focus of our research. The connecting channel at the bottom of the river of Fuzhou Metro is planned to be constructed by freezing method. The main soil layers are the strong permeable strata represented by the coarse medium sand layer and the pebble layer. Therefore, the measurement of the velocity and direction of the groundwater at the bottom of the river was carried out, and the influence of the groundwater on the freezing project was judged based on the measurement results. If the groundwater velocity is too high, normal freezing cannot be achieved. Referring to the form of the cofferdam, a composite reinforcement method is proposed.
Eco-Environmental Effects of Industrial Cities Based on Remote Sensing Images: A Case Study of Shenyang, China
Authors: Tang Yu , Shi Tiemao , Ma Fusheng
Published: April 2021

With Landsat remote sensing image and GIS spatial analysis method, the ecological environment of the built-up urban area in the third ring of Shenyang was studied, which was an industrial city. The LST and NDVI were extracted to analyze the urban spatial patterns and the relationship with urban land use types. The results showed that LST and NDVI were negatively correlated in urban ecosystem. The urban surface temperature and vegetation index of different land use types were significantly different. On the scale of 1 km, LST was weakly positively correlated with SHDI, while NDVI was negatively correlated with SHDI; LST increased with the increase of land use type diversity, while NDVI decreased with the increase of land use type diversity.
An Experimental and Computer Simulation Study of Tailing Flow Attributed to A Dam Breach
Authors: Luo Changtai
Published: April 2021

The tailing flow generated after dam failure will evolve into Geo-hazards like debris flows. Therefore, it is of great significance to study the evolution and influence range of tailing flow for disaster prevention and mitigation. Physical model experiments and numerical calculation are two major methods in Dam-failure research. These two methods can verify and complement each other, because the former can modify parameters of the latter and the latter can expand the research scope. In this study, a proposed tailing dam was simulated and calculated by using physical model experiment and simulation (Ramms). The erosion process of the dam body of the tailing flow was monitored by the model experiments. The numerical calculation parameters were adjusted to make the results closer to the actual conditions. This study aim to verify the reliability and effectiveness of the debris flow Ramms based on Voellmy model in dam failure simulation. The experiment showed that the velocity (Vmax =38.3 m/s), submerge area (Smax=0.558 km2) and the deposition depth (Hmax=36 m) of the tailing flow. It reflected that the Voellmy model can predict the flow state of tailing flow in the physical model experiments. So it can provide theoretical support and technical reference for the design and management of tailing dam.
Characteristics and Exploration of the Geomorphological Evolution of Lingdingyang Estuary in Recent Decades
Authors: Yang Liuzhu , Yu Fenghua , Liu Chaoqun , Liu Shuang , Pan Hongzhou
Published: April 2021

Based on the underwater topographic data of Lingdingyang since 1970s, the new characteristics of the evolution of the swale in Lingdingyang estuarine bay were analysed and the causes of the evolution were discussed. The results indicated that the West Shoal silts eastward and southward, and its spreading speed gradually slows down after 1985. Area in the north of the West Shoal decreases gradually and the in the south of the West Shoal the shoal area increases gradually. Recently, in the north of the Middle Shoal scour occurred, while in the south silt is the primary evolution. The - 5m contour line of East Shoal has little variation, and the swale surface area is also decrease gradually. The average annual erosion and deposition of the East, Middle and West Shoals of Lingdingyang has a certain correlation with the annual average sediment discharge of the main hydrological stations upstream. The correlation of the West Shoal is the best, Due to the high intensity of reclamation, the channels of in the west of Lingdingyang extends significantly to the sea. The runoff channels in the West moves downward, and the sedimentation center of the West Shoal tends to moves southward.
Study on Optimization of Shallow Section Coal Pillar Width of Gently Inclined Medium-Thickness Coal Seam
Authors: Li Feng , Zhang Zhipei
Published: April 2021

This paper takes a coal mine gently inclined medium-thickness coal seam as the object. Firstly, the principal stress characteristics and displacement characteristics of roadway surrounding rocks after roadway driving along goaf under section columns with different breadthes were analyzed by simulation method, and the roadway stability was evaluated to determine the reasonable breadth. The results show that when the breadth of column is 4 m, the Mohr stress circle of the pillar intersects the strength envelope and the roof and side displacement of roadway are significant; when the breadth is 6 m, the Mohr stress circle on both flanks of the pillar intersects at the strength envelope and the roof and side displacement of roadway are significant; when the breadth is 8-12 m, the Mohr stress circle of surrounding rock is separated from the strength envelope and the surrounding rock displacement meets the production needs. Therefore, it is in a stable state. 8-12 m is the reasonable width range of coal pillar. Secondly, through the actual project verification, the 8 m wide coal pillar is the most reasonable for the shallow part of the gently inclined medium-thickness coal seam.
Effect of Confining Pressure and Time on the Permeability of Saturated Remodeled Loess
Authors: Dong Qi , Niu Bo , Jian Liao Hong , Qi He Yu , Dai Qian
Published: April 2021

The permeability of saturated remodeled loess is closely related to slope engineering and digging-filling engineering. In order to explore the permeability of saturated remodeled loess, a list of triaxial permeability test is conducted on compacted loess under different confining pressures. The results show that the permeability coefficient of saturated remodeled loess decreases with the increase of permeability time, and finally stabilizes. The variation of confining pressure in the range of low and high confining pressures greatly affects the permeability coefficient of loess. A model considering the relationship between permeability coefficient and confining pressure is given, and applied to predict the permeability coefficient of loess under different confining pressures.
Geoecological Approach to Justification of Priority Directions for Reducing Negative Ecological Impacts during Implementation on the South Yakutia of Large Energy Projects in the Republic of Sakha (Yakutia)
Authors: Nikolaeva N A
Published: April 2021

The Republic of Sakha (Yakutia) belongs to the zone of the North, rich in natural resources. Distinctive features from other territories are extremely severe climatic conditions, unfavorable both for the population and for the intensive development of industry, construction, transport, and agriculture. Under current economic conditions it is necessary to intensify the development of fuel and energy resources as well as their export which leads to the peaking of environmental problems including environmental pollution. The most significant contribution to this process is made by the fuel and energy complex which determines the urgency of carrying out theoretical developments to minimize the consequences of disturbing the ecological balance of territories of industrial development. This requires a comprehensive geoecological approach involving a systematic study of the relationships between both natural and man-made objects, elements and processes necessary for the most complete analysis of possible changes in nature and their consequences. Based on the application of the geoecological approach, a methodological scheme has been developed that provides a comprehensive study of various fuel and energy complex objects as part of the complex, functionally unified geotechnical system “Energy Object - Environment” in the North which is based on geosystem analysis and the concept of geotechnical systems. Studying the interaction of large power facilities in South Yakutia – the Neryungri TPP, the Elga coal complex and the project of the possible Kankun HPP with the environment as a part of various industrial geotechnical systems, analysis and assessment of technogenic impacts, changes in natural complexes and natural and social consequences, assessment of the degree of environmental stability to technological impacts can form the basis for the development of geoecological directions, differentiated by landscape complexes and ranked by the levels of nature conservation. With that the specific activities are determined by the landscape and ecological specifics of each landscape area and modern regional nature management.
The Influence of Solar Activity Rhythms on Precipitation Cycles during Climate Change in Central Yakutia
Authors: Pomortseva A A , Pomortsev O A , Popov V F , Trofimtsev Yu I
Published: April 2021

The study of global climate warming remains open the questions about predicting process patterns and the used methods. The impact of solar activityon the Earth natural processes is being studied. The revealed features of solar activity fluctuations are consequences of the physics of the phenomenon itself, as well as delays in reactions to fluctuations in various geophysical layers of the Earth. Eleven-year cycles of precipitation dynamics observed at the Yakutsk meteorological station in comparison with solar activity cycles are described. The total number of cycles, according to the weather station, for the period from 1934 to 2018 is eleven. They are compared to eight solar activity cycles. A wavelet transformation of a series of atmospheric precipitation reveals the relationship between precipitation and solar oscillations. Even and odd precipitation cycles are highlighted, in line with Hal’s law of magnetic polarity. Positive precipitation anomalies have been found to be consistent with the maximums of odd-numbered solar cycles and the minimums of even-numbered cycles, while negative anomalies are found to be consistent with the minimums of odd-numbered and maximums of even-numbered cycles. Highlighting cyclic components can be useful in studying changes in humidity due to climate perturbations. The obtained results can be used to make climate and hydrological forecasts for the central region of Yakutia.
Rain Precipitation Parameters for the Design of Surface Effluent Treatment Facilities from the Territory of Industrial Enterprises
Authors: Palagin E D , Strelkov A K , Pavluhin A A
Published: April 2021

Data on the maximum layer of precipitation for rain, the drain from which is allocated to treatment facilities from the territories of industrial enterprises in the conditions of the Russian Federation, are presented. The results are analysed and summarized. The average layer of precipitation with a period of single excess equal to 1 year according to 195 weather stations is determined. The average precipitation layer for the entire area under consideration was 27.8 mm, with a variation range of 12.3 to 72.0 mm. The obtained parameters are intended and can be used for design of surface runoff treatment facilities.
Numerical Simulation of the Working Bodies of the Machine for Removing the Tops of Vegetable Crops
Authors: Frolov D I , Kurochkin A A
Published: April 2021

This article is devoted to the analysis of the kinematic and aerodynamic characteristics of the model of the working bodies of the haulm topper. The problem of removal of lodged tops of vegetable crops was investigated on the basis of finite element analysis of the model. Obtaining data on the density and air flow rates inside the casing of the topper is an urgent task. The aim of the work was to analyze the air flow rates and air pressure during the operation of the topper. The Solidworks FlowSimulation package was used to build and simulate a numerical model of the working bodies. Numerical modeling of the haulm-removing organ obtained maps of the distribution of velocities and pressures in the cutting zone of the haulm. Average values of air flow velocity (12-30 m/s) and pressures inside the casing (1.5-2 kPa) ensure the rise of the haulm to the cutting zone of the knives.
Results of Environmental Monitoring of the Natural Environment of the License Area of Oil and Gas Production in the North of Western Siberia
Authors: Burlaenko V
Published: April 2021

This paper presents data of the local environmental monitoring carried out for environmental components within the license oil and gas production area located in Tazovskiy Raion, Yamalo-Nenets Autonomous Okrug, Tiumen Oblast. The local environmental monitoring of the license area includes analyses of all environmental components: atmospheric air (snow cover), soils, surface water, and bottom deposits. According to the analysis of data obtained in 2006-2018, regulatory limits and average regional values established for contents of hazardous substances in the soil profile were exceeded. Besides, MAC values in surface water were exceeded.
Surface Electromagnetic Wave-Based Wireless Communication System for Mines
Authors: Nikolaev A V , Babenko A G , Lapin S E , Fedosov D V , Erofeev M N
Published: April 2021

The paper discusses the advantages and shortcomings of resonance and single-frequency single-wire induction communication systems for mines. The issues of creating a magnetic induction communication system based on the twin transmission line (the MIKON-Tel queuing system) and the prospects for using small antennas to arrange two-way communication channels through the rock have been considered. The possibility of creating a multichannel queuing system for subscribers, which operates in a wide frequency band using a twin induction transmission line and small ferrite resonator antennas, is shown. The antenna designs used for magnetic induction communication in mines have been considered. High level of radio frequency signals has experimentally been proven when using a twin line and small antennas. The specific signal attenuation along the route in the coal mine was 4 dB/km. The results obtained prove the fundamental possibility of designing multichannel induction communication systems with a guaranteed communication range of over 4 km from the base station.