Table of Content

15 January 2022, Volume 51 Issue 1

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Research Status and Prospect of High Value Building Materials Utilization of Bulk Industrial Solid Waste

GU XiaoweiZHANG YannianZHANG WeifengZHAO YunqiLI XiaohuiWANG Hongyu

2022, 51(1):  1-13. 

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At present,China has entered the ranks of large industrial countries,driving the rapid development of China′s social economy.In the new era,while formulating industrial development plans,it is more necessary to put ecological and environmental protection in the first place.In the historical process of industrialization,many ecological pollution problems have been left,among which the longterm accumulation of industrial solid waste has caused serious damage to the ecological environment.This paper mainly discusses the development status of highvalue building materials utilization of typical bulk industrial solid wastes (iron tailings,fly ash,coal gangue,smelting waste residue,slag and desulfurization gypsum),analyzes the future development trend of six typical industrial solid wastes,and puts forward feasible measures for the utilization of highvalue building materials.The highvalue building materials utilization of bulk industrial solid waste is a longterm strategic policy to ensure the sustainable development of China's industry.In order to improve the comprehensive utilization level of bulk industrial solid waste,people need to choose appropriate disposal and utilization methods of industrial solid waste according to local conditions.On the basis of existing policies,scientific research institutions and relevant enterprises should further strengthen technological innovation and mode innovation,explore cross industry collaborative disposal and utilization methods of industrial solid waste,and provide reasonable reference for gradually realizing the largescale and highvalue development of comprehensive utilization of bulk industrial solid waste and further improving the level of comprehensive utilization of bulk industrial solid waste in China.

Investigation on Properties of Modified Phosphogypsum Plaster Mortar

GAO Yuxin, MA Pengfei, KANG ShengrongCHENG Baojun, YANG WenGU Xiaowei

2022, 51(1):  14-20. 

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In order to solve the problem of poor water resistance of phosphogypsum plaster mortar and promote the application of phosphogypsum plaster mortar in construction industry,modified phosphogypsum was obtained by pretreating,and the effects of waterbinder ratio and water reducing agent dosage on the physical properties,mechanical properties and water resistance of modified phosphogypsum plastering mortar were studied.The water resistance of phosphogypsum plastering mortar was further improved by introducing silicone water repellents into the system.The results show that the mixing amount of water reducing agent and waterbinder ratio are the main factors affecting the properties of phosphogysum plastering mortar.Low waterbinder ratio and low water reducing agent dosoge are beneficial to the improvement of mechanical properties and water resistance,and the mixing amount of water reducing agent should not be higher than 0.9%.Although silicone water repellents can effectively improve the water resistance of phosphogypsum plaster mortar,it will adversely affect its strength,and its dosage should not be higher than 0.6% in practical application.The gel and ettringite in the hydration product can fill the gap between the crystals of calcium sulfate dihydrate,which is beneficial to the increase of the density,strength and softening coefficient of the specimen.And the silicone water repellents will form a waterproof film on the surface and the gap of the hydration product,which can further improve the water resistance of the specimen.

Study on Preparation and Mechanical Properties of Road Base and Concrete with Large Amount of Drifting Coal Gangue

ZHU Xiaoliang, ZHANG MingWANG DongminFANG Kuizhen

2022, 51(1):  21-27. 

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Drifting coal gangue is a kind of industrial solid waste emitted by coal mine energy industry，which has the characteristics of hard texture and stable nature.The preparation and research of drifting coal gangue road base and concrete is in line with the national vision of promoting carbon peak in building materials industry and strengthening the comprehensive utilization of bulk solid waste.The broken drifting coal gangue is used to replace the mechanical aggregate in road base and concrete materials.The influence rules of mechanical properties of concrete with different cement dosage，different grades of drifting coal gangue sand concrete and C30 concrete with different aggregate types and treatment methods are discussed，and the technical feasibility of drifting coal gangue instead of mechanical aggregate is demonstrated.The research results showed that the 7 d unconfined compressive strength of drifting coal gangue road base material reaches 34~65 MPa，which meets the basic requirements of medium and high grade highway，the compressive strength of drifting coal gangue concrete basically meets the requirements under medium and low grade，and the strength of C30 concrete prepared by water washing process and improved gradation of drifting coal gangue sand is improved.

Study on Preparation Method and Performance of Hydraulic Ecological Frame Concrete with Steel Slag Aggregate

FAN Junjiang, YU Linfeng, WANG Lin

2022, 51(1):  28-34. 

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There are both coarse and fine particles in steel slag without fine crushing and screening treatment，aggregate with poor gradation and workability appeared when steel slag replace sand or stone alone.In order to find a method suitable for different sources of steel slag during hydraulic ecological frame concrete preparation，steel slag from Baosteel was regarded as the research object.The steel slag aggregate is divided into coarse particles and fine particles，respectively，and the design of appropriate mix ratio were determined by gradation analysis.Mixture performanc，mechanical properties，durability and stability of the concrete test block prepared under the appropriate mix ratio were tested，and the maximum dosage of steel slag aggregate in the concrete of hydraulic ecological frame was analyzed and determined.The results showed that the coarse particles in steel slag aggregate are between 5~16 mm continuously gradation and 5~20 mm continuously gradation，which can basically meet the requirements of 5~25 mm or 5~20 mm continuously gradation gravel when combined with gravel of 5~25 mm continuously gradation.The gradation of fine particles does not meet the requirements of zone Ⅰ，zone Ⅱ or zone Ⅲ，so it needs to be used with medium sand.The proportion of fine particles replacing natural river sand in zone Ⅱ should not exceed 25%，and the highest proportion should not exceed 45%.The apparent density of steel slag is different from that of sand and stone aggregate.When steel slag aggregate replaces sand and stone in the preparation of hydraulic ecological frame concrete，fine particles and coarse particles should replace sand and stone by volume percentage respectively.The concrete test block of steel slag aggregate hydraulic ecological frame prepared by the above method has good workability，the compressive strength at 28 days of the concrete test block increases by 10%~20%，and the electric flux decreases to less than 700 C at 56 days.However，when the volume replacement ratio of steel slag aggregate exceeds 30%，the stability of concrete test blocks becomes worse.It is suggested that the maximum volume replacement ratio of steel slag aggregate in hydraulic ecological frame concrete should be controlled within 30%.

Preparation of Autoclaved Aerated Lightweight Concrete with Highsilicon Iron Tailings and Its Properties Study

GU Xiaowei, WANG Shenyu, LIU Jianping, NING Baokuan, LIU Peng, ZHANG Yannian

2022, 51(1):  35-40. 

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In order to find a substitute of highcost silica aggregate and improve the utilization rate of highsilicon iron tailings，the autoclaved aerated lightweight concrete (ALC) was prepared by mixing highsilicon iron tailings and fly ash instead of silicon sand，and the influence of the mixing ratio of iron tailings with fly ash and waterbinder ratio on the performance of autoclaved aerated lightweight concrete were analyzed.XRD and SEM were used to analyze the hydration products and microstructure.The results showed that the dry volume density of specimen increases gradually，and the compressive strength increases first and then decreases with the increase of iron tailings proportion.With the increase of waterbinder ratio，the dry volume density and compressive strength of the specimen decrease gradually.When the mass ratio of iron tailings，fly ash，cement，lime and desulfurized gypsum is 62.8∶9.0∶16.9∶8.9∶2.4 and the waterbinder ratio is 1.40，the compressive strength and dry volume density of the specimen prepared are 4.15 MPa and 576 kg/m3,which meets the requirements of strength grade A3.5 and dry volume density grade B06 in stipulated of Autoclaved Aerated Concrete Block (GB/T 11968—2020).XRD results showed that the main hydration products are quartz，tobermorite，silicacalcium hydrate and zeolite.SEM analysis further showed that a large number of platelike tobermorite and a small amount of C—S—H gel are formed during hydration.The good network structure makes it difficult to cause stress concentration under pressure.

Study on the Steel Slag desulfurized Ash Based Solid Waste Cementitious Materials and Its Mortars Interface Transition Zone

SUN Rui, WANG Dongmin, FANG Zhonghua, WU Yanan, ZHANG Shuangcheng, KANG Lizhong, LV Nan

2022, 51(1):  41-52. 

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To improve the utilization rate of solid wastes produced in metallurgy industry,a solid waste based cementitious material was prepared by mixing the steel slag powder with sintering flue gas desulfurization ash.Fly ash was used to adjust the Si/Al minerals composition of solid waste based cementitious material,and triisopropanolamine (TIPA) was used to activate its hydration activity.Firstly,the mechanical properties,hydrates assemble,hydration product morphology,pore structure and hydration heat release were investigated,so the effect of fly ash and TIPA on the hydration progress of steel slagdesulfurized ash based cementitious materials were studied.Secondly,the mechanical properties and interface transition zone (ITZ) characteristic of mortars prepared by steel slagdesulfurized ash based cementitious materials and iron tailings sand were investigated.Conclusion were made as follow:Single blending of 20% fly ash obviously promoted the formation of C—S—H and increased the 14 day compressive strength of paste by 1.86 times,but the 3 and 7 day compressive strength decreased when the fly ash content increased to 50%.Using TIPA alone increased the 3 day compressive strength from 0.52 MPa to 11.44 MPa,and its complexation to iron ions also promoted the hydration of steel slagdesulfurized ash based cementitious materials with high fly ash content (50%),which obtained a 3.69 MPa compressive strength at 3 day.The Ca(OH)2 grew among the C—S—H but did not directly contact the aggregates.Ettringite grown vertically on the surface of the aggregates were observed when fly ash was added for minerals phase adjustment.

Study on Preparation and Mechanical Properties of Cement Mortar with Steel Slag Based Solid Waste Admixture

WANG Hongyu, GU Xiaowei, ZHANG Yannian, XU Xiaochuan, WANG Qing

2022, 51(1):  53-59. 

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In order to solve the problem of low activity index of steel slag powder as admixture，steel slag was mixed with fly ash，lithium slag and phosphorus slag to obtain multiple composite admixture.Through the mechanical performance test，the influence of the admixture ratio on the activity of the binary and ternary steel slagbased multisolid waste admixture was discussed.XRD and SEM were used to analyze the hydration products and microscopic morphology of typical admixtures.The results show that steel slag exhibits lower activity in the early and late stages，lithium slag has good early activity，and phosphorous slag has poor early strength.Among the binary admixtures，the steel slaglithium slag has the highest activity and is greater than the two alone.The steel slag and the lithium slag are hydrated in an alkaline environment and provide different active components，which is beneficial to the improvement of the strength of the mortar.When the steel slagphosphorus slag powderlithium slag compounding ratio is 5∶1∶4 in the ternary admixture，the compressive strength of the mortar is the highest，and the compressive strength of the 28 d mortar is 37.21 MPa.While steel slag and lithium slag undergo hydration reaction，the phosphorous slag silicate glass body dissociates active SiO2 under the excitation of alkaline environment，and more hydration products such as C—S—H are generated.Steel slag，lithium slag and phosphorous slag have a certain coupling effect.

Analysis of Compressive Strength and Microstructure of Iron Tailings Sand Cement Mortar

WANG Ying, GU Xiaowei, ZHANG Yannian, YIN Shiqi, XU Xiaochuan, WANG Qing

2022, 51(1):  60-64. 

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In order to study the influence of the content of iron tailings on the compressive strength and the microstructure of cement mortar under replacement of iron tailings，iron tailings sand obtained by crushing highsilicon iron tailings waste rocks was used to prepare mixed cement mortar with different quality iron tailings sand instead of natural river sand in equal proportion for compressive test.Comparing the differences in composition，grain shape，particle size and gradation distribution between iron tailings sand and natural river sand，the failure modes and compressive strength of cubic specimens of mixed cement mortar were analyzed.Scanning electron microscope (SEM) was used to analyze the interface morphology of fine aggregate and cement colloid and the micromorphology of hydration products under the complete replacement of iron tailings cement mortar and natural river sand cement mortar.The results showed that the silicon dioxide content of iron tailings used is high，which belongs to Anshan highsilicon iron tailings，and it has many edges and rough surfaces due to mechanism reasons.The replacement ratio has no significant effect on the failure mode of cubic specimens of iron tailings cement mortar，and the mechanical properties of iron tailings cement mortar are better than those of natural river sand cement mortar under different replacement ratios.The addition of iron tailings will lead to the deterioration of the internal structure of cement mortar.However，due to the angular and rough surface of iron tailings，the mechanical bite force between iron tailings and cement colloid is large，and the high strength of iron tailings itself makes up for the loss of mechanical properties caused by structural deterioration，so that the basic mechanical requirements of iron tailings cement mortar can still be met.

Study on the Compressive Performance of Binary Solid Wastes Concrete Based on Different Mechanical Activation Methods

WANG Fengdan, XU Xiaochuan, GU Xiaowei, ZHANG Yannian, ZHANG Xinlong, WANG Qing

2022, 51(1):  65-70. 

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In order to improve the compressive performance of binary solid waste concrete，the effect of iron tailingsfly ash composite admixture on the compressive performance of binary solid waste concrete was investigated based on different mechanical activation methods.The hydration mechanism of compressive strength enhancement of iron tailingsfly ash composite admixture concrete was analyzed by using tests such as Xray diffraction (XRD)，scanning electron microscopy (SEM) and thermogravimetric (TGDSC) analysis.The compressive strength enhancement of concrete with iron tailingsfly ash composite admixture was most obvious when the mechanical activation method of blended before grinded was adopted，reaching 70.6 MPa at 28 d of age.Different mechanical activation methods lead to different structures of hydration products，while changed the degree of involvement of the admixture in the secondary hydration reaction.The mechanical activation method of blended before grinded can contribute to the further hydration of cement clinker，consume more Ca(OH)2 to participate in the secondary hydration reaction and generate more and denser reticular C—S—H gels.From the point of view of concrete compressive strength and the hydration and hardening mechanism of concrete cementing materials，the activation effect of mechanical activation by blended before grinded was better，which facilitated the strength development of binary solid waste concrete.

The Study on Preparation of UltraHigh Performance Concrete Utilizing UltraFine Silicon Iron Tailings

GU Xiaowei, XU Jianyu, JIA Zefan, HAN Jibao, CHEN Liangxiao, A Ruri

2022, 51(1):  71-75. 

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Based on the aggregate packing theory and the dense packing theory，a new type of green ultrahigh performance concrete (UHPC) was prepared by utilizing highsilicon iron tailing sand in Liaoning Province instead of natural river sand，and its paste properties and mechanical properties were studied.The results show that the workability of UHPC paste decreases and the air content increases with the increase of iron tailings content.The flexural strength of UHPC increases with the increase of iron tailings content，but the 7day compressive strength decreases with the increase of iron tailings content，while the 28day compressive strength increases with the increase of iron tailings content，and reaches the maximum at 40%.

Study on Compressive Strength and Microstructure of Multicomponent Solid Waste Concrete with Containing Iron Tailings as the Main Material

YANG Bohan, ZHANG Yannian, GU Xiaowei, CUI Changqing, HAN Dong, YAN Fei

2022, 51(1):  76-82. 

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In order to realize the reuse of iron tailings，coal gangue and other solid wastes，reduce the dosage of cement in concrete，and ease of iron tailings as concrete admixture solely against the negative impact of the compressive strength，composite admixture was prepared with the iron tailings，coal gangue and fly ash.The influence of dosing and ratio of composite admixtures on the compressive strength and microstructure of concrete were investigated.The results indicated: ①The addition of composite admixture reduces the compressive strength of concrete.When the contents of composite admixture was 20%，it has little influence on the compressive strength at the later stage，and the compressive strength at 28 d ages could reach 421 MPa，reaching the standard of C40 concrete.When the contents of composite admixture was 30%，the maximum compressive strength reached 384 MPa at 28 d ages.② The activity of iron tailings is low，which degrades the compressive properties of concrete as the sole admixtures，but it has the filling effect and dispersive effect.Both fly ash and coal gangue have certain pozzolanic properties.Fly ash has higher activity and ball effect and its contribution to the compressive strength of concrete is higher than coal gangue.The synergistic effect of iron tailings，fly ash and coal gangue alleviates the deterioration of concrete compressive property caused by iron tailings as the sole admixtures，and the optimal admixture mass ratio is 1∶2∶2.③ The composite admixture with 20% contents promotes cement hydration near the interface transition zone，but degrades the overall pore structure.The composite admixture with 30% contents optimizes the pore structure of concrete，obviously reduces the porosity rate of the interface transition zone，but has a negative effect on cement hydration.The results showed that the composite admixtures change the porosity rate and hydration process of the interfacial transition zone，and the balance of the pore structure and hydration process of the interfacial transition zone is the key to improve the macroscopic strength of concrete.

Study on Compressive Strength of Concrete in Iron TailingsPhosphate SlagDesulfurization Ash Ternary Solid Waste System

YANG Daokui, ZHANG Yannian, GU Xiaowei, CHEN Hao, HAN Dong, JIA Zitao

2022, 51(1):  83-88. 

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In order to realize the recycling of iron tailing solid waste materials and improve the utilization rate of industrial solid waste，concrete was prepared by using iron tailing，phosphate slag and desulfurization ash as admixtures to partially replace cement，and the effect of the synergistic effect of calcium phase solid waste and iron tailing on the compressive strength of concrete under the ternary system was investigated.The effects of different watercement ratio，iron tailing grinding time，admixture amount and admixture ratio on the compressive strength of concrete were tested.The results showed that the compressive strength of concrete was positively correlated with the watercement ratio，mechanical grinding increased the specific surface area of iron tailings，which was conducive to the hydration reaction between the surface of iron tailings and free water，and the compressive strength of concrete at the later stage of 30% admixture did not drop much compared with 20% admixture.When the specific surface area of iron tailings is 1 5893 m2/kg，iron tailings，phosphorous slag and desulfurization ash accounted for 6%，16%，8% cementing materials respectively，the concrete compressive strength is the highest，and the 28 d compressive strength reaches 409 MPa.Mercury intrusion porosimetry(MIP) and backscatter scattered electron(BSE) image analysis were used to study the microstructure of concrete，and the results showed that the admixture incorporation optimizes the pore structure of concrete and promotes the development of interfacial transition zone.The ternary system of iron tailings，phosphate slag and desulfurization ash has less effect on the strength of concrete at 30% admixture and can be used to prepare concrete instead of cement.

Study on Acid Erosion Resistance of Iron Tailings Based Multi Solid Waste Concrete

LIU Wenliang, ZHANG Yannian, GU Xiaowei, YU Yang, HAN Dong, JIANG Dawei

2022, 51(1):  89-94. 

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In order to improve the acid erosion resistance of concrete materials and realize the comprehensive utilization of bulk solid waste,concrete specimens were prepared with iron tailings,steel slag and desulfurized ash as admixtures,iron tailings and iron tailings waste rock as aggregate.The influence of cement replacement rate and waterbinder ratio on the 28 d compressive strength,mass loss,apparent deterioration and neutralization depth of concrete specimens after 60 d acid erosion were studied.The results showed that: ①When the waterbinder ratio is constant and the cement replacement ratio is 10%,the compressive strength of concrete specimens at 28 days is the highest,which is higher than that of pure cement concrete specimen.When the cement replacement rate is constant and the waterbinder ratio is 0.42,the compressive strength of the concrete specimen is the highest after 28 days.②When the waterbinder ratio is constant and the cement replacement ratio is more than 15%,the concrete specimen show strong acid resistance after 60 days of acid erosion.When the cement replacement rate is constant and the waterbinder ratio is less than 0.45,the concrete test blocks show strong acid erosion resistance after 60 days of acid erosion.③When the waterbinder ratio is constant and the cement replacement rate is 30%,the minimum mass loss could be achieved.When the cement replacement rate is constant and the waterbinder ratio is 0.42,the minimum mass loss can be achieved.All are less than the mass loss of pure cement concrete test block.④The compound admixture system makes the internal structure of concrete dense and pores refined,effectively hinders the erosion of acetic acid solution on concrete specimen,and reduces the neutral depth of concrete specimen.In general,concrete prepared by mixing iron tailings,steel slag and desulfurized ash has better acid erosion resistance than pure cement concrete.

Preparation and Performance Evaluation of Semi Dry Desulfurization Ash Autoclaved Aerated Concrete

DONG Qingguang, CAO Yu, CHEN Ning, WANG Juan, XU Bing

2022, 51(1):  95-100. 

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Autoclaved aerated concrete was prepared by semi dry desulfurization ash，and the effects of different desulfurization ash content on the compressive strength，dry density and water absorption of aerated concrete were studied.Through the image processing functions of MATLAB and IMAGE J，the changes of porosity and the relationship between pore diameter and occurrence frequency were studied.Finally，the hydration products were analyzed by Xray diffraction (XRD) and scanning electron microscope (SEM).The results showed that with the increase of desulfurization ash content，the compressive strength and dry density of autoclaved aerated concrete first increase and then decrease，while the porosity and water absorption first decrease and then increase.For the pore structure，with the increase of desulfurization ash content，the frequency of pores from 14 μm to 5.4 μm first decreased and then increased，and the frequency of pores greater than 67 μm gradually increased.XRD and SEM results show that the appropriate amount of desulfurization ash is conducive to the formation of tobermorite，enhancing the crystallinity of tobermorite，making the spatial distribution of tobermorite more compact，and improving the mechanical properties of autoclaved aerated concrete.The results show that the autoclaved aerated concrete prepared with 10% to 20% desulfurization ash can meet the performance index requirements of A3.5B06 autoclaved aerated concrete.

Structural Parameter Design of Sublevel Open Stope and Backfilling in Sanshandao Gold Mine

ZHAO Xingdong, ZHOU Xin, WEI Hui

2022, 51(1):  101-106. 

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Reasonable stope structure parameters are the premise to ensure the safe and efficient production of deep mine.In order to deal with the problem of high stress and poor quality of rock mass in deep metal mines,a design method of structural parameters of sublevel open stope and subsequent filling stope is proposed.Based on the classification of rock mass quality,the structural parameters of stope are preliminarily determined by RMR critical span chart and Mathews stability chart,and then the optimal structural parameters of stope are determined by RS2 finite element numerical simulation software and Mathews stability chart.Taking the sublevel open stope and subsequent filling stope of Sanshandao Gold Mine as the research object,the rock mass quality of stope rock is classified by using Q,RMR and GSI rock mass quality evaluation methods,and the rock mass mechanical parameters are estimated.On this basis,two kinds of stope structure parameters are calculated,the stability of the hanging wall rock which is most prone to instability and damage is analyzed,and the optimal sizes of 8 m × 15 m × 15 m is finally determined,which can provide a certain basis for the design of mining methods.

Optimization Scheme of the Mining Technique of Isolation Ore Pillars of Dongguashan Deposit

DONG Shihua

2022, 51(1):  107-112. 

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In order to ensure the successful mining of isolated ore pillars in the third step of Dongguashan Copper Mine,in view of the serious deterioration of the mining technical conditions in isolation ore pillar mining compared with the mining room in the first step and ore pillar mining in the second step,combing with the negative influence factors of isolated ore pillar mining,the technical scheme including large diameter bottom funnel,vertical deep hole drawing groove,backward ladder blasting and downward hole layout was put forward,so as to further optimize the mining technique,effectively control the ground pressure hazard and improve the stoping efficiency,and enrich and develop the isolation pillar threestep mining technique.The practice results showed that the successful application of the above technical measures could ensure the safe and efficient recovery of isolated ore pillars,and realizes the comprehensive recovery of mineral resources from 70% of twostep recovery to 81% of threestep recovery,which could provide reference for the exploitation of similar mines in China.

Comprehensive Prediciton Study on Rock Drillability Based on RES Theory

XU Mengguo, LIU Hongyang, WANG Ping, CHENG Aiping, ZHANG Weiwei

2022, 51(1):  113-119. 

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The study of rock drillability has a direct impact on mine drilling efficiency and mining operation cost.At present,most of the models and methods for constructing drillability classification rely on various rock physical and mechanical parameters and various statistical analysis methods,which have certain limitations.Rock drillability is not only a unilateral attribute of rock,but also reflects the comprehensive characteristics of the interaction between rock and drilling tools.Based on the theory of rock engineering system (RES),by considering various rock mechanical properties and rock drilling construction parameters as a complete system,neural network coding method is applied to construct the overall interaction strength matrix GRSE,and a comprehensive prediction model of rock drillability classification is established,so as to reveal the complex relationship between various influencing factors and the degree of influence on rock drillability.The model is applied to the construction operation of the deep hole rock drilling rig at the level of -430 m in Chengchao Iron Mine.The results show that the rock quality index (RQD),gypsum content,iron ore grade,and impact pressure all have effects on rock drillability.Based on the above discussion resutls,the physical and mechanical properties of the level of ore rock,mineral composition content and rock drilling parameters are analyzed comprehensively,and according to the drillability level of ore and rock,the regional prediction and classification of this level are carried out.Based on classification results,the drilling parameters and technology of rock are optimized on site,and the unit drilling quantity is increased.

Effect of Different Coarse Aggregates on the Performance of Paste Strength and Its Formulation Optimization

WANG Hongjiang, YANG Yanan, WANG Xiaolin

2022, 51(1):  120-127. 

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The output of granulated slag of a leadzinc mine in Yunnan is gradually decreasing,and it is difficult to meet the filling demand.Therefore,it is urgent to find a new type of coarse aggregate.Using the unclassified tailings,manufactured sand and granulated slag of the mine as experimental materials,the orthogonal design method was used to study the influence of slurry mass concentration,cementaggregate ratio,coarse aggregate content and coarse aggregate types on the compressive strength of the paste.Based on the maximum density curve theory and Bailey method,the mixture gradation is evaluated from the aspects of density and skeleton structure,and the material ratio of the unclassified tailingmanufactured sand is optimized.The results show that the slurry mass concentration and the cementaggregate ratio are the main influencing factors of the compressive strength,and the influence of the coarse aggregate content is small.Under the same conditions,the compressive strength of the unclassified tailinggranulated slag paste is the largest,followed by unclassified tailing paste,and the unclassified tailingmanufactured sand paste has the lowest compressive strength.The gradation of the unclassified tailingmanufactured sand paste is poor,and smaller density,unstable skeleton structure,and higher mud content together lead to the smallest compressive strength of the unclassified tailingmanufactured sand paste.After the material ratio is optimized,the amount of manufactured sand added is 42.78%,and the amount of full tailings added is 57.22%,which achieves a large density while forming a stable skeleton structure,which is conducive to the improvement of the compressive strength of the paste.

Study on Stress Distribution and Movement Law of Overburden Deformation of Waste Rock Tailings Filling Structure

WANG Qihu, HE Yaohua, YANG Fan, WU Meng, YAO Nan

2022, 51(1):  128-135. 

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The roof of stope is supported by the filling structure composed of waste rock and tailings in the alternate filling stope with waste rock and tailings,and its bearing characteristics cannot be simply described by the deformation and strength parameters of a certain material.In order to explore the stress distribution and movement law of overburden deformation,the largescale similar simulation device is used to simulate the alternate filling mining process of waste rock and tailings in a typical gently inclined thin deposit.The evolution characteristics of stope roof stress,unmined rock stress,surface subsidence,filling body bearing and safety coefficient are collected,processed and analyzed.On this basis,loadbearing and stability of waste rock and tailings filling structure are analyzed.The results show that most of the load applied by the roof of the mining area is carried by the waste rock filling body in the waste rock tailings filling structure,and the tailings filling body does not give full play to its bearing effect,and the filling efficiency is not high.Referring to the concept of flexible support in high stress roadway to effectively mobilize the selfbearing capacity of surrounding rock,the idea of stress coordination based on flexible roof connection is proposed,the elastic modulus of the flexible material is lower than that of the waste rock filling body.The early shrinkage deformation of the flexible material releases part of the roof pressure,mobilizes the bearing capacity of the ore rock and tailings filling body and relieves the pressure of the waste rock filling body.This idea helps to improve the uneven bearing state of waste rock tailings filling structure,and improve the overall safety and filling efficiency of stope.

Experimental Study on Blasting Separation Technology in Complex Orerock Mixed Blasting Zone in Barun Mine

LIU Zhanquan, WANG Desheng, CUI Feng, XU Xiaodong, GUO Jianxin, ZHAO Yu

2022, 51(1):  136-141. 

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The genesis of the ore deposit in Barun Mine is complex,and the distribution occurrence and spatial morphology of orebodies are irregular.In the blasting zone,the distribution of ore and rock is often characterized by multiple ore species,multiple orebodies and mixed lithology.Conventional openpit mining makes the broken ore (rock) mixed with each other in the blast pile,resulting in ore dilution and serious loss.In view of the problems such as unclear boundaries of orebodies,orerock mixing in blasting process and difficulty in visually identifying ore (rock) during shovel loading in complex blasting zone,a separation blasting scheme was put forward,which focuses on throwing and accumulating in the middle of orebody and blasting separation into clear grooves at the junction of orebody.Through drilling rock dust detonation zone for delineating the actual boundary of ore (rock) samples,integrated application of orebody (rock) in central isochron directional casting coacervation technique,throwing and blasting separation technique of multifree surface and long time delay on the boundary of orebody,and electronic detonator precise blasting technique,etc.,the goal of orderly accumulation and clear boundary separation of ore (rock) under blasting load was realized.The technical parameters of deephole bench blasting for ore and rock separation were determined preliminarily by numerical simulation study of the particle flow analysis program PFC3D.On this basis,field blasting tests were carried out.In the filed blasting tests,the bench height was 14 m,the borehole diameter was 310 mm,the borehole row spacing was (8~10) m×6 m,and the triangular borehole configuration was arranged.The borehole on both sides of the same row next to the orerock boundary were detonated firstly,and the boreholes on the both sides of the same row across the orerock boundary were detonated simultaneously after a delay of 110 ms.The goal of accumulating in the middle of the ore (rock) body in the orerock mixed blasting zone and separating the deep concave groove at the ore (rock) boundary was achieved by the integrated application of techniques such as multiple Vshaped precise holebyhole initiation and isochronous throwing accumulation with the middle of the ore (rock) body as the zero of initiation in the blasting zone.Observation results of ore removal showed that the ore dilution rate was less than 2%.

Fabrication and Characterization of Underground Mining Emulsion Explosive Containing Thickening Microcapsules

CHENG Yangfan, TAO Chen, XIA Yu, HU Fangfang, ZHANG Qiwei, YAO Yule, WANG Quan

2022, 51(1):  142-147. 

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In order to solve the sloughing problem and weak low temperature resistant performance of emulsion explosives during pumping into the upward blast holes of underground metal mine,a novel underground mining emulsion explosive with thickening microcapsules was developed to realized thickening in the hole.The viscosity and pumping process of emulsion explosive were not affected by the addition of thickening microcapsules,when reaching the point of the pipe nozzle,the thickening microcapsules would be damaged by the highspeed shearing action and then released the thickening agent to the emulsion explosive,increasing the viscosity of the emulsion explosive promptly.The thickening microcapsules were spherical and particle size about 2 mm,which could effectively encapsulate the thickening liquid.After the highspeed shearing,the thickening microcapsules released the thickening agent which would distribute in the emulsion matrix with a linear network structure,achieving the thickening effect of emulsion explosive in the borehole.The viscosity of underground mining emulsion explosive with 2% of thickening microcapsules after shearing was 127.9 Pa·s,which met the requirement of stable adhesion of emulsion explosive in the borehole.The experimental results showed that the detonation velocity of the emulsion explosive with 2% of thickening microcapsules after shearing was 5 030 m/s,and was still 4 618 m/s after storing at the temperature of -20 ℃ for 12 h,which indicated that the underground mining emulsion explosive had an excellent detonation performance and lowtemperature resistance performance.The underground mine emulsion explosive with thickened microcapsule can meet the requirement of explosive performance in underground metal mining.

Study on Frequency Spectrum Characteristics of Blasting Vibration Signals at Different Elevations of Openpit Slope Based on PEMD

LIU Liansheng, ZHONG Shuliang, YI Wenhua, LIU Wei, YANG Yan, CHAI Yaoguang

2022, 51(1):  148-153. 

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In order to study the spectral distribution characteristics of blasting vibration signal more accurately,combining with a blasting vibration experiment of openpit slope,the principal empirical mode decomposition method (PEMD) is used to filter out the noise in the vibration signal,and the spectral characteristics of the blasting vibration signal of the slope at different elevations are studied.The results show that:① For slopes with developed joints and fissures,under the current initiation method,the dominant frequency band of blasting vibration signal energy is 10~100 Hz,and the energy in the frequency band accounts for 64.2%~88.0% of the total energy.② Among the blasting vibration signals at the same elevation and different vibration directions,the radial peak vibration velocity is the largest,and the concentrated vibration energy in the main vibration frequency band is the largest.③ At a specific elevation of the slope,different frequency components of the blasting vibration signal have selective amplification or attenuation effects,and the energy amplification and attenuation degrees of different vibration directions are not the same.④ As the elevation increases,the peak instantaneous energy of the blasting vibration signal first increases and then decreases,and reaches the maximum where the elevation amplification effect occurs on the slope.

Study and Optimization of Mine Underground Space Structure from Syntax Perspective

LI Wenjing, CHEN Manli, REN Dajun

2022, 51(1):  154-161. 

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Underground mining usually lasts for decades to hundreds of years.New roadways are built on the basis of the existing roadway planning.The replacement of the old and the new roadways make the underground space structure of many mines more complex.From the global and local perspectives,taking a domestic metal mine as the study example,this paper constructs a space syntax model of underground mine,analyzes the overall space characteristics of a section of the east area of the mine and the local space characteristics of the main working face by referring to the space syntax indicators,and puts forward the corresponding optimization strategies.Through the quantitative analysis of the underground space structure of the mine,this paper reveals the characteristics of the underground space structure layout of the mine and the mapping relationship between the structure layout and the function of the roadway,which provides direct and effective support and guidance for the early mining design and the later space optimization of the roadway,and has important reference significance for the construction of intelligent construction of the mine.

Stability Analysis and Treatment of Antidip Rock Slope Interbedded with Soft and Hard Rock in Fushun West Openpit Mine

WANG Fenglin, WANG Dongming, YANG Tianhong, LV Bin, GAO Yuan, DENG Wenxue, JI Yushi, WANG Xuefeng

2022, 51(1):  162-169. 

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The soft and hard rock interbedded antidip rock slope has the characteristics of complex formation mechanism,strong concealment of internal joint structure and many disaster causing factors,so its prevention and control engineering is relatively difficult.The risk of geological disaster in Fushun West Openpit Mine is high.There are many buildings and dense population around the mining boundary,especially in the northeast of mining boundary.It is necessary to take strong and comprehensive measures.Based on the historical disaster statistics of Fushun landslide and the refined engineering geological exploration of the study area,the mechanism of E1000 slope instability in the mining area is analyzed from multiple angles.The back analysis method of strength reduction theory to check the limit equilibrium of rigid body is used to carry out the back analysis of the existing landslide morphology.Based on the shear strength parameters of shale interbedding obtained by back analysis,the design of drainage,slope cutting and water filling is done,and the slope stability of backfill and comprehensive treatment scheme is calculated.The results show that the comprehensive treatment scheme has the characteristics of low investment intensity,high safety (safety coefficient is 1.506) and suitable treatment measures.

Estimation of Rockburst Grade Using Acoustic Emission Test Results

WANG Yalei, XU Jinming, WU Shukuan

2022, 51(1):  170-177. 

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Estimation of rockburst grade is an important basis for the early warning of rockburst disaster,but the complexity of rockburst itself brings great difficulties to the estimation of rockburst.In order to realize the rapid and accurate estimation of rockburst grade,the AE (acoustic emission) testing technology was adopted to obtain the AE features of standard rock samples (50 mm in diameter and 100 mm in height) in different directions (longitudinal,oblique and transverse) during the indoor uniaxial compression loading process.Using the ratio of the cumulative AE energy Eq before the main fracture to the cumulative AE energy E after the final fracture of samples in different directions,the corresponding new criteria for estimating the rockburst grade was proposed respectively,and the estimation results were compared with the actual rockburst grade and the estimation results of the traditional rockburst estimation criteria.It shows that the estimation accuracy of the criterion based on Eq/E of samples from different directions reaches 80%,which is in good agreement with the actual rockburst grade.Compared with the traditional rockburst estimation criterion,the estimation results of Eq/Ebased rockburst estimation criterion are more reliable.When Eq/E of samples with different directions is used to estimate the rockburst grade,the reliability of the estimated results from high to low is longitudinal,oblique and transverse.The results presented herein have certain reference value for the prevention and control of rockburst disaster.

Study on Tensile and Acoustic Emission Characteristics of Beishan Granite

WANG Chaosheng, LIU Jianfeng, ZHAO Yaowei, WANG Ju

2022, 51(1):  178-184. 

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Taking Beishan preselected area of China′s highlevel radioactive waste disposal repository in Gansu Province as the engineering background,basic mechanical properties of Beishan granite are studied by Brazilian splitting test,direct tensile test and triaxial compression test.The acoustic emission data were monitored during the test,cracks form and failure process of Brazilian splitting test specimen were studied during the characteristics of acoustic emission.The results show that:① The strength of direct tensile specimens is about 1.23 times that of Brazilian splitting specimens,specimens of Brazilian splitting test show obvious brittle failure,while specimens of direct tensile test shows plastic failure;② The acoustic emission events in Brazilian splitting test increase sharply before the stress reaches 70% of the peak stress,while the number of acoustic emission events in direct tensile test increases sharply around the peak stress;③ The frequency of AE events in triaxial compression test is mainly distributed at 0~80 kHz,while the frequency of AE events in direct tensile test and Brazilian splitting test is mainly concentrated at 0~160 kHz;④ The number of tensile cracks in Brazilian split test specimens is about 20.6 times of the number of shear cracks,the tensile cracks extend from the center of the specimen to the end,and finally form the through fracture surface.

Typomorphic Characteristics and Geological Significance of Pyrite in No.189 Orebody of Qiyugou Gold Deposit,East Qinling

ZENG Tao, TANG Li, SUN Yuchen, HUANG Danfeng, HU Xinkai, WANG Liang

2022, 51(1):  185-194. 

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Qiyugou Gold Deposit is located at the central segment of the Xiong′ershan polymetallic district in Eastern Qinling.In recent years,the No.189 porphyry gold orebody has been recently discovered below the level of 400 m,the mineralization and prospecting potentials in deep remain unsolved.In this paper,taking the No.189 orebody with elevations of 220 m and 280 m of Qiyugou Gold Deposit as the study example,the integrated study,including detailed geological investigation,mineralogy,compositional typomorphic characteristics and thermoelectricity typomorphic characteristics of gold bearing pyrite is conducted.The study results show that:① The oreforming process of Qiyugou No.189 orebody can be divided into three stages,including stage I kfeldspar + quartz + pyrite ± magnetite,stage II quartz + molybdenite + pyrite + chalcopyrite vein and stage III quartz + pyrite + chalcopyrite ± gold ± electrum ± telluride vein.② Pyrite can be divided into two main generations,one is disseminated pyrite in granite porphyry,which has good orebearing property;the second type occurs in quartzpyrite veins,presenting as veins and lumps.③ From the elevations from 280 m to 220 m,pyrites show an increasing trend of iron and decreasing trend of sulfur,w(Fe)/w(S+As) and w(Au)/w(Ag) ratios indicate magmatichydrothermal origin and they are formed in a shallow to medium depth environment.The trace element concentrations are positively correlated with the depth.④ The formation temperatures of pyrites are mainly concentrated at 277.5~332.5 ℃,indicating hydrothermal origin with low to medium temperature.The pyrites at 220 m and 280 m elevations are basically Ntype (more than 97%) and the range of denudation rate is 75.5%~85.5%,which is the feature of midlower part of orebody.In conclusion,it is believed that the deeper level of the No.189 orebody still has potential for Au mineralization,and the periphery of Qiyugou Gold Deposit has prospecting potential for placer gold.

Geological Characteristics and Prospecting Prospective of Zhuyuanxi CuMo Mining Area in Luoshan County,Henan Province

LIU Kun, LI Ruiqiang, LI Kaiwen, CHEN Yonglin

2022, 51(1):  195-204. 

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Zhuyuanxi CuMo mining area is located at the junction of the south margin of North China Craton and Qinling orogenic belt.The metallogenic belt belongs to the TongbaiDabie molybdenum ore belt,which is favorable for copper and molybdenum polymetallic ore mineralization.In order to further explore the metallogenic potential of the mining area,systematic survey and exploration works such as 1∶10 000 geological survey,1∶10 000 soil geochemical exploration,1∶1 000 geological profile survey and exploration of pit and drilling are carried out.Study results of geological characteristics of the mining area show that:① The main ore controlling factors of copper and molybdenum deposits in the mining area are rock mass and structure.Granite porphyry is the parent rock of mineralization.Rich ore bodies are often formed at the intersection of faults.② Two Mo ore bodies and one Cu ore body fornd in the mining area are hosted in granite porphyry,which have the characteristics of typical porphyry and molybdenum deposit.Based on the above analysis results,according to technical process of prospecting including 1∶10 000 geological survey,1∶10 000 soil geochemical exploration,1∶1 000 geological profile survey,trenching and drilling exposure,two molybdenum prospecting targets (named as A and B) have been identified in the mining area.Through engineering verification,it is found that there are concealed granite porphyry and many molybdenum ore bodies in the deep part of the target area.The estimated (controlled) + (inferred) resource scale of molybdenum ore bodies in target area A is medium.According to the metallogenic geological characteristics of the area and the analogy with the adjacent similar deposits,it is considered that the middle and deep parts of Zhuyuanxi CuMo mining area have great metallogenic potential,which is worthy for further work.

Geochemical Characteristics and Deep Prospecting Significance of Primary Halo in Laowan Gold Metallogenic Belt,Henan Province

GUO Peng, CHEN Jianli, CHEN Yingnan, WEI Congling, XUE Yan

2022, 51(1):  205-212. 

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Laowan gold metallogenic belt is the largest single gold deposit in Henan Province,located in the east of QinlingDabei orogenic belt.The element concentration zoning and axial zonality sequence of the primary halo of gold orebody are studied,and the elemental combination characteristics are discussed by correlation analysis,cluster analysis and factor analysis.The results show that the concentration zoning of Au,Bi,Pb,Zn and Mo elements is not closed and extends downward well,indicating that there are still orebodies in the deep.The axial zoning sequence of orebodies is AgMoHgAsWSbZnSnAuCuBiPb,and the hydrothermal elements of high,medium and low temperatures are disordered,indicating that the primary halo is formed by the superposition of multiple orebodies at different times.Au has a good correlation with Bi and Cu,and they migrate and enrich together in oreforming hydrothermal fluids.Bi and Cu can be used as indicator elements for gold prospecting.The main factor F2 (AuBi) represents the geological process that promotes gold enrichment.The spatial distribution of the factor score indicates that the region below -650 m has good potential for prospecting.The target area based on the above prediction has been verified successfully.The above discussion results have certain refernece for the further prospecting work in the mining area.

Research and Development of Short Interval Control Management System for Underground Mine Scheduling

WANG Hao, HU Nailian, LI Guoqing, HOU Jie, QIANG Xingbang

2022, 51(1):  213-220. 

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With the continuous improvement and application of intelligent mine in China,the digitization and informatization of production process control has become an important content of intelligent mining production.The key is to greatly improve the content in accuracy and control in timeliness of production information.To solve the shortcomings of the traditional production scheduling organization of underground mines in transparency and controllability,short interval control (SIC) is introduced as a highfrequency control and response management method.Aiming at the SICoriented highfrequency scheduling management mode,the business model is proposed by analyzing the core requirements of SIC implementation in underground mine scheduling,which includes weekly plan making,SIC scheduling plan making,SIC feedback checking,SIC analysis and improvement.Then,a highfrequency scheduling management mode based on SIC is developed.On this basis,a crossplatform SIC operation mode is designed with basic network,management terminal,mobile terminal,web terminal and industrial big data platform.The system design is carried out and the SIC system is developed.The SIC system is applied to the scheduling of a large underground mine in China and has comprehensively improved its technical and economic effects.The results show that the application of SIC is help for effectively improving the traditional scheduling mode in underground mines.The SIC management process through information technology can realize highfrequency monitoring and closedloop feedback of production progress,effectively improve the management efficiency and production transparency of underground mine scheduling,and comprehensively promote the lean production of intelligent mine.

Vibration Damage Characteristics of Waterbearing Tailings Accumulation Dams Based on the DIC Technology

LIU Meichen, ZHAO Yiqing, JIN Aibing, TIAN Xinran, LIU Xianwei

2022, 51(1):  221-230. 

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In order to analyze the effect of water content on the vibration damage of the tailings accumulation dams,shaking table tests were conducted for different watercontent accumulation dam models on the basis of a series of indoor direct shear tests,and the digital image correlation (DIC) technology was used to analyze their vibration damage patterns,local deformation and damage evolution characteristics.The test results show that the cohesion of tailings shows a trend of increasing and thereafter decreasing as the moisture content increases,which gives a cω fitting formula,but the internal friction angle of tailings does not change much with moisture content,displaying a fluctuation in the range of 30.03°~33.44°.What′s more,the cohesion plays a pivotal role on the stability and cracking moment of the tailings dam.The water content exerts a critical effect on the rupture mode and a damage pattern of the accumulation dam,which shows "local single type" tensile damage at a highwater content of 16.0% and "staggered collapse type" tensileshear compound damage at a low water content of 5.6%.With the increase of water content,the vibration damage mode of the tailings accumulation dam transitions from tensile shear damage to tension damage dominated.Based on the statistical analysis of the local strain field,the damage factor is proposed.The damage factor of 5.6% waterbearing dam shows that a sudden up trend increases,and brittle damage appears,while 13.0% and 16.0% waterbearing dams show ductile damage in the later stages.

Site Stability Evaluation of High Voltage Transmission Lines Based on Improved Fuzzy Analytic Hierarchy Process

YANG Xiangsheng, GUO Guangli, GUO Song, GUO Baode, LIU Zan, WANG Yuezong

2022, 51(1):  231-236. 

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In order to ensure the safety of the construction of highvoltage transmission lines passing through the mine goaf site,it is urgent to carry out the stability analysis and evaluation of the tower foundation construction site along the line.Taking the 110 kV highvoltage transmission line of Shandong Tengzhou Photovoltaic Power Project,crossing the goaf site of Wangchao,Jinqiu and Binhu Coal Mine as an example,and based on the analysis of the structural stress of steel tower and the geological and mining conditions of goaf,nine evaluation indicators that affect the stability of the coal mine goaf site are selected to construct an analytic hierarchy model,and the FAHP (Fuzzy Analytic Hierarchy Process) is improved by the semitrapezoidal membership distribution function coupled with the weight ordering vector.Finally,comparing the evaluation results with the actual site stability survey of the overhead area of highvoltage transmission lines.The results show that the evaluation results of the proposed improved model are consistent with the actual goaf stability,which proves the feasibility of the improved FAHP applied to the site stability evaluation of extended highvoltage transmission lines.At the same time,the improved method can provide reference for site stability evaluation under similar engineering geological conditions.