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Full-Text Articles in Engineering

Review On Lcca And Lca Methods For Pavement Based On Bim, You Shengjie, Hu Yonggang, Liu Xinsuo, Zheng Xiaoyan Jun 2024

Review On Lcca And Lca Methods For Pavement Based On Bim, You Shengjie, Hu Yonggang, Liu Xinsuo, Zheng Xiaoyan

Journal of China & Foreign Highway

Currently,life cycle cost analysis (LCCA ) and life cycle assessment (LCA ) methods are commonly used to assess the economic and environmental impacts of pavement during the whole life cycle.However,there are drawbacks in the application of LCCA and LCA methods,such as a large amount of data and multiple data categories,which lead to a tedious evaluation process.In view of this,some scholars have tried to combine building information modeling (BIM ) with LCCA and LCA methods to optimize the evaluation process.In the pavement field,the combination of LCCA and LCA with BIM is still in its infancy,lacking a summary of relevant research results.Therefore,this …

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Anti‑Freezing Performance Of Cement-Stabilized Mixture For Recycled Aggregate From Solid Construction Waste, Zheng Jiajia, Zhang Laijun, Wang Xihui, Xie Jianwei, Chen Zhiyong Jun 2024

Anti‑Freezing Performance Of Cement-Stabilized Mixture For Recycled Aggregate From Solid Construction Waste, Zheng Jiajia, Zhang Laijun, Wang Xihui, Xie Jianwei, Chen Zhiyong

Journal of China & Foreign Highway

This paper investigated the effects of particle size and content of recycled aggregate on the anti-freezing performance of cement-stabilized recycled aggregate mixture,so as to provide a reference for the fine utilization of recycled aggregate with different particle sizes.The basic performance indexes of recycled aggregates with different particle sizes were tested,and the optimum moisture content and maximum dry density were determined by compaction test.The specimens were prepared with 4% cement content,and the anti-freezing performance of the mixture was evaluated by testing the unconfined compressive strength loss of the mixture after the freeze-thaw cycle.The results show that the optimum moisture content increases,and …

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Experimental Study On Road Performance Of Resin Elastomer For Seamless Expansion Joints Of Bridges, Zhou Wei, Sheng Liang, Gao Qin, Zhang Hui, Zhao Menglong Jun 2024

Experimental Study On Road Performance Of Resin Elastomer For Seamless Expansion Joints Of Bridges, Zhou Wei, Sheng Liang, Gao Qin, Zhang Hui, Zhao Menglong

Journal of China & Foreign Highway

Seamless expansion joint is a new type of bridge expansion joint.In order to study the road performance of resin elastomer for seamless expansion joints,the feasibility of applying resin elastomer to small and medium displacement expansion joints of bridges was explored.Through the rutting test at 60 ℃, low-temperature beam bending test at −10 ℃,dynamic modulus test,Poisson's ratio test,and overlay test (OT),the high and low temperature stability,deformation performance,and fatigue crack resistance of the resin elastomer were compared.The test results show that the dynamic stability of the resin elastomer at 60 ℃ is more than 31 000 times/mm,and the bending strain at low …

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Experimental Study On Adhesive Pe Rformance Of Second-Order Thermosetting Epoxy Asphalt In Bridge Deck Pavement, Zhou Changdong, Dai Mingjing, Zhao Mingyu, Li Zhiqiang, Lei Yuxiang, Ding Qingjun Jun 2024

Experimental Study On Adhesive Pe Rformance Of Second-Order Thermosetting Epoxy Asphalt In Bridge Deck Pavement, Zhou Changdong, Dai Mingjing, Zhao Mingyu, Li Zhiqiang, Lei Yuxiang, Ding Qingjun

Journal of China & Foreign Highway

Based on the Wujiagang Yangtze River bridge project in Yichang,the interfacial shear strength and pull-out strength of the second-order thermosetting epoxy asphalt material between RA asphalt concrete and high viscoelastic SMA asphalt concrete in pavement structure were studied under different spraying amount,different first-stage curing time,different curing time,and different service temperatures.In addition,the influence of spraying amount on shear fatigue resistance was studied.The results show that with the increase in the spraying amount of the second-order thermosetting epoxy asphalt,the adhesive performance and shear strength are improved,and the shear fatigue resistance of the structure is enhanced.At a construction ambient temperature of 25‒35 ℃,the …

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Design And Key Technologies Of Bridges With Long‑Cantilever Closed Steel Box Composite Girder, Ji Jiandong, Wang Bin Jun 2024

Design And Key Technologies Of Bridges With Long‑Cantilever Closed Steel Box Composite Girder, Ji Jiandong, Wang Bin

Journal of China & Foreign Highway

In order to meet the span requirements of bridges over the Yellow River and reduce the interference of temporary construction facilities on flood discharge from the Yellow River,the Linyi Yellow River Bridge was studied.The main bridge adopted a continuous long-cantilever closed steel box composite girder of (112 + 28 × 128 + 120) m and was divided into two parts,with the maximum length of the parts being 1 912 m.The steel box composite girder was constructed by incremental launching method without temporary piers,and the bridge deck was installed after the closed steel box girder was in place.The installation sequence of …

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Supporting Capacity Anal Ysis And Construction Scheme Optimization Of Support System For Cast‑In‑Situ Box Girders In High‑Pier Wading Bridges, Guo Tao, Yao Yuchen, Ma Hongze, Huang Xiaomin, Zhang Yongchun Jun 2024

Supporting Capacity Anal Ysis And Construction Scheme Optimization Of Support System For Cast‑In‑Situ Box Girders In High‑Pier Wading Bridges, Guo Tao, Yao Yuchen, Ma Hongze, Huang Xiaomin, Zhang Yongchun

Journal of China & Foreign Highway

Although a concrete bridge su pport system is a temporary structure,it still has a supporting capacity.With the development of bridge engineering,concrete bridges with high piers and long spans are gradually applied in deep reservoir areas,and the forces on scaffolding are more and more complex.Traditional manual calculations in structural mechanics can no longer completely reflect the stress-strain states of scaffolding with irregular configurations,special parts,and uncommon conditions.Thus,it is necessary to use a numerical method to calculate the supporting capacity of scaffolding and design construction schemes.This paper took a concrete wading bridge with high piers as an example.An evaluation method based on the …

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A Rapid Test Method For Deflection Of Small And Medium‑Span Bridges, Zhang Aipin, Ma Lindong, Chang Zhugang, Fan Zhihao Jun 2024

A Rapid Test Method For Deflection Of Small And Medium‑Span Bridges, Zhang Aipin, Ma Lindong, Chang Zhugang, Fan Zhihao

Journal of China & Foreign Highway

Bridge deflection response is on e of the most important indicators used for structural condition assessment of bridges.There are currently many methods and devices for deflection measurement,but they are not satisfying in terms of economy,applicability,and measurement accuracy at the same time.This paper proposed a rapid and highly accurate method for measuring mid-span deflection of small and medium-span bridges.By using the high accuracy of displacement transducers in direct contact measurement,an auxiliary measurement device was developed to transfer the deflection of the measurement points on the bridge to the displacement transducer in the form of a rigid connection,thus achieving accurate and dynamic …

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Numerical Simulation Of Mechanical Performance For Anti‑Collision Steel Pontoon, Han Xiaolei, Wang Bo, Li Weidong Jun 2024

Numerical Simulation Of Mechanical Performance For Anti‑Collision Steel Pontoon, Han Xiaolei, Wang Bo, Li Weidong

Journal of China & Foreign Highway

Anti-collision steel pontoo n has good plasticity and energy absorption properties in ship-bridge collision.To explore the factors affecting the anti-collision performance of the anti-collision pontoon,a collision model composed of ship,anti-collision pontoon,and pier system was built based on finite element software Ansys/LS-DYNA.The collision mechanism and process were numerically simulated,and the effects of connection type between anti-collision pontoon and pier,peak angle of pontoon,and anti-collision pontoon stiffness on the collision force of the pier were investigated.The three-stage division method of collision force curve was put forward.The analysis shows that the fixed inwall of the anti-collision steel pontoon and connection to the pier surface …

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Deformation And Damage Characteristics Of A Newly Operated Tunnel Caused By Above Foundation Pit Construction, Liu Jiqiang, Zhu Min, Hao Kun, Chen Dengwei, Chen Xiangsheng Jun 2024

Deformation And Damage Characteristics Of A Newly Operated Tunnel Caused By Above Foundation Pit Construction, Liu Jiqiang, Zhu Min, Hao Kun, Chen Dengwei, Chen Xiangsheng

Journal of China & Foreign Highway

The construction of foundation pits in granite residual soil layers is prone to causing upheaval deformation and structural damage in shield tunnels below.Based on the engineering case of a newly operated metro tunnel collinear with the above long-distance deep foundation pit in Shenzhen,a three-dimensional finite element model was established to investigate the variation law of the heave and horizontal convergence of the shield tunnel caused by the deep foundation pit excavation.The correlation between the longitudinal stress of the lining structure and the damage was analyzed.The results indicate that the tunnel deformation caused by foundation pit unloading is primarily vertical heave,accompanied …

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Dynamic Response Rules Of Adjacent Buildings To Blasting Construction In Shallow Buried Tunnels, Luo Yanping, Li Jigang, Wang Sheng, Zeng Bin, Lai Jinxing, Feng Zhihua, Qiu Junling Jun 2024

Dynamic Response Rules Of Adjacent Buildings To Blasting Construction In Shallow Buried Tunnels, Luo Yanping, Li Jigang, Wang Sheng, Zeng Bin, Lai Jinxing, Feng Zhihua, Qiu Junling

Journal of China & Foreign Highway

In order to study the dynamic response rule of overlying buildings during blasting construction in shallow buried tunnels,the urban tunnel in Fuzhou was taken as the engineering background,and the on-site monitoring and Ansys/LS-DYNA simulation were used to analyze the structural response of overlying buildings.The monitoring results show that the building is most obviously affected by blasting in the vertical direction and has an obvious elevation amplification effect,and the maximum vibration velocity is 2.45 cm/s.The vibration velocity in all directions gradually decreases and tends to be stable with the increase in explosion center distance and decays rapidly when the explosion center …

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Deflection Basin Characteristics Of Distressed Roads Under Moving Load, Cai Yingchun, Xie Shenjian Jun 2024

Deflection Basin Characteristics Of Distressed Roads Under Moving Load, Cai Yingchun, Xie Shenjian

Journal of China & Foreign Highway

The deflection basins of roads under moving load imply the distress information of subgrade and pavement.Therefore,how to use the information of deflection basins under moving load to rapidly test road distresses non-destructively has received much attention.In this paper,the finite element model of semi-rigid base asphalt pavement was established.By setting different types and degrees of finite element distress models,the continuous changes of surface deflection basins under moving load were analyzed.The results show that when the load moves to the distress area,the center deflection value of surface deflection basins in each distress model will become larger.When transverse cracks appear in the pavement …

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Curing Mechanism And Influencing Factors Of Cement Mixing Piles Reinforcing Peat Soil, Feng Rongxian, Zhong Gaibing, Liu Liang, Liang Jianyuan, Gu Meixiang Jun 2024

Curing Mechanism And Influencing Factors Of Cement Mixing Piles Reinforcing Peat Soil, Feng Rongxian, Zhong Gaibing, Liu Liang, Liang Jianyuan, Gu Meixiang

Journal of China & Foreign Highway

The cement mixing pile is used to reinforce the deep peat soil foundation in Malaysia's east coast railway construction.The key in this project is to determine the cement mix proportion and additives.Considering the high organic matter content and strong environmental acidity of coastal peat soil,physical and mechanical tests of peat soil and laboratory uniaxial compression tests of cement soil under different mix proportions and influencing factors were conducted.Test results show that the mean compressive strength decreases by 0.35 MPa with the increase in cement-water from 0.5 to 0.9.Adding mineral powder gives a relatively poor curing effect while adding fly ash …

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Safety Of Optimized Concrete Median Barrier Without Planting Soil, Zhong Chunyao, Ma Qing, Li Yangfan, Gong Shuai, Liu Siyuan, Yan Shuming Jun 2024

Safety Of Optimized Concrete Median Barrier Without Planting Soil, Zhong Chunyao, Ma Qing, Li Yangfan, Gong Shuai, Liu Siyuan, Yan Shuming

Journal of China & Foreign Highway

In order to study the safety of optimized concrete median barrier without planting soil,the technology combining computer simulation,sled test,and full-scale impact test of real vehicles was adopted for analysis and verification.In addition,a scheme was proposed to improve the anti-overturning ability of the barrier without planting soil by strengthening the supporting block,and the scheme of setting a 20 cm-high supporting block between the barrier walls was optimized.The safety of the barrier scheme was evaluated by taking the most unfavorable large truck as an example.The results show that the protection level of the optimized concrete median barrier without planting soil is SAm, …

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Aided Design Method And Application Of Rutting Prevention And Maintenance In Asphalt Pavement Based On Digital Holographic 3d Detection, Wang Jingfei, Wang Wang, Xu Xinquan, Huang Zhijian, Ti Jing, Yao Yanru Jun 2024

Aided Design Method And Application Of Rutting Prevention And Maintenance In Asphalt Pavement Based On Digital Holographic 3d Detection, Wang Jingfei, Wang Wang, Xu Xinquan, Huang Zhijian, Ti Jing, Yao Yanru

Journal of China & Foreign Highway

As one of the common diseases of asphalt pavement,rutting has significant impacts on the service life and traffic safety of the pavement.Mild rutting in asphalt pavement during preventive maintenance can lead to increased use of maintenance materials due to rutting deformation.Accurately calculating the amount of materials needed to fill rutting in maintenance designs is of great significance for ensuring maintenance quality and efficiency.Based on the requirements of maintenance engineering,this paper analyzed the problems in maintenance designs that use traditional methods and the data they generate for rutting detection.A design method was proposed for rutting prevention and maintenance in asphalt pavement,assisted …

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How Do Preservice Teachers Learn To Teach Integrated Computational Thinking?: Evidence From Planning, Enactment, And Reflection, Rachael Dektor, Samuel Severance, Kip Téllez Jun 2024

How Do Preservice Teachers Learn To Teach Integrated Computational Thinking?: Evidence From Planning, Enactment, And Reflection, Rachael Dektor, Samuel Severance, Kip Téllez

Journal of Computer Science Integration

This study examines pre-service teachers’ (PSTs) beliefs and understandings about computational thinking (CT) integration and lesson implementation over time. Utilizing a design-based research approach, 3 PSTs led the co-design of integrated CT lessons with support from researchers and enacted these CT integrated lessons with K-5 students. All PSTs participated in a whole-group CT workshop and engaged in one-on-one lesson design sessions with a researcher. We utilized a grounded theory approach to qualitatively analyze pre-surveys, semi-structured interviews, and video data of three PSTs enacting their lessons. We found that PSTs’ initial beliefs about CT instruction – including the importance of it …

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Table Of Contents, The Editors Jun 2024

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Factors Influencing The Productivity And Technology Optimization Of Horizontal Wells For Moderately Deep Coalbed Methane In The Northern Zhengzhuang Block, Zhang Cong, Li Kexin, Jia Huimin, Zhang Wuchang, Yang Ruiqiang, Li Jun, Wang Qi, Hou Weiming Jun 2024

Factors Influencing The Productivity And Technology Optimization Of Horizontal Wells For Moderately Deep Coalbed Methane In The Northern Zhengzhuang Block, Zhang Cong, Li Kexin, Jia Huimin, Zhang Wuchang, Yang Ruiqiang, Li Jun, Wang Qi, Hou Weiming

Coal Geology & Exploration

[Objective] Hydraulic fracturing of vertical wells was adopted during the early production of moderately deep coalbed methane (CBM) of the northern Zhengzhuang block in the Qinshui Basin, generally yielding low productivity and inefficiency. In contrast, single-casing fracturing of horizontal wells has increased the single-well production to 10‒50 times that of vertical wells, establishing horizontal wells as the dominant development well type. However, the horizontal wells differ greatly in CBM production. This study aims to determine the factors influencing the productivity of horizontal wells using staged fracturing for moderately deep CBM in the northern Zhengzhuang block and improve the production performance. …

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Characteristics Of The Pore And Seepage System Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin, Xinjiang, Chen Heqing, Yang Zhaobiao, Li Daoqing, Xu Miaomiao, Liang Yuhui, Liu Changqing, Wang Yuqiang Jun 2024

Characteristics Of The Pore And Seepage System Of Deep Coalbed Methane In The Baijiahai Uplift, Junggar Basin, Xinjiang, Chen Heqing, Yang Zhaobiao, Li Daoqing, Xu Miaomiao, Liang Yuhui, Liu Changqing, Wang Yuqiang

Coal Geology & Exploration

[Objective] Xinjiang boasts abundant deep coalbed methane (CBM) resources, with Jurassic coal seams in the Baijiahai uplift of the Junggar Basin identified as a favorable target area for deep CBM exploration and exploitation. The pore and seepage system of deep CBM directly determines its recoverability. [Methods] Based on appraisal well Caimei 2-004H drilled the most recently in the Xinjiang oilfield in 2023, this study investigated in detail the pore and seepage system of coals in the Jurassic Xishanyao Formation in the Baijiahai uplift using scanning electron microscopy (SEM) observations, mercury injection capillary pressure (MICP), low-temperature liquid nitrogen adsorption, and carbon …

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Impacts Of Observation Line Layout Morphology And Survey Point Missing On The Inversion Of Predicted Parameters Of Mining Subsidence, Guo Qingbiao, Yu Qing, Zheng Meinan, Luo Jin Jun 2024

Impacts Of Observation Line Layout Morphology And Survey Point Missing On The Inversion Of Predicted Parameters Of Mining Subsidence, Guo Qingbiao, Yu Qing, Zheng Meinan, Luo Jin

Coal Geology & Exploration

[Objective] Accurate prediction parameters for mining subsidence are important basis for full cycle green coal mining, while inversion based on the subsidence data of observation lines serves as the main method to obtain these parameters. [Methods] To quantitatively analyze the impacts of the observation line layout morphology and survey point missing on the inversion of prediction parameters for mining subsidence, this study developed a probability integral model-based inversion method for these parameters using the chimpanzee optimization algorithm (ChOA). Using this method combined with digital simulation experiments, this study predicted subsidence parameters under six observation line morphologies and survey point missing …

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Fracturing Evolutionary Law And Energy Utilization Efficiency Of Green Sandstones Under Different Loading Rates, Zhao Huanshuai, Pan Yongtai, Qiao Xin, Wang Xingyu, Yu Chao, Huang Jiacheng Jun 2024

Fracturing Evolutionary Law And Energy Utilization Efficiency Of Green Sandstones Under Different Loading Rates, Zhao Huanshuai, Pan Yongtai, Qiao Xin, Wang Xingyu, Yu Chao, Huang Jiacheng

Coal Geology & Exploration

[Objective] This study aims to explore the fracturing evolutionary laws and energy utilization efficiency of rocks under different loading rates is a pressing issue in the field of rock fragmentation and processing. [Methods] To this end, the microscopic parameters of green sandstones were calibrated based on laboratory tests, followed by the identification of relationships between the macro- and microscopic mechanical responses of the sandstones. Using Particle Flow Code (PFC), this study investigated the stress-strain curves and stress chain distribution of green sandstones under different loading rates. Then, based on the fracturing and crack characteristics, this study analyzed the fracturing evolutionary …

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Hydrochemical Characteristics And Genetic Mechanism Of Geothermal Water In The Wandong Geothermal Area Along The Moxi Fault In Western Sichuan, Huang Xun, Zhang Yunhui, Li Xiao, Lyu Guosen, Guo Hongyang Jun 2024

Hydrochemical Characteristics And Genetic Mechanism Of Geothermal Water In The Wandong Geothermal Area Along The Moxi Fault In Western Sichuan, Huang Xun, Zhang Yunhui, Li Xiao, Lyu Guosen, Guo Hongyang

Coal Geology & Exploration

[Objective] Geothermal energy exploitation is identified as a vital way to achieve the goals of peak carbon dioxide emissions and carbon neutrality. The Moxi fault, located in the southern segment of the Xianshuihe fault zone in western Sichuan, boasts abundant geothermal resources, serving as a significant area for subsequent geothermal energy exploitation. [Methods] This study investigated the hydrogeochemistry of the Wandong geothermal area along the Moxi fault, analyzed the water-rock interaction process in the area based on the hydrochemical correlation, and calculated the reservoir temperatures and the mixing ratios of cold and hot water using geothermometers and the silica-enthalpy mixing …

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Experimental Study On The Mechanics And Deformation Failure Characteristics Of Multi-Source Coal-Based Solid Waste Cemented Backfill, Yang Ke, Zhang Jiqiang, He Xiang, Wei Zhen, Zhao Xinyuan Jun 2024

Experimental Study On The Mechanics And Deformation Failure Characteristics Of Multi-Source Coal-Based Solid Waste Cemented Backfill, Yang Ke, Zhang Jiqiang, He Xiang, Wei Zhen, Zhao Xinyuan

Coal Geology & Exploration

[Objective] In order to study the mechanical properties and deformation failure laws of multi-source coal-based solid waste cemented backfill (CBSWCB), the uniaxial compression, acoustic emission response and microstructure test experiments were carried out with 5 types of typical coal-based waste. [Methods] The factors influencing the uniaxial compressive strength of CBSWCB, as well as their interaction, were analyzed, and a four-dimensional spatial visualization model of the factors influencing the compressive strength based on their interactions was established. Besides, the mechanical evolution characteristics and macroscopic deformation failure laws under uniaxial compression conditions were elaborated by referring to the acoustic emission and microstructure …

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Application Of Microseismic Monitoring System For Coal Mines To The Prevention And Control Of Water Disasters On Working Face Roofs, Fan Xin, Cheng Jianyuan, Li Sheng, Duan Jianhua, Fan Tao, Li Bofan, Wang Yanbo Jun 2024

Application Of Microseismic Monitoring System For Coal Mines To The Prevention And Control Of Water Disasters On Working Face Roofs, Fan Xin, Cheng Jianyuan, Li Sheng, Duan Jianhua, Fan Tao, Li Bofan, Wang Yanbo

Coal Geology & Exploration

[Objective] Increasing coal mining depth in coal mines has caused increasingly prominent risks of water disasters on working face roofs, which restrict the green, safe, and efficient coal mining in China’s coal mines. Therefore, there is an urgent need for new technologies for the monitoring and early warning of these water disasters. [Methods] This study explored the application of the joint well-ground microseismic monitoring system to the prevention and control of water disasters on working face roofs, achieving transparent, intelligent monitoring and early warning of water disaster risks. In this system, microseismic sensor arrays are arranged on the surface above …

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Geological Structures Fine Monitoring Using Seismic-While-Tunneling Technique In Wangpo Mine, Zhao Huibo, Qin Si, Chen Chao, Guan Qi, Zhao Xingwei, Che Jianhang Jun 2024

Geological Structures Fine Monitoring Using Seismic-While-Tunneling Technique In Wangpo Mine, Zhao Huibo, Qin Si, Chen Chao, Guan Qi, Zhao Xingwei, Che Jianhang

Coal Geology & Exploration

Traditional tunnel seismic advance detection technology is limited by the use of explosives, the need for mining stoppages, prediction speed, detection range, and capabilities, making it challenging to meet the high-precision geological structure detection requirements of intelligent tunneling faces. In response, the seismic-while-tunneling technique utilizes the vibration of the roadheader cutting the coal wall as the seismic source. This method employs real-time data upload, automatic processing, and dynamic imaging. By leveraging information technology and software support, and utilizing real-time continuous super-saturation stacking supported by massive data, the imaging precision of geological anomalies ahead of the mining face is significantly enhanced. …

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Pneumatic Directional Drilling Technology And Equipment For Broken-Soft Coal Seams In Underground Coal Mines, Tian Hongliang, Zhang Jinbao, Wang Li, Fang Jun, Wang Jianqiang Jun 2024

Pneumatic Directional Drilling Technology And Equipment For Broken-Soft Coal Seams In Underground Coal Mines, Tian Hongliang, Zhang Jinbao, Wang Li, Fang Jun, Wang Jianqiang

Coal Geology & Exploration

[Objective] The geological conditions of coal seams in China are complex, with a wide distribution of broken-soft coal seams, and a large number of wells have the problems of high gas and coal-gas outburst. Currently, borehole gas drainage is an effective measure for preventing and controlling the gas disasters. [Methods] In response to the problems of uncontrollable drilling trajectory, shallow drilling depth, large blind spots of drainage in conventional rotary drilling process of broken-soft coal seams, as well as multiple stuck drilling accidents, great difficulty in drilling and low drilling efficiency in conventional directional drilling processes, the development history and …

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Build-Up Rate Prediction Of Rotary Steerable Tools Based On Delay Differentiation, Li Fei, Zhang Nan Jun 2024

Build-Up Rate Prediction Of Rotary Steerable Tools Based On Delay Differentiation, Li Fei, Zhang Nan

Coal Geology & Exploration

[Objective] Accurate build-up rate prediction of rotary steerable tools is a prerequisite to achieve the precise control of tools. In order to grasp the variation law of the build-up rate of the rotary steerable bottom-hole assembly (RSBHA). [Methods] Based on the structural charaeteristics of the tool, the Euler-Bernoulli beam equation method is used to analyz the forces outing on the composite RSBHA. At the same time, the calculation method of the tool deflection angle in different sections and the bit pre-drilling deflection angle was obtained with consideration to the geometric relationship of the bottom-hole assembly, and the distance between the …

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Analysis Of Three-Dimensional Nonlinear Fluid-Solid Coupling Vibration Characteristics Of Coalbed Methane Abandoned Well Plugging String, Xu Zhixin, Wan Jifang, Hong Yi, Liu Hangming, Yi Xianzhong, Diao Binbin, Wang Yanbin Jun 2024

Analysis Of Three-Dimensional Nonlinear Fluid-Solid Coupling Vibration Characteristics Of Coalbed Methane Abandoned Well Plugging String, Xu Zhixin, Wan Jifang, Hong Yi, Liu Hangming, Yi Xianzhong, Diao Binbin, Wang Yanbin

Coal Geology & Exploration

[Objective] The plugging quality of cement plug in abandoned coalbed methane wells is critical to preventing pollutant leakage. Current standards for handling these wells involve simple mud pump injection, which often results in cement plugs with issues like particle agglomeration, bubbles, and micropores. These defects reduce the strength of the cement plug and compromise its sealing performance. [Methods] To address this, vibration technology is applied to the plugging operation, using a specialized tool to induce vibrations in the pipe string. This process enhances the fluidity of the cement slurry via the transmission of vibration energy, thereby improving the plugging quality …

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Spatial Distribution And Influencing Factors Of Microseismic Events In Unequal-Length Mining Faces In Coal Mines, Zhou Jinyan, Yang Hongzeng, Gao Jietao Jun 2024

Spatial Distribution And Influencing Factors Of Microseismic Events In Unequal-Length Mining Faces In Coal Mines, Zhou Jinyan, Yang Hongzeng, Gao Jietao

Coal Geology & Exploration

[Objective] The varying length of a mining face along its dip direction or adjusting mining significantly increases water inrush risks of the mining face. This study investigate the hazards and influencing factors brought by unequal length arrangements to the mining face is one of the key issues in deepening the research on coal mine water hazard prevention and ensuring the safe mining face. [Methods] With the No. 15240 mining face, consisting of a narrow part, a wide part, and a slope, in the Jiulong Coal Mine of the Jizhong Energy Fengfeng Group as the engineering background, a large amount of …

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Development And Application Of A Supercritical Co2 Pulsed Fracturing-Seepage Coupling Test System, Liu Jiajia, Zhang Yunlong, Nie Zishuo, Gao Zhiyang, Xu Wensong Jun 2024

Development And Application Of A Supercritical Co2 Pulsed Fracturing-Seepage Coupling Test System, Liu Jiajia, Zhang Yunlong, Nie Zishuo, Gao Zhiyang, Xu Wensong

Coal Geology & Exploration

[Objective] To effectively enhance the extraction effects of coalbed methane (CBM), this study proposed a novel approach for fracturing coals (rocks) using pulsation of supercritical carbon dioxide (CO2) by combining pulsed fracturing with supercritical CO2 fracturing. [Methods] A true triaxial test system coupling supercritical CO2 pulsed fracturing with seepage was independently developed, and its primary structure, characteristics, and functions were elucidated. Then, the supercritical CO2 pulsed fracturing - seepage/acoustic emission monitoring tests under true triaxial conditions were conducted in the laboratory. The test system, controlling the triaxial stress by combining an independent servo system with …

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Remote Sensing Monitoring And Spatiotemporal Characteristics Of Co2 And Ch4 Concentrations In Coal-Electricity Production Bases, Xu Yanfei, Chen Yongchun, Li Jing, Liu Xiaozhou, Miao Wei, Zhao Derong, Rui Chengqi Jun 2024

Remote Sensing Monitoring And Spatiotemporal Characteristics Of Co2 And Ch4 Concentrations In Coal-Electricity Production Bases, Xu Yanfei, Chen Yongchun, Li Jing, Liu Xiaozhou, Miao Wei, Zhao Derong, Rui Chengqi

Coal Geology & Exploration

[Objective] CO2 and CH4 are identified as the primary greenhouse gases emitted from energy production in coal-electricity production bases. Mointoring these emissions and analyzing their spatiotemporal distribution are essential components of building a carbon monitoring system in the study area. [Methods] This study investigated Huainan City, Anhui Province as an example to explore the spatiotemporal characteristics of CO2 and CH4 in coal-electricity production bases. Specifically, this study examined the CO2 and CH4 concentrations in the study area based on data from the GOSAT，OCO-2, and Sentinel-5P satellites，determining the column concentration changes and distribution of CO …

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