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Comparison of seismic effects during deep tunnel excavation with different methods

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Earthquake Engineering and Engineering Vibration 2018年第3期17卷 659-675页

作者： Xie Liangtao Yan Peng lu wenbo Chen Ming Wang Gaohui State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of Education Wuhan University

The rapid release of strain energy is an important phenomenon leading to seismic events or rock failures during the excavation of deep *** theoretical analysis of strain energy adjustment during blasting and mechanical excavation,and the interpretation of measured seismicity in the Jin-Ping Ⅱ Hydropower Station in China,this paper describes the characteristics of energy partition and induced seismicity corresponding to different energy release *** theoretical analysis indicates that part of the strain energy will be drastically released accompanied by violent crushing and fragmentation of rock under blast load,and this process will result in seismic events in addition to blasting *** intensity of the seismicity induced by transient strain energy release highly depends on the unloading rate of in-situ *** mechanical excavation,the strain energy,which is mainly dissipated in the deformation of surrounding rock,releases smoothly,and almost no seismic events are produced in this gradual *** test reveals that the seismic energy transformed from the rock strain energy under high stress condition is roughly equal to that coming from explosive energy,and the two kinds of vibrations superimpose together to form the total blasting excavation-induced *** addition,the most intense seismicity is induced by the cut blasting delay; this delay contributes 50% of the total seismic energy released in a blast *** mechanical excavation,the seismic energy of induced vibration（mainly the low intensity acoustic emission events or mechanical loading impacts）,which accounts only for 1.5‰ of that caused by in-situ stress transient releasing,can be ignored in assessing the dynamic response of surrounding rock.

关键词： seismicity energy release rate blasting excavation mechanical excavation seismic energy

Evaluation of human response to blasting vibration from excavation of a large scale rock slope:A case study

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Earthquake Engineering and Engineering Vibration 2017年第2期16卷 435-446页

作者： Yan Peng lu wenbo Zhang Jing Zou Yujun Chen Ming State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of Education Wuhan University Wuhan 430072 China

Ground vibration, as the most critical public hazard of blasting, has received much attention from the community. Many countries established national standards to suppress vibration impact on structures, but a world-accepted blasting vibration criterion on human safety is still missing. In order to evaluate human response to the vibration from blasting excavation of a large-scale rock slope in China, this study aims to suggest a revised criterion. The vibration frequency was introduced to improve the existing single-factor （peak particle velocity） standard recommended by the United States Bureau of Mines （USBM）. The feasibility of the new criterion was checked based on field vibration monitoring and investigation of human reactions. Moreover, the air overpressure or blast effects on human beings have also been discussed. The result indicates that the entire zone of influence can be divided into three subzones： severe-annoyance, light-annoyance and perception zone according to the revised safety standard. Both the construction company and local residents have provided positive comments on this influence degree assessment, which indicates that the presented criterion is suitable for evaluating human response to nearby blasts. Nevertheless, this specific criterion needs more field tests and verifications before it can be

关键词： Construction industry Excavation Velocity control

Microwave-assisted One-pot Synthesis of Ag NPs/C and Its Application in H2O2 and Glucose Detection

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Chemical Research in Chinese Universities 2016年第3期32卷 433-436页

作者： GE Chenjiao lu wenbo SUN Xuping TIAN Jian Clean Energy lechnology Laboratory Changchun University of Science and Technology Changchun 130022 P. R. China State Key Lab of Electroanalytical Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 P R. China

The facile preparation of Ag NPs/C via a one-pot strategy was carried out by microwave treatment of a mixed aqueous solution of AgNO3 and glucose at 180 ℃ for 20 min without the presence of extra reducing agent. The as-synthesized Ag NPs/C showed high catalytic performance toward the reduction of H2O2. The H2O2 sensor constructed with as-synthesized Ag NPs/C exhibited a short amperometric response time of less than 2 s. The linear range was approximately （0.1-50） mmol/L（r=0.997）, and the detection limit was approximately 3.3 μmol/L at a signal-to-noise ratio of 3. A glucose biosensor was fabricated by immobilizing glucose oxidase onto Ag NPs/C- modified glassy carbon electrode to detect glucose. The glucose sensor had a wide linear response range of 2-22 mmol/L（r=0.999） and a detection limit of 190 μmol/L.

关键词： Carbon Ag nanoparticles Microwave H2O2 Glucose

Electron modulation of cobalt carbonate hydroxide by Mo doping for urea-assisted hydrogen production

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Journal of Energy Chemistry 2022年第7期31卷 258-265,I0007页

作者： Siyu Zheng Hongye Qin Xuejie Cao Tongzhou Wang wenbo lu Lifang Jiao Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Renewable Energy Conversion and Storage Center(Re Cast)College of ChemistryNankai UniversityTianjin 300071China Key Laboratory of Magnetic Molecules and Magnetic Information Materials(Ministry of Education) School of Chemistry and Material ScienceShanxi Normal UniversityTaiyuan 030035ShanxiChina Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Combining urea oxidation reaction(UOR) with hydrogen evolution reaction(HER) is an effective method for energy saving and highly efficient electrocatalytic hydrogen production. Herein, molybdenumincorporated cobalt carbonate hydroxide nanoarrays(CoxMoyCH) are designed and synthesized as a bifunctional catalyst towards UOR and HER. Benefiting from the Mo doping, the dispersed nanoarray structure and redistributed electron density, the CoxMoyCH catalyst display outstanding catalytic performance and durability for both HER and UOR, affording the overpotential of 82 m V for HER and delivering a low potential of the 1.33 V for UOR(vs. reversible hydrogen electrode, RHE) to attain a current density of 10 m A cm^(-2), respectively. Remarkably, when CoxMoyCH was applied as bifunctional catalyst in a twoelectrode electrolyzer, a working voltage of 1.40 V is needed in urea-assisted water electrolysis at10 m A cm^(-2) and without apparent decline for 40 h, outperforming the working voltage of 1.51 V in conventional water electrolysis.

关键词： Urea-assisted water electrolysis Bifunctional catalyst Molybdenum doping Cobalt carbonate hydroxides Hydrogen evolution reaction

An experimental system for release simulation of internal stores in a supersonic wind tunnel

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Chinese Journal of Aeronautics 2017年第1期30卷 186-195页

作者： Liu Wei Ma Xin Jia Zhenyuan lu wenbo Wang Zhengqu Chen Ling Liu Weixiao lu Jiwen Key Laboratory for Precision and Non-traditional Machining Technology of the Ministry of Education Dalian University of Technology Dalian 116024 China AVIC Aerodynamics Research Institute Shenyang 110034 China

Aerodynamic parameters obtained from separation experiments of internal stores in a wind tunnel are significant in aircraft designs. Accurate wind tunnel tests can help to improve the release stability of the stores and in-flight safety of the aircrafts in supersonic environments.A simulative system for free drop experiments of internal stores based on a practical project is provided in this paper. The system contains a store release mechanism, a control system and an attitude measurement system. The release mechanism adopts a six-bar linkage driven by a cylinder, which ensures the release stability. The structure and initial aerodynamic parameters of the stores are also designed and adjusted. A high speed vision measurement system for high speed rolling targets is utilized to measure the pose parameters of the internal store models and an optimizing method for the coordinates of markers is presented based on a priori model. The experimental results show excellent repeatability of the system, and indicate that the position measurement precision is less than0.13 mm, and the attitude measurement precision for pitch and yaw angles is less than 0.126°, satisfying the requirements of practical wind tunnel tests. A separation experiment for the internal stores is also conducted in the FL-3 wind tunnel of China Aerodynamics Research Institute.

关键词： Binocular vision system Pose measurement Release mechanism Wind tunnel

Comparison of dominant frequency attenuation of blasting vibration for different charge structures

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第2期14卷 448-459页

作者： Pengchang Sun wenbo lu Junru Zhou Xincheng Huang Ming Chen Qi Li State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China School of Resource and Environmental Engineering Wuhan University of Science and TechnologyWuhan430081China Changjiang Institute of Survey PlanningDesign and ResearchWuhan430010China

Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration *** is necessary to develop a concise and practical prediction equation describing dominant frequency *** this paper,a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional *** blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction *** fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency *** apparent frequency proved to be more reliable to express the attenuation law of the dominant *** reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction *** smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant *** blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio *** the charge structures applied in the experiments,the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency.

关键词： Dominant frequency Blasting vibration Attenuation law Prediction equation Charge structures

An evaluation of numerical approaches for S-wave component simulation in rock blasting

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第5期9卷 830-842页

作者： Qidong Gao wenbo lu Yingguo Hu Zhaowei Yang Peng Yan Ming Chen State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering Ministry of Education Wuhan University Wuhan 430072 China

The shear wave(S-wave) component of the total blast vibration always plays an important role in damage to rock or adjacent *** approach has been considered as an economical and effective tool in predicting blast ***,S-wave has not yet attracted enough attention in previous numerical *** this paper,three typical numerical models,*** continuum-based elastic model,the continuum-based damage model,and the coupled smooth particle hydrodynamics(SPH)-finite element method(FEM) model,were first introduced and developed to simulate the blasting of a single cylindrical ***,the numerical results from different models were evaluated based on a review on the generation mechanisms of S-wave during ***,some suggestions on the selection of numerical approaches for simulating generation of the blast-induced S-wave were put *** indicate that different numerical models produce different results of *** coupled numerical model was the best,for its outstanding capacity in producing S-wave *** is suggested that the model that can describe the cracking,sliding or heaving of rock mass,and the movement of fragments near the borehole should be selected preferentially,and priority should be given to the material constitutive law that could record the nonlinear mechanical behavior of rock mass near the borehole.

关键词： Rock blasting Blast vibration S-wave Numerical approach

Dam foundation excavation techniques in China:A review

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Journal of Rock Mechanics and Geotechnical Engineering 2013年第6期5卷 460-467页

作者： Yuzhu Zhang wenbo lu Ming Chen Peng Yan Yingguo Hu State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University

A protective layer(PL) is commonly reserved above foundation surface to protect the underlying rock mass during dam foundation excavation. In China, the PL of dam foundation is conventionally subdivided into two or three thin layers and excavated with the shallow-hole blasting method, even by pneumatic pick method in case of soft rock mass. The aforementioned layered excavation of the PL delays the construction of the whole project. After nearly 30-year practices, several safe and effcient methods for the PL excavation of dam foundation are gradually developed. They include shallow-hole bench blasting with cushion material(SBC) at the bottom of the hole, and horizontal smooth blasting(HSB). The PL is even cancelled on the condition that horizontal pre-split technique is employed during dam foundation excavation. This paper introduces the aforementioned two PL excavation methods(shallow-hole blasting and bench blasting) and horizontal pre-split technique of dam foundation without protective layer(HPP). The basic principles of blasting method, blasting geometry, charge structure, drill-and-blast parameters of typical projects are examined. Meanwhile, the merits and limitations of each method are compared. Engineering practices in China show that HSB is basically the optimal method for dam foundation PL excavation in terms of foundation damage control and rapid construction. Some new problems for dam foundation PL excavation arising, such as strong unloading and relaxation phenomenon that encountered in the gorge region of southwest China, are needed to be addressed; and the corresponding countermeasures are discussed as well.

关键词： Dam foundation Protective layer(PL) Excavation Blasting Rapid construction

Ni2P Nanosheets:A High Catalytic Activity Platform for Electrochemical Detection of Acetaminophen

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Chinese Journal of Chemistry 2021年第7期39卷 1849-1854页

作者： Ming Wei wenbo lu Guoqin Liu Yimin Jiang Xuebo Liu Liwei Bai Xiaowei Cao Jianfeng Jia Haishun Wu Key Laboratory of Magnetic Molecules and Magnetic Information Materials(Ministry of Education) School of Chemistry and Material ScienceShanxi Normal UniversityLinfenShanxi041004 China Kangda College of Nanjing Medical University LianyungangJiangsu222000 China Institute of Translational Medicine Medical CollegeYangzhou UniversityYangzhouJiangsu225001 China

Main observation and conclusion Accurate determination of acetaminophen concentration is essential for studying the metabolic status of acetaminophen in clinical *** this study,nickel phosphide was used for electroche... 详细信息

关键词： Acetaminophen Nickel phosphide Electrochemistry Sensors Nanotechnology