摘要:
Dynamic shear modulus and damping ratio are two main parameters for describing the dynamic performance of aeolian soils. This paper presents the influence of the confining pressure, the consolidation ratio and the vibration frequency on the dynamic shear modulus and the damping ratio of aeolian soils with a series of dynamic triaxial tests. Experimental results show that the dynamic shear modulus of aeolian soils increases with the confining pressure and the consolidation ratio, while the damping ratio decreasing with them; both of the dynamic shear modulus and the consolidation ratio increases with the vibration frequency, but the influence is less than that of the confining pressure and the consolidation ratio.
期刊:
Electronic Journal of Geotechnical Engineering,2015年20(25):12113-12120 ISSN:1089-3032
通讯作者:
Feng, Shengyang(fengshengyang13@163.com)
作者机构:
[Feng, Shengyang; Wang, Shuyun; Li, Xiangyang; Chen, Zhi] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, China
通讯机构:
School of Environmental Protection and Safety Engineering, University of South China, Hengyang, China
作者机构:
[Yongjun Y.; Xiangyang L.; Shuyun W.] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China;[Longjun X.] State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China;[Chao X.] School of Environmental Protection and Safety Engineering, University of South China, Hengyang, 421001, China, State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China
通讯机构:
[Xu Longjun] S;State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, China
摘要:
Mn-Zn ferrite powders were produced from low-grade manganese ore(LMO) via the chemical coprecipitation method combined with the ceramic method,after the LMO was leached in sulfuric acid and the obtained solution was purified.The effect of the pH on the magnetic properties of Mn-Zn ferrite was investigated by the varying pH of the co-precipitation system.The crystal structure and phases of the samples were characterized by X-ray diffraction and infrared spectrum,respectively.The magnetic measurements were carried out on a vibrating sample magnetometer.The optimal sample was obtained with a saturation magnetization of 55.02 emu/g,a coercivity of 8.20 G and a remanent magnetization of1.71 emu/g when pH is 7.5.
作者机构:
[Jiang Fuliang; Li Xiangyang; Wang Shuyun; Zhan Jing] Univ South China, Sch Environm Protect & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构:
[Li Xiangyang] U;Univ South China, Sch Environm Protect & Safety Engn, Hengyang 421001, Hunan, Peoples R China.
会议名称:
2012 International Symposium on Safety Science and Technology (2012安全科学与技术国际会议)
会议时间:
2012-10-23
会议地点:
南京
会议论文集名称:
2012 International Symposium on Safety Science and Technology (2012安全科学与技术国际会议)论文集
关键词:
bridge erecting machine tipping;fault tree analysis;minimal path set;structural importance;countermeasure
摘要:
Bridge erecting machine has been widely used nowadays with its efficiency, while just as a coin has two sides, it also brings problem. If a rollover happens, it will lead to equipment damage, casualties or other disastrous accidents. How could technicians take measures to prevent accidents as efficiently as possible? Question remains unsaved. Based on the analysis of “10.26” bridge erecting machine tipping accident, this paper gives a qualitative analysis on the accident by using fault tree analysis. Firstly, fault tree diagram for the bridge erecting machine tipping, namely the causal and generalization relation between events is formulated. All the basic events that influence the way and the degree of the accident are identified, and these can be ascribed to the following three aspects: manufacturing defect, personnel operating error and management oversight. In terms of management oversight, the responsibility of construction unit, safety supervision department and supervision unit are of great importance. Secondly, combining the minimal path set with the structure importance, we conduct a qualitative analysis on the personnel casualties resulted from the accident, thus seek critical approaches to accident prevention. Finally corresponding safety control measures are put forward. It is noteworthy that the approach can be applied in the similar accidents entirely.
会议论文集名称:
2012 International Symposium on Safety Science and Technology (2012安全科学与技术国际会议)论文集
关键词:
locomotive runaway accident;fault tree analysis;cause analysis;safety countermeasure
摘要:
August 12, 2011, a locomotive runaway has happened on the local railway named Xihe railway of a certain city, it led to a death of an older person and serious damage of four automobiles. The causing factors of the runaway accident have been comprehensively analyzed, which respectively include four aspects: human, machine, environment and management. By using the principle of fault tree analysis (FTA), the locomotive runaway accident fault tree has been set up after the accident investigation. Based on the corresponding formula, the authors have calculated the structure importance coefficient of each basic event. By analyzing the causation of the events, the minimal path sets have been obtained, and the order of the structure importance has also been obtained. Through the above analysis, the reasons of this accident have been analyzed systematically and the corresponding safety countermeasures have been proposed. The thesis can provide reference for prevention of similar accidents. (C) 2012 Authors. Published by Elsevier Ltd.
摘要:
The stabilization of slopes by placing passive piles is one of the innovative slope reinforcement techniques in recent years. There are numerous empirical and numerical methods for designing stabilizing piles. They can generally be classified into two different types: (1) pressure/displacement-based methods; (2) finite element/finite difference methods. However, seldom studies have been done on the stratified rock slope reinforced by piles, so in the present paper, the numerical simulation software FLAC3D is adopted to model the stratified rock slope, then the reinforced effect like deformation and stress of slope are studied, showing that if the pile is driven at the mid-bottom place of slope surface, the effect of controlling deformation of rock mass is the best. With increase of the length of pile, the maximum displacement of slope is decreased gradually.
期刊:
Applied Mechanics and Materials,2011年71-78:3197-3200 ISSN:1660-9336
通讯作者:
Wang, Shuyun
作者机构:
[Wang, Shuyun] Univ South China, Sch Environm Protect & Safety Engn, Hengyang 421001, Peoples R China.;[Xie, Xionggang] Guizhou Univ, Min Coll, Guiyang 550004, Peoples R China.;[Chen, Xi] Univ South China, Chuanshan Coll, Hengyang 421001, Peoples R China.
通讯机构:
[Wang, Shuyun] U;Univ South China, Sch Environm Protect & Safety Engn, Hengyang 421001, Peoples R China.
会议名称:
2011 International Conference on Green Building, Materials and Civil Engineering, GBMCE 2011
会议时间:
22 August 2011 through 23 August 2011
会议地点:
Shangri La, PEOPLES R CHINA
会议主办单位:
[Wang, Shuyun] Univ South China, Sch Environm Protect & Safety Engn, Hengyang 421001, Peoples R China.^[Xie, Xionggang] Guizhou Univ, Min Coll, Guiyang 550004, Peoples R China.^[Chen, Xi] Univ South China, Chuanshan Coll, Hengyang 421001, Peoples R China.
会议论文集名称:
Applied Mechanics and Materials
关键词:
Computer Aided Design (CAD);Excavation;Numerical Simulation;Stratified Rock Mass;Tunnel
摘要:
Stratified rock mass is widely existing in tunnel engineering. The most relevant feature of stratified rocks is the occurrence of very persistent bedding, which makes the rock-mass highly non-isotropic. A number of techniques for designing underground excavations in stratified media have been described in the literature, like theoretical method and laboratory test, which can only be applied in analyzing the problem with simple geometry and costs much expense. Recently, with rapid development of computer technique, numerical simulation methods have been widely applied in engineerin. Among all the numerical simulation methods, fast lagrangian explicit finite difference code of continua (FLAC3D) is widely used to solve practical problems, especially in field of elasto-plastic characteristic, large deformation analysis and construction procedure. So in the present paper, numerical simulation for the failure mode of stratified rock mass after tunnel excavation is done by FLAC3D, which can give further guidance to understand the anisotropic characteristic of stratified rock mass.