bluuebunny/crossref_metadata_2025 huggingface dataset:
The Horizontal and Vertical Distribution of Particulates in a Near-Road Environment
Authors: Cao Yong , Zhang Da Di , Liu Jing , Yu Dan
Published: December 2014

The distribution of particulate matters is now receiving significant attention given their role in human health and respiratory related diseases. The concentrations of PM10, PM2.5 and PM1.0 were measured in different test points near the road. Two sampling campaigns were conducted in this study. The results indicated that a gradual decrease in the concentrations of particulate matters with distance from the edge of the road. The concentrations of these particulates decreased with the increase of height when the sites were under trees or other vegetations, while the concentrations of these particulates increased with the increase of height when the sites were higher than the height of trees or other vegetations.
The Research of High-Salt Organic Liquid Waste Incineration Technology
Authors: Li Xin , Li Guo Yi
Published: December 2014

High-salt organic liquid waste treatment was a worldwide problem. It troubled many chemical industries such as medicine, pesticide, metallurgy, papermaking and dyeing. In this article, high temperature incineration technology, a new kind of process route was introduced. That’s especially suitable for organic liquid waste disposal while it divided into a variety of segmentation techniques routes. According to the types and amount of salt or different process routes, the incineration technology can turn organic waste liquid into harmless substances effectively. Meanwhile, salt resources and generate steam also be recycled in this processing as well as the gas emission was on standard. This article will contrast the different treatment methods of process routes for the route selection. By the summary of process optimization, these studies can provide strong support for decision-making in liquid waste incineration technology innovation and for applications planning.
Study on Impact Factors of Reducing U(VI) by S. oneidensis
Authors: Liu Jin Xiang , Xie Shui Bo , Wang Yong Hua , Li Shi You , Li Biao
Published: December 2014

Impact Factors of reducing U(VI) by the Shewanella oneidensis Were studied in this study. The results showed S. oneidensis has highly resistant to acid and Uranium. U(VI) initial concentration has the very big influence on reduction of U(VI) and the optimum U(VI) concentration is 30mg/Lwith removal rate of 95.02% at 4 days, Metal ions Cu2+,Mn2+ and Ca2+ impact on the reduction of U(VI). equal concentrations of Cu2+ and Mn2+ could cause varying degrees of inhibition of U(VI) reduction, Ca2+ acted as a weak role in promoting the reduction, the coexisting ions of SO42-and low concentration of no3-(<0.5mmol/L) did not markedly influence the reduction efficiency of U(VI). zero alent iron (ZVI) can accelerate the reduction of U(VI) by the S. oneidensis .
The Characteristic of Algal Reef Carbonate Sedimentary and Pore Structure in the Xisha Islands: Evidence from Halimeda
Authors: Zhao Xin  Wei , Hao Hui Zhi
Published: December 2014

Halimeda is an important reef-building green alga. Scanning electron microscopy (SEM) and energy spectrum tests on green and white Halimeda collected from Shidao Island in the Xisha Islands show that carbonate is predominantly deposited in the cortexes and medullas, especially in the aragonite raphides of them, as the case of calcium carbonate. These modern carbonate sediments are then compared with their ancient counterparts that are collected from Xichen-1 well in the Yongle Atoll, where a large number of Halimeda segments have been recognized in about 100-m-long late Miocene-middle Miocene whole-coring succession. In addition, there are developed great numbers of algal-frame holes, including secondary dissolved pores and intercrystalline pores in the medullas and in aragonites between cysts, which have formed particular network systems and pore throats.
Research on the Last Train Connection in the Urban Mass Transit System
Authors: Cai Chang Jun , Zhou Lei Shan , Shang Yong Feng
Published: December 2014

With the urban rail transit becoming more and more networked, determining the departure time of last trains has been an important part for the urban rail transit network operations organization. First analyze two aspects of passengers and vehicles to determine reasonable time intervals of last trains, then analyze last train departure time optimization, minimizing the total loss in the transfer station as the objective to build the mathematical model, by adding and shifting line at the transfer station to reduce the connection direction loss, an auxiliary line being added or not according to the operating time so as to determine the final operation result. Finally, use the Beijing subway to verify and the result shows that the method has practical significance for the improvement of urban rail transit operation organization.
Research on Construction Environment Control of High Altitude Cold Regions Tunnel
Authors: Zhang Yu Wei , Xie Yong Li , Li You Yun
Published: December 2014

High altitude cold regions tunnel construction environment is the key factor of tunnel construction progress, also relates to the technical personnel's health, this paper analyzes several key factors of restricting the construction environment, the field test of dust and CO several important indexes such as the maximum value, it is concluded that high altitude cold regions tunnel construction environment is relatively poor, dust and CO value beyond the standard requirements. Based on this, puts forward the measures to control the environment of high altitude cold regions tunnel construction for reference by the similar projects.
Comprehensive Safety Assessment Model of Highway Section Based on the Accident Rate Prediction
Authors: Lu E , Xu Jing Liang
Published: December 2014

At home and abroad research, accident rate prediction model for highway safety assessment contains various influence factors, so it is difficult to find a comprehensive accident prediction model considering so much of them. In this article, we select appropriate accident prediction models through comprehensive literature research respectively about the highway alignment conditions, traffic conditions, interchange spacing conditions, then determine the weights of three accident prediction models using the analytic hierarchy process (AHP), finally obtain the comprehensive safety assessment model after the consistency check. Its’ feasibility is proved by a practical example.
Harmony Search Algorithm with Opposition-Based Learning for Power System Economic Load Dispatch
Authors: Zhang Yi Ning
Published: December 2014

A harmony search algorithm with opposition-based learning techniques (HS-OBL) to solve power system economic load dispatch has been presented. The proposed algorithm integrates the opposition-based learning operation with the improvisation process to prevent the HS-OBL algorithm from being trapped into the local optimum effectively. Besides, a new adjusting strategy is designed to dynamic adjust pitch adjusting rate (PAR) and harmony memory consideration rate (HMCR), which is to further improve the performance of algorithm. The HS-OBL is employed to solve 6 units and 13 units power system, the numerical results indicate that the HS-OBL has perform much better than harmony search(HS) algorithm and other improved algorithms that reported in recent literature.
Numerical Analysis of Optimization Design for Insulation Layer in Cold Regions Tunnel
Authors: Song He , Ye Chao Liang , Mi Jun Feng
Published: December 2014

Setting of insulation layer is widely recognized to prevent frost damage for tunnels constructed in cold region. Optimization design of insulation layers, however, still need deeply investigate. In this paper, taking Houanshan tunnel as example, two-dimensional finite element analysis on the optimization design of insulation layers has been carried out by ABAQUS. The tunnel temperature fields due to various thickness and length of insulation layer are numerically analyzed. It shows that ,1)4.85°C increased at backside of insulation layer with thickness of 5cm, while 5.8°C increased for thickness of 7cm;2) frozen depth of surrounding rock decrease with the increase of insulation layer thickness. The farther distance to tunnel portal, the smaller thickness of insulation layer required to prevent the surrounding rock from freezing;3)According to analysis, frost penetration length should be 450~500m before tunnel holing-through ,while 720m~830m after tunnel holing-through.
Research on Safety Assessment of Blasting Construction in Highway Tunnel Project
Authors: Tian Jian , Guo Peng , Li Zhi Qiang
Published: December 2014

The drilling and blasting method is popular for the construction of highway tunnel,which is easy to cause serious production safety accidents.Based on safety risk analysis of tunnel blasting construction,safety risk probability assessment index system of tunnel blasting construction was put forward,which consist of establishment of blasting scheme,belection of blasting equipment,and safety management,etc.Safety risk probability assessment model was constructed based on the fuzzy comprehensive evaluation,which are divided in five level.The risk matrix method was used to assess risk level of blasting construction,considering blasting construction risk probability and the consequence.Through the case on ChenJiagou tunnel in the province of Hebei proves the feasibility of evaluation method,and the corresponding risk control measurements were proposed.
The Forecasting of Tunnel Water Inflow in Bare Karst Area
Authors: Wu Ya Zun , Wan Jun Wei
Published: December 2014

Rainfall is the main factor that affecting water inflow of the tunnel in the bare karst areas of Southwest China. Affected by the development of karst aquifer system, rainfall infiltration recharge for groundwater has obvious lag time. The water inflow of tunnel is not only concerned with the intraday rainfall, but also related with the antecedent rainfall. In this paper, taking the Yesanguan Tunnel and Maluqing Tunnel as examples, the correlation between rainfall in different periods and water inflow was analyzed, and then the regression equation was established to forecast water inflow. The results show the predicted result is affect by the precision of the observation data, the development degree of karst, the infiltration and the discharge conditions of rainfall. Meanwhile, the correlation analysis is not suitable for some cases, such as the area which has greater changes of groundwater recharge and discharge under different rainfall conditions.
Differential Settlement due to Ground Fissures in Xi’an
Authors: Wang Xin Yuan , Mao Song He , Zhang Yao Jun
Published: December 2014

From 1950s 13 NEE ground fissures have been found in the suburb and downtown area of Xi’an city. Ground fissures bring harm to the Xi'an municipal construction, especially to the subway construction. By dynamic characteristics of Xi’an ground fissures, factors influencing differential settlement are analyzed and a conclusion is drawn that exploitation of ground water and the differential clay thickness on both sides of ground fissures is the governing factor. The amount of differential settlement in the following 50 years is predicted by ground-water Model and Verhulst Model. Good agreement is shown between these results. It leads us to suggest that the differential settlement will cut off the subway tunnel in the future and actions must be taken in the design phase of subway tunnel.
Analysis of the Effects on Metro Station’s Main Structure Generated by Foundation Pit Support Structure
Authors: Wang Hui , Liu Feng Zuo
Published: December 2014

For the present open cut method is still the main method of the construction of metro stations. Foundation pit support structure and lining structure are composed of three basic side wall structure systems (single wall, compound wall and composite wall). In the calculation of internal force of structure, complex interactions between foundation pit support structures including bored pile and diaphragm wall, and the side wall of main structures are investigated. One form is that the foundation pit support structure and side wall can only deliver pressure and separate partly; another is that they deform together by construction measures. In this paper, the effects on the internal force of main structure influenced by foundation pit support structure are quantitative studied, and the reference resources for optimization design are provided.
Seismic Analysis of the Entrance Section of a Nuclear Power Intake Tunnel
Authors: Huang Shi Kui , Zhao Jie
Published: December 2014

For a nuclear power intake tunnel project, large-scale three-dimensional finite difference model is established by Flac3D to simulate the seismic response regularity of the entrance section of tunnel under the action of seismic waves schedule with the nonlinear dynamic analysis method. Through the input of the site seismic wave, the structure response characteristics of the tunnel entrance and slope are explored and duration curve of tunnel hole lining force under seismic waves action and tunnel lining figure can be obtained. The analysis results show that the anti-seismic weak parts of the tunnel entrance is at the location of tunnel spandrel and the sidewall. The analysis method and conclusions can be for reference in the seismic design of similar nuclear power intake tunnel project.
Suspension-Diffusion Mathematical Model Calculation for Wenzhou Shoal in Construction Period
Authors: Li Wen Dan , Li Meng Guo
Published: December 2014

By means of natural condition and mathematical models of tidal flow and sediment, numerical study is carried out on suspension-diffusion in construction period after the reclamation project of Wenzhou shoal at Oujiang estuary in this paper. The main conclusions are: the suspension-diffusion is controlled by tidal current. The range of suspended sediment concentration more than 10mg/L is mostly in Wenzhou shoal area during filling sand construction, which is the continuous operation. Riprap construction is Instantaneous work; the range of scatter is limited.
Analysis of Inhomogeneity of Internal Force in Front Wall of Caisson
Authors: Li Zhe Jiang , Hu Jia Shun , Li Lin Qing , He Liang De
Published: December 2014

Finite element procedure was used to build a spatial model of a perforated caisson, the result was compared with the one that was calculated according to the current standard. It is pointed out that simplifying assumption of the standard is different from the actual structure, the side walls can’t act as fixed constraints for the front wall. The calculated mid-span moment in the middle span is close to the ANSYS result, while that in the side span is much smaller than the ANSYS result. It is recommended that the result is multiplied by a expansion coefficient.
Numerical Analysis of Composite Soil Nailing Wall
Authors: Zhang Shu Long , Lu Fen Ting
Published: December 2014

Abstract. The horizontal displacement of soil in slope and the change law of ground surface settlement are dynamically analyzed by building three dimensional-model of foundation pit with the finite element software, ABAQUS, to simulate the construction process of excavation and support, to figure out the influence of micro pile and waterproof curtain on composite soil nailing wall. The study indicates that mechanical model of soil nailing, waterproof curtain, micro pile, pre-stressed anchor interacting with soil can better simulate the construction process of composite soil nailing wall support and have higher calculation accuracy. The calculation can provide a reference for the design and construction of composite soil nailing wall.
Sediment Siltation at Boundless Pool of Double Happiness Island Zhangzhou
Authors: Fu Ling Fen , Wu De An , She Xiao Jian , Pan Jin Xian
Published: December 2014

the paper is based on numerical model to analyze the siltation of the boundless pool, which built on artificial beach of the east side of double happiness island, Zhangzhou. Using the formulas of W.D.Eysink to calculate the siltation of the pool and analyze the influence of siltation while considering the affect of reflow. The result is that the strength of silation of lowland pool is 0.043m/a, highland pool is 0.017m/a, and the total siltation is 122.73m3.
Duncan-Chang Model Parameters and Normalized Behavior of the Huanggou Pumped Storage Power Station
Authors: Tan Chun , Huang Ru Hui , Li Yan Ping , Ma Dong He , Ma Zhi Fa , Liu Zhi Xin
Published: December 2014

In order to describe the stress-strain characteristic of the geotechnical dielectric material in the Huanggou pumped storage power station, using the samples taken from the construct site, the consolidation-drained shear test is carried out. Combined with Duncan-Chang model, the test results are analyzed to obtain the parameters of the model. Based on this, the Normalized Behavior is studied, and The results show that the normalized degree is highest when used (σ1-σ3)ult as normalization factor.
Numerical Simulation of Seepage Control Effects at a Gravity Dam Site
Authors: Zheng Hua Kang , Liu Ming Ming , Tang Wen Jia , Meng Ru Zhen
Published: December 2014

Located at a narrow and deeply-cut valley in the middle reach of Yalong River in Southwestern China, the Kala Hydropower Station is subjected to serious seepage and leakage problems due to complex geological conditions at the dam site. A numerical method combining a substructure technique, a variational inequality formulation of Signorini’s type and an adaptive penalized Heaviside function (short for SVA method) was adopted for the simulation and assessment of seepage control effects at the dam site in Kala Hydropower Project. Numerical modeling of a typical overflow dam section and the whole dam site demonstrated that the primary design was a proper scheme for seepage control, and furthermore, optimization of the seepage control system can be performed in designing the layout.
Optimizing Study on Navigation Condition of the Outlet of Water Diversion Navigation Project from Yangtze River to Hanjiang River
Authors: Li Jun Tao , Peng Wei
Published: December 2014

The studies have been made on the layout and navigation condition at the outlet section of Water Diversion Navigation Project from Yangtze River to Hanjiang River based on the method with integration of models such as stream physics, remote controlled self-propelled ship, stream mathematics and ship manipulation movement mathematics. At first, it is introduced design proposal of navigation project for entrance of lower reach under the Gaoshibei ship lock section and merging estuary with Hanjiang estuary and then the detail analysis is made on various factors of the design proposal affecting the navigation conditions. Finally, it suggested optimizing layout satisfactory to the safety navigation through improvement of navigation conditions with adopted many engineering measures to the deficiency of design proposal on the navigation conditions.
Simulation of Progressive Failure Process in Rainfall-Induced Landslides
Authors: Su Yan , Lan Si Mei , Xu Li , Ding Jian Hui
Published: December 2014

The landslide process and mechanism of rainfall-induced landslides are assessed by using particle flow code in two dimension based on the discrete element method. The formation mechanism of rainfall-induced landslide is revealed by the analysis of displacement field, velocity field and stress of the slope versus time. The fluid velocity and porosity of sample increase gradually with the increase of water head, the violent fluctuation of contact number of movable particles show the violent motion of slope, then the slope maybe slide.
Some Misconceptions in Pile Insertion Analysis of Offshore Platforms in Shengli Chengdao Oilfield
Authors: An Yong Ning
Published: December 2014

According to some actual cases of pile insertion analysis, combined with specialty norms and principles of soil mechanics in this paper, a few common misconceptions in pile insertion analysis of offshore platforms in Chengdao Oilfield are summarized. Type of common misconceptions, causes and adverse effects are analyzed, and countermeasures are put forward to correct misunderstandings and improve the accuracy of pile insertion calculation and analysis. Cases of analysis errors can be easily found because of unclear soil layer classification, difficultly recognized geotechnical properties, inaccurately divided layer uniformity, inadequately considered structure and soil interaction responses, etc. in offshore platforms pile insertion analysis, thus many unnecessary losses appear in oilfield production. By improving survey quality, using a variety of means of investigation, paying more attention to soil layer uniformity in well field, properly evaluating strength of laminated soil, doing anti-slip platform evaluation when pile is inserted too shallow, etc. can reduce errors effectively.
Asphalt Recycling Agent Diffusion Evaluation Method
Authors: Sun Jian Xun
Published: December 2014

The degree of diffusion is an important index of aging asphalt regeneration process, and diffusion model can more direct regeneration of recycled asphalt pavement material is described. By comparing the different diffusion model, and a variety of different diffusion effect evaluation method, providing basic theoretical research for the regeneration agent in aging effect of diffusion asphalt.
Length Requirements for New Single-Arc Unsymmetrical Crest Vertical Curve for Highways
Authors: Sun Jian Cheng , Chen Chen Feng
Published: December 2014

Existing highway vertical curves may be grouped into two categories: symmetrical vertical curves and unsymmetrical vertical curves. In the past vertical curves design, parabolic arc was used as the vertical curve. This paper presents the new single-arc unsymmetrical vertical curve which is include only one cubic parabola. This curve has the gradual change of the rates of change in grade so that it can provide more comfort to the driver. This paper mainly presents the method by which to find the minimum length for a new single-arc unsymmetrical crest vertical curve based on the minimum sight distance . The discussion will be divided into two situations: the sight distance is longer than the curve length and the sight distance is not longer than the curve length.
Numerical Analysis on the Temperature and Stress Field for Subgrade with Berms in Seasonal Frozen Region
Authors: Wang Tie Quan , Mao Xue Song , Zhang Hui Jun
Published: December 2014

According to the mechanism and influencing factors of subgrade frost heaving , subgrade with berms structure was proposed based on typical highway to prevent the frost heaving.The solid model of subgrade was established. Numerical calculation model of subgrade was established by applying the finite difference software FLAC 3D, boundary conditions and parameters of numerical model were determined, models of subgrade with berms of different widths were analysed and calculated. The results show that subgrade with berms can effectively reduce the freezing depth of subgrade, and decrease the stress and deformation of subgrade frost heaving, berm that is 3m wide in given simulation conditions has the most significant effects on preventing and controlling frost heaving .
Study on the Influence of Asphalt Performance for Ultraviolet Aging
Authors: Ye Song , Ge Mi Rui , Guo Bin
Published: December 2014

In order to study the influence of ultraviolet aging on the performance of different asphalt, we select two kinds of matrix asphalts of the same symbol and two kinds of modified asphalts of the same brand which are used widely in our country. After ultraviolet aging in different time, we use the samples to do the experiments of three indicators and DSR. The results show that the data of the modified asphalts after ultraviolet aging is more stable. Under the irradiation of ultraviolet light,the performance of modified asphalt is more stable.
The Study Summery of Segregation Characters for Asphalt Mixture Based on Discrete Element Method
Authors: Li Jing Yan
Published: December 2014

This paper summarizes the characteristics of the relevant theory research of asphalt mixture segregation at home and abroad in recent years, the use of discrete element methods, by summing up the results of different studies scholars, analysis of discrete element method to simulate Evaluation of asphalt mixture segregation as well as its advantages and disadvantages, numerical simulation to explore the direction of development.
The Summary of Warm-Mixed Flame Retardant Asphalt Acting Mechanism and Adhesion
Authors: Cai Tang Tao
Published: December 2014

Warm mix technology can effectively reduce construction temperature, save energy and reduce environmental pollution, and did not reduce road performance. Retardant technology can effectively inhibit the combustion of asphalt pavement to reduce the generation of smoke. Both at home and abroad for studies in general tend to macroscopic properties and other aspects of road performance, it is necessary to explore the mechanism of its microscopic. This article reviews the large number of domestic and foreign literature, this focus on thermal gravimetric analysis, differential analysis of several common scanning calorimetry and asphalt adhesion evaluation, get a lot of reliable test conclusions for relevant research scholars reference.
The Summery of Warm Mix Agent
Authors: Yao Shu Guang
Published: December 2014

Compared with hot mix asphalt (HMA), warm mix asphalt (WMA), which reduces the mixing and compaction temperatures and energy consumption and emissions, while maintaining the quality of HMA , is a new energy-saving and environment-friendly paving material, with a broad prospect.In order to develop the warm mix asphalt and prompt the sustainable development of pavement, some kinds of warm mix agent are summarized as follows.
The Mechanical Mechanism of Hulking Force Stable Principle of Surrounding Rocks in Soft Rock Roadway
Authors: Xue Wei Pei , Jing Lai Wang
Published: December 2014

This paper aims to reveal the important role of the hulking force in stabilizing the roadway. After introducing the three ultimate strength of the foundation rock upon, starting from the perspective of stress state, the article on the deformation area surrounding rock for a more reasonable division, and thus gives the main factors roadway deformation.Introduced in the basis of the three ultimate strength of the rock, from the perspective of stress state, deformation of roadway surrounding rock area to carry on the reasonable division, and then the main factors of roadway deformation is presented. Second, through the analysis of the formation of the hulking force, analysis of hulking force inhibition of surrounding rock creep mechanism of dynamic mechanics,and analysis of the hulking force to improve the effect of supporting mechanics mechanism. Describes the important role of the hulking force on the stability of surrounding rock. Finally, Huaibei Coal Mining Co., 8203 guobei roadway industrial test site, Demonstrates the effectiveness of the principle. Results of this study have important reference value to change the current research in deep coal mine deep soft rock and loose seam roadway support mechanism and technology.
Bridge Bearing Capacity Test and the Application Research Carbon Fiber Reinforcement Technology
Authors: Xie Xiao Qiu , Chen Zhen Fu , Guo Shan Shan
Published: December 2014

First, conducting static load tests for a 5 span bridge, then carry on application research for the bridge based on the embedded carbon fiber (CFRP) reinforced flexural reinforcement aiming at the shortcomings of its flexural properties, At last, the effectiveness of strengthening reinforced concrete beam that reinforcement by embedded CFRP has been discussed. The results show that embedded CFRP reinforcement beam can make full use of the characteristics of high strength of CFRP, which can improved obviously the capacity of the reinforced beam and the maximum increased capacity can reach 13.2%. In addition, the application of the embedded CFRP reinforcement technology has been discussed, which provides a meaningful reference for the development of the technology.
Dynamic Properties of Coupled Train-Bridge Interaction System
Authors: Si Xue Tong , Chen Ke Jian , Guo Wen Hua
Published: December 2014

This paper investigates the dynamic properties of each sub-system of a coupled railway train-bridge interaction system. Both spatial beam-plate model and spatial grillage model are built for a long-span dual-deck cable-stayed railway bridge by use of finite element method. The railway train is modeled as a mass-spring-damper system. Then free vibration equations are established based on the finite element models and then subspace iteration method is employed to calculate the dynamic properties for each sub-system. Results show that the spatial grillage model agrees well with the spatial beam-plate model in terms of mass and stiffness distribution. The spatial beam-plate model serves as benchmark solution and the grillage model as a tool for dynamic responses of the coupled system due to its computational efficiency. It also shows that first modes of both the railway train and long-span bridge are lateral direction, which indicates that the train may experience much response in lateral direction. Therefore attention should be drawn to the lateral running stability and safety of railway train due to the coupling effect between the bridge and railway train.
Working Performance Analysis of Reinforced Gravel Cushion on Soft Subsoil
Authors: He Jie , Meng Sen Song , Rao Qian Gen , Wang Ya Tao , Tang Lei Hua
Published: December 2014

Model tests are performed to study the working properties of reinforced and non-reinforced gravel cushion on soft subsoil. The effects are analyzed of reinforced materials on the bearing characteristic of the cushion. The stress field and settlement field are studied through the method of numerical simulation. The results show that: The bearing capacity of foundation with cushion increases significantly when the cushion is reinforced. Under the same condition, the effect of geocell reinforcement is better than geogrid reinforcement. The value of coefficient of subgrade reaction increases when the cushion is reinforced. The reinforced materials can adjust the stress distribution and settlement distribution of the cushion.
Seismic Performance Analysis of Continuous Rigid Frame Bridge with High-Piers and Long-Span
Authors: He Lou , Hu He Ping , Guo Chang Qing
Published: December 2014

The dynamic characteristics of Tukan Wujiang Bridge are analyzed numerically. The bridge, which is still under construction, is a continuous rigid frame bridge with high-piers and long-span in Wulong County, Chongqing, China. A spatial finite element model is established for the bridge with the finite element software ABAQUS. The natural vibration characteristics and effective modal participation mass of the bridge in the built-up case is obtained. The variation of dynamic characteristics of continuous rigid frame bridge subjected to the dynamic earthquake loading is studied, and the number of modes necessary to the vibration mode combination when applying the response spectrum method under the earthquake is obtained. In addition, the seismic response of the bridge is analyzed with both the response spectrum method and the time-history method, and the maximum response of structure under various probability of earthquake is obtained. The results of the two methods are compared. The comprehensive seismic performance of the bridge is analyzed and evaluated. The results show that the seismic performance of the rigid frame bridge satisfies the expected design performance.
A Study on Dynamic Performance of Concrete Filled Steel Tube Arch Bridges
Authors: Dong Xue Wen , Liu Qiu Yang
Published: December 2014

With the span of CFST (Concrete Filled Steel Tube) arch bridges getting much longer, the dynamic performance of them is becoming more and more advanced. In order to evaluate the structure of CFST arch bridges in a comprehensive way, it is necessary to take the dynamic performance of this kind of bridges into consideration. Methods of doing the dynamic analysis can be divided into two kinds: one is traditional theoretical analytical method, which is only suitable for simple arch bridge models; the other is FEM (Finite Element Methods), which is able to simulate the real structure and lead to more precise results. This paper attempts to study the calculation theory of free vibration characteristic of arch bridges through theoretical analytical method, and then it will do an empirical study on the dynamic performance of a CFST arch bridge by FEM to test the conclusion of theoretical study.
Concrete Filled Steel Tubular Arch Bridge Diseases and Protective Measures
Authors: Wang Gui Bing , Fan Mei Ting , Liu Yong
Published: December 2014

Bridge is the most modern transportation systems more see the composition of the form, the construction of bridge engineering helps to relieve the pressure on the ground transportation, realize the efficiency of regional traffic comprehensive improvement. Domestic vehicle number has doubled in recent years, frequent traffic activities make bridge is facing serious gravity load, and a variety of diseases, threatening the safety of the bridge deck vehicle. Construction units in construction phase, should pay attention to the maintenance of bridge structure disease treatment, put forward a practical and reliable solutions. Half through bridge were examined in this paper, based on an engineering example, analyzed the common deterioration problems of concrete filled steel tube arch bridge, the corresponding protective measures are put forward.
Study on Anti-Overturning Design of Ramp Bridge Continuous Beam
Authors: Zhao Jia Mei
Published: December 2014

Currently, a lot of ramps adopted continuous box girder with single column pier structure in a bridge design. If the structure is mishandled, the box girder is likely to cause overall overturn under overloaded vehicles. The cause of overturn is analyzed and calculated, and through comparing the anti-overturning ability of different substructures, the key design points are put foreword to provide some experience for the design.
Thermal-Structure Coupling Damage Analysis for the Main Tower of Long-Span Suspension Bridge
Authors: Wang Bing , Huang Qiao , Huang Ping Ming , Mei Kui Hua
Published: December 2014

Long-span suspension bridges are usually affected by the ambient temperature and the moving load during the service life. The concrete tower has lots of visible cracks and other diseases. In this paper, Fengdu Yangtze River Highway Bridge with main span of 450m was taken for example. Based on the thermal structure coupling analysis for the main tower, the elastic damage model for concrete was introduced. The bridge damage field was calculated under different temperature load conditions, which illustrated the reasons of cracks objectively and effectively. The results can provide reference for the future analysis on crack propagation behavior of concrete structure under the temperature effects.
Research on Field Management of Relay Protection Device Based on RFID Technology
Authors: Xiao Zhi Gen , Tong Jie , Wang Yang , Gao Xi
Published: December 2014

In consideration of the slow development of informatization level of relay protection device system business process handling at present, upon the request of relay protection device full life cycle management, this text has put forward the anti-metal RFID technical system for relay protection device field management on the basis of RFID technology, covering the lectotype of tags and read-write device, tag encapsulation, safety protection method. which contributes to settle the problems in relay protection device management, avoid waste of resources, save the economic cost, significantly raise the relay protection management level and working effects, and improve the power grid running performance.
Predictive Direct Capacitor Power Control Based on Fractional-Order PID Controller of Three-Phase Voltage Source PWM Rectifiers
Authors: Zhang Xiao Ying , Ma Xue Jie
Published: December 2014

In order to improve the dynamic performance of three-phase voltage type PWM rectifiers predictive direct capacitor power control, in view of the deficiencies of slow response and poor dynamic performance of present PI control of load disturbance, the fractional order PID controller of the DC side voltage control section is introduced to the capacitive power control. The new predictive direct power capacitor control strategy has been proposed. It consists of two parts: the outer loop of voltage square model of fractional order PID and the inner loop of capacitor power and the reactive power in network side. Through decoupling control with the prediction control of the inner loop and the voltage outer loop of fractional PID, the dynamic performance of a direct power control has been improved. The Matlab/Simulink simulation results prove that the system has better dynamic performance, robustness and response speed of direct power control.
Residual Life Assessment of Power Transformer Based on Random Fuzzy Theory
Authors: Wang Si Yu
Published: December 2014

Both the cost-effective operation of power systems and reliable operation are inextricably linked with the transformer life assessment. This paper analyzes the composition of the transformer life, life assessment factors and existing assessment methods. Based on factors of the current life assessment and problems of assessment methods, the paper analyzed the importance significance of uncertainty in the transformer life assessment and proposed the transformer remaining life assessment model, and methods based the random fuzzy theory. Assessment results can provide the basis for the transformer maintenance and help safe and economic operation of power systems.
Characteristic Analysis of Ship Transformer Magnetizing Inrush Current and its Suppression Method
Authors: Xiang Dong , Yu Fei
Published: December 2014

Medium voltage in the electric power system of ship typically is powered by a large capacity transformer for low voltage electrical apparatus. When switching on, the primary side of transformer will produce very large current, which would endanger the safe operation of power for ships. The mechanism and characteristics of magnetizing inrush current is analyzed when the transformer switches with no load. We think that the reason caused magnetizing inrush current is transformers saturation. Pre-excitation is presented through a small volume transformer magnetizing method of suppressing the inrush current of transformer and validated by simulation and experiment.
Extension Comprehensive Assessment of the Operating State of Turbo-Generator
Authors: Wang Ming Dong , Xu Zhong Hui
Published: December 2014

The assessment of operating state of the generator is an important means to guide the generator overhaul and improve the reliability of power system operation. The traditional pattern is gradually replaced by the real time state assessment model, this paper which is based on the multilevel nature and multivariate of the generator information establishes the state assessment system of the generator and uses extension level assessment method to assess the comprehensive state of the generator. Examples show that the method has a strong rationality and effectiveness.
Application of Fuzzy-PI Controller in the Asynchronous Motor
Authors: Li Guang Zhong
Published: December 2014

This paper proposes an induction motor variable frequency speed control system based on fuzzy-PI self-tuning. The system includes coordinate transformation modules, vector control modules, space vector pulse width modules, fuzzy-PI self-tuning speed regulator, excitation current and torque current PI regulator. Because the speed regulator controlled by the fuzzy-PI self-tuning has better control effect than traditional PI. The performance can be reflected by the shorter response time, smaller overshoot. In addition, when the load torque changes, the electromagnetic torque changes more smoothly and does not have large fluctuations.
Summary of Micro-Grid Control Technology
Authors: Jiang Jun Jie , Ju Rong
Published: December 2014

The inherent drawbacks of the traditional power grid and distributed energy resources are increasingly restricting the development of power systems. The micro-grid integrating of a variety of new green energy and having perfect self-control can meet the load demand and achieve sustainable development of environment at the same time. The basic definitions, system structure, the control strategy and the last research of micro-grid through a comprehensive literature review are presented. The literature analyzes the power supply control, power quality control and overall control and points out the characteristics and deficiencies of each control mode. Finally, some prospects of micro-grid on research findings in China were proposed.
Concept of URT Traction DC Microgrid and its Application Feasibility Study
Authors: Shen Xiao Jun , Yu Chuan Bao , Zhao Shi Min
Published: December 2014

Firstly, based on the structure of urban rail transit traction power supply system and the characteristics of typical dc microgrid, a concept of urban rail transit traction power dc microgrid was proposed in the paper, and the feasibility of photovoltaic generation system, fuel cells generation system and energy storage system gridded to urban rail transit traction power supply system were studied; and then the functions and advantages of the proposed traction dc microgrid were surveyed from energy-saving and power supply reliability; finally, based on analyzing the electrical characteristics of urban rail transit traction catenary, some key issues of urban rail transit traction dc microgrid technology to be solved were discussed.
System Modeling and Simulation of Intentionally Islanded Reconfigurable Microgrid
Authors: Khalid Muhammad Shoaib , Lin Xiang Ning , Sun Jin Wen , Zhuo Yi Xin , Tong Ning , Zeng Fan Tao , Waqar Asad
Published: December 2014

Microgrid reconfiguration plays important role in improving continuity of power supply especially in the event of fault within the power grid or microgrid connected to the medium voltage distribution network. Due to the fault in power grid, intentional islanding through static switch is one possible solution while, fault within the microgrid emphasizes microgrid reconfiguration to recover maximum affected loads in each isolated zone. This paper presents multiagent system based (MAS) approach in order to withstand stably and autonomously in the event of fault within microgrid or power grid. MAS approach includes negotiation agent (NA) for the entire microgrid and bus agent (BA) for each bus within each zone. NA is responsible for selecting a Dominant-BA from each zone and prioritizing the zones by using region weight coefficient (RWC) method. Zone having excessive power will recombine with the zone having lesser power for maintaining power quality of sensitive and less sensitive loads, while normal loads are shed.
The Development about Multifunction Merging Unit Used in Smart Substation
Authors: Fan Chen , Ni Yi Min , Zhao Guo Qing
Published: December 2014

The merging unit is used to realize the digitalization and sharing of the data of process and is widely used with the electronic voltage transformer (EVT) and electronic current transformer (ECT). As the construction of smart substation which is presented by the state grid company of china, a serial new requirements and needs about the merging unit are proposed and the merging unit which only sends the sampling value can not meet it. The new demands of the smart substation are analyzed, The design of hardware and the implement of the function are presented. The multifunction which including the model of sampling, the data catenation, the acquisition of status signal through GOOSE , the voltage parallel and switching and the synchronization of device are analyzed in detailed. At the end, the function of intelligent diagnosis and debug is introduced. The device has been used in the project of smart substation and takes good effect.
The Improvement about the Reliability of Sampling Based on Process Bus in Smart Substation
Authors: Fan Chen , Ni Yi Min , Dou Ren Hui , Xu Xin , Yao Zhi Qiang , Zhao Guo Qing
Published: December 2014

The sampling based on process bus is not widely used in smart substation because there are still some technical problems on synchronization, the design of network architecture and sampling data receiving and processing areas. There are some researches about the problems are carried out, but they only focus on part of them and cannot give the whole solution. In order to improve the reliability of network sampling, a new system method which includes all the segments of the sampling based on process such as the synchronization of data acquisition, data transmission, network optimization and data processing are presented. In the data acquisition segment, the synchronization based on IEEE1588 is provided, In the data transmission segment, a new hardware architecture which is based on FPGA+DSP+VxWorks is described, in the segment of network optimization, the topology structure and virtual LAN are suggested. At last, the automatic resampling is proposed in the data receiving and processing segment. It will be useful to improve the reliability of sampling based on process bus in smart substation.
The Research of Electronic Transformer Data Synchronization Method Based on Newton Interpolation
Authors: Liu Tong Yin , Gao Liang , Zhang Yong Dong
Published: December 2014

Data synchronization of electronic instrument transformer is introduced. Synchronization method commonly used are analyzed in aspects of their advantages and disadvantages, such as interpolation synchronization, impulsive synchronization method; Then, a new approach based on Newton interpolation is presented, and the simulation and error analysis are given. The theoretical analysis results show that this method can reach to the same precision with Lagrange interpolation which is accurate in synchronization of harmonic components and obtain the synchronized data fast. Finally this paper sets equal interval sampling and non-equal interval sampling data, and then calculates maximum error in the case of the steady state and transient state respectively by using Matlab. The simulation results proved the feasibility of this method and its engineering practical value.
The Research of the Distributed Grid Model Maintenance Technologies Based on Logical Unify
Authors: Zhang Hong , Zhuang Wei Jin , Feng Shu Hai
Published: December 2014

To solve the model consistency problem between the power systems which use model combination, and to meet the needs of different models proposed for the grid, in this paper is based on the research of whole grid model information and application requirements, and proposed the method of the model maintenance based on logical unify. And this paper describes the "two deployment, unified management, partition maintenance, on-demand services" architecture design, and detailed model business processes and key technical details. Finally, through prototype software verification of the research, we prove that these model maintenance and management technologies can achieve the whole grid model to efficiently store and manage, and can adapt to various model requirements.
Power Purchase Optimization Model Based on the External Cost of Power Generation
Authors: Liu Dun Nan , Chen Qing Qi , Luo Chao Chun , Li Xiang Qi , Wang Qiang
Published: December 2014

With a significant crisis of energy and environment, low-carbon and clean power resources have gotten strong support from the government. As wind power, solar power and other new energies develop rapidly, the social and economic benefits become increasingly apparent. A new power purchase optimization model is applied in this paper that takes external cost of power generation into account, translates the external cost into economic cost and then analyzes the optimal power purchase policy. In the end, based on the power purchase data of a provincial grid in 2013, this paper studies the optimal power purchase order to prove the feasibility of the optimization model.