bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear Behaviors of Submerged Floating Tunnels under Seismic Excitation
Authors: Shi Chun Xia , Domaneschi Marco , Martinelli Luca
Published: November 2012

The Submerged Floating Tunnels are one new type of infrastructure, representing a challenge in structural engineering, both on the theoretical and operational fields. In this paper, a 3D finite element analysis procedure is developed accounting for material and geometrical nonlinearities, soil-structure interaction and multiple-support seismic excitation. A comparison between dynamic response in case of elastic and inelastic material behavior of the anchor bars is given, which shows the beneficial effect of this source of energy dissipation. Furthermore, the effects of introducing dissipation devices for restraining the tunnel axial motion have been investigated as well. Besides this, the earthquake transmission through water (seaquake) is here introduced as an additional hydrodynamic loading on the tunnel. The ensuing increase of loading in the tunnel indicates that a significant role is played by this loading source and highlights the need of further investigations on seaquake effects.
Deflections of Steel Reinforced Concrete Beams Considering the Bond-Slip Effects
Authors: Cao Xiu Li , Ye Gang , Gou Hai Gang
Published: November 2012

Bond-slip performance between section steel and concrete has influence on deformation of steel reinforced concrete beams based on results of experimental studies. Current standards on steel reinforced concrete structures do not involve bond-slip effects when calculating the deflection of steel reinforced concrete beams and this is not valid exactly. This paper describes a new method of deflection calculation for steel reinforced concrete beams, which considering the bond-slip effects on deformation. Deflection of steel reinforced concrete beams are divided into two parts: deflection of steel reinforced concrete beams under loads considering the fully bond between steel and concrete, and the additional deflection caused by the bond-slip. The sum of the two parts is the total deflection. Results show that the proposed method in this paper fits with experimental results.
A Framework of Assessing Remaining Fatigue Life of Aged Crane Structures
Authors: Qi Kai , Wang Wei Xiong , Wang Xin Hua , Jiang Ai Hua , Liu Bai Qing
Published: November 2012

The fatigue life of crane steel structure will inevitably decrease in the course of work, which directly affects the work of crane. So the correct fatigue life evaluation is necessary. Based on crack propagation theory, a framework of assessing remaining fatigue life of crane metal structures is built in this paper. Moreover, in order to descript the analysis process, an example about fatigue life estimation of a shipbuilding gantry crane whose maximum hoist 100 ton was shown. During assessment of remaining fatigue life of aged crane structure, some important indexes were inspected such as corrosion，strength and defection in focused weld joints, besides of finite element simulation of structure. The results can also be used to evaluate the whole metal structure of this crane.
Temperature Control Measures Optimization of RCC Gravity Dam
Authors: Huang Shu Ping , Fu Jian Yun , Li Yan Cai
Published: November 2012

With the continuous development of dam construction technology, the RCC dam becomes one of the most popular types of dam in the world with its unique advantages. Temperature control measures research is one of the key issues of design and construction of mass concrete structures. How to choose the proper temperature control measures to prevent concrete cracks becomes the important problem of dam construction technology. In a RCC gravity dam, the climate environment is so severe that a single temperature control measure can’t meet the requirements of temperature control and crack prevention. In this paper, 3D FEM simulation analysis is used to calculate temperature field and thermal creep stress field during the whole construction process. According to the simulation results, the temperature control measures design of the dam has been comprehensively evaluated and the temperature control measures of this project have been put forward.
Failure Characteristics of Transmission Towers Subjected to Downbursts
Authors: Wang Jin Wen
Published: November 2012

Downbursts are recognized as a significant threat to safety of transmission towers. The difference between downburst and boundary layer wind profiles will lead to different failure modes and regions of damage of a transmission tower. To account for differences of wind profiles and failure modes, the different design wind loads are proposed, and a novel analytical framework is formulated for checking the section wind-resistance capability. The framework is useful for checking strength of transmission towers under downbursts. It has been found that the peak values of section moments exceed the ultimate section moment capability at about a third of the tower height under downbursts, while failure occurs in the bottom panel of tower under boundary layer winds. The results are consistent with the fact that regions of damage for most collapsed high-rise transmission towers under downbursts were indeed in lower-middle height of tower.
Simulation Study on Construction Process of Complex Spatial Steel Structure Based on the Construction Mechanics
Authors: Zhang Wei Lin , Wu Zhi Xin , Chen Bai Hui
Published: November 2012

The construction process of the large span spatial steel structure was studied by finite element method and the time-varying mechanics. The construction process of complex spatial frame structure was divided into the installation and dismount supporting phase, and each stage was divided into 15 steps in which mainly simulated and analyzed the whole construction process by "life-death" element. The critical control points of each construction step were identified, the stress state, interval value and the maximum stress in the structure of each construction condition were conformed; rod deformation in construction process was analyzed in construction program. The result showed that the large span spatial steel structure construction scheme was numerical simulated and calculated by the method of finite element analysis and the mechanical state, deformation and safety of building structure were predicted accurately during construction.
Numerical Simulation of Mean Wind Pressure on the Roof of Yantai Gymnasium
Authors: Meng Xi , Gao Ri , Zhang Hai Jun
Published: November 2012

In order to determine the distribution of wind load on the roof, wind tunnel test and numerical simulation are both carried out. Then the distribution of mean wind pressure under different wind directions is obtained and the features of mean wind pressure are also analyzed. The datas show that wind pressure distribution of the roof is predominantly negative pressure; only a small area of windward side is positive pressure distribution. The peak of negative pressure appears at the roof ridge or windward long eaves, and varies as changes of wind direction. Meanwhile, the comparison between the results of the numerical simulation and wind tunnel test shows that the distribution law of both is almost the same, but in some areas that flow separation is serious, the error is larger. Then the reasons for the error are discussed.
The Structure Statics Analysis and Optimal Design of Hydraulic Support
Authors: Xue Ke Min , Huang Pu , Li Ping , Chen Long , Liu Wei
Published: November 2012

Hydraulic support is a key equipment of synthesis mechanization caving coal and safe production in modernization coal mine. In this paper, the parametric finite element model of ZZ10800/22/45 thin bedrock hydraulic support top beam was established by ANSYS Workbench. The distribution of stress and displacement were obtained by static analysis under the both ends load working condition. According to the FEM calculated results, the optimized mathematic model was developed and the hydraulic support top beam was calculated based on Goal-Driven Optimization(GDO) to propose a lightweight design. It is shown that the effects of lightweight design are obvious, as the optimized plan is in accordance with actual work condition by comparing the FEM check verification. This would provide a guidance and reference value for the research and development of hydraulic support products in the future.
Affecting Slope Stability Condition of Structure and Engineering Geology Overview in Xiao-Wan Project Region
Authors: Zhang De Sheng
Published: November 2012

In order to sum up structure geology and engineering geology of project area in Xiao-wan by the numbers, the author summarizes it on the base of pre-researchers production. The summarizing includes two parts, that is structure geology and engineering geology, and the paper stands out the keystone and core content respectively. The structure geology content consists of zone of fracture, fault, joint, structural stress field and seism. However, engineering geology summarizing includes terrain, lithology, geological action, hydrogeology and alteration of rock body and so on.
Evolution of Constrained Layer Damping Using a Modified Cellular Automata Algorithm
Authors: Li Xian Bing , Wang Gang , Wen Ji Hong , Wen Xi Sen
Published: November 2012

In order to improve the treatment efficiency of the constrained layer damping (CLD), it is meaningful to have a study on its layout optimization. This paper based on current research of Cellular Automata (CA) algorithm for CLD optimization, points out that the current application of CA algorithm is less efficient, considering that adding or deleting a single CLD patch almost does no change to the entire structure, then makes a simplification and modification of CA algorithm. With the aim at improving the structural modal loss factor, this paper uses the current CA algorithm and its modified algorithm to optimize a partial CLD plate. The results have shown that the modified CA algorithm for CLD optimization can not only substantially increase computing efficiency, but to some extent, improve the optimization effectiveness.
Reliability Analysis of Arch Dam Considering Temperature Change Field
Authors: Yang Ming Zhu , Wu Qing Xi , Lu Jun
Published: November 2012

The loads on the arch dam and the materials physical properties of the dam and the bedrock are uncertain, and can be described with random variable. Due to the huge volume, the complex structure of the dam and excessive random variable, the reliability analysis of the dam is difficult. The dam is a higher order statically indeterminate structure, and the variation of the temperature obviously affects the stress and displacement of the structure, therefore, it is very important to consider the randomness of the temperature change load in the reliability analysis of arch dam. Based on the analysis of the stable temperature field, temperature rise and temperature drop field of the dam, the calculation method of temperature change field is further studied and applied in the reliability analysis of the arch dam. Considering random variables such as temperature change, water pressure, elastic modulus and strength of the materials, the stress and displacement of the arch dam and bedrock are calculated with a three dimensional finite element method, the limit state equations are established by RSM. Then the tension and compression reliability of the arch dam are analyzed using gradient optimization method. The results indicate that the temperature change field significantly influences the tension and compression reliability of the dam, and should be seriously considered in the reliability analysis of arch dams.
Research on the Concrete Dam Damage and Failure Rule under the Action of Fluid-Solid Coupling
Authors: Sun Ke Ming , Li Zan , Bagale Moj Raj
Published: November 2012

This paper evaluates the stability of concrete dam under the action of fluid-solid coupling in the two working conditions of water level raising and rainfall intensity increasing with the method of strength reduction, and the conclusions are revealed as follows: The unstable failure of dam always starts from the slope base, the crack on the slope top and the creep slip in the slop base developed, which led to the gradual destruction of the dam and formed the slip surfaces through the dam; the safety factor of the concrete dam reduced and the potential slip surfaces moved to the inside of the dam with the water level raising; the more rainfall intensity, the larger plastic yield region and the lower safety factor will be, and the dam slip surfaces transferred from the base of slope to the inside of the slope top gradually.
Seepage-Stability Analysis of a Mine Tailings Dam in Yunnan Province Based on ANSYS
Authors: Ma Shu Qi , Cai Si Jing , Guo Miao
Published: November 2012

As a major hazard installation in mine the safe and effective running of a tailings dam is very important, therefore the stability analysis of tailings dam is necessary. In order to evaluate the effect of seepage on stability of mine tailings dam, in this paper, a numerical model of a tailings dam in Yunnan province was established by using ANSYS software. It was focused on the dam seepage field analysis and the seepage-stability analysis, and on using the strength reduction method to derive the safety coefficient of the tailings dam. The results were proved reasonable and could be used to provide helpful guidance of dam safety.
Stability Analysis of Sinkhole Considering Groundwater Level Fluctuation
Authors: Huang Shan Ming , Liu Yu Chuan , Wang Cheng Cheng
Published: November 2012

The Method of Finite Element Method Strength Reduction is used to numerical calculate and analyse the subgrade with soil cave, by considering the influence of groundwater level fluctuation in its stability. Nondimensionalize the effect factors, and draw the stability curve to get the regression curve, then make the result regression coefficient directly to the project cases. The result shows that under the weight of the subgrade, the subgrade with soil cave is damaged by that the soil around the soil cave is sheared. The more the value of is, the larger the stability coefficient is, and the higher groundwater level is, the better the stability of the subgrade with soil cave is. With the value increases, the region of stability expands
Research on the Selecting Control Sections of Internal Force Envelope by Simulation
Authors: Lu Hai Xiang , Diao Jing Hua , Li Zeng Zhi
Published: November 2012

The simulation optimization of internal force envelope in plane bar structure subjected to complex moving loads, including arbitrary concentrated force, concentrated couple, linearly distributed force and etc, was mainly discussed. By means of Vsap2011, the plane bar structure analyzing software, the effects of internal force envelope’s control sections on the solving precision of internal force envelope were analyzed. The research had reached to some important conclusions that in order to the obtain higher solving precision of internal force envelope, the element passed by moving loads should be divided by steps; more than enough dividing points should be inserted between load acting points for the element arbitrarily distributed with live loads; the element without any loads should be divided by defined interval when its both ends are rigid-jointed, while it should not be divided when its single or both ends are hinged-jointed.
The Numerical Analysis and Field Measurements of the Shield Tunnel Passing through the Pipeline Groups
Authors: Liu Guan Shui , Sun Lian Wei , Wang Bo , Wu Shi Ming , Hong Cheng Po , Hong Qi
Published: November 2012

In this work, research was carried out based on the shield tunnel of metro line 1 in Hangzhou. The construction of this tunnel beneath the sewage pipelines, which have large diameter with water pressure. The project studied in this treatise is relatively rare in China in terms of sewer pipes, the number of sewers, spacing between shield and sewers and the crossing times. A numerical model was established to analyze the construction of metro across the sewage pipelines with water pressure, taking the interactions between tunnel, pipelines and soil into account. The stress of pipelines, settlement of pipelines and ground during the crossing process were calculated. The finite element results were compared with measured results to verify the reliability of numerical results. Some meaningful results were achieved.
Monitoring of Large Section Tunnel Crossing Qiantang River during Operation Period
Authors: Liu Guan Shui , Li Zong Liang , Wu Shi Ming , Yu Lu Qing
Published: November 2012

The foreign precision monitoring equipment was used for long term health monitoring in the large diameter tunnel of Hangzhou Qingchun-road. Based on field monitoring data, the force and deformation of the large section crossing-river tunnel during operation period were summarized and analyzed. A detailed analysis of the effect of tide and scour on the tunnel interface force and tunnel settlement were given. Data shows accumulations of both longitudinal settlement of tunnel segments and the earth pressure distribution around the tunnel lining under the loads of both traffic and tide which results in soil disturbance in the construction period. The settlement becomes stable after about six months. The substratum has a great influence on the longitudinal settlement of tunnel segments. The settlement of tunnel invert in sandy substratum is obviously affected by the tide of Qiantang River for short time, while slight changes appear in the deformation of tunnel diameter, stress of steel bar and earth pressure distribution.
Design and Construction of Locking Steel Pile Cofferdam of South Tower Pile Cap for Taizhou Bridge
Authors: Wu Zhen Hong , Xun Yong , Gan Ya Nan , Wang Chun Hua , Li Ying , Tang Shi Chen
Published: November 2012

South tower of Taizhou bridge is located in complex hydrogeological conditions,the amount of its excavation engineering is large.Combined with the successful application of locking steel pipe pile cofferdam in the south tower project of Taizhou Yangtze Highway Bridge,from comparison and demonstration, scheme design and construction, process monitoring to introduce locking steel pipe pile cofferdam in detail,using the classical method and the M method to design and calculation for supporting structure.Construction practice shows that the design and calculation of support structure is accurate,locking steel pipe pile fully played its function of sealing,it also has great rigidity, good integrity strong bending resistance and other advantages.The successfully application of this technology,promoting the technological progress of bridge foundation constructionthe in deep water or complex geological conditions,it provides a basis for the construction of similar projects in the future.
Modal Analysis of a Flexible Beam Attaching Multiple Absorbers
Authors: Li Jun , Liu Chu Sheng , Li Feng , Wang Zhong Xian
Published: November 2012

Structural wave propagation in beam structures can lead to unwanted noise transmission and radiation. Dissipation effects of the multiple absorbers have been proved. This paper presents a model of flexible beam with complex boundary conditions and this model with multiple attaching absorbers which are used to dissipate energy of main structure. The beam model are formulated by linear Lagrange equation and discretized by the Ritz method and the model with multiple absorbers is introduced by substructure method. Consequently, the mass matrix and stiffness matrix are obtained and numerical simulation is processed. Natural frequencies with corresponding modal mode of are obtained. Comparing the results between two models, the absorbers can enhance the natural frequencies effectively and the quantities of absorbers agree with the orders of frequencies and corresponding modes.
Studies on Dynamic Characteristics of a Typical Model of Asymmetric Continuous Rigid-Frame Bridge under Different Ratio of Middle Span to Side Span
Authors: Liang Tian , Dong Jun , Xiang Xue Jian
Published: November 2012

Due to the limit of complicated landform in western China, a typical continuous rigid-frame bridge could be easy to be built, especially for asymmetric spans. Based on the engineering background of Sinan Yantou river Bridge in Guizhou province, dynamic characteristics of the type of bridge are studied in this paper. Firstly, by using Midas/Civil, 6 different models are established and their modal analysis could be done while it is considered that the beam of left T-shaped is gradually decreasing under the same height of piers. Then, all seismic responses are calculated by using response spectra method. Finally, the computational results are discussed and some key features are summarized. Our investigation will have some valuable references for seismic analysis of the same style bridge.
Field Test and Analysis for the Static and Dynamic Behaviour of Multi-Box Steel Concrete Composite Girder Bridge
Authors: He Yu Liang , Xiang Yi Qiang , Ke He Xin , Liu Li Si
Published: November 2012

Taking the four-span 40m simply supported multi-box steel-concrete composite girder bridge in the ProjectⅡ of Qiushi Expressway in Hangzhou as the background, this paper analyzed the static and dynamic behaviour of the bridge by FEM, then finished a field test study for the bridge. Finally, comparing the test values with the results obtained from FEM analysis, it was verified that the rigidity transverse beam method with infinte stiffness is also adaptive to caculating and predicting the load transverse distribution of the multi-box steel-concrete composite bridge. Steel diaphragm and stiffening rib of the multi-box steel- concrete composite bridge can improve the flexural capacity of bridge to some extent, so these contributions should be reasonably considered during the design stage in order to reduce the engineering cost. The measured modes agree well with the results from FEM.
Design Application in Suspender Tensile Force of Tied-Arch Bridges Based on Inversion Optimization Method
Authors: Sun Xue Xian , Wang Yong , Chen Feng
Published: November 2012

Taking an actual tied-arch bridge project as the background, this thesis has a system static analysis by building up the finite element analysis model with Midas/civil, a large-scale FEM software, then establishes a mathematical optimization model for the back analysis to suspender tensile forces through two optimization schemes. Scheme one takes the reasonable bending moment distribution and minimum moment stain energy as the optimal control objective function to inverse analysis. Scheme two takes the bending moment distribution of dead load as the control objective of inversion optimization analysis, when the difference of the positive and negative absolute value is the minimum in the moment envelope under the load combination, which thinks about live load on the finished state. Through comparing the analysis results, the thesis demonstrates that the inversion optimization method could fulfill the requirement of factual project and be widely used for determining suspender tensile forces of tie-arch bridges.
A New System for Dynamic Deflection Measurement of Highway Bridge
Authors: He Xian Long , She Tian Li , Zhao Li Zhen
Published: November 2012

The bridge deflection measurement is an important component to the bridge examination and a important target to the security appraises. Using Slope sensor to test the Dynamic deflection is a good way for highway bridge deflection detection. In this paper, we develop a new slope sensor and new theory to fast calculate deflection from slope angle. It has been use to detect the dynamic deflections of songhuajiang bridge on Harbin-Changchuen highway when car cross at kinds of speed. The test result indicates: comparing with the measurement results of photoelectric deflection detection system, the dynamic deflection measurement results of slope sensors are much closed. Their deflection curves are also similar. The result also shows: Using our slope sensors to test highway bridge dynamic deflection can get precise results and can satisfy the highway bridge deflection testing request. It is also very easy to use. You can finish the testing easily and do not stop the traffic.
The Bridge Health Monitoring System Based on SCM
Authors: Zhu Xiao Ling , Chen Xue Li , Yao Ying
Published: November 2012

It plays a very important role for the national economy and social security to gain bridge structure characteristic signal scientifically, to evaluate the bridge health condition and to guarantee long-term safe operation. The bridge health monitoring system is a major technique to settle those problems, which is in charge of working status inspection, health detection and alarm via field data, providing a solid safeguard for well-balanced operation of the bridge as well as the security of people’s life and property. This paper proposes a bridge health monitoring system based on wireless sensor network, which collects information of each mechanical part of the bridge. Sensor nodes form a smart measurement, and control network through self-organization, then transmit to the control center through network, by this way we can achieve real-time automatic remote monitoring on the bridge health.
Analysis on Potential Alkali Reactivity of the Aggregate and its Inhibiting Method in Dam Concrete of a Hydro Project
Authors: Ye Wen , Yang Yong Min , Wang Heng Chang
Published: November 2012

The aim of this paper is to systematically investigate the alkali activity of the aggregate selected from a stockyard, and examine its supression method, before pouring roller compacted concrete into the hydro project in Lechang gorge. Samples of natural sand, sandstone and limestone will be analysed through comprehensive petrographic method and accelerate mortar bar method. The results showed that natural sand is the aggregate without activity; sandstone core contains some wave shape with extinction characteristics of deformation quartz, because of active alkali-aggregate and the harm expansion of mortar, which is the aggregate with potentially harmful alkali-silicate reaction; wave shape and elastic deformation of the alkali in limestone are also the harmful element in concrete. The addition of level 1 and level 2 fly ash both has the ability to inhibit the reaction between alkali and silicate, and can control expansion rate of sandstone under 0.1 %.
The Iron Ore Dosage of Cement Base Composite Material Mechanics Effect on the Performance of the Experimental Research
Authors: Huang Zhi Qiang , Pi Xin Meng , Liang Fang
Published: November 2012

To study the problem of the relation between the performance of cement base composite material and the dosage of the iron ore. Because of the gradually reducing of natural sand, people will pay attention to the use of the iron ore. The study shows the effect of the iron ore dosage of cement base composite material on the performance based on this condition. We mix with different dosage of iron ore in the test. Try to do the flexural strength test and the flexural strength is the highest of all when the dosage of iron ore is 60%. At the same time try to analyse the energy and we find the energy needed in the process of fracture is highest when the dosage of iron ore is 60%. So we can choose the 60% the iron ore used in practical application instead of the natural sand.
Ultimate Flexural Bearing Capacity Research Based on Carbon Fiber Sheet to Reinforce Rough Sleeper Beam
Authors: Li Zhong Long , Wu Hong Lin , Liu Zhen Yu , Xu De Jian , Gu Hong Jiang , Zhu Xiao Di
Published: November 2012

In this paper, it makes a preliminary study on the material of carbon fiber sheet to reinforce rough sleeper beam in order to enhance the magnitude of ultimate flexural bearing capacity. Considering the actual construction technology and environment, four reinforced concrete sleeper beams are used to experiment simulation to study the influence of carbon fiber sheet to ultimate flexural bearing capacity of reinforced concrete structures. Experiment results show that pasting two layers of carbon fiber sheet under reinforced concrete beam can have about a 25% increase in flexural bearing capacity.
Experimental Study of the Foam Agent in Lightweight Aggregate Concrete
Authors: Wang Yong Wei , Tang Bai Xiao
Published: November 2012

Different content of foaming agent in the lightweight aggregate concrete test, the apparent density and compressive strength of concrete assessment indicators. Studies have shown that, with the dosage increase, the variation of the apparent density of the concrete is first decreases and then increases when the content is 0.8kg/m3 dry apparent density minimum; as the foaming agent content continues to grow, dry apparent density continues to increase, but the magnitude of increase is less obvious. At this point, its 28 days compressive strength of only 0.7MPa, the wall strength of the material does not meet the insulation requirements. Taking into account the apparent density and strength of wall insulation materials, requirements, test data to determine the optimal dosage of the foaming agent should be 0.4 ~ 0.6kg, to determine the content of foaming agent in the lightweight aggregate concrete of the most good range.
Numeric Analysis of Size Effect on Mesol Concrete Random Aggregate Model
Authors: Liang Xin Yu , Dang Fa Ning
Published: November 2012

In order to research that statics properties of concrete cylinder sample are influenced by micro-concrete material heterogeneity, by random aggregate models generated by different random number were established. By fixed aggregate size and constantly changing of the sample size, the concrete numerical model was simulated and Strength change of concrete samples was analyzed .So that strength influence of the aggregate location of the concrete random sample was study. Calculation shows that: the strength of concrete has been little effect by the aggregate random location, the size effect on concrete has been changed regularly, with the size effect ratio coefficient of aggregate and sample gradually increasing, the error square sum of strain was reduced and the brittlness of the samples becomes obvious.
An Energy-Efficient Cluster Head and Router Selecting Protocol for Wireless Sensor Networks
Authors: Huang Shou Zhi , Zhao Xue Zeng
Published: November 2012

Wireless sensor networks (WSNs) based on ZigBee technology are currently popular low-energy, low-cost, short-distance communication technologies that can be applied in many areas, such as industry, environment, agriculture, etc. Energy efficiency is one of the most important research points for WSNs. In this paper, we analyze the existing WSNs protocols, especially LEACH, and propose an energy-efficient cluster head and router selecting protocol (EECRS). EECRS combines both cluster-based and energy-threshold routing protocols to balance the energy consumption of the sensor nodes in the whole network in order to extend the network lifetime. And through the simulation via NS2 software, it is shown that EECRS improves the network performance, network lifetime and data received per energy mount consumption, compared with LEACH protocol.
The Urban Objects Classification Based on LiDAR 3D
Authors: Huang Zuo Wei , He Shu , Qiu Luo
Published: November 2012

The Lidar technology can quickly acquire three-dimensional information of earth surface with high precision.As a new technique of data collection acquisition,it has been gradually applied to many industry. The classification on point cloud is the premise and key step to the feature extraction and the model building of objects. Based on LiDAR 3D and ANN This paper presents a classification method mainly suitable for the urban’s typical objects. It takes the changsha city as the study area,to verify the effectiveness of this method.The result shows that,this classification method successfully classifies the categories of the ground,buildings,trees and bare lands.
Air Quality Analysis and Evaluation in Jinan Based on Field Measurement
Authors: Lei Li , Zhang Heng , Wang Jian Zhang , Wu Xiang Guo
Published: November 2012

At present, the air pollution problem has attracted extensive attention at home and abroad. Based on the field measurement, the authors conducted a multi-day and multi-point monitoring for the air quality indexes in Jinan City. Through a detailed comparison and analysis, a preliminary assessment of air quality status quo in Jinan City were finished. The situation of atmosphere pollution is closely related to the terrain, industry layout and urban planning of Jinan. The most prominent problem is that PM10 and TSP pollution are so severely that over standard rate reaches 100% for several monitoring points. The pollution of SO2 is fine in general, and NO2 pollution level is lighter than SO2. The pollution of CO is rather severe, and the situation of exceeding standards exists at every point. The pollution of NMHC is the weakest one and no indexes go beyond the standards.
Design of Three-Phase Multi-Function Energy Meter Based on Measurement Chip RN8302
Authors: Zhang Xu Hui , Liu Jia , Cheng Zeng Ji
Published: November 2012

According to the development status of the energy meter, we put forward a design of a Three-phase multi-function energy meter based on professional measurement chip RN8302 and High-performance single chip microcomputer MSP430 in this article. It has the characteristics which are low-power consumption, high-precision and electricity anti-theft. It could also real-time measured current, voltage, active power, reactive power, power factor, over-voltage and over-current signal. The design also has the functions of surge prevention, lightning prevention and voltage protection, improving the overall safety and reliability of the system.Use the Low-voltage power line carrier communication, there is no need to build another peripherals,saving the cost of grid investment. The article also gave the overall design scheme and the main hardware principle Schematic.
Design of Automatic Level Control for Microwave Signal Source
Authors: Li Song , Bai Tai Li , Han Yao
Published: November 2012

The performance of the automatic level control（ALC） system determines the stability of the microwave signal source output power, accuracy and linear flatness in each frequency range, directly determining the signal generator power characteristic indicators. This paper gives an implementation of a high-performance feed-forward ALC circuit, the negative feedback loop consists of the power detector circuit, logarithmic amplifier, the integral hold circuit, attenuator driving circuit, PIN attenuation circuit and so on.
The Research of Surface Residual Stress about Glass Ceramics
Authors: Wang Jing He , Wang Kui , Wang Xun , Song Wei , Song Xiao Li , Li Shun Zeng
Published: November 2012

We have researched the residual stress in super-smooth glass ceramics using nano-indentation technology, according to the characteristic that the residual stress in the process of pressure is sensitive to the pileup around the indenter, we can determine the changing area, then combine this with the elasto-plastic contact theory, thus the residual stress calculation formula is obtained. By the continuous strain obtained by a spherical indenter and the research on the yield stress and stress-strain curves of microcrystalline glass through spherical indentation experiments, we can get the rule which can tell us how the residual stress of the microcrystalline glass changes with the depth from surface. This research helps to improve the processing quality as well as the performance of the super-smooth surfaced microcrystalline glass, obviously it has a wide application prospect.
Real Time Monitoring of Structural Health Using Fiber Bragg Grating Sensors Based on Arrayed Waveguide Grating Demultiplexing
Authors: Chen Luan Xiong , Xu Wei , Huang Xu Guang
Published: November 2012

In order to monitoring the health of the structure, a quasi-distributed fiber Bragg grating (FBG) interrogator based on two-channel theory of the arrayed waveguide grating (AWG) demultiplexer is presented. As is known, a slightly change of the temperature or strain or other related parameters applied on the FBG will lead to a shift of the Bragg wavelength of the FBG, which makes sense on the precisely temperature and strain monitoring of structures, including viaduct bridges, towers, railway, skyscraper, etc. It can be interrogated by the relative intensity of two-adjacent-channel of the AWG-based demultiplexer, which offers a low-cost, high sensitivity for the interrogation of FBG distributed sensors.
Case Studies of LDV-Aided Dynamic Testing
Authors: Dai Kao Shan , Ren Xiao Song , Chen Qing Jun , Zhao Bin
Published: November 2012

The laser Doppler vibrometer is a non-contact sensing technique developed based on the Doppler effect of a laser beam emerging from a subject surface. As a vibration transducer, the laser Doppler vibrometer offers many advantages over the conventional contact vibration sensors. It allows remote, non-intrusive measurement of structural vibration and it is very useful in scenarios when traditional contacting measurement is inconvenient. In this paper, four laser-based structural dynamic studies were presented and some results were briefly reported, which include laboratory dynamic testing of a bolted steel beam, a scaled-down high-rise building model, and a prestressed concrete reaction wall, and field vibration measurement of a viaduct bridge. Through these demonstrating cases, it is anticipated to help civil engineers get familiar with the laser-based sensing technology and to extend their selections for effective measurement approaches during experimental research.
An Innovative Approach of Drilling Process Monitoring for Slope Characterization in Mountainous Regions
Authors: Chen Jian , Yue Zhong Qi , Liu Si Jing
Published: November 2012

In Hong Kong, there are so many drill works for landslide prevention, such as drilling holes for soil nailing. To recognize the geotechnical condition of slope in detail based on these drillholes, we have developed and invented the drilling process monitoring (DPM) technique to accurately and quickly quantify and characterize the mechanical strength distribution beneath the slope surface. This technique is associated with the conventional air-driven rotary-percussive drilling machines with down-the-hole hammer. This drilling machine is manually portable to quickly form holes of upto 100 m deep in sloping ground. Such ground can comprise any kinds of geomaterials from soft or loose geomaterials such as caverns, clay or sand to extremely hard or strong geomaterials such concrete or granite. Therefore, we have proposed an innovative approach by using DPM method to accurately and quickly quantify the ground conditions in slopes in mountainous regions. It is trusted that the proposed approach will be able to upgrade our current slope engineering practice in mountainous regions.
Experimental Research of Distributed Optical Fiber Sensor Monitors the Embankment Hidden Hazard
Authors: Lei Hua , Zhu Ping Yu , Liang Hong Qiang , Hou Guo Qin
Published: November 2012

Distributed optical fiber sensor as the basis for temperature difference and strain identification, it has some advantages on deformation monitoring and seepage monitoring of the dams relying on long distance, continuous monitoring ability, distributed performance, strong anti-interference ability and other characteristics that traditional sensors do not have advantages. Taking layout of layered installation for example, this paper studies the relationship between laying bending radius and the strain sensing characteristics of the optical fiber sensor. The test of through the indoor simulated experiment and the outdoor dam model monitoring shows that the distributed optical fiber sensor for dam danger monitoring has good effect and promising applications. The dam model provides experimental platform to further study early warning criterion of dam hidden disaster.
Damage Detection in a Cracked Rod Using High-Frequency Electro-Mechanical Impedance Signatures
Authors: Wang Wei , Yan Wei , Li Wan Chun
Published: November 2012

Electro-mechanical impedance (EMI) analysis is conducted in the paper for a one-dimensional rod. Two identical PZT patches bonded symmetrically onto the top and bottom surfaces of the rod are activated in phase and hence a pure axial excitation is created. Based on the finite element software ANSYS, an electro-mechanical impedance (EMI) model for the coupled structural system consisting of the host rod, bonding layer and the piezoelectric patches is established for structural health monitoring. A comparison study with the mode superposition method usually employed in the conventional EMI model is implemented to validate the effectivity and accuracy of the proposed EMI model. Finally, the numerical results indicate that the cracks appearing in the structures can be detected by using the proposed analysis.
Design and Analysis of Flexure Hinge in the Double Crystal Monochromator
Authors: Zhao Xiang Guo , Zhou Si Zhong , Jiang Bo , Jiang Kai , Mei Chao
Published: November 2012

Abstract. This paper analyzes the relationship between the parameters of CFH (Cosine Flexure Hinge) and the adjustable angle in the measurement and micro-adjustment of yaw, pitch and roll angle in the DCM (Double Crystal Monochromator). We derive the motion equations of CFH during the measurement and adjustment process, and get accurate expression formulas. Then we use ANSYS software to simulate the CFH and compare the simulation value and the theoretical value. It shows that the maximum angular deflection error is less than 3.5 percent. We compare the CFH to the RCFH (Right Circular Flexure Hinge), and get that the maximum angular deflection and the linear displacements of RCFH are all about 1.56 times than the CFH when the parameters are equivalent. Therefore, we provide a simple flexure hinge to improve the stability and accuracy of angular measurement and micro- adjustment in the DCM.
Application of the FTA in the Risk Management of Refined Oil Pipeline
Authors: Zhang Ling Ling , Fu Gang , Wang Xian Fu
Published: November 2012

Building a fault tree for the refined oil pipeline on the basis of fault tree analysis method. By analyzing the potential risks existing in the refined oil pipeline, the main sources of risks have been figured out based on FTA. This paper aims to find out the key risk factors existing in the oil pipeline as followed: corrosion, machinery and material failure, the third-party damage and maloperation. The main risk sources and the vulnerable spots are found out through the structural importance analysis of the fault tree, including neglecting the construction supervision, corrosion detection, poor corrosion resistance, operation inspection and supervision and bad alarm system, cathodic protection failure and the third-party damage.
Research on Ash Removal for the Water Wall of Coal Gasifier under Impact Loadings
Authors: Zheng Xiao Tao , Jing Jing , Yu Jiu Yang , Wang Cheng Gang , Xu Jian Min
Published: November 2012

Vibration responses of the water wall of coal gasifier under impact loads were investigated. The influences of different diameters of water walls and impact loads on the effectiveness of ash removal were further considered. The results showed that the peak acceleration along the axial direction of the water wall is greater than 80% of the peak acceleration at the impact point when rapping devices are installed at the 1/4, 1/2 and 3/4 heights. Moreover, rapping devices should be staggered 30 degree in the hoop direction at different heights to avoid the dead zone of ash removal. Furthermore, vibration accelerations increase with increasing the diameter of water wall, while the impact time should be as short as possible for higher efficiency of ash removal.
Application Research of Support Vector Machine Based on Particle Swarm Optimization in Runoff Forecasting
Authors: Wang Li Xue , Wang Li Na , Li Guo Feng , Luan Ce , Sun Fei Fei
Published: November 2012

In view of the little sample, less data problems, mid-and-long term hydrologic forecasting is a case of which, Support Vector Machine (SVM) can solve this kind of problems perfectly. This paper introduced the basic optimization procedure and PSO-SVM modeling procedure. The PSO-SVM model has been applied in forecasting the monthly runoff of Dahuofang reservoir. The comparison between PSO-SVM and not-optimized SVM implied that the PSO-SVM has a fast convergence speed and strong generalization capability, also the related error has been decreased from 15.5% to 11.9%.
An Algorithm for Connecting Suburban Rail Line to Urban Rail Transit Network
Authors: Wu Fang , Gu Bao Nan
Published: November 2012

A greedy search based heuristic algorithm was proposed to solve the problem of connecting suburban rail line to existing urban mass transit network, aiming to provide efficient trips for passengers from satellite towns within metropolises to urban area. Optimum connection scheme set was sorted out from the perspectives respectively regarding optimization searching process and different transfer coefficients that reveal the predominance of transfer in path length. And at the same time, the searching process can also assure as short rail line and few connection stations be built as possible when adding more connection stations. High quality of connection design schemes can be ensured by these optional designs, which can also cover various connection modes of different station spacing, providing solid basis for evaluation and selection in future stage. Finally, the aforementioned algorithm was implemented in an example, generating an optimized connection scheme set, which proves the applicability of this algorithm in large scale rail network connection problem.
Threshold Noise Reduction Research of Improved EEMD Method
Authors: Zhang Mei Jun , Chen Hao , Wang Chuang , Cao Qing
Published: November 2012

In order to extract effectively detection signals in the noise background for non-stationary signal.On the basis of EEMD, improved EEMD is put forward, the improve EEMD threshold noise reduction is researched in this paper.The simulation signal compared the noise reduction effect of the wavelet,EMD,EEMD,and the improved EEMD. The improved EEMD threshold noise reduction have the best noise reduction result , the highest signal-to-noise ratio, the smallest standard deviation error.After the improved EEMD threshold noise reduction , the measurement signal time domain waveform smooth. More high frequency noise was obviously reduced in Hilbert time- frequency spectrum. Signal-to-noise ratio significantly improve, and signal characteristics are very clear.
Freeway Construction and Management Technology Research Based on the Data Net Toll-by-Weight Fees
Authors: Zhu Ju Fen , Li Zi Qiang , Zhou Ke Qin
Published: November 2012

This paper introduces the present our country freeway generally adopts a closed toll collection mode, and on the adoption of OD matrix estimation algorithm are explained and put forward the feasibility of estimation and correction. By analyzing of the integrity, reliability features of the network weight charge data, the paper discusses networking account weight fees data in-depth mining and development can make it a greater role in the freeway construction management and operation of the maintenance. The use of traffic simulation system combines the data of freeway weight fees, fee information and section traffic information to optimize the selection and provide a more solid basis for decision making on the overall freeway management and control programs. Full text of more comprehensive analysis and expounds the networking weight fees data in freeway construction and management application field, data analysis methods and application of technology route.