bluuebunny/crossref_metadata_2025 huggingface dataset:
Based on One-Dimensional Model to Calculate the Critical Speed
Authors: Wang Jun Feng , Sun Kang
Published: October 2012

Use the simple geometric features of a one-dimensional model to calculate the rotor critical speed, the shaft use the beam element to simulate, considering the shear deformation, continuous mass, the rotation inertia and gyro effect, bearing simplified as linear stiffness and damping element, disc use the lumped mass element to simulate, considering the mass and the effect of inertia, finite element method is applied, established the rotor-bearing system dynamics model, through the example to validate, the results show that the model is the advantage of calculation on a smaller scale, solution speed and high precision, easy to adjust the parameters for the model, suitable for large needs to adjust the parameters in the early stage of design and analysis of the rotor-bearing system, it has great reference value for the design and analysis of rotor dynamics.
The Development of PMD and its Compensation Method
Authors: Wang Feng , Sun Qiu Hong , Jiao Hong Lei
Published: October 2012

With the quickly development of fiber communication, PMD(Polarization mode dispersion) has became one of the key factor which limit high-bit rate system performance. In 1986, C.D.Poole[1] and other people found that if do not consider loss of SOP, two upright PSP will change along certain length SMF. In 1987, D.Andresciani and N.S.Bergano validate the theory of C.D.Poole each either. Late ninety of last century, statistical theory forming[2]. In the paper, we discuss the study of PMD, including statistics of PMD, measure technology, the affect of system by PMD, and PMD Compensation Method.
Research on Strategies of Pricing and Coordinating in Reverse Supply Chain for Remanufacturing
Authors: Zhou Zhan Feng
Published: October 2012

Based on the remanufacturing reverse supply chain consisted of single retailer and single manufacturer, this paper applied game theory to establish a non-cooperative game and cooperative game model and got optimal pricing strategy by solving this two kinds of game model. By comparing the total profits of reverse supply chain in every game model, a conclusion was draw that non-cooperative game model led to profit loss and double marginal effect. In order to solve the problems, revenue sharing contract was used to coordinate the reverse supply chain and coordinating strategy was got. The results show that revenue sharing contract can increase the total profits of the reverse supply chain, while at the same time meet the respective interests of retailer and manufacturer and coordinate the reverse supply chain.
Study on Traffic Flow Characteristics and Simulation Based on the VISSIM
Authors: Zhang Xin , Liu Bao Xin , Yuan De Chun
Published: October 2012

As is known to all，Traffic congestion in Beijing city is Increasingly serious.In order to thoroughly analyze the congestion causes of Beijing`s intersection, this paper uses VISSIM to simulate the traffic phenomenon, and in-depth analysis of traffic flow characteristics. Through the simulation of observation, this paper gets the simulation output parameters and basic characteristics of the intersection, and in-depth researches lead to the intersection of the critical causes of congestion, and put forward the corresponding improving countermeasures.
Research and Practice of Safe Mining Technology in Steeply Inclined Coal Seam under Complicated Geological Conditions
Authors: Ren Xiang , Zhao Rong , Chui Xiao Li
Published: October 2012

Based on the analysis of the current state of mining in steeply inclined coal seam, combination with the mining status of the 3up 509 fully mechanized mining coal face with a max 28°inclination and a high cutting height,The key technologies was Study on the anti-sliding of coal face equipment, ends and advance support, water prevention and control as well as other key technology of steeply inclined coal seam, Good technical and economic results achieved in actual production,Support capability of production safety in mine enhanced,This article Opened up new avenues and new ideas for the promotion of mechanized mining technology under similar geological conditions.
Backstepping Control Design on the Dynamics of the Omni-Directional Mobile Robot
Authors: Cui Qing Zhu , Li Xun , Wang Xiang Ke , Zhang Meng
Published: October 2012

The dynamical model of an omni-directional mobile robot is bulit based on the Newtonian mechanics. Correspondingly, a backstepping-based controller is then proposed with proven global stability by selecting a Lyapunov function and introducing a virtual control input for the built dynamical model. Simulation results show the effectiveness of the proposed controller.
The Use of Automobile Electric Control Technology in the New Energy Vehicles Industrialization Process
Authors: Gu Xiu Rong , Liu Bao Qing
Published: October 2012

this paper analyzes the development situation of new energy vehicles and the problems in the industrialization process. and then introduces the use of automobile electric control technology in new energy vehicles.
A New K-Means Clustering Based on Genetic Algorithm
Authors: Cheng Chang Sheng , Shang Yan Meng
Published: October 2012

The driving force of a genetic algorithm is the fitness function. The traditional fitness function based on the error sum of squares has a poor effect when the number of difference between classes is huge. Furthermore, it often fails to get better clustering results due to the lack of the clustering effect evaluation. So, this paper proposes a new K-means clustering based on Genetic Algorithm. Firstly, we define the concept of difference density and uses it as the fitness function of the genetic algorithm. Secondly, we evaluate the quality of the clustering results by some indicators and find the best cluster centers by iteration. The comparison proves that our method achieves a better result than the traditional K-means clustering based on genetic algorithm.
Vertical Deflection of Simply Supported Box Beam with Corrugated Steel Webs Including Effects of Shear Lag and Shear Deformation
Authors: Ji Wei , Liu Shi Zhong
Published: October 2012

This paper presents an method to solve the vertical deflection of the box beams with corrugated steel webs, considering both the shear lag and shear deformation of corrugated steel webs. The method is deduced by means of the variational principle. The formulas given by this method is simple and practical. Then, a comprehensive analysis on the effects of shear lag and shear deformation of corrugated steel webs is given for a simply supported box beam with corrugated steel webs under uniformly distributed. The results of vertical deflection obtained by this paper are in good agreement with those obtained by the finite element method (FEM) and the model test, respectively.
Estimation Theory on Cable’s Pretension in Pre-Stressed Mega Brace and Steel Frame Structure
Authors: Tang Bai Jian , Gu Sheng , Ma Jun
Published: October 2012

How to determine cable’s pretension is one of key problems in pre-stressed mega brace and steel frame structure. According to superposition principle of structural deformation, the inner force increment of pre-stressed cable under vertical and horizontal loads was approached separately by analyzing the structural deformation and inner force increment. Based on the rule that the required pre-tension force of cable equals to the sum of inner force increment of compressed cable under vertical and horizontal load, the qualitative estimation theory on cable’s initial pre-tension considering construction influence is ultimately established.
Composite Support Structure of Continuous Arch Internal Support Design and Calculation and Analysis of Engineering Example
Authors: Li Hong Xia , Guo Yan Qin , Wang Yong Wei
Published: October 2012

Composite support structure of continuous arch internal support is a new type of maintenance structure of deep foundation. In this paper, as the cylindrical shell in the ring uniform load analytical solutions of elasticity a starting point, the design and calculations methods of composite support structure of continuous arch internal supporting are discussed. Engineering examples of composite support structure of continuous arch internal supporting in deep excavation engineering applications are analyzed and summarized. At the same time, the design parameters are provided for more engineering applications.
Study on Elasto-Plastic Stability Bearing Capacities for K6 Single-Layer Reticulated Shells under Fire Conditions
Authors: Bai Yin , Zhai Jian Lei , Shi Yong Jiu , Wang Yuan Qing
Published: October 2012

The elastic modulus of steel will decrease in case of high temperature which makes the reticulated shells easier to have the global instability phenomenon. In order to obtain the elasto-plastic stability bearing capacities for K6 single-layer reticulated shells [1], nonlinear finite analysis compete process was conducted by ANAYS software under on the two typical cases which include global non-uniform temperature distribution and localized high temperature. Based on the calculation formula for single-layer reticulated shells at ambient temperature, the calculation formula for elasto-plastic stability bearing capacity for K6 single-layer reticulated shells was obtained.
The Study of the Crack-Resistant Plaster Mortar of Sand Autolaved Aerated Concrete Blocks
Authors: Fu Ze Wu , Zeng San Hai
Published: October 2012

In view of the problems of crack and falling off when using ordinary mortar aerated concrete blocks, this paper investigate the plaster mortar of sand aerated concrete blocks. On the basis of single factor experiments of the effects of plaster mortar composition on its performance, the properties of plaster mortar are optimized by orthogonal experimental method. The results indicate that the mixture of vitrified microbeads, perlite, fly ash according to a certain proportion can produce laying and the plaster inorganic insulation mortar that exhibit low thermal conductivity coefficient and mechanical performance that meet the requirements.
Study on Finite Element Algorithm of Jointed Rock Mass in Tunnel in Blasting and Model Building
Authors: Zhang Hong Yan , Yu Qing Yang , Zhou Neng Juan
Published: October 2012

It is a kind of effective way to study blasting to joint rock mass using the finite element method, in which the key is algorithm and model building. Comparing the relationship of explosive and blasting structure simulated by adopting Lagrange method and ALE method, the paper considers that Lagrange method is more close to practice, and could finish numerical simulation analysis of the intact rock blasting.
Deformation and Stability Study of PBA Extension Method Based on Air Defense Tunnel
Authors: Jia Jian , Zhou Shun Hua , Yao Xi Ping , Shen Chen
Published: October 2012

Jiaohua Square Station of Harbin Metro Line 1 is built by PBA method with the existence of No. 7381 air defense tunnel. In order to control the ground settlement during PBA construction, numerical model is performed to analyse the surrounding rock pressure, plastic zone and structure internal force. The result shows the lower pilot headings have stronger impact on existing tunnel than the upper ones in that the lower ones get the loading effect while the upper ones the unloading effect. The internal force of air defense tunnel and ground displacement can be well controlled by reducing the area of lower pilot headings at the stages of pilot heading excavation, but the final surface settlement is unqualified. The scheme of lower big pilot heading in part with the support of portal frame meets the requirement of surface settlement. The in-situ surface settlement and the vault settlement of defense tunnel are essentially consistent with numerical results.
The Construction Technology Development of Immersed Tunnel
Authors: Li Shui Yu
Published: October 2012

This paper summarizes the advantages of the immersed tunnel, reviews the application profiles of the immersed tunnel at home and abroad. Immersed tunnel design and construction process in the selection of structural, foundation treatment, joints waterproof, pipe sections of floating and sinking and other key technologies are analyzed and discussed. Finally, the analysis of the application prospects of the immersed tunnel, and pointed out that with the underground space development and utilization of the immersed tunnel because of its unique advantages and will certainly more and more popular.
Choosing the Supporting Scheme for Foundation Pit through Analytic Hierarchy Process
Authors: Peng Lei , Zhao Dang Shu , Cao Jing , Jiang Kai Yu
Published: October 2012

The choice of supporting plan for a foundation excavation plays a leading role in the optimizing design. For those foundation pits with complex circumstances, a reasonable and optimized supporting construction should be designed to meet the requirements of the surrounding environmental factors. These factors are arranged and rated through a relatively simple analytic hierarchy process (AHP) so as to determine how they affect the design plan of the supporting system. Through ratings and comparisons of relevant factors, a rating method for different design plans is proposed based on AHP analysis. Several supporting plans for a practical excavation engineering in Kunming are analyzed and compared through above method and a reasonable and optimized design plan is selected.
Technology of Pile Foundation Underpinning in Shield Tunnel of Xi’an Subway
Authors: Ma Lan , Wang Jing
Published: October 2012

The technology of shield has been widely used in city subway design, when the shield tunnel encounters a bridge across the river; the key issue is to complete the pile foundation underpinning according to the diverse geological conditions. With an example of subway Shield tunnel project from Xi’an, The paper presents the working procedure and emphases of pile foundation underpinning.Based on the configuration design, both the load beared by one single stake and the distortion of the joists are calculated, the carrying capacity computations indicate that pile foundation underpinning is feasible.
Numerical Simulation of Frozen Construction of the Cross-River Tunnel's Connected Aisle
Authors: Zhai Yong Mei , Cui Zhi Gang
Published: October 2012

Double-line cross-river shield tunnels should be set up evacuation routes for disaster prevention, rescue and ventilation at each distance according to the standard requirement, the evacuation passageway generally chooses transverse evacuation passageway, but in the case of complex geological and hydrological conditions, the risk of the construction of horizontal evacuation passages is very big. This paper takes a cross-river tunnel as an example, to set analysis for the risk of setting a horizontal evacuation passages. Used the ANSYS of a 3-d finite element analysis software, selected the number two horizontal channel as the prototype, according to the size and design of shield tunnel line longitudinal cross section of geological structure, establish the finite element calculation model for the interaction of the tunnel, the channel and the surrounding soil, to simulate the process of the excavation of the channel, and the paper studies the risk in the construction process of the channel.
Experiment Research of the Lateral Properties and Density Variation of Loess Subgrade to Dynamic Compaction for Mountainous Highway
Authors: Wang Yue Xiang , Liao Ying
Published: October 2012

To study the applicability of dynamic compaction for loess subgrade, the model test had been done. According to the test results, some conclusions were drawn out as follows: dynamic compaction can improve the density of loess in a short time, the lateral effective compaction width of loess was narrowed with the depth of loess deepened. In the same depth of soil, the density was improved with the tamping times, and the lateral compaction width was relevant to the distance between tamping pit and discussing spot.
Moisture-Thermal Coupling Model for the Temperature Calculation of the Permafrost Subgrade
Authors: Ye Zhi Qiang , Mao Xue Song , Ye Min
Published: October 2012

Water and heat conditions and their interactive affections are the key factors for the frost damages of highway engineering. In order to understand the moisture and thermal movement of subgrade soil deeply, a moisture-thermal coupling model has been developed for analyzing the temperature distribution in the permafrost subgrade of highway. The model takes into account both the effects of heat generation, internal conduction and convection, and the moisture movement to accurately predict the temperature evaluation. The theoretical calculations are compared to in-situ test results for the Qinghai_Tibet Highway and shown to be in great agreement at accuracy and precision. The coupling model can serves for the prediction of the frost depth of permafrost subgrade, further prevent the highway engineering from damages.
Mechanical and Economic Analysis of Asphalt Pavement Structure on Mix Base
Authors: Peng Hong Wei , Ou Bi Feng
Published: October 2012

Based on asphalt pavement design theory and criterions in China, five asphalt structures are put out, including three mix base pavement structures, one typical semi-rigid base pavement structure and one typical flexible base pavement structure. For contract study, different pavement structures were selected with various combinations of modulus and Poisson ratio, but the total thickness is same for comparative analysis. The stress-strain at different depth in asphalt layer is calculated by using BISAR program. The data analysis is carried out for the maximum tensile stress, and the maximum strain of asphalt layer, and the maximum compressive strain on top of sub grade, deflection on asphalt surface. And budget basis price for base is contrasted too. The data analysis results show that the mix base asphalt pavement structures can be designed to get better pavement mechanical performance than typical semi-rigid base and typical flexible base asphalt pavement structures, while the price is higher than that of semi-rigid base. If we consider fatigue life, the cost performance for mix base of upper base with asphalt stabilized macadam is the best. This gives out the important reference for widespread the mix base in future.
Finite Element Analysis of Composite Soil-Nail Retaining Structure in Foundation Pit Engineering
Authors: Huang Jian Hua
Published: October 2012

Base on general three dimension nonlinear numerical simulation software, mechanism of composite soil-nail retaining structures in foundation-pit engineering are analyzed in this paper. Research contents include construction process simulation of excavation by steps, soil nailing installation and panel manufacture etc. Tension distribution range of soil layer, bottom heaving in the pit and axial force distribution along nail etc. are analyzed through the comparison of mechanical characteristics between computational results and field test data in the case of micro pile composite soil-nail support engineering. The action mechanism and working performance of composite soil-nail retaining support are also systematically studied and theoretical basis can be provided in optimal design, popularization and application.
Analysis for Influence Factors of Cold Recycling Mixture Compaction Test
Authors: Wang Yong Bing , Ying Guo Qiang , Hu Jian Lin , Wei Hua Wei , Zhang Qian
Published: October 2012

In order to study the factors which influence the inorganic binder stabilized material’s compaction test results, different recycled material content therefore different reclaimed gradation mixtures are tested while varying the amount of cement. The experiment results show that contents of the recycled base material and the recycled surface material on the compaction test results are determined by the change of their density and water absorption ratio. Dry density of the recycled mixture increases with the increase of the reclaimed base material density. Low water absorption ratio of the recycled material reduces the reclaimed mixture’s optimum moisture content. Density of the reclaimed wearing surface material reduces the maximum dry density of the reclaimed mixture because the old wearing surface material has lower density. Its low water absorption reduces the optimum moisture content of the recycled mixture. Influence of cement content on compaction test results is the increase of the cement content can enhance the maximum dry density and optimum moisture content of the recycled material. Through the analysis of the results of the compaction test, the key factors in the recycled material compaction test are unveiled.
Discussion for Ageing Features of SBS Modified Asphalt and its Assessment Index
Authors: Ji Xiao Ping , Tan Xue Zhang , Zheng Nan Xiang
Published: October 2012

This paper discusses the ageing features of SBS modified asphalt and its assessment index. The performances for both host asphalt and modified asphalt after different RTFOT ageing times was tested and micro analysis was conducted with infrared spectrum. The quantitative analysis for the micro-changes of ageing process was carried out according to Lambert Beer law. The research results show that the longer the ageing time, the smaller the penetration and ductility of asphalt are, and the greater the softening point and viscosity. In comparison with the host asphalt, the absorption peak of SBS modified asphalt in stretching vibration (C=C) at 1600cm-1, the absorption peaks of polybutadiene in bending vibration at 966cm-1 and 911cm-1 , and the absorption peak of styrene in bending vibration at 697cm-1 are from SBS modifier. The oxygen reaction happens in ageing process of asphalt, producing carboxyl and subsulfoxide. Affected by the higher activity of SBS modifier, SBS modified asphalt can be easily oxidized.There is good correlation between its penetration, softening point, ductility with carboxyl and subsulfoxide , so the above three indexes can be adopted to assess the ageing of SBS modified asphalt.
Mixed-Mode Fracture Characteristics of Cold Recycling Mixes with Emulsified Asphalt
Authors: Gao Lei , Ni Fu Jian , Yang Mei Kun
Published: October 2012

In order to study the Mixed-Mode cracking behavior of cold recycling mixes with emulsified asphalt, the Arcan test configuration was chosen to perform the fracture characteristics of cold recycling mixes in five levels of Mixed-Mode (100, 75, 50, 25 and 0% Mode I) at three loading rates (1.0mm/min, 0.5mm/min, 0.1mm/min). The load and load-line displacement, peak load, crack angle and fracture energy were all used for further analysis. The process of cracking can be divided into three stages: the stage of crack arises, expand stage, and the brittle break stage; 0% Mode I has a significant difference from the others; the loading rates and levels of Mixed-Mode both have great influence on peak load; the higher level of Mode I usually gets lower crack angle; the fracture energy of 100% Mode I ranges from 168 J/m2 to 308 J/m2 and the specimen in 0.5mm/min has greater fracture energy.
Analysis of High-Speed Railway Roadbed Settlement in Seasonally Frozen Regions
Authors: Shi Gang Qiang , Zhang Yu Zhi , Zhao Shi Yun , Zhang Lu Xin , Sun Bao Chen
Published: October 2012

Relying on the roadbed in seasonally frozen region of Harbin-Dalian passenger dedicated line，a finite element analysis model was built to study the changing rules of roadbed settlement in construction and operation. The analog and actual results were in good consistence, the model is suitable for the roadbed deformation analysis of high-speed railway in seasonally frozen regions.
The Combined Guiding Hole Technology of Large Diameter DTH Hammer and Long Screw-Pile Driver
Authors: Liu Qi Xia , Fan Liang
Published: October 2012

From an engineering reality, in order to solve complex stratigraphic drilling problems and improve construction efficiency, the method of combination of large diameter DTH hammer and the pile driver with a special long spiral drill multifunctional is proposed. This method has the characteristics of simple equipment, fast, effective, low cost etc. It can quickly drill through layers of gravel, stone, weathered bedrock, reach to depth up to above 25m. It has been widely used in embedded engineering methods of precast piles, the long spiral rock-socketed piles, piles into the rock currently. The study of this construction method has not only wide range of applications, but also has a wide range of practical and theoretical significance.
Application of Ballastless Track CP III Control Network Measure Method in the Building of High Speed Railway
Authors: Qian Yue Lei , Li Xin Ming
Published: October 2012

In the process of building the ballastless track of the high speed railway from Wuhan to Guangzhou, the measuring method of the CPⅢ control network has played an extremely critical role. In this article, the form layout, measuring method, precision requirements and some other contents of the high speed railway ballastless track CP Ⅲ have been proposed. It has been proved that this control network has reliable technology basis and meets the construction requirements, which is available for other similar engineering.
Comparative Analysis on Hot and Warm Mix Asphalt Pavement Performance
Authors: Sun Heng
Published: October 2012

Warm mix asphalt is a new type of environment-friendly pavement material with high energy-saving and low emission and it has been attracted a number of attentions to its pavement performance. In this paper, LRT, a viscosity and resistance reducing agent for asphalt, was selected as the warm mix agent to add into SMA-13 asphalt mixture. The high temperature and water stability, low temperature crack resistance and fatigue property of both hot and warm mix SMA-13 asphalt mixtures were evaluated, and various aspects of pavement performance of both materials were comparatively analyzed.
Research on Soft Soil Foundation Treatment and Relevant Design Technology for Changzhou Section of the Coastal Expressway
Authors: Mu Huan Sheng
Published: October 2012

The author of this article gives a detailed description of the basic situation of the coastal expressway, focusing on the characteristics and engineering properties of soft soil as well as a in-depth analysis of the successful soft soil foundation treatment technology using cement mixing pile. This article provides useful reference for engineers facing similar situation.
Nonlinear Dynamic Analysis of the Foundation Soil and the Gravity Pier
Authors: Liu Yong , Shao Ming Xia
Published: October 2012

This paper explores the interaction system of nonlinear foundation soil and nonlinear gravity pier. Superstructure resilience model employed ideal elasto-plastic model, foundation adopted tensionfree-consolidated elasto-plastic Winkler foundation model with experimental support. Through an account case of a gravity pier, this paper concludes that co-action of foundation soil and bridge pier needs to be considered in design of seismic prevention for bridge.
Experimental Study on Dry Shrinkage of LSFRC and LHFRC
Authors: Li Peng , He Dong Qing
Published: October 2012

Layered structure (LSFRC and LHFRC) have some characteristics: the composition of complex components, influencing factors, structure forms. Fiber mixed really adds the complexity of the test and theoretical study. In view of the dry shrinkage performance, the study is done on the research of the general concrete structure (C) enhancement effect and strengthening mechanism for the wide use in engineering foundation.
Analysis the Control Techniques of Reflection Crack on Asphalt Overlay of Old Cement Concrete Pavement
Authors: Wang Jue
Published: October 2012

Cement concrete pavement is the main type of highway pavement in our country. The asphalt overlay on old concrete pavement is one of the main measures to improve the pavement performance, to improve the bearing capacity and extended service life. But, the prevention of reflection cracks is a key problem need to overcome. This paper briefly analyzes cause of the formed mechanism of reflecting crack of bituminous paving course on old cement concrete pavement, and elaborated some major technical measures of preventing or retarding reflection cracks.
Chemical Grouting Technique to Strengthen the Bridge (Culvert) Abutment Soft Ground Projects
Authors: Chen Hua Liang , Wang Da Wei
Published: October 2012

Guangxi the Yulin Tieshan'gang Expressway Bridge Grouting roadbed practice, describes a chemical grouting of construction methods to prevent highway traffic bridgehead depression after jumping disease, cone penetration test by heavy cone momentum before and after grouting Deflection detection method for testing the effects of the project, validation of the technology for the new road bridge (culvert) abutment soil reinforcement pretreatment oil with good results, can significantly improve the bearing capacity of foundation.
Condition Assessment of Expansion Joint of a Cable-Stayed Bridge Based on Long-Term Monitoring
Authors: Li Xue Lian , Sun Li Min
Published: October 2012

Based on the long-term monitoring data of Donghai Bridge, span length changes of the main channel of the bridge was analyzed from the expansion joint displacement data monitored，and the correlation between the span changes and the environmental factors, which are temperature and wind load, was analyzed. Results show that temperature is the main factor influencing the span change, while the correlation between span changes and wind load is weak so can be ignored. The linear regression model established between span changes and the structure effective temperature can be used to estimate the interval of bridge span changes and examine the correctness of the expansion joint data monitored. Moreover, the regressive model of accumulated expansion joints displacement and time history can provide valuable information for design, maintenance and replacement of the expansion joints.
Effect of Suspender Tension Order on the Natural Vibration Frequency of a Through CFST Arch Bridge
Authors: Li Zi Lin , Wang Shuai
Published: October 2012

Finite element theory was taken to do a research on a through CFST (concrete-filled steel tube) arch bridge and a change rule of the bridge’s natural vibration frequency was found when its suspenders were tensioning. Through three tension schemes, after solving the first fifteen orders of the natural vibration frequency of each condition and drawing the change curve and analyzing the effect of different suspender tension order on the natural vibration frequency, we come to the conclusion: different suspender tension order will have no effect on the natural vibration frequency when the bridge is completed but when it is constructing, which mainly shows that both the first three and eight to thirteen orders of the natural vibration frequency are discrepant; different location of suspenders has different affection degree on the natural vibration frequency of the bridge. The conclusion has reference value for bridge construction.
Deflection for Pre-Stressing Concrete Thin-Wall Box Girders Bridge under Action of Multi-Span Loads Exposed to Fire
Authors: Zhang Gang , He Shuan Hai , Guo Hong Jun , Hou Wei
Published: October 2012

The deflection for pre-stressing concrete thin-wall box girders bridges under action of multi-span loads exposed to fire was presented in this paper. Based on thermal and mechanics parameters, the fire and load model was designed, the space analysis procedure was performed to analyze the maximum deflection of each span during prophase and anaphase of extending-fire time, altogether 4 kind of load case. The studied results indicate: under condition of the whole span fire and load model of multi span, the mid-span deflection of the second span is down-warping during the fire prophase which its time is about 20 minutes, and up-warding or horizontal during the fire anaphase which its time is about 50 minutes; the deflection of the first and third span is down-warping with extending time during the whole fire time.
Study on the Local Scouring of the Bridge with Sediment Control Dam
Authors: Sun Dong Po , Wang Li Sha , Wang Peng Tao
Published: October 2012

Based on the characteristics of local piers scouring after built the sediment control dam in the downstream of the bridge, by the monomer model experiment of flume, sixty groups of local piers scouring experiments have been carried on.The principle and the influence factors of the local piers scouring have been analyzed. The results of series model experiments show that, with the sediment control dams, the local scouring of the piers, on one hand, is influenced by the approach velocity, down-shearing vortex, dimension of the piers, diameter and gradation of the bed sand; on the other hand, it is affected by the elevation of the dam and distance between the pier and the dam. Therefore, the concept of “control slope” is introduced in order to reflect the impacts of the sediment control dam to the piers. Based on the theoretical deduction and dimensional analysis, the equation, which is used to calculate the local scouring with no-uniform bed sand, is acquired by multivariate regression analysis, has been testified by the flume experiment and has got a good result. The optimum value of control slope and the equation of local piers scouring with that dam provide valuable references for bridge flood-control design of the shallow foundation with downstream sediment control dam.
Singular Function Models of a Simply Continuous Beam Bridge under a Moving Load
Authors: Zhang Jun , Gou Ming Kang , Liang Chuan , Ni Xiao Lu , Zhou Zi Wen
Published: October 2012

The system of a simply continuous beam was looked on as one span beam with several internal elastic supports of inexhaustible stiffness. There were two types of models such as the dynamic models by a moving concentrated force and by a moving mass. A three-span beam was introduced as example solved with the present model by a moving concentrated force and FEM, which verified that the present model was correct. Two cases of the example bridge by a moving concentrated force and by a moving mass were considered. The results indicate that mass of the moving load has little influence over the dynamic responses of the simply continuous beam bridge.
Long Span Prestressed Concrete Continuous Rigid-Frame Bridge ANN Construction Control
Authors: Ren Geng Feng , Zou Cun Jun , Xu Yue
Published: October 2012

Based on the theory of ANN (Artificial Neural Network),The paper raised the method of construction control, and introduced the common forecasting method. According to the characteristic of ANN itself and the complexity of factors which influence the elevation, the paper analysed the influence aspects of ANN. On the promise of bridge construction precision, the paper raised section measure、elasticity model、temperature、delay of construction and cantilever for neural network’s input vector in bridge construction process. With the help of Graphical User Interface, built ANN, made the forecast function in the bridge construction into reality. Introduce the theory of Artificial Neural Network(ANN) into long span prestressed concrete continuous rigid-frame bridge construction control.
Experimental Study on Zhenshui Sand Bar and its Treatment in Xiaolangdi Reservoir
Authors: Wang Ting , Zhang Jun Hua , Chen Shu Kui , Ma Huai Bao , Li Kun Peng
Published: October 2012

Zhenshui is the biggest tributary of Xiaolangdi Reservoir and its original storage capacity is 1.767 billion m3. By October 2010, the amount of sediment in Zhenshui reached 0.1691 billion m3, and the sand bar at Zhenshui estuary was 7m in height. Influenced by operational mode of reservoir and terrain, the formation of sand bar has certain inevitabilities. The sand bar can prevent water and sediment exchange between mainstream and tributary, and the internal storage capacity of tributary is not effectively used. The experimental result shows that during the later sediment retaining period, some small reservoirs can be built at the end of Zhenshui. By restoring water during the high water level in non-flood season in these small reservoirs and discharging flow during the low water level in flood season to scour sand bar, the tributary and main channel in Xiaolangdi Reservoir can be linked up in long term, service efficiency and life of tributary storage can be increased.
Study on Economical Channel Width for Large LNG Vessel
Authors: Guo Wei Zhi , Liu Jing Xian , Liu Zhao , Wang Kai
Published: October 2012

The existing design code of natural gas wharf appears to be rough for LNG channel width in the quantitative, and lacks of testing and risk evaluation. The outstanding problem is studied by relying on the study on navigation safety of Shandong LNG project. Taking a 360 meters LNG vessel as a simulation object, according to the local navigation condition designed of a condition scheme, the NT-PRO4000 type of ship maneuvering simulator is used to make a ship handling simulation experiment about the large LNG vessel, and the statistics of the ship track frequency is analyzed. Large LNG vessel’s acceptable risk standard is designed by introducing the concept of social general acceptable risk standard, to calculate the channel width design proposal based on the acceptable risk standard of large LNG vessel. Finally, the risk probabilities are evaluated about the design proposal and the original plan by grounding model, the economic channel width value in the same risk rate is obtained, and providing a new idea for the study of safety and economic channel width for LNG channel.
Numerical Analysis of the Influence of Saltwater Intrusion on the Deepwater Channel in the Changjiang Estuary
Authors: Gu Jie , Qin Xin , Chen Wei , Ma Dan Qing , Wang Xiao Li
Published: October 2012

Since 2005, the increased quantity of back silting in the Deepwater Channel has a negative effect on shipping. This research sets up a 2D current model for the Changjiang River estuary using Delft3D-FLOW. The model is well calibrated and verified by applying the observed data of tidal levels and velocities, i.e. the water level, flow velocity magnitude and direction computed from the model agree well with the real measured data. In order to explore the influence of saltwater intrusion on the Deepwater Channel in the Changjiang Estuary, the computed velocity along the Deepwater Channel, the horizontal and longitudinal salinity distribution in the Deepwater Channel in the dry and wet season are analyzed. Analyzed results show that the fine suspended sediment flocculates easily in the upper reach of the Deepwater Channel beyond Hengsha Island in dry season, which increases sediment’s falling and deposition in this region.
Long-Period Displacement Spectra of Near-Fault Strong-Motion from Tremendous Earthquakes
Authors: Li Heng , Lian Chao , Kong Yu Yang
Published: October 2012

The characteristics of near-fault ground motion displacements, with the obvious directivity, were analyzed. Along moving direction of the fault, displacements take on the feature of fling-step, and the large pulse is the main characteristic of displacements in the vertical moving direction of the fault. The models of near-fault ground motion with different detailed scales can be obtained by median filtering with different window length on the velocity series. Displacement spectra of the models were compared with observations from tremendous earthquakes. The results show that the highly simplified model can predict the response spectrum in very long periods, but there are distinct errors in the period range in which engineering is interested (Tp 5 sec). The refined model is necessary for very large magnitude earthquakes which include multiple rupture, and should be established according to characteristics of velocity.
Analysis on Earthquake Damage Forms and Affecting Factors of Underground Cavern
Authors: Ren Hua Chun , Shen Zhen Zhong
Published: October 2012

According to the information about underground damage in earthquake all over the world, it is summarized that earthquake damage is caused by mountain slope failure, the collapse of cavern’s export, dislocation damage of cavern’s cross-section, great displacement along the fault intersection, spalling of surrounding rock, disturbance or deformation of the support and lining system, et. The earthquake damage factors of underground cavern were analyzed by using numerical simulation techniques. It is shown that when the earthquake intensity value is high, or the initial stress field is small, or lining stiffness is high, the underground will more easily be destroyed by earthquake. Compared with the square tunnel and horseshoe-shaped tunnel, dynamic stability of circular tunnel is better. The export of cavern is vulnerable to earthquake damage.
Numerical Simulation of Storage Tank Foundation Treated by Water Filling Preloading Method
Authors: Zhang Yan Mei , Zhang Xu Dong
Published: October 2012

The water filling preloading method is the common ground treatment method adopted to reinforce soft tank foundation. The influence laws of load speed, soil parameters on the reinforced effect of soft tank foundation were analyzed by the three-dimension finite element numerical analysis procedure. The research shows that the fovea deformation of single tank bottom under preload is similar to the pan bottom shape; the influence of soil constrained modulus on settlement is remarkable and it also affects the settlement time curve shape; when the constrained modulus is constant, with the permeability coefficient decreasing, the surface doming phenomenon around the tank foundation increases, and the range of upheaval is related to constrained modulus; the influence of loading function on the final settlement is very small, but the influence on pore water pressure is remarkable.
Disasters Characteristics of 2008 Wenchuan Earthquake and Analysis of Buildings Destruction
Authors: Guo Ting Ting , Xu Xi Wei , Yu Gui Hua
Published: October 2012

2008 Ms8.0 Wenchuan earthquake produced Strong surface rupture and deformation, triggered geological disasters: collapse and landslide, and brought about serious buildings damage and casualties. Wenchuan earthquake surface rupture, secondary geological disasters and buildings damage were investigated on-site. Disasters characteristics of the earthquake were discussed, and relationship between buildings damage distribution and seismogenic fault of Wenchuan earthquake was discussed. In light of seismic protection and the Code for Seismic Design of Buildings, typical buildings damage and its causes are analyzed and discussed from following respects of buildings location, seismic design and buildings construction. Corresponding seismic measures are suggested.
Estimation of Strength of Massive Jointed Rock Mass Based on Generalized Hoek-Brown Criterion
Authors: Han Feng Shan
Published: October 2012

The strength of massive jointed rock mass can be estimated based on Mohr-Coulomb criterion and Hoek-Brown criterion without making expensive experiment of massive jointed rock mass in site. Only using regression analysis, through transformation，Mohr-Coulomb criterion is compared with Hoek-Brown criterion, the strength of jointed rock mass can be economically obtained. In this paper, based on Geological Strength Index GSI and parameter Jv(Joint/m3), the strength of massive jointed rock mass can be obtained. As an example of GSI 24 for massive jointed rock mass is taken, generalized Hoek-Brown criterion is analyzed linearly and approximately using regression analysis, strength of jointed rock mass can be economically obtained That provide economical and effective method for practical engineering analysis
Risk Assessment Model of Multimode System for Earthquake-Induced Landslide in Small Watershed
Authors: Tian Shu Jun , Kong Ji Ming
Published: October 2012

This is the first introduction of multimode system theory for risk assessment of earthquake-induced landslide. The paper defines the small watershed as multimode system which included triggering system and environmental system, through studying the relationship between multimode system and risk assessment of earthquake-induced landslide. Then the paper evaluates the risk of earthquake-induced landslide in 138 small watersheds with the multimode system, and verifies the result with the landslide data from interpretation of unmanned plane image. The result indicates 67.01% area of landslide in extremely high and high hazard levels. The structure and function of risk assessment model of multimode system is consistent with the formation mechanism of earthquake-induced landslide, which could avoid and decrease the artificial and random in dividing the evaluation index and risk degree of landslide.
Background Factors Analysis and Risk Evaluation Based on Fuzzy Theory in Wenchuan Seismic Landslides
Authors: Han Meng , Fan Xiao Yi , Qiao Jian Ping
Published: October 2012

Earthquake is one of the most important external factors causes landslide, the geological and topographical conditions of the slope itself is the most important internal factors which induce landslide on landslide’s size and probability. These factors can be described as background factors impact the seismic landslides. Through the analysis and statistics on seismic landslides’ data in this paper, five directions were studied. These are lithology, slope height, slope angel, slope shape and slope direction. The influence features on number, area and volume of the five background factors show the contribution rate and risk degree. Using fuzzy theory to carry out quantitative and semi-quantitative analysis on these factors, the weights of the five background factors can be determined. Then using the risk evaluation on a specific landslide according to the principle of maximum membership, the result shows this method is reasonable.
Visual Processing of the River Cross-Sectional Data
Authors: Duan Qi Qing , Wu Rui Hai
Published: October 2012

The cross-section of Hydraulic engineering (river, embankment) is a kind of cross section which is always perpendicular to the river direction. Section line is a straight line which is created by connecting two endpoint of the section. Cross-section measurements is that collecting a coordinate point (X, Y, H) on the section line every a certain distance. Field measurement, due to the influence of the external environment, especially when measured in the river, is difficult to ensure that the location of the measurement point exactly on the straight line shown in the section. The reason is that tracking ship traveling along with the section will be impacted by the water, resulting in the offset along the flow direction. Therefore we must to constantly adjust the direction of travel in the measurement process. For which the measurement data should be processed. So it is necessary to deal with the measurement data, and the idea of visual data was proposed in the paper, which is easier to analyze the accuracy of the measurement data. The BUFFER analysis method was used in the data processing, which effectively removed measurement invalid point that far away from the cross-section in measurement and improved the accuracy of the cross-section data processing. On the other hand, the effective pedal point coordinates was used in the calculation of the plane location of cross-section point. The coordinate which can make the cross-section data more realistic and different from the translation of point and uniform distribution algorithm closeted to the effective point of measurement. The method that the elevation of pedal point on the cross section calculated using the distance weighted interpolation method has been applied in the measurement process of several rivers. It is proved in practice that the method got good results and achieved the accuracy of the data and quality which the application sector requirements on.
Study on Surveying Data Processing of Engineering Distortion Based on Entropy
Authors: Zhou Fang Bin , Chen Yong Qi
Published: October 2012

The method of surveying data processing about engineering distortion was investigated. While a suited method selected, we must get known some identified prior information according to our professional experience. The surveying data processing is thought as changing information entropy and a new data processing method based on entropy is set forward. An example was applied to confirm the superiority to classical methods.