bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Analysis of Underground Concrete Arch Structure Strengthened with Near-Surface Bonded CFRP Strips
Authors: Jiang Mei Rong , Jin Feng Nian , Luo Shuai Ling , Fan Hua Lin , Wang Bo
Published: November 2012

To strengthen underground arch structure, the method with near-surface bonded carbon fiber reinforced polymer (CFRP) strips is proposed. A nonlinear finite element program is built to analyze concrete arch structure strengthened with CFRP. Factors that influence the strengthening effect are discussed. After arch strengthened with near-surface bonded CFRP strips, the cracking load, the yield load and the ultimate load has been greatly improved, the stiffness has also been greatly improved. The bearing capacity and the stiffness of arch structure increase with the layer quantity of CFRP increasing, increase with the strip quantity of CFRP in units increases. In the condition of the layer quantity and the strip quantity of CFRP being identical, the increasing ratio of load decreases with the reinforcement ratio increasing.
New Technologies for Highway Alignment under Complicated Environmental Conditions in Mountain Areas
Authors: Gao Chuan Dong
Published: November 2012

The concept of design that people want to reduce disasters of highway engineering at the source location is gradually implemented. This article introduces the application of the Computer-aided Design (CAD) technology, Geographic Information System (GIS) technology and mathematical method under complicated environmental conditions in mountain areas. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.
Experimental Analysis of Failure Modes and Pavement Strength Control Parameters to Existing Cement Concrete Pavement
Authors: Yuan Jian Yi , Yu Yi , Cheng Tao , Zhang Ding Bang , Wu Zhen Hua , Xiang Jian
Published: November 2012

Cement concrete pavement as a common form of the road has been widely used because of its high strength, stiffness, and good durability characteristics. In order to explore failure modes and the strength control factors of the cement concrete pavement in the region, site investigation and the orthogonal test method in laboratory are used. Test combination design for the main control factors of the cement concrete strength was executed based on orthogonal test method. Strength of concrete specimen was determined by using indoor pressure test machine. The results show that the chiefly control parameter of affecting concrete strength is water cement ratio and the following are sand ratio and the coarse aggregate grading.
Quantitative Study for the Impact of Fines Content on Soil Surface Cracking
Authors: Lu Yang , Chen Ning Sheng , Lv Li Qun , Deng Ming Feng
Published: November 2012

Cracking development in soils is of significance for their physical and mechanical properties. The fines content in soils is one of the most important factors in cracking development, leading to it being of great importance to quantitatively study how the cracking development is influenced by the fines content. In this paper, experimental simulations on soil surface cracking were first conducted in the lab with soil from Jiangjia Valley. Digital image processing technology was then applied to investigate cracking in soil with different fines content by describing the surface cracks with crack area density Ac (ratio of all cracks’ area to total surface area of the cracked soil) and crack line density Lc (ratio of all cracks’ perimeters to total surface area of the cracked soil). The conclusions are drawn as follows: 1) Surface cracks increase with fines content going up; specifically, when the soil mass with fines content ranging from 20% to 30%, there is a significant increase in cracks; There is no crack developed in the soil with no fines, comparing to the gradual increase in soils with other fines content. 2) With the loss of water content, Ac and Lc will increase until a constant value is reached. However, small cracks will be closed and big ones will evolve into smaller ones if enough water is added. 3) Soil mass with fines content less than 20% is inclined to have small cracks when it is drying and cracks will be closed if enough water is added; on the other hand, soil mass with fines content more than 20% is inclined to have bigger cracks and they will become smaller when submerged into water. 4) After times of wetting and drying cycles, soil mass shrinks and soil dry density increases, which leads to the decrease of Dc and Lc, which suggests soil with larger dry density will probably have fewer cracks.
Research and Application of Anti-Rutting in the Asphalt Mixtures
Authors: Yang Xiu Hua
Published: November 2012

with the development of our country highway traffic to large flow, large axle load and channelized traffic direction, traffic volume and the changes of axial load composition to the present asphalt pavement structure, causing the pavement service capacity declines, structure damage occurs early, rut problem is one of the main factors of asphalt pavement quality, so the anti-rutting in the asphalt mixtures were studied in this paper.
Seismic Analysis of Long Span Double-Curved Arch Bridge
Authors: Zhang Yun , Huang Xiu Feng , Li Bei
Published: November 2012

Take one long span double-curved arch bridge as the example, built the finite element model of bridge structure and analyzed the modeling method, dynamic features and response under ground motion. It demonstrates that response spectrum method could meet the calculation requirement in seismic analysis of the double-curved arch bridge, and the result accords with time-history analysis method. Bridge vibration type is dispersing in quality distribution of double-curved arch bridge; it should take adequate vibration types in bridge combination. At frequent earthquake, it is actual to considerate the coalition function between arch crown structure and the main arch ring. But at rare earthquake, the arch crown buildings of masonry structure is easy to be damaged, it is not suitable to considerate the coalition function in bridge reinforcement.
Vessel-Bridge Collision Force Research on Ordinary Highway Bridge in Fujian Navigable River
Authors: Lin Jian Fan , Su Yan , Du Yue Ting
Published: November 2012

Several methods had been provided to compute bridge collision force among domestic and abroad, the paper took Fujian Saijiang River as a example, and compared ship collision force calculated by different methods and chose the suitable collision force for the collapse of probability calculation. The American AASHTO guidelines and nonlinear finite element were practical to calculate collision force.
Internal Force Calculation of Two-Way Curved Arch Bridge
Authors: Huo Bao Rong , Yang Guang Ning , Zhang Xiang Dong
Published: November 2012

Because of two-way curved arch bridge with low design load, less structural steel, improper construction, overloading and poor integrity, when the bridge structure can’t satisfy the carrying capacity and traffic capacity requirements, we urgently need reinforce the bridge, which has become an important link of safety assessment and insurance of the bridge structures. Internal force calculation of two-way curved arch bridge is done, and calculation conclusions of Aohan Bridge are shown. Plane rod unit’s calculation results show that the bridge under the action of steam-20, hang-100 loads, eccentricity of the section at the arch feet in main arch ring beyond allowable eccentricity, a state of large eccentric's stress appears, and on surface of the arch feet appeared tensile crack in the load simulation. The calculation results of the main arch ring shows that a phenomenon of stress concentration exists in the arch feet, in addition to the influence of big eccentric. Technology processing should be considered when do the arch feet reinforcement. Data from the arch ring calculation results, the bridge has certain overload potential. But according to the bending moment distribution, strengthen the resistance bending moment in the arch feet, an allow full play to the potential of concrete iron in the arch rib under the premise of reinforced the positive bending moment.
Scaffold Design and Stability Design of Tangfangya Bridge
Authors: Xie Yu Jian
Published: November 2012

Based on summarizing three computational models of the rigid node model, the hinge node model and the model of semi-rigid node, the calculated length of scaffold are discussed. The application in the scaffold design of Tang Fang Ya Bridge with the resulting simplified formula shows that the hinge node model can ensure the overall stability of the structure effectively, but it is necessary to set oblique scissors appropriately to ensure the normal working of the structure.
Experimental Study on Behavior of Interface between Coarse-Grained Soil and Gravel-Clay under Seismic Loading
Authors: Liu Ping , Yang Gui
Published: November 2012

The behavior of interfaces between coarse-grained soil and gravel-clay introduced by earthquake plays an important role in analyzing the stability of the impermeable structure in rock filling dams. Using the NGI-type simple shear apparatus, cyclic simple shear tests were performed to study the mechanical behaviors of the interface; shear deformations both along the interface and in the coarse-grained soil were analyzed. The test results indicate that: the cyclic shear strength of the interface was found approximately linearly proportional to the normal stress applied on the interface; meanwhile, the shear deformations reached their peak values in the first cycle, respectively; and the direction of initial shear stress significantly influenced the mode of relative displacement along the interface. In addition, shear shrinkage and shear dilation occurred alternately in each cycle. It also revealed that shear strength of the interface increases as the shear cycle increased and is approximately linear proportional to the normal stress level on the interface.
Research on Performance-Based Design Theory
Authors: Wan Hai Tao , Kong Qing Mei
Published: November 2012

Three level seismic fortification theory is seismic design theory of the bearing capacity,which can not really realize that no damage under minor earthquake, repairable under moderate earthquake and no collapsing under strong earthquake. In order to overcome this deficiency, American earthquake engineering and structural engineering experts have profound conclusion after the previous earthquakes, improved bearing capacity design method, put forward the theory of performance-based design.Firstly,the origin of performance-based design theory is introduced in the paper.Secondly,the main content of performance-based design theory is illustrated,which include Earthquake Hazard Levels,performance levels of building structure,target building performance levels and performance- based design methods.Finally,the paper pointes out that performance-based design theory has attracted extensive attention of Chinese researchers and engineering designer,a series of research work has been carried on,and some achievement has been made.
Seismic Evaluation and Strengthening on Teaching Building of Masonry Structure
Authors: Du De Run , Wu Ya Nan , Jiang Ji Tong
Published: November 2012

"six two building" in ocean university of china has been used over 90 years, which can not meet the requirements for earthquake resistance protection. In order to ensure its safe use, at the same time keeping the original building style, this paper proposes the seismic appraisal method after field detection, structure calculation and appraisal regulation check. Then this paper presents corresponding strengthening suggestion. It can be used for reference in other similar old building.
The Effect of Structural Parameters on Seismic Behavior of Concrete-Filled Steel Tubular Frames with Buckling-Restrained Brace
Authors: Ren Feng Ming , Zhang Jie Biao , Zhou Yun , Du Xiu Li
Published: November 2012

In order to study the parameters influence on seismic behavior of concrete filled steel tubular (CFST) frame with bucking-restrained brace (BRB), the finite element analysis for CFST frame with BRB is studied in this paper, which is performed under low cyclic loading using the software of ABAQUS. Failure model and skeleton curve are comparative analyzed with the related experiment components, verifying that the finite element simulation of the CFST frame with BRB is effective. By changing the axial compression ratio of the column(n) and the steel ratio(α) of the column section respectively, the effect of the structural parameters on the seismic behavior of the CFST frames with BRB had been studied. The results shows that: with the increase of steel ratio of the column section, the lateral ultimate strength and the initial stiffness of the frame get higher, the lateral load(P) versus lateral displacement (Δ) hysteresis curves of the frame get plumper, and the energy dissipation of BRB remain basically unchanged; With the increase of axial compression ratio of the column, the lateral ultimate strength and the hysteretic behavior of the frame become low, whilst the energy dissipated by the BRB get higher.
Seismic Analysis of an Earth-Rock Dam on Thick Alluvial Deposit
Authors: Cen Wei Jun , Wang Shuai , Yang Zhi Xiang , Sun Hui
Published: November 2012

The nonlinear dynamic FEM was applied to analyze the dynamic response of a core-wall earth-rock dam on thick loess alluvial deposit. The dynamic responses of acceleration, dynamic displacement, permanent deformation and the liquefaction state of the dam were obtained. Meanwhile, both dynamic FEM limit equilibrium method and pseudo-static method were used to access the seismic resistance of dam slope stability. The results show that dynamic responses of acceleration and dynamic displacement are reasonable. The permanent deformation is mainly concentrated in the core wall. The downstream dam slope has enough seismic resistance stability. However, there will be big dynamic pore-water pressure in the dam foundation and the loess alluvial deposit will be liquefied during the earthquake. Therefore the resistance method of liquefaction should be adopted for the foundation.
Finite Element Analysis of Unsteady Seepage Flow through the Earth Dam of Huangbizhuang Reservoir
Authors: Du Er Xia , Sun Jian Heng
Published: November 2012

The unsteady seepage through earth dams is analyzed with the finite element method in this paper.Using this method, the seepage through Huangbizhuang earth dam is calculated. Many reasonable suggestions are posed to help the management and reinforcement of Huangbizhuang reservoir earth dam.
Influence of Hydraulic Factor of Vertical-Slot Fishway on Swimming Ability of Fish
Authors: Guo Zhuo Min , Zhu Gao , Bie Yu Jing , Tang Meng Jun
Published: November 2012

Vertical-slot fishway is widely used in different shape of fish-way due to the adaptability to water level amplitude, the hydraulic characteristics of the vertical-slot fish-way of different scale has been extensively researched by researcher domestic and overseas, the energy dissipation mechanism and hydraulic characteristics of the fish-way in different scale under different inflow has been acquainted now. In this paper, the hydraulic characteristics of Vertical-slot fish-way of different size under water depth, inflow and slope is analyzed , influence of water depth, flow velocity, dissipation rating per unit volume and turbulent energy etc. On fish swimming ability is discussed, and design of fish-way is evaluated by relevant hydraulic factor of fish swimming characteristics. Finally the research method and experience abroad is summarized in the paper.
The Evaluation of the Water Quality of Shenwo Reservoir Based on Fuzzy Comprehensive Evaluation Method
Authors: Liu Dan , Hu Na , Liu Han Yong , Gong An
Published: November 2012

The water of Shenwo reservoir has been seriously polluted. In order to avoid the inaccurate evaluation results of a single index, the variable fuzzy comprehensive evaluation method has been adopted to comprehensively evaluate the water quality of Shenwo reservoir based on the water quality data of Lan River section of Shenwo reservoir in 2011. The evaluation results have shown that the water quality of Shenwo reservoir belongs to grade Ⅳ, which tends to be grade Ⅲ. The evaluation results based on this approach will be more stable and reliable.
On the Seepage Stability of a Tailing Dam in Wushan Copper Mine
Authors: Song Liang , Yang Zhen Xing , Wang Hao , Wang Zi Hao , Zhang Huan Qiang
Published: November 2012

The tailing pond of Wushan copper mine is located in a valley among the mountains, with kinds of hidden troubles like the overflow of the saturation line, the swamping and piping of partial section, and some local deformation, which appeared on both the starter dam and the tailing embankment in the early stage. To meet the requirement of production, a new tailing pond named No.2 Tailing Pond was built in the downstream of the original No.1tailing pond. At present, in No.1 dam, the part below 37m water level was totally submerged by the water, then the condition of the seepage field will change with the rising water level. For the safety of production and to provide a scientific basis to the management of the tailing dam, an analysis of seepage stability at four different conditions of two sections was carried out based on the field conditions of the dam. Finally, a comparison between the simulated results and the measured results was made, the results show that the existing drainage system is safe and effective, and the seepage deformation of Wushan tailing dam will not happen.
The Analysis on Energy Saving Reconstruction of a Grade III-A General Hospital in Wuhan
Authors: Li Yu Yun , Zhang Zhi , Li Hai Ceng , Zhang Chun Zhi
Published: November 2012

Take one of Grade III-A general hospitals in Wuhan as the research object with auditing the hospital's energy consuming system. It can be proved that the energy consumption per unit area is 27kgce/m2 , analysis of typical of the hospital exterior envelope, lighting systems, central heating and air conditioning system for hospital energy, gave priority to recycle the boiler flue gas heat and condensation water, natural light using, exterior windows transforming and installation of the sub-metering systems for energy saving renovation. The comprehensive transformation energy-saving rate is 31.71%. Energy saving quantity is 318.01tce. A total investment is 4.3948 million yuan. The payback period is 2.5 years.
Simulation Based on CFD to Temperature and Flow Fields of Vertical Air Conditioner Operation
Authors: Tang Yi , Wang Jin Feng , Xie Jing , Zhang Zheng , Liu Rui
Published: November 2012

The sales volume of vertical air conditioner in China mainland has developed rapidly. The researches in the field to the operation of vertical air conditioner are lacked since it is hardly to analyze different kinds of operating condition. Computational Fluid Dynamics (CFD) has been applied in engineering with the advance of the computer science and technology. In this article, both temperature and air flow distributions were analyzed to a meeting room which putted a vertical air conditioner. The model was used and the equations for numerical simulation (e.g. energy, residual, continuity, etc) were chosen as second order to get the higher accuracy. The results to simulation were showed reasonable and could offer a reference to the practical.
Installation Design and Energy Conservation Analysis of Floor Radiant Cooling/Heating System with Solar Energy
Authors: Li Qi Fen , Li Tao , Sun Wei Dong , Zhou Zhi Tian , Pan Cui Cui , Zhao Li Feng
Published: November 2012

How to reduce the energy consumption of air conditioning, to use new energy such as solar appropriately, and to achieve energy savings, are the problems must be treated in HVAC industry. Because of the high energy consumption of traditional air-conditioning and the need for reduction of emission, an air conditioning system (utilizing solar dehumidifying applied to heating/cooling radiant floor) is designed and installed in this paper. At the same time, as an example, the energy saving potential of system is analyzed. This type of heating/cooling radiant floor system is worth promoted if solve the dehumidification properly. By separating to deal with heat and moisture can reduce the energy-cost of traditional air-conditioning, and to achieve purposes of primary energy saving.
Experimental Investigation on Mechanical Properties of Soft Rock under Instantaneous Triaxial Compression
Authors: Wang Yu , Liu Feng
Published: November 2012

Using the RMT-150C rock mechanics test system, the instantaneous triaxial compression tests for muddy siltstone were carried out under different confining pressures, and the instantaneous mechanical properties of soft rock were obtained. The results show that the strength parameters of sample have a positive linear relation with the confining pressure, and the sensitivity of peak strength on the confining pressure is higher than that of residual strength. The elastic and deformation modulus of sample linearly increase with the confining pressure going up, and the elastic modulus is more sensitive to the confining pressure. The soft rock sample shows typical ductility failure characteristic, while the damage characteristic is mainly shear failure and the shear failure angle linearly decreases with the confining pressure going up.
Numerical Simulation of Natural Ventilation in Typical Residential Layout
Authors: Li Jing
Published: November 2012

In order to research the influence of layout on natural ventilation，the indoor natural ventilation environment of the typical residential layout in Lishui city was simulated by using CFD method, and the influences of building openings and the wind angle were analyzed . The paper put forwards several proposals to enhance the effect of natural ventilation based on the simulation and the analysis. The results show that indoor layout including the area and ratio of the opening can influence interior ventilation,and the layout in which cross-ventilation can form is good for ventilation,and wind angle has an effect upon indoor natural ventilation in the certain layout.
A New Type Thermal Insulation Fireproofing Wallboard
Authors: Wang Xian Li , Wang Lin
Published: November 2012

Exterior thermal insulation technology has many advantages such as light weight, good thermal insulation effect, and so on. So it is widely used in energy-saving building and existing building energy-saving renovation project all over the word. This article describes material selection, product performance and process characteristics of a new type composite phenolic wallboard which has double functions of thermal insulation and fireproofing.
Numerical Investigation of Fire Dynamic Behavior for a Commercial Building Basement
Authors: Lin Cherng Shing , Yu Chia Chun , Wang Shih Cheng
Published: November 2012

In the past twenty years, many severe basement fires occurred and caused huge losses of human lives and damages to property in Taiwan. During a building fire, smoke at high temperatures and poisonous gases (such as CO) may easily spread through corridors and ventilation systems in the entire building. Therefore, protecting against the basement fires in commercial buildings is of important concern for Taiwan’s fire protection authority. This paper utilizes FDS (Fire Dynamic Simulator) to construct a computer simulation model for investigating the Cardon basement fire that occurred in Taipei (1993). The fire accident unfortunately caused tremendous property losses and heavy casualties (22 died and 7 were injured). The major important parameters of the flow field - such as speed to the spread of fire, smoke movement, upper layer temperature, and CO concentration are obtained to analyze and understand the fire dynamic characteristics. The computed results reasonably agree with post-accident reports. The simulation results obtained may be utilized to improve the better and safer designs for basement building fire protection capability. The information can also be valuable for the similar fire disaster prevention and mitigation in the future.
Gas Control in Special Soft Coal with Lower Permeability in Liangbei Coal Mine
Authors: Cheng Le Tuan , Zou Zheng Sheng , Li Qing Bo , Zeng Xian Tao
Published: November 2012

Coal seam B1 has characteristics of soft, poor air permeability, high gas content and gas pressure, therefore, there's strong outburst danger in Liangbei Coal Mine. However, the gas control in the coal with lower strength and lower permeability is still in the exploration. Depth of coal roadway is 610-750m at 11 mining area. The roadway excavating speed is seriously influenced by gas outburst, so it brings unfavorable influence to the mine. Based on the principle of relieving gas pressure in the low permeability reservoir, the shortages of existing methods are analyzed for gas control and optimization measure for gas outburst prevention, i.e. "short, flat, long, subtraction, stay, support", put forward from the view of system engineering. With the new measure, drilling efficiency increase, borehole collapse decrease, single borehole drainage scope increase, the gas control meets the requirement and the coal side is easily to be controlled. After application of the optimization technique, the roadway excavating speed is increased from 45m to 70m every month in 11mining area, and the tight situation of excavation replacement is alleviated.
Study on Social Risk Evaluation Index System for Tailings Pond Dam-Break Based on the Vulnerability Theory
Authors: Mei Guo Dong , Wu Zong Zhi
Published: November 2012

In allusion to the status quo of deficient in evaluation theory and methods on the social risk of dam-break, this paper established 24 index systems for the evaluation of dam-break social risk composed by the dam-break hazard intensity, accident probability, hazard-affected body inherent vulnerability and disaster relief capacity. The quantitative calculation formula has also been put forward for evaluation indexes. In line with the Delphi method, a judgment matrix on the social risk caused by dam-break has been constructed, and has obtained the weight of each index by virtue of analytic hierarchy process. The results show the internal friction angle, the downstream main ditch longitudinal gradient, the current dam height and the monitoring & forecasting capacity are the key indicators that affect the social risks of dam-break. The results of this study help to further enhance and improve the technical level of risk evaluation for the tailings pond.
Study on Quantity Calculation and Influencing Simulation of Debris Flow Based on Three-Dimensional Remote Sensing System
Authors: Yin Yan Li , Xu Bo , Xie Mo Wen , Liu Xiang Yu
Published: November 2012

Debris flow is a huge geological disaster，the prediction of the quantity of debris flow is very significant. In this paper, combined with three-dimensional (3D) remote sensing image interpretation, a quantitative method has been proposed to calculate the quantity of debris flow. In the catchment of debris flow, the topography has been divided into zero-time valleys and one-time valleys, and the quantity of debris flow is calculated by two analytical ways of the full amount of portative matter and the amount of portative matter only caused by rainfall. In addition, based on the digital elevation model (DEM) and the amount of portative matter caused by rainfall, the spatial analysis function of the geographic information system (GIS) has been used to calculate the topographic parameters of the cross sectional area and the regional plane area of the catchment of debris flow. Then the relationship of the soil-rock output and the topographic parameters can be discriminated. Furthermore, the influencing range of debris flow can be stimulated. By practices, the analytical results can be used to estimate the dangerous area of potential debris flow.
A Summary of the Scientific Data and its Quality Evaluation
Authors: Sun Chong Liang , Wang Rui Ping
Published: November 2012

As the carrier of all kinds of study & engineering, the data as well as its quality have always been the focus concerned popularly. With the original source analysis as the beginning, the paper analyzes the relationship between the objective world and the data, as well as the sources of the scientific data uncertainty. Then the intrinsic property of the scientific data was also introduced, followed by the introduction of the relationship between data management and GIS(Geographic Information System). After that, several normal methods to evaluate & manage data were put forward, followed by a summary. And this would be interesting for deeply study of the related fields.
Asphaltene Deposition Induced by Carbon Oxide and its Influence on Displacement Efficiency
Authors: Zhao Feng Lan , Hou Ji Rui , Huang Shi Jun
Published: November 2012

CO2is inclined to dissolve in crude oil in the reservoir condition and accordingly bring the changes in the crude oil composition, which will induce asphaltene deposition and following formation damage. In this paper, core flooding device is applied to study the effect of asphaltene deposition on flooding efficiency. From the flooding results, dissolution of CO2into oil leads to recovery increase because of crude oil viscosity reduction. But precipitated asphaltene particles may plug the pores and throats, which will make the flooding effects worse. Under the same experimental condition and with equivalent crude oil viscosity, the recovery of oil with higher proportion of precipitated asphaltene was relatively lower during the CO2flooding, so the asphltene precipitation would affect CO2displacement efficiSubscript textency and total oil recovery to some extent. Combination of static diffusion and dynamic oil flooding would provide basic parameters for further study of the CO2flooding mechanism and theoretical evidence for design of CO2flooding programs and forecasting of asphaltene deposition.
A Capillary Bundle Model Based on Aperture’s Exponential Distribution and its Application in Porous Media’s Mono Direct Percolation
Authors: Ju Xiao Dong , Feng Wen Juan , Zhang Yu Jun , Zou Zheng Sheng
Published: November 2012

The permeability and changing characters following variation of physicochemical environment outside of porous media like rock and soil are very important for all kind of civil engineering. But until to now, most theories of them are based on phenomenological method, and they cannot interpret the seepage traits and the variation properties induced by environment changing essentially. The author based on the predecessor’s work which consider that pore number obey exponential and built a capillary bundle model to depict the microscopic peculiarity of porous media seepage. The effect of water temperature, the upper limit of Darcy Law, flow rate beyond Darcy Law’s upper limit, and the infection of porosity on permeability etc issues were discussed theoretically with this model. At last, an instance was calculated with this model for its permeability coefficient and critical hydraulic gradient, and at the end the calculation results were discussed.
Research on the Discontinuous Deformation Analysis for Hydro-Mechanical Coupling Model of the Fractured Rock Masses
Authors: Liu Xian Shan
Published: November 2012

Fractured rock masses with many fractures will make the hydro-mechanical characteristics more complex. However, traditional equivalent continuous method just generally reflects the mechanical characteristics for the rocks including large fractures. In order to simulate the mechanical characteristics of the fractured rock masses under complex geotechnical environment, a new method based on Discontinuous Deformation Analysis (DDA) was forward to research on the hydro-mechanical effect. And use the method to analyze the dam foundation, the results compared with that considering non-coupling effect indicated that this model could reflect the hydro-mechanical effect in detail. In addition, FEM and DEM were applied to research on the distribution of the water head, displacement and stress under the same conditions, the results agreed with that by DDA, which further verified the feasibility of the forward method. In addition, the results about the water head and stress analyzed by DDA was greater than that by FEM and DEM, the reason was that this model simultaneously considered the normal deformation and shear deformation of the fractures. Therefore, the forward coupling method based on DDA will provide a research technique for seepage control and stability assessment of the rock engineering.
Modal Analysis of Multi-Span Pipes Conveying Fluid Based on Three Different FSI Methods
Authors: Zhang Ting , Ding Huan Huan , Su Yan , Chen Hong
Published: November 2012

The modal analysis of pipes conveying fluid considering the influence of Fluid-Structure Interaction (FSI) is always a topic in flow and solid mechanics fields worth study. Three methods of coupling, the direct FSI method, the one-way FSI method and the bidirectional FSI method, with the velocity’s influence on pipe system’s natural frequency were considered in this study. The results of pipe’s dynamic behavior indicate that the two-way FSI method can get a more reasonable result. Furthermore, when velocity changes in a small range far from critical velocity, velocity makes very little influence on system’s nature frequency. The result was compared with conclusion in the literature and very good agreement was found.
Determination of Forchheimer Term in Porous Media Consisting of Obstacles of Different Sizes
Authors: Liu Ren Xing , Nakayama Akira , Haung Xiao Lan
Published: November 2012

As a sequel to the study in determining the permeability of the porous media composed of obstacles of different sizes, exhaustive numerical calculations were conducted using the same two-dimensional numerical models of square rods as in the previous study. The models consist of collections of square rod obstacles of two-, three-, four- and five-different sizes. Computations were carried out to reveal the details of microscopic velocity and pressure fields. There results are integrated to find the macroscopic pressure gradients for collections of multi-sized obstacles. The Ergun type general formula has been proposed along with a definition of an effective average size, which, when substituted into the formula, yields a reasonable estimate for the macroscopic pressure drops in multi-sized obstacles.
Analysis on Coupling of Temperature Field and Stress Field for Tunnel Surrounding Rock in Cold Region
Authors: Zhang Hui Mei , Liang Yuan , Chen Chuan Gao , Cao Hai Bo
Published: November 2012

Based on the theory of mass and energy transfer, the coupling theoretical model of temperature and stress fields in the process of rock freeze-thaw was established considering the volume load caused by temperature change within the rock body. Taking Daban mountain tunnel surrounding rock at its exit as example, the heat--stress coupling process was numerically calculated, and the mutual influence and varied laws of temperature and stress fields were researched. The simulating result is similar to the current results and engineering experience, which can verify the correctness of the theoretical model and the reliability of calculation method, and also provide some theoretical basis for determining the engineering parameters scientifically, optimizing the lining and supporting scheme and ensuring the safety of design and construction.
Experimental Study on Fluid-Solid Coupling Seepage Flow in Putaohua Reservoir
Authors: Zhao Yu , Song Kao Ping , Liu Yin Feng
Published: November 2012

According to existing fluid-solid coupling models, reasonable range and control technology of pressure depression cone has not be formed in Putaohua reservoir. In this paper, using laboratory experiment, the relationship between rock elastic-plastic deformation, single phase permeability of oil or water and relative permeability curves has been measured and the following important facts has been established: oil well bottom hole pressure which is lower than formation pressure is in a reasonable range during the initial stage of commissioning, and a gently pressure depression cone is formed between the formation and wellbore, that can reduce the permeability loss by compaction settlement and particle migration and return to production in reasonable bottom hole pressure while the water flooding takes effect and thus enhance the oil recovery.
Calculation of the Tension of Coastal Shore-to-Ship Transmission Cableway
Authors: Tan Zhen Dong , Du Zun Feng , Zhang Jian , He Chao , Wu Wei Guo
Published: November 2012

One of the problems in installing cableway is the estimation of the tension. The mechanical model of coastal shore-to-ship transmission cableway was analyzed with catenary algorithm, compared with the finite element analysis of ANSYS software. The result shows that the tension and its changing amplitude are both gradually decreasing with the increase of the deflection. And, if the deflection is determined, the tension is decreasing with the increase of cableway’s span. These analysis results and conclusions can give the basis to safe installation of the cableway.
Oscillatory Behavior in a System of Coupled Van Der Pol-Duffing Oscillators with Delays
Authors: Lin Yuan Hua , Feng Chun Hua
Published: November 2012

In this paper, a model of coupled van der Pol-Duffing oscillators with delays is studied. Two sufficient conditions to guarantee the existence of oscillations for the system are provided. Numerical simulation is given to demonstrate our result.
Dynamic Response of an Elastic-Supported Bridge Beam Subjected to Velocity-Varied Moving Loads
Authors: Mei Fu Liang , Li Gui Ling
Published: November 2012

Dynamic response of an elastic-supported bridge under speed-varied moving loads was investigated. A mathematical model of vehicle-bridge coupled oscillation for an elastic-supported bridge was built up by means of 1/4 vehicle model (Mass-Spring-Mass) and Euler-Bernoulli beam theory. And then dynamic equations of vehicle-bridge coupled oscillation in matrix form were established using two former orders general coordinates of an elastic-supported beam and model superposition method. The influences of vehicle-bridge coupled vibration model, elastic-supported stiffness, entrance speeds and acceleration /deceleration of moving loads on the dynamic responses of bridges were studied. Vehicle-bridge coupled vibration model based on 1/4 vehicle model can more accurately describe the dynamic characters of bridges than that based on constant moving force model. Elastic-supported stiffness only has an impact on the fluctuation amplitudes of dynamic responses. The vehicle-induced impact factor is dependent on the entrance speeds, acceleration/deceleration of moving loads and elastic-supported stiffness.
Analysis and Comparison Research of Airport Noise Metrics
Authors: Wang Yan Hua , Xia Feng , Xu Tao
Published: November 2012

Systematically analyzes the basic principle, calculation methods and control standards of the noise metrics of the world's major countries and regions. A series of experiments were taken on based on the noise monitoring data of a large busy airport. Through the experimental analysis demonstrated the similarities and differences of the airport noise metrics, pointing out that the existing airport noise metrics are not complete and need improvement.
Study on Sub-Span Oscillation of Bundle Conductor for Transmission Line
Authors: Zhu Da Lin , Ma Chao
Published: November 2012

The excitation mechanism of bundle conductors' sub-span oscillation was introduced 、 the influencing factors of bundle conductors' sub-span oscillation are analyzed and the control computation theory of bundle conductors' sub-span oscillation was summarized. Then listed a number of anti-vibration measures of bundle conductors’ sub-span oscillation and proposed the methods of optimization arrangement about bundle conductors’ sub-span oscillation.
Prediction on the Sound Insulation of a Double -Leaf Lightweight Panels
Authors: Huang Xian Feng , Yang Yan , Yang Zong Xiao
Published: November 2012

Statistical energy analysis (SEA) is utilized to model sound transmission through a double -leaf lightweight. Calculating the sound insulation by this method and comparing with the measured data have shown that the prediction model may generate a certain difference between the prediction and experimental data, this method, moreover, might further solve the problem of the sound insulation of the complex wall structure by optimizing the configuration of the enclosure structure.
Deformation Pattern of Foundation Pit Excavation beside Silt Soil Railway Subgrade
Authors: He Fang Ding , Guo Guang Jun , Zang Ya Nan
Published: November 2012

Foundation pit excavation beside silt soil railway subgrade in the water net plain district is influenced by overload of backfilled roadbed, train's vibrating load and high groundwater level, so foundation pit instability occurs easily. Numerical simulation is done on several parameters such as different depths of pit cutting, distances from subgrade, speeds of the train, and so on. Through analyzing changes and impact ranges of the pore pressure and displacement under various work conditions, it reveals lateral deformation mechanism of the foundation pit. And also it provides references for supporting design of foundation pit beside silt soil subgrade.
Web-Based 3D Visualization of Dam Safety Monitoring
Authors: Wu Bin Ping , Cui Bo , Zhong Deng Hua
Published: November 2012

In the light of the shortcomings of the traditionalIn the light of the shortcomings of the traditional methods on archiving monitoring information of dam safety, the principle of web-based 3D visualization based on Unity3D engine was explored for construction managers to grasp dam operation conditions immediately and intuitively, and the web-based 3D visualization Dam Safety Monitoring System (DSMS) was developed in B/S structure. The networked, digital and 3D visualized system was developed to provide an effective analysis platform for the construction managers to make decisions. The research is of great practical significance.
The Finite Element Analysis of Truss Beam Structure Based on ANSYS
Authors: Xia Liu
Published: November 2012

The structural characteristics of the truss were introduced, and the force status of its bars was analyzed and the combination condition of loading condition for analyzing the strength of the truss was determined. This would transfer the internal complex stress state of abdominal girder withstanding the pressure into the simple compression stress state of truss rods, making it intuitive for us to know distribution and transfer of force, and then facilitating the analyzing of the structure. For example, for Pipe belt conveyor case through the establishment of the finite element model of the truss, the paper analyzed the stress, strain and displacement of its main bars while the truss being at various combination of loading condition. The results showed that: ANSYS could offer theory basis for optimization designing truss structure.
The Fuzzy Matter-Element Comprehensive Evaluation Model for Erosion Stability of Geocell Protection of Slope and its Application
Authors: Wang Guang Yue , Zhao Jan Wu
Published: November 2012

To solve the existing fuzziness in the grading of stability evaluation of geocell protected slope and inconsistent between evaluation result by single index and the fact, this paper establishes index system of the stability evaluation of geocell protection of slope and propose a method. First, two-grade Fuzzy Matter-element Model is established based on the index system. Second, factor weights of evaluation index are calculated by AHP. Finally, the grade of the stability of geocell protection of slope is obtained based on Correlation Degree. Analysis results show that based on comprehensive consideration of subjective factors and objective factors, this method is effective and agrees well with engineering practical.
Economic Applicability Evaluation of the Method of Replacement with Gobi Desert in Tibetan Areas
Authors: Liu Jie , Pan Jie
Published: November 2012

There is lack of building materials in Tibetan areas of PRC, and its region is vast, so even the ordinary materials are usually expensive when construction. In order to take advantage of local materials, one kind of local materials can be seen everywhere, Gobi desert was used in the filling technology. According to application, it indicates that this material can meet the requirement of the code of China. Comparing to method of replacement with coarse sand which comes from local Lasha River and Niyang River, the economic effects of the method of replacement with Gobi desert is obvious. The same time the construction period can be shortened largely. The key control measures of construction quality are presented on the basis of engineering practice.
Application of Oppression Construction Method in Soft Soil of Deep Foundation Pit Engineering Management
Authors: Zhuang Ying Chun , Shen Jie Chao , Pan Xiao Dong , Tong Jian Bo
Published: November 2012

Taking a project of Hangzhou as the example, a new management method named oppression construction method was proposed in soft soil of deep foundation pit engineering management. This method was based on the foundation pit excavation by layer and section. Through timely supporting of foundation pit and construction information management, the foundation pit supporting exposure time and exposed to the breadth and height was decreased. Thus the excavation process to the periphery environment influence was effectively reduced. It provided beneficial reference for the future of deep foundation pit engineering construction management.
Operation Performance Comprehensive Evaluation of Execution Control System in Freeway Construction Project
Authors: Tu Zheng Yu , Qu Na , Li Lu Xiong , Lu Yang
Published: November 2012

The evaluation index of execution control system of freeway construction project is established in this paper. And Delphi method is adapted to analyze the weights of index system. Then the extension comprehensive assessment method is adapted to analyze the execution control system performance of a key freeway construction project, and the corresponding suggestions and countermeasures are given. The goal of this kind of performance evaluation method is clear, and the maneuverability is strong. It has good stimulative effect for the real-time execution, control and adjustment of freeway construction project.
Analysis of Dynamic Response of Landslide Stability to Reservoir Water Level Fluctuation Using Numerical Simulation
Authors: Yi Wu , Meng Zhao Ping , Li Guo Qing , Jin Zhi Wei
Published: November 2012

Reservoir water level is one important factor influencing the stability of landslides. The dynamic response of landslide stability under reservoir water level function and its features are analyzed using theoretical and numerical methods. The results show that, in terms of reservoir water level fluctuation and landslide permeability, the seepage filed of landslide can be divided into four types: lag behind impoundment(X-Ⅰ), lag behind drawdown(T-Ⅰ), synchronization with impoundment(X-Ⅱ) and synchronization with drawdown (T-Ⅱ). Under lag behind drawdown, at a certain rate of reservoir drawdown, the stability drops with the permeability of landslide. Under lag behind impoundment, with the rise of water level, the lower the permeability of landslide is, the more stable the landslide is. Under synchronization with impoundment or drawdown, the stability of landslide drops with reservoir impoundment and rises with reservoir drawdown.