bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Temperature on Enhanced Treatment of Sewage from Discharging Points of Rivers by Biofilm Process Dosing with Enzyme
Authors: Guo Gai Mei
Published: May 2011

The research studied enhanced treatment of sewage from discharging points of rivers by biofilm process dosing with enzyme and promotion effect of enzyme on treatment of sewage by biofilm process, and investigated the changes of removal rates of the main pollution indexes at different temperature to ensure the optimal temperature. The research results indicated that temperature was an important factor influencing the removal rates of the main pollution indexes. When temperature was in the range of 5°C-8°C, the promotion effects of enzyme on the removals of CODCrand ammonia nitrogen (NH3-N) of sewage by biofilm process were not obvious. However when temperature were in the ranges of 15°C -18°C and 22°C -25°C, enzyme had the high promotion effects on the removals of the pollution indexes. Furthermore, within the certain temperature (5°C -25°C), the removal rates of CODCrand NH3-N were on the rise with the increase of temperature. When temperature increased from 5°C -8°C to 15°C -18°C, the removal rate of CODCrobviously increased, but when temperature continued to increase to 25, the rise trend of the removal rate of CODCrbecame slow. On the other hand, when temperature increased from 5°C -8°C to 22°C -25°C, the increase of the removal rate of NH3-N was always evident. Therefore, the optimal temperature was in the range of 22°C -25°C for the enhanced treatment of sewage from discharging points of rivers by biofilm process dosing with enzyme.
Effect of Phenol on Treatment of Sewage from Channel Discharge with Biological Accelerator-Biofilm Process
Authors: Guo Gai Mei
Published: May 2011

The research studied enhanced treatment of sewage from discharging points of rivers by biofilm process dosing with enzyme and the effect of phenol on removal rates of the main pollution indexes, and investigated promotion effect of enzyme (including the laboratory developed compounded enzyme and the foreign composite enzyme) on treatment of sewage by biofilm process. The research results indicated that when initial concentration of phenol was 5mg/L, the removal rates of phenol, CODCrand ammonia nitrogen obviously decreased compared to no phenol added to reactor A, B and C, and the negative effect of phenol was smaller on reactor B and C than on reactor A. Moreover, enzyme had good promotion effect on biofilm process during the sewage treatment process.
The Study of the Correlation between Ground Motion Input and Artificial Boundary Condition
Authors: Wu Yi
Published: May 2011

It is documented that some confusions about ground motion input and artificial boundary condition in present seismic analysis affect engineering anti-seismic security evaluation, and that different treatment effects on security are so lack of verification that they are must be checked, discussed and made clear to get consensus. A study was conducted with a typical example with large FEM software ANSYS and comparison was made between the results of various ground motion input and boundary treatment methods and those of theoretical correct analysis. Study shows that ground motion input and artificial boundary condition is greatly correlative and that correct results can’t be got unless ground motion input and artificial boundary condition can be treated and matched properly.
Numerical Analysis for Oil Pipeline Subjected to Earthquake Liquefaction-Induced Lateral Spreading
Authors: Shao Guang Biao
Published: May 2011

Lateral spreading induced by earthquake liquefaction in soil layers is classified as a main cause of damage of pipeline structures. In this study, non-linear finite element method was applied for three-dimensional shell element analysis of continuous oil pipeline structures against transverse permanent ground deformation due to lateral spreading. The soil-structure interactions were simulated by soil-spring elements and the elastro-plastic of soil property was taken into accounted. Influential factors, such as width of lateral spreading, characteristics of pipe, on behavior of pipeline structures are examined by numerical analysis using finite element software ANSYS. According to the parameters analysis, some recommendations for safety design for oil pipeline across potential earthquake liquefaction areas are proposed.
Displacement-Based Design for RC Bridge Columns Based on Chinese Code
Authors: Zhou Dao Chuan , Chen Guo Rong , Nie Li Ying
Published: May 2011

A comprehensive study of displacement-based design for reinforced concrete bridge columns is conducted. Section analysis software UC-Fyber is used to analyze the bending moment and curvature performance of columns’ sections, based on this, a new calculation method of target displacement of RC bridge columns is educed. Elastic displacement response spectrum, inelastic displacement response spectrum and inelastic demand spectrum are educed from acceleration spectra of Chinese Code JTG/T B02-01-2008; three simplified methods for displacement demand determination are developed. Example of the displacement-based design of bridge column was studied and checked by dynamic inelastic time-history analysis to clarify the reasonableness of the developed methods. Research shows that target displacement of RC bridge columns is relevant with concrete strength grade, longitudinal reinforcement ratio, height and the section form, etc; equivalent linearization method and inelastic displacement response spectrum method are based on the design response spectrum, could reach the target displacement and consider structure safety requirement; demand spectrum method is a simple and direct way to show design with graphics mode, with deficiency of structure capacity spectrum curve from pushover analysis differing from the reality.
Dynamic Reliability of Super Large Cooling Tower Structure under a Stationary Seismic Load
Authors: Zhang Yan , Bai Guo Liang , Xu Yan Zhou
Published: May 2011

This paper analyzed the dynamic characteristics and the random seismic response of a super large hyperbolic cooling tower using 3-D FEM method. The results showed that the tower was very flexible. And it’s meridian direction axial force RMS was relatively bigger in the range of 40m-120m high, the maximum value of annular axial force RMS was at the top of the shell. Furthermore, using the principle of first passage failure mechanism, the dynamic reliability under 7 seismic intensity and different site conditions were analyzed and calculated, in which the structural drift at the height of 40m was considered as the failure criterion, and the dynamic reliability of the tower during the design reference period was obtained. Otherwise, the results of dynamic reliability under a seismic load based on Poisson hypothesis and Morkov hypothesis were also discussed.
Seismic Response Analysis of High-Speed Railway Bridge Fabricated Round-Ended Piers
Authors: Chen Ling Kun , Jiang Li Zhong , Zeng Zhi Ping , Luo Bo Fu
Published: May 2011

The responses of high-speed railway bridge subjected to seismic load were investigated by numerical simulation, the whole finite element model of the multi-span bridge simply supported bridge was set up, and natural vibration properties of structure were analyzed. According to theory of elasticity and elastic-plasticity, parametric study was conducted to assess the influences of different speeds, strong motion record, pier height and earthquake acceleration on the seismic capability of high-speed bridge subjected to different strength of the earthquake, the finite element soft ware and moment-curvature program were employed to calculate the earthquake responses of bridge. The calculation results show that, with the increase of train speed, pier height and earthquake intensity, the earthquake responses of bridge are increase in general, and the bottom of piers step into states of elastic-plasticity under high-level earthquake, elastic-plastic deformation is larger, the stirrup encryption measures should be carried out.
Ground Motion Synthesis Based on Power Spectrum Envelope
Authors: Teng Jun , Zhang Tao
Published: May 2011

The paper proposes a new method, which is used for providing ground motion input for seismic design under rare earthquake action. The crucial step of this method is to use power spectrum envelop, obtained from natural earthquake records but not deriving from response spectrum, as target curve to synthesis ground motion. The result shows that power spectrum obtained from this method fits well with the target curve, and the produced ground motion can properly predict the response spectrum of acceleration. By importing the concept of energy envelope, this method reduces the randomness of the ground motion sampling and the variability of the result in dynamic finite element analysis.
The Tension Fracture Simulation on the Asphalt Pavement with the Insufficient Compaction Roadbed
Authors: Wang Lai Gui , Feng Mei Sheng , Zhang Hong Zhu
Published: May 2011

For the study of soft subgrade pavement cracking process, it establishes the pavement structure tension crack model by elastic layered theory. Based on the finite element method, it studies the tension crack evolution process. It establishes the tension crack stress criterion to the roadbed. Analysis shows that the distresses of asphalt pavement of the real highway results from the damage by asymmetric sedimentation which is under excessively axle loading on pavement structure, rather than the fatigue damage by axle loading repetitions in the condition of asymmetric intensity in the same layer. The results show that the soft degree of the subgrade is proportional to the tensile stress, the more localized soft, the easier to crack the road. The soft roadbed does not have a homogeneous structure of the road surface, the tension stress rupture occurred in the discontinuous surface. The road structure has a set of tensile stress under the circulation wheel load, it formats a new fracture surface, and the structure form corresponding evolves, and causes stress state change. At last most of the road sub-base crack, and surface cracking occurres, so the pavement failure.
Ground Surface Tilts Estimated Based on Acceleration from Wenchuan Earthquake
Authors: Peng Xiao Bo , Li Xiao Jun
Published: May 2011

Dynamic equations of pendulums in strong motion instrument are analyzed. The equations imply horizontal recordings may be significantly influenced by ground surface tilt while the effects can be ignored for vertical recordings. The difference causes anomaly of horizontal to vertical Fourier amplitude spectra ratio, which is used to identify affected low frequency range.. The low frequency filter based on spectral ratio was employed to estimate the coseismic ground surface tilts in WenchuanMs8.0 earthquake. Results show the ground surface tilts are generally less than 1 degree and mainly happened within 30 kilometers to fault surface rupture traces, while rarely discovered in area outside 100 km and squared horizontal peak accelerations less than 200 cm/s2. Comparison of ground surface tilts under spectral ratio being 2 and 4, shows ground surface tilting amplitudes usually increased when spectral ratio is decreased, but residual ground surface tilts have small change.
Seismic Response of a Hill in Wenxian, Gansu, Observed from Aftershocks of 2008 Wenchuan Earthquake
Authors: Lu Yu Xia , Liu Kun , Shi Yu Cheng , Li Qian
Published: May 2011

To help understand the ground motions of the topographic site, the workers of Seismic Bureau of Gansu province deployed a temporary array of seismometers around the Wenxian hill and recorded ground motions from Wenchuan aftershocks. Only 11 aftershocks were recorded on all stations across the hill, these data were collected to facilitate studies of site response, wave propagation effect, and correlations of mainshock damage with local site conditions. In this paper, we analyze the weak motion data as well as the strong-motion data, and conduct comparisons of peak ground accelerations, seismic spectra analysis, and spectral ratio analysis. A more complete description of the site’s amplification, its relationship to topography, and its relationship to earthquake source effects are provided. The result shows that the ground motion was consistently amplified at station at or near the top of the hill compared with stations at the base of the hill and the amplifications frequency dependent and has its maximum at the resonant frequency of the site.
Real-Time Hybrid Simulation of a Steel MRF with Large Scale Passive Magneto-Rheological Fluid Dampers under Selected Ground Motions
Authors: Chen Cheng , Ricles James M.
Published: May 2011

Experimental evaluation of large scale MR fluid dampers for seismic hazard mitigation in buildings is presented in this paper. A simplified design procedure is applied to design a two-story, four-bay steel moment resisting frame (MRF) prototype structure with MR fluid dampers in passive mode. Real-time hybrid simulations are conducted to experimentally evaluate the performance of the MRF. The simulation results show that the simplified design procedure enables an efficient design to be achieved for an MRF with MR fluid dampers in passive-on mode.
Seismic Mechanism Analysis of Chinese Ancient Buildings
Authors: Nan Xi Tao
Published: May 2011

The background of ancient wood structure buildings in China is elaborated in this article, and the seismic mechanism for structural features, pedestals, lateral foot column tendon joint structure and bracket arch of ancient Chinese architecture are analyzed. It is not only a great significance for the conservation , but also a promotion of Chinese culture. And a reference in solving the problem of earthquake control and isolation is provided.
Study on Seismic Performance of Steel-Concrete Mixed Structure Compared with Concrete Structure
Authors: Song Qiang , Liu Xiu Li , Zhang Peng , Bai Zhi Qiang
Published: May 2011

Seismic performance of the steel-concrete mixed structure is studied compared with concrete structure by Sap2000, including modal analysis, response spectrum analysis and time-history analysis. Also, a simplified calculation model of the steel-concrete mixed structure is established, and some formulae are derived from the model including the natural frequency, top displacement, shear of both the core tube and the frame on the basis of finite element method of bar system. Those formulae can be used to explain and approximately count the seismic response of steel-concrete mixed structure.
Seismic Response Analysis for Pier in Considering of Uplift Effect
Authors: Zhao Li Dong , Song Bo
Published: May 2011

In earthquake engineering, researchers have found that many structures were not damaged after strong ground motions because of the rocking effect. In order to reveal the potential application value of the uplift effect on seismic isolation, it will be using numerical simulation software OpenSees to research the seismic response of pier considering uplift. Building the pier’s finite element model and considering the plasticity and nonlinear of the pier and soil spring, the ground motion from El Centro and TCU101 are taken as the input respectively. Through analyzing the result, it is shown that at the base of the pier the maximum bending moment is reduced by 36.93% and 46.70%, and the maximum curvature is also reduced by 78.42% and 87.12% respectively. Meanwhile, the maximum horizontal acceleration at the top of the pier is decreased 12.60% and 16.90%. The uplift effect significantly reduces the plastic deformation and plays a base-isolated role according to the results. It has also found that the earthquakes with velocity pulse effect are dangerous to the structures.
Inelastic Spectrum Method Applied to Evaluate Seismic Safety of Bridge Structures
Authors: Cui Gao Hang , Zhu Xiao Li , Tao Xia Xin
Published: May 2011

For the past few years, Push-over analytical method was regarded as a new evaluation method for seismic resistance capacity of structure in some advanced countries. More available information can be obtained from Push-over analysis than from elastic static, even elastic dynamic analysis and the method is easy to be operated. The elastic spectrum from the Highway Engineering Seismic Design Code (JTJ 004-89) was improved in order to take the inelastic effect into account. The inelastic demand spectra were derived by means of Vidic's strength reduction factors. By comparing capacity curves of bridge structure with the demand elastic spectrum, the earthquake resistance of bridge structure can be estimated. Furthermore, it is applied to evaluate seismic resistance capacity of a real bridge example in this paper. The results show that Pushover method can replace inelastic dynamic history analysis method in some cases.
Micro-Density of Timber Materials via an Image Processing Method
Authors: Yu Chau Cho , Chang Heui Yung
Published: May 2011

The present study is to evaluate micro-density of timber materials on cell level. Density, one of the most important parameters for such materials, is discussed in details. Four kinds of timbers are placed under a microscope for cell photos from which the cavity ratios are obtained through an appropriate image processing computer code. Micro density is calculated by dividing bulk density by cell wall ratio. It is found that three out of four kinds of timbers have similar micro-density and therefore, for those samples, macro-density can be expressed as the multiplication of the cell wall ratio and micro-density which is treated as one of their characteristic constants, no matter it is late wood or early wood. In the future, micro-density can be one of the criteria to categorize structural timbers.
Fractal Analysis to Study the Structural Distribution of Wenchuan Earthquake in China
Authors: Xu Jie
Published: May 2011

A comprehensive study of fractal property applied in earthquakes is analyzed based on the aftershock of 2008 Wenchuan earthquake. Different fractal parameters are analyzed to study the magnitude, epicenter and hypocenter structural distributions in time or space. Theb-valueis found to be 0.86 closed to which is usually 1.0 observed worldwide. This indicates there is a relative abundance of small magnitude events than large ones in the studied range. The spatial correlation is calculated using correlation integral technique, indicating that epicenters are approaching a two-dimensional region and the aftershocks are uniformly distributed along the trend of the aftershock zone. The rate of the fall of aftershock activity with time reflects the decrease of stress is modestly slow. Temporal correlation is 0.59 for aftershocks of M >4.0, indicating a non continuous aftershock activity. Geometrical probability dimension reflecting epicenter clustering degrees of the region was also analyzed. Also the volume fractal dimension of the aftershock region has been calculated using the box-counting technique to study the hypocenter distributions. From the assessment of slip on different faults it is inferred that 67.9% displacement is accommodated on the primary fault and the remainder on secondary faults.
Research and Experiment on the Road Performance of Scoria (Volcanic Ash)
Authors: Fan Zhen Hua
Published: May 2011

According to the tests and researches, this paper combine the constructing condition of scoria (volcanic ash) subgrade and lime-volcanic ash gradation macadam subgrade and the result of investigation and detection after the test section is completed, the physicochemical property, engineering property, compaction mechanism and performance, formation mechanism and increasing rule of strength of scoria (volcanic ash) and lime-volcanic ash are systematically analyzed, propose the construction technology and detection method of scoria (volcanic ash) subgrade and lime-volcanic ash gradation macadam subgrade, provide technical support and theoretical basis for application of scoria (volcanic ash) on road construction.
Study on the Strategy of Slope Ecology Protection of Shaoguan-Ganzhou Expressway and Indoor and Spot Testing
Authors: Lin Xi He , Cheng Ye
Published: May 2011

According to the situation of Shao-Gan expressway slope project, the strategy of expressway slope ecology protection was put forward, including life-span ecology protection, zoology comeback and environment amalgamation, thorough environment protection. Then the slope ecology protection method by using coconut fibre nets and local frutex was brought forward. The validity of the reducing scour ability by using coconut fibre nets and local frutex mix-seminating or herbage and frutex mix-seminating was confirmed by the indoor model test and spot test. The slope ecology protection method which put forward in this paper was applied in the Shao-Gan Expressway and proved effective, which provide a new method and way to the slope ecology protection method of expressway in northern region of Guangdong province.
Study on Preventing from Deformation Diseases of Dolanit Fiber Asphalt Concrete at Road Intersection
Authors: Bao Long Sheng , Zhang Xiao Fang , Yu Ling , Zhu Guang Shan
Published: May 2011

Due to the heavy traffic and channelization, vehicle often brake and park for a long time at the urban road signal intersection, especially at heavy traffic intersection, for which it is easy to present permanent deformation on asphalt pavement. It can significantly improve the technical characteristics of the road intersection with adding Dolanit fiber into asphalt concrete. Based on BISAR3.0 software of applying layered elastic system theory and combined with the surface layer analysis on indoor mechanical property test to Dolanit fiber rein-forced asphalt concrete pavement, the results show that the allowable tensile stress is 0.61MPa. Even if at the condition of overload 50% and emergency braking, there is no shear failure on the Dolanit fiber rein-forced asphalt concrete pavement.
A Study for the Time Effect of Asphalt Pavements on Suburban Roads
Authors: Hsu Hui Mi , Chen Hao Hsien , Chao Sao Jeng , Cheng An , Lee Li Ying , Hong Zhi Wen
Published: May 2011

Taiwan's climate is marine tropical. The northern part of the island has a rainy season that lasts from January through late March during the northeast monsoon, and experiences hot, humid weather from June through September. Thus, road’s maintenance is a difficult issue due to its long-season rains as well as high groundwater levels. In the mean time, the current roads are generally weaker in most suburban areas due to those soft soil bases uncompacted in construction. Those aspects explain the low performance of suburban roads in northern Taiwan. Therefore, this research takes the Yilan county, located in the northeast part of the island and well-known as a rainy county, as a study area where major suburban roads are selected to take asphalt concrete specimens for testing. The major purpose is to investigate the time effect of asphalt pavements for those of specimens with a period time of three years. A total number of 329 asphalt concrete specimens are characterized as Class I specimens, 305 of which were taken in 2007, as well as Class II of 24 taken in 2010. First, as for the Class I specimens, the Indirect Tensile Strength test (ITS) is conducted, together with the Control Chart as a filter, and then the remaining 253 specimens come to the average ITS value of 15.55 kgf/cm2. Secondly, as for the Class II specimens of 24, the Film Stripping (FS) tests are conducted to obtain the Index of Retained Strength (IRS) values, from which the basis of ITS comparisons is found. Thus, the different average ITS value, 19.16% in three years, is obtained. The result also indicates that the annual reduction of ITS value for an area similar to the study area may be taken as approximately 11% (33.14/3 %) and 4.7% (13.98/3 %) for the conditions of high traffic flow and low traffic flow, respectively. It may also address the common effect of traffic and environment on moisture damage in asphalt pavements.
Variation of Moisture Content and Safety Factor of Silt Subgrade under Rainfall Infiltration
Authors: Zhang Hong Bo , Song Xiu Guang
Published: May 2011

Because of the special capillary and water-sensitive characters, the moisture content of silt subgrade in Alluvial Plain of the Yellow River is generally higher than the optimum value, which will lead to bad support conditions of subgrade. In order to analyze the water-absorbent property of silt subgrade, both the rainfall seepage and the capillary phenomenon were simulated in laboratory, which reveals that both factors have distinct effects on the moisture content of compacted silt soil. Triaxial tests of compacted silt soil reveal that the cohesive force reduces obviously with the increasing of moisture content. What’s more, the internal friction angle also reduces rapidly arriving at saturation state. By adopting Geo-slope code, the rainfall infiltration mode of silt subgrade was simulated under different rain type and rain duration. Results show that the subgrade slope is easy to lose stability because of much rainfall infiltration. In addition, the minimum safety coefficient happens at the time of rainfall ending. And the slope safety can be threatened seriously by the repetitious rainfall.
Crack Resistance Function Analysis of Flexible Short Fiber in Asphalt
Authors: Ding Zhi Yong , Dai Jing Liang , Peng Bo
Published: May 2011

after reasonably analyzing characteristics of flexible fiber reinforcement fragile material, the mechanical model of individual fiber is established while being pulled out from asphalt; the spherical coordinates is adopted to establish the calculation model for short fiber bridging stress evenly distributed in space to calculate the value of bridging stress generated by short fibers while asphalt is breaking; the fiber asphalt sample in big size is adopted to perform low temperature tensile failure test to practically measure bridging stress of short fiber; fit the calculated value and measured value of bridging stress by adjusting parameters in the calculation model to check the rationality of fiber bridging stress in calculation method and model.
Experimental Research on the Performances of Warm Mix Recycled Asphalt Mixture in Road Application
Authors: Sun Ji Shu , Yang Chun Feng , Chen Zhao Xia , Pi Hui Ran
Published: May 2011

The effect of sasobit’s quantity exerted on the asphalt viscosity was researched firstly in this paper, and the mixing temperature of warm mix recycled Asphalt mixture was determined. Then, the technical performances of warm mix recycled asphalt mixture on high temperature, low temperature and water stability were studied through systematic experiments. And compared the technical indexes with that of hot mix asphalt. The results showed that sasobit could reduce asphalt viscosity significantly, so it could lower the mixing and compaction temperatures of the recycled asphalt mixture. The technical indexes of warm mix recycled asphalt mixture conform to the current specifications, so it can be used in many pavement structures.
Study on Settlement of Railway Embankment on Deep Completely Decomposed Granite Ground by Centrifugal Model Tests
Authors: Xiao Hong Bing , Lu Guo Sheng
Published: May 2011

The settlement cntrol of high-speed railway is a key technology in embankment engineering. In order to reveal the engineering characteristics of the deep completely decomposed granite soil in Hainan east loop line, a passenger dedicated line, four groups of centrifuge model tests were conducted to study the settlement properties of the subsoils untreated, treated by dynamic compaction, and reinforced with cement-mixed piles, under the action of the embankment, especially the relationship between settlement and time, including the settlement during and post-construction. The results show that the Weibull model can describe the relationship between embankment settlement and time well, and that the post-construction settlements of the subsoil meet the requirements of the relevant code. Among the two foundation treatment measures, dynamic compaction is more effective than reinforcement with cement-mixed piles, and the pressure on the contact surface between embankment and subsoil was obviously different from the commonly used calculated values.
Master Curves of Dynamic Modulus and Phase Angle for High Modulus Asphalt Mixtures
Authors: Geng Li Tao , Ren Rui Bo , Wang Li Zhi , Gao Cui Lan
Published: May 2011

Two types of high modulus asphalt mixtures are introduced. Dynamic modulus and phase angle of these two mixtures are tested with Simple Performance Testing System under different temperatures, loading frequencies and confining pressures. Based on time-temperature superposition principle, dynamic modulus master curves and time-temperature shift factors at reference temperature are obtained using nonlinear square least square regression, and phase angle master curves are constructed utilizing the same time-temperature shift factors. The influence of confining pressure on mechanical properties of high modulus asphalt mixture is discussed.
Water Stability of Interlayer between Asphalt Overlay and Cement Pavement
Authors: Yuan Yu Qing , Gao Dan Ying , Wen Sen
Published: May 2011

To solve damage issues of asphalt overlay resurfacing old cement pavement, authors put forward ideas of interlayer water breakage, expounded the mechanism of dynamic water pressure, designed a kind of composite specimens, and separately finished the direct shear tests with the samples water immersion and freeze-thaw for the first time in China. Based on the model of water-tire-pavement system, it is concluded that dynamic water pressure rises with vehicle speed, directly 2 power proportional to speed, and the dynamic pressure were identified as 0.25MPa, 0.40MPa, 0.55MPa corresponding to the running speed of 80km/h, 100km/h, 120km/h, respectively. According to direct shear tests with soaked samples, the longer the sample soaked, the more is layer structure vulnerable to damage. Compared with the sample not-soaked, the shear strength respectively reduces by 50% or 64.6%, corresponding to the samples soaked 24h or 48h. With the freezing and thawing sample, direct shear tests show that the roles of the hydrostatic water in layer leads to interlayer structure intension lessening by 58.8% over the natural sample. The results declare that the bond is weakened by dynamic pressure, soaking, freezing and thawing of interlayer water, which will eventually result in overlay structure destroyed.
Research on Bearing Capacity of Column Underpinning Joint of Frame Structure Moving
Authors: Du Ai Hua , Tang He Qi
Published: May 2011

An experiment of sixteen frame column underpinning joints of frame structure moving was introduced, the experiment sample failure phenomena and failure type was obtained. The type was like “deep beam” failure type-“tension bar arch”, and the last failure place occurred on the interface of column and beam. Then, the underpinning joint stress mechanism and failure mode was determined based on the experiment’s conclusion. In addition, the failure course of joint was divided two stages which were before and after interface punching slip by theoretical analysis, for the stage before interface punching slip a space “tension-bar-arch” mechanical model was presented for the underpinning joint, then theoretical bearing capacity equation for this underpinning joint were obtained. At the same time, for the stage of interface after punching slip, the theory of interface shear was put into the analysis of joint, then interface bearing capacity equation was obtained for this stage. At last the height equation was obtained by the analysis of the stage of after interface slip.
Selection of Strength Standard of CTB in High-Class Highways
Authors: Du Yin Fei , Yu Xin
Published: May 2011

A reasonable design strength standard is of great practical significance for reducing pavement diseases. First, the bottom layer tensile stress of the typical pavement structure in the operating period is calculated using computer program BISAR while the overload、the interface link status and construction variability are all considered. And then the bottom layer tensile stresses of the upper and lower base are checked under truck load during construction. According to the relationship between cleavage strength (90d) and unconfined compressive strength (7d), it is deemed that the appropriate design strength standard should be 2.1MPa~3.5MPa. Finally, combined with the results of the unconfined compressive strength of core samples in the field it is proved that the current design standard is a little high.
Measures on Improving the Mechanical Properties and Construction Standards of Highway
Authors: Jiang Yan Cang
Published: May 2011

Currently, there are so many heavy vehicles being driven fast and overloading on highway. Carrying capacity of highway are not fit with this situation, They are often run in a serious state of overloading and fatigue. This directly influenced the life of highway. So, to improve the mechanical properties and carrying capacity of highway, and to construction high standard, high speed, large-tonnage, long-life modern highway are urgent and imperative. This article analyzes the current traffic load and design, materials select and construction status of highway, and proposed some measures to improve mechanical properties and construction standards of highway. Life of highway can be greatly improved by adopt these measures.
The Study on Foaming Characteristics of Foamed Asphalt in Cold Recycling Technology
Authors: Liu Jing Li , Wei Lian Yu , Zhang Guo Qiang
Published: May 2011

Through the foaming mechanism and foaming effect evaluation, this paper analyzes the production procedure, optimum content and strength of foamed asphalt mixture thoroughly. Combined with the construction process quality control and inspection and acceptance criteria, this paper provides data for reference and theoretical basis for application of cold recycled technology of foamed asphalt to pavement project. Its construction without disrupting traffic, thus shorten the construction period and improve efficiency, which also have advantages such as energy conservation, environment protection and economy. Above all, it is beneficial to foamed asphalt′s popularization and application.
Comparison of Vertical Model and Spatial Model for Vehicle-Track-Bridge Coupling Vibration System
Authors: Zhang Yuan , Lin Wei , Wang Ze Ming
Published: May 2011

In this paper, models for vertical and spatial coupling vibration of vehicle-track-bridge system are established separately. The track vertical irregularity sample in time domain is established by power spectrum density and taken as the exciting source to analyze the coupling vibration of vehicle-track-bridge system of two models. The advantages and disadvantages and applicability of the vertical vibration model and the spatial vibration model are analyzed by comparing the vertical vibration responses of the two models under excitation with same level of track vertical irregularity.
Finite Element Analysis of the 40ft Container
Authors: Li Ming Hai , Ma Shou Yuan
Published: May 2011

Strength and deflection finite element analysis was given to the 40ft Container which export to Saudi when at the lifting and static conditions in this text. The text applied three-dimensional modeling software Pro / E for solid modeling, HyperMesh finite element software for mesh, ANSYS finite element analysis software to calculate, show maximum deformation and maximum stress position to every conditions of the container .provide the reliability calculating for this type of container.
Accident Analysis of Demolition Quality on a Soil-Rock Blasting
Authors: Qin Ying , Zhang Yuan Juan , Huang Jin Xiang
Published: May 2011

The reason influence blasting is consist of the quality of mixed ANFO explosion and management etc. Mixed ANFO explosion get the optimum proportion of diesel, field experiment is done, the biggest detonation velocity,smallest detonation velocity and average detonation velocity , detonation change along with the diesel allocated proportion increasing. Optimum proportion of diesel is 5.0%, it has important significance for blasting construction.
Research on Performance of Basalt Fiber-Enhanced SMA
Authors: Xu Gang , Zhao Li Hua , Zhao Jing
Published: May 2011

This paper selects three different fibers: short-cut mineral fiber, mineral cotton fiber and lignin fiber, through the laboratory test to analysis the homogeneity and way-use performance of fiber SMA. Contrast test results show that the homogeneity of adding mineral cotton fiber and lignin fiber of SMA mixture is nearly at the same degree, which are all better than adding short-cut mineral fiber. Adding short-cut mineral fiber with SMA has poor water stability, but the high temperature stability is the best; At the same time, the homogeneity of the fiber asphalt mixture in this paper has a certain effect with the road performance, but impacts little with the absolute value of it.
Study on Mechanical Behavior of Asphalt Concrete Pavements with Non-Uniformity Gradient Materials
Authors: Yan Ke Zhen , Zhang Zou
Published: May 2011

Generally speaking, the asphalt concrete pavement will be affected by the temperature and aging when it is in the use, which makes the modulus of asphalt mixtures change as non-uniformity gradient. This paper assumes the different changes on the modulus of surface layer with different gradient and then researched the mechanical characteristics of asphalt concrete pavements with cracks and no cracks by the finite-element method . Moreover, the research focused on the stress and K I & K II of the asphalt concrete pavements affected by the modulus of surface layer changed as non-uniformity gradient. The results demonstrated that the larger the gradient on the modulus of the surface layer,the bigger the tensile stress and K I and K II of the asphalt concrete pavements, and K IIis even much bigger than K I. Consequently, it is of great importance to take into account the effect of the modulus of surface layer changed as non-uniformity gradient. It also makes a great significance for the revision of pavement design and the analysis of pavement damage mechanism.
Load Model and F Coefficient on Asphalt Pavement Deflection
Authors: Xu Yong Li , Xing Zhen Zhen
Published: May 2011

Deflection is the important index of asphalt pavement design and the final acceptance. Using double circular load of Design Specification and four circular load of Benkelman test vehicle, the deflection was analyzed with four kinds of common pavement structures, the results show that the deflection of theoretical calculation was the Benkelman beam test 55%-75%, but Design Specification uses the F coefficient which less than 1 to correct the difference, the two have had the contradiction. The deflection of two and three axles load mode were analyzed, and compared with the axle load conversion coefficient C1. The result could provide the reference of axle load conversion and the correction coefficient for the pavement design.
A New Approach of Detecting and Evaluation Railway by Using the Train-Mounted Ground Penetrating Radar in China
Authors: Liu Jie , Cheng Yuan Shui
Published: May 2011

Stable structure of subgrade of railway is an important foundation for safety of train. Rising of speed and heavy transport tasks accelerate deterioration of ballast and increase disease of subgrade. It is more important how to detect and maintain the condition of ballast and subgrade highly effective, faster and without any destruct. In recent years, the ground penetrating radar has been an effective method for detecting and evaluation ballast and subgrade. This paper present application of detecting and evaluation ballast and subgrade by using the train-mounted-multicenter ground penetrating radar(GPR), data processing and interpretation, acknowledge and some problem.
Analysis on Stability of Subgrade Slope Influenced by Strength Attenuation
Authors: Yi Xiao Ming , Wang Song Gen , Song Xiu Guang , Zhang Hong Bo
Published: May 2011

The water content in the subgrade changes easily as the variation of the environment water, which causes the strength attenuation of the subgrade. It is harmful to the stability of subgrade slope. Strength decay pattern of silt soil in yellow river alluvial plain is studied through the laboratory test. And then the finite element software GEO-SLOPE is used to calculate coefficient of stability under different conditions. Results show strength indexes of silt soil are maximum in the optimal water content, and the change of the water content would cause strength attenuation. The stability of subgrade slope decreases as the strength degradation, while the evolution is different, which is semi-parabolic in the lower subgrade but rectilinear in the higher subgrade. Seismic load leads to stress concentrate at the slope, combined with the strength attenuation the landslide is easily to take place.
Experimental Research on the Rectangular CFST Column and H-Section Steel Beam Diaphragm through Connections
Authors: Bao Quan Li , Wang Hai Liang , Yang Xin Lei , Dong Peng , Ren Quan Chang
Published: May 2011

A full-scale experiment on two kinds of rectangular CFST column and H-section steel beam diaphragm through connections which under low cyclic loading was been carried out. Through the analysis of the destruction shapes, hysteresis curves, ductility indicators, we obtained some practical conclusions.
Research on Mountain Highway Traffic Volume Transferred by Ports
Authors: Wang Wei , Wang Bao Fu
Published: May 2011

With the expansion of port handling capacity and economic benefit, large mountains highway traffic volume are aggregated to and transported by ports, and large increment of traffic volume of mountains highways connected with the port occurred. Based on studying characteristics of port transportation and mountainous highway traffic network, mountains highway traffic volume transferred by ports is analysed, and corresponding analysis model of passenger and goods volume of entering and leaving port is put forward. Firstly, choosing ports which mainly effect mountains highway volume; secondly, conllecting and studying category of goods, characteristic of passenger, throughput of passenger and goods, and development program of these ports in past years; thirdly, investigating goods category, throughput, space, and some other useful data of these ports at the present. Characteristics of waterway goods transportation is studied and spatial distribution of passenger, goods volume between different ports is estimated, and mountain highway traffic volume transferred by ports is forecasted. The method proposed in this paper is applied successfully in practical engineerings, and provides reference for engineering research.
The Relationship between Ramp Length and Traffic Flow Speed (TFS) for Interchange
Authors: Wang Xiao Ning , Ci Yu Sheng
Published: May 2011

The relationship between ramp length and traffic flow speed (TFS) was studied based on analyzing the design elements of geometry alignment for interchange. After analyzing the process of vehicle running in the ramp, the speed change process was divided into four forms, namely, one deceleration and acceleration process, one deceleration process, one acceleration process and more than one deceleration and acceleration process, and then the relationship between the ramp length and TFS was established respectively. Through an example of the HeDa Interchange of Heilongjiang Province, it showed that although the differences of alignment units of ramps can result in various speeds and specific expressions of relationship between ramp length and TFS. However, all of these relations can be expressed by homologous nonlinear function.
Analysis of Characteristics of Vehicle-Bicycle/Pedestrian Conflicts Using Video Drive Recorder
Authors: Lin Qing Feng , Cheng Bo , Lu Guang Quan
Published: May 2011

Vehicle to pedestrian/bicycle accidents account for a large proportion of traffic accidents in China. In order to study the characteristics of vehicle to pedestrian/bicycle conflicts, 50 taxis are chosen as the test vehicles. A field-test was conducted using video driver recorder in Beijing for one year. A large amount of traffic conflict and accident data was collected in real driving environment. Considering the factors including conflict type, conflict time, conflict location, traffic control and conflict speed etc., the traffic conflict characteristics of vehicle to pedestrian/bicycle were analyzed. The results might contribute to the road safety management, road design and accident prevention technology.
Statistics Analysis and Optimization Design for Intersection Traffic Volume on Urban Road
Authors: Wu Jin Rong , Yuan Pu
Published: May 2011

Manual count method is adopted during the statistics of the intersection traffic volume of Dongshan Midway in Huainan. According to the statistics, basic characteristics of traffic volume, such as composition, direction and number, are obtained. Based on the research, the problems existed in the intersection are analyzed, and feasible measures for optimization design of intersection are put forward, in order to ensure the safety of pedestrian crossing and increase the traffic capacity and service level efficiently.
Research on Traffic Volume of Urban River-Crossing Channel
Authors: Wang Wei
Published: May 2011

Traffic volume forecast of urban river-crossing channel is the basis and premise of construction of urban river-crossing channel. By analyzing characteristics of traffic volume of urban river-crossing, a method of traffic volume forecast of urban river-crossing channel was put forward. Firstly, components of traffic volume of urban river-crossing channel were analyzed. Secondly, the OD matrix was divided into urban internal transportation and interurban transportation. Two different forecast methods were adopted, and results of the two parts calculated by different methods were added to work out the total traffic volume of urban river-crossing channel. Thirdly, the total traffic volume was allocated to several river-crossing channels by calculation, and the traffic volume of each river-crossing channel was gained. The method proposed in this paper was proved to be effective by the example calculation of river-crossing channel of Fu Ma Yangtze River Bridge in Wan Zhou district of Chong Qing.
A Simulation Study of Accident Reconstruction in Car to Electric Bicycle Side Impact Crashes
Authors: Lin Qing Feng , Lu Guang Quan
Published: May 2011

In order to analyze the characteristic of cyclist throw distances and head injuries in car to electric-bicycle side impact accidents, this paper presents an approach to reconstruct the car to electric-bicycle side impact accident using PC-Crash. The distribution characteristic of cyclist head impact points with the hood and windshield is analyzed and the relationships between the vehicle impact velocities and the cyclist’s head injuries are described. In addition, based on several factors including road friction coefficient, vehicle load and braking deceleration, we analyzed the relationships between the vehicle impact velocities and the cyclist throw distances. The results show that 50km/h can be regarded approximately as the threshold of impact velocity to cause the cyclist’s head injuries, meanwhile, the cyclist throw distance is less influenced by the road friction coefficient and vehicle load, and the cyclist throw distance might be larger under lower impact velocities and smaller deceleration conditions.
Analysis on the Causes of Crack Formation and New Methods of Temperature Control during Construction of Super-High Arch Dam
Authors: Liu You Zhi , Zhang Guo Xin , Liu Yi
Published: May 2011

In this paper, the mechanism of typical temperature crack is systemically analyzed and the main cause for crack is discussed. Some efficient methods such as surface heat preservation, low temperature placing, interior heat gradient control, cooling height control, selection of water cooling mode have been discussed in depth. In additional, temperature monitoring, feed-back simulation instantaneous and crack risk early-warning are also considered as indispensable component for the temperature control and crack prevention work. At last, a series of temperature control and crack prevention new methods for super-high arch dam are suggested to ensure the safety of the dam under construction.