bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Ground Penetrating Radar in Detecting of Zero-Temperature Boundary under the Railway Bed
Authors: Du Li Zhi , Zhang Xiao Pei , Qiu Jian Hui , Liu Wen Bo
Published: June 2011

The instability of permafrost directly results of the differential settlement of railway subgrade, which brought a great threat to the security operation of railway. In order to obtain the top-limit (zero-temperature interface) data of permafrost, according to the testing environment and the requirements for and use of different dielectric constant, using ground-penetrating radar (GPR) detection. The experimental results show that the method is accurate and effective, and we can get better material data on the zero-temperature interface.
Model Prediction on the Behavior of Cerium in Heavy Rail Steel
Authors: Liu Cheng Jun , Liu Hong Liang , Jiang Mao Fa
Published: June 2011

The thermodynamic model which quantificationally described the behavior of cerium in heavy rail steel was proposed. From the model, the effects of cerium on the composition, sequence and transformation condition of inclusions and the content of cerium dissolved in heavy rail steel were studied principally. When the cleanliness of heavy rail steel is low, the sequence of inclusions precipitation in heavy rail steel is Ce2O3, Ce2O2S, Ce2S3and CeS. With increasing the cleanliness of steel, the sequence of inclusions precipitation is Ce2O2S and CeS. At 1783 K, the necessary condition of Ce2O3precipitation in heavy rail steel isao/as≥0.186, for Ce2S3precipitation isao/as≤0.394. The content of cerium dissolved in heavy rail steel is mainly affected by Ce2S3inclusion. With the precipitations of all inclusions being stable, the curve between the dissolved cerium content and cerium addition becomes linear.
Moment Redistribution of Two-Span Fire-Damaged Reinforced Concrete T-Beams Strengthened with CFRP Sheets
Authors: Xiang Kai , Wang Guo Hui , Han Wei Ping , Yu Jiang Tao
Published: June 2011

Experiments of seven two-span reinforced concrete (RC) T-beams were introduced. One T-beam was normal temperature control T-beam, and the other six T-beams were heated under ISO-834 standard fire. All T-beams had the same geometrical dimensions and reinforcement as well as the loading and support arrangement. The fire-damaged T-beams were classified into two groups according to the fire exposure time. Different fire exposure time including 60 minutes and 75 minutes were investigated. In each group, one T-beam was unstrengthened control T-beam, and the other two T-beams were strengthened with carbon fiber reinforced polymer (CFRP) sheets. The results showed the way of moment redistribution of T-beam changed greatly because of the influence of fire. Different from the normal temperature T-beam, the fire-damaged T-beams had obvious moment redistribution at the beginning of the loading because of the variable stiffness along the length of the T-beams. The stiffness equivalency method for evaluating the moment distribution of RC continuous beams after fire exposure is presented. The scope of application for proposed method is between concrete cracking and yield load. The proposed method is based on the principle of equivalent stiffness. Considering the reduced elastic modulus of concrete and steel bars for fire exposure, a procedure was developed for quantifying the amount of sagging moment and hogging moment that can occur in fire-damaged continuous beams with an external CFRP sheets strengthening or without. The proposed method was verified under the experimental results as well. The proposed stiffness equivalent approach is capable of predicting bending moment of fire-damaged RC continuous T-beams with an accuracy that is sufficient for design purposes.
Study on Prediction Model of Shrinkage and Creep of Prestressed Concrete Beam in Passenger Dedicated Line
Authors: Luo Jun Li , Xu Zhi Sheng , Li Jun , Yang Ji Hao
Published: June 2011

To improve the calculation precision of deformation in prestressed concrete bridge in passenger dedicated line and accurately predict the development of shrinkage and creep in bridge, a universal applicable modified model was put forward in this paper based on ACI 209R(1992) shrinkage and creep model. In the modified model, three influence factors-slump, strength and reinforcement - are corrected. And the modified model results were compared with the experimental results. It shows that the modified model can more accurately predict the development of shrinkage and creep of high-speed railway bridge and better accord with the law of it.
The Application of Crushed Rock Materials upon Railway Embankments in Permafrost Regions
Authors: Mu Yan Hu , Ma Wei , Sun Zhi Zhong , Liu Yong Zhi
Published: June 2011

Crushed rock materials had been utilized extensively upon embankments, termed as crushed rock embankment (CRE), along the Qinghai-Tibet Railway in permafrost regions. Based on a long-term monitoring system along the railway, thermal stability and deformation characteristics and mechanisms of CRE were analyzed by field monitoring datasets from 2005 to 2009. The thermal stability analyses indicated that permafrost tables beneath CRE all had upwards movements but to varying degrees. For U-shaped crushed rock embankment (UCRE), the thermal stability of underlying permafrost kept well; along with permafrost table moving upwards, the shallow ground temperatures beneath the embankment decreased obviously while deep ground temperatures kept almost constant. For crushed rock revetment embankment (CCRE), the cooling effect was effective in cold permafrost regions. But in warm permafrost regions, the shallow permafrost beneath the embankment had no obvious cooling trend while the deep permafrost had a slight warming trend. The deformation analyses indicated that CREs experienced frost heave in permafrost regions with mean annual ground temperature (MAGT) < -1.5 °C but settlement in permafrost regions with mean annual ground temperature > -1.5 °C. The magnitudes of both heave and settlement were not significant. Since the better thermal stability of underlying permafrost, it was inferred that the settlement of CRE mainly originated from compression of warm and ice-rich permafrost layer near permafrost table.
The Influence of Cracks in Track Slab and its Reflection in Structure Design
Authors: Zhao Ping Rui
Published: June 2011

The loads and load combination in ballastless track design was briefly introduced. The influence of cracks to the track slab flexural stiffness was studied. According to the mechanical characteristic of ballastless track, the structural coefficient was proposed and put to use in the amendment of different load effect on track slab. The prerequisite of the combination of moment and tensile force was discussed. Take the track slab in bi-block ballastless track for example, the reinforcement in segmental slab and continuous slab was calculated respectively. The results show the reinforcement ratio will substantially reduce when the structural coefficient was considered in the design. In general circumstance, the thermal force in continuous track slab will cause relatively large cracks, in which condition the bending effects cannot be added. The reinforcement in segmental track slab was controlled by train loads, while that in continuous track slab was controlled by thermal force.
An Idea of T-Shaped Integer Cantilevered Road
Authors: Zhou Zhi Xiang , Fan Liang
Published: June 2011

A new method of widening mountainous highway with T-shaped Integer Cantilevered Road was proposed for steep mountainous areas. Its design principle is casting an integral wall upon the exiting stable roadbed to widen the road without considerable cut and fill. Then the construction technique and work principle were introduced, and the technical, economic and environmental benefits were discussed. Engineering application shows that this method is not only simple, economical, and on the safe side in construction, but also protecting environment further compared with the existing techniques.
Traditional Traffic Demand Definition Defects Analyze and Redefinition
Authors: Chen Yu Guang , Cheng Wei , Xiao Hai Cheng
Published: June 2011

Traditional traffic signal timing theory default the number of vehicles through the stop line per unit time as traffic demand. The traditional traffic demand definition obviously cannot respond the real traffic demand when the intersection is oversaturated. The main objective of this paper includes the following contents: (1) to analyze the defects of the traditional traffic demand definition; (2) to strictly define the concept of traffic demand. To achieve the research objective, researchers propose the “traffic demand in cycle” definition: the summation of the standard vehicles queuing during the red light time and the standard vehicles reaching the effective demand region during the non-red light time. The new definition introduces the concept of “effective demand areas”, referring to the areas follow-up vehicles slow down affected by the vehicles that haven’t pass the stop line. The new definition developed in the study can be directly used by traffic engineers and managers to signal timing.
Measuring the Impact of Latent Variables on Mode Choice Behavior between Bike and Electric Bike
Authors: He Ming Wei , He Min , Yang Xiao Qing , Zhao Qing Qian
Published: June 2011

The researches on competitive mode choice behavior between electric bike and bike are useful for the analysis and forecasting of traffic mode, non-motorized traffic planning and related policy. With the sampling survey data in Kunming, individuals’ attitude and preference are analyzed based on SP data. The competitive choice model between electric bike and bike based on discrete choice model is established. The impact of latent variables on mode choice behavior between bike and electric bike is measured based on the estimation results. The result shows that the latent variables have significant impact on the choice behavior. The latent variables can be used to improve the performance of the model and to better capture taste heterogeneity.
Analysis of Barge Adjustment in Large-Scale Structures Ro-Ro Ship Process
Authors: Gong Meng , Zhang Qing , Liu Ming
Published: June 2011

It is the key factor that the barge adjustment of large-scale structures’ ro-ro ship when the structure moves onto the barge. Generally, the common method on-site shipment is manual measurement which is a waste of time and labor power, at the same time, Barge adjustment is inaccurate and can not fundamentally solve the problem of the stability and real-time adjustment of the barge. In this paper, these questions are discussed based on the auto barge adjustment centralized in the computer, sensor and other technologies. In the process of ro-ro ship, the automatic computer control has been analyzed which makes the barge adjustment more timely, accurate and ensures real-time stability and accuracy of barge adjustment. Depending on the specific project case, it proves the feasibility and effectiveness of this method.
Thermo Mechanical Simulation of the Flue in Coke Dry Quenching Technology
Authors: Chen Xia , Chang Qing Ming , Chen Chang Jun , Zhang Yun Xiang
Published: June 2011

According to the process feature of the coke dry quenching (CDQ), the factors of the destructive mechanism that influence the sequence function properties of the brick were analyzed. The countermeasures have been adopted for the defects of the bricks for CDQ, such as inferior thermal shock stability and short lifetime, etc. In order to search the effect of thermal expansion stress and mechanical load stress on the CDQ, the temperature field and stress field of the flue in the CDQ were analyzed according to the thermal elastic and plastic theory. The Drucker-Prager plasticity model combined with a tension cut-off criterion was described material behavior. All material properties were taken as temperature dependent. The result indicates that the support bracket under high gradient temperature will bring on the highest thermal stress, which is the main reason of fracture of the support bracket. The cycling temperature has the ability to cause repeated crack propagation throughout the whole service period. To solve this problem, the design of the structure, the method of the heat exchange and the properties of the materials will be improved. The obtained results give a good insight into the reasons of material failure and help to find counter-measures for prolonging the lifetime of CDQ.
Research on Design of Neotype Wire Rope Safety Barrier
Authors: Chen Chen Chen , Lei Mu Xi , Lei Zheng Bao , Li Yong Han , Zhang Xin Chao , Liu Guo Bin
Published: June 2011

In order to research and develop a suitable wire rope safety barrier for our country, which will be used as the highway flexible safety barrier for two model demonstrative project of science and technology of Changsha-Xiangtan Highway, the paper presents a new type of wire rope safety barrier, by way of designing the shape of the post, the diameter of the rope, the arrangement and the number of ropes etc., on the basis of the form of structure of the most advanced foreign existing wire rope safety barrier — BRIFEN. The first part is devoted to prove the reliability of the finite element simulation, by comparing the simulation results of the finite element model of BRIFEN with the collision test data, which is published by U.S. Federal Highway Administration. After discussion and analysis, the neotype wire rope safety barrier, which has many posts with C-shaped cross section and 5 ropes, is invented with the post equivalent method. The finite element model of the neotype barrier is established and simulated to determine the dimension of the post. The simulation results achieve the design objective that the maximum dynamic deformation is less than 1.2m when the barrier is impacted by the 10 tons of bus in the speed of 60 kilometers per hour, and provide an important reference for Vehicle Crash Test.
Analysis on Pre-Stressed Friction Loss in Bending Channel under Contact Pressure Non-Uniform Distribution Hypothesis
Authors: Cheng Hai Qian , Cheng Qing Hua , Zhang Kai Yin
Published: June 2011

The pre-stressed friction loss formula in bending channel recommended by Bridge Rules was based on the uniform distribution hypothesis of contact pressure. From some conflicts in application of the formula, the non-uniform distribution law of the contact pressure was revealed. On the basis of elastic contact analysis, two types of non-uniform distribution hypothesis were proposed, including cosine and second-degree parabola distribution. Then the contact positive pressure expressions were derived respectively and the frictional resistance was calculated to compare with the calculated value under the uniform distribution. The results indicate that the friction resistance under any non-uniform distribution of positive pressure is less than under the uniform distribution. So the uniform distribution assumption of contact pressure does not cause Bridge Specifications formula underestimate friction loss. It is necessary to do further research on the applicability of Coulomb’s law under the contact conditions in the curved channel.
Research on Support Spacing of Tower Crane
Authors: Zhan Wei Gang , Wang Jia , Lu Nian Li
Published: June 2011

This paper presents an analysis in attachment spacing of tower cranes. Both the support spacing under the rigid support and the flexible support are obtained for this purpose. For deriving the rigid support spacing, differential equation is used. The principle is used for calculating the support spacing, which the extended segment has the same Euler critical force with the independent segment. The flexible support distance is obtained by setting the integrated stiffness matrix zero, which is equivalent to structural instability. The order of the overall stiffness matrix is big when the tower crane is attached many times. In order to calculate more convenient for solving the matrix determinant, a transfer matrix method is adopted. To verify the influence of the flexibility caused by the support device, an example is carried out by both rigid and flexible support situations for this purpose, and the support spacing is computed numerically. Numerical results for the support distances of a tower crane will be presented and discussed.
Fatigue Life Prediction of Corroded Reinforced Concrete Beams under Repeated Loads
Authors: Song Li , Yu Zhi Wu
Published: June 2011

The behavior of materials under repeated loading has been examined, but extended studies are more and more needed especially for damaged reinforced structures such as bridges, where high-cycle fatigue phenomena and corrosion can be significant. In the present paper, a theoretical model based on fatigue performance of materials and stress analysis for cross-section is proposed in order to analyze the fatigue damage of corroded reinforced concrete beams under repeated loads. Further, fatigue life is predicted by applying this method, and the method is evaluated by test results.
The Surface Properties of Corrosion Specimens
Authors: Xu Shan Hua , Kong Zheng Yi , Zhang Chao
Published: June 2011

The characterstics of corrosion is important to asseess structure safety, however, because of the complexity of corrosion, it is hard to see papers anout it. In order to study the characterstics of corrosion specimen surface, two methods are used to obtain corrosion specimens, one method is constant temperature and humidity, the other is natural corrosion. Then roughness tester is used to detect the profile of corrosion specimen surface, and the surface characterization is analyzed by fractal theory. Through the experimnet, we find the law of power relationship between fractal dimension and the depth of localized corrosion, so it will help to solve the difficulty of safety assessment for in-service steel structure.
The Electrochemical Characterization of Rebar Passivation Film in Simulated Concrete Media
Authors: Gan Wei Zhong , Jin Wei Liang , Shao Jian Ping
Published: June 2011

Based on the fundamental theory of electrochemical anodic polarization, simulated concrete is doped with corrosion inhibitor to prevent corrosion by chloride ion in the marine environment. Thus, with reference to the potential-time curves obtained in different concrete environments and construction conditions, the early dynamic state of active transition of rebar passive films in concretes can be quickly characterized. According to the experiments, the characteristics of passive active transition are synchronous with rebar corrosion. This helps to systematically study the influence of different components of concrete and external media on the durability of the concrete structure. The strong alkaline environment of the concrete is useful in controlling corrosion rate of reinforcing bar. As one of the additional protective measures of the durability of the concrete structure, corrosion inhibitor’s long-term performance contains uncertainty.
Quasi-Plane-Hypothesis of Strain Coordination for RC Beam Strengthened with External-Bonded or Near-Surface Mounted Carbon Fiber Reinforced Plastic Strip
Authors: Ren Zhen Hua , Zeng Xian Tao
Published: June 2011

Rehabilitation of existing structures with fiber reinforced plastics (FRP) has been growing in popularity because they offer superior performance in terms of resistance to corrosion and high stiffness-to-weight ratio. This paper presents strain coordination results of (two groups)15 reinforced concrete beams strengthened with different methods including external-bonded and near-surface mounted carbon FRP strip in order to investigate the strain coordination of CFRP and steel rebar of RC beam. Because there is relative slipping between RC beam and CFRP, the strain of CFRP and steel rebar of RC beam satisfies the quasi-plane-hypothesis, that is, the strain of longitudinal fiber that parallels to the neutral axis of plated beam within the scope of effective height (h0) of the cross section is in direct proportion to the distance from the fiber to the neutral axis, the strain of FRP and steel rebar satisfies the equation: , the value of is equal to 1.1~1.3 according to the test results.
Multifractal Analysis of Reinforcing Steel Bars with Nonuniform Corrosion Degree
Authors: Xu Yi Dong , Bian Li , Wang Jun , Chen Yao Cheng
Published: June 2011

Based on multifractal theory and quantitative stereological method, nonuniform distribution of corrosion morphology in reinforcing steel bars were analyzed and corresponding multifractal spectrum was proposed in this study. The results showed that the corrosion morphology of reinforcing steel bars is multifractal. All the Δf values are greater than 0, which indicating the distribution of corrosion depends on the maximum subset of probability. The width of the multifractal spectrum (Δα) increases linearly as the corrosion mass loss ratio increases, which is a scientific index in characterizing the nonuniform corrosion degree of reinforcing steel bars.
Analysis on Deviation Rectification and Reinforcement of Buildings
Authors: Yin He Ping , Li Chun Lin , Xie Zhong You
Published: June 2011

Deviation rectification of buildings is an arduous task because of its technical difficulty and high risk. So far, the theory of deviation rectification and reinforcement is still incomplete and need to further improvement. In order to investigate the mechanism and construction methods of deviation rectification and reinforcement of buildings, first the paper addressed damage status of inclined buildings in a residential area. And then the causes leading to buildings inclining were analyzed in three aspects. Subsequently, the key construction technologies of rectification and reinforcement were demonstrated. Next, the mechanism of rectifying process was analyzed, and the formula to calculate the amount of steel pipe pile used for deviation rectification and reinforcement was presented. On the basis of research above, some remarkable conclusions are acquired for the engineering rectification and reinforcement, which provide helpful reference information for the similar building rectification engineering.
Experimental Investigation on Steel-Plate-Masonry Composite Column Compressive Behavior
Authors: Jing Deng Hu , Cao Shuang Yin , Zhou Hai Tao
Published: June 2011

The steel-plate-masonry composite structure is an innovative type of structural scheme popular in masonry structures with load-bearing walls removed for a large space. A total of 4 column specimens under static loading were tested to mainly study the failure modes, load-carrying capacity, and strain distribution in the critical cross-section. Results show that the composite columns started an initial failure from local buckling of the steel plate located between binding bolts; the main factors influencing load-carrying capacity included thickness of the steel plate, type of injected material, and initial column eccentricity; the working performance of the composite column with epoxy adhesive was better than that with cement grout; and re-distribution of compressive stress existed in the steel plates of the column. Also, the ratio of service load-carrying capacity to ultimate capacity of the steel-plate-masonry composite column is about 70%.
Analysis on Secondary Effect of Corrugated Webs in Steel-Concrete Composite Beams
Authors: Jiang Ke Bin , Ding Yong , Liu Ya Wen , Zheng Feng
Published: June 2011

Some secondary effect introduced by corrugated configuration of corrugated web was studied and formulas were proposed. The deduction for these formulas was resolved into two steps. Step I: to solve the behavior of whole corrugated web by considering it as an orthotropic plate; Step II: to solve the secondary effect according to the shape parameters of corrugation based on the result of Step I. Subsequently, a numerical experiment was designed to validate the analytical work with the help of finite element package ANSYS taking material nonlinearity into consideration. The results obtained from numerical and analytical methods show good agreement. It indicates that the formulas proposed in this paper are convenient and efficient. This research deals with this secondary effect for the first time; more studies are needed for the effect on local buckling of corrugated webs.
Damage Quantitative Investigation of Beam Structure Based on Changing Ratio of Modal Curvature
Authors: Ge Ji Ping
Published: June 2011

The changing ratio of modal curvature is proposed for damage recognition, and its ability of damage localization and damage quantitative has been studied in this paper. For testing the effect of damage recognition, two research parameters, the different section rigidity and the scope of damages, are included. And changing rules of the index with structure rigidity, constraints, and structure supporting system have been studied at the same time. The numerical analysis results indicated: The relation of linear increase exists between the changing ratio of modal curvature and the extent of damage, the changing slope of the index is bigger with the increase of damage extent; The boundary condition and the structure supporting system will affect the value of index; In the view of one special structure, case study should be carried to establish the relationship between value of index and the extent of damage.
Identification and Damage Detection of Trusses Using Digital Processing of Vibration Signatures
Authors: Niu Lin , Ye Liao Yuan
Published: June 2011

Knowledge of the economic and social effects of aging, deterioration and extreme events on civil infrastructure have been accompanied by recognition of the need for advanced structural health monitoring and damage detection tools. In this paper the time-delay neural networks (TDNNs) have been implemented in detecting the damage in bridge structure using vibration signature analysis. A simulation study has been carried out for the incomplete measurement data. It has been observed that TDNNs have performed better than traditional neural networks in this application and the arithmetic of the TDNNs is simple.
Stream Flow Modeling of River Swat Using Regression and Artificial Neural Networks (ANNs) Techniques
Authors: Daud Suleman , Shahzada Khan , Tufail M. , Fahad M.
Published: June 2011

This paper presents the utility of Artificial Neural Networks and Regression analysis for the stream flow modeling in Swat River at five discharge gauge station. As an appropriate intelligent model is identified, Artificial Neural Networks (ANNs) is evaluated by comparing it to regression analysis and the available field data. ANNs namely feed forward back propagation neural network (FFBPNN) and regression analysis are introduced and implemented. The research study successfully compared the performance of the ANN and regression models that validated the utility of the two modeling techniques as effective applications to stream flow forecasting.
Experimental Study on Mechanical Properties of Timber Columns Strengthened with Carbon-Aramid Hybrid FRP Sheets under Axial Compression
Authors: Pan Jian Wu
Published: June 2011

Based on the experiment of timber circular columns made of pine and fir confined by carbon-aramid hybrid FRP (HFRP) sheets under axial compression, the failure modes, axial bearing capacities, peak compression strains were analyzed. The results showed that: Compared to the unconfined specimens, the axial bearing capacities and peak compression strains of the specimens confined by HFRP sheets were all improved. Axial bearing capacities of pine and fir specimens improved 6.6％～16.8％ and 5.0％～16.9％,respectively. Peak compression strains of pine and fir specimens improved 8.9％～60.2％ and 11.5％～56.8％, respectively.
Experimental Study on Bending Behavior of Timber Beams Reinforced with CFRP/AFRP Hybrid FRP Sheets
Authors: Chun Qing , Pan Jian Wu
Published: June 2011

Based on the experiment of timber rectangle beams made of pine and fir reinforced with CFRP/AFRP hybrid FRP (HFRP) sheets. The failure modes and bending bearing capacity and load-deflection curves and strain distribution at mid-span section were analyzed. The results showed that: Comparing with the specimens without being reinforced by HFRP, there is certain improvement in bending bearing capacity and stiffness of the specimens reinforced with HFRP respectively. Bending bearing capacity of the pine specimens improve 18.1%~62.0% and bending bearing capacity of the fir specimens improve 7.7%~29.7%. Stiffness of the pine specimens improve 13%~21%, and stiffness of the fir specimens improve 6%~10%. Based on the experimental data, the computing formulas of bending bearing capacity of timber rectangle beams made of pine and fir reinforced with HFRP were presented.
Piezoelectric Impedance Based Prestress Force Monitoring for PSC Beam
Authors: Guo Zhi Gang , Sun Zhi
Published: June 2011

This paper presented an experimental study on piezoelectric impedance based prestress force monitoring for prestressed concrete (PSC) beam. The low cost piezoceramic (PZT) patch was attached at the beam firstly and different levels of prestress force were applied to the tendons. The electro-mechanical impedance (EMI) spectra of surface bonded PZT patch were then collected using an impedance analyzer by sweeping the frequency. The statistical index RMSD is then adopted to quantify the variation of EMI spectra due to the variation of prestress force. The relationship between the prestress force and the RMSD index is established. The results show that the EMI technique is a practical and reliable nondestructive test method for prestress force monitoring.
Application of the Pulse Electro-Osmosis Technology in the Control of Seepage of the Underground Structure
Authors: Zhu Jiang Miao , Li Zhi Xin , Wang Ying , Li Ran
Published: June 2011

The water seepage of underground structure is the serious problem in the construction engineering, and becomes one of the most harm in current infrastructure with the huge potential safety hazard and economic loss. The electro-osmosis technology is once widely used in the fields of soft ground stabilization of rock engineering, the biological pharmacy and the oil production engineering in China. This paper referred experiences of overseas, combined electric pulse signal and the electro-osmosis technology to reduce seepage of the underground structure, and solved underground structure water seepage problems. The paper comprehensively analyzed the research status of the technology at home and abroad and its feasibility in theory, also introduced the general implementation methods of projects, and carried on the comparison of the pulse electro-osmosis technology and the traditional moisture-proof technology in application.
Vertical Load-Carrying Natural Frequency of Railway Double-Track Pre-Stressed Concrete Continuous Bridge
Authors: Ren Jian Ying , Li Wen Ping , Su Mu Biao , Zeng Qing Yuan
Published: June 2011

The railway double-track continuous bridge vertical load-carrying frequency is theoretical derived with the vehicle-bridge system mode1. The vertical load-carrying frequencies of the 40 m+4×72 m+40 m party pre-stressed concrete continuous box-girder bridge are calculated, when two trains with 20 same high-speed passenger vehicles are traveling on the bridge from both ends. The change regularity of this double-track continuous bridge vertical load-carrying natural frequency with two trains on it is similar with that of the single-track simply supported bridge and this bridge as one train on it. This bridge vertical load-carrying frequency when two trains on it is smaller than that only train on it. The maximum deviation percentage between the vertical load-carrying natural frequency and the vertical natural frequency is 1.17837%.This bridge vertical load-carrying frequency can be replaced by its natural frequency, and there isn’t obvious error. If the vertical load-carrying frequency should be calculated, it can be replaced by the average value.
Construction Control and Simulation Analysis of Long-Span Cable-Stayed Bridge
Authors: Wu Fang Wen , Xue Cheng Feng
Published: June 2011

Simulation analysis is the basis for construction control of cable-stayed bridges, it monitors the process of the bridge construction. The relationship and importance of simulation and construction control are introduced in the paper. Based on the finite element theory and combined with construction theory of the cable -stayed bridges, according to use the software Midas/Civil, the construction characteristics of Masangxi Bridge is researched by making use of the forward calculation method and the backward calculation method. The results show that the system transformation of the bridge is occurred during the construction, thus, it is important to carry out careful and detailed forward simulation to ensure the safety of construction structure and meet with design requirements. The reasonable results can be drawn when the backward calculation method is combined with the forward calculation method.
Structural Optimization Based on Inversion Reduced-Basis Method
Authors: Li Yong Hong
Published: June 2011

Efficiency and stability of forward problem are important in structural optimum design. A real-time algorithm, called inversion reduced-basis method (IRBM), is applied to solve the forward problem in this paper. IRBM is introduced theoretically. Taking a truck frame as an example, results computed from IRBM are obtained. In the optimization process, a modified micro-genetic algorithm (μGA) is adopted to get the global optimum. In the structural reanalysis, IRBM is used, which greatly shorten the design cycle and improve work efficiency.
Seismic Displacements Reduction for a Long-Span Cable-Stayed Bridge
Authors: Yang Xi Wen , Lian Zi Bao
Published: June 2011

Floating or semi-floating systems are usually employed for long-span cable-stayed bridges to lengthen their fundamental periods, and accordingly, to reduce their seismic inertial force, but the structures’ seismic displacements could be increased by utilizing these systems. Taking Yong-jiang railway cable-stayed bridge which has a low center of gravity as engineering background, the function of viscous dampers in controlling seismic displacements is studied. Firstly, the rational parameters of dampers are determined by parametric analysis, and then the seismic displacements and forces of the bridge, utilizing and un-utilizing viscous dampers, are compared. The results show that: viscous dampers are efficient in controlling seismic displacements of the bridge; the seismic shear forces at the bottom of towers are reduced slightly and the corresponding moments are reduced in a larger extent for cable-stayed bridge with low center of gravity.
A Retrofitted Case Study of Orthotropic Steel Bridge Decks Strengthened with Sandwich Plate System
Authors: Zhang De Ying , Li Yun Sheng , Cui Chun Lei
Published: June 2011

Some retrofitted methods are introduced, and in these retrofitted methods, a strengthening case of using the sandwich plate system (SPS) to strengthen the orthotropic steel bridge deck of a suspend bridge was studied. A local finite element model is established by ANSYS based on an orthotropic steel bridge deck sample, stress distribution of deck due to the wheel load of the vehicle defined in China current code were analyzed under different loading conditions, and the strengthening effect with SPS was evaluated. The influence of the thickness and elastic modulus of elastic sandwich on the transverse stress of deck was analyzed. The results show that, compared with the orthotropic steel bridge deck before strengthened, the stress peak is decreased obviously without new welding residual stress be generated, and the fatigue resistant of bridge deck is increased apparently after the deck strengthened by SPS. The variation of the thickness and elastic modulus of the elastic sandwich have little influence on the stress behaviours of the orthotropic steel bridge deck.
Parameter Correlation Study of Impact Factors on Concrete Curved Box Girder Bridges
Authors: Huang Xin Yi , Zhuo Wei Dong , Ping Shang Guan
Published: June 2011

The impact factors for vehicle load were ever characterized by varied parameters among different countries, and it is now commonly described by the fundamental frequency of the first bending mode for straightened bridges, but there are still no computation formulae proposed for concrete curved bridges. Massive vehicle-bridge interaction analysises are carried out on concrete curved box girder bridges with different span length, curvature radius, section type, span number and boundary conditon, using a validated numerical method. Based on the obtained results, the impact factors for varied effects are discussed, as well as their correlation with parameters of central radius, ratio of bending to torsional rigidity, integral impact coefficient and the fundamental frequency of vertical bending mode. It is indicated that, the impact factor of interal forces, deflection and reaction force are minus correlated with the discussed parameters except for ratio of bending rigidity to torsional rigidity. The impact factors are most closely correlated with the fundamental frequency of vertical bending mode, so it is best suited to characterize the change of impact factors.
Experimental Investigation into Aerodynamic Stability of Narrow Steel Truss Girder Suspension Bridge
Authors: Bai Hua , Li Jia Wu
Published: June 2011

A narrow steel truss girder suspension bridge was designed for pedestrian and livestock in pasture in Xinjiang Province, China. For the complex wind climate at bridge site, the cautious designers resorted to wind tunnel test to confirm the aerodynamic stability of the bridge. The analysis and results from wind tunnel test conducted in Chang’an Wind Tunnel Laboratory indicated the original scheme must be changed considerably to improve the aerodynamic stability under action of wind. Considering the shape feature of Siudirgol Bridge and its geographical location, section model with such mitigation measures as auxiliary cables and central buckles were re-tested in wind tunnel joint with analysis. The auxiliary cables and central buckles can increase considerably the fundamental frequency of the bridge and hence the critical wind speed of flutter.
Assessment of Building Sustainable Performance Based on Set Pair Analysis (SPA)
Authors: Liu Yang
Published: June 2011

How to evaluate building sustainable performance is a hot issue in the world, the paper combine the “natural energy”, “energy recycling” and “ energy consumption” with 12 indicators into a evaluation system, and then use the set pair analysis(SPA) methods to evaluate the building sustainable performance. Through the empirical analysis with 3 cases, the results show that increase the natural energy utilization and enhance the energy recycling can reduce energy consumption and improve the building sustainable performance. In addition, the SPA also can quantitative the evaluation results.
The Analysis of Plant Disease Harms and Study on the Technology of Synthesis Reinforce in Arc-Arched Bridge of Solid Abdomen Type
Authors: Li Xue Wei , Yuan Xin
Published: June 2011

On the foundation of harms in the analytical arc-arched bridge plant disease up, this text propose the bridge floor makes up the strong level and the arch ring increases the section reinforcement, the arch ring spandrel wall steel member pulls ties supplements the pile foundation synthesis reinforcement with the lower part the plan. It not only improves the bridge bearing capacity and structure whole rigidity, also controls the development of the crack nicely, which shows certain model significance in the old bridge reinforcement transformation.
Seismic Response Analysis of CFST Arch Bridge Considering Input Earthquake Characteristics
Authors: Xing Fan , Zhao Lin , Xing Ya Zhe
Published: June 2011

In view of huge destructibility of the near-fault ground motions, structures with long natural vibration period are liable to fall into nonlinear reaction stage. Based on a full understanding of the near-fault seismic spectrum characteristics, the out-of-plane seismic response of a long span concrete-filled steel tube (CFST) arch bridge was studied in depth, and the research result could offer a reference for near-fault aseismic design.
Approximate Deflection Calculation of Variable Box Section Girder Considering the Effect of Shear Lag and Shear Deformation
Authors: Lin Li Xia , Zhang Yuan Hai , Wu Ya Ping , Ding Nan Hong
Published: June 2011

Based on the equivalent stiffness and equivalent stiffness ratio method, an approximate method suitable for hand calculation is proposed to calculate the deflection of variable box section girder bearing load, in which, the double effects of shear lag and shear deformation can be taken into account. It shows that the deflection calculated by elementary beam theory without considering shear lag effect and the shear deformation is smaller, comparing to results calculated by the approximate method proposed in the paper. For such variable box sections girder, transverse shear deformation effect is greater than the shear lag effect when calculating the deflection. The approximate method offers a simple and effective calculating method for the design of box girder with variable cross section, in which, analysis formula can be applied in engineering practice through simple revision.
Influences of Dimension Parameters on the Compression Performance of FRP Rubber Bearings
Authors: Peng Tian Bo , Wang Zhen Nan , Yu Xun Tao
Published: June 2011

FRP rubber bearing was developed just almost 10 years ago, and it is characterized by less weight, lower cost, and better damping capacity. In this paper, the concept of the FRP rubber bearing is introduced first, and a finite element simulation of the bearing is presented then. At last the effects of dimension parameters on the compression performance of FRP rubber bearing are investigated, including the tensile stresses of the FRP plates and the vertical stiffness of the bearing. The influence laws of the dimension parameters are preliminarily concluded, and which can be taken as a reference for the design of FRP rubber bearings.
Application of Dynamic Unstressed State Method in Vertical Rotation Construction of Bridges
Authors: Li Wen Wu , Zhang Zhe , Huang Cai Liang
Published: June 2011

A dynamic unstressed length link element and a catenary element are developed based on classical link element and catenary element, and a dynamic unstressed finite element method is proposed which takes unstressed length as input of the finite element and adjusts cable force by modifying unstressed length of element in finite element calculation. Only a finite element model for initial stage of rotation needs to be set in simulating bridge construction of vertical rotation from above to below, and the whole rotation process could be simulated only by adjusting unstressed length of buckle cable and tractive cable, the internal force of buckle, tractive cable and structure in each construction stage can be accurately calculated. This method can also be applied to tension process for cable-stayed bridge, suspension bridges and other cable structure bridges. This paper takes case study to show the correctness of this method and its practical engineering value in application.
Field Test Research on Treatment of Over-Wet Soil
Authors: Wen Hua , Gu Song , Su You Wen , Zhu Bao Long
Published: June 2011

Take over-wet soil as research object, this paper presents the results of field test to verify the effect and feasibility of ash mixing method, one improvement technique for over-wet soil, on improving the performance of over-wet fill in construction site. This paper also studies the construction technology of utilization of over-wet fill in moist and rainy areas; determines construction parameters; summarizes construction techniques, methods and standards of quality control preliminary. The results show: ash mixing method can effectively improve the performance of over-wet fill; note that additives and over-wet fill should be fully stirred; this approach also works well for managing viscous silty sand.
Model Test Research on Bearing Behavior of Improved Over-Wet Soil
Authors: Gu Song , Wen Hua , Su You Wen , Jia Bin
Published: June 2011

According to the similarity theory, this paper presents a similar model with the similar geometric load and boundary condition to analyze the difference between untreated over-wet soil in Ya’an and improved over-wet soil. The test results show: the bearing capacity of improved soil is enhanced; the settlement of improved soil is much less than which of unimproved soil; the water stability of improved soil is strengthened. These means we have achieved the purpose of improving over-wet soil and the ash mixing method is a feasible means for dealing with over-wet soil.
Model Test for the Cantilever Anti-Slide Pile of Loess Landslide
Authors: Liu Hon Gjia , Men Yu Ming , Cheng Liang Xia , Li Xun Chang
Published: June 2011

Against loess landslide control, two physical model tests of loess landslide have been completed. Test I is model test of loess landslide with preset slide surface, loading on the top of the slope; test II is based on test I, adding the cantilevered anti-slide pile before the slope. The preset slide surfaces are composed of double-layer plastic films. Two testing processes and piling-up weights methods are the same; the only difference is adding cantilevered anti-slide pile and pressure cells placed around the piles. Through analyzing the results of the test I, similarity shear strength parameters of the preset slide surface are determined. In the test II, through analyzing soil displacement before the pile, limit state of loess landslide with the cantilevered anti-sliding model pile is established and load value is obtained, which provides references and bases for subsequent experimental study.
Automated Shear Test on Reinforced Clayey Sand
Authors: Chegenizadeh Amin , Nikraz Hamid
Published: June 2011

Composite soils have been widely used in civil engineering applications, especially in slopes, embankment dam and landfills. This paper aims to investigate effect of fiber inclusion on shear stress of composite soil (i.e. sand composite). A series of laboratory direct shear tests carried out to evaluate fiber effect on strength behavior of composite sand. Clayey sand was selected as soil part of the composite and natural fiber was used as reinforcement. The fiber parameters differed from one test to another, as fiber length were changed from 20 mm to 50 mm and fiber content were varied from 0.5% and 6%.Normal stress kept constant at 200 kpa. For each test, stress_ displacement graph derived and the results were compared. The results proved that inclusion of fiber affected strength behaviour of sand composite so that increasing in fiber content and length caused increasing in shear stress.
Influence of Pipe Roof Reinforcement on Face Stability of Underwater Tunnel
Authors: Wang Kai , Kang Hai Gui , Wang Hai Tao
Published: June 2011

The effect of seepage force on tunnel face stability with pipe roof reinforcement was studied based on the kinematic method of limit analysis. This method can be employed to define the safety factor and its corresponding critical failure mechanism for a given tunnel. The studies revealed that the existence of groundwater may seriously affect the face stability. Under the steady-state groundwater flow condition, most part of the total support pressure is owing to the seepage pressure acting on the tunnel face. There was a relatively large reduction in the seepage pressure by adopting the pipe roof reinforcement technique.