bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Fiber Bragg Grating Monitoring Technique and its Application in Bridge Strengthening
Authors: Ren Zhi Gang , Xu Chang Wu , Wang Er Lei
Published: May 2011

In engineering structures, it is a new approach to evaluate the structural health situation by use of optic fiber sensor. In this paper, a standard specimen beam, 200mm×300mm×3000mm, is chosen and the comparative experiment is executed for strain testing by FBG sensors and vibrating wire sensors which were widely used in bridge health monitoring. Experimental results show that the FBG sensors have a higher measurement precision, higher linearity and better noise resistance. Then we use traditional electrical resistance strain gage to calibrate the FBG sensors and obtain the strain degree of sensitivity, and apply them into bridge strengthening in the Wuhuang Highway in order to collect the strains of reinforcement bar in the deck pavement and the beams before and after the bridge strengthening. The above work is also to evaluate the effects of strengthening projects and carry out long-term structural health monitoring. The monitoring results show that the safety condition can be monitored conveniently with the FBG sensors testing system whose durability and stability can satisfy the need of bridge health monitoring. Finally, we also discuss the key problems and practical approaches in structural health monitoring process by use of embedded FBG sensors.
Structural Damage Detection Using Parameters Combined with Changes in Flexibility Based on BP Neural Networks
Authors: Jun Zhang
Published: May 2011

Modals of BP neural networks with different inputs and outputs are presented for different damage detecting schemes. To identify locations of structural damages, the regular vectors of changes in modal flexibility are looked on as inputs of the networks, and the state of localized damage are as outputs. To identify extents of structural damage, parameters combined with changes in flexibility and the square changes in frequency are as inputs of the networks, and the state of damage extents are as outputs. Examples of a simply supported beam and a plate show that the BP neural network modal can detect damage of structures in quantitative terms.
Interface Properties of Cracked RC Beams Strengthened with Prestressed Hybrid FRP - Part II: Crack Location
Authors: Guo Yong Chang , Xie Jian He , Liu Di
Published: May 2011

This study is the second part of investigation into the interface mechanical performances of cracked reinforced concrete (RC) beams strengthened with prestressed hybrid fiber reinforced polymer (HFRP). Four cases of difference crack location are considered by establishing finite element analysis models to discuss the effort of crack location on the interface stresses in the strengthened beams. The analysis results indicate that the flexural crack obviously changes the distributing of the interface stresses, and an abrupt increase of the stresses arise at the crack location. Moreover, when the crack location is closer from the interface end, the change rate of the stresses is larger.
Finite Element Analysis of Reinforced Brick Wall with Opening Hole
Authors: Zhu Kun , Zhu Er Yu , Yang Wei
Published: May 2011

Based on the result of investigation of farmer’s house in Beijing, a finite element model of reinforced brick wall with a open hole was established, using the ANSYS finite element analysis software. Besides, several reinforcement ways were compared and analyzed. The differences of the maximum displacement and the stress value of different models in the same force condition were discussed. As a result, we put forward a reference reinforcement model.
Finite Element Analysis of Mobile Towers Made of Prefabricated Elements According to Standardization EN1004
Authors: Lv Hui Qing , Zhang Xiang Wei
Published: May 2011

Working aluminum towers is bound to meet the materials, dimensions, design load, safety and performance requirements of the standard EN 1004. Using the FEA(Finite element analysis) software ANSYS, the mechanical analysis of a 8m height tower made of prefabricated elements, according to standardization EN1004,is done in this paper. The geometric imperfection, Such as inclinations between vertical components the inclination position of 1% and the minor eccentricities of castor should be taken account into the finite element model.This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.
Test and Analysis on Seismic Strengthening Effects of FRP Wrapped RC Exterior Joints
Authors: Peng Ya Ping , Dong Guang , Li Peng
Published: May 2011

The method of seismic strengthening the RC frame T-shaped joints with FRP was designed. Its significant effect of seismic reinforcement was verified through cyclic loading tests. The joints models were established using finite element analysis software ANSYS. The whole process of monotonic loading at the beam end were simulated numerically in order to study in depth of the mechanism of FRP reinforcement. Experimental results and numerical simulation analysis showed that: fibers wrapped in the core area of the joints could improve the strength of concrete, and bear part shear of the joints; bending fibers at the beam-column end played to take parts of the moment and reduce the stress of longitudinal bars in the corresponding parts, thus improving indirectly the bearing capacity and ductility of the members strengthened using FRP increased; the stiffness of the joints strengthened with FRP increased when identical loading.
Study on the Effects of Realkalization Rehabilitation Method Auxiliary Alcamines Inhibitors in Simulative Experiment
Authors: Lu Jin Liang , Zhang Jun Xi , Jiang Jun , Wang Kun , Qu Wen Jun
Published: May 2011

In this paper, the feasibility of inhibitor auxiliary re-alkalization was investigated. The effect of realkalization auxiliary inhibitor repair technique was studied by simulative experiment. It studied the changes of electrochemical parameters of the natural carbonated reinforced concrete during the electrochemical realkalization in 1mol/L Na2CO3 solution and the mixed solution of 1mol/L Na2CO3 and 1 mol/L DMEA , as well as the impedance spectroscopy and polarization curves in the process of relaxation. The results showed that: there appears to be no effect of DMEA on the corrosion potential and the impedance of the steel in the process of realkalization. That was, the performance was the same as that in the sodium carbonate solution except corrosion current of rebar with DMEA which showed much lower. But of the samples which the DMEA existed in the electrolyte was significantly shorter at the same relaxation time after realkalization. At the same relaxation time the corrosion potential was more positive and the corrosion current density was smaller. It improved significantly the effect of realkalization.
Displacement-Based Assessment of Seismic Resistance for Transfer Structure with Haunching Braces
Authors: Liang Wei Sheng , Cai Jian
Published: May 2011

The beam-type transfer structure has recently been well adopted in multi-purpose buildings. A new type of transfer structure with haunching braces is introduced in this paper through static elasto-plastic analysis of example structure with specific focus on its unique feature. Based of the deformation damaged criteria, seismic resistance performance for transfer structure with haunching braces is assessed. The results indicate that elastic and elasto-plastic displacement of structure under minor, medium and major seismic events designed against 7 degree seismic fortification intensity satisfy the requirement of the current standards, the structure’s damage status under minor and medium seismic events is Almost Intact and the structure’s damage status under major seismic events is Minor Damage. It can provide reference for engineering practice.
Test Study on the Resisting Shear Strengthening Effect with External Pre-Stressed Wire Rope
Authors: Yu Tian Lai , Ma Qiang , Tian Lei Lei
Published: May 2011

The resisting shear strengthening technology of existing reinforced concrete bridges as an important research topic in the field of old bridges, play an important significance to improve the mechanical properties of old bridges and reduce security incidents. Based on comparative test analysis on two basic beams and twelve reinforced concrete beams strengthened with external pre-stressed wire rope, the influence of the shear strengthening effect was studied systematically caused by the original beam design parameters and the spacing of wire rope, in the meantime the strengthening mechanism was analyzed. Research results showed that the shear capacity of the strengthened beams was improved, because the development of cracks was not only effectively limited, but also stirrup strain was reduced, and yield load was put off. Along with the increasing of the ratio of original beams longitudinal reinforcement and the ratio of stirrup ,and the concrete grade, as well as the decreasing of spacing of external wire rope, the stirrups strain were decreasing and the shear capacity of strengthened beams increased. With the spacing of external wire rope decreasing, the diagonal crack resistance of the strengthened beams increased. The research results can provide reference for the design and research on shear strengthening of bridges.
The Shear Resistant Effect of RC Beam Strengthened with SWR External Prestressing under Dead Load Level when Strengthening
Authors: Yu Tian Lai , Tian Lei Lei , Ma Qiang
Published: May 2011

Ability insufficiently in shear is one of common trouble of old RC (reinforced concrete) beams, so scientific and reasonable shear resistant reinforcement method is one of the important research topics in the old bridge reinforcement and rehabilitation fields, and is of great significance in improving old bridge’s mechanical properties and reducing safe accidents. The shear resistant strengthening effect of strengthened beams with SWR (steel wire rope) external prestressing is studied under different dead load level and damage degree when strengthening, through the indoor experiment in shear. The results of the experiment shows: the width of diagonal cracks of the beams strengthened with SWR external prestressing become smaller and the yield load of stirrups is delayed, and the shear capacity is improved compared with basic beam. Both dead load level when strengthening and damage degree of original beams are the important factors influencing the shear resistant reinforcement effect , and with increasing of the dead load level and damage degree when strengthening, the improved amplitude of the yield load of stirrups and the shear bearing capacity are getting decreasing. The dead load level and damage degree when strengthening should be taken into account.
Heightening Design and Construction of the Reinforcement Concrete Chimney in Heated State
Authors: Liu Hong Bin , Li Meng
Published: May 2011

This paper introduced a project of reinforced concrete chimney with a height of 90 meters, which does not stop construction at nearly 200 degree Celsius, increased the height of the chimney with 10 meters. Reasonable structural measures were promoted to ensure the normal pouring of concrete chimneys. Compared with the normal condition, this measure is economical, low investment, feasible, etc. It provides far-reaching significance that increasing the height of the reinforced concrete chimney at the high temperature state.
One-Dimensional Dynamic Performance of Concrete-Filled Steel Tube
Authors: Zhao Tong Feng , Li Dan , Sun Chang Zheng , Liu Hong
Published: May 2011

The paper puts forward the one-dimensional strain rate related dynamic constitutive model of concrete-filled steel tube. The calculation results are in good agreement with the experimental results. Uniaxial compression performance finite element analysis at the strain rate among 10/s-5—10/s-2 is completed based on the conclusions. The results showed that considering concrete strain rate effect, the bearing performance of CFST is obviously changed. It showed that with the strength of concrete and strain rate increasing, ultimate bearing capacity of concrete-filled steel tube is improved and ductility is reduced. With the confining ratio and strain rate increasing, the ultimate bearing capacity and ductility of CFST are improved. With the slenderness ratios and strain rate increasing, the ultimate bearing capacity and ductility are reduced.
Probability Model of Corrosion Initiation Time of Steel in Concrete Structure in Chloride Environment
Authors: Ma Ya Li , Zhang Ai Lin
Published: May 2011

Probability distribution law of corrosion initiation time of steel in concrete under chloride environment is discussed. Based on the Fick’s second law, by Monte Carlo, frequency distribution, distribution type and probability density is analyzed. The statistic parameters of the factors influencing the probability distribution of corrosion initiation time are studied and the expression for sensitivity analysis of corrosion initiation time is deduced. By sensitivity analysis can know, corrosion initiation time is found to be more sensitive to cover than the diffusion coefficient, and more sensitive to surface chloride concentration than the critical chloride level. The analysis of the paper perfects the methods of predicting the corrosion initiation time.
System Reliability Analysis of Deep Sliding Stability of Gravity Dams
Authors: Jiang Sheng Hua , Hou Jian Guo , He Ying Ming
Published: May 2011

Various potential sliding paths and different failure modes should be considered in the stability of gravity dam against deep sliding when there are several faults. The safety factor of every fault is calculated with nonlinear finite element method, and the most possible sliding path is obtained by strength reduction method. The results indicate that the strength reduction factor is larger than the safety factors of all the faults. Based on the weighted regression response surface method, the reliability indices of the faults are computed and are compared with the safety factors, which shows there’s not an entire equity relationship between the reliability index and safety factor. Each failure mode of sliding path is a parallel system of several faults, and the final failure mode is the serial system composed of all sliding paths. The reliability of every sliding path and the final system are analyzed by means of the gradual equivalent linear method, and the results are consistent with the strength reduction factor. It’s recommended the reliability analysis be applied to the safety evaluation of deep sliding stability of gravity dams to make up the shortcomings of the safety factor method.
Test Analysis of Measuring Working Strains in Concrete Structures by Loophole-Drilling Strain-Gage Method
Authors: Zhang Feng Peng , Qiu Zhao Guo , Jiao Peng Fei
Published: May 2011

Hole-drilling strain-gage method for measuring working strains in concrete structures has been discussed by tests. Pre-loading strain has been used to simulate the working strain in concrete structure, and model beams have been sued for drilling measurement tests in the lab. Some key issues of this work have been studied, such as strain gages selected, waterproof, data continuous transmission out of hole, etc., and the strain release curves have been obtained. On the basis of the work, the effects of drilling depth (h), hole diameter (d), original strain and the environmental temperature have been analyzed, and general laws of working strains measurement described by strain released rates have been obtained. These results have been successfully applied in the existing bridge inspection, and referred for reinforcement design and construction.
Reliability Analysis of Pile Vertical Bearing Capacity
Authors: Cao Shu Wen , Zhao Dong , Liu Jun Qing
Published: May 2011

To provide guidance to engineering practice, the reliability of the vertical bearing capacity of single steel pipe pile is analyzed. The FOSM method, the FOSM method based on fuzzy stochastic and the FOSM method based on artificial neural network are used to calculate the reliability of steel pipe pile through MATLAB program. It is show that the FOSM method based on fuzzy stochastic and the FOSM method based on artificial neural network are more suitable for the reliability analysis.
Discussing Chinese UHV Transmission Tower’s Reliability by Comparing Design Standards Home and Abroad
Authors: Li Mao Hua , Li Zheng , Yang Jing Bo
Published: May 2011

Several representative design standards or manuals of overhead transmission lines home and abroad were selected, including ChineseDL/T5154-2002,AmericanASCE10-97, EuropeanEN50341-1etc., compared the reliability level of axial compression member of transmission tower in these standards, by calculating the comprehensive reliability coefficient under the strength limited state. Basically make the selected standards’ level of reliability degree clear, the specific data was got, and then gave some advice to UHV towers’ design about the setting of reliability level, which could not only provide a reference to understand the differentia of design standards home and abroad, but also to design the UHV transmission lines.
Influence on GGBS to Time Dependent Chloride Diffusion Coefficient of HPC
Authors: Song Lu Guang , Sun Wei , Gao Jian Ming , Zhang Yun Sheng
Published: May 2011

This paper investigates the influences of dosage of ground granulated blast furnace slag (GGBS) (0%, 20%, 40%, 60% and 80%) to chloride diffusion coefficient. And the time dependency of apparent diffusion coefficient as the submerging time from 60 days to 360days has also been studied. The result shows that the addition of GGBS into concrete has great influence on the chloride diffusion. The diffusion coefficients of the mixes containing GGBS decrease rapidly with time than that of the mix PC Control. But there were little differences of the values of apparent diffusion coefficients among the mixes SL20, SL40 and SL60. The addition of GGBS in concrete has great influence on the time dependency of concrete. And the concrete which has 40%-60% replacement of GGBS has greater ability to resist the diffusion of chloride than other replacement.
Research on the Anti-Sulfate and Chlorine Corrosion Property of Concrete
Authors: Du Jian Min , Jiao Rui Min , Yuan Ying Shu , Zhu Xiao Meng
Published: May 2011

In this paper wetting-drying cycle in the natural situation and increasing the concentration of sulfate solution is used in the laboratory , in order to accelerate the sulfate corrosion of concrete. The ultrasonic speed of sound on the opposite face is tested by ultrasonic technique regularly in order to reflect the change of concretes strength with the relative dynamic modulus.And at the same time the cube compressive strength test is used to detemine the corrosioned concretes intensity.Though the trend of relative dynamic modulus development which are in four different conditions to explain that the presence of chlorine ions affected the sulfate corrosion on concretes.Although in the compound solution, the corrosion degree should be depended on the concentration of sulfate ions and chloride ions in compound solution.
New Model for Shear Failure of RC Beam-Column Interior Joints with Different Depth Beams
Authors: Li Hong , Gao Shuang , Wu Tao , Liu Bo Quan
Published: May 2011

On the basis of the experiment of 12 abnormal joints with different depth beams, failure process, seismic capacity and construction measure of this kind of joints are analyzed. Shear strength and failure model of joints with equivalent core height are analyzed by using mathematical model based on quadruple flexural resistance. The model satisfies equilibrium equations relating magnitude of external forces such as column shear, beam shear and axial force in column, to the magnitude of stress resultants. The results show that the model can reasonably explain the reasons for joints failure, have explicit mathematical model and good agreement between experimental results and calculated results of this model is achieved.
Experiment Study on Shear Capacity of RC Beams
Authors: Liu Jun , Zhang Feng Peng , Zuo Yin Bo , Ma Jin Chao
Published: May 2011

Based on cyclic loading experiment of nine beams in the two groups, the relationship among the average web stress, initial diagonal crack width and shear capacity of RC beams was studied. Experimental result shows that the decline of the shear strength of the RC beams due to cyclic loading can be characterized by the width of diagonal crack. Under the same load amplitude, the larger crack width is, the greater the decline of the bearing capacity is. Besides, under the same number of cycles, the greater the load amplitude is, the larger the crack width is, the greater the decline in the bearing capacity of beams is. In addition, according to the experimental phenomena and the shear compression failure mechanism of beam, a formula for shear capacity after cyclic loading is derived for engineering use.
Study on Relation of Structural Reliability Calculation and Fuzzy Mathematics
Authors: Wen Zhong Hua , Zhou Juan , Jia Ming Xiao
Published: May 2011

Randomicity of basic variable results in the problem of structural reliability. A series of statistical parameters is applied in reliability calculation. Statistical parameters are attained by the statistics and analysis of source data of basic variable. However the basic variable source data is imperfect for a lot of structure. On the other hand, the relation of reliability index and basic variable is an important issue in reliability calculation. The two matters are solved in this paper by fuzzy mathematics. First, the matter of statistic data scarcity of load and resistibility and offered scientific evidence for estimation of distributing type of load and resistibility it solved by grey forecast; Second , the correlate degree of reliability index and load is calculated by correlate degree theory which can provide scientific evidence for security inspect of project.
Reliability Analysis of Vertical Bearing Capacity of Pile Based on Static Load Tests
Authors: Liu Shi Qing , Zheng Jun Jie , Xu Zhi Jun , Bian Xiao Ya
Published: May 2011

Based on the sample range theory in Mathematical Statistics, the general standard variance of vertical capacity of single piles is evaluated according to the data from static load tests, and a method is presented to evaluate the reliability of vertical bearing capacity of pile, of which distribution obeys normal distribution. Finally, results from the case study indicate that it is effective to evaluate the reliability using the method presented in this paper, and the number of tested piles specified in Technical Code for Testing of Building Foundation piles and determining sample range can be interpreted reasonably in theory. Meanwhile, it can give good references to designers to determine the design parameters according to testing piles.
Effcets of Water-Cement Ratio on Tensile Basic Creep of Early-Aged Concrete
Authors: Wang Xin Jie , Zhu Ping Hua
Published: May 2011

The effects of water-cement ratio on the tensile creep of early-age concrete under constant load were investigated. Creep and shrinkage of concrete under sealed curing condition was researched to determine the tensile basic creep of concrete. The results indicate that, as in compression, creep of concrete in tensile is very sensitive to water to cement ratio. The results also indicate that the tensile creep increases with the water to cement ratio. And that the tensile creep develops rapidly within the first day after loading.
The Stochastic Dynamic Reliability Research on Nonlinear Pile-Soil-Structure Interaction System with Uncertain Parameters
Authors: Zhou Ai Hong , Yuan Ying , Xu Bai Qing
Published: May 2011

According to the damage characteristics of pile-soil-structure interaction system subjected to the earthquake, the seismic design method of using the dual design guideline of strength and deformation and taking the same reliability for both pile foundation and superstructure was put forward. The stochastic dynamic reliability of pile-soil-structure interaction system with uncertain parameters was studied on the basis of the randomness of earthquake, the nonlinearity of soil material parameters, and especailly the variability of soil material parameters. The results show that the control indexes of pile foundation and superstructure decreases with the increases of failure probability and the variation of material parameters will make the pile foundation structure partial unsafe.
Experimental Study on the Axial Compression Capacity of Condensed Column in Composite Masonry Wall
Authors: Wang Shao Jie , Liu Fu Sheng , Sun Tong , Zhang Shun Ke , Wang Hong Bin
Published: May 2011

On the basis of summary and analysis of the characteristics of concrete hollow blocks and composite masonry walls, this paper puts forward the concept of composite masonry wall with condensed core columns. Regarding the distance between core columns (s=600mm and s=1200mm) as the main influencing factors, two composite masonry walls were designed and built to carry out the axial compression capacity experimental study. The results of the study show that the composite masonry wall with condensed core columns can greatly improve the ultimate axial compression capacity of the wall, delay the fracture process, and influence the failure modes. In the entire experiment, the deformation of concrete hollow blocks and core columns was basically the same, and can work in coordination. The stress mechanism of the composite masonry wall which had splitting fracture changed from the composite masonry wall to the (weak) frame structure, which finally formed column hinge and got destroyed. The experimental results of this paper can provide a new way for the application of concrete hollow blocks as main wall materials in the field of high-rise buildings. The establishment of axial compression capacity formula and the eccentric compression performance of the composite masonry wall with condensed core columns deserve further study.
Numerical Analysis of Tunnel Excavation Method at Greatly Cross Undermine Huangzhuang Station of Beijing Subway
Authors: Xie Jin Shui , Bai Ming Zhou , Xu Zhao Yi , Xu Ming Xing , Shi Zhu , Cheng Guo Ping
Published: May 2011

Combined with the geological conditions and the project features, the selection problem of pilot tunnel construction method of Huangzhuang station is solved. Directing at the commonly used method including CD method, CRD method and double side wall pilot tunnel method, FLAC3D numerical calculation method is adapted to analysis and predict the ground surface deformation and supporting structure hand features. Through analyzing the size and law of surface settlement in this section, the feasibility and differences of these methods is concluded and analyzed. And finally an example is given.
Study on Effect of Lattice Distortion on Infrared Properties of Ceramic Tiles at Ambient Temperature
Authors: Gu Xing Yong , Luo Ting , Chen Yu Xia
Published: May 2011

Effect of the lattice distortion of the main crystal mullite, addition of copper mine tailing and the firing schedule on the infrared properties were studied. The study revealed that the higher lattice distortion is, the higher infrared emissivity of ceramic tiles is. The addition of raw materials containing iron and other elemental impurities could form the solid solution in the body what promote the degree of lattice distortion of main crystal which affects the infrared emissivity of the ceramic tiles. With the increasing of firing temperature, the degree of lattice distortion of main crystals will decrease and the infrared properties also decrease.
Cooling and Heating Source Selection of Air Conditioning Based on Low Carbon
Authors: Wei Jun , Zhang Wei Ya
Published: May 2011

This article analyzes the form of carbon discharge within the building life cycle, and indicates the relationship between energy saving and carbon reduction. It puts forward that when selecting the cooling and heating source, we should define the strength standard and assessment index of carbon discharge. While we weigh the energy rationality, low carbon charge should be taken into consideration, in order to reduce the CO2 discharge in buildings.
Test and Analysis of Large Space Station Field Environment
Authors: Gao Zhi Yong , Zhang Qun Li , Li De Ying , Shi Yong Zheng
Published: May 2011

Field environment parameters of the waiting room of the railway station were measured. By the data obtained by testing, this paper analyzes the indoor field environmental quality of the large space building and evaluates the thermal comfort of activities of the major regional staff. It turned out that the indoor environment barely meets the requirements of thermal comfort, quality of acoustic environment beyond the standards, light environment is perfect and indoor air quality is poor.
Numerical Simulation of Indoor Airflow and Poison Gas Diffusion in Air-Conditioning Buildings with Large Space
Authors: Peng Xiao Yong , Wan Fen , Xie Jing Fang , Yao Lin , Liu Zhen Hao
Published: May 2011

The numerical simulation of indoor airflow and poison gas diffusion and transport process is given for different air systems of air-conditioning in large space buildings in this paper. The numerical results show that the poison gas diffusion is affected by indoor airflow, and the variety air systems make the characteristics of poison gas diffusion differently. After arriving at the air return, the poison gas will soon be sprayed from the air inlet of the air system to the whole space which is serviced by the air system.
2-D Coordinate Transformation Based on Centre of Gravity Datum
Authors: Liu Tao Sheng , Huang Sheng Xiang , Luo Li , Zeng Xian Gui
Published: May 2011

2-D Coordinate transformation between different coordinate system including four parameters: two translations, one rotation, and one scale factor parameter. Because of ill-condition matrix, the common points’ little errors may cause big fluctuation of parameters’ results, which cause the four transformation parameters unreliable. Consider the comparability between coordinate transformation model and centre of gravity datum of free net adjustment, may eliminate the two translation parameters by auxiliary gravity datum condition. This article validate this method with instance.
Application of GTS-311 Total Station in a Slope-Shaft Breakthrough on Error Analysis
Authors: Gan Zheng Ru
Published: May 2011

The breakthrough is usually a mine survey work with a strategy meaning for the overall work. This text analyses total station errors and makes use of the error theory by combining an concrete engineering example in order to instruct practice better and reduce the blind work. At the same time, it is necessary to adopt measures to decrease the error in the breakthrough practice, and then to guarantee the breakthrough work smoothly.
Influence Coefficient of Filler Plates in Built-Up Cruciform Section Members Formed by Two Equal-Leg Angles
Authors: Yang Long Yu , Li Zheng Liang
Published: May 2011

The built-up cruciform section formed by two equal-leg angles has been widely applied in extra high voltage(EHV) transmission towers, however, domestic codes provide structure requirement and overlook the influence of multi filler plates to members’ bearing capacity. For the purpose of this, a pin end experiment covering 3 different cross sections(Q420, L160*12, L160*14 and L160*16) and 7 different slendernesses(25~55) has been run. This experiment contains totally 21 specimens. Furthermore, large amounts of models have been analysis by finite element method whose parameters contain variety b/t, λ, filler plate intervals and forms, amount of bolts in filler plate. A recommended formula is given for evaluating the influence of filler plates. The results show: multi filler plates enhance bearing capacity slightly for members with λ less than 35, and the better interval for filler plates is 10i-40i(i is the minimal radius of gyration); filler plates do not work well when b/t of the member is extreme large or small, a propositional b/t range for this kind of member is 11-16; the amount of bolts in filler plate has tiny influence on members’ bearing capacity; the recommended formula is applicable and feasible for design.
Strain Rate Effect on Transmission Tower-Line System under Earthquake
Authors: Wang Wen Ming , Li Hong Nan , Liu Guo Huan , Tian Li
Published: May 2011

Using ABAQUS software, three dimensional finite element model of a transmission tower-line system is created. Nonlinear seismic responses under three seismic records with and without strain rate effect are studied. The results show that the strain rate effect on the transmission tower-line system is more obvious with an increase in intensity of the earthquake. The influence of strain rate on the top displacement and base shear of tower under certain seismic records is unneglectable. Also, it is shown that the strain rate effect on the deformation of wire is prominent. The strain rate effect on the axial force of wire is neglectable. This simple study reveals the importance of considering strain rate effect in seismic analysis for transmission tower-line system.
Study on the Relationship between Transition Curve and Neighbor Point
Authors: Wang Xiao Guang , Ma Li Xia , Meng Fan Ying
Published: May 2011

In order to satisfy tunnel engineering survey and rapid transit railway engineering survey, this paper makes a study of the relationship between transition curve and neighbor point, and puts forward precise bisection method solution and approximate correction method solution which is suited to calculator. Besides, correction method is verified through comparing with bisection method to prove that its accuracy can meet engineering survey requirement.
Monitoring and Pre -Warning System of Slope Stability in Xinqiao Based on 3S
Authors: Huang Shi Xiu , Gao Fei , Hong Tian Qiu
Published: May 2011

A real-time monitoring and pre -warning system has been established in Xinqiao pyrite mine. 3S and smart monitoring technology is broadly applied in the field for their advantages. The system is integrated by the database management subsystem, smart monitoring subsystem and early warning subsystem. It can accomplish monitoring data analysis and forecast in point or district. The location of monitoring points and the main methods are introduced in detail and the key techniques about data transmission and processing have been designed successfully which find a way out of the difficulty on the condition that the circumstance is bad and the monitoring signal is interfered strongly in long haul transmission. Through this system remote controlling and real-time prediction can be realized easily. So it has great application value to study the system.
Chain Reaction of Mountainside Disasters and its Dispersing Impact on the Traffic and Transportation Network
Authors: Tian Bei Ping , Wang Han Mei , Liu Wen Fang , Yuan Bao Jun , Zhong Xiao Bing
Published: May 2011

There are much mountainous areas in China. Mountainous traffic is greatly different from the plain.Interrelation of mountain landform and the traffic there is analyzed first. Because mountainous traffics and towns are greatly influenced by the disasters there, chain reaction of disasters and its dispersing impact are in particular demonstrated. The course of a disaster could be divided into several stages. Through analyzing their characteristics, solutions in turn to treat disaster are listed. A case is given to elaborate the disaster and its impact on the traffic and town.
Interaction between Crack and Aggregate in Concrete under Dynamic Tensile Loading and Strain-Rate Effect on Material Strength
Authors: Liu Lu Guang , Ou Zhuo Cheng , Duan Zhuo Ping , Liu Yan , Huang Feng Lei
Published: May 2011

Crack propagation behaviors at a mortar-aggregate interface in concrete under dynamic tensile loading conditions are investigated numerically. It is found, for a certain interfacial strength and aggregate size, that the crack can penetrate through the interface under an external load with its loading-rate higher than a threshold value. Moreover, for the crack penetration, the smaller the radius of an aggregate, the higher the loading-rate is needed. Therefore, concrete failure energy increase considerably with the loading-rate (or the strain-rate). Such a strain-rate effect on the strength of concrete is in agreement with previous experimental results.
Global Stability Analysis of Rectangle Prestressed Thin-Walled Aqueduct
Authors: Bai Xin Li , Wu Ze Yu , Ma Wen Liang
Published: May 2011

According to the deformation characteristics of global side torsion buckling for rectangle thin-walled aqueduct, the critical load of side torsion buckling for rectangle thin-walled aqueduct is deduced by Galerkin method. Influences of prestress and vertical deformation before buckling are considered. The variation rules of critical load are analyzed with four factors: span, flange width, ratio of height to width, thickness. The analysis results show that the aqueduct span is the biggest influence on the critical load of side torsion buckling for aqueduct; for rectangular thin-walled aqueduct, in conventional aqueduct section size and span, its critical stress of side torsion buckling is greater than concrete compressive strength design value , therefore side torsion buckling won't happen in usual aqueduct; if steel with high yield limit is used, stability check calculation must be carried out. Results and conclusions obtained can be referenced for the global stability design of thin-walled aqueduct.
Enhancement on Mechanical Properties of Hybrid Concrete by Incorporating Fibers with Different Geometrical Dimensions
Authors: Zhang Ya Fang , Li Lin , Liu Hao
Published: May 2011

With numerical modeling in meso level, impaction of incorporating polypropylene fibers with two different geometry dimensions on flexural strength and toughness of hybrid fiber concrete has been studied in this paper. Mechanism of such hybrid fiber reinforcement has also been analyzed. The results show that hybrid of fibers with different geometric dimensions would bring about synergy, thus fiber enhancement effect could be demonstrated. Furthermore, the closer the incorporation ratio of these two kinds fibers are to each other, the more evident the enhancement will be produced. The most optimized hybrid ratio is in between 2:1 and 1:1.
A New Adaptive Higher Order Response Surface Method
Authors: Han Feng , Li Zheng Liang , Fan Wen Liang
Published: May 2011

Response surface method has won numerous concerns in the reliability analysis of structure due to its simplicity and practicability, especially quadratic response surface taking no account of cross terms is most widely used. However, for the complex ultimate state curved surface corresponding to strongly nonlinear, the approximate accuracy of quadratic response surface is apparently not enough, causing a biggish error in estimation of reliability. Although, theoretically, higher order response surface method can resolve this problem, the sharp increase of undetermined coefficient reduces calculation efficiency, and even, cannot achieve. Therefore, on the basis of univariate analysis of multivariable function, an algorithm which can reasonably determine higher order response surface form is presented in this article, able to effectively reduce the number of undetermined coefficients in response surface, so as to reduce computational difficulties and put forward improving measures for possible problems; In addition, based on the tactics of number-theoretic setpoint, a type of scheme of number-theoretic selecting point applicable to response surface method has been developed. Finally, through the analysis of examples, the suggested algorithm was validated, with the result showing that the algorithm has good accuracy and efficiency.
Mechanics Analysis and FEM Calculation for the Bodywork of Light-Duty Cross-Country Bus
Authors: Gao Chao , Song Zhi Long , Chen Hong Zhou
Published: May 2011

In this paper, the bodywork of lightg-duty cross-country bus, which is made of glass fibre reinforced plastic is comprehensively analysised by finite element analysis software, and its structure, load and movement status are discussed exhuastively. Meanwhile through more comprehensive calculation of the stress, displacement, natural frequency and vibration modes and other aspects under various conditions, providing a necessary theoretic basis for analysis of strength and stiffness and structural optimization.
Study on Detonation Features of Low Powder Detonating Fuse in the Bending Condition
Authors: Mei Qun , Zhu Jun Feng , Li Zuo Liang
Published: May 2011

Detonation of low powder detonating fuse is studied in numerical simulation and experiments in bending conditions using LS_DYNA3D. The results show that pressure of the explosion and detonation velocity are decreased in the same section areas after bending. In bending conditions, detonation wave is similar to small angle corner diffraction. So the detonation velocity is lower than normal velocity.
Research on Distribution and Evolution Law of the Damage-Fracture Field in Mining Process
Authors: Xu Ai Bin , Gao Feng , Cheng Hong Mei , Liu Xing Guang
Published: May 2011

The distribution and spatiotemporal evolution law of the mining-induced fracture field was studied by means of damage mechanics. The damage variable correlated with the excavation process was introduced, which was used to describe the distribution characteristics of fractures in rock mass. In accordance with the damaged theory, the elastic finite element program was developed, by which the analysis of mining process of one coal seam was made of. The material damage accumulation taken into consideration, the distribution and evolution law of the volumetric strain, stress and damage field was obtained, which provided a theoretic reference for the design of gas drainage and improving the efficiency of gas extraction.
Elasto-Plastic Analysis of Frame Structures under Large Displacement-Rotation Deformations
Authors: Yang Dong Quan , Peng Hong
Published: May 2011

A finite element program for elasto-plastic analysis of 3D beams and frame structures under large displacement/rotations is developed. The element is Timoshenko beam element based on mechanics of continuum. Constitutive equations for large displacements/rotations in elastic stage are expressed in an explicit way which is suitable for programming. The modification of constitutive equation is presented for the analysis of elasto-plastic problems. A fiber model is adopted for the calculation of stiffness matrix and internal forces. For solution of nonlinear finite element equations, general displacement control method and semi-modified stiffness matrix method is adopted. The results of numerical experimentation show that the program work well for 3D beams and frame structures under elasto-plastic large displacement/rotations.
Interfacial Spring Element Model with Random Defects for 3D Simulation of Concrete Strength under Uniaxial Tension
Authors: Wang Juan , Li Qin Bing , Qing Long Bang
Published: May 2011

In this study, an interfacial spring element model with random defects was constructed based on the four-phase material model of concrete, which consists of aggregate, matrix, interfacial transition zone (ITZ), and initial defects distributing randomly within the ITZ. The ITZ is modeled by linear spring element of zero length. Simulation of concrete strength under uniaxial tension yielded numerical results that are consistent with reliable experimental data, thus proving that the model is reasonable and applicable. Then, the model was employed to analyze the influence of random initial defects on concrete strength. Results showed that increased initial defects in ITZ leads to a linear decrease in tensile strength of the concrete. Compared with the strength of concrete without initial defects, that of concrete with initial defects equal to 60 % of ITZ elements decreased by about 40%. Based on these results, this study recommends that the fraction of initial defects should be 30 % when using the proposed model to predict uniaxial tensile strength of normal-strength concrete.
Application of Increment-Dimension Precise Integration Method in Numerical Simulation of Two-Phase Oil-Water Flows in a Low Permeability Reservoir
Authors: Mei Fu Liang , Wu Xiang Song , Lin Guang Ping
Published: May 2011

The numerical simulation of two-phase oil-water flows in a low permeability reservoir was carried out by means of an increment-dimension precise integration method (IDPIM). First of all, state equations denoted with pore fluid pressures at mesh nodes were built up according to finite difference method (FDM). Secondly, the recurrence formulae of the pore fluid pressures at mesh nodes were set up based on IDPIM. Finally, the numerical simulations of two-phase oil water seepages for a typical five point injection-production reservoir as an example were conducted by means of IDPIM and IMPES respectively. Calculation results by IDPIM are in good accordance with those by IMPES, and then IDPIM is quite reliable. At the same time, the effect rule of the startup pressure gradients on recovery degree, liquid production rate and oil production rate has been investigated. The start-up pressure gradients have an outstanding effect on recovery degree, liquid production rate and oil production rate, and the existence of the startup pressure gradients will enhance development difficulty and cost.
A Hybrid Radial Boundary Node Method for Biharmonic Problems
Authors: Wang Xue Hai , Liu Ya Mei , Lan Qi Xun
Published: May 2011

The hybrid radial boundary node method is applied to solve the biharmonic problems. Based on modified variational principle, the variational formula of the biharmonic problems is established. The radial basis point interpolation is employed to approximate the boundary variables, while the domain variables are interpolated by a combination of the fundamental solution of the laplace equation and the biharmonic equation. Compared to the regular hybrid boundary node method, as the shape function has the delta function property, the boundary conditions of the original problem can be easily implemented, and the fictitious source points are not involved. Numerical examples show that this method is efficient for solving the biharmonic equation.
Dynamic Response of Viscoelastic Sphere-Symmetric Problems
Authors: Chen Ya Juan , Shang Xin Chun
Published: May 2011

With regard to viscoelasticity, we can’t use elastic-viscoelastic corresponding principle in quasi-static situation in view of dynamic response. In allusion to compressible materials, basis equations were applied, and constitutive equations were applied in convolution form, we derived the equations with which displacement function was satisfied, the displacement solution and stress expression in image space were derived by Laplace transforms. We discussed boundary value problems on the condition of the given displacement on the inner surface of the spherical shell, and the solutions were verified in calculating example.
An Inverse Analysis Algorithm of Material Parameters for Functional Graded Materials
Authors: Huang Li Xin , Yao Qi , Wang Lin , Zhou Xiao Jun
Published: May 2011

An inverse analysis algorithm is proposed to identify the material parameters of functional graded materials (FGMs). The inverse analysis of the material parameters is formulated as the problem of minimizing the objective function defined as a square sum of differences between the measured displacement and the computed displacement by a finite element model. Levenberg-Marquardt method is used to solve the minimization problem. The sensitivities of displacements with respect to the material parameters are based on the finite difference approximation method. A numerical example is given to demonstrate the effectiveness of the proposed algorithm.