bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic Performance Research of High-Rise Diagrid Tube-Core Tube Structures
Authors: Teng Jun , Guo Wei Liang , Rong Bai Sheng , Li Zuo Hua
Published: December 2010

Diagrid tube structure system has advantages on constructing high-rise buildings due to its great stiffness, however, its seismic performance analysis are limited. 10 CFST diagrid tube-concrete core tube structures are analyzed by Mode-Pushover method using Perform-3D program. The plasticity developing process and components yield order are summarized. The force distribution between diagrid and core tubes is researched and the force redistribution reason is explained from the change of diagrid tube forces. The structure lateral stiffness degradation is discussed based on the developing process of diagrid and core tubes lateral stiffness. The influences of main lateral stiffness related factors on the structure plasticity developing process, force distribution and stiffness change of the tubes are discussed at last.
Hysteretic Behavior of Semi-Rigid Composite Steel Frame with Cross-Stiffened Steel Plate Shear Walls
Authors: Guo Hong Chao , Hao Ji Ping , Li Feng
Published: December 2010

Based on the experiment of a one-third scale, single-span, two-storey semi-rigid composite steel frame model with cross-stiffened steel plate shear wall under lateral cyclic loadings, the interactive effect between the joint stiffness and the cross-stiffened steel plate shear wall, the failure mode and energy dissipation mechanism of the structure system were analyzed, some important parameters were obtained in regard to load-carrying capacity, ductility, stiffness and energy dissipation capacity. The results showed that the specimen exhibited excellent ductility, energy dissipation capacity and great safety margin; the stiffness degradation of the joints was not serious, the requirement of ductility was lowered by setting up infill panels, the cooperative work between the frame and the steel plate shear wall was well; stiffeners improved the force condition of steel panels, increased the stiffness and load-carrying capacity of panels, lightened the pinch of hysteretic loops and reduced the noise and tremor of panels. The failure mode of the structure induced by buckling of stiffeners, local buckling and interactive buckling of infill panels，plastic hinges were formed at the bottom of column and semi-rigid connection, the in-plane deformation of specimen was bending failure. The research provides a basis for engineering application and theoretical analysis of the structural system.
Research on Mechanical Behaviors of Composite Frame and Reinforced Concrete Core Hybrid Structures in High-Rise Buildings
Authors: Zhang Shu Yun , Bai Guo Liang , Zhao Lai Shun
Published: December 2010

For mechanical behaviors of composite frame and reinforced concrete core hybrid Structures in high-rise buildings, the three-dimension finite element models were established, modal analysis and elastic time-history analysis were finished, the cooperative work mechanism between frame and core was researched, the dynamic characteristics and seismic response of the hybrid structures under different connection type were studied. the results indicate that the stiffness characteristic of the hybrid structures should be taken between 1 to 2 so that two sub-structure can reasonably afford the internal force, the connection between frame and core bring differences in mode shape and natural vibration periods, the natural vibration periods of hinged model are greater than periods of rigid model, the mode shapes with mainly floor vibration are more likely to appear in hinged model, the connection would lead to significant changes in the deformation and distribution of inner force, the axial force of frame columns would significantly increase for the rigid connection, the shear and bending moment of frame columns would increase for the hinged connection, it was proposed that the hybrid structures should be separately analyzed with hinge model and rigid model for ensuring the frame columns have sufficient capacity of the shearing and bending both.
Analysis of Seismic Performance of Mega Steel Braced Frame-Composite Steel Plate Shear Wall Structure
Authors: Chen Lin , Liu Xing , Zhou Yun , Hu Xiao
Published: December 2010

Mega steel braced frame-composite steel plate shear wall structure, consisting of mega steel braced frame as outer frame and composite steel plate shear walls as core wall, is a new type of hybrid structure that is proposed in this study. Seismic performance of this new structure was analyzed under frequent earthquake and severe earthquake. The analysis focused mainly on displacement response, seismic base shear distribution and failure mechanism. Comparing with traditional steel frame-RC core wall structure, this new type of hybrid structure presents better coorporative working performance since mega steel braced frame provides larger stiffness and composite steel plate shear wall provides a fairly ductile response. It can be observed from the failure mechanism that this structure has multiple seismic resistant systems with composite steel plate shear wall, mega braces and mega frame when subjected to severe earthquakes.
Finite Element Analysis on the Temperature Field within Steel Tube Reinforced Columns
Authors: Xu Lei , Sun Jian Gang
Published: December 2010

The temperature field analysis method of steel tubes reinforced columns under fire by finite element analysis software ABAQUS is proposed in this paper. The theoretical method is validated by tests, and the calculated results agree well with those of tests. On the basis of that, the influencing laws of section perimeter; steel reinforcement ratio and sectional core area ratio on temperature field are discussed. It has been found that the effects of section size and sectional core area ratio on temperature field are significant, but steel ratio has very little effect on temperature both of steel tube and of sectional center. These achievements make it possible to study further theoretical study on the fire resistance of steel tube reinforced concrete columns.
Nonlinear Finite Element Analysis of Beam String Structure
Authors: Jiang Zheng Rong , Xu Mu , Duan Wei Ning , Shi Kai Rong , Cai Jian , Wang Shi Tong
Published: December 2010

Beam string structure (BSS), which is a new kind of semi-rigid hybrid system, composed of arch, strut and string, has been developed rapidly in long-span steel structures in recent years. Based on the principle of virtual work and Updated Lagrange, the formulas of geometric nonlinear F.E.M. for spatial beam element, cable element and truss element are derived respectively in this paper. Taking the one-way BSS model of the steel roof in Guangzhou International Convention and Exhibition Center as a computational example by using both linear and nonlinear analysis method, the analytical results show that it is appropriate when adopting the straight truss element with two joints and equivalent elastic modulus to simulate the cable element with small sag. Although the linear analysis can meet the requirement of practical engineering due to its weak nonlinearity of BSS, the nonlinear method is also important to improve the precision theoretically. The conclusions obtained may be helpful for the designers in similar projects.
Aseismic Analysis on a Strengthened Chinese Ancient Building by Simulation
Authors: Zhou Qian , Yan Wei Ming
Published: December 2010

In order to protect Chinese ancient buildings,a Qing Dynasty building in Sichuan province was taken as example to study its aseismic characters after strengthened. By ANSYS program,semi-rigid character of tenon-mortise joint as well as contact between wooden constitution and walls were simulated.Then by modal analysis basic frequency as well as main modes of the structure were obtained;By response spectrum analysis inner forces as well as displacements of the structure under 7-degree intensity of seldomly occurred earthquakes were obtained.Results show that after strengthened,main modes of the structure are of translation;Under 7-degree intensity of seldomly occurred earthquakes peak values of displacement as well as inner forces of the strengthened building are all within permissible scopes,which proves its good aseismic characters.
Interface Shear Force of Steel and GFRP Deck Composite Beam under the Effect of Temperature and Creep
Authors: Wang De Xuan , Huo Jun Hua , Wang Lian Guang
Published: December 2010

A new type steel and glass fiber reinforced polymer (GFRP) deck composite beam has been proposed. The relative slip and shear force on the interface of steel and GFRP deck composite beam appears to a certainty with the external loading, which induced internal force redistribution between GFRP deck and steel beam and shear connector, especially GFRP is a resin material, its physical and mechanical properties will change with temperature and time. According to the structure and bearing characteristics, the interface shear force differential equations that considering the temperature and creep effects were presented, the theoretical calculating formula of shear force were given under the uniform load. Results of calculation showed that the shear force of composite cross-section would increases with the increase of the connection stiffness, the increase of load, the change of temperature and the time. Loading effect and temperature changes creates a relatively larger impact on the shear force of the composite beam, while the stiffness of the connective interface and the creep effect of the GFRP material to composite beam shear force were much little.
Design of the Digital Simulation System for Corrosion Damage on Marine Steel Structures
Authors: Lv Sheng Li , Xu Cheng Long , Wang Zhen Guo , Zhao Fei , Tong Xiao Yan
Published: December 2010

Corrosion of ocean engineering steel structures leads huge economic loses each year. To decrease corrosive loses and guarantee the safety of ocean steel structures, on the basis of Database on Corrosion of Ocean Engineering Materials and Structures (DCOEMS), the overall architecture of a digital simulation system is proposed based on the collection of existing models of corrosion damage on marine steel structures. Typical models involving uniform corrosion, pitting corrosion, stress corrosion and corrosion fatigue are sorted out and integrated in the simulation system which makes a thorough analysis for calculation and principle of professional module. The effective integration of corrosion damage, structural simulation and visualization is implemented successfully. It achieves the applications of the digital simulation. In the case of prediction and evaluation, it lays a good foundation for the development of the simulation system with independent intellectual property rights.
Experimental Study on Seismic Performance of Mid-Rise Composite Shear Walls with CFT Columns and Embedded Steel Plate
Authors: Zhang Jian Wei , Cao Wan Lin , Dong Hong Ying , Li Gang
Published: December 2010

The shear wall with concrete filled steel tube (CFT) columns and steel plate is a new kind of composite shear wall. In order to know its seismic performance and failure mechanism, six 1/5 scale specimens with the same shear span ratio 1.5, including 3 steel plate shear walls (SPSWs) with CFT columns and 3 reinforced concrete shear walls (RCSWs) with CFT columns and embedded steel plate, were tested under cyclic loading. The thickness of the steel plates in the shear walls changed from 2mm, 4mm to 6mm. Based on the experiment, the load-carrying capacity, hysteresis characteristics, ductility, stiffness degradation, energy dissipation and damage characteristics of the specimens were analyzed. Especially, the ratio of height to sectional thickness of the steel plates in the shear wall was considered. The result shows that both the SPSW with CFT columns and the RCSW with CFT columns and embedded steel plate have good seismic performance and are with important practical engineering value.
Optimal Design of a Complex High-Rise Building Based on Cost-Effectiveness Criterion
Authors: Chen Yue
Published: December 2010

In this paper, an optimal design process for high-rise building structures is presented based on cost-effectiveness criterion. Then, an optimal design of a complex high-rise building based on cost-effectiveness criterion is carried out by using the design process. A minimum life cycle cost and corresponding elastic inter story drift considering initial cost and damage cost as two separate objective functions are obtained by using genetic algorithm. Finally, fitting curves of life cycle cost, initial cost, damage cost and corresponding performance indexes are interpolated by using one-dimensional linear interpolation considering elastic inter story drift ratio as control performance indexes. And lots of life cycle cost designs and corresponding performance indexes of the separated objective function are given. The results show that the optimal design process is practical and optimal results are diverse, and can be chosen flexibly by owners.
Optimal Design of Truss-Plate Structures Using Two Improved Random Optimization Algorithms
Authors: Zhong Gen Quan , Li Li Juan , Liu Feng
Published: December 2010

The size optimization of truss-plate composite structure is presented in this paper. Two improved random optimization algorithms, heuristic particle swarm optimizer (HPOS) and quick search optimizer (QGSO), are combined with finite element method to achieve the optimal design of truss-plate structure. The discrete variables are converted by the mapping function method. An example of the composite structure is given to test this two improved random optimization algorithms. The results show that the QGSO have a better convergence rate than the HPSO in the early time. They are all converged at the same fitness value and feasible on composite structure optimization.
Comparative Experimental Study on Flexural Property of Reinforced and Conventional PHC Pile
Authors: Liu Jun Wei , Zhang Zhong Miao , Zhang Ri Hong , Wang Shu Feng
Published: December 2010

Reinforced PHC piles make use of nonprestressed steel bars to reinforce the initial steel cage, with the intent being to invent novel piles that have better flexural properties than the conventional PHC piles. In this study, a comprehensive test program was carried out with 12 full-scale test piles to compare the flexural properties of two different types of PHC piles. The flexural stiffness of the reinforced PHC pile is greater than the flexural stiffness of the conventional PHC pile. The Reinforced PHC pile and the conventional PHC pile exhibited similar axial stress development, planar section remained in pile mid-span during the initial period and the neutral axis shifted upward after concrete cracking. The cracking patterns and failure modes for two different types of PHC piles are evidently different. The moment capacities for reinforced piles were significantly higher than the values for the conventional piles, and the improvements increase in order from the pile specification of B to the AB to the A.
Shear Performance of Composite Steel Plate Shear Walls with Trilateral Constrained by Experimental Study
Authors: Guo Zhen , Yuan Ying Shu
Published: December 2010

An experimental study was performed to investigate the structural capacity of composite steel plate walls with trilateral constrained. Six one-third-scale models of one-story prototype walls with composite steel plate shear walls were tested. The parameters for this test were the width-thickness ratio of infill steel plates and the strength of compound precast plate. Regardless of the inﬁll plate design, the steel plate wall specimens exhibited excellent strength, deformation capacity. The design of boundary connection method is important to small width-thickness ratio of infill plates. Bolt sliding between the infill steel plates and boundary frame would decrease initial stiffness and shear strength of the steel plate shear walls. And more, this result indicates that the initial stiffness and shear strength would be improved highly with compound precast plate as resistant-lateral of infill steel plate. But the precast plate must be have sufficient strengh in design.
Study on the Numerical Simulation of Massive Concrete Sidewall Hydration Heat under Negative Temperature Transient Boundary
Authors: Li Dong Wei , Fan Ju Hong , Chen Hai Ming , Chen Jun Hao , Wang Ren He
Published: December 2010

To get massive concrete sidewall hydration heat and the frozen wall’s temperature distribution law, the temperature monitor and analysis were applied in the construction process of deep frozen shaft. Combined with frozen sidewall temperature field numerical calculation finite element method, analyzed the concrete hydration heat on the impact of the artificially frozen wall in the frozen wall’s construction process. Concrete hydration heat release made rapid temperature rise of concrete, the temperature was gradually cooling down effected by the frozen wall’s low temperature and the concrete permanent supporting borders. During large release of concrete hydration heat, the frozen soil curtain was partial heating and melting, the Interface moved quickly and reached the maximum. The results showed that: the change laws of the numerical simulation and the measure point temperature were uniform, and their values were more consistent. This had a certain reference value in improving freezing construction methods and the design of deep frozen wall.
A Two-Stage Kalman Estimation Approach to Identify Parameters of a Nonlinear Elastic Structure
Authors: Lei Ying , Jiang Yong Qiang
Published: December 2010

When structural damage occurs, nonlinearity usually exists in damaged structures. So far, some progresses in the identification of nonlinearity in structures have been made. The extended Kalman filter (EKF) has been applied for the identification of nonlinear structural parameters. However, since the extended state vector contains both the state vector and the structural parameters, EKF approach can identify limited numbers of nonlinear structural parameters due to computational convergence difficulty. To overcome such problem, a two-stage Kalman estimator approach, which is not available in the previous literature, is proposed for the identification of nonlinear structural parameters. In the first stage, state vector of a nonlinear structure is considered as an implicit function of the nonlinear structural parameters, and the parametric vector is estimated directly based on the Kalman estimator. In the second stage, state vector of the nonlinear structure is updated by applying the Kalman estimator with the structural parameters being estimated in the first stage. Therefore, analytical recursive solutions for the structural nonlinear parameters and state vector are respectively derived and presented, by using the Kalman estimator method respectively. The proposed approach is straightforward. To demonstrate the accuracy and effectiveness of the proposed approach, numerical example of identifying the parameters of a 4-story nonlinear elastic Duffing-type shear-beam building is conducted. Simulation results show that the proposed approach is able to identify nonlinear structural systems.
Application of Neural Network in Displacement Prediction of Dongping Tunnel
Authors: Yin Zhi Xiang , Gao Zhe , Feng Yao
Published: December 2010

It has been proved that Multi-layer network computing can solve the nonlinear separable problem, but the problem which the hidden layer makes the learning more difficult limits the development of multi-layer network.Back-propagation (BP) algorithm solve this problem and promote multi-network research to regain attention. In this paper, A new method which dynamic matrix control method based on neural network is found. Its essence is that the resulting prediction signal is produced by the manner which regards neural network model as prediction model, and the predictive control of nonlinear systems would be realized by the control law which using the receding optimization algorithm. Neural network Selects the BP neural network which possess a good nonlinear function approximation capability.Aiming at dongping tunnel surface deformation prediction, the article adopt BP Neural Network to train the system basing on the given data. It shows the hiding neural node is close to precision; predictive value in good agreement with measured values, and to some extent be able to guide the construction.
Investigation Concerning Vibration Reduction of Self-Anchored Suspension Bridge under Vehicle Braking Forces
Authors: Yang Meng Gang , Yang Zhu Qing
Published: December 2010

Large longitudinal displacement would be generated by vehicle braking force in the girder of self-anchored suspension bridge, just as the floating system of cable-stayed bridge. In this paper, taking Pingsheng bridge as an engineering example, the vehicle braking force models are established according to traffic survey, furthermore dynamic response and vibration reduction of the bridge under vehicle braking force are investigated by finite element analysis. The results show that the longitudinal displacement of the girder is relatively large, and it can effectively be controlled by viscous dampers with optimal parameters.
Optimized Based on Cloud Model Extension Assessment of Slope Stability
Authors: Guo Feng , Xu Wei Ya , Xu Fei
Published: December 2010

Evaluation of slope stability in the hydropower project construction is extremely important. This Cloud Model will be introduced to the matter-element extension, the extension assessment is proposed based on the sutra field division of the slope stability assessment model. This method combines the Cloud Model theory and the advantages of the extension assessment .On the one hand, the division of the sutra field by means of Cloud Model can overcome the "hard" division of the evils. On the other hand,with different values of Cloud Drops as a sutra field, the statistical results of Cloud Drops can be used as last stable assessment results. Project case study shows that compared with the conventional method, results of the method of extension are more accurate, which fully accorded with the actual state, proving optimized based on Cloud Model extension assessment of slope stability feasible and effective.
A Seismic Effective Method for Double-Layer Reticulated Shell Using Buckling-Restrained Braces
Authors: Wu Chang , Wang Xiu Li
Published: December 2010

In this study a kind of buckling-restrained braces (BRBs) as energy dissipation dampers is attempted for seismic performance of large span double-layer reticulated shell and the effectiveness of BRBs to protect structures against strong earthquakes is numerically studied. The hysteretic curve of such members is obtained through the simulation of the cyclic-loading test, and the equations of motion of the system under earthquake excitations are established. BRBs are then placed at certain locations on the example reticulated shell to replace some normal members, and the damping effect of the two installation schemes of BRBs is investigated by non-linear time-history analyses under various ground motions representing major earthquake events. Compared with the seismic behavior of the original structure without BRBs, satisfactory seismic performance is seen in the upgraded models, which clarifies the BRBs can reduce the vibration response of spatial reticulated structure effectively and the new system has wide space to develop double layer reticulated shell.
Monitoring of External Prestressing Tendons Construction Process of Jiamusi Highway Prestressed Concrete Bridge during Strengthening in China
Authors: Naser Ali Fadhil , Wang Zong Lin
Published: December 2010

Jiamusi highway prestressed concrete bridge is located in the Jiamusi City within Heilongjiang province in the east north of China. The strengthening and repairing of the bridge structure can be provided an effective and economic solution in appropriate situation. The objective of this study are to monitor the construction process of external prestressing tendons for strengthening of Jiamusi highway prestressed concrete bridge. Monitoring process includes measurement of external prestressing tendons natural frequency, monitoring of tensile forces values of external prestressing tendons, monitoring of development of anchor beams cracks, and monitoring of anchor beam deformation. The results of monitoring process show that the box girder No. 11 has the largest values of proportional coefficient (K) and the maximum value is 327.8. Box girder No. 8 has the largest values of frequency, the maximum value is 3.499. Five levels of tension are used in the application of tensile force in the tension process of external prestressing tendons. These levels are level 1=248.2kN, level 2=496.4kN, level 3=744.6kN, level 4=992.8kN, and level 5=1241kN. The measured tendons elongation values of left box girder No.8 are more than the theoretical values. For left and right box girder No. 9, side external tendons of left box No. 10, and left and right box girder No. 11, the measured values are less than theoretical values of elongation. After tension process, there are no new cracks in the top, web, and bottom of anchor beam and a small number of cracks developed slightly. These cracks are found around ducts of external tendons. The length of cracks rang from 0.03m to 0.5m and width rang from 0.05 mm and 0.25mm. The longitudinal deformation of the interface and top of anchor beam is very small, ranging from 0.001mm to0.115mm, which averaged 0.026mm. The overall state of anchor beams and box girders during strengthening is good.
Sensored Elastomeric Bridge Bearing and its Application
Authors: Zhuang Yi Zhou , Fu Gong Kang , Chun Pang Jo , Feng Ji Hang
Published: December 2010

A prototype of sensored bridge bearing was developed, fabricated, tested and planned to be applied in two bridge structures for sensing and monitoring of construction process and service condition. Besides, numerical modeling of the prototype was performed using the finite element method with ABAQUS, and meanwhile the testing results were calibrated. Numerical simulation results of the selected two bridge structures show that certain bearing reactions are sensitive to the interested behaviors and performances. This kind of sensored bearing is considered feasible for monitoring construction, damage scenario, and applied loads.
Analysis on Flow-Induced Vibration of Underwater Horizontal Gate
Authors: Wei Wei , Ren Hao
Published: December 2010

The best is to read these instructions and follow the outline of this text. The physical and numerical models were combined to analyze flow-induced vibration response of Qingshuihe River underwater horizontal gate in this paper; the pressures acting on the gate were divided into two parts: the fluctuating pressure of flow on the stationary gate and the hydrodynamic pressure caused by the gate vibration, which is additional pressure induced by disturbed flow. The temporal-spatial correlation of fluctuating pressures obtained by model experiments between different nodes was analyzed. In the study the coherence function is defined in frequency domain with consideration of different levels of correlation for different frequency components, and the nodal load of the fluctuating pressure could be obtained. A new distribution of additional mass with considering radial vibration of the gate is adopted as equivalent hydrodynamic pressure. Based on random vibration theory, the flow-induced vibration response of the gate was obtained. The results provide the reliable reference evidence for structural dynamic design of the gate and show that the hydrodynamic stability of the gate can meet the requirement. On the other hand, it is shown that this method is reasonable and feasible.
Numerical Analysis and Performance Test of Bidirectional Piezoelectric Control Device
Authors: Liu Yan Hui , Tan Ping , Zhou Fu Lin , Du Yong Feng , Yan Wei Ming
Published: December 2010

Based on the configuration and mechanical characteristics of piezoelectric actuator, the bidirectional piezoelectric variable friction control device which can produce control force in two orthogonal directions was designed and the relation equation of control force with input voltage for this control device was presented. Finally, one piezoelectric variable friction control device was manufactured and performance test of this control device was processed. The result of numerical analysis and experiment shows the bidirectional piezoelectric variable friction control device can produce semi-active control force fast, and the performance of this control device do not change when the frequency of input excitation varies and the control force of this control device has stable mechanical properties.
Engineering Structural Reliability Calculation Based on Algorithm of Most Optimization Calculation and its Realization with Lingo
Authors: Li Li , Jiang Hong Yi , Zheng Yi , Xu Jia Long , Sun Mei Zhu
Published: December 2010

Algorithm of most optimization calculation is favor for the most technology personnel, for its result is ideal and it doesn’t need derivative of performance function. Combined with theory of nonlinear programming and method of optimization calculation for structural reliability, the program calculation is written by means of Lingo, including system reliability calculation. With the example, the results prove the method was accurate and fast. It was very efficiency and convenience and objection to make program of Lingo for the reliability calculation, which is grasped for the engineers. So its applying research would push forward application of structural reliability theory and optimization design in structural engineering.
Predicting the Remaining Service Life of Reinforced Concrete Members after Fire Exposure
Authors: Wang Huai Liang
Published: December 2010

An experimental program was conducted to investigate the effect of elevated temperatures on bond between reinforcing steel and concrete. By regressing the pullout test data, simple empirical models were proposed to predict the percentage reduction in bond strength accounted for effects of high temperature. Based on the empirical models, the resistance and the reliability of RC members after fire were analyzed using J.C. method. The engineering example indicates that the method of reliability analysis is suitable for predicting the change of post-fire resistance with temperature.
Electromagnetic Field in the Chaotic Motion of Thin Plate
Authors: Liu Li Jing , Wang Zhi Ren , Lv Jin Feng
Published: December 2010

Based on the vibration equation of beam plate, under mechanical loading in a uniform transverse magnetic field, the vibration equation of the conductive beam plate is reduced to two cases ,which is no-pertubation system and pertubation system. For pertubation system ,n-order harmonic orbit is given by means of the Melnikov method. Finally, the critical condition of chaos phenomena is given in the transformation of Smale horseshoe.
Reliability Estimating of Existing Bridge Using Dynamic Monte-Carlo Method
Authors: Peng Ke Ke , Huang Pei Yan
Published: December 2010

Based on time-dependent reliability theory, intermediate working state is considered, combining with current specifications, concrete filled steel tubular (CFST) arch bridge is discussed as a case, determination principle of three-stage mode is given. The direct correspondence from reliability indices to working states is made clear consequently. Introducing state variables, dynamic Monte-carlo method is presented. Basic formulas of failure probability and damage probability are derived by variable time increment method. The bridge is an CFST arch bridge with 83.6 meter-span, which operated for 10 years. According to test result, dynamic Monte-carlo method is used to estimate the reliability of this bridge. The analysis result shows that, in the tenth year, both damage reliability index and failure reliability index are above target reliability index. The example bridge is in safe working state at present. This conclusion is consistent with the facts.
Time-Dependent Reliability Analysis of Existing Tunnel Structures Based on the Bayesian Method
Authors: Guo Jian
Published: December 2010

The reliability of the existing tunnel will decline gradually during service period due to various factors. This paper analyzes the structural reliability characteristics of the existing tunnel, the time-varying performance function of the reliability of the existing tunnel is proposed. The statistical value of lining action effect is calculated by using Monte Carlo Method combined with the finite element method .By analyzing the factors which influence the resistance degradation of tunnel lining, at the same time consider the time variability of the concrete strength deterioration and random changes of cross section size, the statistical parameters of each variable during follow-up service period is calculated by using Bayesian Method. The ultimate limit states equation of the concrete lining is established. The reliability index of the lining structures of an existing is calculated and the results show that the reliability decreases with the service time getting long.
Influence of Flexural Loading on Permeablility of Chloride Ion and Diffusion Coefficients in RC Beams
Authors: Zhang Jun Zhi , Lu Lie , Wang Liang Ying , Wang Jian Dong
Published: December 2010

The permeability of chloride ion in concrete can be studied using the accelerated aging method in a short period, but the influence of loading characteristic on chloride ion permeability and diffusion coefficients is not considered generally. Three RC beam (120 mm×240 mm×2400 mm) specimens with different flexural loading state are exposed in an artificial corrosion container filled with salt-fog of 5.0 % sodium chloride for 40 days, the chloride ion concentration in different depths of compressive and tensile region are measured, diffusion coefficients of different region concrete are fitted on the basis of Fick’s second law, the effect of flexural loading on chloride ion concentration and diffusion coefficients of concrete are analyzed. The results show that the effect of the flexural load influences permeability of chloride ion and diffusion coefficients of concrete, content of chloride and diffusion coefficients of concrete are controlled by loading level, and the bending load is one of the important factors that can not be ignored in the study of concrete durability.
Analysis on Fatigue of Natural Corrosion Steel Bars
Authors: Li Shi Bin , Zhang Wei Ping , Gu Xiang Lin , Zhu Ci Mian
Published: December 2010

To reasonablely assess the residual fatigue life of aged existing reinforced concrete(RC) bridges, axial tensile fatigue tests were conducted on fifteen naturally carbonation-induced corrosion steel bars. The fatigue test results indicate that the existence of corrosion pits reduces the fatigue life of steel bars significantly under the same fagitue stress; with the development of corrosion, the fatigue life of steel bars decays according to negative power exponent law approximately and the attenuation rate increases with stress level augment. The fatigue deterioration law of natural corrosion steel bars is similar to that of accelerated corrosion steel bars, but the attenuation rate is different from that of accelerated corrosion steel bars, and also the influence of stress level on the attenuation rate is just cross to that of accelerated corrosion steel bars. For the complexity of fatigue and corrosion, further pertinent conclusions remain to be confirmed.
Study on Durability Damage Rules and Aging Prediction Method of Geosynthetics
Authors: Liu Ze , Yang Guo Lin
Published: December 2010

As geosynthetics is made from polymer, its durability is one of the most important issues people have been concerning. Based on the analysis of data gotten from laboratory, field tests and engineering samplings, the reasons for geosynthetics durability damage are summarized, the injury rules and main factors in various applications are analyzed; after studied the existing durability prediction methods, Support Vector Machine (SVM) theory is applied to predict the durability, and an example is analyzed in which temperature, humidity, UV radiation intensity and the aging time were set as input parameters, residual tensile strength and elongation rate were set as output parameters.
Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading
Authors: Zheng Liang , Chen Zhi Hua
Published: December 2010

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.
Research on Bending Resistance of Corroded RC Beams
Authors: Wang Qing , Xu Gang , Liang Gui Ling , Wei Jun
Published: December 2010

Experiments have been finished for the bending resistance of 4 corroded RC beams with different corrosion degree and sustained load. From test results, the main conclusions are summarized as follows: when the anchoring situation is good, the local steel corrosion has no remarkable effect on the flexural capacity on normal section; even if the crack width reached 1.8mm along bars, the failure type has no change, still the flexural bending failure on normal section; the remained flexural capacity can be calculated based on the formula of uncorroded beam, if only considering the decrease of effective area and mechanical property for corroded steel bar; the degradation of local bond behavior has no clear influence on the bending resistance of RC members.
Reliability Analysis of PC Structure in Chloride Corrosion Subjoining Cyclic Freeze-Thaw
Authors: Chen Yu , Liu Rong Gui , Zhou Wei Ling , Zhang Yi Duo , Liu Tao , Li Huan , Zhang Shao Feng , Lu Chun Hua
Published: December 2010

Based on chloride diffusion and random field theory, an analytical model of PC structures in erosive environment with chloride corrosion subjoining cyclic freeze-thaw was formulated. Models presenting the influence of chloride and cyclic freeze-thaw to failure probability are used to track the structural failure. It is found that cyclic freeze-thaw could be the driving force to damage of concrete in rigidity and mechanics. The computing results show that reliability index increases with the cover thickness, and cyclic freeze-thaw increases with decrease reliability. It is important to reliability calculation whether considering cyclic freeze-thaw.
Water Sorptivity and Permability of New-Old Concrete Composite System
Authors: Long Guang Cheng , Ma Kun Lin , Xie You Jun
Published: December 2010

Several experiments were carried out to investigate the effects of water to binder ratio(w/b) and mineral admixtures on water sorptivity and permeability of new-old concrete composite system in this paper in order to further understand the transport properties and thus degradation mechanism of new-old concrete repair system. Results indicate that a reasonable choice of w/b of new concrete is of great importance for obtaining new-old concrete composite with a low water sorptivity. Addition of ultrafine powder such as silica fume as one of component of repairing materials will benefit for effectively reducing water sorptivity and permeability of new-old concrete repair system in practice. The linear correlative coefficient between capillary sorption coefficient, coulomb electricity and porosity of new-old concrete composite sample is bad and lower compared with those of corresponding new concrete samples. The total porosity of new-old concrete composite sample is not an exclusive factor determined its water sorptivity and permeability. The pore structure of new-old concrete composite sample, especially interfacial transition zone between new and old concrete plays more important role on transport properties of sample.
Aging Behaviors of Natural Rubber in Isolation Bearings
Authors: Gu Hao Sheng , Itoh Yoshito
Published: December 2010

This paper attempts to reveal the aging behaviors of natural rubber (NR) used in isolation bearings. Using various degradation factors like thermal oxidation, ultraviolet, ozone, low temperature ozone, salt water and acid rain, a series of environmental accelerated aging tests were conducted to investigate the aging characteristics. From the test results, it was clarified that the thermal oxidation is the dominant degradation factor, which hardens the rubbers and results in a significant drop of performance. This study is fundamental to predicting the lifecycle of NR isolation bearings.
Study on Predicting Service Life of Concrete through Accelerated Permeability Test
Authors: Li Wen Li , Tao Qi , Chai Wen Ge , Zhang He , Li Zhao Guang
Published: December 2010

In this paper, the corrosion of steel during the accelerated corrosion test was investigated through linear polarization method. The critical chloride ion concentration was determined according to the mentioned experimental results. Through the analysis of the experimental results of accelerated penetration test, the service life prediction equation of concrete structures was established. The 20V predicted results exhibited good compliance with the measured values, which indicated the reasonableness of the mentioned prediction method.
Experimental Study on Short-Term Rigidity for Reinforced Concrete Beams Strengthened with CFRP Board
Authors: Xu Yun , Xu Yin , Cai Jin Tang , Luo Hong Guang
Published: December 2010

The experimental study and finite element analysis of RC beams strengthened with CFRP board are introduced in this essay. Test research of six beams stuck with CFRP board on their tension faces has been carried out on rigidity by contrasting with three non­strengthened beams. Three specimens are primary loading beams and the others are secondary loading beams, the calculating formula for the short-term rigidity on the section of concrete beams strengthened with CFRP board has been established. Calculation is carried out on short-term deflection of RC beams strengthened with CFRP board subjected to primary load and secondary load. The results indicate that the RC structure can be strengthened effectively by sticking with CFRP board, so that the expansion of crack and rigidity of beam can be controlled especially, and the experimental results compared with those predicted by the formula in resemblance.
The Finite Element Analysis of Crack Propagating in Bolt-Supported Jointed Rock-Mass
Authors: Wang Zhong Chang , Yang Qing
Published: December 2010

A new method of inflicting equivalent pre stress is suggested to simulate mechanism on reinforcement of pre stress anchor cable on crack prevention of different angle by mini-plastic zone displacement by finite element method. The change rule of displacement of middle points of crack faces, the change of stress strength gene and strain is compared under different pre-stress consolidated condition. When the angle of crack is 450, the consolidated role of rock mass is the best evident. The effect of compression of jointed rock mass is larger than the effect of shear under pre-stress consolidated condition.
Application of Pile Underpinning for Strengthening Design of Longgan Bridge
Authors: Tan Yi Ping , Li Jian , Zou Jin Hua , Jiang Hai Bo
Published: December 2010

Local scouring around the bridge pier occurs because of flow separation and the development of several vortexes around the pier. Such scour holes can cause a weakness in the bridge which may see cracks occurring on the box girders, especially during flooding. This paper presents a design scheme in which a pile underpinning technique has been adopted for such cases during research into defects in bridges. Furthermore, the finite element model has been established to evaluate the bearing capacity of the bridge before and after adopting this new measure. A large quantity of calculation data indicate that the application of the proposed method performs appropriately and plays an important role in raising the bearing capacity of bridge. The specific program bringing this into effect correctly in a renovation project is illustrated.
Flexural-Torsional Buckling of H-Beams with Corrugated Webs
Authors: Zhang Zhe , Li Guo Qiang , Sun Fei Fei
Published: December 2010

To analyze the flexural and torsional buckling of H-beams with corrugated webs, the stress characteristics were compared with beams with plat webs firstly, then, the previous methods calculating warping constant of the H-beams with corrugated webs was discussed. Based on such works, a new calculation method was put forward. This method is simple in shape, by which the warping constant can be calculated easily. To test the accuracy of the method, plenty of numerical simulation models of beams under uniform bending was used to compare the difference between each method. The results proved that the method in this paper was successful and convenient.
Research on the Properties of the Concrete Filled Steel Tube Columns with CFRP Composite Materials
Authors: Gu Wei , Li Hong Nan
Published: December 2010

This paper presents a phase of the research program to determine the feasibility of a proposed CFRP retrofit method to strengthen the corroded concrete filled steel tube columns. This method is wrapping the corroded concrete filled steel tube column with CFRP material. Eight concrete filled steel tube columns were tested in the laboratory with four of them strengthened using the proposed technique. All specimens were notched in the center zone to simulate the loss of section due to corrosion the four of them were wrapped with CFRP composite tubes in the damage area. All specimens were axially loaded to failure while strain and displacement were measured to demonstrate the validity of this repair concept. This paper presents the experimental results and discusses the findings with preliminary conclusions on the feasibility of the proposed strengthening method.
Prediction of Bond Strength of FRP-Concrete Based on Multiple Linear Regression Method
Authors: Huang Jin Lin , Huang Pei Yan , Li Zheng Wei , Zheng Xiao Hong
Published: December 2010

External bonding of fiber reinforced polymer (FRP) plates or sheets composites has become a popular technique for strengthening concrete structures all over the world. The bond strength between FRP and concrete is a key factor controlling debonding failure of various forms in FRP-strengthened concrete structures. Based on the test data, the bond strength model of FRP-concrete was proposed using multiple linear regression and dimensional analysis, in which the effect of multiple factors on dependent was considered. Finally, the proposed model was verified through the test data, and then compared with 12 bond strength models have been found in the existing literature. The result shows that the proposed model has a better accuracy. It can be used to predict the bond strength of FRP-concrete.