bluuebunny/crossref_metadata_2025 huggingface dataset:
The Research on the Structure Response of Underwater Blasting on 4-Story Masonry-Concrete Building
Authors: Huang Zhi Bo , Lin Cong Mou , Huang Jin Shan , Chen Ying , Meng Fan Bing
Published: December 2010

This article takes the Xiamen Sea reef engineering as an example to research the structure response of underwater blasting vibration on 4-story masonry-concrete building. The blasting seismic wave has been field monitored and the data has been analyzed with some means such as wavelet analysis. As a result, the characteristic laws of different floors’ structure responses under the effect of blasting vibration load have been acquired. With the floor increasing, the particles vibration velocity amplification coefficient of the forth top roof relative to the ground is approximately 1.36 to 2.086. The duration period and the main vibrationa are reduced respectively by 14%-28% and by 38%-56%; each floor’s vibration energy mostly concentrates in 0-25Hz’s band. The first floor’s energy mainly concentrates on 0-60ms, mainly distributing in 1st and 2nd frequency band, with the maximum appearing in the 1st band. And the vibration signal energy peak amplification coefficient relative to the ground is approximately 1.783 to 3.866.
Assessing the Fracture and Damage Process in Recycled Aggregate Concrete under Compressive Loading by Acoustic Emission
Authors: Ryu Seung Hyun , Lee Young Oh , Kim Sun Woo , Yun Hyun Do
Published: December 2010

Acoustic emission (AE) is a powerful nondestructive test that can be used to characterize cracking, growth of cracks, and the degree of damage. This technique is clearly distinguished from other nondestructive techniques as it is a nondestructive test that estimates the degree of damage to concrete. In this study, the AE signals emitted during failure, according to the strength of recycled aggregate concrete specimens was examined, in order to characterize them using existing research results and evaluation theories. In addition, it is demonstrated that AE can be utilized to identify crack source and the mechanism of crack growth, which were monitored using a software program developed from the theory of the location of the source of a microcrack.
Damage Detection for Truss Structures Depending on Method of Change in Elemental Modal Strain
Authors: Li Yong Mei , Sun Guo Fu , Yang Bo Yan , Zhou Xi Yuan , Gao Xiang Yu
Published: December 2010

In order to improve efficiency and reliability for damage detection, based on the characteristics of truss structures, the elemental modal strain can be derived from the nodal modal displacements by means of the finite element method on spatial truss elements connected by pin at elemental two nodes. Therefore it is presented as a new dynamic detective indicator using changes between an intact structure and a corresponding destructive structure in the elemental lower modal strain, and then a new method of damage localization named as change in elemental modal strain is set up for truss structures. A numerical example for a planar truss structure is provided to verify the practicability of the method only by one lower mode. The results show that this method is effective to locate not only single damage but also multiple ones, both light damages and severe ones. Furthermore, the results indicate that the proposed method based on modal strain of truss elements can accurately detect damage locations of truss structures with the noisy modal data.
Influence of the Tension Variety on Non-Linear Natural Frequency of an Inclined Cable
Authors: Li Yan Qiang , Du Yan Liang , Liu Shu Hong
Published: December 2010

According to the vibration characteristics of small sag cable, an equation of non-linear free transverse in-plane vibration of an inclined cable is presented considering the effects of the flexural rigidity. In the equation the influence of the tension variety along the inclined cable was taken into account by using the precise parabola equation of the taut cable. Taking single mode of a cable in consideration, the governing equation was simplified as a traditional Duffing equation with a quadratic term. It was solved by using the method of Fourier series. Combined with engineering practice, an example was provided to study nonlinear natural vibration characteristic of an inclined cable in plane when the length, the inclination angle, the tension were changed separately, whether considering the influence of tension variety along the inclined cable or not.
Analysis and Testing of Dynamic Characteristics of Xinguang Bridge
Authors: Xu Yu Feng
Published: December 2010

Taking Xinguang Bridge as the engineering background, the way of model establishment for the dynamic characteristics analysis according to the features of Xinguang Bridge is presented. On this basis, the dynamic characteristics testing of Xinguang Bridge is preformed. Finally, the comparison between analysis results and testing results is done.
Influences of Tunnel Excavation Blasting Vibration on Surface High-Rise Building
Authors: Wang Hai Liang , Gao Tong Wei
Published: December 2010

According to the 33 floors high building, blasting vibration monitoring had been carried on. The building, along Yunnan road tunnel of Qingdao Cross-harbor Tunnel Guide Line Project, has concrete frame structure. Monitoring data had been analyzed. Results showed that rules of vertical vibration velocity and main vibration frequency have similar relevance. Amplification effect of them was existed on the middle and top of the building. From the 2nd floor of downward ground to ground, the value of them suddenly decreased. Main vibration frequency is in the range of 101~102 order of magnitude.
Application of FBG Sensors in Shaking Table Test of Frame-Shear Wall Structure Model
Authors: Sun Li , Zhang Hai Xia , Liang De Zhi , Li Zhe
Published: December 2010

In this paper, FBG sensors are used to monitor and analyze the response of reinforced concrete frame-shear wall model in shaking table test in order to study the placement of sensors and the protection of the transmission lines. Based on the experiment data, the destructive mode and dynamic characteristics in earthquake are obtained through (by) analyzing the dynamic response of the structures. The experiment results show that using FBG is effective in monitoring the structures.
Effect of Computational Patterns of PCA on Moving Force Identification
Authors: Yu Ling , Zhu Jun Hua
Published: December 2010

Effect of computational patterns of principle component analysis (PCA) on moving force identification (MFI) is studied in this paper. The motion equation of bridge due to moving vehicles are formed, the relationship between moving axle loads and caused bridge responses are established for the PCA-based MFI method in time domain. The measured bridge responses are rearranged in a matrix form for easily performing PCA and are adopted for obtaining an acceptable solution to the MFI problem. A laboratory experimental study was conducted to assess effectiveness and robustness of the PCA-based MFI method. The illustrated results show that the PCA-based method is an easy executive and more effective method for the MFI problem. The PCA computational patterns should be appropriately considered due to its higher sensitivity on response catalogues.
Study on Parameters for Identification of Wavelet Packet Energy Spectrum for Structural Damage Alarming
Authors: Sun Peng , Li Ai Qun , Ding You Liang , Deng Yang
Published: December 2010

The damage alarming analysis based on wavelet packet energy spectrum is performed with regard to the experimental data of Benchmark steel frame structure and online monitoring data of Runyang Suspension Bridge, on the basis of which the damage alarming effects using various wavelet functions are investigated in detail. Results reveal that the Daubechies wavelet functions and Coiflets wavelet functions are applicable to structural damage alarming.
Construction Monitoring of Long Span Continuous Rigid Frame Box Girder Bridge
Authors: Wang Guang Yue , Liu Jian , Fan Qi
Published: December 2010

The construction of a modern long span rigid frame box girder bridge gives impetus to the development of structural analysis design theory and construction technology. Moreover, it makes construction monitoring of the rigid frame box bridge a significant research subject. Construction monitoring of the rigid frame box bridge signifies regulating the structure’s internal force and alignment in the construction process and completion state, and thence satisfies the designed expectation. Based on the construction monitoring of Liang-Ji Canal Bridge project, the construction process and the designed completion state have been simulated and analyzed at a certain precision level [1]. A plane bar finite element computational model is established, and the alignment and internal force of the bridge in each construction stage are analyzed. Then the simulation analysis of construction process is derived according to its construction characteristics [2]. Through systematical research on the form work elevation and the stress monitoring of the cantilevers during the cast-in-situ construction, the factors which influence deflection and stress are analyzed. The elevation is predicated by the Kalman's filter estimation, the modified grey model and the combination of these two methods. The stress monitoring error and corresponding reasons are analyzed. The measured results show that the combination of the two approaches can improve prediction accuracy. The presented analysis, processing and control methods accumulate many experiences for the design and construction of the long span box girder rigid frame bridge.
Numerical Investigation on Block Shear of Coped Beams with a Welded End Connection
Authors: Sun Wei Wei , Wei Feng
Published: December 2010

A numerical investigation on the block shear failure behavior of coped beams with double welded clip angle connection was conducted. Parametric study was conducted based on the validated finite element model. The parameters included the web block aspect ratio and the connection rotational stiffness. Based on the mechanical model of double angle connection, the pitch and the beam element length-to-angle thickness (L/t) ratio of the outstanding leg were selected as two importance parameters to consider the effect of the connection rotational stiffness. The results of parametric study show that the connection rotational stiffness has a great influence on the block shear capacity of coped beams with double welded clip angle connection. This is contributed to the fact that for the connections with a smaller connection rotational stiffness, the shear stresses of the shear area were much less than those of the connections with a larger connection rotational stiffness.
A Real-Time Remote Automatic System for Monitoring the Subsidence of Building
Authors: Xiong Chun Bao , Sun Ming , Liu Dong Quan
Published: December 2010

A system, which is real-time, remote, automatic for monitoring the subsidence of building, is introduced. Hydrostatic leveling, displacement sensing by electromagnetism, GPRS wireless communication and computer technology are integrated into the system. The system has the following functions: real-time, continuous acquisition and management of the monitored data; automatic computation and analysis of the subsidence; remote, wireless release of information and early-warning. Applied successfully to monitor the subsidence of the main building of Tianjin West Railway Station in its integral moving, the system has taken the key directive effect in adjusting the schedule and the methods of construction timely.
Application of Adaptive Control System in High Speed Railway Bridge Construction Control
Authors: Jiang Alan , Yao Chang Jian
Published: December 2010

Bridges monitor and control plays a important part in the bridge construction technology. Besides, It is the key factors of ensuring the bridge construction safety in the construction project and meeting design and construction code requirements. The Article takes a high-speed railway bridge as engineering background, and adaptive control system will be applied to the monitoring measurement. The Main Parameter of construction is proposed, which is based on the sensitivity analysis of design parameter in theory. According to take elastic modulus and volume weight of concrete as the main Parameters, identified and adjusted them by least square method, to forecast errors, analyze and adjust parameters. Using the adaptive control system to collect the data of displacement and stress in bridge construction.Calculate through the Computer simulation model, and obtain initialize height during construction, on this basis, guiding the construction and complete the construction of control successfully.
Precise Transfer Matrix Method for Plane-Bucking Analysis of Circular Arch
Authors: Sun Jian Peng , Li Qing Ning
Published: December 2010

Arch bridge as well as arch frame of building is òne kind of plane-curved-bar system of bearing pressure.When the load of arch carrying reaches some value, the arch will lost the balance stability. Based on the theory of precise transfer matrix method and differential equation of circular arch in plane, a new method for plane-buckling analysis of circular arch under uniform load is derived, by which the critical load of circular arch with two hinge supports is calculated. Compared with the theoretical solution, they anastomosed each other well, that shows the method is right and effective.
Swelling Potential Indexes of Swelling Rock in Zhangjiakou District
Authors: Wang Dong , Yang Guo Xiang , Wu Fa Quan , Dong Jin Yu
Published: December 2010

The indexes to determine the swelling potential of swelling rocks are still not unified. A series of testing results of swelling rocks of Zhangjiakou showed that: the dry saturated water absorption and the specific area of swelling rock are all correlated linearly with the content of smectite and the correlation coefficient can be reached to 87% and 96% respectively; however, content of the montmorillonite and free expansive ratio is in nonlinear correlation, which indicated that the free expansive ratio, the dry saturated water absorption and specific area can all reflect the characters of mineral components in swelling rocks. However, the liquid limit and the plasticity index were all in linear correlation with the montmorillonite content, but value of them were lower than practical ones, so they can not be suitable indexes to determine the expansibility of swelling rocks. The larger the free swelling ratio was, the larger the expensive ratio under no load was, but they have no good correlations which indicated that the properties of swelling rocks was complex, as a result it is defective tightness to determine the swelling potential only by mineral components. The swelling force and the expansive ratio under no load were also in linear correlation, which meant they can all characterize the swelling characters of swelling rocks. The lager the dry saturated water absorption was, the poorer the durability was, but the dry saturated water absorption can not reflect the disintegrative totally. Through comprehensive analysis, we took the dry saturated water absorption, coefficient of disintegrative and swelling force as the indexes to determine the swelling potential of swelling rocks.
Studies of Monitoring Technology of High Formwork Bracket Construction of the Memorial Hall for the Battle of Crossing the Yangtze River
Authors: Ding Ke Wei , Xia Ding , Hu Peng
Published: December 2010

With the accelerating process of urbanization, various kinds of unconventional concrete structure increases day by day. These kinds of unconventional specification concrete structure are characterized as large area, large span space, and great weight. Its scaffolding as the template support is different from the ordinary scaffolding outside. Their setup performs as large span space, high height, complex structure, high risk and sudden accident and so on. According to the Monitoring work achievement of the Memorial Hall for the Battle of crossing Yangtze River, this article systematically summarized this kind of high formwork bracket monitoring technology and the experiences from the aspects of monitoring project, system composition, instrument arrangement, instrument shaping, embedment technology and so forth.
Semi-Active Control on Stay Cable Vibration Based on Fuzzy Logical Theory
Authors: Xiao Zhi Rong
Published: December 2010

A new method of semi-active control on cable-MR system based on fuzzy logical theory in this article is presented. In the method, the voltage to drive MR damper is determined by fuzzy controller, which avoids the difficulty of calculating the voltage from the strong nonlinear MR model. In order to testify the effectiveness of the proposed method, the simulation analysis to a typical cable is made and its results are compared to the passive control (passive-on, passive-off) of MR and active control (LQR). The conclusion is that the operation of fuzzy control method is simple and practical. Its effect is better than the passive methods, but is a little worse than LQR.
Damage Detection of Plane Member Structures Based on Modal Curvature Difference Method
Authors: Zhang Jin , Peng Hua , You Chun Hua , Deng Ye Long , Zhang Hong Yu
Published: December 2010

Modal curvature difference (MCD) method is an effective damage detection technique for beams but not very feasible for plane member structures, because the MCD of each member is difficult to calculate with the structural modal shapes which are expressed in a global coordinate system. By improving MCD method, this paper develops a general and convenient damage detection method for plane member structures. The new method introduces coordinate transformation technique to settle the calculation difficulty of MCD. To validate the availability of the method, the finite element damage model of a typical structure is built up, and detection effects on the case of single member damage and multiple member damages are studied respectively. The results show that the improved method is especially suitable for the damage detection of plane member structures.
A Mixed Control System of 3D High Rise Benchmark Building Model Based on Genetic Algorithm
Authors: Zhang Jian Lin , Hong Zhi , Lin Qian , Jiang Jie Sheng
Published: December 2010

In the former research, the Damper control system, TMD control system and the Mixed Control of the active control and passive control were all optimized alone. It is found that less research of the optimization is on the Mixed Control of the Damper system and TMD system. In order to achieve better control effect, we venture to propose a Mixed Control system of third-generation three-dimensional 20-storey Benchmark model under the multi-directional earthquake in this paper. By means of Rayleigh damping and D-value, dynamic equations including the damping matrixes, stiffness matrixes of the structure are obtained. Then in the process of the optimization, the displacement reducing coefficient (DRF) is used as the objective function to optimize the placement of damping devices and control parameters based on Genetic Algorithm (GA). Numerical results in this paper show that the optimal design method proposed in this paper is effective and flexible. It can obviously reduce the seismic responses of building structure.
Evaluating Identification Indices on Damage Detection by a Fuzzy Analytical Hierarchy Process
Authors: Zhang Shi Lei , Chen Shao Feng , Wang Huan Ding , Wang Wei
Published: December 2010

In order to evaluate the identification precision and the computational efficiency of identification indices on damage detection and provide a reasonable basis to choose identification indices for deeply developing structural damage identification, a fuzzy analytical hierarchy process is used to comprehensive analyse and assess nine kinds of identification indices. By establishing the mathematical relationship between the precedence relation matrix and the fuzzy judgement matrix, the consistency of the judgement matrix in analytical hierarchy process is effectively improved. Using above methods and based on three evaluation standards that include mean error, network scale and measuring difficulty , a fuzzy hierarchy to assess identification indices is set up. On the basis of the fuzzy judgement matrix, the performance of nine kinds of identification indices is ranked. Empirical results show that deflection, first modal shape and fundamental frequency are more suitable for identification indices than other indices. And a fuzzy judgement matrix can be established only using the relative relationship between identification indices in the fuzzy analytical hierarchy process. Thus, the fuzzy analytical hierarchy process can be convenient extended to evaluate other identification indices and effectively improve the identification precision and the computational efficiency on damage detection.
Steel Bar Corrosion Monitoring by Potentiostatic Pulse Method
Authors: Kong Li Juan , Qiao Guo Fu , Zhang Tong , Song Guang Ping
Published: December 2010

Steel bar corrosion monitoring is a very important part of structure health monitoring and full-life design in civil engineering. Many electrochemical methods have been developed in the last decades for corrosion research, but for field corrosion, pulse perturbation is the fast method. The corrosion of Q235 carbon steel in cement mortar has been researched by potentiostatic pulse method. The solution resistance Rs, the polarization resistance Rp, capacity of double layer and time constant have got by cure fitting. The amplitude of voltage perturbation affected the accurate of result little. The polarization resistance decreases with increasing temperature.
All-Solid-State Reference Electrode Based on Polymer Composites for Corrosion Monitoring of Steel in Concrete
Authors: Kong Li Juan , Zhang Tong , Song Guang Pin
Published: December 2010

Corrosion of steel structures has been found to be a problem Corrosion can be managed but not eliminated, so detecting corrosion will remain an issue no matter how effective corrosion prevention programs become. Electrochemical reaction is the basically process of steel corrosion in civil engineering, so electrochemical method is the best way to monitor corrosion grade. Liquid state reference is often used in lab to study steel corrosion by triple electrode system, but it is very difficultly used in steel bar corrosion monitoring in civil engineering. Firstly, liquid reference’s life is, generally speaking, very short. The steel corrosion is a very slow process, corrosion monitoring should be tens of years, so the liquid reference’s life is not long enough for corrosion monitoring; Secondly, the reference electrode’s strength have to be very high. Obviously, liquid electrode reference can not meet the requirement. In this paper, a novel all solid state reference electrode (ASSRE) has been developed. There are three layers in the electrode. Four kinds of components have been included in first and second layer. Additional AgCl powder has been used to inhibit AgCl decrease which is on the surface of Ag wire by complexing effect. There is only one kind of component in third layer. There are four steps to prepare the reference electrode: electrolyze, pre-mixed components, modelling and sintering. Finally, the potential of ASSR has been measured by SCE.
Structural Reliability Analysis with Uncertainty-but-Bounded Parameters Based on Meshless Method
Authors: Zhao Wei , Liu J.K. , Yang Qiu Wei
Published: December 2010

The structural reliability analysis with uncertainty-but-bounded parameters is considered in this paper. Each uncertain-but-bounded parameter is represented as an interval number or vector, an interval reliability index is defined and discussed. Due to the wide application of the Meshless method, it is used in structural stress and strain analysis. The target variable of requiring reliability analysis is estimated via Taylor expansion. Based on optimization theory and vertex solution theorem, the upper and lower bounds of the target variables are obtained, and also the interval reliability index. A typical elastostatics example is presented to illustrate the computational aspects of interval reliability analysis in comparison with the traditional probability method, it can be seen that the result calculated by the vertex solution theorem is consistent with that calculated by probability method.
The Research of Concrete Durability Design
Authors: Zhang Xue Song , Chen Jin Ping
Published: December 2010

Durability design of the concrete structure directly concerns structural durability, the current system of the structural durability design has not formed, merely limited to theoretical analysis condition of the environmental zoning, material preparation and structure life. This article has carried on the durability design factor analysis ,including the environment function, the durable condition monitoring design, the life design, the state control, the material design, repairable design and the mechanical design, based on this the establishment durability design method system is proposed, and the research method of establishing this system is discussed.
Analytic Methods of Main Cable Initial Curve Calculation in Variable Temperature Field
Authors: Ren Xiang
Published: December 2010

In order to study temperature effect on initial curve of main cable, three different temperature models were built about temperature changes of main cable along span direction, and iteration calculation methods to find initial curve of main cable in variable temperature field was proposed based on the theory that the length of non-stress wire strand is persistence in unloaded cable station and construction completion station. The catenary equation in variable temperature field was deduced and the suspender length variation as well as horizontal component of cable forces were calculated based on the catenary equation. Taking some suspension bridge for an example, suspender length variation, horizontal component of the cable forces and node coordinate under three different temperature models were calculated by iteration calculation methods.
Efficient Algorithm of Engineering Structural Reliability and its Realization with Matlab
Authors: Li Li , Jiang Hong Yi , Zheng Yi , Yang Yu Lin , Sun Mei Zhu
Published: December 2010

The paper gives efficient algorithm of engineering structural reliability and its source program in Matlab with example. The paper introduces Mento-Carlo method, and stable reliability formula of slag concrete brick under compressed is established. And combined with data of experiment, it is given that its source program in Matlab. Matlab supplies many kinds of operation of matrix, and includes some toolboxes for the calculation of reliability, and it is very efficiency and convenience to make program of Matlab for the reliability calculation, which is easy to be grasped for the engineers. So its applying research on the reliability calculation will push forward the theory and application of structural reliability theory.
Freeze-Thaw and De-Icing Salt Resistance of Concrete Containing Mineral Admixtures and Air-Entraining Agent
Authors: Yuan Xiao Lu , Li Bei Xing , Zhou Shi Hua
Published: December 2010

The effect of mineral admixtures and air-entraining agent on freezing-thawing and de-icing salt resistance of concrete has been studied. Concrete specimens made with ordinary Portland cement or ordinary Portland cement incorporating fly ash with the replacement of 10% or 20%, or 0.7/10000 air-entraining agent and fly ash with the replacement of 20%, or ground blast furnace slag with the replacement of 15% or 30%, were made and exposed to 500 cycles of freeze-thaw and de-icing salt environment. Concrete properties including loss of mass, relative dynamic elastic modulus, compressive strength, flexural strength and chloride ion diffusion coefficient were measured. Phase composition of samples was determined by means of x-ray diffraction (XRD). Results indicate that concrete exposed to freeze-thaw and de-icing salt environment is subjected to both physical frost action and chemical corrosion. Incorporation of mineral admixtures and air-entraining agent possesses more effect on internal deterioration, mechanical properties and permeability of concrete than on the scaling of concrete.
Three Dimensional Numerical Modeling for the Stratified Rock Slope and the Parametric Analysis
Authors: Lu Guang Yin , Zhu Zi Qiang , Liu Qun Yi
Published: December 2010

Stratified rock mass has been widely existing in geotechnical engineering. With obvious transversely isotropic characteristic, stability of stratified rock mass is not only related to strength of intact rock but also to the inclination and characteristic of structure plane. The parameters of the structure plane have great impact on the stability of stratified rock mass. For the stratified rock mass is no homogenous, the homogenous model is not suitable to describe the characteristic of stratified rock mass. Then building an appropriate becomes necessary. In the present paper, Ubiquitous-joint model is introduced to describe the characteristic of rock mass, and the strength reduction method based on the Ubiquitous-joint model is proposed, which then is used to calculate the safety factor of slope, while the relationships between safety factor, strength properties of structure plane are analyzed, whose results can give guidance for the real practice.
Research Methods of Applicable and Durable Configurations of Concrete Bridge
Authors: Xu Yue , Tang Xian Xi
Published: December 2010

Durability and stress injury of concrete bridge were increasingly prominent on the bridge structure now, the use and safety performances of bridge have been significantly affected. "Applicable and durable configuration" can effectively solve these problems, "applicable and durable" include durability, mechanical properties, enforceability and economy. Impact factors of applicable and durable configuration structural include environmental, vehicle load and material. Combined with the meaning and impact factors of applicable and durable configuration, the proportion of main configurations in whole configurations of concrete bridge and the weight of various factors were identified, and the contents and methods of applicable and durable configuration were determined, which laid the foundation for study of applicable and durable configurations of concrete bridge.
The Research of the Effect of Dynamic Load and Temperature on the Diffusion Performance of Chlorideion in Concrete
Authors: Wang Cai Hui , Jiang Jin Yang , Sun Guo Wen , Han Jian De , Qiao Yun Feng
Published: December 2010

The diffusion performance of chloride ion in concrete under the coupling action of dynamic load and environment was researched by a new set of experimental system. The experiment are composed of study of saturated performance of concrete, diffusion performance of chloride ion with different water binder ratio and under coupling action of dynamic load and temperature. The results show that the transport mechanism of chloride ion in concrete accounted with diffusion theory due to the 99% of saturation degree of concrete; the diffusion coefficient of chloride ion is decreased with the increasing water binder ratio, but is increased with temperature increase; and the diffusion coefficient of chloride ion is changed with cycle number.
Quantitative Characterization of Effective Porosity in Cement-Based Composite Materials
Authors: Sun Guo Wen , Jiang Jin Yang , Zhang Yun Sheng , Wang Cai Hui
Published: December 2010

The method of the second intrusion mercury in MIP was used to investigate the pore characteristics of hardened cement paste with w/c ratio 0.23, 0.35 and 0.53, respectively, in order to research the quantitative relationship between transport properties and pore characteristics in cement-based composite materials. The results show the second intrusion mercury could well determine the effective pore structure parameters, and effective porosity accounts for 25% to 50% of total porosity in cement paste. At the same time, the existence of the first and second peak in pore size distribution curves is confirmed by MIP, such as, the first peak in hardened cement paste with water to cement ratio 0.53 is very distinct, however, with the decrease of water to cement ratio, the first peak gradually disappears. The pore diameter corresponding to the first and second peak is critical pore diameter of capillary pore and gel pore, respectively.
The Passive Energy-Dissipation Study of Braced Steel Frame Structure
Authors: Luo Wen Xia , Lei Jin Song , Hu Ying
Published: December 2010

The seismic performance of braced steel frame was simulated by the finite element software ANSYS based on the passive energy-dissipation under the low-cycle repeated load and the time-history analysis under seismic load for the energy-dissipation braced steel frame structure, no-brace steel frame structure, and conventional braced frame structure. The energy dissipation and seismic performance of three kinds of frame were compared, the results show that the energy-dissipation braced structure can produce strong energy-dissipation control force to enhance energy dissipation capacity of the whole structure significantly, and weaken the seismic load of the main frame. It follows that the energy-dissipation braced steel frame can achieve the purpose of energy dissipation for structure, and has good seismic performance.
Research on Ultimate Bearing Capacity of Coupler Steel Tube Falsework with Initial Defect
Authors: Hu Chang Ming , Ge Zhao Shen , Jing Wang
Published: December 2010

Used of finite element software, based on the material characteristic and node semi-rigid experimentations, the model with material multi-linear kinematic hardening and node semi-rigid was established to simulate the test model of coupler steel tube falsework. According to the measured data of the defect, to analyze the nonlinear stability of the model by methods of the consistent defect mode and stochastic defect, the results indicate that the model’s correctness and consistent mode imperfection method’s in analyzing coupler steel tube falsework is feasible, and the structure is a defect-sensitive structure. The brittleness failure characteristic of coupler steel tube falsework was validated and several effective conclusions were educed after comparative study on the deformation mode and load-displacement curve of the test, consistent defect mode method and stochastic defect method.
Probability Evaluation Method for Cable Safety of Long Span Suspension Bridges under Extreme Wind Load
Authors: Hu Jun , Ou Jin Ping
Published: December 2010

The cable is the main load-bearing component of suspension bridge and its safety assessment under extreme wind load is a key issue to the structure. Take a long-span suspension bridge in the East Sea China as an example, the standard of extreme wind load for structural safety evaluation is established; the wire’s strength model is established by the type I extreme value distribution; cable’s safety assessment function under wind load is established and the Monte Carlo method is used to get the cable’s reliability and reliable indicators. The bridge’s re-service term is taken for 90 years as an example, the results indicate that the wire’s serial effects can’t be ignored, the cable’s reliable indicator decreases as the number of broken wires increases in approximately the linear attenuation relations, the critical percentage of broken wires is about 10%.
Analysis on the Chord Side Wall Failure of RHS T-Joints with Axial Compression Branch
Authors: Chang Hong Fei , Xia Jun Wu , Chang Hong , Zhang Feng Jie
Published: December 2010

A finite element method is proposed to determine the chord side wall failure load of welded RHS T-joints with axial compression branch. The width ratios β (=b1/b0) vary from 0.8 to 0.9, and the range of wall slenderness is 16.1≤h0/t0≤42.3. With strain hardening of the material not take into account, the validity of the FEM model is verified using existing experimental results. The failure of the joints is mainly due to the buckling or crippling of the chord side wall, which agree well with the experiment. The mean failure load determined by FEM is about 93% of the test and with a coefficient of vibration of 0.037. The ultimate strength so determined is also compared with the existing design formulae. The proposed method is more reliable. Further investigations are required to develop design formulae for the side wall failure of RHS joints with width ratio β≠1.0.
Residual Life Predication of Reinforced Concrete Elements Based on Time-Varying Reliability
Authors: Wang Jun , Ji Hong Guang , Wang Juan Juan , Zhang Zi Jian
Published: December 2010

Scientific prediction the residual life of existing reinforced concrete elements is an important basis for assessment the structures. The resistance probabilistic density function of reinforced concrete elements was proposed by analyzing the random processes of resistance attenuation of concrete and steel bars. Since the factors of concrete durability damaged and materials deterioration , considered practical conditions of service structures and durability failure criteria of concrete members, a method of calculation the residual life was given, which is verified reasonable through the engineering case.
Time-Dependent Reliability Analysis of Existing Double-Curvature Bridge Strengthened with Augment Section Method
Authors: Kang Jun Tao , Wang Nan , Huang Yun Jiang
Published: December 2010

The reliability of existing double-curvature bridge strengthened with augment section method is put forward based on time-dependent reliability theory. The concerned statistical parameter is taken by using the finite element software. First-order second-moment method is used to evaluate the reliability indexes which estimate the working state of the structure. Combined with a practical example, the time-dependent reliability is illustrated.
The Application of the Improved Interval Number Fuzzy Comprehensive Method in Bridge Evaluation
Authors: Wei Zhao Lan , Pu Qian Hui , Huo Xue Jin
Published: December 2010

The key issues in the theory of interval number fuzzy comprehensive evaluation are discussed in this paper, which includes weight interval calculation, quantitative index dimensionless method and etc. Due to the deficiency of “line method” for interval number formation, one improved method is given to increase the stability of interval number. Then the existing problems of several initial evaluation models are discussed, and the probability theory is introduced to improve evaluation model combined with coefficient of variable weight method. This improved interval number fuzzy evaluation method is adopted on one concrete cable-stayed bridge to general evaluate its safety and durability. The result shows that this improved fuzzy evaluation method can well reflect the general working status of the bridge and have good feasibility and practicality.
A Least Square Support Vector Machine Approach Based on Uniform Design Method for Structural Reliability Analysis
Authors: Yu Xiao Lin , Zheng Heng Bin , Yan Quan Sheng , Li Wei
Published: December 2010

Since the performance functions of large complex structures can not be expressed explicitly in the process of reliability analysis, support vector machines (SVM) with good ability of generalization are used as the response surface function based on the small training samples. The uniform design method was adopted in selecting the training data. The least support vector machines (LS-SVM) were used to find the support vectors. The limit state function was expressed by the LS-SVM regression. Reliability analysis was then performed by the usual reliability method (e.g., the first-order reliability method, the second-order reliability method or Monte Carlo) on the response surface. The results of calculations of numerical examples and a typical cable-stayed bridge show that LS-SVM using the uniform design method can well approximate the real response of complex structures which has a good efficiency and accuracy and can be applied in complex structures.
Influencing Factors Sensitivity Analysis of Carbonization Life of River-Crossing Tunnel Lining Structures
Authors: Chen Hai Ming , Li Dong Wei , Ying Cheng Juan
Published: December 2010

At present, durability of concrete structures has become one of the problems widely concerned by the academic and engineer circles in civil engineering. Shanghai Yangtze River tunnel project is the engineering background of the paper. The sensitivity analysis has been studied on carbonization life's influencing factors of Shanghai Yangtze River Tunnel segment structure with the method of grey -correlation theory and uniform design. The results show that concrete cover depth has the most important effect. The other less important influencing factors in turn are as follows: concrete compressive strength, fly ash substitution amount, temperature, relative humidity and CO2 concentration. The research achievement has been using in the design and construction of Yangtze River Tunnel, and good results have been achieved.
Effects of the Concentration of Sodium Chloride on the RCM Test
Authors: Lu Ming , Yang Yi Bo , Li Jia Cheng , Guo Wen Ying
Published: December 2010

For decreasing sodium chloride consumption and pollution, the possibility of decreasing concentration of NaCl in the rapid chloride migration coefficient test (RCM) is studied when decreasing NaCl solution from 10% to 3%, 1% and 0.5% by mass, respectively. The chloride-penetration depth and the migration coefficient and electric charge are studied in this experiment. The results as followings: (1) When NaCl concentration is decreased from 10% to 3% in the RCM test, the error is within 5% between migration coefficient values of concrete. It is suggested that a 3% NaCl solution can be used to replace a 10% NaCl solution in Chinese standard GB/T 50082-2009. (2) The content of NaCl solution has a little effect on the electric charge passed. (3) It is not suitable to use the test results of mortar specimens to count conversely the results of concrete specimens, but can use mortar specimens to estimate the performance of different binders.
A New Method of Reliability Analysis on Strength and Stiffness for Frame Structure
Authors: Li Yi , Sun Bo , Zhao Wen
Published: December 2010

An accelerating calculation of reliability analysis on strength and stiffness for frame structure was derived. The method of numerical analysis was combined with recurrence formula, to generatelimit state function of continual variational structure. This methodcan simplify the algorithm for identifying systemic dominant failure modes, because the repeated assembly of global stiffness matrix and repeated inverse matrix operation in analysis are avoided. A new criterion of degenerating the structure into mechanism is introduced. Continual analysis of variational structure can be realized.
Characterization of Steel/Concrete Interface for a Long-Term Corroded Beam Stored in Chloride Environment
Authors: Zhang Rui Jin , Yang Hui Lin , L’Hostis Valérie , Castel Arnaud , François Raoul
Published: December 2010

This paper deals with the steel/concrete interface of a corroded beam B2CL1 after a 23 years exposure in chloride environment. XRD, SEM and Raman techniques were performed to investigate the chemical compositions and the spatial distribution of corrosion products. The experimental results illustrate that the corrosion product layer is a multi-layer constituted as marbling structure. It is composed of a mix of iron oxides and iron oxi-hydroxides. Iron species were found in the vicinity of concrete mainly in cracks, as it was already observed in the literature.
Seismic Reinforcement Conception Design of Existing Masonry Structure
Authors: Qi Hong Wei , Li Miao , Huang Xiao Ning
Published: December 2010

In this paper, earthquake-resistance behaviors of existing masonry structures are evaluated based on a certain masonry building. The existing masonry structure is evaluated in its defects of primary design and construction measurements, seismic bearing capacity and durability. Based on results of evaluation, the seismic reinforcement design is introduced for improving earthquake-resistance behaviors of the whole building and its weak positions. In the seismic reinforcement concept design, the ductility of the masonry structure is improved in bearing seismic loading and plastic deformation. Further more, the masonry building is reinforced for avoiding collapse due to the weak positions of its bottom and top layers, stair halls, short walls and wall corners. Evaluation results and the corresponding seismic reinforcement design are significant for safety of both existing and newly designed masonry structures in earth-quake areas.
Vibration Control of Plan-Asymmetric Buildings Using Active TLCGD
Authors: Fu Chuan
Published: December 2010

This paper examines the effectiveness of the Active Tuned Liquid Column Gas Damper (ATLCGD) when equipped on the plan-asymmetric structures subjected to earthquake excitation. The active behaviour is obtained by adjusting the pressure at the end of the liquid column using a pressurised reservoir. The classical linear quadratic regulator (LQR) control strategy is applied to determine optimal control force of the ATLCGDs. A case study of a four-storey asymmetric structure is conducted to illustate excellent control efficacy of the proposed active TLCGD control system.
Mechanism of Debonding Failure between Reinforced Layer with Stainless Steel Wire Mesh and Polymer Mortar and RC Structures
Authors: Huang Hua , Hou Jian Ling , Liu Bo Quan
Published: December 2010

The study on the rehabilitation of RC members with stainless steel wire mesh and polymer mortar indicates that debonding failure of reinforced layer is one of the main failure models. The key of the successful rehabilitation is that how to ensure the bond performance between reinforced layer and concrete. The experimental studies on the debonding failure between reinforced layer and concrete are carried out, and the influencing factors and characteristics of the debonding failure are analyzed, and the bond-slip curves are tested. At the same time, the program, ANSYS, is used to found the finite element models to simulate the experimental studies. The results show that there is an effective length of reinforced layer, which is extremely remarkable to the bond strength, and the main factors include curing age, interface roughness, concrete and polymer mortar strength. Based on experimental test and numerical simulation, the debonding strength formulas and bond-slip relationship of reinforced layer are presented, which can used to analyze some structures.
Application of Flexible Reinforcement on Anchored Cave Dwelling Based on Numerical Calculation with Rheology
Authors: Ji Dong Yu
Published: December 2010

Pointed to character of flexible support of cave dwelling on prestressed anchor for geotechnical engineering, rheological mechanics was used to analyze support effects,and a new viso-elasto-plastic rheological model was built with locked minimum load formula abtained.Such is the property that bonding soil,surrounding soil,bolts and arc surface were studied.And the finite difference method(FLAC3D) with C++ and inline FISH program were applied to analyze stress, anchor,plastic state,shear strain rate and displacement distribution.Based on calculated results and investigation on spot, plenty of key parameters on whole bonged and prestressed bolt were studied. The numerical calculation is coincident with testing factors.So the theory basis is provided for effective support engineering.