bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Simulation and Calculation Analysis of Suspension Bridge Anchorage System
Authors: Wu Hui Jun , Qiu Wen Liang
Published: February 2012

Based on the background of Xinghai Bay Sea-crossing Suspension Bridge, it reviews the development process of Suspension Bridge anchorage and describes the static theory of gravity anchorage of suspension bridge. Using the soft ansys, a three-dimension finite element model of the suspension bridge anchorage is established to analyze the overall stability of the anchorage foundation, the displacement and stress conditions. The anchorage in various load conditions of displacement and stress is studied by numerical calculation and comparison. The analysis result shows that the first slip area is not in the outer end of the contact surface, and there is a certain distance. The area beginning to slip also increases with the loading nodes increasing. As the level of the load increases, the slip region has gradually developed, the contact surface in the first sliding part opens slowly. The slip area expands to the entire contact surface except for a contact surface opening area with the contact surface in sliding failure.
Study on Diseases of Multi-Box Girder Bridge
Authors: Qiu Wen Liang , Huang Cai Liang , Chen Zhao Yi
Published: February 2012

Because the multi-box girder bridge has many advantages, such as large torsion rigidity, large load-bearing capacity, stability, fine appearance, good applicability and convenient construction, it is widely used in China. But for the defection existing in design and construction, many box girders have serious diseases. Aiming at the diseases of a viaduct bridge, the causes of diseases are analyzed and the enforcement method is proposed in this paper. The study shows that, though the box girders have large torsion rigidity, the diaphragms are designed necessarily to enhance the transversal connection between the box girders, to make them bear the loads together, to reduce their stresses and deformation, and to reduce the stresses of deck too.
Construction Monitoring of Dukeng Bridge
Authors: Yu Xiao Lin , Jia Bu Yu , Hu Jun Liang , Yan Quan Sheng
Published: February 2012

In this paper, a continuous beam arch bridge Dukeng bridge was introduced. Its construction process and its construction monitoring were discussed. In the construction process, the elevations of the box girders measured were closer to the values theoretical calculated. Though construction monitoring, although there were some construction errors, they can be timely adjusted and rectified and the main beam was ensure to smoothly closure.
Longitudinal Vibration Control of Floating System Bridge Subject to Vehicle Braking Force with Viscous Dampers
Authors: Yang Meng Gang , Yang Zhu Qing
Published: February 2012

Excessive longitudinal displacement of the girder would emerge in floating system bridge subject to vehicle braking force because of non-restraint in longitudinal direction of the bridge. To reduce it, viscous dampers are set up in longitudinal direction between the girder and the tower of floating system bridge, and the influence matrix method is applied to determine the optimal parameters of viscous dampers. The analysis results of Pingsheng Bridge show that the longitudinal displacement of the girder is relatively large for floating system bridge, and it can be effectively controlled by viscous dampers with optimal parameters obtained by influence matrix method.
Influence of Cross Beam on the Stress of Joints in A-Type Pier of a Bridge
Authors: Tang Chun Ping , Zhang Liang Liang
Published: February 2012

Non-linear numerical simulation is done on A-type super high pier by using finite element analysis software ANSYS, obtaining the node stress distribution under load in the node area taken in the sequential layer analysis of overall mode. The conclusion is mainly as follows: the change of width and thickness of cross beam exerts slight impact on the maximum stress of the node while the change of cross beam depth impacts the node stress much. From the computation, it can be concluded that proper reduction of cross beam depth is beneficial to the node stress.
Experimental Study on Dynamic Elastic Properties of Gas Hydrate Bearing Sediments
Authors: Li Ling Dong , Cheng Yuan Fang , Sun Xiao Jie
Published: February 2012

As a kind of emerging energy with massive reserves, natural gas hydrates are becoming the hot spot of global research. The elastic properties of gas hydrate bearing sediments (HBS) are the fundamental parameters for gas hydrates exploration and resource evaluations. As the original coring in HBS is difficult and expensive, experimental method is important to study the problem. An acoustic wave in-situ measuring system for HBS was developed. Using the in-situ method, hydrate bearing rock samples of different hydrate saturation were synthesized, of which the supersonic wave measurement was carried out under different confining pressure. According to the elasticity theory, the dynamic elastic parameters were obtained using the measured ultrasonic wave velocity. The results show that compressional and shear waves increase with the confining pressure and hydrate saturation increasing, and so the dynamic elastic modulus is.
A Study on Elastic Input Energy Spectra Based on the Compound Intensity Indicator
Authors: He Li , Ye Xian Guo
Published: February 2012

Determination of a SDOFS elastic input energy is the primary problem to solve for energy-based design approach. The effect of ground motion and damping ratio were analyzed on the input energy spectra. is selected as the compound ground motion intensity indicator to represent the damage potential of strong ground motion. Through inputting of 188 seismic records according to the site classification of Chinese seismic code, three-segment elastic energy spectra are proposed based on normalization methods. The calculation formula of the peak and the value of long-period section of the input energy spectra are presented for four categories of site conditions by statistical analysis. Moreover, calculation procedure of the total energy input is given in the paper.
Research on the Prevention of Shaft Lining Fracturing in the Special Strata Based on the Monitoring Information
Authors: He Peng Li , Liu Cui Ran
Published: February 2012

The method of cement grouting in surrounding soil can be used to fundamentally prevent and cure the shaft lining rapture by its dual effects of release and restraint vertical addition force. The results show that this technique can effectively improve the stress condition of shaft lining and the vertical additional stress of the shaft lining can be released and restrained. The stress release effect is most evident in the deep of the shaft lining and changes in a descending order from the deep to the top. In grouting process, the cement grouting parameters should be adjusted according to the stress state of shaft lining that is monitored , it can ensure the safety of the shaft and reach the reinforcement effect. So this technique can prevent and cure the rupture and ensure safety of shaft lining by means of postponing the rupture time.
Normalized Numerical Analysis for Load-Displacement Curve of Uplift Pile in Soft Soil
Authors: Li Xiao Bing , Wei Jie , Li Yi Pin , Zhu Bei
Published: February 2012

On the basis of Hsiung’s normalization analysis method, the soil is assumed to be in accordance with the elastic-plastic model. Some normalized parameters are selected to normalize different load-displacement curves to a single one, which is obtained by using the parabolic load transfer function. At last, we get a regression formula of the single curve with the regression analysis method. By comparing the results of regression formula with the practical test data of projects, the fact that the calculation results of regression formula coincide well with test data show that this analysis method is correct and it can provide reference for the research and application of uplift pile.
Conductors Vibration Model Improved and Nonlinear Vibration Analysis
Authors: Qin Li , Li Wei , Ai Bin
Published: February 2012

Vibration model can reflect conductors nonlinear vibration under wind excitation .The paper improves and expounds the detailed derivation process based on the previous studies, and studies the movement type of conductors. Comparing with the vertical displacement change of conductors in different conditions to prove that the model derived is reasonable. The paper analyses conductors nonlinear vibration in the case of external condition change to study the movement change of conductors. Lyapunov stability theory and Routh-Hurwitz criterion are used to obtain critical wind velocity of conductors, namely the conditions for conductor galloping. The results shows model derived can reflect conductors nonlinear vibration under wind excitation.
Study on Yield Surface under Different Load Directions for Sekiguchi and Ohta Model
Authors: Dong Zhi Hua , Gao Yan Bin , Yuan Ju Yun
Published: February 2012

Sekiguchi and Ohta model is a well-known elastoplastic constitutive model which can simulate the initial anisotropic behavior of K0 consolidated soils. In this paper, the impact of load direction on the yield surface of this model is well studied by firstly deriving the equation of the yield surface satisfied under different load directions and then by drawing a series of yield surfaces under different load directions (between 0°~90°) in p-q space. Results show that the shape of yield surface changes a lot with different load directions. As the load direction changes from 0°to 45°, the inclined yield surface shrinks, and the angle of inclination decreases as well, which means the anisotropic degree of the yield surface is decreasing. These results are new findings on the study of the anisotropic yield surface for K0 consolidated soil.
Research on Analysis and Design Method of the Pile-Raft Foundation with Post-Cast Concrete Strip
Authors: Shen Zhao Wu , Yang Zhen Min , Zhang Ya Min
Published: February 2012

In order to analysis post-cast concrete strip influence to the pile-raft foundation, it has been taken to developed C++ program that is Poulos displacement solution calculating pile-soil stiffness and thick plank theory analyzing raft stiffness. Taking a frame and shear wall structure for example, it has been calculated to pile-raft foundation whether setting up post-cast strip or not that is foundation settlement, moment and so on. Results indicate that post-cast concrete strip is minutely influence to the pile foundation displacement and moment and not the control factor to this kind of pile foundation’s design. It gives some good references to similar structure analysis and can instruct this kind of pile-raft foundation design and construction
Comparison of Dynamic and Static Triaxial Test on the Soil-Rock Mediums
Authors: Wang Jin Cai , Zhao Ming Jie , Chen Wei , Wang Kui
Published: February 2012

By using dynamic and static triaxial experiments to test the saturated composite soil-rock medium of different soil-rock ratio. Measure related power indicators and analyze the variation rules and tendency, and make comparative research on the dynamic and static strength of composite mediums with different soil-rock ratio. Studies have shown the tendency that the static strength and internal friction angle increases while the cohesive force increases and then decreases with the decrease in soil-rock ratio. Under the same compactness, the dynamic strength of composite soil-rock medium increases with the decrease in soil-rock ratio, and decreases significantly with the improvement of seismic intensity; For one rock ratio, dynamic cohesive force decreases with the gradual increase of intensity, and decreases faster with the decrease in soil-rock ratio. While the dynamic internal friction angle decreases with the increase of intensity. At the same intensity, which means the same vibration frequency, dynamic cohesive force increases with the decrease in the soil-rock ratio and so does dynamic internal friction angle.
Study on the Disturbed Zone of High Red Bed Accumulation Slope by Numerical Simulation
Authors: Wang Huan Long , Li Xiao Ning , Wang Ruo Chen
Published: February 2012

The high red bed accumulation slope is a particular type in red beds areas that widely spreads in China. The red bed accumulation is of low intensity and poor engineering property, which can easily cause engineering disease. Therefore, the key issue is cutting the stability in slope engineering. Use stress analysis to determine the disturbed zone of the area directly, the project derives disturbed zone slope stability factor and propose the analytical method steps for the theoretical basis of high slope construction stability and the retaining structure design. Use MIDAS/GTS finite element analysis software to simulate two typical red bed accumulation slopes of Guangyuan-Bazhong expressway. The result reveals that the method is feasible and effective through main stress analysis by a reasonable simulate model. For the typical characteristics of high red bed accumulation slope cutting instability, the project provides the reference of design.
The Determination of Foundation Force Modulus Coefficient in the Pile and Soil Interaction
Authors: Meng Qing Juan
Published: February 2012

In this paper, by using the nonlinear winkle foundation beam model the theory pile load displacement curve that corresponding to the model test were calculated, which were compared to the model test results, When this approach, the k used in winkle foundation beam model is the same in model test. According to this method the relationship between the soil force modulus coefficient k and the weakening compressive strength of pile diameter of 0.042 m and 0.02 m were determined, which combined with the value calculation results of other different pile diameter by 3 d finite element ,then the equation of k of different pile diameter and soil strength were determined.
Strain of High-Strength Concrete at Peak Compressive Strength
Authors: Lu Zhao Hui , Zhao Yan Gang , Yu Zhi Wu
Published: February 2012

The paper discusses the strain of high-strength concrete (HSC) at peak compressive strength for a wide range of compressive strength. A large volume of selected experimental data has been collected from existing literature and then analyzed. Particular emphasis has been given to studying the effects of concrete compressive strength and the types of coarse aggregate on the strain of HSC at peak compressive strength. The adequacy and applicability of the existing models for predicting the strain of HSC at peak compressive strength has been critically examined, and a new empirical model is proposed to cover concrete strength up to 125 MPa. The new empirical model seems to perform much better when applied to the published experimental data on normal weight concrete over a wide strength range.
Study the Application of PHC Piles to Treat Collapsible Loess Soils
Authors: Liu Hong Xia
Published: February 2012

Some project in Henan Province of China mainly includes high-rise residential buildings, multi-storey commercial building and the garage, and the building fields are collapsible soils which belong to non-weight grade Ⅱ. 315 static pressure PHC piles were constructed in square shape, 7 holes were drilled at the places near or close to the PHC pile, porosity ratio, weight and non-weight collapsibility coefficients were in-door tested, and corresponding calculation results reveal that: static pressure PHC piles can efficiently eliminate loess collapsibility of the fields, there are differences between the porosity ratios of experimental values and theoretical values, so the construction testing and acceptance should be based on the in-situ testing results, and these conclusions provide basis for the similar projects in future.
Study on the Establishment of Integration Cost Dynamic Model of Construction Project
Authors: Yu Qi Yuan , Qiu Hao Yue
Published: February 2012

Based on the study of the influencing law of decision point to cost in the construction process, this paper analyzes the relevance of decision procedure and project cost, establishes integration cost dynamic model of construction project. Based on the model, computer aided decision system can be developed for the cost control of construction project. If the system is applied in the construction practice, overall, whole process and dynamic control of construction project cost can be implemented.
Numerical Simulation of Pumping Well-Underground Concrete Wall-Recharging Well in Dewatering of Deep Foundation Pit
Authors: Wang Jian Xiu , Wang Pei , Sui Dong Chang
Published: February 2012

With the foundation pit of south air shaft nearby Qiantang River, Subway No.1, Hangzhou, Zhejiang province as an example, the interaction between pumping wells and underground concrete wall, together with the soft curtain formed by recharging wells are simulated with numerical method. The results indicate that the proper position of filter tube of pumping well to underground concrete wall can reduce the drawdown outside pit, and the drawdown outside pit can be reduced by recharging curtain.
Numerical Simulation of Dynamic Compaction at Dredger Fill Silty
Authors: Liu Yang , Zhang Duo
Published: February 2012

Current practice of Dynamic compaction (D.C) depends mainly on field trials, past experience, and empirical equations based on reported records. In this paper, a numerical model is used to study the effectiveness of supplemental drains on densification of saturated dredger fill silty deposits during D.C. Typical numerical results are discussed using propose numerical model.
Dynamic Risk Evaluation of Deep Excavation Based on Monitor Indexes of Support Structure
Authors: Zhang Jiao , Yang Guang Li
Published: February 2012

The risk evaluation of deep excavation was investigated based on the monitor indexes of support structure. The potential accidents which may be caused by the abnormal of the monitor indexes were analyzed. The risk sources which might arouse the value variation of the monitor indexes were disclosed. The dynamic control measurements for the risk sources were suggested. The successful application of the dynamic method to the real project further verified its feasibility.
Centrifuge Model Tests of Embankment on Soil Foundation
Authors: Wang Xiao Yue , Cao Jie , Zheng Rui Hua
Published: February 2012

Centrifuge model tests were conducted to investigate the behavior of cohesive soil foundations during a construction of an embankment, considering different dry densities and moisture contents of the soil. During the construction, the deformation of soil foundation gradually increased and reached the peak value at the top of the foundation near the center of embankment. After the embankment was completed, the deformation of the foundation continued increasing. The dry density and moisture content of the soil significantly affected the deformation process of the foundation.
Validation of the Volume Change Behavior in SFG Model Using a Soil Consolidation Test and a Soil Water Characteristic Curve Experiment
Authors: Zhou Yi Yi , Li Jie , Li Wen Hu
Published: February 2012

Constitutive modeling in unsaturated soil is always a big challenge in Geo-technique problems. Since Alonso et al suggested the Basic Barcelona Model (BBM) in 1990. Many researchers contribute works on constitutive models in last two decades. The SFG model presented by Sheng, Fredlund and Gens describes the mechanical and hydraulic behaviors of an unsaturated soil accurately. It is currently considered the most reasonable model for unsaturated soil. In this paper, the authors attempts to prove the volume change behavior in SFG model by two basic unsaturated soil experiments in testing two different soils. The experimental data and the fitting processes are provided.
Contact Force Distribution and Induced Anisotropy in Granular Materials under Biaxial Test
Authors: Hu Min Yun , Chen Qiao Hao , Shen Ying , Tang Xiao Wu
Published: February 2012

A 2-dimensional granular assembly, subjected to isotropic consolidation and biaxial compression, is simulated by applying discrete element method and the particle flow code of PFC2D. The contact force network and distribution are examined and compared to an analogous photoelastic experiment carried out by other studies. The current study shows that the assembly undergoes dilatation and strain-softening after peak strength, and the coordination number (average contact number of particles) increases a little in the initial stage of strain hardening followed by a sharp dropping before the onset of softening. This is correlated with the contact force chain establishment and the evolution of structural anisotropy. The distribution of the normal force and the ratio of tangential to normal force for both the isotropically compressed and sheared stages indicates that the strong normal contacts are crucial for the force chain transmitting stress through assembly. The angular distribution of the contact forces supported this point and could help visualizing the induced anisotropy. These issues are vital for gaining a deeper understanding of the macroscopic behavior of granular material from microscopic analysis.
Analysis of Large-Size Flexible Shallow Foundation Settlement Basing on Foundation-Soil Interaction
Authors: Qiu Hong Sheng , Shi Shu , Li Mei
Published: February 2012

The large-size flexible shallow foundation （LFSF） can not be designed fully in accordance with the shallow foundation design specification, for there are differences between LFSF and traditional shallow foundation. Taking the foundation project of Shenzhen Mawan port for example, considering the interaction between foundation and ground base and adopting a non-linear foundation model, the impact of foundation parameters and load conditions on basal pressure and foundation settlement were simulated to value adoption of the height-width ratio by finite element method. Analysis showed that soil physical parameters of elastic modulus, Poisson's ratio had great impacts on basal pressure and foundation settlement, and the accuracy of these parameters should be ensure in modeling. However the effects of expansion angle and cohesion were relatively small. The values of expansion angle and cohesion can refer to design specification. Foundation of this type mainly focus on flexural design.
Research on the Spacing of Structural Plane Used in Rock Mass Structure Classification
Authors: Han Ai Guo , You Min , Nie De Xin
Published: February 2012

Great achievements have been made in rock mass structure research to evaluate engineering properties of rock mass in the engineering geology field. In fact, rock mass structure can not only indicate the quantity of structural planes (discontinuities) and size of rock blocks, but also indicate the integrity and mechanical properties of the rock mass. More and more attention has been paid to rock mass quality classification by using rock mass structure. During the past 40 years, rock mass structure research has been carried out by many scholars, and various standards of rock mass structure classification have been proposed in different industries of different countries. In these standards, the most widely used index was the spacing of structural plane. However, it is a pity that the method of determining the spacing value is not unified in different standards, therefore, the structure type of a rock mass may be different according to different standard. But which kind of method to determine the spacing value is most reasonable? It becomes an important problem to be solved. In this paper, rational method of determining the spacing of structural planes is demonstrated based on lots of statistical data in dam abutment rock mass of one large-scale hydroelectric project in Southwest China.
Study on Criterion of Vibration Stability for Tether of Submerged Floating Tunnel
Authors: Zhou Xiao Jun , Qin Yin Gang , Luo Gang
Published: February 2012

The submerged floating tunnel moored by tethers is simplified as a simply supported Euler-Bernoulli beam, and its vibration caused by vehicles passing through the tubular is also reduced as parametric excitation, moreover, the vibration governing equation of tether is still propounded by means of Galerkin method, simultaneously, the dynamic stability criterion of tether is also set up by means of Lyapunov function in this paper.
The Failure Model of the Subway Station under Blast Loading
Authors: Li Li Xin , Li Man , Geng Xiao Long
Published: February 2012

Based on The subway station of the blast in typical pressure load model, apply ABAQUS finite element analysis software，analysis the dynamic response of the numerical simulation in the metro station under the explosion peak load. Received the subway station failure mode under the blast load，the results show that the displacements of the structure affected by the blast loading directly are several times larger than that of structure far away from the blast loading.
Simulation Analysis of Metro Station Construction Fire Based on FDS
Authors: Wang Hong De , Cui Tie Jun
Published: February 2012

Taking the Hongqi west road station construction of Dalian metro line 2 as an example, the regularities of the temperature and the smoke concentration distribution are analyzed. Basing on FDS, the simulation model of the metro station fire is set up. Assume six fire points in the station to simulate the smoke diffusion velocity and the personnel evacuation time in fire. Results show that the chimney effect is obvious at the back of the station. The highest temperature of every export is 180°C and the lowest temperature is 40°C during the effective duration. The time duration can meet the needs of the personnel evacuation from the fire metro station. Basing on the analysis of variation of the smoke flows and the temperature, the metro station project is reasonable.
The Study of the Triaxial Rheological Test of the Argillaceous Siltstone in Malin Mine
Authors: Bai Qi Shu , Xia Yuan You , Liu Xin Xi , Yang Zi Han
Published: February 2012

Abstract. Coal being one of the main energy resources in China. Coal industry plays an important role in the domestic economy. Roadway support is a key technology in coal mining, and the mechanical properties of surrounding rock directly affect the stability of roadways and their supporting structure. In order to solve the problem of gateway support for C8 coal seam, In terms of the rheological data got from the argillaceous siltstone samples and the influence that loading history has on rock deformation, it employs Burgers model to reflect the creep characteristics of rock. The analytical results demonstrate that the creep test curves of rock sample basically tallies with the theoretical curves and Burgers clearly describes the creep characteristics of rocks. The relationship between surrounding rock stress and surrounding rock deformation provides roadway support with reasonable evidence.
Mechanical and Acoustic Emission Characteristics of Limestone after High Temperature
Authors: Wu Gang , Wang De Yong
Published: February 2012

The mechanical properties and acoustic emission evolution process of limestone under the action of high temperature load were investigated by combining methods of uniaxial compression test and acoustic emission (AE) technique. The temperature varies in the range of 100, 200, 400, 600 and 800°C. By analysis of AE parameters and the mechanical parameter, the relations of stress-time (strain)-accumulative counts of AE, stress-time (strain)-AE rates under different temperatures are analyzed. The results show that the temperature does not obviously affect the mechanical properties of limestone at the temperature ranging from 100 to 400°C, the accumulative ring-down counts and accumulative energy increase with the rise of temperature. However, when the temperature is above 400°C, the mechanical properties of limestone deteriorate rapidly with the increase of temperature, and also the peak stress of limestone decrease in different extents. In the meantime, the accumulative ring-down counts decrease coupled with the change of mechanical parameter. The brittle fracture is main failure mode of limestone when the temperature is below 800°C and the change of peak strain of limestone is unobvious. The stress-strain curve conforms to the acoustic emission curve which shows that changes of minerals formation and microstructure due to high temperature result in the changes of mechanical and acoustic emission characteristic of limestone.
Seismic Fragility Analysis of Reinforced Concrete Frames with Service Life
Authors: Yuan Li Li , Wang Jian Min , Wang Neng Jun , Jiang Wen Ting
Published: February 2012

An analytical method to obtain the seismic fragility curve of reinforced concrete frames with service life was proposed in this paper. Considering the variation of nonlinear mechanical characteristics of un-carbonated concrete with service life, the seismic fragility curve of frames was developed based on the interstorey drift corner in the weak storey of frame structures. According to the damage state definition of frames, each seismic fragility curve reflects the probability tendency of the defined damage state happening in frames with service life. It is helpful for the seismic performance analysis of reinforced concrete frames to use the proposed method.
Seismic Performance Evaluation of a Super-Tall Building Structure
Authors: Zhou Ying , Hong Lei
Published: February 2012

This paper carried out the seismic performance evaluation of a super-tall hybrid structure. The hybrid structure consists of steel reinforced concrete (SRC) frame and reinforced concrete (RC) core wall. Based on the characteristics of the structure, the structural system, seismic performance objectives and seismic measures are presented. Moreover, the elastic response spectrum analysis, elastic and elasto-plastic dynamic analysis are performed to evaluate the seismic behavior of the structure at different seismic hazard levels. The conclusion can be drawn that through the seismic measures taken in the paper, the super-tall structure could generally achieve the seismic performance objectives.
Comparative Analysis of Seismic Records of Wenchuan in 2008 and other Domestic and International Earthquakes
Authors: Guo En , Zhao Zuo Zhuo , Zhou Xi Yuan
Published: February 2012

There are a large number of acceleration records obtained in the near fault strong motion of Wenchuan earthquake in 2008, which greatly enriched the database of strong motion. This article compares seismic records of Wenchuan earthquake with other domestic and international earthquakes, such as response spectrum, multi-peaks average and R. It also discussed a damage reason of fault zones in Wenchuan earthquake.
Micro-Analysis of Railway Ballast Bond Effects
Authors: Jing Guo Qing , Shao Lei , Zhu Ya Di , Gao Liang
Published: February 2012

Ballast glue is a material to adjust ballast stiffness and stabilize ballast from flying due to high speed train winds; its ballast-glue system is less of microscopic mechanism research. In this paper, 3D DEM method is used to produce sleeper-ballast box model, ballast is made of real size irregular clumps, the ballast glue is represented by bonds to simulate the tensile and shear strength, it works at the ballast-ballast particles interaction contacts physically. The sleeper induced monotonic loadings results show the ballast-sleeper microscopic contact force chain distribution is altered due to ballast glue bonding effects, the glue results in tension forces among ballast system. The ballast-box bearing ability is improved with ballast global stiffness increase; ballast-box global stiffness increases with the glue bonding layer depth non-proportional, and is governed by the top 10cm layer.
Concrete Strength and Deformation Property under Sea Water Erosion Environment
Authors: Cai Jian Jun , Zhang Feng , Cui Wei , Chen Shou Shan , Liu Pu Lun
Published: February 2012

In order to effectively assess the concrete strength and deformation property under sea water erosion environment, concrete stress and strain curve was researched with the number of wet and dry cycle of 0 times, 10 times , 20 times, 30 times, 40 times, 50 times and 60 times based on the large-scale static and dynamic stiffness servo test set. The stress - strain curves of concrete was tested for the lateral pressure 10.8MPa, 14.4MPa, and 18.8MPa at different dry-wet cycles, The failure modes and superficial cracking characteristics of specimens are reported at different dry-wet cycles. Concrete elastic modulus and compressive strength were researched. Based on concrete mechanical theory , the classic Kufer-Gerstle strength criteria of concrete was used, a large number of test samples of multivariate data were nonlinear regressed, a biaxial concrete strength criterion was established taking into account the stress ratio and the number of dry-wet cycles.
Analysis of Time Effects in Steel and Concrete Composite Beams Considering Relative Slippage
Authors: Yan Yuan Jun , Qin Li Ping
Published: February 2012

The effects of creep and shrinkage of concrete is non-ignorable to strength of steel and concrete composite beams under sustained load, and the relative slippage should be considered for internal force. Time-dependent modulus method is presented, formulas of the stress and strain at any time are deduced considering creep, shrinkage and the relative slippage. The variational stress is analysed of the steel and concrete composite beams under sustained load.
Dynamic Model Rupture Tests of Concrete Dams on Shaking Table
Authors: Wang Ming Ming , Xu Qiang , Chen Jian Yun , Lv Shao Lan
Published: February 2012

The seismic safety evaluation of dam is always concerned by designers and researchers. Due to the limited field prototype observation data, the dynamic model failure tests become more effective means than numerical analysis to investigate nonlinear dynamic response and failure mechanisms of concrete dam. A large number of the tests had been performed in Dalian university of technology in china. This paper makes a detailed description on the dynamic model test on shaking table. The similitude rules are discussed, the model material is introduced, the procedure is described for the dynamic model test. Based on the PGA(peak ground acceleration) inducing the first tension crack at the model dam body, the response of prototype dam under strong earthquake can be assessed by the test.
Arch Dam and Rock Base Cracking Processer Analysis
Authors: Chen Ying Ming
Published: February 2012

A numerical implement to simulate the crack propagating process in arch dam and rock base has been given. A new FE style was presented for improving the calculation accuracy and efficiency. In the period of dividing the dam structure and the foundation rock into an appropriate number of discrete subregion (finite elements), the adaptive method was used to divide the original 3-D element into a serial son-elements analogical to its father-elements entirely. Of course the 2-D element was divided into a serial son-elements analogical to its father-elements entirely using the same method. The element shape function was key factor. In the calculating processor, the arithmetic of load step was optimized. The arithmetic has important theory and utility value
Study on the Air Pressure and the Backwater in the Cavity of Aerator on the Chute with an Anti-Arc Section
Authors: Xu Yi Min , Yang Hong Xuan , Zhao Wei , Shen Chun Ying
Published: February 2012

Aeration facility is widely used to reduce cavitation erosion of discharge works caused by high speed flows and it has proved to be an economical, effective and successful measure. For a flow chute with complex boundary conditions, the air pressure and backwater in an aerator cavity are important factors that influence the flow aeration, and there are numerous and complex hydraulic factors to affect them. By the jet trajectory equation and a series of experimental tests, the air pressure and backwater in different aerator cavities are investigated. How these factors such as the size and style of aerator, the arc radius of the chute and flow discharge to influence the air pressure and backwater in an aerator cavity are revealed. These results can be referenced in designing aerators on the chute with a concave surface.
Analysis on the Seismic Torsional Response of Large-Scale Aqueduct Body
Authors: Gao Ping , Wei De Min , Xu Meng Hua
Published: February 2012

The torsion of the multi-span aqueduct body was studied under the lateral seismic excitation by FSI computational analysis. The results show that the difference of stiffness of both sides has little influence on the torque of the aqueduct body. However, the influence of the torque on both end sections of the aqueduct body is not to be neglected. For the simply-supported beam aqueduct, if the centre moment of the aqueduct is adopted as the controlling condition to design the whole aqueduct body and when the bending-torsion effect is small, the safety of anti-seismic structures can meet the requirements. Otherwise, on the section between the centre section of the aqueduct body and the end slot section, the safety of anti-seismic structures could not meet the requirements.
Research Progress on Velocity Model of Iron Release in Water Supply Pipe
Authors: Wu Shan , Yang Long , Zuo Dan
Published: February 2012

The paper gives an overview on velocity models of iron release in water supply pipe at home and abroad, which incorporate empirical statistical models and dynamic models. Meanwhile, the characters of each iron release model are summarized. At last, the author analyzes the frequency of all parameters used in models mentioned in paper and puts forward the developing orientation on velocity models of iron release. The author also concludes that the establishment of velocity models of iron release is conducive to getting command of iron release in water distribution systems and guaranteeing the safety of potable water in drinking water pipe.
Research on the Spatial Stress Analysis of a Large Underground Project
Authors: Xiang Wei Ming , Huang Zhou , Gao Wen Wei , Zheng Xian Chang
Published: February 2012

This report is about the spatial stress analysis of a large underground civil air defense projects in Guangdong province. Aiming at the problems of plane stress models, spatial calculation models are built and the results are compared to those of plane stress calculation models, revealing how internal force of the spatial structure models change in different conditions.
Evaluation of Positive Pressure Ventilation for High-Rise Buildings in Compartment Fire Situation
Authors: Feng Xiao , Li Yan Feng
Published: February 2012

An alternate means for protecting high-rise stairwell enclosures using the positive pressure ventilation is evaluated. An analysis performed by using the Fire Dynamics Simulator (FDS) model shows that the positive pressure ventilation can be an effective method for protecting the stairwell enclosure. Three types of ventilation methods are compared in the same fire condition and the best one is determined based on the decrease of temperature in the stairwell. The optimal rate for ventilating the stair requires optimization of the airflow rate according to postulated fire scenarios for the building and the desired performance with respect to tenability conditions within the stair.
Study on Physical and Mechanical Properties of Clink-Free Cement Stabilized Macadam
Authors: Li Dong , Chen Fu Dan , Che Cheng Cheng , Kong Ling Peng
Published: February 2012

Based on desulfurization gypsum, blast furnace slag and steel slag (DGBFSSS), a new clink-free cementitious material with the meaning of saving energy and environment protection was invented. This paper further study on DGBFSSS in the application of cement stabilized macadam. The results show that DGBFSSS cement stabilized macadam with higher delay unconfined compressive strength and splitting strength, lower compression rebound modulus and better drying shrinkage performance than ordinary Portland cement stabilized macadam.
The Study on Land Reclamation Technology and Ecological Control for Coal Mining Subsidence Area
Authors: Yang Qian , Liu Wen Sheng
Published: February 2012

Both coal mine and land are important natural resources that human depend on for existence and development. Coal mining has contributed greatly to the development of economy and society in China. Meanwhile, subsidence induced by coal mining has seriously affected human life, ecological environment and development of regional economy in mining area. Thus, aiming at coal mining subsidence area, this paper puts forward two kinds of land reclamation techniques containing engineering reclamation technology and biological reclamation technology, which can scientifically guide land reclamation practice, coordinate relationship between human and land and relax ecological crisis.
Research on Load Transferring and Sharing Law of Anti-Sliding Piles under Different Isosceles Trapezoid Cross-Section
Authors: Li Chang Dong , Tang Hui Ming , Hu Xin Li , Wang Liang Qing , Liu Qing Tao
Published: February 2012

This paper presents an effect method to reveal the load transferring and sharing law of anti-sliding piles under different isosceles trapezoid sections. Three kinds of cross-section, including the rectangle and two typical kinds of isosceles trapezoid cross-section, were carried out the load transferring and sharing tests on the basis of soil arching analysis by using the numerical modelling method. The results show that the anti-sliding piles row play an important role in resisting the driving force of the landslide, and the outer-isosceles trapezoid cross-section piles can reduce the driving force of the sliding mass in front of the piles to the maximum extent. The monitoring positions where more close to the piles transfer larger driving force from the soil to the piles. Moreover, the mechanical mechanism the anti-sliding piles with outer-isosceles trapezoid cross-section is end-bearing pattern, while the anti-sliding piles with rectangle and outer-isosceles trapezoid cross-section are end-bearing mixed with friction pattern.
Synthetic Risk Assessment of Catastrophic Failures in Power System Based on Entropy Weight Method
Authors: Feng Jing , Wang Ying , Xiao Xian Yong
Published: February 2012

The synthetic risk assessment method incorporating the severity and the possibility is used to identify the catastrophic event sequences in power system. The weight setting of each severity index is determined by the proposed entropy weight method. Comparing with traditional methods, the entropy weight method can determine the weight coefficients objectively. The simulation results for the WSCC-9 buses system have proved the validity of the proposed method. This method can be used in the practice power system.
Study on Energy Dissipation of Shenzhen Baoan International Airport T3 Terminal
Authors: Yang Yu Chen , Gu Lei , Zhu Zhong Yi , Qin Kai , Zhang Lin
Published: February 2012

The main structure of Shenzhen Baoan International Airport T3 Terminal uses reinforced concrete frame and the steel roof is free-form surface. The main concrete structure which is about 1038m from north to south, and 588m from East to west, is currently one of the largest Terminal in China. Because the Concourse is very long, the temperature force is relatively large when the bearing is hinged. In order to release the force, the spring bearings are set up along the length to Concourse. However, the displacement increases under earthquake because of the reduction of the stiffness .The speed-related viscous dampers are placed near the strengthened truss for limiting the seismic displacement. However, the damper parameters can be obtained by computing several times in practical engineering .It needs a long period to select the damper parameters especially for complex structures. So this paper takes Shenzhen Baoan International Airport T3 Terminal Cross Concourse as the research object, use the viscous damping theory, determine the additional damping ratio from the perspective of response spectra and the nonlinear damping parameters from the energy point, find a reasonable, fast method to set the damping parameters.
Fuzzy Matter-Element Evaluation Method for Analysis of Debris Flow Risk Assessment
Authors: Tan Chun , Chen Jian Ping , Pan Yu Zhen , Niu Cen Cen , Xu Li Ming
Published: February 2012

Based on the principle of fuzzy matter-element analysis, the concept of information entropy is introduced to establish a fuzzy matter-element evaluation method. This method is utilized to comprehensively evaluate the degree of debris flow. The classifications of debris flow are regarded as the objects of matter-element and their indexes for evaluation as well as the corresponding fuzzy values are used to construct the composite fuzzy matter-elements. By calculating the relevancy the comprehensive evaluation of debris flow can be carried out. This model is applied to analyze the degree of debris flow in the practical application. The application shows that the model is effective and practical.
Experimental Study on Eccentric Compression Behavior of Timber Columns with Longitudinal Cracks Strengthened by CFRP Sheets
Authors: Cai Yi Jing , Zhang Wei , Zhang Wei Ping
Published: February 2012

This paper presents a study on reinforcement of timber columns with longitudinal cracks strengthened by CFRP sheets under eccentric compression. An experimental program using special eccentric compression hinged-support was proposed to identify the failure modes and to investigate the recovery in load carrying capacity. Different combinations of eccentric distance and directions of the eccentric plane related to that of the crack plane were considered. This test can provide detailed experimental data for the application of CFRP strengthening on timber columns under eccentric compression which is an efficient method to maintain the original historical structure.
Fatigue Tests of Overlapping Details for Orthotropic Steel Bridge Decks and Transverse Beams of Stay Cables
Authors: Bai Guang Liang , Tang Guang Wu
Published: February 2012

Rail-cum-road cable-stayed bridge with single cable plane is eccentric under moving load, overlapping details for orthotropic steel bridge decks and transverse beams of stay cables are in typical complex space stress condition. A fatigue test is performed to evaluate anti-fatigue performance of overlapping details under the combination of highway and light railway loads. A 1:1 model is adopted for the overlapping details, where a fatigue loading test for 2×106 cycles is carried out. Its test results show: the structural stress level is low, no crack is found on the test model after cyclic loading for 2×106 cycles, then load amplitude is gradually increased and no crack is found after cyclic loading for 4.25×106 cycles, finally a result is obtained that no fatigue crack will be found on the overlapping details for orthotropic steel bridge decks and transverse beams of stay cables within design life, because fatigue strength requirements are satisfied.
Anti-Corrosion of Concrete Structures under Marine Environment and the Durability Design of Pinghai Bridge
Authors: Zheng Guo Dong
Published: February 2012

Based on the anti-corrosion design plans and major response measures of part of the recent international bridges, the advantages and disadvantages of additional measures were compared. For the relatively favorable environment at the site of Pinghai Bridge, the basic measures and additional measures to improve the durability of concrete were proposed. Implementation of these measures played a significant effect to improve the durability of the structure and components of Pinghai Bridge and also provided a reference for the durability design for the same type bridge.