bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability Analysis of Rock Pillar between Tunnel and Large-Scale Concealed Cave on Top of Tunnel
Authors: Guo Jia Qi , Ren Lian Wei , Wang Guang Yong
Published: December 2012

Accompanying the enforcement of strategy to develop western regions, transport and other infrastructures of western China expand substantially and long tunnel in karst zones increases dramatically. Geological hazard of water inrush and mud outburst often occur in the process of karst tunnel construction, which often lead to equipment destroyed and construction period bungled, even serious casualty and economic loss. The influence of large-scale concealed caverns with high pressurized water on top of tunnel on the stability of rock pillar between them is researched in this paper. According to the actual conditions, rock pillar is simplified into beam with both ends built-in. Utilizing the conception of classic structural mechanics, a model is developed to calculate the minimum thickness of rock pillar in order to evaluate its stability by use of the criteria of shear strength and tensile strength of rock pillar. As a example, the proposed model is applied to predict the stability of rock pillar between karst tunnel on Yi-wan rail line and concealed cave with high pressurized water, the result illuminates that this methods is feasible to supply basis for evaluating the stability of rock pillar during construction period of karst tunnel.
Influence of the Cross Section of Hood on the Compression Wave Generated by a High-Speed Train
Authors: Yan Ya Guang
Published: December 2012

An analysis is made of the compression wave generated when a high-speed train enters a tunnel with hood. The purpose of the hood is to reduce as much as practicable the maximum gradient of the compression wave. In this paper the numerical computation simulates the pressure change in the tunnel,analysises regularity of the the initial compression wave and the pressure gradient wave,compares the mitigation effect of the two hoods which have different cross section on the pressure gradient.The following conclusions have been drawn from the research: The amplitude of the first compression wave is not significantly reduced with hood,however,the amplitude of the pressure gradient is significantly reduced with hood.And the mitigation effect of the enlarged-transect hood is better than the equal-transect one.
Comparative Analysis of Analytical Method of the Support Pressure at Tunnel Face
Authors: Li Chao , Qi Shuai , Liu Jia Dun
Published: December 2012

The shape and properties of the sliding wedge in the three models, DIN4085, Jancsecz and Anagnostou/Kovari, are systematically explained, based on the simple and applied properties by using the analytic method to calculate the earth pressure in the tunnel project with shield machine. Combining with the Silotheory proposed by Janssen and the Terzaghi formula, the three pre-add models are applied to calculate the earth pressure in the projects of the Westerschelde tunnel in Holland, the Metro Line 1 in Düsseldorf and the Mostoles railway in Spain, in comparison with the actual earth pressure data of shield machine. The suitable using conditions of the three models in different situations as the shield type, the buried depth, the soil type, the water pressure and the part of the face are summarized, in which the water pressure, the friction angle and the cohesion of the soil are taking a crucial role in the value of the support pressure.
Influence of Pit Excavation Supported by Soil-Nailing Wall on Adjacent Buried Pipelines
Authors: Wang Shu He , Zheng Zheng , Mu Zai Gen , Zhang Ju Bin
Published: December 2012

Underground pipelines affected by pit excavation are a practical problem often encountered in city foundation engineering. The characteristics of soil-nailing wall supporting include simplify, convenience, and low cost which make it widely adopted. Using MIDAS GTS for the integrated modeling, and the affecting factors are studied in four aspects, including excavation depth per step, pipelines’ depth, the distance between the edge of excavation and pipe, and the elastic modulus of surrounding soil. Some valuable conclusions for construction practice are drawn.
Numerical Simulation of Critical Velocity in Obstructed Tunnel
Authors: Sun Da Hui , Yang Hui , Xing Yan Jun
Published: December 2012

When highway tunnel is on fire, obstruction of vehicles in the tunnel have certain effects on the spread of fire smoke and critical velocity. This paper made CFD studies on the critical velocities when the blockage is located in the upstream flow of the fire smoke. The effect of the distance between fire source and blockage as well as the dimension ratio was analyzed. The numerical simulation results show that the critical velocity in upstream obstructed tunnel is smaller than that in empty tunnel and the critical velocity increases with the distance between the blockage and the fire source. The critical velocity increases with the heat release rate and decreases with the dimension ratio. The calculating model for critical velocity of empty tunnel was modified to adapt to obstructed tunnel.
Experimental Research on Rheological Property of Water-Bearing Weak Sandstone in Large Cross-Section Tunnelling
Authors: Zhou Ye , Li Peng Fei
Published: December 2012

Various problems such as sand, mud and water bursting, unstability of tunnel face, large deformation of surrounding rock and severe cracking of primary support occurred in excavation of the water-bearing weak sandstone strata of Huma Ling Tunnel, Lan-Yu railway. Based on the uniaxial compressive strength tests and uniaxial compressive rheological tests on weak sandstone with water content of 0, 2%, 5%, 8% and 12%, the relationship between rheological characteristic and water content of water-bearing weak sandstone is obtained. According to results of tests, factors and water contents are fitted by applying generalized rheological equation of Kelvin. And the rheological equation of water-bearing weak sandstone with various water content is deduced. The test results and conclusion can offer reference for analyzing deformation characteristics and instability mechanism of water-bearing weak sandstone in large cross-section tunnelling.
Monitoring and Results Analysis of Tunnel Engineering
Authors: Xu Xiao Hu , Xiao Ming Gui , Xu Da Hu , Cao Jie
Published: December 2012

Through to the Henan tunnel engineering and observation hole, peripheral displacement measurement, measurement of subsidence of arch roof and surface subsidence measurement on-site real-time dynamic testing, obtained their changes over time curve, and the tunnel monitoring results were analyzed, thus improving the tunnel design and correctly guide the construction, ensure the safety and economy of the tunnel engineering.
Safety and Durability Pavement in Super Long Tunnel
Authors: Liu Jian Wei , Shen Jun Min , Liu Shao Wen
Published: December 2012

In order to solve the problem of design and construction of pavement structure in the long tunnel, through the analysis of pavement using domestic and overseas, combined with the factors of primary carrying capacity, small temperature gradient in the long tunnel, the Continuously Reinforced Concrete Pavement(CRCP) is proposed, which has characteristics of better durability, strong structure integrity and comfortable driving. Mini excavator auxiliary framing construction, layered pouring concrete, lap joint construction of welded steel have solved a series of problems of the relatively small space of construction, the lower concrete vibrators affected by the steel mesh and reinforced scene lashing. So continuously reinforced concrete pavement using welded steel fabric can be used as a major road structure in long tunnel.
Study on Mine Pressure Behavior of Roadway in Highly Irregular Working Face in Daizhuang Coal Mine
Authors: Wen Xing Lin , Gao Lin Hai , Li Chuan Lei , Dong Meng Meng
Published: December 2012

The irregular face mechanized mining is one of the difficult problems in the field of mining engineering. In this thesis, the roadways of 4324 extremely irregular face in DaiZhuang Mine were taken as research object. Through on-site mine pressure observation, the deformation characteristics of the surrounding rock and support force was analyzed. Next the mine pressure appeared rule of the roadways was study. This study benefited that the production of 4324 mining face went on wheels, at the same time, it had important significance to production safety of irregular working face with similar conditions.
Tracking Study on International Large Scale Centrifugal Shakers of 40g-t and Key Technology
Authors: Wang Yong Zhi , Wang Wei Ming , Yuan Xiao Ming
Published: December 2012

Centrifugal shakers are widely regarded as state-of-the-art testing facilities of geotechnical earthquake engineering for providing an effective solution for the unequal gravity stress between models and prototypes typically in traditional test methods. Currently only two large centrifugal shakers are in the United States and Japan respectively, whereas no one has been established in China. Such situation remarkably lags behind the serious seismic conditions and the world largest construction scale of civil engineering in China. Due to the lack of experiences and the lot of difficulty, one significant task of large scale centrifugal shaker construction is tracking study on the world advanced facilities. The paper outlines the technology parameters and components of the two existing large centrifugal shakers. Through investigating and comparing the structural characteristics of the two facilities, the differences between the two are summed up and analyzed. The analyses indicate that key technologies mainly centre upon centrifuge arms, centrifuge buckets, exciting devices, power sources and guide-support devices. The results can provide assistance and reference to the construction of foreign and domestic large scale centrifugal shakers.
Research on Dynamic Behavior of Vehicle-Bridge System
Authors: Wu Yan Hong , Han Guang Cai , Liu Zhi Qiang , Bian Fu Guo
Published: December 2012

Dynamic behavior of a vehicle-bridge system model is presented. A set of time-varying equations of the system considering roughness surface of bridge are given. The equations are rewritten in the form of matrix for numerical simulation. Modal analysis of the equations is carried out. Simulation and visualization of the equations are given. Effects of different speeds and accelerations of moving vehicle and roughness surface of bridge on the vertical displacement of mid-span of bridge are studied.
Evaluation of Ultimate Serviceable State of the Cross-Sea Bridge Pier under Freeze-Thaw and Erosion Coupling Effect
Authors: Zhao Qian Qiao , Jin Lu
Published: December 2012

In order to put forward a durability assessment method of concrete structure based on the engineering calculation and analysis, combining with the characteristics of northern freezing coastal areas and the non-navigable spans bridge construction，the paper built the Ottosen strength criterion on concrete under freeze-thaw and erosion coupling effect. By the application of strength criterion, calculation and analysis, it has been evaluated the crack resistance at a few key points of the concrete pile cap on the bottom. The result illustrates that there will appear concrete cracks at the middle of the cushion cap bottom after a 130-year serviceable period when the bridge is attacked by the once-in-a-century wave load or ice load, that is, the safety serviceable period of the bridge pier is 130 years.
Visual Safety Evaluation of Bridges Based on the Straight Lines Failure Envelope Theory
Authors: Sheng Gui Lin , Ma Shao Chun , Bao Peng
Published: December 2012

The paper deduced visual safety evaluation models in each layer under the action of internal forces for the pole bracing system of bridge structure ,based on failure envelope theory. It calculated and analyzed the actual Xugou especially big bridge project with these evaluation methods. Analyzed visibility graph of bridge structure, tried to find out directly concrete distribution and the safety degree of structure on visible group points in intra-regional each point to corresponding coordinateof octahedral failure envelope. It can finally realize quantitative and visual safety assessment for bridge structure, and can provide necessary reference to scientific management and planning optimal maintenance scheme of bridge engineering.
Experiment Study on Viscosity Behavior and its Temperature Influence of Cement Silicate Grouts
Authors: Han Wei Wei , Li Shu Cai , Zhang Qing Song , Liu Ren Tai , Zhang Lian Zhen
Published: December 2012

The basic characteristics of the cement-sodium silicate grout were researched. Viscosity tests were performed. The viscosity curve and temperature curve with time were obtained. The change law of viscosity was analyzed. According to the varying characteristics of grout viscosity, the process was divided into three stages: low viscosity period, the growth period and curing period. solidification tests were carried out for cement-sodium silicate grout with different temperatures, densities and water-cement ratios. Three parameters affected the initial setting time of the grout significantly.
Statistical Analysis and Evaluation on Cracks of Simply Supported-to-Continuous Split-Type Box Girder Bridges
Authors: Ren Zhen Xing , Zhang Wei , Ren Lei
Published: December 2012

In this paper, the crack diseases of 106 simply supported-to-continuous split-type box girder bridges from G55 Taichang and G55 Changjin highways were statistically analyzed by the number of bridges, the frequency of each meter cracks appeared and the degree of cracks developed. According to the norm that Standard for Technical Condition Evaluation of Highway Bridges and which was recommended by the department of transportation, the crack diseases were evaluated by the two indexes, which were maximum crack width and crack length divided corresponding section size . The conclusion provides a technical basis for the effective prevention and treatment of cracks in the design, construction, repair and maintenance in the future. The proposed crack disease statistics method and evaluation method are provided with practical application value for management and maintenance departments to effectively evaluate the crack development and make decisions to repair.
Dynamic Performance Analysis of Single Tower Self-Anchored Suspension Bridge Using Measured Modal Identification
Authors: Ma Zhi Guo , Li Zhi Jun , Zhu Yi Huan , Zhu Xiao Wen
Published: December 2012

Recent years, Single tower self-anchored suspension structure system is more available around us. The research on dynamic characteristic types of structures is an example Nanjing Jiangxin-island Bridge, together with its field modal test and calculated value from a three-dimensional finite element model which focuses on the boundary sensitivity impact to dynamic characteristics of such bridges. The results show that, larger error appears when we do not consider expansion joint stiffness and bearing friction force relative to measured value, so this phenomenon should have to be considered. The conclusions provide important research basis for design and health monitoring of the bridge.
Application of WebGIS in Process Management of Highway Bridge
Authors: Lan Ming , Zhao Shao Bing
Published: December 2012

According to Road Course management characteristics, this System was built based upon WebGIS technology , SVG technology, Ajax technology and database technology. This paper discussed the main designment solution of this system and to realize bridge CAD map to ZommIn, ZommOut, Pan, Theme, Edit function and so on。
Research about FPS Seismic Isolating System on Bridges
Authors: Ge Nan , Chen Hai Bin , Jiang Pan
Published: December 2012

A numerical model was established for a continuous beam bridge with FPS bearings. It started from Lagrange equation in dynamic mechanics. The software for its numerical solution was presented with Newmark-β method. Computation results show that efficiency of the seismic isolation system is closely related to slipping friction factor on the contacting surface and slide radius. The internal forces (shear forces) for piers exhibit a significant reduction under an optimum combination of friction factor and slide radius. For friction factor being in the range of 0.1-0.2 and slide radius 1.5m, the shear force could be decreased by more than 50%, and the drift of beam would be less than 2cm in horizontal direction and less than 0.1cm in vertical direction respectively.
The Optimization Design Analysis of Loukouni Bridge in the Republic of Congo
Authors: Zhang Long Ying , Zong Liang , Wang Yuan Qing , Li Jun
Published: December 2012

Loukouni bridge is a deck type arch bridge with box section which is a part from the second stage of the 1st national road project of the Republic of Congo. This paper focuses on the optimization design analysis of the Loukouni bridge to make it more economical and reliable. The optimization analysis is implemented by ANSYS and contains two parts. One part focuses on the whole shape of the arch and try to optimize the arch axial coefficient. The other part considers the optimization of the size of the box section. The analysis results could provide useful suggestions for the design of Loukouni bridge and related steel arch bridges.
Research on Arranging Originating Base of Nanjing Weisan Road Tunnel
Authors: Yang Zhao , Yang Yan Hua
Published: December 2012

The originating base of large shield is a fundamental guarantee of shield machine prosperous assembly and originating posture. This paper based on Nanjing Weisan Road Tunnel Across Yangtze River, the requirements of large TBM assembly and the guarantee measures on originating posture is introduced.
Application of Dynamic Compacted Stone Piers in Soft Foundation Road
Authors: Xu Chun , Zhang Yong
Published: December 2012

The dynamic compacted stone piers in reinforcement of soft foundation road are introduced in this paper. The design proposal of dynamic compaction on stone piers, and the construction quality test method are proposed. The settlement detection curve is obtained, finally some suggestions are given. The monitoring results indicate that: the sedimentation velocity is from big to small, and then tends to stop gradually, which is in line with the general rules. It is found that the work of monitoring and tracking detection of road soft foundation after construction until the settlement tends to stop is rare to be seen in domestic. Therefore, the results can give meaningful guidance for the real practice.
Corrosion Resistance Properties of Synchronous Pavement Surface Dressing Composite Structure
Authors: He Zhuang Bin , Qin Feng , Huang Qiong Nian
Published: December 2012

Water erosion was the main pavement disease, and the erosion resistibility of synchronous pavement surface dressing composite structure was evaluated. Specimens’ immersion corrosion tests in still water, vibration water and under the scouring condition were carried out for the research on the corrosion resistance. It is observed that corrosion resistance and scour resistance performances are significantly reduce with the water temperature and immersion time. The diseases of composite synchronous surface dressing are increased beyond 48 hours immersion time. Finally, it is observed that the performance of corrosion resistance decrease significantly when the running speed higher than 60km/h.
Hybrid Finite-Discrete Element Modelling of Dynamic Fracture of Rocks with Various Geometries
Authors: Liu Hong Yuan
Published: December 2012

The hybrid finite-discrete element method Y-2D/3D IDE is applied to model the dynamic fracture of rock specimens with various geometries during impacting a fixed rigid surface. It is found that the modelled primary fractures are highly dependent on the rock geometry determining the weakest plane for a given impact, which agrees well with others' experimental and SPH numerical results. Compared with others' SPH results, Y-2D/3D IDE better simulates the actinomorphic pattern of primary fractures around the impact area and the secondary & tertiary fractures observed in the dynamic fracture experiments. It is concluded that the proposed Y-2D/3D IDE is a valuable tool to model rock dynamic fracture compared with FEM and DEM.
The Research on Compaction Characteristics of Rubber Asphalt Mixture
Authors: He Li Ping , Shen Ai Qing , Tan Ji Zong , Wang Lei
Published: December 2012

Through the crush value test and combustion method test to analyze the relationship between needle flake content and crush value，and analyze the affection to the status of broken at compaction procession .Through the use of static pressure, gyratory compaction and Marshall compaction this three different molding methods of rubber asphalt mixture specimen shape.At the same time, analyze the variation of volume parameters and combination with the methods of specimen trimming to analyze its porosity distribution. At the same time, forming the sample volume parameters and combination of slices to analyze the porosity distribution of three different ways. The same time, through combustion method to analyze the impact of molding methods on rubber asphalt mixture's compaction characteristics.
The Engineering Methods of the Whole Track Bed Structural Reinforcement
Authors: Shi Rong , He Yue Lei
Published: December 2012

Engineering must maintain and repair the whole track bed daily and timely. Considering the different geographical conditions of the construction, soil conditions and the different construction methods and other factors, engineering methods adopted are not the same reinforcement. Mainly three categories: the repair of minor cracks in the surface of the coating law, pressure grouting which has a good condition of strength and durability, grooving repair methods. This paper focuses on various types of reinforcement construction methods for comparison.
Influence of Widened Embankment on the Slope of Existing Pavement on Soft Soils
Authors: Cao Wei Ping , Shi Qi Chao , Hu Wei Wei
Published: December 2012

Adding a new embankment adjacent to the existing highway embankment is a cost effective choice compared with building another new one and can mitigate the heavy traffic pressure. However, it may also cause some engineering problems including the change of slope of existing pavement or even local or global instability of embankments especially those on soft soils. How to prevent excessive change of the slope of the existing pavement induced by widening the existing embankments is of great importance in engineering practice. A numerical analysis by using a commercial FEM program was performed to explore the influence of the thickness of soft foundation soils, the widening width and the embankment height as well as the starting time of widening construction on the slope of the existing pavement. The results indicate that the bigger the thickness of the foundation soils as well as the bigger the widening width will result in bigger values of the slope of the existing pavement, especially at the early period of reconsolidation. Adverse slope will be induced by widening of the existing embankment.
Risk Evaluation of Steel Structure Corrosion in Soft Foundation in the East Coast of Zhejiang
Authors: Wang Juan Di , Gan Wei Zhong
Published: December 2012

The detection index and evaluation for foundation engineering’s corrosion are performed in accordance with the “Code for Highway Engineering Geological Investigation” or “Code for Investigation of Geotechnical Engineering”. For both steel pipe piles and concrete pipe pile joints, the codes don’t consider the dissolved oxygen, Anaerobic organism and other corrosion factors. In order to improve the durability of the pipe pile foundation in coastal region, taking the typical coastal soft soil characteristics in eastern Zhejiang as example and by observing the steel corrosion electrochemical potential variation in the hypoxic environment, this paper analyses the corrosion risk of steel structures in marine deposit soft soil, and puts forward the microbial and electrochemical corrosion mechanism of the steel structures in foundation engineering in coastal environment. This paper argues that the Sulfate-Reducing Bacteria corrosion evaluation is indispensable in geotechnical investigation, and therefore should be included into the Code.
Analogue Simulation of Dynamic Interaction of Sea Ice and a Pier Column Structure
Authors: Song Bo , Qi Fu Qiang , Wu Jin Cheng
Published: December 2012

The process of interaction of sea ice and a pier column structure was studied by using analogue simulation method in the paper, and the dynamic ice force acting on the pier column structure was achieved. Combining with theory analysis, it modified the dynamic ice force model suggested by Croteau. The results showed that the loading stiffness suggested by Croteau is too big to use in the dynamic ice force model and the Withalm formula and simulated results are more suitable. It suggested the calculation formulas of relative displacement in ice force unloading stage and the continuous ice force in ice force continuous stage.
Separation of Wave Setup from Water Level Data of SandyDuck ’97 Experiment
Authors: Liu Shi Chao , Huang Li
Published: December 2012

The observation wave induced setup can be separated from observed total water level which combines tide level, weather induced setup and wave induced setup. SandyDuck ’97 experiment provides lots of observation data. Separation of tide level form preliminary data is using the nearest tide station’s predicted tide. The weather induced setup is given by numerical model which includes the effects of air pressure and wind blows. The residual water level, wave induced setup, seems reasonable and available, and the time series trend match with wave high trend at same location.
Experimental Investigation on Scour around Marine Pipelines in Silt Beds by Jet Trenching
Authors: Bai Zhi Gang , Lv Ruo Chen , Meng Ran
Published: December 2012

Jetting power has been applied more and more frequently to create trench in the seabed to bury cables or pipelines under a protective layer of sand in offshore engineering. However, there are still several key problems to be understood further and solved both in their design and operating. This study investigates the topographic deformation due to the scour of silt beds which lie below marine pipelines and are impinged by moving two jets in a model experimental system. The response of silty sea beds was also examined during the experiment. The important parameter that influences the trenching performance, the jet velocity, was studied. The speed of the jet horizontal motion was varied to examine its effect on the scour profile. By presenting the variation of a scour profile with time after impingement, the change process was analyzed. The asymptotic scour profiles were found to be very similar when made non-dimensional, and a function was employed to describe the non-dimensional profile. The results of the above work will permit a better understanding of the mechanisms controlling the performances of underwater trenching by jet trenching machines.
Simulation of Wave Slamming on Open-Piled Structures Based on FLUENT
Authors: Jin Feng
Published: December 2012

In order to study the specialties of wave slamming on open-piled structures, a two-dimensional regular wave tank was established based on commercial CFD software FLUENT. Three typical cases of regular wave slamming on the open-piled structures were reproduced by using the numerical wave tank and compared with the experimental data available. Good agreements were obtained between the numerical and experimental results and the average of peak impact pressure was chosen as the characteristic impact pressure. Then regular wave impact pressure on the open-piled structures under various wave height, period and over height were simulated. The influences of the three parameters on the distribution of impact pressure were analyzed.
Effects of Inertial Mass Coefficient on Knotless Netting Model Used in Tuna Purse Seine
Authors: Zhang Xin Feng , Xu Liu Xiong , Song Li Ming , Zhang Jian , Li Yu Wei
Published: December 2012

This paper aimed to research the effects of inertial mass coefficient on knotless netting models used in tuna purse seine. Knotless nettings were modeled and simulated using mathematical and mechanical models. In the simulation, the marine environment was imitated in the computer. The results demonstrated that inertial mass coefficient was a key factor to affect the stability of knotless model, especially in the sinking process, and the model presented more stable and quicker convergent as the inertial mass coefficient increased. During fishing operation at sea, the instability of the sinking of purse seine with knotless nettings, especially in the area with complicated currents and waves, might be due to the smaller inertial mass coefficient of knotless nettings.
Research on Urban Earthquake Damage Prediction Virtual Simulation System
Authors: Wang Dong Ming
Published: December 2012

Earthquake damage prediction is a fundamental topic for working out the urban earthquake disaster prevention planning, improving earthquake emergency plans and preparedness, establishing seismic fortification criterion, and achieving the goal of earthquake preparedness and disaster reduction. It’s significant to carry out urban seismic damage prediction. To display and apply the results of damage prediction more scientifically, intuitively, integrally, objectively and fully, the technical methods and ideas of using virtual simulation technology are proposed and studied, and the system requirements, functional design and structural framework are also described in this paper. These studies will provide effective technical support for the damage prediction to serve the urban disaster reduction, improvement of people's awareness of disaster prevention and refuge and so on, and have good application prospects.
The Anti-Seismic Performance of the Multi-Layer Frame-Bent Industrial Factory
Authors: Liu Jun , Kong Ling Jun
Published: December 2012

The multi-layer frame-bent industrial factory is a new structure, in the south of China. The anti-seismic performance of longitudinal and transverse directions of the factory is analyzed by SAP2000 software and nonlinear time-history method, in this paper. The S shaped steel dampers are used to the factory. The results show that the application of the S shaped steel dampers reduced shear forces and bending moments of the pillars bottoms and displacements of the floors of the factory; the S shaped steel dampers formed large hysteresis loops, dissipated earthquake energy and reduced the earthquake response of the factory.
Experimental Study on Seismic Performance of Steel Reinforced Concrete Column with Recycled Coarse Aggregate
Authors: Ma Hui , Xue Jian Yang , Zhang Xi Cheng , Chen Zong Ping
Published: December 2012

In order to evaluate whether concrete with recycled coarse aggregate can be applied for steel reinforced concrete (SRC) under the earthquake, low cyclic loading tests of SRC with different recycled coarse aggregate (RCA) replacement percentage were carried out in this paper. Based on the tests of three SRRC column specimens, the failure modes, the hysteresis curves, the skeleton curves, the ductility, and the stiffness degradation of SRRC columns are investigated. The influence of variation in the RCA replacement percentage on the SRRC column is analyzed in detail. Test results show that the seismic performance of SRRC column is reduced to an allowable extent with the increasing magnitude of the RCA replacement percentage. The SRRC column still has a good seismic performance and the recycled coarse aggregate can be applied for steel reinforced concrete through the proper design.
Stability Analysis of High-Rise Buildings under Seismic Load
Authors: Zhang Xiang Dong , Wang Pu , Guan Jian
Published: December 2012

Analysis of the structure characteristics of the General Hospital of Fuxin Mining Group, through the instrument observation and use the finite element software for structural modeling, modal analysis show that the quality of structural system, the stiffness is more evenly distributed the structure of the torsional capacity to meet the requirements. Through input into Tianjin wave, analysis the dynamic characteristics of the model, the results show that: to tall wall-frame structure, shear wall is very restriction of lateral displacement in the central and bottom, stronger than upper structure on lateral displacement limit ability.
Codes on the Safety of Nuclear Power Plants in Relation to Seismic Design
Authors: Li Yuan Jun
Published: December 2012

Study on the nuclear Safety laws and regulations, and good grasp of relevant definitions are essential prerequisites for Seismic and geologic siting of nuclear power plants. It can be too strongly emphasized that laws or decrees of issue by government and legislature have profound mandatory binding force. The guides and regulations related nuclear safety belong to directing documents of the specific rules, they have not been mandatory in the law significance, and allow some adaptability to a certain degree. Professionally technical specification is merely the inherent stipulations, besides; it must meet the codes demands in the concrete practice. Finally, the assessment of the capability for surface faulting at nuclear power plant sites belongs to the mandatory claims but not in assessment of active fault.
An Analytical Approach to Torsionally Coupled Seismic Response of Eccentric Structure Incorporating Soil-Structure Interaction
Authors: Jiang Xin Liang , Li Yue
Published: December 2012

An analytical approach based on branch mode method is formulated in this paper to study the dynamic response of eccentric structure considering soil-structure interaction The superstructure branch and foundation soil branch are coupled through mode aggregation procedure. The computational scale of system equations decreases to an acceptable level. Sample analysis indicate that the seismic response of eccentric structure increases first and then decreases with the decreasing of stiffness of soil-foundation system, which is affected by the inertia effect of foundation branch. For the soft soil case, the influence of SSI effect is more intensive that the trends of transfer function curves are fundamentally changed comparing to the results of other foundation conditions.
Pseudo-Dynamic Test of Brick Masonry under Different Earthquake Motion
Authors: An Dong , Qu Tie Jun , Liang Jian Wen
Published: December 2012

For further study on the influence of ground motion on the seismic performance of brick masonry structure, two masonry buildings were designed and constructed according to common structure style in towns and villages. Two full-scale buildings were subjected to different earthquake motion using pseudo-dynamic test. The earthquake motions are artificial earthquake motion and strong motion recording. This paper presents hysteretic behavior and deformation under horizontal seismic action. Crack propagation of masonry structure is analyzed. These tests verify that displacement response of masonry structures under different ground motion is pretty much the same. Tie-column and ring-beam can effectively confined brick wall. The cracks are mostly diagonal cracks caused by shear failure.
Study on Strong Motion Records Database and Selection Methods
Authors: Lin Li , Wen Rui Zhi , Zhou Bao Feng , Shi Da Cheng
Published: December 2012

In this paper, PEER Ground Motion Databases (PGMD) at the Pacific Earthquake Engineering Research Center (PEER) was updated by 314 sets of ground motion records of great earthquakes in recent years, which expanded the application of this database. This paper reviews alternative selection methods for strong ground motion records. The expanded database could make the different selection and scaling of strong motion records in great earthquakes, and the conditional mean spectrum (CMS) method could be applied for the strong motion records selection in structural spectrum analysis.
Stochastic Simulation of Ground Motions of the Wenchuan Earthquake Using Slip-Based Corner Frequency and Scaling Factor
Authors: Sun Xiao Dan , Tao Xia Xin , Liu Cheng Qing
Published: December 2012

Ground motions of the great Wenchuan earthquake were simulated using stochastic simulation technique with an improved source spectral model. In the model, the corner frequency for each subfault is determined based on a basic value calculated from the total seismic moment of the entire fault and an increment depending on the seismic moment assigned to the subfault. The model also includes a slip-based scaling factor accounts for the difference of the radiated energy from each subfault. The simulated ground motions were compared to those from using the source spectral model with dynamic corner frequency in terms of the mean spectral ratio over the 52 stations amd to the observation in terms of 5% damped response spectra. Based on the comparison, the effects of the slip-based corner frequency and the scaling factor on the simulation were discussed.
A Comparison of Two Magnitude Estimation Methods Using Predominant Period in Earthquake Early Warning
Authors: Song Jin Dong , Li Shan You
Published: December 2012

Currently, there are two magnitude estimation approaches using predominant period for earthquake early warning, Tpmax method and Tc method. We compared Tpmax method with Tc method from the NSMP strong motion records of 22 earthquakes in United States with moment magnitude ranging from 4.1 to 7.9, to explore which method was with higher precision and could be suitable for the earthquake early warning system. Our results show that scaling relations between the two predominant period parameters, Tpmax and Tc, calculated from P-wave arrivals and earthquake magnitude are consistent with previous research. It was found that Tc method had higher precision than Tpmax method with the same filter band, and had best result in magnitude estimation resulting in a correlation coefficient of 0.78 and a standard deviation of 0.16 using 3 seconds signal after the P-wave arrival. We also found that Tc method without low-pass filter had higher accuracy than Tpmax method without low-pass filter. We recommended Tc method using 3 seconds signal after the P-wave arrival as the priority magnitude estimation method for earthquake early warning.
Two-Stage Design Method for Multi-Story Structures Equipped Metal Dampers, Part II: Case Study
Authors: Song Jing Xu , Pan Wen
Published: December 2012

The two-stage design method for multi-story structures equipped metal dampers is put forward based on the Code for Seismic Design of Buildings (GB50011-2010) and the Code of Japan Society of Seismic Isolation. For preliminary design stage, simplified method is adopted to estimate added stiffness and damping on each story, offering an approximate requirement of dampers. For detail design, the time history analysis is employed to verify the performance of structure with added dampers and determine number of energy dissipation device. In this part, a 10-story frame is analyzed by the new method, and the numerical investigation shows that the new method is simple and flexible for application in engineering.
Seismic Risk Analysis of Concrete Gravity Dams under Near-Fault Ground Motions
Authors: Hebbouche Abdelhamid , Bensaibi Mahmoud , Mroueh Hussein
Published: December 2012

There are a large number of concrete dams worldwide. Some of the dams are in areas prone to seismicity and were built many years ago with minimal consideration to seismic loads. Dam safety during and after an earthquake, is the aim of the present study. The failure of a dam during an earthquake will be catastrophic in terms of human life and financial losses. In the present work, an analytical fragility analysis was performed in order to characterize the seismic vulnerability of concrete gravity dams by using a probabilistic method to model sources of uncertainty that could impact dam performance. The assessment of the seismic vulnerability of concrete gravity dams under near-fault ground motions was performed to assess their performance against seismic hazards. A case study was considered, it is about the dam of Oued el Fodda on the Oued Chelif River, West Algeria. This dam was designed in the early 1930s.
The Design and Error Compensation Research of 3-Axis Electronic Compass Installed in Small Muti-Rotors Unmanned Aerial Vehicle
Authors: Fan Song Wei , Bian Hong Wei
Published: December 2012

A 3-axis electronic compass is designed for small multi-rotors unmanned vehicle. The STM32F103 is used as E-compass’ CPU, and ADXL345 and MAG3110 is used as the acceleration and geomagnetic sensor. The E-compass’ software is programmed by using IAR EWARM. For outdoor applications, the ellipsoid assumption theory is simply proved and used for E-compass’ self-calibration. By using the zero-bias adjustment for pre-calibration and the fitellipsoid compensation for precise calibration, the E-compass’ precision is nearly 1 degree.
Navigational Data Change Detection Based on Rasterizing Features & Attributes
Authors: Li Lian Ying , Huang Zhang , Xu Xiao Lan
Published: December 2012

A necessary updating degree is vital for the digital map data in a vehicle navigation system. Only when the digital map data are well updated, can the quality of the navigation be assured. Today the companies devoting to the production of digital map data for vehicle navigation have to cost much labor, material and capital to collect and update data in order to maintain a necessary updating degree. Throughout the history of electronic navigation data updating, they have made considerable progress both on the methods and processes of data production, and the way of map management. Updating from the CD to the network, from the wired to the wireless, from the replacing to the incremental way, each of the technical changes is a power source to enhance the data updating rate. As we all know, the change detection is a prerequisite and base for the electronic navigation data updating. By rapidly developing the area with changes and using the appropriate updating method, we can scientifically maintain the original database of navigation data and terminal physical data. In view of this, starting from application needs for dynamic data updating, this paper analyses change detection methods of navigation data in different versions used for generating incremental data, and focuses on that of rasterizing features and attributes, exploring a new approach to quickly get the incremental data between versions.
Marine Oil Spill Detection in SAR Image Based on Mathematical Morphology
Authors: Liu Liang , Cui Xin Guo , Chen Ming Jiu , Sun Ying Jun
Published: December 2012

Oil spills are almost constantly present in recent years, which cause ecological disaster of marine environment. It is important to detect the area of oil spill to take rescue measurement in time. The paper took the EnviSat Asar image as example to detect the boundary of oil spills. Firstly, the paper removed speckle noise by Histogram Equalization. Then, image segmentation was carried out by open-close mixed operation in mathematical morphology. At last, the region of oil spill was exacted independently.
Quality Evaluation of Remote Sensing Mapping for Land Cover Based on Cartographic Specifications
Authors: Liao Shun Bao , Cao Jun , Bai Zhong Qiang
Published: December 2012

With remote sensing mapping for land cover of China at scale of 1 to 250,000 as an example, we analyzed main quality problems related to cartographic specifications. In order to improve efficiency of checking the problems and to make checking and evaluating results more objective, we designed and developed a set of quality check and evaluation system based on cartographic specification in loose coupling mode with open source software tools. The actual evaluation results from the system demonstrated that the land cover data generally met requirements of cartographic specifications.
Mixed Unscented Kalman Filter and Differential Evolution for Parameter Identification
Authors: Legowo Ari , Mohamad Zahratu H. , Park Hoon Cheol
Published: December 2012

This paper presents parameters estimation techniques for coupled industrial tanks using the mixed Unscented Kalman Filter (UKF) and Differential Evolution (DE) method. UKF have known to be a typical estimation technique used to estimate the state vectors and parameters of nonlinear dynamical systems and DE is one of the most powerful stochastic real-parameter optimization algorithms. Meanwhile, liquid tank systems play important role in industrial application such as in food processing, beverage, dairy, filtration, effluent treatment, pharmaceutical industry, water purification system, industrial chemical processing and spray coating. The aim is to model the coupled tank system using mixed UKF and DE method to estimate the parameters of the tank. First, a non-linear mathematical model is developed. Next, its parameters are identified using mixed Unscented Kalman Filter (UKF) and Differential Evolution (DE) based on the experimental data. DE algorithm is integrated into the UKF algorithm to optimize the Kalman gain obtained. The obtained results demonstrate good performances.
Ground-Adjustable Inductor for Wide-Tuning VCO Design
Authors: Feng Wu Shiung , Yeh Chin I , Li Ho Hsin , Tsao Cheng Ming
Published: December 2012

A wide-tuning range voltage-controlled oscillator (VCO) with adjustable ground-plate inductor for ultra-wide band (UWB) application is presented in this paper. The VCO was implemented by standard 90nm CMOS process at 1.2V supply voltage and power consumption of 6mW. The tuning range from 13.3 GHz to 15.6 GHz with phase noise between -99.98 and -115dBc/Hz@1MHz is obtained. The output power is around -8.7 to -9.6dBm and chip area of 0.77x0.62mm2.
The Detection Method of Network Topological Property Based on Multiple Sampling
Authors: Huang Cong , Zhang D G , Yang T J , Yang H
Published: December 2012

Recent studies have shown that subnets of scale-free networks are not scale-free, which make it difficult to extrapolate from subnet data to properties of the global networks. Here, we discuss sampling properties of Erdö–Rényi and scale-free networks, then figure out how average degree varies with sampling probability. This finding is developed to be a practical detection method based on multiple sampling. In practice, the method could not only prove global networks and randomly sampled subnets belong to the same family of probability, but also detect unknown networks by least sampling frequency.
Three-Dimensional Numerical Simulation of the Hydraulic Characteristics of Spillway in Gushitan Reservoir
Authors: Jing Shu Guang , Gao Xue Ping , Jia Lai Fei , Xu Li Ping
Published: December 2012

Based on standard k-ε turbulence model and the VOF method for tracking free surface, hydraulic characteristics of the spillway in Gushitan Reservoir are simulated with a 3-D numerical model. The discharge capacity, water surface profiles, bottom pressure distribution and flow pattern are studied. Numerical simulation results have been in good agreement with experimental results, showing fine feasibility to study hydraulic characteristics of the spillway with the VOF method. The hydraulic characteristics acquired by the numerical simulation method can be used for spillway design.
Research on Real-Time 3D Visualization of Dam Transport on Network Environment
Authors: Liu Xu , Cui Bo , Tong Da Wei
Published: December 2012

According to the high earth dam with a large volume, high construction intensity, tense schedule, numerous construction machines, complex technology, and a lot of unexpected risk factors, the construction transportation becomes poor if the arrangement for transportation to the dam is unreasonable, which may result in schedule delays. This paper discusses the system of the real-time 3D visualization on network environment which is based on Unity3D engine, and the query of real-time three-dimensional visual information for transportation to the dam on the network environment is achieved. Users can have a real-time view of the dump truck during transportation and optimize the arrangements of construction organization. The results of research have great practical significance.