bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of Cracking Processes of Sandstone in Rockburst Test
Authors: Li De Jian , Zhao Fei , Ma Run Jie , Han Li Qiang , Wu Xiao Hu
Published: December 2012

High speed camera system is used to record crack propagation on rock surface during the lab rocburst experiment. This paper presents the specific analytical method of crack propagation with high speed images. Crack propagation types and directions are briefly described, and the lengths, growth rate and fractal dimension of cracks are calculated. The results show that the crack grows mainly along the horizontal line on the unloading surface, at a low speed before rockburst and reaches a very high speed abruptly near the burst point. The fractal dimensions demonstrated that the crack turns to be rough when rockburst happens. The study on the crack propagation is benefit to the understanding on the mechanism of rockburst.
Damage Causes and Control about Reinforced Concrete Circular Pipe Culvert under the High Fill
Authors: Zhang Jun , Zhang Xie Dong , Hu Xiang Yu
Published: December 2012

The damages of reinforced concrete pipe culvert appeared in use process brought a lot of problems. Investigated the pipe culvert damage characteristics, analyzed the causes of damages from load, structure stress and production, give the corresponding control methods.
Plane Truss Reliability Numerical Simulation Based on MATLAB
Authors: Li Yuan Ying , Zhang De Sheng
Published: December 2012

Based on the basic principles of structure reliability numerical analysis, the numerical simulation of the displacement and stress reliability of plane truss under vertical load was programmed with MATLAB. The failure probability of the most unfavorable structural vertical displacement and stress and reliable indicators were obtained through direct sampling Monte Carlo method, response surface method, response surface-Monte Carlo method and response surface-important sampling Monte Carlo method. It is found that calculation lasts longer since there are so many samples with Monte-Carlo method, higher accuracy and less calculation time can be achieved through response surface-Monte Carlo method and response surface-important sampling Monte Carlo method with fewer samples. The results of different numerical simulation calculations are almost identical and reliable, providing references to reliability analysis of complex structures.
Research on Life Prediction for One Gravity Piered Wharf Based on the Regulated Reliability Index
Authors: Li Wei Hua , Gao Xiang Zhuang , Sun Cong Tao , Zheng Hai Bing
Published: December 2012

The long-term behavior of concrete structure shows that the main cause of deterioration is reinforcement corrosion. One of the most aggressive exposure conditions for concrete is marine environment. What is worse, the structure mixed with sea sand. Under these conditions, chloride-induced reinforcement corrosion rate could be very high, often leading to reduction of the service life. This paper investigates long-term corrosive beams in the above-mentioned cases. Chloride distribution is analyzed. From Fick’s second law, the parameters for chloride diffusion can be obtained. Then, the service life of the concrete structure is predicted via empolying probability analysis. The characteristics of randomness (concrete cover, diffusion coefficient, surface chloride concentration and so on) have been taken into consideration.
Overview of Concrete Filled Steel Tube Viod Countermeasures
Authors: Wen Ya Nan , Su Jun Chen
Published: December 2012

We found through the statistics of disease that the void is one of the major problems of the CFST in recent decades. In fact, the void is inevitable with the current state of materials and construction method. This paper describes detailedly many methods of repairing void from the two aspects of the existing bridge and the under-construction bridge, including secondary grouting method, longitudinal stiffening rib, inner flange, bell-shaped anchoring box, etc.
Effects of Open Trench Dimension on Screening Effectiveness for High Speed Train Induced Vibration
Authors: Tsai Pei Hsun
Published: December 2012

2D boundary element method in time domain is used to investigate the screening effectiveness of open trenches on reducing vibration generated by a high speed train in this study. The parameter used in the study is the configurations of the trench. In order to evaluate the screening effectiveness of a wave barrier, a reduction of dB value is defined and used in this study. The maximum reduction of dB values is about 25 dB when an open trench is used as a wave barrier. The depth of open trench is a main influential parameter of screening effectiveness. The deeper the open trench, the better vibration reduction. The screening effectiveness increases slightly due to the increase of trench width. Current study facilitates the basics for the optimum configuration of the open trench as the wave barrier for reducing vibration.
A Coupled FE-TLE Model for the Prediction of Subway Train-Induced Ground-Borne Vibrations
Authors: Tang He Sheng , Wang Jie , Shi Jia Wu
Published: December 2012

A coupled finite element–thin layer element (FE-TLE) model for the prediction of subway induced vibrations was developed. With this model, the soil-tunnel system is divided into two parts, i.e., the tunnel structure and layered soil with a tunnel type hole. The tunnel structure is simulated by finite elements and the layered soils with hole by thin layer elements. The model fully accounts for the dynamic interaction between the tunnel and the soil. The numerical models for train-induced ground-borne vibrations were validated by in-situ experiments.
Study & Design on Hanging Assembly Supporting Structure in the Underground Roadway
Authors: Wang Hong Li , Zhang Xian Tang , Bao Wei , Xiu Hu
Published: December 2012

Based on a large number of surrounding rock stability, it sums up the classification of surrounding rock, nature and failure mechanism in the underground engineering. This paper introduces a underground tunnel hanging assembly support, the supporting structure can effectively solve the problem of insufficient rigidity of the roadway support, and provide a supporting structure with a certain amount of shrinkage.
Construction Schedule Real-Time Control Coupling Construction Quality in Large Scale Underground Powerhouse
Authors: Tong Da Wei
Published: December 2012

Underground powerhouse of hydraulic and hydroelectric engineering is a large cavern group structure. Construction process of underground powerhouse is a complex system, whose construction schedule is associated with construction quality. It is necessary to arrange construction schedule adopting construction simulation method and combining with tunnel stability analysis, which can advance the level of construction organization design. By using real-time control theory and methodology, the real-time control model of construction schedule and quality was established, considering construction procedure, geological conditions and resource limitation. The real-time control method of construction schedule and quality was presented, and the practical control procedure was studied. Good effect is obtained through the application of the real-time control method for construction schedule and quality in one real underground powerhouse.
Influence of Vented Tunnel Hood on Aerodynamic Characteristics
Authors: Yan Ya Guang
Published: December 2012

On the basis of the three-dimensional ,unsteady-state , viscous N-S Equation and k-ε two equation turbulence model , the simulation calculation is made with the finite volume method on the aerodynamic effect of a high-speed train passing a tunnel.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 on the pressure gradient.The following conclusions have been drawn from the research: The amplitude of the initial 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 vented hood is better than the unvented one.
Experimental Study on Effect of Longitudinal Ventilation Velocity and Slope on Smoke Movement in Tunnels
Authors: Xing Xue Fei , Zhang Jing Yan , Li Yan Feng
Published: December 2012

The slope effects on the movement of internal smoke cannot be ignored. Fire experiments in a small scale tunnel are conducted in order to observe the smoke movement in a tunnel with three kinds of slope (0%, 3% and 5%) under different longitudinal ventilation velocity, then find the correlation between smoke diffusion velocity and longitudinal ventilation velocity, and slope in tunnel by numerical fitting and dimensional analyses, finally conclude:(1) as longitudinal ventilation velocity increases, smoke diffusion velocity gradually decreases; (2) when longitudinal ventilation velocity is smaller, with the increase of slope, smoke diffusion velocity is gradually increasing; (3) when longitudinal ventilation velocity is large, slope to smoke diffusion velocity is not affected. These quantitative conclusions provide fire Prevention of the tunnel in city with a reference.
Testing Study on Soil’s Moisture Content of Geogrid-Reinforced Clay under Freezing-Thawing Cycles
Authors: Zhao Rong Fei , Mi Yong Ning , Gao Wei
Published: December 2012

A series of moisture content tests were carried out to study the changes in geogrid-reinforced clay moisture content under freezing-thawing cycles, the influences of compaction degree, reinforcement layers and initial moisture content of the soil on the soil moisture content under freezing-thawing cycles were discussed. We can see that the soil compaction degree is the first important factor to the moisture content, the change of upper lay clay moisture content is positive for the low compaction degree and negative for a high one; the reinforcement layers is the second important factor to moisture content, the upper lay moisture content reduces with the increasing of reinforcement layers, it is significant in the high compaction soil; the initial moisture content is the weakest factor, a big change of upper lay moisture content only appears when the initial moisture content is large and the soil compaction is low.
Support Effect and Application of High Convex Steel-Belt in Deep Roadway
Authors: Zhang Jia Lin , Cheng Le Tuan , Zou Zheng Sheng , Li Qing Bo
Published: December 2012

The steel-belt has the ability to improve support effect of the whole system that coordinate the anchorage force of bolt or cable, improve the support effect of the anchor system and diffuse the fore acted on bolt or cable. During the progress of support in the roadway, there has appeared flat, W and M steel-belt, and all of them have played important roles in different stages of support in the roadway. However, steel-belt now is rarely used in the deep rock roadway. High convex steel-belt is a new product, but whether it can adapt or not to the deep roadway, it's well worth our attention. The structure of high convex steel-belt and the characteristics of deep roadway are introduced in this paper. Numerical test on four kinds of mine steel-belt is carried out by ANSYS, and the advantage of high convex steel-belt is comparatively analyzed in deep roadway. At last, an example is shown. Research indicates that the steel-belt bears mainly the point load or local load due to non smooth and even convex wall sides, and it lies in a state of inelastic and large deformation due to non uniformity deformation of surrounding rock in the deep rock roadway. The mechanical behavior of convex steel-belt has the performance of obvious advantages. It can adapt to the large deformation of deep roadway due to the convex structure. This result has been proved in the engineering practice.
Time-Dependent Safety Performance Assessment of Highway Bridges Considering Mechanical Behavior of Corroded Steel Reinforcement Subject to Carbonation-Induced Corrosion
Authors: Peng Jian Xin , Zhang Jian Ren
Published: December 2012

A structural probabilistic resistance model was developed taking mechanical behavior of corroded reinforcing bars obtained from rapid corrosion specimens and real bridges and bonding performance between concrete and steels into accounts in this paper. Probabilistic model was used to capture randomness and variabilities of materials, geometrical size, corrosive process and corrosion ingredients. A time-dependent reliability model was used to predict probability of structural flexural failure incorporating existing dead load and live load model. It is found form results that probability of flexural failure for corrosive condition of highway bridges is about 18% higher than that predicted for no deterioration condition over next 100 years. It is from results indicated that an improvement in concrete durability specification such as increasing concrete cover and concrete strength can ameliorate the time dependent safety performance of highway bridges.
Wind Tunnel Investigations for the Free Standing Tower of the Penang Second Bridge
Authors: Luo Nan , Liang Ai Xia , Liao Hai Li , Yu Mei
Published: December 2012

The Penang Second Bridge is a new bridge under construction in Penang, Malaysia. The aerodynamic behavior of the bridge was one of the main concerns. This paper summarizes of the wind tunnel testing of the 1:40 scaled aeroelastic model testing for the free standing tower. The wind tunnel Investigations were carried out with the objective of verifying the detailed design of bridge towers through measurement of the buffeting response to turbulent wind, susceptibility to galloping instabilities and susceptibility to vortex shedding excitation in smooth oncoming flow.The test results show that explicit vortex-induced vibration was observed for the completed free standing tower, however it will not affect the safety of the tower, and the buffeting response of tower is within acceptable range under the designed wind speed.
Application of Fuzzy Analytic Hierarchy Process to Bridge State Comprehensive Assessment and its Improvement Using Intelligent Control Technology
Authors: Dai Cheng Yuan , Li Guang Hua , Li Heng
Published: December 2012

According to Ji-Shao Expressway ,based on the method of AHP, do the fuzzy evaluation and use Symbolic Math Toolbox based MATLAB established was grades assessment diagnostic model for the Intelligent Control Technology system, make rating of the damage status of each part with accumulative score method. Intelligent assessment method and the traditional AHP get Results are consistent，Show that soft computing based on Matlab modern engineering can be effectively applied to active duty bridges’ fuzzy evaluation. At the same time, it can provide reference and guidance for the general survey of other existing bridges.
Analysis of the Causes of the Formation of Crack in Inclined Web of Prestressed Concrete Continuous Girder Bridge in Cantilever Construction
Authors: Lu Li Hua , Tian Peng , Yu Tao
Published: December 2012

The crack in inclined web of the prestressed concrete continuous girder bridge which is constracted by the way of cast-in-place cantilever method that become one problem that should be more cared about[1-2]. This paper analysis the bridge in three different conditions which are according to the pratical and special engineering to find the causes of the formation of crack in inclined web of prestressed concrete continuous girder bridge in cantilever construction. The results of the analysis show that the additional stress caused by the different temperatures between internal and external components leads to the formation of the crack in inclined web of the bridge.
Dynamic Characteristics Analysis and Parametric Study of a Super-Long-Span Triple-Tower Suspension Bridge
Authors: Zhang Jia Wen , Guo Wen Hua , Xiang Chao Qun
Published: December 2012

Based on the Taizhou Yangtze River Bridge, a 3D finite element model is developed to establish its deformed equlibrium configuration due to dead loading. Strating from deformed configuration,a modal analysis is performed to provide the frequencies and mode shapes. The study focuses on the effects of the vertical, lateral and torsional stiffness of the steel box girder, the rigid central buckle and the elastic restraints connecting the towers and the steel box girder on the dynamic characteristics of the triple-tower suspension bridge. The results show that, variation of vertical, lateral and torsion stiffness of stiffening girders have effects on the vibration frequency in corresponding directions only and have little effects in other directions. The elastic restraints have a more significant effect on the dynamic characteristics than the central buckle, and decreasing the stiffness of the elastic restraints results in the appearance of a longitudinal floating vibration mode of the bridge. The results obtained could serve as a valuable numerical reference for analyzing and designing super-long-span tripletower suspension bridges.
Research on Precast Segment Assembling Bridge Technology in Short-Line Matching Method
Authors: Zhang Hong , Wang Min , Zhang Yong Tao
Published: December 2012

Targeted at key technological difficulties of pre-stressed concrete bridge with precast segment assembling in short-line matching method, combined with the as-built projects and those under construction, this essay introduces systematic segmental precast assembly externally prestressed concrete construction technology in short-line matching method, and the developed serial complete equipments set, thus realizing development trend of factory-orientation, large-scale, mechanization, standardization of modern bridge construction.
Research on Integral Lifting Continuous Steel Box Girder Bridge Construction Technology
Authors: Zhang Hong , Zhang Yong Tao , Zhu Hao , Gao Ji Bin
Published: December 2012

Due to over length and weight of the girder segment, the main bridge steel box girder of Chongqi Bridge adopts large segment integral lifting erection method; two sets of large floating cranes are needed for hoisting. According to the water environment condition at site, select the lifting equipments to research on; conduct restrict checking on the lifting weight, height and amplitude; new automatic balance type lifting sling structure form is adopted during lifting erection to make sure the stress on each lifting point is balanced; conduct optimization design onto the lifting points; aimed at lifting erection of large segments, use ansys to establish large solid simulation model for finite element analysis so as to guarantee safety of steel box girder structure during lifting erection of large segment.
Research on Technology of Porous Tube Grouting Reinforcement to the Subsidence of Semi-Filling and Semi-Excavating Subgrade in Shao-Huai Expressway
Authors: Zeng Sheng , Li Wen , Li Zhen Cun
Published: December 2012

In this paper, subsidence diseases of the semi-filling and semi-excavating subgrade in Shao-huai expressway are taken as an example. And the causes of disease of subgrade subsidence are analyzed. The pertinent scheme of grouting reinforcement is designed. According to the subgrade subsidence, the grouting technology of vertical and horizontal porous tube is proposed innovatively. The FWD means of non-destructive testing is used to evaluate the effect of grouting. The results of the evaluation show that the technology of grouting reinforcement by porous tube can achieve the good grouting effect and solve the treatment problem of subgrade subsidence effectively.
Proposition of Estimation Method for Repairing the Roughness in Expansion Joints of Expressway Bridges
Authors: Saiji Fukada , Takeya Matsumoto , Tadakazu Aiba , Hiroyuki Okada , Yoshiyuki Momiyama
Published: December 2012

When a truck passes on the expansion joint of an expressway bridge, the tire spring vibration of the truck is generated by short wavelength road roughness. Moreover, environmental vibration problems, such as infrasound and ground vibration, occur as a result of the impact force of the tire spring vibration. Then, IRI_10 analysis using a quarter car model was carried out using short wavelength road roughness in the expansion joints of Japanese expressways. This study proposed the IRI_10 value '7 mm/m' and an estimation method for repairing short wavelength road roughness.
Mechanical Property of Pavement with Crack in Base and High Modulus Asphalt Layer
Authors: Tu Shuai
Published: December 2012

When the crack appears in semi-rigid base layer, the stress mode of pavement structure transits from infinite continuum to limited size board, and the crack tips become stress concentration areas. This paper establishes the three-dimensional eight nodes entity reduced integral unit model by the practical tire contact pressure and contact area, to calculate and analyse the influence on the mechanical indexes in pavement structure with or without crack in base layer from high modulus asphalt layer under half-sinusoid load. Analysis shows that enhancing the modulus of surface layer could effectively reduce the tensile stress in bottom of base layer and avoid the bending broken in base bottom, but there exists risk that the bottom subbase and asphalt layer cracking.
A Method to Calculate Porosity of Loess Based SEM and its Application
Authors: Song Peng Ran , Wang Chang Ming
Published: December 2012

Research the structure changes before and after collapsible experiment of loess microstructure. Using artificial preparation methods prepared different moisture samples of Liaoxi loess. Do collapsible test and Scanning electron microscope test with the prepared samples. According to Digital Terrain Model theory, three-dimensional porosities were calculated based on gray scale information from the SEM images extracted by MATLAB. The results are shown following as: the microstructure of loess samples is getting dense, the average number of pore of samples obviously increases and the pore area decreases after the sample is collapsed. The distribution before and after the collapsibility of gray value has certain regularity. The before one has double peaks, large distribution. The after one has single peak, concentrate distribution and meets normal distribution.
Early Warning Technique for Rock Fall of Road in Mountainous Terrain
Authors: Su Tian Ming , Zhang Xiao Liang , Zhang Jin Quan
Published: December 2012

Aim at the difficulty of disaster early warning of rock fall of highway in mountain areas, a new idea, sound and light integrated disaster early warning technique for moving vehicles in mountain areas, was proposed. A new type of traffic sign was designed which can receive the monitoring data of dangerous rocks of road slope and make early warning in the way of sound and light when the rock fall is going to occur or is occurring, the structure and function of the new traffic sign was developed, and technical requirements and installation problems were also discussed.
Suitability Analysis of Ecological Restoration for Coastal Area under Transportation Construction
Authors: Ma Chun , Wang Ying , Zhang Xiao Chun , Zhang Guang Yu
Published: December 2012

Harbors or seaports are major hub of human economic activities, and also centers of environmental issues, which have environmental impacts on the estuary, tidal marshes and coastal wetlands. This paper analyzed the impact of transportation construction on coastal area, reviewed the ecological restoration techniques for habitat under transportation construction, proposed the procedure of suitability analysis of ecological restoration and established an evaluation criteria framework of ecological restoration suitability. The suitability framework which is set up by using Analytic Hierarchy Process (AHP) in this paper could be applied to analyze suitability for ecological restoration of transportation construction projects.
Liquefaction Survey and Case Analysis in Wenchuan Earthquake
Authors: Wang Wei Ming , Wang Yong Zhi , Sun Rui
Published: December 2012

Total 163 survey points distributed in 104 liquefied and non-liquefied sites were selected in the Wenchuan earthquake liquefaction database, where 50 survey points were from intensity VI region. Borehole data show that pure sandy layers could hardly be identified in Wenchuan earthquake affected areas, instead gravel soil layers mingled with sand silty or pebble prevalently exist. Songbai village which suffered severe liquefaction was chosen for case study in this paper. Through MASW and high density electrical method testing, three soil layers can be distinguished from the testing cross section. The discontinuity of resistivity of the first layer by the high density electrical method indicates the location of sand ejection. The grain size distribution curves of sand ejecta were different from drilling soil samples, which explanation need further investigation.
Response Analyses of High-Rise Steel Structure to Wave Passage Seismic Excitations
Authors: Liu Tie Lin , Wang Hui , Sun Yang Yang
Published: December 2012

The earthquake responses of short span structures are usually obtained by using uniform excitations. Wave passage effects are often artificially neglected for short span structures. In this paper, a high-rise steel residence structure of 18-story is adopted to study the earthquake responses of high-rise steel structures to wave passage excitations and uniform excitations by using the software Midas/GEN. Two groups of earthquake acceleration records are chosen respectively from sites of hard soil and soft soil. Comparisons of the shear forces and the bending moments under uniform excitations and wave passage excitations shown that wave passage effects shouldn’t be neglected in the earthquake response analyses even for short span structures.
The Mechanical Parameters of a Rock Slope Displacement Back Analysis Based on the Orthogonal Test Design
Authors: Qu Chun Lai , Jiang Ke , Xue Min , Zhang Zhao Cai
Published: December 2012

The mechanics parameters of a slope are difficult to determine accurately by conventional methods, because of weathering, fracture and excavation induced stress release. Based on the orthogonal test and three-dimensional numerical calculation to get the learning samples of displacement, By using the neural network method to obtain the relationship between the mechanical parameters and displacement, Combined with measurement results of deformation in the field mining, Obtained the reasonable strata parameters to provide the basis for slope treatment.
Analysis and Calculation of Seismic Performance for UHV Equipment of HGIS
Authors: Shi Ke Jian , Xu Bo Wen , Zhou Ling Hui , Lin Xin
Published: December 2012

In order to analyze and understand the seismic performance of UHV HGIS, and further improve it, the analysis of dynamic characteristics and seismic response spectra for 1100kV HGIS was carried out in four kinds of seismic waves, and then acquired structural frequencies and mode features. The situation that the natural frequency of UHV equipment and the main frequency of seismic wave were so similar that quasi resonance occurred was considered in the process of analysis. The calculation is conducted by the string of modulated wave that includes three sinusoidal-resonant waves and five sinusoidal-resonant modulated waves to analyze mechanical strength and seismic performance of integral structure. The results show that 1100kV HGIS under those seismic waves has certain safety margin, provide effective data for analysis of seismic performance of UHV equipment.
An Earthquake Fault Zone Discovered in the Three Gorges Reservoir Area
Authors: Li Yuan Jun
Published: December 2012

The Maluxiang – Changduhe at Badong County is a newly discovered seismic active fault zone in the Three Gorges Reservoir Area, and the occurrence of fault is EW / N ∠60 °-70 °. The fault appears as a deeply linear valley on the topography and the fault breccia bandwidth is up to 200m. The fault is densely distributed with many springs and covered by luxuriant forests. The new site of Badong County is set up on the top of fault zone, and exists a lot of active landslides. The tested data of the absolute age of the landslides slip zone soil indicates that the landslide is active since the late Pleistocene. The Three Gorges Reservoir has continued seismic activity since 2003, and the fault zone suffers the greatest damage which is the most direct evidence as an indication of fault activity. Therefore, research on the fault zone is very important and significant for immigrant settlement in the Three Gorges reservoir.
Time-History Analysis of Seismic Performance of Metro Station by Top-Down Boring with Cast-In Situ Arch
Authors: Ding De Yun , Wang Wei Feng , Huang Mei Qun , Yang Xiu Ren , Wu Zong Zhen
Published: December 2012

Taken the Dawanglu station of Beijing metro line 14 as engineering background, the seismic performance of metro station by top-down boring with cast-in-situ arch under rare earthquake action (E3) is researched. A three-dimensional dynamic model is established by using the finite element program MIDAS/GTS. Through the time-history analysis method, the displacement response of the main structure of metro station is obtained. The storey relative displacement and storey drift angle of the main structure are mainly analyzed. Numerical results show that under rare earthquake action, metro station structure can satisfy the requirements of the seismic performance, and can be regarded as a valuable reference for the design.
Seismic Performance Improvement of Precast Buildings Using Dissipative Friction Devices
Authors: Valente Marco
Published: December 2012

This study presents an innovative approach to enhance the seismic performance of precast structures. Friction devices were inserted at the beam-to-column connections with the aim of providing supplemental energy dissipation and structural drift control. A single-story industrial building and a multi-story frame were analyzed in this study to assess the effectiveness of the dissipative friction devices. A simplified model describing the hysteretic behaviour of the friction device was developed and parametric analyses were carried out in order to establish the optimum value of the plastic moment of the device for the different precast structures. The results of the numerical investigations showed that the installation of the friction devices caused a significant decrease of displacements at the top of the structures. The energy dissipation mostly concentrated in the devices and the plastic demand on structural members was considerably reduced, along with the potential for structural damage.
The Overall Measurement Detection of Existing Structure
Authors: Han Jian Qiang , Liu Yang , Dang Xi Bin
Published: December 2012

Measurement and identification of the existing structure or residential flats have the structure of the safety assessment of the correct structure has important reference value, the detection and results of this paper, the measurement of the actual project , given the project overall lateral , for the structure post- processing programs and strengthening measures provide an important design basis .
Research on Stress Migration and Evolution Law of Coal in Driving Face and Generation Mechanism of Acoustic Emission
Authors: Yang Hui Ming
Published: December 2012

By means of FLAC3D software, firstly 3-demensional model was built, and stress migration and evolution law of coal seam in the process of mine roadway excavation are studied. Then according to the stress evolution law, the mechanism of acoustic emission (AE) generation in coal after excavation was analyzed. The results show that: after excavation, due to lateral displacement constraints in the coal body near the free face is removed, the coal in this zone was in 2-dementional stress condition. Because the vertical stress exceeded the uniaxial strength of coal body, the coal got into the post-peak strain-softening state. With the evolution of time, the stress in the zone gradually reduced until a state of equilibrium. In this zone the principle of AE generation is that lateral stress reduction result in macro crack propagation, coal mass failure, then elastic wave emitted. Signals come from the zone, i.e. stress relief zone, is the main part of AE signals, and should be the focus of study in AE technology of predicting coal or rock dynamic disasters. In stress-peak zone, due to the constraints of the lateral displacement, the lateral stress and strength of coal increased, the vertical stress of coal body gradually increased until the strength peak in the 3-dimensional stress state. After the excavation of roadway, the stress in stress-concentration and stress-peak zone gradually increased to equilibrium state over time. The principle of AE generation in this region is that due to the increase of the vertical stress, coal and rock gradually damaged that resulted in the release of the elastic wave.
Analysis of the Remote Sensing Image Extraction of Building Height’s Method
Authors: Li Jia Liang , Su You Po
Published: December 2012

In this paper, based on high resolution remote sensing image and the corresponding civil areas of digital topographic map, by using modules and effective classification method of ENVI software and ARCGIS software, by calculating the shadow of one building to obtain the height of it in city. Practice has proved that this method brings small workload, owns simple process, and can basically meet the needs of a city’s reference requirements of relevant disaster preventions and mitigations planning. It has practical value.
Based on Three-Dimensional Modeling of Laser Scanning Technology in Antiquities
Authors: Liu Wen Long , Zhao Xiao Ping , Wang Xiao Long , Xu Bao Guo , Lv De Tao
Published: December 2012

This paper makes use of the three-dimensional laser scanning technology measurement speed and high precision which combines the advantage of the field control survey, coordinate system transformation, the point cloud data processing, establish the triangle nets, texture mapping etc process, get the space of ancient cultural relics data and texture, antiquities for 3D modeling provide real, real size, real texture digital model for reference.
Deformation Forecasting Using a Hybrid Time Series and Neural Network Model
Authors: Wang Qiang , Gao Ning , Jiao Wen Zhe , Wang Guan Jie
Published: December 2012

In order to improve the accuracy and reliability of prediction of deformation monitoring data, a hybrid modeling and forecasting approach based on autoregressive model( AR) and the back-propagation( BP) neural network is proposed to forecast the deformation. The results of experiments show that this method can forecast the deformation precisely, and it is more suitable for those occasions where the deformation monitoring data should meet the high demand.
The Low Strain Method to Pile Test and Detection Analysis of a Communication Complex Building
Authors: Chen Chang Liu , Zhu Yan Peng
Published: December 2012

The low strain method has the advantages of simple, fast detection is widely used in the pile testing. The low strain method was presented to pile test on the complex building engineering of China Mobile Group Gansu Co.,Ltd. The basic theory, tesing method of pile and judgment standard about the ultrasonic wave method are analyzed.
FTCR Quantitative Indicator for Measuring Highway Design Quality
Authors: Chang Andrew S. , Shih Jia Shen
Published: December 2012

Engineering design quality is very important for construction projects. Although many quality or performance management methods have been proposed, a simple quantitative indicator is lacking. This research proposes the First Time Correctness Ratio (FTCR) indicator to quantify the percentage of work correctly done the first time. A checklist consisting of major design activities was developed first by reference to design management theory, quality control process of a case consulting firm, and interviews with designers and owners. Then the ways of using the checklist to evaluate design quality and calculating the FTCR scores were discussed for different levels and time phases of a project. Finally four engineering design case projects were used to test the checklist applicability and derive FTCR scores. The results show that the FTCR method is a simple indicator to distinguish performances. In addition, the FTCR approach provides benefits for engineering design organizations to meet the ISO requirements.
The Security Mechanism for Wireless Sensor Networks
Authors: Gao Feng , Hu Zhi Hua
Published: December 2012

In recent years, with advances in microelectronics technology and wireless communication technology which promote the rapid development of low power, low price, multifunction sensor, and it also contributed to the development of wireless sensor networks. Wireless sensor network can be used in military, medical and commercial areas. This paper mainly described the characteristics of wireless sensor networks, security threats in the communication process and analyzed its security needs of taking security mechanisms to ensure the security of wireless communications.
Numerical Simulation for Water Conveyance of Inverted Siphon
Authors: Sun Xiao Pei , Wang Xiao Ling , Sun Rui Rui , Zhang Ai Li
Published: December 2012

The numerical simulation study for water conveyance of inverted siphon on water security is of great significance. Three-dimensional air-water two-phase flow turbulence model coupled with VOF（volume of fluild） method is proposed to simulate water transfer project of Luolingou inverted siphon in the east route of the South-to-North Water Transfer Projec.Moreover, mesh sensitivity and the distribution of air-water volume fraction is analyzed. The simulation results show that the flow capacity of inverted siphon with the increased flow rate 60m3/s is enough for the requirements, which gain the validation of the engineering structure reliability. The analysis of mesh sensitivity suggests that the fine grid model is identified reasonable and effective.
Analysis on Deformation Failure Mechanism of an Open-Pit Landslide
Authors: Zhang Fei , Cao Jing , Zhao Hui Min
Published: December 2012

Taken an open-pit landslide as an example, the cause of formation and the factors inducing the slope to failure are analyzed. According to deformation characteristic of the landslide, the deformation has been exacerbating with the deep mining in depth, and the deformation has close relationship with the rainfall. Rainwater infiltration, which soften the rock mass and induce the pore water pressure to increase, induce envoke landslides. Through analysis on the factors of landslides, the formation lithology(FL) and precipitation are main factors triggering generation and reactivation of landslides. Meanwhile, the deformation failure mechanism and instability mode of the landslide is obtained, which is the sliding and bending deformation model.
Experimental Research on Headwork Spillway Dam of Ecuador Coca Codo Sinclair Hydropower Station
Authors: Li Yuan Fa , Wu Cai Ping , Song Li Xuan , Ren Yan Fen
Published: December 2012

The discharge capacity, pressure and downstream dissipation for scour prevention under fluctuating pressure of the power station headwork spillway dam were measured and analyzed through model test. The research showed that the discharge capacity of the spillway dam met the design requirement, the designed body type of the spillway dam met the requirement of standards. The modified spillway basin body type and the downstream protection type could meet the requirement of dissipation for scour prevention. In the experiment, the mean square root, spectral characteristics and amplitude sampling of the spillway dam flow fluctuating pressure were measured and analyzed. The maximum fluctuating pressure mean root was about 4.31m water column, the dominant frequencies of flow fluctuating pressure at all measuring points ranged from 0.01 to 2Hz (prototype), and the random process of the flow fluctuating pressure conformed to probability normal distribution (Gaussian distribution) on the whole.
Highway Linear Drainage Design Concept and Analysis
Authors: Wang Da Wei , Chen Hua Liang
Published: December 2012

This article discuss the hydrological and hydraulic calculation of the highway drainage, analyzing the formation mechanism and status of the highway stagnant water, by the analyzing of the functionality and the cost of engineering of linear drainage system, Pointing out the advantages of linear drainage.
Study on Natural Vibration Characteristic of Spiral Casing Structure in Hydraulic Turbine Based on Acoustic-Structural Coupled Theory
Authors: Li Ze , Liang Zhi Lin , Zhang Li Xiang
Published: December 2012

Based on the strong interaction method that combines FEM with acoustic theory, the finite element dynamic equations of spiral casing structure are built, which provides the basis for analyzing self-olsillatin characteristics of spiral casing structure. The self-olsillatin characteristics of structure are calculated with the method. The natural vibration frequencies, and mode shapes are obtained.
Practice and Improvement of Agent Construction System in Hydraulic Engineering
Authors: Guo Yong Cheng , Li Jian Lin
Published: December 2012

This paper introduces development of the agent construction system in China and overview of the South-to-North Water Diversion Middle Route Project. The current practical application of three management modes of direct management，agent construction system(ACS) and commissioning system in the Beijing-Shijiazhuang section of the South-to-North Water Diversion Middle Route Project is analyzed, and some of the advantages of the ACS is pointed out. In the process of practice of the ACS, several existent key problems are discussed, such as the choice of the agent construction units, defective section division of the agent construction, unclear responsibilities, rights and obligations of the agent construction unit, the unreasonable agent construction cost and so on. Then,some constructive improvement measures are put forward , such as to improve the supervision and inspection mechanism, to issue the regulations and standard contract templates of agent construction, to establish incentive and punishment mechanism, to strengthen qualification management of the agent construction unit and to actively cultivate the project management company.Through exploration and analysis on the ACS of the concrete practice and applied research, a reference is provided for further promotion and application of the ACS in the hydraulic engineering in China and the direction of development is indicated.
Present Situation Analysis of Cathodic Protection of Natural Gas Pipelines in East Sichuan and Countermeasure Suggestions
Authors: Chen Yu , He Yun Bing
Published: December 2012

There are a large number of natural gas pipelines in East Sichuan. In order to prevent these natural gas pipelines from being corroded, they all use cathodic protection, but in terms of pipeline protection potential, the effect is unsatisfactory. Based on pipeline protection potential data collection, this paper carried out field investigation on anode beds, reference electrodes and management mode, analyzed the common problems of cathodic protection systems and put forward rectification suggestions.
Experiment on Performances of a Thermoelectric Cooler for Electronic Cooling
Authors: Zuo Zheng , Luo Qing Hai
Published: December 2012

An experimental model for electronic chip cooling was designed to investigate the cooling performances of an air-cooled thermoelectric cooler (TEC). The effect on the cold side temperature was experimented on the variation of heat emission intensity of TEC hot side and operating current. It was found that the mean temperature of the TEC cold side will decrease with enhanced the fan power, and the cooling performance would be better. The cold side temperature of TEC appeared a low valley with operating current variation. Optimizing the heat emission and the operating current properly is necessary to make the TEC work at perfect cooling performance.
Air Conditioning with Cold Radiation Technology Research and Analysis of Energy-Saving Comfort
Authors: Li Mao Ren
Published: December 2012

In recent years, the cold application of radiation technology air-conditioning system more and more, have achieved good operating results. this article discusses the radiation cooling and air conditioning system of the basic principles of design points, radiation cooling air conditioning system is proposed comparative analysis of market feasibility, proved the cold radiation from the air conditioning system to improve energy efficiency and comfort of the tremendous use of space. Hope to further promote the class and application of air conditioning to provide a useful reference.
Life Cycle Assessment of the District Heating Distribution System in China — Network Construction
Authors: Li Zhen , Wang Wei Wei , Sun Hong Ming
Published: December 2012

In China, the environmental impact from the construction of the distribution system is seldom discussed. In this study, the environmental impact from construction of district pipes is considered. The purpose is to identify environmental significant parts in the construction of district pipes and to use the results in the actual projects including once more parts of the district distribution system have been investigated with LCA methodology.(Methods) Construction of district pipe networks according to the technical specification was studied. The total consumption of energy and materials was calculated based on budget norm for projects. The functional unit used in the study is construction of 100 metres of pipe system. The studied pipes are: pipe of the dimension DN100, DN200 (Seamless steel tubes) and DN500 (spirally welded steel tubes) .Urban environment surroundings were studied. A short description of the inventory, some inventory results and a life cycle impact assessment are presented. Based on the concept of the End-point damage weighting method, the total environment load is given.
Study on Disaster-Related Epidemic Prevention after Serious Earthquakes
Authors: Chu Jian Yu
Published: December 2012

The disaster-related epidemic is the secondary disaster after serious earthquake. By comparing the epidemic situations and prevention work in Tangshan and Wenchuan earthquakes, this paper summarized the successful factors and deficiencies. Some countermeasures are proposed for disaster epidemic prevention, such as integration of the epidemic prevention system, perfection of disease prevention standard, establishment of hygienic evaluation system, planning of material reservation and development of epidemic prevention equipment.
Study on the Height of Transmissive Fractured Zone Based on the ANFIS
Authors: Wang Yun Gang , Zhang Li
Published: December 2012

Adaptive Neuro-Fuzzy Inference System has the merits of high convergence speed, potentially better generalization capability, high prediction accuracy and definiteness of the training results, and it has been applied to inverse design of slopes and surface displacement due to coal extraction. By training and checkout the collected 19 examples of mining under water body, the optimum ANFIS modeling was established. ANFIS-based approach for the forecast of the height of transmissive fractured belt are applied to the extraction the No.Ⅲ ore body at Kangjiawan Zinc-Lead Mine successfully, some important conclusions are of great significance to the factual issues. All the experiences may be of greatly beneficial reference for the similar projects since then.
Mechanism and Flame Behavior of Small-Scale Oil Tank Boilover
Authors: Yang Da Wei , Zhang Pei Hong , Chen Bao Zhi
Published: December 2012

Boilover is acknowledged as one of the most harmful fire in oil tank fire. A small-scale oil tank boilover apparatus was established to study the flame behavior during boilover process. Visualization experiments were also conducted to discuss the mechanism of boilover formation. The results indicate that boilover process can be divided into three stages: quasi steady combustion stage, boilover premonitory stage and boilover stage. The formation of boilover results from the reciprocity of bubbles and oil vacuoles generated by absorbing energy released from combustion reaction.