bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Simulation and Analysis for the Working Process of Working-Roll of Carder
Authors: Yang Bao Guo
Published: March 2013

The three-dimensional models of the Working-roll of Carder are founded by three-dimensional design software Solidworks and the working process of Working-rolls is simulated by finite element analysis software Cosmos, which obtain overall stress distribution for the Working-roll of Carder. The relations between the working-rolls with different thickness and different length of work roll axis and the stress, strain and radial displacement in the working process of working-rolls are attained by finite element analysis and the important factors of impact of work roll deformation are indicated by analog simulation. The results show that the maximum stress and maximum strain are occur in the place of roller connected with the axis rather than to appear in the middle part of roller and the radial displacement in the working process of working-rolls and the length of work roll axis are not directly relationship. The Finite element analysis results provide an important theoretical basis to design a reasonable the length of axis and the thickness of roller for the working-roll of carder.
Magnetic Test Method Used to Identify Plastic Deformation of Ferromagnetic Material
Authors: Yu Feng Yun , Zhang J.C.
Published: March 2013

Metal magnetic memory testing (MMMT) technique is a kind of new NDT technique. It is interested by NDT area in recent years for its own advantages: early diagnosis, preventing sudden fatigue failure of equipments and the testing samples do not need to be magnetized. In order to find out the variation law of the residual magnetic strength of ferromagnetic material processed by different cutting method, axial tension tests about milling and flat surface grinding samples are completed in elastic and plastic deformation phase. The experimental results indicate that the magnetic strength variation law of two kinds of sample makes a great difference in the same deformation phase. The magnetic strength and standard deviation variation law of the grinding and milling samples are almost reverse. But there is a common ground of the two samples that when the material reaches yield phase, turning point occurs on both the residual magnetic strength and standard deviation curve. So we can identify whether there is plastic deformation according to the residual magnetic strength variation law of ferromagnetic material.
Study on Rational Position of Joint Section of Steel-Concrete Hybrid Girder Bridge
Authors: Qin Feng Jiang , Di Jin , Dai Jie , Lu Wen Ru , Zhao Min
Published: March 2013

Taking Wei River Bridge with span combination of 69m+7×90m for example, the method of determining the steel-concrete joint section for variable cross-section steel-concrete hybrid continuous box girder bridge were investigated by finite element and parameter sensitivity analysis. The results show that it was an effective method for hybrid girder highway beam bridge from the view of mechanical property that the bending moment under dead load combination was employed as the main parameters, considering the negative bending moment in the pier top and the amplitude of bending moment in the joint section under live load. But based on reasonable structure stress conditions, the length of steel box girder that the host material of the bridge was concrete could determined by economy principle.
Temperature Effect Analysis of the Twin Towers Concrete Cable-Stayed Bridge for Construction Control
Authors: Wang Gui Zhen , Li Ying Min
Published: March 2013

It exists a great influence on deformation and internal force of large span bridge when temperature changes, the influence of the temperature must be considered and try to avoid in the process of construction control. Under monitoring to the construction process of Tieluoping super-large bridge on the scene, the influence law on internal force of Tieluoping Bridge is analyzed considering temperature effect, and the influence considering the sunshine temperature difference on cable tower deviation and stress is obtained, and the size of influence of main girder elevation, cable force and strain because of temperature field and distribution rule internal temperature field are clear. It provides powerful help for the smooth construction.
Research on Stability of Slope by Influence of a Rapid Drawdown of Water Table
Authors: Li Zhi Guang , Chai Lin Lin , Li Chun Bao , Xu Yun He
Published: March 2013

The importance of analysis of stability of slope during rapid drawdown of water table is firstly introduced in this paper. Through summary of the current theoretical and model test research on stability of slope during rapid drawdown of water table, the important of considering the matric suction in unsaturated soils, the analysis method of transient unsaturated seepage and safety of slope and the changes of slope safety was summarized and introduced in this paper. In addition, the problems existing in the analysis of stability of slope during rapid drawdown of water table are pointed out and some ideas for its further development are suggested.
On the Principle of “One Line, One Colour”, the Design of “One Station, One Scene” of Stockholm Subway
Authors: Hu Zhao Hui , Tang Jian , Tang Hao'an
Published: March 2013

This essay analyses the design of Stockholm Metro in Sweden, focusing on its planning and design of public art. Under special cultural background, Stockholm Metro has its own comprehension of public art and design. The design has successfully solved problems by giving vivid guidance to passengers in several ways: the use of colour decoration in stations, personalized designs of spaces and the changes of passengers’ sensory focuses, which are valuable to improve the management and the transportation quality of Metro in China.
Simulation Analysis on Deep Foundation Pit Construction Near the History Style Construction
Authors: Liu Chun Yuan , Cao Wei Wei , Liu Yu
Published: March 2013

Based on the impact of deep foundation pit excavation to the adjacent history style construction, FLAC3D was adopted to establish the excavation and supporting calculation model of a pit in Tianjin. The excavation deformation was analyzed, and the contact slip effect of the supporting structure and soil was considered. The results of study are as follows. (1) The pit has been dig to the third layer, and the values calculated are consistent with the monitored ones by comparing simulation values and measured results on B1 section. (2) Digging to the bottom of the pit, we can predict the biggest horizontal displacement of soil is 34.6 mm, and the value is 11.2mm in the history style construction. Therefore, the results of the study can play a guiding role in the engineering construction safety.
Simulation on THM Coupling Process of Deep Rock Roadway with Aquifer in Coalmine
Authors: Yang Jian Guo , Chen Li Chuan , Liao Hong Liang , Yang Fan
Published: March 2013

THM coupling is an important process in engineering rock mass. In order to study the mechanism of THM coupling in surrounding rock of deep rock roadway in coalmine, the interactions between THM fields were analyzed, and the governing equations of THM coupling were given. Finally, a model of rock roadway with aquifer is simulated, and the distribution of pore pressure as well as the thermal and stress fields were obtained after some steps of calculation.
Research on Arching Mechanism of the Lane Arching under Pre-Stress Bolt Supporting
Authors: Zhao Yu Cheng , Zhang Jian Ying , Xiang Zhi Quan
Published: March 2013

Supporting by pre-stress bolt is a kind of active support. It was widely used to support the Coal lane. To improve the stability of surrounding rock through choosing reasonable row spacing and geometric parameters of the bolt in the process of supporting was always a hotspot that exited important engineering significance. In this paper using the software ANSYS to analysis the additional stress field of surrounding rock under the action of the single and multiple pre-stress bolt, Gain the mechanical mechanism of that it will form a stress arch in surrounding rock if supporting lane by bolt, and the arch structure can make good use of the capacity of the surrounding rock to stable itself, thus we can get the purpose of stabling lane.
Simulation of Coal Mechanical Characteristics with Discrete Element Method
Authors: Liu Song Yong , Jiang Hong Xiang , Gao Kui Dong
Published: March 2013

Base on the parallel-bond model in PFC2D(Particle Flow Code in two Dimension) used to describe the contact between coal micro-particles, DEM(Discrete Element Method) model of coal has been established, so that the coal uniaxial compression test could be investigated. By comparing the simulation result and experimental result, it is clear that DEM is suitable to simulate the mechanical characteristics and failure mode of coal. The effects of micro-parameters on the constitutive behaviors of coal simulation sample are discussed, they can provide basis for designing DEM model of other analogous coals with differenet mechanical characteristics. The microparameters of coal DEM model obtained in simulation test could be a guilding role for further developing the applicability of the DEM in coal mining, crushing and some other aspects.
Study on New Treatment Technology of Subgrade Longitudinal Crack in Qinghai-Tibet Highway
Authors: Li Ming , Zhi Xi Lan , Tian Le , Ren Shao Bo
Published: March 2013

Longitudinal crack is one of the main subgrade diseases of qinghai-tibet highway and has large scale.While the existing treatment technology cannot completely solve the problem,especially cannot limit crack propagation,so the driving safety and road life will have huge influenced by the disease.In order to solve this problem,a new solution technology that the flexible beam combined with tenon type geomembrane bag is proposed in this paper.Through field implement,this new method which can effectively reduce and prevent crack diseases is verified.
Fracture Performance of Asphalt Mixture with Styrene Butadiene Styrene Based on the J-Integral
Authors: Li Ping , Pei Jun Jun , Yao Yu , Sun Guo Wei
Published: March 2013

Crack of asphalt pavement is one of the major destruction in pavement engineering. The bending test of small beam at low-temperature is often applied to evaluate the resisting crack for asphalt mixture. In this paper, based on J-integral theory in elastic-plastic fracture mechanics, performance of resisting crack of asphalt mixtures is analyzed in cases of different temperatures and contents of Styrene Butadiene Styrene (SBS) by bending tests of small beam. It is shown that the optimal condition for anti-cracking of asphalt mixtures is SBS contents of 4.2%~5.0% at 10°C using flexural tensile strain and stiffness modulus and the highest flexural tensile strengths of mixture occur at 0°C. Ductile fracture toughness of mixture with SBS modifier may be more sensitive to temperature from -10°C to 0°C and may be more useful to analysis elastic-plastic formation energy and energy releasing rate of asphalt mixture.
Mountain Road Multi-Level Retaining Wall Horizontal Earth Pressure Law
Authors: Wang Yong Wei , Li Hong Xia , Guo Yan Qin
Published: March 2013

Combining with a mountain highway retaining wall earth pressure measured data, carried out a detailed study of the of multiple retaining wall back soil pressure distribution law, based on multi-level retaining wall measured horizontal earth pressure data mountainous retaining wallshorizontal earth pressure formula is derived, summed up the horizontal earth pressure with filling height variation.
Numerical Simulation Study on Self-Settlement Process of High Embankment
Authors: Zhang Yan , Wang Yong
Published: March 2013

This paper uses the FLAC software to simulate self-settlement of high embankment. Analysis and discussion on the simulation results are performed. The final results indicate that the self-settlement of high embankment can't be ignored, the maximum settlement within the embankment occurs at about （1/3～1/2）embankment height. This conclusion has a reference value for guiding the actual construction.
Optimization Design and Research on Gradation of ATB-25
Authors: Huang Xing , Yuan Ling , Wei Ru Ming , Li Xiao Qing
Published: March 2013

The ATB-25 mixture is optimized design base on the Bailey method. The skeleton embeded crowded structure of ATB-25 is better than that of AC-25 through analyzing the Bailey parameters, and the value of high temperature stability is 17.5% higher than that of AC-25, their water resistance are similar. The ATB-25 mixture is more suitable as pavement base materials. The proposed gradations belong to embedded crowed-solid structure which is verified by the calculated Bailey parameters, and the high temperature stability and water stability can be ensured. Combining with the highway pavement engineering project of Qujiang to Nanxiong, It is researched on the design of the mix proportion for asphalt treated base ATB-25 in the paper, and the suitable gradation design scheme is put out for the design and construction of highway pavement in high temperature and heavy duty area. The high temperature stability and water stability of ATB-25 which is designed based on the Bailey method can meet the requirements, and pavement performance can meet the design requirements.
Study on Calculation Method of Reinforced Embankment Bearing Capacity Based on Landslide Equilibrium Method
Authors: Liu Wen Xian
Published: March 2013

Foundation treatment is necessary when the construction is built on soft ground; Reinforcing is superior to many other methods when embankment is built on soft ground. This paper adopts slide block balance analysis of the composite foundation bearing capacity consisting of the horizontal reinforced and discrete material pile, while considering the level friction resistance from the reinforcement and ground on the foundation bearing capacity influence. and it is applied to practical engineering. The results show that the method is feasible.
Three-Dimensional Finite Element Analysis of Dynamic Response of the Stress in Pavement Structure under Overload
Authors: Wang Bao Shi , Liu Jun Qing , Pang Peng Fei
Published: March 2013

In recent years, the phenomenon of vehicle overload in highway transportation is more and more serious. The three-dimensional dynamic FEM was adopted and a three-dimensional simulative model for asphalt pavement with subgrade based on cross-anisotropy under moving load was established by the large-scale finite element analysis software ABAQUS. The response of the stress in the pavement structure was got by using ABAQUS/Standard code. During deceleration, The simulation analysis results under the rated load were compared with those under the different overload ratio. The results show that, under moving load, the surface course of pavement is mainly in three dimension compressive stress state. The horizontal load caused by deceleration has a remarkable effect on the longitudinal stress and the horizontal shearing stress. The stress of the pavement structure under overload is much greater than that caused by the rated load. And the greater the overload ratio, the greater the deviation between them.
Experimental Study of High Temperature Properties and Rheological Behavior of Iranian Rock Asphalt
Authors: Huang Wen Tong , Xu Guo Yuan
Published: March 2013

To evaluate the high temperature properties and rheological behavior of Iranian Rock Asphalt(IRA), convectional test and temperature scanning test over modified asphalt containing A-70 asphalt as base asphalt and IRA as different amount were conducted. The results show 1) an increase in asphalt binder’s capability of deformation resistance under high temperature, decreases both in asphalt binder’s temperature sensitivity and low-temperature performance; 2)an increase in anti-rutting factor, a decrease on loss tangent value, an improvement of dynamic viscosity. Thus the asphalt binder’s high temperature performance is greatly improved and anti-rutting capability strengthened.
Study on Survey of Bituminous Pavement Rut Distress and Patching Material Performance
Authors: Li Jun Wei
Published: March 2013

At present, distresses of national bituminous pavement are mainly rut and crack. Occurrence of these two distresses seriously affects usability and service life of bituminous pavement. The author studied the severity and causes of pavement’s rut distress and crack distress combining with investigation of a highway. Corresponding treatment measures were also proposed aiming at pavement distress characteristics. Determined fiber patching material had good effect on the improvement of bituminous mixture high temperature stability through indoor test and entity paving of pavement, and gave priority to it as pavement patching material.
Test and Analysis of Basalt Fiber Reinforced Concrete’s Mechanical Properties and Pavement Performance
Authors: Ma Song Lin , Peng Bo , Huang Zhi
Published: March 2013

For the research on the application of basalt fiber reinforced concrete in highway engineering, indoor experiments were carried out to study the preparation technology of basalt fiber reinforced concrete specimen. The best preparation technology has been got from the analysis of the test results. Scanning electron microscopy (SEM), combining existing fiber reinforced concrete reinforcement theories were used to analyze the enhancement mechanism. According to analysis on the pavement performance indexes of basalt fiber reinforced concrete, it is proved that basalt fiber can significantly improve the flexural strength of cement concrete, especially for early strength. Basalt fiber reinforced concrete has an advantage in improving the construction efficiency, rapidly opening traffic and increasing social economic benefits when used for the rapid repair and construction of the pavement.
Study on Reasonable Length of Ballasted-CRTS II Ballastless Track Transition Section on High-Speed Railway Bridge
Authors: Liu Yu , Zhao Guo Tang
Published: March 2013

In view of ballasted-CRTSⅡ ballastless track transition section on the bridge of Beijing-Shanghai high-speed railway, the influence of track random irregularity and pier foundation settlement difference on acceleration and stability index of locomotive body are discussed by the finite element method. And then, by using the index of rail deflection gradient to describe the law of dynamic interaction, rail-wheel dynamic response, attenuation distance of locomotive body acceleration and change of sleeper pressure caused by under-rail stiffness difference are analyzed. Finally, the recommended value of reasonable length of transition section is put forwarded.
FEM Analysis and Parameters Determination of Lightweight Concrete Multiple Shear Rivet Paving Project on Steel Box Girder Bridge Deck
Authors: Fu Jun , Han Lu , Ding Qing Jun , Wang Fa Zhou
Published: March 2013

The mechanical response of lightweight concrete multiple shear rivet pavement on the steel box girder bridge deck under wheel loading are analyzed by finite element method. Besides, the effects of various distance、diameter、height of shear rivet to pavement, are researched as well as the effects of thickness of lightweight concrete. Then some recommended parameters are put forward for the paving project.
Analysis of Vibration Frequency Characteristic for Elastic Support Beam
Authors: Li Zhi Zhong , Tang De Gao , Li Wei Wei
Published: March 2013

The dynamics model was established for the simple elastic support Beam structure and derived the natural frequency equations of simple elastic support beam. Then some special frequency equations for certain supporting conditions have been analysis via the above equation. The results show that vertical elastic support constraint and torsional elastic constraint have more influence to the natural frequency of beam.
Research for Bridge Optimal Seismic Retrofitting Strategies
Authors: He Peng , Ge Sheng Lin , Zhai Min Gang
Published: March 2013

Two different retrofitting concepts, including anti-seismic (pier strengthening) and seismic isolation (replacing with isolation bearing) were applied to bridge seismic strengthening. Influence factors of post-retrofitting performance in bridge were determined by the following parameters: pier stiffness and isolation bearing stiffness. By finite element analysis of controlling one parameter, the post-retrofitting performance was evaluated and compared with respect to the strategy with another variable parameter and vice versa. Meanwhile, comparative analysis was concerned by economic factors: bridge importance, labor cost, material cost and transportation, construction period, etc. Quantified parameter and the “performance/cost” which was a popular index in engineering economy were applied to find the best point (it was an optimal retrofitting strategy point). It also served as a project case of using this methodology to testify the rationality and provided a practical reference for expert and scholar in the field of bridge seismic retrofit.
Study on Engineering Site Seismic Effect in Shijiazhuang
Authors: Chen Ji Hua , Yang Ya Hui , Wang Wei
Published: March 2013

Along with the rapid development of city, the research on seismic effect of the sites is gradually recognized. In this paper earthquake effects of several engineering sites selected from Shijiazhuang are studied, using the one-dimensional linear program and considering different seismic wave and peak acceleration. Through analyzing the characteristics of the seismic effects certain rule are summarized, and it can be taken as a reference for site seismic effects and seismic safety evaluation of this local area.
Recovering Seismic Displacements from Underground Strong-Motion Acceleration Records of the 2011 MW9.0 Tohoku Earthquake in Japan
Authors: Li Heng , Zheng Shui Ming , Song Chen , Feng Qian
Published: March 2013

The borehole strong-motion (SM) records from the 2011 MW9.0 Tohoku earthquake are analyzed, and we find ground tilt is the main error source of the SM records. The assumption is made that the time in when ground tilt fluctuates tempestuously (transient tilt) can be determined by the vertical velocity time-series. Then, we propose a two-step algorithm to correct these errors, which involves fitting a straight line to the tail portion of velocity for permanent tilt and average error processing of the transient tilt and noises caused by it. The transient tilt is unknown, but its final influence can be estimated as the velocity at the time when strong shaking ceased. The horizontal accelerograms are corrected and the displacements are obtained by double integration. Comparing with the GPS data, seismic displacements can be recovered by the corrected underground SM acceleration records.
Study on the Methods of Layer Adjustment in Gas Dynamic Reserve Measurement
Authors: Zhang Yi , Liu Bang Hua , Gan Qing Min , Shi Hai Xia , Liu Jun Feng
Published: March 2013

To get the accurate gas pool dynamic measurement is the one of the basic work of oil field development. The geologic conditions, one of the aspects, limited the gas pool. It often appears reshooting another layer to commingled production or block off the seriously water producer in layer adjustment, calculation of reserves depends on the alteration of the model condition. Through the material balance and its further work, set the gas pool reserves calculation methods under the layer adjustment condition. The closed constant volume gas pool, its drawdown curve becomes the transition with the adjustment of the layer. Through the original formation pressure with two different slope straight lines before and after adjustment, Using linear extrapolation can get the reserves before and after adjusted.
Seismic Performance Investigation of Research Status and Problems Analysis of Short-Leg Shear Wall
Authors: Zhang Pin Le
Published: March 2013

Short-leg shear wall is a new type of structure form, which is widely used and developed in our country for its reasonable architectural function, mechanical performance and engineering cost. The work further investigates the seismic performance of three kinds of short-leg shear wall. Classified and brief comments about the seismic performance and the exist drawback of the three kinds of shear wall and its application are conducted. Lastly, some useful suggestions and a new structure: Steel reinforced concrete short-leg shear wall with concealed bracing are proposed for the further research.
Seismic Response Analysis of CFRP Retrofitted Reinforced Concrete Structures
Authors: Jin Bo , Zu De Feng , Wu Han Sheng , Gao Yongwu
Published: March 2013

The use of carbon reinforced polymer (CFRP) to provide lateral confinement for enhanced ductility and strength of reinforced concrete structures has been increasing. The present study, attempts to analytically investigate the effect of the layout of frame columns retrofitted with different layers of CFRP on the seismic performance and damage potential of structures under strong ground motion using realistic and efficient computational models. Based on the shaking table tests of several reinforced concrete (RC) flat slab beamless construction models, the seismic performance of structures strengthened with CFRP composites are investigated. The dynamic response of CFRP retrofitted structures and the components of the model, validation of the model, force-displacement relationship, relative displacement and the time history curves are studied. Then the rational effect of different CFRP layers is found.
Study on Performance-Based Seismic Performance Method for Masonry-Infilled Frame Structures
Authors: Wang Qiu Wei , Shi Qing Xuan , Han Zhao Hui
Published: March 2013

Combining with performance grades of reinforced concrete structures at home and abroad, the seismic performance of masonry-infilled frame structures can be induced into five levels: basically normal, slight damage, medium damage, severe damage and collapse prevention. The limit states of all seismic performance levels and their dominating parameters of masonry-infilled frame structures are put forward, and quantified performance index of this structure are obtained on the basis of statistical test data. The seismic response of pure and masonry-infilled frame structures are compared by using capacity spectrum method and equivalent strut model, and the result indicates that the structure could meet predetermined performance objective under the minor and major earthquake levels by comparing the practical story drift and proposed performance index.
Experimental Study on Seismic Behavior of Strengthening Joints in Light Steel Adding Storey
Authors: Guo Rong , Zhao Shao Wei , Liu Kun
Published: March 2013

In order to acquire the seismic performance of three different types of nodes between the concrete frame and the light steel adding storey, the pseudo-static tests were carried out to analyse contrastively these specimens’ failure modes, stiffness degradation, hysteretic curves and energy dissipation. The test results showed that : Three nodes’ destruction were due to the plastic hinges emerging at the end of beam; both encased steel and carbon fiber strengthening method can improve the seismic behavior, and in terms of the ultimate bearing capacity, energy consumption ability，the encased steel strengthening one can improved more significantly, and the encased steel one can effectively slow down the speed of stiffness degradation.
Shaking Table Test on Seismic Pounding Response of Reinforced Concrete Bridge
Authors: Yan Xiao Yu , Wang Li Hui , Du Xiu Li
Published: March 2013

To investigate the response of the bridge pounding, shaking table test was performed using 1/10 scaled reinforced concrete rigid frame bridge specimen. The influence of traveling effect on pounding and the anti-impact capability using dampers were discussed. The experimental results demonstrate that the acceleration responses of the girder and bridge piers, the frequency and the impact force are increased when the traveling wave excitation is considered. Moreover, relatively displacement of the adjacent bridge frames increased magnitudely. Dynamic responses, the frequency and the impact force are decrease when the dampers are installed.Therefore, installation of the dampers is a sustainable and effective way to improve the anti-impact capability.
Coupled Damage and Plasticity Modeling in Failure Analysis of Heated Concrete
Authors: Li Rong Tao
Published: March 2013

A coupled elastoplastic-damage constitutive model with consideration of chemo-induced material elastoplastic-damage effects due to heating concrete is proposed. A consistent return mapping algorithm for the integration of the rate coupled constitutive equations is developed. Consistent tangent modulus matrices for coupled chemo-thermo-hygro-mechanical analysis are derived to preserve the quadratic rate of convergence of the global Newton iterative procedure. Numerical results demonstrate the validity of the presented algorithm and illustrate the performance of the proposed constitutive model in reproducing coupled chemo-thermo-hygro-mechanical behavior in concretes subjected to fire.
Numerical Simulation of Ground Shock Produced by Chemical Explosion in Closed Soil
Authors: Nian Xin Zhe , Yan Dong Jin
Published: March 2013

Empirical formula can be used to get ground shock parameters produced by conventional weapons buried in soil medium. With the development of finite element technology, ground shock parameters can be obtained by numerical simulation. However, sometimes the numerical simulation results were not consistent with the empirical formula results. A two-dimensional axial symmetry model and a three-dimensional model were set up to calculate the ground shock from a fully buried spherical charge, numerical results and empirical formula results were compared and the causes of the calculation error were analyzed.
Numerical Simulation of Shock Wave Around-Flow in Explosion Test
Authors: Zhu Xin Ming , Zhan Hao , Jiang Zhi Gang
Published: March 2013

Numerical simulations for tests of thin metal plate against explosion were performed by using models with and without taking into account shock wave around-flow. The results show that the center deflections of plates from numerical simulations are in good agreement with those from experiments, and that the shock wave around-flow can reach the back surface of plate during the shock wave acting on the front surface of plate and interact with the plate response. It is found that the shock wave around-flow has significant effect on the plate response when the scale distance and the size of the plate are small.
DQM to Simulate 3D Vortex Structure of Cuboid Cavity Driven Flow
Authors: He Shi Hua , Zhang Li Xiang , Xu Tian Mao
Published: March 2013

The vortex structure of lid-driven flow in a cuboid cavity with one or a pair of moving lids is numerated using the differential quadrature method (DQM). According to the characteristics of cavity driven flow, the dimensionless governing equations and its boundary conditions used to describe the flow are established. Based on a non-staggered grid technology, the polynomial-based DQM is combined with the SIMPLE strategy to solve three-dimensional (3D) cavity driven flow. The suitable boundary condition for pressure correction equation on a non-staggered system is implemented and the continuity equation on the boundary is enforced to be satisfied. The 3D vortex structure distributions in a cuboid cavity are obtained for different Reynolds numbers and different driving modes. The analysis shows that the DQM is very suitable for the simulation of 3D vortex structure in a cavity.
Simulation of Dust Control in Coal Mining
Authors: Yang Xiu Dong , Jin Long Zhe
Published: March 2013

Many different dust control measures have been used to reduce or control the generation of dust during mining operations. As respirable dust control is affected by the overall airflow pattern, a CFD model of the face area could be created to estimate the impact of these factors on airflow in the face area. a steady state CFD model of the airflow developed in the paper with typical field configuration of the line curtain, including leakage along the roof and floor, and with the scrubber idle. This should provide insight for further possible steps for improving dust control.
The Application of Bounded Normal Distribution in Statistics of Concrete Strength
Authors: Yan Xu , Zuo Yong Zhi , Lu Qiao Zhi , Huo Da , Liu Ming
Published: March 2013

23,037 values of concrete compressive strength from construction sites were obtained from Beijing Building Construction Research Institute from 2009-2012 by standard cubes testing method. The mean values, standard deviations, coefficients of variations, maxima and minima were derived from the original strength values analyzed and compared with the data in 1989. The results make up for the lack in C25/C30 and the maxima/minima of every strength class of concrete of the former data. Both the coefficients of variations and mean values have increased in recent years. The log-normal distribution commonly used in concrete compressive strength statistics is not that suitable for strength modeling for it is unbounded. So a bounded normal distribution was given in this paper. By Geary's test, the goodness-of-fit of bounded normal distribution is better than log-normal distribution has been proved.
An Improved Test Method for the Detection on Alkali-Silica Reactivity of Aggregate
Authors: Wang Jing , Li Gu Hua , Zhang Jun Peng , Zhou Jun Jie , Sun Feng Ming , Peng Xian Xiao
Published: March 2013

Test the alkali-silica reactivity of slate aggregate in Guizhou using mortar-bar method in JTG E42-2005of China and accelerated mortar-bar method in TB/T2922.5-2002 of China. The results show that the six months expansion is 0.11% with mortar-bar method, the aggregate has low alkali activity. The 14-days expansion exceeds 0.30% with accelerated mortar-bar method, according to the TB10005-2010, the aggregate has high alkali reactivity. Obviously, the accelerated mortar-bar method is safer than the mortar-bar method, but the test parameters and test conditions of accelerated mortar-bar method have some differences with the aggregate physical environments. According to the accelerated mortar bar method, the thesis proposes an improved test method for evaluating the alkali-silica reactivity of slate aggregate.
Applying Study on the Bayer Red Mud as Fast Building Dam Materials
Authors: Luo Dong Lan
Published: March 2013

In China, the soaring red mud needs outdoor place for stockpiling. The traditional building method of tailing dam is often construction dam only once, which needs the biggish piling up yard or quantities of dam. The construction-dam technology of “three-dimensional seepage drainage stack” was proposed, combining stereoscopic drainage discharging separated water and rainwater, geogrid reinforcement minishing fissured development and enhancing dam stability, and air dry in turn. Using bayer red mud to build dam quickly comes true. The experiment of the method was carried on and makes some conclusions through testing strength indexes: after depositing bayer red mud 4~5m heights continuously, and the ten-days air-curing drying, red-mud strength indices have been improved greatly and it can be used to damming. The way of “three-dimensional seepage drainage stack” makes good use of waste materials，reduces the yard space, saves the red mud rolling or compaction equipment, economizes the constructed cost of the dam. The process provides some references in the field of the bayer red mud as quick damming material in the practice.
Development and Construction Techniques of Foreign PC Continuous Beam
Authors: Huang De Yu
Published: March 2013

In construction of medium span, small span and commonly long span bridges, the prestressed concrete continuous beams are playing an important role and the vistas of development of the bridges is vast. The design , construction and new material application remain to be further improved, through great achievements has been made in China in the construction of the PC continuous beam bridges, the global techniques of the bridges in the country in the recent several decades. Through the study of prestressed concrete continuous beam bridge construction technology development trend and research, understand the international bridge of advanced design concepts and construction technology of foreign engineering project bidding, formulates the reasonable construction plan, strengthen the domestic enterprises to expand overseas bridge construction market competitive force, and provide useful reference.
Effect of Composition of Cementitious Materials on Alkalinity of Pore Solution and Strength of Cement Paste
Authors: Yuan Xiao Lu , Zhou Shi Hua , Liu Dong Mei
Published: March 2013

Alkalinity of the surroundings is the basis to study the MICP technology. Alkalinity of pore solution and strength of cement paste made of various cementitious materials were studied. Results show that the alkalinity of pore solution of cement paste decreased with the increase of sulpho-aluminate cement content. pH value of cement paste was about less than 10 when sulpho-aluminate cement content exceeded 75%. Incorporation of sulpho-aluminate cement decreased compressive strength of paste obviously; however, compressive strength of paste was improved when the addition of sulpho-aluminate cement was more than 75%. Addition of mineral admixtures reduced the alkalinity of pore solution of cement paste and increased its compressive strength. Compressive strength of specimens was decreased when the content of mineral admixtures increased.
In Situ Synthesis of Nylon 6/MgAl Layered Double Hydroxide (LDH) Nanocomposites by Hydrolyzed Ring Opening Polymerization
Authors: Li Hong Lin , Yang Gui Sheng , Wu Yu Cheng
Published: March 2013

Nylon 6/MgAl-LDH nanocomposites had been successfully prepared by In situ hydrolyzed ring opening polymerization in this work. The structures and properties of Nylon 6/MgAl-LDH nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The nanodispersion of exfoliated MgAl-LDH layers in nylon 6 matrix has been verified by the observation of TEM image in Nylon 6/MgAl-LDH nanocomposites with 0.3 wt% MgAl-LDH (MANM-0.3). The XRD results showed that the exfoliated MgAl-LDH favored the formation of the γ-crystalline of nylon 6 form. DSC data showed that the exfoliated MgAl-LDH layers play the role of nucleating agents with strong heterogeneous nucleation effect on the crystallization of nylon 6. But TAG results showed the thermal stability of nylon 6/MgAl-LDH nanocomposites were worse than that of neat nylon 6.
Research on the Strength of High-Strength Steel Slag Concrete with Skeleton Coarse Aggregate Gradation
Authors: Zhuang Yi Zhou , Tian Er Bu , Lian Yue Zong
Published: March 2013

Generally the high density in high-strength concrete results in high strength, and so people often mix superplasticizer and particulate to increase the density of concrete, but ignoring the effect of coarse aggregate gradation on concrete strength. Referring to several Gradation Theories, this paper selects the coarse aggregate gradation with skeleton, uses uniform design method to test the compressive strength of high-strength concrete, and analyses the test results. It can be known from the test results of 7d and 28d concrete specimen that the concrete strength decreases linearly with water-cement ratio and sand ratio; The 7d’s concrete strength has higher variability due to low water-cement ratio with superplasticizer; The coarse aggregate skeleton is interfered by the increase of steel slag and sand rate, and the concrete strength decreases with limited cement paste. Furthermore, the steel slag with less than 30% addition has little effect on concrete strength and it can increase the cement’s possibility of contacting to water, and reduce the amount of cement without lowering the concrete strength. The influential degree on the compressive strength of concrete is followed by ascending sequence of steel slag content, sand ratio and water-cement.
The Carbonized Life of Fiber Reinforced Concrete Nuclear Waste Storage Containers
Authors: Zhang Lu , Zhao Wen , Li Yi , Guan Yong Ping
Published: March 2013

The hybrid fiber reinforced concrete containers for keeping nuclear waste (NWSC) were made by the concrete which mixed polypropylene fibers (0.9kg/m3) and 20mm basalt fiber (2.5kg/m3). The carbonation depth model was established by analyzing carbonation depth of ordinary concrete and hybrid fiber reinforced concrete that through the accelerated carbonization testing. And then two kinds of different concrete NWSC carbonation life were predict according to the similarity theory. The results show that the carbonation life of hybrid fiber reinforced concrete NWSC is 67％ higher than ordinary concrete ones, The addition of fiber can improve the resistance ability of concrete. The hybrid fiber reinforced concrete storage container can meet the requirements of the service life-300a when the thickness of the protective layer is more than 32mm.
Test Machinery System of the Pressure Water Absorption Inside the Lightweight Aggregate Concrete
Authors: Wang Gui Ling , Ma Ming Lei , Miao Dong Mei , Ma Hong Juan
Published: March 2013

Concrete is a composite construction material composed primarily of aggregate, cement, and water. While different formulations provided varied properties. Some times engineering structure need to expand its span length, the commonly thinking is how to decrease the dead load by no harming the structure capacity. The lightweight aggregate concrete focus on the light weight of the aggregate and it can be obtained by using nature stone or artificial stones. The application can decrease the weight by lowering the structure body with 20%-30% total weight. This article proposed an accuracy test machinery system for the lightweight aggregate concrete to determine the water absorption behavior while in pumping pressure.
Hydraulic Method for Earthwork Excavation Construction Technology
Authors: Yu Gai Hua , Chen Jia , Liu Ying Nan , Li Qiao Yan
Published: March 2013

Hydraulic method for earthwork excavation construction technology has a strong advantage in small environmental pollution, low cost, simple process, energy saving. It follows the idea of a harmonious society and the sustainable development, in line with the energy saving and emission reduction policy that the state promoted and also saving cost. This paper put emphasis on the theory of hydraulic method for earth excavation construction technology, construction process and key operation points, and the problems frequently encountered in construction and countermeasures. Combining with the project in Xinxiang new plain area in Henan province, which is about taking advantage of Yellow River to develop agriculture, the paper illustrates the economic benefit and social benefit of this construction technology.
Research on the Construction Technology of Composite Floor of Super High-Rise Core Tube Copestone and Steel Composite Wide-Flat Beam of Hollow Steel Tube and its Application
Authors: Bai Rong , Yao Chuan Qin , Bai Xue , Wang Chao
Published: March 2013

Based on the F2-4 project in Zhujiang New Town of Guangzhou, this paper studies the construction scheme, process principle, technology requirement, etc, of super high-rise core tube copestone and the composite floor of steel composite wide-flat beam of hollow steel tube in order to guarantee the advanced technology, reasonable economy, good quality and excellent performance of the construction scheme. This research could lay a good foundation for the construction of the similar projects in the future.
Optimization Design and Application of Sluice Pier Sliding Formwork
Authors: Xing Jun , Cai Hong Liang , Cheng Jian Bing
Published: March 2013

The sliding formwork, combining high efficiency and low cost, is a kind of advanced technology in the construction of sluice pier of hydropower projects. Number of jacks and elevating shelf spacing are two important parameters in the structure design of sliding formwork, the mathematical model of the relationship between manufacture costs and jack number, spacing between the elevating shelf was established using polynomial least square method, the best value of jack number and spacing between the elevating shelf were calculated by using the simulated annealing algorithm, thereby optimized the design parameters of sliding formwork structure, whilst expatiated the technology of installing, debugging, sliding and disassembly of sliding formwork, put forward the feasible methods for solving the problems that often appeared in the construction of sliding formwork, summed up the merits of sliding formwork, analyzed the technology and economical benefit of sliding formwork
Exploration for Maintenance Measures and Temperature Control of Mass Concrete Pile Caps
Authors: Yu Chen Ming , Qu Jun Tong , Ran Zhi Hong , Ying Hao , Meng Fan Tao
Published: March 2013

Distress in mass concrete is a problem in highway and bridge engineering. These mass concrete structures craze not by external loads, the temperature variation caused by heat of hydration and the temperature stress caused by concrete shrinkage are the main causes () for the leaks [1]. Therefore, the thermal stress and the temperature control have significant meaning in the mass concrete structures. Thermal cracks will break the structure globality and also decrease the durability of the structures during the construction time. In addition, the temperature variation will have a remarkable affection on the stresses variation of the structures during the service time [2]. This paper will discuss the temperature monitoring and the crack control projects of the mass concrete based on the cushion cap of an extradosed cable-stayed bridge which is being constructed.
The Application of the Crack Control Measures Applied in Ultra-Long Basement Concrete Structure
Authors: Liu Lin , Tong Xian Hao , Liu Ming
Published: March 2013

In this study, whether the ultra-long basement structure that have been designed and constructed in recent years generate harmful cracks or not was investigated. The crack prevention technologies applied in the ultra-long basement concrete structure of 62 constructed projects in Shenyang city, China was analyzed. The results show that the harmful cracks in ultra-long basement concrete structure can be avoided by taking effective measures such as: strengthening the reinforcement of structure weakness , setting post-pouring belt of concrete construction , expansion reinforcing band, and using anti-cracking waterproof agent etc. Thereby, the hidden danger in structure is eliminated, and the safety of structure is ensured.
Research on Data Correlation in Structural Health Monitoring System
Authors: Li Qiang , Xiao Chun , Li Wei , Li Li Qiao , Liu Hui
Published: March 2013

In structural health monitoring system, data analysis is one of the most important parts. It is mainly for processing and analysis of the collected data, among of which, the correlation analysis of the collected data can be used to verify the feasibility of the system. This paper applies the method of wavelet de-noising analysis to reduce signal noise and utilizes MATLAB and LabVIEW to calculate the cross-correlation coefficient in simulation statistics independently. To verify the feasibility of correlation analysis method and the data processing, simulation study is finished based on sampled data, which are the information of measuring points of strain and temperature from the Baishazhou Bridge. The cross-correlation coefficients between various signals can provide the reference to the whole health status of the civil engineering structure, and then enhance the accuracy of structural health assessment.
Stress Monitor and Control in Cantilever Construction of a Continuous Bridge
Authors: Zhao Jia Mei , Zhang Jin Yu , Wang Yu Liang
Published: March 2013

Stress monitor and control in Cantilever Construction of a big span bridge is introduced. Influences of load state, temperature and humidity are eliminated through structure testing and parameter identification during construction. The errors between measured data and design values are analyzed to ensure construction to agree with the design.