bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbonation Experimental Study on Thermal Insulation Glazed Hollow Bead Concrete
Authors: Guo Yan Jia , Li Zhu , Liu Yuan Zhen , Qin Shang Song
Published: March 2013

Based on the compressive strength, the thermal conductivity, the elastic modulus and the steel bond strength of thermal insulation glazed hollow bead concrete, referring to the carbonation mechanism and the influence factors of the ordinary concrete, considering the impact of raw materials and the influence of construction technology, the study on thermal insulation glazed hollow bead concrete anti-carbonation was proposed. From the test results, it can conclude that for the same intensity level, the anti-carbonation capacity of the thermal insulation glazed hollow bead concrete is better than that of the ordinary concrete. For different strength grade of thermal insulation glazed hollow bead concrete, to some extend, the higher the intensity level is, the stronger the ability of thermal insulation glazed hollow bead concrete anti-carbonation is.
Research on the Relationship between Clay Content in Aggregate and Water Stability of Rubber Asphalt Mixture
Authors: Xie Zhao Bin
Published: March 2013

In order to verify the characterization degree of water stability, research selects some clay content aggregate retrieved from road engineering field to produce rubber asphalt mixture and carry out the water stability test. Test results show that clay content in aggregate has a significant influence on the water stability of rubber asphalt mixture. When the content of clay in aggregate less than 1%, the influence on water stability is smaller; when the clay content exceeds 2%, the decay rate on water stability performance and long term properties obviously speed up, resulted in serious water damage.
Study on the Pavement Performance of Multi-Modified Asphalt in Steel Deck
Authors: Liu Ke Fei , Jiang Kang
Published: March 2013

Based on the deficiency of high temperature stability among early damages for steel deck pavement, a new material of multi-modified asphalt had been developed, its performances and mixture have been tested. The tests such as the rutting tests, low temperature bend tests and fatigue tests had been done. The results sindicated this multi-modified asphalt had the lower temperature susceptibility and the better ability to resist the shear deformation. Every performance of its mixture had been improved especially its high temperature stability, and its economic benefits are considerable, it is suitable for the steel bridge pavement.
Autogenous Volume Deformation and Creep Properties Analysis of C60 High Performance Concrete and C60 High Strength Concrete
Authors: Chen Xiao Bo , Yin Jian , Song Wei Min
Published: March 2013

Based on engineering practice, autogenous volume deformation and creep properties of C60 high performance concrete(C60 HPC) and C60 high strength concrete(C60 HSC) were evaluated in the study. The results showed that the cement partly-replaced with fly ash could significantly decrease the creep deformation, creep coefficient and creep degree. In comparison with C60 HSC, the creep coefficient and creep degree of C60 HPC were decreased 17.9％and15.8％ in 28 days, 22.9% and 21.0% in 270 days. For C60 HPC and C60 HSC at the same age, autogenous volume deformation of C60 HPC is greater than that of C60 HSC, but they were both less than 80×10-6 , and the autogenous volume deformation was basically completed in 7 days.
Application of Fractal Theory on the Cement Stabilized Recycled Course Aggregate Base Material
Authors: Yin Jian , Chi Yi , Song Wei Min
Published: March 2013

This paper studied different size-distribution of recycled coarse aggregates by fractal theory. Cement Stabilized Recycled Aggregate Mixture were prepared by different fractal rate aggregate gradations and the unconfined compressive strength at 7 d and 28 d of the materials were tested. The results showed that the unconfined compressive strength at 7 d and 28 d of the materials with recycled coarse aggregate were higher than the one with natural aggregate when coarse aggregate gradations were same. The higher source rock strength of recycled coarse aggregate was, the larger base material strength was. Generally, the increase of fractal dimension is conducive to the growth of strength. The base materials performances of the same fractal dimension were different when the max particle size was different. So the fractal dimension of recycled coarse aggregate must be determined by maximum particle size.
Influence of Mineral Additions on the Anti-Cracking Performance of Recycled Aggregate Concrete
Authors: Yin Jian , Song Wei Min , Wang De Hui , Zou Wei
Published: March 2013

The effect of fly ash (FA) and slag (SG) on the anti-cracking performance of recycled aggregate concrete (RAC) is discussed, taking the toughness index as the concrete anti-cracking performance evaluation index, and the mechanism of action is researched at the meantime. The experimental results show that the strength of RAC is reduced when containing fly ash only or slag only, but the crack-resistance of RAC is improved significantly at 3 days and 28 days of hydration process of RAC. Furthermore, the 28 days anti-cracking performance of RCA improved significantly with 30% FA single-doped or 20% SG single-doped .It can improve the 28 days anti-cracking performance of RAC, by using double-mixture of fly ash and slag, there is an optimal FA/SG ratio and a best total content, the FA/SG ratio is 3:1 and the total content is 30%.
Study on Preparation of High Early Strength Recycled Aggregate Concrete
Authors: Yin Jian , Song Wei Min , Chi Yi , Zou Wei
Published: March 2013

An orthogonal experimental design method was adopted for the mix design of high early strength recycled aggregate concrete (HSRAC), and the influence of water-binder ratio, percentage of recycled aggregate(RA）and highly active compound mineral admixture (HACMA) content on the strength of the concrete was discussed. The test results indicated that water-binder ratio was the most principal and significant influencing factor on the strength of HSRAC, regardless of age. An empirical relationship among the strength of HSRAC, the water-binder ratio, the percentage of recycled aggregate and HACMA content was proposed by using multivariate regression analysis. The demand of opening heavy or heavier traffics and rapid repair concrete on strength to HSRAC could be all met.
Effect of Interface Bond Condition on Airport Double-Layer Pavement Overlay’s Load Stress and Deflection
Authors: Weng Xing Zhong , Yan Xiang Cheng , Liu Wen Lu , Liang Lei , Li Xin Qiang
Published: March 2013

In order to study the influence of interface bond condition between new and old cement concrete pavement on overlay performance, the three-dimensional finite element model of the airport double-layer pavement was established. The pavement overlay's load stress and deflection were analyzed, the coupling coefficient between new and old cement concrete pavement was calculated based on the bottom of overlay deflection basin shape factor. The results show that the coupling coefficient reflects the degrees of interface bond condition well. Poor interface bond condition increases the overlay's load stress and deflection. The points that more closely distance from the wheels load center, the bigger the pavement overlay's load stress and deflection is. Therefore, more attention should be paid to the interface bond condition during the airport pavement overlay's designs and constructions.
Study on Critical Speed of Freight Train Derailment on Bridges
Authors: Zhou Zhi Hui , Liu Guo , Qian Zhi Dong , Wen Ying , Zeng Qing Yuan
Published: March 2013

The mechanism of train derailment was demonstrated to be the loss of lateral vibration stability of train-bridge (track) system. Based on the theory of energy increment analysis for system movement stability, the energy increment criterion for derailment evaluation and the method of analyzing critical speed of train derailment Vcr were presented. The critical speed of empty freight train on Laoluanhe bridge, Huanghe bridge and Youshui bridge were calculated as 65.2 km/h，64.8 km/h and 66.5 km/h respectively, which were close to actual derailment speed. It is manifested that the method of analyzing critical speed of train derailment is reasonable. According to the calculated results of the critical speed on bridges with different lateral rigidity, it is testified that the critical speed of train derailment rises with the bridge lateral rigidity strengthened. The measure to prevent derailment on bridge is to ensure enough bridge lateral rigidity to meet the running safety of train.
Numerical Simulation of Wind Pressure Distribution on Regular Mega-Frame Surface
Authors: Xiong Yao
Published: March 2013

One of the critical loads in engineering design is wind load, especially for high-rise structure or multi-story structure. In order to forecast the distribution of wind effects on structure, how to accurately predict the building surface wind pressure distribution is very important. Using the wind tunnel model test and numerical simulation calculation methods, the surface wind load on the mega-frame structure were comparatively analyzed and researched in this paper. The results show that combined the realized к-ε model with the standard wall function will not only satisfy the mega-frame structure surface wind pressure value requirement, but also provide complete wind filed around, which could provide meaningful information for further research on wind load.
Numerical Prediction of Wind Flow over Sinusoidal Hills Using Multigrid Method
Authors: Jiang Guang Biao
Published: March 2013

The finite volume method and multigrid method are presented to solve Navier-Stokes equations. MG method is introduced in this work and applied on solving the discrete systems of the governing equations. For turbulent flow, the standard k-ε model is adopted. The non-orthogonal collocated grid systems are generated. The numerical prediction were done for the flow over sinusoidal hills. The numerical results were obtained from the simulations of flow over three types of sinusoidal hills. Comparisons have been made between experimental data and the computational data and agree with each other.
Adaptive Negative Stiffness: A New Structural Modification Approach for Seismic Protection
Authors: Nagarajaiah Satish , Pasala Dharma T.R. , Reinhorn Andrei , Constantinou Michael , Sirilis Apostolos A. , Taylor Douglas
Published: March 2013

Yielding can be emulated in a structural system by adding an adaptive “negative stiffness device” (NSD) and shifting the “yielding” away from the main structural system-leading to the new idea of “apparent weakening” that occurs ensuring structural stability at all displacement amplitudes. This is achieved through an adaptive negative stiffness system (ANSS), a combination of NSD and a viscous damper. By engaging the NSD at an appropriate displacement (apparent yield displacement that is well below the actual yield displacement of the structural system) the composite structure-device assembly behaves like a yielding structure. The combined NSD-structure system presented in this study has a re-centering mechanism thereby avoids permanent deformation in the composite structure-device assembly unless, the main structure itself yields. Essentially, a yielding-structure is “mimicked” without any, or with minimal permanent deformation or yielding in the main structure. As a result, the main structural system suffers less accelerations, less displacements and less base shear, while the ANSS “absorbs” them. This paper presents comprehensive details on development and study of the ANSS/NSD. Through numerical simulations, the effectiveness and the superior performance of the ANSS/NSD as compared to a structural system with supplemental passive dampers is presented. A companion paper presents the NSD and its mechanics in detail.
A Direct Solving Method for the Minimun Height of Rectangle Extended Foundation under Column that Meets the Punching Requirement
Authors: Huang Tai Hua , Zhou Xian Yan , Tan Ping
Published: March 2013

To meet the punching requirement of rectangle extended foundation under column, it is common practice to assume foundation’s height first, and then use the formula to check according to the current code. If the foundation’s height is not suitable, set it again to check until a suitable value. It is found that the minimum height of rectangle extended foundation under column can be solved directly, and all larger than the minimum height can meet the punching requirement through analysis program taking MATLAB as a platform for everyone to use.
Vertical Loading Test on the Bearing Capacity of Large-Diameter Filling-Piles in the Mudstone and Sandstone Foundation
Authors: Yang Hui , Jiang Xue Liang , Fu Jun
Published: March 2013

Based on the vertical loading test results of large-diameter filling pile near an electric factory in the sandstone and mudstone foundation, the load transfer mechanism and vertical loading bearing behavior of the pile were discussed. The analysis shows that the pile mainly behaves as friction piles and the vertical bearing capacity is mainly supplied by side friction resistance. The pile side friction is related to the section displacement of pile, the pile load and the soil characteristic. The pile end resistence is related to pile end settlement, pile diameter, rock-socketed length,rock elasticity modulus of pile end, sediment thickness and pile construction technical. The pile end resistence linearly increases with the settlement of pile end. In tis paper, the dead-load test is recommended in determination the pile bearing capacity and the sediment thickness should be strictly controlled in order to meet the standard. In the intermediary weathered sand-mudstone, the pile end should inset two times of pile diameter for pile whose diameter is 800mm. The pile end should inset 2 meters for pile whose diameter is 1500mm.
Research on Deformation Control of Anchor Bolt Supporting Red Clay Deep Foundation Pit
Authors: Deng Yong Liang , Li Qi Ming , Lu Ying
Published: March 2013

In order to study the deformation characteristics of red clay deep foundation pit, the horizontal displacement of lateral wall and the subsidence of surrounding surface were analysed in the step-by-step excavation of red clay deep foundation pit in the construction process. Using finite element software and D-P model, the numerical simulation of a deep foundation project was done. On this basis of differentiated models, the deformation characteristics of different support schemes were further analysed. This study indicates that the spacing of anchor bolt affects the deformation most, followed by the length of anchor bolt and pre-stress. The result shows that selecting a rational scheme for design and construction according to special conditions is important, which can not only guarantee the foundation pit safety, but also save the engineering cost．
The Application of Principal Component Analysis in Zone Subway Structural Performance Assessment
Authors: Yang Hai Ping
Published: March 2013

The PCA (principal component analysis method) of statistical mathematics theory is used to establish the evaluating model of zone subway structural form. Aiming at the complexity, ambiguity and lack of reasonable evaluating methods of the subway structural performance, the model selected the leading indicator which affecting the structures of subways and having the aid of using Matlab mathematical tools to evaluate comprehensively the functional and structural performance of them. The analysis showed that it’s feasible to use PCA to evaluate the zone subway structural performance, which can objectively reflect the strength of the evaluation index’s influence on the comprehensive evaluation value and it has some practical value and referential significance.
Research on the Pile Side Friction of Composite Foundation with Long-Short-Piles under High-Rise Building
Authors: Yu Rong , Ge Xin Sheng
Published: March 2013

It is used as an example that the composite foundation with long-short-piles is used in liquefied soil under a high-rise building .By using the finite element method, the effects of short pile replacement ratio, long pile replacement ratio, raft thickness on side friction of the pile are discussed respectively. The results show that: Short pile replacement ratio changes have an effect on side friction of the long pile from 4m to 15m. With long pile replacement ratio increasing, negative friction and positive friction of the long pile decreases gradually. With the raft thickness increasing, negative friction and positive friction of the long pile decreases gradually. Otherwise, the distance of side friction of the long pile comes up to zero increase gradually. These conclusions are provided as references for future optimum design.
Dynamic Response of Multiple Holes in Half Space Saturated Soil to the Effect of the P Waves
Authors: Liu You Ping
Published: March 2013

According to the Biot wave theory and the complex function combined with multi coordinate method, seismic wave dynamic response of underground holes in the half space saturated soil is studied. Given P wave on two circular holes of the dynamic stress concentration factor of the numerical results, the distribution situations of the dynamic stress concentration factors are discussed with the variation of the hole spacing, incidence angle and the dimensionless wave number. The results show that, the effect of the underground hole spacing to the interaction effects of the holes is obvious. When the hole spacing reaches up to 6 times the radius of the hole, the peak value of the dynamic stress concentration factor decreases obviously, and the peripheral distribution of offset is weakened. With increasing of the incident angle, the hole peripheral stress concentration coefficient showed the trend of first increasing then decreasing, distribution also occurs at certain angle deflection. In low frequency waves, the hole stress peak value will influence mutually more, while in the high frequency input, interaction between holes will reduce.
The Consolidation State of Red Clay Determined by Cone Penetration Test
Authors: Li Zhen Yu , Tian Qing Qing , Xiao Hong Bin
Published: March 2013

It is of significance to determinate the consolidation state of soil for evaluation of deformation and strength of foundation soil. The consolidation state of red clay is determined through laboratory experiments combined with static cone penetration tests. The results show that the law of consolidation history of red clay is opposite to other soils. The static point resistance obtained from cone penetration test decreases linearly with soil depth increasing. The over-consolidate rate of different soil layer gotten by laboratory experiments also decreases linearly with soil depth increasing. The slopes of two linear regress curves are similar. The change of static point resistance can be used to estimate over-consolidate rate of red clay at different depth.
Identification of Creep Model and Parameters Inverse Analysis for Nanning Expansive Soils
Authors: Xiao Hong Bin , He Cong , Li Zhen Yu , Xiao Guo
Published: March 2013

A series of loading - unloading consolidation creep experiments had been carried out on Nanning unsaturated expansive soils. Lots of loading - unloading creep curves under different stress levels were obtained. Through the various stages of creep deformation analyzed, it was concluded that the creep deformation of expansive soil contained elastic deformation, viscoelastic deformation and plastic deformation of components. Then model components in constitutive model of expansive soils were discussed. The rheological model of the seven components was proposed, which can describe unsaturated expansive soil elastic - viscous - plastic behavior. According to the experimental datum, all parameters of this model under different stresses were determined by the inverse analysis method. It is showed that the values of numerical calculated using this model agree well with those obtained by the creep tests. The conclusions provide a reliable theoretical basis for the rheological model of expansive soils to further study.
Hybrid Simulations: Theory, Applications, and Future Directions
Authors: Mosalam Khalid M. , Günay Selim
Published: March 2013

Hybrid simulation is a testing method for examining the seismic response of structures using a hybrid model comprised of both physical and numerical substructures. Because of the unique feature of the method to combine physical testing with numerical simulations, it provides an opportunity to investigate the seismic response of structures in an efficient and economically feasible manner. It is this feature of the method which made it gain widespread use in recent years. This paper presents the theory of the method including an overview of the previous research related to various aspects of the method, an overview of two hybrid simulation applications, and the future directions for transforming the method to its next generation.
Modeling of the Cyclic Behavior of Loose Sand by an Elasto-Plastic Fuzzy Set Model
Authors: Chen Cheng , Kong Li Wei , Wang Quan Qing , Liu Zhong
Published: March 2013

The paper focuses on the development of a cyclic plasticity model based on the fuzzy set theory, which is implemented as a computational tool in order to simplify the computer programming of the constitutive driver. The constitutive model is a rate independent elasto-plastic model which is capable of describing repeated load cycles, dilatancy, material memory, and critical state soil mechanics features. Also, with the aid of membership function, the validity of the constitutive model is enhanced by comparing the theoretical output with a set of experimental data obtained from a variety of cyclic triaxial tests of loose sand.
Layout and Hydraulics Model Experiments of Filling and Emptying System of Shiplock Structure with Chamber Wall’s Long Culvert and Short Side Orifice Outlet
Authors: Zou Kai Ming , Yang Xi'an , Li Jun
Published: March 2013

The safety and efficency of operation of shiplock ralate closely to the filling and emptying system,so its related hydraulics will become the research focus of the current navigation hydraulics.According to requirement of the general layout codes and relevant design provisions of filling and emptying system,the hydraulic characteristics of the filling and emptying system with chamber wall’s long culvert and short side orifice outlet，is carried out by generalized numerical model and overall physical mode.The results showed that the hydraulic property of the structure can meet the requirements of the standard,and the research is also very important to ensure the safe operation,the reseach method can make reference for similar project.
Experimental Studies on Glue-Laminated Bamboo Trusses
Authors: Chen Guo , Xiao Yan , Shan Bo
Published: March 2013

Prefabricated light-frame bamboo trusses are widely used in light-frame construction as the main vertical load-carrying elements in roof and floor systems because of their long-span capabilities, ease of use, versatile configuration, rapid installation, and competitive cost. This paper presents experimental studies on glue-laminated bamboo trusses. Six full-scale model trusses with two types of configuration and sizes were tested to failure under gradually increased vertical load. The failure of the model trusses was caused by lateral buckling of the top chords. Tests show that the modern glue-laminated bamboo trusses have adequate stiffness and strength.
Study on the Performance of Full-Length Pre-Stressed Anchor Bolts
Authors: Wang Da Sai , Liu Ai Qing
Published: March 2013

In order to reveal the the performance of full-length pre-stressed anchor bolts, and research the rock pressure behavior law, a combination method of FLAC3D and situ tests were presented, the conclusions were drawn as following: the prestress of full-length pre-stressed anchor bolt was approximately uniform distribution along the slow anchoring section of the rod, while in the fast anchoringthe segment showed a negative exponential or linear form of attenuation, and the bolt axial load was biggest in the neutral point; the neutral point of full-length pre-stressed anchor bolt move to deeper of the drill hole with the reduction of rock strength, while neutral point shifting deeper would accelerate the destruction of the anchorage zone in deep rock formations, deteriorating the anchoring effect. the methods of pre-grouting and grouting bolt (or cable)should be taken to improve the anchoring force.
The In-Plane Buckling of Elastic Support Circular Arches Considering the Geometrical Imperfections
Authors: Yi Zhuang Peng , Wang Lian Hua , Tu Guang Ya
Published: March 2013

The equilibrium equations of elastic support circular arches considering geometrical imperfections are deduced from variation principle. And the relations between external load, radial displacement and axial forces are determined; also the equilibrium conditions of snap-through buckling and bifurcation buckling in circular arch are ascertained respectively. Further, influences of geometrical imperfections and elastic supports on in-plane stability are analysis with analytical and finite element (FE) method. And the compared results display that the two methods coincide with each other very well for smaller opening angle in circular arches. The geometrical imperfections have only certain effects on the buckling path, while the elastic support rigidity play a significant role in both the path and critical load of snap-through buckling.
Dynamic Characteristics Research of Structure with Nonlinear TMD System
Authors: Chen Zi Li , You Xiao Liang , Chen Chang Ping , Ma Ao Ling
Published: March 2013

The dynamic control equations are derived for the mechanical model with two degrees of freedom that the soften spring is considered in the dynamic vibration absorber. In order to facilitate the computation to the equations, through the integral of the dynamic control equations which became a four order ordinary differential equation. The amplitude frequency response curves of the primary structure excited by a harmonic force were drawn with harmonic balance method, the influence of the dynamic characteristics of primary structure about this kind of nonlinear dynamic vibration absorber was discussed.
Earthquake Response and Design of Energy Dissipation for a 22 Story Apartment Building
Authors: Lv C.C. , He W.F. , Guo Yan , Liu W.G.
Published: March 2013

Vibration control of a 22 story RC frame-shear wall apartment building with large aspect ratio was studied in this paper. Three vibration control plan with mild steel dampers, viscous dampers and viscoelastic dampers were proposed to control structural dynamic responses under earthquake. The dynamic responses of the structure with the proposed control schemes under earthquake excitations were investigated and their vibration control effects were compared. The numerical analysis results show that structural dynamic responses under earthquake excitations can be decreased effectively using the proposed plan. The earthquake response with viscous dampers was smaller than that with mild steel dampers and viscoelastic dampers. The shear force, drift and the acceleration of the structure with viscous dampers were 20%-40% less than the structure without any dampers for the slender structure.
Probabilistic Characteristics of the Ductility Indices of Compression-Bending Reinforced Concrete Columns
Authors: Zou Zhong Quan , Teng Jun
Published: March 2013

The probabilistic characteristics of the seismic performance indices for the compression-bending reinforced concrete columns were studied, which is important for the Performance-Based Seismic Design (PBSD) and seismic performance evaluation of civil engineering structures. First, five damage states with four limit states were defined for the seismic performance level of ductile reinforced concrete components, along with the strain limit definition for each limit state. Then, based on the mechanical behavior and statistical characteristics of reinforcement and concrete, the deformation characteristics of circular reinforced concrete ductile component were analyzed probabilistically for each performance level. Hereby the probabilistic distribution characteristics of the performance indices for each performance level were obtained, and the regression formula as well as its probability distribution model for the performance index of each performance level was proposed, which can be used in the probabilistic analysis of seismic performance of civil engineering structures.
Seismic Response and Hysteric Performance Analysis in Different Base Isolated Structures
Authors: Yuan Ying , Zhou Ai Hong , Gao Yan Li
Published: March 2013

Firstly, the motion equation for parallel composite isolation system was formulated. Then, taking system with seven degree of freedoms for an illustrative example, the nonlinear dynamic responses of ordinary aseismic system, isolation system with friction sliding bearings, isolation system with laminated rubber bearings and parallel composite isolation system with the above combined bearings were calculated. Finally, the seismic responses of the above four structures were compared and discussed comprehensively and systematically, and the hysteretic performance of isolated floor was investigated. The results show that the isolation effect of isolated systems compared with the ordinary aseismic system is very notable and the hysteretic energy dissipation performance of isolated structures is excellent.
Applied Research on Dynamic Replacement Method in Tailings Residue Subgrade Reinforcement
Authors: He Jiao Long , Zhou Yong , Jiang Zhong Ai
Published: March 2013

Based on the reinforcing mechanism of dynamic replacement method ,this article put forward the construction parameters and measures of dynamic replacement method , combining with the result of actual engineering field testing experiment. The field load test, standard penetration test and pore water pressure test results show that the characteristic value of subgrade bearing capacity is more than 130 kpa when the tailings residue subgrade has been managed with dynamic replacement method, providing references for applied research on dynamic replacement method in tailings residue subgrade reinforcement.
Deformation Effect of Buried Pipeline in Shield Tunneling Crossing Thick and Hard Rock
Authors: Wang Hong De , Cui Tie Jun
Published: March 2013

The shield tunneling construction would cause the buried pipeline deformation. In order to predict the influence to the buried pipeline when shield tunneling crossing the thick and hard strata, taking 201 contract section shield tunneling of Dalian Metro construction as the research object, the buried pipeline deformation effects are analyzed. Firstly, the shield tunnel excavation and support simulating model is constructed basing on Flac3D technique. Secondly, the ground settlement and its influence to the buried pipeline are analyzed with finite difference digital computation. According to the simulation for the shield tunneling crossing the thick and hard riverbed, the settling volume of the ground, the deformation modes and degrees of the buried pipelines are discussed to reveal the deformation rules. Results show that the deformations of two groups of measuring points tend to be uniform; the excavation process includes the stabilization period, the critical point and the deformation period in 50m long simulation model; the drainpipe appears deformation from three directions, and the severity of deformation mainly comes from the vertical direction settlement.
Torsional Stability of Research and Discussion on the Conductor-Spacers System
Authors: Gan Feng Lin , Wang Hai Man , Lin Ze Nan
Published: March 2013

According to the instance of turnover and twist of conductor-spacers system,a question of torsional stability of conductor-spacers system is proposed.The paper analyzes the reason why the torsional instability of the entire system occurs and puts forward that the residual torque moment has existed during the process of conductor stranding,which creates a security risk to the stability of the system.In addition,the torque moment caused by the uneven ice-covering and different periods of ice-shedding will leave the system unbalanced.Finally, methods of improving the stability of conductor-spacers system is discussed.
Modal Parameter Identification of a Rigid Frame-Continuous Girders Bridge under Ambient Excitation by Fast Bayesian FFT Method
Authors: Han Jian Ping , Zheng Pei Juan
Published: March 2013

Bayesian theory is adopted in modal parameter identification, finite element model updating and residual capacity evaluation of the structures recently. Fast Bayesian FFT modal identification approach provides a rigorous way to obtain modal parameters and well-separated modes using the fast Fourier transform under ambient excitation. Moreover, it avoids choosing the modal order or removing false modes based on the stable diagram and has its obvious advantages. In this paper, modal parameters of a rigid frame-continuous girders bridge under ambient excitation are identified by this approach. Comparison with stochastic subspace identification (SSI) method indicates that Fast Bayesian FFT is a good approach to identify the modal parameters even for a large number of measurement channels.
Safety Inspection and Evaluation on the Main Structure of a Framework Wharf
Authors: Zhang Zai Hua , Chen Bo Wang , He Ran
Published: March 2013

Yiyang rubber machinery group cargo terminal is a vertical frame wharf established in the early 1970’s. A certain degree of deterioration and damage has occurred to the structure because of the long service time and long-term exposure of some parts of the structure. Taken the subsequent use of safety into account, the structure was completely detected. The detection content included array of structure, apparent damage and rebar corrosion situation, carbonation depth and compressive strength of concrete, distributions of reinforcement and cover thickness, verticality of the overall structure and so on. The bearing capacity of the main structure was checked according to the corresponding detection results and standards. Then the safety of the wharf structure was comprehensively assessed and some suggestion about repairing and reinforcement was also made which could provide the reference for the follow-up repair and reinforcement or other similar engineering.
The Photocatalytic Properties of Br-Doped Titania Nanotube Arrays and its Application in Degradation of Sugar Wastewater
Authors: Meng Zhi Peng , Zhong Fu Xin , Wang Dan Yu , Zhang Zhong Ming , Li Hua Ying , Li Feng Jiao
Published: March 2013

This paper presents a novel approach for preparing titanium dioxide nanotube arrays (TNTs) loaded with highly dispersed Br through an ultrasound aided photochemical route. The content of Br doped on the arrays was controlled by changing the concentration of NaBr and the ultrasound time. The Br doped TiO2nanotube arrays were characterized by SEM, XRD and UV–Vis spectrum. Doping the bromine did not basically affect the morphology of the surface of the TNTs, but part of the anatase phase transformed into rutile phase, which led to the formation of the mixed crystal and increased the photocatalytic activity. The results showed that Br doping significantly enhanced the photocatalytic degradation rate of titanium dioxide nanotube arrays under UV-light irradiation. The main factors which affected photocatalytic degradation of sugar wastewater were the illumination time and pH. The results showed that the longer the exposure time was, the initial pH of wastewater was more favorable to photocatalytic degradation of the sugar wastewater for the Br-TiO2nanotube arrays, and compared to undoped TiO2nanotube arrays Br doped TiO2nanotube arrays had better photocatalytic properties.
Reaction Characteristics of Ce-Based Oxygen Carrier for Two-Step Production Syngas and Hydrogen through Methane Conversion and Water Splitting
Authors: Wei Yong Gang , Zhu Xing , Li Kong Zhai , Zheng Ya Ne , Wang Hua
Published: March 2013

The two-step steam methane reforming for production syngas and hydrogen was investigated by using Ce-based oxygen carriers (CeO2, CeO2-ZrO2，CeO2-Fe2O3) which were prepared by co-precipitation method and characterized by means of X-ray diffractometer and Raman spectroscopy. CH4 temperature programmed and isothermal reactions were adopted to test syngas production reactivity, and redox properties were evaluated by a successive redox cycle. The results showed that the incorporation of ZrO2 into CeO2 was found to be an effective approach for enhancing the reducibility of CeO2 in methane conversion reaction and redox performance, and the addition of Fe2O3 into CeO2 could obviously increase the amount of reactive oxygen species in CeO2-Fe2O3 and the yields of syngas and hydrogen reached maximum in the 3rd cycle, but the redox stability of CeO2-Fe2O3 needs to be enhanced.
AlCl3·XNaCl Complex Compound as Catalyst Synthesis Dichlorophenylphosphine
Authors: Fan Tian Bo , An Gui Qi , Tang Tao , Lui Yun Yi , Han Xiao , Zhou Zhi Heng
Published: March 2013

Dichlorophenylphosphine(DCPP) was prepared by the catalyst of AlCl3·XNaCl complex using C6H6, PCl3as raw materials. The influences of the catalyst amount, raw material ratio and the choice of extractant on the production rate were studied, as well as the recycling of the catalyst. Fourier transform infrared spectroscopy was employed to characterize the products. The results show that the products by experiments were dichlorophenylphosphine(DCPP). All above have some reference value for the industrial production.
Preparation of L-α-Glycerophosphocholine from Natural Lecithin Catalyzed by Tert-Butylamine
Authors: Li Hong Ya , Zhang Xiao Li , Bai Wei Li , Zhao Bin Xia
Published: March 2013

L-α-glycerophosphocholine, transesterification, tert-butylamine, natural lecithin Abstract. Tert-butylamine was confirmed as effective catayst for preparing L-α-glycerophospho -choline at mild conditions. The process using this catalyst would be much simpler, since the recovery of the catalyst can be combined with the recovery of methanol by distillation. The conversion of phosphatidylcholine could reach over 98% after 4 h, with a catalyst content of 2.4% under 60 °C. The mechanism of the methanolysis reaction was proposed and the experimental data fit the equation model well. GC was used to analyze the product, it was indicated that the product had high purity, and the catalyst could get similar effect to the fresh after repeatedly used.
A Case Study of Cd, Hg and Pb Spatial Distributions by RS and GIS in Agriculture Soil
Authors: Ouyang Chun Llie , He Yun Xiao , He Dan
Published: March 2013

The objective of this agricultural geochemistry survey project was to study the enrichment distribution of Cd, Pb and Hg in the agricultural soil in Mianyang City, sichuan Province China. More and more geochemists in field of agricultural geology become to concern heavy metal (Cd, Pb and Hg) pollution problems in soil. Basing on geochemical investigation method, and employing remote sensing ( RS ) and geographic information system (GIS) techniques and methods, it indicates that the distributions of soil Cd, Pb and Hg are controlled by the terrain and landform features, and human constructions in working site. The study shows as well that distributions of Cd, Pb and Hg contents are influenced by highway and river, and there is enriching tendency of Cd in the project site with the risk of contamination.
Internal Electrolysis Intensified by Microwave for the Treatment of Nitrobenzene – Containing Wastewater
Authors: An Zheng Yang , Wang Yuan Yuan , Xu Xiao Jun
Published: March 2013

Treatment of nitrobenzene-containing wastewater was carried out by iron-carbon internal electrolysis and microwave and its degradation mechanism was investigated. The parameters is found in the process of treating nitrobenzene-containing wastewater. The experimental results showed that the microwave intensified the internal electrolysis effect of iron-carbon and the existence of iron was beneficial to the regeneration of activated carbon. Under the optimized electrolysis conditions as follows: iron dosage was 175g, molar ratio of Fe to C was 3, pH was 3, microwave power was 640W, irradiation time was 4 min and aeration amount was 2.5L/min, the removal rates of CODcr, chroma and turbidity were 94.7 %, 95.6 % and 90.3 %, respectively.
Detection of the Intermediate in Preparation of Ammonium Polyphosphate by Ammoniating Rate Factor
Authors: Liu Gou Sheng , Liu Yue Long
Published: March 2013

Ammonia atmosphere is significant to controllably obtain a certain crystalline forms. In this paper, the effect of ammoniating rate is investigated. Some intermediates are detected during the preparation process of APP, the XRD spectra of these intermediates are discussed. The results show that low ammoniating rate is suitable for preparation of APP form II. With ammoniating rate increasing, most of the crystals transform to APP V in the intermediate and water insolubility of the product increases. The results are informative for controllable preparation of APP in industrial production.
The Preparation and Characterization of Polycaprolactone Elastomer Polymer
Authors: Su Hong , Guo Li Mei , Wang Lian Yong
Published: March 2013

polycaprolactone diols (MW=540, 1000, 2000) and citric acid were used as monomers, polycaprolactone-citric acid preformed polymer was preparated firstly by the heating polycondensation, then the preformed polymer was heated and cross-linked to obtain biodegradable elastomeric material. The molecular structure and Molecular weight was proved respectively by 1-HNMR and Gel Permeation Chromatography (GPC). The shape and glass transition temperature (Tg) of polycaprolactone-citric acid polymer was certified by differential scanning calorimetry(DSC). The hydrophilicity of the polymer was evaluated by its contact angle. The polymer’s mechanical property and degradation speed was also investigated.
Research on the Isolation, Identification and Degradation Characteristics of a Diesel Oil Degrading Strain
Authors: Huang Lei , Xie Jing , Shi Xiao Feng , Lian Jing Yan
Published: March 2013

A hydrocarbon-degrading strain ZRS was isolated from petroleum-contaminated soils sampled from Xinjiang oil field and identified as Acinetobacter beijerinckii, which could use diesel oil as solo carbon source. The optimal temperature and pH for strain utilizing ethanol was 25°C and 7.2; the optimal concentration of ethanol and the biomass concentration was 4.5% and 109 CFU/mL, respectively. Inoculated to artificial seawater which added (NH4)2SO4 2.64g/L、Na2HPO4 1.5 g/L and yeast extract 13 mg/L after 7 days of culture at temperature 25°C, the rate of degradation was 73.9％.
Comparison Activating Ability of Three Hydrogen Peroxide Activators
Authors: Guo Sheng , Huang De Yi , She Ji Feng , Liang Xiang Qun
Published: March 2013

The bleaching efficiency of hydrogen peroxide can be promoted by using suitable activator. In our research, two methods were applied to compare the activating ability of three activators, TAED (tetraacetylethylenediamine), acetamide and dicyandiamide. The first part was hydrogen peroxide bleaching. TAED was excellent, because the brightness improvement was the maximum; the viscosity was acceptable. Acetamide was an applied activator in peroxide bleaching，for it could get same effects as TAED if the bleaching process had enough time and enough dosage. In the last part our study was about the kinetics of a lignin model compounds, acetovanillone, in peroxide-alone system, TAED/H2O2 system, acetamide/H2O2 system and dicyandiamide/H2O2 system. The rate constant, k and half-life period, t1/2 can be used to compare the rate of oxidation of acetovanilone. Compared to peroxide-alone system, three systems with activator and H2O2 could accelerate the reactions of hydrogen peroxide and acetovanillone. The t1/2 of TAED/H2O2 system was least of them. It was just 1/5 of t1/2 of peroxide-alone system, 1/4 of t1/2 of acetamide/H2O2 system and dicyandiamide/H2O2 system. The activating ability order of activators was: TAED> acetamide> dicyandiamide.
Bacterial Diversity and Community Structure Analysis for Two Samples of Mine Drainage from Shimen Realgar Mine, China
Authors: Yang Yu , Yang Li , Xiang Xiao Ming
Published: March 2013

Two samples of mine drainage, named SY and XY respectively, were collected from Shimen Realgar Mine, Hunan province, China. In addition to physic-chemical analysis, bacterial diversities and community structures of these samples were described at genetic level by restricted fragment length polymorphisms (RFLP). A total of 66 and 76 different operational taxonomic units (OTUs) patterns were obtained from 160 clones respectively. Total 30 patterns, which were dominant or both appeared in these two samples, were re-amplified and sequenced. The sequence data and phylogenetic analysis showed that uncultured bacteria represented 62% of the population in samples due to the high concentration of arsenic. And almost all of the affiliated sequences have very close relationships with extreme environment. However, samples SY and XY contained more diverse colonies of bacteria. These diversities were characterized by the reciprocal of Simpson’s index (1/D).
Determination of Solubility of Hydrogen in Polymer Solution at High Pressure
Authors: Gao Guang Hua , Zhai Guang Wei
Published: March 2013

Abstract. The solubility of hydrogen in styrene-butadiene-styrene (SBS) block copolymer-cyclohexane solution was determined under 3, 6 and 10 MPa pressures and at temperatures from 50°C to 150°C respectively. The experimental results showed that the solubility of hydrogen increases with risen pressure, temperature as well as concentration of SBS polymer in the cyclohexane solvent. The measured data of gas solubility could be successfully correlated by PRSV equation of state.
Preparation of Granular Sorbent (GS) from Red Mud by Thermal Activation and its Application for Cu2+ Removal
Authors: Yue Qin Yan , Wang Xiao Juan , Zhao Ya Qin , Zhang Xiao Wei , Gao Bao Yu , Li Qian , Wang Yan
Published: March 2013

In this study, granular sorbent (GS) which was prepared from red mud, clay and coal by sintering method was studied. With the aim of determining the optimal parameters for GS production, the influences of several important factors (including raw material ratio, sintering temperature and sintering time) on the adsorption capacity of GS for Cu2+ removal were evaluated in the single-experiment. The results indicated that the raw material ratio was the key factor that influenced the property of GS. The optimal conditions for GS preparation were as follows: the raw material ratio (red mud: clay: coal) of 85:10:5, sintering temperature of 400 °C and sintering time of 20 min.
Analysis on Phosphorus Removal from Domestic Wastewater Treatment Plant by Biological Aerated Filter
Authors: Liu Yin Song , Han Hong Jun , Xu Chun Yan , Wang Bing , Tan Jian Feng
Published: March 2013

Hydrolysis acidification / pre-denitrification biological aerated filter was adopted in a domestic wastewater treatment plant. The effluent was accorded with a standard in the Integrated Wastewater Discharge Standard（GB18918-2002）, in which the effluent phosphorus was demanded below 0.5mg/L. Through analysis on the process biological phosphorus removal, biological method can be found to total phosphorus 1.5 mg/L. If you reach level to an emissions standards, phosphorus chemical experiment research, finally determined by strategy for the CN pool, point for adding potions FeCl3, dosing quantity for 35mg/L.