bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Performance of Resisting Foundation Displacement of High Voltage Electricity Transmission Tower in Mining Subsidence Area
Authors: Shu Qian Jin , Yuan Guang Lin , Zhang Yun Fei , Guo Guang Li
Published: December 2010

The performance of resisting foundation displacement of a typical single return circuit transmission tower under all kinds of load conditions including foundation horizontal displacement, foundation vertical uneven downward displacement was analyzed by finite element modeling. Results showed that stability failure of single steel angle represents tower’s limit state under foundation displacement. And the corresponding foundation displacement limits were calculated. Results indicate that foundation pull condition is more dangerous than press condition. Under complex foundation displacement conditions, foundation horizontal displacement is primary factor leading to stability failure of towers. Under foundation press condition and pull condition, wind load is primary factor. Result also indicates that, tower does not fail when foundation displacements are smaller than 1.25% (under foundation press condition and pull condition) or 0.5% (under single foundation sink condition) of tower root distance.
Model Test Research of Cushion Thickness on the Long-Short Piles Composite Foundation
Authors: Ge Xin Sheng , Xue Jiang Wei , Zhai Xiao Li
Published: December 2010

In order to study the impact of cushion thickness on the long-short piles composite foundation,the relation between bearing capacity and settlement,distribution of the axial force and skin friction along pile,pile-soil stress ratio, load sharing ratio and the bearing mechanics of long-short-pile composite foundation with long and short piles were studied based on laboratory tests in three different conditions:zero-centimeter-thick cushion, two-centimeter-thick cushion and five-centimeter-thick cushion in this paper. Conclusions were as follows: The settlement of long-short piles composite foundation increased with the increasing of cushion thickness,Without cushion,the maximum axial force occurred in the pile top.After having paved cushion,it occurred in the neutral dot.The axial force of long and short piles decreased with the increasing of cushion thickness; Without cushion, only positive skin friction occurred. After having paved cushion,negative skin friction came into being existence.The value of long piles skin friction increased with the increasing of the cushion thickness,the value of short piles skin friction decreased with the increasing of the cushion thickness;The pile-soil stress ratio of long pile decreased with the increasing of the cushion thickness while the pile-soil stress ratio of short pile change little,The load sharing ratio of long piles were larger than that of short piles and soil.With the increasing of cushion thickness,the load sharing ratio of long and short piles became smaller while that of soil became larger.
Study on Longitudinal Vibration of Pile in the Viscous Damping Layered Soils
Authors: Wang Yin Hui , Wang Kui Hua , Zha Zhi Xiang , Que Ren Bo
Published: December 2010

Taking axisymmetric wave effect of soil into account, longitudinal vibration of pile in viscous damping layered soils undergoing arbitrary load is theoretically investigated. An analytical solution for admittance at the level of the pile head in frequency domain is yielded. So is a semi-analytical solution for velocity response in time-domain subjected to a semi-sine exciting force. Based on the solutions proposed herein, the effects of variety of soil modulus on admittance curves and reflection wave curves are emphatically discussed. The conclusions can provide theoretical guidance for non-destruction test of piles.
Study on the Improved Model of the Internal Force of the Shield Tunnel Segment
Authors: Yang Yue , Chen Xiao Guo
Published: December 2010

The design of the shiled tunnel segment is one of key and difficult problems in design of subway. The soil round the segments and the joint among them are tow factors must be considerd on the establishment of the calculation model of the segment. Simplification of joint in the calculation model of segment is improved,then a new model is built with the stratum-structure method. Taking Harbin Metro Line No.1 for example, a comparative analysis between the improved model and existing routine model is made. Then some conclusions are got from different deduction ratio of stiffness of joint.The study results show that the new model is tolerable,and significant to design and construction of tunnel segment in theory and practice.
Effect of Natural Ageing on Precipitation of Al-Zn-Mg-Cu-Li Alloys
Authors: Zhao Zhong Kui , Li Chang Long , Sun Qing Zhou , Zhang Pu Qing , Wang Gui Qing , Chen Chang Qi
Published: December 2010

Effect of natural ageing on the precipitation of Al-5.6Zn-1.9Mg-1.6Cu- 1.1Li-0.24Cr (in wt.%) alloys were investigated. The ageing processes, microstructure and hardness of the alloys were investigated by Vickers hardness and transmission electron microscopy (TEM). The results show that natural ageing makes the exothermic temperature range of the Al-Zn-Mg-Cu-Li alloys to shift to lower temperature. Natural ageing for 48h and followed by ageing at 120 , precipitates in the matrix of Al-Zn-Mg-Cu-Li alloys are sparse, which lowers the age hardness of the Al-Zn-Mg-Cu-Li alloys.
A Study on Stability of Expressway Tunnel Surrounding Rock Containing Weak Intercalated Rock
Authors: Shi Da Kun , Zhang Yang Song
Published: December 2010

Weak intercalated rock plays an important role in the stability of engineering rock mass. It controls the mechanism of deformation and breakage of rocks. Systematic numerical tests have been carried out to study the stability of surrounding rock mass with different distributions of weak intercalated rock has been analyzed by the FEM software ABAQUS. All of the numerical modelings are plain-strain type with elasto-plastic constitutive law and Drucker-Prager failure criterion. Some quantificational results about the influence of weak intercalated rock are summarized, especially the influence on the deformation, stress of surrounding rocks and plastic zone. Because of weak intercalated rock, the stress of surrounding rock appears the character of discontinuity. In addition, the distribution of plastic zone is also affected. When weak intercalated rocks exist in vault, spandrel and bottom, the situation of surrounding rock is comparatively unfavorable. These results have a certain role in guiding significance to the site selection and layout, the majorization of supporting system and the construction of tunnel of the same kind.
Application Studies of Optic Fiber Measuring Techniques for Field Tests of Overlength Piles in Subway Engineering
Authors: Wang Xiao Rui , Li Feng , Jia Xiao Feng
Published: December 2010

Testing the overlength pile in urban subway engineering is the key for quality control. Because of the limitations of urban construction sites, it is difficult to achieve efficient results with the normal testing method. Optical fiber measuring technique has gradually replaced the application of the traditional strainometer in geotechnical engineering testing as a result of the unique advantages it offers. In this study, first, the principles underlying the optical fiber measuring technique are introduced and its application in pile foundation testing in subway engineering is discussed. Then, combined with engineering practice, the optical fiber measuring technique is employed to study the law of development of strain in the overlength pile with the loading process under the action of vertical load. Finally, some meaningful conclusions are arrived at and reference foundations are provided for the optimized design of the same kind of engineering.
Study on the Reclaimed Binder Properties Using Vacuum Rotating Reclaim
Authors: Jia Liang , Zhu Yan Peng
Published: December 2010

In the past few years, recycled asphalt has been used successfully in asphalt concrete pavement in China. However, the performance of recycled asphalt does not know. The objective this study is analyses the performance of asphalt which using vacuum rotating reclaim. Lanlian No.70 petroleum asphalt was put into pressure aging vessel after one hour, five hours, ten hours, fifteen hours, and twenty hours of aging. Afterwards, the different aging degree asphalt was dissolved by trichloroethylene, and then asphalt reclaimed which using vacuum rotating reclaim method. In the end, performances indexes of recycled asphalt were tested, such as penetration, softening point, ductility, viscosity, dynamic shear modulus, phase angle, bending creep stiffness. Performances indexes of Lanlian No.70 original petroleum asphalt were also tested. The performances indexes were compared of different aging degrees recycled asphalt and origin asphalt. Comparison results indicate that some performance indexes of recycled asphalt are decease; these indexes consist of penetration, ductility and phase angle. The other performances indexes are rise; those indexes include softening point, dynamic shear modulus, bending creep stiffness and viscosity. However, variation of performances indexes is minimal. Therefore, vacuum rotating reclaim method will not make asphalt ageing for considering equipment and human factors. We can use vacuum rotating reclaim method to reclaim discard asphalt concrete.
Structure Dynamic Signal Denoise Using Multi-Scale EMD
Authors: Yang Dong , Ren Wei Xin , Xiao Xiang
Published: December 2010

For structure dynamic signals with low signal to noise ratio (SNR), Multi-scale EMD is proposed to extract useful information from signals contaminated by noise. This method is an adaptive way, and achieves better performance than traditional methods. A complex signal composed of signal and noise, which is first decompose into a series of different characteristic IMFs. Then sum of the first few IMFs including useful information and noise are further decomposed by EMD, and iterate this process for several times in order to extract useful information. The final step is deleting some IMFs obtained from the last decomposing which is considered as noise, and rebuilt the signal using the rest IMFs from different scale. This method can smooth signal effectively. The effectiveness of the proposed method is verified with the numerical simulating signal, and useful information in signals is retained. It also has some superior performances such as concise computer process, robust application, etc.
Study on Application of PCM in Asphalt Mixture
Authors: Ma Biao , Wang Sha Sha , Li Jun
Published: December 2010

The application of Phase Change Material (PCM) to asphalt mixture can lighten the temperature-dependent disease of the asphalt pavement and improve the usability as well as extend the operating life of it. We choose agreeable PCM with comprehensive consideration to the technical requirement of its application in the construction industry and the characteristic of asphalt mixture. Through simulating temperature experiment, we make a conclusion that incorporate the carrier accompanied PCM into asphalt mixture can reduce the increasing rate and cooling rate of the mixture, which shows that PCM can put into use of adjusting the asphalt mixture operating temperature, softening the negative influence of ambient temperature variation on asphalt mixture.
Preliminary Development of Indirect Tensile Tester Cooperated with Industrial Computered Tomography for Asphalt Mixture
Authors: Li Xiao Jun , Jiang Li Hua , Wang Yun Xian
Published: December 2010

In this paper, a new Indirect tensile tester (IDT) which can be cooperated with Industrial Computered Tomography (IDT) is developed. The new tester uses a set of sliders to transfer the vertical stress to hoop stress which applied to a hollow cylindrical sample. The micro-crack will be appeared and propagated in the weakest direction of hollow cylindrical sample with the increase of vertical stress and tensile strength can calculated with the maximum vertical stress. Due to the existence of central slider, the stress state of hollow cylindrical sample will be kept even after unloading and the mixture sample would not have recovery when it is moved for scanning with ICT. The test results show that the combination of the developed ICT with IDT will help obtain more useful information on understanding the nature of asphalt concrete with different tensile damage stages.
Research on Expanded Polystyrene Light-aggregate Concrete
Authors: Ning Xun An , Liu Jing Yong , Yang Zuo Yi
Published: December 2010

EPS(Expanded polystyrene)is used as light-weight.By adding fly ash and modified polymers in proper proportion aggregate, and cement is used as adhesive material, the uniformity and stability of pastes can be improved. The EPS light-weight concrete is obtained with good physical mechanical perform ance and some problems of segregated layers, weak interfacial bonding, and low density and strength etc, can be solved. The effects of water cement ratio and fly ash proportion on the mobitity of the mixture and the strength of the concrete are analyzed.
Experimental Research on Dynamic Poisson’s Ratio of Silty Clay
Authors: Pan Hua , Chen Guo Xing , Sun Tian
Published: December 2010

Cyclic triaxial and cyclic torsional shear tests were performed on undisturbed marine silty clay by the hollow cylinder apparatus, and the Young’s modulus and shear modulus were obtained respectively. Furthermore, the influence of effective confining pressure and stress ratio on dynamic Poisson’s ratio was investigated on this basis. It was found that the dynamic Poisson’s ratio increases with generalized shear strain, but decreases with increasing effective confining pressure and stress ratio. The effect of effective confining pressure and stress ratio on dynamic Poisson’s ratio was weakened as the generalized shear strain was increasing. The dynamic Poisson’s ratio was about 0.48 when the Poisson’s ratio was increased to 1.8E-2 or so, and the test was terminated. There was no shear dilatation during all tests because the Poisson’s ratios were smaller than 0.5. It indicates that the marine silty clay tested in this paper has a good stability under cyclic loads.
Simplified Computation of 1D Consolidation for Unsaturated Soil when Air Phase Neglected
Authors: Xu Hao Feng , Xie Kang he
Published: December 2010

It is a complicated problem for consolidation analysis of unsaturated soils. Nowadays’ theories are very theoretical, and the parameters in them are so many that it is difficult to solve the equations, i.e., they are not excellently fit for application in engineering. So it is significant to get a simplified theory for consolidation analysis of unsaturated soils. In this paper, according to the phenomena observed in consolidation’s experiments for unsaturated soils, it is assumed that pore-air pressure undergoes an instantaneous dissipation and the consolidation of unsaturated soils can be described as the process of dissipation of excess pore-water pressure. Then a simplified consolidation model is put forward. And based on the principle of the whole soil mass conversation, the continuity equation is founded. Subsequently one- dimensional consolidation equation is derived, which is similar to Terzaghi’s equation for consolidation of saturated soils. Finally, the numerical results from the derived equation are compared with the experimental results from laboratory tests reported in the literature, and the agreement is good. It can be concluded that the hypothesis is rational and the simplified computation is practical in engineering.
The Performance Analysis of Semi-Flexible Pavement by the Volume Parameter of Matrix Asphalt Mixture
Authors: Ding Qing Jun , Sun Zheng , Shen Fan , Huang Shao Long
Published: December 2010

The volume parameter of matrix asphalt mixture is an important target in the design of the semi-flexible pavement. The research used volume-standar to design four kinds of matrix asphalt mixture, fulfilled mechanics performances and performances of semi-flexible pavement material with different aging, compared with common asphalt mixture and researched the effect by air void and pore structure. It proves that the compacted intensity, high-temperature stability and low temperature bend of the semi-flexible pavement material is better than common asphalt pavement material, the performances of matrix asphalt mixture with high air void is better. As for matrix asphalt mixture with same air void but different pore structure, the performances of homogenous grade design is prior to consecutive grade disign.
Damage Analysis for Quasi-Birttle Materials of CT Image under Uniaxial Compression
Authors: Yi Cheng , Zhu Hong Guang , Liu Li Zhen
Published: December 2010

In the damage research before on the CT image of quasi-brittle materials such as concrete, the damage evolution is often described by the change of average CT values or image threshold segmentation method. However, the evolution of average CT values is insensitive to the damage, and the threshold value is always not only, which grimly depends on the researchers’ judgment. Because CT image is a gray image and different grayscale expresses different density distribution, it is tried in the paper to express the variety of material density with variety of grayscale of CT image. A description index of Rd from fractal theory is introduced in the paper to describe the variety of grayscale. Thereby, a damage variable is defined by Rd index, which can be used to study the developing process and evolving rule of concrete damage.
Experimental Study on Freeze-Thaw Resistance Durablilty of High Performance Concrete
Authors: Huo Jun Fang , Ji Xiao Xia , Yang Hui
Published: December 2010

Freeze-thaw cycle experiments on high performance concrete were carried out while cement was respectively replaced by fly ash for 30%～50%. The test results showed that maximum weight loss rate of concrete was 1.78% and minimum relative dynamic elastic modulus was 94.08% after 300 freeze-thaw cycles for high performance concrete based on low water-cement ratio, efficient air-water-reducing agent and large quantities of industrial waste fly ash. The test data were far less than limits of 5% and 60% in specification. Freeze-thaw resistance performance of high performance concrete with large volume fly ash was excellent according to test results. The high performance concrete with large volume fly ash can meet the requirements of frost resistance performance of concrete in the cold regions. Particularly, it can be fit for the railway concrete engineering.
Construction and Experiment of the Harbin Ice Shell
Authors: Nie Gui Bo , Zhi Xu Dong , Fan Feng , Kokawa Tusomu , Niu Shuang , Yu Zhi Wei
Published: December 2010

The city of Harbin is famous with its ice art and which attract the attention from the whole world. Ice shell is a kind of new architectural form in China which can be a suitable method for structure by using ice and snow-ice as structural material especially in cold regions. In this paper, an ice shell with span 9m and height 3.5 was completed to investigate the performance of this special structure under human loads and temperature. The results show that the ice shell maintains a bearing capacity under human loads due to the well-known mechanical behavior pf shell. However, the bearing capacity of the shell was largely depend on the variation of temperature. Furthermore, some rational suggests were given during the design and construct the ice shell. Finally, the works of this paper provides some material for the revision of ice code.
Analytical Modeling of Flutter Aerodynamic Derivatives for Open-Truss Stiffened Suspension Bridge
Authors: Mohamad El Katt , Raafat Shaker , Younis Kassem
Published: December 2010

An analytical model is developed for modeling aerodynamic flutter derivatives for long-span Open-Truss Girder Suspension Bridges and their interaction. The approach suggested here is to synthesize the wind derivatives based on proposed functions interpolated from experimental results of previous studies. The model solves the equation of motion and the synthesized aerodynamic forces are solved to find the critical wind velocity of the suspension bridge. The solution procedure and assumptions of the approach are verified using the Golden Gate Bridge flutter analyses, where the experimental aerodynamic coefficients of the bridge are modeled as a function of the wind velocities in the proposed procedure and compared with the analysis based on the interpolated coefficients. The results agree with the results in the literature. The result of the proposed analytical model is close to the values extracted from previous researches.
The Effect of Salt Admixtures on Foam Stability of Different AEAs
Authors: Ge Yong , Li Qin Fei , Yang Wen Cui , Yuan Jie , Yu Ji Shou
Published: December 2010

The paper mainly researched the influence of salt admixtures on foam stability of air-entraining admixtures (AEAs). Foaming power and foam stability of SJ-2 and DH-9 were analyzed. The results indicated that calcium chloride and calcium nitrate reduced the foaming power regardless of kinds of AEAs. On the contrary, sodium sulfate and sodium nitrite increased the foaming power, but with the increase of their added content, the foaming power taked on the tendency of descension. In addition, these four salts declined the foam stability of SJ-2 and had hardly effect on that of DH-9.
Influences of Microelement on Microstructure and Mechanical Performance of Alite-Strontium Calcium Sulphoaluminate Cement
Authors: Li Qiu Ying , Lu Ling Chao , Wang Shou De
Published: December 2010

Alite-strontium calcium sulphoaluminate cement, a new type of cementitious material, is synthesized by combining strontium calcium sulphoaluminate with minerals of Portland cement clinker. The influences of excessive SO3 and SrO on the microstructure and performances of this cement are studied by XRD, SEM-EDS and lithofacies. The results show that the optimal excessive mass fraction of SO3 and SrO are 50% and 80%. The compressive strength of the cement prepared under the testing conditions reaches to 32.8MPa, 66.8MPa and 126.4MPa at 1d, 3d and 28d curing ages, respectively. The additions of SO3 and SrO are benefit to improve the content of strontium calcium sulphoaluminate, and promote the formation of alite at low sintering temperature.
Effect of Waterproof Emulsion on Properties of Calcined Gypsum from Flue Gas Desulfurization
Authors: Wang Fei Fei , Li Guo Zhong , Liu Min Rong
Published: December 2010

Effect of the vinyl acetate - ethylene copolymer emulsion (VAE emulsion), styrene-acrylic emulsion and paraffin emulsion were studied on waterproof properties and mechanical properties of calcined gypsum from flue gas desulfurization (FGD). The results showed that waterproof properties of samples which mixed paraffin emulsion were most excellent, but mixing paraffin emulsion caused the negative effect to the mechanics properties of samples. Adding appropriate content of VAE emulsion was advantageous to waterproof properties and mechanical properties of samples. Scanning electron microscope was used to observe the microstructure of samples, and the mechanism of waterproof emulsion was discussed.
Experimental Study on Strength Characteristics Comparison of Tamped and Poured Concrete
Authors: Liu Xi Yuan , Li Yan Feng , Chen Zhao Xia , Wang Ling
Published: December 2010

Piles formed by tamped concrete are a kind of technology in foundation treatment. In order to study the difference of strength characteristics between tamped and ordinary poured concrete, optimum parameters of mix proportion on tamped concrete are obtained by heavy compaction test in laboratory, then unconfined compressive strength tests are accomplished on the basis of optimum parameters of mix proportion. Influence factors of strength characteristics of tamped concrete are studied, such as cement-aggregate ratio, curing age, curing condition and so on. Finally, strength characteristics of tamped and ordinary poured concrete are compared. The test results indicate that the tamped concrete is hardened quickly and early-strength. In standard, water and saturated soil curing condition, compressive strength all grows sufficiency, thus tamped concrete can be used in ground and underground environment. At the same time, a higher strength can be obtained by smaller cement content, and the cost of tamped concrete can be reduced effectively.
The Influence of Limestone Powder on Fluidity, Strength and Hydration of Cement Mortar
Authors: Yang Hua Shan , Fang Kun He , Tu Sheng Jin
Published: December 2010

An experimental program has been conducted to investigate the influence of limestone powder (LP) on fluidity, strength, and hydration of cement mortar. Four laboratory grinds were prepared using a ball mill. The relationship between roundness of the LP and water requirement of paste, fluidity and strength of mortar was studied. The influence of LP on hydration of cement was investigated. Hydration products were determined by X-ray diffraction (XRD) analysis. Test results show that the roundness of LP significantly affected the water requirement of paste, fluidity and strength of mortar. In addition, the sites for the nucleation and growth of hydration products, provided by LP, accelerate the hydration of cement at early ages. While the enhancement of cement hydration at later ages mainly due to the formation of calcium aluminate monocarbonate.
Homogenised Dynamic Material Model for Brick Masonry and Its Application
Authors: Li Xin Zhong , Wei Xue Ying , Zhao Jun Hai
Published: December 2010

Brick masonry is a traditional building material widely used loading-bearing or partition walls in various building structures. The detailed distinctive modelling of brick and mortar of a realistic masonry structure or a structure with masonry infilled walls are usually not possible due to the computational cost. In this paper, a homogenized dynamic material model which including the damage of brick and mortar and strain rate effect is developed based on dynamic test results of brick and mortar. The proposed homogenized material model was used in analysis of blast response of brick masonry wall.
Design Flexibility of Growing and Transformable House in Malaysia
Authors: Utaberta Nangkula , Spalie Nurhananie , Abdullah Nurakmal Goh
Published: December 2010

The ubiquitous terrace house is undeniably the most popular and affordable housing type in Malaysia. It has long been considered as one of the densest forms of property development and has become the common typology of accommodating the masses for this country. However, in Malaysia (like other third world countries), the design of a house has never grow from novelistic idea of style and revivalism. As stated by Tajuddin Rasdi (2003), housing in Malaysia has been plague with various issues for decades. We are currently living separate and individual lives in the sea of congested modern housing and we will be forever plagued by the mercy of crime, climate, cultural tensions and threats from accidents. For the last 50 years it has never grown to create the idea of community and fulfill the true need of a family with its culture and context called ‘Malaysia’. Based on our paper N. Utaberta (2009), we have identified the ability of traditional Malay house to grow and transform based on the need and interest of one family. This paper tries to study and evaluate the flexibility of a low rise house in Malaysia. It will explore some design and construction framework based on the flexibility of our traditional (timber) Malay house of growing and transformable house.
Study on the Construction Technique of Xigeda Soil House
Authors: Chen Wei , Jiao Tao , Li Xue Wei
Published: December 2010

With the attributes of low strength, serious denudation and crack easily, Xigeda soil is unique in Pan-xi Region and currently is widely adopted in many rural house construction. In this paper, by mixing different proportion of lime and broken rice straw, the physical and mechanical properties of Xigeda soil are tested, and the improvement measures to avoid disadvantages are studied. At the same time construction dimension is proposed. By constructing experimental houses, key construction steps are put forward.
Research on the Load Capacity of Separation Concrete-Filled Steel Tubes Subjected to Eccentric Compression on Separation Side
Authors: Liu Xia Ping , Tang Shu , Tang Chun Hui , Yang Zuo Yong , Sun Zuo
Published: December 2010

This paper deals with the ultimate load capacity test on 14 short columns of separation concrete-filled steel tubes (CFST) which are subjected to the eccentric compression on separate side. The experimental parameters include the separation ratio and the eccentricity ratio. The result shows that the separation ratio and the eccentricity ratio will influence the load capacity of the components of the concrete-filled steel tubes which are subjected to the eccentric compression. The confinement of steel tubes to core concrete will be continuously weakened and the ultimate load capacity of the components will be decreased obviously with both the separation ratio and the eccentricity ratio increasing gradually.
Design and Application of Special Slop Retaining
Authors: Wen Li Ping , Wang Su Li , Zhu Xu Ping
Published: December 2010

Taking the design of composite soil-nailing in deep foundation pit in complex surroundings for example, the paper discusses numerical analysis of soil-nailing using FLAC, a general analysis program of geotechnical engineering, used to predict the displacement and interior force in soil-nailing. Furthermore, a comparison about the interior force in soil nails between the numerical analysis and the traditional methods is made. The measurements show that the numerical analysis is more accurate than traditional methods. The conclusion is drawn that by contrast with the deficiency of traditional methods, more satisfactory results can be got from numerical analysis on composite soil-nailing using the program of FLAC.
State-of-the-Art Review on Concrete Softening Curve
Authors: Zhao Zhi Fang , Zhao Zhi Gang , Feng Xiao Jie , Li Ming
Published: December 2010

The cohesive crack model is widely employed to the fracture analysis of concrete for mode I crack. The tension softening relationship is a very important constitutive law in the cohesive crack model. The determination methods of tension softening relationship of concrete are introduced in this paper which are direct tension methods, J-integral method and inverse analysis method. Meanwhile, those simplified softening curves including linear form and nonlinear form are summarized.
Study on Characteristic of Saturated Soft Clay under one-Way Cyclic Loading
Authors: Liu Tian Jun , An Guan Feng , Zhang Hong Bin
Published: December 2010

Simulating traffic loading, the high liquid limit clay specimens and the low liquid limit clay specimens of the Pearl River delta are engaged in cyclic triaxial tests under one-way cyclic loading respectively. The influence of axial stress, confining stress and plasticity index are taken into account. A critical dynamic stress ratio of saturated soft clay under one-way cyclic loading and the variations of axis strain and pore pressure with number of cycles were obtained. The conclusions are helpful to compute the settlement of saturated soft foundation under traffic loading after work.
Study on Chemical Compositions and Elements of Artocarpus Heterophyllus Lam Wood
Authors: Chen Cong Jin , Yang Xiu Tuan , Luo Jian Ju , Qin Wen
Published: December 2010

The chemical compositions of Artocarpus heterophyllus Lam wood were investigated and content of trace elements in wood were determined. The result showed that the chemical compositions of Artocarpus heterophyllus Lam wood are as following: ashes 15.5 g•kg-1, cold water extraction 35.2 g•kg-1, hot water extraction 55.1 g•kg-1, 1%NaOH extraction 157.7 g•kg-1, benzene-alcohol extraction 79.2 g•kg-1, sodium nitrate-alcohol cellulose 467.6 g•kg-1, holo-cellulose 709.8 g•kg-1, pentosan 212.6 g•kg-1,Acid-soluble lignin 44.9 g•kg-1, Acid insoluble lignin 237.4 g•kg-1, Organic solvent soluble lignin 248.3g•kg-1, Phenolic hydroxyl content of organic solvent soluble lignin 0.25 mmol•g-1; the content of 12 trace elements in Artocarpus heterophyllus Lam wood are: Fe 959μg.g-1, Mn 9.37μg.g-1, Cu 5.60μg.g-1, Zn 17.1μg.g-1, Ca 2.26 mg.g -1, Mg 433μg.g-1, Na 28.1μg.g-1, K 1.05 mg.g-1, Al 46.2 μg.g-1, Pb 0.603 μg.g-1, Cd and Ni were not detected.
Seismic Assessment of a Historical Masonry Building
Authors: Huang Chao Hsun , Yin Shih Hsun , Chou Shun
Published: December 2010

To revitalize a historical building, the Taipei Camphor Factory, a major renovation is being coordinated by National Taiwan Museum. As part of the project, a seismic assessment was conducted to ensure the structural safety of the building. A three-dimensional finite-element analysis was carried out based on material data collected from the field, and it was found out that both the as-is building and the current retrofit plan would not provide adequate seismic capacity. To resolve this problem, an shear walls scheme was configured and seemed to yield a much better performance.
Effect of Heat Treatment on Mechanical Properties of 1500MPa High Strength Wear-Resistant Steel
Authors: Liu Kai , Zhang Jin Jin , Wu Kai Ming
Published: December 2010

A high strength low alloy wear-resistant steel was quenched at 900°C and tempered at varying temperatures. The microstructures were observed utilizing optical and electron microscope. Results show that microstructures consist of predominantly martensite and lots of bainite in the as-quenched specimens. When the specimen was tempered at 250°C, no obvious change in the microstructure was observed. It has an optimized strength and elongation in this condition of heat treatment. With the increase of tempering temperature, the lath or plate of martensite were coalescenced. The strength of the steel is thus greatly reduced and the elongation was accordingly increased.
A Summary of Cold Patch Material for Asphalt Pavements
Authors: Zhao Li Dong , Tan Yi Qiu
Published: December 2010

The disadvantages of traditional hot asphalt mixture were very obvious in repairing damaged asphalt concrete pavements, which was affected by seasons easily and highly construction condition requirement. Therefore, the study on cold patch material for asphalt concrete pavements became so necessary for curing and repairing in time, and insuring traffic smoothly in winner. The developing history of cold patch material was reviewed, and the characters of typical cold patch material at home and abroad were analyzed also in this paper. The main problem and research direction of cold patch material were put forward based on damaged pavements resulted from icing in plateau and humid region, especially, the snowstorm in southern China early in 2008. References were offered for the future research of cold patch material so that improved serve life of highway.
Fiber-Reinforced Rapid Repair Material for Concrete Pavement
Authors: Zhao Jing , Song Ting
Published: December 2010

The main problems of repair materials for concrete pavement are big shrinkage and weak bond etc. The rapid repair material discussed in this paper is concrete with compound early-strength admixture. Its compressive strength and flexural strength (1d) is up to 23.1MPa and 3.74MPa respectively, which meets open to traffic demand in one day. Repair materials mixed with alkali-proof glass fiber or polypropylene fiber mesh were studied. Flexural strength and interfacial bond strength increased, shrinkage value reduced when fiber was blended. The results indicate that there is a strong linear correlation between splitting strength of repair material and bond strength.
Microstructure Characteristics and Mechanical Properties of in-Situ Composite Steel Processed by Severe Cold-Rolling and Subsequent Annealing
Authors: Zhao Jun , Wang Zhi , Zhang Han , Zhai Hong Yan , Wen Quan Xing , Chen Jiu Chuan , Gao Yu Wei
Published: December 2010

In this paper, Q235 steel was investigated in order to manufacturing ultra-high strength material. The process of severe cold-rolling and low temperature annealing of lath martensite effectively reduced the crystal size from about 300 nm to 20 nm, and introduced mass weak interfaces in steel, has been demonstrated a new promising technique for producing in-situ composite multi-nanolayer steel with ultra-high strength (b 2112 MPa). Cold rolling and subsequent annealing have great impact on microstructure evolution as well as material mechanical properties. In the as-rolled state, the strength is approximately four times increased than as-received material (hot-rolled state, b 515 MPa), which is attributed to work hardening and grain refining during cold rolling. As the cold-rolled sample subjected to further annealing below 500 , deformed microstructure underwent further recovery and recrystallization, finally became refined equiaxed grains, microstructure characteristics along rolling direction arrangement was decreased; In addition to ultraﬁne ferrite grains, nano-carbides precipitated uniformly in the specimen annealed at 500 , total elongation increased to 16%, the corresponding yield strength was 1208MPa, much higher than that of as-received samples. The phenomenon of fracture delamination was observed from the specimens, which were cold-rolled and annealed at 500 , and the delamination plane was parallel to the rolling plane. In-situ composite weak interfaces effect has great impact on the fracture surface.
PS-MMT/SBS Composite Modified Asphalt: Preparation and Aging Property
Authors: Zhou De Jie , Han Nian Feng , Tang Xin De
Published: December 2010

The PS-MMT was synthesized through intercalating styrene monomer into the layer of MMT by in-situ polymerization. Composite modified asphalts with PS-MMT and SBS were prepared by melt blending. Rolling thin film oven test (RTFOT) was carried out to study the aging property. The results demonstrate that both modified MMT and SBS homogeneously disperse in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Impact of the PS-MMT on the properties of SBS modified asphalt appears as a decreasing penetration, an increasing softening point, and a decreasing ductility. Compared with that of SBS modified asphalt, the anti-aging property of PS-MMT /SBS modified asphalt was greatly improved.
Experiment on Cement-Based Materials with Various Compositions against Sulfate Attack
Authors: Xie You Jun , Tang Xu Guang , Long Guang Cheng
Published: December 2010

According to the method of semi-immersion in 5% sodium sulfate solution, the property against sulfate attack of cement-based materials with various compositions are studied with the indexes of the amount of crystal salt in unit exposing area and the ratio of total mass change. The experiment indicates that the order of mortar with w/c=0.4 against sulfate attack from high to low are SAC 42.5>PO 42.5>Clinker>HAC 42.5. When w/b is constant and the cement was replaced by the same quantity of salic material, the order of mortar against sulfate attack are Clinker> PO 42.5> SAC 42.5> HAC 42.5. The replacement of SAC and HAC with the same quantity of salic material leads to the sharp decrease of its property against sulfate attack while the result is opposite for the clinker serial and PO 42.5 serial. Addition of redispersible polymer powder can lead to decrease of penetration and increase the properties of products to sulfate attack. Then, it comes to the conclusion that multi-binder with PO.42.5cement 70%–80% (quality percentage), and internal mixing of 5%–10% silica fume, 10%–15% fly ash can meet the high corrosion resistance requirements.
Development of Low Carbon High Strength H-Beam Steel
Authors: Qian Jian Qing , Chen Ji Ping , Wu Bao Qiao , Wu Jie Ca
Published: December 2010

The application of vanadium-nitrogen alloy to develop a certain low carbon high strength H-beam steel was determined through the combination of theoretical study, product requirements and existing practical conditions. The specific rolling process was further defined through laboratory experiments. The developed low carbon high strength H-beam steel was trial produced and its properties were also analyzed. The results showed that the newly developed low carbon high strength H-beam steel had excellent mechanical properties and good weldability.
Constructive Algorithm to Two-Directional Biorthogonal Shortly Supported Wavelets with Poly-Scale Dilation Factor
Authors: Yu Yu Min , Sheng Zong Sheng
Published: December 2010

In this work, the notion of biorthogonal two-directional shortly supported wavelets with poly-scale is developed. A new method for designing two-directional biorthogonal wavelet packets is proposed and their properties is investigated by means of time-frequency analysis methodand, operator theory. The existence of shortly supported biorthogonal vector-valued wavelets associated with a pair of biorthogonal compactly supported vector-valued scaling functions is investigated. A new method for designing a class of biorthogonal shortly supported vector-valued wavelet functions is presented by using multiresolution analysis and matrix theory.
Adsorptive Removal of Cd(II) by a Novel Extracellular Biopolymer Produced by Pseudomonas alcaligenes: Equilibrium and Kinetics
Authors: Ji Zeng Quan , Wang Tian Hai , Luo Kai Hong , Wang Yao Qing
Published: December 2010

An extracellular biopolymer (PFC02) produced by Pseudomonas alcaligenes was used as an alternative biosorbent to remove toxic Cd(II) metallic ions from aqueous solutions. The effect of experimental parameters such as pH, Cd(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Cd(II) was 6.0. The FTIR spectra showed carboxyl, hydroxyl and amino groups of the PFC02 were involved in chemical interaction with the Cd(II) ions. Equilibrium studies showed that Cd(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Cd(II) ions was estimated to be 93.55 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Cd(II) from wastewater.
Study on Hybrid Genetic Simulated Annealing Algorithm for Multi-Vehicle and Multi-Cargo Loading Problem
Authors: Wang Xiao Bo , Sun Jin Ying , Ren Chun Yu
Published: December 2010

This paper studies multi-vehicle and multi-cargo loading problem under the limited loading capacity. Hybrid genetic simulated annealing algorithm is used to get the optimization solution. Firstly, adopt hybrid coding so as to make the problem more succinctly. On the basis of cubage-weight balance algorithm, construct initial solution to improve the feasibility. Adopt the improved non-uniform mutation so as to enhance local search ability of chromosomes. Secondly, through utilizing Boltzmann mechanism of simulated annealing algorithm, control crossover and mutation operation of genetic algorithm, search efficiency so as to improve the solution quality of algorithm. Finally, the example can be shown that the above model and algorithm is effective and can provide for large-scale ideas to solve practical problems.
Determination of Dipole Spacing in Electrical Landfill Leakage Detection
Authors: Cheng Hong , Liu Peng Kun , Wang Yu Ling , Nai Chang Xin
Published: December 2010

The dipole spacing can directly affects the detecting sensitivity and accuracy in the landfill leakage detection by the high voltage direct current method. Based on the high voltage DC detecting model, the impact of dipole spacing on locating leaks is analyzed taking a single leak and multiple leaks as example. The results show that the greater the dipole spacing is, the higher the detecting sensitivity is; the smaller the dipole spacing is, the higher the detecting accuracy is. For multiple leaks, only one leak can be located when the dipole spacing is greater than the distance between the two leaks. In order to detect all leaks correctly, the dipole spacing should be smaller than the distance between the two leaks.
Study on the Econometric Model for Cost of Regional Eco-Urbanization of Poyang Lake Eco-Economic Zone
Authors: Yu Da Jin
Published: December 2010

Based on the analysis of the cost of urbanization, this paper constructs the econometric model for broad and narrow sense economic cost of regional eco-urbanization, and carries out case study on urban system of Poyang Lake Eco-economic Zone. The results indicate that we should highlight the construction of small towns, and take a development road of new urbanization of balance development of large, medium-sized and small cities and towns. The Econometric model for cost of regional eco-urbanization provides a new quantitative and practical method for the study of urbanization, and this paper provides a practical way for urbanization development of undeveloped areas.
iTunes U and the Construction of Open Educational Resources
Authors: Lu Zhen Xia , Zhang Yi Chun
Published: December 2010

To co-construct and share OERs is a common goal of global for education fields. iTunes U is an open and free educational platform constructed on the basis of iTunes, which provides brand-new development conditions and ideas for the co-construction and sharing of OERs. This article first raises the key problems for the co-construction and sharing of OERs and then analyzes why it is not only possible but also necessary for iTunes U to support the development of OERs.
A RBF Neural Network Approach for Fitting Creep Curve of Sandstone
Authors: Tan Yun Liang , Zhang Ze
Published: December 2010

In order to quest an effective approach for predicate the rheologic deformation of sandstone based on some experimental data, an improved approaching model of RBF neural network was set up. The results show, the training time of improved RBF neural network is only about 10 percent of that of the BP neural network; the improved RBF neural network has a high predicating accuracy, the average relative predication error is only 7.9%. It has a reference value for the similar rock mechanics problem.
Study on Relationship of Miners′ Psychological Characteristic and Safety Degree
Authors: Liu Xiao Li , Zhang Zhi Ye
Published: December 2010

The high rate of coal mine accident gives our country enormous economic loss, gives human heart heavy striking, and gives our country bad impression in international society. According to accident-causing theory, human unsafe behaviors and unsafe conditions of thing are the main reason of accident. The paper analyzes the relationship of miners′ psychological characteristic and safety degree, quantifies miners′ safety degree and brings forward measures to improve miners′ safety degree.
Risk Nonlinear Dynamic Model Based on Predictive Control of Engineering Project Management System
Authors: Feng Yan Ping , Zhu Da Chang
Published: December 2010

Many projects have the characteristic of large-scale, wide-rang, and at very important role in national economy. Nowadays engineering project management is still suffering from many problems due to various uncertainties kind of risks. Risk management is a crucial parts of successful engineering project management, but it is often not well predictive in many projects. Risk predictive is valuable and essential for decision support system. But risk factors in projects are complex and couple with each other, and normal risk predictive can not manifest this relationship fully. According to the uncertainness parameters in risk management, predictive control strategy is proposed in this paper. Considering the nonlinear dynamical process, the model of external disturbance is built as a part of control system, and its stability is also analyzed. The effectiveness of the proposed method is demonstrated through a numerical simulation.