bluuebunny/crossref_metadata_2025 huggingface dataset:
XPS and AES Study of Oxygen Interaction on the Surface of the ZrNi Intermetallic Compound
Authors: Roustila A. , Rabehi A. , Souici M. , Chene J.
Published: February 2012

ZrNi intermetallic compound is used in several application fields due to its very favorable characteristics for the storage of hydrogen. The hydrogen reactions are important, it is vital to examine the evolution of physico-chemical properties at the surface. X-ray photoelectron spectroscopy, is used to follow the evolution of electronic properties of ZrNi versus the ion sputtering in ultra high vacuum in the range 300-600°C. Morever, the evolution of species concentrations at the surface of ZrNi in the range 100-700°C is followed by means of Auger electron spectroscopy. The present results show that temperature and ion sputtering favor significant changes in surface properties of ZrNi. In situ annealing of ZrNi favors the oxygen decontamination associated with segregation of zirconium metal on the surface. The values of binding energies deduced from the reconstruction of XPS spectra, allowed the identification of species present at the surface. The results indicate that nickel is not contaminated and all the obtained sub-oxides are related to bonding states of oxygen with zirconium (Zr2O, ZrO, ZrO2 and Zr2O3). The ion sputtering of the surface of ZrNi causes preferential sputtering phenomenon. The later results from the removal of surface layers and from the appearance of zirconium oxide layers initially present on the surface. The results obtained by AES show the segregation of impurities (oxygen and carbon) and of zirconium on the surface of ZrNi. AES observations of Zr segregation start to be important above 300°C and this is in agreement with XPS analysis showing a Zr enrichment of the surface of ZrNi.
Influence of Material Properties in Explosive Cladding of Dissimilar Metals
Authors: Saravanan Somasundaram , Raghukandan K.
Published: February 2012

Explosive cladding produces a strong weld between two dissimilar metals using explosive energy. The influence of material properties in achieving strong AluminiumSteel, CopperSteel explosive clad is discussed in this study. The solidification microstructure is determined by the nature of the competitive growth between adjacent columnar grains and, therefore, has a significant influence in the final characteristics of fusion zone. A compatible interlayer can significantly reduce the solidification time resulting in an intermetallics free interface. The influence of interlayer in the lower limit of weldability window is also discussed.
Effect of Tool Rotation Speed and Feed Rate on Friction Stir Welding of 1100 Aluminum Alloy to Carbon Steel
Authors: Habibnia M. , Shakeri Mohsen , Nourouzi S. , Karimi Namdar
Published: February 2012

To achieve a defect-free butt joint of dissimilar metals by friction stir welding procedure, there are some major parameters, such as tool material and geometry, tool rotational speed, feed rate and tilt angel. This research is focused on dissimilar metals welding, namely 1100 Al alloy and 1045 carbon steel. In this paper, the effect of tool rotation speed and feed rate are experimentally investigated on surface appearance, microstructure and micro hardness of the friction stir welded plates. Optimum values of tool rotation speed and feed rate have been achieved experimentally by the quality of the butt joint.
Investigation on Wettability and Metallurgical and Mechanical Properties of Cemented Carbide and Steel Brazed Joint
Authors: Akbari Mousavi Seyed Ali Asghar , Sherafati P. , Hoseinion M.M.
Published: February 2012

In this study the wettability, microstructure and mechanical properties of joining between cemented carbide and CK35 steel which brazed with two filler metals, L-Ag40Cd and L-Ag34Cd, were investigated. Wettability test shows that with increase of brazing time, the contact angle decreases and the best situation was resulted in the 20 minute brazing. Microscopic investigation of the brazed area with both filler metal shows that there is a copper enriched primary phase and eutectic microstructure in the silver enriched matrix which composed of copper enriched particles. The amount and the dispersion of precipitates are depended upon type of filler metal and brazing temperature. The results show that brazing with L-Ag34Cd filler metal at 800 °C exhibit superior shear strength in the level of 108 MPa.
Preparation of Pure Silica Oxide (SiO2) and Zeolite Y from Rice Husk as an Ion Exchanger for Emergency Water Treatment System Using in Flood Affected Area
Authors: Rahman M.M. , Awang M.B. , Mohd Yusof Alias
Published: February 2012

Thermal and acid wash treatment of rice husk has been conducted 550 to 600 °C in air atmosphere and chemical treatments consisted of acid, H2SO4. Purity, pore size distribution, FT-IR and SEM micrographs of treated and non-treated samples are presented. In this study the acid treated rice husk ash was used as SiO2 source in the preparation of zeolite Y, a medium siliceous zeolite used as an ion exchanger in water treatment process. Obtained zeolite Y, BET Surface area 621.18 square meters per gram, pore volume is 0.33 cubic centimeters per gram and its average pore diameter is 21.222 Å. Ion-exchange capacities were tested through a column packed in zeolite Y by the artificially polluted water filtration, filtrate was analysed by ICP-MS and elements (As, Ba, Ca, Cd, Co, Cr, Bi, Be, Pb Ni etc.) in filtered waters was found in negative amounts. Zeolite Y is found a highly efficient ion-exchange material. So, mini water filtering system is a good for water treatment, even water is highly polluted by toxic elements.
Preparing of CaCO3 Nano-Particles by Mechano-Chemical Method
Authors: Sargheini J. , Ataie Abolghasem , Salili S.M. , Johari M. , Hadad M.
Published: February 2012

This research was aimed to synthesize calcium carbonate nanoparticles from CaCl2, NaCl and Na2CO3 precursors by mechano-chemical route without any subsequent heat treatment of the as-milled powder. Effects of intensive milling duration and amount of NaCl as a diluting agent on the powder particle characteristics have been investigated. XRD results showed that CaCO3 nanoparticles were obtained after 30 minutes of continuous milling in the planetary ball mill regardless of the amount of NaCl. Further milling up to 10 hour resulted in peak broadening indicating the crystallite refinement. For the 10-hour milled sample in the presence of 3.5 mole% NaCl, the mean crystallite and particle sizes were 12 and 56 nm, respectively. Those values decreased slightly when the amount of NaCl increased from 3.5 to 10.3 mole%.
Artificial Dry Heat Temperature Effects on Tensile Properties of Chlorinated Poly (Vinyl Chloride)
Authors: Bazoune A.
Published: February 2012

Chlorinated-PVC (CPVC) pipes are used extensively for water supply pipes, wastewater, and gas distribution. They are desired for their quick installation, durability and strength. CPVC is a heat resistant type of plastic that welds, bends and shapes easily. Its utilization in harsh environmental conditions requires an understanding of weathering effects on its mechanical properties. In this work, the effect of dry heat on the tensile properties of CPVC is studied using artificial weathering procedures. CPVC specimens were prepared according to ASTM standard D 638 and exposed to accelerated dry heat temperature to simulate natural weathering effects of long term outdoor exposure. Tests were performed at two different temperatures of 40o C and 70o C for duration up to 3000 hours. Stress-strain curves were developed for this material and weathering effects on the tensile strength, modulus of elasticity and strain at fracture were obtained. The results of this investigation show that the ultimate tensile stress and the fracture stress exhibit a slight increase over the period of the exposure. The modulus of elasticity was not affected by the exposure while the fracture strain decreases slightly at the beginning of the exposure and remains constant for the remaining period of the exposure.
Fabrication, Mechanical Characterization and FTIR Spectroscopic Analysis of Fish Scale Reinforced Epoxy Composites
Authors: Satapathy Alok , Pradhan Manoj Kumar , Mishra Debadutta , Patnaik Amar
Published: February 2012

This paper describes the processing and characterization of a new class of epoxy matrix composites reinforced with short fibers obtained from the scales of a fresh water fish (Labeo rohita). The functional groups involved in the formation of the resulting composite are identified. Fourier Transform Infrared (FTIR) spectroscopic analysis shows that the formation of hydrogen bonds occurring at the fiber-matrix interface between the oxygen atom of the epoxy and hydrogen atom of the polypeptide chain of fish scale is responsible for the formation of this new class of composites. These composites possess improved micro-hardness and exhibit tensile and flexural strengths marginally different from those of neat epoxy. These composites are expected to find applications as potential materials for conveyor belt rollers, pipes carrying pulverized coal in power plants, pump and impeller blades and also as low cost housing materials.
Theorical Analysis of Leakage in High Pressure Pipe Using Acoustic Emission Method
Authors: Davoodi Saman , Mostafapour Amir
Published: February 2012

Leak detection is one of the most important problems in the oil and gas pipelines. Where it can lead to financial losses, severe human and environmental impacts. Acoustic emission test is a new technique for leak detection. Leakage in high pressure pipes creates stress waves resulting from localized loss of energy. Stress waves are transmitted through the pipe wall which will be recorded by using acoustic sensor or accelerometer installed on the pipe wall. Knowledge of how the pipe wall vibrates by acoustic emission resulting from leakage is a key parameter for leak detection and location. In this paper, modeling of pipe vibration caused by acoustic emission generated by escaping of fluid has been done. Donnells non linear theory for cylindrical shell is used to deriving of motion equation and simply supported boundary condition is considered. By using Galerkin method, the motion equation has been solved and a system of non linear equations with 6 degrees of freedom is obtained. To solve these equations, ODE tool of MATLAB software and Rung-Kuta numerical method is used and pipe wall radial displacement is obtained. For verification of this theory, acoustic emission test with continues leak source has been done. Vibration of wall pipe was recorded by using acoustic emission sensors. For better analysis, Fast Fourier Transform (FFT) was taken from theoretical and experimental results. By comparing the results, it is found that the range of frequencies which carried the most amount of energy is same which expresses the affectivity of the model.
Sintering Effect on Boron Based Bioglass Doped Composites of Bovine Hydroxyapatite
Authors: Gunduz Oguzhan , Ahmad Zeeshan , Salman S. , Inan Ahmet Talat , Ekren Nazmi , Agathopoulos Simeon , Ozyegin L.S. , Kayali E.S. , Oktar Faik Nuzhet
Published: February 2012

The use of bovine hydroxyapatite (BHA) provides an alternative approach in bioceramics based on natural resources, time and cost efficiency. In this study, composites of calcinated bovine derived BHA were utilized. These were doped with known quantities of boron based bioglass (5 and 10 wt. %) and a range of composites were prepared at selected sintering temperatures (1000-1300 °C). The resulting structures were tested for several mechanical properties (porosity, compression and microhardness). Micro-structural analysis (electron microscopy and x-ray diffraction) was also performed on these samples, and these findings were correlated with results obtained from mechanical tests. The results indicate that there is a positive correlation between compression strength and sintering temperature and the optimal properties are obtained at a temperature of 1200°C and a boron oxide bioglass doping content of 5 wt. %.
Experimental on the Service Behavior of Large-Span Steel-Concrete Box Beams
Authors: Li Lei , He Gui Chao , Zhou Ling Yu
Published: February 2012

Bending properties of steel-concrete box beams with three different design parameters are tested under the function of monotonic load to better understand the influences of degree of shear connection and height-thickness ratio of web on nonlinear property, bearing capacity and failure modes thereof. In addition, study on failure modes, slip between the concrete desk and the steel box beam, overall service behavior of the cross section, bending bearing capacity of the normal section, shear lag, etc. is conducted on composite box beams, through which, the failure modes and degree of shear connection of composite box beams are proved to be related to the height-thickness ratio of the web. Finally, slip distribution and relation between slip-strain curves and strain curves of vertical distribution of composite box beams are made clear.
A Research on Prediction and Control of Welding Distortion and Residual Stress for an All-Welded Steel Bridge
Authors: Yan Xing Fei , Shi Lei , Zhou Liang
Published: February 2012

A typical case of integral all-welded panel joints on Shanghai Minpu Second Bridge is discussed in this paper. The prediction of welding residual stresses at joints is achieved by thermal elasto finite element analysis, and the research reveals that a proper scheme of multi-layer welding craft will reduce welding distortions and residual stresses through mutual offset. The welding distortions at upper and lower chord joints (Type I) and those of the overall structural model are predicted with the distribution of residual stresses obtained. The research aims to provide a theoretical basis for the control of welding distortion, the optimization of welding craft and the constitution of optimal assembly welding craft.
Seismic Risk Analysis of Bridge Structures Based on Total Probability Theorem
Authors: Wang Guo Liang , Wang Jian Min
Published: February 2012

Considering the uncertainties in structural capacities and seismic motions, a probabilistic-based seismic risk analysis approach for bridges is proposed in this paper. In this approach, the Total Probability Theory (TPT) is used to divide seismic risk analysis into three main steps: seismic hazard analysis; structure damage analysis; and failure probability analysis. The parameters of seismic risk analysis are assumed to be an independent and discrete Markov process, resulting in rigorous and consistent seismic risk functions for calculating the annual average probability of exceeding a designated limit state of structure under a specific level of seismic intensity. A case study of seismic risk analysis was performed on a three-span continuous rigid-frame bridge. The results show that the approach presented in the paper is applicable for the seismic risk analysis of bridge structures, and is an effective tool to assess the performance of bridge structures under earthquake actions.
Study on Steel Strand’s Reasonable Tension Order of Reaction Wall
Authors: Chen Dai Guo , Yao Yong , Gu Wei
Published: February 2012

Pre-stressed reaction wall is an important test facility in structure laboratory．Reaction wall will bear large static and dynamic loads when working, so pre-stressed concrete structure is often used. A model of micro-concrete pre-stressed reaction wall is made in the test in order to insure tension quality of steel strand of reaction wall. Proposed 4 different tension schemes of reaction wall pre-stress rebar, and a comparative study on the variety trend and distribution of strain on reaction wall in the 4 different schemes．The experimental results show that the best schemes of tension pre-stress rebar is：use the wall cross-section center of gravity as the symmetric point, tension symmetrical up and down from central to outside．And we suggest that two times or supplement tension methods be use to stretching steel strand of reaction wall.
Reliability-Based Optimization Design of Variable Cross-Section Component
Authors: Zhang Tian Xiao , Liu Xin Hui
Published: February 2012

Abstract: Variable cross-section components are widely used in engineering practice. It is clear that reliability-based optimization design of variable cross-section component is important for engineering design. This variable section widget for reliability and the perturbation design, we propose a perturbation method of the reliability design about the variable cross-section components. We may rapidly obtain the variable cross-section component's reliability information accurately, in basic random variable probability characteristic certain situation. We propose a method with practicality for the relevant reliability design.
An Experimental Study on Fire Resistance Performance and Evaluation of Asymmetric Slim Floor Beam
Authors: Kim Hyung Jun , Kim Heung Youl , Park Soo Young
Published: February 2012

Composite beam using asymmetric H-shaped steel is one of the constructional structures developed in the advanced countries in Europe since early 1990s. The purpose of this study on composite beams where H-shaped steel is partially laid in concrete slabs was to find how to design fire protection and improve fire-resistance to make deep deck plates provide the beams with advantages upon a fire and to improve stiffness in structural aspect. Only lower flange which is directly exposed to a fire was included in fire-resistance design in order to decide optimal fire- protection design condition and test was conducted for spray-coating and paint-coating. In the fire resistance test, web thickness and lower flange thickness were varied to derive the optimum condition for improving fire-resistance performance. It was observed from the test that 90-minute-protection employed to lower flange provided fire resistance for 3 hours. It was also observed that the basic shape resisted fire for 89 minutes, while web reinforcement and lower flange reinforcement provided fire-resistance for 112 and 157 minutes, respectively. The result showed that lower flange reinforcement is the most effective way to improve fire-resistance.
Research the Weathering Characteristics of Tertiary Silty Mudstone along Chengnan Freeway
Authors: Wan Shi Ming , Wu Qi Hong , Yang You Lian
Published: February 2012

In order to research the weathering characteristics of Tertiary silty Mudstone along Chengnan Freeway, the experiment of the engineering characteristics, the weathering durability, the weathering speed to be done for the different weathering degree silty mudstone. The test result show that when the weathering degree of the rock mass deepen, the content of clay minerals in the rock mass is increase, the activity chemical composition in the rock mass is decrease relatively, the dry density of the silty mudstone is decrease, the total porosity and the water absorption of the silty mudstone is increase, the mechanical properties is weak, the rock mass is soften and collapse easily. The weathering speed of the rock mass with the relevant to the weathering degree and the exposed area of the rock mass.
Reliability Analysis on Shear Capacity of Broad-Limb Special-Shaped Columns
Authors: Wang Tie Cheng , Chen Xiang Shang , Zhao Hai Long
Published: February 2012

Abstract. The limit state equation of the shear capacity with earthquake action effect combination is presented, and the statistical parameters and probability distribution of the representative value of gravity load and earthquake action effects in the limit state equation are discussed, in which, the representative value of gravity load complies with normal distribution, while the earthquake action effect complies with extreme value type-I distribution. By statistics on the test results of broad-limb special-shaped columns under repetitive-loading, indefinite coefficient statistical value on calculation model of shear capacity formula of broad-limb special-shaped columns is obtained, and then JC method is adopted to make a reliability analysis on the calculation formula. It is shown from the results that the formula is safe enough in calculating shear capacity of broad-limb special-shaped columns.
The Security Study of Train Derailment on High-Speed Railway Bridge
Authors: Lin Yu Sen , Xin Li Hua
Published: February 2012

In this paper vehicle-bridge coupling system is divided into vehicle system and bridge system. The equations of vehicle vibration and bridge vibration are solved in numerical method, considered the displacement of wheel and rail as convergence criterion. The security of running train is studied on the hand of wheel-rail force, derailment coefficient, load decrement rate of wheel weight, and the reason of train derailing on high-speed railway bridge is analyzed. By the example of multiple span simple supported beam bridge, the result derived by this method is proved that the bridge meet train security and amenity requirement.
Technologies on Replacement of Structural Members in Prestressed Concrete Cable-Stayed Bridges
Authors: Li Hong Jiang
Published: February 2012

Different from traditional strengthening methods, the technology on replacement of structural members is a new strengthening concept for solving the problem of local failures in prestressed concrete cable-stayed bridges. To clarify the characteristics and realization ways of this technology, practical experience and latest achievements of strengthening prestressed concrete cable-stayed bridges in recent years in China were summarized comprehensively, such as replacement of stay cables, replacement of closure segment, replacement of tension rocker bearing cables at subsidiary piers, et al. Forms of Special diseases were described, and their failure mechanisms were given. Then calculation methods and key techniques of these strengthening ways were introduced. Engineering application and practice showed, the technology on replacement of structural members is a system engineering, namely, not only new structural members should meet the mechanical requirements of their own, but also the structural condition of whole bridge should be improved through replacing structural members. Establishment and development of this technology had important and far-reaching significance to promote the technical level of strengthening long-span bridges under the condition of special diseases and ensure bridges in the sate of safe and sustainable operation.
Study on the Development of Bridge Detection Vehicle Test
Authors: Song Jin Bo , Xu Zhao
Published: February 2012

Bridge construction is the national important foundation construction of bridge engineering, is the relationship between society and economy to coordinate development of lifeline engineering. Bridge construction of rapid development, huge capital investment, the economic society of the prominent role, making it to the bridge's safety, durability, more and more attention. Based on the analysis of detection results of existing bridges, bridge on the future work state of speculation, pointed out the possible development trend for the future to provide advice, bridge maintenance. As the bridge reinforcement and reconstruction to provide accurate and comprehensive data.
Overall Stability Analysis of Dome Steel Structure on Dome Roof in Large Tanks Based on FEM
Authors: Cao Jin Feng , Ji Cai Hong
Published: February 2012

In petrochemical industry, single layer dome steel structure is usually used to support dome roof in cylindrical tank. This paper takes a dome steel structure with a diameter of 52m（type Kiewitt）designed by a petrochemical corporation of Lianyungang as an example. According to the People's Republic of China industry standard JGJ61-2003, utilizing Arc-Length method of the finite element analysis software Abaqus to analyze this example’s overall non-linear geometry, and utilizing finite element increment iteration to analyze this example’s response during the whole loading, we obtain the instability critical loads eventually. The results reveal that under given loading the load factor of dome steel structure is 5.426 and overall instability will not occur.
Stress Monitoring on Cantilever Construction Stage of the Main Bridge of South-to-North Water Transfers Canal
Authors: Du Qing , Yang Yi Peng , Li Xiao Hui
Published: February 2012

This paper presents the importance of stress monitoring in cantilever construction stage of concrete continuous bridge. The stress analysis model based on the actual bridge is established by the beam elements. The measuring measurement scheme and influencing factors of stress monitoring are introduced. The measured results matched the calculated results very well, which meet the needs of construction safety.
Study on Bridges’ Global Flexibility Index for Ambient Vibration
Authors: Du Qing , Jiang Hong Yu , Li Xiao Hui
Published: February 2012

The present study uses the Global Flexibility Index (GFI), which is the flexibility matrix’s norm. For cases of ambient vibration, in which excitations are unknown, the flexibility matrix is unavailable, and the GFI cannot make out. Using the ANSYS set up and fixes the modal of structure in the condition of Vibration model to a unit, and then put the modal in the condition of Vibration model to a quality. Get natural frequencies and mode shapes, make up flexibility matrix, and then calculate Global Flexibility Index. Measure the Index regularly. With the change of the Index, judge the damage degree of the bridge. A sharp increase in the index calls for further detailed investigation for appropriate actions, such as reinforcement or maintenance.
Mechanical Analysis on Anchorage Structure of Self-Anchored Suspension Bridge
Authors: Zhou Jia Xing , Su Qing Tian , Wu Chong , Yang Guo Tao
Published: February 2012

Main cables of self-anchored suspension bridge are anchored at each end of main girder, thus producing a self-balancing system. In order to transfer the cable force to main girder safely and smoothly, the anchorage region is one of the most critical issues in design of a self-anchored suspension bridge. It is hard to fully understand the mechanical behavior only by spatial beam and column model, so a 3D shell finite element model is established to overcome the limitation of spatial beam and column model. The mechanical behavior of initial designed anchorage structure is then analyzed and a modified anchorage fabrication is proposed to improve the stress distribution. Analysis results show that: the modified anchorage system effectively reduces the stress level of anchorage structure and enhances the efficiency of anchorage structure.
Numerical Research on Relationship between Displacement and Ground Overloading of Soil Nailing with FLAC
Authors: Sun Jian Ping , Shao Guang Biao , Jiang Zong Bao
Published: February 2012

Based on an engineering example,the FLAC-3D was applied to set up numerical analysis,analyzing the influence of the overloading acting position and the magnitude on the horizontal and vertical displacement of the foundation pit.Some useful conclusion was obtained,which will offer reference to the design and construction of the soil nailing.
The Study for the Critical Moment of Arches in the Action of Endmoment Considering Shear Lag
Authors: Chen Y. J. , Luo Qi Zhi
Published: February 2012

Based on six basic assumptions and deformation behaviour, the total potential energy of arches are obtained. The basic displacement functions are expressed with spline function. According to minmum potential energy principle, the characteristic equation is deducted. The characteristic value is solved by multiplication power method. An exampleof arches in the action of endmoment is calculated. The critical positive and negtive moment of out-of-plane stability in arches with single sysmetry axis section are studied.
Simplified Models to Evaluate Site Characteristic Period
Authors: Chen Long Wei , Wang Wei Ming , Yuan Xiao Ming
Published: February 2012

Characteristic site period is an important index in seismic zonantion and seismic resistance design. In seismic response spectrum theory, the characteristic design period is closely related with site characteristic site period which is comprehensively covering site parameters (site categories, site shear wave velocity, site thickness, etc.). Two models, i.e., single-layer model and double-layer model, are adopted and theoretical solutions are deduced by means of the amplification coefficient function. The natural site period are theoretically deduced and presented
Creep Property of Reticulate Red Clay under Stepped-Load Creep Tests
Authors: Li Jian Zhong , Cao Yan Fu , Qing Ya Jun
Published: February 2012

Stepped-load creep tests of undisturbed and remodeled specimens of reticulate red clay was performed in the present study. Test results and analyses of the results show that: (1) Both undisturbed and remodeled specimens showed significant creep deformation in primary loading, unloading and reloading stage, and the creep deformation of remodeled specimen is much bigger than that of undisturbed one in primary loading and reloading stage; (2) The effect of a previous loading stage on the deformation induced at a succeeding stage is significant in primary loading and reloading stage; (3) The amount of the creep deformation can be calculated accurately by an empirical formula.
Research on Shear Failure Criterion for Layered Rock Mass
Authors: Zhang Zhi Zeng , Zhou Lan Lan , Yuan Zhen Xia , Sun Zhong Hua
Published: February 2012

In order to study the stability of layered rock mass, a shear failure criterion for layered rock mass is presented and its program is compiled in C language. The shear failure criterion consists of two parts: firstly, four empirical expressions are suggested in which shear strength parameters vary with the direction; secondly, a pilot calculation method is developed to judge whether a shear failure plane in layered rock mass occurs or not and give its occurrence under three dimensional stress condition. A triaxial numerical experiment on layered rock mass is designed to test the shear failure criterion, and its results reflect the characters including obliquity effect, confining pressure effect and failure mode which conform to the previous triaxial tests.
Nonlinear Finite Element Analysis of Diamond Bird-Beak TX-Joints
Authors: Zhu Zhao Quan , Liu Sheng Liang
Published: February 2012

Abstract. The diamond bird-beak TX-joint is a novel configuration for tubular structures and there are few correlated papers for it. Non-linear FE analysis is carried out on axially loaded TX-joints in order to study the local static behavior of this type of joint. The individual influence of the following geometric parameters on the joint capacity, section width ratio β of brace to chord members, section width to wall thickness ratio 2γ of chord member, and wall thickness ratio τ of brace to chord members is made clear. Increasing either β or τ will enhance the joint capacity and increasing 2γ will lower joint capacity. A reduction equation is proposed to consider the load effect of chord and the axial forces of out-of-plane braces. The tension of out-of-plane braces always lowers the ultimate capacity of joint. The same tension and compression have the equal influence on the joint capacity.
Correlation Analysis Between the Treating Depth of PVD and the Subsidence of Soft Ground Foundation of Expressway
Authors: Chen Ji Bin , Zhao Qi Hua , Peng She Qin , Xiong Ping Hua
Published: February 2012

The quality of pre-investigation and other reasons would lead to the disagreement between the depth of prefabricated vertical drain(PVD) and actual soft ground foundation. All these factors would have a seriously bad effect on the subsidence and the stability of soft ground foundation. The author combines the Suining-Ziyang-Meishan expressway project, detailedly analyses the correlation between different depths of PVD and actual soft ground foundation based on observation settlement data. The results shows: Before the limit fill height(LFH), with load increases, the depth of PVD has little effect on subsidence rate, the curve of PVD depth-subsidence rate is approximately linear; when backfilling height exceeds the LFH, the closer depth of PVD is to actual depth, the more obvious soft foundation reinforcement effect is, the larger rate and value of subsidence are. However, when PVD depth is 1m deeper than the actual, subsidence rate decreases. In addition, according to the difference of observation total settlement and theoretical calculation settlement due to the difference between PVD depth and actual, adjust preloading period to meet the requirements of pavement construction and post-construction settlement.
Research on the Weathering Problems of Longmen Grottoes
Authors: Xu Tao , Ding Wu Xiu
Published: February 2012

Longmen Grottoes is the world’s cultural heritage, now it is facing with serious weathering problems. The weathering problems of Longmen Grottoes are divided into three categories: physical weathering, chemical weathering and biological weathering. With the continuous deterioration of environmental and climatic conditions, the damage of chemical weathering to Longmen Grottoes becomes more and more obvious. The damage and damage mechanisms of three categories of weathering to Longmen Grottoes are discussed based on the previous studies.
Research on the Feasibility of Shape-Stabilized Phase-Change Materials at Lower Temperature Used in the Phase Change Wall
Authors: Yan Quan Ying , Huo Ran , Jin Li Li
Published: February 2012

The shape-stabilized phase-change paraffin at lower temperature is an ideal material used in the phase-change wall. It can enhance the thermal storage capacity of the wall and save energy. The thermal properties of shape-stabilized phase-change paraffin were studied experimentally in this paper. The phase change temperature, latent heat and the stability of shape-stabilized phase-change paraffin with different component were analyzed. The critical mass fraction of paraffin required in the materials was discussed. The results may provide the basis for the application in the practical engineering in the future.
Study on Stress-Strain Behavior of Cohesive Soil Mixing with Gravel by Triaxial Test
Authors: Wang Yuan Long , Zhu Jun Gao , Zhou Jian Fang
Published: February 2012

The mechanical behaviors of a cohesive soil mixing with gravel were investigated in consolidated-drained triaxial tests. Three soils with different percentages of gravel mixed with the cohesive soil, i.e. 50%, 75% and 87.5%, were tested, and the inference of gravel percentage to the stress-strain behavior is investigated. The results indicate that the shear strength of the soil increases with the increase of gravel percentage. Compared to peak strength of GP50, that of GP75 and GP87.5 increases by 14.4%~32.8% and 20.9%~40.5%. The initial and secant Young’s modulus of the soil increases significantly when the gravel percentage is greater than 75%.
Experimental Study on Concrete-Filled Glass Fiber Reinforced Gypsum Wall Panel Compression Members
Authors: Zhao Kao Zhong , Wang Feng , Bian Xiao Feng
Published: February 2012

The concrete-filled glass fiber reinforced gypsum wall panel is a kind of panel that the inside cavums of the glass fiber hollow gypsum panel are filled with concrete, which can be used as the bearing wall of a building. The influences of eccentricity distance and height to thickness ratio on the bearing capacity of the compression wall panels were studied, and the failure mechanism and bearing capacity of compression wall panels were gained through the experiments of twenty-seven(nine groups) axial compression wall panel specimens and twenty-seven(nine groups) eccentric compression wall panel specimens. The analysis results indicate that the bearing capacity of compression wall panels is obviously affected by the eccentricity distance and height to thickness ratio, and there is a linear relation between bearing capacity and eccentricity distance. The bearing capacity calculation formula of the concrete-filled glass fiber reinforced gypsum wall panel is obtained by regression analysis, which provides reliable gist for structural design of concrete-filled glass fiber reinforced gypsum wall panel buildings.
Analysis of Dilatancy Effect when Mortar Bolt Interface Destroying
Authors: Song Zhi Fei , Lei Jia Hao , Sun Shi Guo
Published: February 2012

The experimental study on the case of bond failure happening at the grout-rock interface about mortar bolt, the concrete matrix is sudden destroyed when loading specimen which grouting length 60mm, compared to previous research, it is reduced by dilatancy effect when mortar is pressed out of the body, this paper analyzes the concrete axial radial pressure when mortar is pressed out and the dilatancy effect using the finite element method.
Test Study on Dewatering Effect of Sewage Sludge by Vacuum Method
Authors: Gao Yu Feng , Du Guo Qing , Zhou Yuan , Wang Shu Mao
Published: February 2012

The aeration-vacuum dewatering method is a new kind of solid-liquid separate technique. The filter clogging problem in the routine vacuum dewatering procedure of sludge can be solved by the method. This method is used to dewater the sewage sludge in this paper. Through the dewatering model test of the sewage sludge with this method, the change law of the solid content and the volume of the sewage sludge are studied. The dewatering effect of sewage sludge is got further more. The test results indicate that there is a great promotion for improving the solid content and reducing the volume by using the aeration-vacuum method.
Mechanical Behavior of Broken Stone Fills under Dynamic Consolidation
Authors: Gao Zheng Guo , Du Yu Long , Huang Xiao Bo , Huang Xin
Published: February 2012

This paper studies the dynamic response characteristics of broken stone fills. Numerical simulation and in-situ test of the acceleration and settlement of a high fill under dynamic consolidation are carried out. The result shows that increasing compact energy and the compact numbers can improve the reinforcement effect. There is no significant relationship between the dynamic compaction number reaching the stable settlement and compact energy. When the compact energy is the same, compaction with a heavier hammer is better than compaction with a lighter hammer.
Upper Bound Solution for Ultimate Bearing Capacity of Foundation Based on Unified Strength Theory
Authors: Tang Yao , Tang Ping
Published: February 2012

Based on unified strength theory, an upper bound solution for bearing capacity of foundation is established considering the strength of soil above the basement by using Prandtl slip model. The proposed method could be degenerated to classical slip-line method in some certain situations. A series of results could be presented by means of changing the parameters of unified strength theory. The results obtained by this proposed method are greater than those by Terzaghi method, which is mainly because the positive effects of soil strength above foundation base. Since unified strength theory could be simplified to Mohr-Coulomb strength theory in a certain situation, the results are close to those obtained by Meyerhof method. This proposed solution can consider the effects of intermediate principal stress so that we can make full use of the potential capacity of soil, which is a rigorous upper-bound solution. Other solutions are special cases of this proposed solution.
Application of Comprehensive Evaluation Method to Foundation Pit Engineering
Authors: Zhang Jian Xin , Dai Jia Li , Liu Bin
Published: February 2012

Based on the monitoring data of the deep foundation pit, established an adjacent deep foundation pit safety risk fuzzy synthetic evaluation model, and then determine safety grades , using the method to evaluate the safety of the environment surrounding the foundation pit. Practice proves that the method can reflect the risk condition of the pit, and provided a new way to check the security of the pit.
Study on the Deformation of Supporting Structure for Foundation Pit in Strata with Rock-Soil Combination
Authors: Yao Ai Jun , Zhang Xin Dong , Zou Xian Jun
Published: February 2012

Taking the deformation of row pile supporting structure of foundation pit in strata with rock-soil combination as the research target and taking an open cut metro deep foundation pit as an example, by in-site monitoring and numerical simulation, analyze the horizontal displacement of retaining piles and the change law of steel support axial force in the strata with rock-soil combination, and summarize the change law of row pile supporting structure in the process of excavation under the conditions of this strata, so that to provide experience and guidance for similar engineering design and construction. The results show that: the structure of foundation pit has obvious effects on deformation and internal force of supporting structure, the result obtained from numerical simulation fits well with the tendency of monitoring data changing. In which, the deformation of row pile supporting structure in the middle and upper part of soil strata is larger, the deformation of middle and lower part of soil strata is comparatively smaller, the lateral deformation of row piles to basement has a tendency of gradual decreasing by taking the interface of rock-soil as a boundary.
Study on the Influence of the Shield Tunnel Deformation Due to Excavation of Foundation Pit with Field Data
Authors: Ding Jiang Shu , Xian Yao Qiang , Liu Tian Jun
Published: February 2012

The deep excavation of the foundation pit adjacent to the metro tunnel will change the stress state of the neighboring soil. And the deformation of tunnel will be induced which will cause impair to daily operation and the safety of metro tunnel. According to the practice of deep excavation neighboring the metro tunnel in Guangzhou, the main influence factors of deformation and stress of tunnel will be analyzed based on exaction conditions and field data. The conclusions will be benefit to similar projects.
Icon, Archetype and Symbolic Meanings of Dragon: An Interpretation of Design Theme and Image
Authors: Wen Yi Feng
Published: February 2012

"Dragon" is an important design theme and image, to be applied in many design fields, so summing up and interpreting relevant issue of dragon connotation can help better application of dragon image in design. This paper tries to expound dragon iconography, archetype and symbolical meanings in terms of etymology, document research and Jung’s psychology theories. In the light of both objective and subjective meanings this paper regards that the essence of dragon which is mythological being in human subconscious imagination symbolizes and integrates the various great power of nature.
A Comparative Study on Locating Critical Slip Surface in 2D and 3D Limit Equilibrium Stability Analysis of Slopes
Authors: Xie Mo Wen , Wang Zeng Fu , Liu Xiang Yu , Jia Ning
Published: February 2012

The Various methods of optimization or random search have been developed for locating the critical slip surface of a slope and the related minimum safety factor in the limit equilibrium stability analysis of slope. But all these methods are based on a two-dimensional (2D) method and no one had been adapted for a search of the three-dimensional (3D) critical slip surface. In this paper, a new Monte Carlo random simulating method has been proposed to identify the 3D critical slip surface, in which assuming the initial slip to be the lower part of an ellipsoid, the 3D critical slip surface in the 3D slope stability analysis is located by minimizing the 3D safety factor of limit equilibrium approach. Based on the column-based three-dimensional limit equilibrium slope stability analysis models, new Geographic Information Systems (GIS) grid-based 3D deterministic limit equilibrium models are developed to calculate the 3D safety factors. Several practical examples, of obtained minimum safety factor and its critical slip surface by a 2D optimization or random technique, are extended to 3D slope problems to locate the 3D critical slip surface and to compare with the 2D results. The results shows that, comparing with the 2D results, the resulting 3D critical slip surface has no apparent difference only from a cross section, but the associated 3D safety factor is definitely higher.
Vibro-Stone Column Reinforcement Mechanism and Numerical Analysis
Authors: Liu Yang , Yan Hong Xiang
Published: February 2012

Numerical simulation of vibro-stone column is taken to simulate the installation of vibro-stone column. A relationship based on test is adopted to calculate the excess pore pressure induced by vibratory energy during the installation of vibro-stone column. A numerical procedure is developed based on the formula and Terzaghi-Renduric consolidation theory. Finally numerical results of composite stone column are compared single stone column.
Application Study on Technology of Closure by Curtain Grouting in Mine Two of Dongfeng Coal Mine
Authors: Zhu Xue Jun , Wen Xing Lin , Peng Jie , Gao Lin Hai , Qu De Ming
Published: February 2012

The closure is just a way to build an underground wall blocking water by curtain grouting, by which in the district rich in water of mine two of Dongfeng coal mine curtain grouting was done to closure the passageway of water, reduce the water, remove the threat from water disasters, and improve the operation conditions, to promote the safety in production and increase the economic efficiency and the social efficiency; at the same time, protect the valuable water resources in periphery of mining area, maintain the balance of ecological environment, was worth to be popularized.
Application of Geological Modeling in Carbonate Reservoirs
Authors: Li Xu Tao , Lin Qing Fu , Lin Chang Song
Published: February 2012

Stochastic modeling technology of reservoirs has been broadly applied in clastic reservoirs while scarcely applied in carbonate reservoirs. The heterogeneity in carbonate rocks more severe than that in clastic rocks leads to more tough problems for geological modeling precisely. Taking into account of the difficulties such as extensive area to be modeled, insufficient drilling information, incomplete seismic interpretation data, lack of facies controlling constraints and sophisticated gas-water contact, a solution is proposed in this paper in which the inversed information of reservoir thickness is used as plane constraints during attribute simulation, two gas fields are constrained by different correlation coefficients and precise geological models have been set up finally through reserve calculation by use of variable gas-water contact, obtaining good results and providing a reference for this type of geological modeling.
A Variable Stiffness Method Application to Tunnel Support
Authors: Zhao Yu Cheng , Liu Zhan , Liu Ming Yuan
Published: February 2012

This paper focuses on finding a more effective bolting design method. Stress and displacement of variable stiffness beam were calculated by using material mechanics, variable stiffness bolting designs was simulated using FLAC5.0 software. The calculation indicates that the maximum displacement of a variable stiffness beam is less than that in a constant stiffness beam, while same material quantity is used; and proper variable stiffness designs can improve the bolting effect while same total quantity of bolts is used according to the simulations.
Study on Structural Development of Universal Segment Lining
Authors: Li Wei
Published: February 2012

The new type of segment lining for shield tunnel was developed, which is a kind of universal ring applied in metro tunnels. Based on Beam-spring Model, mechanical characters and controlling assembling modes of universal segment lining were obtained by simulating the possible assembling schemes.
The Field Ultrasonic Test of the Disturbance of Surrounding Rock by the TBM Construction
Authors: Wang Yu Suo , Wu Zheng Qun , Li Mao Hong , Yang Qi Xin
Published: February 2012

Measurement of the loose zone of tunnel surrounding rock is of great significance in the determination of its support measures and stability analysis. By identifying the loose zone, the effective measures can be adopted to ensure a safe tunnel construction. The ultrasonic test is conducted to the TBM construction of Zhongtianshan Tunnel to specify the disturbance range of the TBM construction on the surrounding rock and the anchoring lengths of bolts.