bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Method for Measuring the Residual Stresses in Multi-Layered Thin Film Systems
Authors: Liu Mei , Ruan Hai Hui , Zhang Liang Chi
Published: November 2012

To meet different electrical or optical functionalities, thin films are often of multiple layers processed at high temperatures. Substantial residual stresses can therefore develop in such thin film systems due to the disparate thermal properties of the individual material layers. High stresses can lead to mechanical failure of the systems and thus understanding the residual stresses in thin film systems is important. This paper presents a systematic way to characterize the residual stresses in epitaxial, polycrystalline and amorphous layers by using X-ray diffraction (XRD) techniques. The single-point XRD pattern renders the stresses of crystalline layers and the scanning XRD gives the curvature of the whole film. Based on the newly-developed analytical model, the residual stresses of each layer can all be determined.
The Interface Behavior of Micro Overmolding
Authors: Liu Hang , Xu Yan , Yung Kai Leung , Kang Chun Lei
Published: November 2012

Micro overmolding is becoming more important with the rapid development and applications of microproducts in bioengineering, electronics and other areas in recent years. This paper presents our findings in studying polymer interfaces in micro channels of a micro mold during overmolding process. The bonding strengths between polycarbonate (PC) and thermoplastic polyurethanes (TPU) were examined and compared under different overmolding conditions. Results show bonding behaviors in micro channels are not only affected by temperatures, they are also influenced by surface roughness.
Impacts on the Particle Size and Shape of Silica Sands by Different Methods of Cooling
Authors: Sun Qing Zhou , Wang Jian , Zhang Pu Qing , Zhao Zhong Kui , Han Yong , Jin Li
Published: November 2012

This paper studies the impacts on the particle size and shape of silica sands by roasting times and different methods of cooling, which finds out that different methods of cooling may lead to different cooling rates of sands; that is, adopt water-cooled fluidized bed to cool down sands, the cooling rate is the highest; the secondary is by cooling cylinder, and common fluidized bed leads to the lowest cooling rate. After being roasted and cooled, no matter which method is adopted, the sands are not changed obviously in particle size and shape, which indicates that roasting times, different cooling methods and cooling rates have no obvious impacts on the particle size and shape of silica sands.
Study on the Microstructure and Properties of Laser Remelted Ceramic Coatings on Low Carbon Steel Surface
Authors: Jiang Xin , Zhang Fu Qing , Jin Yu Jie , Qu Xing Tian , Wang Zhi Ping
Published: November 2012

The plasma spraying Al2O3-13%TiO2 (abbreviated as AT-13) ceramic coatings on Q235B steel surface were dealed with laser remelting technique. The microstructure and properties before and after laser remelting were studied. Experiment results shown that the microstructure of laser remelted ceramic coatings was dense, no porosity appeared. The main compositions of laser remelted ceramic coatings were α-Al2O3 and a small amount of TiO2 and TiAl2O5. Microhardness of AT-13 plasma spraying coatings and laser remelting coatings were measured with vickers, and the maximum microhardness value of the former was 1000 HV0.2 , while that of the latter was 1700 HV0.2; The average bonding strength value of AT-13 plasma spraying coating was 24.36 Mpa, while the average bonding strength value of laser remelting coating was more than 67.02 Mpa. The wear resistance of laser remelting coatings was higher than that of AT-13 plasma spraying coatings through the pin-dish particle wear test.
Compound Helicopter Optimum Design Based on Genetic Algorithm
Authors: Wang Fang , Chen Ming
Published: November 2012

Install thrust propeller and wings to coaxial helicopter, constitute a compound helicopter. Compound helicopter has greater speed, farther voyage, while retaining advantages of the helicopter which can take off and land vertically without runway.Preliminary design is an important stage in compound helicopter design work. It covers aerodynamic analysis, flight mechanics analysis, dynamic analysis, flight performance calculation and weight characteristics calculation. These aspects intertwined, which deepened the complexity of the preliminary design. Use genetic algorithms to optimize the design of the general parameters. Under constraint conditions of meeting flight performance requirements, calculate the general parameters which make the objective function optimal. Objective functions usually include weight efficiency and Miri’s criterion. This method without repeated design can shorten development cycle, improve economy and ensure design quality.
Luminescence Properties and Energy Transfer of Sm3+-Eu3+ Co-Doped Gd2(MoO4)3 Red Phosphors
Authors: Geng Xiu Juan , Chen Yong Jie , Tian Yan Wen , Xiao Lin Jiu
Published: November 2012

The red phosphor Gd2(MoO4)3:Eu3+,Sm3+ was prepared by sol-gel method. The morphology and luminescence characteristics of the phosphor particles were characterized by scanning electron microscopy (SEM) and fluorophotometer. The results showed that the phosphor had the advantages of small particle size and the uniform particle size distribution. The luminescence properties of Eu3+ ions in Gd1.37Eu0.6Sm0.03(MoO4)3 could be evidently improved by co-doping of Sm3+ ions, which was due to the efficient energy transfer process from Sm3+ to Eu3+ ions. The chromaticity coordinates for Eu3+ doped Gd1.4Eu0.6(MoO4)3 and Eu3+ and Sm3+ codoped Gd1.37Eu0.6Sm0.03(MoO4)3, are(0.662, 0.329) and (0.668, 0.331), respectively. Because of the introduction of Sm3+ into the red-emitting phosphors, the chromaticity coordinates of Gd1.37Eu0.6Sm0.03(MoO4)3 phosphor is closer to the standard values of International chromaticity coordinates(0.67, 0.33). So Gd1.37Eu0.6Sm0.03(MoO4)3 shows good prospect for red phosphors of white LED.
Functions of Step Gating System in the Lost Foam Casting Process
Authors: Zhou Hong , Luo Li Heng
Published: November 2012

In order to explore whether the step gating system played a role in lost foam casting (LFC) process, this paper simulated the mold filling process of a step gating system with an auxiliary sprue and three side ingates by using the gravity LFC model of the code FLOW-3D, and analyzed its mold filling characteristics in LFC. It is found the mass flux ratio through the bottom-side ingate exceed 82% the total mass flux, much more than through the others. And it is also found the metal temperature of the middle region in the height direction is lower than the upper region or bottom region. The results show that the step gating system is not able to achieve its main roles in LFC. Our results can be used to design gating system in LFC.
Influence of Smoke on Metallographic Structure of Short Circuited Melted Mark
Authors: Wang Lian Tie , Gao Wei
Published: November 2012

When fire breaks out, the gas composition and concentration as well as smoke concentration of burning part vary from those in normal environment. The gas and smoke absorbed during solidification of short circuited melted mark occurred in such environment will certainly have an effect on grain shape, grain size, holes distribution and impurity element distribution of organization of melted mark. The gas in the environment has a certain influence on the organization of short circuited melted mark, but the influence is smaller than that of smoke. The reason may be that the gas is mingled with certain amount of tiny smoke particles inevitably which play a role in the solidification of melted mark. Compared with short-circuit samples in normal atmosphere, carbon content of short-circuit samples increases and oxygen content decreases in the environment of smoke.
Constitutive Modeling of the Rate-Dependent Behavior of Ti-6Al-4V Using an Arrhenius-Type Law
Authors: Xiao Jun Jie , Li Dong Sheng , Li Xiao Qiang , Jin Chao Hai , Zhang Chao
Published: November 2012

Uniaxial tensile tests were performed on a Ti-6Al-4V alloy sheet over the temperature range of 923K-1023K with the strain rates of 5×10-4s-1-5×10-2s-1 up to a 25% length elongation of the specimen. The true stress-strain curves reveal that the flow stress decreases with the increase of the temperature and the decrease of the strain rate. In the same process, the accompanying softening role increases. It is found that the Ti-6Al-4V shows the features of non-linearity, temperature sensitivity and strain rate dependence in hot environment. Finally, an Arrhenius-type law has been established to predict the experimental data and the prediction precision was verified by the plotting of parameter and flow stress, which revealed that the error of stress exponent was only 4.99%. This indicates the flow stress model has high precision and can be used for the process design and the finite element simulation of hot forming thin-wall Ti-6Al-4V alloy components.
The Influence of Different Subbase Materials on the Crack of Cement Stabilized Macadam Base during Construction
Authors: Liao Xiao Feng , Xiao Fen , Chen Zhong Da , Xing Lei
Published: November 2012

According to actual axle load data and the measured mechanical parameters of cement stabilized macadam material with different cement dosages, the bottom tensile stresses of different subbase structures are calculated and the results show that: to graded gravel subbase, the weight of construction vehicle is inadvisable to be more than 35t and the cement dosage of base course shall be more than 3.0%; and, the maximum bottom tensile stress of graded gravel subbase shall be much more than that of lime-flyash soil subbase. According to the measured dry shrinkage strain and dry shrinkage coefficient, the dry shrinkage crack space of base course is analyzed and the results show that: under the same cement dosage, the crack space of the base course with graded gravel subbase is smaller than that of lime-flyash soil subbase; with the increase of cement dosage, the crack space of base course increase first and then decrease, and when the cement dosage is 3.5%, the dry shrinkage strain and dry shrinkage coefficient is minimum and the crack space of base course is maximum.
An Experimental Study on Lubrication Behavior of Glass Lubricants during Hot Plastic Deformation of Ni-Based Alloys
Authors: Li Rui , Sun Chao Yang , Zhang Qing Dong
Published: November 2012

Friction factor and flow behavior of melt glass lubricants A5 and up68/2886 during hot plastic deformation of Ni-based alloys Incoloy800H and Inconel 690 were studied by using ring compression tests. The results indicated that glass up68/2886 had higher mobility than glass A5. Friction factor between interfaces went up with temperature in sufficient lubrication, but the opposite in inadequate lubrication, and the friction factor went down with strain rate under both conditions. Besides, yield strength of specimen material also slightly influenced lubrication performance of glass lubricants in inadequate lubrication. Low friction factor about 0.1 was still obtained in inadequate lubrication by using glass up68/2866, therefore excellent performance could be expected when glass up68/2886 was used properly such as at higher strain rate.
Test on Electrical Conductinity of Oil Shale
Authors: Wang Qiu Wen , Sun You Hong , Yang Fang
Published: November 2012

In this paper, two different layers of Huadian oil shale were selected. In the basic of oil shale density, moisture and oil yeild, and electrical physical properties of oil shale are researched by theoretical, experimental and comparative analysis. The experiments showed that under room temperature, the oil shale does not have a conductivity, but when the temperature increases, the ions are activated, so the ions has a higher energy to break through to the energy dam limits. Therefore, with the temperature increases, the conductivity of oil shale is getting better. And it has another three factors impact the conductivity: the higher temperature, the greater moisture content, and the less oil content.
Thermodynamic Analysis of a Brown Glass Containing Fe, C and S
Authors: Hu Chang Sheng , Zhang Jun , Yan Hong Fei , He Jin Xin
Published: November 2012

The ground state geometrical of cyclic sulfur molecules S8 has been studied with RHF/6-311G* of ab initio methods. Gibbs free energy of CO, SO2, S8 and CO2 from 300 to 1673K has been calculated using ab initio method. Besides, the reaction free enthalpies were calculated. The results show that resultants of reaction of CO and SO2 are S8 and CO2 below 1451K and the reaction is spontaneous.Fe2O3 in glass can is reduced into FeO whose redox number is negative. The Gibbs free energy of FeO is smaller than that of FeS while chemical stability of FeO is higher than that of FeS. Structures of cycle sulfur are versatile. Bond energy of S8, S12 and S18 is broken, which need high energy. When small sulfur ring molecules be formed, the chemical and heat stability of S8 are improved.
The Responses of Soft Ground Materials Subjected to Dynamic Loading
Authors: He Jun , Bai Bing , Chen Quan Fei
Published: November 2012

The responses of saturated soft soil foundation under dynamic loading are analyzed using numerical method. The distributions of pore pressure in space are given, and the variations of pore pressure with time are also discussed. Besides, the distributions of vertical stresses and vertical displacement are also given. Studies show that during the period of dynamic loading, the pore pressure and stress in soil layer grows very fast, and also decreases rapidly in the unloading phase. With the increase of dynamic compaction time, the locations of the maximum values gradually move down. Moreover, the pore pressure and stress gradually decreases with the increase of the distance away from hammer point. On the other hand, the tamping pit in ground surface under dynamic loading has a larger settlement, and furthermore decreases with the increase of depth.
Preparation and In Vitro Degradation of PLGA/HA Composite Fiber Scaffolds by Electrospinning
Authors: Xu Xu Fan
Published: November 2012

The preparation of scaffolds consisted of a polymer composites with inorganic materials has received extensive attention in the field of tissue engineering recently.Electrospinning is a good method to obtain nano-scaled fibers from polymer solutions. In this paper ,we successfully prepared nanofibers of poly(lactide-co-glycolde) (PLGA)/hydroxyapatite(HA)by electrospinning.Their structure morphology and degradation behaviors were studied.The in vitro degradation of PLGA/ HA composite membranes was examined for up to 16 weeks in phosphate-buffered saline (PBS, pH 7.4) at 37°C. The results indicated that the surface of hybrid fibers was much coarser because of the introduction of HA nano-particles. The alkaline HA nano-particles inhibited the self-catalysis of PLGA during the degradation and slowed down the degradation rates of hybrid fibers.The introduction of hydroxyapatite component changed the hydrophilic/hydrophobic balance and, thus, influenced degradation behavior and mechanical properties of the composite membranes during degradation. The preliminary results show that comprehensive properties are well better on the hybrid scaffolds than pure scaffolds and PLGA/ HA bionanocomposites have the potential in tissue regeneration applications.
Effect of Alloying Elements on the Microstructure and Properties of AZ91D-xCa-ySr
Authors: Sun Qing Zhu , Wang Hai Bo , Zhu Yong Chang
Published: November 2012

In this paper, the microstructure and properties of AZ91D-xCa-ySr were studied by adding alloying elements. The mechanical properties were investigated by WDT-10 micro-electric universal testing machine and WD-T low cycle fatigue testing machine. The OLYMPUS-GX71 Optical electronic microscope, XRD and SEM were employed to investigate the microstructure of AZ91D. The results showed that the grains were refined by adding Ca,Sr,Gd and Y. Low cycle fatigue (LCF) behavior of AZ91D-0.4Ca-0.3Sr was improved obviously by adding 3.0%Gd and 3.0%Y into material, the tensile strengthen was up to 299Mpa, the elongation was 0.78%.
Analysis on Mesoscopic Dynamic of Soft Soil Foundation in the Pearl River Delta Region Based on the Vacuum Preloading Method
Authors: Song Jing , Yue Ren Yi , Zhang Peng
Published: November 2012

The behavior of particle migration on soft soil foundation in Pearl River Delta region is analyzed considering the mesoscopic dynamic with vacuum preloading method. The numerical predictions are compared with the fine particle data in terms of settlements, horizontal displacements and vacuum degree of horizontal preloading. The repercussions of including the displacements law of fine particles are also studied. It is found that the analysis considering displacements law results in consolidation by rose diagram of particle migration, which is related to the consolidation of the vacuum preloading of soft soil foundation in Pearl River Delta region. It is apparently inconsistent with the vacuum preloading of the drainage which results from the fine particles migration, but it is fully justified by the fact that the real soil consolidation coordinates corrected for rose diagram obtained.
Kiln-Courtyard Residence in Western of Henan：Research of the Characteristics of Ancient Residences in Qiaozhuang Village
Authors: Hu Yun Jie
Published: November 2012

This article take the folk dwelling in QiaoZhuang Village of Mengjin County as a carrier, from two aspects that is the ecology and the shape summarized the compatibility of the kiln--courtyard residence in the west of Henan Province. The natural energy is made full use of in the village location, and according to the local conditions, conservation of the land. The appropriate materials and techniques are adopted and courtyard form is adopted. These have reference for contemporary residential design.
Surrounding Rock Stability Analysis and Rock Burst Prediction of Underground Cavity in High In Situ Stress
Authors: Zang Hai Yan , Wang Guang Di
Published: November 2012

Based on Sidoroff isotropic elastic damage model, the damage deterioration constitutive equation was constructed for rigid and brittle rock mass. The excavation numerical simulation of a diversion tunnel with large section in Jinping hydro station was carried on. The displacement and stress evolution was analyzed considering stress transfer and dissipation of the tunnel surrounding rock mass. The stability evaluation parameters were put forward such as stress relaxation coefficient of surrounding rock mass, safety factor, the scale and distribution of plastic region of surrounding rock mass. The rock burst predication index was presented in viewpoint of energy such as sub-range statistic average energy release rate and sub-range statistic failure volume. The excavation methods for the diversion tunnel with large section were evaluated with multi criteria and the guideline for large section cavity in high in-situ stress was summarized.
Mechanical Behaviour of Shallow Tunnel in Unsymmetrical Strata
Authors: Yang Shang Yang
Published: November 2012

Triaxial compression tests have been performed to determine the properties of the surrounding rock. The displacement and stress of surrounding rock have been analyzed according to Silin 2 at Yungui railway under three kinds of conditions: the initial state, excavation without supporting , and supporting after excavation.Plane strain FEM is established to analyze the stability of the surrounding rock. Contrasted the monitor measuring data,the results show that: the most unfavorable position in the tunnel is found at the ridge side of the arch; and the implementation of support to ensure the stability of surrounding rock, and the design of the early support approach to meet the safety requirements. The results have a certain significance for understanding the mechanical behavior of shallow tunnel in unsymmetrical strata
Analysis of Fire Smoke Control System of under Construction Tunnel
Authors: Sun Jia Yun , Fang Zheng , Yuan Jian Ping
Published: November 2012

Compared with operated tunnel, one of the distinguishing features of a tunnel during construction is its single-ended geometry. The direction of fire smoke movement is the same as the direction for worker to evacuate the tunnel. This paper calculates fire-induced conditions, including temperature, smoke movement and visibility, which are influenced by two different ventilation systems. According to the simulation, when the fire located at bottom of tunnel, forced extraction is more effective; when the fire located at middle of tunnel, forced injection can protect workers in tunnel. Besides，increasing ventilation rate can control smoke spread effectively.
Controlling Technology Research of Deforming due to South-to-North Water Transfer Tunnel down Crossing Subway
Authors: Li Dong Hai , Liu Yong , Wang Meng Shu , Zhang Ding Li
Published: November 2012

As one of national important engineering, South-to- North Water Transfer middle line crossed the Beijing subway route 1. Various controlling technologies of deforming were applied during construction of water tunnel in order to control the deformation of the existing subway tunnel. At the same time, automatic monitoring technology was applied too. By the system analysis of monitoring data and controlling measures, the rule of structure deformation is concluded and the validity and fitness of controlling measures are validated. At last, it is useful experience for similar engineering.
Analysis on Damage Cause of Shield Tunnel Segments during Construction
Authors: Zhou Jun Hong , Wu Di , Zhou Shun Hua , Cui Yi Xiao
Published: November 2012

Abstract. Due to the complexity of shield tunnel construction process, some segments may be damaged. To obtain the cause of segmental damage, stress acting on segments is needed to be analyzed. In this paper, the damage characteristics of a shield tunnel segments were summarized firstly, then a 3D discontinuous model considering of shield tunnel segments and bolts was established to analyze the stress characteristics of segments during construction. The study has manifested that squeezing of segmental bump tenon, thrust force and its obliquity, uneven jack thrust are the main causes of segmental damage during the shield tunnel construction.
Quantitative Analysis of Several Influencing Factors on TBM Advance Speed
Authors: Li Chao , Tiedemann Joachim , Zhou Hong Wei
Published: November 2012

Aiming at the problem of a difference between the TBM advance speed estimated by the NTNU and CSM model, and the actual advance speed, a quantitative analysis is carried out in the paper. Combining the experimental results of the uniaxial compressive test with the rock mechanics experiment system TAW-2000 and MTS815, the paper quantitatively characterizes the main parameters including the rock compressive strength, elastic modulus, abrasiveness, and the thrust force of cutterhead, corresponding to TBM advance speed by using the method of quantitative analysis of multi-factors. Moreover, the relationship between the TBM advance speed and the parameters was established. It is indicated that higher rock strength, abrasion and a smaller thrust force of cutterhead are reasons resulting in a lower TBM advance speed.
Study on the Existing Cavity-Disease Tunnel Influenced by Blasting Vibration of the Newly Built Tunnel
Authors: Wang Bo , Fu Wei
Published: November 2012

Under the mass of finite element analysis, the dynamic response characteristic and the influence law on lining mechanical of the existing disease tunnel which is influenced by newly built tunnel in process of construction are studied. The study shows that the cavities behind the lining have amplification effects on both the vibration speed and stress of the lining, which may induce structural failure of the lining structure; while superimposed effect between cavities has little effect on vibration speed, it has significant amplification effect on stress and leads to surging of additive tension stress; it is recommended that for the condition with more than one cavity, stress criterion should be introduced in as a complement. The study results can be applied to conducting the site monitoring and construction.
Stress Characteristic Analysis of Repaving Asphalt Pavement Structure on Old Cement Road
Authors: Mao Hong Lu , Zhuang Pei Zhi , Zang Ya Nan , Yi Xiao Ming
Published: November 2012

To solve the early destruction problems occurred when overlaying asphalt pavement structure containing semi-rigid base on broken cement concrete pavement, finite element software is used to compare the stress characters between the repaving pavement and ordinary pavement, and analyze the repaving structures under different loads and different road transverse grade. It shows that the value of compressive stress at the top of base of repaving pavement is significantly higher than that of ordinary pavement, meanwhile, its value of tensile stress of base bottom is lower; the asphalt surface and new base top of repaving pavement need to bare a high value of shear stress and compressive stress under overload, so it’s prone to splitting failure in the base. With the increase of transverse grade, both the shear stress difference of road surface and maximum vertical compressive at top of the base increase in a lower position, but the situation is opposite in the higher position.
Study on the Effect of Jet Grouting Pile Reinforcing Soft Soil Subgrade
Authors: Liu Gang Yu , Wang Bing Long
Published: November 2012

Composite foundation is commonly used to control the soft soil subgrade settlement. Considering that post-construction settlement of high speed railway is strictly controlled, it’s supposed to use jet grouting pile to strengthen the existed composite foundation and it’s necessary to analyse the effectiveness. Take a line as an example, analyse embankment settlement regularity of the original design mixing pile reinforcement and jet grouting pile reinforcement, evaluate the effect of the jet grouting pile reinforcement. The results show that the jet grouting pile reinforcement on the basis of original design does not have obvious effect on the embankment surface and ground surface settlement control, but effectively controls horizontal displacement at toe of slope and improves the foundation stability.
Numerical Simulation on Stress Transmission under Vehicle Load for Western Expressway
Authors: Li Chi , Zhang Jing Jing , Gao Li Ping
Published: November 2012

Based on the typical Pavement-Subgrade structure form of western expressways, the interaction of the Pavement-subgrade system under vehicle load is researched. The model of stress transmission is established through numerical simulation. The vehicle load transfers stress to subgrade surface via the pavement structure layers. According to the different properties and functions of pavement layers, similar pavement layers are combined into equivalent structure layers. In this study, stress distribution of vehicle load on subgrade surface is analyzed according to the different degrees of thickness and stiffness of the equivalent structure layers. Also, the effect of different subgrade fillers on stress transmission is studied.
Evaluation of Highway Alignment Safety Design Based on Operating Speed
Authors: Hu Sheng Neng , Qiu Pan , Fan Qin Dong , Hu Zhong Huang
Published: November 2012

Highway safety is one of the targets of the road design, coordination of highway design index and the actual vehicle speed is the key. According to the analysis of automobile speed observation data, established the plain or hilly area two road car model, put forward highway alignment design safety evaluation standards and safety design method.
Study on Fluid-Solid Coupling Analysis Method of Bridge Pier
Authors: Yang Ji Xin , Zuo Sheng Rong , Huang Yi Feng
Published: November 2012

This paper introduces the numerical analysis method to analyze the dynamic characteristics of pier in water. The method comes to realize by the software ANSYS. By the calculating of ANSYS, the 1~3 order frequency can be found regular when the pier in full of water and anhydrous conditions. Water has a strong impact on natural vibration frequency of structures, as the water level rises, the natural vibration frequency decreases gradually, the value of the reducing is about 13%. At the same time, the frequency decreases as an increasing rate. So the natural frequency effect which the water acting on the structure can not be ignored.
Prestressed Concrete Continuous Girder Bridge Reinforcement Simulation Analysis and Carrying Capacity Assessment
Authors: Yu Ling , Qiao Tie Zhu , Bao Long Sheng , Zhu Guang Shan
Published: November 2012

This article simulates prestressed concrete continuous girder bridge reinforced many times and evaluates carrying capacity after reinforcement. Taking the FuFeng bridge for an example, we analyze the bridge’s stress state in using by Midas software, evaluate the concrete ability of crack resistance, check the reinforced concrete structure ultimate carrying capacity, the cracking resistance and the stiffness, assess reinforcement effect and verify the accuracy and reliability of the simulation results. The maximum main compressive stress, maximum compressive stress, maximal main tensile stress and maximum tension stress of mid-span cross-section of the bridge are 1.6Mpa, 1.6Mpa, 0.3~0.5Mpa, and -1.2Mpa respectively, the mid-span center cross-section of deflection is 2.89cm. Reinforcement suppresses the development and expansion of the crack; the mid-span deflection tends to stabilize; the ultimate bearing capacity meets the Standard requirement basically; the emergency capacity is not enough; and the car whose weight over 55 tons is prohibited from passing.
Experimental Research on Concrete Shrinkage and Creep for Main Girder of Sutong Continuous Rigid-Frame Bridge
Authors: Zhang Yun Tao
Published: November 2012

In order to obtain shrinkage and creep of HPC used in Sutong continuous rigid-frame bridge, shrinkage and creep of plain concrete and RC are investigated under natural environment over two years. Reinforcement ratio 0.76% is close to that of the middle span. Loading stress of creep test is about 15MPa, which is near the maximum stress of the bridge. Four loading ages, 7d, 14d, 21d and 28d, were used to simulate different loading ages in construction. The curves of creep and shrinkage were fitted from test values. The results show the test values of creep and shrinkage were less than the current Chinese bridge code JTG D62-2004, and the creep and shrinkage of RC is less than plain concrete. If the reinforcement ratio is low, reinforcement exerts less influence on creep and shrinkage, and the influence of reinforcement can be neglected in engineering application. Reinforcement can effectively reduce creep and shrinkage if the reinforcement ratio is high.
Geological Protection Project of the Longmen Grottoes in Luoyang
Authors: Liu Qi Xia , Duan Yong Hui , Deng Jun Yan
Published: November 2012

This paper starting with the analysis of weathering actuality of Longmen Grottoes in Luoyang, combined with the result of geological hazard investigation of 3 caverns ( Qianxi temple, HuangPuGong cave and Lu hole ), divides the damage effects of Longmen Grottoes into mechanics effect, chemical effect and biology effect, then analyses the geological condition and the solution to protect caverns, and proposes a geological protection project for this kind of stone cultural relics. So as to this paper can provide reference to the similar stone cultural relics protection works.
Earthquake Action of Cold Storage Structure
Authors: Zhang Ji Mei , Dong Hong Bo
Published: November 2012

In recent years,cold storage which is the central pivot of low temperature circulation of food developes faster overseas.It shows single-story and assembly and fast speed of low –temperature storage.In china it is being developed from multi-storey to single-storey of high goods shelves.Earthquake action of cold storage with reinforced concrete frame building is quantitatively analyzed by using three methods for bottom shearing and mode-superposition response spectrum and linear elastic time history analysis.Applicable condition of method for bottom shearing is verified.The paper aims to do the comparison and analysis of seismic precautionary of six or seven degrees,so as to provide some valuable references to the same type of buildings.
Earthquake and Underground Powerhouse: On the Aseismic Issues of Baihetan Underground Cavern Complex
Authors: Leng Xian Lun , Liu Jia Jin , Zhen Cui , Qian Sheng
Published: November 2012

A hydropower plant is usually the major electricity supplier in the region, the failure of underground powerhouse in an earthquake may cause not only the damage to itself, but also secondary disasters to the region in a way of an electricity outage. Seismic stability of these underground complexes is required to be seriously addressed. The underground cavern complex of the Baihetan hydropower plant in Yunnan Province, China, is currently the world's largest underground rock cavern group under construction. Aseismic issues of the underground cavern complex are discussed in this paper. On the basis of this research, seismic variables of the Baihetan project are firstly determined for Design Basis Earthquake and Safety Evaluation Earthquake. The artificial seismic motions for the dynamic analyses are simulated. Two alternative scheme of layout plans of the underground cavern complex are studied, with full 3-D elasto-plastic dynamic response analyses based on the parameters given by the cyclic dynamic loading tests with medium strain rate. The seismic response of seismic displacement and failure zones of each scheme are studied, respectively. A performance verification of the supporting measures during earthquake is also discussed. The results indicate that in spite a wider powerhouse cavern, the scheme "A" which involves a gallery-shaped surge chamber is more stabilized during an earthquake than the scheme "B" whom with barrel-shaped surge chambers. The underground cavern complex with scheme "B" is relatively stable under Design Basis Earthquake and Safety Evaluation Earthquake, despite a minor damage of the surrounding rock. And the implementation of the proposed support system may further guaranteed a safe state of the underground cavern complex in earthquake events.
Hybrid Base Isolation System with Friction Sliders and Viscous Dampers in Parallel: Comparative Dynamic Nonlinear Analysis with Traditional Fixed Base Structure
Authors: Cancellara Donato , de Angelis Fabio
Published: November 2012

In the present paper we have analyzed a multi-storey reinforced concrete (RC) building in presence of a hybrid seismic protection system for highlighting the limits of the conventional fixed base seismic design of structures. This hybrid seismic protection system is a passive structural control system that combines the Base Isolation System (BIS) and the Passive Supplemental Damping (PSD). The Viscous Dampers (VS) and Friction Sliders (FS) are the devices adopted in parallel for realizing the innovative base isolation system. The fixed base structure and the base isolated structure have been designed and verified according to the European seismic code EC8 and the European code for the design of concrete structures EC2. A three-dimensional dynamic nonlinear analysis for a base isolated structure has been performed adopting recorded accelerograms for the defined bi-directional ground motions according to the conditions imposed by EC8. The seismic isolation is a promising alternative for the earthquake resistant design of buildings and its peculiarity is that the base isolated buildings are designed such that the superstructure remains elastic and the nonlinearities are localized at the isolation level. In this paper a comparative analysis is presented between the base isolated structure, with the viscous dampers in parallel with friction sliders, and the traditional fixed-base structure.
Analysis of the Calculation Method of Active Earth Pressure of Unsaturated Expansive Soil
Authors: Zhang Jia Shan
Published: November 2012

The properties of unsaturated expansive soil were analyzed, and the shortcomings of present methods which are explored to calculate the active earth pressure of unsaturated expansive soil on the retaining structure were discussed. Based on Coulomb’s earth pressure theory, a calculation formula of active earth pressure of unsaturated expansive soil was proposed taking into account of the swelling pressure parameters according to the condition of static equilibrium of sliding soil. The formula has simple composition and derivation process, is convenient for application, and the example shows that this method is reasonable.
The Dynamic Response and Stability Analysis of Nuclear Power Station Water Intake Diversion Dike
Authors: Zhao Jie , Deng Lin Yan , Wang Gui Xuan
Published: November 2012

This paper uses the equivalent linear model of Hardin-Drnevich and the dynamic effective stress analysis method, gets the safety coefficient of stability, the liquefaction zone distribution and seismic residual deformation of diversion dike under the seismic action of SL1 and SL2. The paper also uses the minimum safety coefficient and average minimum safety coefficient of the whole process of earthquake to evaluate the stability of diversion dike under different seismic action and compares the results. Compared with SL2, the diversion dike foundation liquefaction range is smaller than under the SL1 seismic action, so it is does not affect the normal use of diversion dike structure. When meet the seismic action of SL2 which is appears about one time in a ten thousand, diversion dike will produce bigger deformation, but the integral slip to the heart of canal will not happen, so the use of water of the nuclear power plant is safe. The result has a certain reference value and guiding significance for the similar engineering design.
Failure Mechanisms of the Landslides Triggered by the 2008 Wenchuan Earthquake, China
Authors: Cui Fang Peng , Yin Yue Ping , Hu Rui Lin , Yu Jin Qing
Published: November 2012

Taking the landslides triggered by the 2008 Wenchuan Earthquake as examples, their dynamic responses with different epicenter distances due to single and combined action with regionality and spatial heterogeneity of the Primary and Secondary waves were simulated by applying the Universal Distinct Element Code software. The results shows that the slope suffered from the combined action between P and S waves appears instability prior to the slope under single action of P wave. With the epicenter distance increasing, the key controlling factor resulting in the slope failure varies from the combined seismic action between P and S waves to the single seismic action of the P wave. As for the formation mechanism of slope instability, coupled action between the vertical and horizontal seismic forces results in the slope dynamic failure with key action varying from the vertical to the horizontal one. Finally, the initial instability originates always at slope shoulder due to the peak ground acceleration amplification effect and the variation trend of the slope mechanical parameters on its fracturing of the seismic action.
A Simplified Analysis Method for the Validity of Pipeline Rock Armour Berm Protection Design
Authors: Liu Wen Bin , Liu Run , Sun Guo Min , Yan Shu Wang
Published: November 2012

Submarine pipelines located near harbour areas and in major shipping lanes are likely to be exposed to potential damage due to anchors and dropped object impact. To protect these pipelines, they are buried and protected with rock armour berms. The design of these rock berms has been traditionally based on model test results. In this paper, a simplified method is proposed to simulate the interaction between the anchor, seabed soil and rock armour, on the basis of the thrust earth pressure theory. The results agree well with the centrifuge test results.
An Improvement of General Design Methods for Lock Castle Structures
Authors: Cao Zhou Hong , Lian Ji Jian , Liu Xi Zhu
Published: November 2012

Longitudinal cracks often appear on the top of the large locks’ floor built on soft foundations, but the cause can’t be explained by general design methods. Based on the simulation of lock’s construction and clay’s consolidation, the paper analyses the evolution process of the floor stress, and find the regular pattern of stress’ change over the time, then improves general design methods by omitting the floor’s deadweight when calculating the negative moment. The conclusion serves as a reference for the design and the construction of similar projects.
Temperature Control Measures and Feedback Analysis in Rapid Construction of Guandi RCC Dam
Authors: Zhou Wei , Jing Xiang Yang , Liu Xing Hong
Published: November 2012

Due to the shortcomings of conventional methods, the temperature control in rapid construction of Guandi dam is less effective. Then improved measures are designed and implemented based on the dynamic control method of pipe cooling, which depends on the real-time adjustment of five factors affecting pipe cooling (beginning time of cooling, lasting time of cooling, water temperature, rate of flow and direction of flow). The monitoring and feedback calculation are conducted. It is found that the newly-designed measures have obvious effect, and that there are no harmful cracks in the whole construction of Guandi dam. The conclusion is that it can effectively solve the problem of temperature control and crack prevention of high RCC dam via these measures, and provide some guide and reference to other similar projects.
Research on Influence of Sediments Mechanical Parameters of Seismic Arch Dams
Authors: Yan Yi Zhi , Su Zhi Min , Wu Liang
Published: November 2012

The problem of sediments on seismic response of arch dams was not solved. Thus pressure wave formula of saturated porous fluid-solid two-phase medium was applied from the Bait’s consolidation theory, and was determined the seismic response magnitude of sediment on arch dam. And the method was applied to analyze the influence of sediments thickness, cohesion and friction angle on dam seismic response. The result shows sediments is relatively obvious on arch dam seismic response.
The Normal Depth and Critical Depth of Special Cross-Section
Authors: Wei Bing Qian , Wang Zheng E , Meng Wen Qiang , Liu Yang
Published: November 2012

In water diversion project and water delivery project, horseshoe cross-section and circular cross-section are commonly used. The hydraulic elements of nonstandard horseshoe shape and circular shape are difficult to calculate because of their complex section. This article gives the formulas of hydraulic elements and iterative formulas of normal depths and critical depths of horseshoe shape section composed of 6 arcs and 2 kinds of irregular circular shape section by mathematical derivation. And on the basis of the relation with depth, normal depth and critical depth, we can estimate the type of water surface profile. It can be applied in calculation of water surface profile 81.68 km Qinling tunnel of south water to north project. The formulas of normal depth and critical depth and hydraulic elements can be used in other similar water delivery project.
Research on Urban Water Demand Prediction
Authors: Wan Kun Yang
Published: November 2012

Water demand prediction adopts combined prediction method based on BP neural network prediction model, grey G (1,1) prediction model, time sequence prediction model (second multinomial exponential smoothing model) and single linear regression model (Cubics Ratio model). Empirical results show that combined prediction method makes comprehensive use of information of every separate prediction model, and thus enhances prediction accuracy.
Simulation Study on the Radiant Tube Transferring Characteristics for the Gas-Infrared Heated System
Authors: Zhang Da Ying , Zhuang Wei Dong , Gong Ke Qin
Published: November 2012

The numerical simulation for radiant tube heat transferring process of the gas-infrared heated room was finished. By means of numerical calculation, the influences of radiant tube emittance to the indoor temperature and workspace air temperature as well as the heat radiation flux were studied. The results show: The greater of radiant tube surface emittance, The higher of the total heat flux, meanwhile, workspace average temperature and average radiation temperature are rise.
Comparing of Temperature Variation with Different Types Greenhouse
Authors: Shi Yu Liang , Chen Ming Dong , Li Min
Published: November 2012

Greenhouse temperature of the three different types was measured under sunny winter weather conditions. The variation regularity of greenhouses temperature with outdoor temperature was studied according to the monitoring data of experimental greenhouse, which was different roof and floor structure. The results showed that the greenhouse temperature of the herringbone roof construction higher than the greenhouse of the serration roof construction; the greenhouse temperature of the serration roof construction is higher than the greenhouse of arch roof construction. Through analysis of temperature variation on the different type greenhouse, it will provide theoretical basis to construct greenhouse in different areas.
The Application of Catalytic Combustion in Natural Gas Power Generation
Authors: Shi Xing Xing , Xiao Min , Zhang Shi Hong
Published: November 2012

This paper put forward some advantages of natural gas power generation, in the views of power generation efficiency and environmental protection perspective, compared with common fossil fuel power generation, and through comparing the economy, we elaborate the superiority of natural gas power generation. Simultaneously, there brings in the new technology of catalytic combustion in gas generation, which would improve power generation efficiency and reduce pollution in industrial fields. We also propose the corresponding solution to salve the difficulties encountered by the technology promotion, so as to achieve Low carbon energy saving.
Advanced Alert and Warning Systems
Authors: Turekova Ivana , Turňová Zuzana , Pastier Martin
Published: November 2012

Modern autonomous systems (AUS) correspond to the current global technical standards and European principles of prevention of industrial accidents. Their construction requires a purposeful and systematic approach of investors. The paper presents an elaborated standard project of an autonomous system with ammonia as a kind of refrigerant for an ice rink. The implementation of the proposed project can make the process of warning and alerting the population in danger more effective.
Experimental Research of Three-Phase Foam Fire-Fighting Technology in 7312-2 Caving Face Prevention Goal of a Coal Mine
Authors: Jian Liu , Liu Ming Ming , Xie Zhen Hua
Published: November 2012

Spontaneous combustion of coal is a serious threat to the normal working of the mine and the safety of miners, the research to prevent spontaneous combustion of coal has a great significance. Technology based on the three-phase bubble theory, combined with characteristics of coal of 7312-2 caving face of a coal mine in Xuzhou, using laboratory studies to determination the fly ash , Wong and a variety of surfactant , then determining the formula of three-phase foam which is fit for a coal mine coal, it can restrain goal spontaneous combustion effectively and beneficial to safety production and environmental prevention.