bluuebunny/crossref_metadata_2025 huggingface dataset:
Weldability Windows for Explosive Cladding of Dissimilar Metals
Authors: Saravanan Somasundaram , Raghukandan K.
Published: February 2012

Explosive welding is achieved by the application of pressure, released from explosives, sufficient to cause large plastic deformation at the interface of dissimilar metals being welded. This study addresses the analytical estimation of the weldability domain for Aluminium-Low carbon steel and Copper-Stainless steel combinations. The use of an interlayer is proposed for the control of kinetic energy loss to alleviate the formation of intermetallics at the interface. Welding window the analytical estimation to determine the nature of interface was formulated using empirical relations proposed by various researchers and was verified experimentally. The lower limit of weldability window in three dimensions is developed in this study. Microstructural characterization of interfaces shows a wavy morphology in concurrence with the design expectations.
Synthesis and Mechanical Properties of a Novel Al/Β-Al3Mg2 Nanocomposite Prepared by Mechanical Alloying Process
Authors: Khosroshahi R.A. , Zolriasatein A. , Emamy Masoud , Nemati N.
Published: February 2012

Complex metallic alloys (CMA) are new crystalline intermetallic phases representing an upcoming field in materials science. The β-Al3Mg2 intermetallic compound belongs to this new class of materials. Different amounts of pre-alloyed β-Al3Mg2 nanoparticles (from 0 to 20 wt.%) were mixed with aluminum matrix powder and then co-milled in attrition ball mill for 10 hours. Consolidated samples were prepared by hot pressing of blended composite powders. Microstructural characterization, applying an optical microscope (OM) and scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) analyzer confirmed the formation of uniformly distributed β-Al3Mg2 nanoparticles in the matrix. Furthermore the results indicated that, increasing the amounts of β-Al3Mg2 nanoparticles leads the matrix grain size to be reduced. Effects of reinforcement contents on mechanical properties of nanocomposite samples were also investigated via hardness, compressive and wear tests. The results revealed that with increasing reinforcement content in the matrix, mentioned attributes of the composites are significantly improved.
Automatic Machining Setup Generation for Prismatic Components
Authors: Abedini Vahid , Shakeri Mohsen , Siahmargouei Mohammad Hasan
Published: February 2012

Computer aided process planning is the bridge between CAD and CAM. Setup planning is the major key to transform design concept into manufacturing domain, which is mainly experience based activity in modern manufacturing industry. Setup planning is a complicated non-linear task constrained by many factors such as tool approach direction, geometric feature relationship, fixturing constraint, tolerance requirement and manufacturing practice. Setup planning identifies which features must be machined in each setup and determines locating datum for each setup. This paper focuses on the development of a formalized procedure for automatic generation of feasible setups. For preventing of tolerance stack-up tried to use datum face as reference plane in fixture design. So, this paper presents a new method for setup planning with accurate respect to datum faces in design and machining. For the proposed work the authors have introduced two concepts namely, inferiority face and control face. A rule-based procedure in several steps is used for solving the problem. The system is developed in Visual Basic on a Solid Works platform. Trial runs with industrial parts indicate that the system is applicable for industrial use.
The Effect of Loading History on Unstable Fracture of Austenitic Steel (304)
Authors: Jendoubi Khemaies , Merah Necar , Bernard Marie , Bazoune Abdelaziz
Published: February 2012

The present paper presents an analysis of the influence of loading history on unstable fracture of austenitic steel 304 (SS 304) using the J-integral and its applicability in situations where a loading history exists. A CT specimen is employed for the purpose. The loading history effect on the unstable fracture of SS 304 is studied by performing cyclic loading with different load histories at constant load range (ΔPi) and at constant stress intensity factor range (ΔKj). The results show that the plastic singularity is well described by the integral (J) for the different types of loadings used. Moreover, the real meaning of (JIC) as a representative of the maximum energy release rate is quite limited if it ignores the loading history. The experimental results show that the dissipated energy ΔJ is more active when the loading is done at constant ΔP. The evolution of ΔJ can be directly linked to the crack growth rate and to the extent of the plastic zone developed at the crack tip.
Analysis of Importance of Concrete Bridge Configurations Based on AHP
Authors: Tang Xian Xi , Zhu Yan Peng , Tang Xian Zhou , Xu Yue
Published: February 2012

The applicability and durability proportions of the main structures in concrete bridge were determined based on AHP, and the influence degree of different influencing factors on applicable and durable structures of concrete bridge were also analysised, which laid the foundations of applicable and durable configurations study of concrete bridge.
Research on Lifting Techniques of Large Segments of Steel Box Girder of Chongqi Bridge
Authors: Zhang Hong , Zhou Ren Zhong
Published: February 2012

Techniques of lifting large segments of steel box girder by floating crane is used in construction of Chongqi Bridge. Considering the hydrological environment on the site, characteristics of steel box girders and performance parameters of floating crane, the selection of floating crane is carried out. To ensure hoisting work achieve function and safety, a new type of lifting device named Self-balance lifting device is designed, and the lifting-points design is optimized to make the reaction of all lifting-points of large segments equal. In the erection process of large segments, the security risk control is analyzed to ensure the steel box girders and lifting equipments safety.
The Impact of Cold Wave Strike on Thin-Walled Concrete Structure
Authors: Wang Zhen Hong , Wang Zhao Gang , Zhang Guo Xin , Liu Yi
Published: February 2012

When the cold wave comes, there are worse effects on thin-walled concrete structure than its on mass concrete structure during construction. In the view of this problem, the 3-D FEM is adopted to simulate the thermal field and stresses field of thin-walled concrete launder during construction when it is struck by cold wave. The simulation results show that shrinkage stress in the surface and inner of thin-walled concrete structure will appear and bring a lot of difficulties for temperature control and crack prevention. In order to reduce the impact degree of cold wave strike, some effective measures should be taken, including enhancing the level of external heat preservation and prolonging the form removal time and so on. This research is of practical reference value for the construction of the concrete structure which is built in the area where cold wave easily occurs.
Dynamic Performance and Seismic Analysis of Tied Arch Bridge
Authors: Wu Hui Jun , Qiu Wen Liang
Published: February 2012

Based on the anti-seismic research achievements of tired arch bridge at home and abroad, taking River City Bridge in Jilin as an example, a finite element model is established for dynamic performance analysis by general finite element software midas civil. Natural vibration characteristics of tied arch bridge are calculated as a basis for further dynamic calculation. Firstly, choose appropriate seismic waves according to the geological data. Then perform the dynamic response analysis of this bridge under different loading cases. Dynamic responses of this bridge under longitudinal and transverse seismic waves are studied respectively, and the influence of vertical seismic wave is also considered. It is shown that the influence on seismic response of vertical seismic waves is very obvious. The vertical seismic waves should be considered while doing seismic design of tied arch bridges.
Seismic Response Analyses of Isolated Bridges with Different Isolation Bearings
Authors: Wang Shuai , Heisha Liu Han Wen , Yu Fang , Wang Guo Xiang
Published: February 2012

In order to research the different types of isolation bearings impact on bridge performance, parameters of lead rubber bearing, super high damping rubber bearing and friction pendulum bearing are designed for the three-span continuous bridge. With the method of nonlinear time-history analysis, dynamic characteristic of this isolated bridge is studied by using sap2000. Analysis results show that the isolated bridge with three types isolation bearings has a good seismic isolation effect under rare earthquake. The difference of shear force between friction pendulum and other two types is about 4% below.
The Impact Analysis of Temperature on the Line Shape in Cantilever Construction
Authors: Zhang Dong Ming , Zhao Chen , Chi Yan Bin
Published: February 2012

The Fu River bridge in Hechuan district is located in Chongqing where the summer temperatures could be overed 40°C. It is necessary to analyze the temperature to reduce the impact of high temperature to the line shape. The impact of temperature on the line shape was described in this paper. Based on the analysis of monitoring results and Newton method of interpolation, the change rate of cantilever elevation and the temperature influence law were shown. And the control measures were also proposed. Finally achieved the design requirements of the line shape of bridge and construction monitoring.
Determination of Transverse Amplitude of Microbeam Vibrating Accounting for Nonlinear Effects
Authors: Li Cheng , Huang Wei Guo
Published: February 2012

The nonlinear dynamics of a microbeam with initial axial tension is presented. The nonlocal theory with a small scale effect is applied to the problem model. Considering the axial protraction due to the transverse deformation of the microbeam, a nonlinear partial differential equation that governs the dynamic motion is derived. Explicit solution of transverse amplitude is obtained by the method of multiscale analysis. Both nonlinear and nonlocal effects are found to play significant roles in the vibration behaviors of a microbeam. The results may be helpful for the application and design of various micro-electronic-mechanical devices, where a microbeam acts as a basic element.
Analysis of Eccentric Load Causing Torsion Effects of Variable Cross-Section Continuous Box Girder during Cantilevered Casting
Authors: Xiang Min , Yang Cong Juan
Published: February 2012

The construction with hanging basket eccentric loading was studied for the cantilever casting of a 32m +48 m +32 m continuous box girder. The calculation of center deflecting angles of cantilever box girders with variable cross-section due to pure torsion was derived, and correspondingly a program was developed to calculate this formula. An analysis model of cantilever casting continuous beam bridge with hanging basket eccentric loading was established based on finite elements software, and the shear stress, the longitudinal normal stress and the combined stress of different section were analyzed under different construction process. The torsional effect due to hanging basket eccentric loading was studied and the results are helpful to guide the construction in practice.
Seismic Response of Baihua Viaduct during the Wenchuan Earthquake and Methods of Reducing Seismic Damage
Authors: Yang Xiao Dong , Yan Wei Ming , Chen Yan Jiang , Li Yong
Published: February 2012

Baihua Viaduct which is an important transportation project of 213 National Highway was severely destroyed during the 512 Wenchuan earthquake. The fifth segment of the bridge suffered the most severe unrepairable damage, such as the rupture of the piers and falling of beams. It is worth to study the performance through the FEM dynamical analysis to explain the damage performance of Baihua Viaduct in the earthquake. The dynamical FE model of the Baihua Viaduct is established considering the non-liner properties of piers and bearings. Further the earthquake records of the nearest Wolong station is chosen to be as the earthquake excitation input to conduct the seismic analysis. The analysis shows that the results of damage position and damage degree of components of the bridge calculated by elastic-plastic dynamic analysis are close to the actual damage of Baihua Viaduct. The reinforcement ratio of piers is low, while there is not any shear failure on piers. The damage degree of elastic hinge is related with the arrangement of bearings. The girders’ displacement is much larger because there are not any anti-dropping devices on the bridge. Damage of the fifth segment of bridge may be caused by plasticity destroy of some piers.
Research on Horizontal Scheme for Multi-Pylon Cable-Stayed Bridge
Authors: Qiang Yue , Li Li , Li Peng Cheng , Jian He
Published: February 2012

Longitudinal assembled stiffness is the biggest problem for multi-pylon cable-stayed bridge. The longitudinal displacement and midspan deflection could be effectively controlled by setting horizontal cable at the top of pylon of multi-pylon cable-stayed bridge. This paper obtains the area and the cable force change formula of the horizontal cable through simplified model analysis of the mechanical behavior of setting horizontal cable at the top of pylon. The comparative analysis is performed by application of finie element model to discuss the effect of setting horizontal cable at the top of pylon of multi-pylon cable-stayed bridge.
Research on the Modal Analysis and Reinforcement of Suspension Line Old Bridge
Authors: Luo Hui Zhong , Xu Jin Jun , Liu Jun , Wang Ke Yu , Zhang Yan
Published: February 2012

Suspension line Old bridges are rare exception in our country. Researching this kind’s old bridge is very interest to the bridge scholar. Zhejiang Yucheng bridge, located in Shengzhou of Shaoxing city, it is a typical suspension line bridge structure; it has been 150 years of history. Despite the impact of flash floods for so far, but, at present, it is still good for normal used, only local stone blocked off. Based on this old suspension line bridge, measuring the bridge size data, using the finite element software ANSYS for the modal analysis, the calculation results show that the fundamental frequency as 19.650Hz, and ten vibration modes and frequency bands can be obtained. In the end, about the reinforced methods are study, such as foreign adhesive steel and carbon fiber reinforced polymer (CFRP), pressure grouting way on the gap and so on. All of this may be help for old suspension line bridges research and reinforced.
Ultimate Bearing Capacity Analysis of Concrete Filled Steel Tubular Arch Considering the Initial Defects’ Influence
Authors: Hu Jun Liang , Yan Quan Sheng , Yu Xiao Lin , Zheng Heng Bin
Published: February 2012

In the CFST arch bridge construction process, for the reasons of arch axis deviation as prefabricated or constructed, the bearing capacity of arch-rib decreased. This paper considers material and geometric non-linear double factors, calculates the arch-rib ultimate bearing capacity of a CFST arch/continuous beam bridge with defects of arch axis deviation and steel yield stress decrease because of heat treatment, obtain the influence of defects to arch bearing capacity.
Constitutive Model of Saturated Structural Clays Based on SMP Failure Criterion
Authors: Yu Min
Published: February 2012

For normal consolidated or low over consolidated saturated structured clays, a constitutive model of the clay was proposed by introducing a structural parameter d in order to quantitatively describe the change of its deformation and strength based on unified hardening model. Stress-strain and body strain of the clay were predicted by the new model and were measured by K0 consolidated compression and shearing tests. The rationality and feasibility of the new model were proved by comparing the predictive and experimental value. The results show that the model can well describe structural characteristics, deformation and mechanical properties of the saturated structured clays; predictive value of stresses and strains are basically in agreement with experimental ones, and this further proves the rationality and feasibility of the new model.
Effect of Side-Web Slope on Loading Properties of Prestressed Continuous Box-Girder Bridge with Changed Sections
Authors: Li Feng Lan , Zhang Shi Min , Liu Shi Ming
Published: February 2012

Combined with the practical design of a prestressed concrete continuous box-girder bridge with changed sections, the effect of side-web slope on the loading properties of this bridge was analyzed. The numerical modes of this bridge were built using the specialist FEM software, 5 side-web slopes were considered by changing the width of box floor. The results show that the changes of side-web slope influence the mid-span deflection of box-girder in a small range under vehicle load, but affect obviously on the transversal loading properties such as crack width and flexural resistance of the box roof. Based on this, the suitable side-web slope is selected. It may be referenced by the similar design of this kind of bridges.
Study on the Pore Distribution Characteristic of Sandstone
Authors: Zuo Jing Yan , Zhou Li , Yu Heng Da , Liu Ya Qi
Published: February 2012

In order to study the characteristic of the hydrophilic and softening rate on the sandstone , which is the east guard mine in SHUANG YASHAN, it is experimented by the Hg-injection, the relation curve of the capillary pressure in the Hg-injection and the mercury ejection, the reason of the curve un-reclosing is analyzed and the inner porosity microstructure on the sandstone core is interpreted. It can be noted that the reason of the curve lagging on mercury ejection ,one is that the pore throat radius varies in the porosity microstructure of the sandstone and the more delaying lag can accelerate the hydrophilic rate; the other reason is that half close pore in the porosity microstructure of the sandstone residual mercury trapping lagging, when the trapping lagging is more bigger , the wetting phase is unease to exhaust.
Selection Analysis of Enclosure Structure for Deep Foundation Pit under Complicated Geological Conditions
Authors: Hu Qi , Luo Sheng Ming , Jiang Zhu Jin
Published: February 2012

By comprehensive consideration of soil conditions, geometric shape of deep foundation pit and many other kinds of factors, enclosure structure design needs to select optimal supporting and enclosure system with safety, economy and construction feasibility. On case study of enclosure structure selection about typical soft soil foundation, this paper researches effects of force- deformation of enclosure structure by brace layout, and of economy and construction feasibility. The research results may offer reference for similar projects.
Application of Cusp Catastrophe Model to Predicting of Water Inrush from Mine Floor
Authors: Zhang Chun Lei , Zhong Guo Sheng
Published: February 2012

Based on cusp catastrophe characteristics of water inrush from floor, a cusp catastrophic mechanical model of a key stratum of floor is established by catastrophe theory. By the model, the paper analyzes mechanical mechanism of water inrush from key stratum of floor with the cusp catastrophic theory. Using an engineering example, the numerical simulation proves that this method of the theory analysis is practical.
Frequency Response Characteristic of a Flexible FBG Sensing Beam for Measuring Dynamic Lateral Displacement of Soil in Shaking Table Tests
Authors: Wang Yun Long , Yuan Xiao Ming , Li Yu Run , Chen Long Wei
Published: February 2012

Flexible fiber Bragg grating (FBG) sensing beams are used to measure dynamic shear response of liquefied soil to ground motions in a shaking table test. Measurement systems typically consisting of bulky arrays of sensor bundles can be instead. But the different frequency response characteristics between the soil and beam generate testing errors. In this work, the sensing beam method is introduced, and the frequency response of the sensing beams will be obtained in an experiment on a shake table.
Numerical Analysis for the Excavation of Geotechnical Material in Tunnel and Grouting Effect
Authors: Cai Ke Jian
Published: February 2012

Gravity forces can significantly affect the support pressure required for equilibrium of a tunnel, especially in shallow tunnels, weak materials and/or large excavations. In the present paper, the calculation model is founded by FLAC3D, to study the effect of tunnel excavation to the rock mass. In the modeling, different types of material are considered, and different loads are considered. And finally, the effect of grouting in tunnel is studied to compare the shear strain increment and vertical displacement of rock mass.
Mechanical Properties Analysis of Heat Insulation Structure in High Temperature Circular Roadway
Authors: Liu Yan Wei , Chen Yuan Ping , Li Guo Fu
Published: February 2012

Roadway insulation and active cooling supporting structure is a complex system, and the mechanical properties play an important roal in its safety. Analyse the shotcrete layer pattern heat insulation structure by Midas-GTS software, calculation results shows that tensile stress zone appears in the top and bottom of heat insulation layer, while the will compressive stress area appears in two sides of the roadway insulation layer; in the case of 500m buried depth, heat insulation layer material, such as vitreous micro-bead, can well meet the engineering mechanical strength requirements.
A Practical Saturated Sand Elastic-Plastic Dynamic Constitutive Model and Application
Authors: Zhang Yan Mei , Ruan Dong Hua
Published: February 2012

A practical saturated sand elastic-plastic dynamic constitutive model was developed on the base of Handin-Drnevich class nonlinear lag model and multidimensional model. In this model, during the calculation of loading before soil reaches yielding, unloading and inverse loading, corrected Handin-Drnevich equivalent nonlinear model was adopted; after soil yielding, based on the idea of multidimensional model, the composite hardening law which combines isotropy hardening and follow-up hardening, corrected Mohr-Coulomb yielding criterion and correlation flow principle were adopted. A fully coupled three dimension effective stress dynamic analysis procedure was developed on the base of this model. The seismic response of liquefaction foundation reinforced by stone columns was analyzed by the developed procedure. The research shows that with the diameter of stone columns increasing, the excess pore water pressure in soil between piles decreases; with the spacing of columns increasing, the excess pore water pressure increases. The influence of both is major in middle and lower level of composite foundation.
Study on Mine Shaft Liner Breaking Mechanism and Application of Monitoring System in Deep and Thick Overburden
Authors: He Peng Li , Liu Cui Ran
Published: February 2012

The non-mining damage of shaft liner in deep and thick overburden occurred frequently in China. This causes heavy losses to the coal industry in China. The paper had a discussion on theories that explain the breaking mechanism of the mine shaft liner. As pointed out, the mining activities could make underground water table dropping and the strata consolidation and compaction could cause the overburden subsidence. Therefore a vertical additional force would be affected on the mine shaft liner and the vertical additional force would be the main factor to cause breakings on the mine shaft liner. According to the cause, the paper holds that a monitoring system should be built to monitor the additional strain of the mine shaft liner. Based on the analysis of these data, the safety of the mine shaft liner can be accuracy evaluated and timely forecasted. Therefore the mine liner breaking could be prevented before fracture by decreasing the vertical force or strengthening mine shaft liner.
Pullout Tests Study on Performance of Interface between Geogrid and Soil
Authors: Sun Jian Cheng , Jia Zi , Xiao Cheng Zhi
Published: February 2012

The interface interaction between geogrid and soil is one of key issues on stability of geosynthetic-reinforced soil structures. Comparative analysis of properties of geogrid-clay interface under the different kinds of geogrid, different normal stresses, speeds of pullout and water contents of clay are conducted by medium-sized pullout tests. The tests results showed that ultimate pullout force of geogrid, interfacial cohesion and frictional coefficient are significantly affected by various water contents of clay. Ultimate pullout forces of geogrid tending to remarkably difference when subject to different normal stresses at lower water contents, and frictional coefficient of interface decrease with the increase of water content, interfacial cohesion has a tendency to increase followed by decreasing with increase of water contents. Moreover, the curves of load and displacement possess three piecewise consisting of linear increase, non-linear increase and ultimate pullout, and as water content increase interval nonlinear changing stage is not conspicuous.
Study on Consolidation Mechanism of Debris Flow Deposit
Authors: Chen Hong Kai , He Xiao Ying , Zhong Ying , Tang Hong Mei
Published: February 2012

The damage of debris flow effected on highway subgrade, pavement, protective structure, bridge and culvert laid on debris flow impact fracture and buried damage. Thus far, research on debris flow burying mechanism is still fuzzy. According to the two-phase flow theory of debris flow deposit, analyzed the consolidation mechanical mechanism of highway debris flow deposit. On the basis of Terzaghi one-dimensional consolidation theory, established the consolidation formula, which described the change process of excess pore water pressure, consolidation degree, settlement and compression with the consolidation time and deposit size, and then verified the correctness and feasibility of the formula by the indoor consolidation test. It adopted these results and combined it with the field survey data, it could develop a proper program for emergency mitigation of highway debris flow buried disaster more quickly and accurately.
Research on Stability Analysis of the Hinge Joint Concrete Block Slope under Seepage Function
Authors: Zhang Yu Qing , Mi Yong Ning , Zhao Lin , Liu Kan , Wang Guo Li
Published: February 2012

The actual project—the Bird Island Park in Shenyang, an example of hinge joint concrete block revetment ,using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29 slope angle the role of a 45kg block under the action of the seepage stability of the slope. Variation in water head discussed in further detail and the role of the different blocks on the slope stability of the quality of the impact of the slope to provide a reference design and application.
The Deformation Characteristics of Soft Clay under Cyclic Loading
Authors: Zhang Yong , Wan Li , Li Xiong Wei
Published: February 2012

Through the undrained dynamic triaxial experiment, the deformation characteristics of saturated soft clay under cyclic loading are investigated. The cyclic loading was simplified as sine wave. It is found that under different dynamic stress, the deformation patterns of specimen in this experiment can be divided into three kinds, such as dense compressed, tensile break-up and shear failure type. In the process of vibration, the deformation forms of samples can also be divided into three types by dynamic stress amplitude, such as stable, destructive and critical type. The dynamic stress amplitude corresponding to the critical type is called critical dynamic stress. With the dynamic elastic strain increasing gradually, the dynamic elastic modulus decreases and rigidity softening occurs. Furthermore, dynamic elastic modulus and dynamic elastic strain curve decrease while the cyclic number is increasing. Finally, to establish the equation of the relationship between dynamic elastic modulus and dynamic elastic strain, the factor of cycle number should be considered.
In Situ FT-IR Studies on the Urethane Reaction Kinetics of 3-Methyl-1,3-Butanediol in Nitrogen-Contained Solvent
Authors: Yang Peng Fei
Published: February 2012

Phenyl isocyanate is used to react with 3-methyl-1,3-butanediol at different temperatures. Dimethylformamide is used as solvent. In-situ FT-IR is used to monitor the reaction to work out rate constant, Arrhenius equation and Eyring equation. The urethane reaction has been found to be a second order reaction, and the rate constant seems different between initial stage and final stage. The activation energy (Ea), activation enthalpy (ΔH) and activation entropy (ΔS) for the urethane reaction of tertiary hydroxyl group are calculated out, which are 75.2 kJ•mol-1, 72.4 kJ•mol-1and -44.8 J•mol-1•k-1, respectively. They are very useful to reveal the reaction mechanism.
Seepage Analysis for Dashiban Landslide Applied Typical Rainfall
Authors: Feng Qiang , Fang Feng Hua
Published: February 2012

Saturated and unsaturated seepage analysises are given for Dashiban Landslide applied a particular rainfall type, The impaction of typical rainfall on the stability of landslide is discussed, and further research foundation is layed.
Numerical Simulation of the Interfacial Behaviour of Grouted Rockbolts in Tunnel Support Based on a Tri-Linear Bond-Slip Model
Authors: Ren Fei Fan , Yang Zhen Jun , Xu Chao
Published: February 2012

Grouted rockbolts are widely used in tunneling excavation. However, the rockbolt design is still basically empirical, the mechanical behavior of grouted rockbolts, especially the interfacial behavior, has never been studied systematically. First of all, a tri-linear bond slip model is proposed for modeling the rockbolt interfacial behavior. Then analytical solutions to grouted rockbolt are presented on the basis of a tri-linear bond-slip model. Finally, a numerical model using Abaqus program to simulate the tunnel rockbolt is proposed. This model uses cohesive elements to simulate debonding along the anchorage interfaces, meanwhile, tabular damage variable is obtained on the basis of the damage evolution law in order to correspond with the tri-linear material model. The developed model was validated by monitored data. It was found that the model was capable of predicting accurately the interfacial shear stress distribution, load on the bolt as well as the rock movements. Therefore, this model can be used to optimize the control parameters of grouted rockbolts.
New Construction Method of Marine Cofferdam on the Soft Ground in Tideland
Authors: Liu Ai Min , Yan Shu Wang
Published: February 2012

The marine cofferdams of the littoral new town in Lianyungang were constructed with geotextile bags filled with solidified soil and the soft ground under the cofferdams was treated by under water vacuum preloading method. The dimension of the cofferdams was reduced while the foundation kept stable. And the cofferdams were configurated with the geotextile bags filled with solidified soil, the silt clay was utilized adequately, the sand stone resource was saved and protected, the obvious effect was achieved. This method can be promoted in construction of marine cofferdams.
Non-Working Wall's Slope Stability Analysis with the First Mining Area in Weijiamao Open-Pit Mine
Authors: Peng Chen , Chen Peng Fei , Ti Zheng Yi
Published: February 2012

To ensure the non-working wall's slope stability in Weijiamao open-pit mine,the paper analysis the engineering geological condition and hydrogeology condition of Weijiamao open-pit mine's slope,on this basis,combine the typical rocky slope's deformation and failure mode,physical properties of glutenite and weak layer from experiment,determined the latent destruction mode of non-working wall's slope in Weijiamao open-pit mine;calculated the slope's stable coefficient and the stable coefficient after cutting slope and unloading with rigid body limit equilibrium method ;make the numerical simulation of slope stability with FLAC3D,these expound the evolution law of slope rock mass stress field,reveal landslide mechanism of non-working wall,determined the landslide model is along the circular slip surface;basis for the numerical simulation result,puts forward prevention measures by cutting slope and unloading to realize stable slope.All these provide guidance for slope stability in Weijiamao open-pit mine,provide reference for open-pit mine's slope stability.
Study on Durability of Cement Soil under Brine Erosion
Authors: Liu Zhi Ping , Liu Quan Sheng , Qu Jia Wang , He Jun
Published: February 2012

In the coastal areas, deep mixing method or high pressure jet grouting method are usually used to form cement soil during the ground treatment. It’s easy to inflict corrosion damage of cement soil when the underground confined water is connected to the brine. Therefore, research of the cement soil’s durability under the brine erosion is of important significance to engineering. Start from the theory of chemical dynamics and damage mechanics, based on the chemical reaction formula between MgCl2 and the cement soil, with appropriate assumption, the relationship between ion concentration and corrosion time is deduced: (C1/C2)β=t2/t1, that is: when the soil eroded to equivalent mechanic effect, the relationship of corrosion time can be obtained in the solution with high and low concentration. Based on stress strain relationship, incorporate chemical damage factor into compression modulus, suggest certain assumptions, the same relationship between corrosion time and ion concentration is deduced.
Research to Performance of Basalt Fibre Strengthen SBS Modified Asphalt Mixture
Authors: Liu Zhao Hui , Chen Chang Yu , Qin Ren Jie , Zou Xin Te
Published: February 2012

This paper made a research into each performance index of basalt fibre strengthen SBS modified asphalt mixture by using two kinds of gradation, which are AC-20C of mid-surface and AC-13C of upper layer. And compared and analyzed with the same gradation of carbon fiber strengthen SBS modified asphalt mixture. The results showed that compared to carbon fiber strengthen SBS modified asphalt mixture Conbasalt , basalt fibre strengthen SBS modified asphalt mixture is equivalent on water stability and fatigue resistance,etc. It is relatively weak on low-temperature crack resistance. But it has decided advantage on high temperature stability.
Field Test Research on Soil Compacting Effect of Cast-In Situ Concrete Pipe Pile
Authors: Ma Zhi Tao , Liu Han Long , Wang Yong Ping , Zhu Ji Ming
Published: February 2012

Combined with practical engineering application, the test researches were carried out to analyze the soil compacting effects of Cast-in-situ concrete pipe pile while the pile was driven by vibration hammer. This article is focused on the characteristics of soil uplift and lateral deformation around pile, included surface soil and deep soil. In addition, the change characteristic of pore water pressure of soil around pile is also analyzed, and some useful rules were concluded. All researches are helpful to optimize the construction parameters, such as distance between piles, pile diameter etc., to improve the quality of pile foundation, also to reduce the construction impact on environment.
Three-Dimensional Numerical Analysis of Excavation and Support of Deep Foundation Pit
Authors: Zhu Chang Zhi , Zheng Xing Lian
Published: February 2012

Based on a project, a numerical analysis model was established by the finite difference program and the process of the deep excavation and support was simulated by computer, the distribution of the horizontal displacement and settlement of the top of slope of the slope soil were obtained. The simulation result was consistent with the test results. It shows that the method of numerical analysis can be used to the simulation of the excavation and support of Deep Foundation Pit, and it will provide the basis for the design and construction of practice project.
Study on the Reliability of Loess Cutting Slope Considering the Variability of Soil-Water Characteristic Parameters
Authors: Liang Yan , Huang Li Juan , Xing Xian Li , Li Ping , Li Tong Lu
Published: February 2012

The complexity of the geological conditions and the non-uniformity of geotechnical material make the study of slope stability with big uncertainties, so it is necessary to analyze the reliability of slope. In this paper, firstly, the matrix suction of Malan loess in Gansu Province is measured by tension meter, and a fitted soil-water characteristic curve (SWCC) is obtained according to the empirical formula; then SWCC parameters of Malan loess such as a, n and θs (saturation volumetric water content) are thought as random variables, the method of simplified Bishop is used to calculate of slope stability, and the reliability of cutting slope of Malan loess is analyzed according to Rosenbleuth method. Through calculating, obtain mean factor of safety, failure probability and reliability index of the slope. After analyzing the relations between mean factor of safety, failure probability, reliability index and variability of parameters, the results show that, the factor of safety is 1.005 and it is stable when the variability of SWCC parameters are not considered. When variation coefficients of a, n and θs are all 0.3, the average factor of safety is 1.051, the reliability index is 10.94 and failure probability is 29.81%. It is obvious that variability of SWCC parameters has certain influence on stability of the slope. In parameters of SWCC, comparing with a and θs, the variability of n has the most important influence on the mean factor of safety and failure probability. But the corresponding reliability index is minimum (the change ratios of the mean factor of safety， failure probability and reliability index with variation coefficient of n are 0.37，3.247 and 282.0 respectively). So variation level of n should be specially taken into account in reliability analysis of the slope. This research provides an important basis for the determination of the SWCC parameters of Malan loess, the stability calculation, stability estimation and prevention sliding of loess cutting slope caused by rainfall.
The Stability Research and Evaluation of Jiuzi Collapse Accumulation
Authors: Wang Ke , Wang Chang Ming , Niu Cen Cen , Ma Dong He , Lin Rong
Published: February 2012

Collapse accumulation is one of the most common bad geology bodies in mountain and canyon regions in southwest of China. Jiuzi collapse accumulation, which is located in the left bank of 400~1200 meters from wanjiakouzi hydropower station in the Xuanwei city Yunnan province, is primarily performing as a collapse body with some sliding character. Due to the close location to the dam site, Jiuzi collapse accumulation shows a tremendous safe hidden trouble to the engineering construction, and studying on its stabilization is of prime importance. Taking Jiuzi collapse accumulation as an example, expound the application of the Rosenblueth moment estimation method into probabilistic analysis of slope stability, effectively combined the traditional safety factor method with probability assessment method.
Review on the Mesomechanical Compressive Strength Model of Single-Directional Fiber Composites
Authors: Ma Xiao Jun , Chen Li , Ding Yong
Published: February 2012

The longitudinal compression strength of single-directional fiber-reinforced composite is related to many factors, such as the mechanical properties, the fractions of components, and the distribution of flaws. There are no abroad and uniform opinions about its longitudinal compressing break mechanism yet. Thus, a review of recent developments in the compression strength mesomechanical forecasting models of single-directional fiber-reinforced composites is presented. The damage mechanisms based by these models and the affecting factors considered in them are analyzed. The application conditions of each models are shown, and the model choosing method of combining experiment and theoretical analyze is suggested.
The Correlative Analysis of Testing Results of Dynamic Compaction Gravel Clay Foundation
Authors: Deng Tong Fa , Wu Zhou Ming , Gui Yue , Luo Si Hai
Published: February 2012

In this paper, we conducted some experiments as geotechnical test, standard penetration test, dynamic penetration test, loading capacity test on the dynamic compaction gravel clay foundation in Guangdong Province. We also conduct the lineal regression analysis and work out the normalized formula and the minimum-maximum equations based on PLT and other tests. We also make comparisons between the fitting equations in this paper and that in other specifications and reference items. Finally, the testing methods and empirical formulas available for the evaluation of the dynamic compaction gravel clay foundation are advanced for further surveys and designs.
Study on the Equivalent Width Coefficient of Tunnel Entrance in Metro Station
Authors: Chen Jun Min , Lin Sun Tao , Yao Xiao Lin , Ye Hai Bin
Published: February 2012

The numerical simulation results of 12 typical fire scenarios prove that the boundary conditions of tunnel entrance exert a significant influence on the accuracy and reliability of the fire numerical simulation results in metro station. In the fire scenarios with four 400-metre-long tunnels at both ends of the platform, the fire numerical simulation result is the most accurate, but the total numerical calculation time is twice more than the other fire scenarios, due to the additional volume of the computational meshes of the 4 tunnels. In order to guarantee the accuracy and reliability of the fire numerical simulation results on the condition that the computational mesh volume and numerical calculation time have not to be increased, 18 new fire scenarios with the different width of the tunnel entrance have been designed to simulate fire smoke movement in metro station, and the results are inserted into Lagrange's Interpolation Equation, then the equivalent width coefficient ε of tunnel entrance is found to be in the range of 0.34～0.55. In consideration of the mesh cell size and evacuation safety, ε is suggested to be 0.375.
Stability Analysis on Rectangular Transition Section Tunneling in Beiwan Horsehead Region of No. 7 Subway
Authors: Tan Wen Hui , Sun Hong Bao , Li Run Jun
Published: February 2012

The settlement of ground and vault by tunneling has important effect on construction safety and normal operation of urban transport system. The soils around reserved shaft of Beiwan region in No.1 section of Beijing Metro Line No.7 are backfilled and complex. In order to tunnel safely and keep surrounding structures safe, the stability of rectangular transition section by tunneling of Beiwan horsehead region is analyzed. Based on the data of surface survey, drilling, prediction detection of the strata and engineering design, the software of 3D FLAC is used to study the vault and ground settlements during the excavation of six pilot tunnels of rectangular transition section, and the results are also compared with the results of in-situ monitoring. The research shows that the results of numerical simulation and in-situ monitoring are matched very well, the ultimate ground settlement will be 17 mm when the transition tunnel is excavated by non-shrinkage (WSS) pre-grouting method and CRD method, and meets with the requirements of standard specification. Therefore, the six-pilot-tunneling method is good for keeping the transition tunnel stable.
The Research of Backfill Grouting Pressure in Shield Tunneling
Authors: Qiao Jin Li , Fan Yong Li , Liu Bo , Zhang Yan Ping , Li Yan Yan
Published: February 2012

As to shield tunneling, that soil is reinforced into the void is one of the most important reasons which cause the ground settlement, and always most important factor in the tunnel construction and the relative research. The numerical simulation studies presented in this paper focus on the different grouting pressure causing different ground settlement, plastic area and stress growth behavior. Based on the simulation results and the engineering ground settlement limit, propose reasonable synchronous slurry injection pressure and the relative method of controlling ground settlement. Propose reasonable suggestion for the determination of grouting pressure during shield construction.
Crack Propagation Detection and Simulation Research of Jiulong Tunnel
Authors: Wang Ning , Chen Pei Han , Wang Jing Chun , Liu Wei Hua
Published: February 2012

According to the specific engineering examples, the detailed analysis of the lining crack damage in process, status, characteristics and the distribution of disposal has been done. Based on the exploration and analysis of construction process and topography and geology factors , this paper discusses the genesis of lining crack , establishes the numerical model in lining cracks section taking the real topography condition, structure parameters of surrounding rock, the actual construction sequence,etc. Focus on the principal stress distribution law in lining structure and collapse deformation of surrounding rock, this paper explaines the cracks mechanism in theory, and the results is consistent to the actual practice.
Seismic Response Analysis of Cable-Stayed Bridges
Authors: Qiu Wen Liang , Jiang Meng , Zhang Xing Bo
Published: February 2012

For floating system cable-stayed bridge, the longitudinal displacement of stiffening girder and moments of towers are very large when strong earthquake happens. Too large displacement of stiffening girder leads to collision between girders of the main bridge and the approaches. Using spatial finite element model and time history analysis method, the seismic responses of cable-stayed bridge are studied considering the elasto-plastic effects. The results show that the displacement of stiffening girder is very large when no seismic reduction measures are adopted. The viscous dampers installed between the stiffening girder and towers can efficiently reduce seismic responses of the cable-stayed bridge. Especially, the displacement of stiffening girder can be controlled well to meet the design requirement. Using the optimum parameters of damper, the height of pier under tower and intermediate supports in side span on seismic responses are studied in detail. The longitudinal displacement of stiffening girder increases with the pier height increasing. The intermediate supports in side span are benefit for seismic reduction.
The Seismic Performance Study of Steel Pipe Concrete Column in the Absence of Beam Floor System
Authors: Ma Li Jie , Zhang Jin Yu , Wang Shao Jie
Published: February 2012

Architecture is the concrete columns with steel pipe flat floor slab, the 100mm × 100mm of steel pipe concrete column is in the center of the floor. The variation of moment and horizontal anti-force under horizontal displace of steel concrete columns are researched, and the steel columns working are analyzed, from that we can know steel concrete column in the slab-column structure has a good deformability under earthquake.
Probabilistic Seismic Risk Assessment for Transportation Network
Authors: Wang Zeng Zhong , Zhang Yu Xin
Published: February 2012

This paper presents a probabilistic seismic risk assessment methodology developed for Highway Bridge including models for transportation network analysis, hazard estimation, and seismic performance of highway components and evaluation of the economic impact to serve as a tool in the decision process for earthquake disaster management including pre-earthquake and post earthquake actions. This study is focused on the development of a procedure for seismic risk assessment, based on a probabilistic seismic hazard analysis.