bluuebunny/crossref_metadata_2025 huggingface dataset:
Brick Chimney in Complex Environment Demolished by Accurate Directional Blasting
Authors: Zong Qi , Zhou Shao Ying
Published: June 2012

High and thin brick chimney in complex environment was successfully demolished by directional blasting. By accurate orientation by theodolite, symmetry directional opening window, used small cut length, lower cut position, appropriate cut height and rational blasting parameters, the chimney dumped accurately according to design direction and eliminate the recoil phenomenon effectively when it down. Sandbags wall putting on ground for reduce the impact of the vibration effect; strictly coverage of the incision position can stop the flying rock effectively.
Finite Element Analysis of Static Characteristic for Gantry Crane
Authors: Zeng Qing Dun , Li Qin E
Published: June 2012

The strength and stiffness characteristics are important parameters in the design of metal structure of gantry crane. In this paper, the modeling of a gantry crane before and after reconstruction was performed by using Finite Element Method, and the strength and static stiffness of the gantry crane were analyzed. The results show that the insufficient stiffness of the reconstructed gantry crane in the shaking direction causes its laterodeviation. A strengthened method was determined after comparison of four reinforcement measures. The present results can provide an importantly theoretical basis for the reconstruction or strengthening of gantry cranes.
Study on Installation Technique for Steel Structure Dome
Authors: Fan Tao , Bian Guang Sheng , Li Zong Cai , Cheng Fang
Published: June 2012

The large-scale steel dome construction method is studied in the paper. Combined with Shandong province museum of steel construction dome, the piecewise processing methods are determined. According to the type of weight component chose lifting equipment types and model, aiming at the actual situation of construction formulated the steel structure installation overall process, the stress of the bed-jig to install a performance is calculated, and the steel frame column installation method is studied. The engineering experience and research content in the paper can provide a reference for the similar engineering.
Study on Deep Drawing Law of the Cylindrical Part with Prefabricate-Holes Based on Inverse Finite Element Method and Forward Finite Element Method
Authors: Tan Li Guang , Xiao Xiao Ting , Wen Hua Dian , Chen Qiao Yu
Published: June 2012

According to processing characteristics of getting rectangular holes after forming of the cylindrical part with prefabricate-holes, the optimum blank shape of the cylindrical part is necessary to improve product quality and reduce production cost. Theory analysis and numerical simulations combined with inverse finite element method and forward finite element method by using ETA/ DYANFORM were employed to investigate the influence on blank shape by the holes, modify the reverse blank shape and optimize the deep drawing by forward simulation,and finally obtain the forming law of the cylindrical part with prefabricate-holes.
The Comparison of the Estimation of Bridge Crane Real-Time Fatigue Life Based on JIS and FEM
Authors: Hu Xiong , Wei Ming
Published: June 2012

This paper aims to achieve a crane real-time software programming methodology for estimating the fatigue life,the core idea of this method is to capture the whole life cycle of real-time stress load,gets real-time fatigue life results by using JIS and FEM and compares the two results.The method is more accurate than the traditional one and has guiding significance for real-time fatigue life estimation of port machinery.
Analysis the Influence of the Viscous Damp Coefficient to Slump Viscous Particle Motion
Authors: Ji Xian Jun , Ou Guo Qiang , Yang Shun , Wang Jun
Published: June 2012

It is very complex that the viscous slump particle motion. The obtained motion parameters of the viscous particles which can’t be captured by experimental facility through PFC3D, which are used to analysis the influence of the viscosity damp coefficient to the motion of it. The influence includes the peak translation velocity, peak rate of rotation of the special particle and the biggest impact force. All of which have the maximum value when the viscosity damp coefficient is 0.3, but all of which reduce when the viscosity damp coefficient is 0.5. The smaller particle is easy to suffer to the influence of the viscosity damp coefficient than the bigger particle.
Application of Phase-Sensitivity Detector in Air-Coupled Ultrasonic Testing
Authors: Dong Wei , Zhou Zi Wei , Zhou Zheng Gan
Published: June 2012

The signal to noise ration of air-coupled ultrasonic testing is very poor and there is long time pulse residue, so it need adopt appropriate signal processing method to enhancing the SNR of received signal. Factors, which affect the received signal in ultrasonic testing process, is analyzed, phase sensitivity detection technology is presented to process the received signal, and ultrasonic testing information can be acquired by the calculation of phase signal. The principle of super-heterodyne receiver and phase sensitivity detector is introduced; some problem which should be pay attention in ultrasonic testing process is explained. Based on the research result, air-coupled ultrasonic testing system with phase sensitivity detector is constituted. Experiment results of image testing on carbon fiber reinforced plastic plate indicated that, phase sensitivity detection technology can improved signal to noise ratio of system and testing effect in evidence.
Application of a Modified Vacuum Preloading Method on a Dredged Fill Soft Foundation
Authors: Cui Yun Liang , Gao Ming Jun , Liu Zhi Hao
Published: June 2012

A lot of large area lands were made in China coastal areas by dredging sludge from the sea. The dredged fill ground had a very low bearing capacity which should be increased as soon as possible to meet the requirements of constructions. However, conventional vacuum preloading could not be used for this purpose because the sand cushion could not be laid on the sludge ground due to the very low bearing capacity. To solve this problem, a modified vacuum preloading method without sand cushion was proposed. This method has been successfully tested and applied in the reclamation project in Wenzhou. Based on this project, the technological process and the key technology were introduced and the reinforcement effect was analyzed. Project results showed the modified vacuum preloading method could achieve a good reinforcement effect on large area dredged fill ground in a short period. It is worth to promote the application of this method in coastal reclamation projects.
Steel Channel Lifting Using Tubular Gin Pole-Assisted, Multi-Point, High-Position Whole Lifting Technology
Authors: Jin Yong Chao , Wang Rui , Lu Yu Zhang
Published: June 2012

Heavy-duty structure lifting operation involves a complicated lifting process, great technical difficulty and high safety requirements. Also, the material/human resources and time spent on heavy-duty structuring lifting operation have a direct impact on the safety, quality, progress and cost of the whole projects. Therefore, it has become a common critical concern of the construction engineering circle to adopt advanced, reasonable lifting methods, select proper lifting equipment, prepare pertinent safety & technical measures, minimize the duration of lifting operation and reduce project cost. This paper introduces an easy, high-efficiency, safe, reliable, economical and practicable heavy-duty steel channel lifting technology, wherein the channel is lifted wholly via a tubular gin pole-assisted, multi-point, high-position lifting method. There is no need for large tonnage lifting equipment and ideal site conditions. As this lifting technology is conducive to operating efficiency maximization and cost minimization while ensuring safety and quality, it is suitable for wide application in today’s technical environment which prioritizes energy saving and emission cuts.
Analysis of the Influences of Matric Suction of Unsaturated Soil on the Slope Stability
Authors: Wang Li , Liu Cui Ran
Published: June 2012

There is suction in unsaturated soil. This is the most obvious difference between unsaturated soil and saturated soil. It is very difficult to measure it, so research has always been done without account of the influences of matric suction of unsaturated soil. In this paper, based on the test result of engineering characteristics of unsaturated soil from Yellow River Embankments, the stability of slope of Yellow River Embankments is analyzed using ultimate equilibrium method and the influencing rule of matric suction on slope is advanced.
Construction Technology of Concrete Filled Steel Tubular in Shenyang Wanxin Building
Authors: Yin Su Hua , Dong Ying Na
Published: June 2012

Concrete filled steel tube is widely used in super high-rise steel structure, but there are many problem in the construction of concrete filled steel tube. With the construction of Wanxin building as an example, this paper described the selection of the construction program, and analyzed the disadvantages in construction such as the difficulties of concrete pumping and the problems of pipe blockage, pipe explosion and concrete curing during the process of construction. Based on structural characteristics and construction difficulties, the key technique of steel tube concrete construction are introduced in detail. It can provide significant reference and guide for super high-rise building construction.
Experimental Study on Temperature Data of Mass Concrete Construction in Hot Weather Conditions
Authors: Wang Jun , Zhang Yu , Zhu Xin Long
Published: June 2012

Through studying on temperature data of mass concrete poured completely after 20 days, the temperature time-history curves were plotted in different heights section of the raft foundation. Moreover, the characteristic parameters such as solid concrete temperature, temperature difference between inside and outside , also between surface and atmosphere, and its cooling rate were studied. Then by checking cracks of the mass concrete, the most likely period of temperature stress cracks appearing is pointed out. The useful experience data of the mass concrete construction in conditions of hot weather is accumulated, whose concrete strength standard is evaluated by 28d age.
Numerical Simulation of Ligament Force in Pitching Motion
Authors: Li Bin
Published: June 2012

The knee joint is a vulnerable joint that is easily injured. This is due in part to the fact that the joint is in the middle of two long lever-arms, the femur and the tibia. This makes the knee ligaments prone to injury from any strong contact to the knee, or sometimes even from just the force of the body moving through space with a hard muscle contraction. Simulation of ligament force in pitching motion of basketball player is studied in this paper.
The Selection of the Collapsible Loess Foundation Treatment Methods
Authors: Xu Yun Bo , Sun Yan Fei
Published: June 2012

The collapsible loess ground treatment methods include dynamic compaction, soil replacement cushion method, lime-soil compaction pile composite foundation, pile foundation, etc. Each method has its advantages and disadvantages. The bearing capacity of collapsible loess is not lower, it is non-soft soil. The purpose of the collapsible loess ground treatment is to eliminate the collapsible at the most, few to increase the capacity and improve the heterogeneity of the foundation. In this paper, the collapsible loess foundation treatment methods are been compacted from the technical and economic factors. And the key issues of the collapsible loess ground treatment methods are discussed.
Computer Simulation of the Magnesium Silicide Polymorphs
Authors: Chen Dong , Xu Chao
Published: June 2012

The anti-cotunnite magnesium silicide was constructed, and its absorption coefficient, dielectric function and loss function have been investigated through the plane-wave pseudo- potential calculations based on the density functional theory. In our scheme, we consider the Mg2Si crystal without defects or cracks. Significant features have been observed for the optical properties in the low-energy region and the high-energy region. The main focus of this paper is to determine the high-pressure optical properties of Mg2Si and find out if this material can be used as high-performance thermoelectric devices.
A Reduced-Order H∞ Controller Design for Linear Structures
Authors: Hu Lian Hua , Yang Xiao Feng
Published: June 2012

A robust reduced-order H∞ controller for the linear structures is investigated. This controller is with disturbance decoupling. First, a necessary and sufficient condition for the H∞ state feedback control problem is established. Second, based on the parametric design approach for generalized Sylvester matrix equations, we obtain a reduced-order H∞ controller for linear structures. Finally, numerical example is given to illustrate the validity of the results.
An Emulation Method of Sensor Clutter Plots Elimination Using Statistical Characteristics Analysis
Authors: Wu Zhong Hong , Shi Zhang Song , Shi Zhao Ming , Lv Ying
Published: June 2012

Aiming at problem about real-time processing power is poorer as the cause of too many clutter plots in multisource information fusion conditions when traditional information algorithm is used, method of sensor clutter elimination based on statistical characteristics analysis is put forward. Firstly, statistical characteristics of clutter plots are extracted, calculated and analyzed. Secondly, in combination with the advantages of multi-sensor detection, the plots of real-target have been filtered according to certain threshold values and safeguarded. Finally, a specific simulation experiment is given. Experiment shows this method can achieve the real-time processing power effectively.
Computer Simulation of the Metal Silicide
Authors: Chen Dong , Xu Chao
Published: June 2012

We have investigated the optical properties of the Fm-3m-Mg2Si using the first-principles plane-wave pseudo-potential method. Some important optical parameters (reflectivity, refractive index, extinction coefficient, loss function and dielectric function) are calculated and investigated at high pressure. The calculated static dielectric constant ε(0) is 15.9. The computed plasma frequency is 12eV. Some interesting features in the optical parameters are found in the low frequency region. Nevertheless, the calculated result needs to be testified by experiments in the near future.
A Comparison of Cohesive Crack Model and Crack Band Model in Concrete Fracture
Authors: Wu Liang , Li Ze , Huang Shang
Published: June 2012

The cohesive crack model and the crack band model are two convenient approaches in concrete fracture analysis. They can describe in full the fracture process by the different manner: The entire fracture process zone is lumped into the crack line and is characterized in the form of a stress-displacement law which exhibits softening; or the inelastic deformations in the fracture process zone are smeared over a band of a certain width, imagined to exist in front of the main crack. The correlation of the two models is developed based on a characteristic width of crack band. The analysis shows that they can yield about the same results if the crack opening displacement in the cohesive crack model is taken as the fracturing strain that is accumulated over the width of the crack band model. Some basic problems are also discussed in finite element analysis.
Research of Secure Sharing of Electronic Medical Records in Internet
Authors: Si Zhi Gang , Wan Ying , Shi Yun Shuai , Li Ping
Published: June 2012

Regional sharing in electronic medical records (EMR) system are the main problems that the system must face in the development. This paper comprehensive analyzes the existing secure sharing program of EMR, and based on it this paper proposes the program that uses the Trusted Computing technology to ensure the secure sharing of EMR. For ordinary computer can not build trusted computing platform, the embedded trusted system based on the USB interface is used to build trusted computing platform, and based on it this paper proposes the EMR secure sharing scheme based on the embedded trusted system.
Simulation and Experiment on Landing Gear Component Noise
Authors: Li Long Shuang , Nie Hong , Xu Xin
Published: June 2012

Simulation analysis and experiment research are performed on the aeroacoustic noise of a landing gear component in this paper. Detached Eddy Simulation (DES) is used to produce the flow field of the model. The Ffowcs-Williams/Hawkings (FW-H) equation is used to calculate the acoustic field. The sound field radiated from the model is measured in the acoustic wind tunnel. A comparison shows that the simulation results agree well with the experiment results under the acoustic far field condition. The results show that the noise radiated from the model is broadband noise. The directivity of the noise source is like a type of dipole. The location between shock absorber and strut, shock absorber and bogie can induce the interaction noise which is presented by two energy peaks in the spectra. The shock absorber and the bogie is the main contributor while the strut is the least contributor to the total noise.
Study on Medium and Long Term Power Load Forecasting in Cold Regions
Authors: Li Jian , Jiang Zhen Huan
Published: June 2012

A large part of Qinling Mountains and north of the Yellow River in China belongs to cold regions, so accurate forecasting of power load in cold regions plays an important role in economic development. This article summarizes the basic theory of power load, power load forecasting and medium and long term load forecasting power load forecasting in cold regions, studies on the affecting factors of the medium and long term power load in cold regions, proposes the study road map on the affecting factors of the medium and long term load in cold regions and analyzes empirically the medium and long term power load forecasting in the northeast of China.
Application of Ant Colony Algorithm to Volumetric Thermal Error Modeling and Compensation of a CNC Machine Tool
Authors: Guo Qian Jian , Qu Qing Wen , Yang Jian Guo
Published: June 2012

Volumetric errors are the major contributor to the dimensional errors of a workpiece in precision machining. Error compensation technique is a cost-effective way to reduce volumetric errors. Accurate modeling of volumetric errors is a prerequisite of error compensation. In this paper, a volumetric error model was proposed by using neural networks based on ant colony algorithm. Finally, a volumetric error compensation system was developed based on the proposed model, and which has been applied to a CNC machine tool in daily production. The results show that the volumetric errors are reduced and the machining accuracy of the machine tool is improved.
Numerical Simulation of Hydraulic Shape Optimization for Bifurcated Pipe of Hydropower Station
Authors: Ji Chang Zhi , Wu Xu Min , Meng Jiang Bo , Xu Jiang Tao , Chen Wei Bo , Zhang Xin
Published: June 2012

Steel bifurcated pipe is one important part of the water diversion buildings in a hydropower station. And its hydraulic characteristics are crucial to reduce the head loss of the bifurcated section. The numerical simulation was carried out with spherical trifurcate branch pipe, shell type trifurcate branch pipe without deflecting plates and shell type trifurcate branch pipe with deflecting plates under a serious of operating conditions based on a case study. After this, the flow conditions and the head losses in the bifurcated sections were analyzed. The shell type trifurcate branch pipe with deflecting plates had the most advantageous hydraulic characteristics of the three schemes. The shell type and the deflecting plates improved the flow condition effectively. The scheme could improve the flow condition and reduce the head loss of the bifurcation section effectively. The results might provide some references to the bifurcated pipe design and operation.
Theoretical Study and CFD Simulation of Airflow Distribution through a Cold Store
Authors: Tang Yi , Xie Jing , Miao Chen , Wang Jin Feng , Zheng Yi
Published: June 2012

Recently, the quantity of the cold store has been increased quickly. It is a key point to improve the uniformity of airflow field to the cold store. In this paper, a model of simulating cold store by computational fluid dynamics (CFD) was introduced. Simple algorithm combined with Boussineq assumption was used and turbulent equation combined with standard wall function was applied to define the flow of air in the cold store. Both the structured mesh and unstructured mesh to cold store model were simulated. The simulation methods of airflow in a cold store between three-dimension (3D) technology and two-dimension (2D) technology were also discussed. The experiment was validated and proved that unstructured grid was in better agreement with the result of experiments and it was gotten that the three-dimension (3D) technology had a higher accuracy in simulation of airflow distribution. The airflow distribution in the vertical plane and horizontal plane in cold store were gotten, respectively.
Prediction of Dynamic Impedances Functions Using an Artificial Neural Network (ANN)
Authors: Badreddine Sbartai , Goudjil Kamel
Published: June 2012

Artificial Neural Networks (ANN) has seen an explosion of interest over the last few years. Indeed, anywhere that there are problems of prediction, classification or control, neural networks are being introduced. Hence, the main objective of this paper is to develop a model to predict the response of the soil-structure interaction system without using the calculate code based on sophisticate numerical methods by the employment of a statistical approach based on an Artificial Neural Network model (ANN). In this study, a data base which relates the impedance functions to the geometrics characteristic of the foundation and the dynamic properties of the soil is implemented. This leads to develop a neural network model to predict impedances functions (all modes) of a rectangular surface foundation. Then the results are compared with unused data to check the ANN model’s validity.
The Second Development of ADINA
Authors: Zhou Wen , Cao Lin
Published: June 2012

The second development of Duncan-Chang － model suitable for geomaterials widely used home and abroad is made in ADINA with FORTRAN. The applicability of User-Defined Materials in ADINA is proved by engineering case.
The Design of Ring Oscillator Accelerometer Low-Frequency Signal Measurement Circuits
Authors: Zhao Zhi Gang
Published: June 2012

The basic principle of Ring Oscillator Accelerometer is analyzed in this paper. On the basic of simulation and analysis of the structure of the Ring Oscillator Accelerometer, a four-silicon beam structure is put up . Then the mixer- principle of the dual-gate MOS mixer is analyzed in theory. Finally, We have simulated the ring oscillator circuit and the dual-gate MOS mixer circuit using the PSpice. The result of the simulation fits theory well.
Simulation Study on the Stability of Mining Thin Flat-Grade Iron Ore Body with Hydraulic Support Longwall Method
Authors: Zhao Shu Guo , Song Wei Dong , Xu Wen Bin , Song Huan Hu
Published: June 2012

This paper proposed hydraulic support longwall method for mining glacis thin orebody. The DaZhuang ore section of Guandian Ore Mining whose orebody in the line of -8＇—-16＇was chosen as the research object. It applied the FLAC numerical simulation method to study the changes of surrounding rock stress in the mining face, displacement and plastic zones, and put forward the changing law of the rock stress, displacement and plastic zones in the mining process. Besides, it proved that the mechanical condition of the roofs changed in different stages. When the distance between pillar and mining face was in the range of 4m—8m, the state was relatively stable, and the pillar and surrounding rocks were in small range of shearing and tensile yield. When distance was 12m, the roof suffered from compression. When it was up to 16m, the roof and bottom rock displayed tension. However，the appreciation of stress changed very little at different stages. The stress concentration circle formed between the top and bottom of the pillar, and the unloading appeared in the top and bottom gap. The nearer to the coal face, the more powerful of stress concentration, and the influence of pillar’s position on stress concentration degree is very little in the front of coal face. The structure would be in stable equilibrium when the distance between single stent and coal face is 12m. In such circumstances, the security of roof would be improved if more stents are added
Rock Slope Stability Analysis Based on FLAC3D Numerical Simulation
Authors: Wang Hao , Chen Zi Xiong , Zhang Dong Ming
Published: June 2012

The rocky slope instability has brought great danger to human activity, and often causes economic losses, property damage and casualties, also can cause huge overhead expenses. Rock slope stability analysis must understand the geological conditions as the foundation, be under the analysis to effects of geological factors of rock slope stability, be under the premise of analysis to the engineering geological factors and then make evaluation, this is the best method of analysis and evaluation of stability of rock slope effective. This paper utilizes quick Lagrange difference analysis (FLAC3D) to Zhu Jiadeng landslide in Chongqing, the numerical simulations are to determine the landslide static stability, and provide the basis for management.
Method for Getting the Soil Elastic Modulus in the Finite Element Analysis of the Deep Foundation Excavation in Tianjin
Authors: Feng Shi Lun , Li Pu Lin , Li Jun , Zhou Yuming
Published: June 2012

The finite element method has been used widely in foundation pit engineering to simulate the deep foundation excavation, but it is troublesome and time-consuming to get the important calculation parameter of the soil elastic modulus. So a method based on the comon soil parameters is proposed to get the soil elastic modulus. And a real foundation excavation was simulated using the finite element software ABAQUS and the soil elastic modulus got according to the proposed method. The three-dimensional finite element analysis results were compared to the field data, and both results were close to each other.
Generalized Variation Problem of the Fractured Rock Mass under the Linear Elastic Unloading Stage
Authors: Li Yu , Fu Ming Fu , Xie Zhi Long
Published: June 2012

First, the constitutive equation of the linear elastic and the basic equations flexibility of the unloading rock mass were introduced, and then using the equations and the boundary conditions the variation principle was contracture. Prior to construct an appropriate minimum potential energy functional, on this basis, pending the introduction of two Lagrange multipliers, and absorb the variation constraints to establish the new functional. Last will 、、、as an independent variable, considering the variation stationary conditions functional of the new functional can identify the Lagrange multipliers 、 to be determined, so can build the generalized variation principle of dual variables
Seepage Analysis and Prevention Technology Research of Wastewater Reservoir in Metal Mine
Authors: Zhao Jiang Qian , Ju Hai Yan , Li Jian Hua
Published: June 2012

Based on the investigation of the seepage causes wastewater reservoir of in one metal mine, the erosion mechanism is analyzed that the acid mine drainage erosion the earth-rock dam, and the technology program of vertical anti-seepage wall is chosen that use concrete with coal fly ash as anti-seepage wall. The practice has proven that such concrete vertical anti-seepage wall can improve the impermeability and structure of concrete, enhancing the anti-seepage wall durability under acidic environment. It can be reference to similar projects.
Predicting Joint Roughness Coefficients Using Fractal Dimension of Rock Joint Profiles
Authors: Xu Hong Fa , Zhao Pei Sheng , Li Chao Fu , Tong Quan
Published: June 2012

The Joint Roughness Coefficients, JRC, is presented Barton and Choubey in 1977. A series of different rock joint profiles were reconstructed by means of the independent cut method (Voss, 1988) using the programs written by MATLAB language. The reconstructed joint profiles have different amplitude and roughness. JRC values of the joint profiles were calculated on the basis of an empirical formula founded by Tse & Cruden in 1979 using measure interval space 0.5mm on the profiles. The fractal dimension values of the joint profile were calculated by means of stick-measuring methods suggested by Xu in 1996. The relationships between JRC and fractal dimension for all joint profiles were analyzed and exist strong correlations. A new empirical equation describing the relationships was established based on nonlinear fitting analysis and can predict JRC values accurately.
Safety Factor Calculation Method of Anchored Slope Based on Pseudo Cohesion Theory
Authors: Shi Chong , Zhang Yu Long , Zahng Qiang , Wang Hai Li , Wang Sheng Nian
Published: June 2012

The stability of slope is closely related to stress-state. Assumptions about stress-state in the rigid body limit equilibrium method are not satisfied with the demands of deformation compatibility principle. So the stability analysis method compatible with slope stress and anchorage system should be established for anchored slope. The pseudo cohesion concept theory is used to analyze the improvement of stress-state due to anchoring measures, and the stability safety factor of anchored slope by sliding surfaces searching method is obtained, in which grid control is used and embedded in FLAC3D. The result shows that the safety factor with the pseudo cohesion theory is 1.43 while the strength reduction method is 1.41. The similar results for them show the validity of proposed method. What's more, the suggested method has an advantage of short time consuming.
Study on the Deformation and Stability of Surrounding Rock
Authors: Jin Sheng Ji , Rui Yong Qin , Shu Zhe
Published: June 2012

To rely on nuclear power plant water tunnel project, through the numerical simulation methods, we analysized the extent of rock deformation and stability of the process of excavation and supporting to reveal the deformation near the working face of rock tunnel.The research results show: When carrying out tunnel excavation, the plastic deformation zone in the horizontal direction perpendicular to the tunnel axis and the vertical downward direction are extended, the vault appears to sink, but also occurred in surface subsidence. Contrast the extent of tunnel excavation: The minimum extent is the tunnel axis perpendicular to the vertical downward, followed along the tunnel axis, the maximum extent is perpendicular to the direction of horizontal tunnel axis. Three kinds of excavation methods, a substantial volume reduction of sinking takes place in short steps and extra short steps excavation than the excavation of the top arch , and the surrounding area within the plastic is significantly reduced, which shows the smaller footage of the excavation the better control of the sinking of the crown.
Comparative Study on Laboratory and Field Test of Maximum Dynamic Shear Modulus
Authors: Sun Jing , Yuan Xiao Ming , Gong Mao Sheng
Published: June 2012

The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the laboratory and in the field. The experimental result of maximum DSM by using resonant column devices is compared with the field test data obtained from shear wave velocity measurement in the paper. By testing two engineering sites, the reason of difference of the maximum DSM between laboratory and field test is presented and the effect of the consolidation ratio on the maximum DSM is investigated. The results here indicate that consolidation ratio is one of the most important influence factors to make a great difference of the maximum DSM between laboratory and field test. By comparing to the isotropic consolidation, the consideration for the actual anisotropic consolidation makes the maximum DSM increase up to the value obtained by field test, and the error decreases significantly.
The System Safety Analysis Method Contrast Analysis
Authors: Lv De Chao
Published: June 2012

The system safety analysis method is the foundation to guarantee the safe operation production system. In this paper, all kinds of system safety analysis methods are introduced. Contrast analysis is fully used to grasp the advantages and disadvantages of each method and their application scopes, which will make it better to apply the theory to practice.
Study of Foundation Behaviors Consisting of Single Piles Penetrating Bedrock in Taipei Basin
Authors: Chen Shong Loong , Ho Cheng Tao
Published: June 2012

For the stratum distribution around Taipei Basin, it is typical that the top part of stratum formation is covered in soft or very soft soil with uneven thickness and sits on bedrock with extremely high bearing capacity. For the tall building located at the basin rim, pile foundations are often required due to lack of bearing capacity, as these buildings are sitting on soft or extremely soft soil. When it comes to calculating the bearing or pulling capacity, there are two major ways of calculation, equation of static mechanics and estimation with “N” value from in-situ penetration tests, as specified in the current “Design Code for Building Foundations.” However, the methods mentioned above apply only to general soil, and there is no specific recommendation for the friction and pile tip resistance. Therefore, in foundation pile design, the calculation of friction and pile tip resistance on the part of piles in bedrock is always bothering engineers. Yet, the contribution from the part of piles in bedrock, in fact is significant. As a result, the characteristics of the part of piles in bedrock are a topic worth studying. In this study, pile loading tests at 7 locations at Nangang, Taipei City are taken as examples. Finite element method (FEM) is introduced for simulation of in-situ drilled foundation piles mentioned above that are commonly used. The result of simulation is compared with that of actual static pile loading tests, and it is found that there is consistency between the simulation result and that of loading tests when the bedrock penetration depth of foundation piles reaches 1.6~2.0 times of pile diameter, as FEM is introduced for the simulation of the relationship of axial loading of pile versus pile-head top settlement.
A Brief Review of Previous Studies on Regularity of Stress Waves Propagation in Micro-Cracks of Rock
Authors: Yu Jin , Cai Yan Yan , Song Bo Xue , Chen Xu
Published: June 2012

The research of stress wave propagation law under cracked rock has important theoretical value and practical significance. Because of the discontinuity, nonelasticity and nonlinearity of the cracks, the theoretical interpretation and mechanism research about tress wave propagation law are a great challenge to researchers for a long time. From the establishment of the research method, the determination of mathematic model of micro-cracks and the main solutions, this paper brief reviews the current development of the influence of the complicated micro-cracks on stress wave propagation law.
Experimental Study on Determining Thermal Conductivity of Soil
Authors: Jia Dai Yong , Sui Lu Yan , Fan Liang Kai , Wang Jin Sheng
Published: June 2012

Ground source heat pump (GSHP) is an effective energy saving technology for heating and air conditioning. Thermal conductivity of soil is a critical parameter for designing a GSHP system, as the parameter is indispensable in analyzing and determining initial investment, energy saving effects, and operating performance of the system. In this study, the major influencing factors of soil thermal conductivity were analyzed. With different compositions and water contents of soil, the values of conductivity were determined experimentally, which can provide essential data for designing a GSHP system. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text
Dynamic Analysis on Rammed Soil-Cement Pile Composite Foundation
Authors: Guo Wei Tong , Meng Yan Jie
Published: June 2012

The test on was rammed soil-cement pile composite foundation was done,On the basis of the test. Numerical simulation was analyzed to rammed soil-cement piles.The conclusions were draw from the main frequency,level acceleration, vertical acceleration and influence factors.Theory basis was provided for the study on rammed soil-cement pile composite foundation in the future
Equivalent Proof and Applicability Evaluation of Two Types of Simplified Bishop’s Methods
Authors: Shen Yang , Xu Guo Jian , Yan Wei , Chen Lei
Published: June 2012

In order to consider the influence of water pressure on cohesive soil slope with groundwater, the local and global water pressure methods are proposed. The equivalence and applicability of the two methods based on the simplified Bishop’s method are analyzed. The local water pressure method considers the water pressures on boundaries as components and the global water pressure method considers the water pressures as a resultant force. The physical analysis and numerical verification showed these two methods are completely equivalent. While the global water pressure method is more convenient in hydrostatic condition, the local water pressure method is prior in seepage condition. It is also pointed out that there are significant defects in some regular expressions of simplified Bishop’s method. Because they neglect the moment generated by water pressure on the top boundary of slope or wrongly evaluate of the hydrodynamic failure states with hydrostatic stress parameters.
The Application of Analytical Solution for Critical Anchorage Length on the Bolt of Rock Bolt Crane Girder
Authors: Yang Chun Ming , Shao Sheng Jun
Published: June 2012

The anchorage length of the bolt in rock bolt crane girder is obtained by means of rigid limit equilibrium method and the critical the anchorage length of bolt is calculated by analytical solution. Combined with the calculation results, the analysis on the mechanical characteristics is carried on by building the finite element model of rock bolt crane girder with different anchorage length of bolt. The analysis results indicate that the bearing characteristics of rock bolt crane girder are not improved significantly with the increase of anchorage length when the anchorage length of bolt exceeds the engineering critical anchorage length. The existence of critical anchorage length of blot is proved further, and the rationality of analytical solution for critical anchorage length is validated.
Experimental Research on the Change of Soft Soil’s Strength and Deformation Characteristics Caused by Dewatering
Authors: Yuan Hua , Zhang Jian Wei , Zhao Zhi Liang
Published: June 2012

Present research results have verified the significant soil reinforcement effect of dewatering. But the reinforcement effect of dewatering suffers ignorance in current excavation design process due to lack of systematic experimental study on the strengthening mechanism, causing a certain amount of waste. This paper first theoretically describes the relationship between the increase of soil shear strength and that of compression modulus owing to pumping, then investigates the influence of well-point pumping on Shanghai soil’s shear strength and deformation properties through indoor test. The results may provide useful suggestions for future excavation support design.
Thermodynamic Properties of Soft Sedimentary Rock in Geotechnical Engineering
Authors: Wang Jing Yin , Liu Fang
Published: June 2012

In geotechnical engineering such as supporting of deep and soft rock roadway ,oil drilling , and construction of military underground defensive facility, thermodynamic properties of soft sedimentary rock has guiding significances .The study of the thermal constitutive behavior of rock under temperature has been done for many years, and many achievement have been got on this issue. In this paper, some experimental researches on the thermo-mechanical characteristics of soft sedimentary rock have been presented. Some test results have been simulated with a thermo-elasto-viscoplastic model. The results show that the proposed thermo-elasto-viscoplastic model reflects the visco-elastoplastic properties of rock，and can describe the thermo-mechanical behaviors of soft shale rocks in not only drained conventional triaxial compression tests but also drained triaxial creep tests. So it can be used for analysis of theology and stability of rock engineering.
An Improved Finite Element Method of Rock Stress Field Back Analysis Coupling with Genetic Algorithm
Authors: Zhou Hua , Wu Xiao Tao , Huang Yuan , Zhou Dong Ni , Tian Tian
Published: June 2012

Aiming at the deficiencies of traditional linear optimization methods in back analyzing, an improved finite element method of rock stress field back analysis coupling with genetic algorithm is put forward, in which the finite element analysis is embedded in genetic algorithm as a single module and rock stress field is gotten by nonlinear solution. Then an assumed geological cross-section is taken for an example to verify its validity. The result demonstrates that the back analyzed stresses of all the measuring points are in good agreement with the measured ones and the relative error is very small, which verifies the feasibility and effectiveness of the proposed method.
Laboratory Tests on Engineering Properties of Wind-Blown Sand
Authors: Jia Zhao Lin , Yan Shu Wang , Huo Zhi Liang
Published: June 2012

By means of laboratory tests and theoretical calculation, the physical, mechanical properties and compaction mechanism of the wind-blown sand are studied to deal with the problem of how to use the wind-blown sand as roadbed materials. It is revealed that water content doesn’t affect the compressibility and the shear strength of the wind-blown sand obviously and the wind-blown sand can be compacted both in dry and wet conditions. The compaction curve of the ordinary fine sand is consistent with that of wind-blown sand and the main factors affecting the compaction properties are the grain composition, water content and compaction work.
The Study on Outer Shift Lining Structure of Freezing Shaft in Aquiferous Instable Rock
Authors: Yao Zhi Shu , Deng Xin , Cheng Hua
Published: June 2012

Aiming at the supporting problems of inner shift lining of freezing shaft in the deep thick aquiferous soft rock of west area in China,the test result of frost heaving indicates:the frost heave of rack in west area is feeble,and freezing pressure is small,the design of outer lining mainly suffices thick require of thick wall cylinder structure .First, the model of reinforced concrete is designed and the test pieces are manufactured according to simlilarity theory, then,through loading test, the stress,strain and strength characteristics of this shaft lining structure are gained.the studied results can provide a reference for engineering application of this shaft lining structure.
Permeability and Porosity of Tight Rock Materials under Conditions of High Temperature and High Pressure
Authors: Deng Ying Er
Published: June 2012

Experiments were performed by using an improved test system of physical parameters of rock materials. Influence of effective stress, temperature and flow velocity of fluid on permeability or porosity of tight rock materials under high temperature and high pressure was investigated. A micro-mechanism was given to interpret changes of the permeability or the porosity by means of a microscopic imaging method. Results show that the permeability decreases with an increase in effective stress or temperature and increases with an increase in flow velocity of fluid, and that relative change of the porosity increases with an increase of effective stress and is not detectable with an increase in temperature. The main reasons for the above changes are nonlinear flow and narrowing of micro-cracks under action of effective stress or thermal effects. Changes of the micro-cracks play a more important role in the permeability than in the porosity. The results can provide engineering geological disposal of high level radioactive waste with basis.
A Study on the Effects of Water Content on Strength Parameters of Landslide Soil
Authors: Qi Jian Feng , Song Xue Lin , Liu Ji Chao
Published: June 2012

Soil samples of slide body and slide zone are obtained to study the strength parameters from a landslide in Yunnan Province, China. Firstly, the basic physical properties of the two soil samples are measured. Then geotechnical tests are performed to study the variation law of strength parameters under different water content by using the automatic KTG triaxial shear apparatus. The results show that the cohesion of soils rapidly reduces with water content increasing, and slowly reduces when plastic limit attains, and it seems that a turning point appears at the location of plastic limit.The relation of cohesion with water content approximately conforms to the exponential function, and the relation of internal friction angle  with water content approximately conforms to the linear relation.
Analysis of Soil’s Horizontal Displacement behind Retaining Wall Caused by Foundation Pit Excavation
Authors: Jiao Tao , Chen Wei , Zhou Jian Ping
Published: June 2012

Currently the study of soil’s horizontal displacement caused by foundation pit excavation is still deficient. Based on existing research material, this paper builds the displacement models of soil’s horizontal displacement. Through adopting three-dimensional finite difference method, working process and related influencing factors are simplified into displacement boundary condition which is applied to numerical model to analyze soil’s horizontal displacement. The conclusion can be used to estimate displacement of soil behind retaining wall, such as soil’s horizontal displacement and range of influence.
Research on Numerical Simulation Model for Crack Growth Driven by Detonation Gas in High-Deep Rock Strata
Authors: Chen Li Jing , Zheng Jian , Zhang Cheng Ke
Published: June 2012

The effect of detonation gas upon rock fracture is the cross-frontier research project of fluid dynamics coupling and rock dynamics of crack dynamic growth, having the important scientific significance and explicit application value. In the process of detonation gas driven fracture growth, the varying law of the denotation gas pressure distribution in cracks is inter-influent with the geometric morphology variations in crack growth. This paper analyzes the denotation gas flowing behaviors, establishes the flowing model for denotation gas in rock cracks and the models for the rock crack dynamic response. Also suggests the fluid-solid coupling model for the denotation gas flowing, rock crack response and the numerical model for simulating crack growth driven by the denotation gas. The simulation program is developed on the large-sized rock engineering finite element software (FINAL platform). This numerical analysis platform is used to carry out the systematic numerical experimental study of several main influencing factors of core problems concerning pressure fracture length.