bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature Evolution and Optimization of Hot Extrusion Process for Al-Zn-Mg-Cu Aluminium Alloy Based on FEM Simulation
Authors: Xu Lei , Dai Guang Ze , Huang Xing Min , Zhao Jun Wen , Han Jing , Gao Jiewei
Published: June 2012

Hot extrusion process of Al-Zn-Mg-Cu alloy billet had been simulated under different temperature of billet and container. It was proposed that due to large deformation and friction, maximum temperature of the billet occurs on the skin near extrusion export and is under three direction tension stress state, where surface is likely to crack if temperature surpassed the incipient melting point. The right temperature of the billet and container is 425°C~450°C and 400°C respectively with the constant extrusion speed 0.8mm/s
Experimental Research on Mechanical Properties of Sandwich Wall Panels with Bamboo Shear Connection
Authors: Wang Meng
Published: June 2012

Sandwich wall panels are often used as non-bearing structure and just need to bear lateral wind load. Steel truss is normally used as the shear connectors in the wall panels. Traditional steel connectors are poor thermal insulators and heat is easily been transfer through them. As a result, they lead to enormous energy lose. In order to improve the energy efficiency, composite bamboo connectors, which are ideal thermal insulators, are used to replace steel ones. In this experiment, three full-size models of composite sandwich wall panels were built and their displacement, surface strain, crack load, as well as ultimate strength were determined. Experimental results shows that wall panels with bamboo connection has a relatively better mechanical property than traditional ones.
Flexural Strength Evaluation of one-Way Void Deck Plate Slab with Polystyrene Foam
Authors: Kim Seung Hun , Hong Seong Uk
Published: June 2012

Use of hollow material in deck plate can reduce slab weight and improve the performance of fixing and installing hollow material. In this study, one-directional slabs were experimented with presence or absence of hollow material and deck plate depth etc as variable to evaluate the bending performance of deck plate that includes rectangular cross-section polystyrene hollow material. As a result of the experiment, when compared with the deck plate without hollow material, deck plate with hollow material was found to have similar bending yield strength and deformation performance. In addition, hollow material deck plate was evaluated to have greater strength performance than bending strength provided in ACI318-08 standard.
Piezoelectric Impedance Based Elastic Modulus Monitoring for Concrete during Curing
Authors: Guo Zhi Gang , Sun Zhi
Published: June 2012

This paper presented an experimental study on piezoelectric impedance based elastic modulus monitoring for concrete during curing. The piezoceramic (PZT) patch was attached on the concrete specimen to collect the monitoring signal. The electro-mechanical impedance (EMI) spectra of surface bonded PZT patch were collected using an impedance analyzer by sweeping the frequency. A regression analysis is conducted to establish the empirical relationship between the relative elastic modulus of concrete and the monitored relative resonant frequency change of the EMI spectra. The established empirical formula is used for concrete elastic modulus monitoring via EMI spectra. The experimental results tell that the EMI technique is a practical and reliable nondestructive test method for concrete elastic modulus monitoring.
Creep Prediction Model for Concrete Made of Crushed Clay Bricks as Coarse Aggregate
Authors: Ahmad Syed Ishtiaq , Roy Sushanta
Published: June 2012

A simple design office oriented empirical model containing only two parameters has been developed to predict creep behavior of concrete made of crushed clay bricks as coarse aggregate. For this, concrete samples having three different normal compressive strengths in the range of 18.9 up to 24.0 N/mm2 are first prepared and then tested for their creep deformation. For each of the samples, a hyperbolic equation is developed from their creep-time behavior. These equations are then combined and modified according to statistical norms to finally obtain a generalized equation. Comparison of creep strain obtained from this equation with that of experimental values show that the proposed model can closely predict creep in brick aggregate made concrete.
Research on the Application of the Infrared Thermal Image Method in Detection of Concrete Density of Concrete-Filled Steel Tube
Authors: Xu Rong , Jiang Dahao , Lu Xuewei
Published: June 2012

With the extensive application of concrete-filled steel tubular structures, much attention has been paid to the detection of concrete density of the concrete-filled steel tube. Based on the advantages and research results of infrared thermography non-destructive testing, the paper established physical model and applied ANSYS finite element analysis module to numerical simulation of temperature field to make initial exploration on the applicability of such technology to the detection of concrete density of concrete-filled steel tube.
Reliability Analysis of the Emergency Logistics Supply Chain
Authors: Zhang Yi Ming
Published: June 2012

Emergency logistics is not a normal logistics, the objective of its supply chain is to maximize time efficiency and minimize disaster losses. It is an important protection mechanism of emergency rescue system, after the emergency incident ,the reliable operation of the logistics supply chain is the basis and key of emergency rescue. This paper introduces the characteristics of emergency logistics and reliability theory, establishes the reliability model and its evaluation system of emergency logistics supply chain, and explores the optimization problem of the reliability, the system logical structure and logistics cost.
A Qualitative Approach for the Performance Evaluation of Artificially Prepared Water Resistant Fine Soil
Authors: Farooq Qazi Umar , Uchimura Taro
Published: June 2012

Water resistant fine soil is required to be prepared for the development of an oil contamination control system, which is currently part of an ongoing research topic at the University of Tokyo. For this purpose, Fujinomori clay has been chemically treated in a laboratory to create a form of water proofing on the clay particles. The effectiveness of water repellent properties of the treated Fujinomori clay is articulated by using model tests and image analysis. The basic principle of the image analysis is the variation in soil color, with respect to moisture / fluid content.
Searching for the Central Coordinates of Critical Failure Surface Based on Simplified Bishop Method
Authors: Li Lei , Zhang Meng Xi
Published: June 2012

Central coordinates of the critical failure surface of uniform slope are searched by using procedural Simplified Bishop equation. Comparison of stability factor K calculated by the program with existing ones shows that the program is available. The sensibilities of the factors influencing on slope stability are analyzed by orthogonal test method. The results indicate that the sensibilities of the factors are as follows in their magnitude order: slope height H, ratio m, internal friction angle φ, cohesion c and unit weight γ. Central coordinates of the critical failure surface is located at center of the K contours, the results of Fellenius straight-line method and Taylor chart method are different from the program’s. The fitting curves of central coordinates change with γtanφ/c and the corrected values are obtained based on a large number of calculations. It can be conveniently used in actual engineering.
The Anlysis of Sand Particle Dynamic Characteristic on Sand of Storm Two-Phase Flow
Authors: Shen Xiang Dong
Published: June 2012

Based on momentum equations of signal sand particle in airflow, the sand particle dynamic model was derived. Furthermore, the calculation equations of time, velocity and distance when the sand particle flies from leaving land to getting land are being offered by analyzing the dynamic model. Meanwhile the velocity distribution integral and differential equations of sand particle in dust flow are built up according to the definition of dust flow. Particularly the author puts forward the approximate method to calculate it, and analyzed the motion characters of sand particle dynamic model on sand of storm two-phase flow in theory.
Design Research and Technical Application of the Multi-Type-Pile Composite Foundation
Authors: Gao Yan , Li Hui Min , Yao Ji Ling
Published: June 2012

Through project example, analysis of the multi-type-pile composite foundation (lime pile plus CFG pile) in the practical application of liquefied foundation of high-rise building, especially using the ZFZ construction technology which forwards formed a hole and reverses packed into a compaction pile by a long spiral drilling machine to eliminate liquefaction of foundation soil and improve the bearing capacity of foundation is very notable, in addition, it also produces good economic and social benefits, so it has great value of promotion and use.
The Research Methods of Mechanical Characteristics on the Soil-Structure Interface
Authors: Dong Xiao Li , Wang Lei
Published: June 2012

There are general three kinds of means to research the mechanical properties of soil-structure interface, and they are soil-structure contact experimental studies, constitutive model and numerical calculation. Through the tests, the observation and measurement results in different experimental conditions can be obtained about soil-structure interface stress-strain characteristics, and then basing on the existing constitutive model theory researchers can put forward reasonable explanation to the phenomenon of the tests. Finally the constitutive model theory can be applied to the numerical calculation to predict and reproduce the test phenomenon, so as to fully reveal the nature of the soil-structure interface mechanical characteristics.
A New Method of Analyzing Aquifer Water Abundance
Authors: Han Chao , Liu Jing Wei , Li Guo Liang , Pan Xiao Hua , Tu Jie Nan
Published: June 2012

To prevent water bursting in mining coals and boring tunnels, analysis of water abundance of aquifer has to be done firstly. Based on analysis of main factors that can influence the water abundance of aquifer, five indices were used-aquifer thickness, drilling fluid consumption, structure distribution density, specific capacity and permeability coefficient. And the fuzzy analytic hierarchy process was introduced to determine the weight of each factor. Combining the data management and spatial analysis of GIS, we calculated and estimated the characteristic of water abundance for the study area. Due to the wide variance of water abundance over the whole study area, we set five rates to show the different results. So the study area was divided into five parts whose water capacity from high to low. The division was consistent with the hydro-geological conditions. So our method could be an alternative.
Stability Prediction of Zhaoshuling Landslide by Physical Model Test
Authors: Tang Hui Ming , Hu Xin Li , Xiong Cheng Ren
Published: June 2012

Physical model experiments are conducted to study the potential deformation and failure mechanism of Zhaoshuling landslide in the reservoir area of the Three Gorges project under the action of reservoir impoundment, water level fluctuation, building load and possible seismic load. Dial gauges, grid lines and digital cameras are used to monitor and record the deformations and displacements of the models. Research results indicate that the landslide will be basically stable while covered with seven-floor buildings whether the water level be at 145m or 175m, or falls abruptly from 175m to 145m. When the intensity of an earthquake is beyond certain degree, the rock mass will deforms and lose stability partly; and its stability will be worst when the water level falls from 175m to 145m, stability will be better when the level being at 145m and it will be best when the level being at 175m. It also indicate from deformation and failure mechanism revealed by the experiments that the best position of reinforcement measures is in Yanjiang Avenue, and the sliding resistance of the rock mass in the front part of the landslide can be used.
Study on Post-Failure Deformation and Residual Strength of Rock Mass Based on Hoek-Brown Criterion
Authors: Han Jian Xin , Tong Xing Hua , Wang Lei , Sun Guo Fu
Published: June 2012

In order to predict the stability of surrounding rock mass in geotechnical engineering, it is important to study the post-failure deformation property and residual strength of rock mass. Based on evolutional behavior of strength parameters, aiming at generalized Hoek-Brown strength criterion, selecting major principal strain as strain softening parameter, this paper presents the method of solving post-failure stress-strain curve . In numerical case, the effect of evolutional law of strength parameters ， and to deformation and residual strength is discussed and we can draw the following conclusions: the greater the residual values of ， are and the smaller the residual value of is, the post-failure strain softening curve falls more gently and the greater the residual strength is.
Numerical Simulation Analysis of Buried Ground Fissures’ Propagation in Xi’an
Authors: Liu Cong , Chen Li Wei , Leng Yan Qiu , Qiao Jian Wei
Published: June 2012

Ground fissure disasters are main environmental geological hazards in Xi’an. Therefore, carrying out researches on causes of cracks and mechanisms of hazard-formative, as well as setting economical and effectively countermeasures are major geological disaster puzzles to be solved.According to the key issues existing in the ground fissure researches, we use numerical simulation analysis method to solve them. Numerical simulation analysis shows that, it is reasonable that we use elastic breaking theory to describe its rupture propagation process. This paper introduces smeared crack model and explains the fracture morphology and process of sample which has microcracks inside it. Results show that such sample’s tensile strength is greatly weakened and its tensile failure is brittle fracture. Differential subsidence movement on both sides of the buried ground fissure (fault) not only leads to upwards propagation of existing cracks, whose tendency are opposite to the existing ones, but also leads to the development of nearly vertical crack belt, which is located on the uplift block and develop from top to down. Because of width of buried ground fissures’ affected zone depends on many factors, there are still lots of work to be done on the division of buried ground fissure’s deformation zone.
The Influencing Factors of CaCO3 Scaling in Oilfield
Authors: Yu Lan Lan , Sun Xu Rui , Wang Bao Hui , Lei Liang
Published: June 2012

For the problem of serious scaling in Daqing oilfield, using XRD and SEM to detect the scale sample, investigating the influences of concentration of NaCl, KCl, Mg2+and temperature on the solubility of CaCO3, and analyzing these factors on the rule of influence on CaCO3scaling. According to the field test, the curve of solubility of CaCO3in every conditions was drawed, and study the effect of ultrasonic technique to CaCO3scaling. Results indicated that the scaling in oilfield is mainly CaCO3, temperature is an important factor to affect CaCO3scaling, NaCl、KCl and Mg2+have a certain effect on CaCO3solubility, and the ultrasonic can achieve the purpose of anti-scaling.
Analysis of Slope Instability Based on Strength Reduction Method
Authors: Li Xue Wei , Yuan Xin , Li Xiao Wei
Published: June 2012

Abstract. Combined the strength reduction method with ABAQUS, the development of the slope plastic strain of different reduction coefficient is obtained by constantly adjusting reduction coefficient to change the strength index of the soil. The reduction coefficient is obtained from the criterion of numerical convergence and displacement mutation and plastic zone breakthrough. Through the analysis and comparison with the results, the reduction coefficient by the criterion of displacement mutation is consistent with the result of the criterion of plastic zone breakthrough. The reduction coefficient is the safety coefficient of the slope, and compared and analyzed with the slope factor of limit equilibrium method Bishop. The result shows that the displacement mutation and the plastic zone breakthrough as criterions to judge the slope instability are reasonable.
Design and Calculation of Block Gravity Dam in Debris Flow Treatment
Authors: Zhou Hai Hui , Li Zhi Guang , Chen Ji Hua , Yuan Ying , Cao Hong Yang
Published: June 2012

Based on project practice, this paper in detailed studies the design and calculation process of block gravity dam in debris flow by researching related standards.
Regional Land Subsidence Vulnerability Assessment Based on Grey Correlation Analysis
Authors: Chen Yu , Shu Long Cang
Published: June 2012

It is well-known that land subsidence seriously affects the regional social and economic development and becomes a world-wide problem. Xixi-Chengnan district, Jiangsu province is one of the most important area affected by land subsidence in China. The damage of the hazard to physical, social, economical and environmental systems has been increasing during recent years, which mainly caused by the long period groundwater overexpolitation in the area. This research presents a vulnerability assessment model based on grey correlation analysis (GCA) for the regional land subsidence in Xixi-Chengnan district of Jiangsu province, by the assessment results, the rank of relative vulnerability of each township in the study area can be obtained without weighting and aggregating the vulnerbaility indicators and with avoiding the subjectivity of weighting in general vulnerability evaluation methods. The study can be expected to raise public awareness of land subsidence risk and vulnerability, lay the foundation for risk decision-making, and provide theories and technological supports for taking comprehensive and active measures to prevent and alleviate land subsidence vulnerability.
Stability Analytical Method of Stepped Loess Cutting High Slope
Authors: Ye Wan Jun , Yang Geng She , Wang Jian Zhi
Published: June 2012

stability analysis is the base for control the loess high slope in loess area. on the assumption of arc-model in below segment, straight slip surface in model, uprightness in the up sect, a general expression of safety factor for Step-shaped Cutting High Loess Slope is deduced According to the balance of force and torque balance. Regard the parameters of the intersection of arc and line coordinates of the location and the inclination of the line segment as variable, the loess high slope stability analysis are programmed, he automation of the calculation is achieved. This method is verified by k202+020～k202+158 loess high slipe in Huangling –YAN’AN expressway.
Analysis on Deep Excavation in Soft Soil Located on Sloped Bedrock
Authors: Chen Shong Loong , Ho Cheng Tao
Published: June 2012

Deep excavations in soft-clay layer on sloped bedrock often leads to lateral displacement on retaining structures and uneven settlement due to unbalanced pressure generated from excavation. A construction project for which an excavation was complete in soft clay layer on sloped bedrock in Taipei City was adopted in the study. It is learned from the observation logs of the studied case that a significant difference exists in the lateral displacement of diaphragm wall and settlement between up and down-slope sides of sloped bedrock. Deep excavation is in fact profoundly complicated interaction between excavation strutting and soil. In general practice, the design of excavation is frequently simplified as a 2D strain behavior. However, the actual excavation on sloped bedrock is quite different from 1D or 2D simulation in a symmetric manner. Therefore, 2D finite element analysis program, PLAXIS, is introduced for the analysis on the behaviors of soil clay layer on sloped bedrock in excavation. The result is compared with onsite observation data, including displacement of retaining wall, settlement, axial loads of struts and others. The result of retaining wall displacement analysis is found consistent with the trend derived from onsite observation, which is possible for reference of similar engineering analyses and designs in the future.
Study on the Influencing Factors of Sampling Representativeness of Rock Joints
Authors: Huang Man , Du Shi Gui , Luo Zhan You , Zhang Xiao Ying
Published: June 2012

The non-uniformity feature of rock joints’ surface profiles is the main influencing factor of the sampling representativeness. In order to analyze the sampling representativeness of rock joints statistically, the joint roughness coefficient (JRC) of 18 pieces of natural slate rock structural plane samples with size from 100mm to 1000mm were measured. The results show that it is necessary to evaluate the representativeness of rock joints in engineering practice due to the large non-uniformity of JRC. The total variation of JRC for different measurement sections, sizes and samples indicates that the sampling representativeness can be evaluated by the average value and the distribution probability of JRC; moreover, the sampling representativeness should be considered the statistical law evaluation of JRC for the concrete size and sample, and offered the accurate standard in changing range.
Analysis of Shear Strength Parameters on Soft Clay Slope Stability at Short Term
Authors: Hou Jing Fang , Cao Yong Hua , Yan Shu Wang
Published: June 2012

The slope stability is an important problem for the slope building on the soft clay ground. At present, the vane shear strength is common used to calculate the factor of slope stability at short term. In fact, a lot of cases show that the vane shear strength underestimates the real shear strength of the sliding surface. Therefore, based on Mohr-Coulomb theory, and using the linear relation between the vane shear strength and the depth, a method of converting in-situ vane shear strength into undrained shear strength parameter is presented. Two shear strength parameters c and φ are from statistical regression analysis. The anisotropy, the lateral compression coefficient and the average consolidation degree of the soft clay are considered. The two shear strength parameters are used to calculate the short term safety factor of the slope stability. The safety factor is greater than 1.0 for steady slope.
Tree Induce Suction for Slope Sustainability
Authors: Ishak Mohd Fakhrurrazi , Ali N. , Kassim A.
Published: June 2012

Many slope areas in Malaysia whether it is man made or natural slope are particularly vulnerable to soil erosion and shallow failures due to the increasing of soil moisture and porewater pressure. This study will determined the active root zone of the tree near the toe of the slope which suctions have been generated within this section. Hence, the effect it only focusing on hydrological aspect with soil moisture pattern near vicinity of the tree. The mechanical aspect of tree root such as tensile strength and bonding between root and soil which can led to increasing soil strength are assumed negligible in this study. From preliminary result of field monitoring show significant increase of total suction at near vicinity of tree which can lead to stability analysis on slope. The comparison of FOS will be presented between at the toe of slope with and without the tree. Furthermore, for slope studies area the reresult indicates that tree induced suction can be related to cause the factor of safety against slope failure improve up to 33.07%.
A Study on Development Adjustment Technique in the Block Bei301
Authors: Kong Fan Shun
Published: June 2012

In view of the broken fault, rapid sediment, high heterogeneity，high structural dip and rapid reservoir change in Block Bei301, fine reservoir description research was implemented including small fault identification, fan delta sedimentary microfacies subdivision and facies-constrained modeling, and the problems existing in production were analyzed zone by zone and interval by interval. Moreover, other unique adjustment strategies were implemented including reservoir engineering and numerical simulation researches, well pattern thickening, injection-production system adjustment, separated layer system adjustment, as well as horizontal well technology. Finally, oilfield development effect was improved and a series of unique adjustment technologies for complex fault block reservoir were preliminarily formed, which provides reference for the development adjustment in similar oilfields
A Study of the Graph Topology of the Complicated Rock Mass’ Hexahedral Grid Dissection
Authors: Wei Lu Shuang , Jiang Hua , Wang Yu Biao , Wei Qun
Published: June 2012

It was a common method to simulate the complicated rock mass’ exterior profile, interior structure and corresponding project structure through the graphic platform of 3D digital modeling in modern geotechnical engineering. Based on such a modeling, this paper introduced a graphic method of hexahedral grid dissection in numerical calculation, which regarded the rock mass modeling cut by faults, cracks and buildings as a compound entity of hexahedral entities, and on every adjacent interface of any two hexahedral entities there would be the same number of grids of the same size and they were of the same topological relations. With overrun mapping method to traverse calculate all the single grids of all hexahedral prisms, a grid calculating system of the complicated rock mass would be formed. After applying such a method to several major projects, we are very satisfied to find that with such a method the rock mass is divided reasonably and the calculation accuracy meets the requirements.
Mechanical Analysis of the Selection of Cross Section of the Buried Tunnel
Authors: Dang Ling Bo , Zhang Min
Published: June 2012

Based on to the theory of elasticity and structural mechanics, a reasonable cross section of a pressure tunnel was derived, and the computing formulas of the hoop and radial stress in the tunnel were given,and some suggestions were advanced for the rational design of buried tunnel.
Coordination Analysis for Urban Underground Space and Rail Transit Based on Space Syntax
Authors: Zhu Wen Jun , Kan Xing De
Published: June 2012

Rational planning for the underground space development in subway station areas, in coordinate with the urban rail transit development, has positive impacts on the sustainable development of cities. This paper induces the space syntax method for calculating the quantitative accessibility index of the urban rail transit and detects the coordination between urban underground space use intensity and rail transit system of the 7 selected subway lines in Tokyo. The results show that the station areas with higher accessibility index are the same sort with higher underground space use intensity. This means that the space syntax method is suitable and feasible for calculation of the quantitative accessibility index of subway lines. The higher the accessibility index is, the more underground space will be needed potentially in future. The areas with high accessibility of subway lines and low intensity of public underground space develop are the key districts under potential exploitation of underground space.
Study on the Construction Time of Secondary Lining in Loess Tunnel
Authors: Cui Jian Ning , Gao Yong Tao , Wang Jin Qiang , Li Jian , Deng Fu Gen
Published: June 2012

The construction time of secondary lining in loess tunnel has been the focus of attention in the tunnel field, but no specific quantitative discriminant index of the construction time of the secondary lining has been applied. Relying on the Wofosi tunnel of Zhangjiakou-Zhuolu highway, based on the deformation characteristics and deformation rate analysis of the crown settlement and surrounding convergence, proposed that the stability of basic rate as the indicators of construction time of secondary lining, determined preliminarily the construction time of secondary lining by optimizing the regression model, combined with the characteristics of the rock pressure and pressure distribution state along the hole to determine the best construction time of secondary lining
Reliability Method and its Standard of the Composite Foundation Bearing Capacity
Authors: Peng Xiao Yun , Cui Peng Ju
Published: June 2012

The general reliability analysis method of composite foundation bearing capacity was established with the example of cement injection pile, its limit state equation and the optimize method was presented, and the standard of reliability index was also proposed according to the corresponding demand of architectural structure. It indicate that the method is reasonable, convenient to calculation and can be popularized in the whole geotechnical engineering.
Numberical Analysis in the Deformation of Adjacent Buildings and Underground Pile Caused by Tunnel Shield Construction
Authors: Zhang Jian Xin , Wu Ting Liang
Published: June 2012

Based on the ABAQUS software, set up the tunnel and adjacent buildings and their pile of calculation models, analysis shield construction on the deformation of adjacent buildings and pile foundation. Analysis shows that the construction of the tunnel shield leading to surface subsidence, causing deformation of the framework structure and underground pile. Also shows Shield construction on the impact of adjacent buildings and underground pile deformation is integrally related.
Numerical Study on the Effect of Twin-Tube Shield Excavation on Adjacent Pipelines
Authors: Wang Xin , Zhao De Shen , Xu Meng Lin
Published: June 2012

Based on Dalian subway line 2 from Chun-guang street station to Xiang-gong street station,the three dimensional finite element model was established using FLAC3D software , the shield excavated surface against the pressure, the stress release, the shield tail escape and grouting. The numerical result indicated that the pipeline displacement increases gradually with the advance of the tunnel excavation. When one-sided tunnel excavation is carried out, the largest displacement is located at the tunnel axis, the settling curve basically conforms to the normal distribution curve with the unimodal characteristic. The excavation of right-side tunnel is disadvantageous to the left-side tunnel. The analysis indicated that the pipeline is in a secure state. The work in this paper provided theoretical basis and the practical guidance to this project.
Study of Dynamic Analysis Model on Subway Vehicle-Tunnel Vertical Coupled System
Authors: Liang Bo , Luo Hong , Qing Wei
Published: June 2012

In this paper, vehicle systems and track-tunnel system are regarded as an interactional, mutual coupling overall system and the interaction between wheel and rail is regarded as the “ligament” of these two subsystems. The vehicle vibration model and vibration equation are established by considering the body vertical vibration, a suspension of vertical vibration and wheelset vertical vibration. By the displacement compatibility condition of the vehicle and track, integrating the vehicle equations and discretized track-tunnel vibration equation, the dynamic coupling model and the equations that reflect the vehicle-track systematicness is constituted. It provides a reference for the further research of the dynamic analysis of vehicle-tunnel coupled system.
Model Test Research on Excavation Technology of a Tunnel in Altered Granite Zone
Authors: Cui Kai , Ling Zhong Cheng
Published: June 2012

Phenomenon of surrounding rock deformation and collapse, groundwater lowering, ground collapse and cracking appeared in a tunnel project. It is necessary to guaranty construction safety and ensure the reliability of supporting structures. This paper, using large-scale model, considers the surrounding rock deformations and stress adjustments caused by cavern excavation and tunnel support in the alteration zone. It suggests engineering protective measures by summarizing the major determinant of excavation deformation.
Complexity and New Ideas of the Auti-Bursting Stability of Confined Water Foundation Pit
Authors: Sun Yu Yong
Published: June 2012

With the excavation depth increase，the bursting stabilization had become a major factor affecting the security of foundation pit. On the base of research situation about foundation pit stabilization and a large number engineering practices，the factors and the complexity that affected the stability of foundation pit were analyzed. The new ideas about mechanism and determining methods of bursting in foundation pit were proposed，that with the “hydraulic fracturing” to explain the mechanism of bursting and the factors that affect the stability of foundation pit as a system to analyze the anti-bursting stability and the factors that affect bursting stability could be divided into two types, system strength and system stiffness.
Dynamic Interaction of Viscoelastic Soil and Fractional Derivative Type Lining with a Circular Tunnel
Authors: Wen Min Jie , Su Zi Ping , He Hui Tuan
Published: June 2012

Coupled harmonic vibration of viscoelastic soil and fractional derivative type lining system with a deeply buried circular tunnel is investigated in the frequency domain. Based on theory of elastic and fractional derivative, steady state response of the viscoelastic soil and lining system is studied. Regarding the lining as a medium with fractional derivative constitutive behavior, and the analytical expressins of the displacement and stress of the soil and lining are respectively obtained by the continuity conditions on the inner boundary of lining and the interface between the soil and the lining. The order of fractional derivative model has a greater influence on system dynamic response, and it dependent on the material parameters of lining. With the frequency increasing, the resonance effects of system decrease.
Research on Elastic Resistance Calculation Methods of Curved Wall Tunnel
Authors: Yun Yong Feng , Wu De Lun
Published: June 2012

Analyze the role of tunnel lining structure calculation for the elastic resistance, and point out the influence of assuming elastic resistance of Budd-chiarieva method on calculation result and its shortages. Then put forward a new calculation method — Iterative method which can accurately determine elastic resistance distribution law of curved wall tunnel, and introduce basic idea, influencing factor of elastic resistance distribution law, practical method of Iterative method, and the method of improving iterative speed, and the process for calculating internal force of structure is given using Iterative method; contract the calculation results of internal force of structure by Iterative method and Budd-chiari eva method and point out the differences by practical calculation examples. Finally, the application scope of iterative method and necessity for further study are suggested.
Full Waveform Acoustic Logging for Slope Weak Layer Evaluation
Authors: Xie Zhong Qiu , Fan Jin Zhao , Xiao Hong Bin Xiao , Zhang Yu Chi
Published: June 2012

Rock deformation and unstable failure of slope is controlled by weak structural plane whose identification and evaluation is greatly influenced by deformation failure prediction of slope and design treatment. Based on the propagation characteristics of acoustic wave in shaft lining strata, attenuation of stoneley wave and inherent attenuation of strata are analyzed and permeability relationship among shaft lining strata is researched. The relationship between reflected stoneley-wave intensity and the width and filling ability of strata crack is studied. By application example of landslide investigation, attribute parameters and characteristics of acoustic wave are discussed. Strata division, the practicability and accuracy of recognition for fracture and holes evaluation and mechanic characteristics of rock mass also are studied.
The Direct Solution on Normal Water Depth of I Type Horseshoe Tunnel with Flat–Bottom
Authors: Wen Hui , Li Feng Ling
Published: June 2012

Abstract: I type horseshoe with flat–bottom evolved from standard I type horseshoe cross-section. It is composed of a flat-bottom and three arc sections. It is commonly applied in the field of hydroelectric engineering. The normal water depth computation equation for I type horseshoe cross-section with flat–bottom tunnel is a transcendental equation and no analytic solution. In this paper, based on the mathematics transformation for the basis equation and the relationship analysis between the dimensionless normal water depth and the relative parameters, a direct solution is established for the calculation of normal water depth for I type horseshoe cross-section with flat–bottom tunnel according to the fitting principle. This method overcomes the shortage of other iterative trial calculating methods, such as complex calculation step, depend on the special chart and curve, and existed serious error. The formula is simply and the maximum error is less than 0.3% under the general engineering design range (ratio of normal water depth and arch radius is between 0 to 1.4471). it can be used on the engineering designing practice and the edit of the handbook of hydraulic structure design.
Analysis of Surveillance for Deep Foundation Pit of Subway Station
Authors: Duan Bao Fu , Li Lei
Published: June 2012

Deep foundation pit of subway station project are affected by the geological conditions with rich water and sand seriously. So the construction has a greater difficulty. We have to analyze the measured data and study on the deformation law of retaining structure and soil. That can be used as theoretical verification about the design scheme of retaining structure. The results show that this design scheme can be used as the support form in the similar geological conditions.
Analysis of Surrounding Rock Deformation Behavior and Supporting Measures in High-Level Strata Pressure Tunnel
Authors: Wu Li , Zuo Qing Jun , Shi Li , Lu Zhong Le
Published: June 2012

According to geological investigation and monitoring results, this paper analyzed the reasons for large deformation in Baozhen Tunnel, discussed the deformation characteristics and presented the corresponding supporting measures.
Joint Controlling Effect on Stability of Surrounding Rock in Horseshoe-Shaped Underground Opening
Authors: Chen Lu Wang , Qin Yuan , Chen Jiang Hong , Zhang Shi Lei
Published: June 2012

This paper presents a numerical study on the mechanical behavior of the jointed rocks around the underground opening. By comparing different obliquities and the different locations of the joint, its controlling effect on stability of surrounding rock is evaluated in terms of the shear stress distribution, displacement distribution and the plastic zone pattern, which are induced by underground excavation. The results clearly indicate that, the maximum shear stress occurs mainly near the corner of the opening and the joint plane. When the joint inclination angle is less than 60º, the maximum vertical displacements occur where the joint locates near the skewback. Once the joint inclination angle reaches at 75º, the maximum vertical displacements occur where the joint is through the cross section of the underground opening. The plastic zone reaches minimum at the joint inclination angle of 45º where the joint locates either near the skewback or near spandrel of the opening, while it reaches minimum at the joint inclination angle of 60º where the joint cuts through the cross section of the opening.
Type Selection of Arches in Primary Support of Loess Tunnel with Small Interval under Shallow Buried & Unsymmetrical Pressure
Authors: Su Zhong Ming , Wang Xiao Feng , Liu Rui
Published: June 2012

The problem of arches selection in primary support of loess tunnel is one of the problems that are now focused on. Based on the two type support of gird and shaped steel, the plastic zone and internal forces are mainly analyzed, by means of numerical simulation, in the loess tunnels with small interval under shallow buried & unsymmetrical pressure. Analysis results indicate that the internal forces in the gird support is slightly smaller than that of the shaped steel support, and the plastic zones are almost the same in the two type support; so it is suggested that the grid support should be adopted in the design of such tunnel from the comprehensive analysis.
Numerical Simulation and its Application in Configuration Optimization of a Spillway Tunnel
Authors: Xu Lian Feng
Published: June 2012

Based on the turbulence characteristics of spillway, a turbulence model for simulating turbulent flow with free water surface under a body-fitted coordinate is established and a computer program is developed for numerical experiment in this paper. A spillway flow is numerically simulated, and the results are quite fitted with the experimental ones. Thus, the proposed model is also applied to the spillway tunnel optimization.
Fatigure and Reliability Analysis on Tether of Submerged Floating Tunnel under Vortex-Induced Vibration
Authors: Zhou Xiao Jun , Luo Gang
Published: June 2012

The tether used to balance a submersed floating tunnel under water current is definitely subject to greater pre-tension, and is simplified as a Bernoulli-Euler beam. The fatigure characteristics of vortex-induced multi-modal resonance of tether under traverse shear flow are analyzed. In terms of the principle of energy equilibrium, both the mean square root displacement and mean square root stress of the dynamic response of tether is derived.The reliability index of tether is obtained in combination with S-N curve and fatigure probability model.
3D Numerical Analysis of Metro Station by PBA Method to Enlarge Existing Large-Size Shield Tunnel
Authors: Yan Mei , Ding De Yun , Yang Xiu Ren , Yang Xiu Ren , Lu Wei Dong , Liu Wei Ning , Li Ai Min
Published: June 2012

There is no engineering experience for metro station construction by the PBA (Pile-Beam-Arch) method to enlarge an existing large-size shield tunnel in China. During enlarging construction by the PBA method, the spatial mechanical and deformational characteristics of metro station structure are still not clear. In this paper, the Gaojiayuan station is taken as an engineering background to study the spatial mechanical and deformational characteristics during enlarging construction by the PBA method. Based on soil-structure interaction theory, a three-dimensional finite element model is built to simulate the enlarging construction by the PBA method. The three-dimensional numerical results can be regarded as a valuable reference for enlarging construction by the PBA method in Beijing metro line 14.
Surrounding Rock Consolidation Numerical Analysis of Unsymmetrical Loading Tunnel
Authors: Yang Xiu Zhu , Lei Jin Shan , Ning Ye Hui
Published: June 2012

Jet grouting piles were used to reinforce overlying soil of shallow buried tunnel under unsymmetrical pressure. Displacement and strain was simulated during tunnelling with three steps excavation method under condition of reinforcement and unreinforcement. The results show that larger vertical displacement and shear strain occur during excavation of upper bench, and it changes very little when center and subjacent bench was excavated. This is because upper bench is located in soil, part of center bench in rock, and the whole subjacent bench in rock. Largest shear strain occurs at the arch foot of upper bench. It is concluded that jet grouting piles can control surrounding rock deformation effectively.
Contrast Analysis on Deformation Characteristic of Urban Subway Tunnel Excavation by Numerical Simulation and Field Measurement
Authors: Yang Wei Feng , Liu Xi , Wang Yi , Li Ming
Published: June 2012

Under the particular geological conditions of clay and sandy soil interbed, through numerical analysis and field monitoring, the surface settlement, horizontal deformation and the stress distribution were analyzed after the tunnel excavation in a metro station in Beijing, China. There are differences of surface deformation whether the backfill grouting behind arch during tunnel excavation. While the backfill grouting behind arch, the ground surface settlement and the horizontal displacement reach 9.36 mm and 2.16 mm respectively. But while no backfill grouting behind arch, the ground surface settlement and the horizontal displacement are 14.51 mm and 8.85 mm respectively. The maximum ground settlement induced by tunnel excavation is directly proportional to ground loss ratio. When the ground loss ratio is 1%, the result is well consistent with the field measurement value and the numerical simulation result.
Safety Study on Connection Joint for Submerged Floating Tunnel
Authors: Zhou Xiao Jun , Wang Zhi Yuan , Fan Yin Hua , Pan Ji
Published: June 2012

On the basis of working surroundings of submersed floating tunnel(SFT), a new type of connexion joint is designed to link its tubes, and its mechanical behavior and safety under water condition are also analyzed by means of finite element method(FEM). The analysis shows that the connection joint proposed in this paper satisfies the requirement of safety under water environment and will be a new option for future use of submersed floating tunnel.
Comparisons of Tunnel Greenhouse for the Carrying Snow Loading Capacity
Authors: Sun De Fa
Published: June 2012

Through the Comparisons of tunnel greenhouse for the carrying snow loading capacity under the different mode of transfer force, some conclusions are summed up: different mode of transfer force has much influence upon the carrying capacity under the same snow loading. The unite of structure scheme to whole-part should be thought much in the structure design for greenhouse according to the principle of equal strength. The results indicate that the structure of east-china type multi-span tunnel plastic greenhouse is rational, and has fine mechanics properties.
Attitude Measurement for Underground Self-Walking Tunneling
Authors: Wei Hong Hu , Bao Yan
Published: June 2012

Self-walking tunneling is at present the most advanced technology to underground pipeline construction. One of the difficulties is orientation measuring technology, that involves if tunneling can keep along with designed line. There is no mature method for self-walking tunnelling. This paper, based on the eleventh five-year plan national science and technology subject, comprehensive utilization of total station and rangefinder and combination with the characteristics of the tunneller, researches a set of practical and low cost measurement method. The application shows that the method meets with the need of orientation measurement to curve tunneling.
Field Monitoring of Segments Deformation during Metro-Station Construction Based on Shield Tunneling
Authors: Li Tao , Liu Ying Chao , Liu Bo , Yang Wei Hong , Liu Yang
Published: June 2012

To ensure the influence degree on the environment during constructing metro-station based on shield tunneling is very important in the subway construction. After the shield machine passed the metro-station, the field monitoring of these segments is carried on during getting rid of the segments. The connecting seam opening length of segments, the tunnel convergence and the internal force of the segments’ bolt are estimated. The results show that the opening length of segments of circular connecting seam is larger than that of longitudinal connecting seam, and all the changes of the opening length value is within 1.5 mm. Tunnel convergence change generally contains a gradually becoming smaller and a gradual recovery process, and the tunnel convergence is primarily vertical. Bolt internal force change generally involves stress increasing rapidly, and then decreasing slowly. The field monitoring study will potentially provide the knowledge and reference for similar projects