bluuebunny/crossref_metadata_2025 huggingface dataset:
Impacts of Different Pile Parameters on Stress and Settlement of Composite Foundation
Authors: Cui Ying , Zhao Jun Hai , Sun Shan Shan
Published: September 2011

The composite foundation fully takes the carrying capacity of pile and soil into account, which decreases the settlement of oil storage tank foundation and differential settlement of oil storage tank bottom apparently. Analyzing the changes of stress and settlement under different conditions and optimizing the parameters of pile have important significance in engineering practice. In this paper, with an actual project of oil storage tank for background, basing on the Drucker-Prager yield criterion, the FEM model of composite foundation has been carried out by using ANSYS procedure. And with simulating the status of composite foundation under the working load, the project properties of composite foundation are investigated. Further more, analysis on the impacts of different pile parameters on stress and settlement of composite foundation have been carried out. In the end, the optimization scheme of composite foundation design has been proposed.
Numerical Simulation on the Influence of Mining-Induced Fractures Field on Gas Drainage and its Application
Authors: Zhang Shu Jing , Peng Yong Wei , Yu Yong Jiang
Published: September 2011

In order to study the influence of mining-induced fractures field on gas drainage,the paper adopts software of numerical simulation COMSOL Multiphysics to simulate gas drainage of coal seam under the condition of high-strength underground mining. The main aspects can be seen as the following: (1) In the case without considering the fractures, gas drainage in single hole, the gas pressure distribution showed a funnel-type distribution in space along the drainage holes around. (2) The orientation and direction of fractures play a major role on the flow field of gas. In the region that exits fractures, the distribution of gas pressure has a clear fluctuation and adjustment.(3) The numerical simulation of coal seam gas drainage that considered the fracture of coal mining, was closer to the true gas flow.
Studies on Influence of Tunnel Surrounding Rock Stability Analysis Based on Material Yield Criterions
Authors: Huang Mu Kun , Jin Xiao Guang , Wang Yan , Zhu Ling
Published: September 2011

Numerical simulation is one of main methods for tunnel surrounding rock stability analysis. By now, there hasn’t be unanimous view on that what kind of yield criterion is adopted for different surrounding rock class and different buried depth. Mohr-Coulomb yield criterion is always adopted abroad, Drucker-Prager yield criterion is always adopted in China, moreover, the principles are different when adopting D-P yield criterion at home and abroad. Based on introducing the Mohr-Coulomb yield criterion and D-P yield criterions, this paper uses the M-C exterior angle point of circle criteria, which is popular in the international arena for the D-P yield criterion, and finds parameters of geotechnical material for D-P yield criterions through the parameter transformation. Combining with 3D elastic-plastic finite element simulation of the tunnel construction process, with the tunnel buried by soft and weak surrounding rock (V class) at shallow (15m) and deep (550m), this paper analyzes the impact of the M-C and D-P yield criterions on surrounding rock’s displacement, stress, strain effects, and proposes the appropriate yield criterion for the simulation of shallow and deep soft and weak rock tunnel construction and for tunnel surrounding rock stability analysis.
Preliminary Study on Shear-Flow-Creep Experiment for the Fracture of Hard-Rock
Authors: Wang Gang , Jiang Yu Jing , Wang Ming Bin
Published: September 2011

The nuclear waste storage projects, hydropower and etc are often installed in the hard crystalline rocks. The creep phenomenon of the hard rocks appears in virtue of the complex geological conditions, especially when the excavation brings about damage and cracks to the rockmass, and they largely weaken the hydraulic performances of surrounding rock. Once the excavation-caused cracks are well connected with the native ones together, the engineering safety will be brought great harm to. By dint of newly developed shear-flow-creep coupled experiment system, on condition of the constant normal stiffness boundary conditions, the coupled shear-flow-creep tests are conducted. Not only the tests testify that the equipments is reasonable and effective and the creep largely influences the seepage performance of the rock crack, but also the coupling characters are primarily proved up.
Model Experimental Research on Anti-Sliding Characteristics of the Frame Anti-Sliding Piles
Authors: Qian Tong Hui , Xia Wen Cai , Chen Fang , Ding Hong Xing
Published: September 2011

Through analysis of model test results, some of the basic sliding piles features of the frame anti-slide pile can be obtained. Under the thrust of landslide, a complex parabola and line function could be used to describe the relationship of load and lateral displacement of pile head. At the same time, there was a big crack in front of the pile. It was shown by monitoring the soil pressure that pushing force acting on the back frame pile was trapezoidal distribution and on the leading frame pile was parabola distribution. The soil pressure value was larger at back piles central and around sliding surface and smaller at the head of piles. the landslide thrust acting on the back piles more larger than the front row piles, the central of piles’ maximum soil pressure minimum 1:3 ratio of the middle pile at the before and after row, the ratio between the changes with the load. Frame pile of the inflection point after another figure appeared, at the top of the link beam and ring beam structure of the entire framework of the pile Showed a synergistic effect of spatial, compare to other forms of single row of piles and others forms, it can significantly reduce the size, to achieve the economic security landslide treatment goal, there is wide application prospect.
Research on Preparation of Jointed Rock Mass Samples in Site
Authors: Liu Yong , Qiao Chun Sheng
Published: September 2011

The intensity and deformation characterization of a rock mass is an important input parameter in any analysis of rock mass behavior. Field tests to determine this parameter directly are time consuming, expensive and the reliability of the results of these tests is sometimes questionable. Consequently, several authors have proposed empirical relationships for estimating the value of an isotropic rock mass deformation modulus on the basis of classification schemes. But the result is different by different people. Therefore, A new approaches to the mechanical characterization of jointed rock masses has been studied based on the test of little rock mass sample. But preparation of jointed rock mass samples in site is very difficult. In this paper, a method for collecting, preparing and describing samples with extremely to very closely spaced fractures is described where no cementing material is required.
An Optimization Model of Extension Sets on Supporting Scheme for Foundation Pit and its Application
Authors: Qin Zhe , Wang Lei , Meng Li Bo
Published: September 2011

This paper aims at the incompatibility of indices in comprehensive evaluation of supporting scheme for foundation pit. An optimization model based on extension sets is presented. The model takes the scheme to be evaluated, evaluating indices and its characteristic value as matter elements, relational function are constructed according to the expertise and practice and optimum scheme is obtained by calculating the comprehensive relational degree. Compared it with fuzzy optimization theory model, the results achieved is consistent coincident.
Discussion on Design and Construction of Soil and Foundation in Coastal Saline Soil Area
Authors: Gao Fu Ju
Published: September 2011

Based on the recent 20 years' observation and research, this paper briefly discusses the mechanism of forming, mechanical properties of coastal saline soil and the main factors which bring the important influence to buildings. Some reasonable comments on design and construction of the work in this area are put forward.
Deformation Analysis of Adjacent Metro during Deep Pit Excavation
Authors: Liang Yue Ying , Liu Guo Nan , Hu Rong Hua , Zhang Ming
Published: September 2011

At space compacted, pipeline-intensive, buildings and underground structures adjacent places, environmental deformation is sensitive to deep pit excavation, so deformation as well as slope stability is the control factors for safety. With FEM and automatic remote monitoring, the deformation of adjacent metro in operation was analyzed during the deep pit excavation; acquired results showed deformation caused by pit construction met the requirements of metro tunnel structure less than 4mm.
Ground Deformation Rule Induced by Shield Tunneling Construction
Authors: Wei Xin Jiang , Zhou Yang , Wei Gang , Hong Jie
Published: September 2011

In this paper, Ground deformation in shield tunneling construction is researched. It is put forward that ground deformation is caused by three reasons, which are ground loss, the positive thrust and the friction. By solving the three-part respectively, the three-dimensional solution formula can be obtained after superposing these. This method is used to calculate the tunnel construction phase at any point in the level of vertical settlement and horizontal displacement. As shown in analytical calculation, the predicted ground displacements of this method are in good agreement with the measured values.
Determining the Contact-Length and Critical-Value for Deformed Foundation with Curvature Variation in Mining Area
Authors: Liang Wei Min , Qiao Jun Feng , Guo Zeng Zhang
Published: September 2011

In mining area, the ground surface level is lowered and curved after the claps of cover-layers of coal-seams evacuated regions. The curvature variation of ground surface causes the variation of contact-surface relation between the structure base and the ground foundation. For this research, the position of maximum curvature variation point is predicted. At this position, for the potentially worst case, the contact-length between structure base and ground foundation is calculated. Then, the internal bending moment within the structure base caused by the ground foundation curvature variation is formulated by taking the contact-length as variable. The results show that the base bending moment is a function of fourth power of contact-length. Based on this result, the critical value of contact-length in mining area is established. Hence, the critical contact-length concept can be taken as a measure of curvature variation in mining area.
Cellular Automata to Simulate Crack Propagation of Quasi-Brittle Materials
Authors: He Jun Lian , Li Ming Tian
Published: September 2011

Crack propagation in quasi-brittle material such as rock and concrete is studied by a new numerical method, lattice cellular automata. Cellular automaton method is an efficient method that simulates the process of self-organization of the complex system by constructing some simple local rules. It is of the advantage of localization and parallelization. Lattice model can transform a complex triaxial problem into a simpler uniaxial problem as well as consider the heterogeneity of the materials. Lattice cellular automata integrate advantages of both cellular automata and lattice model. In this paper the importance of the study of crack propagation, fundamentals and applications of cellular automata are briefly introduced firstly. Then the cellular automata model is presented, and in order to verify lattice cellular automata, the propagation of mode-I crack in homogeneous material is studied. Results of the numerical simulation are in good accordance with the experimental results and theoretical results of classical fracture mechanics. Furthermore, based on lattice cellular automata, the crack propagation of single crack under uniaxial compression was simulated. During the crack growth the wing crack and secondary cracks were found. The simulation results were consistent with the experimental results.
Performance of Permeable Asphalt Pavement during Rainfall Infiltration
Authors: Huang Xiao Lan , Xiong Jun
Published: September 2011

The purpose of this paper is to summarize the performance of permeable asphalt pavements (PAP) and to recommend future areas of research and development. The development of PAP as an integral part of sustainable drainage systems is reviewed in the context of traditional and modern urban drainage. The difference between the permeable asphalt pavement and the ordinary bituminous concrete pavement is discussed. A description of the seepage calculation model based on the structural characteristics of PAP is presented. And also water level fluctuations of both the water permeable asphalt pavement and the ordinary bituminous concrete pavement are analyzed by comparing their numerical simulation results. Finally the drainage performance of the water permeable asphalt pavement is demonstrated. The long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement is examined. The simulation results could provide significant guidance for the structure design of water permeable asphalt pavement.
Study of a High Slope Stability Considering the Stochastic Distribution of Rock Joint Set
Authors: Guo Yun Hua , Zhu Wei Shen , Yu Da Jun , Li Xin Ping
Published: September 2011

A hydropower station is located in the middle reach of the Dadu River in southwest China. The natural slope angles at the project site are generally 40~65 and the relative elevation drop is more than 600m. Complex different fractures such as faults, dykes and dense fracture zones due to unloading are developed. The stability of these steep and high slopes during construction and operation period plays an important role for the safe construction and operation of the project. According to the statistical distribution of joints at the construction site, the slope is divided into a number of engineering geological zones. For each zone, a stochastic fracture network and a numerical model are established by the Monte-Carlo method. The mechanical characters of fractured rock with different sizes are studied using FLAC3D. The REV characteristic scale is identified for rock masses. Numerical simulation is performed to obtain the mechanical parameters and the strength of the jointed rock. With the numerical model and the site monitoring data, a self-developed stochastic mechanical analysis software is applied for back analysis and stability assessment.
Large Scale Triaxial Rheological Apparatus Development and Granular Soils Rheological Properties Analysis
Authors: Chen Xiao Bin , Zhang Jia Sheng
Published: September 2011

To study the granular soil’s rheological properties, a large triaxial rheological apparatus was developed by assemblying a axial pressure and confining pressure providing equipments for the SZ30-4 large scale triaxial apparatus, and the stability examinations proved that the stability of this pressure providing equipments was competent for granular soil’s rheological tests. The large triaxial rheological apparatus have the axial pressure ranging from 0 to 1.0 MPa, confining pressure of 50kPa, 100kPa, 150kPa, 200kPa, 250kPa and the soil sample dimension of Φ=300mm, h=600mm. A series of granular soil creep tests were executed on this apparatus. The tests discussion shows that stress conditions are the main factors, which affects the creep properties of granular soil. There are different rheological properties at different stress level. eg. at low stress level (S=0.1) for the elastic, at middling stress level (0.20.8) for the non-linear viscous plastic. The total rheological strain nonlinearly increase with stress level increments but linearly increase with confining pressure increments. According to the discussion of redstone granular soil’s creep properties, a rheological component based on hyperbola function was presented, and a nonlinear viscous elastioplastic rheological constitutive model was set up by putting the component and the Burgers model in series. The creep properties analysis shows the rheological model can describe the granular soil’s whole rheological phase well.
Study on Inhomogeneous Collision Effect of Curved Girder Bridge under Seismic Action
Authors: Qi Xing Jun , Shen Yong Gang
Published: September 2011

For the irregular rotational displacement of curved girder bridge under seismic action there are some limits to calculate collision effect with pounding element approach. In order to analyze the inhomogeneous distributing rule of seismic collision effect for curved girder bridge, the new approach of explicit dynamic contact algorithm is presented. Seismic impactive response characteristic of girder, pier and block is analyzed. The results indicated that pounding action between girder and abutment limits longitudinal displacement of girder and makes bending moment of fixed pier less than that with collision effect unconsidered. After pounding the radial stress of block inside and outside the curve distribute severely inhomogeneously. The radial stress of block outside the curve is more than that inside the curve distinctly. This can provide theoretical guide for interpretation of the seismic damage of pounding for curved girder bridge.
Analysis on Seismic Pounding of Curved Bridge
Authors: Xu Qiang , Qi Xing Jun
Published: September 2011

Based on the impact phenomenon between the end of the beam and the bridge abutment of the curved continuous bridge during earthquakes, a spatial finite element calculating model with collision element is presented. The law of collision is studied by the nonlinear contact time history analysis method under two three-dimensional ground motions. The variation laws of relative displacement and the internal force at the bottoms of piers are researched. In addition the changing of displacement and internal force at the end diaphragm are studied. The results show that the pounding action can easily lead to significant collision forces between the end beam and the abutment of the curved bridge which increases the axial force of girder evidently. The collision forces and longitudinal displacements from the inner to outer of the diaphragm generally are showed by an increasing trend, and the pounding action is more fierce under Elcentro ground motion than that under Tianjin ground motion.There is no relative displacement of consolided pier, bending moment and shear force of the consolided pier are greater than that of the mobile pier.The conclusions from the present study may serve as a reference base for seismic design of continuous curved bridges.
Multi-Span Closure Construction and Optimization Analysis of the Main Channel Bridge on the Left Branch of Beijiang River
Authors: Zheng Guo Dong , Zhang Huan
Published: September 2011

Multi stages such as side span closure, middle span closure, ten years after construction and so on are simulated with the finite element method in the main channel bridge on the left branch of Beijiang River. Many issues such as unreasonable incremental launching force in construction are found. The optimization made the vertical displacement of the main beam controlled, the secondary moment value on the top of the pier by the side bending of the anchorage and the secondary effect of pre-stressed tendons significantly reduced, and the force of anchorage more balanced. Construction sequence optimization can make the construction process more reasonable and provide a reference for the closing segment construction of the bridge.
Reliability Analysis of Self-Anchored Suspension Bridge by Improved Response Surface Method
Authors: Yu Xiao Lin , Yan Quan Sheng
Published: September 2011

The response surface method (RSM) developed in recent years is an effective way to solve the structural reliability problems with implicit performance function. In order to improve the computational efficiency and make RSM suitable well to large and complex engineering structures, the reliability analysis method based on uniform design method (UDM) and support vector machine (SVM) was proposed. UDM is adopted to select training data and SVM is used as response surface. Structural reliability index is calculated in combination with the traditional reliability analysis methods (such as, the first-order reliability method (FORM), the second-order reliability method (SORM) or Monte Carlo simulation method (MCSM)). Numerical examples show that sampled with the UDM can greatly reduce the number of samples required for training by SVM model, and a very good approximation of the limit state surface can be obtained to get the failure probability. The reliability analysis of the under serviceability limit-state of a typical self-anchored suspension bridge——Sanchaji Bridge was carried out with the improved response surface method.
Research on Embodiment and Utilization of Environmental Value Oriented Spatial Planning of Harbin Marginal Area
Authors: Xue Bin Xia , Zhao Zhi Qing , Liu Sheng Jun
Published: September 2011

As the joint connecting urban and rural areas, the special ways are needed in the spatial urban planning & design of the urban marginal areas. Based on the cases of environmental planning in Harbin’s marginal area under urban expansion background, the paper discusses the interdependent and symbiotic relationship between city and natural environment, and explores the effective modes finding, changing and utilizing the value elements of suburban environment. Finally the paper puts forwards spatial planning & design strategies oriented in the discovery and utilization of environmental value for urban marginal area according to the location characteristics of the urban marginal areas and value embodiment of natural environmental conditions, such as ecological priority, advantages intensification and images construction.
Analysis of Vehicle Loads on Guangzhou-Shenzhen Expressway
Authors: Hu Da Lin , Chen Long Gang , Ding Ding , Xia Chun Mei
Published: September 2011

This paper presents statistical analysis of vehicle loads, which were measured by Weighing in Motion (WIM). The vehicle composition, distribution of gross vehicle weight (GVW) and load distribution of classified vehicles are obtained; Axle load proportions and wheelbases of different type of vehicles are also statistically analyzed. Based on statistic theory of extreme value distribution, characteristic values of different type of vehicle loads within design reference period are deduced. The analysis results can be used for safety evaluation of road pavements, bridges and culverts in the expressway, and can be as a reference for both design load formulation and overloading control of bridges.
Dynamic Behaviors of a Fractional Order Viscoelastic Two-Member Truss
Authors: Li Yuan Ping , Zhang Wei
Published: September 2011

The fractional dynamics equation of a viscoelastic two-member truss system, in which fractional derivative model introduced to simulate the materials’ characteristics, is proposed. The simplified single DOF differential equation is developed combined with boundary conditions and symmetry. Dynamic behaviors of the fractional single DOF system with harmonic loads are discussed by numerical calculations. The results show that: the system may lead to chaotic motion via period-doubling bifurcations or intermittent routes; the dynamical character is greatly inflected by the varying of excitation amplitude or damping coefficient or fractional order.
Experimental Study on the Maximum Allowable Hydration Temperature for 900t Box Girder of High-Speed Railway
Authors: Li Xue Min , Zhu Er Yu , Zhou Yong Zheng , Qin Yue Hong
Published: September 2011

Due to the usage of high-strength concrete, excessive hydration heat is generated in the whole span box girder of high-speed railway. The maximum allowable temperature should not exceed 60°C according to the Technical Guide on Railway Bridge Construction of Passenger Dedicated Line. However, according to the field measurement and simulation to the maximum temperature of box girder concrete, we find that the maximum hydration temperature of concrete is generally more than 60°C which is the limited value of the specification. The research results show that the limited value of maximum hydration temperature for box girder concrete can be relaxed to 65°C.
Elatic Bending and Buckling of Steel-Concrete Composite Plate Considering Slip Effect
Authors: Li Fa Xiong , Nie Jian Guo , Zhang Jing Quan , Li Wan Heng
Published: September 2011

Steel-concrete composite plates are formed using steel plates connected to a concrete slabs by means of welded stud shear connectors. The flexibility of connection between the steel plates and concrete gives rise to interface slip and additional deflection. An analytical model considering slip effect for composite plate is presented in this paper. Analytical solutions for deformation of composite plate under lateral load and elastic critical buckling load of composite plate under axial compressive load are deserved. The model and the solutions are then validated by means of finite element analysis. According to the parametric study, when impact factor greater than 5, the critical buckling load of simply composite plate is close to the superposition of the critical buckling loads of steel and concrete slabs and the interaction of both slabs can be ignored.
Study on Mechanical Behaviors of New Reinforced Concrete Hollow Floor Slab
Authors: Zhao Xin , Kong Dan Dan , Zhang Zhi Wei , Wu Mai
Published: September 2011

In this paper a new type of reinforced concrete four-way rib hollow slab was proposed by the authors first. Further in order to research on the mechanical properties of the new floor slab the other two common slabs were compared with the new one, that was two-way rib hollow slab and solid slab. The rational finite element (FE) models of the three kinds of slabs supported by four corner columns were built up respectively by ANSYS. The deflection and stress of the three kinds of slabs under three load cases were calculated separately, on the basis of which thorough comparisons and analysis were carried out. The study results showed that the new reinforced concrete four-way rib hollow floor slab has superior mechanical properties.
Monitoring the Inner Force of the Frame-Shear Wall Structure with MR Dampers by FBG Sensors
Authors: Li Xiu Ling
Published: September 2011

The experiment system of a three-floor reinforced concrete frame-shear wall eccentric structure has been built based on Matlab/Simulink software environment and hardware/software resources of dSPACE. And then a shaking table test for the hosting structure with and without magnetorheological (MR) dampers is implemented subjected to three different ground motions. The FBG strain sensors were used in this experiment for strains measurement of the columns and monitoring of the appearing and developing of cracks under different stages. The experimental results show that the control strategies of MR dampers have significant effect on axial force of the column.
Structural Physical Parameter Identification of Nonlinear Parametric System in Time Domain
Authors: Wang Xiang Jian , Cui Jie
Published: September 2011

The modified Levenberg-Marquardt (mLM) method is introduced for nonlinear parametric system, such as stiffness proportional damping and Rayleigh proportional damping. Since the mLM method is sensitive to the initial values of parameter, a SVD-mLM method is proposed with combination of singular value decomposition (SVD). Parameter identification of five-storey shear-type is simulated with incomplete output. The results show that the identified parameters have high precision, and the proposed method is effective and robust on noise.
Prameter Study to Validate Buoyancy Preflex Effects on Structural Performance of Floating Structures
Authors: Lee Du Ho , Jeong Youn Ju , You Young Jun , Hwang Yoon Koog
Published: September 2011

In this study, a Buoyancy Preflex Method was introduced to enhance structural safety and performances for a large floating structure on which recently many studies are actively conducted worldwide. To demonstrate the effect of the Buoyancy Preflex introduced to the floating structure, an analytical study was conducted using parameters such as the ratio of the lengths of center modules to those of end modules. The analysis models for parameter were modeled into 5 cases, then a hydrostatic analysis on live load was selected from Equivalent Static analysis methods, then was conducted. The analysis procedure was divided into two steps, before and after live loading. As The result of this study, first analysis step, it was confirmed by each analysis model that excellent buoyancy preflexes were introduced. Even after the live loading, the 2nd analysis step, compressive stresses occurred at the bottom slabs of all analysis models, which enabled a determination that all analysis models can afford to secure safety and structural performance against live load.
Vibration Control Analysis of High-Rise Cantilevered Floors under Pedestrian Walking Loads
Authors: Qi Man Yi , Zhang Zhi Qiang , Ma Fei , Li Ai Qun
Published: September 2011

Aimed at the human comfort problem with cantilevered floors arising from normal human activities, the Tuned Mass Dampers are used to control the vibration of the steel cantilevered floors which span 16.3m. Based on studies on the dynamic characteristics of the overall structure, with the position of TMDs optimized and the parameters set reasonably, the vertical vibration response of the cantilevered floors under different cases of pedestrian walking loads is calculated. The results show that the TMD system can effectively reduce the dynamic response of the cantilevered floors, in order to meet the requirements of human comfort.
The Failure Mechanism Research of Jointed Rock Mass Slope
Authors: Ni Zhen Qiang , Kong Ji Ming , Fayou A.
Published: September 2011

It was difficult to analyze the stability of the rock slope for its complex geological structure. Rock mass was the geological body that subjected to intense deformation and suffered damage, which was composed by rock and jointed rock mass. When the rock mass was in the high steep rock, its loading state was further complicated. First we analyzed the failure mechanism of jointed rock mass in theory, and we used Flac3d with the Mohr-Coulomb yield criterion to simulate the displacements and stresses. We built three models that included angles with level line were 25°, 45° and 65°. The results showed that, all around the joints stresses concentration occurred, the maximum compressive stress occurred at the crack tip; the final crack direction always tended to the direction of maximum compressive stress; and when the angle was bigger, before the crack expended further, the strength of rock decreased first, and destroyed first.
The Practice of Risk Identification and Assessment of EPB Tunnel in Mixed Face Ground
Authors: Song Tian Tian , Wang Chun He
Published: September 2011

Earth Pressure Balance shield machines are used to construct metro tunnel in Shenzhen mixed ground. The ground condition is full of water and the diversity of two grounds in juncture is drastic. The risk mechanism of this ground is studied, and the main risks are found out. The main risks are assessed and classified employing the method of P=R×C, then the risk classification is determined. These studies ensure the projects in Shenzhen metro advance successfully.
Ultimate Bearing Capacity Analysis of Axially Compressive Circular Steel Tube Columns Filled with Bar-Reinforced Concrete
Authors: Liu Zhao , Zhao Jun Hai
Published: September 2011

The mechanical behavior and ultimate bearing capacity of the circular bar-reinforced concrete filled steel tube (BRCFST) short columns under axial compression are analyzed in this paper based on the unified strength theory. Considering the restriction effect of steel tube and hoop bar on concrete, the calculation formula of bearing capacity of the column is deduced. Parametric studies are carried out to evaluate the effects of intermediate principal stresses, diameter-thickness ratio of steel tube and the stirrup ratio on the bearing capacity of the column. A good agreement is reached by comparing the results calculated by the formula with the test results. It is concluded that the unified strength theory is applicable in the theoretical analyses of the BRCFST columns.
Study on Node Link of Precast Reinforced Concrete Wall Structure
Authors: Dou Li Jun , Zhang Min , Li Jiu Yang
Published: September 2011

This paper analysised the mechanical characteristics of precast reinforced concrete wall，introducing a fitting that can sliding along two directions and rotate round the last direction.It realized the flexible connection between the precast reinforced concrete composited wall and the structure beam，and make the hypothesis of wall not exposed to structural force come true。The paper analysised the mechanical characteristics of node fitting，sponsored design method，and explained the designation by an example.
Research on the Identification Method for Void Location of Semi-Rigid Base Pavement
Authors: Zhong Yan Hui , Zhang Bei , Guo Cheng Chao , Qi Jin
Published: September 2011

Using finite element software, the analysis model of semi-rigid base pavement with voids is established. Variation of deflection under load of Falling Weight Deflectometer (FWD) is studied and the reference critical value is obtained to determine whether there are the voids. According to analysis of the deflection basin data under different location, the identification method for the void location of semi-rigid base pavement is established. The field test shows that it is feasible to use this technology in void identification for semi-rigid base pavement.
Experimental Investigation of Large Eccentrically Compressed Reinforced Concrete Column Consolidated with FRP Sheets
Authors: Guo Guang Ling
Published: September 2011

According to the experiment of 11 eccentrically compressed reinforced concrete columns and 1 comparative column under the monotonic loading, the bearing capacity，ductility，and the destruction mode of the columns before and after their consolidation have been compared and analyzed．The experimental results illustrates that external coherence of FRP could effectively enhance their bearing capacity and the improvements have relation to many aspects, such as the number of fiber layers, the category of fiber, approaches of how fiber sheet paste, the width of FRP and consolidation space and so on; the ductility of consolidation column mainly depends on how fabric pasted. Longitudinal pasting fiber sheets can greatly improve the bearing capacity of the column, but its ductility declined; the longitudinal-horizontal pasting fiber sheets can enhance column’s the bearing capacity and ductility and this brings about the best consolidation effects. Additionally, based on the analysis of experimental results, a formula for the bearing capacity of the normal section of the large eccentric loading reinforced concrete column consolidated with FRP sheets has been proposed, and the calculation results tally with the experimental results.
Test Study on Support Span of Sheet Sandwich Structure of Steel Fiber Concrete
Authors: Wei Ming Shan , Feng Jin Ji , Cao Hai , Ye Ya Qi
Published: September 2011

The layer structure is a common structural form in the civil air defence. According to the shortage of the structure, a new type of structural form called steel fiber sheet sandwich structure is setup. For studying the influence caused by the support span of this structural form on structural blast-resistant ability, this paper has carried out a group of explosion model tests, which studies the optimal support span of this structure form and the influence on the failure characteristics of structure induced by the change of the support span. The test results show that: the support span of the steel fiber sheet is a very important factor for improving the whole structural blast-resistant ability; the thickness and support span of Steel fiber sheet shall make the steel fiber sheet not to reach the roof surface under the loads of explosion; the whole resistance of sheet sandwich structure in the tests is obviously higher than that of ordinary layer structure.
Alkali Reactivity of Construction Spoil Gravel from Qingdao Jiaozhou Bay Subsea Tunnel
Authors: Gao Jie , Zhang Peng , Li Qiu Yi
Published: September 2011

Abstract: Nowadays, a huge amount of concrete has been used as main construction material. This as a consequence will consume a large quantity of natural aggregates which quantity is not limitless. On the other hand, for instance, in the tunnel construction, a lot of spoil rocks could be produced. It will be beneficial both from the aspect of economy and ecology if these spoil rocks could be used as concrete aggregates. In this case, the alkali reactivity of the spoil aggregates will have to be determined to avoid the potential reaction between aggregates and cement. In this contribution, the spoil aggregates from Qingdao Jiaozhou Bay Subsea Tunnel have been used to prepared concrete specimens. And their alkali reactivity has been determined by swelling test. The results indicate that the swelling rates of all specimens made by spoil aggregates, both from 6 different places in underground part and from 13 places in subsea part of the Tunnel, are at most 0.08 %, which is not higher than the limit value of 0.1 % according to the standard. This means the tested spoil aggregates do not have potential alkali reactivity, and they can be used as concrete aggregates.
Self-Balanced Prestressed Latticed Shell Structure and it's Research Development
Authors: Li Guo Dong , Liu Wan Cheng , Li Qing Qing
Published: September 2011

Self-balanced prestressed shell structure assembled with elements is a new spatial system composed by prestressed cable and strut elements. The structure can achieve the latticed shell design that the large span without the center column by the rational use of high strength bars and prestressed technology. This paper illustrates the design idea, stress mechanism and structure characteristics of the self-balance prestressed latticed shell. The current research status of self-balanced prestressed shell structure assembled with elements on structure form, shaping method, static and dynamic performances are briefly described in the presented work; It is seen that the research on test of structure mechanical properties, molding technology and structure dynamic performance is an urgent work to be solved in the development of the self-balanced pre-stressed latticed shell structure theory.
Experimental Study on the Seismic Behavior of Damage RC Frame Structure Strengthened with Carbon Fiber Reinforced Polymer (CFRP) and Steel Plate
Authors: Zhao Shao Wei , Zhao Hong Liang , Zhou Ji
Published: September 2011

In this test, three models of concrete frame structure are made with the same dimension. The experiment of the models under low-cycle repeated load is studied. One of them is not reinforced for reference, and others are damaged to one certain degree then reinforced with CFRP and steel plate in completely uninstall cases respectively. This test is to study the effects of the two reinforcement methods to the seismic behavior of damaged concrete frame structure. Research shows that: the role steel plate in improving bearing capacity and rigidity of the damaged concrete frame structure is better than CFRP. Comparing with steel plate the CFRP can improve well damaged concrete frame structure ductility and energy dissipation capacity.
The Effect of Organic Fibers on Crack Resistance and Permeability of High Performance Concrete
Authors: Cao Qing Yu , Sun Wei , Guo Li Ping
Published: September 2011

In this paper, high-performance concrete (HPC) incorporated organic fibers, i.e., polyvinyl alcohol fiber (PVA fiber), polypropylene fiber (PP fiber), cellulose fiber (UF fiber), polyethylene fiber (PETF) was produced. The properties measured included strength, crack resistance performance and water permeation of the concrete. The effect of organic fibers on the shrinkage and water permeation properties was investigated. Test results indicated that the organic fibers of different types could reduce the size and amount of crack source; organic fibers provided better enhancement for shrinkage resistance and impermeability of HPC; the improvement of the shrinkage resistance and the impermeability of the concrete resulted from the use of organic fiber, which was dependent on the types, total volume fraction and of fibers, proportions of organic fiber.
Numerical Solutions for Capillary Absorption by Cementitious Materials
Authors: Wang Li Cheng , Li Shu Hong
Published: September 2011

Capillary absorption is essential to mass migration in cementitious materials. Based on previous studies, capillary rise involving gravity effects is of much greater interest in porous building materials because equilibrium is attained at the wetting front when gravitational force balance the capillary force. In this paper, two different solution forms, semi-analytical and numerical, are presented to account for the gravity effect for realistical prediction of water penetration process. The former is stable against small perturbation proved by Stepanyants [1]. The comparison of predicted results by the two methods confirms the reliability of the technique in estimating water transport.
Discussion for Solar Energy Application of Green Buildings
Authors: Zhang Jian , He Cun Tao , Liang Chen , Cai Liang
Published: September 2011

Green building, a kind of sustainable development and energy-saving buildings, has a very important significance for alleviating strained resources, protecting the environment to reduce pollution; And the solar energy as a kind of important renewable energy, with features of energy saving, environmental protection and natural, is more and more widely using in the green building. This paper will mainly discusses the actual application of the solar energy technologies in green building.
Vibration Analysis Method of Cracked Beam Based on the Principle of Energy
Authors: Chen De Liang , Wang Wen Ting , Liu Feng
Published: September 2011

Using the theory of nonlinear elastic mechanics and fracture mechanics, the equation of motion governing equation of cracked beam is derived by the energy method, and solved with separation method of variables. Vibration analysis method based on the energy principle in this paper is proved feasible.Through numerical analysis, the effects of structural damping, crack location and depth on natural frequencies of linear vibration is investigated.
Crack Propagation Analysis of Concrete Beam Subjected to Three-Point Bending Using XFEM
Authors: Ru Zhong Liang , Zhao Hong Bo , Zhu Chuan Rui
Published: September 2011

Extended finite element method (XFEM) has been applied to the crack propagation problems. A standard displacement-base approximation is enriched near a crack by incorporating both a discontinuous field and the near crack front asymptotic fields through a partition of unity method. This technique allows the entire crack to be represented independently of the mesh, so remeshing is not necessary to model crack growth. Applications of the proposed technique to beam subjected to three-point bending have been presented, results shown the location of the crack imposes important effect on the crack propagation direction.
Comparative Analysis of Dynamic Characteristics under Two Iced Conductor Galloping Models
Authors: Liu Xi Jun , Sun Xiao Qin , Zhang Su Xia , Liu Peng , Liu Bing
Published: September 2011

Considering strongly nonlinear characteristic of iced conductor rotating around its center of mass in the wind-deviation plane, two dynamic equations are constructed by using Den. Hartog criterion and O. Nigol criterion, and galloping characteristics between them are studied, which can provide references for constructing correct iced conductor galloping models. By comparative analysis of two models, the vibration frequency of O. Nigol model is slightly higher than that of Den. Hartog model, and the amplitude of O. Nigol model is smaller. Then the stability of iced conductor galloping and the effects of parameters on galloping amplitude are discussed, from which can conclude that the trends of two models varying with parameters are basically identical. But for numerical, O. Nigol model is more accurate.
New Technology of Efficient Blasting Rock for Large Section Rock Roadway Drivage in Deep Shaft with Complicated Conditions
Authors: Zhang Wei , Zhang Dong Sheng , Shao Peng
Published: September 2011

Based on the different failure mechanism for shallow and deep rock mass, combined with the test result of ground stress and difficulties of blasting rock in Xinwen mining area, used mines rock mass mechanics and modern blasting theory and actively carried out technical reform, the new forming control technology of directional fracture blasting and control technology of multi-directional fusion blasting and efficient blasting technology of compound cut had been adopted, which produced a set of new efficient blasting rock technology for large section rock roadway drivage in deep shaft with complicated conditions. The engineering practice application results showed that the new efficient blasting rock technology could decrease the numbers of shot holes and explosive material consumption, enhance drivage efficiency and circulation footage, ameliorate integral forming quality of roadway and realize maximum month drilling footage at 146 m, the research achievements can provide reference for deep roadway drivage construction in other mining areas with similar conditions.
Spatial Effect Analysis on Shaking Table Tests of Subway Station Structure in Liquefiable Ground
Authors: Chen Guo Xing , Zuo Xi , Wang Zhi Hua , Du Xiu Li , Qi Cheng Zhi
Published: September 2011

Based on the test data of shaking table tests of subway station structure in liquefiable ground under both near-field and far-field earthquakes, the spatial effects of dynamic pore water pressure (PWP)and peak ground acceleration (PGA)of liquefiable ground as well as peak strain response of the subway station structure are analyzed. The results show that there exists time-lag phenomenon of dynamic PWP ratio of each measuring point on different observation planes. The characteristic of input ground motion has a noticeable influence on the spatial effect of dynamic PWP ratio. The PWP ratio obtained on the major observation plane presents to be larger than that on the minor one when under far-field Songpan wave. Meanwhile, the peak acceleration of measuring points on both major and minor planes increase with the growing peak acceleration of earthquake. The law of PGA and frequency spectral character of measuring points on different observation planes or at different depth varies with each other, and there present remarkable spatial effect. The peak strain of central cylinders at the top and middle floors on the major plane appear larger than that on the minor planes. However, the peak strain of central cylinders at the bottom floor are more remarkable than that of the top and middle floors, There are sharp contrasts among the peak strain responses in different spatial positions of the station structure.
Study on Layered Basin Earth Excavation Construction Technology
Authors: Yuan Wei Guo , Chen Hai Ying
Published: September 2011

Through comprehensively analyzing of the present earth excavation methods and combined with Kangwang road tunnel engineering earth excavation, proposing the layered basin earth excavation construction technology of excavation. We put the layered basin earth excavation construction technology of excavation in the practice of Kangwang road tunnel earth excavation, applying "MIDAS-GTS" software to simulate and cost accounting, from the technical and economic sides to validate this new layered basin earth excavation is advanced. And finally puts forward the conditions for the layered basin earth excavation, this new layered basin earth excavation construction technique can be popularized.