bluuebunny/crossref_metadata_2025 huggingface dataset:
Equivalent-Beam Theory of the Self-Anchored Suspension Bridge
Authors: Wei Biao , Zeng Qing Yuan , Liu Wei An
Published: June 2011

Taking one typical two-tower three-span self-anchored suspension bridge as an example, structural response has been characterized in detailed followed by its own construction steps. Meanwhile, the structure’s mechanics properties have been mathematically formulated through theoretical analysis method. Finally, the formulation has been further expressed by using a simplified beam subjected to external equivalent forces, and then the equivalent-beam theory of the self-anchored suspension bridge has been well established thereafter. As been demonstrated, the equivalent-beam theory can be easily and clearly applied to determine the vertical mechanical properties of the self-anchored suspension bridge, and could be utilized to guide the self-anchored suspension bridge deign in the future.
Research on Setting of Pre-Camber of Long-Span Continuous Rigid Frame Bridge with High Piers
Authors: Zhang Yun Bo , Liu Da Peng
Published: June 2011

In the design of continuous rigid frame bridge setting reasonable pre-camber can eliminate the impact of various loads on the linear in construction process, reduce shrinkage and creep in the process of post-operation, the late loss of pre-stressed, deformation produced by live load and so on ,resulting in deflection phenomenon. Based on the current specifications of the continuous rigid frame bridge camber setting methods, this thesis proposes the reasonable setting suggestions of pre-camber and sets examples to illustrate this.
Seismic Response Analysis of Double Chains Suspension Bridge Considering Non-Classical Damping
Authors: Ding Nan Hong , Lin Li Xia , Chen Jia De
Published: June 2011

Damping in double chains suspension bridge is non-uniform, which leads to coupled motion equations in main coordinate system. Based on the complex damping theory to solve equivalent viscous damping ratio used to describe energy dissipation characteristics of non-classical damping system approximately, a method is proposed to analyze seismic response of double chains suspension bridge considering non-classical damping modified by measured value. Influence of different damping forms on seismic response of double chains suspension bridge is analyzed, considering classical damping and non-classical damping respectively, through an example of double chains suspension bridge. The analysis shows that non-classical damping has significant effect on seismic response, and response based on the classical damping model is not reliable to double chains suspension bridge. Non-classical damping model should be used in seismic analysis of double chains suspension bridge, however, the seismic response of non-classical damping system under the longitudinal or vertical seismic wave can be substituted approximately by the seismic response calculated according to damping ratio of concrete tower and steel stiffening girder respectively, which can simplify the calculation during preliminary analysis.
Construction of Steel Tube Concrete Arch Bridge after Axes Change
Authors: Li Chuan Xi , Wang Xin Zhong
Published: June 2011

In this paper ,the axes of a three-span dumbbell-shaped steel tube concrete arch bridge was changed due to deviation in bridge piers, tie beam construction and steel tube production, thereby steel tube arch ring can not be closed, and suspender hole can not be aligned. The side-span hollow steel tubes were intercepted and adjusted for three times through calculation and analysis, therefore the structure stress is reasonable and achieved original design standards under the condition of not changing the original arch axes, and the bridge was successfully constructed, thereby providing reference for engineering staff.
Wind Vibration Effect on Unit Glass Curtain Wall Considering the Turbulent Wind
Authors: Hu Xiao , Gao Yong Tao
Published: June 2011

Due to the applicable installation height, small mass, flexible characteristic, large span, and small damp, the unit glass curtain wall (UGCW) could easily result in vibration with the wind effect. The main factor is the turbulence among the cause effects. Combining the structural dynamic theory, and considering the characteristic of the UGCW, a wind effect calculation formula is set up considering the turbulent wind that is resulted by the 1st vibration type. Hope to provide some reference for similar designs.
Analysis of Parameter Sensitivity in Construction Control of Inclined Pylon Cable-Stayed Bridge without Backstays
Authors: Zhang Qing Chen , Sun Quan Sheng
Published: June 2011

Parameter changes of a bridge in construction process must have an effect on its stress and alignment.And different parameters ,in the same bridge ,affect state of bridge to a different degree. While we have no need to consider every parameter in practical construction process, just paying attention to some sensitive parameters with a great effect on bridge structure instead .So a reseach of parameter sensibility of bridge construction is necessary to find out sensitive ones of all to limit their great effect .In this paper, based on JinZhou cable-stayed bridge without backstays,we use Midas civil to analyze the degree of impact of each parameter on stress and alignment of main girde ,which is depended on to put forward the main sensitive parameters of the bridge in construction process and a few of advice about its construction technology.
Research on Skeleton Curves of Steel-Concrete Composite Beams
Authors: Liu Yang Bing , Chen Fang , Liu Jing Bo
Published: June 2011

In order to model the elasto-plastic behavior of steel-concrete beams in high-rise buildings correctly and conveniently, plastic hinge method is used. Based on experimental and theoretical research on composite beams, the trilinear moment-curvature skeleton curve of steel-concrete composite beams is amended by numerical simulation and theoretical analysis. And the 4 poly-line moment-curvature skeleton curve model is suggested for elasto-plastic analysis of steel-concrete composite beams. The elastic-plastic model is then used for real composite beams under monotonic load experimental analysis to verify its precision. The suggested model can lay a foundation for the dynamic analysis under strong earthquake for the globe steel-concrete composite structures.
Construction Simulation of Long-Span Arch Rib Bridge
Authors: Tian Wei Feng , Zhou Shui Xing , Zhang Liang Liang , Alghabsha Ayad Thabet Saeed
Published: June 2011

Non-framework cable hoisting erection is a main construction method for long-span arch rib bridge. Geometric nonlinearity is a key problem in the construction simulation of this type of bridge. A general method for construction sequence simulation of long-span arch rib bridge is proposed, and stage-by-stage construction of the Daning River Bridge is simulated. Comparisons of cable forces and finial arch rib geometry between results obtained from actual measurements and those from the simulation analysis are presented. Results showed that the developed method can be used effectively for nonlinear finite-element simulation of long-span arch rib bridge construction.
Asymmetric Construction Technology of Partially Cable-Stayed Bridge with Single Tower and Single Cable Plane
Authors: Sun Xiao Meng , Yan Zi Cai , Zhu Da Yong , Chen Hui
Published: June 2011

According to the structural characteristics and the surrounding environment of partially cable-stayed bridge, an asymmetric construction method combinded with support cast-in-place and cantilever casting is applied for main girder construction, based on project of Yuyao cable-stayed bridge. Its basic idea is as follows: One deck section is concreted with brackets in advance, which to offer counterweight for basket construction symmetrically. The technical features and construction key point are described in detail, which provides reference for similar bridge construction.
The Research of the Application of Reactive Powder Concrete Wind Barriers of High Speed Railway Bridges
Authors: Lu Xiao Lv , Gao Ri
Published: June 2011

In this paper, completes the selection of preliminary Reactive Powder Concrete (RPC) wind barriers, and on the basis of the theories of the computational fluid dynamics ( CFD), relying on the model-building and analysis platform of FLUENT, 3D models of trains under crosswind with and without wind barriers are built. From the calculation results of the pressure distribution,path lines and aerodynamic forces of model trains under 3D turbulence flows ,the stability of trains under crosswind is analysed ,and the effects of the wind barriers on traffic safety of trains are discussed.The results show that rationa1 design of the wind barriers is able to improve the traffic safety of trains.
Direct Strut-and-Tie Model for Ultimate Shear Strength of Reinforced Concrete Structural Walls
Authors: Wang Ji Yang , Sun Yi Lin , Sakashita Masanobu
Published: June 2011

A direct strut-and-tie model to calculate the ultimate shear strength of structural walls based on an interactive mechanical model (C.Y.Tang et al.) is presented. Two common failure modes, namely, diagonal splitting and concrete crushing, are examined in this paper. Ultimate shear strengths of structural walls are governed by both the transverse tensile stresses perpendicular to the diagonal strut, and the compressive stresses in the diagonal strut. Such proposed model is verified aganist three experimental case studies of structural walls. Generally, predictions by the proposed model are not only accurate and consistent in each case study, but also conservative.
Chained Analysis of Effective Prestress for Long-Span PC Bridge: Identification, Simulation and Prediction
Authors: Guo Qi , He Shuan Hai
Published: June 2011

In order to make much detail and more practical evaluation on structural safety and durability for long-span PC bridges, the condition for prestressing reservation in service stage turns out to be a necessary key index. For the sake of measuring it exactly, an invented instrument named Stretching Force Tester is applied to monitor the effective prestressing force of strand. The precision of this technology is guaranteed by means of amending analogous boundary condition and minimizing test errors through the tool of double-stage differences. Based on comparatively sophisticated prestressing loss method in current code, an evaluation model on attenuation of effective prestress is built up. By means of obtained stress datum on strand, recognition on two types of nominal coefficients for prestress losses is realized and regularities of practical distribution can be simulated simultaneously. The experimental results of a large-scale beam model show that the relative error for cable tension force between test value and standard one is able to meet the needs of engineering use and general principle for effective prestress can be demonstrated. Therefore, it laid the foundation for inspection and evaluation on structural deterioration of existing long-span PC bridges.
Study on Placement of U Tendons in Box-Section Pylon of Cable-Stayed Bridge
Authors: Tang Hong Yuan , Meng Shao Ping
Published: June 2011

Through the analysis of the stress distribution in anchorage zone of bridge pylon with different placements of tendon, the placement with the equal coefficient of anti-crack in both sides is proposed. At the same time, several models whose outsides are crossed by tendons at different angles are analyzed. Compared the corresponding cracking loads and cracking place of them, a reasonable angle range is obtained. At last, the vertical attenuation ratio of the prestressing in the anchorage zone under the tendon is analyzed to give the appropriate distance between the adjacent tendons.
Analysis of Shrinkage and Creep Effect on Improved Truss Composite Arch Bridge
Authors: Wu Hai Jun , Gao Yu , Lu Ping
Published: June 2011

In order to study the shrinkage and creep effect on improved truss composite arch bridge , this paper analyzed and compared different parameters' influence on the truss composite arch bridge by changing parameters such as shrinkage days, the age of loading, computation theory and diagonal web member forms. It was based on Shiqiaohe bridge, the result showed that shrinkage days and the age of loading were the key parameters; the longer the shrinkage days makes the effects of creep bigger; the longer the age of loading makes the effects of creep smaller. The effect of shrinkage of rigid diagonal web member was larger than that of cables, the applied computation theory has little influence to shrinkage and creep effect on truss composite arch bridge.
Service Life of European and American Bridges
Authors: Wu Hai Jun , Kang Yu Qiang , Lu Ping
Published: June 2011

The short service life of bridges exerts a negative influence on the operation. The service life of European and American bridges and maintenance is illustrated in this paper. A lot experience has been accumulated which also provide enough data to understand the problem. Some examples are listed in the paper. These data and analysis are of important reference value to understand the bridges in service and the actual service life at present in China.
Study on the PC Beam for Extradosed Prestressed Bridges
Authors: Zhang Xue Song , Sun Shu Hong , Gu An Bang
Published: June 2011

This paper is described about the research work on the PC beam for extradosed prestressed bridges. After summing up domestic extradosed prestressed bridges with PC beam, we recommended that the PC beam should be more diversity and creative. We have drown some conclusions through the numerical analysis and reduced scale prototype model test for Jiayue Bridge in Chongqing China, this bridge has double-cable-plane, and the PC beam’s broad flange is 8m. Finally, we suggested that further research on the PC beam of extradosed prestressed bridges should focus on the phenomenon of shear lag and extra-prestressing, etc.
Numerical Simulation of Flow over a Circular Cylinder at Low Reynolds Number
Authors: Bai Hua , Li Jia Wu
Published: June 2011

The hydrodynamic characteristics of a circular cylinder in two-dimensional unsteady uniform cross flow was simulated numerically by the laminar model with the reasonable mesh used the method of fluent. The focus of this numerical simulation was to research the characteristics of pressure distribution, drag coefficient and lift coefficient, and the Strouhal number was calculated at Reynolds-numbers value of 200. The results agree well with experimental data and other numerical results according to the reference. In order to study the control measures of the flow over a circular cylinder, the different baffles inserted at various locations downstream of the cylinder have been compared. The results shows that the vortex shedding of flow over a circular cylinder could be well controlled by place the baffle at a right position of the downstream medial axis of the cylinder, which could reduce drag and resist vibration.
Bearing Capacity of Reinforced Concrete Simple Beam Bridge Inspection and Analysis
Authors: Bin Jian , Lei Jin Song , Liu Juan Juan
Published: June 2011

According to the recent series of bridge collapse ,and points out the importance of safety testing and bearing capacity evaluating of the bridge in active service. RC simple beam bridge occupies a considerable proportion of the existing bridge in China, this paper discussed the commonly used inspection methods and its advantages and disadvantages, and draw a conclusion that load test method is the most commonly used and the most reliable way.Then, take “Ren jia dam bridge”bearing capacity inspection test as a example ,which in the “5.12 earthquake” disaster areas JiangYou ,MianYang.Discusses the whole prosess of bearing capacity calculation and field inspection in detailed.Compares the calculation results with the field inspection,the bearing capacity of the bridge meets the requirements of passing through "80t" vehicle loads, although is strongly impacted by the seismic force.
Thermal Stresses Simulation Analysis of Concrete Box Water Bridge under the Solar Radiation
Authors: Sun Jian Ping , Chen Jian Ping , Li Gang
Published: June 2011

The reasons why the producing of the difference in temperature distributing and thermal stresses of box aqueduct under solar radiation are analyzed. The difference in temperature distributing and thermal stresses are effectively simulated by the finite element software ANSYS.The calculation results indicate that concrete box aqueduct body inter-surface whatever along the longitudinal and transverse will produce considerable thermal stresses under solar radiation, and its value has exceeded the design of concrete tensile strength. Therefore, the thermal stresses under the solar radiation must be considered in the design of box aqueduct body structural. We should appropriately configure temperature reinforcing steel bar.
Development of a Kind of Multi-Defense Seismic Spherical Bearing
Authors: Peng Tian Bo , Yu Xun Tao , Wang Zhen Nan
Published: June 2011

For continuous girder bridges, each bearing has different function requirements under normal traffic conditions and under earthquakes of different intensity levels. To meet the requirements of the three-level seismic design for continuous girder bridges presented in this paper, a new kind of multi-defense seismic spherical bearing is developed and its configuration and working mechanism are introduced in this paper. Then the results of mechanical properties test of the bearing are presented and it’s shown that the design requirements are all satisfied and the seismic performance of the bearing is effective and reliable.
A Conceptual Design of a Cable Stayed Bridge with a Curved Back Span
Authors: Avşar Özgür , Caner Alp , Sarici Barbaros
Published: June 2011

The existing Komurhan Bridge was built over the dam reservoir prior to water storage. The aging segmental post-tensioned concrete bridge with two lanes had an active sagging problem at its mid-span. As the traffic demand increased over the years, the authorities decided to add two more lanes to have a twin two-lane road for this part of highway network. Therefore, a need was developed to build a new bridge. Unlike the existing one, the suggested crossing needed to pass 300 meters wide water body with a depth of 45 meters to avoid piers at water body. Couple of alternatives was considered to cross the deep water at conceptual design phase. The focus of this study is given to the conceptual design of a cable-stayed bridge with two towers crossing the water at the narrowest location. This option results in a curved back span at one side of the water. A three-dimensional computer model was developed to assess challenges in design. Special care is given to the design details of the cables and the superstructure. Even if one of the back spans is curved, the proposed conceptual cable-stay bridge design is satisfactory under service and earthquake loads.
Parametric Sensitivity Study on Fluid Viscous Damper of Long Span Suspension Bridge
Authors: Zhao Guo Hui , Zhang Yu Min
Published: June 2011

Damping coefficient and damping exponent play a dominant role on the displacement constraint effect and the damping force of the fluid viscous damper. In this paper, parametric sensitivity study of the fluid viscous damper is carried out by using nonlinear dynamic time history method based on a long suspension bridge. Acceptable damping force and reasonable displacement between stiffening girder and tower are set as the optimization objectives of the damping parameters. It is shown that: as to long suspension bridge, bigger damping coefficient can lower the displacement but increase the force of the dampers, and the smaller damping exponent can aggravate the trend. Fluid viscous damper can play the biggest role of displacement constraint effect while with little additional seismic force is introduced in the whole structure with suitable damping parameters.
Chloride Diffusion Characteristics of the New Interface Transition Zone in Recycled Aggregate Concrete
Authors: Wang Hai Long , Wang Jun Jie , Sun Xiao Yan , Cheng Juan
Published: June 2011

A three-part model (mortar, original concrete and ITZ) was established in this study to analyze the chloride coefficient of the new interfacial transition zone (ITZ) in recycled aggregate concrete (RAC). Based on this model, a formula for calculation was derived from the chloride transport characteristics in the steady state. Two types of RAC were used to study the properties of ITZ by steady-state migration test and Scanning Electron Microscope (SEM) method. The results indicate that the chloride diffusion coefficient of new ITZ in RAC is about 1 to 4 cm2/year, and that the addition of superfine phosphorous slag (PHS) not only reduces the chloride diffusion coefficient of mortar but also decreases the thickness and the chloride diffusion coefficient of new ITZ in RAC due to its pozzolanic reaction effect. The chloride permeability of mortar containing 20% PHS is only 1/5 of that in normal RAC. The chloride diffusion coefficient of ITZ in normal RAC is about 10 times greater than that of ordinary mortar. When modified with PHS and superplasticizer, the permeability of chloride in new ITZ is 3 to 7 times greater than that in the ordinary bulk cement paste. Furthermore, the mechanism and the effects of superfine phosphorous slag (PHS) on the resistivity of chloride permeation were discussed on basis of the experimental results and the images of SEM.
Ground-Liner Interaction Analysis in Underground Opening
Authors: He Yun Xiang , Wu Heng Bin
Published: June 2011

The ground-liner interaction research has important engineering value for the underground engineering design optimization and evaluation of construction safety. The interface between ground and liner is considered. In this paper, the effect of different ground-liner stiffness ratio, lateral pressure coefficient, thickness and different interface stiffness ratio and other factors on the support structure for internal forces and interface stress is analyzed. The analysis results show that liner internal force and interface stress increase with the increase of stiffness ratio between liner and ground, and the impact is very significant. Effect of lateral pressure coefficient on liner internal force and interface stress mainly reflects on laws around the cavern, where 1 is the limitation of lateral pressure coefficient. It presents symmetrical distribution. With the increase of liner thickness, the liner internal force and interface normal stress increase, but it make no difference to the contact interface tangential stress.
Research and Development of System of Shield Tunnelling to Adjacent Buildings
Authors: Ding Zhi , Ge Guo Bao , Wei Xin Jiang , Hong Jie
Published: June 2011

Considering different types of building structure and foundation, the system refers to acceptable ground settlement and acceptable soil loss ratio was established by establishing the control of building’s bending and deformation. The system which adopted Delphi dynamic data binding technology and used Access as database was developed by Delphi7.0 visual tools. The system which named "Analysis system about shield tunnel construction to adjacent buildings" is developed to judge the extent of damage of buildings influenced by adjacent shield tunnel construction.
Probability Analyses of Response Spectra on Soft Soil Site
Authors: Liu Wen Feng , Fu Xing Pan , Sui Jie Ying
Published: June 2011

The analyses on the statistical probability of the response spectra have an important role in determining the earthquake demand. Elastic and inelastic spectra on acceleration of the 369 records with a long characteristic period for SDOF systems were presented in statistical analyses. The empirical probability distributions of the spectral values were derived according to the Kolmogorov-Smirnov (KS) goodness-of-fit test. And the spectra considering the probability guaranty were developed to investigate the characteristic of the response spectra. The formula for statistical average spectra of the ground motion ensemble were recommended, which were valuable for current research and code revisal. The results show:(1)the inelastic responses decrease with the increase of ductility demand μ when μ<4, and they decrease unclearly when μ≥4;(2) the inelastic spectra has a large value of Cov (coefficient of variance),the Cov range from 0.2 to 0.3 when T<1s,and it increases linearly when T≥1s;(3)the probabilistic distribution of the spectra value on acceleration is validated as the lognormal or the Gumbel type I distributions;(4) the probabilistic spectra may be a feasible way to determine earthquake load in the future.
Research on Dynamic Rheological Parameters and Rheological Model of Soft Soil
Authors: Hu Hua , Zhu Meng Yun
Published: June 2011

The soft soil is covered widely in China. Soft soil has obvious rheological character, it will induce landslide etc serious geologic disasters, and make severe threaten to stability and security of projects. The dynamic loading such as earthquake, raging billow, vibration are the important factors and mainly power of inducing landslide geological disaster. The rheological parameters of soft soil are tested and analyzed under dynamic loading, and the rheological model of soft soil is established. All these have important theory and actual signification for us to reveal rheological dynamic mechanism of landslide geological disaster under dynamic loading.
Field Tests and Numerical Simulation of Pile Head Load Influences on Negative Skin Friction Behaviors of Piles
Authors: Xia Li Nong , Miao Yun Dong , Tong Xin , Li Shun
Published: June 2011

In order to study influences of different load at pile top on the behaviors of negative skin friction piles, field tests of negative skin friction behaviors of three identical piles with different loads at pile top are made in the same site. According to the field test condition, the corresponding numerical simulations are accomplished. The comparison shows that numerical simulation results and field test results in accordance well. The additional settlement induced by negative skin friction is bigger and the neutral position is higher, the additional axial force induced by negative skin friction reduces obviously in piles with pile head load compared with that in piles without pile head load induced by negative skin friction. Along with load increase, the additional settlement increases, the neutral point position becomes higher; the additional axial force reduces obviously. The result indicates there is regularity about the influences of pile head load on negative skin friction. It may be useful to the research for negative skin friction behaviors of pile.
Rockfall on the Slope of the Embankment of Finite Element Analysis of the Impact of the Impact
Authors: Wang Zi Jian , Xiao Sheng Xie
Published: June 2011

This article in a typical road slope model as an example, through large-scale general-purpose finite element simulation software ANSYS/LS-DYNA rockfall on the slope of the roadbed impact for three-dimensional dynamic analysis in the roadbed, slope geological parameters and falling stone initial state is not at the same time on the roadbed impact the results of comparative analysis. The result is the mountain slope of the road construction project provides reference.
Analysis on the Influence of Debris Flow Entrainment of Path Material
Authors: Fan Yun Yun , Liang Li , Wang En Zhi , Wang Si Jing
Published: June 2011

Debris flow has a very strong destructive power which can cause a great loss of human lives and belongings, so for the purpose of a better disaster prevention and reduction, it is necessary to strengthen the knowledge about the characteristics and regulations of the motion process of debris flow. In order to analyze debris flow entrainment of path material and the influence of the distribution of entrainment zone on the dynamic process of debris flow, the numerical simulation of debris flow dynamic process of different entrainment zones is achieved by combining the theory of SH granular flow and the method of finite volume discretization. The calculation results show that due to energy loss and momentum transfer, the overall speed of debris flow is decreased and the part flow depth increased, but when the entrainment zone is at high position, the entrainment happens early, and the after-entrainment acceleration is more significant, so the mass increased by the entrainment will cause a larger disaster zone and a stronger destruction.
A Practical Performance-Based Seismic Design Method for Regular Highway Bridges
Authors: Sun Ying , Ping Shang Guan , Gu Yin , Zhuo Wei Dong
Published: June 2011

In this paper, a simple and practical performance-based seismic design (PBSD) method for regular highway bridges is suggested. In the proposed PBSD method, the drift ratio of the bridge column is employed as quantitative indices of seismic performance levels, and its target values for each seismic performance level are given. The whole design processes of a regular highway bridge with various performance objects under different seismic levels are demonstrated.
Study on Dynamic Calculation Method for Pile Supporting Structure with One Layer Prestressed Anchor
Authors: Zhu Yan Peng , Dong Jian Hua , Zhou Yong
Published: June 2011

A dynamic calculation model of the pile supporting structure with one layer prestressed anchor for the slope is proposed in this paper. The prestressed anchor is regarded as the elastic support of the pile body. According to the theory of one-dimension elastic wave propagation, the interaction between the pile and the soil is obtained. Then the motion equation of the pile-prestressed anchor is established based on the dynamic interaction. The analytical solutions are obtained. In addition the proposed method is applied to a project case to carry out the seismic analysis and design of the pile supporting structure with one layer prestressed anchor. The calculation method provides a theoretical basis for earthquake response analysis and seismic design of the pile supporting structure with one layer prestressed anchor.
Highway Slope Monitoring System Based Multi-Antenna GPS Network
Authors: Xie Feng , Li Quan Wen
Published: June 2011

Highway slope deformation monitoring is an important guarantee for the safety of road transport means, the conventional GPS monitoring system has many advantages, but the monitoring of high cost lead to difficult application. Through the use of GPS multi-antenna network technology, use of automatic control technology, low-noise signal amplification technology, the wireless GPRS data transmission technology, remote automated highway slope monitoring, GPS network monitoring system can greatly reduce the cost to obtain reliable slope deformation information.
Valley Settlement Characteristics Analysis in Northwest of China - Exampled by Qingcheng Town
Authors: Meng Xiang Wu , Ye Ming Hui , Zhang Han
Published: June 2011

Known as “the Millennium Town beside the Yellow River” Qingcheng Town in Yuzhong County has many rich cultural heritages and profound cultural foundation. Its terrain belongs to the typical Yellow River Valley. It was an important traffic wharf of the ancient Silk Road, and a terminal frontier military center from Tang Dynasty to Ming Dynasty. By researching and analyzing the Qingcheng town, the thesis summarizes its characteristics of the spatial layout and ecological culture.
Numerical Analysis Method for Dynamic Stability of a High and Steep Rock Slope in the Sichuan Wenchuan Earthquake
Authors: Xiao Shi Guo , Feng Wen Kai
Published: June 2011

Near-field ground shock features are analyzed according to the seismological record of the May 12 Wenchuan earthquake made at the Wolong observation station. A numerical analysis model is established by taking the record as the input seismic load and a real high and steep rock slope on the bank of the Zipingpu Reservoir. The acceleration response and shear strain increment distribution features at different locations of the slope under horizontal seismic force are analyzed using Plaxis software. The moment when the widest plastic zone occurs for the slope is obtained by time history analysis. The corresponding stability factor of the slope at that moment is calculated using the strength reduction method (including shear strength and tensile strength). The above is the Time History Analysis–Strength Reduction Method presented in this article. In addition, the stability factor of the slope can be calculated using the pseudostatic method by taking the seismic force as the external load. This is the Time History Analysis–Pseudostatic method put forward in this paper. Analysis results demonstrate that, as far as the studied high and steep slope is concerned, at 31.89 s, the stability factor calculated with the Time History Analysis–Strength Reduction Method is 1.004, which is slightly larger than the 0.833 obtained using the Time History Analysis–Pseudostatic Method (Spencer method). Both results demonstrate that there is collapse and sliding failure of the localized rock mass at the top of the slope at that moment because of joint fracture. Field investigation after the earthquake further verified the calculation result, proving to a certain degree the rationality of the analysis method presented.
Experimental Research on Flexural Behavior of Recycled Concrete One-Way Slab Reinforced with CFRP
Authors: Xie Jian Jun , Tao Jun Lin , Gu Song , Lei Ting , Hu Wen Jun
Published: June 2011

This paper is supported by National 863 Plans Projects and Sub-project of Science and Technology Department of Sichuan Province, through experimental research on flexural behavior of non-crack recycled concrete one-way slabs reinforced with CFRP, research the ultimate bearing capacity and maximum deflection of it, and comparative analysis the results with recycled concrete one-way slabs which is not been reinforced and reinforced with CFRP after post-cracking. The results show that, the ultimate bearing capacity is higher than the non-crack reinforced concrete slabs, at the same time the deflection is smaller. The ultimate bearing capacity of non-crack recycled concrete one-way slab reinforced with CFRP is lower than post-cracking recycled concrete one-way slab reinforced with CFRP, at the same time the deflection is greater. But found bearing capacity and deflection is lower than that post-cracking recycled concrete one-way slab reinforced with CFRP when experimental on flexural behavior of non-crack recycled concrete one-way slabs reinforced with CFRP, and do a preliminary analysis for this phenomenon.
Inner Damage and Anti-Chloride Penetration of High-Performance Concrete under Axial Tensile Load
Authors: Jiang Fu Xiang , Xin Lei , Zhao Tie Jun , Wan Xiao Mei
Published: June 2011

The total porosity of high performance concrete specimens after different level uniaxial tensile loading were measured to reflect the damage degree of mechanical load to the microstructure of the concrete. Meanwhile, considering the environmental characteristics of the ocean tidal zone, chloride penetration tests of the concrete were carried out with salt solution capillary absorption method. Based on the profile of chloride measured from specimens, chloride diffusion coefficients of the concrete under uniaxial tensile load with different levels are determined further by Fick’s second law. Results show that both of total porosity and chloride diffusion coefficient of the concrete are increased significantly after short-term tensile loading. And the evolutions of the porosity and chloride diffusion coefficient are similar with the development of micro-cracks under uniaxial tensile load.
The Bad Effects of Foundation Pit Heave on Foundation Piles
Authors: Feng Shi Lun , Liu Jie , Li Jun , Li Pu Lin , Han Yong
Published: June 2011

Deep excavations release stresses in the earth and redistribute these stresses causing deformation. The pressure loss due to excavation may result in a base instability, where the soil flow beneath the sheeting into the excavation, producing a rise in the base elevation commonly termed as heave. The heave can lead the foundation piles casted before excavation to floating and being in tension, and even induce the tensile failure of pile in severe case. The characters of foundation piles in different excavation conditions, different location have been analyzed by a case study. The calculation results show that the deeper excavation, the larger vertical force acted on the foundation pile and the heave could induce the tensile failure of the foundation piles. So it is recommended that the tensile capacity of the foundation piles should be verified when the excavation is very deep.
Pseudo-Static Experimental Research and Seismic Behavior Analysis on Elevated Pile Cap Foundation
Authors: Zhou Mi , Hou Jian , Zhang Yue , Yuan Wan Cheng
Published: June 2011

The paper deals with experimental activity on 4 scale-models of elevated pile cap foundation belonging to a real bridge. The foundation was composed of 9 piles, pile cap and pier and the special soil box was built to consider soil-pile-superstructure interaction. Two specimens were strengthened by steel protective pipe at each pile top. The tests consist of cyclically imposed displacement to 4 specimens, performed in the state key laboratory for disaster reduction in civil engineering of Tongji University. According to the test result, the peak strength of strengthening specimens is about 1.77 times of the others and the ultimate displacement is 1.66 times of the original models. Additionally, the dissipated hysteric energy capability of strengthening specimens is more than 2.15 times of the others as the equivalent viscous damping ratio is reduced by 50%. Other relevant phenomena are the pinching effect of original specimens is more obvious and the hysteretic loops of reinforced specimens are more plumpness. Moreover, the failure and collapse mechanisms of the elevated pile cap foundation were summarized. Finally, the measures to enhance the aseismic capability for elevated pile cap foundation were proposed.
Experimental Study on Mechanical Characteristics of Deformation of Red Sandstone
Authors: Wang Rui Hong , Jiang Yu Zhou , Guo Jing , Wen Shi Yi
Published: June 2011

For geotechnical engineering, it has great significance to research the mechanical characteristics of rock mass under three dimensional stresses. Through triaxial compression failure test, the characteristics of stress-strain curve and deformation of red sandstone from Sichuan under different confining pressures has been analyzed. The results show that: with the increment of confining pressure, the failure mode of rock mass changes from brittle failure to ductile failure gradually, and an obvious yield platform appears near the peak strength of stress-strain curve; the elastic modulus, deformation modulus, peak strain and residual strain of rock sample increase with the increment of confining pressure, the elastic modulus and deformation modulus are not a fixed value, and the relation between deformation parameter and confining pressure can be fit through quadratic curve.
Polyester Fibers in the Concrete an Experimental Investigation
Authors: Malagavelli Venu , Rao Paturu Neelakanteswara
Published: June 2011

Construction field has experienced a growing interest in Fiber Reinforced Concrete (FRC) due to its various advantages. The disposal of industrial waste especially non biodegradable waste is creating a lot of problems in the environment. In the present investigation, an attempt has been made by using non biodegradable waste (polyester fibers) in the concrete to improve the crack resistance and strength. Concrete having compressive strength of 25MPa is used for this study. Samples were prepared by using various fiber contents starting from 0 to 6% of with an increment of 0.5% for finding Compressive strength, split tensile strength and flexural strengths. It is observed that, compressive strength, split tensile strength and flexural strengths of concretes is increasing as the fiber content is increased up to some extent.
Numerical Model of Road Tunnel with Void between the Liner and Surrounding Rock and its Application
Authors: Zheng Jia Yan , Liu Hai Jing
Published: June 2011

Void between road tunnel liner and surrounding rock is one of the most frequent defects in tunnel engineering. In this paper, contact method is introduced into the numerical model to simulate the interaction between tunnel liner and surrounding rock. The relationship between the key parameters of void and safety factor of the structure is systematically studied with the numerical model. Results show that position and width of void are the key parameters, while depth and shape of void are unimportant and negligible. It can also be concluded that the decrease rate of safety factor to the increase of circular width is almost the same while void is in different position. Conclusions gained are helpful for inspection, operation status assessment and rehabilitation of road tunnel in future.
Defects Inspection and Cause Analysis of Six Tunnels in Chongqing
Authors: Zheng Jia Yan , Liu Hai Jing , Zou Zong Liang
Published: June 2011

This paper presents defects inspection and cause analysis of six road tunnels in Chongqing based on information of construction, operation and maintenance, defects property and related factors. The unfavorable factors including ground disturbance and load nearby, complex structure form, construction deformation that threaten the safety of tunnel structure and operation are thoroughly analyzed. Based on the discussion and analysis recommendation and suggestion on measures of urban tunnel maintenance and management are carried out. Experience gained is helpful for future urban road tunnel maintenance and management.
Analysis of Tunnel Defect Characteristic Caused by Cavities behind Lining
Authors: Wang Wei , Liao Shi Chao , Ding Peng , Chen Dong Zhu
Published: June 2011

Back-cavity of lining is a main factor resulting in tunnel defect. But as the concealment of the cavities behind linings, it is hard to judge the existence and conditions of cavities. In this paper numerical simulation analysis was carried out to analyze the mechanics of lining when there were different size of cavities which located in vault, hance, sidewall or foot of sidewall respectively, then to study the tunnel defect caused by back-cavity and set up corresponding relationship between cavity condition and tunnel defect. The research has some auxiliary help for rapid diagnosis of tunnel defect according to defect characteristics observed in site inspection.
Numerical Tests of Tunnel Reinforcing Influences on Zonal Disintegration within Rockmass around Deep Tunnel
Authors: Zuo Yu Jun , Zhang Yong Bin , Li Shu Cai , Zhang Yi Ping , Chen Chun Chun
Published: June 2011

Nnumerical tests on three-dimensional failure process of rock samples containing vertical wall semi-arched tunnel with and without reinforcing are carried out with Mechsoft’s RFPA-Parallel system running on Lenovo 1800 Cluster, reproducing zonal disintegration phenomenon within rockmass around deep tunnels, and then the deep tunnel reinforcing influences on zonal disintegration within rockmass around tunnel is analyzed. Numerical results indicate that deep tunnel reinforcing does not change the general nature to form zonal disintegration phenomenon, but it can improve the stability of the tunnel wall.
Preparation and Characterization of CCCW/Foamed Concrete Composite
Authors: Li Ke Qing , Chen De Ping , Zhang Shi Li , Liu Bao Shun
Published: June 2011

Aimed at improving the waterproofing property of foamed concrete, a heat-insulating and waterproofing composite applied in underground engineering was prepared by using cementitious capillary crystalline waterproofing material and foamed concrete. The properties of foamed concrete and composite such as compressive strength, water absorption and thermal conductivity were tested and contrasted, and the compounding reaction mechanism was analyzed. The results show that, compared with foamed concrete, the water absorption of composite has been significantly reduced while the heat-insulating property of foamed concrete is maintained and the overall waterproofing and heat-insulation performance has been significantly improved. A new approach solving underground heat-harm such as high temperature and high humidity is provided.
Experimental Research on Restoring Force Characteristics of Light Composite Structure
Authors: Li Sheng Сai
Published: June 2011

Pseudo dynamic test and pseudo static test were carried out on 1/2 scale model of light composite structure. By experimental research, hysteretic curves of base shear force and top displacement of the model structure were got, which come from various sections of pseudo dynamic test and pseudo static test, and through hysteretic curves of base shear force and top displacement of the model structure, skeleton curve of base shear force and top displacement of the model structure can be got. Outside line of all skeleton curves was skeleton curve of the light composite structure model. By analyzing and simplifying of the skeleton curve, finally restoring force model of the model structure was obtained, so reasonable dynamic analysis method of seismic design of the model structure can be offered. Research shows that as peak acceleration of inputting seismic wave continuously grows, especially when the peak acceleration reaching 800 gal, after the model structure reached plastic stage and in the stage of pseudo static test, the hysteretic curves become fuller and fuller, which shows that, with continuous emerging and propagation of crack, the structural rigidity losses gradually, and its energy dissipation capacity increases gradually. So earthquake fortification level of not collapse when hit by rarely occurred earthquake will achieve.
Stability Analysis of S-RMS under Seismic Loading
Authors: Han Jing Jing , Liu Bao Xian , Zhang Dong Liang
Published: June 2011

Earthquake is one of the main geological disasters that cause slope instability. The stability analysis of soil-rock mixture slope under earthquake is made with FLAC3D in this paper. According to finding the shear strain concentrated deformation zone and the size of the displacement, they can help us to find the possible instability of the scope and location. The study result shows that the slope is stable in the natural state and certain displacement would occur in the potential slide mass of the slope under earthquake, and this must be taken into serious consideration in practical engineering.
Comprehensive Assessment of Water Inrush Risk in Deep Mining of Beiminghe Iron Mine
Authors: Li Chang Hong , Zhang Li Xin
Published: June 2011

In view of one-sidedness and the limitations in comprehensive evaluation index for water inrush risk, a variety of factors of water inrush induced by deep mining of Beiminghe iron mine are analyzed from hydrogeological characteristics, structural characteristics and mining. Faulted structure, water storage capacity, water pressure, water-resisting layer, miming effect and the change of stress in surrounding rock of two levels of deep mining in mine area are quantized by rock permeability test, field pumping test and finite element numerical analysis. Mathematic model of risk assessment of water inrush in deep mining of Beiminghe iron mine is established by using fuzzy comprehensive evaluation method. Quantitative assessment of water inrush risk is carried out to obtain the value of rank tendency for water inrush risk through that mathematic model.
Study on Zero Discharge Treatment Technology of Waste Bored Pile Slurry
Authors: Zhang Zhong Miao , Fang Kai , Luo Jia Cheng , Liu Xing Wang
Published: June 2011

Construction wastes have attracted more and more public attention with the development of the city construction. On the basis of summarizing the existing slurry treatment technologies in relevant area, a new slurry treatment process is proposed according to the characteristics of waste bored pile slurry. Three steps included in this process: slurry purification, flocculation and pressure filtration. A practical application is used to demonstrate the feasibility of this process. The results show that the slurry is disposed without pollution, achieving zero discharge of pollutants.