bluuebunny/crossref_metadata_2025 huggingface dataset:
Influences on Asphalt Pavement Performance of Graded Broken Stone Sub-Base Based on Cross-Anisotropy
Authors: Duan Li Min , Yue Jin Chao , Niu Xiang Fei
Published: May 2011

Graded broken stone materials show cross-anisotropic behavior, but now most pavement structure analysis are based on assuming pavement structure to be isotropic layered system. In order to accurately evaluate pavement responses based on cross-anisotropy utilizing graded broken stone as sub-base materials, the influences of sub-base thickness, horizontal modulus and breaking force on the stress in pavements are studied by using the three-dimensional finite element software ABAQUS. The results show that the shear stress of the pavement decreases with the increasing of the sub-base thickness or the horizontal resilient modulus but the shear stress of the pavement increases obviously with the increasing of braking forces.
Study on Shear Properties of Rock Structural Plane by Grouting Reinforcement
Authors: Zong Yi Jiang , Han Li Jun , Han Gui Lei
Published: May 2011

In order to study the grouting reinforcement effect of structural plane in cracked rock mass under uniaxial compression test and reveal the essence and mechanisms of grouting reinforcement, the roughness of structural plane in cracked rock mass was measured and studied. The influence of grouting on strength, JRC and stiffness was analyzed through shear tests of structural plane of cracked rock samples around grouting reinforcement. Test results were back-analyzed using JRC－JCS mode. The results showed that the JRC of structural plane in artificial cracked rock of the same rock mass was similar and replicable, the JRC value was about 8-10. Stiffness, roughness, peak shear strength (PSS), residual strength (RS), shear strength parameters (SSP) and slope of upward section (SUS) of structural plane were significantly improved by grouting reinforcement. The theoretical formula of structural plane stiffness was given by theoretical analysis.
Parametric Study of Static Strength of Multiplanar KK-Joints：Square Chords and Circular Braces
Authors: Chen Ai Guo , Huang Wei Liang , Shan Rui Zeng , Yang Qing Shan
Published: May 2011

Pre-stressed spatial tubular truss system is adopted in steel roof truss structures of China International Exhibition Center New Venue. Bottom chord joints are multiplanar KK-joints consisting of chord with square hollow section and brace with circular hollow section. However, not only that relatively little research has been carried out on such joints, but also that no detailed design guidance on KK-type joints consisting of chord with square hollow section and brace with circular hollow section can be found Current design code for steel structure (GB 50017-2003). This paper reports the study into the strength of this type of KK-joints under axial loading. The numerical models were adopted, and several various geometric parameters which affect the strength and failure modes, were investigated. It was indicated that the geometric parameters affects significantly the ultimate capacity and failure modes of the joints. The varied relationship of the strength and failure mode with parameter varying was studied in detail. The results of the work presented provide initial discussion on behavior of this type of KK-joints and lay the foundation for a future large-scale parametric study and put out design formula.
Application of Lead Rubber Bearing in Curved Continuous Bridge
Authors: Liu Zheng , Wang Tao
Published: May 2011

Based on the general FEA program, the bidirectional nonlinear behavior of lead rubber bearing is taken into account by using two orthogonal nonlinear spring elements. Considering the effect of radius of curvature, lead diameter and dissimilar seismic motions, dimensional FEA model of seismically isolated curved continuous bridge is established. And the seismic energy response analyses for seismically isolated curved continuous bridge are carried out under the three-dimensional seismic motions. So, some meaningful references are provided for the design of vibration absorption and isolation of the curved beam bridge in this paper.
Research on Expanding Properties of Limestone under High Temperature
Authors: Luo Yun Jun , Qin Ben Dong , Liu Yang
Published: May 2011

The expanding properties of limestone from 200°C to 700°C were investigated under high temperature and bidirectional restraints with the device used to heating rock designed by ourselves. The experimental results show that the two directional expanding stress of limestone increased with temperature increasing during raising temperature before 600°C, and decreased after 600°C. The expanding stress perpendicular to bedding plane was bigger than that parallel to bedding plane. The curves of expanding stress and temperature ascend steadily during constant temperature before 600°C, but the slopes were much less than those during raising temperature. The expanding stress tended to steady value at last with the time of constant temperature prolonging. The expanding stress when constant temperature ended was smaller than those before constant temperature at 700°C. It showed that the limestone had expanded to the limit value after a certain temperature. The expanding stress reduced possibly after a certain temperature because the rock sample was restricted and some fissures closed and the number of cracks reduced after over-high temperature, but the detailed cause needs more researches to testify it.
The Alignment Control Analysis of Cantilever Construction for Large Span Composite Continuous Box-Girder Bridge with Corrugated Steel Webs
Authors: Li Ming , Lu Jian Ming , Song Jian Yong
Published: May 2011

Juancheng Yellow River Highway Bridge is the largest externally pre-stressed concrete continuous box-girder bridge with corrugated steel webs in the world with the total length of 1460m and span arrangement of 70m+11×120m+70m. Based on the monitoring practice for this bridge construction, the paper illustrates the application of the two modeling methods for box-girder with corrugated steel webs in the calculation of alignment control using bridge analysis system GQJS, i.e. the one-node method and two-node method. Additionally, the comparison between the measured and predicted deformation under different construction stages including cantilever construction, closure construction, system transformation and external prestress tension is presented and discussed. The results turn out both the two proposed modeling methods can perfectly meet the requirements of alignment control of this kind of bridge.
Study on Sublevel Open Stoping with Subsequent Backfilling Mining Method Stope Parameters Optimization
Authors: Song Wei Dong , Wang Dong Xu , Tang Ya Nan
Published: May 2011

This paper discusses the stope parameters of the sublevel subsequent filling stage in Daye Iron Shizishan section. According to the similar material simulation technology, which is the main means, displacement monitoring and internal stress monitoring, several conclusions are summarized as bellow: When the parameter of the room and pillar is 18m, the underground mining is safe and steady. Impacts, which come from different regions’ mining, is different, and the greatest impact comes from the pillar’ mining. Stress monitoring shows that before roof fell down, there is a process of stress concentration. The stress in the roof is shear stress, and compressive stress in the pillar.
Experiment Study of the Uplift Mechanism of Disk Piles
Authors: Lu Chen Yuan , Lai Shu Na , Meng Fan Li
Published: May 2011

Based on the analysis of the uplift mechanism theory of the disk piles, a model test device was designed to study the uplift bearing capacity and deformation behavior of the disk piles and to compare with the equivalent diameter piles. Uplift loading tests were carried out on the equivalent diameter pile, the single-disk pile and the double- disk pile respectively. Through the test, it was proved that the uplift bearing capacity of the disk piles was much better than the equivalent diameter pile. The bearing capacity of the single-disk piles was better than the double-disk piles in the test. This was mainly related to the embedded depth of the upper disk was not enough and the specific failure mode. So, a reasonable design was necessary.
The Statistical Laws of Surficial Deformation of Loess Ground during Dynamic Compaction
Authors: Luo Si Hai , Wang Yang , Yang Jian Yong , Deng Tong Fa
Published: May 2011

Through the method of dimensional analysis, the dimension equations of loess ground deformation of dynamic compaction are established. Based on the data obtained from practices of dynamic compaction and the methods of statistics , empirical equations of both the crater depth and the average enforced settlement relating the soil parameters and construction parameters are presented. Finally, the equations are verified by several project examples, and the results show that the calculated results agree well with experimental results. These equations provide a practical way for the prediction of surficial deformation of loess ground during dynamic compaction.
The Structure Selection Analysis on the Support Tower of H-Type Vertical Axis Wind Turbine
Authors: Bao Chong Shan , Zhang Yong
Published: May 2011

H-type vertical axis wind turbine is a new type wind turbine. Currently the research on its support tower is still in the blank stage. Based on the work principle of H-type vertical axis wind turbine, the factors about the structure selection of the support tower were analyzed, and parametric analysis of structure selection was carried out for a pilot project. Finally some useful conclusions were obtained to guide the design.
Seismic Response Analysis for Hong Kong-Zhuhai-Macau Bridge
Authors: Wang Tao , Ning Jing , Li Yu
Published: May 2011

According to the behavior of seismically isolated continuous bridges, the bidirectional nonlinear characteristics of lead rubber bearing are taken into account by using two orthogonal nonlinear level spring elements. Based on the FEA software, the analysis models of seismically isolated and non-isolated continuous bridges are established. And the nonlinear seismic response for these analysis models is carried out under the function of the reasonably chosen seismic motion.
Statistics Analysis of the Bridge Dynamic Response in the Survey of Expressway Traffic Loads
Authors: Wang Tao , Han Wan Shui
Published: May 2011

Nowadays, with the rapid development of the traffic infrastructure construction and the growing of the traffic flowing and speed, the vehicle-bridge coupling vibration research has become the focus of the bridge engineering study. The dynamic response of the bridge under the traffic flowing is one of vital parameters for the vehicle-bridge coupling vibration analysis. In this paper, a methodology, employing the radar speed gun, the video recorder, and the dynamic strain tester in combination with manually recording is used to continuously and detailed investigate the traffic loads on the expressway bridge within 24 hours a day. With this approach introduced by this paper, all the critical parameters, such as the vehicle type, speed, traffic lane, the arriving time of the traffic and the bridge-vehicle dynamic interaction are all recorded. In this investigation, firstly the dynamic responses of 8 pieces of beams of the bridge under 5650 individual vehicles driving through the bridge are recorded, secondly statistics analysis are made for the record of each beam, and finally the space-time distribution laws of the dynamic response of the bridge under the traffic flowing are studied extensively. The result of this study could provide helpful theoretic guidance and supporting data for the vehicle-bridge coupling vibration research.
Data Envelopment Analysis Used in Taiwan Performance Evaluation of Highway Maintenance
Authors: Wei Kuang Yi , Peng Jr Hung , Lin Jyh Dong , Ciou Cin Rong
Published: May 2011

DEA (Data Envelopment Analysis), Charnes has been published since 1978, due to the method of the correct value of properties in recent years have taken full advantage in the corporate performance assessment. In this study, each road maintenance units in Taiwan is to be a Decision Making Unit, the last two years of each DMU manpower, equipment number, maintenance expenses, etc., as input data, and score above the level units as output data, to analyze the performance of road maintenance authority, then proposed suggestions for improvement to the less efficient units, it can be a reference for follow-up work to enhance the efficiency of the road to the maintenance unit.
Experimental Study on the Dynamic Compressive Mechanical Properties of Concrete
Authors: Sun Ji Shu , Dou Yuan Ming , Li Bo , Chen Zhao Xia
Published: May 2011

Dynamic compressive tests of plain concrete specimens (C30 and C40) are carried out on MTS, with the uniaxial strain rate ranging from 10-5/s to 10-2/s. The impacts of strain rates on concrete strength are studied systematically. The mechanical properties of compressive strength, elastic modulus and compressive stress-strain curve of concrete under different stain rates are also analyzed. The experiental relationships between strain rate and compressive strength of concrete are established. It is found that the compressive strength of concrete increases with the strain rate increasing. Modulus is also showing a growth trend, but the growth rate varies greatly; and the stress-strain curve under dynamic loads is similar to the one under static loads. These research achievements can provide us with a more accurate grasp of concrete actual working conditions and provide some guidance to structural design of concrete. These are important to build the dynamic damage constitutive models, too.
Study on Strength Forming Process of Cement Stabilized Soil
Authors: Chen Huie , Yan Huan , Zhang Jun
Published: May 2011

Series of indoor tests were done to study the strength forming process of soft soil stabilized by cement. Dry cement was used to consolidate soft soil through modeling the field construction situation, and the stabilized soil samples in different curing days were studied by means of direct-shear test, grading analysis test and scanning electronic microscopy. So the parameters of shearing strength, granularmetric compostion and microstructure feature of treated soil in each curing stage were determined. Results shown that, at the early stage, there was a slow increase in the strength of cement-soil, and with the curing days increasing, the mechanical property, component and microstructure feature of samples were improved obviously.
Predicted Behaviour of Partially Restrained Connection with Cold Formed High Strength Steel by 3D Finite Element Modelling
Authors: Taufik Syaril , bin Baharom Shahrizan , Xiao Robert Y.
Published: May 2011

Thispaper investigates the behavior prediction of partially restrained (PR) connection with high strength steel bythree-dimensional nonlinear finite-element (FE) analyses. The connectionmodel is such that angle cleats are represented by radiuses corner section shell elements. The full interaction between angle and beam and/or column is simulated by contact element. The analysis results of the moment- rotation relationship and behaviour characteristic of the connection with high strength steel are compared and discussed. It is found that contact element and strength enhancement of the corner regions employed to the model are very important parameters for accurate prediction of PR connection behaviour with cold-formed high strength steel. The moment capacity prediction of top and seat angle connections based on EC3 has been shown to be reasonable compared with FE modeling. Theproposed connection FE model is capable of predicting the ultimate load capacity and the plastic strain pattern with good accuracy. The model presented gives excellent results for increasing the connection capacity significantly due to employed higher strength steel section.
A New Approach to Model Asphalt Pavement Overlay Cracking
Authors: Hsie Machine , Lin Chih Tsang , Ho Yueh Feng
Published: May 2011

The study proposes the Genetic Operation Tree (GOT), which integrate Genetic Algorithm (GA) and Operation Tree (OT), to build the model for Asphalt Pavement Overlay Cracking. The training data sets of pavement cracks were collected from a 15-year experiment conducted by the Texas Departments of Transportation. Even without a presumed formula structure, the GOT still can self-organize formula and produce a very concise model for predicting the length of pavement cracking.
Performance of Cross Bracings under Reverse Cyclic Loading
Authors: Zhao Zuo Zhou , Liu Qin Zhi , Qian Jia Ru
Published: May 2011

Steel braces are widely used in seismic retrofit of buildings. However, their tendency of buckling under compression impairs their efficacy. In this paper, characteristics of a cross bracing with rigid intersection, including its bearing capacity, hysteretic property and fracture ductility are investigated. With the analysis results, performance-based design requirements of a steel cross bracing are proposed based on its width-thickness ratio and effective slenderness ratio.
Influence of Variable Temperature Curing on Mechanical Properties of Fly Ash Concrete
Authors: Zhao Ya Ding , Li Xue Ying , Kong Ling Chao , Du Wei
Published: May 2011

Under variable temperature curing conditions(30 oC ~70 oC), concrete with fly ash whose compressive strength, flexural strength, and dynamic elastic modulus are better than ones without fly ash.Compared with constant temperature 20oC, 50 oC and 70 oC, variable temperature curing(VTC) is benefit for the improvement of mechanical properties of 30% fly ash concrete, but which is no advantage to improve performance of 50% fly ash concrete.
Strategy on Improving Lateral Driving Stability of the Automobiles Passing by the Vicinity of A-Shaped Pylon of Zhengxin Yellow River Highway-Railway Bridge in Cross Wind
Authors: Wang Da Lei , Chen Ai Rong , Ai Hui Lin
Published: May 2011

Problem of lateral driving stability of the automobiles passing by the vicinity of pylons of cable-supported bridges in condition of strong cross wind exists obviously because of the alternative wind environment above the deck due to complex flow fluid around the pylon and the deck. Based on numerical wind tunnel technology, the numerical simulation investigation of alternating wind environment above the girder near A-shaped pylon for main span of the steel truss girder cable-stayed bridge of Zhengxin Yellow River Highway-railway Bridge is carried out, considering wind barrier set up on the deck or not. The result shows that the original program has significant effect on wind speed amplification and mutation near the pylon domain in cross wind. Further investigation on wind barrier set up on both sides of the girder section or near the A-shaped pylon along the bridge gives that wind barrier near the A-shaped pylon is useful for reducing wind speed above the leeward deck near the pylon and weakening its mutation. Deeply, taken a medium-size commercial bus as an example, lateral driving stability of the automobiles passing by the leeward lane near A-shaped pylon is discussed through the dynamic response simulation of the vehicle controlled by ideal-driver under cross wind. The results confirms again that the wind barrier near the A-shaped pylon is good for driving safety of vehicles passing by the leeward lanes in vicinity of A-shaped pylon. In all, above work provides technical support for the final implementation of the wind barrier as an engineering measure.
A Case Study of Effect of Horizontal Drains on Rainfall-Induced Landslide
Authors: Tang Lin , Tang Xiao Wu , Liu Wei
Published: May 2011

Rainfall-induced landslides are of frequent occurrence in the south of China. One of the most effective methods to stabilize landslides is to lower the groundwater table by installing horizontal drain. A shallow landslide caused by typhoon Morakot happened along Shangyu - Sanmen Expressway in Zhejiang. Horizontal drains were installed and served as an important part of the slope stabilization scheme. The relationship among rainfall intensity, groundwater level, and slope stability was indicated by field monitoring data. Using software GeoStudio, the stability states of the original slope under rainfall are simulated, based on Fredlund’s Unsaturated Soil Strength Theory. After the rain ceases, the draining processes of the original slope and the slope with horizontal drains are compared. It is obvious that the factor of safety recovers rapidly in the slope with drains. The simulated discharge rate of drain and slope surface, and the change of groundwater table also prove the benefits of the drains, which agree well with the field monitoring data.
Study on Physical-Mechanical Properties of Xiamen Coast Silt
Authors: Xiang Xian Chao , Zhu Chang Qi
Published: May 2011

Silt is widely distributed in coast area. Its consolidation is a popular geotechnical engineering issue. Coast silt is always under seasonal wave and tide, which made great influence on the consolidation process. Abundant lab and in-situ tests are used to study on the physical-mechanical properties of Xiamen coast silt. The engineering characteristic of the coast silt taken from Xiamen is evaluated and the relationships between physics and mechanics indexes such as compression coefficient, water content, void ratio, cohesion and internal friction angle are analyzed, and the linear regression equations between silt parameter is established. Then two in-situ tests cone penetration test (CPT) and flat dilatometer test (DMT) are applied to study the properties of coast silt, abundant in-situ test data obtained.
Performance of a Rigid Frame Arch Bridge under Near-Fault Earthquake Ground Motion
Authors: Huang Yong , Wang Jun Jie , Jin De Yin
Published: May 2011

During May 12th 2008 Wenchuan earthquake with the magnitude of 8.0, a 4-span rigid frame arch bridge named as Xiaoyudong Bridge which situated close to the epicenter was hit by strong ground motion and was severely damaged. The earthquake response analysis of the bridge was made using FE software MIDAS based on recorded ground motion during the Wenchuan earthquake in this paper. The study showed that the main and minor arch legs on the both ends piers were weak links which may be damaged firstly under strong ground motion. The next damage at the pier with weakest horizontal stiffness is one of the important reasons causing the bridge collapsed. This paper will introduce our work on those respects and some drawn conclusions.
Environmental Isotopic and Hydrochemical Approach of Groundwater in Kerian Irrigation Scheme, Perak
Authors: Ahmad Nazri Mohd Ariff , Syafalni  , Abustan Ismail , Dor Najihah , Abdul Rahman Mohd Tadza , Mejus Lakam , Mostapa Roslanzairi
Published: May 2011

The study scrutinizes the groundwater evolution and its relation in the Kerian irrigation scheme of Perak region using isotope and hydrochemical analyses. Nine representative groundwater samples were collected from nine different wells that cover the Kerian area. The samples are analyzed on geochemical characteristics, ionic composition and hydrofacies. Resistivity image profiling (RIP) surveys were carried out in tracing the existing of aquifer layer. The major ionic compositions show a wide variation in the hydrochemical properties of groundwater of the area. The degree correspondences among cations and anions have been estimated in order to evaluate their mutual relationship. The important hydrogeophysical parameters have been estimated for reasonable assessment of groundwater quality for irrigation purposes. Piper Diagrams have been plotted to classify the hydrofacies and Wilcox plot as well to quickly determine the viability of water for irrigation used. Interpretations of environmental isotope (18O and 2H) are applied to groundwater studies in the study area. The isotopic composition of 18O and 2H of groundwater and surface water have small variations and plot close to the global meteoric water line as well as local meteoric water line.
Experimental Research on Integral Large Span Prestressed Concrete Roof
Authors: Zhao Ke Chao , Xie Lei
Published: May 2011

In this paper, a new type of large span prestressed concrete integral roof was studied. The test uses full scale specimens, the roof’s span is 24 meters, the width is 2 meters, across the tallest is 3.6 meters. The different condition of roof structure properties is examined. Through experiment obtaines the deformation and the ultimate bearing capacity of the roof, the design is proved to be correct. Test results show that the roof system with one piece casting has enough bearing capacity and rigidity. Roof destruction presents brittleness nature, destroying position is in lower chord board near the end of place. This research conclusion provides a reference data for this type of roof of popularization and application.
Calculation of Consolidation Coefficient and Percent Consolidation from Measured Pore Water Pressure of Soft Clay
Authors: Zhang Yong Mou , Zhao Jian Chang
Published: May 2011

Consolidation coefficient and percent consolidation of soft clay were calculated according to the measured pore water pressure of a project in Pudong Shanghai. Calculated coefficient of consolidation was one magnitude larger than the experimental one. This was in conformity with the actual consolidation process of dynamically-consolidated soft soil.
The Analysis of Impacting Urban Expressway Operating Speed Factors
Authors: Jiang Zhang Ming , Wang Hong
Published: May 2011

With many large cities accelerating the pace of urban expressway construction, at the same time it has to be thought-provoking which factors is related with the urban expressway operating speed? In this paper, the difference is based on the use of certain urban expressway speed of the computational model and measured to compare the average operating speed of analysis. Then analyzed and listed that may affect urban freeway speed factors, for the future of urban freeway speed computing model to provide some ideas.
Simulations on Expansive Strain of Concrete Caused by Ettringite Growth under Sulfate Attack
Authors: Zuo Xiao Bao , Sun Wei
Published: May 2011

In order to assess theoretically the expansive strain of concrete caused by the ettringite formation and growth under the sulfate attack, some models are proposed to investigate the strain responses of concrete exposed to the sulfate solutions. Firstly, an 1-D nonlinear and nonsteady diffusion-reaction equation of sulfate ion in concrete is proposed; Secondly, based on chemical reactions between sulfate and aluminates in concrete, the expansive strain is obtained due to the ettringite growth resulting in concrete expansion. Thirdly, numerical simulations are carried out to analyze the formation process of the concrete expansive strain under the sulfate solution, and results show that the models can be used to predict the concrete responses with the diffusion time, such as the distribution concentration of sulfate ion, dissipated concentration of the calcium aluminates, expansion strain of concrete due to the formation and growth of ettringite.
Observation and Numerical Simulation on Post-Construction Settlement of Dynamically Consolidated Foundation
Authors: Zhang Yong Mou , Zhao Jian Chang
Published: May 2011

The consolidation coefficient, permeability coefficient and other parameters were calculated out based on field measurement data of pore water pressure in this paper. The post-construction settlement behaviour of dynamically consolidated foundation was also simulated. The simulation results were consistent with the actual observation results. The method of this paper provides an effective way for the prediction of post-construction settlement of dynamically consolidated foundation.
Constitutive Model of Strain Softening for Soft Rock
Authors: Li Song , Liao Hong Jian , Li Hang Zhou
Published: May 2011

This paper aims to study the strain softening behavior of soft rock. A modified equation of unified strength theory is proposed that is convenient to be applied in geotechnical engineering where compression is customarily taken as positive. And also the limit line on deviatoric plane of this modified equation is derived and introduced into the three dimensional (3D) elastic viscoplastic constitutive model of Yin and Graham. Parameters of the model are determined from experiments of the diatom soft rock specimens. Numerical simulations are performed to compare the strain softening behavior predicted in this paper and triaxial experimental results. Simulation results show that the proposed model can accurately describe the strain softening of soft rock.
Numerical Simulation of Stability to Muzhuping Slope Failed by Impoundment in Shuibuya Reservoir
Authors: Zhou Jian Jun , Zheng Tian Ya , Gong Zhi Peng , Fu Zhan Ling
Published: May 2011

The Shuibuya Dam is the highest concrete faced rockfill dam (the height is 233m) in the world. The dam site is located in Enshi Autonomous Prefecture, Hubei province, china. The reservoir level is a maximum of 400m. When the dam was partially completed, water impoundment was started. On May 10, 2007, when the reservoir level achieved at 289m, a landslide located on the bank of Modao-he River moved rapidly, a tributary of the Qingjiang River. 14 houses collapsed and moved into the river, but nobody was killed due to timely geological prediction. For the purposes of landslide disaster mitigation in the reservoir areas and identification of landslide movement and deformation caused by the change of reservoir level, some researches were conducted, such as geological exploration, some soil tests and numerical simulation and monitoring system. In this paper, the causes of landslides and slope failure mechanism and the stability of slope were simulated by using DDA method and FLAC3D for the different reservoir’s level.
Durability Based Indexes of Coarse Aggregate for Cement Concrete
Authors: Zhao Shang Chuan , Xia Jing Liang
Published: May 2011

Indexes of coarse aggregate, such as powder content, sediment percentage, maximum particle size, gradation and coarse aggregate volume ratio, are experimented and analyzed for impermeability, cracking resistance and freezing and thawing. Recommendation value based concrete durability is provided. (1) Coarse aggregate should be washed to keep surface clean during producing. (2) Clay content should not exceed 1%. (3) Coarse aggregate maximum size should not be greater than 26.5mm. 19mm and 26.5mm is the beat generally. (4) Smaller equivalent size should be used within the same gradation. (5) Coarse aggregate volume ratio is not more than 0.75 in improving anti-cracking performance for earlier concrete and in 0.70 to 0.75 in increasing impermeability of concrete.
Study of the General Form of 3D Limit Equilibrium
Authors: Zhang Chang Liang , Lei Xiao Feng , Li Tong Lu , Li Ping
Published: May 2011

On the base of the equilibrium of the whole force equilibrium, the whole moment equilibrium of the slope, and the force equilibrium of the differential column, this paper provides a general form of the 3D limit equilibrium which includes three equations. Through these equations and each assumption of the classical methods, their analytic forms can be gotten. Thus, not only the computation quantities of the classical method can be decreased greatly, but also the programming of them become very easy, and the computation efficiency also can be developed. At last, through the example in Zhang Xing’s paper and the analytic forms of the classical methods, this paper analyzes the effect of the sliding body width, the shearing strength parameters and the shearing force direction on the safety factor.
Study on Time-Variant Robustness Assessment Method of Complex Bridges
Authors: Zhu Jin Song , Song Jian
Published: May 2011

In order to accurately assess the robustness of the complex bridge structure, a method of robustness assessment that takes structure degradation and accidental loads into consideration is proposed. Firstly, the degradation rates of member section properties and the increasing rate of live load are set as variables. The parametrical model of structure is established by the finite element software of ANSYS. Secondly, the structure robustness is based upon analysis from the robustness index, the reserve strength factor and the residual strength factor. The effects of three degradation rates of section properties, the established increasing rate of live loads and accidental loads on the robustness of bridges are considered. Finally, this method is used to analyze the time-variant robustness of Guotai Bridge located on the Haihe River of Tianjin. The results indicate that different degradation rates of member section properties have different effect on the robustness of Guotai Bridge, the effect of accidental loads has a close relationship with its acting position.
Seismic Performance Analysis of a Continuous Girder Bridge with Precast Segmental Pier
Authors: Ge Ji Ping
Published: May 2011

Based on available research results of precast segmental bridge pier, seismic performance of a continuous girder bridge with precast segmental bridge columns using match-cast dry joints was analyzed with the lumped plastic hinge method verified by experiment, the similarities and differences of seismic performance between the continuous girder bridge with precast segmental bridge columns and that of cast-in-placement reinforced concrete bridge columns were gained. Results show that the maximum displacement response of the continuous girder bridge with precast segmental bridge columns is bigger than that of the continuous girder bridge with cast-in-place reinforced concrete bridge columns. While for the residual displacement, the opposite is true. The reason is that the restoring force exists in the precast segmental bridge pier by the prestress strands. The concentrated plastic hinge method for cast-in-place reinforced concrete bridges could be used to bridges with precast segmental bridge columns.
A New Approach of Steel Frames-Reinforced Concrete Shear Wall Hybrid Structure Considered Semirigid Connection
Authors: Liu Jian , Huang Xiang Yun , Zhou Guan Gen , Wu Zhao Hui , Wang Qi Bei , Zhang Hong Yan
Published: May 2011

A new approach, which is suitable for analyzing steel frames-reinforced concrete shear wall hybrid structure considered the semirigid connection for beam and column in horizontal load, is presented. The new simplified method considered the semirigid connection for beam and column in hybrid structure is established. The inter-story drift stiffness of steel frames considered the semirigid connection of beam-column in hybrid structure is derived.The traditional continuum method used in RC frames-shear wall structure is expand to steel frames-reinforced concrete shear wall hybrid structure in the paper.The numerical examples of considered the semirigid connection for beam and column in hybrid structure are analysed. The analysis results show that the proposed method is suitable for adoption in practice.
Research on Factors of Flutter Critical Velocity in Suspension Bridge Stiffened with Steel Truss
Authors: Bi Ji Hong , Shu Chun Sheng
Published: May 2011

Take the Liujiaxia bridge as engineering background. Based on classical flutter theory, It focus on research critical factors which affect the critical velocity about the ultra-narrow steel truss stiffening girder suspension bridge in order to provide theoretical basis to the problem of low flutter stability of Liujiaxia bridge. The results show that critical velocity will decrease with increase about the vertical bending frequency and will increase with the torsion frequency and torsion-bend-frequency ratio. But the critical velocity will keep stabilize when torsion-bend-frequency ratio exceeds than 1.2. Though Changing sag-span ratio, width and height of beam can improve the critical velocity, it maybe increase cost of bridge remarkably when width and height of beam reach to some level. It is uneconomic if only adopting structural measures by means of optimization of design parameters, as a result, aerodynamic measures is more important.
Full-Scale Model Test and Numerical Modelling for Behaviour of Saddle Segment of a Extradosed Bridge
Authors: Liu Chao , Xu Dong , Sun Yuan
Published: May 2011

Najin Bridge, located in Lasa of China, is an extradosed bridge with three towers and with the (70+117+117+70)m spans. The turning radius of all saddle in the main tower of this bridge is 2.5 m. Now minimum radius of the saddle at extradosed bridges in China is 2.8m. For the security and reliability of the bridge, we researched and analyzed the stress of saddle segment by the ANSYS software accurately, and carried on the full-scale model test. Some suggestions are proposed for this bridge.
Study on System Reliability Updating through Inspection Information for Existing Cable-Stayed Bridges
Authors: Zhu Jin Song , Wu Jian Hui
Published: May 2011

In order to accurately evaluate the reliability of the existing cable-stayed bridge, a method based on inspection information is proposed to update the system reliability. Using Bayesian method and inspection information, the modified model of cable-stayed bridge random variables is established, and then the failure probability of cable-stayed bridge components is updated. Theβ-Tcurves of changing rules of inspection information on system reliability index and service life are obtained. The method has been applied to a cable-stayed bridge, the results show that the proposed method is effective to update the system reliability and can predict the residual life of the existing cable-stayed bridges.
Research of Polyocarboxy Acid Water-Reducer with Modified Ployether and its Effect on Concrete’s Workability
Authors: Pang Lu Feng , Zhou Xin Xin
Published: May 2011

In this paper, polycarboxylic type high performance water reducers have been synthesized through using TPEG modified monomer. If synthetic temperature and addition time of copolymer monomers can be controlled, the performance of polycarboxylic superplasticizer will be improved. Testing results indicates that when temperature is at 60~65°C, addition time of copolymer monomers is three hours, the performance of superplasticizer is best. Through High Performance Liquid Chroma- tography (HPLC) testing, we can find it is almost the same with the famous brand abroad of the same type. The ues of polycarboxylic type high performance water reducers cooperated with naphthalene series high range water reducing agents thereby markedly improv the workability of concrete mixture.
Study on Pressure-Bending Stress Transfer in the Joint of the Steel-Concrete Composite Arch Bridge
Authors: Yao Guo Wen , Zhou Liang , Zhou Zhi Xiang , Li Shi Ya
Published: May 2011

Effective combination and carry-loading together between steel and concrete play important roles for the steel-concrete composite structure. The steel-concrete composite joint decides the constructing safety and life-cycle performance as the key member for the steel-concrete composite arch bridge. The stress distribution in the steel-concrete composite joint was studied by model test under pressure-bending load. And the stress transfer was probed in the steel box, composite joint and reinforced concrete box. The result shows that the steel and reinforced concrete boxes are under elastic compression in the steel-concrete composite joint. The bearing plate can effectively reduce the stress in concrete and steel boxes. This plate and stiffener can smoothly transfer and scatter the stress from steel box to concrete box. The failure mode is concrete cracking near the interface between steel box and concrete box under large eccentric compression.
A Simple and Practicable Approach on Implementing for the Reduced Triaxial Extension by the Conventional Triaxial Apparatus
Authors: Li Rong Jian , Li Xi An , Che Gao Feng , Zheng Wen , Chen Wen Jun
Published: May 2011

Stress path is one of the very important factors of soil strength. It is significant to study the strength and reveal the importance of the impact of sand in different stress path conditions. Firstly, an ameliorating approach on implementing for the reduced triaxial extension by the conventional triaxial apparatus was discussed. Then, In order to study shear behaviors of the eolian sand under different stress path, two monotonic shearing tests with the conventional triaxial compression and the reduced triaxial extension stress path were performed and analyzed. The test results not only indicate that the amelioration on conventional triaxial apparatus is simple, practicable and inexpensive, but also reveal the difference of strength’s parameter between the reduced triaxial extension and conventional triaxial compression stress path. In sum, the stress path has important effect on the strength of the eolian sand.
Mechanical Characteristics of Ningbo Marine Deposit Soft Clay under Different Stress Paths
Authors: Bin Chen , Ye Jun Neng , Liu Gan Bin
Published: May 2011

Based on a series of consolidated-undrained stress path tests, the mechanical characteristics of Ningbo marine deposit soft clay under K0 consolidation condition are systematically studied for different consolidation pressure, i.e.,60, 120 and 200kPa, in the GDS stress path triaxial system. Three kinds of stress path, i.e., DE (increase p), DG(constant p) and DF(reduce p), are carried out, and the characteristics of stress-axial strain relation, stress path and strength under different stress paths are compared. The test results show that the effective stress paths under consolidated-undrained shear are mainly related to initial consolidation, and the controlled shear mode has evident effect on the effective stress paths. In addition, the stress path has a certain influence on both the total stress and the effect stress strength.
Simplified Calculation Model of Eco-Composite Wall Structure Based on Composite
Authors: Tian Ying Xia , Huang Wei , Zhao Dong , Zhang Cheng Hua
Published: May 2011

The eco-composite wall structure is a new structural system, characterized by ecology, low weight, high strength, saving energy and good aseismic performance. As the main load-bearing member of the structure, Multi-ribbed composite wall consists of concealed frame, concrete frame grids, ecological filling blocks and so on, which makes the entities calculation model extremely complicated. Therefore, it is necessary to present the simplified calculation model of the structure. Based on constitution and mechanical analysis of the multi-ribbed composite wall, the wall is equaled to an elastic plate with the filling blocks as matrix and concrete grids as reinforced fibers in elastic stage, consequentially rigid frame-composite elastic plate of eco-composite wall structure is proposed, and the model is employed to perform the time-history analysis. Experimental analysis shows that rigid frame-composite elastic plate model can meet the usage of engineering in elastic stage, and it provides a more simplified calculation method.
Field Survey of Mw8.8 Feb. 27, 2010 Chile Earthquake and Tsunami
Authors: Wen Rui Zhi , Sun Bai Tao , Zhou Bao Feng
Published: May 2011

In this paper, it is a brief summary for the field survey on the 27 February, 2010 Malue mega-earthquake, Chile by a Chinese scientist team. This mission is to investigate the reason why such a great earthquake caused less causalities, less loss compared with Chinese Wenchuan and Yushu earthquake. This survey was sponsored by China Earthquake Administration and this paper focused on the strong motion data analysis, some building damage observation and tsunami. We gave a preliminary analysis for the strong motions characteristic and some typical building damage. The understanding of this great earthquake could be improved our knowledge for advancing societal resilience.
Research Protecting Methods to Perilous Rock Landscape: Taking an Example of Protecting Elephant Trunk Hill in Dragon Tiger Mountain, China
Authors: Jiang Fu Wei , Guo Fu Sheng
Published: May 2011

In the mountain scenic area, we can enjoy the perilous rock landscape in nice style actually with the vivid, infectious, unique, aesthetic appreciation of the value. These vivid perilous rock landscapes not only represent a natural beauty, but also offer a good place to go for the psyche. But the increasing number of tourists aggravates the destruction of perilous rock landscape nowadays, which also harms the tourists and the non-renewable geological heritage. So it is necessary to study the methods to protect perilous rock landscape. However, the current prevention technique about the unstable rock is hard to satisfy the protective requirement of non-destruction and aesthetic on perilous rock landscape, such as the protection of Elephant Trunk Hill. The Elephant Trunk Hill is located in the world geopark of Dragon Tiger Mountain, Jiangxi province, which is a typical natural beauty of Danxia landform, in where are 99 peaks, 24 cliffs, 108 natural and cultural scenic spots. It was formed by the purple-red sandy conglomerate and its angle is almost horizontal. There are two fissures developing in the root of nose and are still expanding. By long-term effect of synergism of endogenic and exogenic geological process, Elephant Trunk Hill take shape a characteristic spot belonging to the grade one landscape, which is a non-renewable nature resource. According to the field engineering geological conditions and the satisfaction of protective principles on perilous rock landscape, the paper proposes a hang-pull method that made by the rope, cable, etc. to provide some upward pull to make the unstable rock suffice the required coefficient of stability, which can protect Elephant Trunk Hill. From the treatment effect, the theoretical calculation of method is easier and the construction is more convenient, so it can be widely applying in unstable rock’s protection in all kinds of construction.
Vibration Control of Serially Connected Isolation System Using Piezoelectric Actuator
Authors: Liu Yan Hui , Tan Ping , Zhou Fu Lin , Du Yong Feng , Yan Wei Ming
Published: May 2011

This paper presents a bidirectional piezoelectric actuator, which can be used to vibration control of serially connected isolation System. Firstly, the performance test of this control device was processed. Then vibration control experiment of serially connected isolation system with this control device based on sweep sine shaking table was carried out. The experimental results show that this control device has stable mechanical properties, produces semi-active control force fast and has the outstanding control efficiency for serially connected isolation system. In addition, this control still has the satisfactory control efficiency when the piezoelectric actuator of this control is failed, which indicates the fail-safe function of this control.
The Influence Coefficient Method and its Linear Increment Calculation Research of the Creep Effect for an Un-Cracked Concrete Beams Reinforced with FRP
Authors: Zheng Guo Dong
Published: May 2011

On the basis of the time-adjusted effective modulus method (AEMM method) and the steel influence coefficients, the combined influence coefficients of the concrete beams strengthened with FRP is proposed. It will have a higher numerical accuracy if the initial stress is substituted with the average stress of concrete and the stress is assumed to remain linear with time during the period in the step by step calculation process. The linear incremental calculation method based on the idea of the creep combined influence coefficient method of concrete beams reinforced with FRP is proposed, which provides a theoretical basis for the creep calculation and long-term stress prediction for an un-cracked concrete beams reinforced with FRP.