bluuebunny/crossref_metadata_2025 huggingface dataset:
Finite Element Analysis on the Bottom Slab of Box Beam in Zhaohua Beijiang Bridge under Radial Force
Authors: Xu Shi Jun , Zheng Guo Dong
Published: September 2011

Based on summarizing the purpose and main working conditions of horizontal analysis of the box beam in bridges, combined with the force status of the chambers under the radial force of the bottom slab in Zhaohua Beijiang Bridge, the stress distribution in the cross-section under the pre-stressed radial force of the bottom slab at the center of a span of 210m and 85m respectively is analyzed with finite element method. The horizontal and vertical stress distribution and chambers displacement under the radial force are respectively researched. The results show that appropriate size should be used in the angle between both sides and the end of a box beam with a large span; the box beam lower, the girder webs bending stress generated by the radial force greater; the bending stress of the webs weakens their own principal stress state. These conclusions have certain significances for the study of the box girder stress, deformation and crack control.
Influence of Pile-Soil-Structure Interaction on the Dynamic Characteristics of Cable-Stayed Bridge
Authors: Chen De Liang , Liu Feng , Wang Wen Ting , Chen Chang Ping
Published: September 2011

The dynamic characteristics of cable-stayed bridge will be affected greatly by soil action. In the paper, a spatial dynamic analysis model of a cable-stayed bridge was built by using the general finite element software ANSYS. The dynamic characteristics of the frequencies and modal shapes are investigated and compared with considering the pile-soil-structure interaction or not. From the analysis, the results indicate that if the pile-soil-structure interaction is taken into account, there will have a significant effect on the dynamic behaviors of bridge.
Safety Control Research of Steel U Girder of Composite Bridge with Incremental Launching Construction
Authors: Wang Jin Feng , Lin Jian Ping , Fu Yi , Jiang Yong , Li Jian Zeng , Zhang Zhi Cheng
Published: September 2011

With both the high efficiency and economic advantages, the incremental launching has been widely used in bridge construction. As the steel U girder of the composite bridge has not formed the designed section during the launching construction, it has small stiffness relatively and poor torsion resistance ability. The structure mechanical behaviors are complex. Bridge structure collapsed during the incremental launching construction had been reported. Real-time strain monitoring of the adverse sections of the structure during the launching has important significance. By taking the Hangzhou Jiubao Bridge as background, this article introduced the real-time strain monitoring of the steel U girder and analyzed the monitoring results. Effective mastery of the safe state of the structure during launching construction was achieved. It had ensured the launching construction finished successfully. The research results can provide a reference for the design and construction of other similar engineering.
Effect of Soil Conditions on the Strength of Cemented Soil with Deep Bidirectional Mixing
Authors: Luo Da Sheng , Xiao Chao , Zhang Ke Neng , Chen Xing Guang
Published: September 2011

Soil condition is a major impact factor on the strength of cemented soil. In order to study the relationship between the soil conditions and the strength of cemented soil in deep mixing column under the circumstance of thick soft clay in the Nansha area, the uniaxial and unconfined compressive strength tests were carried out, from which stress-strain curves of the cemented soil and strength-depth curves of column body were obtained under three different soil conditions. Analyzing these curves, conclusions can be made that the strength of different parts of cement soil from deep mixing pile varies greatly in the Nansha area. Among the samples, the cement mixed with silty clay has the highest strength, while the lowest one is the cement mixed with mud. Besides the above results, compressive strength values(fcu)of cement soil is determined, which can be of great significance to calculate the bearing capacity of deep mixing piles.
Strength Test of Parallel Carbon Fiber Bundle for Prestressed Bridge
Authors: Xia Shan Shan , Jin Wen Cheng , Huang Wen , Yang Hong Yin
Published: September 2011

Because of good mechanical properties of the fiber composites, the fiber bundles without the resin curing process and with the features of high modulus, high strength and good performance of creasing resistance etc, can be used in prestressed structures. According to the strength properties of the fiber, the tensile characteristic function of the fiber bundles is derived. The tensile test is designed and the parameters of the weibull distribution are estimated based on the result of the test. The ultimate strength of fiber is inversely proportional to the length of fiber. The calculating strength should be reduced in design, because the discreteness of the strength of the fiber bundle in test is much larger than the calculated values.
The Fatigue Research of Straight Thread Sleeve Connection for Beijing South Railway Station
Authors: Chen Yue Ping , Wang Yuan Qing , Zhao Xin Yue , Shi Yong Jiu , Zhou Hui , Li Yun Sheng
Published: September 2011

As for Beijing South Railway Station, railway track just lies on the roof slab of the basement, in railroad bridge or the railroad station orbit layer structure, the reinforcing bar designs general is used thick diameter reinforcing bar.However weld can’t assure the quality, and the reinforcing bar is dense, it is hard to site operation;But the mechanical connection has many advantages, such as have high quality, convenient construction,high productivity ,so now more and more project will choose it.Railroad station orbit layer has a total of 500 000 steel bar joints inside and directly bears the live load of moving trains,which need to do a fatigue search for assuring its satisfy use and specification request.Finally,through the test and application,the result is very good, gives reference for other construction projects of machinery connectivity on the live load.
Study on Wall Rock Pressure Equations of Deep-Buried and Large-Span Tunnel
Authors: Wang Bo , Jiang Mei Rong , Zhou Jian Nan , Jin Feng Nian
Published: September 2011

Theory equations and specification equations are currently main methods to calculate wall rock pressure. These equations are created in certain backgrounds, and are applicable in certain ranges, not fit for deep-buried or large span tunnels. Analysis methods combined with actual project are used, and measured data are contrasted with the theoretical results. Common used calculation equations are discussed from the aspects including calculation accuracy, the relationship with buried depth and the relationship with span of underground structure. Revised calculating equation for wall rock pressure of deep-buried and large-span tunnel are put forward, and is proved to be better on the aspects above. It has significance in theory and practice.
Reinforced Concrete Members Strengthened with Subsequently Bonded Steel Sheets
Authors: Li Zong Ming , Wang San Zhi , Yan Xiao Xin
Published: September 2011

The Paper reviews the mechanism and structure performance of reinforced concrete members strengthened with bonded steel sheets. It enriches the concept of restrained area of bonded steel sheets and method of design of these kind of members based on enormous experiences.
Reliability Analysis of Composite Space Truss Based on Integral Loading Ultimate State
Authors: Liu Feng , Zhang Mei Fang
Published: September 2011

The paper makes a reliability analysis of composite space truss based on integral loading ultimate state. Double nonlinear numerical model is established based on finite element software ANSYS to track the ultimate loading capacity of the structure and confirm the failure mode of the structure; by the deep research and discussion for the composite space truss based on integral loading ultimate state, the scope of structural reliability index and sensitivity degree of various parameters to the reliability are obtained and the measures for improving reliability are proposed.
Study on the Transverse Load Distribution Coefficient of Different Spans of Reinforced Concrete Rigid Fame Arch Bridge
Authors: Li Chong , Niu Yu Ting , Li Song Hui
Published: September 2011

To study the effect of transverse stiffness on the mechanical behavior of reinforced concrete rigid-frame arch bridge, an integral model was set up by using the spatial finite element analysis software, four different spans rigid frame arch bridges were analyzed and the influence of transverse load distribution coefficients on different deck stiffness was studied. Compared with the results of deflection method, it shows that the transverse load distribution coefficient calculated by elastically supported continuous beam method is smaller; also, the transverse stiffness is directly related to the magnitude of transverse load distribution of the bridge and a serious difference of the forces calculated with traditional design theory, which should be modified in the design.
Quasi-Static Test Study on Concrete Sandwich Panel Structure Model
Authors: Li Yan Bo , Ren Cui Cui
Published: September 2011

In order to study the seismic performance of the concrete sandwich panel structure,design a 1:2.8 scale model, an experiment was conducted, in which the low cyclic reversed load was applied to the model . The results such as the failure forms, hysteresis curve, stiffness degradation and ductility are analyzed. The test results indicate that the mechanical properties of the structure model is similar with shear wall; the failure pattern is the destruction of the weak parts;a good seismic and energy dissipation behavior. Finally, set up a finite element model, do the preliminary analysis.The result reveals that it is coincide with the expermiental study in terms of capacity,so the finite element method can be used stimulate structure to analyzed and calculated.
Damage Detection and Quantification of Circular Arch Structures Based on Strain Mode Data
Authors: Nie Zhen Hua , Zhao Jun , Ma Hong Wei
Published: September 2011

Intensive research efforts have been spent on vibration-based structural condition monitoring since structural vibration parameters are closely related to structural stiffness which can be used to identify, locate and quantify structural damage. This makes the vibration-based methods quite attractive for structural condition monitoring. This paper proposes to use strain mode for structural damage identification. A new index named Breach Threshold Value of Damage Levels (BTVDL) is proposed to quantify damage. To demonstrate the proposed method, responses of a circular arch with single and multiple damages are simulated using commercial software ANSYS. The simulated dynamic responses are used to identify the location and degree of the damage of the arch. The results demonstrate that strain mode is more sensitive to damages than others indexes such as frequencies and curvature modes. To further verify the method, a scaled arch model was fabricated and tested in the laboratory. Experimental results also confirm the high sensitivity and accuracy of using strain mode in structural damage identification. It is found that the simulated damages can be reliably identified by using the first two strain modes. The proposed method is more sensitive to damages and can be applied to monitoring structural conditions.
The Triple-Shear Unified Yield Criterion and its Applications
Authors: Hu Xiao Rong , Fan Xiao Mei
Published: September 2011

By taking account of the functions of shear stress couples acting on the dodecahedron element, a triple-shear unified yield criterion for materials is proposed to interpret a series of criteria, especially the commonly used criteria such as the Tresca’s yield criterion, the Von Mises’s yield criterion and the Mohr-Coulomb’s failure criterion through changing its contributive coefficient of the intermediate principal shear stress couples b and the tensile to compressive yield limit ratio α . In spite of that, problems of the limit inner pressures for thin and thick-wall cylinders are analyzed and the new unified solutions are deduced under the hypothesis of the perfectly elasto-plastic materials. The classical solutions based on the Tresca’s yied criterion, the Von Mises’s yield criterion and the Mohr-Coulomb’s failure yield criterion are only the special cases of the new unified solutions. Detailed analyses show that both the contributive coefficient of the intermediate principal shear stress couples b and the tensile to compressive yield limit ratio α have influences on the limit inner pressures for thin and thick-wall cylinders
Study on Shear Bearing Capacity of Composite Reinforced Concrete Block Masnory
Authors: Zhu Ying Jie , Li Lan , Yang Wen Hui
Published: September 2011

constructional column- core column ; Combination of reinforcement concrete block wall; Hysteresis curve; Ductility; Height-width ratio Abstract: The two groups of constructional column- core column composite of reinforced concrete block masonry wall under low cyclic test is made, considering the different height-width ratio, open hole and don't open hole, the setting of the horizontal reinforcing steel bar and reinforced such as the effect not set level parameters on the wall the failure process and failure pattern, hysteresis characteristics, bearing capacity, ductility, skeleton curves, the viscous damping coefficient, stiffness and steel strain change the properties including the influence law. Test results show that this wall system has better seismic performance.
The Study on a New Loads Calculation Method of Multi-Arch and Extra Large Cross Section Tunnels
Authors: Xu Chong Bang , Xia Cai Chu , Wang Hua Lao
Published: September 2011

Increasing numbers of tunnels adopt super large sections due to the advance of design and construction technology, but the calculation method for the loose loads of such tunnels still follows the traditional method for tunnels constructed by the method of whole face excavation. The calculated loads using such method are always lager than their actual values of super large sections tunnels, and as a result the supports for such tunnels are too conservative which lead to unnecessary construction cost. As said, a new calculation method for the loose loads of multi-arch and extra large cross section tunnels (MELCST) is proposed in this paper considering the characteristics of construction for such tunnels. The method accounts for the influences caused by the multi-step construction procedure and temporary support on tunnels. Compared with old methods, this method is more practical and close to field situation, which provides a new idea for calculating surrounding rock loose loads in MELCST. This new method is demonstrated using Luohanshan tunnel of airport-highway in Fuzhou city, China.
The Method of the R Part Calculation in Dry Scarf Connection of FPC Frame
Authors: Huang Xiang Hai , Zhu Xiao Jun , Liang Shu Ting , Jiang Shi Lin
Published: September 2011

Different failure mechanism of dry scarf connection is decomposed into its end of the beam as a whole destruction of inclined cracks, R part of partial compression damage, destruction of inclined cracks, vertical shear damage and concave corner of the tensile damage in five forms, and describes the destruction of time corresponding to the six kinds of fracture morphology. This paper gives the R part constructed and reinforced concrete way. R part of the connection non-linear finite element analysis of level-load, compared to the relevant test results, verify the theoretical calculation method proposed in this paper. The proposed method of calculation for the corresponding FPC frame of dry scarf connection, designed to connect R to provide a useful reference.
The Research of Reliability of Axial Forced Components from Steel Structural Design Codes between China and Foreign
Authors: Luo Wen Hai , Nie Zhi Hua
Published: September 2011

Aiming at the actuality which exist in construction parts that the setting-level of the safety of steel structural design codes between China and America is different in present, this paper use the reliability theory to compares the reliability of axial forced components from Chinese (Code for Design of Steel Structure)GB50017-2003 and American (Loads and Resistance Factor Design Specification for Structural Steel Buildings)LRFD-2001.From the result of comparing, some conclusions about the setting-level of the reliability of axial forced components from steel structural design codes between China and American are obtained, which can provide reference to the constructions.
Structural Damage Localization Based on AR Model and BP Neural Network
Authors: Diao Yan Song , Yu Fei , Meng Dong Mei
Published: September 2011

When the AR model is used to identify the structural damage, one problem is often met, that is the method can only make a decision whether the structure is damaged, however, the damage location can not be identified exactly. A structural damage localization method based on AR model in combination with BP neural network is proposed in this paper. The AR time series models are used to describe the acceleration responses. The changes of the first 3-order AR model parameters are extracted and composed as damage characteristic vectors which are put into BP neural network to identify the damage location. The effectiveness of the method is validated by the results of numerical simulation and experiment for a four-layer offshore platform. Only the acceleration responses can be used adequately to localize the structural damage, without the usage of modal parameter and excitation force. Thus the dependence on the modal parameter and excitation can be avoided in this method.
A Novel Chirped Fiber Grating Sensor for Strain Detection
Authors: Yu Hai Ying , Liu Xiao , Liu Tong Yu , Suo Lin , Yu Ling Song
Published: September 2011

In this paper, a novel strain sensor based on chirped fiber grating with temperature compensation is presented. The proposed strain sensor uses double chirped fiber gratings. The temperature compensation exploit the principle that the wavelength shifts of these two chirped fiber gratings induced by temperature is consistent. This strain sensor is demodulated by the light intensity detection with low cost. Furthermore, the strain sensor is simulated in the end of this paper.
Flexible Ergonomic Principle of Construction System
Authors: Yang De Qin , Yan Wei Ping
Published: September 2011

Idea of element co-adaptation of construction ergonomics claims the elements of construction ergonomic system mutual fitness. Flexibility of construction system embodies the element co-adaptation. Flexible ergonomic principle indicates that construction system design and update must make the system to have and keep the function of fit in with and conversion of noise to meet the needs of flexibility of construction system. Principle of factors fit in with system expresses the relations between construction ergonomic system and its factors. The principle claims any one of the factors should co-ordinate the system, and that is the precondition of system flexibility. Principle of factors mutual fitness expresses the relations between the factor and factor of system. It voices that any one of the factors (and fine factors) should adapt to other ones and keep on the adaptation. The paper names the last two principles combined as “fit flexible principle” and proofs it by using system evolutionary equation through defining the conception of adaptable coefficient of factors. Findings of the research have corrected the ergonomic system design idea that based on cybernetics as well as the optimizing idea of construction resource that based on static thinking.
Research on Stress Corrosion of Concrete in Sodium Sulfate Solution
Authors: Liang Yong Ning , Ji Tao , Zhuang Yi Zhou , Lin Xu Jian
Published: September 2011

An investigation was carried out on the behavior of concrete under both sulfate attack and mechanical stress. The specimens of concrete with/without fly ash were subjected to flexural load with a level of 0.2 and 0.4 of their initial strength and also immersed into a 10% sodium sulfate solution or water respectively. The bending strength of the concrete was tested at certain time intervals. The results indicate that fly ash could effectively relieve the deterioration of the concrete in corrosive environment; flexural load could accelerate the corrosion damage and that the development of concrete strength is related to the internal structure, hydration product and the interface between coarse aggregate and cement paste.
Dynamic Elasto-Plastic Analysis on the Steel Spatial Arch Truss with 90 m Span and 0.3 Rise-Span Ratio
Authors: Li Hai Wang , Jiang Lu , Liu Jing
Published: September 2011

In this paper, the elasto-plastic dynamic analysis on the steel spatial arch truss with 90 m span and 0.3 rise-span ratio is carried out under earthquake wave with SAP2000. the geometric and material nonlinear effects are considered during the analysis simultaneously based on the plastic hinge theory. Under the action of EL wave with the peak increasing gradually, its elasto-plastic dynamic responses have been obtained. The results show that its failure mode under the earthquake action is elasto-plastic dynamic buckling; that its critical peak acceleration of EL earthquake wave when applied in horizontal direction is 363 gal, and is 408 gal when applied in vertical direction; The ratio of its maximal node horizontal displacement and its structural height is 1/796, and its displacement ductility coefficient is 1.06 and the ratio of its bars with plastic hinge appearing when buckling is 0.96% when EL-Centro waves applied on structure in horizontal direction; The ratio of its maximal node vertical displacement and its structural span is 1/1418, and its displacement ductility coefficient is1.12 and the ratio of its bars with plastic hinge appearing when buckling is 1.28% when EL-Centro waves applied in vertical direction.
Experiment on the Deformation of the Reinforced Concrete Beam NSM Prestressed Steel Spiral Ribs
Authors: Zhang Chun Sheng , Zhang Mei Xiang , Ding Ya Hong
Published: September 2011

A new reinforcement technology with prestressed helical rib steel wire bonded in sawed grooves in the concrete cover is presented, based on the deficiency of the presented reinforcement methods. Four test beams NSM prestressed steel spiral ribs are tested in this paper. The stiffness expression of the reinforced concrete beams in different stages is derived and the stiffness formulas of the reinforced concrete beams are gained, based on the general deformation principles of reinforced concrete beams and the characteristics of the reinforced concrete beam NSM prestressed steel spiral ribs. The results of the calculation and the experimental results show good agreement. It shows that the reinforced concrete beam NSM prestressed steel spiral ribs can effectively delay the development of cracks, reduce the component deformation and increase its stiffness. The results provide an experimental basis for the reinforcement method in practical engineering applications.
Experimental Research on Properties of Interface between New and Old Concrete
Authors: Wu Wei , Zhang Chao , Chen Rong Jun
Published: September 2011

It has studied the influence of roughness, binder and freeze-thaw cycles on strength, durability and other characteristics of interface between new and old concrete in the progress of airport concrete pavement maintenance by doing tests in the conditions of normal temperature and freeze-thaw cycles.
Experimental Study on Deformability of Fang Ren Glass Cloth in Strengthening Autoclaved Fly Ash Brick Masonry
Authors: He Xiao Yan , Li Na
Published: September 2011

This article studies the deformability of Fang Ren Glass Cloth in strengthening autoclaved fly ash brick masonry, based on the experiment of the mechanical behavior of specimens under single-direction loading. It also analyzes grid sticking method and the effect of U、L trim strips anchoring of specimens. One polymer mortar specimen and three strengthening specimens are used in the experiment. The results illustrates that the cracking load、ultimate load and deformability of strengthened masonry are higher than the un-strengthened one. The study has also shown that anchoring is important; the effect of strengthening is remarkable when anchored well.
A Review on Numerical Simulation of Pile Caps in Large-Scale Structures
Authors: Yang Jian Jiang , Wang Rui , Zhou Bo
Published: September 2011

Cap plays a transitional role in the structure. It is an important part to ensure the effective pass of load between the upper structure and the foundation. In the bridge, water tank, ocean platforms, oil tank and other large-scale structures, the force mechanism and force mode about cap are more and more valued by researchers. The research method about large cap structure mainly includes theoretical research, experimental research, numerical simulation and other aspects. This article summarizes the domestic research status, reviews and compares the caps’ numerical simulation methods and analyzes the advantages and disadvantages of different models. Finally, some problems are proposed for further research, which can provide references for engineering design and study.
Seismic Damage Analysis and Reinforcement Measures Research of a Long-Span Structure
Authors: Deng Yong Jun , Yao Yong , Chen Dai Guo
Published: September 2011

Abstract: Taking a Practical Big Span Stadium Project as the Background, in View of its Particularity that it Suffered Earthquake Damage and Fortification Intensity Increased after Earthquake, through the Field Detection and Finite Element Model to Analyze Earthquake Damage of Structure Caused by Wenchuan Earthquake, and Research the Feasibility of Seismic Strengthening with Hadas on the Structure Whose Fortification Intensity Increased after Earthquake. the Results Show that: 1) the Big Span Structure Severely Damage by the Earthquake, the Second Layer Is Relatively Weak Layer, Prone to Local Damage and Affect Whole Anti-seismic Performance of Structure, 2) Hadas Can Increase the Initial Stiffness and Effectively Reduce the Structure Seismic Response, Has Better Effect on Overall Reinforcement, 3) it Is Reasonable to Improve the Seismic Fortification Intensity of this Region.
Research on Precision Construction Measurement of Curved Surface Steel Structure Project
Authors: Wang Deng Jie , Wang Guang Yue
Published: September 2011

The positioning measurement of spatial curved surface steel structure project is a key link in construction process. How to measure position fast and precisely is an important problem concerned by steel structure project field. Taking actual project as an example, this article studied precision construction measurement technology in curved surface steel structure project, put forward resemble-leveling method elevation measurement, and naturalization lofting method which is based on spatial linear equation. This article has important guiding significance to precise position measurement of curved surface steel structure project and to construction control.
Computational Analysis of Point-Supported Full-Glass Roof Structure
Authors: Sun Ping Ping
Published: September 2011

In order to deepen the understanding to security of point-supported full-glass roof structure, in combination with the case study, this paper calculated and analyzed the static force of glass sheet, glass rib and glass void. The results show that the strength and reflection meet the security requirements. Meanwhile, the paper proposed to further verify its reliability through the combination of static force test.
Research Status and Prospects of Cable Domes
Authors: Xue Su Duo , Gao Zhan Yuan , Li Xiong Yan
Published: September 2011

Advances in the research on cable domes were summarized and reviewed, such as structural improvements and innovation, prestressed mode and optimize designing of cable dome structure, dynamic and wind resistance performance analysis, construction technology, model experiment and sensitivity analysis. Some topics worthy further research were proposed, including seismic property study, improvement and innovation in construction techniques and methods, fire resistance study, stiffness analysis of structures, general design methods and software. This work will provide a meaningful reference for the design and application of cable domes.
Study on the Method for Calculating Shear Strength of RC Beams Strengthened with Externally Prestressed Wire Rope
Authors: Yu Tian Lai , Li Xin Yu , Ma Qiang , Jiang Zhen
Published: September 2011

Through shear test data analysis of 13 RC beams Strengthened with externally prestressed wire rope, shear failure mechanism was elaborated, and shear bearing capacity of reinforced beams were not only calculated respectively by truss -arch model and other simplified calculation methods, but also were compared with test data. Based on the result of comparation, shear capacity calculation method of RC beam Strengthed with externally prestressed wire rope was discussed. The analysis results show that the mechanism of the wire rope shear externally prestressed reinforced concrete beams against the shear is similar with stirrups inside beam. When the shear span ratio is less than 2.7, the static average ratio of the truss-arch model shear capacity caculation value and tested value is 1.02, and standard deviation statistics is 0.07. In another word, calculation value agree with experimental value. When the shear span ratio is larger than 2.7, the calculation value is bigger than test.
Effect of Ceramsite Prewetting Degree on the Internal Relative Humidity of Ceramsite Concrete
Authors: Chen Cai Yi , Ji Tao , Chen Yong Bo , Liang Yong Ning
Published: September 2011

The water absorption and desorption process of different prewetting degree ceramsites embedded in ceramsite concrete was obtained by a U-tube micro pressure measurement device. The internal relative humidities of ceramsite concrete using different prewetting degree ceramsites were monitored by humidity sensors. The study reveals that, with the increase of ceramsite prewetting degree, the internal relative humidity of ceramsite concrete increases because the reservoir function of ceramsite is more obvious.
Research on Post-Tensioned Unbonded Prestressed Concrete Hollowed Floor
Authors: Yang Xiao Hua , Zhou Chao Yang , He Xue Jun , Chen Teng
Published: September 2011

In order to study the mechanical behaviors of post-tensioned unbonded prestressed concrete hollowed floors, a 1/4 scale post-tensioned unbonded prestressed reinforced concrete hollow slab-column structure model is used to act uniform distributed load on the floor. The test results showed that the load carrying capacity is enough. The points of maximum displacement are at the centers of slabs. By means of the experimental studies and elastic finite element analysis methods, the results showed that post-tensioned unbonded prestressed concrete hollowed floor presents anisotropy with layout of circular-tubes in one way. In direction parallel to layout of hollowed tubes, the continuity of floor is destruction and bending stiffness of slab is weakened. For studying the deformations of slab, it can still be considered continuous cross-slab in two directions.
Study on Bottom Stress Distribution of Circular Foundation on Rock Subgrade
Authors: Yin Ke , Yang Sen
Published: September 2011

The bottom interaction stress distribution of circular foundation on rock subgrade is generally nonlinear. Different from in soil, it is more complex and have no common conclusion. But it is important for design of this kind foundation. According to the circular foundation’s axial symmetry, using the homogeneous Lame equation in the circular cylindrical coordinates, and the Boussinesq-Galerkin’s general solution, selecting the Love’s strain function as a trial function, the analytic expressions of the bottom stress distribution of the circular foundation on rock subgrade is obtained by the trial Love’s strain function satisfying the boundary conditions. The results of field model tests and numerical simulation analysis are discussed here. It is provided about the bottom interaction stress distribution of circular foundation that is based on rock subgrade by compared the theoretical analysis with the test and numerical calculation. This study conclusion is valuable for design and practice of this foundation engineering.
Experimental Study on Flexural Strength of Reinforced Concrete Beam Exposed to Acid Deposition in the Laboratory
Authors: Fan Ying Fang , Wang Da Wei , Zhang Shi Yi
Published: September 2011

In this study, the flexural behavior of the reinforced concrete beams attacked by acid rain environment is investigated. The objective is to discover the deterioration mechanism of the concrete beams servicing in the acid rain environment. An artificial rainfall device was designed. Eleven reinforced concrete beams, 120mm×200mm in cross-section were prepared in the laboratory. Three accelerating corrosion methods, which inclusive of immersion method, dry-wet cycle method, and artificial rainfall method, were applied to simulate the action of the real acid rain respectively. The acid solutions with pH level 1.5 and 2.5 were prepared by the mixture of sulfate and nitric acid solution respectively. One of the beams was tested in the natural condition to serve as reference; the remaining ten beams were tested after being exposed to the simulated acid environments for certain periods. Ultrasonic technology was applied to evaluate the damage depth and the compressive strength of the concrete. Dynamic test was applied to estimate the integrity of the beam. Three-point bending tests were performed to investigate the load carrying capacity of the beams. Mechanical properties of concrete and load carrying capacity of the beams exposed to different accelerated corrosion methods are obtained and compared. It is illustrated that the designed artificial device is efficient to simulate the real acid rainfall. It is shown that the strength of concrete, frequency and ultimate load of the beams, have a direct relationship to the damage degree of the beams.
Analysis on Mechanics and Reliability of Drill String during Deep Drilling
Authors: Yang Shang Yu , Yang Xiu Juan , Yan Xiang Zhen
Published: September 2011

The deep drill string is subjected to many kinds of loading under the condition of vibration and precession, such as tension, compression, bending and torsion, while the temperature and press are very high. Under this circumstance, the shallow drill string is more likely to failure. Based on the force analysis of the drill string, the drilling process of the deep drill string is simulated using finite element software. The stress distribution and displacement of the drill string is obtained under the interaction of drilling pressure, torque and temperature. At the same time, the effect of transverse vibration, longitudinal vibration and torsional vibration, on the stress and displacement of the drill string, is compared. The change law of the natural frequency of transverse vibration varying with the length of drill string, rotational speed and the hole size is discussed. Connected with concrete examples, the reliability and sensitivity of some influencing factors such as external diameter, wall thickness, the minimum yield strength, temperature, elastic modulus, Poisson’s ratio, axial loading and torque is obtained. The main factors that influence the reliability of the drill string are the yield strength and torque. The reliability of the drill string increases as the increase of yield strength, and decreases as the increase of the torque.
Fatigue Behavior of Corroded Reinforced Concrete Beams-a Review
Authors: Li Shi Bin , Tang Hong Wei , Wang Xin
Published: September 2011

Reinforced concrete (RC) structures are widely used in civil engineering for their merits. A good-quality concrete provides a highly alkaline environment that forms a passive film on reinforcement surface, preventing steel bars from corroding. Due to chloride attack or concrete carbonization, corrosion of embedded reinforcement in concrete members is common for RC structures. Much importance should be attached to the fatigue of corroded concrete bridges because they bear not only static loads but also alternate loads. Followed along with the aging of bridge structures, the increase of traffic volumes, the augment of vehicle loads as well as the deterioration of service environment, many corroded concrete bridges are urgently needed security appraisal and residual fatigue life forecast. Fatigue of corroded RC beams is a key problem for the existing corrosion-damaged concrete bridges. But the interrelated research was little. Based on the most new study information, the production on fatigue of corroded concrete beams was listed and analyzed, and the problems on fatigue of corroded concrete beams were indicated.
Reliability Analysis of Locally Thinned Submarine Pipelines in ChengDao Oil Field
Authors: Shao Bing , Yan Xiang Zhen , Yang Xiu Juan
Published: September 2011

Local thinning of submarine pipeline always exists due to the complexity and dynamic of marine environment loads. However, the location and extent of thinning areas are random. Mechanical research on the randomness of local thinning of submarine pipelines is significant for pipeline’s stress analysis and failure evaluation. In this paper, finite element model of locally thinned submarine pipeline is established and based on the Monte-Carlo method, the effect of input random variables on the submarine pipeline’s reliability is analyzed. Probability distribution ranges of equivalent stresses are got and further, relationship equation between confidence level and stress limit has been obtained. The result more accurately reveals the relationships of locally thinned pipeline and its elastic modulus with equivalent stress, which can provide foundation for safety analysis of locally thinned submarine pipeline with internal pressure.
The Life Analysis of an Aircraft Main Hydraulic Pump
Authors: Jiang Xiao Ming , Liu Wang Sheng
Published: September 2011

The life of the hydraulic pump is affected by many factors. According to the statistical information of failure of the main hydraulic pump of an aircraft, we apply the reliability engineering theory to calculate and analyze its service life. As known in calculation, the service life of hydraulic pump conforms to Weibull distribution, and there is no the useful life period. The basic reasons resulting in the decline in the service life of the pump are the higher work pressure, the poor work condition and serious hydraulic system pollution. Furthermore, several measures for use and maintenance are given.
Study on Bending Behaviour of Triangular Web Profile Steel Section by Finite Element Analysis
Authors: De’nan Fatimah , Hashim Nor Salwani
Published: September 2011

A triangular web profile (TRIWP) steel section is a built-up section made up of two flanges connected to a web plate of triangular profile. This paper describes the study on the bending performance in major (Ix) and minor (Iy) axes of Triangular Web Profile (TRIWP) compared to flat web (FW) steel sections. A number of finite element models were developed using finite element software LUSAS version 14.3. Thin shell element which is a family of shell element in 3D dimension was chosen to represent the element type of the model. Two sizes of FW as control specimens and two sizes of TRIWP steel section which is 200×100×6×3 mm and 180×75×5×2 mm were used. Each of steel section was modeled using several spans such as 3m, 4m and 4.8m. The finite element results show that the deflections in major axes for TRIWP more than FW steel section. It was noted that, the value of Ix for the TRIWP is 0.754 to 1.523 times the Ix of FW steel section. On the other hand, the deflections in minor axes for TRIWP lower than FW steel section. The value of Iy for the TRIWP is 1.818 to 1.686 times the Iy of FW steel section. It can be concluded that the TRIWP is stiffer compared to FW steel section in minor axes and TRIWP has a higher resistance to bending in minor axes than FW steel section.
Analysis the Cracks and Failure Modes of the External Walls of the LNG Storage Tank
Authors: Cheng Xu Dong , Zhu Xing Ji , Peng Wen Shan
Published: September 2011

Walls of the LNG storage tank are mainly built by the prestressed concrete, but the material of prestressed concrete is complex nonlinear materials. The characterized of concrete is that it can bear very big pressure, but cannot bear the pull. The LNG storage tank is a typical pressure vessel; it has a great significance to research the stress distribution and the cracks of the wall of concrete. In this article, using the ADINA numerical simulation software to establish separate model of reinforced concrete, and research the cracks and the failure modes of the concrete in the normal using state and leakage state by using the stress contour of prestressed steel and ordinary steel and concrete crack map of external wall. Identify the most dangerous place of the storage tanks in several of state. It can provide theoretical basis for domestically independent design and construct LNG storage tank in the future, and then provide domestic reference for crack treatment of LNG storage tank.
Static Analysis of Wind Energy Building under the Action of Equivalent Wind Load
Authors: Guan Xiao Jun , Chen Guo Ping , Yang Ying
Published: September 2011

In the recent years, people begin to concern more about the development of new energy source, because of the global economic development and more stringent environmental requirements. The wind power is rapidly developed for its low price and it’s friendly to environment and the wind energy and building integration also becomes a very important mode to develop new energy sources. The wind driven generator and high-rise building structure were integrated, and ANSYS was used to complete the static analysis of the equivalent dead load action of high-rise building with wind driven generator under six different wind pressure. By comparing the results of the calculations, the feasibility of the wind energy and building integration was initially verified.
Investigation on the Index System for Durability of Concrete Bridges in Codes
Authors: Wang Yu Qian , Cheng Shou Shan , Li Wan Heng , Li Yi
Published: September 2011

This article surveys and studies the design, construction and verification codes related to durability of concrete bridges both home and abroad, contrastively analyzes their requirements on environmental effect, durability design, construction and testing indices, and finally brings up the durability index system suitable for Chinese concrete bridges which covers the four hierarchies of environment, material, components and structure, and also considers the three phases of design, construction and verification.
Investigation of Seismic Properties and Shear Carrying Capacity of Concrete Hollow Block Walls Retrofitted with CFRP Sheets
Authors: Meng Ling Yun
Published: September 2011

Abstract.The seismic properties, failure characteristics and lateral load-deformation curves of the three specimens were investigated by testing two specimens retrofitted with CFRP(carbon fiber reinforced polymer)sheets(fabrics) and one specimen without any attachments and by attaching CFRP sheets to the two specimens in two ways. At the same time , the strain level in CFRP sheets on one of specimens was investigated. It came to the conclusion that CFRP sheets were able to improve the seismic properties of concrete hollow block structures significantly and the patterns in which CFRP sheets were attached to structures were a dominating factor influencing retrofit effects. The equations for the shear carrying capacity were presented by introducing a truss model. The validation of the equations was made by contrast of computed values and observed ones and it can be used as a reference to design retrofitted structures.
Advances on the Influence of Joint Stiffness on Mechanical Behavior of Single-Layer Reticulated Shell
Authors: Wang Ning , Xue Su Duo , Li Xiong Yan
Published: September 2011

The bolt-ball joints and welded hollow spherical joints are used frequently in the reticulated structures. Many researches on the influence of the bolt-ball joints stiffness on dynamic and static mechanical behavior of these structures are carried out by far. This paper reviews these researches, and points out the limitation as well, then the future work of which has been put forward. In addition, the progress made in our work team in this filed is illustrated.
A Study on Flexural Bearing Capacity of RC Beams Combination Strengthened with CFRP by Comparative Experiments
Authors: Chen Xiao Qiang , Jia Bin , Yao Hua Chuan , Zhang Yu
Published: September 2011

This paper compares the flexural bearing capacity, rigidity, and ductility of the reinforced RC beams after comparative tests of reinforcing RC beams by three different ways: directly bonding CFRP, bonding CFRP after replacing concrete and bonding CFRP after replacing concrete and planting bar. The results show that the method of replacing concrete can sufficiently avoid the debonding between CFRP and concrete, improve the flexural bearing capacity, and further strengthen the rigidity and ductility; whereas the method of planting bar can well guarantee the bond of Young and old concretes, let the replacing concrete together with CFRP work better, and carry capacity increase in reinforcement.
Solution of Microseismic Monitoring Non-Linear Location Equations Based Matlab
Authors: Shi Hong , Pang Lai Xue , Shi Rui Ying
Published: September 2011

Microseismic will produce when rock mass break. The occurrence of microseismic monitoring has close relationship to the energy release and crack's evolution in the rock mass. Therefore the microseismic monitoring can be used to predict the future rupture of the rock mass. MS location is the base of this prediction. The method of solving locating equation and the stability of answer are the key matter of microseismic monitoring applications in engineering fields. This paper uses Gauss-Newton iterative method to solve locating equation in order to advancing the precision and stability of answer and reducing the calculation workload. Based on the optimization toolbox of Matlab, the non-linear locating equations are solved and the visible locating results of microseismic are achieved.
Study on Particle Inconsistency Problem in Smoothed Particle Hydrodynamics
Authors: Rong Gui Ming , Kisu Hiroyuki
Published: September 2011

In the smoothed particle hydrodynamics (SPH) method, the particle inconsistency problem significantly influences the calculation accuracy. In the present study, we investigate primarily the influence of the particle inconsistency on the first derivative of field functions and discuss the behavior of several methods of addressing this problem. In addition, we propose a new approach by which to compensate for this problem, especially for functions having a non-zero second derivative, that is less computational demanding, as compared to the finite particle method (FPM). A series of numerical studies have been carried out to verify the performance of the new approach.
A New Torsion Element of Thin-Walled Beams Including Shear Deformation
Authors: Wang Zhao Qiang , Zhao Jin Cheng , Gong Jing Hai
Published: September 2011

Restrained torsion analysis of open thin-walled beam is presented in this paper. A finite element model is developed. The element is based on the first-order torsion theory, which accounts for the warping deformation and shear deformation due to restrained torsion. The interpolation functions of total rotation and twist rate of free warping rotation of cross section are constructed respectively by using the relationship between these two rotations. Numerical example is illustrated to validate the current approach and the results of the current theory are compared with those obtained from classical Vlasov theory and first-order torsion theory.