bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Initial Geometric Imperfections on the Stability of Steel-Concrete Composite Ribbed Shell
Authors: Wang Ling Ling , Chang Yu Zhen
Published: May 2011

The paper proposed a new system of spatial structure: steel- concrete composite ribbed shell, and briefly compared the three analysis methods considering the initial imperfections of structures: the random imperfection mode method, the consistent imperfection mode method and the improved random imperfection mode method. By using of the consistent imperfection mode method and nonlinear finite element analysis software ANSYS, we analyzed a composite steel-concrete ribbed shell with the span of 40m and span ratio f/L=1/4, which is simply supported at its surrounding and is subjected to uniform loading along it’s whole span. The critical load and instability regions of this shell are presented. The results show that with the increasing of the initial imperfections, the value of critical load decreased from 27% to 36%; the trend of load-displacement curve and the location of structural instability regions remain unchanged, only the shape of instability regions will change. This indicted that the effect of the initial imperfections within composite ribbed shell is far less than its influence to the single-layer shell. The steel-concrete composed ribbed shell is not sensitive to the initial geometric imperfections and shows a strong post-buckling performance.
Experimental and Numerical Simulation Study on Compressive Performance of Autoclaved Fly Ash Perforated Brick Masonry Long Columns
Authors: Xu Chun Yi , Liu Ming , Xu Bo
Published: May 2011

To study the influence of slenderness on the compressive bearing capacity of autoclaved fly ash perforated brick masonry long columns and provide experimental evidences for making corresponding technical code, compression tests were conducted on 9 autoclaved fly ash perforated brick masonrys long columns of different slenderness. The damage patterns and compression performance are analyzed. The experimental results indicate that compressive capacity decreases proportionally as slenderness increases and the proposed formula of axial compressive bearing capacity for autoclaved fly ash perforated brick masonry columns is given. The nonlinear FEA program ANSYS is also adopted to simulate the behaviors of masonry columns. By comparing results find that the simulated results agree well with the test ones, the rationality and applicability of the model are verified.
Ultimate Strength Research of the Tube-Plate Connection of K-Shape
Authors: Wang Meng Hong , Xiong Bao Chao , Shi Song Song , Zhang Yu Wei
Published: May 2011

Based on relevant flow rule, Von Mises yield condition and the virtual displacement principle determined by the updated-Lagrange configuration, nonlinear finite-element analysis of the tube-plate connection of K-shape by ANSYS program is studied in this thesis. In order to study the influence of main pipe to the ultimate strength of the tube-plate connection of K-shape, two geometric parameters are considered, D, diameter of the main pipe; T, thickness of the main pipe .Three typical failure modes, gusset yielding, main pipe excessive plastic deformation failure and branch local buckling are also summarized. A comparison was made between formula result and analysis of finite element stimulation to validate the veracity of the existing formula.
Rotational Fourier Spectrum of Wind Turbine Systems: A Physical Model
Authors: He Guang Ling
Published: May 2011

Wind loads encountered by wind turbine systems exhibit obvious randomness. Conventional researches of wind loads mainly target developing power spectrum density models or correlation functions. However, it is extremely difficult to deal with several key problems of stochastic dynamics of wind turbine systems in such a frame due to the absence of physical mechanisms. In this paper, the physical tradition in the study of stochastic dynamics is followed to investigate wind loads of wind turbine systems. Along the physical tradition, the physics-based modeling is primarily put forward. Based on the random function description of stochastic processes, a new concept of random Fourier function is proposed to establish two physical wind spectrum models of wind turbine systems. One of them is the random Fourier spectrum model which determines wind loads on wind turbine towers, the other is the rotational Fourier spectrum model which decides wind loads on rotating blades. As the two physical wind spectrum models can effectively prevent the essential drawbacks of the phenomenological ones, they are suggested to be adopted in the wind-induced dynamic reliability evaluation of wind turbine systems.
Coupling Vibration Analysis of Reinforced Concrete Rectangular Liquid-Storage Structure on Elastic Foundation
Authors: Cheng Xuan Sheng , Wang Jun Ling
Published: May 2011

According to liquid-solid coupling vibration analysis model of reinforced concrete rectangular liquid-storage structure on Winkler elastic foundation, and assuming that liquid is ideal. According to existing literature, for the sake of engineering application, the influence of dimensionless parameters on liquid-solid coupling vibration frequency of rectangular liquid-storage structure is discussed. And so a theory base about the design calculation of rectangular liquid-storage structure is provided for subsequent engineering structure.
Research on Secondary Moment of Prestressed Slab-Column Structure
Authors: Guo Nan , Li Hua , Guo Yi Hong
Published: May 2011

In this paper, beginning with the mechanism of secondary moment, the calculated difference of secondary moment between slab-column structure and skeletal structure is indicated, and the secondary moment distribution of prestressed slab-column structure is provided by finite element analysis. The effect of edge beams setting or not and arrangement types of prestressing tendons on the magnitude and distribution of secondary moment is analyzed, and the magnitude relation between secondary moment and external load moment is compared. It can be served as reference to understand the distribution of secondary moment and design slab-column structure reasonably.
Two-Dimensional Capacity Spectrum Method and Seismic Damage Assessment for RC Structures
Authors: He Hao Xiang , Li Hong Nan
Published: May 2011

The force-deformation curve of a reinforced concrete structure in push-over analysis is used to compute the corresponding damage index. A simplified and practical method is established for seismic damage assessment in combination with capacity spectrum method. The two-dimensional capacity spectrum method and the combination of the damage in two directions are discussed. A numerical example using single and double horizontal capacity method and time history analysis demonstrate that the response and damage of structure can be computed accurately in the two-dimensional capacity method. The common trend of structural torsional response can also be reflected. The results show the two-dimensional capacity method is valid and simple.
Accurate Wind-Induced Response Analysis of Long-Span Structure Based on Quick Modal Response Estimate for Mode Selection
Authors: Zhang Li Gang , Lou Wen Juan , Huang Ming Feng
Published: May 2011

By the combination of POD method and mode superposition method, the eigenvector similarity factor is introduced on the representation of the similarity between the load spacial distribution and the structural mode. Meanwhile, the eigenvalue got from the wind pressure field decomposition indicates the relative ratio of the energy associated with the corresponding load spacial distribution to the total of the wind load energy. It is proved that the eigenvector similarity factor and the eigenvalues are two of most important factors when measuring the relative significance of each modal response. So the quick estimates of the modal responses are provided, which predominates in picking structural modes to obtain wind-induced dynamic response of long-span roof structure with frequency-domain method. Then, by arranging the estimative response of each mode in reduced-order and truncating higher modes to expedite computations, the accurate wind-induced response is calculated by ACQC method, which has taken into account the partial correlation of wind loads and the quad-spectra (imaginary parts of XPSD) of the generalized wind loads. Finally, utilizing the rigid model wind tunnel test data of some large railway station platform, the effectiveness of the scheme proposed is verified.
Nonlinear Analysis of Mechanical Behavior of the Eccentric In-Plane Beam-Wall Joint
Authors: Bai Jie
Published: May 2011

On the basis of previous experimental research, the nonlinear finite element analysis of the eccentric in-plane beam-wall joint is made with nonlinear bond-slip constitutive relation between steel and concrete. The mechanical behavior of the joint is studied in detail, and parametric analysis is carried out for mechanical behavior of the joint. Results of experiment and nonlinear analysis proved that: the important guarantee for mechanical behavior of the eccentric in-plane beam-wall joint is macro resistance capability, which is a precondition of local force transmission of the joint. In addition, the length of beam plunging wall, eccentricity of the joint and the stirrup ratio of beam within wall are the main factors influencing on mechanical behavior of the joint.
Experimental and Theoretical Analysis on Carrying Capacity and Deflection of Bond-Retarded Prestressed Concrete Continuous Beams
Authors: Xia Cao , Zhou Hong Mei , Jin Ling Zhi , Liu Ya Qiong , Duan Shu Fen
Published: May 2011

Based on the experiments of four bond-retarded prestressed concrete continuous beams, an unbounded prestressed and a bonded prestressed concrete continuous beams, this paper analyzes the ultimate bearing capacity and the deflection of the continuous beams by comparing the theoretical and experimental results, shows that the bond-retarded prestressed beams has the same character with the unbonded prestressed beams when retarding mortar is not hardening; while the bond-retarded prestressed beams has the same character with the bonded prestressed beams when retarding mortar is hardening.
Discussion on the Method of Pushover with Cyclic Loading
Authors: Xiao Ming Kui , Xu Huan Huan , Long Xiao Yan , Zhu Jing Meng
Published: May 2011

The cyclic loading pushover method which can simulate the real ground motion are suggested, and the target displacements of cyclic loading are discussed to overcome the drawbacks of traditional Pushover method which cannot consider the important seismic response of plane frames under earthquake, such as cyclic loading history, duration of strong motion, and the cumulative damage of structures. Through the comparison analysis of the story drift and hysteretic energy of plane framed structures gotten by adopting cyclic loading pushover method, traditional pushover method, and dynamic elastic-plastic time-history analysis method respectively, the conclusion that cyclic loading pushover method can better reflect the loading process with ground motion and the cumulative disruptive effect caused by hysteretic energy of structure can be obtained ,which provides some references for performance evaluation of elastic-plastic analysis of seismic structures.
Analysis of Ice Response Spectra with Nonlinear Interpolation Method
Authors: Jia Ling Ling , Jing Hang , Han Yang
Published: May 2011

In this paper, the successive computation formulas of ice response spectrum are derived and deduced based on the assumption of nonlinear interpolation method. And with the new way, the ice response spectrum of two true different ice temporal curves are analysized. The results indicate that the ice spectra value obtained by the new method is a litter greater than the values of the called precision method. And the error of the acceleration response spectra amplification coefficient is only 0.53%. therefore, this ice response spectra method presented by this paper can meet the request of precision. As this method is more preciser than linear interpolation method, it can be used in the design of ice resistance.
Design Approach of Stiffeners and Model of the Initial Stiffness in Extended End-Plate Connection
Authors: Zhao Wei , Liu Qian
Published: May 2011

End plate stiffener failures occure in a number of tests in recent years. And no relevant rules are given in design codes for steel structures. A design method for angles and thickness of stiffeners in extended end plate connecionts is derived by requiring the eqaul distribution of tensile force among bolts inside and outside of beam flange. And a balance between the force transmitted by the stiffener and by the beam flange is considered too. Comparisons with results of ANSYS show that the stiffeners designed by the proposed method in this paper are able to change the extended portion of endplates from one side clamped to 2 panels fixed on two adjacent sides. Simple formulas for calculating rotational rigidities of the connections with and/or without stiffeners were also proposed with component method, in which the end-plate stiffness, column flange stiffness and bolt stiffness are inclueded. Comparisons with results of ANSYS show that the proposed equations have good precision and can be applied to pratical engineering.
Force and Compression Analysis for Rigid Retaining Walls with EPS Buffer
Authors: Wang De Ling , Guo Li
Published: May 2011

In this paper, the force against rigid retaining walls from backfill soil under static loads and vibration loads is analyzed within three cases. The first case is an ordinary retaining wall without expanded polystyrene (EPS) geofoam buffer. In the second and the third case, a layer of vertical EPS buffer with different density and elastic modulus is placed between a rigid retaining wall and backfill soil. Numerical simulation results show that the force against the same retaining wall in the treated cases is less than that in the untreated case, under both static loads and vibration loads. Moreover, the compression of different EPS buffer is studied. Under vibration excitation, when the density and elastic modulus of EPS buffer decreases, its compression increases and more wall force is mitigated. Simulation results accord with the physical shaking table test data. Numerical results and physical test demonstrate that EPS geofoam seismic buffers hold great promise to reduce loads against rigid retaining wall structures, especially earthquake-induced dynamic loads.
AN Identification Method of Damping Matrix for Frame Structures
Authors: Dong Sha Sha , Wang Wei Ying , Liu Fu Shun , Gao Zhi Qiang
Published: May 2011

Nowadays, damping is still the important dynamic characteristic that is the least understood and the most difficult to quantify. The advantage of the proposed damping matrix identification method is that several low order complex modes achieved by Experimental Modal Analysis (EMA) are capable of calculation precision. In order to identify the damping matrix, this paper also proposes a general damping matrix decompositon technique, which can be used in the situation that different parts of the structure have different damping. Then a five-story frame structure is applied to demonstrate the proposed method ,and the results obtained show the suitability of this approach for damping matrix identification in frame structures.
The Engineering Application of Free Form Structures Derived by Structural Morphogenesis Methods
Authors: Cui Chang Yu , Jiang Bao Shi , Zheng Hong Yan
Published: May 2011

The structural morphogenesis methods are numerical methods for seeking various‘good structure shape’ based on mathematical and mechanical principles. The methods are to realize the coordination between structural shape and mechanical properties. In this paper, the height adjusting method and Extended-ESO (extended evolutionary structural optimism) method are successfully applied in practical engineering design schemes, which could be a meaningful reference and a powerful tool to the present design in structural shape and mechanical performance.
Study of Equivalent Static Wind Loads on a High-Rise Building with 204 Meters High
Authors: Wang Qin Hua , Shi Bi Qing , Xu Ping Sheng
Published: May 2011

Equivalent static wind loads (ESWL) are the bridge between engineer in the structure design field and researcher in wind engineering field. In this paper, a practical high-rise building with 204 meters high was tested in wind tunnel, and then ESWL was calculated by load-response correlation (LRC) method based on the results of wind tunnel. Some results are useful for design of building structures.
The Local Flexibility of A Pipe with A Part-Through Circumferential Crack
Authors: Feng Xin , Zuo Chun Yuan , Hu Jia Shun , Zhou Jing
Published: May 2011

The part-through circumferential crack is a typical crack form in pipe structure, which often lead to the structure failure. Firstly, the local flexibility equations of a pipe with a part-through circumferential crack are derived by using linearly elastic fracture mechanics. Secondly, an adaptive Simpson quadrature-revisted was used to numerically calculate the local flexibility coefficients. Finally, the model test were performed to validate the local flexibility for a part-through circumferentially cracked pipe. The results show that the natural frequencies of cracked pipe obtained by the model test agree well with the theoretical values from the proposed equations of the local flexibility. It is demonstrated the feasibility of the proposed method for vibtaion analysis and damage identification of a cracked pipe.
Experiment on the Cement-Tailings Ratio of Cemented Filling with Tailings of Daye Iron Mine and Research on Hydration Reaction Mechanism
Authors: Du Cui Feng , Chen Li , Cai Dan
Published: May 2011

In this paper, tailings from Daye iron mine as aggregate, ordinary 425 # cement as cementing agent were adopted to make the filling samples in the test. Aimed at the three factors including cement-tailings ratio, curing age and slurry which influenced the strength of filling sample, single factor experiments were tested. Based on data analysis of the uniaxial compressive strength of 225 samples, it was shown that the compressive strength of filling samples was positively correlated with these three factors. According to the compressive strength of filling sample at 28d of age, the cement-tailings ratio of filling sample suitable for Daye Iron Mine was determined, which provided a theoretical basis for the choice of technical parameters of filling mining technology in Daye Iron Mine. Through the Scanning Electron Microscopy (SEM) experiments for filling samples with different ages, the composition of chemical elements and resultant of the samples of different ages were analyzed, and reasons for the strength differences between the samples at different age was obtained, and a useful probe was conducted about the reaction mechanism.
Study on RC Short Column Strengthened Reliability
Authors: Chu Yun Peng , Yao Yong , Jia Bin , Zhang Zhao Qiang
Published: May 2011

The RC frame structure in epicentral area was severely damaged in the 8.0 magnitude Wenchuan earthquake. After the earthquake have using three strengthening methods, such as enlarging the cross-section, exterior steel clad reinforcement and Paste CFRP was used in reinforcement the short RC columns damaged. To analysis the three-dimensional mechanical properties of short RC columns reinforced under nonlinear load in the condition of different strengthening methods and axial compression ratio by using finite element software ANSYS, the results show that: ( 1) The ultimate bearing capacity of short RC columns reinforced by using the paste CFRP and steel method has improved greatly as well as the ductility, can effectively avoid the brittle failure of short columns. (2) Axial compression ratio has a greater impact on the ultimate load and ductility of RC columns strength by enlarging the cross-section but the impact on that reinforced by using the paste CFRP and steel methods is relatively weak.
Effect of Iron Ore Tailings as Fine Aggregate on Pore Structure of Mortars
Authors: Yu Lei , Tian Jing Song , Zhang Jin Xi , Yang Rong Jun
Published: May 2011

Effect of iron ore tailings as fine aggregate on pore structure of mortars has been studied in this paper. The purpose is to investigate, as fine aggregate, comparing to natural sand, whether the iron ore tailings can improve the pore structures of mortars or not. Pore structure parameters were measured with the instrument of MIP and calculated with corollary software. The pore structure parameters from four kinds of mortars with different fine aggregates are compared with each other. This paper will provide more data about the use of this artificial aggregate, which may increase the feasibility of the use of this by-product in the mortar or cement concrete industry.
Use of P-Wave Velocity to Estimate the Strength of Hardened Self-Consolidating Concrete
Authors: Lin Yi Ching , Lin Yung Chiang , Lin Yu Feng
Published: May 2011

This paper investigates the feasibility of using the P-wave velocity measured by the impact-echo technique to estimate the strength of hardened self-consolidating concrete. The relationship between the through-transmission ultrasonic pulse velocity (UPV) and the strength of high performance concrete was established previously by performing experimental studies on water-cured cylinders made of concrete having variations in water-cementitious amterial ratio and aggregate content. However, the through-transmission UPV measurement is not applicable to concrete elements with only one accessible surface. In this paper, two plate-like specimens were made of self-consolidating concrete and they had different curing conditions. One specimen was immersed in water and the other was covered with wet gunny sack for 7 days. The impact-echo technique, one-sided wave velocity measurement technique, is adopted to determine the P-wave velocity of the plate-like concrete specimens at an age of 28 days. The difference between the impact-echo P-wave velocity (IE-PV) and the through-transmission ultrasonic pulse velocity (UPV) is studied. In addition, the measured IE-PV is used to estimate the strength of the plate-like concrete specimen and the estimated strength is verified by taking cores from the specimen.
Experimental Investigation on Slip-In Connection for Cold-Formed Steel Double Channel Sections
Authors: Tan Cher Siang , Tahir M.Md. , Shek Poi Ngian , Kueh Ahmad Beng Hong
Published: May 2011

The application of cold-formed steel in light steel framing design can become a popular choice of Industrialized Building System, by moving huge amount of construction work to the factory and leaving the construction site cleaner and safer. However the joints behaviour for primary structures, particularly the partial strength semi-rigid beam-to-column connection has not been studied in depth. This paper presents the isolated joint test on slip-in connection using 6 mm hot-rolled steel gusset plate. Two cold-formed lipped channel sections were placed back-to-back to form beam and column members. Three specimens with the depth of beam ranging from 150 mm to 250 mm were tested. From the experimental results, it is observed that the ratio of moment resistance of joint to the moment resistance of the connected beam increases in the range of 0.46 to 0.70. The rotational capacities of the joints exceed 30 mRad. The rotational stiffness achieves 511 kNm/rad to 1671 kNm/rad. It is concluded that the proposed connections could be classified as partial strength connection.
Discuss on Trust Level Evaluation Indexes of the Owner to the Controlling Based on Project Controlling Mode
Authors: Sun Ji De , Wang Da Wei , Guo Hui
Published: May 2011

This paper firstly introduces the concept of project controlling management and the application status in China, then analyzes the problems of project controlling management mode in application – the owner’s mistrust, explains the necessity of research on trust level evaluating indexes of the owner to the controlling, discusses the trust level evaluation indexes of the owner to the controlling, points out the next research direction..
Experimental Study on Drying Shrinkage and Water Absorption Rate of Recycled Concrete Hollow Block
Authors: Zeng Zhi Xing , Su Li Xing
Published: May 2011

On the premise of using the five dosage levels of recycled coarse aggregate, the paper primary study on the drying shrinkage and water absorption rate of recycled concrete hollow block in order to determine the maximum dosage of recycled coarse aggregate, then find out the relationship between the drying shrinkage and the water absorption rate of recycled concrete hollow block. The results showed that: the maximum dosage of recycled coarse aggregate can reach 100%; there is a quadratic relationship between the drying shrinkage and the water absorption rate of the block.
Elimination of Debonging of FRP Strips in Shear Strengthened Beams Using Grooving Method
Authors: Mostofinejad Davood , Tabatabaei Kashani Amirhomayoon
Published: May 2011

One of the methods of retrofitting reinforced concrete structures is use of FRP sheets to increase the flexural and shear strength of concrete elements. Use of FRP materials is in rapid progress because of their high strength, light weight and easy installation of FRP composites. Poisson’s ratio mismatch between FRP sheets and concrete is resulted premature debonding of FRP strips. Hence, the use of ultimate strength of FRP sheets is difficult if EB (External bonded) is applied in installation of FRP. Therefore, debonding has been repeatedly reported in most experimental studies. Recent studies in Isfahan University of Technology (IUT) show that use of grooving method (GM) to attach the FRP sheet to concrete surface for flexural strengthening is much more effective compared to conventional methods. In present experimental study, small scale reinforced concrete beams were strengthened with FRP strips for shear. Comparison between the ultimate load and deflection of the test beams demonstrates that grooving method was effective and led to elimination of debonding of FRP strips used for shear strengthening.
How Human-Computer Interface Redefines Original Lifestyle in Architecture?
Authors: Huang Yu Chun
Published: May 2011

In the twenty-first century, with the development of technology, architecture is not just a shelter or even “a frozen music” (by Johann Wolfgang van Goethe). Instead, architecture becomes a huge communication channel between people and space. Thus with the integration of computational technology into architecture design, the new term—“smart space” has emerged. Some researchers have applied technology into intelligent space design, such as intelligent kitchen, smart collaboration design studio and smart health care environment. Sometimes creating a fancy or an alternative smart space is not enough, the essential factor of smart space is to satisfy human needs and keep good relationship between human and space. Therefore, this research will find out what the role of human-computer interaction in smart space design is. And the purpose of this research is to present two different cases of smart space: “Time home pub” and “BCI studio” and make the analysis of the transition from traditional architecture to smart space design. Also this research further discusses how HCI redefines the functions and lifestyle of traditional architecture.
Effect of Heat Treatment on Microstructure and Mechanical Properties of 30MnSi Pre-Stressed Concrete Steel
Authors: Cui Hong Bao , Zheng Li Feng
Published: May 2011

In the present work, the effect of heat treatment parameters on microstructure and strength of the 30MnSi PC steel bars was investigated and analyzed systematically. The results show that the fine tempered martensite, thinning tempered troostite and tiny tempered sorbite can be obtained when quenching temperature reach 920°C and the temper temperature is 240°C, 430°C, 600°C, respectively. The relationship between heat treatment parameters and tensile strength was also obtained. Optimum strength can be obtained by quenching at 920-950 °C and tempering at 430 °C with constant heating time.
A Global Damage Indicator Based on the Modal Parameters in the FE-Simulation of the Structures
Authors: Noh Sam Young , Sin Eun Mi
Published: May 2011

The purpose of the study is the development of a tool for the prediction of the structural damage by means of the numerical damage simulation in the design stage. For the evaluation of the structural integrity in the numerical damage analysis, a global damage indicator was defined based on the modal parameters obtained from the tangential equation of motion: a set of natural frequencies and mode shapes. As they are given in a set, it may be difficult to treat them as a damage indicator. In this study a new damage indicator based on the natural frequencies was defined using the contribution factors of the mode shapes under consideration of the external modal energy. A numerical example of a frame structure showed the efficiency of the damage indicator defined in the study.
Flexural Behavior of Beam Reinforced by Deformed Bars and Untensioned Wire Strands in Combination
Authors: Jo Min Joo , Noh Sam Young
Published: May 2011

A new moment-resisting precast concrete beam and column joint system using untensioned wire strands was developed in the study, mainly for the use in underground parking lot in which the influences of the seismic load may be neglected. For the evaluation of the performance of this new joint system, the behaviors of the beams, reinforced by the deformed bars and the untensioned strands in combination were experimentally investigated. The reinforcement ratio of the wire strand to the deformed bar was selected as the test parameter. The test results showed that the flexural capacities of all five specimens were sufficient. However, the wire strand ratio has to be used limitedly in the aspect of the serviceability due to the large deflection.
Development of Non-Autoclaved Aerated Concrete by Alkali Activated Phosphorus Slag
Authors: Jiang Xiao Jun , Yun Yan , Hu Zhi Hua
Published: May 2011

The feasibility of manufacturing non-autoclaved aerated concrete using alkali activated phosphorus slag as a cementitious material was investigated in this paper. Liquid sodium silicate with various modules (the molar ratio between SiO2 and Na2O) was used as alkali activator and a part of phosphorus slag was replaced with fly ash which was used to control the setting time of aerated concrete. The influences of the fly ash, curing procedure, modulus of sodium silicate solution and concentration of alkalis on the compressive strength and bulk density of non-autoclaved aerated concrete have been studied. Moreover, the types of the hydration products were investigated using XRD and SEM. The results indicate that: the compressive strength of aerated concrete was influenced by concentration of alkalis obviously. The compressive strength of 11.9MPa and the bulk density of 806kg/m3 were obtained with an activator of 1.2 modulus of sodium silicate and 6% concentration of alkalis under the circumstance of 60°C curing for 28 days.
Load Carrying Capacity of Hybrid FRP-Concrete Composite Pile
Authors: Park Joon Seok , Lee Seong Sik , Nam Jeong Hun , Kang In Kyu , An Dong Jun , Yoon Soon Jong
Published: May 2011

In the study, in order to enhance the durability and constructability of the pile foundation, hybrid FRP-concrete composite pile is developed and its applicability considering construction is discussed. Existing FRP-concrete composite pile is consisted of concrete pile and filament winding FRP wound outside of the pile. To improve the axial and transverse load carrying capacities longitudinal reinforcement is also needed additionally, and hence a new type hybrid FRP-concrete composite pile (HCFFT) is suggested. A new type HCFFT which is composed of pultruded FRP, filament winding FRP, and concrete filled inside of the FRP tube is proposed to improve compressive strength as well as flexural strength of the HCFFT pile. The load carrying capacity of proposed HCFFT pile is evaluated and discussed based on the result of experimental and theoretical investigations.
Numerical Investigation into Rockburst Proneness of Deep-Buried Tunnels with Arch-Shaped Wall
Authors: Wang Xin Yu , Shao Zhu Shan , Cui Yu Ming
Published: May 2011

During the construction of the deep-buried tunnels, high surrounding rock stress and the rockburst are the important factors affecting the stability of surrounding rock. Xiabandi hydraulic engineering is the key project in Tarim River basin. Due to the deep buried excavation, rockburst is particularly prominent and should be received adequate attention. According to the rockburst practice during construction, numerical analysis is adopted to study the stress characteristics along depth with the same lateral pressure coefficient. Furthermore, the rockburst tendency along the tunnel with different burying depth is investigated. The conclusion is of great value to guide the rockburst control during the tunnel design and construction.
Research on Shaking Table Test of Masonry Building with Rowlock Cavity Walls
Authors: Chen Zhong Fan , Lu Fei , Yuan Yang , Miao Sha Sha
Published: May 2011

Rowlock cavity wall was widely used in rural house in Southern Jiangsu Province from 1980s to 1990s. As one type of masonry structures, the seismic performance of rowlock cavity wall has rarely been studied on. Based on the report of General Seismic Investigation in Jiangsu Qidong, one 1/2-scale rowlock cavity wall structure was modeled as the existing rural house, and was tested on shaking table in lab of Southeast University. After analyzing the failure state of the model, and examining the structural parameters such as natural frequency, damping ratio, floor acceleration, floor shift, strain and crack of the model in load condition of different earthquake wave and intensity, the seismic performance of rowlock wall structure was assessed. And the seismic capacity of the whole model and each piece of rowlock wall was also analyzed. Based on the mortar strength field inspected in model wall, the seismic capacity of model structure under the action of rarely occurred earthquake of level 6 seismic precautionary intensity was estimated. The result showed that the model structure would collapse under the load condition. Obviously, this can not satisfy the seismic precautionary requirement in Code for Seismic Design of Buildings (GB50011-2001). Therefore, some principal reinforcement suggestions were discussed and proposed for existing rowlock cavity wall buildings. The research result of this paper could provide some theoretical foundation for the Aseismic Residential Project of rural peasant house, and also could be referred to for further research on rowlock cavity wall structures.
Mechanical and Microstructure Characterization of Fresh High- and Normal- Strength Concrete with Non-Contact Electrical Resistivity Measurement
Authors: Tian Ye , Jin Xian Yu , Zhan Yuan , Jin Nan Guo
Published: May 2011

This paper reports the investigation on both high and normal strength concrete using a non-contact electrical resistivity facility. The bulk resistivity development (ρ(t)-t curves) of the fresh concretes was evaluated from casting to 72h. The relationship between the electrical resistivity and the pore structure obtained from mercury intrusion porosimetry (MIP) method was analyzed. And the compressive strength evolution of fresh high- and normal- strength concrete was studied based on the bulk resistivity at early ages. The experiment results indicated a linear relationship between the fractional porosity and electrical resistivity. A further correlation between the compressive strength and electrical resistivity was analyzed with Archie’s law. Based on these studies, it appears that the electrical resistivity test could provide information for the design, quality control, quality assurance, and utilization of both high- and normal- strength concrete.
Large Deflection of Cantilever Beam with Uniformly Distributed Load Using Homotopy Analysis Method
Authors: Xiao Yi
Published: May 2011

The large deflection behavior of prismatic cantilever beams subjected to uniformly distributed load is investigated. An approximate analytical solution is obtained using the homotopy analysis method (HAM). The solution is validated by the nonlinear shooting method. This reveals that the solution is accurate, efficient and convenient for cantilever beams with uniformly distributed loads.
Study on Geomorphologic Spatial Information Mining and Application
Authors: Liang Li Heng , Xing Li Xin , Li Tong Lin , Jiang Hong Yan , Jiang Li Jun
Published: May 2011

Digital Elevation Models (DEM) implies numbers of geomorphologic spatial information. It not only includes the three-dimensional coordinate but also has unique texture information, which can describe the ‘true’ land surface adequately at relation of neighbors (plan) and relative (amplitude). We will use a method to study the wavelength characters by data mining and distribution of slope and local relief on the altitude steps through a local window. The Shuttle Radar Topography Mission (SRTM) collect detailed Digital Elevation Models(DEM) data between 60°N and 57°S, 80 percent for all land masses, and it provides reliable, high precision surface elevation data for us, suits to analyze efficiently landscape pattern. SRTM-DEM data simulate three-dimensional land surface with regular gridded matrix, and these discrete points are fit for spatial neighbors’ analysis and statistics, and convenient to geomorphologic pattern computation and analysis in digital computer. Geomorphologic pattern is influenced by Physical properties and human activities in a most direct way, but whilst it record numbers of geological evolution evidence, and these records provide some important information for climate change, geological and geographical processes and ecological environment researches in science. In this study, making the whole Jilin province as study object, we propose a fourth-order equation to approximate land as a continuous curved surface, association neighbors’ analysis method, utilize digital elevation matrix to validate an optimal statistic window, and subsequent study the area spatial distribution by parameterization and classification, get a satisfactory effect.
Geological Disasters Induced by Wenchuan Earthquake and Site Selection for Post-Earthquake Reconstruction
Authors: Jian Wen Bin , Li Run
Published: May 2011

Based on the field investigation for secondary geological hazards induced by 5.12 Wenchuan Earthquake, the types of geological disasters during or after earthquake are analyzed in this paper. The main secondary geological hazards are rock fall and collapse, landslide, debris flow, dammed lake，sand liquefaction and so on. The development and distribution rules of secondary geo-hazards, with a long-term sustainability and a formation of hazard chains, are of relation with earthquake fault zone, and consistent with seismic intensity. The buildings located in secondary geo-hazards areas with a high risk are damaged severely, thus the site selection for post-earthquake reconstruction and related geotechnical engineering issue are discussed, which are useful in reconstruction of Wenchuan earthquake area.
Model Test on Soil Stress and Displacement Changes Induced by Active Ground Fissure
Authors: Liu Yue , Huang Qiang Bing , Peng Jian Bing
Published: May 2011

With a large-scale physical model test of active ground fissure, the rules of the soil stress and displacement changes induced by active ground fissure are studied. The results show that, the active ground fissure causes soil stress and displacement field changes within a certain area, namely, soil stress reduce in the hanging wall, but increase in the foot wall. The farther from ground fissure the area is, the smaller the reduction and increase of soil stress caused by ground fissure movement. There are generally 4 soil stress distribution zones induced by active ground fissure, which are, original stress zone of the foot wall, stress increase zone, stress reduction zone and original stress zone of the hanging wall and among which, stress reduction zone is 1.0 to 1.5 times that of stress increase zone. The active ground fissure leads to abrupt displacement phenomena, taking the step shape at its both sides, and as the strata goes from deep to shallow, soil deformation area in section increases obviously. The influence area in the hanging wall is bigger than that in the foot wall.
Experimental Study of Seismic Performance on Three-Story Prestressed Fabricated Concrete Frame
Authors: Song Man Rong , Liu Bing Kang , Huang Shen Jiang , Zhou An
Published: May 2011

Based on the low reversed cyclic loading experiment of a specimen of three-story prestressed fabricated concrete frame, this paper investigates the carrying capacity, the failure mode, the load-displacement hysteresis curve of frame. The research includes the seismic performances such as failure mechanism, rigidity degradation, hysteretic behavior and etc. The results indicate that the plastic hinge first appears at the ends of beam at lower story. The connections of frame are in a state of bi-direction compression and have more joint stiffness, which therefore enhances the frame lateral stiffness and improves the deformation recovery capability. The carrying capacity of the frame hasn’t serious degradation at story drifts between 1/39 and 1/64. The post-tensioned prestressed fabricated concrete frame is a “strong column weak beam” structure.
Discussion on the Cohesive Strength of Sand
Authors: Huang Qing He , Huang Jian Nan , Zou Yan Hong
Published: May 2011

The geotechnical test can't be applied to sand as the original sample is difficulty to collected by drilling, so the cohesive strength C of sand can't be acquired in geotechnical test. Generally speaking, according to the Mohr–Coulomb law, C=0. From the numerical point of view, when the slope angle is greater than the internal friction angle, the global stability of slop can’t meet the requirements of standard. However, that’s not the case in fact. In practice, the slope angle can be determined by means of analogy. Although successful experiences have obtained, there still exist some potential hazards. In this paper, we have made some studies on the cohesive strength of sand based on the control of instability of a deep foundation in Xiang'an District, Xiamen, China.
Analysis of the Effect of Stopping Dewatering on Group Piles Foundation
Authors: Zhang Jun Fa , Tao Lei , Wen Jian Jun , Liu Wen Xiang
Published: May 2011

After the construction of building foundation with high groundwater table was finished, stopping dewatering of pit could create some effect on the force of foundation. In this paper, equivalent temperature-changed method was brought forward to simulate the influence of stopping dewatering which could conveniently use current structural analysis program to simulate the change of pore water pressure in soil. And based on ANSYS program, this method was applied in the project of Telecom Network Management Center in Shaanxi Province. Numerical results indicate that the effect of stopping dewatering on pile-raft system is significant, and some ‘abnormal phenomenon’ in In-Situ Testing is reasonably explained.
Present Situation and Consideration of Rock Burst Hazard
Authors: Deng Lin , Lv Yan , Deng Rong Gui
Published: May 2011

Rockburst is a sudden disaster that endangers greatly the security of operators and facilities in the production.The problem of rockburst is the most important issues in the underground space. This paper describes the present situation of the disaster at home and abroad ,which includes the conception，classification, intensity classification, mechanism, forecasting, and prenvention. Based on these analysis, This paper summarizes the following questions：Conception and intensity classification of rockburst has not level , its major and minor influencing factors has not compartmentalized; without taking full consideration in the influence of rock mass structure and dynamic action in comprehensive prediction, and there are fewer considerations of it in practical project; Attribute weights of all the factors are always subjectivity, it can not give the mathematical explanation; Study on rockburst mechanism are not enough, It can not exactly prodict when and where occur,can not raise the perfect time to prenvent the disasters.At the end of this paper, it is pointed out that it is the emphasis topic which comprehensive prediction with computer.
Experimental Study on the Uplift Resistance of Plate Anchor in Sand
Authors: Zhang Xin , Yue Jin Chao
Published: May 2011

An experimental investigation on the uplift resistance of circular plate anchor in both loose and dense sand is performed. A test set-up and an in-house data acquisition system are developed to capture the force and displacement when anchor uplifting. Two distinct load-displacement responses for plate anchor in loose and dense sand are observed. The peak uplift resistance and dimensionless breakout factor are significantly influenced by the sand density as well as the embedment ratio. The increasing rate of peak uplift resistance with embedment ratio is limited by the critical embedment ratio beyond which a smaller increasing rate is occurred. The critical embedment ratios for this study are determined as 4 and 6 for plate anchor in loose and dense sand respectively.
Study on Seismic Behavior of Vertical Connection in Prefabricated Reinforced Concrete Structures
Authors: Song Guo Hua , Wang Dong Wei , Liu Bing Kang
Published: May 2011

The paper attempts to research the seismic behavior and mechanical mechanisms under repeated low-cycle loading of vertical connections in prefabricated reinforced concrete structures. Eighteen specimens were designed and tested, the test process and the mechanical mechanisms are studied, the seismic behavior of connections is analyzed, and the shear resistance formulas are proposed. The theoretical values based on proposed formulas are good agreement with test results. Under repeated loading, the shear resistance decreases, the connection ductility increases with connecting bar, but decreases with connection width. However, all the connections fail crisply with poor ductility. At sudden-cracking, the shear resistance increases with connecting bar, but changes nonlinearly with connection width. The resistance is composed of attributions of mechanism of diagonal-compressive column (MDCC) and mechanism of compressive friction action (MCFA). After sudden-cracking, the shear resistance is provided by weakened MDCC and dowel action of connecting bars (DACB). It increases with connecting bar and connection width.
Strait Crossing Cable Stayed Bridge Girder Evolution
Authors: Guo Long , Chen Ai Rong , Xu Li Ping
Published: May 2011

The design of bridges, in particular long spanned ones, is challenging in the sense that there are many complicated issues to be considered. Amidst the loads to be considered, like dead load, live load, wind load, and earthquake load, the wind load becomes the prime concern for the design of the bridges. The paper will introduce several newly evolved kinds of girder that were based on commonly known physic natural law by structural engineer. Further structural analysis and wind effect research should be done in the future to validate and decide the structural member dimensions. The main problem to be solved in strait crossing bridge is lateral wind load that will effect traffic safety as well as wind effect on structures (statically and dynamically) for long span bridge arrangement.
Analysis on Surrounding Rock Deformation of Shallowly-Buried Portal Part of Double-Line Tunnel
Authors: Ma Le Min , Wang Lei , Xu Long Xian
Published: May 2011

Through studying the ground surface settlement monitoring for Fang Dou Shan highway tunnel Shallowly-buried Portal Part, this paper mainly discusses the deformation of surrounding rock range from ground surface to the arch crown of double-line tunnel, and analyses the effect on stability of surrounding rock during construction, with the whole process of excavation of highway tunnel being simulated by FLAC_3D. It can make great significance for construction safety and some other related parts.