bluuebunny/crossref_metadata_2025 huggingface dataset:
Availability of Chemically Modified Wheat Straw Application on Oil Spill Clean up
Authors: Gao Yuan , Bai Lu , Zhou Yi Tong , Zhang Li Ping , Li Fan Xia
Published: May 2011

In many countries, wheat straw is an abundant byproduct from wheat production in farming, only a minor portion of the straw is reserved as fuel, or raw materials for industry. In order to make good use of wheat straw, a series of materials based them are prepared by acylation grafting with propionic anhydride in a solvent-free system. The capability of the grafted straw to absorb oil from aqueous solution was studied and compared with the raw straw. It is found that wheat straw is more effectively at absorbing oil after chemically modification than the raw one in 15 minutes. And the grafted material is significantly more hydrophobic than the raw wheat straws. Characterization of chemically modified straw was performed by SEM, XRD.
Effect of CO2 Remover on Decomposition Rate of Glucose in Supercritical Water
Authors: Li Wei Hong , Liu Xue Wu , Chen Cheng , Liu Da
Published: May 2011

Experiments for decomposition rate were carried out in subcritical and supercritical water in a batch-type reactor biomass set up by ourselves. Glucose was used as a model compound, and CaO was used as CO2 remover in experiments. The effects of temperature, pressure, residence time, initial concentration of glucose and n(Ca)/n(C) on glucose reactions were examined. The optimal process was also suggested after added CaO. Under the condition of 500°C, above critical pressure, 3-10 min resident time, n(Ca)/n(C) of 0.4-0.5.
Application of Biomass Materials for Heat Insulation in Rural Buildings
Authors: Luo Qing Hai , Peng Wen Wu , Zhang Peng Fei
Published: May 2011

Heating energy consumption of rural buildings in China was analyzed in this paper. Thermal insulations were compared between some kinds of biomass and fossil materials. Application forms of biomass materials were discussed for heat insulation in rural buildings, and the potential was analyzed for energy-saving and CO2-emission-reducing. As a big agricultural country, the benefit and potential of biomass materials may be remarkable in heat insulation in rural buildings in the light of local conditions.
The Effects of Nanofluid on NH3H2O Bubble Absorption Performance under Adiabatic and Non-Adiabatic Conditions
Authors: Wu Wei Dong , Pang Chang Wei , Liu Si Mei , Zhang Hua
Published: May 2011

The object of this paper is to study the effects of nanofluid on NH3/H2O bubble absorption performance under adiabatic and non-adiabatic conditions. Mono nano Ag with the concentration of 0.02wt% was used as the enhancement medium, and the absorption performance experiments under the heat insulation and water cooling for absorption test section were respectively conducted and contrastively analyzed. The results showed that the absorption rate with mono nano Ag in bubble absorption process is higher than that without any nanoparticles; in adiabatic case, when the initial temperature of NH3/H2O solution is gradually increased within 6～18°C, the absorption rate decreases correspondingly, and so does the effective absorption ratio; in non-adiabatic case, with the cooling water temperature rising within 10～25°C, the absorption rate decreases but the effective absorption ratio increases. Therefore, it is concluded that the heat transfer enhancement of nanofluid can promote the NH3/H2O bubble absorption performance to a certain degree, and the enhancement of the absorption is not completely dependent on heat transfer.
Effect of Solidification Pressure on the Interface Heat Transfer Coefficient in Counter-Gravity Casting
Authors: Chen Zhong Wei , Ma Cui Ying , Zou Ji Zhao , Zeng Xie Rong
Published: May 2011

A combined theoretical and experimental program was carried out to study the effect of different solidification pressures on the heat transfer coefficient at the metal-mould interface during counter-gravity casting of A357 alloy. The interface heat transfer coefficient ( IHTC) at different temperatures and pressures could be calculated by substituting the dates of the experimental temperatures into the heat transfer coefficient equation, and the variable curves of the IHTC at the different temperatures had been obtained. The results showed that, the IHTC increased with raising the solidification pressure and it made a better contact between the metal and mould. IHTC is decreased with the temperature of interface of metal-mould falling. However, when the temperature of interface of metal-mould is less than a certain value, the IHTC is tend to a stable one.
Synthese of Cancrinite from Alkali-Fused Fly Ash by “Dry Method”
Authors: Zhao Ya Juan , Zhao Xi Cheng , Xie Hui Dong , Jiang Yuan Ru
Published: May 2011

In this study, zeolite was prepared from fused fly ash with very little water treatment. The as-prepared zeolite was characterized by X-ray diffraction (XRD) and scanning electron microscope. XRD results showed that cancrinite was the major phase in the product. The influence of preparation conditions on the yield of zeolite was described. Experiments showed that the crystallization time of zeolite became shorter and the crystallinity of cancrinite became higher with the increase of NaOH dose in fusion stage. Based on the fact that the water was not enough to be as the solvent which was different from conventional method, it can be concluded that the synthesis mechanism of zeolite from fused fly ash is the Solid-state Conversion Theory.
Study on the Solid-State Fermentation Conditions for Producing Thermostable Xylanase Feed in a Pressure Pulsation Bioreactor
Authors: Yang Ge , Hou Li Li , Zhang Fu Liang
Published: May 2011

Air pressure amplitude serves as a critical control parameter in periodic pressure solid state fermentation process. Effects of air pressure amplitudes on thermostable xylanase production byThermomyces lanuginosusSD-21 were investigated. Under the optimum periodic pressure amplitude, namely: at lower limit of 0.05 MPa and upper limit of 1.5 MPa. Among the lignocellulosic substrates tested, corn cob and wheat bran supported a high xylanase (EC 3.2.1.8) secretion byHumicola lanuginosain solid-state fermentation (SSF). Enzyme production reached a peak in 96 h followed by a decline thereafter. Enzyme production was very high, xylanase activity 8237 IU /g of dry moldy bran can be obtained in the system compared with 4520 IU/g in conventional tray fermenter, cultivation of the mold in large enamel trays yielded a xylanase titer comparable with that in flasks. Parametric optimization resulted in a 45.13% increase in enzyme production in PPSSF.
Influence and Mechanism of Cu2+ on Removal of U(VI) by Sulfate Reducing Bacteria
Authors: Liu Yue Lin , Xie Shui Bo , Ling Hui , Wang Wen Tao , Li Shi You , Liu Ying Jiu
Published: May 2011

In order to research on the inhibition of Cu2+to removal of U(Ⅵ) by sulfate reducing bacteria(SRB), the experiment investigated the removal of U(Ⅵ) by SRB through H2S reduction process, elecrton transfer process and adsorption process respectively. The results showed that the electron transfer was the main process in removing of U(Ⅵ) by SRB, It accounted for 80% of the total removal. Extracellular polymeric substances (EPS) adsorption of U(Ⅵ) had little effect. When the concentration of Cu2+was 5mg/L, Cu2+had little effect on the removal U(Ⅵ) by SRB; It inhibited the removal of U(Ⅵ) significantly when the concentration was 15mg/L because of the competition of H2S and the electronics of lactic acid between Cu2+and U(Ⅵ); When the concentration of Cu2+exceeded 25mg/L, it would damage the integrity of SRB’s membrane and the removal of U(Ⅵ) was completely inhibited.
Effect of Different Ways of Ammonia Removal on the Fine Structure and Properties of Hemp Fibers
Authors: Zhang Hua , Chen Mei Yu , Zhang Jian Chun , Tang Zhan Wei
Published: May 2011

Liquid ammonia treatment can improve the properties of a hemp fiber and widen its application in textiles. This study investigated the effects of different ways of NH3 removal on the fine structure and properties of hemp fibers, including thermal property and dyeing behaviour. It was found that, of the three ways of ammonia removal, removal of ammonia with glacial acetic acid resulted in the highest transition of cellulose Ⅰinto cellulose Ⅲ and removal ammonia with water resulted in the lowest transition of cellulose Ⅰinto cellulose Ⅲ. Removal of ammonia with water also resulted in better thermal stability and higher dye uptake than the other ways of ammonia removal. Of the three ways of ammonia removal, removal of ammonia by evaporation resulted in the lowest dye uptake.
Determination of the Antioxidant Capacity of JiangHuang JiangZhi Capsule with DPPH Assay in Vitro
Authors: Zhang Sheng , Li Xiang Zhou , Kuang Chun Tao
Published: May 2011

To investigate the antioxidant effect in vitro of JiangHuang JiangZhi capsule, different concentrations of content of capsule were determinated by DPPH assay method. Results showed Jianghuang Jiangzhi capsule had antioxidant capacity on eliminating DPPH free radicals.
Research on Load Transfer Model of Super-Long Single Pile
Authors: Zhou Hua Cong , Yao Wen Juan , Zhang Ze Rong
Published: May 2011

Currently, super-long piles are designed based on the theory of normal long piles. There is no recognized reasonable mechanical model for qualitative analysis. In this paper, based on load transfer function method, an improved load transfer model is proposed, which gives consideration to both the degradation of skin friction and the asynchronous work between lateral friction resistance and pile-tip resistance caused by pile-soil slip. By applying it in various working conditions, the corresponding pile-soil displacement and axial force of super-long piles are derived. Finally, the proposed model is validated by comparing its analytical solutions to the results of FEM and practical survey of super-long piles, and it provides a new efficient approach for the study of the mechanical behavior of super-long single pile.
Study on the Design Methods Based on Beam Hinge Mechanism of Frame Beams in Seismic Zones
Authors: Guo Jun Qing , Dong Shan Sheng
Published: May 2011

With the calculation methods for the sectional curvature ductility of reinforced concrete flexural components, analysis was conducted on the factors affecting the formation of plastic hinges at the ends of RC frame beams and their rotational capacities; on the basis of which, singly-doubly reinforced rectangular section method for flexural design calculation was put forth, which is favorable to the realization of beam hinge mechanism. The analysis of a practical design case shows that the method proposed is not only beneficial to the formation of plastic hinges at the beam ends and their rotational capacities, but also results in considerable reduction of longitudinal reinforcement, hence lowering of cost, ease of construction, so that it is worthy of popularization and application in design practice.
Study of Stress Amplitude along the Welding Seam in the Composite Cellular Beam with Eye-Shaped Openings
Authors: Fang Li Xin , Chen Geng Jun
Published: May 2011

The behaviour of composite cellular floor beams is becoming important as such members are increasingly used in multistory buildings. But, in the design of some special cellular beam with sharp corner web holes such as eye-shaped openings, the issue of low cycle fatigue failure becomes increasingly critical. In this paper, three-dimensional nonlinear finite element models of composite cellular floor beams with eye-shaped openings have been developed, taking into consideration the influence of the changes in degree of shear connections. The assessment based on stress amplitude for risk of fatigue failure under low cycle service load is presented as design guides in this paper. It is concluded that the risk grows along with the increase of composite actions in beams.
Test on Embedded Perforated Steel Plate Shear Wall with Concrete Filled Steel Tube Columns
Authors: Cao Wan Lin , Zhang Wen Jiang , Zhang Jian Wei , Dong Hong Ying
Published: May 2011

In view of the proposal of embedded steel plate concrete shear wall with concrete filled steel tube columns which contains a new kind shear connector of tie-bars through the circular holes linking concrete layers on both sides of the plate. In order to prove the seismic performance of walls with circular holes on the plate, three steel plate shear wall specimens, including the plate without holes bolted with columns, welded with columns, and the perforated plate welded with columns, were tested under cyclic loading. According to the results, the load-bearing capacity, ductility, energy dissipation, hysteretic behavior and failure phenomena were analyzed. It is showed that the load-bearing capacity of the three specimens were quite close. However, the wall with perforated steel plate has better ductility, energy dissipation and hysteretic behavior. So, it is an effective way to improve the seismic performance of walls by means of embedded perforated steel plate instead of ordinary ones.
Study on Fatigue Load and Fatigue Life Estimation for Concrete Bridges
Authors: Guan Guo Dong , Wang Chun Sheng , Li Gan , Wang Yu Jiao
Published: May 2011

Using truck weigh device, the data of traffic stream was collected from a toll station in Shaanxi province for 24 hours. A standard fatigue truck was developed based on the regular traffic data. Then S-N curves and Palgrem-Miner summation method was introduced in assessing fatigue life of the reinforcement in negative region of one continuous concrete bridge. It was concluded that the welding detail of reinforcement in negative region had long service life under normal traffic state. The fatigue life of reinforcement would be weakened considering overloading vehicles.
Prediction Models of Shrinkage and Creep for Concrete Columns
Authors: Lv Yi Gang , Zhang Jian Ren , Xu Kang
Published: May 2011

In constant temperature and humidity environment, the properties of shrinkage and creep for a group of plain concrete and reinforced concrete columns were observed in long-term and experimental method. The curves of concrete shrinkage and creep effect with time were obtained. Checking coefficient and type coefficient of shrinkage and creep effect were put forward in order to predict models of shrinkage and creep. Using the least square method, functions of checking coefficient and type coefficient were acquired and the prediction models of shrinkage strain and creep coefficient of concrete were obtained based on the modification of the formula of JTG D62-2004. The foundation is laid for the application of the long-term performance research in bridge structure.
Analysis of Static Load Tests for a Simple-Support Prestressed Bridge
Authors: Wang Wen Xing , Guo Qi Ming
Published: May 2011

This paper explains the static load test of a simple-support prestressed bridge. Deflection and stress are measured by the static load test of the simple-support prestressed bridge. This bridge performance and quality are evaluated by using check coefficient of the static load test.
The Development of Beam-Arch Combination System Bridge Based on Mechanics and Aesthetic
Authors: Ma Wen Gang , Huang Qiao , Yang Ming , Ren Yuan
Published: May 2011

The mechanical characteristics and common forms of beam-arch combination system bridge and its new development are introduced. With the rapid development of economy, more and more steel structures are applied to bridge engineering. The usage of steel structure makes the pursuit of aesthetic possible besides the requirements of safety, economy and practicality. Furthermore, the aesthetic design is playing an important role in bridge design, especially in the design of an urban bridge. Aesthetic of a bridge is part of the aesthetic of environment, but which far surpasses the limited rang of environment where it is constructed. The beam-arch combination system bridge has achieved considerable development because of the requirement of aesthetic, which makes it widely used in highway bridge and urban bridge. Especially in urban bridge engineering, a new combination of beam-arch, beam and arch combining in transverse direction of bridge, has been invented and more and more used besides the conventional combination form of beam and arch combining in longitudinal direction of bridge, which is more beautiful but also more complicated for design and construction.
DHGF Theory Based on the Concrete Bridge Safety Evaluation Methods
Authors: Sun Quan Sheng , Chang Ji Feng
Published: May 2011

This paper to bridge safety evaluation as the starting point, the current evaluation method is based on the collection of the Delphi method, the level of analysis, grey cluster theory and the theory of fuzzy evaluation DHGF comprehensive evaluation method is applied to bridge safety evaluation, the establishment of a bridge safety evaluation of the DHGF evaluation model, and based on actual projects will DHGF evaluation method used in the actual concrete bridge safety evaluation, so as to verify the DHGF bridge safety evaluation of the scientific method, accuracy and operability. The main innovation is the first time DHGF evaluation theory is applied to bridge the field of evaluation and the establishment of the corresponding class bridge safety evaluation criteria and indicators in order to achieve the safety of the bridge accurate evaluation.
Geometric Nonlinear Analysis of Curved Box Continuous Girders Considering Shear Lag Effect
Authors: Luo Qi Zhi , Chen Yu Ji
Published: May 2011

The analytical theory and computational method for thin-walled curved box girders in terms of the shear lag effect and geometric nonlinearity are presented. Based on the potential variational principle and the theory of thin-walled box girders, the geometry nonlinear governing differential equations of thin-walled curved box girder considering the influence of the shear lag effect of flange’s stress and the large deflection is established. The equation is solved by means of Newton-Raphon iteration method. The results from the present method are in good agreement with those of the test and the segment method. The numerical examples are conducted to verify the accuracy and reliability of the present theories. It is shown that the proposed formulae and method could be referenced to the design for the thin-walled curved box girders considering shear lag effect.
Study on Structure Sensitivity Analysis Using ANSYS PDS
Authors: Peng Ke Ke
Published: May 2011

As to sensitivity analysis, based on traditional sensitive factor definition and concept of reliability vector, two kinds of sensitivity problems are putted forward in this paper. And factor sensitivity matrix is defined. As far as large and complex structures are concerned, factor sensitivity matrix of incremental form is given. Furthermore, sensitivity surface is putted forward. ANSYS PDS（ANSYS Probabilistic Design System）can solve the above two kinds of sensitivity problems efficiently. The example bridge is a CFST arch bridge with 83.6 meter-span, which operated for 10 years. The analysis result shows that the definitions enhance the maneuverability of sensitivity analysis, and ANSYS PDS is practical.
Experimental Research on Special-Shaped CFST Arch Bridge Model
Authors: Gu Da Peng , Chen Yan Jiang , Yan Wei Ming , Li Yong
Published: May 2011

The main bridge structure of the bridge engineering cross Yitong river, on the 102 national road, is a three-Span flying swallow type special-shaped CSFT arch bridge. This paper introduces the design, process and results of the static model test of the CFST arch bridge.
Analytical Model for the Hysteretic Behavior of SRC Columns
Authors: Zheng Shan Suo , Li Long , Wang Wei , Tao Qing Lin , Li Zhi Qiang
Published: May 2011

To simulate the hysteretic behavior and propose the analytical model of steel reinforced concrete (SRC) columns under low cyclic loads, different fiber models which can reflect the mechanical behavior of materials are used in this paper. The unconfined concrete, partially confined concrete, highly confined concrete, structure steel and longitudinal reinforcement bars of the complex cross section can be established by OpenSees program which can define the different fibers for kinds of materials with their own stress-strain relations, respectively. Based on fiber models, the analytical model for simulating the hysteretic behavior of SRC columns is proposed. By comparing with the conventional simulation results, the results which are obtained from the proposed analytical model in this paper agree with the experimental results better.
Determination of Cast-In Situ Section Lengths of Reinforced Concrete Arch Bridge in Arch Centering Method
Authors: Zhou Shui Xing , Zhang Min , Liu Bin , Xu Jun
Published: May 2011

It is a common construction method to pour arch concrete in arch centering. The deformation law of arch centering was analyzed in process of pouring arch concrete, a new method to determine concrete cast-in-situ section lengths and corresponding formulas which based on deformation scale of arch centering were presented. According to influence line of arch centering deflection, a program used to calculate cast lengths and arch centering deformations was developed. This program could automatically calculate each segment of arch concrete based on the assigned deformation conditions. A numerical result shows that when the arch centering deformation scale was taken as the target, deformation proportion caused by each segment of concrete should be controlled on 0.5-0.6.
Mining Research of Coal Replaced with Gangue in Folded Fault Area
Authors: Xie Sheng Rong , He Fu Lian , Yang Hong Zeng , Li Hong Bin , Tian Chun Yang
Published: May 2011

Aiming at problem of low coal mining rate and environmental pollution by gangue, replacement mining technology of source recovery by excavating large span roadway and backfilling with gangue is put forward in this paper. Then combined control technology of roof cable truss and coalside cable-channel steel is applied to support the large span roadway, its control mechanism is discussed and the combined support scheme is defined by way of numerical simulation. Besides, according to the practice production condition, the replacement system which consists of gangue pretreatment, transport and replacement is established, achieving harmonic extraction of resource recovery and environmental protection and providing scientific basis and technological means for resource recovery under other geological conditions.
The Effect of Nonlinear Dynamic Shear Modulus under Anisotropic Consolidation on Response Spectrum of Soil Layer
Authors: Sun Jing , Yuan Xiao Ming , Gong Mao Sheng
Published: May 2011

The dynamic shear modulus (DSM) is the most basic soil parameter in earthquake or other dynamic loading conditions and can be obtained through testing in the field and in the laboratory. By using the resonant column tests, the effect of the consolidation ratios on the nonlinear behavior of DSM versus the shear strain,G/Gmax-γ,for two types of sands and fourteen types of undisturbed silty soil is investigated and its effect on the surface response spectrum is presented in the paper. The results here indicate that consolidation ratios have certain effect on the shape of the nonlinear behavior of DSM versus the shear strain andG/Gmaxincreases with increasing of the consolidation ratios. By comparing to the isotropic consolidation, the consideration for the actual anisotropic consolidation makes the acceleration peak amplitude increase and makes the characteristic period decrease. For the incidence of the strong seismic excitation, the effect of the anisotropic consolidation on earthquake ground motion should be considered.
Analysis of Earth-Rockfill Dam Slope Stability by Strength Reduction Method Based on Nonlinear Strength
Authors: Yu Shu , Chen Li Hong , Xu Ze Ping , Chen Ning
Published: May 2011

In the design process of the earth-rock dam, the slope stability problem was always focused on. The shear strength of rockfill in the earth-rock dam had strong nonlinear characteristics. The characteristic directly affected the factor of safety (FOS) of stability of dam slope and the determination of the critical slip surface. The shear strength parameter of rockfill was related to the minimum principal stress σ3 closely. And the value of σ3 had close relationship with the deformation characteristics of filling material and the process of dam filling etc. Strength reduction method has been widely used in solving the FOS of slope stability, and this method has the advantage on the searching of the critical slip surface. Combining the deformation and stress analysis of earth-rockfill dam filling process and the strength reduction method, this paper proposes a comprehensive method of dam slope stability analysis.
Experimental Study on Fracture Behavior of Jointed Rock with Filled Crack in Uniaxial Compression
Authors: Li Ming Tian , Li Shu Cai , Shao Dong Liang
Published: May 2011

The influences of the ways in which the surface cracks were made and fillings in the surface cracks on the fracture behavior of the jointed rock masses were studied by a number of experiments. In the experiments the surface cracks were made in different methods such as placing polyester and aluminum thin plate, cutting. The experiment results show that the surface crack made by placing polyester thin plates and cutting may well simulate the natural cracks in jointed rock masses, but the specimens can’t initiate and fracture through the surface cracks formed by placing aluminum thin plate. In order to study the influences of the fillings in the cracks on the fracture behavior of the jointed rock masses polyester and aluminum thin plates were placed in the surface cracks to simulate different fillings. Compare with the surface crack without fillings those with fillings initiated and coalescence at a higher load. However the influences of fillings on the crack growth were very complex, which required to be studied further.
Experimental Study and Finite Analysis on Flexural Capacity of Laminated Glass
Authors: Chen Jun , Lv Jia , Zhang Qi Lin , Tao Zhi Xiong , Chen Jun
Published: May 2011

Laminated glass has been increasing widely used in high rise buildings as a kind of safety glass in recent years. So we should analyze its material property. In this paper, we use flexural experiments and ANSYS program to analyze the main factors that affect the flexural capacity of the laminated glass. The test results show that the flexural capacity is closely related to film. And the ANSYS program had got good agreement with the experimental results. Comparison of experimental results with calculated ones indicates that the current design code will lead to conservative results and the equivalent thickness of laminated glasses provided in the code should be further discussed.
The Primary Exploration for the Using of South CASS7.0 Mapping System Drawing Profile Map
Authors: Zeng Zhen Hua
Published: May 2011

Southern surveying and mapping instruments company CASS terrain, cadastral mapping software is based on AutoCAD platform technology of digital mapping data acquisition system. Widely used to terrain mapping, cadastral mapping, engineering survey three major areas of application, by using terrain mapping, cadastral mapping software of CASS7.0,the author explored a method about using terrain mapping, cadastral mapping software of CASS7.0 to drawing profile map, through the application for line project theoretical and practical research to achieve the desired effect, solved the problem by using terrain mapping, cadastral mapping software of CASS7.0.
Effects of Complex Initial Stress State Parameters on Dynamic Shear Modulus of Loess
Authors: Wang Zhi Jie , Luo Ya Sheng , Guo Hong
Published: May 2011

The foundation soil of the buildings and structures is often in complex initial stress states. The dynamic torsional shear triaxial tests are carried out on undisturbed and remodeling loess under different complex initial stress states by using the remolded DTC-199 torsional cyclic load triaxial apparatus, and the effects of each complex initial stress state parameter on dynamic shear modulus of loess are discussed. Results show that, other conditions being the same, the influence of angles of initial principal stressα0on dynamic shear modulusGdof loess show a trend of the biggerα0is, the smallerGdis. The effect laws of efficient of initial intermediate principal stressb0onGdof loess are not obvious. When the dynamic shear strain is larger, the bigger initial deviator stress ratioη0is, the smallerGdof loess is. The influence of initial average principal stresspm0on loess is significant. The biggerpm0is, the biggerGdof loess is.Gdof undisturbed loess is greater than that of remodeling loess under the complex initial stress states.
Study on the Stability of Jointed Rock Slopes Based on Network Simulation of Discontinuities
Authors: Liu Fei , Liu Rong Di , Cai Zheng Fan
Published: May 2011

Discontinuities influenced the stability of jointed rock slopes are taken as the main subject of investigation, network simulation of discontinuities in the rock mass was produced by using Monte-Carlo method. The establishment of jointed element model to carry out that the network model of discontinuities was applied to the numerical one, which made it feasible to consider the influence of discontinuities in course of analyses of the finite element method when evaluating the stability of jointed rock slopes. Finally, the method was preliminarily applied with real project of artificial slope for BaiLong nuclear power plant, it is proved that it is feasible to expand for engineering applications.
Shear Band Analysis of Sand Based on Digital Image Processing Technique
Authors: Du Xiu Li , Hou Shi Wei , Lu De Chun , Cheng Xing Lei
Published: May 2011

A series of drained tests of ISO medium sand were performed to study the onset and formation of shear band. Using the digital image processing technique, the multifunctional triaxial equipment of GDS was improved. Strain isogram and local stress-strain relation at every sampling time point were recorded based on the improved equipment. The onset of shear band was from inhomogeneity of soil, while the inhomogeneous deformation can be induced by end friction and initial defect. Based on results of global stress-strain and local stress-strain relation, the end friction effect was found to have a strong influence on the radial strain. The macroscopic non-uniform sample was obtained by putting silt clay block into sand sample, evolution of shear band during the loading process showed that the discontinuation of stiffness formed at interface of two materials, with inhomogeneous deformation developing, macroscopic continues shear band fully formed.
Pore Water Pressure Variation Characteristics Analysis of Soft Soil Foundation Disposed by Dynamic Drainage Consolidation Method
Authors: Yang Gui Hua , Han Jin Liang
Published: May 2011

The pore water pressure variation during the process of dynamic drainage consolidation is calculated and analyzed with numerical simulation method, using constitutive model of Finn. The pore water pressure in mud presents transient vibration process, and decreases with depth. The pressure in mud is always higher than in sang bag well, which reveals that sang bag well is an effective vertical drainage channel in process of dynamic drainage consolidation. In addition, seen from the characteristics of pore water pressure variation, effective consolidation depth can be accurately forecasted.
Observed Soil-Water Interaction in the Centrifuge Dynamic Test
Authors: Su Dong , Li Xiang Song
Published: May 2011

Centrifuge physical modeling technique has been increasingly used in geotechnical earthquake engineering. A centrifuge dynamic model test has been conducted on the centrifuge on a saturated sand deposit model. The input motion at the base of the model was a strong earthquake waveform with a peak acceleration of 0.55 g in prototype. Some interesting phenomena, which include disappearance and reappearance of acceleration in soils during the shaking event, and existence of double plateaus or one plateau and one peak in the time histories of excess pore pressure, were recorded. The mechanism behind the phenomena was investigated by comparing the time history of excess pore pressure with the time history of acceleration, and with the derived shear modulus.
Model Test Research on Moisture Control of Saturated Over-Wet Soil
Authors: Wen Hua , Wang Ru Heng , Yao Yong , Wang Yue Ming
Published: May 2011

Based on laboratory model test, this paper presents the draining efficiency of vacuum pre-loading method and electro-osmosis method with over-wet soil in moist and rainy areas. The results show that: both methods can effectively reduce the water content of saturated over-wet soil in Ya’an area, to achieve the desired effect of drainage and consolidation; and the degree of the effects of both methods differ with spatial variation.
Analysis and Solutions of Deformation Behavior of Fault Zone Side Slope Hazard
Authors: Zhou Chun Er
Published: May 2011

The side hill cut of certain road cutting has a gradual slope and low slope height. But due to the location in fault zone, serious slump damage occurs during construction, leaving large crack. Aiming at the deformation damage of the side slope of the road cutting, this essay provides analysis of the deformation behavior and mechanism causing the slump through the geographic environment and monitoring data, and through summing up the experience in design and construction management, provides engineering analogy case and experience reference for similar side slope management.
Study on the Formation and Repeated Opening Mechanism of Ground Fissures under the Role of Surface Water
Authors: Jiang Zhen Wei , Wang Qi Yao
Published: May 2011

The role of surface water is also the main reason for the formation and development of ground fissures. Five mechanisms were obtained on the formation of ground fissures under the role of surface water in the loess region through theoretical analysis, i.e., fissuring mechanism induced by loess collapsible deformation; that induced by dissolution and suffosion; that induced by water-loss shrinkage; that induced by hydraulic pressure; that induced by humidification and softening. As the role of surface water had certain phased and periodic characteristics, repeated fissuring mechanism of ground fissures was analyzed. Consequently, it could be known that the repeated fissuring of ground fissures under the role of surface water was mainly shown as horizontal openness and closure with little vertical displacement, and fissures were intersected and cross-cut with each other to form a complex network structure.
Sensitivity Analysis of Rockfall Kinematic Parameters in Expressway
Authors: Li Ya Li , Zhou Min
Published: May 2011

The rockfall trajectories are affected by many kinematic parameters. So it is very necessary to exactly analyze the sensitivity of rockfall kinematic parameters to the control indices for design of protective structures. In this paper, the kinematics combined with the orthogonal test is adopted to analyze the sensitivity of rockfall kinematic parameters. Taking the rockfall hazard near the DK27+120 section of the jing-ying expressway in china for example, three control indices are taken as the testing indices, and five kinematic parameters are taken as the testing factors. The orthogonal test table is used to design twenty-five kinds of schemes, and the numerical simulation tests of rockfall trajectories are carried out. The range analysis are performed to study the sensitivity of rockfall kinematic parameters, and then the main parameters influencing the control indices for design of protective structures are obtained, which provides scientific basis for the rockfall prevention in jing-ying expressway.
Moraine Lake Outburst Simulation of Glacier Sliding and Risk Assessment
Authors: Peng Cheng Hui , Wang Chang Ming , Wang Gang Cheng
Published: May 2011

Moraine Lake outburst is a common geological disaster in Tibet. Meltwater infiltrates into glacier through the cracks and lubricates it, increasing the instability of glacier. There is a close relationship between glacier landslide and Moraine Lake outburst. In order to explain it, we established the glacier sliding model, and analyzed the sliding characteristics. Then we discussed the link between glacier landslide and Moraine Lake outburst, and then proposed a quantitative expression. Finally we analyzed the glacier stability of Aya Moraine Lake and others, forecasted and evaluated the risk degree of Moraine Lake outburst. Field investigation conclusions are consistent with calculated results, that is to say, the calculated results are accurate and the predictions are reasonable.
Structural Optimization of Reinforced Concrete Aqueduct with Multi-Longitudinal Beams Part I: Method
Authors: Guan Jun Feng , Li Xiao Ke , Zhao Shun Bo
Published: May 2011

Former approaches fordesigning reinforced concrete aqueduct with multi-longitudinal beams were mostly based on experience. In this study, an optimization method is proposed instead. According to the mechanical characteristics of aqueduct, optimization principlesfor structural deformation coordination and sectional crack-resisting are developed. Furthermore, in optimization of large and complex reinforced concrete aqueduct, this method employs nominal tensile stress to control the maximum crack width. In addition, a 3D beam-shell element model is suggested for calculating internal force of aqueduct.
The Comparative Study on the Impact of Tunnel Excavation with Footage Different CRD to Testability of Surrounding Rock
Authors: Shi Lin Po , Jiang Bin Song , Zhao Yao Qiang
Published: May 2011

This article used Geotechnical Engineering General Software FLAC3D to simulate the tunnel CRD method under 1.5m, 2.0m, 2.5 m, 3.0 m footage separately and analysis the influence to the tunnel surrounding rock stability in the different footage construction. This paper selected a real tunnel project as the research object and analysis comparatively the rule and characteristic of various methods of tunnel surrounding rock displacement, stress distribution and the plastic zone size through simulated computing the different footage construction. The results show that,Ⅰ.Considered from the surrounding rock stress control that the 1.5m footage adjacent formation stress adjustment effect is best, next is 2.0m, 2.5 m, 3.0 m;Ⅱ.Considered from the plastic zone size that the 1.5m footage control effect is best, next is in turn 2.0m, 2.5 m, 3.0 m;ⅢConsidered from the surrounding rock displacement control that 1.5 meter footage adjacent formation control effect is best, but 2.0 meter, 2.5 meters and 3.0 meter phase differences are not big.
The Study on the Construction Mechanical Behavior of the Shield Tunnel Crossing the Ultra-Deep Ventilation Shaft
Authors: Wang Shi Min , He Chuan , Lan Lei Lei , Liu Si Jin
Published: May 2011

With the development and utilization of underground space and the construction of large quantities of shield tunnels, the phenomenon that shield tunnel go through the existing buildings at close quarters is in the rise. The stiffness mismatch between shield tunnels and existing buildings has a significant impact on the deformation and stress of the connection part. In order to explore the affection on the shield tunnel from the existing buildings while the shield tunnel crosses the later, taken the shield tunnel crossing Wuchang ultra-deep ventilation shaft in Wuhan subway as an example, the influence to the shield tunnel by the existing building is studied. In the sphere of influence, the closer to the ventilation shaft enclosure structures, the more notable the uneven deformation of the tunnel segment structure would be; the closer to the rigid structure, the smaller the transverse bending moment would be; the nearer to the rigid structure, the greater the horizontal axial force, vertical axial force and vertical bending moment would be. The impact on deformation and load-carrying capacity from ventilation shaft enclosure structure on shield tunnel segment weakens sharply by the increasing of their distance.
Seismic Analysis of Intake Tunnel for Nuclear Power Plant
Authors: Zhao Jie , Zheng Yang , Wang Gui Xuan
Published: May 2011

Aiming at the nuclear power plant structure and adopting time domain analysis approach, the seismic analysis of an intake tunnel for nuclear power plant is performed with FLAC3D in this paper. Contraposing the characters of the field rock of the nuclear plant, the internal force distribution of the tunnel under different wall rocks is researched and analysed, and the envelope diagram of inner force in the lining of the tunnel is drawn. The obtained law can provide the basis for the seismic response analysis of tunnels.
Study on the Multi-Layered Excavation Scheme of the Large Underground Powerhouse
Authors: Yao Qiang , Li Hong Tao , Yang Xing Guo , Zhou Jia Wen , Sun Xing Yu , Zhou Hong Wei
Published: May 2011

It is very important to make reasonable construction procedure during excavating the underground powerhouse. The factors that influence the multi-layered excavation of the underground powerhouse are analyzed in this paper. And the typical multi-layered scheme is made considering of these factors. Further research shows that for the underground powerhouse that is as large as Shuibuya and Dachaoshan project, the scheme of multi-layered excavation and construction procedure can be made referring to the typical multi-layered scheme. But for those super-large underground powerhouses, some benches which are too high must be further divided based on the typical scheme. And some temporary access tunnels must be designed on appropriate benches in order to make relevant benches have no less than two working faces. Thus the speed of excavation can be improved.
Experimental Study on the Seismic Behavior of SRHSC Columns
Authors: Zheng Shan Suo , Tao Qing Lin , Hu Yi , Li Lei , Li Zhi Qiang
Published: May 2011

Based on the experiments of 4 SRHSC (steel reinforced high strength concrete) column specimens, which were different in concrete strength, axial compression ratio and spacing of hoop reinforcement, this paper investigates the seismic behavior and flexural strength of SRHSC columns under cyclic lateral loading which is controlled by the displacement. According to the date and phenomenon of experiment, adopting existed theory and foreign codes for composite columns, the failure mode, lateral load-deflection relationship, strength and stiffness deterioration, ductility capacity and energy dissipation capacity of SRHSC columns is analyzed.
Analysis of Destructiveness on Mud Outburst in Yuanliangshan Tunnel, China
Authors: Chen Qiang , Zhu Bao Long
Published: May 2011

Since karst landform distributes widely in south China, highway and railway construction usually adopt the method of embedding long and large tunnel in great depth so that they could pass these karst areas safely. Water outburst and mud outburst accidents occurring on the stable karst area are major hazards in highway and railway construction and operation. The grave mud outburst accident occurring at the entrance of Yuanliangshan Tunnel has the following features: (1) the dissoluble rocks distribute widely, possessing a sound catchment capacity. (2) Water storage structure exists above the elevation of tunnel body; (3) feature of geologic structure and attitude of stratum in that area benefit the development of karst; (4) underground karst pipe is smooth and unobstructed. And there are certain underground rivers. (5) Besides, the thickness of water-proof layer has less power than the hydraulic pressure of ground water. (6) Karst mud outburst hazard features suddenness and concealment. Taken the example of Yuanliangshan Tunnel, the paper conducts preliminary analysis and careful calculation of the speed of karst mud outburst and its impact force, providing some research ground for disaster assessment and prevention.
Study on SMA Pseudo-Rubber Metal Damper
Authors: Meng Qing Li , Zhang Min Zheng , Feng Jun He
Published: May 2011

In this paper, Shape Memory Alloy (SMA) Pseudo-Rubber Metal (PRM) was studied, and comparative test with common Pseudo-Rubber Metal was carried out. The enveloped area of hysteresis curve of SMA PRM is clearly larger than that of common PRM, which indicates the damping of SMA PRM overmatches that of common PRM. The stiffness value of SMA PRM and common PRM increases with their distortion amplitude’s increase, and the stiffness value of SMA PRM is less than that of common PRM. The carrying capacity, stiffness and damping of PRM are related with its relative density. The hysteresis behavior of SMA PRM is stable and basically not related with repeating load effect. Moreover, SMA PRM damper device was studied and developed, and comparative test with common Pseudo-Rubber Metal was carried out.
Microstructure of High Strength Concrete Mercury Intrusion Porosimetry and Thermogravimetry Analysis
Authors: Mohammad Iqbal Khan
Published: May 2011

Microstructural properties such as pore structure and hydration play a decisive role in determining the properties of a concrete. This paper presents the investigation on pore structure and hydration process of high strength concrete. Pore structure study was conducted using mercury intrusion porosimetry and hydration progress was monitored using thermogravimetry analysis on various blended combinations of cementitious materials incorporating fly ash and silica fume as partial cement replacement. It was found that silica fume refined the pore structure efficiently and reduced the calcium hydroxide content as early as 1 day. All ternary blended systems containing fly ash and silica fume exhibited lower calcium hydroxide content and refined pore structure in comparison to their respective blended pastes.
Connecting Parameter Study on Adjacent Structures Linked by Dampers
Authors: Sun Huang Sheng , Cheng Li Nuo
Published: May 2011

In order to research the optimal parameters of dampers linking adjacent structures for seismic mitigation, two SDOF systems connected with visco-elastic damper (VED) are taken as research object and the primary structural vibration frequency ratio, connection stiffness and linking damping ratio as research parameters. Modified Kanai-Tajimi spectrum is selected to model the earthquake excitation. The peak distribution of power spectral density curves are analyzed, then the formulas of structural mean squared displacement (MSD) and research parameters is derived based on random vibration theory. Then the relationship of the adjacent structural seismic response versus the research parameters was presented. The optimal value of the linking visco-elastic damper damping ratio and stiffness ratio are investigated. Finally, the seismic responses of example structures with or without connecting dampers are contrastively analyzed. The dependence of response mitigation effective on research parameters is highlighted. The results indicate fine earthquake-reduction effectiveness of dampers connecting adjacent structures. It is also shows that optimal parameters of damper cannot reduce the seismic responses of the primary structures connected to the best extent simultaneously. The damper parameters should be determined according to the best seismic mitigation effectiveness of the primary, auxiliary structure or the combined structure system.
Experimental Study on the Dynamic Destruction of Rock Slope with the White DSCM Method
Authors: Wang Lai Gui , Zhang Hong Zhu , Feng Mei Sheng
Published: May 2011

To study the stability of rock slope under dynamic load,the digital speckle correlation measurement (DSCM) is used for dynamic failure of rock slope containing two weak layers.It observes the displacement field, deformation field, and stress field during the process of crack formation, crack through the slope and slope collapse. Experimental results show that the initial deformation cracking on the surface around the structure of the weak layer, and then extended to top and the foot of the slope, and finally through the loose structure.The slope stability is controlled by the weak layer’s angle, the space form of the weak layer and the slope Mechanical Properties.It gives the failue model of the different positon in the slope.