bluuebunny/crossref_metadata_2025 huggingface dataset:
Inner Defect Induced Crack Growth Analysis and Fatigue Life Prediction for Anthropogenic CO2 Pipelines
Authors: Jin Qiao , Li Ming , Wen Quan
Published: October 2012

One approach to limiting CO2 emissions from oxidation of carbon-based fuels is to capture the CO2 and store it, possibly in onshore or offshore subsurface geologic formations. From the CO2 transportation structure perspective, a critical component of this approach is the pipeline transportation of supercritical or dense CO2. In CCS, the pipelines undertaking a CO2 transportation task suffer various loads, the effects of which is easily aggravated due to the existence of a high working pressure (above 7.4MPa) and inner corrosion. For the application of anthropogenic CO2 pipe transportation technique, this paper will address a LEFM-based finite element method which can evaluate fatigue life for a CO2 transmission pipeline containing a semicircle inner defect. Specifically, a portion of welded round steel pipeline is selected as the object of our analysis. Under the inner pressure fluctuation scenarios, an FRANC2D finite element procedure is generated to simulate mode-I crack extension from a given inner edge crack, which initiates from the half circle defect,and the corresponding stress intension factors(SIFs), , and its increment, , varied with different cracking depths, are calculated and compared. Afterwards, the fatigue lives for the pipeline with the defects of different sizes are obtained by using a modified Paris formula which can analyze the influence of crack closure and stress ratio. Thus, the relation between the fatigue life of CO2 pipelines and the dimension of the inner defect can be determined by performing the proposed fatigue crack growth analysis.
Reliability Appraisal of a Detachment of Traffic Police Houses
Authors: Wang Zhong Qiang , Ouyang Tao
Published: October 2012

The reliability appraisal of buildings is an indispensable part of the daily management of the existing buildings[5], we should pay more attention to it; Through the detection and appraisal of a planned, which will provide the scientific basis for technology management and safe use of buildings. This article combined the reliability appraisal of a traffic police roof damage, discussed the property and function of the structure reliability. The freon air tank of Tongxin heat preservation material factory have exploded, which in the distance of 300m away from the traffic police, produced strong shock wave, resulting in the injury of adjacent homes, accordingly, took technical appraisal of three housing of the traffic police detachment; Three homes structure component has not seen the damage caused by the explosion, at present, the structure is safety, reliable, and failed to meet the standard of dangerous building, can continue to use normally.
An Efficient Method for Structural Reliability Analysis
Authors: Ying Liu
Published: October 2012

An efficient reliability analysis method has been proposed in the paper, which based on stochastic response surface method. The key advantage of the stochastic response surface method is that the collocation points are selected for minimizing the mean square error, and from high probability regions, thus leading to fewer function evaluations for high accuracy. Compared with Monte Carlo method, the proposed technique can be more efficiency while achieve comparative accuracy.
Analysis of Properties of Reinforcing Steel Bars: Case Study of Collapsed Building in Lagos, Nigeria
Authors: Odusote Jamiu Kolawole , Adeleke Adekunle Akanni
Published: October 2012

The chemical compositions and the microstructures of reinforcing steel bars obtained from three different collapsed building sites were studied. Optical emission spectrometer was used to carry out the chemical analysis, while the microstructure was examined using an optical microscopy. The carbon contents of the steel bars were found to be higher than BS4449 and ASTM706 standards, but they are in close range with the Nst-65-Mn standard. The manganese contents of the steel bars are lower, while the sulphur and phosphorus contents are quite higher than the BS4449, ASTM706 and Nst-65-Mn standards. The hardness values of the investigated bars are higher than recommended BS4449 standard but lower than Nst-65-Mn standard. Brittle globules of Fe3P and FeS were observed within the structure possibly due to higher contents of deleterious sulphur and phosphorus. The results suggest that the investigated reinforcing bars are brittle and thus contributing significantly to the collapse of the building structures.
Cracking Behavior Analysis of Carbon Fiber Reinforced Concrete Beam
Authors: Lu Zhao Hong , Gu Xiao Song
Published: October 2012

This paper analyzed the cracking behavior of carbon fiber reinforced concrete beam under static load using the finite element numerical analysis. By the way of finite element numerical simulation and the method of increasing the load gradually to analyze the carbon fiber content influence on the beam cracking, crack developing, beam deflection and beam average crack spacing. By comparing with the simulation result of common reinforced concrete beam test piece, it turned out that the carbon fiber reinforced concrete beam has a good cracking and deformation behavior under the same ratio of reinforcement. Under the same load, both the carbon fiber reinforced concrete beam and the common reinforced concrete beam have a small deformation, but the carbon fiber reinforced concrete beam showed a better resistance to deformation as the load increasing, its deflection increasing extent showed an obvious decrease compared with that of the common reinforced concrete beams. Its crack width can be revised by the common reinforced concrete beam rules.
A Study on Carbon Fiber Influence to Rebar Corrosion in Concrete
Authors: Yang Qiao , Zhu Xiao E
Published: October 2012

Rebar corrosion test of Carbon Fiber Reinforced Polymer (CFRP) concrete was did. Carbon fiber in concrete improved the compression strength of the concrete, but width and number of concrete cracks was not reduced, carbon fiber has not obvious act for improving concrete corrosion crack behavior. CFRP concrete Corrosion potential was a little high than common concrete, carbon fiber has not obvious act for improving concrete behavior in protecting steel beyond corrosion. The porosity of the carbon fiber reinforced polymer concrete was twice of the common concrete, carbon fiber added to concrete lead to increase porosity and maybe decrease concrete behavior in protecting the embedded steel in corrosion.
Testing Research for Deformation and Rigidity of Lightweight Aggregate Reinforced Concrete Beams under Fatigue Loading
Authors: Lei Guang Yu , Wu Chang Hong , Li Shi Ming
Published: October 2012

Through the experiment of eight lightweight aggregate reinforced concrete beams under static loading and fatigue loading with constant amplitudes, the deformation rule under fatigue loading was analysed, the rigidity calculation means and formulations of lightweight aggregate reinforced concrete beam under fatigue loading were also discussed.
The Durability Study of Concrete in Sulfate Environment
Authors: Qiao Hong Xia , Li Yu , He Zhong Mao , Dong Jin Mei
Published: October 2012

Aiming at determining the durability of concrete in very salty regions, this study examines the performance of various high performance fine aggregate concretes in a sulfate environment, such as high performance concrete inside a composite additive, and Portland cement concrete and sulfate resistant cement concrete, all of which experienced dry-wet cycles in sodium sulfate solutions. By examining the changes of elastic moduli and analyzing the SEM of the concrete, this paper has found that the salt resistance of sulfate resistant cement concrete is no better than that of Portland cement concrete in the extremely aggressive dry-wet cycle environment but high performance concrete containing a composite additive has better resistance in a sulfate environment. Besides, the composite additive can create the environment for a second hydration to reduce the amount of Ca(OH)2 inside the concrete, and build additional C-S-H gel to reform the microstructure of concrete effectively. Finally, the paper offers some advice for mixing concrete in salt regions.
Research on Safety Risk Identification of Continuous Beam Based on Deflection Reliability
Authors: Luo Wei Hua , Wang Peng , Yang Wei Jun
Published: October 2012

Based on the construction process of the structure stress, especially the construction of continuous beam linear control plays a role in determining the characteristics, based on the deflection reliability safety risk identification method, is introduced into the deflection reliability index.Give the calculating formula and example to verify the applicability of the method.
Experimental Analyses of Dynamic Damage of the Reinforced Concrete Pile
Authors: Li Rong Jian , Yan Rui , Li Hai Tao
Published: October 2012

The earthquake often leads to the damage of stabilizing concrete pile. In order to analyze the damage mechanism of the reinforced concrete stabilizing pile, this article uses the developed concrete model piles, studies the seismic deformation of a slope reinforced with stabilizing piles and the dynamic broken damage phenomenon of pile by using the dynamic centrifuge model test without groundwater. The results show that the earthquake action leads to the obvious increase of dynamic excess bending moments, eventually results in the pile’s breaking damage.
Study of Post-Fire Bearing Capacity of Self-Stress Ceramsite Concrete Filled Steel Tubes
Authors: Wang Jian Min , Zhang Jinyi , Wang Xin Tang , Sun Hong Liang
Published: October 2012

Mechanical behavior and bearing capacity of self stress ceramsite concrete filled steel tubes (noted as SCCST) after exposure to fire are experimentally studied. Effect of the parameters, such as value of furnace temperatures, self stress on the post-fire bearing capacity and ductility of the specimens after exposure to fire were especially discussed. The experimental results show that all the specimens of SCCST have higher post-fire bearing capacity and better ductility, and there was no obvious descending segment in the load-strain curves of the most specimens after exposure to fire. It was concluded that the furnace temperature subjected to the specimens and the initial self stress produced in the specimens of the composite short columns has some effect on the axial bearing capacity of ceramsite concrete-filled steel tubular short columns after exposure to fire, and the volume of expansion agent of 10% has most great effect on post-fire bearing capacity of SCCST after exposure to fire.
Study on Buckling of an H-Shaped Steel Member with Initial Geometric Imperfection
Authors: Niu Peng , Yang Gang , Jin Chun Fu
Published: October 2012

Based on Ježek method of computing the elastic-plastic buckling of the member under the axial compressive load and the bending moment, considering the initial imperfection, the analytical expressions of calculating the ultimate load of buckling about the neutral axis with the maximum moment of inertia for an H-shaped member are derived. Using the elastic-plastic finite element method and the theory of nonlinear buckling, the impact by initial geometric imperfections on the H-shaped steel member under the axial compressive load and the bending moment are analyzed and the numerical solutions of ultimate bearing capacity are obtained. By compared with the values of the finite element method (FEM), it shows that the analytical method in this paper is valid. The results of the example show that the presence of initial imperfections reduces the ultimate bearing capacity of the steel member to a great extent. It is also found that the influence of the initial geometric imperfection on the ultimate bearing capacity of member is smaller when the bending moment increases.
Fatigue Stress Analysis of Diaphragm Cap Hole in Orthotropic Steel Bridge Decks
Authors: Yang Mu Ye , Liu Rong , Ji Bo Hai , Xu Han Jiang , Chen Ce , Zhao Duan Duan
Published: October 2012

Influence of diaphragm parameter on stress amplitude and fatigue damage of diaphragm details were investigated based on Tai Zhou Yangtze River Bridge. FEM of steel bridge deck and diaphragm detail were established. Boundary conditions of the diaphragm details FEM were interpolated by sub-model method, and the accurate local stresses of diaphragm details correspond to different lateral distribution of wheels were calculated. Results show the stress amplitude of diaphragm details reach maximum when wheel off-center position is 150mm, and it decreases with the increase of wheel off-center position greatly. The stress amplitude of diaphragm details increase with the increase of the distance of diaphragms, and increasing diaphragm’s thickness can improve fatigue stress of steel bridge deck.
Structural Stress Analysis of Trough to Deck Plate Weld in Orthotropic Steel Bridge Decks
Authors: Wang Man Man , Chen Ce , Ji Bo Hai , Liu Rong , Zhao Duan Duan
Published: October 2012

A comparative study among five methods to calculate the structural stress of the trough to deck plate joint in orthotropic steel deck was carried out. The five methods used are surface stress extrapolation method (SSE), Haibach method, Xiao and Yamada method and CAB method. FEM analysis shows the five methods are mesh sensitive. Structural stress calculated using element type solid95 is larger than that of solid45. For fine and medium mesh model, structural stress calculated by Haibach method is larger than other methods, which means a lower fatigue life. Structural stress calculated by Yamada method is lower than other methods, which means a higher fatigue life than that calculated by other methods. For coarse mesh model, structure stress calculated by quadratic extrapolation method is larger than other methods, and, structural stress calculated by Yamada method is much lower than other methods.
A Probabilistic-Based Durability Analysis of Concrete Structures Exposed to Chloride Containing Environment
Authors: Shi Wei Hua , Yu Zhi Wu , Kuang Ya Chuan
Published: October 2012

Time dependency of chloride transport has been studied and an improving model for predicting the apparent chloride diffusion coefficient has been proposed. A probabilistic-based durability analysis to estimate failure probability on the chloride ingress into concrete has been carried out. Results of the analysis demonstrate that the improving model in this paper is appropriate for long term service life prediction of concrete structures exposed to chloride containing environment.
Influence of Stirrup Corrosion on Shear Strength of RC Beams
Authors: Xue Xin , Seki Hiroshi , Song Yu
Published: October 2012

There have been few reports on shear behavior of reinforced concrete (RC) beams with corroded stirrups, and the influence of stirrup corrosion has yet to be identified. Given this background, experience was carried out to investigate the shear behavior of RC beams containing corroded stirrups. Investigation results indicate that if the percentage local maximum mass loss is below 35%, there is little influence on the load-carrying mechanism. The concrete shear resistance seems to change little and the shear capacity can be calculated by just taking into consideration the reduction in stirrup shear resistance. It is also found that the anchorage conditions of the stirrups have a predominant influence on the shears of RC beams.
Influence of Aggregates on Cracking Sensitivity of Concrete
Authors: Chen Xia , Yan Jian Jun , Yang Hua Quan
Published: October 2012

Concrete cracking sensitivity made from different aggregates was compared with employment of advanced temperature and stress test machine by tracking thermal and stress development of concrete with age and elements distribution in interfacial transition zone of each concrete was explored by SEM and EDS. Test results indicated that compressive strength of concrete made from basalt and limestone was greater than diorite and natural aggregate and crack resistance of concrete based on cracking sensitivity comparison in terms of cracking temperature varying from minus 0.3°C to minus 2.5°C as diorite, basalt, limestone and natural aggregate. Elements Ca and Mg were apparently accumulated in vicinity of ITZ and some reaction between limestone and cement matrix might have taken place which blurred the boundary between aggregates and cement matrix.
Analysis of Soil Consolidation Characteristics Caused by Pit Dewatering
Authors: Tong Huai Feng
Published: October 2012

Consolidation in soil mechanics is the process that the soil to produce compressive deformation under load, and pore volume is smaller, pore water is squeezed out, the soil volume is gradually reduced and finally become stable. In the pit dewatering Project, due to the pore water is expelled, the soil effective stress increases, the pore volume decreases, and the soil produce compression within the influence of precipitation. In this paper, based on the analysis of classical consolidation theory, the differences of two classical consolidation theory is compared, the consolidation characteristics of soil is obtained in the process of pit dewatering.
The Numerical Analysis of Failure Length about Buried Steel Pipeline with Frusta under Static Load and Dynamic Load
Authors: Li Xiao Li , Yin Zhao Long
Published: October 2012

A mechanical model of buried pipeline with frusta was established under the research of being collapse and gulch. A finite cell model of buried pipeline was built by using ANSYS finite cell analysis program. The seismic response of the finite cell model under the action of siesmic waves were simulated in different earthquake intensity，and its stress and distortion under static load and dynamic load of collapse and gulch was given, then the length of pipeline failure was given. the important foundation for the earthquake is provided by the simulated results.
Aerated Concrete Composite Reinforced Concrete Shear Wall Thermal Insulation Layer Stress Analysis and Crack Control
Authors: Yang Mu , Liang Jian Guo , Yang Wei Jun
Published: October 2012

Drying shrinkage loads are converted into the equivalent temperture,using the model of composite material mechanical analysised layer stresses and interlaminar stresses of the shear wall under the influence of temperture load stress,combined with wind load and weight ,acquired the thermal insulation layer’s stress effect under the combined effect. According the failure criterion of material and adhesive surface, to determined the cracking mechanism and crack control of aerated concrete thermal insulation layer.
The Detection and Analysis of Reservoir Dam Crack Depth and Grouting Quality Analysis
Authors: Zhang Jin Yang , Gao Xiu
Published: October 2012

Ultrasonic method is a considerably mature method to test the defects of concrete. As for a certain dam deep crack with merely one test surface, the operations can be done such as drilling holes on both crack sides, filling clean water as coupling agent and finally the crack depth is tested with cross-hole sonic logging, subsequently, the data processing and depth judgment with the test principle of the said method. The result manifests that before grouting treatment, the measured dam crack depth is 1.2~9.0m, and the tested point wave shape has not been obviously abnormal and the criterions of wave amplitude and wave speed against the intact local concrete remain no greater differences and the cracks grout in the tested zone are generally solid after the grouting.
Numerical Simulation of Flow over Mountainous Valley Terrain
Authors: Li Chun Guang , Chen Zheng Qing , Zhang Zhi Tian
Published: October 2012

With the increase of the span length of bridge, the wind field characteristics at bridge site play crucial role for the safety of bridge. The present paper discusses the results of a numerical simulation of the wind flow over mountainous area called Aizhai, located in Hunan province, where a super long span bridge with main span of 1176m will be constructed. The results indicate that it is inappropriate to describe the mean wind velocity profiles by power law using the same roughness exponent along the span wise direction in the mountainous valley terrain. The speed-up effect and the significant change in wind direction of the mean flow were observed, which provide the information necessary for determining the design wind speed such as for a long span bridge across the valley.
Numerical Simulation Research on Coal-Gas Outburst in the Process of Development
Authors: Cai Feng
Published: October 2012

Coal-gas outburst is a kind of complex disaster induced by engineer operations in the process of extracting or developing in coal seams. According to the theories of gas seepage and deformation of coal or rock seams, taking consideration of the heterogeneity property of coal or rock materials in mechanics of materials as well as non-linear permeability characteristic of coal or rock materials in the process of deformation and fracture, SPH algorithm of LS-DYNA software is used to numerically simulate the coal-gas outburst induced by development in coal seams. Simulation results represent the whole process of coal-gas outburst from the growing, extending and connecting of cracks to final outburst under the impact of gas pressure, ground stress and mechanical properties of coal-rock. The nonlinear nature of the mutation of outburst induced by gradual destruction of the coal or rock materials under the influence of developing operations is revealed, including the evolution of the stress field in the rupture process of the coal or rock material. This provides a theoretical foundation for further understanding the mechanism of coal-gas outburst as well as preventing outburst technology.
Research of Forecasting Method for Horizontal Displacement of Deep-Seated Subgrade
Authors: Guo Yun Kai , Cheng Gang , Le Xiao Yong
Published: October 2012

Accurately predicting the subgrade deep horizontal displacement is important to subgrade stability. The study on subgrade deep horizontal displacement is not sufficient. It studies several displacement prediction methods,and builds matching prediction models to predict horizontal displacement. Referring to the posteriori error ratio and small error probability, we get the following results. GM(1,1) model is suitable for predicting the subgrade horizontal displacement,and the trend of GM(1,1) model is consistent with actual values. Its accuracy is higher than the logarithmic curve fitting.What more, the stability is better than the exponential smoothing model.
Zonation of the Landslide Hazards Based on Artificial Neural Network
Authors: Wang Zhi Wang , Li Duan You , Ning Jing
Published: October 2012

This paper applies RS and GIS technology to study zonation of the landslide hazards in the study area from Badong county to Zigui county in TGP reservoir region. The causative factors involves lithology, distance to faults, slope angle, slope aspect, elevation, drainage network, distance to river and distribution of plant, which are derived from geological map, Spot imagery data and Digital Elevation Model (DEM) based on RS and GIS technology. We analyze the zonation of the landslide hazards with artificial neural network. The research result is very coincident with the occurrence of the known landslides in the study area.
Validation Experiments of Five Fire-Extinguishing Agents on Preventing Wood Stack Fire from Reburning
Authors: Li Shu Sheng , Gao Ye , Zou Gao Wan , Dong Hui , Zhang Yu Ming
Published: October 2012

Experiments of five fire extinguishing agents on the fires of wood stack and oil were conducted in ISO9705 room. It focused on comparing the extinguishing abilities of the five fire extinguishing agents on Class A fire represented by wood stack fire. It is can be concluded that FM200 had the best extinguishing performance for wood stack fire, and it could prevent wood stack reburning; while IG541 and hot aerosol extinguisher do worst on preventing the wood stack fire reburning. In addition, the effects of extinguishers on heat release rate were compared.
A Review of Study on Chinese Debris-Flow Risk Assessment
Authors: Wang Jun , Yang Shun , Ji Xian Jun , Ou Guo Qiang
Published: October 2012

Debris-flow risk assessment plays an important role in territorial planning and hazard prevention and alleviation, especially after 5.12 Wenchuan Earthquake, it can provide guidance for post-disaster restoration and reconstruction. Based on plenty of references, such as monograph, journal, thesis and other document, this paper summarized the present research situation of Chinese debris-flow risk assessment, put forward that the current debris-flow risk assessment model is not suitable for earthquake-stricken areas and urgently need to establish a new risk assessment model to guide post - disaster planning and reconstruction.
Numerical Analysis and Simulation of Spatial Concrete Frames after Fire
Authors: Xia Min , Yu Jiang Tao , Lu Zhou Dao
Published: October 2012

In order to analyze the mechanical properties under three conditions of fire-damage, rehabilitation and strengthening of spatial concrete frame structures after fire, two novel numerical models are developed in this paper by dividing the cross-sections of beams and columns into a lot of concrete fibers and steel fibers and dividing slabs into several layers along the direction of the slab thickness based on the concept of the fiber element model and the layered shell element model. These two models can consider the distribution of non-uniform temperature in the cross-sections of structural members and the changing of mechanical properties of fire-damaged, rehabilitated and strengthened materials. Besides, the Analytical System of Fire-damaged Concrete Frame (ASFCF) is established through the secondary development of ABAQUS Software that is completed by the programming language of Python. This system is used to analyze and compare the mechanical responses under three conditions of fire-damage, rehabilitation and strengthening of a multi-story, multi-span spatial concrete frame after fire. The results indicate that ASFCF can properly analyze the mechanical properties under three conditions of fire-damage, rehabilitation and strengthening of spatial concrete frames after fire, and it provides valuable references for assessing the residual mechanical properties and the mechanical properties after rehabilitation and strengthening of global concrete frame structures after fire.
Experimental Investigation on the Fire Resistance Performance of L Special-Shaped Steel Reinforced Concrete Columns
Authors: Gao Li Tang , Gao Yun Fei , Yang Zhi Xin , Shan Qi Yun , Gao Gang
Published: October 2012

Four full-scale SRC columns with special-shaped cross section were experimentally investigated in fire following ISO834 standard heating process and were implemented in the compression test after fire .The section temperature field after two hours of fire, deformation laws under fire and the mechanical behaviors after fire were got. Find: (1) Bond slips between concrete and steel were small which indicates that concrete and steel can work together. (2) Reasonable way with steel cross-section had a significant effect on the mechanical properties of columns. (3) The two sides of SRC special-shaped column were under fire conditions, sections were damaged. When the load was at the centre of the cross section, columns were in the state of axial compression before fire and the state of eccentric compression after fire.
The Calculating Method of Erosion Depth of Viscous Debris Flow
Authors: You Yong , Zhao Yan Bo , Liu Jin Feng
Published: October 2012

Gully erosion depth is one of the most important parameters for the assessment and prevention of debris flows. So far, there is no good method for calculating the gully bed erosion depth of viscous debris flow. This paper discussed the calculation method of erosion depth of viscous debris flow based on theoretical deduction. The formula for calculating the erosion depth was constructed based on deduction from the viewpoint of theoretical mechanics. Then, the affecting factors of gully erosion were discussed. This method can be used to calculate the erosion depth for viscous debris flow under different frequencies and provide a better evaluation and prevention tool for mitigating debris flow disaster.
Calculating Temperature Distribution in Concrete Encased H-Section Steel Column in Fires Using TFIELD
Authors: Liu Yong Jun , Bi Ran , Wang Yan
Published: October 2012

Steel–concrete composite columns are used extensively in modern buildings in recent decades due to the benefits of combining two construction materials: reinforced concrete is inexpensive, massive, and stiff, while steel members are strong, lightweight, and easy to assemble. For concrete-encased composite structural members, an additional advantage is that the concrete used for encasing a structural steel not only increases its stiffness, but also protects it from fire damage and local buckling failure. Traditionally, the fire resistance of composite structural members has been determined in standard fire tests, with the temperature-time curves representing more severe heating conditions compared to that which occurs in many typical natural fire compartments. To design a concrete encased H-section steel structure safely and economically, it is necessary to calculate temperature distribution in composite steel-concrete columns under natural fire. In this paper, the program TFIELD written by first author is used to calculate the temperature distribution in a concrete encased H-section steel column under natural fire and ISO 834 fire. The calculating results under the standard ISO 834 fire and a natural fire have been compared which exhibit obvious differences.
Mechanism and Prediction Research of the Surface Mining Subsidence of Thick Loose Layers in Mining Area
Authors: Zhang Hong Ri , Zhang Gui Bin , Sheng Yuan Yuan , Sun Pei Cong
Published: October 2012

The paper has analyzed the mechanical mechanism of movement and deformation of overlying strata and surface on stope, defined the moving structures of the overlying strata of three strata space forms, explored the mechanism of surface subsidence caused by loose layers’ pressure consolidation , and pointed out that when the loose layers are much thicker, what is indispensable is that, the pressure consolidation of loose layers loosed water, or soil body’s deformation leading to additional stress in the mining soil body, and the dissipation of excess pore water pressure resulting in the consolidation. And according to the surface subsiding features of thick loose layers in mining area, the paper has applied the correction model by probability integral method to predict subsidence with a rather satisfying prediction result.
Comparison and Validation of Thermal Radiation Models for Hydrocarbon Jet Fire and Fireball
Authors: Yang Shi Gang , Zhang Ya Dong , Wu Hao
Published: October 2012

Primary consequences of ﬁre hazards include personnel injuries, fatalities and/or facility and equipment damage due to high air temperatures, radiant heat ﬂuxes or direct contact with ﬂames. Many methods have been proposed to evaluate the thermal radiation incident on a target. This paper presents a survey of thermal models that can be used in quantitative consequence analysis and recommends a model that should be used to examine accident-related hazards. The capabilities of the existing conventional empirical models for estimating the incident thermal radiation from fireballs and jet fires were thoroughly evaluated by conducting several field trials. First, it was found that for estimating a fireball’s diameter, duration and surface emissive power in the downwind location, the TNO (The Netherlands Organization of Applied Scientific Research) model should be employed. Second, for estimating surface emissive power from fireballs in the crosswind location and incident thermal radiation power absorbed by the target located in the fireball’s diameter, the CCPS (Center for Chemical Process Safety of the American Institute of Chemical Engineers) solid flame model is proposed. Third, for estimating incident thermal radiation from fireballs one diameter away and elevations of fireballs, the Roberts point source model is recommended. Finally, for estimating incident thermal radiation from jet fires and flame length, the TNO model is suggested.
Characterization and Triggering Mechanism of Underground Engineering Hazards in a Terrestrial Oil Field in Central China
Authors: Zhu Wei , Li Cai Wen , Gu Shao Qiu
Published: October 2012

On the basis of the statistics data extracted from underground hazards in “A” region of Yuan Shi oilfield, and with casing failures as an example, engineering hazards such as sand production, casing damages etc. in different geological structures are compared and distinguished. A detailed examination of their relationship is conducted in terms of mineral composition, sedimentary facies and other reservoir aspects. The triggering mechanism of engineering hazards is also theorized. Especially, under water injection, the effect of geological structures on engineering hazards is illustrated. Finally, engineering hazards prevention and minimization measures are presented. The latter include: 1) the shallow underground water must be fine filtered with oxygen removed & sterilized, and water pipelines corroded in the entire process; 2) reduce the casing pipe intensity by injected water corrosion.
The Stability Analysis of Nantong Coal Mine Waste Dump, Chongqing and Prevention Measures
Authors: Zhao Xin Tao , Gao Xin Chun , Li Dong Sheng
Published: October 2012

Coal mine waste dump often occur landslide and collapse disasters, the prevention measures and stability analysis of the waste dump must be studied.Firstly,the major factors that can cause landslide in Nantong coal mine waste dump,Chongqing were analyzed,secondly,the stability of four geological cross sections were analyzed by the limiting equilibrium method and FLAC numerical simulation method,the conclusions from two methods are same,and the conclusion is the safety factors of cross sections A and C are smallest and landslide and debris flow disasters will occur easily when face with a long heavy rainfall.thirdly, according to the main factors that can cause waste dump landslide easily and combine with the analysis results of limit equilibrium method and discrete element numerical simulation seven prevention measures were proposed, these measures can provide references for similar waste dump.
Virtual Construction Technology Applications in Building Based on DELMIA
Authors: Cui Jian Hua , Jiao Guo
Published: October 2012

This paper simulated 3-D virtual construction environment to achieve visualization of the building construction process by using the CATIA and DELMIA software. It confirmed the best construction program through comparing the advantages and disadvantages from multiple the construction programs for the aim of improving the constructability of the construction program.
Test Research on Loading Safety and Space Finite Element Analysis of Existing Buildings Reconstruction
Authors: Wang Zhong Qiang , Ouyang Tao
Published: October 2012

Existing buildings continue to use, maintenance or reconstruction, are required to appraisal and evaluation the security of structure[3], to ensure the in-service safety. Combing with a practical example of Better-life Commercial Chain Share Co,. Ltd in Changsha Red Star shop add billboard, have a visual inspection to the billboard support structure, investigate the use of the current situation and analyze the type of disease; using the finite element software MIDAS to establish finite element model of billboard and the main structure of its support, have a large number of numerical simulation; the results showed that the billboard design is reasonable, the flexural rigidity and carrying capacity of the main structure is acceptable, but the disease is more, endanger the use of safe, should carry out prevention and control processing.
A Study on the Balcony Thermal Environment Design in China’s Cold Zones
Authors: Chen Bing Li
Published: October 2012

Thermal environment of the residence balcony has important impact on the indoor living condition especially in the residence buildings built in the recent decades in China’s cold zones. Supported with case studies on the newly built urban residence in Hohhot of north China’s Inner Mongolia Autonomous Region, possible technical measures are discussed to provide a better thermal environment solution in the residence balcony in China’s cold areas, which feature significant temperature difference between day and night and obvious indoor temperature change from balcony to inner space.
A Nonlinear Analysis for the Retrofitting of a RC Existing Building by Increasing the Cross Sections of the Columns and Accounting for the Influence of the Confined Concrete
Authors: Cancellara Donato , de Angelis Fabio
Published: October 2012

In the present paper a nonlinear analysis is presented for the retrofitting of a Reinforced Concrete (RC) building by increasing the cross sections of some columns and by considering the effects of the confined concrete in the nonlinear model. The adopted design methodology is based on a displacement based approach in order to ensure the compatibility condition between the displacement capacity of the structure and the displacement demand according to the seismic codes. The displacement demand is achieved through the increase of the cross section of the RC columns with a consequent increase of the lateral stiffness of the existing structure. In the case of the retrofitted columns the disposition of the reinforcement makes realistic to consider the beneficial contribution of the confinement action of the transversal reinforcement with respect to the internal core. Consequently in the nonlinear analysis the influence of the confined concrete has been considered in the definition of the proper constitutive law for the retrofitted columns. An analysis of the beneficial effects of this confinement action on the nonlinear capacity curve of the structure is described and details are illustrated on the possible ways to take into account the confinement action in the verification of the inelastic behavior of the retrofitted structure.
Effect of Hydration Products Transformation for Compressive Strength of Autoclaved Silicate Products
Authors: Ke Chang Jun , Wang Shu Ying , Liu Jun Li
Published: October 2012

the relationship between hydration products transformation and the compressive strength was studied with X-ray diffraction, infrared spectroscopy analysis. The results showed, 0.505nm hydrogarnets diffraction peaks weakened and 0.183nm CSH diffraction peak enhanced with different autoclaved time under 1.2MPa saturated steam pressure. 0.505nm hydrogarnets diffraction peak enhanced under lower saturated steam pressure for autoclaving 6h, then weaken under higher saturated steam pressure. And 0.183nm CSH diffraction peaks enhanced with different saturated steam pressure for autoclaving 6h. During autoclaving, hydrogarnet translate into Al-substituted calcium silicate hydrate (C-S-H). Transformation of hydration products is favorable for compressive strength of autoclaved sample.
Thermal and Drying Cyclic Loading for Cement Based Mortars and Expanded Polystyrene Foam Layers
Authors: Passa Dimitra S. , Sotiropoulou Anastasia B. , Pandermarakis Zacharias G. , Mitsopoulos George D.
Published: October 2012

The results of the experimental investigation of the developing expansion and contraction strains of both plastering mortar and Expanded Polystyrene Foam (EPS) coatings, during thermal and drying cyclic loading are presented. The mortar used, is cement based with hydrated lime and fine marble aggregates. The EPS specimens were cut from boards of various qualities, appropriate for the external insulation of buildings. Mortar and EPS specimens were subjected to temperature cyclic changes, during which the occurring expansion and contraction strains were recorded. Based on these data, assumptions were made for the nature and the mechanism of the growing strains, in order to collect the necessary information to develop solutions for the critical problem of mortar cracking when applied over EPS insulating boards.
Study on the Temperature and Humidity Control Performance of Hwang-Toh Finish
Authors: Lee Kyuin , Yeom Dong Woo , Lee Byeon Gho
Published: October 2012

This research tried to analyze the effects of ecological materials on indoor environments. For this purpose, two full scale mock-ups were constructed: one with silk wall paper, which is generally used for indoor finishing and the other with hwang-toh (yellow soil), which is the preferred material for wall finishing. Comparison and performance evaluations were conducted, and the effects of hwang-toh finishing on a humid indoor environment were verified. Through this research, it was verified that a hwang-toh plaster finish is effective in maintaining the comfort of an indoor environment
A New Yielding Bolt for Rock Support in High Stress Rock Masses
Authors: Wang Gang , Wu Xue Zhen , Jiang Yu Jing
Published: October 2012

High stress in the surrounding rock mass causes serious stability problems. The applied support system used in this conduction should be able to carry high loads and also accommodate large deformations without experiencing serious damage. In this paper, a brief overview of the history of yielding/energy-absorbing rock bolts is provided. And then, a new yielding bolt invented by the author is introduced in detail, including its layout and principle. Theoretical analysis shows that the bolt has large load-bearing and deformation capacities, thereby absorbing a large amount of energy to maintain the stability of surrounding rock.
Influence of Shrinkage Compensation in Cement Matrix on the Tension Stiffening of Reinforced Strain-Hardening Cement Composite (SHCC) Tension Ties
Authors: Yun Hyun Do , Wang Su Chang , Cho Chang Gun
Published: October 2012

This paper investigates the interaction of structural deformed bar reinforcement and strain hardening cement composite (SHCC). The SHCC shows excellent mechanical properties such as multiple cracks and strain-hardening. Generally, SHCC material consists of cement, silica sand and fibers and is rich mixture without aggregate. Rich mixture leads to much shrinkage strain of SHCC material. In this research, the replacement of a part of cement by expansive admixture (EXA) is considered as an alternative to compensate the shrinkage strain of SHCC material. This paper presents the experimental results of tests on tension stiffening and cracking behavior of reinforced conventional and shrinkage-compensating SHCC ties in monotonic and cyclic tension. Each tie specimen had a square cross-section dimension of 100 x 100mm and length of 1,500mm. A 16mm diameter deformed bar was embedded centrally and mixed with 1.5% hybrid fibers composed of Polyethylene(PE) and Steel core(SC). The test results indicated that the shrinkage compensation of cement matrix in SHCC improve the tension stiffening and cracking behavior of reinforced SHCC ties in monotonic and cyclic tension loading.
Study on the Waterproofing Agent for the Mineral Wool Board
Authors: Dai Dang Hui , Sun Chen Yi , Li Feng Yan , Yang Ya Jun , Ren Xiao Guang , Wang Zhen Ming
Published: October 2012

The petroleum resin emulsion was prepared from the C5-C9 petroleum resin, malay rosin, maleic anhydride, anhydrous aluminium sulfate, NaOH and water. The influence of manufacturing parameters on the emul¬sion included the modification time and temperature, the dosage of the malay rosin, the stabilizing agent and the alkali liquor. The test results showed that w (C5-C9)=31.5%, w (Maleic anhydride)=1.5%, w (Maleic rosin)=10%, w (anhydrous aluminium sulfate)=0.6%, the alkali liquor was NaOH with 10% concentration, the modification temperature was 200 °C, the the modification time was 3 hours, the saponification temperature was 120 °C, the saponification time was half an hour, the emulsifying temperature was 95°C. Under these conditions, the petroleum resin emulsion was prepared with its particle size equating to 111.193 μm.
Effect of Stray Current on Chloride Binding Mechanism in Concrete
Authors: Zhu Qiao , Jiang Lin Hua , Chen Yi
Published: October 2012

In this article, simulation tests of chloride binding were made under the condition of sodium chloride as an internal admixture while loaded with stray current externally. Through the potential titration method, free chloride ion concentration Cf 、 total chloride ion concentration Ct and chloride binding rate RCl were determined. The results show that: With the increase of the strength and action time of the stray current, the number of internal free chloride ions in the cement paste increases while that of the corresponding bound chloride ions reduces significantly, leading to the decrease of chloride binding rate. The relationship between chloride binding rate and the two can be shown as follows respectively:RCl=50.754e(-I/28.258)+42.532、RCl=63.427 e(-T/8.238)+27.325.
Experimental Study on Accelerated Speed of Concrete Sulfate Attack
Authors: Liu Hong Fei , Huang Fa Jun
Published: October 2012

Through test on compressive strength of concrete and mass changes, the effects of solution concentration and temperature on speed of concrete sulfate attack were investigated. The results show that, the speed of attack is accelerated with increasing concentration and temperature, as well as the decreasing of the size of the specimen, sulfate attack speed at 45 °C sodium sulfate solution soak with wet and dry cycle is insignificant difference with at 20 °C.It is suitable to adopt compressive strength as the assessing criterion of the sodium sulfate attack.
Demolishment in Laterite Embankment by Calcium Hydroxide
Authors: Yang Hua Shu , Wei Hai , Yan Yi Zhi , Hu Ying Ting , Wang Hao , Wang Yi
Published: October 2012

Reinforcement using alkali substance produces plentiful calcium hydroxide, and calcium hydroxide has engendered long-term demolishment in laterite embankment. Particle contents were analysed and significant ions were tested at demolished laterite in embankment, and chemical reactions of acidic laterite with calcium hydroxide were canvassed. Accelerated life tests were performed, changes of basilic engineering indexes and content changes of significant ions were tested in laterite fore-and-aft demolished. Mechanism of laterite embankment scathed by calcium hydroxide was explored. Acid-alkali reaction is rootstock of benefit descending and life shortening, and is important inducement of permeability exacerbating in laterite embankment.
The Research on the Effect of Granite Powder on Concrete Performance
Authors: Ying Pi Jie , Liu Fu Sheng , Ren Shu Xia , Dong Gang Gang
Published: October 2012

Abstract: The experimental research on the effect of different incorporation of granite powders on the workability, mechanical property and impermeability performance of concrete is carried out. The result show that the concrete with an appropriate dosage of granite powder exhibits favorable workability, impermeability performance and cohesiveness. And granite powders agree with cement-based materials. Within some dosage of granite powders, the compressive strength of the mixture is approximate to that of common concrete. When the 10% of cement was replaced by the granite powder, good impermeability performance exhibits, with the relative permeability coefficient 30% lower than that of common concrete.
Influence of Superplasticizer on Anti-Carbonation Property of Concrete
Authors: Zeng Chong Sheng , Gong Ming Zi , Gui Miao Miao , Guo Xin Qi , Liu Jun Xiu , Lin Tian Xing
Published: October 2012

It investigated the influence of superplasticizer on anti-carbonation property of different strength grade concrete with seven kinds of polycarboxylate superplasticizer. The results indicated that concrete carbonation property would be more impacted by superplasticizer for low-strength concrete. With the growth of the concrete strength, the impact gradually decreased. The anti-carbonation property of concrete could be improved by using an appropriate amount of compound mineral admixtures or lowing water-binder ratio.