bluuebunny/crossref_metadata_2025 huggingface dataset:
Liquefaction Macro-Characteristics in Chengdu Region in Wenchuan Ms8.0 Earthquake
Authors: Wang Wei Ming , Chen Long Wei , Yuan Xiao Ming
Published: February 2012

In Wenchuan earthquake, liquefaction phenomena and relevant damage in Chengdu region was extensive. Through field investigation, macro-liquefaction characteristics in Chengdu region are outlined, i.e., (1) Liquefaction zones (belts) mainly were located in Dujiangyan city; (2) Liquefaction has been observed in seismic intensities VI, VII, VIII, IX and X, but mainly concentrated in intensities VII and VIII; (3) Heights of liquefaction water-jet mostly ranged in 1m to 3m, and the highest was more than 10m; (4) The ejected materials in liquefied sites covered many soil categories, nearly 67% of fine sand and 11% of gravel; (5) Liquefaction generally caused ground fissures, but obvious ground subsidence were not detected. Although the ejected materials mainly were fine-grained soil, the actual liquefaction was prevalent gravel soil
Development of Slope Stability Evaluation Process of Frozen Soil in Coupling Temperature Field
Authors: Liu Zhi Yun , Chen Jian Bing , Jin Long , Xu Jian
Published: February 2012

The slope stability analysis in cold region is special for its non-uniform temperature field. Considering the special characteristic of the slope in cold region, the physical parameters of frozen soil are treated in this paper as the connection between temperature field and stress field. The temperature influences mechanical properties of frozen soil and forms freezing-thawing interface in the slope, which make great influence on the stability of slope. The critical slip surface searching algorithm for cold region is developed and the moment center solution method in the computation of slope’s stability coefficient is also improved. The critical slip surface and stability of 4m subgrade with 1: 1.5 slopes under different soil temperature condition is computed using the developed frozen subgrade stability computation program. The results shows that the line segment type slip surface is more accuracy than circle type slip surface in cold region slope stability analysis; moreover, the minimum stability coefficient of frozen subgrade does not happen in tenth months when the thawing soil goes to deepest, but show in the early time of warm season, forming the phenomenon of thaw slumping. And it is also found that the occurring time of yearly minimum landslide stability coefficient postpones as the decreasing of soil temperature.
Properties of Emulsification and Recycling of Reclaimed Asphalt Pavement in Room Temperature
Authors: Ge Zhe Sheng , Li Xi , Hu Xiao Qian
Published: February 2012

In the existing technology of cold asphalt pavement recycling, it is only the aggregate that is used again after the crushing and screening of the Reclaimed Asphalt Pavement (RAP), but the asphalt is discarded. So a lot of asphalt resource is wasted. The technology of emulsification and recycling of RAP in room temperature reuses the aged asphalt in the RAP thereby effectively reducing the quantity of newly added asphalt and also improving the performance of the mixture. The application of this technology will save a lot of valuable resources, reduce material costs and save project investments. The technology also contributes to the practice of “resource-saving and environmental-friendliness” in road construction.
Engineering Geological Condition Analysis of some Beijing Engineering
Authors: Shangguan Yun Long , Wang Qing , Niu Cen Cen , Wang Ke , Zhang Yan Ge
Published: February 2012

With the high speed railway construction in our country, the launch of the railway engineering will inevitably lead to all kinds of engineering geological problems, resulting in the construction and operation of landslides, sudden gushing mud, rock blasting and other diseases. So with geological environment and engineering geological conditions of the station tunnel excavation , analysis and evaluate the influence of the engineering geological conditions of the tunnel, put forward the measures and suggestions for the engineering, and provide the basis for tunnel design and construction .
A New Method to Quantify Morphology of Pyrite, and Application to Magmatic-Hydrothermal Gold Deposits in Jiaodong Peninsula, China
Authors: Yan Yu Tong , Li Sheng Rong , Jia Bao Jian , Zhang Na , Jiang Liang , Yan Li Na
Published: February 2012

Morphology of pyrite has been an important indicator of conditions in the ore-forming environment. This study establishes a new pyrite morphology quantification method to characterize different types of magmatic-hydrothermal gold deposits, applying this method to the Linglong, Sanshandao and Xiadian magmatic-hydrothermal gold deposits in Jiaodong peninsula, China. We used K curve and coefficient Y to characterize the Linglong type and Jiaojia type gold deposits. It showed that Linglong type and Jiaojia type gold deposits had different K curves and coefficient Y characteristics. The results showed that this method was proper in magmatic-hydrothermal gold deposits. It is concluded that the K curve and the coefficient Y are important parameters to characterize pyrite morphology in magmatic-hydrothermal gold deposits. This quantification method was called “K curve method”.
Study on the Seismic Damaging Effects of Mountainous Towns in Wenchuan Earthquake
Authors: Zhang Hong Chang , Li Yu Sheng , Bao Jie
Published: February 2012

Through the survey and research on seismic damage phenomena of damaged towns by Wenchuan Earthquake and geological environment , this article identify that the seismic damage effect of towns damaged by Wenchuan Earthquake mainly includes four types which are fault dislocation effect、site and foundation effect、topography motion amplified action and geologic hazard effect. Site selection of the reconstruction of damaged towns and seidmic design of building and other problems are complex and systemic engineering problems, and they refer to many complex factors such as earthquake faults、geologic hazards、national well-being and the people's livelihood, economic development and so on. The basic principles of consideration should be: for the mountain towns which are located at seismic fault zone and exist serious geological disaster, they must be avoided and relocated off-site; for the towns which are away from the fault for a distance and have no fatal geological disaster risk, we should follow the principles of "scientific planning, normative avoidance and reasonablely adjust the seismic standards" and reconstruct in the former location. Reconstruction site should also pay attention to the concealment of geological hazards, the multiplicity and long-term sustainability of induced factors and so on, so we should enhance the suitability evaluation of the geological environment and risk assessment of geological disaster.
Rock Slope Stability Study for Yujian River Dam Site Based on Kinematic Analyses
Authors: Wang Liang Qing , Kulatilake P.H.S.W. , Tang Hui Ming , Liang Ye
Published: February 2012

Lithological information, rock mass fracture data and discontinuity shear strength obtained through field investigations have been used in conducting kinematic analyses for the rock slopes that exist in the Yujian River dam site to evaluate the stability of the slopes. Results given in the paper can be considered as conservative because of several conservative assumptions used in the analyses. Dam site slopes seem quite stable up to 40º dip angle. Out of the three basic failure modes, possible wedge sliding seems to be the most likely one followed up with possible plane sliding as the second. Irrespective of the considered slope regions, slope dip direction ranges 270-315º and 200-210º seem to be the worst cases for possible instability of slopes in the dam site. Regional slopes in the dam site can be ranked with respect to safety from the lowest to highest in the following order: R-c-1, R-e-2, R-c-2, R-d-1, R-b, R-a, R-d-2 and R-e-1. Note that the dam site slopes are currently stable and the existing slope angles agree well with the results obtained from the rock slope stability analyses.
Analysis on Seismic Damage Mechanism and Anti-Seismic Measures of Tunnels in Fault Fracture Zone
Authors: Li Ting Chun , Yin Yun Teng , Liu Jian Zhang
Published: February 2012

Fault fracture zone is an important factor that leads to tunnel seismic damage. In order to research failure mechanism and anti-seismic measures of tunnels across large fault fracture zone, theoretical analysis and numerical simulation has been done to Jiaozhou Bay submarine tunnel in Qingdao. The research results indicate that: in fault fracture zones, surrounding rocks instability resulting from ground motion, the huge earthquake inertial force, and the deformation energy by bedrock surface wave with macro energy all can cause damage to tunnel lining, yet the latter is the primary reason; when the differences of mass density and stiffness between tunnel lining and wall rocks become big, ductile tunnels with light weight will aggravate damage to tunnels rather than improve their anti-seismic capability; keeping stability of surrounding rocks and guaranteeing mass density and stiffness of tunnel lining to be the same as or similar to that of surrounding rocks could prevent tunnel damages in fault fracture zone, yet the latter is the most effective way. This research achievement can set particular examples for research on seismic damage mechanism and for anti-seismic design of tunnel structure in highly seismic regions.
Impact of Broken Rock behind Expressway Tunnel Lining on Structure Safety
Authors: Zhu Chun Sheng , Yang Xiao Hua , Lai Hong Peng
Published: February 2012

According to the model tests of the broken rock behind the tunnel lining impacting on the structural safety, and numerical simulation studying the tunnel in 3 different stress fields while the broken rock locates 2 different positions, the article studies the safety of tunnel structure. The results showed that: in a uniform stress field, the lining played a maximum carrying capacity whenever the broken rock on the vault or behind the right side of the wall. In the horizontal pressure based stress field, when broken rock is on the vault, the grouting effect is most significant and the negative moment was controled by the rate of 75%. In the vertical pressure based stress field, when the broken rock is behind the right side wall, the disease spread sporadically throughout the arch after grouting.
Bending Behavior of Segmental Joint Structure of Under-River Shield Tunnel
Authors: Feng Kun , He Chuan , Wang Jun , Qi Chun , Liu Si Jin
Published: February 2012

The bending stiffness of segmental joints is the key factor which affects the mechanical characteristics of shield tunnel. In this paper, full-scale tests and numerical analysis were carried out to study the bending stiffness, joint opening variation and failure characteristics of segmental joint structure for under-river shield tunnel. The results showed the bending stiffness and joint opening behaving non-linear significantly. And the concrete cracking and bolt breaking were detected in the tests.
Effect of Strip Size on Neutral Angle during a Novel Semisolid Shearing-Rolling Process
Authors: Guan Ren Guo , Zhao Zhan Yong , Chao Run Ze , Zhang Qiu Sheng , Liu Chun Ming
Published: February 2012

Based on the SCR process, semisolid shearing-rolling process was proposed. Effect of strip size on neutral angle during the process was analyzed. Neutral angle decreases gradually with the increment of the strip width. When the strip width is less than 40 mm, the neutral angle decreases more obviously with the increment of the strip width. When the strip width is greater than 40 mm, the neutral angle decreases slowly with the increment of the strip width. The neutral angle decreases gradually with the decrease of the strip thickness. Neutral angle is mainly affected by the strip thickness.
Construction Process Numerical Simulation and Experimental Research of Parallel-Adjacent Loess Tunnel
Authors: Guo Jian , Wang Qi Cai , Zhang Rong Ling , Yang Zhi Guo
Published: February 2012

According to the mechanical properties of the parallel-adjective tunnel, the construction process is simulated and the displacements and concrete stress of the lining structure is monitored of an actual tunnel in the loess region. The influence which the new tunnel on the existing tunnel lining during the new tunnel construction process studied by comparatively analyzed the numerical simulation and monitoring the results. The results show that the impact on the existing tunnel during the new tunnel excavation changes with tunnel distance and the excavation method of the new tunnel, when the line distance increases the impact on the existing tunnel has been remarkably reduced.
State of the Art on the Prediction of Tunneling-Induced Ground Deformations
Authors: Zhao Yong , Zhao Ming
Published: February 2012

Many problems and dangers are brought forward during the construction of tunnels and they can be identified to the ground deformations around the tunnels. A large number of methods are proposed to predict the ground movements due to tunneling and some of them are proved to be effective in engineering practice. The state of the art on the prediction is reviewed, including Peck curve, analytical solution and numerical simulation. Some new approaches, such as artificial neural network and centrifuge model test are also referred.
Risk Analysis on the Accident of TBM’s Cutterhead Jamming Caused by Collapse of Tunnel
Authors: Wen Sen , Liu Han Zhou , Zhao Li Min
Published: February 2012

If TBM does the excavating work in jointed rock mass, the cutterhead may be jammed. In order to decrease the loss, it is necessary to carry out risk evaluation. Whether the cutterhead is jammed or not depends on the relationship between torque and resistance torque. The magnitude of resistance torque depends on height of collapse, so according to the randomicity of height of collapse and probability theory, a formula for calculating the probability of cutterhead jamming is established. Meanwhile, according to the magnitude of resistance torque and cutterhead’s parameters, consequence of cutterhead jamming is divided into five ranks. Based on probability and consequence ranks, risk evaluation matrix for TBM’s cutterhead is proposed. The research results are demonstrated logically by the calculation of practical engineering.
Seismic Reliability Analysis of Complex Structure
Authors: Zhang Zhi Yong , Huang Wen Bo , Zhou Yue Fa , Song Tian Shu
Published: February 2012

The seismic reliability analysis of complex structure is carried out based on the response surface method and finite element method. Firstly, the appropriate design points are selected based on the mean values and standard deviations of the basic random variables. Secondly, the finite element method is employed to obtain the values of the limit state function of the complex structure. Thirdly, with selected design points and the obtained values of the limit state function of the complex structure, a polynomial function is constructed to approximate the original implicit limit state function. Then, with the established explicit polynomial limit state function and available methods of structural reliability analysis, the seismic reliability of the complex structure is estimated. Numerical analyses show that the established method is simple to use for the evaluation of the reliability analysis of complex structure.
Seismic Response Analysis of Interaction for Tall Building’s Superstructure, Foundation and Ground Base
Authors: Zhang Zhen Guo , Yang Xiao Ming
Published: February 2012

The paper analyzes the Seismic response of the interaction among frame-shear wall structure、foundation and ground with ANSYS, and the internal force dynamic characteristics of the ground floor column and the displacement of structure based on the comparison of consideration and taking no account of the interaction among superstructure、foundation and ground base in the static load and earthquake load. Some valuable conclusions have been given in this paper and may offer a reference for the engineering design.
Research and Application of Warm Recycled Asphalt Mixture
Authors: Yang Li Ying , Tan Yi Qiu , Liu Hao , Li En Guang
Published: February 2012

Reclaimed asphalt pavement (RAP) develops rapidly throughout the world. Hot recycling is one way to make effective use of the waste, but the percentage of RAP in hot recycling is no more than 30%. By way of warm asphalt technology, the percentage of RAP can increase greatly. In this paper, warm recycling is researched. The RAP and the virgin materials including aggregates and asphalt are tested and analyzed. Then, two warm recycling mixtures with different amount of RAP are designed and their properties are investigated. As a comparison, the performances of hot recycling are also tested. At last, the performances of warm recycling and hot recycling are compared and discussed. After the laboratory research, the warm recycling made its debut in Beijing and it exhibit very well, which testifies that warm recycling owns good properties. Warm recycling can make use of pavement waste, and it can decrease the emission and energy consumption. Warm mix is environment-friendly and it is promising in the near future.
The Assessment to Environment Influence for Moving Vibration of Subway in a City of China
Authors: Yao Wen Hong , Kang Jing Wen , Ding Bo Yang , Pan Xiao Dong , Ouyang Ming
Published: February 2012

The subway in a city of China is located in an alluvial plain. There are many universities and residential distribution districts. The vibration influence in corresponding zone of the subway should be made evaluation before construction. Based on the parameters of dynamic soil test, the one-dimensional elastic column is used to simulate for computation of the vertical vibration of the subway site. Considered the nonlinear and pseudo-damping of soil, the ground accelerations calculated are shown in this paper. Finally, according to the results of computation of the vibration response and comparing with the interrelated code authors present the relevant conclusion for environmental assessment for moving vibration of subway in this city.
Influence of Damaged Pavement on Saturated Headway and Average Travel Speed of Urban Road Section
Authors: Wu Li Xin , Cheng Guo Zhu
Published: February 2012

To evaluate the capacity and service level of road section under damaged state accurately, it is necessary to study the quantified influence of damaged pavement on headway and average travel speed of road. In this paper, pot hole’s width, rut depth, crack ratio and gap repair ratio were used as the evaluate indicators of the status of damaged pavement. Based on the parameter that surveyed on different level of damaged pavement sections, the affects of damaged pavement on saturated headway and average travel speed are analyzed. It shows that saturated headway and average travel speed are correlated with urban road grade and pavement’s status.
Research on Evaluation Model and Application of Highway Alignment in Mountainous Area Based on Operating Speed
Authors: Feng Xiao , Wang Yang , Ling Jiu Zhong , Yu Cai Xia
Published: February 2012

Based on the road conditions of the low-grade highway (lower Grade 2) in China southwest mountainous area and speed investigations under different conditions, the estimation model of running speed in this region was established, meanwhile, the criteria for the safety appraisal of line based on running speed in southwest is put forward. Finally, according to the above achievement we developed software for the safety appraisal of line that oriented the low class highway in southern mountainous area in China, and achieve a real-time evaluation of visualization in its design and service life. This method is available for multiple engineering projects.
Finite Element Analysis of Composite Volleyball Upright Structures
Authors: Shan Lu Yang , Shan Yi
Published: February 2012

A composite FRP volleyball upright structure is analyzed by finite element (FE) method. A static analysis is performed using commercial finite element software ANSYS. Deformation and stress distributions under regular and upper bound force (i.e., to include dynamic/impact effect) are provided. An elastic eigenvalue analysis is carried out as well to predict the buckling load and modes.
Study on Vehicle’s Arrival Rule and Relation between Traffic Flow Parameters on Snowy Pavement
Authors: Wu Li Xin , Cheng Guo Zhu
Published: February 2012

There are great difference in traffic flow characteristics between snowy pavement and non-snowy pavement. Ten road sections were investigated and the data of traffic volume, headway, speed and density on snowy and non-snowy pavement were collected. Vehicle’s arrival rules were compared and reasonable distribution was given. The relation between traffic volume and speed, density and traffic volume were compared between snowy pavement and non-snowy pavement. It indicated that negative binominal distribution is more fit to vehicle’s arrival frequency on snowy pavement. Speed decreases for the same traffic volume and traffic volume decreases for the same density on snowy pavement.
Research of the Characteristics of the Transmission Matrix of the Absorption Material of the Automotive Body
Authors: Zhu Cong Yun , Jiang Chun Ying , Yang Shu Feng , Hui Li
Published: February 2012

The characteristics of the transmission matrix of the absorption material of the automotive body are researched in this paper. According to these characteristics, the calculation result is right which is proved that the theory method is right.
Vehicle Parameters Influence on Railway Double-Track Pre-Stressed Concrete Continuous Bridge Vertical Load-Carrying Natural Frequency
Authors: Ren Jiang Ying , Su Mu Biao , Li Wen Ping
Published: February 2012

When two lines with 20 same high-speed passenger vehicles are traveling on the 40 m+4×72 m+40 m party pre-stressed concrete continuous box-girder bridge from both ends, this bridge vertical load-carrying frequency is calculated with the vehicle-bridge system mode1. When the vehicle parameters, such as the unsprung mass of each wheel-set of the vehicle, the suspension spring stiffness, the vehicle length and the mass of the vehicle, are changed, the bridge vertical load-carrying frequencies are changed too. But when the train speed is changed, the bridge vertical load-carrying frequencies aren’t changed. It is shown that the bridge vertical load-carrying frequency is the vehicle-bridge system natural frequency, it is only depend on its natural parameters.
Analysis on Effect of Tunnel Crossing Underneath Foundation of Tall Buildings on Anti-Seismic Mortar Anchor in Weathered Rock Area
Authors: Shi Xiao Bei , Wei Kai , Wang Bing Long , Huang Da Wei
Published: February 2012

Depending on a project of constructing a tunnel of high-speed railway which crosses underneath the foundation of tall buildings in weathered rock area, the paper analyzes the failure process and its law of anti-seismic mortar anchors under the foundation of tall buildings by simulating the whole process of construction with finite element model. Then the coverage scope, influence rules and extent of tunnel excavation on the anti-pulling effect and stability of mortar anchors are analyzed according to the changes of lateral pressure and axial force of anti-seismic mortar anchors before and after construction. The results show that the influence area can be divided into three parts， of which the main area where the anti-seismic mortar anchors are badly affected is on the top of the tunnel and extends horizontally to a certain range. Finally, the paper gives an applicable method to estimate the area where the anti-seismic mortar anchors should be strengthened by grouting, which also applies to the similar projects in weathered rock area.
Dynamics Model of Vehicle in Two-Dimensional Collision
Authors: Pei Yu Long , Wang Lian Zhen , Fu Chuan Yun
Published: February 2012

The progress of vehicle collision can be broken into three stages: pre-collision, collision and post-collision. Although the direct collision lasts very little time, it is one of the most important stages of the whole process. On the basis of Momentum Conservation, Energy Conservation and improved Coefficient of Elastic Recovery, using Newtonian Mechanics, the paper constructs dynamics model for vehicles’ two-dimensional collisions, which can be used to calculate the velocities at the moments of before and after the collision. The paper uses the Software of PC-Crash as a comparative study, the results of which show that the proposed models are suitable for the analysis of collisions involving only two cars without second collision.
Analysis on Factors Influencing Deformation of the Underground Cavities during the Construction Period
Authors: Gao Chun Yu , Deng Jian Hui , Meng Fan Li
Published: February 2012

The underground cavities of the Guandi Hydropower Station are Complex large-scale underground caverns. The quality of the surrounding rock masses of the underground cavities of the Guandi Hydropower Station is good and the deformation is normally less than 30mm. The structure surfaces have noticeable action for controlling the surrounding rock mass deformation. The time characteristic of the surrounding rock mass deformation is not noticeable.
Study on Cracking and Strengthening Measures in the Sluice Piers of a Overflow Dam
Authors: Jiang Huai Yan , Zheng Hong Yu , Hu Hui Juan
Published: February 2012

Based on the character of the penetrated cracks in the sluice piers of a overflow dam, the reasons inducing cracks are investigated. The results of the finite element (FE) nonlinear analysis on a representative cracked sluice pier indicate that the current cracks will expend, and the piers need to be strengthened. Four strengthening schemes with prestressed anchorage cables are designed, and their effects are analyzed and compared with FE method, the best strengthening scheme is found.
A New Technique of Low-Pressure Long-Distance Soft Clay Pipeline Transportation
Authors: Tao Song Lei , Lian Xing Ge , Zhang Zi He , Yu Yuan Hong , Zhao Zhi Fang
Published: February 2012

A new technique of long-distance pipeline transportation of soft clay, which is related to Non Newton--Bingham pipe flow studies. Propose a method of non-continuous pneumatic conveying method with surface film lubrication, which will obviously reduce the friction between pipe wall and mud column and the Viscous resistance of clay. The air is injected to form air-column between mud columns. Adjust the lengths of mud column and air column and their proportion, and make the pushing force bigger than or near equivalent to the resistant force, until the optimum air-mud ratio for the required delivery distance is achieved. Long distance transportation of soft clay through low pressure pipeline is achieved. The method, with the features of energy-saving, high efficiency, profitable, can be applied in fields of water conservancy, petroleum, chemical, mining, and environmental protection, etc.
Enzymatic Saccharification of Cellulose Pretreated from Lignocellulosic Biomass: Status and Prospect
Authors: Wang Yu Xiao , Dong Meng Jiao , Zhuang Wen Chang
Published: February 2012

Lignocellulose biomass is the most extensive, cheapest raw material in the world, the saccharification of cellulose pretreated from lignocellulosic biomass for production of fuel ethanol has become the world-wide research focus currently. This paper reviews the status of enzymatic saccharification of pretreated cellulose, including the improvement of structure and composition of the substrate by pretreatment, the operation of high substrate concentration, the efficient mixing of multi-enzyme system, the addition of non-catalyst, the recycling of enzyme, the elimination of product inhibition, and finally summed up the present challenges and the future prospects.
The Characteristics of the Aerobic Granular Sludge on Nitrogen and Phosphorus Removal Simultaneously
Authors: Liu Jin Sheng , Ni Yong Jiong , Jia Gen Yuan , Li Jun
Published: February 2012

By using the conventional activated sludge as seed sludge in SBR to cultivate the aerobic granular sludge system, the mechanism of nitrogen and phosphorus removal was explored. The results showed that the aerobic granular sludge system consisted of the heavy aerobic granular sludge and the light flocculent activated sludge was formed in the reactor after 15 days. The SVI of the aerobic granular sludge system was about 50ml/g～60ml/g, the MLSS was about 3000mg/L～4000mg/L steadily, and the weight ratio of granules in the total sludge was about 70%.The removal rates of NH4+-N, TN, and PO43-P in the anaerobic-aerobic operation mode were 80%～97%, 80%～97% and 70%～85%, respectively. It indicated that granules and flocs were beneficial nitrogen and phosphorus removal, respectively.
On Water-Saving Design of Buildings
Authors: Cao Shuang Mei , Li Jian Hua
Published: February 2012

Abstract. In order to promote the application of water-saving technology, to use natural resources effectively and to realize the sustainable development of our economy, we should explore and summarize the experience of water-saving for water supply and drainage and meanwhile create conditions for the design and layout of buildings and districts.
A Cost Analysis of Wall-Hung Mounted Gas Boiler Using in Residential Buildings of Beijing
Authors: Yang Tong , Na Wei , Li De Ying
Published: February 2012

In order to improve the city environment, and achieve a leap in making reasonable use of natural gas and optimizing energy structure, the Beijing municipal government has established its basic policy to “transform its coal-based energy structure, introduce large amount of natural gas”. As the wall-hung gas boiler has easy operation, flexible adjustment and high energy efficiency, the application of it is becoming more widely considered among the residential building. The work proposes the survey of the heating way about affordable housing and the “two limit” commodity housing in Beijing. The adaptability between the household wall-hung gas boiler heating way and other heating ways is compared. The energy efficiency, initial investment and operating cost of all the heating ways that are being used in Beijing are discussed in the paper. The final analysis is then evaluated by a panel of experts to determine its accuracy and potential for use in a greenway development plan of heating way in Beijing. Analysis shows that the commercial housing is more suitable than affordable housing to use the wall-hung gas boiler. This is mainly be effected by the characteristics of the user’s economic condition and the residences’ distribution.
Earthquake Damage Prediction of Base-Isolated Structures Based on Fuzzy Comprehensive Evaluation Method
Authors: Ma Yu Hong , Zhao Gui Feng , Chen Rui Hai
Published: February 2012

Earthquake damage prediction of base-isolated structure includes many fuzzy factors, for example damage grade, intensity and so on, so by use of the fuzzy comprehensive evaluation method to predict the earthquake damage probability of the base-isolated structure should be feasible and effective. The isolated building usually consist of the isolated layer and the upper structure, so the damage grade of the base-isolated structure is divided by the performances of the isolated layer and the supper-structure. And then, the basic frame system of earthquake damage prediction based on fuzzy comprehensive evaluation method is established: the damage influence factors of the earthquake damage prediction for the isolated structure are analyzed, the corresponding hierarchy evaluations system is presented. Grade standard of damage influence factors and the determining method of membership degree for the base-isolated frame structure are given, and then the weight coefficients of the damage influence factors are studied by use of the judgment matrix analysis method, the fuzzy comprehensive evaluation model of earthquake damage prediction is given. Lastly, a numeral example is analyzed, the rationality of the method is proved.
Optimization Analysis of Mining Sequence to Danhou Coal Mine under Complicated Hydrogeological Conditions
Authors: Wang Shu Ren , Wang Hu , Li Yong , Liu Cheng Wei
Published: February 2012

Taking mining region No. 3 of Danhou Coal Mine, located in Yu County in Hebei Province, as the engineering background, the 3D visual model with three aquifers of mining region No. 3 was generalized and constructed by using SURPAC software based on the geologic drilling datum. Then 3D numerical model and its meshing were completed with the MIDAS/GTS-FLAC3D coupling modeling technique. Considering the complicated hydrogeological and mining conditions, two practicable mining sequences to No. 5 & No. 1 coal seams were designed respectively. Through fluid-solid coupling computation, the response characteristics of deformation field, principle stress field and plastic damage were analyzed during the dynamic mining process, and the mining sequences to No. 5 & No. 1 coal seams were optimized. The reasonable mining sequences provide the basis for mining safety to mining region No. 3.
Composite Structure Stress Analysis of Row Posture Micro-Piles on Slope Protection
Authors: Xu Xiao Lin , Wang Quan Cai , Wang Hao , Wu Qing
Published: February 2012

The composite structure of row posture micro-piles is a light-weight protection structure for slope, which has the advantages of safe and quick construction, high adaptability to some special environment, and is suited to small size slope protection, especially in the emergency project. The design theory research of this composite structure is obviously deficient comparing to the engineering application. The basic requirement of the elastic foundation-beam theory application is that the foundation should be stable. Because of the row posture micro-piles composite structure improved the stability of slope, the resistant force in front of different location micro-piles is different. On the basis of the elastic foundation-beam theory, using the idea of the general micro-piles horizontal bearing capacity calculation method, the row posture micro-piles advantage have been revealed during the different calculated values of “m” and limited conditions of pile top large deformation. The computational formula of row posture micro-piles composite structure has been established on three basic calculation models, and the special response to seismic force has been calculated and analyzed in a practical case, which will provide certain reference for the micro-piles design.
State of the Art on the Monitoring Methods of Offshore Wind Energy Conversion System
Authors: Zhao Ming , Wang Xu
Published: February 2012

Along with the rapid economic development, the large power-generating wind energy conversion systems are increasing both in number and in size. Because of the high construction cost, the consequence of any structural failure, especially offshore where replacing a damaged member such as blade which weights tones, is pretty expensive. Consequently particular actions are required to the protection of these structures. Among these many strategies, continuously monitoring of the condition of the system which provides a predication long before the actual failure should be one of the most efficient ways. In the paper, the main problems and their corresponding surveillance schemes of the system including tower, foundation, blade and turbine nacelle are discussed.
Behavior of GFRP Strengthened Reinforced Concrete Columns under Large Eccentric Compression Load
Authors: Wang Ji Zhong , Wang Yong Feng , Wang Su Yan
Published: February 2012

This paper compares three standards of FRP strengthened concrete columns published by ACI committee, Concrete Society and China respectively. A test is designed according to the comparison. A total of five columns were cast and tested. The analysis of the load bearing capacity and ductility of the test result indicates that wrapping hoop GFRP can enhance load bearing capacity slightly and the ductility greatly, wrapping axial GFRP can enhance load bearing capacity greatly but the failure of column is brittle, wrapping axial GFRP over-wrapped with hoop GFRP can both enhance load bearing capacity and the ductility.
Numerical Simulation on Multi-Direction Splitting Test and Crack Process of Concrete
Authors: Zhang Shan , Liu Yan
Published: February 2012

In the paper, the conclusion on the effect of micro-crack damage on the chloridion permeability of concrete are drawn through the multi-direction splitting tests and the chloridion permeable tests for cracked concrete specimen. Limited units numerical simulation method are applied to simulate the whole process of concrete splitting and cracking and further analyse crack spreading rules to testify and explain the test results. Numerical simulation represents the complete process of concrete materials that include the initiation, propagation, and penetration of microcracks. It is feasible to simulate the cracking process of concrete because the analysis results on the patterns are consistent with testing results. At the same time, numerical simulation analysis results about transverse displacement, cracking process of microcrack can testify and explain testing results. Therefore, numerical simulation method is instructional for study of concrete durability.
Test Study on Size Effect of Flexural Capacity of RC Cantilever Beams
Authors: Zhou Hong Yu , Li Zhen Bao , Guo Er Wei , Liu Li Fei
Published: February 2012

Analysis and calculation methods of reinforced concrete structure at present are based on test results of small-size component. This paper carried out test research on size effect of flexural capacity of RC cantilever beams. Sectional height of the biggest experimental specimen is 1000 mm. Obtaining detailed test data during different loading stage, such as carrying capacity, deflection, steel and concrete strain etc. Through observing test phenomenon and analyzing test data, verifying the safety to calculation formulas for ultimate bearing capacity of flexural members. Strength and ductility reserves show a growing trend with specimen size increasing.
Bond-Slip Constitutive Behavior between Fiber-Reinforced Polymer and Masonry
Authors: Zheng Yi , Jia Jin Qing , Li Li , You Shi Kuan
Published: February 2012

To study the bond behavior and the force transference of FRP plates adhered to masonry. In this paper, experiments of anchorage strength of FRP attached to masonry are done, a 100KN capacity hydraulic jack activated by a manual pump was used to load the specimen. The tensile strength was measured by using a loading transducer, and strain gauges were mounted directly onto the surface of the FRP composite to measure the strain during application of load. Besides the strain and bond stress development and distribution under every grade of loading were studied. Test results show that the maximum local bond stress is not influenced by the FRP bond length, instead it increases with masonry strength. At the same time, the local bond stress--slip curve is obtained. Based on the test results, two new bond stress-slip constitutive models between FRP and masonry were proposed and they turned out to be good matches to the experimental results, which indicate its valuable references for the corresponding codes and engineering applications.
Effects of Coating/Electroplating on Corrosion Resistance of Steel Bar in Reinforced Concrete
Authors: Zhou Qun , Shui Zhong He , Xiao Yi De , Xu Chang Sheng
Published: February 2012

One of the main reasons for the damage of reinforced concrete is the expansion caused by corrosion of steel bar in concrete. In this paper, the equivalent circuit that inflects corrosion process of steel bars in reinforced concrete was analyzed, with the A.C.Impedance Spectrum method. And the effects of surface treatment of the bars on corrosion resistance of the reinforced concrete were investigated. Study results show that the surface coating (plating) on the built-in reinforcement can effectively prevent corrosion of steel bar, thereby enhancing the durability of concrete structures.
Study on a New Extraction Method of Statistical Information of Urban Buildings Based on High Resolution Remote Sensing Images in Earthquake Damage Prediction
Authors: Zhai Yong Mei , Zhao Qi , Li Tie Zheng
Published: February 2012

How to get the enormous statistical information of target buildings has long been a very significant subject in urban earthquake disaster prevention planning. However, the traditional methods to extract the statistical information of urban buildings are complex and time consuming, proved to be difficult in application. This paper presents a new practical method to extract statistical information of urban buildings through rotating high resolution remote sensing images and scanning the pixels, and then compares the data from high resolution remote sensing images with measured data to verify the precision of the method. With this method, some buildings in a county in Henan province are analyzed as an illustrative example, the encouraging results of which demonstrate that this simple and practical method is not only theoretically correct but also precise enough to satisfying the demands of fast extraction of building information on in urban earthquake disaster prevention planning.
Analysis on Surface Settlement Caused by Soil Pressure in the Chamber of Shield-Tunneling
Authors: Sun Hai Xia , Zhao Wen , Zhou Qi , Zhang Zhao
Published: February 2012

Soil Pressure in the chamber is one of the important construction parameters. It is very important to set up reasonable soil Pressure in the chamber for controlling the ground settlement, promoting the peed of drift and lowering the cost of drifting. Take some subway tunnel for example, and carry out the 3D finite element simulation. In order to investigate the influence on ground settlement from soil pressure in the chamber, take 15% of the progressive increase in earth pressure to simulate over-balance conditions and also take 15% of the progressive decrease in earth pressure to simulate under-balance conditions. The results indicated that while the soil pressure achieves equilibrium, the swell and the settlement are all small. While over-equilibrium, the swell increases, on the contrary, the settlement increases while under-equilibrium. So, a good control over the soil pressure is one of the most effective therapies for decreasing the ground settlement.
The Reinforced Concrete Durability and Rebar Erosion Monitoring
Authors: Zhang Jin Yang , Cui De Mi , Lv Lie Min , Yang Zhi
Published: February 2012

On the basis of the advantages of low construction cost, remarkable dynamics property, easy cast moulding and more controllable construction, the reinforced concrete construct are widely applied in buildings and main structures of constructions in China. However, the reinforced concrete is found more or less aging after many years’ utilization and erosion from the environment, which will lead to a hidden risk to affect its functions. After technical development for decades, the concrete can assure its durability under normal situation, yet the function would be deteriorated due to the erosion from the complex and harsh environment to make it hardly reach its designed service life. With the assist of CorroWatch erosion monitor system, the concrete structures’ erosion can kept watched on to obtain the depassivation development and information feedback of some key data dynamically and in long term so as to foresee precisely the erosion starting time. The newly cast concrete depassivation frontline is located on concrete surface and will tend to go through the protective layer and penetrate towards rebar as time goes on. Its structure service life can be enhanced with the re-designed durability in terms of the mentioned characters and do well the erosion proof measures.
Correlation Study on Modal Frequency and Temperature Effects of a Cable-Stayed Bridge Model
Authors: Sun Li Min , Zhou Yi , Li Xue Lian
Published: February 2012

In recent years, structural health monitoring has been paid more and more attention in bridge engineering community. Previous researches showed that ambient temperature was one of principal factors affecting structural modal parameters in long-term. In this paper, an experimental study on correlation between dynamic properties of a cable-stayed bridge and its structural temperature was performed under temperature controlled laboratory environment. Using hammer impacting method, a dynamic testing was conducted based on a steel cable-stayed bridge model which had a span layout of 0.9+1.9+0.9m. During the experiment, the first six vertical bending modes under the environmental temperature of 0, 20 and 40°C were identified with the consideration of three kinds of boundary conditions at the deck’s ends as to two degrees of freedom, i.e. the longitudinal translation (UX) and the rotation about the transverse beam (RotZ). The above boundary conditions are UX & RotZ not constrained, UX constrained only and UX & RotZ constrained, attempting to simulate the different conditions of the bridge expansion joints. The efforts were paid to explain the physical mechanism of the results based on the updated FE model. This experimental study indicates a tendency that the frequency of the cable-stayed bridge model decreases with the increase of temperature. And furthermore, the relative difference of frequencies between 0 and 40 °C is affected by boundary conditions; in other words, when the deck is free to expand, the variation of model’s frequencies is smaller than that when the deck is restrained to expand, which is similar to the condition of the bridge’s expansion joints cannot work as normal. This experimental study can give some reference to the research of SHM and damage identification for cable-stayed bridges.
Numerical and Experimental Studies on the Seismic Retrofit of Simply Supported Bridges Using Superelastic Restrainers
Authors: Cardone Donatello , Sofia Salvatore
Published: February 2012

In this paper, the effectiveness of Shape Memory Alloys (SMA) restrainers for the seismic retrofit of multi-span simply supported deck bridges is investigated through a series of numerical nonlinear dynamic analyses and shaking table tests on an experimental mock-up of a typical bridge structure. Both numerical analyses and experimental tests have been carried out on the structure with and without seismic restrainers. The results of these studies clearly prove the effectiveness of the SMA-based restrainers in controlling the displacement response of simply supported deck bridges.
Research on the Apparent Thermal Expansion Coefficient of Concrete Subject to Freeze-Thaw Cycles and Chloride Salt Attack
Authors: Wang Zhen Di , Yao Yan , Wang Ling
Published: February 2012

The aim of the research is to determine the strain-temperature rate and investigate the apparent thermal expansion coefficient of three kinds of concrete (ATEC). The strain of concrete with the dimension of 100mm×100mm×100mm subject to freeze-thaw cycles and chloride salt attack were measured using an embedded strain gauge. The ATEC was calculated from the strain-temperature rate using linear regression. The results show that the absolute value of ATEC of specimen saturated by 3.5 wt. % chloride salt solution was reducing with the progress of freeze-thaw cycles. However, the ATEC of the dried specimen subject to heating and cooling is independent from water to cement ratio, and approximately maintains the same level during the whole heating and cooling cycle, and the ATEC of air-entrained specimen is constant within 20 cycles. Overall, deterioration of concrete matrix can be evaluated by apparent thermal expansion coefficient besides weight loss and dynamic elastic modulus.