bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Real Estate Market of St. Petersburg
Authors: Vatin Nikolay , Gamayunova Olga , Nemova Darya
Published: September 2014

Currently, more than half of the residents of St. Petersburg are not satisfied with their housing conditions. Plus a constant influx of migrants, which gives additional burden to domestic demand. The article analyzes the secondary housing market and the market of apartments in buildings under construction, the dynamics of the activity of demand for apartments. There are the comparison of the prices of residential real estate, depending on the type of apartment, house type, the district where the housing is located. Shown prospects for real estate investing. Highlighted the importance of energy saving technologies and good condition of communications when choosing real estate.
Analysis and Optimization of Management Organizational Structure of Intellectual Property Right of Chinese Power Enterprises
Authors: Yang Wei Jun , Liang Long Teng
Published: September 2014

With the advent of the era of knowledge economy, Chinese power enterprises realize that intellectual property is becoming an important intangible asset. How to optimize the management organizational structure of intellectual property right has received increasing attention. This article analyzes the present situation of Chinese power enterprises, sums up the characteristics of advanced enterprises’ management organization structure, and provides an idea of optimization.
Study on Shear-Shear Deformation Hysteresis Relationship of Reinforced Concrete Shear Walls
Authors: Zhou Guang Qiang , Liu Qing Yang , Zhang Xin
Published: September 2014

In order to study and improve shear-shear deformation hysteresis model of reinforced concrete shear walls, experiment of reinforced concrete shear walls was conducted. Based on experimental data, shear-shear deformation relationship is deduced and shear-shear deformation hysteresis curves are obtained. The existing shear-shear deformation hysteresis models of reinforced concrete walls are discussed and improved, and the calculated shear-shear deformation hysteresis curves with the modified model fit well with experimental results.
Temporal and Spatial Evolution of Acoustic Emission in the Damage Process of Reinforced Concrete Column
Authors: Li Qiang , Chen Zhong Gou , Wu Dan
Published: September 2014

To study the whole process of fracture and damage of reinforced concrete column, temporal and spatial evolution of acoustic emission in the damage process of reinforced concrete column were tested. The results show that AE events of corroded column were much more during the whole loading process than that of the none-corroded one due to reinforcement corrosion. At the same loading speed, the corroded column was failed earlier than the none-corroded one. AE can obtain the internal temporal and spatial evolution damage parameters of the reinforced concrete members before the macro crack visible. The AE results were in well agreement with the brittle failure of both corroded and none-corroded columns. 3D location of AE events can directly reflect the fracture and failure process of reinforced concrete column but its accuracy needs further study.
The Research of the Relative Rigid Effect in the Numerical Simulation of the Steel Plate Reinforced Concrete Coupling Beams
Authors: Song Li , Chen Dong , Li Bao Lei
Published: September 2014

The coupling beam work as an important component in coupled shear walls, the strength,stiffness and deformation properties of which have great influence on the seismic performance of shear walls, the steel plate reinforced concrete coupling beams have the advantages as follows: simplify the constructional details, make the construction convenient and reliable performance [1][2]. The numerical simulation model in this paper is a coupled shear wall connected by steel plate reinforced concrete coupling beams in reference [3], and the loading mode is the same as the reference [4] . The relative stiffness effect was explored by study the internal force and displacement of the model with changing the stiffness of the coupling beams and the shear walls while the span-depth ratio is stable .The study will provide a reference for the numerical simulation of the finite element simulation analysis of the coupling beams and the steel reinforced concrete structures.
To Explore the Causes and Preventive Measures of Floor Cracks
Authors: Tong Zhi Neng
Published: September 2014

This paper analyzes the causes of formation of concrete slab crack from design, construction, the concrete characteristics of multiple perspectives, and puts forward some concrete measures to reduce cracks in the concrete plate, and provides reference for the similar engineering and technical services.
Thermal Isolation Character of Reinforced Concrete Hollow Floor
Authors: Huang Zhu Ye , Wu Qian , Wu Min Gui
Published: September 2014

Reinforced Concrete Hollow floor system was named by its typical inner core and worked as an excellent horizontal bearing structure. It has fine mechanical ability and good thermal isolation character. The author compared reinforced concrete hollow floors and traditional reinforced concrete floor. And studied their development in long span or large loaded building.
Transient Finite Element Simulation Analysis on Dolphin Structural under Ship Collision
Authors: Pan Ying Ying , Tao Gui Lan , Fan Xiao Jing
Published: September 2014

Taking a certain dolphin structure of the ship lock in Jiangsu as an example, the finite analysis software ABAQUS was used to establish the 3D finite element model of ship, dolphin and foundation, and the process of collision was simulated for the transient dynamic analysis, obtained the collision force-time curve and the stress and strain of the dolphin, calculated ship collision force and compared with the norms used both in China and other countries. The results show that the maximum compressive stress is on the contact surface, the tensile stress is both on dolphin floor and back surface of the dolphin, and the maximum tensile stress is on the front teeth of dolphin floor; the ship collision force of finite element simulation is between Chinese norms and European norms. The results provide reference for the design of future dolphins.
Vibration Control of Offshore Platform Structure with Friction Dampers
Authors: Zhao Da Hai , Zhang Jing Lin
Published: September 2014

The performance of friction dampers to mitigate waves and earthquakes in tower-type offshore platform is investigated in this paper. Taking the offshore platform of TOWER-1 as an example, the equation of motion of offshore platform structure under earthquake and wave loads was established. The response reductions of offshore platform structure by different peak earthquakes were analyzed. The results show that the responses of the tower-type offshore platform structure under wave and earthquake could be effectively reduced by friction damper, and the energy dissipation ability of the friction damper differs in the different floors. The friction dampers give good response reductions in different peak earthquakes, and the response reductions of displacement are better than those of acceleration.
Discussion and Dynamic Characteristics of the Offshore Jacket Structure
Authors: Zhao Yue , Zhao Duan Duan , Jiang Qin Han
Published: September 2014

In this paper, based on the finite element method, the K type common jacket structure connection in the form of positive connection and reverse connection conditions is being do comparative analysis. Research focus on dynamic characteristics, including of power spectrum analysis under the action of random vibration and fatigue properties of two kinds of connection type structure. The calculation results show: the inverted K type connection of jacket structure is about 10% increase in the stiffness and the dynamic performance, the inverted K type connection form is more worthy of popularization and application in engineering.
Study on the Risks and Instability Factors of an Operating Reinforced Concrete Coal Storage Bunker
Authors: Song Bo , Oloya Kalongo Richard
Published: September 2014

Based on results of a deformation monitoring exercise, a numerical analysis was done to identify the causes of defects and assess the stability of a reinforced concrete bunker. Different scenarios were tested, among them the effects of coal lateral pressure on the wall, loading of different quadrants of the bunker, temperature differences and effect of differential settlement on crack formation. In calculating the coal pressure, classical theory presented by Rankine was used together with provisions of the design codes. Temperature differences are seen to have a significant effect on the stress distribution whereas differential settlement presents a major concern to the stability of the Bunker.
A Semi-Analytical Method to Calculate the Consolidation Problem of the Soilbag Filled with Mud Soil Buried with PVD
Authors: Niu Ben , Zhang Chao Jie , Chen Xiu Liang , Wang Heng Yu
Published: September 2014

A semi-analytical method to calculate the degree of consolidation of the soilbag filled with mud soil with PVD built in is proposed. First a unit-body model is founded to obtain the low-dimensional solution. Through the successive iterations of the low-dimension solution, the solution considering the situation when the physical or geometry parameters of the model vary is finally obtained. The solution of the rectangular area is obtained by summing solutions of two square area with coefficients set. A lab experiment was done in Liubao test base of Zhejiang institute of hydraulics and estuary to research the consolidation performance of soilbag filled with mud soil buried with PVD. The semi-analytical method and FEM are applied to calculate the lab experiment case. From the comparison among the lab experiment, the semi-analytical method and FEM, it shows that the semi-analytical method calculates a good result of the degree of consolidation of the lab experiment.
Crack Identification of Frame Structure by Means of Wavelet Analysis of Strain Mode
Authors: Huang Yan
Published: September 2014

Based on wavelet transform of strain mode, the damage identification of plane frame was studied in this paper. After solving strain modal parameters of plane frames with cracks by means of the finite element theory, applying the gauss2 wavelet transform to analyze the stain mode of plane frame, and denoising the wavelet coefficients of the strain mode by db3 wavelet, the crack location of the plane frame could be identified by the maximum of wavelet coefficients after denoising. Taking one-story plane frame for example, three finite element models, including a frame beam with a crack, each frame column with a crack, and each frame beam and column with a crack, were set up separately, then the above-mentioned method was applied to identify the location of the crack. The results show the method is effective, and it may be useful in damage identification and diagnosis in structures.
Application of Earth Berm in Foundation Pit Engineering
Authors: Fan Ji Liang , Ren Yan Hua , Wu Yong Hong , Li Jun , Liu Xiu Feng
Published: September 2014

Referring to a project in Tianjin, the paper has described the mechanism of the earth berm, and analyzed the influence on supporting structure from the earth berm using finite element. It was observed that the wider of the earth berm with constant height the smaller of the supporting structure deformation, and the deformation will tend to be stable when width reaches specific value. With constant width, the higher of the earth berm the smaller of the supporting structure deformation. The retaining of the earth berm should be reasonable and safe. Under the premise of the slope stability, the paper suggests that the height of the earth berm should be 2/3 of the excavation depth, and the width should be 1/2 of the excavation depth.
Damage Monitoring Research of the Concrete Structure Based on the Piezoelectric Impedance
Authors: Qin Lei , Shi Yue Hua , Ren Hong Wei , Wang En Rong , Qin Qi , Hua Zheng Xiao , Tian Kai Ge
Published: September 2014

Based on the piezoelectric impedance technology, damages in concrete specimens could be monitored. The structural damages were simulated by pasting piezoelectric ceramic chips and boring several holes on the surface of concrete specimens. And then, with the precision impedance analyzer HP4192A, we measured the conductance spectrum curve of the specimens.The specimens were in two different damage situations：one was damaged in one place to varying degrees and the other was damaged in different locations to the same degree. The experiment results show that the damages in the specimens can lead to the drift of the conductance spectrum curve and the greater the damages are, the greater the change will be.
Direct Measurement of the Contact Normal Stress Distribution between Two Smooth Joint Surfaces
Authors: Yang Zon Yee , Chiu Wei Chieh
Published: September 2014

The shear strength of rock joints is highly depended upon the failure mode of joint asperity. At lower normal stress slide-up of one asperity up over another mode, however at high normal stress the joint asperities are sheared off at the base. This research uses pressure measurement film to directly measure the contact normal stress between smooth joint surfaces. It demonstrates that the density of color impression is capable of capturing the normal stress distribution behavior. The contact normal stress distribution during shearing is changed. After shearing, the contact stress becomes large. This increase in contact normal stress is to fracture the joint wall material.
Model Test Research on Horizontal Bearing Characteristics of Close-Ended Valibale Section Pipe Pile
Authors: Yang Qing Guang , Chen Yi Han , Tian Jie , Liu Jie
Published: September 2014

Base on indoor model tests of three variable section pipe piles and two constant section pipe piles performed in foundation pit,the load transfer mechanism of two kinds of close-ended pipe piles are studied by comparing horizontal load-displacement curves, critical load and bending moment of piles. Results show that horizontal load-displacement curves change slowly and horizontal bearing capacity of valiable section pipe piles will be higher than constant section pipe piles with equal average diameters.Comparing with constant section pipe piles 1# and 2# with equal average diameters, unit volume horizontal critical bearing capacity of 3# and 4# are improved 8.7% and 34.2% respectively and which have different degrees of increse with improvement of valiable section ratio. Moreover,there are two maximum bending moment to valialble section pipe piles insteard of one to constant section pipe piles.To pipe piles 3#,4# and 5#, maximum bending moment ratio of big diameter pipe to small diameter pipe of valiable section pipe pile are 3.13、2.33 and 1.89 respectively. To pipe piles 3# and 4#, maximum bending moments of big diameter pipe are improved 26.8% and 28.4%.Howeverm,maximum bending moment of small diameter pipe are improved 54.1% and 111.8%.So,it is very clear that valiable section pipe pile is more reasonable than constant section pipe pile in bearing characteristics.
Model Test Research on Mechanism of Close-Ended Variable Section Pipe Pile
Authors: Yang Qing Guang , Wang Ya Hui , Liu Feng , Liu Jie
Published: September 2014

Base on indoor model experiments of two constant section pipe piles and three variable section pipe piles performed in foundation pit,the load transfer mechanism of two kinds of close-ended pipe piles are studied by comparing load-settlement curves,shaft load distribution behaviors,skin resistance and resistance on pile end.Results show bearing capacity of variable section pipe piles is bigger than constant section pipe piles when settlements on pile top are equal.The bearing vertical capacity, unit volume bearing vertical capacity and availability of material of pipe pile will increase with improvement of average diameter and variable section ratio of variable section pipe piles.To variable section pipe pile, shaft load distribution suffered a sudden drop on position of variable section and shaft load distribution of small diameter pipe piles decrease quickly than constant section pipe piles.Resistance on pile end of variable section pipe piles are bigger than constant section pipe piles and resistance, ratio of resistance on pile end to bearing capacity of variable section pipe piles will increase with improvement of average diameter of variable section pipe pile. Action point of max skin resistance of variable section pipe piles are closer to pile top than constant section pipe piles .Max skin resistance will increase with decline with ratio of variable section pipe pile.If settlements on pile top are equal,force of skin resistance of variable section pipe piles are bigger than constant section pipe piles when the average diameters are same.
Monitoring Study of a High Artificial Backfill Soil Slope in Large Thermal Power Plants in Karst Region
Authors: He Lei , Wei Guang Guang , Feng Zi Xia , Wang Jian Xun
Published: September 2014

According to the actual conditions of a high artificial backfill soil slope in a large thermal power plant’s in karst region with very developed caves in Guangxi Zhuang Autonomous Region, we carried out a number of slope monitoring works in order to timely and accurately getting of the stress and displacement distributions of slope retaining structure, to ensure safety of the thermal power plant, and to verify the safety and reliability of the slope design. Through a large number of monitoring data, obtained the development and change rules of the displacement, reinforcement stresses and anchors tension of the slope protection pile and retaining wall. Monitoring data shows that the design for the slope engineering has a good effect, and slope retaining structures are stable as a whole during the monitoring period. This research provides reference in design and monitoring for other projects in this area.
Realization of Uniform Deformation under Three-Dimensional Condition Based on Soil-Water Coupled Analysis Considering Inertia Forces
Authors: Xu Bin Bin , Noda Toshihiro , Nakai Kentaro
Published: September 2014

In the paper, based on soil-water coupled finite deformation analysis, theoretical considerations and numerical calculations were carried out under undrained three-dimensional condition in order to reproduce a uniform deformation field. At first, a theoretical consideration was assumed to realize a uniform deformation for a saturated soil, according to which the initial velocity and acceleration in both vertical and circumferential directions should be applied to each node to remove the influence of inertia effect. This first theoretical analysis is useful and can guide the numerical calculation. Next, the paper realized a uniform deformation of a three-dimensional cylinder specimen under undrained boundary conditions using the soil-water coupled analysis in which the SYS Cam-clay model is employed as the constitutive model for soil skeleton. The numerical results show that without the inertia forces there is no localized deformation in the specimen.
Research on Soil Nailing Method for Large Foundation Pit Treatment
Authors: Peng Zi Mao
Published: September 2014

Based on the introduction of the characteristics of the supporting project of a large building foundation pit, the paper analyzed the main reasons for side wall collapse and pile fracture, including leakage water in the backfill soil, complex geological environment and unreasonable soil pressure value, low safety factor and improper design parameters, and then respectively proposed three kinds of treatment schemes for side wall sliding and pile breaking, landslides and other dangers. Finally, tracking observation showed that the satisfactory effect can strongly verify the suitability and validity of the main control parameters for the deformation of deep foundation pit, which may provide reference for the design and construction of similar projects.
Self-Reaction Static Loading Test for the Determination of Pile Capacity of a Super High-Rise Building Structure with Super Deep Foundations
Authors: Xiao Zhi Yu , Ji Yong Xin , Li Xin Gang , Lei Yong
Published: September 2014

In this paper, the ultimate bearing capacities of piles of a super high-rise dual-tower building structure in Guiyang were investigated. A stepwise test procedure was developed and carried out to obtain the pile capacity because of the limitation of experimental equipment and the complicate geological conditions. In the proposed procedure, the deep plate test, side friction test, and an in-situ test of full-scale pile were all carried out in the same hole in sequence. The equipment and procedure of the stepwise test are described in details. The test results are meaningful to provide reference values for investigating mechanical behaviour of pile and statistical analysis of pile capacity in the typical karst geology of Guizhou province. Since such a large-scale field test in Guizhou is limited, some recommendation values are also given to engineers for the pile foundation design in this district.
Study of Stability Assessment Method for Deep Surrounding Rock
Authors: Mao Zhi Tong , Zhu Yan Peng
Published: September 2014

According to the three characteristics of deep surrounding rock: high stress, high temperature and high seepage, the three field coupling control equation of temperature-stress-seepage are established, the finite element method is used for solution. Considering stress transference of surrounding rock after creep and deformation, the finite element incremental equations is deduced. Combining the finite element method and strength reduction method, The defect of deep surrounding rock stability that never quantitatively assess before was overcome. The proposed calculation method is applied to project, the analysis results show that the proposed method is feasible.
Study on Risk Management of Deep Foundation Pit Engineering
Authors: Nie Shu Min , Ren Feng
Published: September 2014

Deep foundation pit engineer is characterized with high risk, and it is important to have a study on the risk management of deep foundation pit engineering. Risk Measurement, Risk Assessment and Risk Control of Deep Foundation Pit Engineering is very necessary. There is a need to establish a set of operational foundation pit engineering risk management system to comprehensively and accurately identify and measure the risks of deep foundation pit engineering; and conduct risk control on the basis of risk analysis. Using engineering testing technology, establishes a monitoring based deep foundation pit engineering risk management mode.
The Survey of Karst at Guizhou Section of Chengdu-Guiyang Railway
Authors: Yue Zhi Qin
Published: September 2014

Guizhou section of Chengdu-Guiyang Railway is located in northwestern GuizhouPlateau, which belongs to Chishui River and Wujiang Drainage Area. Thegeologic structures are mainly the fold or fracture in the direction of North-North East, and have Flat rock. Carbonate rocks are widely distributed on the surface of this area. All kinds of karst pronounced,and water and soil conservation is very bad. Rocky desertification is serious, and environmental is sensitive. Karst is one of the main unfavorable geology of control line scheme. In this paper, from the regional geological environment and regional hydrological environment ,analysis of the factors influencing karst has been done. The development regularities of karstis summarized, and the corresponding classification standards are provided. Through the comprehensive analysis of each line program of geological factors,karst geological basis for the route plan is provided .
The Techniques of Grouting Management for Gushing Water of Fault Fracture Zone
Authors: Li Zhao Feng , Li Shu Cai , Li Hai Yan , Liu Ren Tai , Xu Cheng , Zheng Zhuo , Zhang Shi Jie
Published: September 2014

Gushing water in deep well and roadway has become a crucial technique problem which threatens mining safety. Taking advantage of transient electromagnetic, high-density electrical method and a combination of geological analysis, drilling testing analysis, an analytical method for gushing source and path was proposed, and types of gushing water were sorted in light of the cause of formation and governing strategies. Each gushing characters were systematically studied, thus forming the corresponding governing key techniques. Governing methods and main qualification for surrounding rock safety were proposed, with a careful consideration of the surrounding rock safety during grouting. The achievements are widely used in Guotun coal mine in Juye coal field with success, which offers a reference for similar engineering.
Hainan Tropical Rainforest Landslide Analysis and Prevention Measures
Authors: Xiang Wen , Li Guang Fan , Li Yan Rong
Published: September 2014

By Hainan tropical rainforest area geology, physiognomy, the characteristics of climate, tropical rain forest complex typhoon heavy rainfall weather conditions, and the characteristic of the tropical rainforest landslide occurred, researching and analyzing the relationship of among tropical rainforest landslide, tropical rain forest vegetation destruction the relationship ,the heavy rainfall and human engineering activities. Summed up the vegetation destruction, heavy rains and engineering activities of the three factors of coupling is the most important characteristics of tropical rain forests of landslide, and put forward reasonable tropical rainforest landslide protection and management measures.
Evaluation of the SIF for the Multiple Crack Problems
Authors: Liu Jun Yu , Zhang Ping , Liao Meng Han , Ning Bao Kuan
Published: September 2014

In elastic fracture mechanics the evaluation of the stress intensity factor (SIF) for multiple cracks problems is an important issue. In the paper the scaled boundary finite element method (SBFEM) is used to solve the SIF of mode I of multiple crack problems. The solving domain is partitioned into several sub-domains according to the number of cracks. Every sub-domain has its own scaling center. The characteristics of the SBFEM are preserved in every sub-domain. Numerical examples show that the SBFEM is effective with high accuracy in evaluating the multiple cracks fracture problems. It can be applied to treat the anisotropic materials conveniently. The stress intensity factors of unequal double-edged cracks in orthotropic material are provided.
Analysis on Reliability of Load Test on Bearing Capacity of Foundation Piles
Authors: Sima Yu Zhou , Sun Qing Hua
Published: September 2014

In static load test, most of piles do not destroy, the piles still exist capacity, which reduce the reliability index of pile foundation. This paper employs Bayesian Statistic method to update the measured capacity of piles. Meanwhile, based on updating data, the reliability index is calculated considering the destruction of piles. The case study shows that the reliability index of capacity becomes large when the time of pile destruction increases. Therefore, when judging the safety of pile foundation, it is highly necessary to consider the influence of pile destruction on reliability of piles.
Finite Element Study of Settlement of Cement Mixing Composite Foundation and Non-Probabilistic Reliability Analysis
Authors: Mu Huan Sheng , Gao Ling
Published: September 2014

This paper presents a non-probabilistic method for reliability analysis of cement mixing composite foundations. First, the load transfer mechanism of composite foundations is described. Then a three-dimensional finite element model of cement mixing composite foundation under embankment is built. The settlement of subgrade is analyzed. Finally, a non-probabilistic reliability method is used to investigate the settlement reliability. The results show that the cement mixing composite foundation can significantly improve the compressibility of soft soil.
Modeling Slope Anchor Reinforcement Using Enhanced Discontinuous Deformation Analysis Method (EDDA) with Natural Neighbor Interpolation
Authors: Ma Yong Zheng , Cai Ke Jian , Li Zhan Tao , Song Chun Xia
Published: September 2014

A new enhanced Discontinuous Deformation Analysis method (EDDA) in conjunction with Natural Neighbor Interpolative (NNI) bases for modeling the system composed of high order deformable solids is developed. The advantages of NNI lie in its efficiency and the interpolative property when employed as the shape functions. The anchor reinforcement algorithm is also implemented in the EDDA for modeling high order deformable solids. The numerical results of simple problems by using the proposed method agree well with the corresponding analytical results, and certain slope reinforcement problems are also simulated with rational numerical results, which verify efficiency and accuracy of the EDDA.
Quantitative Characteristic of Meso-Damage Granite under Cyclic Loading with Different Frequencies
Authors: Ni Xiao Hui
Published: September 2014

The failure damages of granite under cyclic fatigue load were caused by the propagation and coalescent of cracks at mesoscale, so it was helpful to understand the mechanical behaviours of rock by quantitatively investigating on meso-damage of granite. Stress amplitude of 10 MPa and sine wave cyclic loads with five different frequencies of 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1 Hz were adopted as dynamic disturbance. Then, the microtest (SEM) is carried out to study its fractography morphology and the meso-structural images of marble were processed by regional growing theory based on image processing technique. The meso-damage information of granite microcracks was obtained from SEM images. Quantitative analysis of meso-damage characteristics under cyclic fatigue load wase made from angle, length, width and area. The results showed that with the frequency of cyclic load increasing, the dispersion of microcrack growth azimuth value increased and the average of microcrack growth azimuth value fluctuated in the range. It is great helpful for seismic response analysis of the nuclear power factory in Chang Jiang.
The Risk Management Practice of a Deep Foundation Pit Project
Authors: Nie Shu Min , Liu Jun Yan
Published: September 2014

Risk management consists of Risk Identification, Risk Measurement, Risk Assessment, and Risk Monitoring and Control. This paper based on An office building in Dongying, uses Monitoring data to analyze, in order to gain an applicable Risk Management Practice. This article suggest we have to do the survey work well and also should pay attention to the empirical analysis of experts and field technicians at the same time to analyze risk to deep foundation pit engineering.
The New Method of Connecting Projection of Structural Planes Exposed Points into a Line
Authors: Zhang Qian , Wang Zhi Yuan , Yang Jun , Liao Xin
Published: September 2014

Structural planes in rock mass play a regulatory role in strength, deformation and fracture. It is the primary task to find out spatial distribution of controlling structural planes. The new method of connecting projection of structural planes exposed points into a line is realized by the certain distance from exposed points to the plane. And the plane is determined by its occurrence. Then select the suitable data and project to the ground surface using trigonometric function conversion. Finally connect these projection points into a line. Computation process can be simplified through MATLAB. This new method is applied to draw the exposed trace line of III-class structure in the left dam abutment adits of Yebatan hydroelectric power station in Jinsha river. The results are accurate, which means this method is feasible.
A Preliminary Discussion of Build Rubber Dam in Bayi Linzhi’s Fuqing River
Authors: Song Xin Wei , Cao Zhi Xiang , Chen Fang Chao
Published: September 2014

Rubber dam is a type of soft shell hydraulic structure, which is rechargeable and scalable. Relative to other hydraulic structure that has the same function, rubber dam has many advantages, low cost, short construction period, simple to operation and maintenance, and long service life. Rubber dam is now widely used in industrial and agricultural production, which have improved the ecological environment and cityscape. The Fuqing River, whose water is stench, dirty, have been seriously affecting the city appearance. This paper discusses on construction three-level cascade rubber dam in the Fuqing River to improve the water quality. Build those rubber dams project on the Fuqing River, which not only improve the water quality, beautify the environment, improve the urban ecological environment, create good environment for residents living, can also create social and economic benefits.
Effect of MgO Admixture on Stress Characteristics of Concrete Plates Faced on Rockfill Dam during Construction
Authors: Xie Zhi Qiang , Chen Qin , Gong Ya Qi , Qi Yong Feng
Published: September 2014

Concrete plate is mainly anti-seepage structure for rockfill dam and essential to avoid dam destruction. Cooling shrinkage will be effectively compensated by mix MgO, as a result, it have been widely used in hydraulic structure. However, with large radiating surface, uniform heat exchange and small bottom restriction, stress characteristic of concrete plates is much different from conventional massive concrete structure. Therefore, impact of MgO on stress characteristic of concrete plates is unclear. In view of this, construction process using MgO concrete and ordinary concrete are simulated based on practical project data. Conclusions indicate that tensile stress of concrete plates in cooling stage can be reduced by adding MgO.
Sensitivity Analysis of Concrete Curtain for the Seepage Control of Dam Foundation
Authors: Li Biao , Tong Fu Guo , Liu Chang
Published: September 2014

The seepage control is one of the most important aspects of dam security measures, which is usually related to the depth, thickness, permeability of concrete curtain. Based on finite element method, this paper calculated the sensitivity of dam foundation seepage discharge with the permeability, depth, and thickness of concrete curtain. The results show that seepage discharge mainly relies on the depth of curtain in case of shallow overburden. The total seepage discharge will sharply decrease when the curtain trend to be closed. The thickness is a key factor of seepage control for a thinner concrete curtain. The effect of increasing the curtain thickness on seepage control becomes more and more unapparent as it thickening. The sensitivity of curtain permeability to the seepage discharge increases first and then decreases with the strengthening of curtain impermeability.
Research on Sediment Problem in Dam Area of Three Gorges Project
Authors: Wang Jun , Guo Wei , Xu Hai Tao
Published: September 2014

The Three Gorges Project is the biggest hydraulic engineering and it brings great comprehensive benefits such as flood control, power generation, navigation, and water supply. According to the sedimentation prototype observation on the early stage of the Three Gorges Project operation, the sedimentation pattern of dam area and the upper part of power plant, as well as the channel sedimentation are analyzed after the systematic arrangement of the prototype observation, at the same time, the formation mechanism and development of siltation are studied based on river dynamics theory. The analysis shows that: the early siltation does not have important influence on the operation of the Three Gorges Project, the sedimentation of dam area occurs mainly in the wide section while little siltation in the narrow section and the siltation intensity is greater while the location is close to the dam from the view of the siltation distribution.
Analysis of Deformation Mechanism and Control Technology of Soft Rock Tunnel with High Geostress
Authors: Pan Fei , Cheng Sheng Guo
Published: September 2014

With the development of transportation construction, soft rock tunnel with high geostress construction has become a key problem to overcome of traffic engineering construction. In order to explore the deformation mechanism and control technology of soft rock tunnel with high geostress, Xiakou tunnel engineering as an example, the geological characteristics and deformation characteristics of the tunnel were analyzed, to obtain the deformation mechanism of soft rock tunnels with high geostress, and to develop deformation control technology, the results provide a basis and reference for the domestic and foreign the similar engineering construction.
Metro Construction Safety Risk Assessment of Xi'an Based on CIM Model
Authors: Zhang Bi Xue , Ma Feng Hai
Published: September 2014

According to the geological characteristics of Xi'an, analyze the accidents may occur in metro construction. A metro construction safety risk assessment system should be built on the basis of the cause of the accident. Combined with the data of survey and design of Xi'an No.4 subway construction, using the fuzzy AHP to reach the parameters of risk assessment and build a CIM model. CIM model is applied to the risk assessment of Xi'an No.4 subway construction. The total metro construction safety risk can be gained through analyzing. In addition, risk events that may occur based on specific risk factors to determine the risk level. Lastly, control measures are put forward.
Stability Analysis of Central Haulage in Baluba Copper Mine
Authors: Yao Gao Hui , Wang Yi Ming , Hu Kai Jian
Published: September 2014

Site observations were conducted to investigate the reasons for the poor current rock-mass conditions being experienced in essential crosscuts, to provide recommendations for remedial support measures. Conceptual analyses of mining induced stresses within abutment pillars were undertaken using elastic analytical and mathematical modelling. The results showed that damage to the crosscuts is due to high mining-induced stresses, with the major stress probably acting vertically, the protection pillar for the 480 Level crosscut should be at least 100 m wide. The research demonstrated that only 2.4 m grouted rock-bolts and timber sets is not enough in these conditions, so the 480 Level and 580 Level central haulage should be re-supported with a combination of 4.0 m pre-tensioned cable-bolts, a 75 mm layer of steel mesh (or fibre) reinforced shotcrete, and even steel arch sets with lots of log.
Study on Numerical Simulation of Construction Processing for No.1 Shaft of Weihe Tunnel
Authors: Wang Yu Suo , Lin Yu Sen , Feng Gao Fei , Ding Ti , Yang Chao , Li Jun Jie
Published: September 2014

In order to analyze the construction processing for No.1 shaft of Weihe Tunnel on Baoji-Lanzhou Passenger-dedicated Railway, a two-dimensional numerical model for the simulation of the shaft was built with the finite difference method. Mohr-Coulomb model was chosen as the soil constitutive model. The result shows that the maximum lateral displacement appears at the upper part of the shaft, and the lateral displacement is in effective constraint at the shaft’s bottom. After the construction, the maximum uplift at the shaft’s bottom is in the center, while the uplift decreases from the shaft’s center to its both sides. The maximum pressure stress turns up at the bottom sides of the shaft, and the maximum tensile stress appears at the middle of the shaft.
Experimental Study and Theoretical Analysis of Ultimate Strength for Steel Tubular Joint of UHV Transmission Towers
Authors: Jiao An Liang , Li Zheng Liang , Liu Hong Jun
Published: September 2014

Both experimental research and theoretical analysis of ultimate strength for steel tubular tower joint are developed. The experimental data comprise four different specifications of steel tube, that is, without ribbed plate, with 1/4 annular ribbed plate, with 1/2 annular ribbed plate and with annular ribbed plate. This paper considers that the ultimate strength of steel tubular joint depend on the following four parameters, that is, the ratio of length of joint plate to outer diameter of steel tube B/D, outer diameter D, axial force and ratio of length of annular plate to outer diameter of steel tube R / D as well as the ratio of thickness of annular plate to thickness of steel tube. Furthermore, a recommended formula of the ultimate strength of steel tubular joint is derived by the potential energy principle and the principle of virtual work in elasticity and plasticity based on the failure modes of experimental specimens. It is demonstrated that the applicability of the recommended formula is better.
The Analysis of the Concrete Lining Damage under Blast Load
Authors: Han Bang Xin , Li Li Xin
Published: September 2014

Subway is an important part of city traffic system. Once terrorist attack happens in the subway, it might lead to strong response of concrete lining, which seriously threatens the safety of lives and properties. The analysis of the subway concrete lining damage under blast load has become an important question. By the means of finite element software AUTODYN, this essay simulates the highly nonlinear response and dynamic damage of concrete lining when 100kg TNT explodes different altitude above bottom of subway tunnel. It analyses attenuation of pressure and influence on the structure of concrete lining. The damage of concrete lining mainly concentrated in the vicinity of explosion source. Different explosive height will lead to different dynamic damage of concrete lining.
Study on Stability of Layered Roof Surrounding Rock Reinforced by Anchor in Rectangular Roadway
Authors: Zhao Zhong Ming , Xi Zhi Yuan
Published: September 2014

Under the assumptions of plane strain, vertical normal stress and shear stress distribution in surrounding rock of rectangular tunnels before and after installing anchor cable are studied. And according to the mechanics of materials, the formula of stress distribution in the roof is corrected. According to the corrected formula of the stress distribution, the dangerous points are found. And the dangerous point location does not change before and after installing anchor cable. It still locates in the middle and ends of roadway roof. Just the dangerous stress value decreases after installing anchor cable. There are the maximum tensile stress in the midpoint roof and the maximum shear stress on both ends of the roof.
Numerical Simulation of Rock Breaking by Disc Cutter of Tunnel Boring Machine
Authors: Wu Qi Xing , An Guang Feng , Zhou Xiao Wen , Chen Lin
Published: September 2014

By using the explicit nonlinear dynamic analysis program of LS-DYNA, three-dimension finite element model of rock breaking by disc cutter of tunnel boring machine is established, in which elastic material is adopted to describe the elastic behavior of cutter ring and Holmguist Johnson Concrete (HJC) model is adopted to describe the brittle behavior of rock. With the finite element method, the process of rock breaking by disc cutter is simulated, and then the movement characteristics, forces of disc cutter and rock fragmentation mechanism are analyzed. The results indicate that the numerical technique can contribute to gaining an understanding of rock breaking mechanism by disc cutter and improving the design of disc cutter parameters.
A Method to Optimize Composite Fore-Fulcrum Form Travelers in Single-Plane Cable-Stayed Bridges
Authors: Wu Yang Yang , Chen De Wei , Jia Fan Xin
Published: September 2014

This paper presents a method to optimize the composite fore-fulcrum form traveler which makes the traveler more reasonable and economical, and the method can be conveniently used by designers while designing form travelers for single-plane cable-stayed bridges using cantilever cast-in place construction method. After a general theoretical description (theory and process) of the optimization model, an engineering case is optimized using this method. And the method is proved feasible by analyzing the primary and optimized travelers in Midas Civil and comparing their properties.
Aerodynamic Interference Study of Vortex-Induced Vibration of Twin-Separate Rectangular Sections Based on POD
Authors: Ma Kai , Zhou Zhi Zhong
Published: September 2014

To study aerodynamic interference of twin-deck sections under vortex-induced vibration (VIV), a series of wind tunnel tests are implemented. Horizontal interval ratio (D/B) is taken into consideration a factor influencing VIV behavior, and the results are compared with single section. Surface pressure distribution of the twin sections are acquired by synchronous pressure measurements when the sections are under vertical and torsional VIV. Proper orthogonal decomposition (POD) is employed to reconstruct the randomly fluctuating wind pressure field. It identifies the vertical and torsional vibration frequency of model and energy proportion of eigenmodes. VIV behavior of twin-deck sections is different from single section, and it changes with different D/B. In general, the position, where D/B=1, is unfavorable to VIV behavior of twin-deck sections. The aerodynamic interference does not always amplify or restrain the amplitude of VIV. Several lower modes can reconstruct fluctuating pressure field to the accuracy meeting the requirement of engineering.
Experimental Study on Three-Span Continuous Wide Curved Box Girder Bridge Model
Authors: Wang Jie Jun , Tan Peng , Yuan Jiang Ya , Yuan Hai Qing , Zhang Gui Ming
Published: September 2014

This paper simulates the practical engineering, using plexiglass to make a three-span continuous wide curved box girder model by the geometry scale ratio 1:30. With the model load test, measured the strain and deflection of the control cross-sections, got the distribution about the stress and deflection of the wide curved continuous box girder; And we proposed the “uniformity coefficient” to express the uneven force of the curved bridge. Compared the finite element analysis results and experimental data, the results show both are in good agreement.
Impact of Track Longitudinal Resistance on the Calculation of Continuous Welded Rail Sited on the Bridge
Authors: Hao Liu , Wei Qi , Wang Ping , Xiao Jie Ling
Published: September 2014

In order to find the impact on longitudinal resistance of continuously welded rails on bridge under different longitudinal resistance of the lines, based on the principle of the interaction between bridge and track, an integrative rail-bridge-pier calculation model of CWR on bridge is developed. Take simple-supported and continuous beam bridge as example to analyze the influence of continuously welded rails on bridge under different line resistance. The result shows that whether simple-supported or continuous beam bridge, the additional expansion forces which conducted by the constant resistance are smaller than the bilinear and power-exponential resistance, and the gap becomes greater as the increasing of the expansion length, and the calculation of the bilinear and power-exponential resistance becomes more and more similar. Besides, the calculation of the braking forces which conducted by the constant resistance is smaller than the bilinear and power-exponential resistance, while the displacement between the rail and beams is bigger, and has exceeded the calculation standard; the breaking joint of rail conducted under different longitudinal resistance is basically the same, but decreased gradually with the maximum line resistance increased.
Manning’s N Value of Bridge-in-Backpack
Authors: Ma Jing , Yang Ling Qiang
Published: September 2014

Bridge-in-a-Backpack is a new type bridge. this study will investigate the interaction of flow under the bridge with the tubes and decking, and recommend Manning’s roughness coefficient for water flow under the composite backbridge system.