bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Landslide Early Warning of Mayanpo Slope at Xiangjiaba Hydropower Station
Authors: Sun Jian Hui , Jiang Long , Wang Wan Shun
Published: September 2011

The paper has in-depth systematically studied stability and early warning of high engineering high slopes in depth, and established the early early-warning model of slope and the health diagnosis system. The results show that: ① displacement deformation increases with time and decreases with increasing depth. Changes of displacement can be divided into three stages: deformation rapidly increases in the early, and slowly increases in the medium term, and becomes gradually stable in the later; ② by through stability analysis of Mayanpo slope of Mayanpo slope ofby finite element strength reduction FEM, stability coefficient is 1.72; ③ Using using boundary displacement method and taking the equivalent plastic strain region through as a criterion for the early- warning analysis of slope landslide landslide, the paper presents establishes the early-warning monitoring system of slope based on double controlleding indicators of displacement deformation amount and safety factor.
Wetlands Dynamics in Nansi Lake, Shandong, China
Authors: Meng Fei , Yu Ming Yang , Liu You Cun , Cui Jian
Published: September 2011

Abstract.The wetlands dynamics was investigated in Nansi Lake for the period between 1987 and 2007. Four periods of remote sensing images, including TM&ETM and SPOT images, were used to locate and quantify the changes. Results show that from 1987 to 2007 the reclamation in Nansi Lake was serious. A large part of the lake had been replaced by land, the open water region only accounted for 51.3 percent. Farmland was distributed along the coast of lake accounting for 13.3 percent. Aquaculture ponds area was 37430 hm2，accounting for 29.7 percent. Comparing the three time period (1987-1991, 1991-1999 and 1999-2007), more changes in the cover areas occurred during the period 1991-1999 and 1999-2007 which is characterized by human interventions.
The Research of 3D Terrain Visualization Based on ArcGIS and 3DMAX
Authors: Tian Mao Yi , Wang Xing , Zhao Qian
Published: September 2011

The paper researches how to import the large amount of discrete data into 3DMAX and realizes high precision 3D terrain modeling. By analyzing and researching the data type and the feature of discrete data which can be accepted in 3DMAX, this author proposes a technical by importing data to ArcGIS, adding and modifying the characteristic points and lines, smoothing the data, exporting the 3D model in the use of the ArcGIS, and finally importing the result model into 3DMAX, and then generating the high precision 3D terrain model. In practice, the feasibility of this process is proved very well.
Accessibility Evaluation of Guangzhou Subway Network Based on Space Syntax Model and GIS
Authors: Mei Zhi Xiong , Ou Yang Jun , Chen Si Min
Published: September 2011

Based on the current condition of Guangzhou subway network, the authors used GIS methods and extended the space syntax theory to analyze the accessibility of the subway network, and compared with actual passenger flow. The results show: 1)Space syntax is practicable to measure the accessibility of subway system; 2)Among all sections by division, the accessibility of Tiyuxilu-Chen Clan Academy is the highest, the accessibility of Yantang-Panyu Square is the second highest, while the accessibilities of Jiaokou–Xicun and Dongchong–Jinzhou are the lowest, the accessibility of Xilang -Chen Clan Academy is the second lowest; 3)The accessibility level of subway and actual passenger flow have a positive correlation, the higher the accessibility, the larger the passenger flow; 4)As a whole, line 1 has the highest accessibility and the largest passenger flow, followed closely by line 3. Their departure frequency and number of carriages should be properly increased to relieve passenger flow pressure. Line 4 has relatively low accessibility and less passenger flow, so it should appropriately decrease train frequency or extend departure interval to reduce operating cost at present. Certainly, space syntax inevitably has its limitations, but after proper extension, the space syntax method can be used to instruct traffic reconstructing and urban planning etc.
Generation Mechanism of Coal Pillar Rock Burst
Authors: Ning Zhang Xuan
Published: September 2011

Aiming at the problem of the isolated coal pillar occurring the rock burst easily and having no the occurrence and damage theory of the rock burst according with actual, it discusses the generation mechanism of tension rock burst of the isolated coal pillar, uses finite element software of the tension fracture to simulate the fracture and evolution process on the function of the triangle load of the isolated coal pillar. The result shows that the coal pillar generates tension fracture on its both sides, the fracture direction is horizontal. After the coal pillar cracks, the stress is released, forms new stress concentration and the loose region. The coal pillar generate to slide on the horizontal direction on the interaction of the coal pillar and the top and bottom roof and on the function of the geological. This can provided the theory basis for the prediction and forecast of the rock burst of the isolated coal pillar.
Study on the Concentration of Chlorophyll a and Suspended Solid Using Hyperspectral Quantitative Model in Nansi Lake
Authors: Zheng Guo Qiang , Li Yong Xia , Wang Jing Wei
Published: September 2011

This paper process spectral data of the water based on normalization and Envelope elimination methods, by correlation analysis between land surface spectral data of single band or combining band and concentration of chlorophyll a and Suspended Solid to select band with max correlation coefficients, construct the best linear regressive models between spectral data and chlorophyll a and suspended solid. Firstly, the reflectance of the land surface of Hyperion images were obtained through geometric rectification and atmospheric modification adopted the 6S model, then the maps of spatial distributions of the concentration of chlorophyll a and suspended solid in the Nansi Lake were obtained using the best linear regressive model of chlorophyll a and the best linear regressive model of suspended solid. The results show that, data process of envelope elimination can remove the effect of the background spectral effectively and stand out the features of spectral absorption and reflection, and the combination of spectral R700/R560 and R736/R759 can be used to retrieved the concentration of chlorophyll a and suspended solid in the Nansi Lake.
Construction of Vehicle Dispatching Service System Based on GIS
Authors: Cai Fei , Li Jin , Cui Jian
Published: September 2011

Construction of nice vehicle dispatching service system is the key of urban intelligence modern transportation management. The three-tier architecture and the development platform of the system are introduced in the paper. The key technologies of implementation are discussed in detail. In key technologies, real-time signal is decoded by using control of serial communication in order to implement real-time position and optimization of classical Dijkstra algorithm is realized in the paper. System can obtain all kinds of information about vehicle rapidly and provide the effective service for the vehicle management and development.
The Study of a Solution for the Rural Roads Infrastructure Data Examination
Authors: Liu Hong Yuan , Ye Jing Song , Duan Cheng Min
Published: September 2011

The infrastructure data plays a significant role in the construction and maintenance of the rural roads. It is highly necessary to better examine the rural roads infrastructure data, ensuring the authenticity, accuracy and validity of the data. This paper studies a method for the data examination, including the real time examination in the field procedure, and the indoor complete examination, examining the road line shape, mileage, important technical indices and the ancillary facilities’ positions and import technical indices. This paper designs a solution for the data examination and develops the Rural Road Infrastructure Data Examining System. According to the experiments, the efficiency of the solution is proved.
An Experimental Study on Basic Engineering Properties of Paper Sludge Ash (PS Ash)
Authors: Zhu Chun Peng , Wu Hai Qing , Wang Li Wei
Published: September 2011

Large amounts of sludge are produced in China each year. Its safe disposal and the recycling technology is the only way to solve the problem of sludge pollution, in which the sludge solidification technology is very important. Since the hygroscopic property and self-hardening property of paper sludge ash are important factors for developing cheap and effective sludge curing agent formulations, the research is practically valuable. The present research studies the basic engineering properties of paper sludge ash, its PH value, heavy metals in the extracting solution, hygroscopic property, microstructure and shear strength. The results show: the PS ash was weakly alkaline; the extracting heavy metals are of little pollution; hygroscopic property decreases with increasing pressure and there is a minimum water absorption; shear strength decreases as the water content increases.
Numerical Simulation of Transient Electromagnetic Response of Unfavorable Geological Body in Tunnel
Authors: Meng Lu Bo , Li Tian Bin , Duan Zheng
Published: September 2011

To investigate the transient electromagnetic method of response characteristics in the tunnel geological prediction, the finite element numerical simulation of unfavorable geological body of different location, different resistivity sizes, different shapes, and different volume size were carried out by ANSYS finite element software. The results show that secondary electromagnetic field of different location of unfavorable geological body have same decay rate, when detection distance from 30m to 70m, transient electromagnetic responses are strongest, followed distance from 10m to 30m and from 70m to 90m. The shape, volume and resistivity of unfavorable geological body have strong influence on transient electromagnetic response, unfavorable geological body more sleek, the greater the volume and the smaller the resistivity of unfavorable geological body, the secondary electromagnetic field decay slower.
Research on Stability of an Excavated High Slope
Authors: Chen Xiao Ping , Chen Teng Teng
Published: September 2011

Stability analysis of excavated high slope is a complex problem. This work aims to a real excavated high slope in argillaceous mudstone, the strength properties of mudstone and instability mechanisms of slope had been studied separately by laboratory tests and numerical stimulate. The test results of residual-strength under large strain and softening-strength under rainfall infiltration were presented. The stability estimate basis of Bishop circular arc method and non-linear stress-strain analysis based on Duncan constitutive model had been carried out on the slope, using different strength indexes and Duncan model parameters obtained by triaxial drainage shear test. The results show that the landslides mechanisms caused by excavation and rainfall infiltration are relaxation failure and soften failure, separately. The deformation zone lies within the 0-4m soil layer and slope toe. The reinforcement measures of resistance piles set at slope toe and combined bolting and shotcrete set at slope surface were presented. After reinforced, the stability of excavated slope increased.
Research on Treatment Scheme Optimization for Slope Based on Analytic Hierarchy Process
Authors: Sun Lin Lin , You Chun An , Liu Jian Xin , Liu Qiu Yuan
Published: September 2011

At present, there are numerous treatment schemes for slope, while there is a lack of research on scheme evaluation and optimization. According to analytic hierarchy process, this paper takes two treatment schemes for Cangshang pit slope as research object, which are reducing load by cutting slope and strengthening by grouting, handles the complicated problem hierarchically and systematically, and establishes hierarchical structure model. Judgment matrixes are constructed to analyze multiple factors synthetically, which combine qualitative analysis and quantitative analysis preferably, and optimal scheme is selected finally.
Dry and Wet Cycle Tri-Axial Test Research of Silt
Authors: Liang Hong , Wang Yan , Zhou Tian Ping , Zhang Zhen Tao , Li Zhi Gang , Zhao Jin Fang , Rigele Te
Published: September 2011

Abstract. Silt in some areas of our country is very extensive, its distribution is different from the cohesive soil, or sand soil, has unique engineering characteristic. Silt regional characteristics make it has many unique physic-mechanical performance. This article take the G209 (Inner Mongolia Helin to Qingshuihe section) the roadbed silty soil as the study object, study its basic physics, the mechanical properties as well as the distortion and the intensity change rule under the dry-wet circulation, do a comprehensive and systematic analysis about varieties of basic engineering characteristic of the silt in the region Through the condition of dry-wet circulation of unconsolidated tri-axial tests, this article study the silt sample failure pattern under different degree of compaction, stress-strain relations and the change rule of strength. The test results show that: as cycle index less and confining pressure down, test sample is basically brittle failure, on the contrary case, it is behaved for plastic failure and stress-strain curve is close to sclerosis type; When cycle index increase gradually, the cohesion of silt reduced significantly ,with the increase of dry-wet circulation times internal friction angle is on the trend of the attenuation oscillation ; On this basis, we build the relationship expression of shear strength parameters cohesion internal friction angle and dry-wet circulation times.
Research on the Relief Degree of Land Surface (RDLS) Calibration Coefficient of Highway in Plateau Mountainous Area
Authors: Liang Guo Hua , Ma Rong Guo , Zhang Chang Sheng , Wu Feng Xia
Published: September 2011

Different reasons leaded to highway circuitous between plateau mountainous area and plain lightly undulate area were analyzed. The main reason which leaded to highway circuitous is the RDLS was concluded. The regression model between the RDLS and calibration coefficient of different technological levels of highway in plateau mountainous area was acquired by the least square method and the statistical tests based on the RDLS and calibration coefficient basic data. Taken Yunnan Province which is mountainous plateau province for example, the regression model between the RDLS and calibration coefficient was acquired, using the RDLS and Calibration coefficient basic date form all technological levels of highway in Yunnan Province of different elevation plateau mountainous areas.
Nonlinear Active Earth Pressure Distribution Based on Coulomb's Theory
Authors: Chen Jian Gong , Deng Mei Lin , Zhang Yong Xing
Published: September 2011

On the basis of coulomb’s concept that the active earth pressure against the back of a retaining wall is due to the thrust force exerted by a sliding wedge of soil between the back of the wall and a plane which passes through the bottom edge of the wall and has an inclination of θ, two basis differential equations of first order are set up by considering the equilibrium of the forces and the moments on a partial wedge of soil. The distributing coefficient of active earth pressure is obtained through comparing two basis equations. The unit earth pressure and the application point of the resultant force are deduced. The effects of parameters such as the internal frictional angle of backfill, the frictional angle between the wall back and the backfill, slope angle of filling and dip angle of wall back on distributing coefficient of active earth pressure, the unit earth pressure, the application point of the resultant force, rupture angle are analyzed in detail. Meanwhile the non-linear distributing features are concluded.
Internal Force and Deformation Analysis of Pile-Brace Support Structure of Foundation Pit Considering Deformation Compatibility
Authors: Xu Chang Jie , Luo Zhi Yuan
Published: September 2011

For the current simplified calculation of pile-brace support structure can not calculate the displacements of pile and brace, the authors try to start from the deflection differential equation of beam on elastic foundation, considering the deformation compatibility of pile and brace, and obtains the internal forces and displacements of pile by using Finite Difference Method. Meanwhile, Finite Element Method is used to analyze and calculate the horizontal displacements of pile. The results show that the values obtained by this article are closer to the measured values than that obtained by Finite Element Method. The method is accurate, reliable and simple. Besides, this author also analysis the different horizontal displacements of pile under different parameter conditions of support structure, which can provide some valuable suggestions for the design of foundation pit.
Experimental Study on Vibration Propagation of Rail Transport
Authors: Chen Shi Hai , Qi Gui Feng , Bi Wei Guo , Gao Wen Le
Published: September 2011

Rail traffic greatly alleviates the pressures of urban traffic, but it also has many negative effects, such as vibration and noise, which bring many inconveniences on the production and people’s daily life. Through the tests of railway vibration, we have got a number of ground vibration signals, and we analyze the basic frequency and peak speed of the vibration by dimensional analysis and wavelet packet analysis as the straight-line distance between the test point and track centerline changes, understanding the propagation of the vibration caused by rail and providing a basis for future research on vibration control of rail traffic.
Effects of Active Filler Selection on Foamed Bitumen Mixture in Western Australia
Authors: Huan Yue , Jitsangiam Peerapong , Nikraz Hamid
Published: September 2011

This study investigated the effects of different active filler types and contents on the mechanical properties of foamed bitumen treated materials under laboratory conditions. Four different active fillers were tested namely Portland cement, hydrated lime, quicklime and fly ash, at varying concentration of 0%, 1%, 3% and 5%. To evaluate the effects of the additional active fillers, samples were prepared under laboratory conditions and tested using indirect tensile strength, indirect tensile resilient modulus and unconfined compressive strength tests. Based upon our findings, all active filler types except fly ash contributed in improving the strength of foamed bitumen mixtures at different levels. Cement, regardless of adding contents, always provided the highest mechanical performance compared with the other two counterparts: hydrated lime and quicklime. Fly ash was deliberated to be precluded because fly ash on its own did not affect any mechanical strength of foamed bitumen mixes instead it acted as a mineral filler to modify aggregate gradation. The addition of active filler content should be limited within 3% in terms of strength gain and potential cracking prevent when mixing with 4% foamed bitumen content and locally sourced raw materials for base course.
A New Method to Analyze Seismic Stability of Cut Soil Slope
Authors: Wang Jun Jie , Zhang Hui Ping , Liu Tao
Published: September 2011

A new method to analyze the seismic stability of the cut soil slope is suggested in this study. In the method, the limiting equilibrium theory and the stress analyzing method are used. The stress acceptability criterion is based on the limited strength of soil. Two basic assumptions are given in the method. One is that the slip surface can be replaced by a series of straight lines. The other is that the interslice boundary is an inclined plane. Three balance equations for any slice, which are two for force equilibrium and one for moment equilibrium, are proposed. An iterative method, which solves the balance equations from the first slice to the last slice, is also suggested. In the new method, the slip surface is not predefined, but is obtained slice by slice going from downhill to uphill in terms of the force and moment balance equations of the slice.
Mechanical Analysis of Enclosure Pile under Different Constraints
Authors: Guo Li , He Peng Li , Zhang Guang Jun
Published: September 2011

The enclosure pile is extensively used as retaining structure in the foundation pit excavation. And it is always combined with other reinforcement measures. So it is unreasonable to a certain degree that the enclosure pile is analyzed as cantilever structure. Taken the deep foundation pit of a subway station in Hefei for instance, the effect of other reinforcement measures on restrained conditions of enclosure piles in the paper was taken into account. And the behavior of enclosure pile under various restrained conditions was analyzed. Based on that, some helpful suggestions for practical retaining structure of foundation pit were put forward.
Particle Flow Simulation of Rock Uniaxial Compression Process
Authors: Yin Yan Chun , Zhao Tong Bin , Tan Yun Liang , Zang Chuan Wei
Published: September 2011

The research of rock deformation and breaking has important scientific significance and engineering significance. Deformation is a long process, while the breaking happens in a monent relatively. In this paper the rock uniaxial compression test was simulated by using PFC2D. The complete curve of stress-strain was devided into six stages: compaction stage, elastic deformation stage, plastic sclerosis stage, plastic softening stage, breaking stage and breaking residual stage. It was found that the deformation localization generated the formation and extension of the cracks. When there were enough cracks, the specimen began to damage. Only a few crack bands evolved to breaking bands. The specimen’s breaking was mainly caused by indirect tension, supplemented by shear.
Model Test of Mechanical Characteristics of Cantilever Retaining Wall with Mutual Anchor
Authors: Zhang Hong Bo , Song Xiu Guang , Jiang Jian Hong , Zang Ya Nan , Dou Zhi Gang
Published: September 2011

In order to analysis force characteristics and changes of the anchor tension during the process of filling soil of the pull cantilever retaining wall, a model test is designed for research. The test mainly monitors basal earth pressure, lateral earth pressure of the retaining wall, anchor shaft force, lateral displacement of the retaining wall.
Research on the Supporting Mechanism of Gravity Retaining Wall with Grouting Anchor in High Filling Embankment
Authors: Zhang Hong Bo , Zheng Li Zhi , Song Xiu Guang , Xu Jun Ping
Published: September 2011

In order to make up for defects, including big gravity stress, large mansory and higher ground stress, in traditional gravity retaining wall, a new type of gravity retainwall combining grouting anchor is developed to support higher embankment. By installing soil pressure cells and anchor dynamometric cells, the vertical pressure on the bottom, lateral pressure on the retaining wall and the axial force of grouting anchor are analyzed during filling of embankment.
Numerical Simulation of Regional Stress Field under Complex Geological Condition
Authors: Wang Tong Xu , Zheng Wen Hai , Liang Sai Jiang
Published: September 2011

In this paper ,the geostress field of a large area complicated in geological structures was inverted with the stress data of a few measured points by using FLAC3D numerical stimulation and regression analysis. Two types of models were built. One type is a big model without geological structures, which considered the influence of layer thickness, lithology, stratigraphic dip and ground surface fluctuation first, and then corrected the simulation results according to the measured data, and finally got the geostress field without regional structures by regression analysis. The other type is small regional structure models, which paid attention to the influence of depth, fault type and fault throw, or fold type and fold amplitude, and gained the influence range and coefficients of each geological structure to the geostress field. At last, the results of two types were integrated together, and the large area geostress field under complex geological condition was got. According to this method in allusion to a specific example, the principal stress isoline and vector horizontal projection of coal seam roof including three faults and one fold were obtained, which could analyze the stress magnitude and direction. The method above can solve the problem of how to use the stress data of a few measured points to gain a wide range geostress field under complex geological condition, which could also promote the study of geostress field inversion and have certain engineering application value.
Prepartion and Atypical Mechianical Performance of Epoxy Asphalt Cement Mortars Composite Material for High Speed Railway
Authors: Fang Xing Long , Chen Zhi Ming , Jiao Zhen , Pan Gang Hua , Zhou Wen Ping , Feng Kai
Published: September 2011

Cement asphalt mortar is a key part of flexible adjusting layer in slab ballastless track structure. In this paper, new materials of epoxy asphalt cement mortar (EACM) was prepared with epoxy and chemically modified asphalt emulsionwhich showed excellent in terms of durability and weather resistance. This paper through changing the proportions of the eopxy-asphalt cement ration studies the relationship among fluidity, compressive strength, and elastic modulus of EACM and cement asphalt mortar (CAM) use chemical modification of asphalt emulsion and normal asphalt emulsion. The results showed that chemically modified epoxy asphalt emulsion cement mortar turned out to be relatively better in compressive strength, frost resistance and weather ability compared with CAM. The chemical reaction mechanism of epoxy asphalt emulsion were investigated by the means of environmental scanning electron microscope (ESEM) method.
Research and Development of Pneumatic Anchor Rock Driller & Drilling Tools
Authors: Wang Hong Li , Zhao Jin Qiao , Bao Wei , Song Li Xin
Published: September 2011

Now, pneumatic rotary anchor roofbolter is widely used in the underground. Pneumatic rock driller is mainly operated in hard rock tunnel, but it often exists in the phenomenon of hard rock and soft rock sections alternately. The result is occured in the replacement of drilling rigs and drilling tools, to produce a great deal of inconvenience. This not only affects seriously anchorage operating speed, but also increases production costs and brings insecurities factors of replacing driller. This study analyzes the performance and parameters of traditional rock rigs & roofbolter. Mechanical Model is established on the basis of studying rock breaking mechanism. Drilling parameters are comprehensively evaluated. It is put forword of specific rotary-impact function of pneumatic anchor rock driller. On this basis, specific rotary-impact function of pneumatic anchor rock driller has been systematically studied.
Rock Damage Constitutive Equation Based on Weibull Distribution of Intensity
Authors: Li Xiao Wei , Jiang Cheng Lin , Liu Wen Peng , Ji Ming
Published: September 2011

the evolution of rock microdefect is a random variation, and we can consider evolutionary process of microdefect system as nonequilibrium statistic processes. The microbit’s intensity distribution obey Weibull distribution, therefore, this paper adopts Druckr-Prager yield criterion, establishes the damage evolution equation using strain as characteristic parameter under the uniaxial stress, and derives relevant damage constitutive equation. Experiments prove that this equation, to some extent, reflect damage evolution processes under the uniaxial stress.
Dynamic Response of Horizontal Bedded Rocky Slopes under Earthquakes and Influence of Ground Motion Parameters
Authors: Hu Xiao , Chen Zhen Lin
Published: September 2011

Two dynamic numerical simulation models of horizontal bedded rocky slopes were established with Finite Element Analysis (FEA) according to the archetype of rock slope in “5.12” Wenchuan earthquake, and the simulation was validated with a shaking table model test. In the two models, one named A is the upper is hard and the bottom soft rock, and the other named B is the upper is soft rock while the bottom is hard. The result indicates that there exists amplification effect on elevation in both slopes under horizontal earthquake wave, the amplification factor of PGA in model A is larger than that in model B following the increase of the amplitude and the duration, and the slope displacement in model A is also larger than that of model B in the effect of the amplitude, frequency or duration. These show that model A is in disadvantageous compared to model B, and the stability destroy is produced easily in model A.
Simulation and Analysis for Laterally Loaded Pile in Clay
Authors: Li Fen , Tang Hu
Published: September 2011

It was presented for the results of 3D finite difference analysis on the behavior of single pile in clay. Firstly, it was discussed to the effect of model’s mesh fineness and soil parameters on pile response. And it was founded that the mesh size less than 0.2d (diameter of pile) was reasonable. In additions, when the soil was soft or the E(soil elastic modulus) was small, the effect E of on lateral capacity of pile was larger than the soil was stiff clay with soil elastic modulus increasing. Lastly, the results of the numerical simulation carried out in this study were compared with a published field lateral loading tests, a good correlation between the field test and the numerical simulation was obtained based on reasonable mesh size and material parameters.
Experimental Study on the Anisotropic Properties of Undisturbed Loess
Authors: Ye Chao Liang , Zhu Yong Quan , He Ben Guo
Published: September 2011

Loess has been subjected to long-term deposit, geological structure and weathering under the condition of self-weight and above covered load. Accordingly, it would result in many vertical joints and differences in mechanical response and deformation properties for vertical and transverse. In order to obtain different mechanical properties of vertical and transverse, laboratory physical mechanics tests (collapsible test, consolidation test, direct shear test, triaxial compression test and unloading test) were carried out to investigate typical Q3 loess from field above He Jia-zhuang tunnel of Huang Tu-liang district on Zhengzhou-Xi’ an high-speed passenger rail line in China. The results suggest obvious anisotropic properties of undisturbed loess. Not only do the conclusions supply theoretical foundation for design and construction of tunnel in loess, but also can act as guiding reference for similar underground engineering.
Optimization on Gateway Section of Soft Coal Seam and Hard Roof and Supporting Technology
Authors: Chen Lu , Zang Chuan Wei , Yu Feng Hai , Yu Xiang Kun
Published: September 2011

Support invalidity of a roadway have a largely influence on production safety of coal mines, especially the soft coal roadway, which deforms heavily. To solve this problem, it began from the gateway section optimization, based on the actual geological condition of Chang-gouyu Mine. The computational model was established up to optimize tunnel shapes using FLAC3D. The scopes of plastic zone, stress field, displacement field were compared and analysed for different shapes of roadway. The irregular trapezoid section is adopted, then the bolt support parameters were designed and field application was done. By using the irregular trapezoid, the stress distribution around the roadway is improved and the deformation and plastic zone is decreased. Under the geological conditions of the soft coal seam and hard roof strata, the stability of roadway was effectively controlled by using optimized trapeziform cross-section and bolting support.
Liquefaction-Induced Damage of Banqiao School Following the 2008 Wenchuan Ms 8.0 Earthquake
Authors: Cao Zhen Zhong , Yuan Xiao Ming
Published: September 2011

Banqiao school building had to be demolished for rebuilding because of severe damage induced by liquefaction following the 2008 Wenchuan Ms 8.0 Earthquake. The mechanism of the building damage and the characteristics of liquefied soils were investigated by trench, borehole drilling, and Dynamic Penetration Test. The detailed field investigation and in-situ tests show that: (1) The Banqiao school building suffered more severe damages than its surrounding buildings from the liquefaction rather than inertia force of shaking during the earthquake; (2) The subsurface liquefied soils are gravelly soils at the depth of 3.0 to 6.1m, which are significant different from the ejected fine sands; (3) It is unreasonable to regard gravels as non-liquefiable soils and a new procedure for gravels liquefaction evaluation need to be developed.
Dimensional Influence of Tunneling on Adjacent Pile Foundation
Authors: Ma Shao Kun , Zhou Xiao Bing , Hu Ping , Han Guo Liang , Xiao Yao , Ou Xiao Duo
Published: September 2011

In order to study the dimensional influence of tunneling on adjacent pile foundation, successive segmental excavation is simulated considering the geological background in Nanning. The different stiffness ratio of pile and soil is obtained by changing the pile’s elastic modulus, radius or length. The additional displacement and inner force due to tunneling are compared for different stiffness ratio. Many useful conclusions can be drawn. Foundation settlement occurs on the top of the tunnel while upheaval arises below the tunnel. The range of influence is enlarged with the distance from tunnel. Pile foundation is influenced obviously in the area of 1.5 times tunnel diameter from the tunnel face. The additional displacement changes clearly with different stiffness ratio, especially the vertical settlement. The conclusions will be useful for the construction and design of tunnel.
Coupling Numerical Analysis for Excavation of Deep Foundation
Authors: Cao Li Hui , Zhang Fu Guang , Feng Huai Ping
Published: September 2011

Using coupling model, the time-effect behavior for deep pit during excavating and dewatering is studied. The distribution of the seepage field, the horizontal displacement of wall, the settlement of surrounding soil and the settlement of the road are all obtained from the coupling analysis. Taking the deep foundation pit engineering of one station as engineering background, the coupling of seepage and consolidation is simulated in the process of excavating. According to the comparative analysis between the simulation value and the measured results, it can be known that the calculation value considering the coupling of seepage and consolidation is well in accordance with the measured value. The analysis shows that the provide method can be used to simulate the deep foundation under the coupling effect and it is reasonable, feasible, and can provide some kind of references to design and construction.
Stability Analysis of a 3D Vertical Slope with Transverse Earthquake Load and Surcharge
Authors: Nian Ting Kai , Zhang Ke Li , Huang Run Qiu , Chen Guang Qi
Published: September 2011

The stability and failure mode for a 3D vertical slope with transverse earthquake load and surcharge have been an interesting issue, especially in building excavation and wharf engineering. In order to further reveal the seismic and surcharge effect, a three-dimensional elasto-plastic finite element(FE) code combined with a strength reduction procedure is used to yield a factor of safety and failure mode for a vertical slopes under two horizontal direction pseudo-static(PS) coefficient and surcharge on the slope top, respectively. Comparative studies are carried out to investigate the effect of seismic coefficient, surcharge intensity and location on the stability and the failure mechanism for a 3D vertical slope including an inclined weak layer. Several important findings are also achieved.
Study on Earth Pressure on the Top of Trapezoid Ditch-Buried Culverts
Authors: Li Yong Gang , Xing Shu Yan , Feng Lin Wei
Published: September 2011

The vertical earth pressure on the top of ditch-buried culverts was analyzed theoretically under the condition of trapezoidal ditch and square culverts. A calculation model to evaluate the earth pressure on the top of the culverts based on Duncan earth model was established. The study results show that the height of plane of equal settlement decreases and turns to a constant gradually as the depth of soil overlying culverts increases. The primary influencing factors of earth pressure are the ditch width and the ratio of height to width of the culverts and the foundation. Each of them can make the coefficient of earth pressure increase or decrease more than 30%. When the width of the culverts become wider, ditch buried culverts turn to projecting buried culverts gradually, and the uniform calculation theory of earth pressure on the top of ditch-buried culverts and positive buried culverts is formed.
Numerical Analysis of Faults on Deep-Buried Tunnel Surrounding Rock Damaged Zones
Authors: Hu Jun , Xu Ling , Xu Nu Wen
Published: September 2011

Fault is one of the most important factors affecting tunnel instability. As a significant and casual construction of Jinping II hydropower station, when the drain tunnel is excavated at depth of 1600 m, rockbursts and water inrush induced by several huge faults and zone of fracture have restricted the development of the whole construction. In this paper, a progressive failure progress numerical analysis code-RFPA (abbreviated from Rock Failure Process Analysis) is applied to investigate the influence of faults on tunnel instability and damaged zones. Numerical simulation is performed to analyze the stress distribution and wreck regions of the tunnel, and the results are consistent with the phenomena obtained from field observation. Moreover, the effects of fault characteristics and positions on the construction mechanical response are studied in details. Some distribution rules of surrounding rock stress of deep-buried tunnel are summarized to provide the reasonable references to TBM excavation and post-support of the drain tunnel, as well as the design and construction of similar engineering in future.
Dust Generation within the Vicinity of Malmberget Mine, Sweden
Authors: Qi Jia , Nadhir Al Ansari , Knutsson Sven
Published: September 2011

Mining activities are usually associated with environmental impacts, particularly that of air pollution by fugitive dust. Malmberget mine is one of the most important iron mines in Sweden and the dust problem has been noticed by the inhabitants for a long time. Dust collectors had been installed to measure the dust fallout around the mining site. In this research the dust fallout recorded during the period August 2006 till July 2010 were analyzed. Generally speaking the amount of dust fallout was decreasing year by year due to some implemented dust control methods. Mining activities produced more dust during summer than winter. The peak value was 265g/100m2/30d appeared in May 2007, and the lowest dust fallout was 25g/100m2/30d happened in August 2009. Dust was determined to be originated from the open pit area and the industrial center area. Truck transportation on the haul roads, wind erosion of stockpiles and exposed areas were the main activities that caused dust generation.
Application of Damage Rheology Model in Study on an Underground Cavern Group
Authors: Qi Yin Ping , Xiang Lv , Zhu Wei Shen
Published: September 2011

A great number of large-scale hydropower stations are to be constructed in southwest China. Many of them feature great depth or high in situ stresses. In this paper, a coupled damage and rheology method is adopted for stability analysis of an underground cavern group with time effect to consider the rock deformation. Meanwhile, a new method considering the crackopening displacement is used for back analysis. The stability of the surrounding rock masses is then evaluated.
Application and Inversion on Mechanical Parameters of Pipe Shed Support Layer for the Subway Passing Through the Existing Structure
Authors: Gao Wei Liang , Li Yun Peng
Published: September 2011

The stability study is one of the hot spots of the urban transport design for the subway through the existing structure. The maximum settlement of the structure is regarded as the index of underneath the subway construction and design in this article, the mechanical parameters for pipe shed reinforcement layer on a subway station passing through the existing structure is back analyzed by utilizing the orthogonal experiment design methods, and the mechanical integration properties parameters which is close to engineering practice including elastic modulus, Poisson ratio, cohesion and internal friction angle for the material in the pipe shed reinforcement area are got. The steel pipe reasonable spacing range of advanced pipe shed support is got mainly on the basis of flexural rigidity. The stability analysis and evaluation for the construction of the new subway through the existing subway structure are carried out by utilizing the obtained optimum parameters.
Economical Effects of Using Subway in the Reduction of Fuel Consumption
Authors: Safa Ebrahim , Safa Arman
Published: September 2011

Abstract .Transportations one of the important indexes of air pollution in cities has always occurred in the form of a big Unavoidable problem. Lack of comprehensive approach and enough (Sufficient) attention toward transportation and traffic issues have unsparing social, economical and environmental costs and damages in the country which the most important of them are: high fuel consumption and growth of the fatal and injury crashes, air pollution and environmental damages. Among the public transportation networks, railway public transit is known as the healthiest, fastest, safest and generally the most efficient transportation network which is proved the undeniable role in solving economic, social and environmental problems caused by public transport and traffic problems. Considering the political and economic centrality of Tehran as capital of Islamic Republic of Iran with an increasing population of over 10 million people, and the construction of satellite cities, and conducting population to these cities, it is important to construct several connecting subway lines for these satellite cities. This paper focuses on economic problems via comparing underground subway as public vehicle with motor vehicle.
Assessment and Study on Seismic Fortification Standards of Highway Bridge in Wenchuan Earthquake
Authors: Lan Hai Yan , Tang Guang Wu
Published: September 2011

This paper mainly aims to investigate and analyze seismic fortification standards, the actual earthquake intensity and damages of the existing bridges in the 51 hard-hit areas in Wenchuan Earthquake. Based on the investigation and studies on the relationship among highway bridge damages, building year, bridge type and seismic protection classification, the assessment of seismic fortification standards is also presented.
The Research on Dynamic Performance of Straight Going Fast Assembling Car Overpass
Authors: Qiu Hong Sheng , Yuan Jing Jing , Liu Shu Guang , Huang Xiao Min
Published: September 2011

In order to solve the traffic jams and congestion of urban transportation in most cities, the steel trussed cable-stayed car overpass model is analyzed through the finite element modal analysis by ANSYS software based on the design concept of straight going fast assembling car overpass. After understanding the laws of free vibration characteristics of the structure, the variation of maximum deflections and stresses of the structure which is under the loads moved at different speeds are studied by moving load transient analysis of full method. The result further testifies that the structure is reliable and safe. Also, the range of the optimum speed is summarized to provide reference for the design of speed-limiting facilities of the car overpass.
Concrete Random Damage Prediction Model under Seawater Chemical Erosion Environment
Authors: Xu Xiang Feng , Wei Cheng Long , Zhang Feng
Published: September 2011

In order to effectively assess the concrete damage under sea water erosion environment, concrete prediction damage model was presented based on damage mechanical and the experimental test. The degeneration of tension strength of concrete was tested after dry-wet cycles. The fact is proposed that the degeneration of concrete is an interior damage evolving process. Freezing and thawing damage accumulation of concrete was analyzed based on the discrete grid with probability of stochastic method. Three-dimensional multi- parameters Weibull distribution model about concrete damage evolutions were presented. Parameters were estimated based on gradient method. The mathematical model was verified using measured data. Corresponding algorithm was designed to establish concrete durability prediction model under sea water chemical erosion conditions. The research can be referenced for prediction of frost damage of concrete.
Research on Stability Calculation of Variable Section Slender Pier with Initial Eccentricity
Authors: Liu Xiao Yan , Xiao Sheng Cai , Xi Sheng Ming
Published: September 2011

Aiming at eccentricity in the central position at the top of variable section pier during construction and based on the current stability theory, this paper studies the stability calculation of variable section slender pier with initial eccentricity in order to evaluate the availability of the pier. Firstly, theoretical equations to calculate the critical load of variable section compressed bar under ideal condition are derived in accordance with the functional principle. And the corresponding critical loads are worked out through using these formulae. Then, Finite Element Method (FEM) ANSYS is adopted to establish the spatial solid models of the bridge pier with or without initial eccentricity respectively. Critical load values of variable section slender pier under ideal condition are figured out, which are compared with the theoretical values in order to check the model’s reliability. On these bases, researches on stability of pier are performed and stability of the pier with initial eccentricity is calculated under the worst load condition at the stage of construction and completed state. Finally, all the calculated results are compared with Code’s specified values to judge the availability of this pier, which provides a firm protection for project constructions.
The Reinforcement and Optimum Design of JiShan Bridge
Authors: Chen Xu Yong , Li Shu , Li Jie
Published: September 2011

In this paper, Jishan Bridge is taken for example to introduce a strengthening method focusing on strengthening the vault and arch foot control sections and making full use of the surplus cross section to thicken the main arch ring, i.e., the special-shaped section arch-strengthening method, and put forward the reasonable construction procedure. Subsequently, the strengthening effect is verified from three aspects: static load test, dynamic reliability-based post-strengthening life prediction and strengthening economic indicators. Finally, the finite element software ANSYS is used for further study on the strengthening Optimum design.