bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamic Response Analysis of Vertical Cylindrical Storage Tanks Based on ADINA
Authors: Cheng Xu Dong , Hu Jing Jing , Zhao Li Ming
Published: September 2011

Storage tanks after earthquake disaster may create the serious consequence, so their anti-seismic problems have drawn greater attention, and their seismic response become the focus of research. Considering the liquid-solid coupling and the interaction between foundation and storage tanks，three different volumes of storage tanks that have different liquid height were simulated under the earthquake using the software ADINA. The liquid sloshing wave height, peak acceleration of tank wall and hydrodynamic pressure were analyzed. The results show that the peak sloshing wave height shows a rising trend basically with the increase of liquid height, and the roofs of large tanks are more easier to be destroyed by liquid sloshing. With the increase of liquid height and tank volume, the response of peak acceleration is greater. The hydrodynamic pressure increases with the decrease of liquid height. Near the bottom of tank wall the value of hydrodynamic pressure is relatively large, so elephant foot buckling is easier to happen in that area.
Vulnerability Analysis for Steel Frame Structure Due to Strong Earthquakes
Authors: Xu Long He , Shan Xu , Li Zhong Xian
Published: September 2011

To evaluate the damage level of steel structure under different earthquakes, a kind of vulnerability analysis method based on seismic damage assessment was developed using the improved two-parameter damage model which was proposed by considering the effect of hysteretic deformation amplitude to accumulative damage energy dissipation. This method is firstly to establish large samples of earthquake-structure, conduct a series of dynamic analysis to obtain the probability function of structural response and bearing capacity corresponding to different damage states, and then to draw the vulnerability curves and evaluate the damage state of the structure under different earthquake intensity. As a numerical example, a 9-story steel benchmark structure model under strong earthquakes was analyzed, and the theoretical vulnerability curves with lognormal distribution were obtained and the exceeding probability of structure at different damage level had been assessed.
Particle Flushing and Migration Regularity by Runoff in Different Functional Districts of Beijing City
Authors: Wang Jian Long , Feng Wei , Che Wu , Sun Tian
Published: September 2011

In order to obtain runoff particle flushing and migration regularity in different functional districts, surface runoff and dust of the campus, sidewalk, business street and viaduct in Beijing city were selected as research objects. Through the particle size distribution detection of surface dust and instantaneous rainwater runoff samples, the runoff particle flushing and migration regularity in different functional districts were analyzed. The relationship between runoff particulate and COD, SS, TN, TP and other pollutants, the particle size variation regularity in the flushing and migration process were analyzed, and the reasons were construed too. The results of the runoff pollutants impact of different size particles will provide a theoretical basis for the filter design and urban runoff pollution control planning.
The Study of the Influence of the Incident Angle, Frequency and Diameter on Blasting Vibration Velocity of the Underground Chamber
Authors: Lv Xiao Shi , Wang Guang Yong , Guo Jia Qi
Published: September 2011

Based on model tests, the wave function expansion method was used to study scattering on the interaction of explosive stress waves and the underground chamber, and analyze the influence of the incident angle, frequency and diameter on blasting vibration velocity of underground chamber. It is obtained that when the cavern was under the plane waves of the vault, the radial vibration velocity of the vault is the largest among the four measured data, and it is the most intense vibrating place. When the incidence direction offsets from the vault to the horizontal direction on the left, the radial velocity facing burst are all larger than the radial velocity back of the burst. When the incident direction is on the dome, the tangential vibration velocity will increase first and then decrease from the vault to the side wall. When the incident direction is at the haunch, the tangential vibration velocity in the corner should be noticed. With increasing of the frequency, the radial vibration velocity and tangential vibration velocity increase accordingly. At the forward part of the burst, the larger the chamber diameter is, the bigger the radial and tangential velocities are. At the back side of the burst, the bigger the chamber diameter is, the smaller the radial and tangential vibration velocities are.
Base Isolation Systems Employing Variable Friction Dampers Based on a STFT Controller
Authors: Dai Zi Shu
Published: September 2011

Conventional isolation systems may induce an excessive response in near-fault earthquakes. A new short time Fourier transformation (STFT) control algorithm for variable friction dampers (VFD) is developed to improve the performance of base isolation buildings in near-fault earthquakes. The STFT controller varies the clamping force in the VFD damper to achieve the response reduction. In addition, the STFT algorithm is implemented analytically on a multi degree of freedom system (MDOF) with laminated rubber bearings and variable friction dampers in Simulink environment. Three types of earthquakes representing a wide variety of ground motions are considered as the ground excitations in the simulation. The numerical show that, compared with conventional isolation systems, the semi-active isolation system controlled by the STFT algorithm can reduce the excessive response in near-fault earthquakes effectively.
Effects of Adjacent Ground Treatment on Site Seismic Response
Authors: Ge Gang , Liu Jian Min
Published: September 2011

The effect of adjacent soil improvement on ground motion is studied using finite element method, when seismic wave is introduced from the single layer on bedrock. The influence of ground motion on soil reinforcement is analyzed; the impacts of the reinforcement zone width, depth, elastic modulus, and the soil improvement interval on response of the ground motion are also investigated. Study shows: for the same site, when the distance between two adjacent foundation consolidation interval is less than 3 to 4 times the width of the reinforcement area, the interaction acceleration response amplitude of various points on the surface of the two adjacent reinforcement area increased significantly than the single block; within the interval , increasing one of the two adjacent foundation’s width, depth, and the other foundation surface, the horizontal acceleration response will Subsequently enlarged; when the interval between the reinforcement area is greater than the range, this effect is negligible.
The Experimental Study on Dynamic Characteristic of Diversion Dike’s Foundation Soil
Authors: Wang Gui Xuan , Zhou Jin Ling , Zhao Jie , Zheng Yang
Published: September 2011

Through the indoor resonance column and dynamic tri-axial test of liquefaction on diversion dike soil of a nuclear power plant, its got the curves of dynamic shear modulus-dynamic shear strain and damping ratio-dynamic shear strain, analyzed the dynamic deformation characteristics of diversion dike soil, studied the exponentiation function between liquefaction resistance strength and liquefaction shake times of sand soil, confirmed the indexes of liquefaction resistance strength, providing the relevant parameters for evaluating seismic stability and liquefaction analysis of diversion dike, and reference value for the seismic safety evaluation and liquefied evaluation of the dam project site.
An Improved Method for Fitting Ground Motion Attenuation Relationship
Authors: Li Wei , Li Shan You , Lu Jian Qi , Zhao Zhen
Published: September 2011

With the continuous research in earthquake engineering, great advances have been made in the theoretical research of ground motion attenuation. A lot of new achievements and views [1,2,3] provide the theoretical basis for the improvement of the ground motion attenuation experience models and the parameter estimation. Additionally, it provides a good environment for deeper study on the ground motion attenuation by the increase of strong motion records and the improvement of pertinent information. In this paper, the improved two-step method is put forward, and the regressed ground motion attenuation coefficients are obtained by the improved models and analysis method. This method not only considers the correlation of magnitude and distance, but also makes the regression coefficients more stable. The results can better show the characteristics of the ground motion attenuation.
3D FEM Analysis of Effects on Adjacent Pipelines by Pit Excavation
Authors: Lu Qun , Li Hui Xia , Yuan Jian Bo
Published: September 2011

Pit excavation influences the stress and deformation of adjacent underground pipelines seriously. On the base of former study, the project was analyzed with the aid of general finite element soft ABAQUS, in which the interactive action of soil with pipeline and pit protection structure were taken into account. Wall-soil friction and pipeline-soil friction contact were used. The influence on adjacent pipelines of pit excavation was analyzed. The laws of deformation and the stress were gained. The results showed that the horizontal displacement was much bigger than the vertical displacement, and the pipeline would lift at the end close to the symmetric plane and fall at the other end. The displacement would decrease with the increment of the distance between pit and pipelines. The laws of influence of the pipeline’s embedment and wall-soil friction were similar, while the latter’s influence was greater than the former’s. The influence on horizontal displacement aroused by wall-soil friction was greater. The principle tensile stress mainly aroused by the pipeline’s horizontal displacement would cause tension fracture. The sections of the pipeline around the area of the end and the middle of the pit were dangerous, which should be particularly protected.
Study on Change Regularity of Air Temperature Underground Tunnel Based on Intermittent Operating of Heat Pump
Authors: Li Yong An , Gao Ya Nan , Yang Zong Jin , Liu Xue Lai
Published: September 2011

In this paper, based on the analysis of strata soil temperature variation, the DeST software is used to simulate changes of outdoor air parameters under typical meteorological year in Jinan. One-dimensional unsteady state soil air heat transfer model is regarded as the research object, this paper theoretically studies export air temperature change rules for the whole year under tunnel intermittent running condition. The results show that the tunnel plays a preheating role for outdoor air in winter and the cold role in summer, which provides a good cold、heat source conditions for the application of air source system based on the tunnel wind, especially the most hot and cold day throughout the year, the system has a remarkable effect.
A Consensus-Based Approach for Information Fusion
Authors: Jiao Li , Zhang Hai , Liu Hong Wei
Published: September 2011

The purpose of data fusion is to combine and process the data of multi-sensors, thus to obtain much more exact and reliable results than that of the single sensor. An improved data fusion method for commensurate sensors is presented in this paper. It overcomes the shortcoming of the traditional consensus algorithm with two sensors, which has different confidence distance while measuring in different precision. The relation matrix is fuzzified to avoid the subjective error in determining the threshold value. The results of numerical simulation shows that the improved method can make full use of the effective information from the sensors and it can help to improve the accuracy of measurement. Even when parts of sensors are affected or fully disabled, it still can get correct diagnosing results in damage identification.
Influence of Source Distance on the Characteristics of AE Signal from Cement-Based Materials
Authors: Liu Yu Qing , Wang Wei Lun , Qin Lei , Huang Shi Feng , Cheng Xin
Published: September 2011

The influence of source distance on the characteristics of acoustic emission (AE) signals from mortar and normal concrete were investigated in this research. To collect AE signals of high signal to noise, which can be used in AE research for cement-based materials, the influence of source distance on the characteristics of AE signal were analyzed. The results showed that distance made a significant influence on the characteristics of AE signal from cement-based material, such as rise time, counts, peak amplitude and average frequency.
Extraction of Soil Salinization from Remote Sensing Information and LUCC Data Based on Knowledge Discovery over the Arid Area: A Case Study on Kuka County in Xinjiang
Authors: Wang Qian Qian , Hu Yun Feng , Song Wen Long , Wang Feng
Published: September 2011

Soil salinization is a most important factor to influence agriculture in arid area. There is a dire need to monitoring the soil salinization information based on Chinese own satellite data. In the study, a remote sensing classification method of soil salinization land based on knowledge discovery and decision-making process that is benefit to arise classification precision through a decision tree method has been constructed. The result shows that near 80% area of the entire county has suffered soil salinization with different grade. The percent of heavy, middle and light grades soil salinization area are 11.29, 20.53 and 49.01 respectively.
Study on Bearing Capacity of Incline-Pile Groups in Thick Soft Soil
Authors: Xia Xiong , Dong Liang Liang , Wang Xiao Ping
Published: September 2011

The presence of incline-piles can provide some advantages when the group is subjected to vertical loadings. Based on model tests of the static pressed pile groups, this paper describes the bearing capacity of incline-pile groups in soft soil. In order to study the incline-pile groups capacity behavior , a series model test and computer analysis were performed. In the model tests, a series of static vertical load tests were conducted on a group of eleven piles arranged in interval pattern., that constructed with aluminum tube, each 1.20m long, were used as pile groups with inclination angle of 0°,5°,8°and12°.And there is an optimal angle, which close to 8°, corresponding to the maximum bearing capacity. A single isolated pile was also tested for comparison to the group response. By comparison with the experiment result, a finite difference method was employed to simulate the incline-pile groups capacity behavior. The agreement between the experimental results and the numerical predictions is shown to be reasonably good. Therefore, accurate prediction of the ultimate bearing capacity of incline-pile groups in a mixed soil is very challenging. But the work is helpful to the design and construction of the incline-pile groups in thick soft soil.
The Contrastive Research of Direct Shear Test on Different Pile-Soil Interface
Authors: Wang Dong , Zhang Jian Xin , Tian Bin , Cao Jia
Published: September 2011

In order to discuss the friction resistance properties between pile and soil, three groups of shear laboratory tests of pile-soil interface are adopted among concrete-soil , steel-soil and plastic(HDPE)-soil, and each test applies six normal stresses. The result indicates that with the growth of normal stress, the shear strength of pile-soil are increased; under the same normal stress, there is little change in frontal parts of curve with shear stress and displacement, but the rest of curve have a striking change along with the increase of normal stress; when the normal stress is less, the shear stress of different interfaces have little change; when the normal stress is greater, it shows that the shear strength of HDPE-soil interface is the greatest.
Research on Rc Beams Strengthened with near-Surface Mounted Helical Rib Bar
Authors: Ren Zhen Hua , Zeng Xian Tao , Liu Han Long
Published: September 2011

Four concrete beams were cast with normal reinforcement bars. According to different the amount of mounted strengthening, grooves are opened in the concrete cover of tensile region in the concrete beams. Helical Rib Bar（HRB）is inserted in the grooves that is filled with resin. Flexural experimental results indicate that the limit bearing capacity, rigidity and crack resistance of beams strengthened with HRB are all improved obviously. With the increase in the amount of mounted strengthening, the limit bearing capacity of the strengthened beam is improved obviously. In comparison with the contrastive beam, the limit bearing capacity of the beam strengthened with one near-surface mounted HRB is increased by 20.91%, and that of the beam strengthened with two near-surface mounted HRB is increased by 54.55%，and that of the beam strengthened with three near-surface mounted HRB is increased by 90.91%.
Shearing Stress Model of Damage Bolt in Tunnel
Authors: Xi Xiao Hua , Gu Shuan Cheng
Published: September 2011

When bolt is damaged, character of stress is different from character of shear stress integrated bolt. Firstly, Based on the displacement formula of the tunnel surrounding rock，the shear stress and axial force calculation formula of integrated bolt are educed. Subsequence, based on the BOUSSINESG formula of displacement, models on fully grouted bolt shear stress and axial force of uniform rock are educed under pullout load. Consequently, the author deduces shear stress model of bolt damage (completely void of bolt and grouting), combining modes on shear stress and axial force of integrated bolt and shear stress model of bolt under pullout load..
Research on Sunshade Survey of Building in Anshan City
Authors: Yang Feng Yun , Zhao Wen , Xu Mao Lin
Published: September 2011

The author analyzes cause of sunshade survey—a new surveying domain coming into being ,and introduces some methods of sunshade survey applied in Anshan city at present and discusses it, and then puts forward improving some steps of sunshade . To overcome the drawback of method the author concludes establishing method of the digital sunshade system.
The Application of VC++ Serial Communication Technology in Real-Time Subsidence Monitoring
Authors: Xiong Chun Bao , Ai Hai Ying
Published: September 2011

The function of vc++ is powerful, and the application of its serial communication technology is more and more extensive. This paper introduces the settlement monitoring system first, and then focuses on the application of vc++ serial communication technology and real-time data monitoring technology in the subsidence monitoring. Next we debug the system and draw the final conclusion: using computer and wireless communication technology can successfully achieve the accurate monitoring of the remote settlement.
Comparative Analysis of CRD Method and Three-Bench Method with Temporary Invert
Authors: Wang Ri Bin , Lin Xin Ni , Shao Hua Ping , Yang Jun Sheng , Huang Yuan Liang
Published: September 2011

CRD method and three-bench method with temporary invert, which are applied to shallow buried and large cross-section tunnel engineering, are discussed, and simulated by FLAC2D so as to study the variation feature of displacement field, surrounding rock disturbance and internal supporting force caused by the excavation. According to the simulation results, it is proved that CRD method, with higher safety, can control tunnel collapse effectively while three-bench method quickens construction schedule. Therefore, it is recommended that the two methods are used for excavating tunnels alternately if possible so that it will increase economic benefit.
Influence of Shield Tunneling on a Nearby Buried Pipeline
Authors: Li Da Yong , Cao Li Xue , Fan De Wei
Published: September 2011

The influence of shield tunneling on a nearby buried pipeline is studied by using the analytical method. Equations of displacements, rotations, bending moments, and shearing forces of a buried pipeline are set up respectively on the base of the theory of Winkler’s beam on elastic foundation. It shows the maximum settlement of the buried pipeline occurs in its middle span. Both the maximum bending moment and the shearing force of a buried pipeline take place at its two ends. The diffusion angle of the subgrade and the buried depth of the buried pipeline play an important role in the behavior of the buried pipeline.
The Application of Matter-Element Bayesian Network Model in the Road Damage Evaluation
Authors: Dong Li
Published: September 2011

Abstract: the extent of roads damage and road safety are closely related. This article analyzes the advantages and disadvantages of Bayesian networks and it proposes that using matter-element Bayesian network model , the extent of road damage can be evaluated . The model is more scientific, more accurate and effectively ensures the unified state between subjective probability information with the objective state information . It provides accurate information for the investment decision of project maintenance .
Study on Poisson Ratio of Soil-Rock Mixture in Low Strain
Authors: Zhang Xian Min , Lv Yao Zhi , Zhao Yi Ming , Zhang Yu Hui , Liao Zhi
Published: September 2011

Longitudinal wave velocity and shear wave velocity of two kinds of the soil-rock mixture samples with different stone content and water content are tested. Then the poisson ratio of the samples in Low Strain can be calculated with the method of wave velocity testing. Analyzing the relationship between poisson ratio, water content and stone content, the dualistic nonlinear models of poisson ratio, water content and stone content are established. The result of verifying is shown that the absolute error of poisson ratio is less than 0.01 and the relative error is less than 2%. The models not only can show the relationship between poisson ratio, water content and stone content but can provide the reference when changing the Rayleigh wave velocity to shear wave velocity each other.
An Approximate Prediction of Metro Pit’s Sub-Step Excavation
Authors: Wang Wen , Liu Hong Shan
Published: September 2011

To combine the characters of metro pits and time-space effect, an approximate prediction method is studied. Sub-step excavation width, depth, unsupported exposure time and space effect are the main reasons for the displacement of excavation. To calculate the comparative displacement ratios of different parameters variational conditions and standard excavation condition, the displacement effective modulus of every parameter are obtained, and the differences of every layer excavation are also considered. The displacement of excavation can be predicted when the excavation parameters changed based on this method, and the displacement can be controlled by modulating the excavation parameters.
Stability Analysis of Tunnel Surrounding Rock and Shotcrete Lining and Rock Bolts Based on Strength Reduction Finite Element Method
Authors: Li Ying , Sun Rong Guan
Published: September 2011

Based on the practical engineering ,by using the 3D-FEM of elastic-plasticity, a reasonable model for simulation of tunnel excavation and shotcrete lining and rock bolts builds up, surrounding rock using Mohr-Coulomb constitutive model of ABAQUS, lining using Concrete Damaged Plasticity constitutive model, and bolt using elastic-plasticity constitutive model. By using strength reduction finite element method, analysis for safety coefficient of stability of surrounding rock with primary shotcrete lining and rock bolts under the four limit state criteria. It is concluded that the appearance of divergence of the computation may precede by displacement of characteristic points, The safety coefficient of the running-through of the plastic zone of the surrounding rock and the running-through of the plastic zone of the shotcrete and a great amount of rock bolts yielding are less than the divergence of the computation and displacement of characteristic points.
Verification of UDEC Modeling 1-D Wave Propagation in Rocks
Authors: Lei Wei Dong , He Xue Feng , Chen Rui
Published: September 2011

Three cases for 1-D wave propagation in ideal elastic rock, through single rock joint and multiple parallel rock joints are used to verify 1-D wave propagation in rocks. For the case for 1-D wave propagation through single rock joint, the magnitude of transmission coefficient obtained from UDEC results is compared with that obtained from the analytical solution. For 1-D wave propagation through multiple parallel joints, the magnitude of transmission coefficient obtained from UDEC results is compared with that obtained from the method of characteristics. For all these cases, UDEC results agree well with results from the analytical solutions and the method of characteristics. From these verification studies, it can be concluded that UDEC is capable of modeling 1-D dynamic problems in rocks.
VB on the Highway Pavement Performance Prediction and Optimization of Maintenance Programs
Authors: Cheng Pei Feng , Zhao Qian Qian
Published: September 2011

Highway maintenance is the main new task after highway construction. In order to predict pavement performance reasonably, and choose the most reasonable maintenance plan, based on investigating and inspecting the pavement condition , use computer language of VB from inputting the data module, establishing evaluation module, maintenance module, prediction module, economic evaluation module and statements processing module of pavement maintenance management system. Put the original data into this system. The system can predict pavement performance and choose maintenance scheme automatically, and use multi-objective optimization model, the effect of the definition and dynamic programming method to optimize the scientific and reasonable maintenance plan, which is from technical and economic aspects to realize by using the limited maintenance funds to achieve the best maintenance effect and to obtain the biggest social and economic benefits.
Study on Scouring Stability of Powder Sand Embankment Slope with Cover Layer
Authors: Cheng Pei Feng , Xu Yun Zhe
Published: September 2011

Abstract. The content of clay particles in powder sand is low, with small cohesion. Embankment erosion by water will lead to instability, to make a cover layer with clay. In order to resolve the erosion of powder sand embankment slopes affected by the rain, tested the powder sand and the cover layer soil, and conducted a survey of slope erosion situation in the embankment, divided the types of erosion. On this basis, base on the energy method, analysis the slope erosion by the impact of slope gradient, slope shape, the density and width of cover layer soil, rainfall intensity, conclude some applicable scouring protective measures for conditions of slope. The results provide a reference for the design of powder sand slope protective technology.
Study on Optimization of Blasting Parameters and its Effect on Anchoring Rock Beam of a Underground Workshop
Authors: Zhang Cheng Liang , Li Xin Ping
Published: September 2011

The optimum model for blasting parameters of anchoring rock beam is established and its blasting parameters are optimized by making use of a strong mapped function of the neural networks technology with the typical samples of other practical smooth blasting parameters. The explosive types, the extent of joint development of rock mass, the diameter of bore-hole, the depth of bore-hole, the linear charge density, the burden line of least resistance and the spacing of bore-hole are considered as the primary effective factors in the excavation of anchoring rock beam. In the meantime, the experimental blasting parameters for anchoring rock beam are determined by the in-site blasting experiments of the protective layer and platform of rock mass in similar conditions. The results show that the in-site experimental blasting parameters are preferably identical to those of the optimum design. The acoustic wave examination for the blasting of the protective layer and platform of rock mass indicates that the blasting effect is satisfied and its smaller loose ring of surrounding rock mass is obtained.
The Application and Analysis of Pressure Grouting Technique on Filling Pile Bottom in Coastal Areas
Authors: Xu Jin , Cheng Guo Yong , Li Bin , He Jing
Published: September 2011

Pile grouting technology is widely used in engineering to effectively improve the vertical bearing capacity, in this paper; we made a comparative study on the bearing capacity of grouting pile and General pile in Wuqing district Tianjin City. And proving this method can improve the pile bearing capacity, with good effect, and significant economic benefits.
Three-Dimensional Dynamic Response Analysis of Shield Tunnel under Train Loads
Authors: Wu Zhan Rui , Qi Tai Yue , Zhong Lin
Published: September 2011

The vibration loads will be produced between wheel and rail on the running of the high-speed Train. The vibration energy will be transferred to the ground formation through the rail, guiding bed and tunnel lining structure, thereby causing vibration between the formation and surface and environmental interference effect problems. Thus the research of related issues caused by the high-speed train vibration has the vital great significance. The train design speed of the Shiziyang shield tunnel for Guangzhou-Shenzhen-Hong Kong passenger dedicated line is up to 350km/h. In this paper the research object is located in the segment of the homogeneous formation of the Shiziyang shield tunnel. The analysis of this paper includes the dynamic response rules of the shield tunnel and formation under the single high-speed train loads and the law of the pore water pressure accumulation and dispersion under train cyclic loading.
The Stability Control Technology of Crosscut while Mining without Coal Pillar in Steep Seam
Authors: Wang Yu Feng , Liu Zhi Qiang , Jiang Bin Song
Published: September 2011

In order to improve the mining benefit of coal resources, Chang Gouyu Coal Mine carried out the technology of mining without coal pillar in steep seam. The key of the technology was to ensure a long-term stability of the cross-entry roadway across the seam. Through the analysis of the nature of steep seam roof and floor rock, and based on the stability analysis and loose circle measured of surrounding rock of crosscut roadway, we brought forward adopting shotcrete rockbolt mesh and U-shaped steel complex support structure system. This complex support system could flex lengthways and compress in radial direction. The entirety integrated with the surrounding rock, and they formed into a whole. Application of the complex support system could effectively control the deformation of the surrounding rock collapse, and maintain the stability of the crosscut.
The Numerical Analysis of CFG Pile Technology in the Disposing Soft Foundation in GuangWu Expressway
Authors: Meng Yun Mei , Cao Yun
Published: September 2011

The problem of disposing the soft soil foundation will appear inevitably during the construction of modem high way. There are many ways to dispose the soft foundation. One of those is CFG pile technology. Take the CFG pile technology in the GuangWu Expressway for example, the influence factors of embankment settlement were discussed in detai by numerical analysis, some useful conclusions are obtained from the computational results.
The Uplift Behavior of Large Underground Structures in Liquefied Field
Authors: Zhang Xi Wen , Tang Xiao Wei , Shao Qi , Bai Xu
Published: September 2011

Soil liquefaction due to the earthquake causes serious damages and engineering problems, such as the reduction of the soil strength, large settlement of the ground surface, the flow of liquefied soil and the uplift behavior to the underground structures, and the large deformation induced by the uplift force threatens the stability and safety of the structures. In this paper, a FE-FD coupled method is used in the simulation, the cyclic elasto-plastic constitutive model and the updated lagrangian formulation are applied to deal with the material and geometrical nonlinearity of liquefied soil. The results show that after the earthquake, the exceed pore water pressure will still exist for some time and the structure has an obvious vertical uplift displacement related to the liquefied area and the flow of liquefied soil. The uplift displacement will decrease as the thickness of the upper liquefiable soil layer is reduced. The results can be regarded as a guidance and reference for the design of the large underground structures.
Study on Soil Conditioning and Key Construction Parameters of EPB TBM Advancing in Sand-Pebble Layer of Beijing Metro
Authors: Jiang Hua , Jiang Yu Sheng , Huang Mao Lan , Nie Xin
Published: September 2011

Mechanical properties of sand-pebble layer is very unstable, it is unfavourable for TBM excavation. For the reasons of poor soil conditioning and low plastic flow of muck, EPB TBM tunnel construction in sand-pebble layer of Beijing metro has exposed variety of issues: continuous dynamic earth pressure balance is hard to established, mud cake is formed frequently in earth chamber, key construction parameters such as thrust, torque, advance speed can not be controlled in reasonable scopes, which lead to low efficiency of TBM construction. Taking“Xi-Liu”of line 10 lot 11 as an research object, the mechanical characteristics of sand-pebble layer and construction problems of TBM advancing are analyzed, variety of soil conditioning measures are used for improving plastic flow of muck and minimizing construction influence induced by poor geological conditions, meanwhile contrast studies on key construction parameters before and after soil conditioning are carried out. The results indicate that effect of soil condition plays very significant roles in controlling TBM construction parameters and improving advancing efficiency.
Evaluation on Features of Soft Foundation Engineering and Bearing Layer of Pile in Jiaxing City
Authors: Zhou Jin Long , Li Qiao , Cai Wei Zhong
Published: September 2011

Through the investigation into composition of major shallow foundation soil mass and the correlation of mechanical indicators in this study, the regression equation of mechanical indicators of the features of local foundation soil mass and the data of in situ testing was obtained. Based on massive quantities of exploration materials, this study analyzed engineering features, distribution status, and the feasibility of silty clay to be used as the bearing layer of the pile in Layer ④2 . The analytical results showed that the silty clay with the uniform depth of over 3.5m and the cone tip resistance in static sounding of over 400MPa could be used as bearing layer of the pile. This study could provide the reference for the accurate understanding of the engineering features of soil mass, and the design and evaluation of foundation in Jiaxing City.
Study on Shock Absorption Measures of Highway Tunnel in Karst Areas
Authors: Chen Lin Jie , Liang Bo
Published: September 2011

Based on soil-structure interaction model, the response analyses of the Menglian tunnel by using viscous-spring artificial boundary and time history analysis method under earthquake accelerations and multiform conditions of surrounding rocks are presented. The seismic responses of the tunnel are calculated by changing parameters of surrounding rocks within certain influencing distances to the linings. The shock absorption effects, applicability, and shock mechanisms of grouting in the surrounding rock are analyzed. The results show that the displacements and stresses of the tunnel linings in karst areas decrease by grouting in the surrounding rock, under the high-intensity seismic load, and the linings are protected when the grouting measure is used. It also shows that the shock absorption effect is better with the increase of the grouting density and range. By calculating analysis, it can achieve the shock absorption effects when the grouting range is 5.5 to 7.0m in the Menglian tunnel. The results provide useful reference for the shock absorption design of tunnel.
Study on the Dispersion Curves of Rayleigh Wave in Foundation of Obstacles
Authors: He Fang Ding , Guo Guang Jun , Dou Zhi Gang , Yang Yang
Published: September 2011

It is difficult to accurately identify dispersion curves of Rayleigh wave for the foundation with obstacles. Displacement curve of time-domain of half-space foundation have been obtained with the finite element in the paper. Then time-domain curve have been transformed Rayleigh wave dispersion curves. Rayleigh wave dispersion curves have been analysed in half-space foundation with water drain pipes. The results show that, there are reflection waves at the receiving signals in front of the obstacles, there are no reflection waves behind the obstacles basically. The location and spacing of the sensor have a greater impact on the results. The results provide the reference for the recognition of dispersion curves and disposition patterns of the sensors.
Calculation Model for Ground Settlement Process of Xi’an Subway Tunnel Non-Synchronous Excavation with Double-Line
Authors: She Fang Tao , Shao Sheng Jun , Fang Juan , Jiao Yang Yang
Published: September 2011

The current calculation models of ground settlement for tunnel excavation cannot reflect ground settlement of tunnel non-synchronous excavation with double-line. Based on the Peck ground settlement formula and Attewell ground settlement formula, displacement release of excavation place and tunnel non-synchronous excavation with double-line have researched. By means of finding a function to replace the accumulated probability curve, the new control function was beneficial to parameter introduced and improvement of the current ground settlement formula. By introducing the non-synchronous excavation distance and the displacement release coefficient of excavation place, A new calculation model for ground settlement process of tunnels non-synchronous excavation with double-line is proposed. The reliability and practical of the calculation models was verified. Research results were very important to analyze the ground settlement affecting the building foundation and pipe under ground.
Study on the Changing Rule of Excess Pore Water Pressure during Dynamic Compaction
Authors: Li Xiao Jing , Yao Kai , Zhu Shao Chun , Pan Xiang Hong
Published: September 2011

The changing rule of excess pore water pressure during dynamic compaction is important for construction. The following conclusions could be drawn by observing and analyzing the excess pore water pressure in test area. Under ramming strike energy of 2000kN•m, the best hit number during the 1~2 times is 8~9, the best hit number during the third time is 6~8. After compaction, the shallow excess pore water pressure is basically larger than the deep. The shallow excess pore water pressure needs more time to dissipate. The horizontal distance of the shallow excess pore water pressure is larger than that of the deep. During the dissipating process of the pore water pressure, we should pay attention to avoid vibration interference of load in the surface and prevent liquefaction of the powder soil. Under ramming strike energy of 2000kN•m, the biggest influence depth of dynamic compaction is 8～9m, the effective reinforcement depth is 6～8m. The conclusions can provide the theoretical basis for dynamic compaction construction.
Study on Seepage under the Hinge Joint Stability of Concrete Block Slope
Authors: Zhang Yu Qing , Mi Yong Ning , Wang Lu , Wang Xin
Published: September 2011

Slope is the wide range of large in channel works to ensure the safety of critical infrastructure.The actual project—the Bird Island Park in Shenyang, an example of hinge joint concrete block revetment ,using the FLAC analysis software, and the finite difference method percolation theory to calculate the 29 slope angle the role of a 45kg block under the action of the seepage stability of the slope. Variation in water level discussed in further detail and the role of the different blocks on the slope stability of the quality of the impact of the slope to provide a reference design and application.
Model Test Study on Failure Mechanism of Unsupported Tunnels Constructed in Soft Rock Masses at Different Cross Section
Authors: Wang Cheng Bing , Zhu He Hua , Wang Hua Lao
Published: September 2011

The failure conditions of tunnel surrounding rock under different cross section after full face excavation were studied through a number of model tests. The simulation of unsupported tunnel failure process under gravitational stress is carried out successfully in the tests. The test results show that failure of surrounding rock initiates from the upper part of the tunnel and develops upward progressively. Failure form of tunnel is different under different cross section type. Comparing with two-lane tunnel, the surrounding rock of three-lane tunnel keeps shorter stabilization, failure develops to the ground surface more rapidly, the stress changing amplitude of those beside tunnel is larger, and the rock mass on the top of the tunnel slides downward more clearly.
Study on the Shaft Height of Natural Ventilation Using Smoking Shaft in Urban Tunnel
Authors: Zhong Wei , Yang Jian Peng , Pei Bao An , Zhang Wei
Published: September 2011

The characteristics of smoke flow in natural ventilation shaft are studied in this paper, Using the computational fluid dynamics software FDS5.0 to build a 3D model of an urban tunnel with a smoking shaft, Large Eddy Simulation model was used to obtain the structure of flow field and the mass flow rate of natural ventilation at different shaft height, The results show that when the shaft height is low, the driving force of exhaust is weak and the exhaust capacity reduces rapidly, the flow state in shaft is controlled by horizontal inertia force; when the shaft height increase to a critical height, the exhaust effect enhance significantly, the flow state in shaft will change to stack effect control.
The Analysis of the Influence of Different Rock and Soil Qualities on the Loss of Anchorage Force
Authors: Wang Qing Biao
Published: September 2011

The mechanism of the anchorage effect of the anchorage cable is very complicated. There are many factors which affect the anchoring effect. The loss of anchorage force concerns with the qualities of rock and soil masses, materials, anchor clamping, the construction technology and operation and management level and so on. Taking the Pre-stressed anchorage projects as examples, with the method of geological survey, experimental study, numerical simulation, theoretical analysis, the paper makes study on the loss of anchorage force caused by the qualities of hard rock, weak rock, and broken rock and soil masses. This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text.
The 3-D Finite Element Numerical Analysis of Composite Soil Nailing Walls in the Foundation Pit Engineering
Authors: Ding Jiang Shu , Xian Yao Qiang , Liu Tian Jun
Published: September 2011

Combined with one foundation pit engineering in Guangzhou, the method was adopted in this paper, by which the in-situ test and finite element analysis were integrated. According to situation of study and demand of engineering, the study in composite soil nailing walls system was focused on working mechanism. The law of soil-nailing support technology for deep excavation was pointed out and summarized to provide reference to similar projects.
Three Dimensional Numerical Analysis of Deformation and Stability of Zone II of Xiazanri Slope Deposit
Authors: Zou Li Fang , Xu Wei Ya , Shi Chong
Published: September 2011

Xiazanri Slope is a large-scale deposit slope located at the left bank of Liyuan hydropower station in Southwest China. The construction of the water intake there will form a very high excavation slope. Possible failure modes are analyzed based on geological conditions. Numerical simulation is conducted in FLAC3Dto obtain the deformation and failure characteristics of slope under excavation and normal water table conditions. Strength reduction method is used to obtain factor of safety. Results show the overall deposit is stable and attention should be paid to local parts.
The Stability Analysis of Reinforced Earth Retaining Wall System and the Study of its Reinforcement Optimization
Authors: Ju Hai Yan , Gao Gui Qing , Li Jian Hua , Zhao Jiang Qian , Li Zhang Ming
Published: September 2011

Because the relationship is not considered between physical behavior and cross sections of bars, the conventional reinforced earth retaining wall design based on constant value would lead to some limitations: the haul-resistant coefficient of the top wall is not enough, but it goes beyond at the bottom of retaining wall. In the paper, considering the SARMA method, based on computing formula of traditional slope stability, the detailed programme is realized by the language of FORTRAN, it can make up deficiency that lies in the tradition reinforced earth retaining wall by considering the relationship of physical behavior and cross sections, lengths and layers of bars. Finally, the system program has been applied to a slope treatment project in Guangzhou. Compared with the design method of traditional regulations, it is demonstrated that the optimum length required is obtained, the cross section and length of bars are fully used, and the design is simplified.
Study on Risk Assessment Method of Water Bursting Disaster in Railway Tunnel
Authors: Wang Cheng Liang , Bai Ming Zhou , Kuang Xing
Published: September 2011

Karst Water Bursting in Railway Tunnel is the main content of tunnel risk evaluation，there are lots of empirical factors in the actual work. Through the investigation on site, this study analyses Karst Tunnel on many respects, establishes the index system of venture evaluation on Karst Water Bursting Geological Disasters. Moreover, the concept of fuzzy information analysis is introduced to establish the fuzzy information analysis model, on the basis of information extraction of a large amount of geological disasters of Karst water bursting in Railway Tunnel, in which applied hierarchy analysis method to determine the weight of each index. Risk assessment on typical operating point shows that the risk evaluation method of fuzzy information can correctly assess the Karst water bursting disasters in railway tunnel.
Comparision between UTM and GRAUSS KRUEGER Projection in NIGERIA Rail Project
Authors: Jin Li Xin , Wang Lian Jun , Yang Song Lin
Published: September 2011

The national coordinates system used in Nigeria is the Universal Transverse Mercator projection, while China adopts the Gauss Krugger Transverse Mercator projection (GKTM). This paper studied the difference between UTM and Gauss(TM) projections and the regulation of projection deformation, and put forward the model of the coordinates system for the Nigeria railway, which shall be of great benefit in the survey, design, construction and referencing of the Nigeria railway project.
Simulation of Wind Field on Long-Span Cable-Stayed Bridge Based on SPT
Authors: Huang Yi Feng , Yang Ji Xin
Published: September 2011

The simplified of fluctuating wind field and the basic theory of Spectral Proper Transformation（SPT）were expatiated. SPT was used to simulate the random wind field on long-span cable-stayed bridge, then the random wind field of the bridge was simulated by MATLAB program, an actual example was used to validate the validity and correctness of the MATLAB program. The results showed that SPT had the advantage of explicit physical meaning, high computational efficiency. It is an effective method to simulate the random wind field.