bluuebunny/crossref_metadata_2025 huggingface dataset:
Seepage Filed Studies on the Effect of the Proposed Underground Garage
Authors: Liu Qi Xia , Zou Xin , Wang Kai Qi , Zhao Yang , Zhao Qing
Published: August 2013

This paper intends to solve the leakage of the surface waters on the proposed underground garage impact from a practical engineering, so we carry on the detailed analysis about the surrounding hydro geological conditions to provide scientific basis for underground garage waterproof design. On that basis, we establish the hydro geological conceptual model, using Visual MODFLOW4.1 software to simulate the seepage field in two kinds of working conditions, and get the result of the surface waters on the proposed garage impact. Thus in the underground garage of the soleplate waterproof design we adopt different block waterproof practices which may save a lot of fund, and have the important theoretical and practical significance to us.
The Application of the TM30 Measuring Robot in the Open Pit Slope Monitoring
Authors: Xu Mao Lin , Li Li Yan
Published: August 2013

This article introduces the application of measuring robot in the open mine slope monitoring, and it proves its feasibility via analyzing the monitoring data and measuring accuracy. It indicates that TM30 measuring robot is able to finish the measuring task with high accuracy by the practical application. Therefore it concludes the measuring of operating items.
A Regional Zenith Tropospheric Correction Model Based on the Guangxi CORS Network
Authors: Liu Li Long , Huang Liang Ke , Zhang Teng Xu , Zhou Miao , Yao Chao Long
Published: August 2013

In this paper, the relationship between zenith tropospheric delays and the altitude of stations is analyzed using the EGNOS tropospheric correction model. The new model (EHT model) is proposed for estimating zenith tropospheric delays from regional CORS data without meteorological data. The proposed model is compared with the direct interpolation method and the remove-restore method using data from Guangxi CORS. The results show that the new models significantly improve the calculated precision.
The Understanding, Definition, Redress and Application Based on the Figure Symbol “∞” of Probability Theory
Authors: Zhu Jun Tao , Sun Chang Yu , Wu Xiao
Published: August 2013

The paper points out that the figure symbol “ ” should be named as “double zero”, not infinity. “ ” has the similar meaning as “0”. They all express no numerical value. In this paper, the application based on the definition above in probability theory is discussed.
Ambiguity Resolution with Single Epoch for GNSS Reference Network Based on Atmospheric Delay Information
Authors: Guo Qiu Ying , Guo Hong Xia , Han Bao Min , Zhang Ying Sheng
Published: August 2013

Correct resolution of ambiguities for GNSS reference network is prerequisite for generation of corrections for network RTK. Due to the presence of atmospheric delay in the double-differenced observations, the convergence time of ambiguity is about a dozen minutes and even dozens of minutes for medium and long baselines. And in the case of loss-of-lock or new rising satellites, the integer ambiguities have to be redetermined over and over again. But for the application of GNSS network RTK, the resolution of ambiguity needs to be determined real time as possible. Atmospheric delays of previous epochs are used to predict atmospheric delays of following epochs, and then wide and narrow lane combination of carrier-phase observations as well as ionosphere-free combination is used to resolve ambiguities with single epoch. Our test results show that the precision of predicted double-differenced tropospheric and ionospheric delays is about 2-3 cm using temporal-and spatial-correlation exponent model, and the success rates of L1 ambiguities resolution with single epoch reach above 90% for medium and long distance GNSS reference station network.
Study on Construction Measurement of Chongqi Bridge Pier
Authors: Xie Xu Yang
Published: August 2013

The pier construction measurement is one of the most decisive steps to ensure the quality of bridge construction, and plays an important influence in the bridge's safety and service life. This paper makes an analysis of the implementation method of pier bearing platform construction measurement of Chongqi Bridge connecting Shanghai with Suzhou, and provides a reference for similar projects.
A Direct Calculating Method and Experiment of Absolute Orientation for Unmanned Aerial Vehicle Photograph
Authors: Wang Jing , Duan Lian Fei
Published: August 2013

The traditional photogrammetric space similar transformation is used for Unmanned Aerial Vehicle (UAV) photograph digital positioning with the quite precise initial value. The new method based on the unit quaternions is presented. The rotation parameters are solved without iterative calculating and initial value. The absolute orientation is still carried out under the condition of the large angle photograph and the uneven ground control point, in which the non-linear angle parameters calculation is substituted by direct calculation. The direct calculating improves the reliability of the absolute orientation. The experiment result shows that the method is practicable and available.
Landslide Susceptibility Mapping and Model Performance Assessment
Authors: Xiao Chen Chao , Tian Yuan , Si Kang Ping , Li Ting
Published: August 2013

In this paper landslide susceptibility mapping and model performance assessment was conducted using three models, logistic regression, GAM, and SVM, in a study area in Shenzhen, China. Ten factors, slope angle, aspect, elevation, plan and profile curvature of the slope, lithology, NDVI, building density, the distance to the river, and the distance to the fault were selected as influencing factors for the landslide occurrences. All three models were trained and the resulting susceptibility maps were created. The performances of the three models were then assessed by AUC values through a 10-fold cross-validation. It could be concluded that in the study area GAM had the best overall performance among the three models, while SVM was better than logistic regression. Based on the derived DPR values, the optimum thresholds between stable areas and risky areas for all three models were also determined.
Construction of Urban Traffic Information Service System Based on WebGIS
Authors: Cai Fei , Ding Ning , Qu Xiao Xiao
Published: August 2013

In order to improve utilization of traffic information, this paper introduces the construction of urban traffic information service system based on SuperMap iServer for Java. Overall structure of urban traffic information service system is designed. The system uses the remote sensing image and electronic map of Jinan as basic data and implement functions including route guidance, parking guidance, real-time traffic information and statistical analysis. The system makes advantage of the superiority of Ajax in asynchronous transmission which enhances the user's browsing experience. Efficiency of traffic flow guidance and traffic management decisions increases by the system, which greatly facilitates the daily activities of city residents. Applications show that the system is a beneficial exploration of intelligent transportation with strong practicality and versatility.
Research on Image Retrieval Method Based on Shape Feature
Authors: Ding Ning , Cai Fei , Cai Xun
Published: August 2013

To meet requirements of fast and accurate image retrieve, this paper present a new method to retrieve image based on shape feature. Firstly, the technique pre-processes the image and extracts the foreground object using multi-threshold image segmentation based on color feature. In division process, threshold value can be gotten by the quick sort made used of characteristics of the background and the target pixels difference in order to avoid massive computing of other algorithms. Secondly, contour tracking method is used to obtain the contour feature which described by Fourier descriptor. Finally, similarity is measured by Euclid distance measurement. In order to verify the effectiveness of the technique, a framework for image retrieve is constructed based on shape. The result of the experiment shows that the technique is effective for image retrieve based on shape.
PSO-BP Combined Artificial Neural Network Method Research
Authors: Liu Gui Ling , Gao Feng
Published: August 2013

BP artificial neural network(ANN) based on gradient algorithm method is widely applied, but because the error surface of object function is very complex and the choose of initial value effects network training results, convergence rate is slow and local minimum is likely to fall into. Particle swarm optimization(PSO) algorithm has better global searching ability to get rid the puzzles of falling into local minimum. By adequately studying on the two algorithms’ characteristics, a new type of combined ANN training method is put forward, and PSO-BP ann model is successfully built.
The Application of ABAQUS in a Spiral Staircase Analysis
Authors: Liu De Wen , Liu Juan , Li Xiang Xiu , Zhang Zhan Ting , Liu Liang Kun , Fang Chuang Jie , Pan Zhao Dong
Published: August 2013

This paper first introduces the units which are used in general-purpose finite element analysis software ABAQUS simulation of steel and concrete as well as their material constitutive models, and then taking the simulation analysis of a spiral staircase for instance to draw displacement of a spiral staircase along the outer edge lines, the inner edge lines, and the axes of the stair treads under static loadings. By comparison, we find the rationality and insufficient points of the simplification of the spiral staircase to the calculation assumption which makes the axle wires as rod pieces. According o the displacement and stress of the spiral staircase, we give some suggestions to provide some useful references to the designers of the spiral staircase.
The Prediction of Blast Vibration
Authors: Zhang Wei , Chen Shi Hai
Published: August 2013

Blasting on large mounts of experiments, we construct mathematical model of seismic wave of blast with systems response method and predict waveform of blast seismic wave. The model can reflect the influence of seismic wave from several kinds of factors and can simulate the attenuation low of amplitude and frequency in the whole process of blast seismic wave. It not only simulates better for simple blast seismic wave, but also can get consistent result in simulating porous blast seismic wave.
Different Heights of Upstream Buildings on Wind Pressure Distribution of the Downstream Low Building
Authors: Wang Cheng Jiang , Wang Shen Wei , Yang Qing Xiong
Published: August 2013

In this paper, in order to study the wind interference effect,with change of height of the upstream building, the numerical simulation of the downstream construction disturbance of wind pressure distribution has been done. With architecture of upstream, wind pressure coefficient values of windward and leeward faces of downstream building basically reduces,and interference effect shows shielding effect.
Study on Bond-Slip Behavior of the Channel Steel Connectors at the End of Novel Prefabricated Prestressed Concrete Beams
Authors: Wu Jiang Chuan , Zhang Ji Wen , Yang Dong
Published: August 2013

The channel steel connectors of novel prefabricated prestressed concrete beam play an extremely important role in structures. They act as the connectors of prefabricated beams and columns and support the prefabricated beams temporarily at construction stage, work as shear connectors of the adjoining faces between the old and new concrete at using stage. But they are easy to be bond slip failure for its complicated stress states. To analyze their mechanical behavior and failure mode, the interaction between concrete and channel steels is considered by adopting the spring unit and nonlinear analysis with finite element software ANSYS. The results indicate that the channel steel connectors of novel prefabricated prestressed concrete beam are effective in bearing various loading effects and meet the requirements of prefabricated structures.
Compared Analysis of Deformation Monitoring with Numerical Simulation on Pile-Anchor Supporting System of Deep Foundation Pit in Soil-Rock Dualistic Area
Authors: Yi Xiao Dong , Huang Peng , Wang Zhi Chao
Published: August 2013

Deep foundation pit supporting in soil-rock areas has been occurred commonly in Dalian. In the dual structure deep foundation pit in which platform is reserved, pile-anchor support as a typical form of foundation pit support, how to play its role effectively and make the design economical and safety is the subject which was explored continuously in recent years. Through a practical engineering case, this paper will use finite element software ABAQUS to simulate the whole process of pit excavation. Simulation results show that the boundary of the dual structure is the key position that caused the “sharp deformation” of the supporting structure. Compared with monitoring data, the results indicate that the reliability of the numerical model and the relevant deformation laws are verified, which can be used for the reference for the design, construction and monitoring of the deep foundation pit support in the similar location.
Numerical Analyses of Axial Load Effect on Shear Strength of Concrete and Gypsum Composite Walls
Authors: Liu Kang
Published: August 2013

Gypsum walls are a green product that helps to save energy and protect the environment. This paper numerically investigates the effect of axial load on shear strength of glass fiber reinforced gypsum (GFRG) walls fully or partially filled with concrete in the hollow cores. The conclusion drawn in this paper is general and applicable to other kinds of walls.
Research on Hydration Heat Temperature Stress of the Pier by Finite Element Method
Authors: Zhao Liang , Zhang Liang Liang , Yang Zhi Yong
Published: August 2013

Hydration heat, one of the most severe factors, makes great effects on the mass concrete construction, especially on bridge structures and dam structures. Based on the experiment, this paper adopted large-scale finite element method with ANSYS software to analyze the transient temperature field during concrete placement. The atmosphere temperature, construction method, thermodynamics as well as material parameters (cement hydration heat, elastic modulus) were taken into account. The results clarity the distribution characters and process of the hydration heat temperature and stress. Besides, the computational and experimental results were compared. The results indicate that the surface cracks occur due to the large stress which is induced by the extensive internal and external temperature difference. As a result, references are provided to avoid harmful temperature cracks during pier construction period.
Model Tests on Force Characteristics of Reinforced Retaining Wall
Authors: Zhang Hong Bo , Wu Jian Qing , Li Ying Yong , Song Xiu Guang , Xue Zhi Chao
Published: August 2013

The recent research and development of the reinforced retaining wall is composed of cantilevered reinforced concrete retaining walls which symmetric set on both sides of subgrade and through roadbed width of counter-pulled anchors. The prestressing force can be applied on anchors.The retaining wall has the advantange of high safety, lateral small deformation , wide applicable range and low requirements for the foundation bearing capacity. But due to the lateral restraint of bolt, the soil pressure distributions of retaining wall change a lot. The change will have a significant impact on structures. In order to reveal the reinforced soil retaining wall pressure distributions, laboratory model test was done. The monitoring instruments such as earth pressure cells, anchor rope dynamometers and dial indicators were installed. Research and analysis on the loading process reinforced type soil retaining wall under soil pressure, the lateral earth pressure and anchor rope tension change rule were researched and analysed. The experimental results showed that with the increasing of filling soil height, the retaining wall had a tendency to tilt outward. The basolateral external pressure is larger than the inside pressure. At the same time, anchor tension increased as the top loading increased. Lateral earth pressure distribution is parabolic. Soil pressure around the anchor is larger than other area, the soil arch effect is significant.
Numerical Simulation of Advanced Small Pipe in Tunnels during Excavation by Steps
Authors: Jin Chang Yu , Xia Zi Feng , Xiang Chun Fu , Dong Long Bin , Zhao Pan Pan , Liu Dong
Published: August 2013

Advanced small pipe support is one of the advanced support patterns in tunnel engineering construction for weak and fractured surrounding rock. The support effect cannot be predicted because of depending on engineering experiences. Efforts are made to study and analyze the support mechanism of advanced small pipe in the excavation of soft - fracture wall rock. By the numerical simulation of FLAC3D of Dawangou tunnel based on rock mass deterioration model (RDM), the plastic zone, displacement and stress filed of the surrounding rock are simulated with and without the advanced small pipe support. The support effect of advanced small ducts in tunnels during excavation by steps is presented.
Research on Optimization of Excavating Seguence for Dawangou Tunnel
Authors: Jin Chang Yu , Zhao Pan Pan , Xiang Chun Fu , Xia Zi Feng , Dong Long Bin , Liu Dong
Published: August 2013

In response to the limitation of conventional index for stability and optimal design of underground rock mass engineering. The new evaluating indicator, local energy release rate, which can analysis the energy release intensity in the process of the brittle failure of hard rock is used in numerical analysis. Numerical simulation of construction sequence was studied for Dawangou tunnel using energy release rate index and a new constitutive model reflecting the brittle failure of hard rock. Based on the change trend of energy release rate, rock displacement and plastic zone, an optimization excavation is suggested. The optimal excavating sequence could serve as reference in the design and construction.
Simulation of Wind Environment around a Commercial Complex Building in Shenyang China
Authors: Zhang Xiao Ming , Li Bo , Zhang Xiao
Published: August 2013

The pedestrian safety and comfort is closely related to the wind environment around the commercial complex building. In this paper, we simulate the steady-state three-dimensional flow field around a commercial complex building which is still under construction in Shenyang city by using CFD (Computational Fluid Dynamics) software. The distribution of wind speed and pressure around the commercial complex are obtained. In summer wind speed around complex is 0.5-3.6 m/s and the differential pressure greater than 1.5 Pa under the dominant wind. In winter wind speed is 0.5-4 m/s and the differential pressure less than 5 Pa except windward under the dominant wind. Local vortex appeared in both summer and winter due to the shape of complex building. The commercial complex building also had an impact on the wind environment of the surrounding buildings, larger the building, greater the impact.
Study on Damage Constitutive Model of Cemented Tailings Backfill under Uniaxial Compression
Authors: Yu Gen Bo , Yang Peng , Chen Ying Zhou
Published: August 2013

Under the premise of isotropic and continuum cemented tailings and damage proportional to the external doing work, the damage evolution equation and damage evolution constitutive equation were derived by using the strain equivalent principle. Under the consideration of the damage also transferring stress when uniaxial compression, the damage corrected parameter was introduced to obtain the damage evolution constitutive equation containing corrected parameter. Based on the experimental data from the uniaxial compression of cemented tailing, this article validates the theoretical curves consist with the experimental ones under certain damage corrected parameter.
Finite Element Numerical Simulation Analysis on Deformation of Adjacent Building with Shallow Foundation due to Excavation
Authors: Yang Yong Kang , Li Xiao Yuan , Yang Wu , Feng Chun Yan
Published: August 2013

Based on deformation of adjacent building with shallow foundation of foundation pit excavation, Midas GTS is adopted to establish the finite element model. Through the numerical simulation, the maximum horizontal and vertical displacement in different conditions, Influence of different SMW pile stiffness and influence of different anchor position are analyzed. The results show that (1) horizontal deformation of SMW pile is decreased at the anchor construction; (2) compared with maximum horizontal displacement of SMW pile with 25a25b28a, the maximum horizontal displacement of SMW pile with 28b is increased by 50.9, 43.3, 11.5% respectively; (3) compared with the second anchor at 1.5, 3.5m, the horizontal displacement of adjacent building is minimal by the second anchor at 2.5m.
Research on Surrounding Rock Stability by Ideal Point-Rough Set Efficacy Coefficient Method
Authors: Lu Guo Ren , Zhang Le Wen , Qiu Dao Hong , Feng Xiao
Published: August 2013

The ideal point method is a kind of multiple-goal decision analysis method, the basic idea is to construct the ideal and anti-ideal solution of multi attribute problem, with degree that near ideal solution and away from the anti-ideal solution as the basis to judge each evaluation object. Based on the basic principle of ideal point method, and comprehensive consideration of the actual geological conditions of Qingdao metro, we selected rock compressive strength, integrity coefficient, structure surface behavior, groundwater and softening coefficient as the evaluation factors of surrounding rock stability, and used the rough set theory to determine the index weight. At last, established the evaluate model for the surrounding rock stability of metro based on the rough set efficacy coefficient method. The research show that the stability analysis results are consistent with the actual excavation, so using rough set efficacy coefficient method to analysis surrounding rock stability of Qingdao Metro is feasible, which provides a new idea for the stability analysis of surrounding rock.
A Few New Methods of Stability Coefficient Calculation of Landslides
Authors: Wu Xin Xing , Lu Ying Fa , Fu Xu Dong
Published: August 2013

The advantage and shortage are analyzed for the conventional calculation of stability coefficient of landslides, the four new calculating methods of safety factor of landslides are proposed. The stability coefficient of the comprehensive sliding resistance force and the maximum main stress are fit for describing the landslide state, the stability factor of each sliding block of landslide is useful for the tracting landslides. The new joint constitutive model and calculating methods of landslide are useful for describing the landslide state.
Research on Static Mechanical Properties of Interface between Structure and Gravel Underlayer
Authors: Liu Rong Di , Zheng Jian Guo , Li Zhi Yuan
Published: August 2013

A series of soil-structure shear tests was taken by self-made large single shear apparatus and the main factors affecting behavior of the interface are studied. It was shown that the deformation and mechanical properties are determined by the roughness of structural surface, particle size distribution and normal stress. The interface deformation includes the shear deformation of the soil near the structure due to the constraint of structural surface and the slipping deformation of soil-structure interface, they happen at the same time and interact each other . The thickness of the interface element is 4 to 5 times of the average particle diameter away from the structure surface.
Stability Prediction of Surrounding Rocks and Optimum Design of Roof-Bolt Parameters in Deep Roadway
Authors: Kong De Sen , Chen Yong Po
Published: August 2013

In order to forecast the stability of deep roadway and optimize the parameters of bolts, the complex stress environment and the multivariate surrounding rocks characteristics of deep roadway were analyzed. Then the classification prediction method and the numerical simulation method were simultaneously used to analysis the stability of surrounding rocks. Furthermore, the supporting parameters of bolts were also designed optimally. It was shown that the characteristics of stress distribution, deformation and failure zone of surrounding rocks are not ideal. So it is necessary to optimize the supporting parameters of deep roadway. All these research findings will provide the theory basis for bolts of deep roadway and will ensure the optimization of bolts and the stability of deep roadway in the long run.
Estimating Diffusion Radius Grouting into Broken Rock Mass
Authors: Xu Hong Fa , Wang Chen , Li Chao Fu , Jiang Miao , Geng Han Sheng , Chen Feng
Published: August 2013

The influencing factors of grouting diffusion in broken rock mass were divided into four classifications: grouting pressure, grouting time, permeability coefficient and grout viscosity. Relations among similar factors were expressed to each other using an equation. Empirical formulas of relations among grout water-cement ratio, viscosity and time between the joint density of broken rock mass and permeability coefficient, and between water absorption and permeability coefficient were established. The differences among the four diffusion radius formulas grouting in porous continuous media were compared. A new empirical formula of diffusion radius was obtained using multivariate nonlinear fitting analysis based on the mean value of the four empirical formulas. The tests of grouting diffusion in broken rock mass were done in the field. The mean empirical formula is consistent with the measured value of the field tests on grouting diffusion radius, which provide a reference for the design of grouting into broken rock mass.
Experimental Study on Test Methods of the Intergranular Suction of Unsaturated Lateritic Soil
Authors: Lu Hua , Wang Yang , Wang Xiao Yan , Hou Li Jun , Jiang Xin Zhao
Published: August 2013

This paper aims at the test methods of the suction between grains of lateritic soil which is widely distributed in southern China, and proposes the test methods and principles according to the variation of the suctions various components. This paper works over the relationship between the suction and the degree of saturation through tests, and also analyzes pore fluid chemistry influence on the suction between grains. The test results show that the test principles and methods are feasible. They also show that the quantitative relationship between the unsaturated soil’s shear strength and saturation (water content), and a new understanding of the physical meaning in unsaturated condition of X, which is a empirical parameter in the principle of Bishop‘s effective stress.
Analysis Influence of Pile Embedded Depth and Diameter on Pile Tip Resistance
Authors: Zheng Ying Jie , Fang Bin , Li Lian Xiang
Published: August 2013

Pile tip absolute settlement curves and relative settlement curves of several working cases were analyzed. It is found that load-settlement curve characteristic related to the selection standard. The tip resistance initial stiffness of each case was analyzed. Results show that the small diameter pile has higher initial stiffness than large diameter pile, embedded depth has little influence on initial stiffness ratio, but increment of initial stiffness is linear with embedded depth growth.
Slope Stability Control Technology during the Horizontal Chamber Driving
Authors: Li Tao , Zhou Zhi Long , Liu Qing Nan , Zhang Chi , Wang Xin Peng , Chen Hui Xian
Published: August 2013

It is of great importance to guarantee the safety of slope and buildings when driving a horizontal chamber in the slope.In order toresearch slope stability while driving the horizontal chamber on this slope, the software FLAC3D was used to study the horizontal displacement of slope soil in different driving depth. The transverse settlements rules of the slope soil and the building foundation are analyzed numerically. And the numerical simulation results were compared with field monitoring. The results show that both the maximum transverse settlements position of the slope top and the building foundation were at the center line of the chamber. The horizontal displacement values were larger at the top andend but smaller in the middle. And it is beneficial for the slope stability and the buildings safety to enhance the supporting parameters of the entrance zone of the chamber. The results from the numerical simulation are consistent with the field monitoring, which can supply a reference for the similar engineering.
The Sensitivity and Reliability Analysis of Slope Stability Based on Strength Reduction FEM
Authors: Wu Ying Xiang , Liu Qiang , Cang Yu Jun
Published: August 2013

A new method for reliability and sensitivity analysis of slope stability is proposed in this paper, which is based on strength reduction FEM. In this proposed method, the safety factor of slope can be calculated without assuming the shape and position of failure surface beforehand, and the randomness of physical and mechanical parameters of slope are considered in the calculation process. Meanwhile, the slopes failure probability is researched when the coefficients of variability change, and some useful conclusions are achieved.
Numerical Simulation and Analysis of Centrifuge Model Tests with Nonhomogeneous Materials in Geotechnical Engineering
Authors: Tang Lie Xian , Guo Lian Jun , Zhang Da Ning , Zheng Jian Ming
Published: August 2013

The primary methods are antetype observation and model tests which to check the actual engineering status in geotechnical engineering field. The antetype observation is the best direct and convictive method, but approach miscellaneous and spend hugely. The general model tests can not fulfil the same stress between model and antetype. Geotechnical centrifuge model test can not only minish the measure of model and fulfil the comparability condition, but also can found all kinds of non-symmetrical models and simulation all kinds of complicated engineering. So the geotechnical centrifuge model test is applied widely in the geotechnical engineering.
This paper used the RFPA-Centrifuge and recured to the principle of geotechnical centrifuge model test, evaluated the safety of model only by increase the physical strength. Though the numerical calculating in nonhomogeneous models with different scales showed that stress, displacement and failure mode were accord with conform ratio of centrifuge model tests. Showed the advantage that the results of RFPA can be validated each other with results of physical tests. For some specifical complicated items in geotechnical engineering, make a good test model is not only very hard and have to spend much time, but also need expensive test equipment and much money for test materials. It is very good if we can use a method to conquer these shortages. So it is advisable that using the mechod which geotechnical centrifuge tests combine RFPA-Centrifuge numerical simulation analysis method.
Study on Energy Evolution Process of Hard Brittle Rock under Uniaxial Compression
Authors: Xu Su Chao , Jiang Q. , Jin C.Y.
Published: August 2013

In long term practice of rock engineering, the strength and failure rules based on classical elasticity and plasticity theory is always dominated in judging the safety and stability of practical engineering. However, stress-strain relationship is only a certain state of rock mass in loading process, and it is hard to give an accurate evaluation for the engineers especially due to the diversity and divergence of mechanical parameters. For actual loading process of rock mass is always companied with energy dissipation and releasing, in this paper, we put emphasis on the ratio of dissipated energy to overall absorbed energy in the cyclic loading process. From this point of view, three important sections are gained as follows: a) condensing section: the ratio is higher due to the closing effect of original cracks; b): elastic section: the value of ratio sharply goes down and is nearly a constant in the elastic section; c) approaching to failure section: this is a section closely to the failure because the newly cracks occurs ceaselessly and the ratio value becomes higher.
Testing Study on Bearing Behavior of Belled Large-Diameter PHC Pipe Pile by NAKS (Nakabori Kakutei System) Construction Method
Authors: Xu Wen , Hou Yu Bin
Published: August 2013

Through field static load test and pile shaft axial force test, field testing study is conducted on bearing behavior of NAKS-construction-method belled large-diameter PHC pipe pile; besides, the test result is compared with that of hammering-method PHC pipe pile and bored pile with same pile length and diameter under the same site condition. The result shows that the ultimate bearing capacity of NAKS-construction-method belled large-diameter PHC pipe pile is slightly inferior to hammering-method PHC pipe pile but obviously superior to that of bored pile. Compared with traditional hammering-method pipe pile, the pile side resistance of NAKS-construction-method belled pipe pile is smaller; however, the higher toe resistance will give better play to bearing capacity of bearing stratum of pile toe; moreover, it is found that under the action of ultimate load and failure load, the maximum settlement and final settlement of NAKS-construction-method belled pipe pile tip are obviously lower than that of other test piles, which is conductive to lessening foundation settlement of upper structure.
Research on Natural Settlement Rule of Dredged Silt in Tianjin Binhai Region
Authors: Liu Xiao Qiang , Zhang Yu Ting , Yang Yan Hua , Li Ming Ming
Published: August 2013

Main research object of this article is marine dredging silt in Tianjin Binhai region. It discusses natural settlement rule of dredged silt with different moisture content in Tianjin Binhai region through conducting indoor natural settlement model experiment to dredged silt of different moisture content. The results indicated that natural settlement of dredged silt in Tianjin Binhai region can be divided into three stages: the first stage is quick subsidence stage within 4-5 hours at the start of the experiment, during which settlement rate of dredged silt is fast and settlement volume is large; the second stage is natural deposition transition section stage within 2 days after the experiment, when settlement rate of dredged silt starts slow down but settlement volume is obvious; the third stage is dead-weight consolidation settlement stage of slow settlement after 2 days since the start of the experiment, in which settlement rate of dredged silt is slow and settlement volume is less. Settlement of Dredged silt in Tianjin Binhai region is greatly influenced by its initial moisture content. The higher the initial moisture content is the faster initial settlement rate of dredged silt will be and so is the final settlement volume of dredged silt.
Searching Sliding Surface of Homogeneous Soil Slope by Maxing Residual Sliding Force
Authors: Zou Ming Wei , Jiang Wei , Lu Zhi Qi
Published: August 2013

The stability of soil slope is a common engineering problem and many scholars and experts have done abundant works on it since 1940s. By utilizing limit equilibrium equations, some slice methods had been proposed to search the most dangerous sliding surface, and they obtain enormous success. This article focuses on the fact that residual sliding force is an important parameter to design resistant structures in Chinese engineering practice. While the most dangerous sliding surface does not coincide with the sliding surface which the largest residual sliding forces locates on. So we compile the program to find the sliding surface by maxing residual sliding force. And some sample examples are executed, the surfaces comes from new method are compared with surfaces form Janbu Method. Some interesting conclusions are obtained.
Experimental Study on Fly Ash Using for the Measurement of Preventing Frost Heave of Road
Authors: Lin Zeng Hua , Zhang Yan Hui
Published: August 2013

In order to avoid the frost damage to subgrade, an objective method that using fly ash as the anti-frost heave is proposed in this paper. The effects of the frost heave rate on the thickness of replacement layer, the depth of replacement layer and the depth of groundwater were investigated through the uniform design method. The mathematical model of the relationship between the frost heave rate and three influencing factors also was indicated by indoor simulated tests and regression analysis. The results show that the thickness and the depth of replacement layer respectively are 16 cm and 55 cm below subgrade, which provides the specific anti-freeze measurement to the guidance of design and construction.
Compressive Properties of Crushed Stone-Loess Reinforced with Geogrid
Authors: Hu You Chang , Shen Jun Min , Gu Guang Dou , Cai Hua Nan
Published: August 2013

In order to study the mechanical properties of Crushed Stone-Loess (CSL), a mixture of loess and crushed stone, and Geogrid-reinforced CSL (GCSL), a series of unconfined compression tests were conducted using samples prepared respectively with CSL, GCSL, Pure Loess (PL) or Geogrid-reinforced PL (GPL). Samples varied either in the number of geogrid-reinforcement layers or in the relative compaction / in the content of crushed stone. Based on the analysis of the test results, the following conclusions are given: (1) The pattern of compressive stress-strain curves of GCSL changes gradually from obvious strain softening to strain hardening with the increase of the geogrid-reinforcement layers and the relative compaction. (2) While the compressive strain is greater than a certain value, the compressive strength of GCSL increases significantly with the increase of crushed stone content. (3) Under a larger compressive strain, the crushed stone inclusions improve apparently the compressive property of GCSL with closely spaced geogrid-reinforcement layers due to the interlocking between the crushed stone and the geogrid.
Review of Design Methods of the Ultimate Side Shear and Base Resistance for Rock-Socketed Pile
Authors: Dai Guo Liang , Boucheloukh Abdellatif , Gong Wei Ming
Published: August 2013

To determine the ultimate load capacity of drilled shaft socketed into rock under axial compression loading, it is necessary to predict both the ultimate side shear resistance and the base resistance based on field load test or/ and laboratory tests. In geotechnical engineering there are several methods proposed the relationship between rock properties (the unconfined compressive strength) and the ultimate side shears resistance and base resistance. This paper presents the review of design methods of ultimate side shear and base resistance for rock-socketed pile. These empirical functions depend on the socket type and the range of the unconfined compressive strength of rock.
Study on Strength Properties and Crack Expansion Evolution Laws of Rock Containing Multiple Fissures
Authors: Zhao Hong Hui , Jing Hong Wen , Su Hai Jian
Published: August 2013

Through experiments that were carried out to study the rock-like specimens with nine fissures under uniaxial compression by YNS2000 electro-hydraulic servo test system, to reveal the mechanism about strength and mechanism about crack expansion evolution laws of rock containing multiple fissures. Applying numerical simulation (RFPA) for the whole failure process of rock containing multiple fissures with reasonable parameters, the results present the influence mechanism of different confining pressures for strength and crack expansion characteristics. The experimental results show: the peak strength of specimens with nine fissures degrades obviously compared with complete specimens; Specimens containing multiple fissures begin to crack with tension cracks, and break with shear cracks finally. With the increase of confining pressure, the compressive strength of rock containing multiple fissures increases gradually; And crack expansion generally occurs on the middle diagonal fissure-plane under high confining pressure.
Displacement Prediction for Soil Nailing Based on ANN
Authors: Gao Lang , Tang Zhao Wen , Liu Quan Zhong
Published: August 2013

Soil nailing has become an important excavation support system for its good performance and cost-effectiveness. It is complicated to predict deformation of soil nailing during excavating. The Artificial Neural Network (ANN) is developed very quickly these years, which can be applied in diverse applications such as complex non-linear function mapping, pattern recognition, image processing and so on, and has been widely used in many fields, including geotechnical engineering. In this paper, the artificial neural network is applied for deformation prediction for soil nailing in deep excavation. The time series neural networks-based model for predicting deformation is presented and used in an engineering project. The results predicted by the model and those observed in the field are compared. It is shown that the artificial neural network-based method is effective in predicting the displacement of soil nailing during excavation.
Research on Seepage Field in Fractured Rock Mass of Underground Oil Storage Cave Using Distinct Element Method
Authors: Yu Song , Zhang Yun Peng , Zhu Wei Shen
Published: August 2013

The distribution of hydraulic pressure in fractured rock mass surrounding caverns after excavation and technique of stochastic generation of joint network are investigated based on discrete element method. In order to seal the oil in underground caverns with water in the actual engineering, a water curtain with water pressure is installed, and the changes of hydraulic pressure are simulated with a series of curtain pressures. It is shown that some joints that have been drained out during excavation can not be saturated if the water curtain pressure is less than a certain value. Water curtain pressure with a certain value gives a strong safe guarantee of saving oil in the underground petroleum storage caverns.
An Experimental Study on the Mechanical Characteristics of Sandstone-Like Material with Preset Filling Joints
Authors: Liu Xin Yu , Liu Ai Hua , Wu Bang Biao
Published: August 2013

This paper investigates the strength and deformation characteristics of the sandstone-like material containing the preset filling joints. The test specimens are designed with different height-diameter ratio. The uniaxial compression and shear tests were performed during the experimental studies. The results show that: (1) the failure models of the 3 kinds specimens including ones without joints, ones with "cruciform" joints and ones with "intersecting parallels" joints are similar to the general trend, e.g. X-shaped conjugated single-slope shear failure and single-slope shear failure under compression and shear tests ; (2) under uniaxial compression, the performance of intact specimen is clearly affected by its size, and the strength of jointed one is significantly affected by the weakening of the structure. This impact depends on the joints conditions, e.g. joint density, with filling material or without filling material; (3) Deformation modulus E and Cohesion c have no significant change for the 2 kinds jointed specimens, but the internal friction angle is obviously affected by joints and their fillings. The internal friction angle decreases rapidly with the increase of joints number.
Study on the Geotechnical Engineering Properties of Polluted Soil
Authors: Zhang Zhen Ying , Wu Da Zhi , Yan Li Jun
Published: August 2013

To investigate the geotechnical engineering properties of polluted soil, ten soil samples are collected from Anqing copper ore, Anhui Province, China. The geotechnical engineering parameters of the polluted soil are measured in the soil mechanics laboratory. Tests results show that the natural density varies from 1.56 to 2.04t/m3, the moisture content varies from 15.36% to 27.87%, the modulus of the compression varies from 1.27 to 8.10MPa, the cohesion force varies from 32 to 210kPa, and the internal friction angle varies from 25.4 to 57.9 degree. Finally, the properties of the shear strength and the compression are studied, and find that the compressibility of the polluted soil is very big, and the relationship between shear strength and the normal pressure conforms to the law of Coulomb.
The Fluid-Solid Coupling Analysis of Three-Dimensional Slope Based on ABAQUS
Authors: Yang Bei Bei , Chen Yong , Wei Shu Ang
Published: August 2013

The coupling analysis has been the focus of study in the practical engineering; its assumed that the material is porous medium in the classical seepage mechanics, processing seepage problems as a single field without considering the coupling factor. The fluid-solid coupling analysis, in short, is the interrelationship between the seepage field and the stress field. Based on the basic theory of coupling model analysis and the establishment of coupling model in the finite element calculation software ABAQUS, this paper analyses the interrelationship between the seepage field and the stress field under the rainfall condition, and proves the two field coupling analysis is more suitable to the actual situation than just considering one single field. It states the microscopic mechanism of the internal coupling field of a slope under the condition of rainfall, and the interaction between the void ratio and the matrix suction.
The Formation of Ice Lenses in Unidirectional and Multidirectional Freezing Soil
Authors: Zhu Xian Feng , Wei Xiang Yang , Huang Xing , Zhang Yun Peng
Published: August 2013

Experimental studies were conducted on unidirectional and multidirectional freezing of artificial soils in a rectangular cavity. The ice lenses were observed through transparent plexiglass plate. Temperature gradients in soil specimen were obtained during freezing process. The experimental results indicated that the temperature gradient may change the shape of ice lenses. The amount of frost heave of multidirectional freezing was less than unidirectional freezing, so multidirectional freezing mode is helpful to restrain vertical frost heave.
Research on the Mechanical Behavior Effect of around Composite Foundation under Soil Lateral Displacement
Authors: Ren Guo Feng , Qiao Jing Sheng
Published: August 2013

This paper takes Nanhu project of Tangshan City under the soil condition of foundation pit excavation as an example. A model is established to research on the mechanical behavior effect of around composite foundation of CFG under soil lateral displacement by using ANSYS finite element software. The model analyzes the distribution law of horizontal displacement, stress of pile, soil between piles of CFG composite foundation under soil lateral displacement. Put forward a calculation formula of pile displacement by considering excavation depth, excavation distance.
Discrete Element Simulation of Rock Crushing Considering Different Shape
Authors: Liu Yang , Li Xiao Zhu , Wang Cheng Lin
Published: August 2013

Numerical simulation was conducted to study the particle breakage of rock in rolling compaction (RC) test based on discrete element method (DEM). Different shapes of particles were formed to represent the real particle shape. A quantitative analysis method of particle breakage was proposed according to the grading curve before and after compaction. The numerical results had a good agrrement with the field test, which indicated that the method adopted in this paper was feasibile and could consider the influence of the particle shape on the particle breakage in RC test.