bluuebunny/crossref_metadata_2025 huggingface dataset:
Discussion on the III-Conditioned Problems in Geodesy
Authors: Sun Tong He , Yan Guo Qing
Published: August 2013

Ill-conditioned problems are widely existed in Geodesy. To resolve this problem, many experts and scholars both at home and abroad are devoted to the research of the ill-conditioned problems. And they offer the methods to dealing with the ill-conditioned problems. There are ridge estimation, generalized ridge estimation, principle components estimation, Tikhonov regularization, singular value decomposition and virtual observational approach. This text mainly generalizes the basic principle of these methods, and simply argues the development of the ill-conditioned problems.
Attitude Measurement Method of GPS Compass
Authors: Yang Fan Lin , Chen Yun Yue , Liu Zhi Min
Published: August 2013

Compared with the traditional compasses, the GPS compass had many advantages, such as small volume, high precision, fast location, easy installation, low price and so on. On the paper the development status of GPS compass were introduced, then the system architecture and attitude measurement methods of the GPS compass were designed and analyzed, finally the conclusions of attitude measurements on GPS compass and its development tendency were discussed.
Spatio-Temporal Change of Land Use and Land Cover in Chao River Basin Based on GIS
Authors: Li Zi Jun , Gong Can Juan
Published: August 2013

Spatio-temporal change of land use and land cover from 1985 to 2005 in Chao River Basin, the important water source to Miyun Reservoir, was analyzed based on GIS technology. The results showed that woodland was the main land cover type in the basin, and then the arable land and grassland. During 1985-2005, the area of woodland increased, while the area of grassland greatly reduced. Changes of land use and land cover were more violent from 1985 to 1995 than that from 1995 to 2005. There were obvious regional differences in land use change in the basin. The conversion from grassland to woodland was the dominant process of LUCC in the basin, and this was relevant to the national ecological construction policies on water resources conservation.
Calculation Method of Bearing Capacity Improvement of Soft Soil Foundation under Vacuum Preloading
Authors: Shen Yang , Huang Wen Jun , Li Yan De , Xu Hai Dong
Published: August 2013

The theory of vacuum preloading was mainly focused on calculations of settlement and consolidation degree, but not on the bearing capacity improvement under vacuum preloading. Based on the Mohr-Coulombs failure criterion and elastic-plastic theory, the formula of bearing capacity improvement of vacuum preloading foundation was deduced under undrained condition. The consolidation and vacuum attenuation degree were taken into the consideration, and a calculation formula with fewer parameters by using CU total stress strength index was derived. Meanwhile the relation between bearing capacity and undrained shear strength was presented as well as that of bearing capacity and vertical effective stress increment.
Application of GIS to Iron Tailing Investigation and Exploitation
Authors: Yan Shun Xi , Wang Xiao Lei , Zhang Yang
Published: August 2013

The research of minesecondary resource comprehensive utilization and industrialization are afreshconcerned about resource development and environmental protection. According tothe problems in current resource development and utilization of Hebei, thepaper firstly carries out the research on mine secondary resource comprehensiveutilization technologies,then manages survey result by means of GIS, and further more uses space position toanalyze and visualize traditional structured data, more intuitional thanbefore. We can also inquire about iron mine anywhere, retrieve eligibleinformation according to amount of iron tailing or name and show itsdistribution on map. In addition, we can extract deep-seated information; exertphenomenon’s distribution, law of development and correlations, so as toprovide decision support for iron tailing’s comprehensive utilization.
Numerical Simulations of Regular Wave Impact on Horizontal Plate Based on SPH Methods
Authors: Zheng Kun , Sun Zhao Chen , Chen Chang Ping , Zhou Feng
Published: August 2013

The numerical wave flume was established for simulating the impact effects of regular waves on horizontal plate by adopting the method of Smoothed Particle Hydrodynamics (SPH).The impact process of regular waves on horizontal plate was analyzed, and the impact pressure-time curves were gotten using a new estimation method. The comparison of numerical results and experimental results shows that the new estimation method can predict the peak impact pressure more accurately.
Influence of Air Leakage of the Overburden Layer on Pit Temperature from Open Pit to Underground Mining
Authors: Liu Hai Jiao , Zhang Ya Bin , Chen Yong Li
Published: August 2013

To mines turning from open pit to underground mining with caving method as transition, air leakage of overburden layer in winter can lead to lower pit temperature, affecting their regular production. The paper is based on the theory of fluid flow in porous media, simulating wind velocity of overburden layer air leakage with FLUENT software and calculating influence of air leakage of the overburden layer on pit temperature under the condition of various porosities and thickness. The conclusion is drawn that overburden layer thickness is above 40m,air leakage influence on pit temperature is relatively little, thus offering scientific basis for rational overburden layer thickness and structure of open pit into underground mining.
Curvature Connection of Surface Patches around a Common Vertex
Authors: Meng Qing Xian , Meng Hui Hui
Published: August 2013

Based on the properties of curvature connection and theory of differential geometry, a sufficient condition of curvature connection between two adjacent surfaces is obtained, and then a new method of curvature connection of surface patches around a common vertex is put forward by using these conditions and consistency. As a result, the obtained surface patches have the lowest degrees, whose degrees are five, and the relevant system of equations can be solved easily.
Numerical Analysis of Seismic Behavior of a New-Type Horizontal Wall-to-Wall Connection for Precast Concrete Shear Walls
Authors: Jin Qiao , Dui Xin , Zhao Wei Jian , Wu Tao Gao , Guo Wan Nan
Published: August 2013

Structural connections are among the most essential parts in prefabricated concrete structures and good-quality design of connections is one major key to a successful prefabrication. A new horizontal wall-to-wall connection way for precast shear wall systems, which have been attempted in the field of modern residential buildings in China, is presented in this paper. An abaqus-based nonlinear finite element (FE) analysis under monotonic loading is implemented in order to understand the seismic performance of the proposed connection way of precast shear walls in comparison with that of the cast-in-place connection way. From the numerical results, it is concluded that the seismic performance of the presented connection technique, such as the deformability and the energy-dissipation capacity, is not weaker than that of its cast-in-place counterpart.
Flow Characteristics for High Prandtl Number Fluid under Zero Gravity
Authors: Liang Ru Quan , Yang Shuo , Ji Jun Hong , He Ji Cheng
Published: August 2013

This paper investigated the flow structure in liquid bridge of high Pr Number fluid under zero gravity condition. The free surface deformation and the effects of gas phase around liquid bridge were considered. Navier-Stokes equations coupled with the energy conservation equation were solved on a staggered grid. The two-phase surface was captured by using the mass conserving level set method. The results indicated that location of vortex center move gradually toward the free surface due to thermocapillary convection. The flow velocity nearby the surface of liquid bridge is faster than the internal flow velocity, and the overall velocity level tends to decline with time evolution.
Numerical Study of Crack Propagation Path in Three-Point Bending Beam Using Extended Finite Element Method
Authors: Fan Cheng , Jing Xue Qing
Published: August 2013

This paper is based on the basic principles of the extended finite element in the large commercial software ABAQUS on the platform of different fracture energy of three point bending test of concrete are numerically simulated, and three-point bending crack initiation, through expansion path analysis. The results show that has a direct impact on the size of the fracture energy of concrete specimens destruction, Fracture of brittle fracture can be small more obvious, produce more harmful. When softening decline stage after peak stress occurred in the "jump back" phenomenon.
Sketch Simulating Based on Non-Photorealistic Rendering
Authors: Zhao Yang , Qian Wen Hua , Xu Jin , Chen Zhi Ming
Published: August 2013

To provide with an effective method for non-photorealistic rendering for computer generated images with sketch artistic appearances from 2D images motivates our work in this paper. The character of lines, details in the source image can be smoothed by the technique of guided filter, and then the abstract smooth appearance of the image can be simulated. In addition, the smooth effect can be enlarged and enhanced by the technique of improved line integral convolution, so the final sketch artistic image can be obtained. Experimental results show that the proposed method can simulate the real sketch effect.
Analysis on Stability of the Short-Pylon Cable-Stayed Bridge
Authors: Wen Hai Ying , Liu Yang , Yang Gang
Published: August 2013

This thesis took the Changshan Bridge in Dalian Changhai county as an example and adopted the general finite element software ANSYS to simulate it. Analyzed the stability of the completed bridge and the single free-standing tower state, and studied the buckling of the main girder and the thin-walled pier.
A Re-Parameterization Transformation of Bézier Curve
Authors: Guo Feng Hua
Published: August 2013

A re-parameterization transformation is discussed. With this re-parameterization transformation, a polynomial curve can be reformulated as a rational curve, with a parameterization that is optimal in the sense that no other rational representation of the curve approximates more closely arc-length parameterization. Computing instances are included.
The Exploration about Support Constraints of Rectangular Statically Indeterminate Beam in the ANSYS Model
Authors: Gao Zhen Xing , Cheng Hang , Cui Xiao Feng
Published: August 2013

This essay stimulates multiple sets of constructional elements and a variety of constraints with the help of ANSYS. Collecting and sorting out the first principal stress simulation of each model which is under the same load .Calculating the theoretical value of each constructional element under the first principal stress by using related formulas in mechanics of materials. The optimal form of constraint was gotten by comparing the simulation value with the theoretical value. The conclusion could provide theoretical basis for simulating structural constraints of ANSYS.
An Integrated Accurate Collision Detection Algorithm and its Applications in Construction
Authors: Wang Yong , Li Ding , Liu Peng , Zhang Jian Ping
Published: August 2013

Based on the octree decomposition method and the hierarchical bounding boxes method, an accurate collision detection algorithm integrating spatial decomposition and spatial occupancy is proposed. Through an example of a three-tiered steel building, a quantitative analysis approach to roughly judging the relative efficiency is obtained by comparing the algorithm with several others. The analysis results indicate that the proposed integrated algorithm is applicable to accurate collision detection of building structures. In addition, focusing on two special collision detection issues in construction projects, namely collisions of pipeline projects, and collisions between dynamic construction machines and building components during construction process, the integrated algorithm is also improved according to the corresponding characteristics. A real construction project of a medical building is used to verify the feasibility and effectiveness of the improved algorithms. The results illustrate that the improved algorithms can solve the existing problems and provide satisfied efficiency.
Numerical Simulation on Deformation Features and Filling Efficiency of Channel Goaf Foundation
Authors: Zhou Zhi Dong , Zhang Hong Bo , Song Xiu Guang , Yue Hong Ya
Published: August 2013

For analyzing and evaluating the deformation features of channel goaf foundation and its effect on superstructure, according to the foundation reinforcement engineering of Ji-Liang Channel Check Gate, the comparative analysis on the differential settlement between the unfavorable foundation and natural foundation was performed by numerical simulation with FLAC3D. The computer results showed that the present foundation had obvious effect on the stability and security of the superstructure, so the engineering treatment are needed. Based on technical-economic comprehensive analysis among three treatment methods for strengthening the channel golf foundation with different kinds of filling, the reasonable method is put forward in this paper. By comparing mechanical characteristic of flashboard in channel goaf before and after strengthening, we confirmed the foundation stability of channel goaf and the security of the ground building which can satisfy the long term usage requirements.
Numerical Analysis of Soil Pressure inside the Sunken Large Diameter Cylindrical Structure Based on ABAQUS
Authors: Gui Jin Song , Zhang Bo , Gao Zhi Qi , Fu Yu
Published: August 2013

The filling earth pressure calculation inside the Sunken Large Diameter Cylindrical Structure is very complex. This paper used large-scale finite element software ABAQUS to establish numerical model, and validated it by the experimental data, then analyze the main cause of earth pressure change inside the cylinder.
Elastic-Plastic Analysis of Peak Stress of Anchor in Circle Tunnel
Authors: Wu Guo Jun , Chen Wei Zhong , Yang Dian Sen
Published: August 2013

In this paper,the rule of direct proportion between anchor stress and creep strain of rock mass is taken as a starting point. After tunnel excavation,stress distribution of anchor in perfect circle tunnel is analyzed,then an important conclusion that the location is coincident between peak stress of anchor and plastic zone border of rock mass can be drawn in terms of theoretical derivation when rock mass is in plasticity.
Dam Phreatic Line Simulation on FLAC3D: A Case Study
Authors: Huang Gang Hai , Wang Hao , Adoko Amoussou Coffi
Published: August 2013

Based on fundamental principle of saturated/unsaturated flow and characteristic of FLAC3Ds showing pore pressure nephogram, this paper was aimed at obtaining steady seepage within the dam, capturing the face on which pore pressure was equal to zero, and then identified the phreatic line of the dam. Using this method, phreatic line of a tailing dam in a mine was computed. The results were compared to field data. It was indicated that, the phreatic line calculated by this method was slightly higher in the mass, but was lower near the surface of the dam. This method has the merit of being faster and simpler to obtain approximate phreatic line of dams in comparison with site exploration.
Analysis and Calculation of the Additional Stress in the Foundation under Trapezoid-Distribution Load
Authors: Shao Yan , Guan Yi , Xing Wei Zhong
Published: August 2013

Based on J. V. Boussinesq's solution, the additional stress in the foundation is calculated under the trapezoid-distributed line load, and with the help of the line load, a formula is derived for calculating the additional stress in the foundation under the center line of trapezoid-distribution load along the Y-axis. By means of the formula, the different calculation formulas of the additional stress are determined under the load of rectangular, triangular and semi-infinite long stripe along with the change of the initial conditions. The formula can be applied to the additional stress's calculation of space problem more widely and is better than that seems to be dispersed in the reference books. Therefore, the calculation result has practical significance.
Application Research on Dynamic Compaction Replacement Pier Foundation Treatment Methods
Authors: Yang Yong Shou , Li Bin Xin
Published: August 2013

The dynamic compacted replacement pier technique is a new ground-treatment technology, which developed from the dynamic consolidation method. It can be used for the improvement in high-saturated silts and soft plastic to flow plastic clays, which cannot be treated using dynamic compaction method. T his new approach has many advantages, such as its simple equipment, significant reinforcing effects, construction time-saving, low-cost, no requirement of dewatering, and etc. In this paper, combined with engineering examples, according to analysis and evaluation of the monitoring results, it is feasible to adopt dynamic compaction replacement pier in uneven thickness hard plastic silt-clay foundation. Concrete-gravel dynamic compaction replacement pie can enhance the bearing capacity of pier and compound foundation. It provides a practical basis to expand the application scope of dynamic compaction replacement foundation treatment and enrich this technology.
Stability Analysis Based on a Highway Slope in Yunnan
Authors: Huang Wei Hui , Li Ke Gang , Liang Jiang Bo
Published: August 2013

This paper analyses the stability of a highway slope in Yunnan by using the FLAC3D numerical software. To simulate the stability coefficient only considering the gravity loads and also taking into account the action of groundwater and then in comparison with the result calculated by the limit equilibrium method consider the influence of groundwater , the results show that the slope in a state of instability with the effect of groundwater. Then use anchorage to upgrade the slope, and the slope in a stable state after reinforcement. The simulation results have certain reference significance to the slope management.
Dynamic Finite Element Analysis for Contact Stress of Dynamic Consolidation
Authors: Zhang Fu Yuan , Zhu Deng Yuan , Ge Shou Ren , Sun Xiao Bao
Published: August 2013

Based on Abaqus/explicit dynamics finite element program, an ax symmetrical numerical model, the infinite fringe condition and friction contact condition were built, and then the surface contact stress condition of the dynamic consolidation was studied. The time-load properties of dynamic consolidation, the spread law of contact pressure for rammer bottom and the friction influence to contact stress between the hammer and foundation were gained. The results indicate that the dynamic consolidation load can be simplified to triangular load with the weight of the hammer itself; the contact stress distribution between the hammer and the foundation is not uniform; and frictionless contact hypothesis can led errors to the simulated result.
Experimental Study on Three Dimensional Coupled Stress-Seepage Law of Single Fracture
Authors: Yin Li Ming , Chen Jun Tao , Sun Wen Bin
Published: August 2013

Equation of three dimensional stress, seepage pressure and permeability coefficient was obtained by theoretical analysis. Applying the true triaxial rock testing system of coupled stress-seepage, seepage test of granite sample with prefabricated single fracture was made under three dimensional coupled stress-seepage. The results show that three dimensional stress have the inhibition effect on single fracture seepage, and the normal main stress, having the leading role, obviously influences the permeability coefficient; seepage pressure has the promote effect on single fracture seepage, resisting the normal main stress. Fitting formula of granite permeability coefficient was gained under coupled stress-seepage which indicated the exponential relationship between permeability coefficient and three dimensional stress and seepage pressure.
Impact of Rigid Pile Composite Foundation with Lateral Unloading
Authors: Ma Jing , Chen Wen Sheng , Hu Xue Feng
Published: August 2013

The effects on rigid pile composite foundation caused by lateral unloading in horizontal direction are studied in this paper. Considering the excavation of neighborhood deep foundation ditch, a calculation model for the composite foundation is proposed and the theoretical formula of pile deformation is given. Furthermore, the formula of bending moment of the pile in the composite foundation is deduced in this paper.
Analysis of the Reliability of Soil Nailing Supporting Structure
Authors: Hui Chen Yi , Zhu Yan Peng
Published: August 2013

Based on the limit equilibrium theory and the failure model of the soil nailing structure, used the circular slice method and the geometric relationship of circular sliding surface with the center of the circle to derive the stability coefficient formula. The most dangerous slip surface was searched by genetic algorithm. To establish the reliability analysis function through the stability coefficient formula. Finally, the reliability calculation of engineering examples, compared the results with the Monte Carlo method, the reliability analysis method was reasonable and valid.
Experimental Research on Wetting Deformation of Laterite with Different Stress Paths
Authors: Chen De Fang , Wu Lang
Published: August 2013

The Modified strain triaxial apparatus is used to reveal the deformation mechanism of humid laterite. Taking into account the impact of different factors on the laterite wet deformation, the test designs different confining pressures, different degrees of compaction, different wet partial stress levels, to analyze the multi-angle of wet deformation of laterite. Humid laterites parameters are studied in different test conditions. The relationships of principal stress differences, axial strain, bulk strain, radial strain are analyzed.
Experimental Research on Soil-Water Characteristic Curve of Unsaturated Soils
Authors: Xu Xu , Zhang Fu You , Gu Ming
Published: August 2013

The soil-water characteristic curve (SWCC) reflects water storage capacity, Measuring it accurately is important in engineering. This paper concluded main factors of SWCC, measured soil-water characteristic of loess under conditions of different dry densities, the curve of volume water content, saturation and matric suction were presented, the curves showed similar change trend, saturation mainly determined the matric suction when matric suction was small.
Comparative Study on Force Characteristics of Vertical and Inclined Cantilever Retaining Pile
Authors: Kong De Sen , Zhang Qiu Hua
Published: August 2013

In order to comparative study the force characteristics of vertical and inclined cantilever retaining pile in foundation pit engineering, a practical excavation engineering was considered. Based on the engineering geological conditions of this foundation pit, two three-dimensional simulation models for computing the force characteristics of vertical and inclined cantilever retaining pile were built. Then the horizontal displacement of pile top, the lateral displacement and the bending moment of pile body were illustrated and contrasted in detail. It was shown that the horizontal displacement of inclined pile top is significantly less than that of vertical retaining pile. Moreover, the deformation and bending moment of inclined pile body are more reasonable than that of vertical retaining pile. Therefore, the stability of foundation pit was guaranteed through inclined pile support.
Experimental Research of Fine Sandstone Strength and Deformation Characteristics under Different Confining and Hydraulic Pressure
Authors: Liu Zai Bin
Published: August 2013

In order to study sandstone rock strength and deformation parameters under pore water pressure conditions, triaxial compression tests of different hydraulic pressure were executed. Fitting equations of fine sandstone confining pressure and hydraulic pressure coupling effects were established. This research show that fine sandstone rock strength increases with confining pressure increases. Rock mass strength and cohesion have negative exponential relationship with hydraulic pressure. When the hydraulic pressure is 3MPa, elasticity and confining pressure fit to logarithmic relationship. Fine sandstone Elasticity modulus decreases with hydraulic pressure increases. Poisson’s ration and hydraulic pressure fit to linear relationship.
A Study on Constitutive Relation of Unloading Rock Mass Under Compression-Shear Stress
Authors: Wang Fei , Liang Xu Li , Hao Gang Li
Published: August 2013

We conducted the model test of unloading rock mass under compression-shear stress .Based on analysis and fitting to test data, we proposed the unloading rock mass three-dimension constitutive model.
Numerical Simulation of Post-Construction Deformation Characteristics of Storage Oil Tank Ground
Authors: Zhang Yan Mei , Zhang Xu Dong
Published: August 2013

Ground soil was looked as porous medium, a three-dimensional finite element model of shell-liquid-foundation-ground was built, and the influence of soil parameters, filling liquid mode, and liquid height on the tank ground deformation was discussed. The research shows that the subsidence range caused by additional stress is the 0.3D range of the tank bottom edge outer; the influence of soil constrained modulus on settlement is remarkable, with constrained modulus decreasing, the tank ground settlement increases; with soil permeability coefficient decreasing, the tank ground settlement decreases; the ground settlement curve shape is decided by soil constrained modulus and permeability coefficient; the influence of filling liquid mode on the ground final settlement is very small ,but on the pore water pressure peak is remarkable.
Monitoring and Numerical Analysis on Displacement of High-Voltage Pole around Foundation Pit Excavation
Authors: Liu Jie , Hou Kun , Feng Shi Lun
Published: August 2013

The influence of excavation on surrounding buildings has been studied widely,but there was little attention to its reliability of reinforcement. In this paper, which was based on an excavation project of a security housing in Tianjin, about fourty thousand square meters, numerical analysis on wire poles were carried out by using finite element software Plaxis2D,and the comparative analysis is made with monitoring results.The results show that,when there is no reinforcement, foundation pit excavation will cause the displacement of wire poles more than allowed; after reinforcement, the numerical results of wire poles displacement conform to the requirements,monitoring data also shows that the wire poles displacement is in the allowable range. Results indicate that the reinforcement can improve the soil deformation effectively, and the design method is reliable.
Analysis of Anti-Floating Measures and Construction Parameters of Shield Tunnel through River under Ultra-Shallow Covering
Authors: Li Xiao Long , Wang Bing Long , Li Xue , Ji Chang
Published: August 2013

Shield tunnel through the river under shallow covering usually facing the phenomenon of tunnel floating due to the thickness of overburden layer inadequate,and resulting in flooding accident due to the overburden layer split.Aiming at the project of Hangzhou metro line one through the Tangjia river under ultra-shallow covering,checking the thickness of overburden layer and taking the measures of anti-floating plate,uplift pile and jet-grouting piles to resist tunnel floating;through the control of soil chamber pressure,driving speed and grouting pressure in the process of construction,tunnel axis is controlled within±30mm,the amount of surface uplift is less than 10mm,tunnel segments without breakage and leakage.The results show that using anti-floating plate,uplift pile and jet-grouting piles,and controlling the construction parameters strictly are effective measures to resist tunnel floating and ensure construction safety.
Deformation Monitoring and Numerical Analysis at the Top of Slope of a Foundation Pit
Authors: Liu Jie , Cao Heng Heng , Jiang Xiao Feng
Published: August 2013

This paper based on a foundation pit in Tianjin shown the monitoring data and simulated the excavation process by finite element software ABAQUS. The lateral and vertical displacement of the top of slope obtained by calculating at different excavation stages were compared with the measured values. At last this paper made a conclusion about the deformation rules in the process of excavation, which can provide reference for design and construction of similar engineering.
Study on Slope Instability Disciplinarian on the Condition of Rainfall
Authors: Zhang Nan Tong , Zhang Xiao Chun , Wang Hua Rong , Yan Chen
Published: August 2013

Slope stability is one of the problems of road construction which should be faced with and solve. Rainfall can reduce the shear strength of slope soil and raise the underground water level which can lead to increase slope soil pore water pressure. The influence of rainfall infiltration on slop is mainly to change the slope seepage field, increase dynamic and hydrostatic water load on the slope soil and decrease of soil shear parameters. More abundant rainfall of typhoon area could make the road slope stability more fragile. Based on Matoushan Mountain along 104 state roads in Taizhou city, Zhejiang province, slope instability disciplinarian on the condition of rainfall is studied using the method of numerical simulation in this paper. As the results, when the rainfall intensity was 0.006 m/h and continuous rain was in 24 hours, the slope surface compressive stress tends to zero which began to appear tensile stress area on the condition of self-weight. And when the rainfall intensity was 0.01 m/h and continuous rain was in 24 hours, the large area of the slope surface was tensile stress area which means to appear break zone in slope surface and likely to landslide at the same time.
On Numerical Simulation of the Stepped Soil-Nail Wall
Authors: Zhu Chang Zhi , Gao Quan Chen
Published: August 2013

Based on an Engineering Example which was supported by the stepped soil-nail wall, a numerical analysis model was established by FLAC3D,and the process of the excavation and supporting was simulated, and the numerical results of the soil nails internal force and foundation pit deformation were obtained. The simulated result was consistent with the measured results. It shows that the method of FLAC3D numerical analysis can be used to the numerical analysis of foundation pit excavation and supporting, and it will provide the basis for the design and construction of practice project.
Recent Advance of Horizontal Drainage Cushion in Vacuum Preloading Method
Authors: Cao Yong Hua , Chen Yun Tao
Published: August 2013

Horizontal drainage cushion plays a key role in vacuum preloading projects. The traditional horizontal drainage cushion is sand blanket which consumes large amount of sand and is not enviromentally friendly. Several improvements or modifications of horizontal drainage cushion were developed in engineer practices in recent years. Drainage net was used as horizontal drainage cushion in ultra-soft soil improving projects in order to solve the laying problem of sand blanket. Sand ditch was used to deduce the consumption of sand. Direct vacuum preloading method linked the PVDs and filer tubes together in order to improving the transfer efficiency of pressure and canceled the sand blanket at the same time. Low position vacuum preloading method set horizontal drainage cushion below the surface of the ground in order to cancel the sealing membrane.
Analysis of Particle Crushing in Rolling Compaction for Rockfill Dam Using DEM
Authors: Liu Yang , Wang Yan Tao , Li Xiao Zhu
Published: August 2013

Based on the rollingcompaction (RC) test of the Nuozhadu coarse rockfill zone of upstream anddownstream I district rockfill engineering, numericalsimulation was conducted to study the particle breakage of RC test usingdiscrete element method (DEM). The movement and the crushing mechanism of theparticles in the RC process were analyzed according to the numerical results ofDEM. The numerical results indicated that the dominant damage were tensionfailure. The crushing zone was approximate inclined 45 degrees to horizondirection and extended to the bottom in the RC process.
Study on Initial Cracking of Expansive Soil and FEM Simulation
Authors: Wu Jun Hua , Yang Song
Published: August 2013

Swelling and shrinkage due to moisture-change is one of the expansive soils characteristics, which is similar to the behavior of most materials under thermal effect. The stress is defined as moisture-change stress and is adopted to analyze swell-shrinkage deformation based on the elasticity mechanics theory. A FEM program is established which is used to calculate the stress caused by moisture-change considering the defect of theoretical calculation. The stress via FEM program can be accordance with the actual characteristics and the moisture-change is more applied extensively.
Influencing Factors of Bearing Behavior of Settlement Reducing Pile Foundation for Immersed Tunnel
Authors: Huang Xiao Hui , Gong Wei Ming , Huang Ting , Xie Ri Cheng , Xu Guo Ping
Published: August 2013

Settlement reducing pile foundation has recently been proposed as an important progress in the design theory of pile foundation, which is one type of deformation-based foundations. Compared with the common design method, settlement reducing pile foundation can greatly reduce the number of required piles. Aimed to the influence of pile cap, cushion, pile spacing, pile length on bearing behavior of settlement reducing pile foundation, the indoor tests on steel pipe settlement reducing pile foundation for immersed tunnel were carried out in sand. Based on uniform design, the six groups of tests with 3×4 pile groups were conducted, furthermore, earth pressure, axial force of pile shaft, and foundation settlement were measured. When the load applied increased, the plastic failure of the soil occurred under the corner of immersed tunnel. The result shows that the earth pressure distribution against immersed tunnel is similar to the normal base reaction in sand which is big in the center and small in the border. The correlation analysis result indicates that apply pile cap, reduce cushion thickness, increase pile spacing and increase pile length can increase the pile load sharing ratio. Compared with the average value of correlation coefficient of each influencing factor, pile length has the most remarkable effect on the pile load sharing ratio, then cushion and pile cap, and pile spacing has the minimal effect among these influencing factors. The research can provide a reference for design of relevant projects.
The Inclination of Bridge Pier due to Neighboring Embankment Construction and its Rectification Technique
Authors: Shi Ming Lei , Zhang Hao , Zhang Rui Kun
Published: August 2013

In case of highway road construction often beneath existing overpass project, the filling of neighboring embankment may cause lateral displacement of bridge piers, which seriously threaten the safety of bridge. One case history, for inclination disease of overpass bridge piers in soft soil area, was presented. Aiming at the deformation of piers caused by the neighboring embankment construction, the displacement feature of bridge bearings were tracked and measured by site monitoring, and the damaged position of piles were clarified with low strain dynamic test. For these geological traits, the reasons of the inclination were analyzed. And the rectification method of applying surcharge load for smaller deviation (50mm) and the rectification method of pushing combined traction for serious deviation (>50mm) were respectively put forward on the basis of the lateral displacement statistics of bearings and the analytical standard set by Bozozuk. Site observation indicates these rectification methods can achieve the desired results.
Study on Earth Pressure and Engineering Properties of Solid Waste during Foundation Pit Excavation
Authors: Zhang Yan , Feng Xiu Li , Liu Tao
Published: August 2013

A mechanical behavior of solid waste during foundation pit excavation is discussed on the base of the in-situ monitoring results of earth pressure and field measured data in solid waste. During excavation, the soil strength increases, which is mostly because of the variances of characteristics of soil in unloading state. Measurement of earth pressure is less than computation, and the value gradually decreases during excavation. In the end, it tends to be stable or slightly higher than the minimum. Compared with soft soil, the change is not only related to the deformation but also the change of soil property, especially, the influence of fiber to the shear strength of solid waste. By analyzing changing characteristics of earth pressure in solid waste, from the surface of earth within 0m~5m, experience value of lateral earth pressure coefficient is 0.35 during excavation and 0.25 after excavation, and within 5m~10m, the value is 0.55 during excavation and 0.45 after excavation.The conclusions will provide the reference for future similar projects.
Model Test Research of Surcharge Contribution to Ground Bearing Capacity
Authors: Chen Le Yi
Published: August 2013

To investigate the influence of surcharge on bearing capacity, model tests were performed. In the tests, 5 kPa and 10 kPa surcharge was applied on silt respectively. The bearing capacity factor Nq is smaller than theoretical solution, and is only of 60.3% and 80.5% of theoretical solution. Model test show that the ground failure mode is not general shear failure mode in condition of ground under surcharge. In bearing capacity calculation, if bearing capacity factor theoretical solution which is from general shear failure mode is applied, the result will be overestimate.
Dynamic Interaction between Reservoir and a High Concrete Face Rockfill Dam on Deep Alluvium Deposit
Authors: Cen Wei Jun , Sun Hui , Xiong Kun
Published: August 2013

Potential-based fluid model and Westergaard added mass model were used to reflect the dynamic interaction of reservoir-CFRD(concrete face rockfill dam)-foundation coupling system. The deep alluvium deposit was treated as porous medium using Biot's dynamic consolidation theory. In the coupled analysis, the paper focused on hydrodynamic pressures in the reservoir zone, dynamic response and pore water pressure in the structure zone. The result shows that the dynamic response of added mass model is greater than that of potential-based fluid model. The porous medium of alluvium deposit is of great significance in performing soil liquefaction analysis and reservoir-dam-foundation system.
Experimental Study on Strength of Rock Masses with Transfixion Joint under Uniaxial Compression
Authors: Wang Lei , Li Shi Chen , Han Jian Xin , Zeng Zhong Yi
Published: August 2013

The relationship between the peak strength of rock masses and joint inclination angle is closely, to study its relationship, experiment on pre-existing persistent jointed rock cylindrical standard specimens was made under uniaxial compression by high stiffness servo control testing machine, experiment found that: the residual peak intensity and peak strength are increased with the decrease of jointed and nonlinear. Analysis on the peak intensity changing with the fissure inclination using Kulun strength theory, theory analysis conclusion is consistent with the experiment, prove the conclusions of experiments and theoretical analysis all can reflect the law of rock masses with transfixion joint failure strength well.
Measures and Mechanism of Reinforcement of Soft Subgrade of High Speed Railway in Operation
Authors: Wang Jiang , Yang Long Cai
Published: August 2013

Some subgrade of high-speed railway in operation occurred abnormal settlement,so need to reinforcement, however, the reinforcement measures and these mechanism have got little attention. Numerical analysis method was adopted to study the mechanism and effects of the grounting and churning pile which was used to reinforce soft soil subgrade a high-speed railway Results shows that the settlement and lateral deformation not symmetrical distribution but got larger along the inclined derection of stratum, reinforcement by grouting can decrease the settlement and the transverse differential deformation by improving the properties of soil, which can decrease the viod ratio and increase the compression modulus; reinforcement by churning pile which can increase the stability of embankment on soft soil subgrade. The result could provide theoretical guidance for reinforcement of soft soil subgrade of high speed railway in operation.
Research on Detection of Breaking Rock Zone of Roadway Surrounding Rock with Ground Penetrating Radar
Authors: Zhang Fu Jun , Cui Hai Feng , Hao Yi Rui
Published: August 2013

Based on the detection principle of ground penetrating radar, the feasibility of detecting breaking rock zone of roadway surrounding rock with ground penetrating radar is analysed. In the case of detecting breaking rock zone of roadway surrounding rock in Huafeng Colliery, the method of radar detection and image analysis is suggested. The results show that using ground penetrating radar to detect breaking rock zone of roadway surrounding rock can achieve good result, so it provides a new technical way for the field detection.
Soil Resistivity Measurements to Predict Moisture Content and Density in Loose and Dense Soil
Authors: Abidin Mohd Hazreek Zainal , Ahmad Fauziah , Wijeyesekera Devapriya Chitral , Saad Rosli , Baharuddin Mohamad  Faizal Tajul
Published: August 2013

In the past, most of the soil electrical resistivity charts were developed based on stand-alone geomaterial classification with minimal contribution to its relationship to some of geotechnical parameters. Furthermore, the values cited a very wide range of resistivity with sometimes overlapping values and having little significance to specific soil condition. As a result, it created some ambiguities during the interpretation of observations which were traditionally based on qualitative anomaly judgments of experts and experienced people. Hence, this study presents soil resistivity values based on laboratory experiment with a view to predict the soil moisture content and density in loose and dense soils. This study used a soil box and a resistivity meter to test a clayey silt soil, increasing its water usage from 1-3% based on 1500 gram of dry soil. All the moisture contents and density data were observed concurrently with 25 electrical soil resistance observations being made on the soil. All testing and formula used were in accordance with that specified in BS1377 (1990). It was apparent that the soil resistivity value was different under loose (L) and compact (C) condition with moisture content (w) and density (ρbulk) correlations being established as follows; ρbulk(C) = 2.5991ρ-0.037, ρbulk (L) = -0.111 ln (ρ) + 1.7605, w(L) = 109.98ρ-0.268, and w(C) = 121.88ρ-0.363 with determination coefficients, R2 that ranged between 0.69 0.89. This research therefore contributes a means of predicting these geotechnical parameters by related persons such as geophysicist, engineers and geologist who use these resistivity techniques in ground exploration.
Anti-Floating Anchor Rods and Waterproof Construction Technology for Deep Pits
Authors: Chen Liao Jiang , Wang Xiao , Hou Shu Li
Published: August 2013

Pouring base cushion first and then construct anti-floating anchor to avoid strong weathered diorite prolonged exposure and disintegration. The post-poured wedge concrete resistance to water pressure, the middle concrete pads fixed waterstops, Reinforced fixed seal ring, The cement penetration crystalline deal with concrete construction joints. With polyurethane, BAC waterproof coiled material for anti-floating anchor root waterproof treatment.
Research on Design and Application of the CDM Pile
Authors: Kong Xiang Guo
Published: August 2013

From the view of design, this paper have discussed some problems of design and application of deep cement mixing pile, and have analyesd the determination of single pile bearing capacity method, the checking of soft stratum, defects or errors existing in the calculation of cement mixing pile of composite foundation settlement, and have put forward some suggestions for improvement.
Research on Controlled Permeability Formwork of Nonwoven Fabrics to Retain the Humidity on the Concrete Surface
Authors: Wang Tao , Lu Ji Jun , Zhong Ya Hong , Xing Ming Jie
Published: August 2013

It is of great significance for concrete to be cured using controlled permeability formwork of nonwoven fabrics especially in dry area. CPF can improve durability of concrete through decreasing the ratio of water and cement in concrete surface. CPF could also retain the water within it. The role of concrete curing using CPF or not is test by MOIST200B type microwave moisture meter. In addition, the permeability of concrete surface between the concrete which use CPF or not is analyzed through the air permeability test, the initial surface absorption of concrete test (ISAT). The testing results indicate that there is little effect on curing of concrete using controlled permeability formwork liner.
Prediction of the Elastic Modulus of Self-Compacting Concrete Based on SVM
Authors: Cao Yan Fei , Wu Wei , Zhang Han Lei , Pan Jun Ming
Published: August 2013

With the powerful regression and fitting of support vector machines in uncertainty and the non-linear,based on the determination of the content of the coarse aggregate and characteristic parameters, this paper established a predictive model of self-compacting concrete elastic modulus based on support vector machine.Through analysis and comparison with experimental results, it proves the accuracy and effectiveness of the model.
Refractory Performance Study on Foamed Concrete and Concrete
Authors: Yu Shui Jun , Zhang Peng Fei , Yang Xiao Fang , Zhao Hong , Chen Xiao Li
Published: August 2013

Foam concrete is used in building energy saving and heat preservation project, and its refractory performance is very important to improve the fire resistance ability of the building. In this paper, fireproof property of the foamed concrete were studied.In the simulation fire conditions, compressive strength value of foamed concrete in different density, different calcination time, and different water content cases were determined first, then influence of these conditions on the foamed concrete refractory performance were researched. The results showed that foamed concrete compressive strength loss rate increase with density decreases in fire cases; Density of 300kg/m3 and 800kg/m3 foam concrete block, calcinated under 800°C fire in 20 min, its compressive strength loss rate were 66.3% and 25.5% respectively; The same density of foamed concrete compressive strength gradually reduce with the increase of calcining time; Moisture content on the different density of foam concrete affect differently on the fire safety. Foamed concrete is incombustible, but its compressive strength reduced due to fire inflammable material of high temperature calcined.
Experimental Research on Bamboo Fiber Reinforced Concrete
Authors: Zhang Chang , Huang Zhen , Chen Guo Wei
Published: August 2013

This paper studied the mechanical performance of bamboo fiber reinforced concrete through a series of compression, splitting and flexural tests. The comparative variables are the length and volume ratio of the bamboo fiber. The test results show that concretes splitting tensile property has obvious improvement when bamboo fibers are added, but the enhancement to the compression property and flexural property is not obvious.