bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Construction Technology of High Brick Chimney
Authors: Deng Hua Feng , Zhu Min , Guo Jing , Lu Tao
Published: June 2011

Chimney is the building which is high but the horizontal cross section is small, so the high altitude work surface is small and difficult to construct, in which the stability of the scaffold and the safety of vertical transport equipment are especially important. For the serious problems arising in the prophase construction of the 50m chimney, double rows steel pipe scaffold was designed outside the chimney, and the vertical transportation uses the external grillage hoisting frame. Reformed the internal existing scaffold into pedestrian passage to separate people and material, and a detailed calculation analysis of the structural members such as scaffold, grillage hoisting frame and other structures was carried out. Large deformation, destabilization and other safety problems of the scaffold, grillage hoisting frame and other structures were not arising during the anaphase construction process, which indicates that the construction technical measures and calculation and analysis results are with important guiding significance to guarantee the smooth of the construction, and also can be referenced by other similar projects.
Improvement of Mechanical Properties and Lateral Resistance of Brick Masonry Walls by Using Indigenous Materials
Authors: Shahzada Khan , Goto Tetsuro , Naeem Khan Akhtar , Naseer Amjad , Fahad M.
Published: June 2011

In this paper, improvement of mechanical properties of unreinforced masonry walls based on the laboratory test results is discussed. Various masonry specimens have been tested by Portable Structural Testing Equipment (PSTE). Masonry prisms have been reinforced with indigenous materials (wire mesh and bamboo) and confined with reinforced concrete elements. The tensile strength, shear strength and lateral resistance of masonry walls increases up to 5.4, 2.73 and 5.65 times respectively by using plaster, wire mesh, bamboo and confinement. The Indigenous materials used in this research work are cheap and easily available as compared to FRP and other materials. Analysis for lateral resistance of masonry walls has been made by using different relationships.
Bond Strength Modelling of Corroding Steel Reinforcement in Concrete
Authors: Zou Roger , Shayan Ahmad , Collins Frank
Published: June 2011

Corrosion of reinforcement can significantly affect the bond strength between the steel bar and the surrounding concrete thus greatly reducing the load bearing capacity of the concrete structure. In this paper, a simple analytical model is proposed to evaluate the maximum bond strength of corroded concrete with varying rebar diameters and concrete cover thickness. Predicted results compared well with experimental test data.
Analysis of Creep and Shrinkage Mechanism of Bridge Considering the Effect of Shrinkage on Creep Stress Reduction
Authors: Lin Sheng , Xu Xian Fen , Wang Cheng , Ye Jian Xin
Published: June 2011

The effect of concrete shrinkage and creep on the deformation of the bridge structure is posing a serious issue with increasing numbers of large-span bridges are being built. At the moment, only the creep coefficient is usually considered for calculating bridge creep, without taking other factors into consideration. This paper, based on aging theory, considers the influence of shrinkage on creep stress reduction, by simplifying the formula of creep strain under discrete load by using the integral mean-value theorem and deriving the formula of concrete creep strain. Taking a continuous rigid frame bridge for example, the paper calculated the creep considering creep stress reduction under shrinkage, which showed that the method can well predict the final shrinkage and creep values of large-span concrete bridge.
Design and Analysis of Slanting Cross Special-Shaped Arch Bridge
Authors: Wang Hui Li , Jiang Rong Bin , Pan Zhe
Published: June 2011

The slanting cross special-shaped arch bridge is fit for urban landscape bridge, with unique design and updated style. Based on Tongtai Bridge in Zhangjiakou, the design method, static characteristic, and stability of the bridge are introduced. The stress envelopes of girder and arch under the most unfavorable load combination, the arch stability of various stages are obtained by spacial FEM. From the results, a conclusion can be drawn that the lateral load is governing load for slanting cross special-shaped arch bridge because of horizontal component of suspender and wind load.
Applicability of Modal Pushover Analysis on Bridges
Authors: Wei Biao , Zeng Qing Yuan , Liu Wei An
Published: June 2011

Taking one irregular continuous bridge as an example, modal pushover analysis (MPA) has been conducted to judge whether it would be applicable for seismic analysis of irregular bridge structures. The bridge’s seismic demand in the transverse direction has been determined through two different methods, inelastic time history analysis (ITHA) and MPA respectively. The comparison between those two results indicates that MPA would be suitable only for bridges under elastic or slightly damaged state. Finally, some modifications are used to improve the MPA’s scope of application, and the results illustrate that the adapted MPA will be able to estimate bridges’ seismic demands to some extent.
Alignment Control during Construction of Continuous Bridge Suspended by Triangle Frame
Authors: Huang Yan , Qi Lu Kuan , Zhou Wu
Published: June 2011

The features of a new type of continuous bridge suspended by triangle frame are introduced in this paper. In view of the segmental cantilever construction method engaged in main girder construction, we put forward to the method of pre-camber setting and the calculation of formwork elevation and field measurement of displacement.
Research on the Rigidity of Continuous Beam with Equal Span under the Temperature Load
Authors: Zhang Yong Shen , Li Yan Ying
Published: June 2011

Cracks appeared in concrete structure is always concerned in construction engineering. As the cracks appear, the rigidity of structure will descend. So only the combination of slip theory and the non-slip theory could reflect the development of cracks in the course of analysis of cracks development. For axial tension and bending components, stiffness changes before and after cracking. The continuous beam with equal span is analyzed under the temperature load by the finite element method. As the cracks with different space appear, there is an abrupt bending moment with every crack. Different crack spacing, crack steep drop differently. So the wider the crack’s space is, the higher the abrupt bending moment is.
Research on the Application of Horizontal Rotation Construction Method with Flat Hinge in Cable-Stayed Bridge Construction
Authors: Sun Quan Sheng , Guo Xiao Guang , Zhang De Ping , Guan Xi Kun , Zheng Yu
Published: June 2011

Rotation construction method includes building the bridge parallel to the obstacle being spanned (a river, a highway or a railway) and then rotating the superstructure into place. The method can optimize bridge construction in terms of reducing impacts on traffic, safety, and overall project budget and duration. Therefore, the method became so popular that it has been used successfully in about one-hundred bridges in China. In this paper , taking the Suifenhe cable-stayed Bridge as project background, the design idea (single point with flat hinge) of bearing system has been brought forward. The successful rotation construction of Suifenhe cable-stayed Bridge proved the feasibility and technical advancement of the horizontal rotation construction method with flat hinge in similar engineering construction, especially the bridges with symmetry structure.
Chain-Styled Mechanism and Chain-Cutting Disaster Mitigation for Masonry Arch Bridge
Authors: Tian Wei Feng , Zhang Liang Liang , Alghabsha Ayad Thabet Saeed
Published: June 2011

Based on the chain-styled theory, disease mechanism of masonry arch bridge is analyzed in the paper, which indicates that not only the causes of diseases but also results show the complex chain-styled relationship, stages of diseases are divided according to the law of disaster chain, and the measures of chain-cutting, prevention and reinforcement are put forward. Based on the Dongqing Bridge, disease mechanism is analyzed and reinforcement method is proposed according to the idea of chain -cutting disaster mitigation.
Design and Optimization of Concrete-Filled Steel Tube Arch Bridge Using Cable-Hoisting Method
Authors: Liang Xiao Fei , Xu Yue , Du Hong Jing
Published: June 2011

Based on the hoisting construction feature of large hinge-support tower and field circumstance, the cable hoisting system for Meng-dong river grand bridge at the west of Hunan province is designed. Studying on cable hoisting system design and construction of the CFST arch bridge, the paper takes systematic analysis and calculations on the key construction technology of the CFST arch bridge, and puts it in practice successfully which provides experience for the similar long—span bridge construction of the follow.
Analytical Solution of Bending and Vibration of a Rectangular Plate on the Elastic Foundation
Authors: Zhang Hong , Wang Chun Ling , Wang Ai Qin
Published: June 2011

The analytic solutions of steady vibration of a rectangular plate loaded with vertical force on the semi-infinite elastic foundation were given by combining the general solution of double trigonometrically sine series with supplementary terms with the dynamic integral representations for displacements of the semi-infinite elastic foundation loaded with arbitrary vertical force. Some computational results were presented. The agreements were found to be satisfactory which proved the validity of the new method in solving the problem. This new method would be feasible in practical applications.
Effects of Frequency Content of Earthquake Ground Motions on Probabilistic Seismic Demand Assessment of Long-Span Bridge Structures
Authors: Chen Liang , Zhang Jin Song
Published: June 2011

Earthquake ground motions were reasonally selected for the nonlinear dynamic time-history analysis conducted for a two-tower long-span cable-stayed bridge. The correlation between frequency content of earthquake ground motions and probabilistic seismic demands reveals that the geometric mean and dispersion of response spectra from earthquake ground motions have significant effects on probabilistic seismic demand assessment of long-span bridge stuctures and these effects are related to the difference of the shape of geometric mean spectra in the important period ranges where cumulative modal mass participation is significant. Response spectra of selected earthquake ground motions should match well with target spectra in the important period ranges. If input ground motions are reasonally selected, analytic results can be obtained more precisely and effectively and more amplitude parameters can be selected as intensity measures.
Study on Calculation of Rock Pressure and Determination of Depth for Shallow Asymmetric Tunnel
Authors: Zhou Xiao Jun
Published: June 2011

The method to calculate rock pressure for shallow asymmetric tunnel is analyzed by means of taking a mountainous tunnel with semicircular crown and straight sidewall as the object in this paper. The calculation method of tunnel rock pressure has been presented with consideration of both tunnel structure size and its overburden depth. Finally the way to determine the shallow or profound depth of asymmetric tunnel is also obtained.
Seismic Landslide Risk Assessment of Levee Project
Authors: Su Yan , Du Yue Ting , Wu Jia Zhong
Published: June 2011

Different landslide analysis methods were compared in this paper, and the analysis method of levee project seismic landslide risk probability was established based on Morgenstern-Price and Monte Carlo methods, and then the landslide risk assessment standards were developed. The result shows that liquefaction can lead soil layer strength reduction, and will trigger and accelerate landslide, therefore, the impact of soil liquefaction must be reasonably considered in levee and dam seismic stability analysis.
Field Monitoring of Surrounding Rock Stress and Rheological Analysis in Tunnel Construction
Authors: Huang Qiang , Dong Ying Na , Li Zhi Da
Published: June 2011

The stress field monitor and rheological analysis have been done during excavation. The field monitoring data are compared with numerical simulation results. The result shows: Rock stress variation is influenced by both spatial effect and time effect; when the distance from monitoring section to tunnel face is less than a tunnel diameter, the surrounding rock stress is mainly affected by spatial effect and changes violently; when the distance is more than a tunnel diameter, the surround rock presents rheological properties and stress changes smoothly and continuously. Analyzing the monitoring data and fitting by Poynting-Thomson three-parameter rheological model, we can get the radial stress variation equation with time and predict the final variation value. The final value and numerical simulation results are in comparative agreement.
Study on the Test of Soil Water Characteristic Curve
Authors: Yang Yu You , Zhang Qin Xi , Wang Gui He , Liu Chen
Published: June 2011

The test of soil water characteristic curve (SWCC) and its mathematic model are present. The SWCC can describe the relationship between unsaturated soil matric suction and water content. Matric suction is an important parameter to address when studying the engineering properties of unsaturated soil. And while the measurement of substrate attraction is a very difficult issue, it is also one of the biggest obstacles in the engineering applications of unsaturated soil. By analyzing and researching the test data of SWCC researchers can initially establish the mathematic model which is the SWCC equation. The Van Genuchten model and the Fredlund and Xing model were used to simulate better the changes between the volume water content and the matric suction. Predictions were compared with experimental results to determine the simulation capability of the model for the soil of Beijing.
Study on Ionic Soil Stabilizer Reinforcing Red Clay of Wuhan
Authors: Lu Xue Song , Xiang Wei
Published: June 2011

With fast research and development, economic and effectual materials have been the focal point of all over the world all the time. This experiment studies and uses a new kind of economic and suitable Ionic Soil Stabilizer (ISS for short). Based on the red clay of Wuhan reinforced by Ionic Soil Stabilizer, the red clay is treated by different matches of ISS and water at first, then is tested in the unconfined compressive strength test, shrinkage test, free swell test, and spectrum test. The results show that unconfined compressive strength increases, and the linear shrinkage, shrinkage limit and free swell decrease after mixing the ISS into the red clay. In addition, spectrum tests show that after the red clay is treated by ISS, soil particles on the surface of the C elements had changed markedly, from scratch, confirmed the ISS elements combined with the role of soil particles.
Efficiency of Pile Groups of Large Diameter Bored Cast-in-Place Pile
Authors: Gong Xiu Bin , Fan Qing Lai , Xu Yong Jie
Published: June 2011

Based on the framework of the FEM, the three-dimensional numerical analysis for evaluating the efficiency of pile groups of large diameter bored cast-in-place pile is conducted in this paper. The effect of the pile numbers and pile spacing on the efficiency of pile groups is obtained by studying the ultimate bearing capacity behavior of different arrangements of pile groups under vertical loading. Then they are compared with the calculated results gained by the formula of the efficiency factor of the pile groups based on superimposed stresses. The findings can serve as a reference for the design of large diameter bored cast-in-place pile.
The Application of an Unsaturated Soil Elastoplasticity Model in Dam-Reservior Coupling System
Authors: Guo Li Na
Published: June 2011

This paper summarized the research of an unsaturated soil elastoplastic model(BBM), then a revised elastoplastic incremental stiffness matrix for unsaturated soil is deduced,discrete the governing equation in space domain and time domain with Galerkin weighted residual method and Euler method,a nonlinear finite element program is developed for the analysis the water-mechanical coupling system of unsaturated soil.The constitutive model is used for a homogeneous dam’s FSI problem, and the seepage and deformation in dam’s distribution consistent with law.
Information Entropy Analysis of Rainfall Deformation of Talus Slope
Authors: Ruan Yong Fen , Hang Xing Zhou , Li Shi Sheng , Wang Dong
Published: June 2011

The large talus landslide of is very complicated and difficult to deal with. In order to make a good research on the influence of rainfalls to the high talus slope deformation, the method of information entropy is employed by using the principle of information transfer and relativity to analyze and calculate the rainfall influence on the deformation velocity. Moreover, taking the full and accurate data of the accumulation body with high slope on the left bank in front of Xiaowan Dam as an example, the information transfer function between rainfall and deformation is established. The actual shows that this new method is convenient, universal and precise. It also demonstrates its great advantage for the analysis of such complex slope deformation problem that has a lot of influencing factors. The method does not make any hypothesis before putting into consideration.
Theoretic Analysis of Inner Force of Shield Tunnel According to Elastic Hinge Model
Authors: Ding Hai Rong , Rao Jun Yong
Published: June 2011

Elastic hinge model is one kind of reasonable models to analysis shield tunnel. However, no formulas are valid to calculate inner force caused by load of water pressure and elastic reaction. Mechanical equations of two kinds of load are built and inner force formulas are deduced. Results calculated by homogeneous ring model are contrasted with those by elastic hinge model and conclusion is derived. The contrast shows that the results according to elastic hinge model are more reasonable.
Deposit Slope Failure Analysis and Prestressing Loss Study of Anchorage Cable
Authors: Zhang De Sheng , Wu Shi Yong
Published: June 2011

Slope project is often appearing in rock and soil engineering such as water conservancy, mine, highway and railway etc. And deposit slope is a special natural one. For probing into slope failure mechanism and prestressing loss of anchorage cable in deposit body, this paper researches it by numerical simulation. Study result shows: First, three leading influence factors, which are deposit slope lithology and structure, in-situ stress, and groundwater, may induce slope failure; Second, slope failure patterns chiefly includes landslide along the interface between bed rock and deposit, and part circular slippage in shallow deposit body; Last, it appears prestressing positive loss and negative loss of anchorage cable in study area, especially the latter occurs because of the slide interface existing in deposit body, and changing technical parameters of anchorage cable can partly improve prestressing loss.
Cusp Catastrophe Models and Instability Mechanism of Underground Cavern’S Roof
Authors: Jiang Xue Liang , Yang Hui
Published: June 2011

The underground caverns were divided into underground spherical cavity and underground tunnel. From bean-slab theory and energy principle, the catastrophe models of underground spherical cavity and tunnel were built and the necessary and sufficient condition of roof failure was derived. Taken the cavern roof of Wenfu phosphate mine for example, the minimum thickness of roof was derived. The analysis of spherical cavity shows that the roof fails more easily when the roof thickness is smaller, the elastic modulus is smaller, the Poisson's ratio is smaller and the roof span and loads are bigger. The analysis of tunnel roof shows that the stability of tunnel roof is closely related to the vertical load and the horizontal load. In order to guarantee the roof stability, the observation of load acted on roof should be reinforced and some control measures should be taken according to the necessary and sufficient condition of roof failure.
Determined Methods of Dynamic Stability Critical Length of the Foundation Pile
Authors: Sun Qiang , Lin Qiu Yi , Wu Jing Wei
Published: June 2011

Based on the principle of elastic stability, this paper deduces the calculating formulas for dynamic stability critical length of foundation piles when lateral syntony occurs under the axial dynamic loads, and analyzes the effects on dynamic stability critical length of foundation piles from the aspects of parameters such as section dimensions of piles, horizontal resistance forces of foundation soil and excitation frequency etc. Study shows that different soil stratum has the bigger effects on the critical length of piles, while damping coefficient smaller. It also puts forward some related measures for reducing vibration of foundation piles, and can provide reference values to the practical engineering.
Study on Micro-Structure of Loess under one-Dimensional Consolidation
Authors: Gao Ling Xia , Luan Mao Tian , Yang Qing
Published: June 2011

The SEM images were obtained from three different sections of the specimens which suffered to one-dimensional consolidation under 5 grade pressures. Basic micro-structure parameters were obtained from these SEM images and their relations with various consolidation pressures were studied. The result indicated that the particle area ratio increase with the increasing of consolidation pressure. Synthesis parameters were studied using principal component analysis. The result showed that the first principle component linearly increased with the increasing of consolidation pressure. When established soil mechanics relation, the Synthesis parameters of micro-structure can be used. That can reflect the integrated character of micro-structure of loess.
Study on the Slope Stability Based on Catastrophe Theory
Authors: He Jun Zheng , He Ke Qiang , Yan Yong Shan , Hao Wei
Published: June 2011

Based on the Drucker-Prager yield criterion which matches with the Mohr-Coulomb yield criterion under the plane strain condition, this paper sets up a cusp catastrophe model of maximum horizontal and vertical displacements to strength reduction factor by using the cusp catastrophe theory. And the catastrophe criterion of slope failure is quantified to the control variable (u) and discriminant (△) which are evaluated by comparing with zero. Taking the above study as the foundation, the cusp catastrophe model is applied to solve one of the standard test ACADS examples. On the two criterions for slope failure of horizontal and vertical displacements catastrophe model, the safety factor of the slope is 0.988 which is consistent with those by ACAS. It shows that the cusp catastrophe model in slope failure analysis is feasible and practical.
Research on the Interaction of Tunnel Surrounding Rock Masses and Supporting Structure
Authors: Fan Jin , Liu Qin Qin , Zhang Yang Song
Published: June 2011

To reveal the mechanical property on the interface between the surrounding rock and the supporting structure, inducting the definition of the interface, based on ABAQUS software, two finite element models were established to compare and analysis the interaction through the aspects of stress, deformation and plastic region of surrounding rocks and the resistance of supporting structure. At last, compare the simulative and the metrical results. The result shows that the ideal full-constraint between the surrounding rock and the supporting structure isn’t possibility. It becomes more reasonable to define an interface during the numerical analysis and design calculations, the selection of the constitutive relation of the interface is directly related to the accuracy of the numerical calculation results.
Experimental Study of Silty Clay's Deformation Fields Based on the Principles of Oedometer Tests
Authors: Liu Wen Bai , Cao Liang , Li Xiao Zhao , Li Ye Xun , Wang Peng
Published: June 2011

Based on the principles of conventional oedometer tests, half mold consolidation apparatus which attained Chinese Patent Certificate of New and Practical Device was designed for non-saturated soil's micro-observation with axial drainage conditions. By half mold consolidation tests, we could get similar stress-strain curves at different water content, which could illustrate the feasibility of the new apparatus. Besides, on the application of DPDM (the digital photogrammetry for deformation measurement) technology, the deformation fields of the silty clay were analyzed under monotonic increasing load, which could obviously show the macro mechanics properties by digital image analysis. According to the distribution of deformation fields, the analyzing area could be divided into three parts from top to bottom sequence: soil in top area subsided with upper porous-stone in balance; the deformation in the central area was changing the most whereas there had always been inapparent changes near down porous-stone. Such study could put forward a new conception for the development of conventional soil tests, which could be helpful to further establish the theoretical constitutive model for silty clay.
Stability Analysis of High Rock Slope at a Open Pit Mine and its Control Measure
Authors: Li Ke Gang , Hou Ke Peng , Yang Ze
Published: June 2011

A lot of slopes will be formed in the process of engineering construction, and how to ensure the slope stability has become a very key field and common concern to geotechnical engineering. Taking the slope of a open pit mine as an example, the slope stability at original state is analyzed firstly, and then, the optimal control measure and the slope stability trend during the treatment are also researched. The results show that at the original state, the slope stability is worse, and a large contiguous plastic regions will occure on the slope. After comparing to some methods, local unloading is identified as the optimal control measure. When unloading works are carried out and finished, the slope will be in a steady state, and the slope safety factor will up to 1.46, it satisfy engineering requirement.
Experimental Study on Flexural Toughness of Steel-Polypropylene Fiber Reinforced Concrete
Authors: Ren Zhi Gang , Hu Peng Tao , Zou You
Published: June 2011

The Steel-polypropylene fiber reinforced concrete take full advantage of steel fiber’s macro-scale crack resistance function on the concrete as well as the polypropylene fiber’s micro-scale crack resistance and toughening effect on the concrete matrix. In this paper, the three kinds of concrete specimens including plain high-strength concrete, steel fiber reinforced concrete and steel-polypropylene fiber concrete are selected for a flexural toughness experimental study, their compressive strength and deformation performance are analyzed, and their toughness index are investigated with ASTM-C1018 and PCS(post-crack strength) method. The results show that steel-polypropylene fiber reinforced concrete has better strength and toughness property as well as deformation performance.
Google Earth as a Tool in Terrain Survey of Debris Flow Watershed
Authors: Xu Lin Rong , Su Zhi Man , Ugai Keizo , Cai Fei , Yang Qing Qing
Published: June 2011

Google Earth (GE) has powerful functions to view landscapes in fairly realistic three dimensions (3D) as well provides digital elevation model (DEM) data. A GE-based method in terrain surveying of debris flow watershed was elaborated, consisting of DEM data and related functions in GE. The method was employed in 9 debris flow watersheds along Ya-lu Expressway, Sichuan, China. It was proved to be able to get a similar result with traditional map method, especially in the debris flow watershed with a large area, such as more than 12 km2. Moreover, the GE method is a time-saving method and can extract some of the terrain parameters directly, which is obviously better than traditional method.
Fuzzy Comprehensive Evaluation Method in Rock Classification of In-Situ Expansion Tunnel
Authors: Peng Nian , Gan Lin Kun
Published: June 2011

With the increase of traffic volume, the enlarging tunnel span and the decreasing of surrounding rock integrity, the level of surrounding rock will be lower. This article proposed the calculating method of relative integrity index based on the concept of relative integrity of surrounding rock and established the Fuzzy Comprehensive Evaluation Method for rock classification by analyzing the impact of tunnel span enlargement upon rock stability. It also specified the determination factors, discussed the selection of weight indexes and proposed methods of establishing the qualitative and quantitative subordinate degrees. Based on practices of the expressways of Fuzhou, Xiamen and Zhangzhou, this article made fuzzy comprehensive evaluation of rock classification and fully analyzed the results of the evaluation. Results showed that with the enlargement of tunnel span, levels of surrounding rock would lower accordingly, and that the worse surrounding rock was, the more it would lower.
Numerical Analysis on Interaction of Superstructure-Piled Raft Foundation-Foundation Soil
Authors: Li Yong Le , Wang Jiang Feng , Wang Qian , Yang Kun
Published: June 2011

based on the finite element method of superstructure-the pile raft foundation-the foundation soil action and interaction are studied. Research shows that the common function is considered, fundamental overall settlement and differential settlement with the increase of floor of a nonlinear trend. The influence of superstructure form is bigger for raft stress, the upper structure existing in secondary stress, and the bending moment and axial force than conventional design method slants big; With the increase of the floors, pile load sharing ratio is reduced gradually,but soil load sharing ratio is increased. Along with the increase of the upper structure stiffness, the load focused on corner and side pile; Increasing thickness of raft, can reduce the certain differential settlement and foundation average settlement, thus reducing the upper structure of secondary stress and improving of foundation soil load sharing ratio, at the same time the distribution of counterforce on the pile head is more uneven under raft, thus requiring more uneven from raft stress, considering the piles under raft and the stress of soils to comprehensive determines a reasonable raft thickness, which makes the design safety economy. As the foundation soil modulus of deformation of foundation soil improvement, sharing the upper loads increases, counterforce on the pile head incline to average, raft maximum bending moment decrease gradually.
On-Site In-Suit Test Research of Horizontal Bearing Capacity on Inclined Steel Pipe Piles
Authors: Zhu Zhao Qing , Gong Wei Ming
Published: June 2011

The in-situ tests of horizontal bearing capacity on inclined steel pipe piles were conducted in the sea near Shanghai. Based on the field experiment with the lateral unidirectional and single cycle loading test method, this document presents the horizontal displacement and bearing capacity on the inclined steel pipe piles with negative and positive inclination angles. And the horizontal bearing capacity of the steel pipe pile with positive inclination angle is larger than the one with negative inclination angle. And the tests results can be provided for similar engineering reference.
Study on Grain Breakage in Triaxial Test of Rockfill Material
Authors: Pan Jia Jun , Rao Xi Bao , Zuo Yong Zhen
Published: June 2011

Large-scale triaxial test has been conducted on various rockfill materials in an attempt to study the degrees of grain breakage. The result has shown that, the grain breakage occurred during sample preparation can not be neglected, and to maintain the initial gradation design prior to consolidation, the gradation design shall be adjusted downwards to a certain extent accordingly before sample preparation. The breakage of large-sized grains mainly occurs on the surface, and the grain breakage and confining pressure has shown linear relations after triaxial test.
Numerical Simulation of the Forming and Failure Process of Soil Arching Between Anti-slide Piles
Authors: Sun Jin Shan , Chen Ming , Jiang Qing Hui
Published: June 2011

The mechanism of soil arching effect is important for anti-slide pile design. With the 2D particle flow method (PFC2D), the forming and failure process of the soil arching between anti-slide piles are simulated. The results show that the forming mechanism of soil arching mainly depended on stress transit process of micro soil granule. In the anti-slide pile numerical models (PFC2D), the contact stress transit trace lines present the tree crown shape, which centered about the anti-slide pile. The load from far field is transited to the front and side part of piles through the compress soil. When the soil between anti-slide piles collapses, the failure surface presented the arching shape. The cross-section and spacing of anti-slide piles affect the soil arching shape strongly. With the same pile spacing and soil parameters, the ultimate bearing capacity of rectangular cross-section pile is larger than the circle cross-section pile.
Concealed Karst Cavity’s Treatment in Kunming New Airport
Authors: Tan Feng Yi , Ren Jia Li , Jiang Zhi Quan , Hu Sheng Gang , Gong Quan
Published: June 2011

The different treatments, such as the sleeve valve grouting method and the high pressure grouting with sleeve valve grouting method is adopted according to the concealed cavity in Kunming new airport. Test results show that: (1) after treatment, the equivalent shearing wave velocity of whole soil layer of NO.GR1 is higher and the physical property of foundation is improved than before, meanwhile although a great deal of concrete are used in the engineering, there is only a little cement paste found between 2.2m~18.0m during the core-drilling test, which means the test is not successful. (2) The shearing velocity of improved layer is higher in NO.GR2, the shearing velocity of other layers is lower than before treatment, which means the high pressure grouting with sleeve valve grouting method is feasible method to treat the concealed karst cavity.
Polypropylene Fiber Reinforced Concrete for Airfield Pavements:Modeling of Stress-Strain Curve Under Compression
Authors: Merhej Tammam , Feng De Cheng
Published: June 2011

An analytical model for compressive stress-strain curve of polypropylene fiber reinforced concrete (PPFRC) was proposed. The polypropylene fiber used was 60-mm long twisted fiber with aspect ratio of 120. The fiber was added in three volume fractions 0.2%, 0.4% and 0.6%. Tow concrete mixtures with varying water-cement ratio were used. The accuracy of the proposed model was evaluated by comparing the area under stress-strain curves for experimental and analytical model. The results showed good agreement between the experimental and analytical curves. In addition; empirical equations were proposed to quantify the effect of polypropylene fiber on compressive strength, strain at peak stress, and toughness of concrete in terms of fiber volume fraction.
Testing Study on the Permeability Characteristics of Unsaturated Soils
Authors: Cui Ying , Miao Lin Chang
Published: June 2011

The coefficient of permeability of unsaturated soil is an important parameter which is used to analyze moisture migration. For complexity and diversity of unsaturated soil behaviors, it is difficult to perform test of unsaturated soil because of many factors. With GDS system, the permeability characteristics of unsaturated soil are tested and studied in this paper which makes it possible to directly measure the coefficient of permeability at various combinations of net normal stresses and matric suction values. The research shows the coefficient of permeability of unsaturated soil is the function of suction and cell pressure.
Mechanical Behavior of Segmented Lining Structure of Tunnel under Acting Ground Fractures in Xi’an Zone
Authors: Shao Sheng Jun , She Fang Tao , Fang Juan
Published: June 2011

Xi’an ground fracture, caused by the extraction of groundwater and the movement of fault under soil strata, is a geo-hazard. The movement of ground fracture originates the uneven settlement of upward block and downward block. In Xi’an ground fracture region, the segmented lining structure was adopted in subway tunnel to pass through the ground fracture, so as to adapt for the uneven settlement. Three-dimensional elastic-plastic finite difference method was applied to simulate the initial lining structure, second segmented lining structure, surrounding soils and ground fracture. The horizontal and vertical displacement of segmented lining structure, surrounding soils pressure and internal force of segmented lining structure in subway tunnel were analyzed by the calculation results. The knowledge on mechanical behavior of segmented lining structure passing through an active ground fracture and surrounding soils was shown as following. The relative vertical displacement between segmented lining structure sects beside the ground fracture increases remarkably with the movement of ground fracture, and the segmented lining structure located in upward displaceent block near ground fracture originates notable rotary. Tension or compression deformation occured in the deformation joint between adjacent segmented lining structures near the ground fracture.There was a significant change in the contact pressure of the first sect of lining structure in the upward displace block. Under the same uniform settlement at the bottom of upward diaplacement block, the relativly vertical displacemtn on the surfaceof ground fracture strata without tunnel equals 50cm, but the relativly vertical displacement between adjacent segmented lining structure at ground fracture is 18.2cm on the design level of arch top of lining strcutre. the maximum tensile stress of segmented lining structure is 2.02MPa, the maximum compressive stress of segmented lining is 3.49MPa. In conclusion, segmented lining structure can adapts to the uneven settlement caused by the movement of ground fracture. Though maximum tensile and compressive stress of sengmented lining structure passing through the active ground fracture is bigger than the general lining structure located in soils strata without the ground fracture, the segmented lining structure constructed by the steel fibre concrete can bear with the maximum tensile stress.
Study on the Engineering Properties of the Cement Stabilized Full Weathering Granite Soil
Authors: Li Zhi Yong , Wei Bin , Hu Yue Hua , Dong Cheng , Zheng Zu En
Published: June 2011

When the full weathered granite is regarded as highway subgrade filling material, it is restricted to the application because of its high mica content, lax construction, bad water stability, and small cohesion. For these reasons, the full weathered granite soil should be improved before using for subgrade filling, and the cement was taken as an improver in this paper. The dynamic and static characteristics of cement stabilized soils were studied systemically. It was shown from the experiment results that there is a decrease in the content of mica and clay, and an increase of quattz of the cement stabilized soils. The unconfined strength of the cement stabilized full weathered granite increases linearly with the increase in cement content. There is power function relationship between water stability coefficient and the cement content. The unconfined strength and water stability coefficient increases with degree of compaction and with age as well, while the increasing rate decrease with age. The dynamic strength of the cement stabilized full weathered granite increased with the increase of the degree of compaction and the cement content. However, as the water content increases, the dynamic strength increased first and then decreases, there is an optimum moisture content. A linear model was proposed to describe the dynamic modulus and dynamic relationship between the stress amplitude. The results can provide an important reference for engineering practice.
The Stability Analysis of Slope of Shegang Protecting Dyke
Authors: Yao Hui Qin
Published: June 2011

Appraisal of dam slope safety is essential for security and stability of the dyke that has been constructed for many years. According to the requirements of the appraisal of dam safety, the stability analysis of slope of Shegang dyke has been carried out by using Sweden circular-arc method, Bishop method, Engineer Corps method and Lowe method four methods under many kinds of working conditions and some conditions when the saturation line raising. Combined with the design code form embankment dam, the calculation results can be analyzed. The analysis can show that the security indexes of anti-slide under four kinds of working conditions and some conditions when the saturation line raising meet the requirements of the design code. This can provide basis for the reinforcement design of the dam, which also has a certain directive significance for the safe operation and observation of the dam in the future.
Study on Fracture Evolution of Complicated Cavity Group-Surrounding Rock System Structure Effect
Authors: Chen Qing Fa , Liu Yun Xiang
Published: June 2011

It is very important to study the structure effect of cavity group for controlling disasters in engineering and coordinating mining of the hidden danger resources. The cavity group structure was defined and classified. The structure effect of the twelve kinds of working conditions were simulated by using Rock Failure Process Analysis code (RFPA2D). the results show as follows: 1) The stability order of the typical cavity group structures was the second one, the third one and the first one; 2) The phenomena of small cavities interpenetrating and forming a big cavity often appeared in the kinds of the first and the third structure in the process of system catastrophe, but not in second structure; 3) The system appeared catastrophe easily with the number rising of the first structure, the third structure taking the second place and the second structure taking the last place; 4)The risk of the system consisting of two groups of the third structures was greater than one of the system consisting of one group of the first structure; 5) he more the number of the poor stability structures was in the up of system, the more poor stability the system had; 6) The same structures were placed in the upper and lower order in system, the lower structure would appear prior into the failure and instability status.
Engineering Application on Steel-Tube Bored Grouting Anti-Sliding Retaining Wall in the Treatment of Landslide
Authors: Zhu Bao Long , Wu Xi Yong
Published: June 2011

Steel-tube bored grouting anti-sliding retaining wall is a kind of technique combined with grouting and micropiles, treated as the retaining wall in mechanics analyzing. It is the significant feature that steel-tube bored grouting anti-sliding retaining wall change the partial sliding mass to anti-sliding mass. Taking the case of landslide located in south K108 of Guangdong segment of Beijing-Zhuhai highway, the landslide is reinforced by steel-tube bored grouting anti-sliding retaining wall and discharged groundwater from sliding mass. The K108 landslide is in the situation of stability by means of displacement analysis on monitoring bores and stability computation. The result of treatment show that the steel-tube bored grouting anti-sliding retaining wall is an effective method on treating landslide.
Calculation of Slope Stability Anchoring Force by Using Inclined Slice Method
Authors: Ge Hai Yu , Tu Jin Song , Wang Jian Guo
Published: June 2011

Generally, the slope stability anchoring force is calculated by using vertical slice methods. A more feasible algebraic expression for the calculation of slope stability anchoring force is presented herein, which is obtained from the force limit equilibrium conditions of inclined slices based on the concept of the inclined slice method. The examples described herein show that the results from the calculation of the anchor force by using this method are similar to those by using conventional methods such as Swedish slice method and simplified Bishop method if the slope stability and safety factor are given. In addition, calculation of the anchoring force is simplified by using this method with accurate results, making it significantly easy for engineers and technicians to familiarize with and apply.
Effects of Sand Particle Size and Gradation on Strength of Reactive Powder Concrete
Authors: Ji Tao , Chen Bao Chun , Zhuang Yi Zhou , Li Feng , Huang Zhi Bin , Liang Yong Ning
Published: June 2011

After modification, Toufar model was used to calculate the packing degrees of sand mixtures with different particle sizes. For four gradations of sands, the weight ratios of different types of sands with different size ranges, which achieve maximum packing degrees, have been obtained using the modified Toufar model. A strength test of reactive powder concretes (RPCs) with the four gradations of sands was reported. The test results show that the strength of RPC is related to both the maximum grain size and the packing degree of sand mixture. The smaller maximum grain size and larger packing degree of sand mixture can achieve the higher strength of RPC.
Carbonation Depth of Recycled Aggregate Concrete Incorporating Fly Ash
Authors: Tian Fang , Hu Wei Xin , Cheng He Ming , Sun Ya Li
Published: June 2011

This paper addresses the efficiency of using recycled concrete as an aggregate by systematically presenting results on the influence of fly ash on recycled aggregate concrete (RAC) properties. The percentage of recycled aggregate replacements of natural aggregate used by weight was 50%. Fly ash (FA) was used as 0, 10, 20, 30, and 40% by weight replacement of cement. The results showed that an increase in the W/B decreased the resistance to carbonation depth. Nevertheless, the use of FA as a substitute for cement decreased the carbonation depth of the recycled aggregate concrete. Being analyzed on the basis of Gray Theory, it can be seen that the biggest influence on the depth of carbonation of the recycled aggregate concrete comes from W/B, then the carbonation age and FA content affects the least.
The Apparent Density, Tensile Properties and Drying Shrinkage of Ultra High Toughness Cementitious Composites
Authors: Cai Xiang Rong , Fu Bai Quan , Xu Shi Lang
Published: June 2011

A new class of high performance fiber reinforced cementitious composites called Ultra High Toughness Cementitious Composites (UHTCC) is developed in the last few years. It is a pseudo strain hardening material with maximum tensile strain capacity more than 3%, yet the fiber volume fraction no more than 2%. The multiple cracking patterns accompanying pseudo strain hardening behavior are obtained which implies high ductility, energy absorption capacity, and toughness. A remarkable characteristic distinguish it from conventional high performance fiber reinforced concrete is the maximum crack width of multiple cracks which is about 60µm under ultimate tensile load. Such micro-cracks are often small enough to prevent the intrusion of aggressive agents. From a durability point of view this composite can be considered as an effectively uncracked material. The performances of this new material, including the apparent density, the uniaxial tensile property, and the drying shrinkage performance, are experimental studied in this paper.
Mechanical Properties and Failure Criteria of Concrete under Biaxial Tension and Compression
Authors: Yao Jia Wei , Song Yu Pu , Qin Li Kun , Gao Ling Xia
Published: June 2011

Utilizing the large static-dynamic triaxial test system, 7 proportional loading biaxial tensile and compressive tests of concrete were conducted. The proportional loading paths are 0 (uniaxial compression), -0.05, -0.1, -0.15, -0.2, -0.25 and ∞ (uniaxial tension). Compressive and tensile strength were measured as well as the strains at two loading directions. Considering the ratio to tension and compression, failure criteria of ordinary concrete under biaxial tension and compression was established, which has a good agreement with test value.