bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Regionalization of Project Management Based on the Construction Enterprise
Authors: Zhang Lu
Published: November 2013

This paper studies the regionalization of project management on the construction enterprise, compares four companies of industry with the different mode about regionalization of project management. It is pointed that the construction enterprises exist the main problems, including the definitude of management functions. The results indicate reasonably that the total five countermeasures and suggestions on the regionalization of project management about the construction enterprise, such as clear market division and the responsible units.
The Impact Analysis of Bearing Capacity of Steel Reaction Column on Eccentric Problems in Integrally Lifting of Yuzhen Palace
Authors: Bian Zhi Hui , Zhao Shi Yong , Qiang Wan Ming , Fu Su Juan
Published: November 2013

Based on Yuzhen palace integral lifting engineering of Wudang Mountain, the writer uses the finite element analysis to simulate bearing capacity of section steel column in the bidirectional eccentricity. The finite element data is slightly larger than the test, but the date keep in same value in the main. During the process of the integral lifting, the bearing capacity of steel column will sharply decrease with the bidirectional eccentricity increasing and produce torsion; it has a lethal effect on the whole upper structure. And the writer analyzes the problem that how to avoid the eccentric problems from two aspects of the design and construction, and the writer proposes some relevant suggestions and opinions. It can provide reference that how to design and construction in a similar project.
Topic Selection and Quality Control of Undergraduate Graduation Design for Building Environment and Equipment Engineering
Authors: Pei Gui Hong , Zhang Lin Zhi , Liu Li Li
Published: November 2013

Topic selection is the first step for undergraduate graduation design. It which formulates the orientation and extent of graduation design is the precondition of high quality graduation design. In order to improve the effect of undergraduate graduation design and enable student's practice ability, innovation ability to obtain the comprehensive exercise. The experiments were conducted from 2009 to 2011. The experimental group undergraduates were in building environment and services engineering major of Southwest Petroleum University. The research testifies selecting topic that combining the students future jobs and diversified is an important part of perfect graduation design and favorable factor to improving the study enthusiasm and initiative of students.
Benchmarking the Patent Portfolio: A Study of the Italian Wind Energy Manufacturing Industry
Authors: lo Storto Corrado
Published: November 2013

A benchmarking study on innovation in the Italian wind energy manufacturing industry is presented. The study calculates a set of patent portfolio specialization indexes - RSI, PSI, and OPSI - to map companies and compare them to one leading international company considered as a benchmark in the industry, the Vestas Wind System A/S.
Online Reviews' Trustworthiness Analysis Based on Power-Law Distribution
Authors: Yao Qi Chang , Feng Xin , Sun Qi Ming
Published: November 2013

In online shopping, studies on consumer reviews are mostly based on the Attitude Change Model. Illustrated from the perspective of perceived trustworthiness, however, it is not easy to measure and characterize the subjective perception of consumers. Starting from the inherent property of online reviews and based on the real data of 360buy which is the domestic large-scale B2C commerce website in China, this paper focuses on the interval distribution of consumer reviews and the data for statistical analysis. Research finds that the distribution of reviews interval can be depicted by the power-law function and there is a monotonically increasing relationship between power-exponent and the customers concerns with the commodity, the higher exponent, the attention consumer get. The findings give an objective basis to judge the credibility of online reviews. The relationship between power-exponent and the consumer attention has demonstrated the vital role of consumer attention in online shopping, and then the double parity between attention and exponent will effectively regulate the e-commerce market environment and promote its healthy operation. Tech Publications.
Simulation of Formation Process of Conductive Organic Polymeric Materials for Gas Sensor Systems
Authors: Falchary Marta M. , Plugotarenko Nina K. , Petrov Victor V.
Published: November 2013

In this work was carried out modeling of organic polymer materials for gas sensors on the example of a homogeneous polypyrrole and polyacrylonitrile with metal silver. The implementation was carried out by modeling the Wang-Landau and entropic Monte Carlo simulation based on a model with a fixed valence angle. To simulate the polymerization process using an algorithm based on the principles of irreversible aggregation of Eden. Methods of quantum chemistry has been investigated and the possibility of obtaining property silver-PAN and polypyrrole
Chinese Date Grading Based on Computer Vision
Authors: Wang Fu Juan
Published: November 2013

In order to implement the accuracy and robust classification of Chinese dates according to size and color based on computer vision techniques on line, the method of classification according to size and color for Chinese date was studied. Taking the black rollers as background, the Chinese date images were pre-segmented by double thresholds in RGB color space. Through morphological operation, contour trace and region fill, the whole Chinese date target was obtained. the maximum diameter value was used to be the character value for size classification. The difference of saturation and hue of pericarp area in HIS color space was the color grading criteria. The results indicated that the accuracy of diameter measurement is 1.92mm, Experiment results proved the methods is effective to classify Chinese date by size and shape.
Mode Choice Behavior Analysis by Using a Semi-Compensatory Discrete Choice Model
Authors: Wei Chong , Xiao Lin , Shao Chun Fu
Published: November 2013

In this study we proposed a semi-compensatory model to analyze the mode choice behavior. The proposed model formulated the conjunctive rule through a straightforward way. The proposed model can take into account the probability distribution of the threshold involved by the conjunctive rule. To estimate the parameters of the proposed model, we derived the posterior distribution of the parameters by using the Bayes theorem and developed a blacked Metropolis-Hastings algorithm to carry out the estimation based on the posterior distribution. We also employed the data augmentation technology to simplify the estimation procedure. The proposed model was validated by using a SP survey dataset. We compared the performance of the proposed model to that of the logit model.
Dynamic Response Analysis of Single-Layer Spherical Reticulated Shell under Horizontal Impact Load
Authors: Wang Xiu Li , Ma Xiao Tong
Published: November 2013

Compared to the vertical impact, horizontal impact load is closer to real life. For example, external objector collision, debris flow hazards, terrorist attacks, etc. In this paper, a K6 single-layer reticulated shell structure model was established with ANSYS/LS-DYNA, and the influence of material strain rate was considered. Firstly, the basic theory of finite element method and the model parameters which were used in the analysis were introduced. Then changed the mass and velocity of impact body to analyze the dynamic response of the structure. Analysis results show that failure mode of the structure can be divided into five kinds under horizontal impact load; Horizontal deformation, the force of the main bar and impact force continued to increase as the increased of mass and velocity of impact matter; When the mass and the velocity increased to a certain value, the three of all were no longer change.
Safety Risk Analysis of Box-Culvert Jacking Construction by Using Fuzzy Fault Tree Method Based on WBS-RBS
Authors: Xu Ke , Li Hui Min , Lu Sha Sha
Published: November 2013

The box-culvert jacking of highway constructions crossing the existing railway is construction difficult and technically complex. If there are safe accidents, it will bring great loss. According to this situation, a new method based on WBS-RBS is presented in this paper to comprehensively identify the risk factors of safety accident with the fault tree, and then the fuzzy probability of basic events are described to triangle fuzzy numbers. Furthermore the happening fuzzy probability of the top event can be calculated. The proposed method provides a scientific method for the safety risk analysis of similar engineering.
Influence of Different Curing Conditions on Shrinkage of Concrete
Authors: Chen Jing , Li Xiao Huan , Wang Feng Ling , Xu Fen Lian
Published: November 2013

Experiments for studying the shrinkage of concrete cured under three conditions were designed, and the impact of different curing conditions on the 28-day shrinkage and 180-day long-term shrinkage of concrete was researched. The results are as follows: There are significant influences of different curing conditions on shrinkage of concrete; The variation rule of 28-day shrinkage of concrete is consistent with that of 180-day shrinkage of concrete, the shrinkage of the concrete cured under standard condition is less than that cured under indoor natural condition, and larger than that cured under totally enclosed condition; In addition to mixing polypropylene fiber and expansive agents to optimize the proportions of concrete mix in the manufacturing process of concrete, adequate curing, after placing, is quite necessary for effectively controlling the shrinkage development of concrete, reducing the risk of concrete cracking and improving the quality of concrete structure.
Foundation Slab in Interaction with Subsoil
Authors: Čajka Radim , Burkovič Kamil , Buchta Vojtech
Published: November 2013

In the paper the experiment results of deformation in foundation slab segment in interaction with subsoil are presented. Pilot measurement is carried out on original subsoil with characteristics which were tested in cooperation with geotechnics specialists. Concrete precast slab with square dimensions 500 mm and with thickness 48 mm made of plain concrete is exposed to vertical load. The tests results are compared with bending moments and deformations analysed according to subsoil models given in Eurocodes using FEM analysis.
Study of Visual Simulation for Decomposition Assembly Tower by Derrick Supported by Inner Suspension and Inner Backstay
Authors: Wang Yan Hai , Hu Ming
Published: November 2013

Derrick supported by inner suspension and inner backstay group tower is a construction technique commonly used in the construction of overhead transmission lines, the locale sketch and construction technique are complex, and not conducive to the analysis of the key construction and improve the level of decision-making. Through analysis assembly tower construction technology of derrick supported by inner suspension and inner backstay, using engineering visualization design software 3ds Max, the establishment of a three-dimensional model of the tower, the pole, tackle. According to the construction process for dynamic visual simulation, accurate image show the complexity of the construction process. Visual simulation provides an intuitive basis for the construction organization design and construction scheme optimization; enhance the level of construction management.
Analysis of Internal Force and Deformation for Pit Retaining Structure by Considering the Interaction of Pile Stiffness
Authors: Li Ming , Liang Ren Wang
Published: November 2013

In this paper, taking one deep excavation engineering as an example, modeling by the FLAC3D finite difference software, combining with the Lizheng deep excavation supporting design software, taking the equivalent stiffness of combination pile as 2.300-4.789(10-2m3), and analyzing the pile body bending moment, anchor axial force and pit deformation by considering interaction of pile stiffness. In addition, in this paper the influence factors of pile stiffness has been discussed, and provides a reference for the engineering design.
Experimental Study on Concrete Columns with Various Sizes Confined by BFRP and Hybrid FRP under Axial Compression
Authors: Long Yue Ling , Zhu Jiang
Published: November 2013

Fourteen concrete columns with various sizes confined by BFRP and hybrid FRP and six plain concrete columns as the control specimens were axially loaded to failure in order to investigate both confining effects and size effects in concrete columns confined by BFRP and hybrid FRP. Experimental results show that BFRP and hybrid FRP can increase considerably both the capacity and ductility of the concrete specimens. Furthermore, the peak stress of the unconfined concrete decreases with the size of the specimens increasing. Similarly, the peak stress of BFRP confined concrete decreases with the size of the specimens increasing when the lateral confining stresses are the same. Hence, both confining effect and size effects should be considered carefully in the stress-strain model of concrete confined by BFRP. In addition, both strength and ductility of concrete confined by hybrid FRP in case of CFRP as inner layers and BFRP as outward layers are better than those in case of BFRP as inner layers and CFRP as outward layers.
Influence of Metakaolin on Strength and Microstructure of Steam-Cured High-Strength Concrete
Authors: Zeng Jun Jie , Fan Zhi Hong , Chen Long
Published: November 2013

The influence of metakaolin (MK) on strength and microstructure of steam-cured high-strength concrete has been investigated using compressive strength test, XRD, MIP and SEM. Three MK replacement levels were considered in the study: 5%, 10% and 15% by weight of cement. A mix double blended with 10% MK and 10% slag was prepared too. Test results have indicated that MK can increase the compressive strength of steam-cured concrete, especially at early age. Compressive strength up to 90MPa at 1 and 28 days is obtained with the incorporation of 10% MK and 10% slag. When the replacement level of MK is higher than 10%, the enhancement of strength becomes less significant. Content of Ca (OH)2 crystals is decreased while content of hydrates with Al is increased due to the pozzolanic reactivity of MK. Concrete pore structure is significantly refined and a denser hydrates structure is obtained due to the pozzolanic reaction and filler effect of MK. Meanwhile, combination of aggregate and paste is enhanced too. The improvements of strength and microstructure become more obvious when MK and slag are double incorporated.
Experiment on T-Shaped CFT Stub Columns with Binding Bars Subjected to Axial Compression
Authors: Zuo Zhi Liang , Liu Da Xin , Cai Jian , Yang Chun , Chen Qing Jun
Published: November 2013

To improve the mechanical behavior of T-shaped concrete-filled steel tubular (T-CFT) column, the method that setting binding bars along the height of steel tube is proposed. Five T-CFT stub columns with binding bars and another two without binding bars subjected to axial compression were tested. The influences of the spacing and diameter of binding bars on the failure modes, maximum strength, and ductility of T-CFT stub columns are investigated. The experimental results demonstrate that by setting binding bars or decreasing the spacing of binding bars, the buckling modes of the steel plates are changed, the local buckling of the steel plates is postponed, and the confinement effects on the core concrete can be improved significantly. By setting binding bars, the bearing capacity and ductility of the columns are enhanced by 1.17 and 3.38 times at most, respectively. By increasing the diameter of binding bars, the ductility of the columns is improved, but the bearing capacity and buckling strength cannot be improved when the diameter is large enough.
Sensitivity Analysis of Profiled Steel Sheet in Profiled Steel Sheet Dry Board System (PSSDB)
Authors: Vafa Maryam , Wan Badaruzzaman Wan Hamidon , Osman Siti Aminah
Published: November 2013

This study examines the effect of different variables of Profiled Steel Sheet (PSS) on various aspects of Profiled Steel Sheet Dry Board (PSSDB) system. PSS is an important component of PSSDB. The sensitivity of PSS variables at the 70% to 140% of Peva45 dimensions, the profiled steel sheet at local markets, to the cross-sectional area of PSS, the ultimate load carrying capacity, and the flexural stiffness of the PSSDB system is analysed. Results are shown in charts, and the most effective variables are determined. The dominant variables are found by saving computational time in the optimization of PSS in the PSSDB system.
Three-Dimensional Finite Simulation Analysis of Forepoling Bolt Pre-Supporting at Tunnel Entrance
Authors: Duan Yong , Wang Bao Qun , Zhang Jian Guo
Published: November 2013

In order to ensure construction safety of tunnel entrance under complicated geological condition, surrounding rock should be pre-supported. Forepoling bolt pre-supporting has been adopted in the paper and three-dimensional finite numerical simulation has been used to analyze its effect. Calculation results show that vault displacement is less than 50mm, displacement of side wall is no more than 45mm and the final safety factor fo primary support is about 5.0. So forepoling bolt pre-supporting could ensure safety of supporting structure at tunnel entrance. Meanwhile, maximum axial force of forepoling bolt is higher than 13kN appreciably. And axial force along the bolt shows step-like. Maximum is located in middle of forepoling bolt and it derecases to two ends gradually. Alao axial force of forepoling bolt in vault is larger than side wall. These conclusions coulde provide theoretical basis for safety construction of tunnel entrance.
Static Mechanical Performance of Mega Steel Frame-Prestressed Composite Bracing Structure
Authors: Shen Chao Ming , Guo Jun Yuan
Published: November 2013

Mega steel frame-prestressed composite bracing structure is a new kind of mega structure with a rigid-flexible composite bracing system composed of rigid Λ-shape steel brace and inverted Λ-shape flexible cable set up in the mega steel frame. By establishing the three-dimensional finite element model and considering the material and geometric nonlinearity, this paper analyzed the structural performance under whole process of static loading. The results indicate that the lateral deformation is mainly determined by horizontal load and the corresponding lateral deformation curve is bending type on the whole, whereas the deflection of mega beam is mainly governed by vertical load and pretension of cables.
The Cast-in-Place Soldier Pile Model and its Construction Techniques
Authors: Zhang Ze Wei
Published: November 2013

The building operations of cast-in-place structure mostly need to have a certain shape of cast-in-place soldier piles. The cast-in-site soldier pile model proposed in this study includes a baseboard, stepped holes set in the central part of the baseboard, and a pile body set on the stepped surface of stepped holes. The pile body can be installed at the location of stepped hole on the baseboard during the construction process, and then solidification and compaction operations shall be taken on the cement paste inside the pile body through the pre-set vibrating hole. These results can increase overall support strength of the civil construction, and also facilitate the overall installation and transportation of this device and reduce the production cost by using the split-type baseboard and pile body.
Dynamic Analysis of Power Transmission Tower Collapse with Wind Load
Authors: Wang Liang , Qu Wei Lian , Li Yan Fei , Wang Yi Fei
Published: November 2013

Transmission tower collapses in adverse weather conditions now and than,which always accompanied thunderstorm.The simulation of transmission collapse under downburst wind load is studied. The tower is modeled as an assembly of beamcolumn elements,fournode isoparametric curved element,and prestressed pole unit simulation insulator,using bilinear restoring force model to formulate the material nonlinear.Simulated downburst wind load time history samples,apply it as external load to the established transmission tower model.Analysis of transmission tower know that transmission towers destroyed in the lower part of the body of the Tower, compressive failure modes in the beam , causing transmission tower's final collapse.
Ultimate Load-Carrying Capacity of Pipe-Plate Vierendeel Truss Joints
Authors: Luo Jie , Xiao Jian Chun , Lu Zhe , Wei Xiao Xiao , Li Hong Xi , Li Shu Lian
Published: November 2013

To study the ultimate load-carrying capacity of pipe-plate Vierendeel truss joints, the analyses of joint failure modes and parameter effects were undertaken using nonlinear finite element method and uniform design approach. The plate instability was included in the failure modes. Factors such as the pipe diameter, the pipe thickness, the plate width, the plate height, and the plate thickness were considered in the joint models. Three kind of loading conditions on the plate, the axial force, the moment, the composed loading of axial force and moment were analyzed. The relationships between the joint failure modes and the factors are achieved. The joint ultimate load-bearing capacity formulas are proposed by regression analysis. The effects of factors on the joint strength are illustrated.
Experimental Study on the Ductility of SIFCON Blocks
Authors: Liu Kang
Published: November 2013

This paper investigates the ductility of SIFCON blocks with various structural measures adopted to further increase their ductility. Ten SIFCON blocks with various designs were tested using a compression machine to investigate their ductility. The variables examined included fiber alignment, confinement, perforation, and longitudinal bars. Results of the tests indicated that SIFCON blocks with confinement in the form of stirrups and additional perforation can produce better ductility than others.
Influence of Concrete-Filling Inner Steel Tube on Compressive Behavior of Double-Skin Tubular Columns
Authors: Louk Fanggi Butje Alfonsius , Ozbakkaloglu Togay
Published: November 2013

This paper reports on a part of an ongoing experimental program at the University of Adelaide on the behavior of fiber reinforced polymer (FRP)-concrete-steel double-skin tubular columns (DSTCs). Influence of concrete-filling inner steel tube on the compressive behavior of FRP-concrete-steel DSTCs was investigated experimentally through the test of 8 normal-and high-strength concrete DSTCs. The results of the experimental study indicate that concrete-filling inner steel tubes of DSTCs results in a slightly increase in the compressive strength and decrease in the ultimate strain of concrete in DSTCs, compared to companion DSTCs with hollow inner steel tubes. The results also indicate that concrete in both types of DSTCs is confined effectively by FRP and steel tubes.
Analysis on the Analogue Slab Methods for Hollow Floor
Authors: Huang Chuan Teng , Wang Zhi Jun , Zhang Yu Jiang
Published: November 2013

This paper presents the results of numerical analysis of hollow floor supported by the column under vertical load and horizontal load. The validity of three different analogue methods were examined and compared. The macroscopic elastic constitutive method (MEC) gave satisfactory predictions but involves an elaborate procedure for determining the equivalent elastic material parameters. The equivalent thickness approach (ETA) gave moderately higher values for the section moment than the exact values. An alternative simplified approximate method based on the effective elastic modulus (EEM) is recommended by the specification. Numerical calculation for section moments by the proposed method were on the safe side and close to exact results. The proposed method could also be appropriate for the column supported structure and the horizontal load.
Experimental Study on Seismic Behavior of High Strength Steel Composite K-Type Eccentrically Braced Frames
Authors: Duan Liu Sheng , Su Ming Zhou , Li Hui
Published: November 2013

High strength steel composite K-type eccentrically braced frame is a new structural system, in which the link is made from low yield point steel and the others are made from high strength steel. In order to study the seismic behavior of such a structure, four one-bay one-story 1/2 scaled plane specimens were tested under the monotonic and cyclic load respectively. The failure modes and the main indexes of seismic behavior of specimens with various links length were analyzed. The results show that this new structural form is good at energy dissipation and ductility, and the way of energy absorbing by shear yield is better than by flexure yield. Under cyclic load, the main failure were concentrated at links, while the other parts of the eccentrically braced frame kept in elastic status. This kind of structure is an excellent dual resistance system and easy to rehabilitate after earthquake.
Effect of the Expansion Agent on Early-Age Autogenous Shrinkage Stress of Concrete
Authors: Wang Pan Xiu
Published: November 2013

Early-age autogenous shrinkage is key problem of high performance concrete. It can cause a lot of early-age cracks in concrete structure and further endanger the permeability and durability. Adding expansion agent can control the early-age autogenous shrinkage strain and reduce the risk of early-age cracks. In this paper, the early-age autogenous shrinkage stress of concrete cube is calculated. The results show that, early-age autogenous shrinkage stress is larger than early-age tensile strength of concrete. So some cracks occur on the surface of concrete structure. By adding expansion agent, the early-age autogenous shrinkage strain and stress both decreases.
Round Timber Bolted Joints with Mechanical Reinforcement
Authors: Klajmonová Kristýna , Lokaj Antonín
Published: November 2013

This paper presents the results of static tests of round timber bolted joints with inserted steel plates. All round timber joints static tests in tension were carried out on pressure machine EU 100 in laboratory of the Faculty of Civil Engineering VŠB-TU Ostrava. At first, timber specimens were tested without reinforcement. Based on these results, mechanical reinforcement methods were proposed: using modified washers and boost with screws. These samples were also tested. Rate of improvement in tensile strength was established for used reinforcement method.
Study on Three-Point Bending Numerical Tests of CFRP Reinforced Concrete Beam with Initial Crack
Authors: Li Xing Quan , Sun Xiao Yan , Li Ya Wei
Published: November 2013

Based on extended finite element method (XFEM) of the finite element software platform-ABAQUS, three-point bending numerical simulation of CFRP reinforced concrete beam with initial crack has been made to predict the 3D crack propagation path. The numerical tests present the crack propagation path under ultimate load and crack damage modes of non-CFRP and some different CFRP plies. The results show that the strength of CFRP reinforced concrete beam is obviously improved and the crack which previous penetrate through doesnt penetrate through concrete beam under CFRP reinforce based on multiple optometric numerical simulation results. The results of this paper can also provide some foundations for damage mode, the ultimate load and CFRP overlay design of reinforced concrete beams.
Influencing Factors Analysis on Temperature Field of Reinforced Concrete Columns under Fire
Authors: Cao Jian Long , Long Hai Tao , Luo Wen
Published: November 2013

Using the finite element analysis software ABAQUS, the section temperature field of reinforced concrete columns under fire was analyzed. On this basis, the influence of the section size, the number of heated surface and the time of fire on the surface temperature were analyzed. Calculations indicate that the impact of the section size on temperature field cannot be considered when one surface was heated, three or surrounded by fire-sectional dimensions the influence was time-related. When the cross-sectional size reaches a certain value, the number of exposed surface on the temperature field can be neglected. Sectional temperature increased by time and the temperature rise rate is high at start then slow down close by fire surface, however, the rate is more stable all the time at internal surface.
Analysis of Bearing Capacity of Steel-High Strength Concrete Composite Beams
Authors: Xiao Liang Li , Pan Ming Yang , Han Jian Wei
Published: November 2013

It is very crucial to analyze the flexural bearing capacity of the steel-high strength concrete composite beams, but the combination on the flange of steel beam and their bearing capacity is limited with certain inevitability,in addition, in the negative bending regions of continuous composite beams, with the constant increase of load, the process of the whole structure will cause damages in the negative moment region. In order to avoid this kind of damages, we must use general finite element program ANSYS to analyze thebearing capacity of the steel and high strength concrete composite beams. Besides further studying the influence factors of bearing capacity, and ensuring the safety of our engineering performance can be in favor of the engineering structure.
Rheological Model Identification of Debris Filled with Mud Weak Interlayer
Authors: Xu Xiang Tao , Li Hua , Huang Qiu Xiang
Published: November 2013

Under the shear rheological conditions, debris filled with mud weak interlayer shows viscoelastic rheological laws. On the basis of non-linear regression analysis of rheological parameters, the relationship between shear stress and rheological parameters was researched. The study reveals that, with the increase of shear stress, weak interlayers instantaneous deformation, constant strain rate and the final elastic strain increase, while the delay time has not been found certain regularity. Under the shear rheological conditions, when the stress level is low, the constitutive model of weak interlayer can be described by Burgers model; when the stress level is high, Cvisc model should be used.
Experimental Study of the Relationship between Matric Suction and Strength of Unsaturated Residual Clay in Xiamen under Different Drying-Wetting Cycle Paths
Authors: Chen Dong Xia , Meng Ming Xin , Luo Ji Wei
Published: November 2013

To discuss the relationship between matric suction and strength under different drying-wetting cycle paths of residual clay, soil water characteristic curve was determined by the filter paper method. The shear strength, unconfined compressive strength and matric suction were obtained during desorption and adsorption at the drying and wetting cycle. The experimental results show that the matric suction of soil specimens subjected to different drying and wetting cycle paths are different although at the same water content. Contributions of internal friction angle and cohesion to shear strength are different at different matric suction. In the low matric suction stage, matric suction mainly contribute to shear strength by affecting the cohesion, yet in the high matric suction stage by increasing both the internal friction angle and cohesion; in the transition matric suction stage, the contribution of cohesion decreases while the contribution of internal friction angle increases. Furthermore, the unconfined compressive strength of specimens subjected to the drying and wetting cycle path of desorption first and then adsorption is reduced and increase with the opposite path.
Study on Rapid Solidification of Metal Strips
Authors: Zhou Cheng , Wang De , Luo Deng Chao , Fang Yong , Yao Shun , Luo Jun Jie , Xu Guo Jin
Published: November 2013

Aim to produce metal strips in millimeter scale, the Top Side-pouring Single Roll Casting process and the Top Side-pouring Twin Roll Casting process were investigated in this paper, using commercially pure lead and commercial-purity aluminum as the experimental materials. Numerical simulation was conducted before the experiment. The results show that, the Top Side-pouring Single Roll Casting process and the Top Side-pouring Twin Roll Casting process can both realize the uniform flow distribution and rapid solidification, but the surface of the strips cast by the former are irregularity because of free solidification, while that from the latter present a state of rolling. And one can change the gauge of nozzle and the speed of cooling roll, to regulate the thickness of thin strips, and by changing the shape of the nozzle, the thickness distribution can be handled.
Experimental Study on Mechanical Properties of RAP Fiber Cement Stabilized Macadam
Authors: Zhang Xiao Tian , Liu Zhan Jian , Yang Ming Cheng
Published: November 2013

The basic mechanical properties of RAP used as semi-rigid cement stabilized macadam base were researched. To add fiber to improve the crack resistance of the cement stable macadam mixture, reduce pavement reflection crack. Sixteen groups orthogonal experiment were arranged by the factors as cement, fiber, waste asphalt concrete and fly ash, the unconfined compression test, split test and drying shrinkage experiment were carried out. The results showed that the effect of the factors on the sensitivity of unconfined compression strength is obviously different, and from large to small order is cement, fly ash, fiber, waste asphalt concrete. RAP fiber cement stabilized macadam can satisfied with the strength requriments of base and subbase of all levels of the road. It should set cement and fly ash as the main control factors in the optimization design of RAP fiber cement stabilized macadam.
Design of Ground Water Control in Super Large Deep Foundation Pit
Authors: Zhang Hao Chen , Wang Mao Yuan , Liu Yang
Published: November 2013

The construction project is located in Beijing personnel concentration areas which is the special geographical position. The height of the surface construction is about 80m. And the foundation cushion bottom elevation in the most area of foundation excavation project, the circumference is more than 700m, belongs to super large deep foundation pit. During the excavation process, the scheme of setting heavy curtain pile between two adjacent reinforced concrete slope protection piles could effectively control groundwater variation, prevent the possibility dangerous condition in advance and ensure construction period. It has an obvious benefit and provides reference meaning to other similar super large deep foundation pit in ground water controlling.
Diagonal PCG Method for FE Solution of 3D Biot's Consolidation Problem
Authors: Zhang Kun Yong , Xie Gui Heng
Published: November 2013

To solve large symmetric indefinite linear systems in finite element discretization of 3D Biot's consolidation equations.This paper adopted diagonal preconditioned conjugate gradient method to FE program. Several numerical examples show that the diagonal PCG method are significantly more efficient than direct solution method for large-scale symmetric indefinite linear systems.
Stability Evaluation and Analysis of Homogeneous Rock Slope Using Finite Element Method
Authors: Liu Yu Ning , Cao Li Juan , Shangguan Zi Chang
Published: November 2013

Rock mass is simplified as homogeneous material. Shear strength reduction approach is applied to evaluate stability of rock slope and calculate safety factor of sliding surface. Mohr-Coulomb fracture criterion is used to evaluate the sliding state of every element of finite element model for rock mass. The shear strength parameters of rock mass are evaluated from the laboratory tests and engineering analogy. The distributions of plastic zone at collapse state and safety factor of sliding surface are determined.
The Study on Movement of Underground Water and its Effect on the Stability of Surrounding Rocks
Authors: Sun Lan Ning , Zhao Zhong Hu
Published: November 2013

Because of the special geological structure, folds are the main place where underground water gathers and moves. When we build roads or tunnels in folds of the western mountain areas, we should consider the effect of underground water on surrounding rocks and on stability of lining of a tunnel. The author explains in system the movement of underground water in anticlines, limbs and synclines, analyzes the physical, chemical and mechanic effects on rocks during its movement, then puts forward the reasonable advices in choosing the location where a tunnel should be built and specifies the stability of a tunnel. Also, in order to solve the water-gushing problem which may occur during the construction, the author brings forward some control measures for reference when selecting tunnel line and constructing.
Analysis on Surrounding Rock Mass Plastic Zone of Deep Underground Chamber Based on Hoek-Brown Criterion
Authors: Yin Nan
Published: November 2013

Generalized Hoek-Brown criterion is indicated as a dimensionless quantity, on this basis, elastic-plastic analytical method of circular underground chamber is presented based on generalized Hoek-Brown criterion in uniform stress field. Take into account a number of factors such as deep rock mass quality, rock strength, etc, surrounding rock mass plastic zone of deep underground chamber is analyzed by the analytical method. The results show that taking measures to improve the quality of rock mass can effectively control surrounding rock mass plastic zone for soft rock underground chamber, however, taking measures to improve the quality of rock mass can not appreciably control surrounding rock mass plastic zone for hard rock underground chamber.
Exploration and Practice of Innovative Support System of Large-Scale Deep Foundation Pit in Beijing
Authors: Jiao Shen Hua , Wang Jin An , Liu Ya Ming
Published: November 2013

Foundation pit engineering is a critical part during the development process of underground space. With the increasing demands of underground space, foundation pit engineering is exposed to new challenges. This article firstly reviews the main features of shallow foundation pits in Beijing as well as the relevant design concepts of support, and then elaborates the features and challenges of urban large-scale deep foundation pits; a case study was introduced with the exploring practice of design and construction of the large-scale deep foundation pit of Wangjing SOHO project, the innovations of support design for this foundation pit are summarized; new prospects for development of support techniques of foundation pits are proposed.
Experimental Study on Performance of Large Stone Permeable Asphalt Mixtures
Authors: Wei Jin Cheng , Lu Sheng Di , Li Jin
Published: November 2013

This study focused on the performance of the Large Stone Permeable Asphalt Mixture (LSPM) with neat asphalt and its feasibility to use as asphalt pavement flexible base. For comparision, LSPM mixtures were designed respectively with neat 60/70-grade asphalt and modified asphalt and the performance of LSPM was studied and compared by volume index test, draindown test, Hamburg Wheel-tracking Test and dynamic modulus test. The results showed that the performance of LSPM with modified asphalt was superior to LSPM with neat asphalt and cellulose fiber, but draindown and rutting performance of LSPM with neat asphalt met requirements of corresponding specification and dynamic modulus of LSPM with neat asphalt had the same characteristic with LSPM with modified asphalt, which proven that LSPM with neat asphalt can use as asphalt pavement flexible base by properly mix design and pavement structure design.
The Fitting Analysis of the Miscellaneous Filled Slope Deformation Monitoring
Authors: Zheng Da Wei , Li Shuai , Zhao Yi Meng
Published: November 2013

In this paper, through the analysis of miscellaneous fill slope horizontal displacement of supporting structure and the vertical displacement monitoring results, the simulation results are compared and analyzed with FLAC3Dsoftware, verify the support form the deformation in the controllable range, the actual monitoring data and simulation results in the difference between the standard allows range, fitting deformation curve can be used as a conventional deformation monitoring based on integral deformation analysis, advanced demonstration of engineering construction scheme optimization.
Study of Shear Constitutive Model for Schistose Rock Mass
Authors: Liu Shang Ge , Xu Hua , Liu Jian , Tao Xiao
Published: November 2013

Based on the direct shear tests of schist and shale at dry and water-saturated states, combed with the advantages and disadvantages of models for rock mass and structure surface, we proposed shear stress-displacement constitutive model of schistose rock mass. The model is in the form of piecewise exponential function and its advantages are as follows: Piecewise function can reasonably describe the nonlinear pre-peak shear hardening and post-peak shear softening characteristics; Regard peak strength, peak displacement and residual strength as critical points, so it can accurately describe the strength characteristics of the material; The fitting degree is high with direct shear tests both at dry and water-saturated states; Only one parameter value is needed to obtain by fitting experimental curves while others are convenient to determine. All of those are benefit to applications in engineering practice.
Finite Element Analysis on Energy Dissipation Ability of Geo-Materials under Impact Load
Authors: Yan Shu Wang , Yu Chang Yi , Wang Wu Gang , Sun Guo Min , Lei Zhen Ming
Published: November 2013

The non-linear finite element program Ls-DYNA/ANSYS is applied to simulate numerically the capacity for the geo-materials to dissipate the energy induced by the falling objects. The calculation results for the crushed stone coincide well with those recommended by the current Code of《DNV-rp-f107_2010》, which is on the basis of experiment data, implying the feasibility of using this program to estimate the energy dissipating capacity of the geo-materials. Because little research has been performed with clay soil, the program Ls-DYNA/ANSYS is used to predict the energy dissipating capacity of clay layers.
Non-Probabilistic Reliability Research on Slope Stability Based on Interval Analysis
Authors: Lu Xiao Chun , Gan Liang
Published: November 2013

In this paper, slope stability considering non-probabilistic reliability analysis based on interval analysis was discussed. We can get safety factor, safety factor interval, non-probabilistic reliability by slope stability computation based on interval analysis. Based on the hypothesis that interval variable of structural performance function numerical value obeys uniform distribution, failure probability based on interval analysis was put forward. These form plural evaluation system about slope stability; it perfects safety evaluation for slope stability.
Research on Effects of Pressure Loading on Rock Lateral Cracks Occurrence under Confining Pressure
Authors: Chen Pei Qi , Cui Jin Tao , Zhou Xiao Jie
Published: November 2013

Numerical simulations of effects of confining pressure on occurrence of rock lateral cracks were performed by using the numerical analysis software. The results indicate that the rock tends to have median cracks with the increasing of penetration under no confining pressure, while the rock tends to have lateral cracks with the increasing of penetration under confining pressure. The relative position of lateral crack initiation is dependent on the confining pressure when loading, which is independent of the penetration. The greater the confining pressure, the closer the lateral crack location to the rock surface. With the increasing of penetration and confining pressure, the lateral crack direction is towards to the direction parallel to the rock surface.
The Effect of Rainfall on Cementatory Characteristics of Laterite in Slope
Authors: Zhang Zu Lian , Huang Ying , Shi Chong Xi
Published: November 2013

Through indoor artificial rainfall test on the model slope of the laterite, the soil tests on samples of different parts of the model slope of laterite were carried out in the end of rainfall. According to the test results, the changes of the water content, the grain composition and the shear strength of the laterite in the model slope were analysed. The results showed that the effect of rainfall caused the water content of the laterite in the model slope to increase, and the altitude of the model slope was lower, the water content of the laterite in the model slope was higher. The effect of rainfall led to the density of the laterite in the model slope to decrease gradually when the altitude of the model slope was lower gradually. The grain composition exhibited that the silt content was increased and the clay content was reduced with the decrease of the model slope altitude. Based on analysing the variation of the water content, density and grain composition in the laterite of the model slope under the effect of rainfall, the changes of the shear strength of the laterite in the model slope were studied, further the changes of the cementatory characteristics of the laterite in the model slope were analysed under the effect of rainfall.
Establishment and Application of Microseismic Monitoring System to Deep-Buried Underground Powerhouse
Authors: Li Biao , Dai Feng , Xu Nu Wen , Sha Chun
Published: November 2013

The right bank underground powerhouse of Houziyan hydropower station is a typical deep-buried type with high geostress and complicated geological conditions. To monitor and analyze the stability of surrounding rock mass during continuous excavation of the powerhouse excavation and locate the potential failure zones, an ESG (Engineering Seismology Group) microseismic monitoring system manufactured in Canada was installed in April, 2013. The wave velocity of the monitoring system was determined through fixed blasting tests. And the average location error is the minimum while P-wave velocity is 5700m/s, less than 10m and meeting the system request. By combining the temporal and spatial distribution regularity of microseimic events with field excavation, micro-crack clusters and potential instability zones were identified and delineated. The results will provide a reference for later excavations and supports of the underground powerhouse. Furthermore, a new monitoring method can also be supplied for the stability analysis of surrounding rock mass in deep-buried underground powerhouses.
Influence of Chloride Contamination on the Specific Surface Area of Loess
Authors: Chen Wen Wu , Xu Yan Rong , Guo Zhi Qian
Published: November 2013

The main chlorides that pollute soil are NaCl, KCl, MgCl2and CaCl2, who will change the physicochemical properties of soil. It takes Jiuzhoutai loess as the object, using methylene blue method and ethylene glycol monoethyl ether method to determinate the specific surface area of loess, which was immersed by chloride with different concentrations and cations to analyze the influence of chloride contamination, respectively. The specific surface area decrease with the increase of chloride concentration, while has the negative correlation with the affinity of cations to clay which immersed by different cations. Different absorbents that have lead to the difference of test results, and the results of ethylene glycol monoethyl ether method are always bigger than methylene blue method.
Study on Design of Uplift Piles According to the Elastic Foundation Beam Theory
Authors: Chen Kun , Dou Yu Bin
Published: November 2013

Taking the every arranged uplift pile in a practical project for example and selecting the column strip on the scale board as the research object, this paper analysis mainly focuses on the pullout capacity of piles at different locations with different vertical loads from columns by using the Winkler elastic foundation beam model. The results show that design with assumption that uplift piles evenly share the net buoyance would lead to successive failure of the piles. Then further parametric analysis was conducted to study the influence of stiffness, thickness and column space on the vertical forces of piles. The conclusions could provide positive reference to related uplift pile design.