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中文核心期刊
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    15 April 2009, Volume 28 Issue 2 Previous Issue    Next Issue

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    Shaking Table Tests on a Single-Column-Bent Double-Deck Viaduct-I Pier Model: Structural Dynamic Properties
    PENG Kai, , LI Jian-zhong, ZHU Yu, PENG Tian-bo
    2009, 28(2): 161-167.  DOI: 10.3969/j.issn.1674-0696.2009.02.01
    Abstract ( )   PDF (764KB) ( )  
    Shaking?table?tests?were?done?on?a?single-column-bent?double-deck?viaduct?pier?model?with?horizontal?structural?dynamic?properties?acquired?and?analyzed,?which?indicated?that:the?structure?has?similar?mode?shapes?and?identical?mode?sequence?between?corresponding?vibration?modes?in?longitudinal?and?transverse?directions;?the?basic?vibration?mode?alone?is?insufficient?to?account?for?the?main?horizontal?structural?dynamic?properties;?the?higher-order?modal?frequencies?are?sensitive?to?the?change?of?lumped?mass?change?at?the?single?column's?upper?part?;?cracking?of?the?single?column?markedly?lowers?down?horizontal?structural?modal?frequencies?and?increases?modal?damping,?but?little?influences?mode?shapes?and?mode?sequences;?in?the?cases?of?relatively?low-intensity?stimulation?and?small-amplitude?vibration,?modal?tests?could?hardly?reflect?the?structural?damage?condition?after?serious?seismic?attack.
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    Exploration of New Steel-Concrete Composite Chorded Arch Bridge
    ZHOU Zhi-xiang, XU Yong, , LI Zu-wei, QIAO Dun, JING Shi-hong
    2009, 28(2): 168-172.  DOI: 10.3969/j.issn.1674-0696.2009.02.02
    Abstract ( )   PDF (440KB) ( )  
    Techno-economic analysis of conventional concrete arch bridge and continuous prestressed concrete rigid frame bridge is conducted. Then a new kind of rigid-frame arch bridge structure bestriding deep valleys or rivers in mountainous areas is proposed based on the advantages of the both above. The proper construction steps are suggested as follows : half of the rigid-frame arch rib is constructed in pillar on two banks respectively at first, and then.two halves are rotated down vertically, closed up to form a whole arch rib. Its structural characteristics, construction technology and technical-economical benefits are analyzed. The rigid-frame arch structure has been successfully applied to Gulu Middle School Overpass Bridge over Yu-Lin highway. The past researches and engineering application have proved that the rigid-frame arch bridge is convenient, safe, efficient and field-saving in construction with excellent integration and ductility seismic performance. Its construction method can also be functioned as a valuable reference to the efficient non-bracket construction of large and medium span bridges.
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    Analysis on the Lateral Vibration Control of Top-Bear Arch Bridges
    LI Feng-bao, ZHU Dong-sheng
    2009, 28(2): 173-177.  DOI: 10.3969/j.issn.1674-0696.2009.02.03
    Abstract ( )   PDF (707KB) ( )  
    Taking two different span top-bear arch bridges as example, the dynamic characteristics of them are analyzed and then the results are compared by utilizing ANSYS program. Then lateral damping braces are set in two bridges, making use of three seismic records, the seismic response of bridges is analyzed by dynamic time history method. The results show that the lateral damping brace can remarkably decrease seismic response of the bridge in the lateral plane.
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    Discussion on Aerodynamic Admittance of Flat Double-Girder Bridge Decks through Cross-Correlation Spectrum Recognition
    LI Si-han, WEN Shui-bing
    2009, 28(2): 178-182.  DOI: 10.3969/j.issn.1674-0696.2009.02.04
    Abstract ( )   PDF (845KB) ( )  
    On the basis of simulation of structure of Jingsha River Yangtze Bridge, the aerodynamic admittances are studied by means of cross-correlation spectrum recognition with data gotten from segmental modeling's dynamometer wind-tunnel experiment in turbulence flow. Through comparison with traditional method, it is found that aerodynamic admittances gotten by cross-correlation spectrum recognition are less than traditional ones and Sears function on quantity in general, although both results had the same trend of change with the rise of reduced frequency. The buffeting force is calculated through complex aerodynamic admittances, and the spectrum analysis is also carried out. Comparing with those data measured from experiments, it is found that both of them have the same trend of change with the rise of reduced frequency, although they have certain differences in quantity. Through the comparison of buffeting force spectra in different turbulence flow, whose turbulence intensity are 6%, 10%, 20% respectively, with the consideration of different wind attack angle ranging from -5°to + 5°, it is found that the difference of quantity between results calculated by complex aerodynamic admittances and those measured from experiments are steady and almost independent on the change of wind attack angle and turbulence intensity.
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    Performance Analysis on Local Compression of Continuous Rigid Frame of Lightweight Aggregate Concrete
    LU Wei-wei, SU Si-guang, HAO Fu-jun
    2009, 28(2): 183-186.  DOI: 10.3969/j.issn.1674-0696.2009.02.05
    Abstract ( )   PDF (159KB) ( )  
    The crafts of the design and construction of long span continuous frame bridge using lightweight aggregate concrete are different from those using common concrete, since the performance of lightweight aggregate concrete is different from that nf the common one. Taking the Shuitu Jialingjiang Bridge as an example,the differences of the performanee of local compression hetween lightweight aggregate conerete and that of common concrete are analyzed according to the standard of "Technical Specification for Lightweight Aggregate Concrete Bridges". The result shows that the performance of local compression of lightweight aggregate concrete is lower than that of common concrete, and when the parameters applied to the two kinds of concrete are the same, the results of local compression of lightweight aggregate concrete cannot fit the requirements of specification. It is tested by the ease study that the appropriate addition of steel fiber can improve the performance. of local compression of lightweight aggregate concrete and make it to satisfy the standards of the specification.
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    Technical Discussion on Reasonable Fulcrum Optimization of Setting Support as Flat Arch Bridge Reinforcement
    WU Dian-kun, ZHOU Jian-ting, QI Yong-li, MO Xi-Jing
    2009, 28(2): 187-189.  DOI: 10.3969/j.issn.1674-0696.2009.02.06
    Abstract ( )   PDF (165KB) ( )  
    Based on the theory that the influence line determines the location of the most unfavorable load of section internal force, the general and special control principles of fulcrum optimization of setting Y support as flat arch bridge reinforcement are analyzed. Combining with mathematical thought of bisection iterative method among numerical analysis, a new way to choose reasonable supporting point rapidly and conveniently is put forward, which provides primary theoretical basis and technical reference for the application of multi-point supporting to strengthening flat arch bridge, girder bridge and other bridges.
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    Analysis on CFST Disengaging Mechanism Based on Temperature Impact
    WU De-ming, WANG Fu-min, YIN Xiang-lin
    2009, 28(2): 190-194.  DOI: 10.3969/j.issn.1674-0696.2009.02.07
    Abstract ( )   PDF (204KB) ( )  
    On the basis of brief introduction to the status quo of concrete-filled steel tubular(CFST) arch bridge disengaging, the impact of temperature from different sources on longitudinal tensile stress and radial direction tensile stress which is in interface between steel tube and core concrete is analyzed. The results show that: in arch rib longitudinal direction, the relative slip in interface between steel tube and core concrete is caused by the difference in temperature resulting from hydration heat, sunlight and the changes of atmospheric temperature; in arch rib radial direction, the concrete will be disengaged because of the difference in temperature resulting from sunlight and the changes of atmospheric temperature.
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    Technology?of?Alignment?Control?for?Site?Welding?of?Steel?Box?Girder?of??Guangzhou?Huangpu?Pearl?River?Bridge
    ZHOU Yun-gang, XIAO Ru-cheng, ZHANG Yang-yong, WU Wan-zhong, SUN Bin
    2009, 28(2): 195-198.  DOI: 10.3969/j.issn.1674-0696.2009.02.08
    Abstract ( )   PDF (364KB) ( )  
    There are two key factors during the site welding of the long-span suspension bridge. One is how to control the length; the other is how to control the center line of the steel box girder. They can be controlled effectively by the width of the weld which is the key parameter during the side welding. Based on the welding test, the length of the steel box girder can be adjusted by adjusting the width of the weld in the different stage. The longitudinal axis of the steel box girder can be controlled by setting the width of the weld or controlling the contraction of the weld to make the steel box deflection and come to the axis of the bridge.
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    Solution on Cable Force and Segmental Camber in Arch Bridge Construction by Modified Inverted Method
    MEI Gai-wei, ZHANG Min, ZHOU Shui-xing
    2009, 28(2): 199-202.  DOI: 10.3969/j.issn.1674-0696.2009.02.09
    Abstract ( )   PDF (603KB) ( )  
    Taking Da-ning River Bridge in construction as the engineering background, the optimization analysis of cable forces and segmental cambers has been carried out during the process of arch rib segmental installment. A modified inverted mcthod including cable force penalty factor is put forward, a formula of calculating penalty factor is deduced, and a corresponding FEA model is established by ANSYS. The analytical result shows that this method is of high accuracy, and the restilts of this method are in good accordance with those got in practice.
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    Study on Anti-Ship Collision for Anqing Yangtze River Railway Bridge
    CHEN Ming-dong, CHEN Ming, CHEN Guo-yu, ZHENG dan
    2009, 28(2): 203-207.  DOI: 10.3969/j.issn.1674-0696.2009.02.10
    Abstract ( )   PDF (371KB) ( )  
    According to the velocity of ship collision with the non-navigable passage piers of the Arkansas River Bridge in U. S. and the Guangdong Jiujiang Bridge in China, the method proposed in American Road and Bridge Desig Code that the ship speed declines proportionally to the distance that the ship migrates from the shipping route is questioned. The conclusion that the ship velocity won't stall when ship loses rudder is brought forth thereafter. Combining with the anti-ship collision study on the Anqing Yangtze River Railway Bridge, several meaningful ideas are put forward for the speed selection and the confirmation of the ship collision force with bridge and the number of piers which need to be established for bridge anti-collision, and the discussion on the anti-collision scheme are also explored.
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    Preparation and Application of Steel Fiber Reinforced Sprayed Concrete with Superfine Sand in Tunnel Construction
    PENG Zhao-hui
    2009, 28(2): 208-211.  DOI: 10.3969/j.issn.1674-0696.2009.02.11
    Abstract ( )   PDF (419KB) ( )  
    Aiming at the status quo of lacking natural sand in Chongqing area, the performance of steel fiber reinforced sprayed concrete (SFRSC) with superfine sand mixing with the machine-made sand and its application to the tunnel construetion are studied. It is shown that compared with the properties of SFRSC with natural coarse sand, SFRSC with mixed sand( the sand ratio 54% - 58% )exhibits similar performance, which is made of mixing superfine sand with machine-made sand in accordance with the 2 : 3 ratio of sand mixed. The fineness modulus of the superfine sand mentioned above is 1.2 and 3.5 respectively. The application in practical engineering indicates that it is obviously advantageous for SFRSC to be used at the early stage of lining construction in tunnel engineering.
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    Derivation and Discussion of Vertical Curve Design Formulas
    WANG Zhong-ren, LIAO Chao
    2009, 28(2): 212-214.  DOI: 10.3969/j.issn.1674-0696.2009.02.12
    Abstract ( )   PDF (322KB) ( )  
    The highway vertical curve design formulas for both crest and sag vertical curves with the consideration of stopping sight distance are first analytically derived. Driver height, object height, and vehicle headlamp height are explicitly considered as the key elements for stopping sight distance determination. Based on these formulas, the minimum vertical curve length values, as recommended in the China Road Alignment Design Guide are then shown to be inadequate, especially for crest vertical curve during nighttime operations with no illumination. It is suggested that vertical curve length design should consider the limitations of vehicle headlamps, and the recommended values in the China Road Alignment Design Guide should be increased.
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    Effect of Bonding Condition between Asphalt Layer and Semi-Rigid Layer on Structural Mechanics Response of Asphalt Pavement
    BAI Xue-mei,
    2009, 28(2): 215-218.  DOI: 10.3969/j.issn.1674-0696.2009.02.13
    Abstract ( )   PDF (741KB) ( )  
    Bonding condition between adjacent layers is complicated in semi-rigid asphalt pavement, which can directly affect the road performance. By using a multi-layered elastic analysis program (GAMES) superior to BISAR, a study is conducted to analyze the mechanics response when changing the bonding condition between asphalt layer and semi-rigid layer. The results indicate that the bonding condition has the most significant effect on the tensile strain at the bottom of asphalt layer and the shear stress between the asphalt and semi-rigid layer, followed by the tensile strain at the asphalt layer surface as well as the bottom of base layer. Relatively, the shear stress in asphalt layer and the surface deflection are not sensitive to the change of the interlayer (asphalt-semi-rigid) bonding condition.
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    Study on Paving Width of Fiberglass-Polyester Paving Mat Based on Fatigue Performance of Asphalt Overlay
    ZHAN Qi-qi, YANG Wen-jun, ZHU Hong-zhou, HOU Chang-yong
    2009, 28(2): 219-221.  DOI: 10.3969/j.issn.1674-0696.2009.02.14
    Abstract ( )   PDF (210KB) ( )  
    The paving width of fiberglass-polyester paving mat has great influence on fatigue performance of asphalt overlay and project efficiency. Considering the fatigue performance of asphalt overlay as the guidepost, the method of designing fiberglass-polyester paving mat with reasonable paving width is proposed to meet the needs of the fatigue performance of asphah overlay. Based on Chongqing-Chengdu Highway Asphalt Overlay Project, the design of its paving width is conducted to fix the reasonable result.
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    Factors Affecting Freezing-Thawing Split-Strength for AC-13 Asphalt Mixture
    LU Xue-yuan, ZHANG Su-yun
    2009, 28(2): 222-227.  DOI: 10.3969/j.issn.1674-0696.2009.02.15
    Abstract ( )   PDF (291KB) ( )  
    Taking AC-13 SBS modified asphalt mixture as the research object, the freezing-thawing split-strength, not-freezing-thawing split-strength and TSR are studied based on the estimation of water stability index. The results show that the grading is the main factor of controlling the change of its freezing-thawing split-strength, and the key sieving pores are 0. 075mm, 4. 75mm and 9. 5mm respectively; however, the impact of asphalt is not so significant. Porosity and quality of raw materials is another key factor of controlling water stability. It is confirmed that using lime as filler is more conducive than using other materials as filler to improve the freezing-thawing split-strength. Therefore, the technical measures and recommendations to control the design and the construction quality are put forward.
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    Deviation Analysis of Extraction Method in Measuring Asphalt-Aggregate Ratio of SMA
    WANG Rui-lin, , LIU Yin, ZHOU Jin-chuan
    2009, 28(2): 228-230.  DOI: 10.3969/j.issn.1674-0696.2009.02.16
    Abstract ( )   PDF (122KB) ( )  
    Through analysis of the extracting test results of SMA modified asphalt mixture, it is discovered that the wooden fiber after the extraction selected out by manual work enwraps some fine aggregate, which leads to the quality deviation of asphah-aggregate ratio and wooden fiber. Aiming at this deviation, the test is carried out and some improvement projects are proposed. Finally, the calculation to asphalt-aggregate ratio of the SMA modified asphalt mixture is amended.
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    Experimental?Study?on?Pavement?Performance?of?Nanometer??Layered?Silicate?Modified?Asphalt
    HUANG Wei-rong
    2009, 28(2): 231-235.  DOI: 10.3969/j.issn.1674-0696.2009.02.17
    Abstract ( )   PDF (422KB) ( )  
    Aiming at the cause of asphalt pavement diseases, Nanometer Layered Silicate modified asphalt(NLS) is used to improve the resistance capability of asphalt pavement. Conventional indoor tests, such as penetration, ductility, softening point, RTFOT and SHRP DSR, BBR and PAV pressure aging test are conducted. Contrastive tests of pavement performance are carried out between NLS and base asphalt, SBS and PE modified asphalt, such as temperature sensibility, high-and-low temperature behavior and aging behavior. The conclusion is drawn that rosin-hased bentonite NLS modified asphalt has better pavement performance, which provides the basis for engineering application.
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    Experimental Study on the Sedimentation Stability and Its Treatment for Cliff Debris Subgrade by Centrifuge Model Test
    YANG Xi-wu, ZHAO Ming-jie, WANG Chang-xian
    2009, 28(2): 236-240.  DOI: 10.3969/j.issn.1674-0696.2009.02.18
    Abstract ( )   PDF (741KB) ( )  
    The cliff debris subgrade is a special type of subgrade in mountainous highway construction. Based on the cliff debris subgrade conditions of Shui-ma Highway (from Shuifu to Maliu Bay) in Yunna Province, the rule and the influence factors of sedimentation change of rock subgrade settlement which is of different ratio of soil and rock, of different density, and of different thickness are studied by centrifuge model test. According to the centrifuge model test results, three methods of reducing cliff debris subgrade sedimentation are proposed, including replacing soft cliff debris with block stone, rein-forcement soil and stability soil respectively; and their effects on reducing the sedimentation are tested by centrifuge model test. The centrifuge model test results of three processing methods show that the stability soil replacement and block stone replacement have better effects in reducing the sedimentation of cliff debris subgrade and can be used in reducing the sedimentation of cliff debris subgrade under different condition.
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    Experimental?Study?on?Incipient?Motion?of?Gravel?Sediments?at??the?Foot?of?Slopes
    YANG Sheng-fa, WANG Han, ZHOU Hua-jun
    2009, 28(2): 241-245.  DOI: 10.3969/j.issn.1674-0696.2009.02.19
    Abstract ( )   PDF (349KB) ( )  
    Aiming at the transporting characteristics of gravel sediment in low water and urgent shoal in mountainous rivers, it is found that incipient motion first starts at the foot of the slopes through the experiment observertions of the gravel on the slopes and theoretical analysis of the phenomenon. According to the gravel sediments stress state at the foot of the slopes, a rolling model is adopted to conduct a theoretic deduction; and the bottom velocity, drag coefficient, gravel underwater grav- ity and the impact of additional gravity are taken into account; then the incipient motion flow formula at the foot of the slopes is deduced, which relates to the slope gradient. Through the flume experiment, the gravel sediment incipient motion flow formula at the foot of the slopes is fitted out, and a comparision with Shamo Fu formula is made.
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    Effect?Analysis?of?Confining?Pressure?on?Young's?Modulus
    LAI Yong
    2009, 28(2): 246-249.  DOI: 10.3969/j.issn.1674-0696.2009.02.20
    Abstract ( )   PDF (355KB) ( )  
    Based on the effect of rock specimen on Young's modulus, the influence mechanism of confining pressure on Young's modulus is discussed. The increase of confining pressure, resulting in the decrease of the micro-crack density and the closure of the crack, and the fictional sliding effect between crack and slip surface are main causes of the increase of Young's modulus. Through the analysis of test data, it is concluded that the Young's modulus increases with the increase of confining pressure. While the confining pressure becomes bigger than the compacting strength, the increasing of Young's modulus becomes diminished and tends to be a definite value gradually. The formula of the relation between the rock Young's modulus and the confining pressure is determined, which reflects the characteristic that the micro-crack density decreases in an exponential relationship with the increase of confining pressure.
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    Analysis on Failure Modes of Expansive Soil Subgrade Embankment
    HUANG Shi-wu, LIU Ming-wei, YIN Jian
    2009, 28(2): 250-254.  DOI: 10.3969/j.issn.1674-0696.2009.02.21
    Abstract ( )   PDF (459KB) ( )  
    The embankment diseases of Nanbai Highway (from Nanning to Baise) are serious, and the slide and collapse occurred in embankment of expansive soil inclined ground are most serious. The embankment will slide when it has certain degree of slope between the highway route and its vertical direction. Through investigating collapses of embankment in K169 + 500m - K189 + 400m on the Nanbai road, three failure modes of expansive soil embankment are generalized by the method of FEM, that is, the slide in the cross direction, the slide in the longitudinal direction and the longitudinal-cross slide mode. The failure modes of embankment are simulated by the strength reduction finite element method and the causes of embankment failure are discussed. New thoughts about rule of the "Specifications for Design of Highway Subgrades" ( JTG D 30--2004) are put forward, which provides a new way of thinking to the research on the subgrade filling of expansive soil.
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    Cusp Catastrophe Model for Cutting Slope Failure of Expansive Soils in Rainy Season
    LIU Qing-fang
    2009, 28(2): 255-258.  DOI: 10.3969/j.issn.1674-0696.2009.02.22
    Abstract ( )   PDF (270KB) ( )  
    Taking cutting landslide of expansive soils controlled by discontinuities as an example, a simple mechanical model considering water swelling is proposed, which takes the strain-softening and water-softening of slip surface materials under the condition of rainfall into the consideration. Furthermore, the mechanism of the cutting slope of expansive soils is analyzed by catastrophe theory. Many factors trigger landslide, such as moisture content and stiffness ratio. The results show that evolution process of landslide is resulted from internal and external factors, and the cause of rainfall resulting in softening-swelling of discontinuities belongs to the external triggering factors. The water controlling should be taken into consideration in the process of reinforcing cutting slope.
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    Study on Framework of Evaluation System of Water Hazard in Mountainous Highway
    LI Jia-chun, DONG Wei-wei, CUI E, LI Zhi-qiang
    2009, 28(2): 259-263.  DOI: 10.3969/j.issn.1674-0696.2009.02.23
    Abstract ( )   PDF (332KB) ( )  
    In order to improve the anti-water hazard ability of the mountainous highway, the basic concepts included in the risk evaluation system of water hazard, such as danger, vulnerability, loss, risk and benefit, have been explained in detail on the basis of site investigation and research. The proposal that the system should include hazard evaluation, vulnerability evaluation, risk evaluation and disaster reduction benefit evaluation is put forward. And the water hazard evaluation system of road net should be laid on the points, lines and sections. A three-dimensional hazard evaluation system has been established first time. Meanwhile, it is pointed out that the engineering evaluation of the ability of waterproof, drainage and antiwater hazard of current road is an important basis of the investment decision of washout protective project, which should be paid enough attention. The evaluation should lay particular emphasis on sites, considering lines appropriately. At last, the basic evaluation models are set up from four aspects, including hazard factors, hazard bodies, hazard situation and hazard reduction.
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    The Method and Application of Fuzzy Optimal Theory and Entropy Weight Decision-Making Method in Landslide Treatment Schemes Selection
    WANG Bao-liang, TANG Hong-mei
    2009, 28(2): 264-267.  DOI: 10.3969/j.issn.1674-0696.2009.02.24
    Abstract ( )   PDF (368KB) ( )  
    In view of the complexity and uncertainty of optimization selection of the landslide treatment scheme, taking geological data, execution conditions, engineering economy, environmental influence and etc. factors in full consideration, the multi-objective and multi-layer optimal model is established. The model first generates judge-array based on fuzzy optimal theory ; and latter determines the optimal plan with the entropy weight decision-making method. Under this method combined with the preparation of the VB based on the fuzzy optimal and the entropy power multi-scheme optimization selection program, it is convenient to make the quality synthetic evaluation to various schemes. Through the Kang-Jiazui landslide treatment scheme's optimized analysis, it is proved that on the basis of the fuzzy optimal theory and entropy weight decision-making method, the optimal selection is of simple, quantitative and strict characteristics and has the strong ability of recognition and judgment. This method also has certain referential significance to other synthetic evaluation work.
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    Exploratory for In-Site Compression Evaluation Criterion of Asphalt Pavement
    WANG Dong-wei
    2009, 28(2): 268-272.  DOI: 10.3969/j.issn.1674-0696.2009.02.25
    Abstract ( )   PDF (1111KB) ( )  
    The in-site degree of compaction or voids for asphalt pavement directly influences the water failure resistance to asphalt pavement. But the research results for the density and the voids of asphalt mixtures with each a 50 groups of grade for AC13, AC16 and AC25 respectively at different experiment ways show that the in-site degree of compaction or voids based on the bore-in-site sample density to laboratory criterion density has an error of 2% with the actual in-site degree of compaction or voids of asphalt pavement that results in the evaluation of compaction quality for finished asphalt pavement not to be true to the original. Therefore, it is proposed that the completion inspection for finished asphalt pavement based on the bore-in-site sample density to the laboratory criterion density should give 2% discount for the in-site degree of compaction (or increase 2% for the in-site voids) as a final result.
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    Hot Seam Stitching Technology of Old and New Asphalt Pavement in Shanghai-Nanjing Expressway Extension Project
    MA Jun
    2009, 28(2): 273-278.  DOI: 10.3969/j.issn.1674-0696.2009.02.26
    Abstract ( )   PDF (872KB) ( )  
    The stitching technology of asphalt pavement joints has always been one of the technical problems that deal with asphalt pavement design and construction, and it even does so for the whole road running through the seams of asphalt pavement in Shanghai-Nanjing line extension project. Combined with the hot seam stitching and construction practice in the Shanghai-Nanjing road expansion project, the hot seam stitching technology adopted in Shanghai-Nanjing road expansion project and its key points in construction control are introduced in detail. Furthermore, it is proved that the hot seam stitching is much advantageous than the conventional cold splicing technology either from its internal quality or surface effect, according to the test results and the surface effect of asphalt pavement core samples got from two different technologies.
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    Study on New Method of Natural Zoning of Highway in Chongqing
    GUO Hong-rui, LIANG Nai-xing
    2009, 28(2): 279-282.  DOI: 10.3969/j.issn.1674-0696.2009.02.27
    Abstract ( )   PDF (179KB) ( )  
    Facing the problem of current standards of natural zoning of highway in the feasibility of Chongqing highway construction, the new general research plan is brought forward according to the actual circumstance and the AcrGIS analyzing software; then aiming at the different impact on road construction influenced by elevation, gradient, surface incision density, rock-soil type, vegetation resources, climatic resources, geological hazards and so on, the three-level zoning guide line system suit for the natural and geographical environment of this region is brought forward ; finally, the category system composed of individual natural zoning for Chongqing highway, thematic natural zoning for Chongqing highway and natural zoning for Chongqing highway is established. This method takes more factors and deeper zoning into consideration, and can provide better service to the local highway construction, which promotes the development and consummation of the current zoning standards.
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    An Approach of Signalized Intersection Delay Calculation Based on Floating Vehicles Data Survey Method
    YU Quan, SUN Ling, RONG Jian
    2009, 28(2): 283-286.  DOI: 10.3969/j.issn.1674-0696.2009.02.28
    Abstract ( )   PDF (258KB) ( )  
    Aiming at the current research on the signalized intersection delay calculation of GPS floating vehicles in city, a new method to estimate delay using the floating vehicle data is proposed to get rid of the traditional method. The delay process at signalized intersection is mainly analyzed, and the range and expedite travel speed of the signalized intersection is determined, which lays a foundation for determining the calculation process and calculation formula of the signalized intersection delay. At last, this method is validated based on the real data.
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    Research on Longitudinal Slope and Slope Length Limit of Mountain-Expressway Based on Heavy Vehicles' Braking Ability
    SU Bo, FANG Shou-en, WANG Jun-hua
    2009, 28(2): 287-289.  DOI: 10.3969/j.issn.1674-0696.2009.02.29
    Abstract ( )   PDF (422KB) ( )  
    The GSRS's temperature prediction model of the brake drum is modified by the brake drum's temperature data measured in the field test on mountain-expressway. Based on the modified model, the relationship between the temperature of large trucks' brake drum and longitudinal slope, slope length, vehicle weight, vehicle speed is deduced. With this rela-tionship, that the longitudinal slope and slope length limit guaranteeing the brake drum's temperature are no higher than its safety-temperature is figured out. This limit will lower the probability of brake failure. So, it can be a reference for safer design of mountain-expressway's longitudinal profile.
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    Study on Application of Grey-Markov Model to Forecasting Elastic Coefficients in Highway Transportation Volume
    REN Qi-liang
    2009, 28(2): 290-293.  DOI: 10.3969/j.issn.1674-0696.2009.02.30
    Abstract ( )   PDF (156KB) ( )  
    Owing to the great fluctuation of the elastic coefficients in highway transportation volume, the Gray-Markov forecast model is built to forecast elastic coefficients in highway transportation volume, for the grey model can reveal the development trend of forecast data and the Markov model is fit to describe the problem with tempestuous fluctuation. The reasonability of the Gray-Markov model is tested by its application to forecasting the elastic coefficients in highway transportation volume of Beijing. The example shows that the Gray-Markov forecast model is helpful to forecast the elastic coefficients in highway transportation volume and it can improve the forecast precision of highway transportation volume.
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    Discussion?on?Patterns?of?Transport?Modes'?Coordinated?Development
    HU Jun-hong, LI Jing
    2009, 28(2): 294-297.  DOI: 10.3969/j.issn.1674-0696.2009.02.31
    Abstract ( )   PDF (232KB) ( )  
    Through the calculation of generalized external costs of various transport modes, three transport patterns are proposed on the base of the status quo of transportation in Jiangsu Province. That is, giving priority to the development of high-way and highway transportation, giving priority to the development of the railway and railway transportation as well as equating both development. Through results of calculating generalized external costs of various transport modes, the advantages and disadvantages of three transport modes are analyzed and compared. Finally, the proposal that the comprehensive transportation mode mainly depends on the highway transportation and modestly improves the railway transportation is put for-ward, which is a kind of comprehensive mode that coordinates highway, railway and water transportation.
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    Study?on?Boundary?Condition?of?Vehicle?Head-Lamp?Follow-Up??Turning?Control?System
    HOU Xiao-mei, LIU Jian-xun, LI Yang
    2009, 28(2): 298-301.  DOI: 10.3969/j.issn.1674-0696.2009.02.32
    Abstract ( )   PDF (1217KB) ( )  
    Based on the achievements of the previous studies on the rule of vehicle head-lamp follow-up turning, four stages in the process of head-lamp follow-up turning are analyzed. Two important boundary conditions which must be resolved are proposed, and the quantifiable analytic equation of the boundary conditions is obtained, which offers the theoretical basis about the quantitative solution of the boundary value and the implementation of intelligent control of the vehicle head-lamp follow-up turning.
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    Study on Two Dimensional Mathematic Model for Navigation Flow of Zhouhe Bridge in Heshi
    YU Tao, WANG Ping-yi
    2009, 28(2): 302-305.  DOI: 10.3969/j.issn.1674-0696.2009.02.33
    Abstract ( )   PDF (399KB) ( )  
    With two dimensional mathematic models, the navigation flow condition before and after the bridge construction is analyzed. The water surface profile and flow field is calculated and analyzed, which indicates that the construction of Zhouhe Bridge has small impact on the change of the water level, the discharge area and the width of the river and little impact on the main fiver flow field. The feasibility of the construction of bridge is proved.
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    Experimental System for Unsteady Flows of Open-Channel Based on PIV Technology
    HU Jiang, YANG Sheng-fa, WANG Tao
    2009, 28(2): 306-309.  DOI: 10.3969/j.issn.1674-0696.2009.02.34
    Abstract ( )   PDF (357KB) ( )  
    One experimental system with high accuracy is established for unsteady flows of open-channel, which can generate continuously unsteady flows through the rotation speed of water pump controlled by computer and transducer. The discharge and the change of water level are monitored in real time by electromagnetic flow meter and ultrasonic water level recorder; and the flow field measurement are carried out by particle imagine velocity (PIV). It is showed that the experiment system can not only generate unstable flows continuously and stably, but also promote the experimental measures of unsteady flows of open-channel.
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    Experimental?Study?on?Flood?Energy?Dissipation?and?Erosion?Control?of??Zuan'gen?Water?Control?Project
    ZUO Guang-dong, YANG Xue-feng, ZHANG Xu-jin
    2009, 28(2): 310-314.  DOI: 10.3969/j.issn.1674-0696.2009.02.35
    Abstract ( )   PDF (667KB) ( )  
    The design of energy dissipation and erosion control is worthy of attention which relates building's security and the stability of river bed and river bank. The unreasonable determination of the design condition of energy dissipation and erosion control might be one of the key reasons for the scouring commonly occurring behind sluices. Through the experimental study carried out on a scale of 1 : 50 solid hydraulic model for Zuan'gen hydro project, the arrangement of the flood outlets is studied further, which has not only resolved the problem of flood energy dissipation, simplified the structural arrangement, reduced construction quantities but also improved the flow regime and the shape of scouring hole.
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    Hydrology?Monitoring?Technology?in?the?River?Closure?of?Xiluodo?Hydropower?Station
    YANG Shi-lin, LI Zhi
    2009, 28(2): 315-318.  DOI: 10.3969/j.issn.1674-0696.2009.02.36
    Abstract ( )   PDF (285KB) ( )  
    River closure is the key engineering issue for the construction of hydropower station, and the hydrological monitoring achievements are the basic messages for fiver closure. Some traditional methods are adopted in the hydrology monitoring of Xiluodu hydropower station and the application of new technologies is also emphasized. The successful implement of these monitoring technologies is not only helpful to the triumphant realization of fiver closure, but also significant to the mo- nitoring of similar rivers in the future.
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    Methods of Vegetation Rehabilitation on Mudstone Slopes in Jinsha River Xerothermic Valley
    HE Jin-feng, YANG Zhong, CHEN Guo-jie
    2009, 28(2): 319-322.  DOI: 10.3969/j.issn.1674-0696.2009.02.37
    Abstract ( )   PDF (161KB) ( )  
    The eeo-environment of low mountain area is the most fragile in Jinsha River hot-dry valley. And it is also one of the most difficulties to improve the vegetation coverage, biomass and biodiversity for a degraded mudstone slope. Some tests of vegetation rehabilitation, including closure, semi-closure and artificial vegetation rehabilitation are implemented in Yuanmou soil and water conservation ecological experimental station, Chinese academy of sciences. Then the impact of the different measures to vegetation rehabilitation is analyzed by field survey. The results show that: closure, semi-closure and artificial vegetation rehabilitation are effective to the vegetation rehabilitation in Jinsha River valley. The height, coverage and biomass are improved by ways of vegetation rehabilitation. Nevertheless, compared with artificial vegetation rehabilitation, closure leads to a vegetation with relatively high hiodiversity.
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    Extraction Effects of Different Solvents on Chlorophyll in Damask Rose Ⅲ Leaves
    LIU Jun, HE Jin-feng, SU Chun-jiang, LIU Yan-yan
    2009, 28(2): 323-324.  DOI: 10.3969/j.issn.1674-0696.2009.02.38
    Abstract ( )   PDF (94KB) ( )  
    The chlorophyll is extracted from leaves of Damask Ⅲ rose by spectrophotometer, in which 5 kinds of extracting solvents are applied to have a contrastive study on extraction effects of different extracting solvents on chlorophyll in Damask rose Ⅲ leaves, including acetone, ethanol, and the different volume ratio of acetone and ethanol mixture. The experimental results show that the best method for chlorophyll extraction in damask Ⅲ rose leaves is to use a solvent mixing acetone with ethanol (v/v, 1 : 1 ).
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    Research on the Optimization of Repositioning Container Stochastically on Sea-Bound
    WANG Bin, TANG Guo-chun
    2009, 28(2): 325-329.  DOI: 10.3969/j.issn.1674-0696.2009.02.39
    Abstract ( )   PDF (210KB) ( )  
    The optimization of repositioning container stochastically on sea-bound is studied by use of chance-constrained programming. Both heavy and empty containers are combined into an integral system. The model that the objective function is to maximize the total profit of container repositioning is proposed. The profits caused by heavy containers repositioning subtracting costs resulting from both heavy and empty containers are equal to the total profit. The constraints to the modal inelude meeting the need of heavy and empty containers, the limit to transport ability of a line and the number of empty container supported. The number of empty container needed is stochastic. The chance-constrained programming is transferred into integer programming. LINGO 9.0 is used to solve the integer modal. The model in varied parameters are shown by simulation. The aim of the paper is to provide a reasonable project of repositioning container, so the container repositioning cost of a shipping company ean be reduced and the its profits made by container repositioning are maximized.
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    Periodic Solution for a Class of Non-Autonomous Second Order Systems
    JIA Hong-en, LIU Xi-lan
    2009, 28(2): 330-332.  DOI: 10.3969/j.issn.1674-0696.2009.02.40
    Abstract ( )   PDF (136KB) ( )  
    Existence of periodic solutions for a class of non-autonomous second order systems is studied. Some new existence condition is considered,and four new existence theorems are obtained by using the least action principle under new condition.
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