Archive

15 June 2013, Volume 32 Issue 3 Previous Issue    Next Issue

---

For Selected:

Download Citations EndNote Ris BibTeX

Toggle Thumbnails

Select

Limitation Span of Self-Anchored Cable-Stayed Bridge ( II) Zhang Yangyong 2013, 32(3): 369-373.  DOI: 10.3969/j.issn.1674-0696.2013.03.01 Abstract ( )   PDF (459KB) ( )   From the angle of structural deformation，buckling stability and pneumatic stability，the research on limitation span of the whole self-anchored cable-stayed bridge structure system was carried out on current level of material and construction. The analysis shows that the effect of transverse limit static gust wind is the first factor to be considered and the secondary factor is the impact of live load in the control of construction condition in cable-stayed bridge design. In design， the primary problem to solve is lateral stiffness of the main girder. It is feasible preliminarily to build a main span of 1 500 m self-anchored cable-stayed bridge in current condition. Through the analysis of limit span，some technical measures to increase the span of the cable-stayed bridge are proposed，which provides reference in concept design of super long span cable- stayed bridge. References | Related Articles | Metrics

Select

UnstressedCableLengthandGeometricLinearControl of HybridGirder Cable-StayedBridgewith1000mSaleSpan XieMingzhi ，BuYizhi ，Wei Ran 3，Li Shaopeng 2013, 32(3): 374-378.  DOI: 10.3969/j.issn.1674-0696.2013.03.02 Abstract ( )   PDF (707KB) ( )   Inthelight of themechanical behaviorandthemajorproblemsinmanufactureanderectionphaseof hybridgirder cable-stayedbridgewith1000mscalespanduringconstructionstage，thecontrol methods of unstressedcablelengthand geometricprofilewerestudiedonthebaseof thegeometrycontrol method，accordingtotheconstructioncontrol of Edong Bridgewithamainspanof926m. Basedonthestudiesmentionedabove，unstressedconstantswereadjustedbothinmanufactureanderectionstage. Besides，thecontrol of unstressedcablelengthandgeometricprofilewereconvertedtothecontrol of tensionamount andgirder angle，whichwastobeinaccordancewithideal profileandcableforce. Theproposedmethod wasanefficient methodwithhighprecisionfor bridgeconstructioncontrol. Withthismethod，undesirableinfluencecaused bynatural environment canbereduced，andsomeconstructionerrorscanbeavoidedaswell. Constructionexperienceindicatesthat thetheoretical calculationisinwell accordancewiththefieldresults，whichprovesthat themethodpresentedis prettyeffectiveandreliable. References | Related Articles | Metrics

Select

AnalysisonFixedTower-Beam-PierPart of Cable-StayedBridge SongJun，ZhouJianting，ChenZengshun 2013, 32(3): 379-384.  DOI: 10.3969/j.issn.1674-0696.2013.03.03 Abstract ( )   PDF (809KB) ( )   Basedonthefiniteelement analysis of thewholestructureof thelong-spancable-stayedbridge，thesub-model methodwasappliedtodofiniteelement structural stressanalysisof thepylon-girder-pier joint，andthestressandstrainof thestructurewerecalculatedinfour different workingconditions. Theresearchshowsthat sub-model methodcancalculate thestressdistributionof thepylon-girder-pierjoint moreaccuratelyandthecalculatingresultscanbeconsideredasthereferencetothedesignandconstructionof fixedtower-pier-beampart of thelong-spancable-stayedbridge References | Related Articles | Metrics

Select

BaseImpact of InterfaceMaterial ParametersandLayerStateontheForceof Steel BridgeDeckdonSub-Model Method ZhaoChaohua，HanXu，Li Ya 2013, 32(3): 385-388.  DOI: 10.3969/j.issn.1674-0696.2013.03.04 Abstract ( )   PDF (447KB) ( )   Bymeansof thefiniteelement numerical analysis method，stress of steel deckpavement systeminfluencedby References | Related Articles | Metrics

Select

NonlinearSeismicResponseAnalysisonConcrete-FilledSteel TubularFramePiers ChangShan 2013, 32(3): 389-395.  DOI: 10.3969/j.issn.1674-0696.2013.03.05 Abstract ( )   PDF (568KB) ( )   Takingconcrete-filledsteel tubular framepier andhollowthin-walledpier as theresearchprojects，thedynamic time-historyanalysismodelsareestablishedbyusingthefiberelement forconcrete-filledsteel tubularframepierandhollow thin-walledpier. Byinputting3actual seismicwavesintotheanalysismodels，thelinearandnonlineartime-historyresponse is analyzedrespectively. Basedontheanalysis results，theeffect of seismicresponsefor different piers is compared，and seismicresponsecharacteristicsof framepierarediscussed. Theresultsshowthat shearresponseappearslineardistribution， moment responserepresentsserrateddistributionandaxial forceresponseemergesstepwiseincreasealongthecolumnheight for framepier under theactionof waves. Shear，moment andaxial forceresponseof onecolumnof framepier arerelatively smaller comparedwithhollowthin-walledpier under theactionof waves. References | Related Articles | Metrics

Select

CompressionTestsof theRectangularPlainChloropreneRubberBearingsin SaltyFrozenCondition ShenXiaojun ，ChenBokui ，GaoFei ，XieYingshuang ，ZhengYi ，MaLiang 2013, 32(3): 396-399.  DOI: 10.3969/j.issn.1674-0696.2013.03.06 Abstract ( )   PDF (707KB) ( )   Inorder todotheresearchonthechangeof themechanical indexes of therectangular plainchloroprenerubber bearings，therectangular plainchloroprenerubber bearingswereprocessedunder saltyfrozenconditionfor20，40，60and 80days. Moreover，theaxial compressiontestswerealsocarriedout bypressuretestingmachine. Theeffect of thesalt-frost onbearingcapacity，ultimatecompressivestrength，vertical stiffness，andcompressiveelasticmodulus of therectangular plainchloroprenerubber bearingswasalsostudied. Theresultsshowedthat insaltyfrozencondition，brittlefractureof the plainchloroprenerubberbearingswaseasiertoappear; theelasticstagewasshortenandthephenomenonof steel plateexposure，cracksandlayereddestructionweremoreserious; thebearingcapacities，ultimatecompressivestrength，vertical stiffness，andelasticmodulusof compressiondecreasedwiththedeepeningof thesaltyfrozendegree. Theattenuationcurveof compressivestrengthandcompressiveelasticmodulusandtheattenuationmodel wereacquiredin50yearsbyregressionanalysiswiththeleast squaremethod. Thestatistical analysisresult showsthat theattenuationcurveandtheattenuationmodel conformtothereal situation References | Related Articles | Metrics

Select

HealthMonitoringof Long-SpanRailwayArch-AuxiliaryGirderBridge ManJianlin，ZhangYongshui，Gui Chengzhong 2013, 32(3): 400-403.  DOI: 10.3969/j.issn.1674-0696.2013.03.07 Abstract ( )   PDF (495KB) ( )   Onthebasisof newly-built GuangyuanJialingRiver super long-spandouble-linerailwaybridgeonLan-YuRailway，thepresent situationandshortages of theBHMsystemwas introduced，accordingtothecharacteristics of long-span railwayarchauxiliarygirder bridges. Bytheresearchesonthecomponents，structuresandfunctionsof theBHMsystembasingonstaticanddynamicforceparameters，whichinfluencethebridgestructureresponses，acomputational exampleof the sensors optimal designintheBHMsystemwas proposedtodesignandoptimizethesensors selectionandlayout. The computational exampleprovidesareferenceforthesametypeof long-spanrailwayarchauxiliarygirderbridgehealthmonitoringdesign. References | Related Articles | Metrics

Select

Impact of RoadSlopeonWaterFilmThickness ZhangLi，ZhangZhuo 2013, 32(3): 404-406.  DOI: 10.3969/j.issn.1674-0696.2013.03.08 Abstract ( )   PDF (372KB) ( )   UsingtheManningformula，thewater filmthicknessformulais deduced. Bymeans of thewater filmthicknessformula，thepartial derivativefunctionof thewater filmthickness oncross slopeandlongitudinal slopewas obtained. Accordingtotheanalysisonthepartial derivativefunctionobtained，it isdrawntheconclusionthat thepartial derivativefunctiononcrossslopeislessthan0constantlyandit meansthat thewater filmthicknessdecreaseswiththe increaseof crossslopegradient; thepartial derivativefunctiononthelongitudinal gradient isgreater than0constantly， andit meansthat thewaterfilmthicknessincreaseswiththeincreaseof longitudinal gradient; theratiobetweentheabsolute valueof thepartial derivativesof thecrossslopegradient andtheabsolutevalueof thepartial derivativesof longitudinal gradient ismorethan22，andit indicatesthat thecrossslopegradient hasgreater influenceonthewater filmthicknessthan thelongitudinal gradient does. References | Related Articles | Metrics

Select

ResistingSegregationAnalysisintheConstructionof Ultra-ThinLayerAsphalt Pavement Li Pengwei，Wei Ya，ZhongLi 2013, 32(3): 407-409.  DOI: 10.3969/j.issn.1674-0696.2013.03.09 Abstract ( )   PDF (209KB) ( )   Throughtheanalysisonpavingtechniqueof ultra-thinlayer，thecharacteristicsandrequirementsfortheconstructionworkmanshipof theultra-thinlayerpaverwasdiscussed. Accordingtothespecial requirementsfortheasphalt pavement surface，theimprovement measuresareput forwardedtoreducesegregationphenomenonof mixturesintransportation，rolling andmechanical structuretoimprovehomogeneityof mixtures，evennessandqualityof pavemen References | Related Articles | Metrics

Select

Effect of HighFrequencyVibrationonAir-EntrainingParametersand FreezingResistanceof theAirEntrainedConcrete ZhangYancong ，HanLijun ，GaoLingling 2013, 32(3): 410-414.  DOI: 10.3969/j.issn.1674-0696.2013.03.10 Abstract ( )   PDF (576KB) ( )   Highfrequencyvibrationof different timewasappliedontwokinds of air-entrainedconcrete. Porestructure analyzer of hardenedconcretewasappliedtoquantitativelydescribetheinfluenceof vibrationonair content of theairentrainingconcrete，thespacingfactorandtheporesize. Meanwhile，thefreeze-thawcycletest couldaccuratelyreflect therelationshipbetweenhighfrequencyvibrationandthefreezingresistance. Theresults showedthat theair content changedlittlewhenvibrationwasimposedat thebeginning. Then，it begantodecreaseobviously( about 60slater) . After about 105s，theair content decreasedslowlyandfinallytendedtobestable. Thecoefficientsof thespacingfactor of concreteincreasedinitiallyandthendecreased. Meanwhile，averagediameterof bubbledecreasedandthespecificsurfaceareaincreased. Theair bubblewhosediameter wasbetween480 mand960 mwasmoresensitivetohigh frequencyvibration. Onthecontrary，theair bubblewhosethediameter between480 mand960 mwasstable. In addition，longtimeof highfrequencyvibrationwoulddirectivelydegradetheair-entrainedabilityandthefreezingresistancewoulddecline. References | Related Articles | Metrics

Select

Three-Dimensional SlopeStabilityof EarthquakeZoneBasedonStrength ReductionFEM ChenLinjie，ZhengXiaowei 2013, 32(3): 415-418.  DOI: 10.3969/j.issn.1674-0696.2013.03.11 Abstract ( )   PDF (719KB) ( )   Combiningwithengineeringexamples，thestrengthreductionFEMisusedtodostaticandpseudo-staticanalysis onthethree-dimensional slope; thebasicprinciple，yieldcriterion，instabilitycriterionetc. of thestrengthreductionFEM arealsodiscussed. Thesafetyfactorsof thethree-dimensional slopeareobtainedbyuseof thefiniteelement softwareANSYS; furthermore，theslopestabilityisevaluated. At thesametime，thesafetyfactorsgot bytheproposedmethodarecomparedwiththose got by the traditional limit equilibriummethodand2DFEM. The results showthat it is feasible that strengthreductionFEMisappliedinthree-dimensional slopestabilityanalysisof theearthquakezone References | Related Articles | Metrics

Select

ResearchontheMechanical Propertiesof InvertedYTypeRetainingWall ChenLiang ，ChenXiaojing 2013, 32(3): 419-423.  DOI: 10.3969/j.issn.1674-0696.2013.03.12 Abstract ( )   PDF (655KB) ( )   Thestructurecharacteristicsandmechanical propertiesof theinvertedYtyperetainingwall areintroduced. And theinvertedYtyperetainingwall iscomparedwiththecantilever andgravityretainingwall. At thesametime，thestability coefficient，lateral earthpressureandbasestressof threekindsof retainingwall aresolvedbyanalyticcalculationandnumerical analysismethod，combiningwiththeengineeringexample. Andthecalculationresultsarecomparedandanalyzed， whichshowsthat theinvertedYtyperetainingwall isbetter thanthecantilever andthegravityretainingwall. References | Related Articles | Metrics

Select

Numerical Analysisof Soil ArchingEffect andTensionedMembrane Effect of Geogrid TengQianliang，HuRunzhong 2013, 32(3): 424-428.  DOI: 10.3969/j.issn.1674-0696.2013.03.13 Abstract ( )   PDF (1231KB) ( )   Inorder tohaveabetterunderstandingof thesoil archingeffect inthosepile-net supportsembankments，asimplifiedmodel for singlepileisestablished. Fromtheangleof settlement，vertical stress andprincipal stress，themechanism andthechangingcharacteristicsof soil archingeffect arestudied; andthetensionedmembraneeffect of geogridisalsostudiedat thesametime. Theresearchresultsindicatethat theheight of equal settlement sectionis about 1.7times lengthof pilenet spacing; theembankment canbedividedintosoil archaffectedzoneandnon-affectedzone. Insoil archaffected zone，thevertical stressof theembankment inthecenter of thesoil amongpileschangeswith"S" shape. Insoil archnonaffectedzone，thestressvaries linearly. Thestress onthetopof piledistributes unevenly. Whenpilenet spacingis less thanonemetre，thestressinthecenterof pileistheminimumandthestressontheedgeof pileisthemaximum. Whenpile net spacingismorethanor equal to1metre，stressontheedgeof pileisminimumandthestressnear theedgeof pileis maximum. Thedirectionof majorandminorprincipal stressisrotatedandtheflowlinesof themajorprincipal stressareapproximatetoelliptical arc. Thedistributionof geogridstress is approximateto"M" shape，thestress closetotheedgeof pileismaximumandthestressinthecenter of thepileandsoil amongpilesisminimum. References | Related Articles | Metrics

Select

Evaluationof PileTest byUltrasonicWaveBasedonFuzzyComprehensive EvaluationMethodandFiniteElement Method ZhangHongjun ，ZhouShiliang ，YangHufeng 2013, 32(3): 429-433.  DOI: 10.3969/j.issn.1674-0696.2013.03.14 Abstract ( )   PDF (410KB) ( )   Onthebasisof establishingmembershipfunctionof evaluationset，weightedaveragemethodis appliedtocarry out fuzzycomprehensiveevaluationonfiletest byultrasonicwave. Thevertical bearingcapacityof pilefoundationiscalculatedat different positionsof pilebodyunder thesamedefect condition，andthedefect impact factorsat different positions arealsocalculated. Firstly，theresultsof fuzzycomprehensiveevaluationandcorrespondingdefect impact factorsaremultiplied; then，all theobtainedresults areaddedtoget acomprehensiveevaluationwhenthecertaindefect positioninpile foundationisconsidered. Comparedwithother evaluationmethodsof piletest byultrasonicwave，theproposedmethoddependsonthevertical bearingcapacityof pilefoundationandconsidersdefect position，whichisamorecomprehensiveand accurateevaluationmethod References | Related Articles | Metrics

Select

CalculationPrecisionof WaveResponseSpectraBasedonTrigonometric InterpolationMethod WangZijian，XiaoShengxie 2013, 32(3): 434-437.  DOI: 10.3969/j.issn.1674-0696.2013.03.15 Abstract ( )   PDF (586KB) ( )   Onthebasisof thebasicconcept of responsespectrumandlinearinterpolationmethod，thetrigonometricinterpolationmethodisproposedtosolvethefluctuationresponsespectrum. Firstly，thecalculationformulaof responsespectrumis deduced，andchainrecursiveformulaof theresponsespectrumcalculationinequal timeinterval is established. Theresponse spectrumof the simple harmonic dynamic loadis calculatedby trigonometric interpolationmethod，the analytical methodand"precisionmethod". Thecomparativeanalysisresultsshowthat thespectrumresponsevaluegot bytrigonometricinterpolationiscloser thanthat got by"precisionmethod" totheanalytical solve，whichisof higher precision. Thenumerical calculationiscarriedout onthespectrumresponseof thefluctuationaccelerationcurveof twoactual recordsbytrigonometricinterpolation. Theresultsshowedthat，theresponsespectrumvaluesgot bytrigonometricinterpolationmethodare stable，andtheresponsespectrumvalues aregenerallyslightlylarger thantheresults obtainedbythelinear interpolation method. Theresponsespectrumvaluesgot bytrigonometricinterpolationmethodmeet therequirementsof accuracy，which simplifiescalculationtoacertainextent References | Related Articles | Metrics

Select

Boundary between Shallowly-Buried and Deeply-Buried Tunnel Dynamic and Its Influence Factors Gao Feng，Tan Xukai，Sun Changxin 2013, 32(3): 438-441.  DOI: 10.3969/j.issn.1674-0696.2013.03.16 Abstract ( )   PDF (802KB) ( )   The boundary of shallowly buried tunnel and deeply buried tunnel on dynamic characteristics and its influence factors are studied by using finite element to simulate the seismic response of tunnel with different surrounding rock condition， different tunnel span and different seismic intensity. The research results show that the stress of tunnel structure increases at first，and then decreases with increase of the buried depth. It indicates that the inflection point is the boundary of shallowly buried tunnel and deeply buried tunnel. The better the surrounding rock condition，the deeper the depth of the boundary will be，and in that condition the depth of the boundary in grade Ⅲ，grade Ⅳand grade Ⅴ rock is about 100，80 and 60 m respectively. The depth of the boundary decreases with the increase of the tunnel span，but the influence is little. In that condition the span is 6，10，20 m，and the corresponding depth of the boundary is about 100，100，80 m respectively. The seismic intensity will not influence the boundary of shallowly buried tunnel and deeply buried tunnel. References | Related Articles | Metrics

Select

Application of Auto-Regression and Subsection-Regression Method in Tunnel Deformation Analysis Zeng Shan，，Xu Xi3 2013, 32(3): 442-445.  DOI: 10.3969/j.issn.1674-0696.2013.03.17 Abstract ( )   PDF (414KB) ( )   Forecast and analysis of the civil engineering deformation rely on the mathematical statistics theory. The tunnel subsidence is monitored by applying auto-regression and subsection-regression theoretical methods. The results show that the auto-regression theory is suitable for the project safety and quality forecast; the subsection-regression method could describe the deformation rule of the monitoring object. The auto-regression and subsection-regression method are practical in tunnel deformation monitoring. References | Related Articles | Metrics

Select

Rockfall Hazard Assessment Method and Its Application Gao Maiyan，Tang Hongmei，Zeng Yunsong，Lv Tao 2013, 32(3): 446-450.  DOI: 10.3969/j.issn.1674-0696.2013.03.18 Abstract ( )   PDF (809KB) ( )   The rockfall threat range is determined by use of numerical simulation software of RocFall. The homeostatic capacity and disaster capacity are two prerequisite，which demonstrated rockfall is dangerous. Based on these，the assessment indexes of rockfall risk are selected. Through the calculation of grey correlation coefficient，the relative priority order has been obtained. The generalized set pair analysis and analytic hierarchy process method are combined to obtain the assessment index weight of hazard risk. Through the multi-index assessment method，the assessment of rockfall has been established. According to the most dangerous principle，the rockfall zone is divided into four ranks，which are extremely high risk，high risk，medium risk and low risk respectively. This proposed method was applied in Wangxia rockfall of Wushan， which showed that Wangxia rockfall of Wushan was high risk. The assessment results fit well with the actual situation. References | Related Articles | Metrics

Select

Essence of Difference in Flow Duration in Different Flow Construction Wei Daosheng 2013, 32(3): 451-454.  DOI: 10.3969/j.issn.1674-0696.2013.03.19 Abstract ( )   PDF (325KB) ( )   On the basis of different flow construction and according to the form of non-idleness and interval or non-interval and idleness，different flow construction results are researched and the difference in two flow duration and the relationship between D-value and flow duration are also studied. The results show that the difference in flow duration is that when m construction sections and n work procedures are put into flow construction，there is takt time among any three continuous flows， and the middle takt time is the minimum. The relationship between flow duration ( T) of the non-idleness and interval and the flow duration ( T') of the non-interval and idleness is that T ＞ T'，and the D-value of them is related to the D-value between minimum of the three continuous flow takt time and the maximum from another side，which is the multiple of m-1， otherwise，T = T'. References | Related Articles | Metrics

Select

Traffic Organization Optimization Method of Fully Enclosed Construction of Secondary Road Mei Zijun，Liu Tangzhi，Tang Boming 2013, 32(3): 455-458.  DOI: 10.3969/j.issn.1674-0696.2013.03.20 Abstract ( )   PDF (500KB) ( )   On the basis of road classification，the influence of fully-enclosed construction on different grades of roads is analyzed. Taking the fully-enclosed construction of the secondary road of Nan-Fu road as an example，four indexes are adopted to reasonably distribute the traffic flow，which are road load degree，the average link speed，the safety degree crowded and expressway toll. According to the actual situation of Nan-Fu road，some feasible measures are proposed. References | Related Articles | Metrics

Select

Early Warning of Storm Grade in Expressway Zhang Xuguang，Gao Jianping，Wu Guoxiong 2013, 32(3): 459-462.  DOI: 10.3969/j.issn.1674-0696.2013.03.21 Abstract ( )   PDF (470KB) ( )   According to the research on the impact of stormy weather on traffic，the snow storm warning principle has been established，which is divided into 2 periods，which are pre-disaster warning and real-time warning. For the real-time warning， it has been established by explicit warning method and the Fisher distinguishing law based on the effect of snowfall to traffic. At last，the reliability of the discrimination of expressway storm warning level model is verified by using an example application; further more，it is proved that the model can be used for the discrimination of expressway storm warning level， which provides technical reference to guarantee the safe operation of expressway under snowstorm weather. References | Related Articles | Metrics

Select

Dynamic Prediction Method of Transfer OD Matrix for Urban Transit Hub Hu Hua，Liu Zhigang，Zhu Haiyan 2013, 32(3): 463-466.  DOI: 10.3969/j.issn.1674-0696.2013.03.22 Abstract ( )   PDF (502KB) ( )   A transfer OD matrix is the basic data for coordination dispatching among transit lines in a transit hub under Advance Public Transportation System ( APTS) . A BP artificial neural network ( ANN) model is applied to track the weights of OD pairs within a transit hub through using the data of boarding and alighting transfer passengers at each transit line. The key issues associated with the estimation process are deeply studied，including the design of ANN，the learning and stopping rules，and the calibration of model parameters through computational experiment. The results of the example from a transit hub reveal that the proposed model provides an economic and effective method for dynamic prediction of transfer OD matrix for a transit hub. References | Related Articles | Metrics

Select

Division and Features of Small Watershed along Mountain Roads Tian Jia，Lin Xiaosong，Yu Shasha，Zhou Lilei 2013, 32(3): 467-470.  DOI: 10.3969/j.issn.1674-0696.2013.03.23 Abstract ( )   PDF (705KB) ( )   Taking the main arterial road of Anlan and Tiaoshi in Chongqing Ba’nan District as the research projects，the large scale topographic map is used as basic data to build digital elevation model along roads. On the basis of ArcGIS hydrological analysis module，some studies are carried out to divide the small watersheds along the mountain roads and analyze the watershed features，such as the DEM filling，flow direction analysis，confluence accumulation calculation，extraction of river network and so on. The research results show that the extracted water system is most approximate to the actual river nets when the set water grid threshold value is 15，000; and then the research areas are divided into 87 small watersheds，in which the road passes 31 watersheds. In the 31 small watersheds，the areas of the watersheds accounting for 58. 06% are between 1and 5 km2 ; the shape coefficients of the small watersheds are between 0. 32 and 4. 96; the undulation of small watershed is between 121 and 535 m; the biggest confluence accumulation of small watersheds which cross the road is between 46 and 759， 348. References | Related Articles | Metrics

Select

Change of Heavy Metals Content in Soil of Water-Level-Fluctuating Zone in Three Gorges Reservoir Area Wang Tujin，Yang Qingwei，Pan Jin，Liu Xuelian 2013, 32(3): 471-474.  DOI: 10.3969/j.issn.1674-0696.2013.03.24 Abstract ( )   PDF (568KB) ( )   Taking the soil of water-level-fluctuating zone in Three Gorges Reservoir area as the research object，the features of migration and transportation of the heavy metals in the soil of water-level-fluctuating zone in the condition of alternate drying- wetting are studied. The results indicate that the content of heavy metals in water in flood season is higher than that after the flood season. The environmental risk caused by migration and transportation of the heavy metals in the soil of waterlevel- fluctuating zone is low. Cu and Cr in soil of water-level-fluctuating zone exist in the form of residue and the ecological risk is low. Heavy metals could be extracted from Pb and Cd，whose potential ecological risk is high. Heavy metal concentration inclines to increase generally in a periodical alternate drying-wetting environment for a long time. The average increasing amount of Cu，Pb，Cd and Cr is 17. 04%， 24. 49%， 12. 99%， 13. 70% respectively. In general， the increment sequence is Pb ＞ Cu ＞ Cr ＞ Cd. References | Related Articles | Metrics

Select

Change of Channel Conditions of the Reach from Wanzhou to Fuling in the Yangtze River at Incipient Stage of Three Gorges Reservoir Wu Wenjun 2013, 32(3): 475-479.  DOI: 10.3969/j.issn.1674-0696.2013.03.25 Abstract ( )   PDF (481KB) ( )   To study the changes of channel conditions and trends of the reach from Wanzhou to Fuling in the Yangtze River since the Gorges Reservoir begins to impound，various kinds of water level and water flow rate data are respectively collected from each hydrometric station in various periods of water storage. One-dimensional mathematical model is adopted to calculate the navigation flow condition ( water depth，the flow speed，slope) from Wanzhou to Fuling and comparatively analyze the changes of navigation flow condition on each storage period. When the water level is increased in the water storage period， the velocity of water flow decreases at the same time，which is good for the channels. However，it also leads to sediment accumulation at some reaches. References | Related Articles | Metrics

Select

Landslide-Generated Wave Theory in Reservoir Areas Luo Xiang，Li Yi，Zhou Shiliang 2013, 32(3): 480-484.  DOI: 10.3969/j.issn.1674-0696.2013.03.26 Abstract ( )   PDF (380KB) ( )   The landslide-generated wave in reservoirs is a complicated hydrodynamic problem. In the recent decades， through the logical assumptions of boundary conditions，wave-generating mechanisms and flow conditions，many theories have been applied for describing the landslide-generated wave. Firstly，some typical theories of landslide-generated wave are reviewed，such as solitary wave，impulsive wave，rarefaction wave，etc. Then the applicability and defects of all theories in practical projects are contrasted in detail. Finally，a practical standard for establishing the reliable landslide-generated wave models is proposed. References | Related Articles | Metrics

Select

Stability Analysis of High Rock Slope on Left Bank of Jinfoshan Hydraulic Engineering Wang Junjie，，Qiu Zhenfeng， 2013, 32(3): 485-488.  DOI: 10.3969/j.issn.1674-0696.2013.03.27 Abstract ( )   PDF (683KB) ( )   Combining with the engineering geological condition，the scale of slope shape as well as the mechanism of deformation and failure，FEM strength reduction method is used to do stability analysis of high rock slope on the left bank of Jinfoshan hydraulic engineering dam site in Chongqing，considering the two moisture states in the rock slope，natural and saturated. The stability safety factors of the high rock slope in different conditions of natural state，excavation and strengthening are studied. The results show that the safety factors in all kinds of conditions meet the requirements of the specification; the slope is a potential thrust landslide with bedding traction-plastic flow property at the bottom and compressing and tension cracking at the top. Weathering of rock mass at the excavated part is good for slope stability，and the safety factors increase obviously when the shotcrete rockbolt stabilization technique is applied. The slope is stable at present and the possibility of massive destruction is minimal. References | Related Articles | Metrics

Select

Key Techniques and Reliability Analysis of A Novel Floating Bollard Device Zhang Xingxing，Chen Mingdong，Ba Tian 2013, 32(3): 489-493.  DOI: 10.3969/j.issn.1674-0696.2013.03.28 Abstract ( )   PDF (562KB) ( )   The instantaneous amplitude of water level has great influence on the safe mooring on the vertical-face wharf， which is in the downstream of the hydropower station. Based on the principle of floating bollard of lock，a new kind of floating bollard device is proposed，which refers to four spring balance devices installing symmetrically around the buoys，to resolve the key technical issues，such as unbalanced resistance in the case of the maximum mooring rope tension during its up and down. Through the theoretical calculation and the model test of Jinshajiang Shuifu comprehensive port，the results show that the technique is feasible，and it can be applied in the similar projects. References | Related Articles | Metrics

Select

Optimal Control of Vehicle Suspension Based on the Simulated Annealing Algorithm Meng Jie，Chen Qingzhang，Zhang Kai 2013, 32(3): 497-501.  DOI: 10.3969/j.issn.1674-0696.2013.03.30 Abstract ( )   PDF (624KB) ( )   A method based on the simulated annealing algorithm is designed to optimize the weight matrix of the LQR controller. The proposed method utilizes the random searching of the algorithm to optimize and design the weight matrices of the target function of chassis performance indexes. The proposed method improves the design efficiency and control performance of the LQR control，and solves the problem of the LQR when defining the weight matrices. The method is adopted to simulate the vehicle active chassis control. The results show that the actively controlled chassis using LQR optimized by the simulated annealing algorithm can greatly improve the chassis performance，comparing with the chassis controlled by the normal LQR and the passive one. Meanwhile，the advantage of the normal LQR is sufficiently utilized. What's more，the problem of defining the weight matrices is greatly improved. References | Related Articles | Metrics

Select

Design of the Turbine Rotor Blade Based on Bezier Curve Method Li Jun，Jiang Rui 2013, 32(3): 502-505.  DOI: 10.3969/j.issn.1674-0696.2013.03.31 Abstract ( )   PDF (606KB) ( )   According to the preliminary design formula of turbine and Bezier curve construction method，the meridian surface shape and the blade profile is designed by NUMECA software Design3D module，which takes the runoff radial-inward turbine efficiency of 0. 5 as the target value. Hydrodynamic mechanics calculation is carried out on the blade and the meridian surface，which is designed on the basis of the NUMECA software. The parameters of the blade type and the efficiency target value are obtained，and the distribution of the absolute temperature and absolute pressure of medicinal surface is also obtained. The runoff radial-inward turbine efficiency is taken as the target value，and the design methods of blade profile and medicinal surface line is proposed，combining with Bezier curve construction method. References | Related Articles | Metrics

Select

Simulation Analysis on the Effect of Trailer Arm Suspension on the Steady Turning Characteristics Guo Lina，Xue Nianwen，Pan Jian 2013, 32(3): 506-510.  DOI: 10.3969/j.issn.1674-0696.2013.03.32 Abstract ( )   PDF (822KB) ( )   By applying the ADAMS /Car software，four types of flexible trailer arm rear suspensions and a rigid-flexible coupling virtual prototype model of mini car are established. Carrying out the steady turning test，the results of test and simulation are compared to verify the correctness of the whole vehicle model. The kinetic simulation of the rear suspensions of different structure are carried out and the effect of the change of the trailer arm suspension on the steady turning characteristics are studied. The simulation of steady turning characteristics is applied on the whole vehicle model on which four types of rear suspensions installs. The results show that the rolling angle stiffness of the rear suspensions will decrease by controlling the length of reinforcing rib of trailer arm，which will improve the steady turning characteristics efficiently. References | Related Articles | Metrics

Select

Power Loss Analysis on Electrical Hydraulic Power Steering System Li Qiang，Xia Changgao，Jin Qiao，Zhang Qinglong 2013, 32(3): 511-514.  DOI: 10.3969/j.issn.1674-0696.2013.03.33 Abstract ( )   PDF (707KB) ( )   Through the real vehicle test，the characteristic curve of the steering system and the idling power of the power steering motor in condition of non-steering are achieved. The electrical hydraulic power steering system is established on the platform of AMEsim. Simulation is carried out on the basis of the proposed model，and the simulation results indicate that the loss of steering valve power is the largest in case of the vehicle steering; in the case of vehicle non-steering，the loss of the idling power of the power steering motor is the main loss. Finally，through the change of the main structural parameters of the steering valve，it shows the effect of power loss. References | Related Articles | Metrics

Select

Oxygen-Enriched Combustion in Idling Condition of Gasoline Engine Yao Jiayan 2013, 32(3): 515-519.  DOI: 10.3969/j.issn.1674-0696.2013.03.34 Abstract ( )   PDF (766KB) ( )   Oxygen-enriched combustion is realized on a gasoline engine by controlling the different intake oxygen volume fraction. The characteristics of combustion and emission of a gasoline engine in the idling condition are studied by controlling the oxygen volume fraction at 21. 1%，22. 6%，25. 5% O2 . The research results show that with the increment of oxygen volume fraction in idling condition，the in-cylinder pressure and combustion heat release rate increase obviously; the time when the angle of peak appears advances and cumulative heat release increases sharply. As the intake oxygen density increases， the cycle-to-cycle variation decreases，and the combustion stability of the gasoline engine is improved; meanwhile，fuel consumptions are almost invariable. Realizing oxygen-enriched combustion in idling condition，the emission of THC and CO reduces largely and emission of NO2 increases，but the increment is at a low level. References | Related Articles | Metrics

Select

Trajectory Planning of Lane Changing for Intelligent Vehicles Yang Zhigang，Qi Zhijin，Huang Yan 2013, 32(3): 520-524.  DOI: 10.3969/j.issn.1674-0696.2013.03.35 Abstract ( )   PDF (721KB) ( )   Two defects in the traditional lane changing models at present are pointed out. The first one is the situation in which the front wheel turning angle of 0 degree is ignored in the process of lane changing; the second one is that there are several problems，for example，high lateral acceleration，the jump occurrence，the non-continuous curvature. Comparing the traditional lane changing models with other lane changing models and combining the advantages of lateral acceleration which is 0 constantly with excellent characteristics of smoothness of sine functional lane changing path，a new lane changing model is proposed，which can solve the above mentioned defects which exist in traditional models. Comparing several lane changing models by means of MATLAB simulation test，the feasibility and advantages of proposed lane changing rules are verified. References | Related Articles | Metrics

Select

Energy-Absorbing Characteristics of Front Rail of Light-Duty Truck in the Course of Collision Du Xuejing，Wang Zhanyu，Chen Lin，Lu Hao 2013, 32(3): 525-528.  DOI: 10.3969/j.issn.1674-0696.2013.03.36 Abstract ( )   PDF (857KB) ( )   Based on the collision theory，the energy-absorbing characteristics of light-duty truck are analyzed by establishing the finite-element model in CATIA and carrying out the simulation through the software ANSYS /LS-DYNA. The results show that most collision energy is absorbed by front rails of vehicle frame. The maximum deformation position is located in variable cross-section of vehicle frame. The deceleration peak caused by the failure of plastic deformation appears 2 ms later， when the initial collision velocity is 13. 5 m/s and the whole equipment quality of truck is 2. 5 t. Similar to the deceleration， the absorbing peak of vehicle frame appears 2 ms after the collision. References | Related Articles | Metrics

Select

Development of Container Sea-Rail Intermodal Transportation System Based on System Dynamics Wu Huirong， ，Zhu Xiaoning 2013, 32(3): 529-533.  DOI: 10.3969/j.issn.1674-0696.2013.03.37 Abstract ( )   PDF (577KB) ( )   Based on the analysis of the main influencing factors which is related to the development of container sea-rail intermodal transportation，system dynamics theory and method is used to describe the development situation of the container sea-rail intermodal transportation. By use of casual loop diagram，the relationship among the container sea-rail intermodal transportation development，economic development and transportation policies are analyzed. Meanwhile，SD model of container sea-rail intermodal transportation system development is established and the effectiveness of the model is verified by taking Dalian Port as the example. Taking the three factors as the three controlling variables，which are improving the forming mechanism of transportation tariff，strengthening port and railway construction and information sharing of port and railway， the influence of different policies on the container sea-rail intermodal transportation system and economic development is simulated by the models. Corresponding suggestions are put forward finally. References | Related Articles | Metrics

Select

Design and Implementation of Embedded Platform for Video Communication System Xu Dengyuan，Wang Xiaoli，Wang Peng 2013, 32(3): 534-537.  DOI: 10.3969/j.issn.1674-0696.2013.03.38 Abstract ( )   PDF (692KB) ( )   The X. 264 video compression coding on the embedded platform is used to do the research and development of real- time video communication system front. FFMPEG video decoding on the Linux platform is used to do the research and development of real-time video communication system background. The proposed methods realize the design and development of the video communication embedded system，which has the function of video capture，video storage and wireless internet transmission. This system is with wide application，low cost，as well as the practical and reliable function. References | Related Articles | Metrics

Select

Design of Laser System of Self-Adjusting Level for Deflection Monitoring Zhang Kaihong，Zhang Wenhui，Li Cong 2013, 32(3): 538-542.  DOI: 10.3969/j.issn.1674-0696.2013.03.39 Abstract ( )   PDF (581KB) ( )   When we use the laser image method to measure the deflection，the case whether the laser transmitter can automatically adjust the level，the length of adjusting time and the size of the projected spot have direct impact on the accuracy of the deflection monitoring. So，a laser system of self-adjusting level for deflection monitoring is designed. Gravity pendulum is used for self-adjusting. Through the analysis of stress and trajectory of the gravity pendulum，critical damping conditions are used to determine damping coefficients and to adjust the electromagnetic damper magnetic induction intensity and the drag coefficients，which finally realize rapid hovering. In order to maintain good concentration of energy when laser is shooed in long distance，Fermat Theorem is used to design the corresponding focusing lenses，which are combined with the Galileo beam expander to compose the laser lens to realize long distance shoot. The laser lens parameters and the electromagnetic damper parameters are obtained after analyzing and deducing. The achievement provides theoretical foundation for the appearance of the real laser emission device. References | Related Articles | Metrics

Select

Application of Improved Ant Colony Algorithm in System Reliability Optimization of Redundancy Allocation Hu Qiguo，Hu Xiaohua，Wu Yonglong 2013, 32(3): 543-546.  DOI: 10.3969/j.issn.1674-0696.2013.03.40 Abstract ( )   PDF (522KB) ( )   Ant Colony Algorithm is easy to fall into partial optimizer and slow computing speed in the process of solving NP problem. On the basis of Ant Colony Algorithm，state transition rule and pheromone updating rule of the ant colony algorithm are re-designed. The experiment results show that the improved ant colony algorithm is an effective way to solve the redundancy allocation problem and could find optimum solution in a relatively short time at the same time. References | Related Articles | Metrics

Select

Adaptive Median Filter Based on Neighborhood Correlation Feng Huanfei，He Youquan，Liu Chong 2013, 32(3): 547-550.  DOI: 10.3969/j.issn.1674-0696.2013.03.41 Abstract ( )   PDF (595KB) ( )   To improve image effect，a new improved adaptive median offset filtering based on the statistic of the neighborhood pixels is put forwarded，through analyzing existing methods of adaptive median filtering on salt and pepper noise. The proposed algorithm improves process of adaptive median filtering. Based on the distribution of gray value of neighborhood pixels， when the filter window size is larger than the setting maximum，the recovery of the gray value of pixels is divided into large or small case. The gray value of contaminated pixel is reconstructed by offset median. The offset distance is determined by size of filter window of improved adaptive median filtering. Simulation results show that this proposed method has a better improvement on preserving the details of image and removing salt and pepper noise. The restored image can obtain superior peak signal to noise ratio. References | Related Articles | Metrics