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15 December 2010, Volume 29 Issue 6 Previous Issue    Next Issue

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Calculation of Main Cable with Double-lifts in Single Span with Non-support Cable Crane System LIU Rui，LEI Yu-liang，ZHOU Shui-xing 2010, 29(6): 841-845.  Abstract ( )   PDF (972KB) ( )   Based on the principle of static equilibrium of cable，segmental curve equations of main cable with double-lifts in single span were established; formulae of the sag and horizontal tension were obtained; the influence of distance of doublelifts， span，self-weight，load and the like on horizontal tension was analyzed． Results indicated that the ratio of distance of double-lifts and span of main cable played an important role in affecting horizontal tension of the cable; the tolerance by the method of double-lifts and single-lift was quite small，which can be ignored． References | Related Articles | Metrics

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Analysis on Causes of the Web Plate Crack at L /4 Section of a Continuous Rigid Frame Bridge XIAO GUANG-hong，ZHANG QIU-ling 2010, 29(6): 846-848.  Abstract ( )   PDF (1114KB) ( )   The web cracks of box girder usually appear in the 0 block of continuous rigid frame bridge． According to location， direction and distribution of the web crack at L/4 section of box girder of a bridge in Chongqing，this paper analyzes the causes of the appearance of crack and the development of crack on the basis of on－site construction work． It is indicated that the pouring time difference between the former segment and the latter segment is the main cause for crack formation and development． References | Related Articles | Metrics

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Mechanical Behavior Analysis on Stone Arch Bridge Strengthened by Composite Main Arch Circle Method ZHOU Jian-ting，LI Xiao-gang，QU Jian-qiang，HAN Xue，XU Zheng-qiang 2010, 29(6): 849-851.  Abstract ( )   PDF (1595KB) ( )   Based on mechanical behavior of strengthened composite main arch and practical strengthening projects，internal force of main arch bridge before and after reinforcement was calculated． Increase rate of the main arch cross-section strength and the overall“strength-stability”was expounded． Shear capacity of old and new arch ring combination surface and the impact of new structure on the original structure were checked． As a result，an increase overall effect reinforcing evaluation index based on increase rate of bearing capacity was proposed，which played a positive role in design options and quality assessment of arch bridge reinforcement． References | Related Articles | Metrics

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Reinforcement Effect Evaluation for Arch Bridge Based on Dynamic Characteristics CHEN Yue，ZHOU Jian-ting，YANG Jian-xi，SUN Hong-wei 2010, 29(6): 852-854.  Abstract ( )   PDF (1888KB) ( )   Due to imperfect method for reinforcement effect evaluation，strengthening effect evaluation for arch bridge was proposed according to the second load for the strengthening treatment of arch bridge，rigidity evaluation of overall deflection change rate and characteristics of dynamic frequency． According to specific projects，advantages of the evaluation method based on the frequency of dynamic characteristics were confirmed through MIDAS /CIVIL for calculation; it was demonstrated that this method could provide useful guidances for strengthening effect evaluation of other bridges． References | Related Articles | Metrics

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Analysis of Mechanical Influence Factors of Pavement on Orthotropic Steel Bridge Deck CUI Chen，SUN Li-jun，LIU Li-ping 2010, 29(6): 855-858.  Abstract ( )   PDF (1450KB) ( )   The influence of structural and load factors on mechanical responses of pavement on orthotropic steel deck was studied through finite element method． The influence of main girder，thickness of deck plate and thickness of stiffener on stress was compared． The effect of vertical and horizontal loads on bridge pavement was analyzed． The results indicated that maximum tensile stress existed beyond the main girder; increase of deck plate thickness could lower the stiffness difference of deck and reduce maximum stress; change of thickness could be favorable for steel structure rigidity while unfavorable for stress of pavement． Overloading could be rather unfavorable for stress and horizontal stress caused by emergency braking could lead to great longitudinal tensile stress． References | Related Articles | Metrics

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Impact of Beam-end Lateral Expansion of Steel Truss Girder on Geometrical Shape of Track QUAN Shun-xi，WANG Ping，CHEN Rong 2010, 29(6): 859-861.  Abstract ( )   PDF (2154KB) ( )   In order to obtain influence of beam-end lateral expansion of steel truss girderon geometrical shape of track，finite element method was employed to establish the calculation model． The model was to analyze variation of geometrical shape of ballast track and its influence factors when relative subgrade of beam-end of steel truss girder had horizontal expansion under the action of the diurnal temperature range． Results indicated that lateral relative expansion between the steel truss girder and subgrade made larger lateral displacement of ballast track while it exerted little influence on track gauge; ballast and fastening lateral resistance had little effect on lateral displacement of track，and on the change rate of track alignment after its increase to normal value when beam-end of steel truss girder had horizontal expansion; the distance from lateral fixed support of steel truss girder to central line of the route was mainly responsible for variation of geometrical shape of track． If the distance could be controlled within 6． 7m，the maximal lateral displacement track would be less than 2mm and change rate of track alignment less than 1‰． References | Related Articles | Metrics

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Research on Abutment Sliding Displacement and Trends in Meizoseismal Areas CUI Ying-ming，LIU Jia-min 2010, 29(6): 862-866.  Abstract ( )   PDF (2630KB) ( )   After summaring the existing abutment displacement computation theory，the model of the bridge abutment sliding displacement，rotation displacement and the mixture of sliding and rotation displacement in earthquake was established based on Newmark，Zeng and Steedman rotational slider block theory; a compuation method of platform displacement was proposed． The change trend of displacement index，sliding displacement and the percentage of displacement under different seismic in ten sity was analyzed． Performance of the abutment was measured through quantizaiton which could provide new feasible ideas for seismic performance of abutment design in meizosesmal areas． References | Related Articles | Metrics

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Application of Exponential Scale of AHP in Bridge Evaluation SUN Dong-sheng，ZHU Yi，ZHOU Shui-xing 2010, 29(6): 867-870.  Abstract ( )   PDF (1033KB) ( )   For problems of 1－9 scale in the Analytical Hierarchy Process ( AHP) ，exponential scale and corresponding indicator of random consistency test were employed to evaluate bridge technology condition based on the Weber-Fechner＇s Law． Taking concrete filled steel tubular( CFST) arch bridge as an example，weight of each component could be calculated after judging matrix of exponential scale and 1－9 scale based on the same importance to relations． Calculation results indicated that exponential scale could accurately reflect the relationship among components of CFST arch bridge． References | Related Articles | Metrics

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Calculation and Analysis of the Ship Collision Force in Jiangjin Zhongdu Yangtze River Bridge WEN Cen，ZHAO Hai-yan，ZHANG Yan-zhi 2010, 29(6): 871-874.  Abstract ( )   PDF (1769KB) ( )   Based on ship impact calculation of ready-built Jiangjin Zhougdu Yangtze River Bridge，the effect and selection of ship impact speed and impact angle were discussed in the paper． Code formula，empirical formula and finite element simulation method were employed to calculate the impact force of 3000-t ship and 5000-t ship． The results demonstrated that calculation results of road and railway code formula were small． The U． S． AASHTO formula，modified Worthing formula and finite element results were in agreement． References | Related Articles | Metrics

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Similarity Relation in Tunnel Shaking Table Model Test ZHENG Sheng-bao，JIANG Shu-ping，WANG Xiao-wen，LIN Zhi 2010, 29(6): 875-879.  Abstract ( )   PDF (2504KB) ( )   Taking Galongla tunnel shaking table model test as an example，similarity relation was studied on the basis of similarity theory． The model test similarity criterion was deduced through equation analysis and dimensional analysis． The similarity of geometric conditions，boundary conditions，loads and materials was simulated in the table test． Finite element model was established and comparison was made from the perspective of the curve of acceleration time，spectrum feature， coefficient of acceleration and failure． The results of the tests coincided highly with calculation results; the failure phenomena and location also agreed well，which indicated that the simulation relation was reasonable for the model． References | Related Articles | Metrics

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In-situ Test of Grouting Reinforcement for Subway Tunnel Foundation in Soft Ground ZHOU Liang，LIAO Shao-ming，SHI Ning-qiang，LI Jia-ping 2010, 29(6): 880-884.  Abstract ( )   PDF (2593KB) ( )   Grouting is a traditional reinforcement method to improve bearing capacity of soft soil and control the compression settlement． However，it has been criticized by engineers for its uncontrollable process and indeterminate reinforcement effect shown by long-standing engineering practice． When grouting is applied to reinforcing the underlying soil of subway tunnel，it needs taking the disturbance during reinforcing process and the long-term effects of grouting into consideration． It is of practical significance to study the effects of grouting parameters on disturbance of saturated soft soil and ultimate reinforcing effect． Therefore，this in-situ test was carried out to obtain reasonable parameters during grouting process． References | Related Articles | Metrics

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Optimal Design of Airport Runway Pavement Based on Pilots’Subjective Evaluation JIYANG Bei-bei ，SU Kai ，HACHIYA Yoshitaka 2010, 29(6): 885-887.  Abstract ( )   PDF (2921KB) ( )   The fourth runway of Tokyo Haneda International Airport was partly constructed with pier structure to evacuate river water as this part was located on a river mouth． Deformation of pier deck under load and uneven settlement at the joint of pier structure and reclaimed ground were two major factors responsible for aircraft riding comfort and operation safety． With the help of flight simulation test，this paper aimed to optimize concrete plate thickness and settlement standard according to pilots’subjective evaluation． The results indicated that operation safety and riding comfort decreased with the increase of deflection or faulting． Deflection and uneven settlement exerted greater influence on riding comfort． Based on the criterion that at least 50% of the pilots rated the riding comfort of a runway surface as uncomfortable or worse，bridge deck thickness and uneven settlement standard at the joint were optimized． References | Related Articles | Metrics

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Evaluation of Asphalt Pavement Performance Based on Principal Component Analysis Method PAN Huai-bing 2010, 29(6): 888-890.  Abstract ( )   PDF (1156KB) ( )   Due to the complex，fuzzy and unreasonable evaluation methods of synthetical performance evaluation of asphalt pavement，the Principal Component Analysis ( PCA) and Matlab Software were applied and several main evaluation indexes determined by current specifications were employed to evaluate the performance of asphalt pavement． Compared with the results based on gray-clustering decision method，it could be indicated that the PCA was feasible and effective，which could reflect the effect of indexes on synthetical evaluation objectively and show special advantages． References | Related Articles | Metrics

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Study on Impact of Loading Mode and Clamp on Fatigue Performance of Epoxy Asphalt Mixture ALLIE Y． Mansaray，HUANG Ming 2010, 29(6): 891-895.  Abstract ( )   PDF (1794KB) ( )   One of the main test objectives of this project is the fatigue performance evaluation of Epoxy Asphalt Mixture on steel bridge deck． The pros and cons of the three-point small beam fatigue test and cross-loaded small beam fatigue test were compared through a large number of comparative tests and the applicability of strain and stress control in the fatigue evaluation of epoxy asphalt mixture． Two common types of epoxy asphalts were used in the research and a large number of comparative results with actual data confirmed the analysis． In order to comply with the steel bridge pavement surface engineering practice and traffic situations，the control of small beam fatigue test mode，test temperature，loading frequency， loading time and the waveform of the proposed options were recommended． References | Related Articles | Metrics

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Research on Asphalt Mixture Bulk Specific Gravity by Vacuum Sealing Method Wu Guo-xiong，YANG Rui，YANG Da-tian，YUAN Chuan-min 2010, 29(6): 896-899.  Abstract ( )   PDF (2209KB) ( )   Through vacuum sealing method，bulk specific gravity of rutting core samples after being rolled different times was measured，reasons for the errors were discussed; comparative analysis was made between results by conventional method of saturated-surface dry method and by wax-enveloped method． Results showed that the vacuum sealed condition and quality of sealed bag were the main factors for the error． The result by vacuum sealing method had good reproducibility，and its measured value had good linear relationship with the values measured by saturated-surface dry method and by wax-enveloped method; however，there were significant differences between values． References | Related Articles | Metrics

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Research on Water Stability of Cold Recycled Mixtures with Emulsified Asphalt HE Liang，ZHANG Jie，JIN Kang-kang，PENG Bin 2010, 29(6): 900-903.  Abstract ( )   PDF (1601KB) ( )   Water stability is one of the key indicators of emulsified asphalt cold recycling technology． Through laboratory tests，it was found that absorption and hydration of cement could improve the initial strength and water stability of the mixture． Adequate curing time could exert great influence on the road strength and water stability． After construction，loss of moisture and condensation of cement could further enhance the strength and water stability of recycling base． Plenty of new fine aggregate with coarse aggregate in RAP could ensure the dense skeleton structure and internal friction resistance，therefore it could guarantee strength and water stability at the initial stage． References | Related Articles | Metrics

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Research on Influencing Factors of Low-temperature Crack Resistance of Asphalt Mixture Based on Grey Correlation Entropy Method HOU Wei 2010, 29(6): 904-906.  Abstract ( )   PDF (2027KB) ( )   Low temperature bending tests were carried out to obtain the critical bending strain of asphalt mixture． Then grey correlation entropy method was applied to the significance analysis of influencing factors of low－temperature crack resistance of asphalt mixture such as aggregate gradation，type of stone，asphalt penetration，asphalt content，volume of air voids，passing percent of 4． 75 mm mesh and mixing temperature． The results indicated that asphalt content，asphalt penetration and aggregate gradation could exert great influence on the low-temperature crack resistance of asphalt mixture． References | Related Articles | Metrics

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Research on the Technique of PE Composite Modified Asphalt ZHAO Ke，DU Yue-zong 2010, 29(6): 907-911.  Abstract ( )   PDF (1894KB) ( )   On the basis of principles of“similitude and compatibility”and“space steric hindrance”，by means of micrographic image analysis，rheological and mechanical behavior，and conventional tests as well ，this paper made systematic research on technical performance，processing technology and influence factor of several kinds of PE composite modified asphalt in which different chemical agents had been added． The results indicated that PE modified asphalt not only had excellent performance，but also didn’t separate during the course of thermal storage． PE modified asphalt could reach technical standard of the trade on the level of Ⅲ－B and Ⅲ－C． Moreover，parameters of the technological conditions could be regarded as the foundation of industrialized production technique． References | Related Articles | Metrics

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Impact of Earthquake on Micro-structure and Strength of Fresh Concrete HAN Hai-ling，LI Gu-hua，WEI Jian-dong，HE Guang-jie，WANG Ke 2010, 29(6): 912-915.  Abstract ( )   PDF (3105KB) ( )   After observing the concrete shaken by the simulation of seismic station and aggregates interface by stereo microscope， structural morphology of the fresh concrete was obtained and its internal defects were confirmed; the load－deformation curve was gained through ultrasonic wave measurement; the differences between concrete property with vibration damage and without vibration damage were further analyzed; the influence of internal defects on concrete strength was studied from the perspective of concrete component elements and microstructure． It was demonstrated that after 28 days of maintenance， effective recovery mechanism of the interface of the concrete shaken by 6－9 magnitude quake was obtained． References | Related Articles | Metrics

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Research and Development of Unsaturated Polyester Temperature Decreasing Coatings of Asphalt Pavement LI Wen-zhen，LI Liang，SHI Fei，WEI He-guang，ZHONG Zhi-ming 2010, 29(6): 916-918.  Abstract ( )   PDF (1902KB) ( )   With self-made modified unsaturated polyester as matrix resin，methyl ethyl ketone peroxide ( MEKPO) /cobalt naphthenate system was chosen to be asphalt pavement heat-reflective coating based on comparison among three kinds of the room temperature UPRcuring system geltime; the ratio of functional fillers TiO2 /SiO2 as 2∶ 1 was determined; it was suggested that the best content of paint filler was 13%－15%; when the paint filler was 14%，the ratio of TiO2 /SiO2 should be 10∶ 4 to ensure the coatings abrasion strengthened; gray paint composed of the red( 0． 5%) and green( 0． 8%) of the coating showed the best temperature lowering performance; unsaturated polyester coatings with good water resistance，oil resistance， flexibility and the ability to reduce the surface temperature could be compounded． References | Related Articles | Metrics

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Seismic Resistance Behavior Check and Seismic Damage Mechanism Analysis of the Shoulder Retaining Wall in Wenchuan Seismic Area WANG Jing-mei，YAO Ling-kan，YANG Ming 2010, 29(6): 919-924.  Abstract ( )   PDF (3346KB) ( )   Seismic damage of the shoulder retaining wall was investigated in Wenchuan earthquake． According to design drawing and specification，the seismic resistance behavior of the shoulder retaining wall was checked and the seismic damage mechanism was analyzed． The conclusions were as follows: firstly，relevant regulations in the current highway codes showed that the vehicle load wasn’t considered when checking the stability of highway retaining wall，therefore the retaining wall designed based on the current highway codes could resist 8 degree earthquake． Secondly，the reason of the shoulder wall’s inclination distortion in 9 degree earthquake zone was that the foundation stress went beyond the bearing capacity． Thirdly，the cause of the shoulder wall’s serious inclination distortion and collapse in 10 degree earthquake zone was that the toppling stability coefficient didn’t satisfy requirements of the codes and the foundation stress went beyond the bearing capacity． Lastly，the stability safety factors value of retaining walls in the current highway codes was reasonable; it was applicable in 9 degree earthquake intensity zone and could be extended to 10 degree earthquake intensity zone． References | Related Articles | Metrics

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Analysis of Influencing Factors on Fatigue Life of Cement Stability Base by Ansys LI Bin，LIANG Nai-xing，BAN Wu-dong，WANG Xin-yang 2010, 29(6): 925-927.  Abstract ( )   PDF (2381KB) ( )   Based on Ansys software，the tensile stress of the cement-stabilized base with different structure and material parameters was analyzed with soild45 unit; with the semi-rigid fatigue equation in AASHTO2002 and the tensile stress on base bottom，the corresponding fatigue life and the influence of each factor on fatigue life of the cement-stabilized base were analyzed． The results indicated that: the tensile stress on base bottom increased while the fatigue life decreased with the tire contact pressure increased; the tensile stress on base bottom increased with grass-roots modulus increased and it decreased with the sub-base and surface layer modulus increased; the tensile stress on base bottom decreased with each layer thickness increased，and the decrease rate of the tensile stress on base bottom was the fastest with the change of sub-base thickness． References | Related Articles | Metrics

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Experiment on Electrical Resistivity Properties of Polyphase Soil-stone Mediums ZHAO Ming-jie，LI Geng，HUANG Wei-dong，LI Jian 2010, 29(6): 928-933.  Abstract ( )   PDF (3164KB) ( )   Based on experimental test of electrical resistivity of polyphase soil－rock samples，the relationsip between electrical resistivity and physical parameters，such as soil-rock ratio and compaction properties and moisture content of polyphase soil-rock mediums，was analyzed． The electrical resistivity equation of polyphase soil-rock mediums was proposed and it was the same form as Keller equation on unsaturation soil electrical resistivity． The research results indicated that the electrical resistivity equation of polyphase soil-rock mediums could be analyzed by taking Keller equation after taking the influence of soil-rock ratio for soil indicators and cementation coefficients and saturation exponents into consideration． References | Related Articles | Metrics

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Experimental Study of Influence Factors of the Compaction Degree of Xigeda Roadbed Filling WANG Wei-zao，XU Qiang 2010, 29(6): 934-937.  Abstract ( )   PDF (2516KB) ( )   Xigeda soil as roadbed filling was studied in the paper． The influence of moisture content，gradation composition， effect of construction process on degree of compaction was studied． The results demonstrated that: degree of compaction was the best as the moisture content of Xigeda Filling was 12% ～ 17%; Cu and Cc of Xigeda Filling could meet the needs before and after compaction，therefore it was a good-grading filling; loose laying depth of Xigeda Filling was 30cm ～ 35cm under 16T road roller rolling and 35cm ～ 40cm under 18T road roller rolling; higher degree of compaction was achieved when firstly applying strong vibration and then weak vibration with road roller; it should be compacted six times with 16T road and five times with 18T road roller． References | Related Articles | Metrics

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Study on Confirmation of the Construction Parameter of Saturated Soil Reinforced by Dynamic Compaction ZHENG Hong-juan，ZHOU Shi-liang 2010, 29(6): 938-941.  Abstract ( )   PDF (2216KB) ( )   Construction parameter of saturated soil reinforced by dynamic compaction through numerical simulation was discussed; the optimal rammer times were determined according to the varying curve of the increase of pore water pressure along with the rammer times; interval time of dynamic compaction was confirmed based on dissipation of water pressure of the pore; effective consoliation depth soil was ascertained according to vertical deformation of the soil; consolidation range of dynamic compation was determined according to vertical deformation of the soil along with horizontal direction，which could provide basis for dynamic compaction design and reinforcement effect evaluation． References | Related Articles | Metrics

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Finite Element Analysis of Load-bearing Properties of Large Diameter Rock-socketed Single Pile XU Xi-bin，ZHOU Liang，LIU Tao 2010, 29(6): 942-946.  Abstract ( )   PDF (2502KB) ( )   Constitution of rock－socketed piles’load-bearing properties was analyzed; based on the possibility of slippage between the pile and surrounding soil，the pile side resistance，tip resistance and embedded rock depth were calculated through three-dimensional finite element software． The relationship between the load-bearing capacities and aspect ratio， pile diameters，rock－socketed depth and bedrock was discussed． The research result indicated that the aspect ratio and pile diameters played an important role in influencing bearing capacity; excessive aspect ratio exerted little influence on bearing capacity; the existence of the optimal depth embedded in the rock-socketed piles was verified，however，it was not certain whether there was the maximum depth of embedded rock or not; the weaker the rock strength，the deeper the optimal socketed rock． References | Related Articles | Metrics

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MNL Model Characteristic Variables Selection on Forecasting Corridor Mode Split WANG Jiang-tao，MA Si 2010, 29(6): 947-950.  Abstract ( )   PDF (1555KB) ( )   Based on the theory of disaggregate discrete choice and characteristics of different transportation mode in transportation corridor，the selection principle of utility function explanation variables of MNL model was determined． According to the selection principle，relationship among travel mode split influencing factors such as travel time，safety，comfort，convenience， cost and adaptability of these factors as characteristic variables were analyzed in the paper; travel time，departure frequency and relative cost ( cost divide by income) should be considered as characteristic variables when forecasting transportation corridor mode split by MNL model; meanwhile，corresponding calibration method was given． According to travel mode split data，empirical analysis and sensibility of the characteristic variables analysis were carried out by MNL model． The parameters indicated that the influence of travel time，cost and change of income should be taken into consideration while making operation strategies of passenger dedicate line． References | Related Articles | Metrics

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Emergency Rescue Transportation Route Optimization Model after Disaster REN Qi-liang，QIAO Dan 2010, 29(6): 951-954.  Abstract ( )   PDF (1645KB) ( )   The limitation of existing transportation route optimization was that its decision mainly relied on experience． Uncertain factors such as network reliability，capacity liability，time，transport demand，transport loss in rescue transportation were analyzed． Among them，three priority objectives，namely time，reliability and loss were determined． Multi-objective stochastic programming model with network diagram theory for rescue transportation was built． Genetic algorithm was applied to calculating． Each parameter could be illustrated by concrete example and validity of the model was verified through actual simulation． References | Related Articles | Metrics

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Risk Management and Decision-making of Highway Pavement Construction Based on Utility Theory WU Yi-fei，TAN Jian-ming，HE Shou-kui，LI Ming 2010, 29(6): 955-957.  Abstract ( )   PDF (1639KB) ( )   In this paper，basic principles of risk management were employed to identify quality，safety，schedule and cost risk of northeast section of Chongqing by pass expressway． Optimal decisions by different decision makers were analyzed through applied risk management utility theory． The study indicated that risk attitude could exert great influence on risk decision． Risk management decision－making incentive and restrictive mechanism were established． References | Related Articles | Metrics

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Design and Implementation: Project Business Process Management Subsystem GAO Li-chun 2010, 29(6): 958-959.  Abstract ( )   PDF (2591KB) ( )   Dealing with informationizaiton of construction enterprise through processing was proposed． With an open and advanced information system through middle soft and existing resources，an improving informationization system platform was established with the change of businesses and processes． In this way，the enterprise could achieve the optimization of processes automatically without the support of bottom technology． References | Related Articles | Metrics

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Study on the Influence of River Side Bar on Bifurcated River Reach FU Zhong-min，ZHENG Jing-tao，WANG Ping-yi，LIU Huai-han，HAN Ting 2010, 29(6): 960-964.  Abstract ( )   PDF (3084KB) ( )   On the basis of previous studies，a simple flume experiment on Yaojian reach in the middle Yangtze River was carried out，and the evolution rule of braided channel was studied under the condition with /without river side bar． The results indicated that the variation trend of the thalweg with side bar was the same as that without aide bar，except that the former bed elevation was slightly lower than the latter’s; as to the region of separated flow，the lowest points of the river sections would lean to the right bank when the flow of the case with river side bar leaned to the right bank． As to the region of bifurcated river reach and river outlet，the flow and the cross-section would lean to the left bank; river side bar played an important role in the evolution process of the river island，and the river island volume would be smaller than that with no side bar． References | Related Articles | Metrics

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Stable Width of the Shima River Based on the Maximum Sediment Transport Rate YANG Sheng-fa，YUAN Guan-dong，LUO Ling-yuan，HU Peng-fei 2010, 29(6): 965-968.  Abstract ( )   PDF (1798KB) ( )   If the plane shape of river bed were straight，rectangular and steadily flowed，and the discharge，river bed components and gradient were fixed valued，the relationship between stable river width and sediment transport rate in Shima River of equilibrium of sediment transport rate would be obtained through mathematical methods． References | Related Articles | Metrics

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On the Construction Water Level of Wharf in Mountainous Rivers WEN Yan-qing，WANG Duo-yin，SONG Cheng-tao，HUANG Ran 2010, 29(6): 969-971.  Abstract ( )   PDF (2054KB) ( )   After the Three Gorges Reservoir was built，the experience value could not be applied to determining construction levels of inland mountainous river． After taking Cuntan Wharf as an example，the monthly average water level and water level after the completion of each month in natural situation were analyzed and the number of days of continuous construction was obtained． The said number was compared to the estimated construction period based on engineering quantity; adjustments were made according to specific flood of special circumstances． Compared to traditional method of experience， the present one was more accurate and reasonable and it could play a positive role in improving construction quality and reducing costs． References | Related Articles | Metrics

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Evaluation of the Waterline Level Based on Uncertainty AHP and Group Decision Theory JIANG Jun 2010, 29(6): 972-977.  Abstract ( )   PDF (1676KB) ( )   After selecting the indexes which affected the level of waterline based on policies，regulations，natural conditions， economy，traffic location and ancillary services，uncertainty AHP and group decision theory were introduced to determine the weights of evaluation indexes，which made the evaluation more accurate and convincing． Based on empirical analysis， the waterline was divided into three classes and opinions about its development and application of different classes were proposed，which had a certain value of promotion and application． References | Related Articles | Metrics

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Studies on Debris Flow Development Properties in Quaternary on the Eastern Edge of Qinghai-Tibet Plateau LIANG Xue-zhan ，CHEN Hong-kai，TANG Hong-mei 2010, 29(6): 978-983.  Abstract ( )   PDF (2707KB) ( )   Based on the investigation in the field and test analysis，typical sediment profile of debris flow on the eastern edge of Qinghai-Tibet plateau was analyzed． According to the relationship among terrace geomorphology，debris flow deposition profile and the geological age，the Quaternary debris flow activities in Bailongjiang River basin and Xiaojiang River basin could be divided into eight periods． The Quaternary debris flow activities in Bailongjiang River basin were mainly concerning 1． 5 Ma，0． 73 Ma，0． 565 ～ 0． 425 Ma，0． 245 ～ 0． 165 Ma，( 116． 8 ± 9． 9) ka，50 ～ 25 ka，5 ～ 4 ka，3 ka，and the Quaternary debris flow activities in Xiaojing River basin were concerning 1． 42 Ma，0． 985 Ma，0． 562 ～ 0． 52 Ma，0． 218 Ma，0． 137 Ma，14 ka，0． 73 ka，0． 3 ka． Based on analysis of debris flow deposits and activity cycle on eastern edge of Qinghai- Tibet plateau as well as comparison between debris flow and climate characteristics in glacial and interglacial areas，the following conclusions were drawn: the debris flow activity process on the eastern edge of Qinghai-Tibet plateau was consistent and it had unbalanced features． References | Related Articles | Metrics

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Flow Characteristics Analysis and Structure Optimization of Gas Valve Port in Gas Engine Mixer LANG Hua，GAO Song，TAN De-rong，SHAO Jin-ju 2010, 29(6): 984-987.  Abstract ( )   PDF (2074KB) ( )   Through analysis of flow characteristics model of rectangular gas valve port in gas engine mixer，it was found that there was nonlinear relationship between gas flux through the valve and its opening proportion． Segmental design thought was applied to designing a gas valve port profile with quasi-linear flow characteristics． The simulation result indicated that there was quasi-linear relationship between gas flux through the valve and its opening proportion after optimization． References | Related Articles | Metrics

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Numerical Simulation of Different Intake Pressures on High density-low temperature Diesel Combustion LIU Jian-xun，WAN Pu-peng，ZHAO Er-li，ZHANG Yu 2010, 29(6): 988-991.  Abstract ( )   PDF (3258KB) ( )   The effct of air pressures on high density-low temperature diesel combustion and performance was analyzed through FIRE． Simulation calculation of 4100 engine demonstrated that the combustion path could avoid the Soot and NOx main generating areas under different intake pressure; pressure and the cumulative heat release increase as intake pressure increased; intake pressure had a significant effect on engine performance; further increase in intake pressure could reduce Soot and NOx emissions，significantly improve the dynamic performance of the engine and reduce fuel consumption，which indicated that the high density－low temperature combustion mode could reduce emissions and increase thermal efficiency by controlling intake pressure． References | Related Articles | Metrics

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Optimization of Aluminum Alloy Case of Commanding Car WEN Xiao-Xia，DU Zi-xue，KANG Zhong-wen，SUN Ze-bo 2010, 29(6): 992-996.  Abstract ( )   PDF (3208KB) ( )   In order to reduce weight and improve assembly efficiency，a newly-developed command vehicle compartment frame is made up of aluminum with its vertical and horizontal frame beam connected through the block and L－shape flat steel． Based on finite element theory，calculation of strength was carried out in the newly－developed vehicle according to two counterweight plans． Results indicated that rigidity of the original structural design could not meet the requirements and structural optimization and improvement of design were put forward to make the rigidity meet the needs． References | Related Articles | Metrics

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Study on Control Strategy for Four-wheel steering Vehicle Based on Co-simulation FENG Ying，DENG Zhao-wen，GAO Wei 2010, 29(6): 997-1001.  Abstract ( )   PDF (2543KB) ( )   Based on the four-wheel steering technology and fuzzy control theory，a new control strategy for four wheel steering vehicle，namely the combination of proportional front feed control and fuzzy back feed control was put forward． With the help of ADAMS /Car，a multi-body dynamics model of four-wheel steering vehicle was built and a controller was designed in Matlab /Simulink． The co-simulation of the contro1 system and the vehicle model was realized through data exchanging between ADAMS and Matlab; dynamic response of the vehicle with four-wheel steering under typical driving conditions was simulated． Simulation results demonstrated that the rear wheel steering controller could accurately follow the ideal turning model，therefore the handling stability of vehicle could be improved． References | Related Articles | Metrics

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Analysis of Commercial Vehicle Braking Vibration SHEN Xiu-min，JIN Yan，DIAO Jin-dong，LI Jin，QIN Li-zhou 2010, 29(6): 1002-1005.  Abstract ( )   PDF (2831KB) ( )   Possible causes for braking vibration were identified through analysis; then road driving test was carried out and vibration acceleration signals of the commercial vehicle were measured; after analyzing the test data，the main reason for brake vibration of the commercial vehicle was identified． After adjusting the braking force of two wheels of vehicle front axle and replacing brake shoes，braking vibration in the cab could be significantly inhibited，which achieved the level of satisfaction． References | Related Articles | Metrics

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Determination of Trace Amount Mercury Based on Hg( Ⅱ)－Br－-MB ion-pair Complex by Solvent Extraction-fluorophotometry PAN Jin，LIU Xue-lian 2010, 29(6): 1006-1008.  Abstract ( )   PDF (1926KB) ( )   In acidic medium，Hg( Ⅱ) and Br－can react with methylene blue ( MB) to form the ion－pair complex，which can be easily extracted by 1，2－dichloromethane solvent and result in strong fluorescence． The maximum emission wavelength ( λem ) is 689 nm; fluorescence intensities are proportional to concentrations of the Hg( Ⅱ) over the range 0． 01 ～ 6． 4( g /mL with a detection limit ( DL) of 3 ng /mL． The method was applied to the determining of trace amount mercury in Wujiang water with satisfactory results． References | Related Articles | Metrics