1、20 6 S/Z2000 M12Te: (1956) ), 3, ,) =, V,1V Y .系杆拱桥吊杆初始张拉力的计算方法彭宣茂(Zvr !, 2 210098)K1:针对系杆拱桥施工中的吊杆初始张拉力问题提出一种新的简单实用方法.该法以每根吊杆应该施加的初始张拉力为基本未知值,根据吊杆的张拉顺序,采用结构变刚度有限元法求出单位力作用下的吊杆内力矩阵,建立典型方程.通过简单的回代方法求出每根吊杆的初始张拉力,从而使得最终吊杆的预张拉力达到规定的设计值.1oM:系杆拱桥;预应力;内力矩阵;回代ms |:TU32 DS M :A cI|:1006O7647(2000) 06O0032O02“
2、B11 aa“(: ) B“dF, “Mvl,Ys “ a“ “ . w “, s w ,#Vy/ . “ , ,. M.: S,1990.368.( l :1999O04O10 I : )(上接第33页) !9, |V _ f Z.Ni= 20kN, . KEsY69 p, ptj,i“ 1 - 11625 - 01386 - 01042 01028 010111 - 01558 - 01145 - 01003 010081 - 01455 - 01118 - 010901 - 01360 - 010611 - 011781 T(1) Sf :T0= T06 T05 T04 T03 T02
3、T01T =100.6 45.5 38.1 29.7 23.6 20.0TkNN V A,1 Kf 20kN, Sf AvKf .Kf T/, “ 3 = nV1.A ,BKf !9,f , F Sf vl ,7f = M.4 “ Bf H s +,4 Be L p Sf 9ZE,I M9 q. q -m) 9 ?, V %“ B!9 ?9 5 45,CX L=,i V .V1 f = | /kNg /kN /kN#m “A ) 1 - 9216 6913 -1073131) 2 - 7619 5818 - 654132) 3 - 6210 4813 - 311143) 4 - 4917 36
4、11 145174) 5 - 4019 2214 260105) 6 - 3613 716 29811A) 1c 3517 - 11010 1073131c ) 2c 3517 - 9010 523132c ) 3c 3517 - 7010 - 276173c ) 4c 3517 - 5010 - 526184c ) 5c 3517 - 3010 - 676185c ) 6c 3517 - 1010 - 72618 ID:1S $. B M.: Y,1987.210.2Qr.%8 K ZE#M.: ,1983.108125.( l :2000O07O04 I : )#38#conditions
5、 are also discussed. Installation quality,flexibility,andreset accuracyof gearsand sealsmust beensuredfor the laser collimator system,and highqualitylase-rtube, stable votage, and moisture proof measuresmustbeadoptedinordertoimprovereliability.Inordertoreduce investment and improve accuracy of GPS,
6、sigle-frequency automatic system;laser collimator;GPS;optical fiberOverbank Flood Routing Regularity for TransitionalStretch of Lower Yellow River/YAO Yu-de, et al( Shandong Bureau of Yellow River Affairs, Jinan250013, China)Abstract: By use of the observed data from Gaocun)Sunkoureachesonthe downst
7、ream of the Yellow Riveranalysed the overbank flood routing regularity and theimpact oftransitionalreachareanalysed.Theresultshowsthat these transitional reaches are characterized bywinding river channels,mult-iriver floodplain, large areaand poor linking and passing ability. By means ofcontrolling
8、andprotecting projectsof those floodplains,themain river channel has become stable, however, thedistributionof siltationinthelateral direction isuneven.The main cause of the peak overbank flow deduction,changeof thepeakflowshapeandchangeofthetransitiontimeisthedifferent combinationsofthe abilitiesof
9、 floodstorageanddetentionoffloodplains,andthefloodcarryingcapacityofthemainriverchannel.Key words:flood;overbank;YellowRiverComputational Method for Analysis of Rod InitialTension of Bowstring Arch Bridges/PENG Xuan-mao(College of Civil Engineering, Hohai Univ., Nanjing210098, China)Abstract:A pract
10、ical computational method is proposedfor analysis of the initial tension in rods duringconstruction of bowstring arch bridges.According to thesequenceofrodtension,theinitial prestressisconsideredtobe anunknownvariable,andthe matrix of tension isresolvedbystiffnessFEM.Theinitialtensionintherodisfound
11、out by iteration, so that the prestress of the rodreachesthedesignvalue.Key words: bowstring arch bridge; prestress; tensionmatrix;iterationFoundation Forms and Ant-i Seismic Properties ofReinforced Concrete Frames/WANG Chun-wu, et al(Collegeof WaterConservancy andArchitecture, YangzhouUniv., Yangzh
12、ou,Jiangsu 225000, China)Abstract:Two types of model frames are analyzed andinvestigated. One is fixed to the base without crossfoundationbeamsandtheotherishingedat thebasewithcross foundation beams. Concentratedreversed horizontalloadisexertedonthetopsofthetwo frames.Theverticalloadonthetopsisa con
13、stant staticload.Thetest resultsshow that thesecondframeissuperiortothefirstnotonlyin load-bearing capacity but also in energy dissipatingcapability.Key words: mode-lframe; pseudo-static test; limit load-bearingcapability;energydissipating capabilityHydrodynamic Model Study for Beach ReclamationClos
14、ure of Shanghai Pudong, International Airport/JIYong-xing,et al(Shanghai Water Conservancy Design mouth; closure;hydrodynamicmodelWater Metering Methods and Application Strategy inIrrigation Districts/CHEN Yu-ling, et al( College ofWater Conservancy and Hydropower Engineering, HohaiUniv.,Nanjing 210
15、098, China)Abstract: Hydraulic structures, velometers, weirs, andflumes are used to gauge water in many irrigationdistricts. The fundamental principles and suitableconditionsofthesewatermeteringmethodsare introducedinthispaper.Themainproblems inthe development ofwatermetering instruments andfaciliti
16、esaswell asmaincauses of difficulty in popularization of the methods inirrigation districts are analysed. It is suggested thatselection and construction of water metering facilitiesshould be combined with canal lining in irrigationdistricts. It is also pointed out that for realization ofautomationofwatermeteringitisnecessarytodevelopandpopularize portable and stationary water meteringinstrumentsstep by stepbasedoneconomicdevelopmentlevelsinirrigationdistricts.Key words: irrigation and drainage; irrigation district;water metering; water metering instrument; irrigationmanagement#69#
