第三章-预应力及预应力损失

lconpeσσσ−=σconApσconApσconApσconApσcon1σcon4σcon122σcon3σσ0.5~0.950.4~0.8pkconf.σ750≤pkconf.σ900≤σpelconpeσσσ−=()(),,peconlixtxtσσσ=−∑ApσconApσconApσconApσconl1l2l3l4l5l6l7“”σl1——21dF22µ/Rk=σlconNN=lx[]kx)(µµconxconeNNN∆N+−−=−=13-23-2vHθθθ22+=1.2σcon)1()(1kxconle+−−=µθσσ3-1σl1x2300.100.15σcon1.05σcon2minσcon00.100.15σcon1.05σcon2min0σcon00.10σconσcon2minσconP52)a(2pplEl∆lεEσ∑==σl21σl2ApσconApσconApσconApσconaσl22σl2ac[]{}()1()111(()kxlconconconxekxkxµθσσσµθσµθ−+⎡⎤=−≈−−+⎣⎦=+1112()12()1lconffconfcxxkllklrlµσσµθσ⎛⎞⎛⎞=+−=+−⎜⎟⎜⎟⎝⎠⎝⎠pfconcEllkrµσΣ∆=⎛⎞+⎜⎟⎝⎠DVSL:1caa’2x3caa’ealfσ∆1lflx2lflxca’bd∑⋅∆=pElAcd=∆'σσσzσ12σl3——t1σcont2σcon’t1σcon’’σcon()()MPa212123ttEttαα∆tEEl∆lσpppl−=−===()21ltlttlαα∆=∆=−12zσl3200C,7.5~10N/mm2σl4cpεε=02000IeNANσppppc+=σlσl∑∆=pcEplσασ4,,iiniincEσε++=,4,EP,111mimimiiinlpiinpiinEPpcnnncEEEσσεασασ−−−+++=======∆∑∑∑∑l/4∑∆pcσ⎟⎟⎠⎞⎜⎜⎝⎛+=nipnnppcI.yeAmN∆σ1pcpcpcσm∆σσ=∆=∑m∆σpcpc/σ=()1412mEppciilEppcmimmασσασ=−∆−==∆∑σl1σl2zσl4412lEPpcmσασm−=2pppnpcnnNNeσAI=+3-1Ape0pσEPα4lσ02000IeNANσppppc+=4lEPpcσασ=150%234150%2480%540%~60%12~5σl5pekpe4)26.052.0(σσζψσ⋅−⋅=plf0.91.0σl5=0.05σconσl5=0.035σcon1.00.3σl5=05.0pkpef≤σzσσl61221iepsps+=ρ()()()[]pspcEPcsPlttttEtρρφσαεσ151,,9.0006++=2zσ()()()[]pspcEPcsPlttttEt''151,',9.0'006ρρφσαεσ++=1lIconσσσ−=pelIIlIconpeσσσσ−−=220%-30%25%-40%20%)1()(1kxconle+−−=µθσσσl1σl21lfl2lfl3-2σl3()1232ttσl−=σl4pcEPl∆σαmmσ214−=σl5pekpe4)26.052.0(σσζψσ⋅−⋅=plf()()()[]pspcEPcsPlttttEtρρφσαεσ151,,9.0006++=σl612()()()[]pspcEPcsPlttttEt''151,',9.0'006ρρφσαεσ++=