1、英文文献河北工程大学水电学院文献翻译指导老师 李 彦 军 学生姓名 胡 娅 婷 专业班级 11级水利水电工程 2 班时 间 2015 年 6 月 6 日Thermal Stress Analysis of A Hydraulic aqueduct Prestressed G.P.Harrison and H.W.Whittington Abstract Large scale aqueduct is adopted as a optional plan for the crossing yellow river structure of the project of transferring
2、water from the South to the North. Prestressed reinforced concrete structure is the best choice. The designed aqueduct span is 50m. Self-weight of the upper part of the structure for one span is 15.93MN, and corresponding weight of the water in one span is19.85MN. The stress in every part of the str
3、ucture varies largely. As the project is located in the area that has large temperature variation, the thermal stress produced in the structure by the variation of the surrounding temperature is a big problem. In this paper, the thermal stress in the aqueduct is studied for all possible conditions,
4、and suggestions to guarantee the safety of the aqueduct under possible large temperature variation is made. Keyword hydraulic aqueduct； prestressed reinforced concrete； thermal stress； 1 Preface South-North Water Diversion centre line wear Huang aqueduct engineering design adopt one pair of troughs
5、to pass water, the top structure of the aqueduct selects the U aqueduct for use, it is 4m to cross water section interior radius of underpart semicircle, the top of the semicircle trough is the straight wall and wing reason board, design 5.13m of depth of water , the clear width 8m of the aqueduct i
6、n the trough . The minimum thick middle part of wall of section is 0.35m, the tip is 0.5m, is 0.85m that the position part of the baseplate is thickenned in stepping, thick 1.35m of tip. The trough carries section 0.5m * 0.5m of the crossbeam , interval 5m. Tall 7.45m of trough , single total wide 9
7、m of trough , horizontal total wide 19m of pair of troughs , trough minimum and net from 1m. The top grade ofintensity of structure concrete is C50. Mound cap level measurement is 19.0m * 5.0m, thickness 2.8m. Mound cap have horizontal antidetonation block lump and cushion stone, horizontal to block
8、 piece assign in both sides , mound of cap. Combining the U aqueduct tip structure pattern, block one and adopt the ladder-shaped section , the height is 1.10m；It is the cylindrical trough mound of 2.8m that the body of mound of both sides of the aqueduct adopts 2 pieces of diameter, adopt the round
9、 mound of shape entity of end in the middle, the radius 1.4m of very beginning of mound, high 5.14m- 9.93m, the distance is 7.35m in the mound of the post. It is C40 and C30 respectively to overlay the roof beam and grade of intensity of body concrete of mound; Pour into the foundations including to
10、pses and bear the platform and each of underpart . It is the rectangle to bear a level, the total length is 21.2m, the width is 10. 0m, thickness 3.5m. Foundation adopt armored concrete is it pour into to hole, each bear platform along trough to assign two row hole and pour into one, arranging 4 eac
11、h time, a foot-path is 2.2m. Outside with bearing obey trough of distance of sets of edge to, to 0.8m trough not horizontal. It is 6.2m to the centre-to-centre spacing that one arranges the trough , the horizontal trough is 5.8m to the centre-to-centre spacing, its grows between 68m- 80m. It is C30
12、to bear the platform and grade of intensity of a base Pierce through Huang aqueduct trough body typical section place side wall concrete thickness 35cm only , during using normally, under the sunshine and warm situation that lower suddenly, the wall is influenced by temperature in the trough, the in
13、ternal and external surface of concrete must form very great temperature gradient . Therefore, under the sunshine and warm situation that lower suddenly, it is very easy to cause and draw the stress more greatly on the concrete surface. This text wear to South-North Water Diversion centre line aqued
14、uct Huang structure receive strength complicated characteristic under temperature function, adopt ANSYS procedure wear aqueduct Huang go on three-dimensional finite element is it calculate to analyse to South-North Water Diversion centre line, operate one , overhaul one in order to verify the aquedu
15、ct security problem. 2 Water conservancy project aqueduct temperature stress analytical methods 2.1 Pierce through the natural conditions of the Huang s It is the waiting area of the atmosphere of continental half-dried dry season to dress district Huang, meteorological statistics stand in standing
16、according to standard Meng County of weather station of Henan Province and Mengjin, the locality makes a clear distinction between the four seasons, the difference in temperature is relatively high in June - August every month, 25 degrees Centigrade- 27 degrees Centigrade on average, it is relativel
17、y low in December - February, is 0.1 degrees Centigrade- 2.0 degrees Centigrade. Whether minimum temperature consult near materials of two county town (according to wear Huang district Meng County and Mengjin county of 43km ) written down to have. 1961- 2000 40 average temperature of the whole year
18、of Mengjin: Day minimum temperature extreme value - 11.9 on average for many years (appear January 31 , 1969 such as time); The minimum average of temperature - 6.42 degrees Centigrade on average on day for many years (1961 - 2000); The minimum temperature extreme value- 6.1 degrees Centigrade on av
19、erage in ten days for many years (appear in mid-February of 1964 of time);The minimum average of temperature - 2.5 degrees Centigrade on average in ten days for many years (1961 - 2000). 1971- 2000 30 average temperature of the whole year of Meng County: Day minimum temperature extreme value -10.6 o
20、n average for many years (appear December 27 , 1971 such as time); The minimum average of temperature - 5.5 degrees Centigrade on average on day for many years (1971 - 2000); The minimum temperature extreme value -4.9 degrees Centigrade on average in ten days for many years (appear in the last ten d
21、ays of December of 1971 of time); The minimum average of temperature -1.7 degrees Centigrade on average in ten days for many years (1971 - 2000). Average rainfall 604.3mm for many years, among them the rainfall is centralized with July particularly. The largest wind speed 22.0m/s, wind direction NW.
22、 2.2 The border condition of temperature and computing technology 2.2.1 Border condition of temperature The border condition is solid surface and interactive law of medium around, can be dividedintothefollowingtwokinds:Thefirsttypebordercondition:SolidsurfacetemperatureTisthetimeknownfunctionoft,nam
23、ely(onborderB)Thesecondtypebordercondition:Whensolidsurfaceandfluid(suchasair,water)keepintouch,passthesolidandsuperficialdensityofthermalcurrent,indirectproportiontodifferenceoffluidtemperatureTcwithsolidsurfacetemperatureT,namely(onborderC) 2.2.2Weartemperatureborderprincipleoffetchingetc.ofaquedu
24、ctHuang(1)WaterborderWhentheconcretekeepsintouchwithwater,coefficientbecomesmoreandmoreinfinitelygreattosendoutheat,canhaveT-Tcbythesecondtypebordercondition=0,namelyT=Tc,turnsintothefirsttypebordercondition.(2)AirborderWhentheconcretekeepsintouchwiththeair,itsborderconditionshouldbedealtwithaccordi
25、ngtothesecondtypebordercondition.Asksolvinginconditionthathowever,accordingtothesecondtypeborder,thecoefficientthatmustchoosetheaccuratesurfaceandsendoutheat,couldreceivemoresatisfactoryresultofcalculation.Becausedeterminethesurfaceofthestructurebordertosendoutheatcoefficientisverycomplicated,so,the
26、realtestthatstilllacksinthisrespectsofarteststhedata.Inviewofabove-mentionedsituations,thecomplexityofcoefficientthatconsiderthesurfaceandsendoutheat,canusesurveyingthetemperaturedataoftheborderastheborderconditiondirectly,namelythefirsttypebordercondition.Thiskindofmethodismoreaccurate.Butonlythere
27、aretemperaturematerialsoftheconcreteslabinbridgesandcivilengineeringatpresent,namelywhatinside,surfaceandairexposedtosurveymaterials,seeforwateryet,fortosurveymaterialsair.2.2.3CalculatethetheoryandformulaLargeandmedium-sizedaqueductcomplicatedtothestructure,thesimulationofitstemperaturefieldandcalc
28、ulationofthetemperaturestressshouldadoptthelawoffiniteelement，couldreceivethecomparativelyaccurateresult.,in order to lead warmcoefficient,inordertoriseadiabaticallyandwarmlyamongthem.PiercethroughtemperaturefieldofaqueductHuangfortemperaturefieldofstabilizing,totheunstableheat-conductionquestion,te
29、mperaturefieldTisbesidesmeetingtheheat-conductionequation,mustalsomeetinitialconditiontypeT=(x,y,z)andbordercondition.Distributedaccountingtemperaturestressaccordingtothedifferenceintemperatureaftercalculatingtemperaturefield,accordingtosuffusedwiththetermsofrealizingtheextremevalueoflettering,2.2.4
30、CalculateloadingandoperatingmodeTheonesthatconsiderwhilecalculatingload：Waterloads,windloading,troughbodyconductingoneselfwithdignityloading,temperatureloading,liveloadthetroughofprestressingforce.1)Waterloads:Thewaterleveliscalculatedaccordingto5.01minthetrough;2)Thewindloads:Accordingtothewind-for
31、cesituationofZhengzhouandterrainconditionoftherivertrough,confirmwindpressurestrengthas0.86kN/m2;3)Thetroughbodyconductsoneselfwithdignity:Theaqueductunitweightofarmoredconcreteis=25.0KN/m3,conductsoneselfwithdignityandcalculatesautomaticallybytheprocedure4)Prestressingforceloads:Theprestressingforceconductloadsandisparticipatedincalculating,isth
