外文文献翻译原文(大型水工预应力渡槽的温度应力分析研究).doc

精品文档外文参考文献Thermal Stress Analysis of A Hydraulic aqueduct PrestressedG.P.Harrison and H.W.Whittington Abstract Large scale aqueduct is adopted as a optional plan for the crossing yellowriver structure of the project of transferring water from the South to the North. Prestressedreinforced 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 correspondingweight of the water in one span is19.85MN. The stress in every part of the structure varieslargely. As the project is located in the area that has large temperature variation, thethermal stress produced in the structure by the variation of the surrounding temperature isa big problem. In this paper, the thermal stress in the aqueduct is studied for all possibleconditions, and suggestions to guarantee the safety of the aqueduct under possible largetemperature variation is made. Keyword hydraulic aqueduct； prestressed reinforced concrete； thermal stress；1 PrefaceSouth-North Water Diversion centre line wear Huang aqueduct engineering designadopt one pair of troughs to pass water, the top structure of the aqueduct selects the Uaqueduct 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 5.13mof depth of water , the clear width 8m of the aqueduct in the trough . The minimum thickmiddle part of wall of section is 0.35m, the tip is 0.5m, is 0.85m that the position part ofthe baseplate is thickenned in stepping, thick 1.35m of tip. The trough carries section0.5m * 0.5m of the crossbeam , interval 5m. Tall 7.45m of trough , single total wide 9mof trough , horizontal total wide 19m of pair of troughs , trough minimum and net from1m. The top grade ofintensity of structure concrete is C50.Mound cap level measurement is 19.0m * 5.0m, thickness 2.8m. Mound cap havehorizontal antidetonation block lump and cushion stone, horizontal to block piece assignin both sides , mound of cap. Combining the U aqueduct tip structure pattern, block oneand adopt the ladder-shaped section , the height is 1.10m；It is the cylindrical troughmound of 2.8m that the body of mound of both sides of the aqueduct adopts 2 pieces ofdiameter, adopt the round mound of shape entity of end in the middle, the radius 1.4m ofvery beginning of mound, high 5.14m- 9.93m, the distance is 7.35m in the mound of thepost. It is C40 and C30 respectively to overlay the roof beam and grade of intensity ofbody concrete of mound; Pour into the foundations including topses and bear the platformand each of underpart . It is the rectangle to bear a level, the total length is 21.2m, thewidth 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 4each time, a foot-path is 2.2m. Outside with bearing obey trough of distance of sets ofedge to, to 0.8m trough not horizontal. It is 6.2m to the centre-to-centre spacing that onearranges the trough , the horizontal trough is 5.8m to the centre-to-centre spacing, itsgrows between 68m- 80m. It is C30 to bear the platform and grade of intensity of a basePierce through Huang aqueduct trough body typical section place side wall concretethickness 35cm only , during using normally, under the sunshine and warm situation thatlower suddenly, the wall is influenced by temperature in the trough, the internal andexternal surface of concrete must form very great temperature gradient . Therefore, underthe sunshine and warm situation that lower suddenly, it is very easy to cause and draw thestress more greatly on the concrete surface. This text wear to South-North WaterDiversion centre line aqueduct Huang structure receive strength complicated characteristic under temperature function, adopt ANSYS procedure wear aqueduct Huanggo on three-dimensional finite element is it calculate to analyse to South-North WaterDiversion centre line, operate one , overhaul one in order to verify the aqueduct securityproblem.2 Water conservancy project aqueduct temperature stress analytical methods2.1 Pierce through the natural conditions of the Huang sIt is the waiting area of the atmosphere of continental half-dried dry season to dressdistrict Huang, meteorological statistics stand in standing according to standard MengCounty of weather station of Henan Province and Mengjin, the locality makes a cleardistinction between the four seasons, the difference in temperature is relatively high inJune - August every month, 25 degrees Centigrade- 27 degrees Centigrade on average, itis relatively 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 ) writtendown to have. 1961- 2000 40 average temperature of the whole year of Mengjin: Dayminimum temperature extreme value - 11.9 on average for many years (appear January31 , 1969 such as time); The minimum average of temperature - 6.42 degrees Centigradeon average on day for many years (1961 - 2000); The minimum temperature extremevalue- 6.1 degrees Centigrade on average in ten days for many years (appear inmid-February of 1964 of time);The minimum average of temperature - 2.5 degreesCentigrade on average in ten days for many years (1961 - 2000). 1971- 2000 30average temperature of the whole year of Meng County: Day minimum temperatureextreme value -10.6 on average for many years (appear December 27 , 1971 such astime); The minimum average of temperature - 5.5 degrees Centigrade on average on dayfor many years (1971 - 2000); The minimum temperature extreme value -4.9 degreesCentigrade on average in ten days for many years (appear in the last ten days ofDecember of 1971 of time); The minimum average of temperature -1.7 degreesCentigrade on average in ten days for many years (1971 - 2000).Average rainfall 604.3mm for many years, among them the rainfall is centralizedwith July particularly. The largest wind speed 22.0m/s, wind direction NW.2.2 The border condition of temperature and computing technology2.2.1 Border condition of temperatureThe border condition is solid surface and interactive law of medium around, can be12欢迎下载12欢迎下载12欢迎下载12欢迎下载。divided into the following two kinds:The first type border condition : Solid surface temperature T is the time knownfunction of t, namely (on border B)The second type border condition : When solid surface and fluid (such as air , water )keep in touch, pass the solid and superficial density of thermal current , in directproportion to difference of fluid temperature Tc with solid surface temperature T, namely(on border C )2.2.2 Wear temperature border principle of fetching etc. of aqueduct Huang(1)Water borderWhen the concrete keeps in touch with water, coefficient becomes more and moreinfinitely great to send out heat, can have T-Tc by the second type border condition =0,namely T =Tc, turns into the first type border condition .(2)Air borderWhen the concrete keeps in touch with the air, its border condition should be dealtwith according to the second type border condition. Ask solving in condition thathowever , according to the second type border, the coefficient that must choose theaccurate surface and send out heat , could receive more satisfactory result of calculation .Because determine the surface of the structure border to send out heat coefficient is verycomplicated, so, the real test that still lacks in this respect so far tests the data. In view ofabove-mentioned situations, the complexity of coefficient that consider the surface andsend out heat, can use surveying the temperature data of the border as the bordercondition directly , namely the first type border condition . This kind of method is moreaccurate. But only there are temperature materials of the concrete slab in bridges and civilengineering at present, namely what inside , surface and air exposed to survey materials,see for water yet, for to survey materials air.2.2.3 Calculate the theory and formulaLarge and medium-sized aqueduct complicated to the structure, the simulation of itstemperature field and calculation of the temperature stress should adopt the law of finiteelement，could receive the comparatively accurate result ., in order to lead warmcoefficient , in order to rise adiabatically and warmly among them.Pierce through temperature field of aqueduct Huang for temperature field ofstabilizing, to the unstable heat-conduction question, temperature field T is besidesmeeting the heat-conduction equation, must also meet initial condition type T =(x , y ,z ) and border condition. Distributed accounting temperature stress according to thedifference in temperature after calculating temperature field, according to suffused withthe terms of realizing the extreme value of lettering,2.2.4 Calculate loading and operating modeThe ones that consider while calculating load：Water loads, wind loading , troughbody conducting oneself with dignity loading , temperature loading , live load the troughof prestressing force.1) Water loads: The water level is calculated according to 5.01m in the trough; 2)The wind loads: According to the wind-force situation of Zhengzhou and terraincondition of the river trough , confirm wind pressure strength as 0.86 kN/m2; 3) The trough body conducts oneself with dignity: The aqueduct unit weight of armored concreteis =25.0KN/m3, conducts oneself with dignity and calculates automatically by theprocedure 4) Prestressing force loads: The prestressing force conduct loads and isparticipated in calculating, is the simplified calculation, regard cable wire and concrete asseparate breaking away from the body, replace the function on the concrete of the cablewire in form that loads equivalently, the function equivalent of the shape prestressingforce cable wire of the straight line is the attention of the tip5) Temperature loads:Examine station Mengjin and Meng County and survey the temperature materials for many years according to near twoing, fetch the temperature loading value asfollows:Summer: 37 degrees Centigrade of surface temperature between top surface , side wall(the sun penetrates directly ), 30 degrees Centigrade of surface temperature of side wall(not that the sun shoots directly ), the surface temperature is 27 degrees Centigrade ofbottom of the trough , the temperature is 24.5 degrees Centigrade in the trough; Winter:The surface temperature- 11 degrees Centigrade outside, the temperature is 4 degreesCentigrade in the trough; The concrete intensifies 27.5 degrees Centigrade evenly ; Theconcrete lowers the temperature 27.5 degrees Centigrade evenly 6) Load for 3KN/m2 the trough .2.3 Pierce through aqueduct Huang analyse the finite element model selected for useBecause centre line wear aqueduct Huang for being simple to prop up structure ,fetch among them is it analyse to stepping, top structure consider for concrete unit , toprop up aqueduct trough body flat place is it imitate knuckle joint punish to go on incalculating, one end one side prop up flat to regular along three, another side can alonghorizontal trough to move among them; Another end one side can along along trough tomoving,another side along obeying trough to and to the getting more portable trough nothorizontal. Fetch and step net subdivision of finite element among them ,three-dimensional 23576 units of subdivision altogether of finite element model, 30382pieces of joint .3 Calculates achievement analysis3.1 Temperature does not load the stress situationIn a situation that temperature does not load function , because of the function ofprestressing force, the top trough body has not presented the stress of drawing basically.Have supported in the place side wall of the seat and baseplate interface point andpresented the stress of drawing of 0.23MPa only in both ends. Locate in baseplate , evenunder using the operating mode , there is stress of pressing of 2.39MPa outside thebaseplate;3.2 Heat degree after loading the stress is distributedUnder the function that temperature loads, the stress of the aqueduct has beendistributed and taken place certain change. In the operating mode of winter, the baseplatepresented the stress of drawing of a certain limit, it is 0.16MPa to draw the stress mostgreatly while stepping, prop up seat place appear most heavy to draw stress 0.66MPa; Inthe operating mode of summer, every stress has no stress of drawing , the place baseplateappears when stepped in stepping- the stress of pressing of 14.65MPa; In lowering theoperating mode evenly and warmly, every stress has no stress of drawing , the placebaseplate appears when stepped in stepping- the stress of pressing of 14.64MPa; Inpromoting the operating mode evenly and warmly, every stress has no stress of drawing ;Because the aqueduct supports in the flat and simplifies in order to prop up simply, soeven temperature loads only displacement out of shape emerges the structure, have a littleeffect on stress result.4 Conclusions(1)Because the aqueduct supports in the flat and fetches in order to prop up simply, itis very small by the aqueduct temperature stress emerging in temperature change of thelong-term, for pierce through aqueduct Huang , long-term temperature is it make structureproduce and shift only to load, and the stress to structure is distributed and stress valueinfluence smaller.(2)As a whole, it is the same trend that temperature stress and other that the operatingmode causes load the stress produced in winter, disadvantageous to baseplate in theaqueduct, so this operating mode is the most unfavorable operating mode.(3)By the look of result of calculation, because of the function of prestressing force,most operating mode stress value are to press the stress , the stress of drawing of 1.09MPahas appeared in propping up in the flat office baseplate surface in the operating mode inwinter only, and draw range very little stress, but some to is it strengthen muscle can theall over foot project is it require to run to dispose in right amount.5 ReferencesIEE Proc-Gener.Transm.Distrib.Vol.149,No.3,May 2002大型水工预应力渡槽的温度应力分析研究G.P.Harrison and H.W.Whittington摘 要 南水北调中线穿黄工程渡槽属特大型工程，该渡槽采用钢筋混凝土预 应力结构，单跨跨度50m，单跨自重15.93MN，正常运用时承受水荷载达19.85MN，各部位应力变幅很大。由于渡槽地中原，年温度变化达60.6，温度应力是渡槽结构需考虑的主要因素之一。本文研究温度作用下该渡槽各种工况条件下的运行情况。 关键词 水工渡槽 预应力 温度应力 有限元分析 1 前言 南水北调中线穿黄渡槽工程设计采用双槽过水，渡槽上部结构选用U形渡槽，过水断面下部半圆内半径为4m，半圆槽上部为直墙和翼缘板，槽内设计水深5.13m，渡槽净宽8m。断面最小壁厚中部为0.35m，端部为0.5m，跨中底板部位局部加厚为0.85m，端部厚1.35m。槽顶横梁断面0.5m0.5m，间距5m。槽身高7.45m，单槽总宽9m，横向双槽总宽19m，槽间最小净距1m。上部结构混凝土强度等级为C50。 墩帽平面尺寸为19.0m5.0m，厚度2.8m。墩帽上设有横向抗震挡块和垫石，横向挡块布置在墩帽的两侧。结合U形渡槽端部结构型式，挡块采用梯形断面，高度为1.10m；渡槽两侧墩身采用2个直径为2.8m的圆柱形槽墩，中间采用圆端形实体墩，墩头半径1.4m，高5.14m9.93m，柱墩中距7.35。盖梁和墩身混凝土强度等级分别为C40和C30；灌注桩群基础包括顶部承台和下部桩群。承台平面为矩形，总长度为21.2m，宽度为10. 0m，厚度3.5m。基础采用钢筋混凝土钻孔灌注桩，每个承台下顺槽向布置两排钻孔灌注桩，每排4根，桩径为2.2m。边桩外侧与承台边缘的距离顺槽向、横槽向均0.8。桩顺槽向中心距为6.2m，横槽向中心距为5.8m，其桩长在68m80m之间。承台及桩基混凝土强度等级为C30。 穿黄渡槽槽身典型断面处侧墙混凝土厚度仅为35cm，在正常运用期间，在 日照及骤然温降的情况下，槽内壁受水温影响，混凝土内外表面必然形成很大的 温度梯度。由此可见，在日照及骤然温降的情况下，很容易在混凝土表面引起较大拉应力。本文针对南水北调中线穿黄渡槽在温度作用下结构受力复杂的特点，采用ANSYS程序对南水北调中线穿黄渡槽进行了三维有限元分析计算，以验证渡槽运行期、检修期的安全问题。 2 水工渡槽温度应力的分析方法 2.1 穿黄地区的自然条件 穿黄地区属大陆性半干旱季风气候区，据河南省标准气象站孟县站及孟津站气象资料统计，当地四季分明，各月温差不等，68月较高，平均2527，122月较低，为0.12.0。最低温度参考了邻近有记录的两个县城（据穿黄地区43km的孟县及孟津县）的资料：孟津19612000四十年平均气温：多年日平均最低气温极端值-11.9（出现时间1969年1月31日）；多年日平均最低气温平均值-6.42（1961年2000年）；多年旬平均最低气温极端值-6.1（出现时间1964年2月中旬）；多年旬平均最低气温平均值-2.5（1961年2000年）。 孟县19712000三十年平均气温：多年日平均最低气温极端值-10.6（出现时间1971年12月27日）；多年日平均最低气温平均值-5.5（1971年2000年）；多年旬平均最低气温极端值-4.9（出现时间1971年12月下旬）；多年旬平均最低气温平均值-1.7（1971年2000年）。多年平均降雨量604.3mm，其中尤以7月份降雨集中。最大风速22.0m/s，风向NW。 2.2 温度边界条件及计算方法 2.2.1温度边界条件 边界条件是固体表面与周围介质相互作用的规律，可分为以下两类： （1）第一类边界条件：固体表面温度T是时间t的已知函数，即（在边界B上） （2）第二类边界条件：固体表面与流体（如空气、水）接触时，通过固体表 面的热流密度，与