1、翻译 原文Thermal Stress Analysis of A Hydraulic Prestressed Abstract Large scale aqueduct is adopted as a optional plan for the crossing yellow river structure of the project of transferring water from the South to the North. Prestressed reinforced concrete structure is the best choice. The designed aqu
2、educt 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 structure varies largely. As the project is located in the area that has large temperature variation, the thermal st
3、ress 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, and suggestions to guarantee the safety of the aqueduct under possible large temperature variation is made. Keywo
4、rd hydraulic aqueduct; prestressed reinforced concrete; thermal stress;1 prefaceSouth-North Water Diversion centre line wear Huang aqueduct engineering design adopt one pair of troughs to pass water, the top structure of the aqueduct selects the U aqueduct for use, it is 4m to cross water section in
5、terior 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 in the trough . The minimum thick middle part of wall of section is 0.35m, the tip is 0.5m, is 0.85m that the positi
6、on 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 9m of trough , horizontal total wide 19m of pair of troughs , trough minimum and net from 1m. The top grade of inten
7、sity 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 piece assign in both sides , mound of cap. Combining the U aqueduct tip structure pattern, block one and adopt th
8、e 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 mound of shape entity of end in the middle, the radius 1.4m of very beginning of mound, high 5.14m- 9.93m, the d
9、istance 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 topses and bear the platform and each of underpart . It is the rectangle to bear a level, the total length is 21.2m
10、, 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 each time, a foot-path is 2.2m. Outside with bearing obey trough of distance of sets of edge to, to 0.8m trough not
11、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 to bear the platform and grade of intensity of a base concrete. Pierce through Huang aqueduct trough body typical
12、 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 internal and external surface of concrete must form very great temperature gradient . Therefore, under th
13、e 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 aqueduct Huang structure receive strength complicated characteristic under temperature function, adopt ANSYS
14、 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 aqueduct Security problem. 2 water conservancy project aqueduct temperature stress analytical methods2.1 Pier
15、ce 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 according to standard Meng County of weather station of Henan Province and Mengjin, the locality makes a
16、 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 relatively low in December - February, is 0.1 degrees Centigrade- 2.0 degrees Centigrade. Whether minimum tempera
17、ture consult near materials of two county town (according to wear Huang district Meng County and Mengjin county of 43km ) written down to have. 1961- 200040 average temperature of the whole year of Mengjin: Day minimum temperature extreme value - 11.9 on average for many years (appear January 31 , 1
18、969 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 average in ten days for many years (appear in mid-February of 1964 of time); The minimum average of temperat
19、ure- 2.5 degrees Centigrade on average in ten days for many years (1961 - 2000). 1971- 200030 average temperature of the whole year of Meng County: Day minimum temperature extreme value - 10.6 on average for many years (appear December 27 , 1971 such as time); The minimum average of temperature- 5.5
20、 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 days of December of 1971 of time); The minimum average of temperature- 1.7 degrees Centigrade on average in
21、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. 2.2 The border condition of temperature and computing technology 2.2.1 Border condition of temperature The
22、 border condition is solid surface and interactive law of medium around, can be divided into the following two kinds: The first type border condition : Solid surface temperature T is the time known function of t, namely (on border B) The second type border condition : When solid surface and fluid (s
23、uch as air , water ) keep in touch, pass the solid and superficial density of thermal current , in direct proportion to difference of fluid temperature Tc with solid surface temperature T, 2.2.2 namely (on border C ) wear temperature border principle of fetching etc. of aqueduct Huang (1)Water borde
24、r When the concrete keeps in touch with water, coefficient becomes more and more infinitely 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 border When the concrete keeps in touch with the air, its border
25、 condition should be dealt with according to the second type border condition. Ask solving in condition that however , according to the second type border, the coefficient that must choose the accurate surface and send out heat , could receive more satisfactory result of calculation . Because determ
26、ine the surface of the structure border to send out heat coefficient is very complicated, so, the real test that still lacks in this respect so far tests the data. In view of above-mentioned situations, the complexity of coefficient that consider the surface and send out heat, can use surveying the
27、temperature data of the border as the border condition directly , namely the first type border condition . This kind of method is more accurate. But only there are temperature materials of the concrete slab in bridges and civil engineering at present, namely what inside , surface and air exposed to
28、survey materials, see for water yet, for to survey materials air. 2.2.3 Calculate the theory and formula Large and medium-sized aqueduct complicated to the structure, the simulation of its temperature field and calculation of the temperature stress should adopt the law of finite element , could rece
29、ive the comparatively accurate result . , in order to lead warm coefficient , , in order to rise adiabatically and warmly among them. Pierce through temperature field of aqueduct Huang for temperature field of stabilizing, to the unstable heat-conduction question, temperature field T is besides meet
30、ing the heat-conduction equation, must also meet initial condition type T = (x , y , z ) and border condition. Distributed accounting temperature stress according to the difference in temperature after calculating temperature field, according to suffused with the terms of realizing the extreme value
31、 of lettering, 2.2.4 Calculate loading and operating mode The ones that consider while calculating load: Water loads, wind loading , trough body conducting oneself with dignity , loading , temperature loading , live load the trough of prestressing force. ( 1) Water loads: The water level is calculat
32、ed according to 5.01m in the trough; ( 2) The wind loads: According to the wind-force situation of Zhengzhou and terrain condition 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 concrete is =
33、25.0KN/m3, conducts oneself with dignity and calculates automatically by the procedure ; ( 4) Prestressing force loads: The prestressing force conduct loads and is participated in calculating, is the simplified calculation, regard cable wire and concrete as separate breaking away from the body, replace the
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