【正文】 為原則而進(jìn)行，根據(jù)大壩的實(shí)際情況，確定溢流堰仍為實(shí)用堰，堰面曲線采用規(guī)范推薦的冪曲線。溢流堰下游直線段坡比1:，反弧半徑4m。加固后的溢流面部分采用C25混凝土結(jié)構(gòu)，為保證新溢流壩面與原壩面的整體性，施工時(shí)，除應(yīng)采取對(duì)原溢流壩面進(jìn)行鑿毛（呈臺(tái)階狀）、部分拆除改建等措施外?！　∫?yàn)橐缌髅婕庸毯螅锤淖円缌髅娉叽绾托螤?，所以過流能力及消能防沖驗(yàn)算與溢流面未加固前數(shù)據(jù)相同，滿足要求。故無需再進(jìn)行計(jì)算，取未加固前數(shù)據(jù)即可?！　∫缌鲏巫蠖嗽O(shè)有放水洞，結(jié)構(gòu)采用圓形鋼筋混凝土管，閘閥為鑄鐵平面圓形閘閥，目前閘閥老化，漏水嚴(yán)重，已影響到灌溉、泄洪的正常運(yùn)用。本次設(shè)計(jì)將放水洞進(jìn)水口焊鋼筋網(wǎng)防止放水洞堵塞，出水口采用DN400手電兩用蝶閥控制流量?！　　　》潘吹南滦沽髁堪聪率龉接?jì)算Q 　　　　( 35)Q—放水洞流量 m/sA —過水面積 m —流量系數(shù) A= ； 　　　　Q/s，所以滿足要求。所建防浪墻為C20混凝土結(jié)構(gòu)。為保證管理和防汛安全，需維修壩頂路面及下游側(cè)護(hù)欄。路面采用C20混凝土澆筑。對(duì)大壩下游側(cè)破損護(hù)欄進(jìn)行拆除。英語翻譯DAM SAFETY AND EARTHQUAKESA great tragedy was averted in the 1971 san fernando earthquake just north of Los Angeles in southern california .The tower Van Norman Dam ,less than 10 kilometers from the ruptured fault,had been built 30 years before by using mon method carrying soil for fill in toposition by water sluices .Subsequently ,additional hydraulic fill had been place in the interior portion of the dam ,leaving only a meter or so of soil on the downstream side to stop the water flowing down onto a densely populated suburban area .Fortunately ,the water in the reservoir wad not at the allowable maximum at the time of the earthquake and the silm earth lip of the dam did not erode ,but held the water in the reservoir until it could be drawn down .Meanwhile , 80,000 persons were evacuated from the downstream area . The incident exemplifies the importance of evaluating prospective dam sites for seismic sidk .Not only is an earth or concreat dam an expensive structure ,ut it directly affects the economy of the region ,through power generation ,flood control,and irrigation .Asthe population contiues to grow ,structural failure of a large dam will pose increasingly greater disaster for the sizsble numbers exposed to the sudden inundation of the flood plains ,Indeed ,in various counstries major dams are located in areas that in the past have suffered large earthquakes .The likelihood of future damaging earthquakes must be most carefully studied. The naturally occurring earthquakes aside ,however , we must consider also a curious connections between. Reservoirs and earthquakes .There have been at least 13 incidents countries in which swarms of earthquakes have occurred under or very near a large teservoir soon after it has been newly filed .The idea that earthquakes might be triggered by impounding surface water is not new .In the 1870’s ,the . corps of engineers rejected proposails for major water storage in the salton sea in suothern California on the grounds that such action might cause earthquakes .the first detailed evidence of such an effcet came will the filling of Lake Mead behind hoover Dam (height 221 meters),NevadaArizona ,beginning in 1935 .Although there may have been local seismicity before 1935, the fact is that after 1936 earthquakes were much more mon .Nearby seismographs in operation since 1940 have shown that the largest earthquake (magnitude about 5)in 1940, the seismicity declined .The foci of hundreds of detected earthquakes cluster on steeply dipping faults on the east side of the lake and have focal depths of less than 8 kilometers .In the ensuring years ,similar case historise have been acumulated for several dozen large dams ,but only a few are well documented .Most of these dams are more than 100meters high and ,although the geological framework at the sites varies ,the most convincing examples of reservoirinduced earthquakes occur in tectonic regions with at least some history of earthquakes .Most of the thousands of large dams around the world give no sign of any onnection between reservoir filling and earthquakes。 of 500large dams sorutinized in the United States, a pooll in 1976 showed that for only 4 percent of them was an earthquake roported with magnitude greater than within 16 kilometers of the dam .Of particular interest are the following four wellstudied examples of earthquakes induced by manmade reservoirs. First ,Lake Kariba in Zambia began filling in 1985 behind a 128meter high dam . Although there is some evifence for minor earthquakes in the vivinity befor the construction ,up till 1963, when the reservoir was full , more than 2,000 local shocks, most under the reservoir ,were located with the use of nearby seismographs .The largest shock in September 1963 had a magnitude 。since then the activity has decreased. . Another series of earthquakes,which were quite conclusively reservoir induced occurred in China north of Hsingfengkiang Dam(height 105 meters)was pleted in increasing numbers of local earthquakes were recorded,the grand total in 1972 amounting to more than 250,000 of course ,most were very small ,but on March 19,1962,a strong of magnitude occurred. The energy releaste was enough to March 19,1962,a strong shock of magnitude occurred. The energy released was enough to damage the concrete dam structure,which required partial dewatering and strengthening. Most earthquake foci were at deepest,and some of the foci coincided with intersections of the main nearby faults. The data are not yet plete for the final example:the massive Nurek Dam(height 317 meters)in Tadzhikistan,USSR,the highest earthfill dam in the in 1972,before its pletion but after water impounding began,signs of increased local seismicity were this writing the plan is for the full load of stored water to go onto the crust in 1978。the few years following will be anxious ones as many wait to see if a large nearby earthquake shakes the facilty. How does water in a large reservoir stimulate earthquakes? It is hard to belive that it is entirely the effect of the added weight on the rocks。the actual additional pressure a few kilometers below the reservoir is a small fraction of the natural tectonic stresses already presend.(Calculations indicate that a few kilometers down the added stress to shear the rock is only a fraction of a bar.)A more plausible explan