【正文】 159PH13PVU10U2U3PskPwkEaEpΣΣ總↓→↗1　 抗滑穩(wěn)定計算 == 經(jīng)過計算求出的大于容許最小抗滑穩(wěn)定安全系數(shù)。 所以在設(shè)計洪水位下，溢流壩抗滑穩(wěn)定滿足要求。2　 應力計算 壩基允許壓應力[]=～ ＞0 ，上游壩踵處未出現(xiàn)拉應力，滿足要求。 ＜[]，下游壩趾處小于壩基允許壓應力，滿足要求。 綜上所述，應力滿足要求?！　?校核洪水位時，溢流壩抗滑穩(wěn)定計算和應力復合荷載計算(1)壩體自重 面板自重 蓋重 橋、閘墩單寬平均自重(2)水平靜水壓力上游水平靜水壓力P1 下游水平靜水壓力P2 (3)垂直水壓力 上游垂直水壓力、 (4)動水壓力 動水壓力水平分量為 動水壓力垂直分量為 (5)揚壓力　 ，所以將揚壓力分為以下幾個部分計算： (6)泥沙壓力 (7)浪壓力 (8)土壓力主動土壓力 被動土壓力 表37 作用在溢流壩上的各力及力矩大小和方向表荷載垂直力（kN）水平力（kN）力臂(m)力矩（kNm）↓(+)↑()→(+)←()↖(+)↗()W18184W2294W3W4486W5397W6P1P2PH13PVU110290U281U31107PskPwkEaEpΣ2217Σ總↓→↗1　 抗滑穩(wěn)定計算 == 經(jīng)過計算求出的大于容許最小抗滑穩(wěn)定安全系數(shù)。 所以在校核洪水位下，溢流壩抗滑穩(wěn)定滿足要求。2　 應力計算 壩基允許壓應力[]=～ ＞0 ，上游壩踵處未出現(xiàn)拉應力，滿足要求。 ＜[]，下游壩趾處小于壩基允許壓應力，滿足要求。 綜上所述，應力滿足要求?！　?，正常蓄水時，溢流壩抗滑穩(wěn)定計算和應力復合荷載計算(1)壩體自重 面板自重 蓋重 橋、閘墩單寬平均自重(2)水平靜水壓力 上游水平靜水壓力P1 下游水平靜水壓力P2 (3)垂直水壓力 上游垂直水壓力有、(4)揚壓力 ，所以將揚壓力分為以下幾個部分計算： (5)地震慣性力 (6)上游地震動水壓力 (7)地震作用下的土壓力 式中： 主動土壓力： 被動土壓力： (8)泥沙壓力 (9)浪壓力 表38 作用在溢流壩上的各力及力矩大小和方向表荷載垂直力（kN）水平力（kN）力臂(m)力矩（kNm）↓(+)↑()→(+)←()↖(+)↗()W18184W2294W3W4486W5W6Q0P12941P2P0U10U2U3PskPwkEaEpΣΣ總↓→↗1　 抗滑穩(wěn)定計算 == 經(jīng)過計算求出的大于容許最小抗滑穩(wěn)定安全系數(shù)。 所以在地震情況下的正常蓄水位時，溢流壩抗滑穩(wěn)定滿足要求。2　 應力計算 壩基允許壓應力[]=～ ＞0，上游壩踵處為出現(xiàn)拉應力，滿足要求。 ＜[]，下游壩趾處小于壩基允許壓應力，滿座要求。 綜上所述，應力滿足要求。 針對現(xiàn)狀所存在的問題，上述的計算過程是加固完的方案，通過對加固完的PS水庫現(xiàn)狀校核。主壩、溢流壩抗滑穩(wěn)定及應力在四種荷載情況下都是安全的，所以此加固方案可行?！　〈髩我缌鲏味挝挥跀r河壩中央，寬度22m，由于大壩運行多年，溢流壩面混凝土大面積脫落，凹凸不平，剝蝕嚴重，鋼筋外露。本次設(shè)計對原溢流壩面拆除重建。　　由于溢流堰面損毀嚴重，需對溢流壩底面混凝土拆除重建。溢流面壩改造以不破壞大壩的結(jié)構(gòu)安全為原則而進行，根據(jù)大壩的實際情況，確定溢流堰仍為實用堰，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，除應采取對原溢流壩面進行鑿毛（呈臺階狀）、部分拆除改建等措施外?！　∫驗橐缌髅婕庸毯?，未改變溢流面尺寸和形狀，所以過流能力及消能防沖驗算與溢流面未加固前數(shù)據(jù)相同，滿足要求。故無需再進行計算，取未加固前數(shù)據(jù)即可。　　溢流壩左端設(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，漏水嚴重，已影響到灌溉、泄洪的正常運用。本次設(shè)計將放水洞進水口焊鋼筋網(wǎng)防止放水洞堵塞，出水口采用DN400手電兩用蝶閥控制流量。　　　　放水洞的下泄流量按下述公式計算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)護欄。路面采用C20混凝土澆筑。對大壩下游側(cè)破損護欄進行拆除。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 ,alth