簡介
烏江(jiang)(jiang)(jiang)渡水(shui)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan)(Wujiangdu Hydropower Station) 是(shi)對烏江(jiang)(jiang)(jiang)流(liu)(liu)域(yu)實施梯級開(kai)發興建的(de)第一(yi)座大型水(shui)電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan),位于烏江(jiang)(jiang)(jiang)中(zhong)游(you)遵義(yi)縣烏江(jiang)(jiang)(jiang)鎮,南(nan)距貴(gui)陽105公(gong)(gong)里(li),北離遵義(yi)55公(gong)(gong)里(li)。工(gong)(gong)程(cheng)先(xian)后由長江(jiang)(jiang)(jiang)流(liu)(liu)域(yu)規(gui)劃辦公(gong)(gong)室、中(zhong)南(nan)勘測設(she)計院設(she)計,集(ji)團公(gong)(gong)司水(shui)電(dian)(dian)(dian)(dian)(dian)(dian)八局負責施工(gong)(gong)。1970年(nian)(nian)開(kai)始(shi)施工(gong)(gong)準備,中(zhong)間因補做(zuo)地質工(gong)(gong)作停工(gong)(gong)二年(nian)(nian),1974年(nian)(nian)開(kai)始(shi)澆筑大壩混凝(ning)土,1979年(nian)(nian)第一(yi)臺機(ji)(ji)組發電(dian)(dian)(dian)(dian)(dian)(dian),1983年(nian)(nian)竣工(gong)(gong)。該電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan)向貴(gui)州、四川送(song)電(dian)(dian)(dian)(dian)(dian)(dian),支援兩省(sheng)工(gong)(gong)農業(ye)建設(she),是(shi)西(xi)南(nan)電(dian)(dian)(dian)(dian)(dian)(dian)網的(de)骨干電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan)之一(yi)。該電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan)共(gong)裝有3臺水(shui)輪發電(dian)(dian)(dian)(dian)(dian)(dian)機(ji)(ji)組,其(qi)中(zhong)一(yi)號(hao)(hao)、二號(hao)(hao)機(ji)(ji)組已分別于1979年(nian)(nian)、1981年(nian)(nian)發電(dian)(dian)(dian)(dian)(dian)(dian);三號(hao)(hao)機(ji)(ji)組安裝調試(shi)完(wan)成后,于1982年(nian)(nian)12月(yue)4日投產(chan)發電(dian)(dian)(dian)(dian)(dian)(dian),比原計劃提前(qian)27天。電(dian)(dian)(dian)(dian)(dian)(dian)站(zhan)(zhan)總裝機(ji)(ji)63萬(wan)千(qian)瓦(wa)(wa),多年(nian)(nian)平均發電(dian)(dian)(dian)(dian)(dian)(dian)量31.05億千(qian)瓦(wa)(wa)小(xiao)時,是(shi)中(zhong)國在大陸巖溶地區修(xiu)建的(de)第一(yi)座大型水(shui)電(dian)(dian)(dian)(dian)(dian)(dian)工(gong)(gong)程(cheng)。
修建背景
烏(wu)江(jiang)是云貴高原上(shang)的(de)一條大(da)河(he),長江(jiang)的(de)主要支(zhi)流(liu)之一。它發源于(yu)(yu)云、貴兩(liang)省交界線(xian)上(shang)的(de)烏(wu)蒙(meng)山東(dong)麓。源頭河(he)段叫做(zuo)三岔(cha)河(he)。在貴陽之西(xi)北(bei)與六(liu)沖(chong)河(he)匯合成(cheng)烏(wu)江(jiang)上(shang)游(you)干流(liu)。烏(wu)江(jiang)干流(liu)大(da)體上(shang)沿近東(dong)西(xi)向經(jing)烏(wu)江(jiang)渡穿越川(chuan)黔線(xian)。經(jing)思南(nan)北(bei)上(shang),再經(jing)龔灘(tan)(tan)轉向西(xi)北(bei),于(yu)(yu)四川(chuan)涪陵注入長江(jiang)。分(fen)別在川(chuan)黔線(xian)以(yi)西(xi)、以(yi)東(dong)的(de)貓跳(tiao)河(he)和(he)清水(shui)江(jiang),是烏(wu)江(jiang)中上(shang)游(you)南(nan)側(右(you)岸)的(de)兩(liang)條主要支(zhi)流(liu)。烏(wu)江(jiang)中游(you)穿行(xing)在大(da)婁(lou)山以(yi)東(dong)的(de)崇山峻嶺之間。由于(yu)(yu)河(he)水(shui)侵蝕和(he)地下水(shui)溶蝕,往(wang)(wang)往(wang)(wang)形(xing)成(cheng)兩(liang)、三百(bai)米深(shen)的(de)峽谷。烏(wu)江(jiang)干支(zhi)流(liu)水(shui)急(ji)灘(tan)(tan)多(duo),水(shui)能資源豐富。
烏江渡位于川黔線上、烏江南(右)岸,是(shi)(shi)(shi)貴州省遵義(yi)市(shi)遵義(yi)縣的一個城鎮。其北面(mian)(mian)是(shi)(shi)(shi)遵義(yi)市(shi)(較近),南面(mian)(mian)是(shi)(shi)(shi)貴陽市(shi)(較遠),西面(mian)(mian)是(shi)(shi)(shi)畢節縣,東面(mian)(mian)是(shi)(shi)(shi)玉(yu)屏縣。
烏江渡水電站位于烏江渡以西附近,烏江中上游峽谷(gu)河段。這是世界上巖溶地(di)貌發育(yu)最典型的(de)地(di)區之一。
烏(wu)江渡(du)水電站設(she)(she)計(ji)與施工質(zhi)量優(you)良。自(zi)1979年蓄(xu)水發電以來,壩(ba)基滲漏微(wei)小(xiao),揚壓(ya)力(li)遠低于設(she)(she)計(ji)值,各泄洪建筑物以及電站機組設(she)(she)備運行情況良好(hao)。被評(ping)為全(quan)國(guo)優(you)秀工程之一(yi)。
烏江渡(du)水(shui)(shui)電(dian)站(zhan)(zhan)工程(cheng)(cheng)質量優(you)良(liang)。主體工程(cheng)(cheng)混凝(ning)土全部合格(ge),優(you)良(liang)率達85%。帷(wei)幕灌漿(jiang)、金屬(shu)結構、機組(zu)安(an)裝及各類泄洪建(jian)筑物全部達到設(she)計要求。革新成果791項(xiang)。其中(zhong)有9項(xiang)達到國(guo)(guo)內先進水(shui)(shui)平,成功地(di)解決了(le)巖(yan)溶地(di)區(qu)建(jian)設(she)水(shui)(shui)電(dian)站(zhan)(zhan)的(de)水(shui)(shui)庫防滲(shen)、大(da)壩(ba)基(ji)礎穩定、泄洪及施工后(hou)期導流等重大(da)技(ji)術難題,為我國(guo)(guo)今(jin)后(hou)在(zai)西南巖(yan)溶地(di)區(qu)建(jian)設(she)大(da)型水(shui)(shui)電(dian)站(zhan)(zhan)積累了(le)有益的(de)經驗。烏江渡(du)水(shui)(shui)電(dian)站(zhan)(zhan)自開工以來,精打細算(suan),共節(jie)約資金8000多萬元,木材1萬多立方米,水(shui)(shui)泥(ni)11萬多噸。整個工程(cheng)(cheng)造價沒有超過工程(cheng)(cheng)概算(suan),是我國(guo)(guo)近年來大(da)型水(shui)(shui)電(dian)站(zhan)(zhan)建(jian)設(she)經濟效(xiao)益最好(hao)的(de)一個工程(cheng)(cheng)。
發電能力
烏(wu)江渡水(shui)電(dian)(dian)(dian)(dian)站共裝(zhuang)有三臺高水(shui)頭大(da)型(xing)水(shui)輪發(fa)電(dian)(dian)(dian)(dian)機(ji)組。單機(ji)容(rong)(rong)(rong)量(liang)21萬(wan)千瓦(wa),總(zong)(zong)裝(zhuang)機(ji)容(rong)(rong)(rong)量(liang)為63萬(wan)千瓦(wa),年發(fa)電(dian)(dian)(dian)(dian)量(liang)33.4億度。它(ta)的(de)總(zong)(zong)裝(zhuang)機(ji)容(rong)(rong)(rong)量(liang)約(yue)占貴(gui)州省(sheng)水(shui)火電(dian)(dian)(dian)(dian)總(zong)(zong)裝(zhuang)機(ji)容(rong)(rong)(rong)量(liang)的(de)40%。該電(dian)(dian)(dian)(dian)站全部建成投(tou)產,使貴(gui)州省(sheng)的(de)發(fa)電(dian)(dian)(dian)(dian)能力增加了2/5左右,在貴(gui)州電(dian)(dian)(dian)(dian)網中發(fa)揮(hui)著骨干(gan)作用。不僅如此(ci),該電(dian)(dian)(dian)(dian)站的(de)電(dian)(dian)(dian)(dian)力還并入西(xi)南聯網運行,除滿足(zu)貴(gui)州省(sheng)的(de)用電(dian)(dian)(dian)(dian)需要外,還將多余的(de)電(dian)(dian)(dian)(dian)輸往四川,主要補充重(zhong)慶地區(qu)電(dian)(dian)(dian)(dian)力之不足(zu)。
主要結構
烏江渡水電站控(kong)制(zhi)流域面積:27790平方(fang)公里。
多年平(ping)均流量:502立(li)方米/秒。
設計洪水流量:19200立方米(mi)/秒。
校核(he)洪水位:762.8米。
正常高(gao)水位:760米。
死水位:720米。
校(xiao)核尾水位:672.9米,
設(she)計尾(wei)水位:668.3米。
最低尾水位:625.72米。
總(zong)庫容:23億立(li)方米。
主壩壩型(xing):混凝土拱形重力壩。
壩頂(ding)高程(cheng):765米(mi)。
最大(da)壩(ba)(ba)高:165米(為當(dang)時(shi)我國(guo)已建成水電(dian)站的第一(yi)高壩(ba)(ba))。
壩頂弧長(chang):368米。
壩體工程量:193萬立方米。
主要泄洪(hong)方式:壩(ba)頂(ding)溢流、隧洞泄洪(hong)。
壩體(ti)在700米高(gao)程以下為整體(ti)結(jie)構(gou),橫(heng)縫灌漿(jiang);700米高(gao)成以上為懸臂梁(liang)結(jie)構(gou),橫(heng)縫不灌漿(jiang)。壩型結(jie)構(gou)特點(dian)是:由(you)于拱(gong)軸曲率很小,因而在兩岸拱(gong)座范圍內,軸向力(H)較小,順(shun)河(he)流方向(近東西向)拱(gong)端剪(jian)力(V)較大。
主壩中部(bu)為溢(yi)(yi)流(liu)壩,設(she)(she)有4個溢(yi)(yi)流(liu)表(biao)孔(kong)。溢(yi)(yi)流(liu)孔(kong)設(she)(she)有弧形閘門(13×19 ),并設(she)(she)有檢修閘門井和(he)(he)工作閘門井。溢(yi)(yi)流(liu)面(板)末端挑(tiao)流(liu)鼻坎高程669.367米。溢(yi)(yi)流(liu)壩頂設(she)(she)有行車和(he)(he)閘門啟閉設(she)(she)備。
溢流壩(ba)北、南(nan)兩側設有左、右溢洪(hong)(hong)道。兩岸分(fen)別設有左、右岸泄(xie)(xie)洪(hong)(hong)洞。在壩(ba)體內,左、右泄(xie)(xie)洪(hong)(hong)洞高(gao)程720米。左、右泄(xie)(xie)洪(hong)(hong)道內側左、右泄(xie)(xie)洪(hong)(hong)中孔(kong)高(gao)程680米。導流底孔(kong)高(gao)程628.7米。
電站主廠房(fang)為壩(ba)后式廠房(fang)。付(fu)廠房(fang)在主廠房(fang)上(shang)游側的壩(ba)內(nei)。主廠房(fang)與壩(ba)體(ti)之間設(she)有(you)廠壩(ba)分縫。壩(ba)體(ti)下游面22萬伏(fu)開關站基(ji)面高(gao)程686米(mi)(mi)。引(yin)水鋼管(guan)埋設(she)在壩(ba)體(ti)內(nei),進(jin)水口高(gao)程700米(mi)(mi)。水輪機的安(an)裝高(gao)程622.5米(mi)(mi)。
壩體下游面(mian)人(ren)行道高程724.2米。
壩頂左側(ce)設置(zhi)有升船機。壩體上還安裝有攔污柵等設備。
上(shang)游圍堰右岸(an)設有(you)導流隧洞(dong)(dong)(dong)。在平面上(shang)它位于(yu)右岸(an)泄洪(hong)洞(dong)(dong)(dong)外側(靠河(he)道一(yi)側)。右岸(an)泄洪(hong)洞(dong)(dong)(dong)內側(靠山里一(yi)側)設有(you)放空(kong)洞(dong)(dong)(dong)。在立面上(shang),放空(kong)洞(dong)(dong)(dong)在右岸(an)泄洪(hong)洞(dong)(dong)(dong)和(he)導流洞(dong)(dong)(dong)之間(高(gao)程(cheng)在680米和(he)700米之間)。
左岸(an)有上壩隧洞。右岸(an)有進廠交通洞。
壩基(ji)進行了固(gu)結(jie)灌漿。在壩基(ji)上游側(ce)和(he)廠(chang)基(ji)下游側(ce)分別設置了防滲帷幕。
壩(ba)(ba)軸線位(wei)于(yu)壩(ba)(ba)基上游帷幕前面。
地質特征
烏江渡水電站(zhan)壩址河(he)段兩岸山(shan)高(gao)300余米。河(he)水位625.7米。河(he)面寬70米。700米高(gao)程(cheng)以下谷(gu)坡坡度(du)約為60°,700米高(gao)程(cheng)以上谷(gu)坡坡度(du)約為40°。河(he)谷(gu)呈“V”型(xing)。
壩基地層(ceng)(ceng)(ceng)為下三疊統玉龍山(shan)石灰(hui)(hui)巖(yan)(yan)(yan)(T1)總厚(hou)度233米(mi)。按巖(yan)(yan)(yan)性可分為兩大層(ceng)(ceng)(ceng):第一大層(ceng)(ceng)(ceng)(T1)以深灰(hui)(hui)色中厚(hou)層(ceng)(ceng)(ceng)和(he)(he)薄層(ceng)(ceng)(ceng)石灰(hui)(hui)巖(yan)(yan)(yan)為主,夾多層(ceng)(ceng)(ceng)極薄的炭質(zhi)頁巖(yan)(yan)(yan)和(he)(he)鈣質(zhi)頁巖(yan)(yan)(yan),厚(hou)110米(mi)。依(yi)頁巖(yan)(yan)(yan)夾層(ceng)(ceng)(ceng)的多少(shao)(shao),第一大層(ceng)(ceng)(ceng)可分為三個(ge)小(xiao)層(ceng)(ceng)(ceng)。第二(er)大層(ceng)(ceng)(ceng)(T1)為深灰(hui)(hui)色厚(hou)層(ceng)(ceng)(ceng)塊狀(zhuang)和(he)(he)中厚(hou)層(ceng)(ceng)(ceng)致密(mi)石灰(hui)(hui)巖(yan)(yan)(yan),夾極少(shao)(shao)量炭質(zhi)頁巖(yan)(yan)(yan)和(he)(he)炭質(zhi)薄膜(mo),厚(hou)123米(mi)。石灰(hui)(hui)巖(yan)(yan)(yan)堅脆質(zhi)純(chun),平均飽和(he)(he)極限抗壓(ya)強度在600公斤(jin)/厘米(mi)以上。
玉龍山石灰巖以下,據壩趾50米處,為下三疊統九級灘頁巖——粘土頁巖(T1),厚55~83米。壩后式廠房距九級灘頁巖僅20米。玉龍山石灰巖之上,為下三疊統沙灣堡頁巖(T1)壩(ba)址(zhi)上游(you)1公里處(chu),地(di)層至(zhi)西向東倒轉。壩(ba)址(zhi)區(qu)地(di)層走向NE 5°~15°,傾(qing)向NWW(上游(you)),傾(qing)角60°左右。壩(ba)區(qu)地(di)質(zhi)構造主要受燕山期NNE向構造體系控制。地(di)層在(zai)近東西向應力場作用下(xia),強(qiang)烈擠壓、倒轉,并產生(sheng)多組斷裂(lie)(lie)及(ji)扭曲(qu)破(po)裂(lie)(lie),構造破(po)壞嚴重(zhong)。其中,右岸(an)斷裂(lie)(lie)密(mi)集(ji),巖體完整性差。
玉龍山石灰巖地下巖溶發育。巖溶形態(tai)有溶洞、暗河、豎井及斜井等。兩(liang)岸(an)已見溶洞14個,可測長度1456米,總體積達86193立(li)方米(右岸(an)77843立(li)方米)。巖溶發育主(zhu)要規(gui)律(lv)是:
⑴、發(fa)育(yu)強度與石灰巖(yan)(yan)性(xing)狀和夾層(ceng)(ceng)(ceng)巖(yan)(yan)性(xing)有(you)關。第(di)二大層(ceng)(ceng)(ceng)較第(di)一(yi)大層(ceng)(ceng)(ceng)發(fa)育(yu)。在(zai)第(di)一(yi)大層(ceng)(ceng)(ceng)中,第(di)二小(xiao)層(ceng)(ceng)(ceng)巖(yan)(yan)溶(rong)最(zui)發(fa)育(yu),第(di)三小(xiao)層(ceng)(ceng)(ceng)次之,第(di)一(yi)小(xiao)層(ceng)(ceng)(ceng)最(zui)弱(ruo)(夾層(ceng)(ceng)(ceng)最(zui)多(duo))。
⑵、發(fa)育方(fang)向(xiang)受構造控制。主要方(fang)向(xiang)為NNE向(xiang)(巖層走向(xiang))及NWW向(xiang)(張性斷裂方(fang)向(xiang))。局(ju)部受NE向(xiang)構造控制。
⑶、發育成層性(xing)明顯。右岸巖溶(rong)(rong)可(ke)分為四層,其(qi)高(gao)程分別(bie)為:630~640米(mi)(mi)(mi)、660~670米(mi)(mi)(mi)、695~705米(mi)(mi)(mi)和725~735米(mi)(mi)(mi),與烏江兩(liang)岸階(jie)地(di)高(gao)程基本(ben)相應。其(qi)余(yu)各高(gao)程巖溶(rong)(rong)以(yi)垂直巖溶(rong)(rong)為主,并與各層水平溶(rong)(rong)洞相連,形成樹(shu)枝狀巖溶(rong)(rong)系統。在(zai)近代河床以(yi)下300米(mi)(mi)(mi)的(de)深度(du),亦(yi)見(jian)有(you)沿(yan)NE向斷層垂直發育的(de)深部巖溶(rong)(rong)。
壩基工(gong)程(cheng)地質條件(jian)右岸較差,左岸次之,河床較好。
上述(shu)壩(ba)型結構特(te)點(dian)決定(ding)了兩岸(an)(an)壩(ba)肩(jian)(jian)深(shen)部抗滑穩(wen)定(ding)條(tiao)(tiao)件是影(ying)響大壩(ba)安全的(de)重要(yao)(yao)因素(su)之一。分(fen)(fen)析壩(ba)肩(jian)(jian)抗滑穩(wen)定(ding)條(tiao)(tiao)件,主要(yao)(yao)是要(yao)(yao)查明(ming)和分(fen)(fen)析700米高程以下拱(gong)形重力壩(ba)的(de)兩岸(an)(an)壩(ba)肩(jian)(jian)拱(gong)座(zuo)基礎部位的(de)巖體(ti)中,沿拱(gong)座(zuo)方(fang)向(xiang)(北西西向(xiang))和底平面(mian)有(you)無明(ming)顯而(er)連續的(de)軟弱結構面(mian)存在。這是壩(ba)肩(jian)(jian)深(shen)部抗滑穩(wen)定(ding)的(de)關鍵因素(su)或控制因素(su)。
復雜的(de)(de)地質(zhi)條件決定了烏江(jiang)渡水(shui)電站(zhan)的(de)(de)主要工程地質(zhi)問題是:⑴、庫、壩區滲(shen)漏(lou);⑵、壩基(ji)和壩肩(jian),主要是右岸壩肩(jian)的(de)(de)深(shen)部抗滑穩定問題。為了防滲(shen)和提高(gao)壩基(ji)、壩肩(jian)巖體的(de)(de)整體性和穩定性,對(dui)壩基(ji)進行了固結灌漿(jiang);設置了防滲(shen)帷(wei)幕(mu),并與兩岸上游相(xiang)對(dui)隔水(shui)層相(xiang)連(lian)接;對(dui)右壩肩(jian)的(de)(de)軟弱結構面進行了專門的(de)(de)處(chu)理(li),同時采取了改(gai)選壩型等措施。
修建原理
烏(wu)江渡水(shui)電(dian)站(zhan)壩(ba)(ba)(ba)(ba)(ba)基巖(yan)(yan)(yan)體內(nei)軟(ruan)弱結構面(mian)的(de)(de)發育沒有明顯的(de)(de)分(fen)(fen)異(yi),不(bu)同方(fang)向的(de)(de)裂(lie)隙(xi)普遍存在(zai)。在(zai)這(zhe)(zhe)種情(qing)況下,深(shen)部(bu)滑動面(mian)往往是由(you)壩(ba)(ba)(ba)(ba)(ba)基內(nei)最大(da)剪(jian)應力(li)(li)帶的(de)(de)分(fen)(fen)布所決定(ding)(ding)。因此,在(zai)設(she)(she)計(ji)過程中(zhong)(zhong),需要沿最大(da)剪(jian)應力(li)(li)帶,并根據這(zhe)(zhe)個帶的(de)(de)綜合工(gong)程地質性(xing)質指(zhi)標,校核壩(ba)(ba)(ba)(ba)(ba)基的(de)(de)深(shen)部(bu)抗(kang)(kang)滑穩(wen)定(ding)(ding)性(xing)。據試驗和有限單元法計(ji)算,由(you)于(yu)距河床(chuang)壩(ba)(ba)(ba)(ba)(ba)段(duan)很(hen)近(jin)的(de)(de)下游九級灘(tan)頁巖(yan)(yan)(yan)強(qiang)度(du)低,變形(xing)大(da),因而應力(li)(li)在(zai)玉龍山(shan)石灰巖(yan)(yan)(yan)內(nei)高(gao)度(du)集中(zhong)(zhong),其剪(jian)應力(li)(li)最高(gao)帶與壩(ba)(ba)(ba)(ba)(ba)底面(mian)約成20°~25°的(de)(de)交角。實際上(shang),壩(ba)(ba)(ba)(ba)(ba)基內(nei)也確實有一(yi)組裂(lie)隙(xi)沿這(zhe)(zhe)一(yi)方(fang)向發育。因此,根據這(zhe)(zhe)個帶的(de)(de)加權(quan)平均(jun)(包括(kuo)裂(lie)隙(xi)與完整(zheng)巖(yan)(yan)(yan)石)抗(kang)(kang)剪(jian)強(qiang)度(du)指(zhi)標,校核了壩(ba)(ba)(ba)(ba)(ba)基巖(yan)(yan)(yan)體深(shen)部(bu)抗(kang)(kang)滑穩(wen)定(ding)(ding)性(xing)。結果發現,按原來設(she)(she)計(ji)的(de)(de)壩(ba)(ba)(ba)(ba)(ba)型,壩(ba)(ba)(ba)(ba)(ba)基巖(yan)(yan)(yan)體深(shen)部(bu)抗(kang)(kang)滑穩(wen)定(ding)(ding)性(xing)不(bu)能(neng)滿(man)(man)(man)足要求。于(yu)是,將原設(she)(she)計(ji)的(de)(de)一(yi)般類型的(de)(de)重力(li)(li)壩(ba)(ba)(ba)(ba)(ba)改為拱形(xing)重力(li)(li)壩(ba)(ba)(ba)(ba)(ba),把20%~30%的(de)(de)水(shui)平推(tui)力(li)(li)傳(chuan)到兩岸壩(ba)(ba)(ba)(ba)(ba)肩上(shang),以保證大(da)壩(ba)(ba)(ba)(ba)(ba)有足夠的(de)(de)抗(kang)(kang)滑穩(wen)定(ding)(ding)性(xing)。這(zhe)(zhe)樣一(yi)來,對于(yu)選(xuan)定(ding)(ding)的(de)(de)拱形(xing)重力(li)(li)壩(ba)(ba)(ba)(ba)(ba),河床(chuang)壩(ba)(ba)(ba)(ba)(ba)基和左壩(ba)(ba)(ba)(ba)(ba)肩的(de)(de)深(shen)部(bu)抗(kang)(kang)滑穩(wen)定(ding)(ding)安全系數分(fen)(fen)別達(da)到4.67和4.69,均(jun)能(neng)滿(man)(man)(man)足穩(wen)定(ding)(ding)性(xing)要求。雖然右壩(ba)(ba)(ba)(ba)(ba)肩在(zai)天然狀(zhuang)態下穩(wen)定(ding)(ding)性(xing)較差,但是對右壩(ba)(ba)(ba)(ba)(ba)肩主要軟(ruan)弱結構面(mian)進行(xing)專(zhuan)門處理后,亦能(neng)滿(man)(man)(man)足拱形(xing)重力(li)(li)壩(ba)(ba)(ba)(ba)(ba)的(de)(de)穩(wen)定(ding)(ding)性(xing)要求。
施工特點
施(shi)工方(fang)面(mian),成(cheng)功(gong)地采用(yong)(yong)人(ren)工砂(sha)石(shi)料,建成(cheng)了年(nian)產(chan)200萬(wan)噸的砂(sha)石(shi)加工系(xi)統,多年(nian)平(ping)均生(sheng)產(chan)成(cheng)本為(wei)9.13元(yuan)/米(mi)3;采用(yong)(yong)高壓(ya)水(shui)(shui)泥(ni)灌(guan)漿帷(wei)(wei)幕,成(cheng)功(gong)地解(jie)決了水(shui)(shui)庫滲漏問(wen)題,帷(wei)(wei)幕總(zong)(zong)長約(yue)1000米(mi),帷(wei)(wei)幕灌(guan)漿鉆孔總(zong)(zong)深(shen)度(du)達19萬(wan)米(mi);試制(zhi)成(cheng)功(gong)壓(ya)力(li)為(wei)100公斤(jin)/厘米(mi)2的高壓(ya)灌(guan)漿機(ji)(ji),實際(ji)使用(yong)(yong)最大灌(guan)漿壓(ya)力(li)60公斤(jin)/厘米(mi)2;采用(yong)(yong)大型鋼木模(mo)板及混凝(ning)土預制(zhi)壩面(mian)、廊道模(mo)板;在混凝(ning)土中(zhong)使用(yong)(yong)不同(tong)性能的外加劑,單(dan)位體積混凝(ning)土平(ping)均水(shui)(shui)泥(ni)耗量(liang)為(wei)195公斤(jin);在施(shi)工工藝不斷革新的基礎上,各主要(yao)施(shi)工工序實現了綜合機(ji)(ji)械化,多年(nian)平(ping)均全員勞動(dong)生(sheng)產(chan)率為(wei)4028元(yuan),節約(yue)了大量(liang)建設投(tou)資。
歷史沿革
烏江(jiang)渡(du)水電站(zhan)(zhan)(zhan)是(shi)我國20世紀(ji)80年(nian)代初在(zai)貴(gui)州喀(ka)(ka)斯(si)特(te)地(di)(di)貌上興建(jian)(jian)的(de)第一個大(da)型水電站(zhan)(zhan)(zhan),是(shi)我國烏江(jiang)梯(ti)級電站(zhan)(zhan)(zhan)開(kai)發(fa)10座(zuo)(zuo)大(da)中(zhong)型電站(zhan)(zhan)(zhan)的(de)第一座(zuo)(zuo),總裝機容(rong)(rong)量為(wei)(wei)三(san)臺(tai)21萬(wan)(wan)千瓦機組;電站(zhan)(zhan)(zhan)大(da)壩高165米,是(shi)當時我國在(zai)喀(ka)(ka)斯(si)特(te)地(di)(di)貌上興建(jian)(jian)的(de)第一座(zuo)(zuo)高壩。20年(nian)來,這座(zuo)(zuo)水電站(zhan)(zhan)(zhan)已累計發(fa)電500多億度(du)電,為(wei)(wei)貴(gui)州的(de)經(jing)濟建(jian)(jian)設(she)做出(chu)的(de)巨大(da)貢獻。貴(gui)州“西(xi)電東送”首批開(kai)工(gong)項目(mu)——烏江(jiang)渡(du)水電站(zhan)(zhan)(zhan)擴機增(zeng)容(rong)(rong)工(gong)程,正(zheng)在(zai)這里進行緊張的(de)建(jian)(jian)設(she),首臺(tai)擴機機組將(jiang)于2012年(nian)8月15日(ri)試投產發(fa)電。這座(zuo)(zuo)電站(zhan)(zhan)(zhan)擴機增(zeng)容(rong)(rong)項目(mu)完工(gong)后,將(jiang)新(xin)增(zeng)加2兩臺(tai)25萬(wan)(wan)千瓦機組,原三(san)臺(tai)21萬(wan)(wan)千瓦機組將(jiang)增(zeng)容(rong)(rong)12萬(wan)(wan)千瓦,總裝機容(rong)(rong)量將(jiang)達125萬(wan)(wan)千瓦。這座(zuo)(zuo)有20年(nian)歷史的(de)水電大(da)壩將(jiang)在(zai)我國“西(xi)電東送”建(jian)(jian)設(she)中(zhong)煥(huan)發(fa)青春。
該水(shui)(shui)電站位于(yu)巖(yan)溶(rong)地(di)區,防止(zhi)壩(ba)基和兩(liang)(liang)岸(an)滲(shen)漏是關鍵問題。自(zi)1958年起對 壩(ba)址的(de)(de)工程地(di)質(zhi)和水(shui)(shui)文地(di)質(zhi)條(tiao)件進行(xing)勘探,完(wan)成(cheng)(cheng)了(le)大(da)(da)量的(de)(de)勘探試(shi)驗工作(zuo)。采(cai)(cai)用高壓(ya)水(shui)(shui)泥灌(guan)(guan)漿帷(wei)幕(mu)(mu)與(yu)上游(you)砂頁巖(yan)隔水(shui)(shui)層相聯接的(de)(de)防滲(shen)措施。帷(wei)幕(mu)(mu)線路布置,在(zai)壩(ba)體范圍內與(yu)壩(ba)軸線平(ping)行(xing),自(zi)建基面垂直向下在(zai)玉龍山灰巖(yan)中(zhong)形成(cheng)(cheng)幕(mu)(mu)體。左、右兩(liang)(liang)岸(an)因被兩(liang)(liang)條(tiao)大(da)(da)斷層將 頁巖(yan)錯斷,形成(cheng)(cheng)滲(shen)漏通道(dao),因此,兩(liang)(liang)岸(an)防滲(shen)帷(wei)幕(mu)(mu)線路均自(zi)壩(ba)肩折向上游(you),并向山體內延伸(shen)。壩(ba)基帷(wei)幕(mu)(mu)總(zong)長(chang)1020m,帷(wei)幕(mu)(mu)線底部最(zui)深處達河床(chuang)以下200m,帷(wei)幕(mu)(mu)總(zong)面積(ji)18.9萬m2,灌(guan)(guan)漿鉆孔總(zong)長(chang)約(yue)19萬m。采(cai)(cai)用不(bu)沖洗(xi)高壓(ya)水(shui)(shui)泥灌(guan)(guan)漿,最(zui)大(da)(da)灌(guan)(guan)漿壓(ya)力(li)6MPa,壓(ya)力(li)下限不(bu)低于(yu)2MPa。在(zai)左岸(an)壩(ba)肩巖(yan)基內高程640~670m緊靠大(da)(da)壩(ba)建基面設(she)置了(le)長(chang)93m的(de)(de)混凝(ning)土(tu)(tu)防滲(shen)墻。在(zai)廠(chang)(chang)房(fang)(fang)下游(you)邊線和廠(chang)(chang)房(fang)(fang)兩(liang)(liang)側設(she)置有全長(chang)242m的(de)(de)水(shui)(shui)泥灌(guan)(guan)漿帷(wei)幕(mu)(mu)。河床(chuang)以上較(jiao)大(da)(da)溶(rong)洞清(qing)理后,回填混凝(ning)土(tu)(tu)。深部溶(rong)洞用高壓(ya)灌(guan)(guan)漿處理。壩(ba)基和兩(liang)(liang)岸(an)處理后,在(zai)120m工作(zuo)水(shui)(shui)頭下,每24h滲(shen)漏量20m3。實(shi)際揚壓(ya)力(li)遠(yuan)小于(yu)設(she)計值(zhi)。
為(wei)了更大(da)程(cheng)度滿足系統的(de)調峰、調頻和事故備用(yong)需(xu)要,2003年12月完成了擴(kuo)大(da)裝機(ji)(ji)容(rong)(rong)量的(de)施工(gong)(gong)(gong)。擴(kuo)大(da)裝機(ji)(ji)容(rong)(rong)量2×25萬(wan)kW,擴(kuo)機(ji)(ji)后水庫死水位736m。擴(kuo)機(ji)(ji)工(gong)(gong)(gong)程(cheng)電(dian)站廠(chang)(chang)房采用(yong)地(di)下(xia)式廠(chang)(chang)房布(bu)(bu)置方案,引水發(fa)電(dian)系統布(bu)(bu)置在壩下(xia)左岸山體內。擴(kuo)機(ji)(ji)工(gong)(gong)(gong)程(cheng)主要建(jian)筑(zhu)物包括岸邊壩式進水口(kou)(kou)、引水隧洞(dong)、尾(wei)水洞(dong)、尾(wei)水出口(kou)(kou)主廠(chang)(chang)房(長×寬×高:84.2× 23.9× 55.3m)、主變(bian)洞(dong)開關(guan)站、出線平臺、進廠(chang)(chang)交(jiao)通洞(dong)、地(di)下(xia)廠(chang)(chang)房防滲排水設(she)施等(deng)。除進水口(kou)(kou)的(de)部分建(jian)筑(zhu)物及尾(wei)水出口(kou)(kou)、出線平臺地(di)面副廠(chang)(chang)房以外,其(qi)它均布(bu)(bu)置于地(di)下(xia)。工(gong)(gong)(gong)程(cheng)土(tu)(tu)石(shi)方明挖量35.35萬(wan)m,石(shi)方洞(dong)挖36.4萬(wan)m,混凝土(tu)(tu)總量13.34萬(wan)m。擴(kuo)機(ji)(ji)工(gong)(gong)(gong)程(cheng)概算總投資(zi)為(wei)8.33億元(yuan)。