芒果视频

主要作品

李春是(shi)中國隋代著名(ming)(ming)的(de)(de)(de)橋(qiao)梁(liang)(liang)工(gong)匠，舉世聞名(ming)(ming)的(de)(de)(de)趙州橋(qiao)就是(shi)他最偉(wei)大的(de)(de)(de)杰作(zuo)，這個濃(nong)縮了(le)中華人民智慧(hui)結(jie)晶的(de)(de)(de)標志性橋(qiao)梁(liang)(liang)，開創了(le)中國橋(qiao)梁(liang)(liang)建造的(de)(de)(de)嶄新局面，為中國橋(qiao)梁(liang)(liang)技術的(de)(de)(de)發展作(zuo)出了(le)巨大貢獻(xian)。

趙州(zhou)橋(qiao)的(de)敞(chang)肩(jian)(jian)圓弧(hu)(hu)拱(gong)形式是中國勞動人(ren)民(min)的(de)一大創(chuang)造，西方在(zai)14世紀才(cai)出現敞(chang)肩(jian)(jian)圓弧(hu)(hu)石(shi)拱(gong)橋(qiao)，已經比中國晚了(le)600多年(nian)。英(ying)國著(zhu)名中國科學(xue)技(ji)術(shu)史專家李(li)約瑟(se)博士在(zai)其巨著(zhu)《中國科學(xue)技(ji)術(shu)史》中曾經列舉(ju)了(le)26項(xiang)從(cong)1世紀到(dao)18世紀先后由中國傳到(dao)歐洲和(he)其他地區的(de)科學(xue)技(ji)術(shu)成(cheng)果，其中的(de)第18項(xiang)就是弧(hu)(hu)形拱(gong)橋(qiao)。趙州(zhou)橋(qiao)建成(cheng)后成(cheng)為(wei)中國北(bei)南交通的(de)要沖(chong)，有“坦途(tu)箭直千(qian)人(ren)過(guo)，驛使馳驅萬國通”的(de)美譽(yu)。舟船在(zai)橋(qiao)下航行，人(ren)馬(ma)車輛(liang)從(cong)橋(qiao)上駛(shi)過(guo)，大大方便(bian)了(le)交通運輸和(he)人(ren)民(min)生活，為(wei)**河兩岸人(ren)員來往提供了(le)便(bian)利條件。

這座(zuo)大橋自建(jian)成至今(jin)已有1300多年，這期間(jian)經(jing)歷了8次以上地震的(de)(de)影響，8次以上戰(zhan)爭(zheng)的(de)(de)考驗；承(cheng)受了無數次人(ren)畜車輛的(de)(de)重壓(ya)，飽經(jing)無數次風刀霜劍(jian)、冰雪雨水(shui)的(de)(de)沖(chong)蝕，卻雄姿(zi)不減當年，仍巍(wei)然屹立在洨(xiao)河上。

解放以(yi)(yi)后，趙(zhao)州橋(qiao)(qiao)(qiao)被(bei)列為全國(guo)(guo)重點文物保護單(dan)位(wei)，有(you)關部門對(dui)這(zhe)一古代(dai)大橋(qiao)(qiao)(qiao)進(jin)行了徹底維修，以(yi)(yi)保持其(qi)輝(hui)煌的(de)(de)歷史地位(wei)。趙(zhao)州橋(qiao)(qiao)(qiao)已(yi)(yi)成(cheng)為中(zhong)(zhong)國(guo)(guo)人民聰明智慧(hui)的(de)(de)象征和進(jin)行愛(ai)國(guo)(guo)主(zhu)義、歷史主(zhu)義教育的(de)(de)場所。趙(zhao)州橋(qiao)(qiao)(qiao)的(de)(de)建(jian)成(cheng)在中(zhong)(zhong)國(guo)(guo)橋(qiao)(qiao)(qiao)梁(liang)史上具(ju)有(you)重要影晌(shang)，它的(de)(de)大跨度(du)、圓(yuan)弧拱(gong)、敝肩形式力(li)以(yi)(yi)后的(de)(de)橋(qiao)(qiao)(qiao)梁(liang)建(jian)設開創了新(xin)的(de)(de)天地。隋代(dai)以(yi)(yi)后，出現了許(xu)多與趙(zhao)州橋(qiao)(qiao)(qiao)相類似的(de)(de)大型(xing)拱(gong)橋(qiao)(qiao)(qiao)，已(yi)(yi)經發現的(de)(de)就有(you)十幾座，如山西(xi)崞縣(xian)(xian)的(de)(de)普濟(ji)橋(qiao)(qiao)(qiao)、晉城的(de)(de)景德橋(qiao)(qiao)(qiao)、河北趙(zhao)縣(xian)(xian)的(de)(de)永通橋(qiao)(qiao)(qiao)、濟(ji)美橋(qiao)(qiao)(qiao)等。趙(zhao)州橋(qiao)(qiao)(qiao)已(yi)(yi)經成(cheng)為中(zhong)(zhong)國(guo)(guo)橋(qiao)(qiao)(qiao)梁(liang)建(jian)設的(de)(de)典范。

然而象趙(zhao)州(zhou)橋(qiao)這樣(yang)(yang)突出的技術成就(jiu)和象李春這樣(yang)(yang)杰出的橋(qiao)梁專(zhuan)家(jia)，在封建(jian)社會中(zhong)并不為(wei)封建(jian)統治者所(suo)(suo)重視，甚(shen)至在史(shi)書中(zhong)也沒有留下多少痕跡，我(wo)(wo)們(men)除了知(zhi)道隋朝工匠李春設(she)計(ji)建(jian)造了這座(zuo)舉世聞名的大橋(qiao)外，其他(ta)卻一無所(suo)(suo)知(zhi)，不能不說是一個很大的遺憾(han)。但(dan)是即使如此我(wo)(wo)們(men)仍然堅(jian)信：李春作為(wei)一代(dai)橋(qiao)梁專(zhuan)家(jia)和趙(zhao)州(zhou)橋(qiao)作為(wei)一座(zuo)歷史(shi)名橋(qiao)將(jiang)永載祖(zu)國史(shi)冊，為(wei)后人(ren)所(suo)(suo)牢記(ji)。

貢獻影響

趙州橋的設計在中(zhong)國橋梁技術(shu)史有(you)以(yi)下創新：

1．采(cai)用(yong)圓弧拱(gong)形(xing)式，改變了中(zhong)國大(da)石橋(qiao)(qiao)多(duo)為半(ban)圓形(xing)拱(gong)的(de)(de)(de)(de)傳統，中(zhong)國古代石橋(qiao)(qiao)拱(gong)形(xing)大(da)多(duo)為半(ban)圓形(xing)，這種形(xing)式比(bi)(bi)較(jiao)(jiao)優美(mei)、完整(zheng)，但也存在兩方面的(de)(de)(de)(de)缺陷：一(yi)是交通不便(bian)，半(ban)圓形(xing)橋(qiao)(qiao)拱(gong)用(yong)于(yu)跨(kua)(kua)度(du)(du)比(bi)(bi)較(jiao)(jiao)小的(de)(de)(de)(de)橋(qiao)(qiao)梁(liang)比(bi)(bi)較(jiao)(jiao)合適，而大(da)跨(kua)(kua)度(du)(du)的(de)(de)(de)(de)橋(qiao)(qiao)梁(liang)選(xuan)用(yong)半(ban)圓形(xing)拱(gong)，就(jiu)會使(shi)拱(gong)頂很高，造(zao)成橋(qiao)(qiao)高坡(po)陡、車馬行人過橋(qiao)(qiao)非(fei)常不便(bian)。二是施(shi)工(gong)不利(li)，半(ban)圓形(xing)拱(gong)石砌(qi)石用(yong)的(de)(de)(de)(de)腳手架就(jiu)會很高，增加施(shi)工(gong)的(de)(de)(de)(de)危險性。為此，李春(chun)和(he)工(gong)匠(jiang)們一(yi)起創造(zao)性地(di)采(cai)用(yong)了圓弧拱(gong)形(xing)式，使(shi)石拱(gong)高度(du)(du)大(da)大(da)降低。趙州橋(qiao)(qiao)的(de)(de)(de)(de)主孔凈跨(kua)(kua)度(du)(du)為37.02米，而拱(gong)高只有(you)7.25米，拱(gong)高和(he)跨(kua)(kua)度(du)(du)之比(bi)(bi)為1:5左右，這樣就(jiu)實現了低橋(qiao)(qiao)面和(he)大(da)跨(kua)(kua)度(du)(du)的(de)(de)(de)(de)雙重目的(de)(de)(de)(de)，橋(qiao)(qiao)面過渡平穩，車輛行人非(fei)常方便(bian)，而且還具(ju)有(you)用(yong)料省、施(shi)工(gong)方便(bian)等優點。當然圓弧形(xing)拱(gong)對(dui)兩端(duan)橋(qiao)(qiao)基的(de)(de)(de)(de)推力(li)相(xiang)應增大(da)，需要(yao)(yao)對(dui)橋(qiao)(qiao)基的(de)(de)(de)(de)施(shi)工(gong)提出更高的(de)(de)(de)(de)要(yao)(yao)求。

2．采用(yong)敞(chang)(chang)肩(jian)(jian)。這(zhe)是李春對(dui)(dui)拱(gong)(gong)(gong)(gong)肩(jian)(jian)進行的(de)(de)(de)重(zhong)大(da)(da)(da)改(gai)進，把以(yi)(yi)往橋(qiao)(qiao)(qiao)(qiao)(qiao)梁建(jian)筑中采用(yong)的(de)(de)(de)實(shi)(shi)肩(jian)(jian)拱(gong)(gong)(gong)(gong)改(gai)為敞(chang)(chang)肩(jian)(jian)拱(gong)(gong)(gong)(gong)，即在大(da)(da)(da)拱(gong)(gong)(gong)(gong)兩端各設兩個(ge)小(xiao)拱(gong)(gong)(gong)(gong)，靠近(jin)大(da)(da)(da)拱(gong)(gong)(gong)(gong)腳(jiao)的(de)(de)(de)小(xiao)拱(gong)(gong)(gong)(gong)凈跨為3.8米(mi)，另一(yi)拱(gong)(gong)(gong)(gong)的(de)(de)(de)凈跨為2.8米(mi)。這(zhe)種大(da)(da)(da)拱(gong)(gong)(gong)(gong)加小(xiao)拱(gong)(gong)(gong)(gong)的(de)(de)(de)敞(chang)(chang)肩(jian)(jian)拱(gong)(gong)(gong)(gong)具有優異的(de)(de)(de)技(ji)術性(xing)能(neng)(neng)，首先可(ke)以(yi)(yi)增(zeng)(zeng)加泄洪(hong)能(neng)(neng)力(li)，減(jian)(jian)輕(qing)(qing)洪(hong)水(shui)(shui)季節由于(yu)(yu)水(shui)(shui)量增(zeng)(zeng)加而產生的(de)(de)(de)洪(hong)水(shui)(shui)對(dui)(dui)橋(qiao)(qiao)(qiao)(qiao)(qiao)的(de)(de)(de)沖擊力(li)。古代洨河每逢汛期，水(shui)(shui)勢較大(da)(da)(da)，對(dui)(dui)橋(qiao)(qiao)(qiao)(qiao)(qiao)的(de)(de)(de)泄洪(hong)能(neng)(neng)力(li)是個(ge)考驗，四(si)個(ge)小(xiao)拱(gong)(gong)(gong)(gong)就可(ke)以(yi)(yi)分擔部分洪(hong)流(liu)，據計(ji)算四(si)個(ge)小(xiao)拱(gong)(gong)(gong)(gong)可(ke)增(zeng)(zeng)加過水(shui)(shui)面積16%左(zuo)右，大(da)(da)(da)大(da)(da)(da)降低洪(hong)水(shui)(shui)對(dui)(dui)大(da)(da)(da)橋(qiao)(qiao)(qiao)(qiao)(qiao)的(de)(de)(de)影響，提高大(da)(da)(da)橋(qiao)(qiao)(qiao)(qiao)(qiao)的(de)(de)(de)安全性(xing)。其次敞(chang)(chang)肩(jian)(jian)拱(gong)(gong)(gong)(gong)比實(shi)(shi)肩(jian)(jian)拱(gong)(gong)(gong)(gong)可(ke)節省大(da)(da)(da)量土石材料(liao)，減(jian)(jian)輕(qing)(qing)橋(qiao)(qiao)(qiao)(qiao)(qiao)身(shen)的(de)(de)(de)自重(zhong)，據計(ji)算四(si)個(ge)小(xiao)拱(gong)(gong)(gong)(gong)可(ke)以(yi)(yi)節省石料(liao)26立方米(mi)，減(jian)(jian)輕(qing)(qing)自身(shen)重(zhong)量700噸(dun)，從而減(jian)(jian)少橋(qiao)(qiao)(qiao)(qiao)(qiao)身(shen)對(dui)(dui)橋(qiao)(qiao)(qiao)(qiao)(qiao)臺(tai)和(he)(he)橋(qiao)(qiao)(qiao)(qiao)(qiao)基的(de)(de)(de)垂直壓(ya)力(li)和(he)(he)水(shui)(shui)平推力(li)，增(zeng)(zeng)加橋(qiao)(qiao)(qiao)(qiao)(qiao)梁的(de)(de)(de)穩固。第三增(zeng)(zeng)加了造型的(de)(de)(de)優美，四(si)個(ge)小(xiao)拱(gong)(gong)(gong)(gong)均(jun)衡對(dui)(dui)稱，大(da)(da)(da)拱(gong)(gong)(gong)(gong)與小(xiao)拱(gong)(gong)(gong)(gong)構(gou)(gou)成一(yi)幅(fu)完整的(de)(de)(de)圖(tu)畫，顯得更加輕(qing)(qing)巧秀麗，體現(xian)建(jian)筑和(he)(he)藝術的(de)(de)(de)完整統一(yi)。第四(si)符合結(jie)構(gou)(gou)力(li)學(xue)理論，敞(chang)(chang)肩(jian)(jian)拱(gong)(gong)(gong)(gong)式結(jie)構(gou)(gou)在承載時使橋(qiao)(qiao)(qiao)(qiao)(qiao)梁處于(yu)(yu)有利(li)的(de)(de)(de)狀況，可(ke)減(jian)(jian)少主拱(gong)(gong)(gong)(gong)圈的(de)(de)(de)變形，提高了橋(qiao)(qiao)(qiao)(qiao)(qiao)梁的(de)(de)(de)承載力(li)和(he)(he)穩定性(xing)。

3．單(dan)孔(kong)。中國古代(dai)的傳(chuan)統建(jian)筑方法，一(yi)般(ban)比(bi)較(jiao)長的橋(qiao)梁往往采(cai)用多孔(kong)形式，這樣每(mei)孔(kong)的跨度小、坡(po)度平緩，便于(yu)修建(jian)。但(dan)是(shi)多孔(kong)橋(qiao)也有缺點，如橋(qiao)墩多，既(ji)不(bu)利于(yu)舟船航行，也妨礙(ai)洪水(shui)宣泄；橋(qiao)墩長期受水(shui)流(liu)沖擊、侵(qin)蝕，天(tian)長日久容易塌毀(hui)。因此，李春(chun)在(zai)設計大橋(qiao)的時候，采(cai)取了單(dan)孔(kong)長跨的形式，河心不(bu)立橋(qiao)墩，使(shi)石拱跨徑(jing)長達(da)37米之多。這是(shi)中國橋(qiao)梁史上的空前(qian)創舉。

趙州橋不僅(jin)設計獨特，而且有許多(duo)創造性。

1．橋(qiao)(qiao)址(zhi)選擇比較(jiao)合理，使橋(qiao)(qiao)基(ji)穩固牢靠。李春根據(ju)自己多年豐(feng)富的實踐經(jing)驗，經(jing)過嚴(yan)格周(zhou)密勘查、比較(jiao)，選擇了洨河(he)兩(liang)岸較(jiao)為(wei)平直的地(di)方(fang)建橋(qiao)(qiao)，這里(li)的地(di)層(ceng)(ceng)是由河(he)水沖積而(er)(er)成，地(di)層(ceng)(ceng)表(biao)面是久經(jing)水流沖涮的粗(cu)砂層(ceng)(ceng)，以(yi)下是細石(shi)、粗(cu)石(shi)、細砂和粘土層(ceng)(ceng)。根據(ju)現(xian)代測算(suan)，這里(li)的地(di)層(ceng)(ceng)每平方(fang)厘米能(neng)夠承受(shou)4.5到6.6公(gong)斤的壓(ya)力，而(er)(er)趙州橋(qiao)(qiao)對地(di)面的壓(ya)力為(wei)每平方(fang)厘米5——6公(gong)斤，能(neng)夠滿足大橋(qiao)(qiao)的要求。選定(ding)橋(qiao)(qiao)址(zhi)后在(zai)上面建造地(di)基(ji)和橋(qiao)(qiao)臺，建橋(qiao)(qiao)到如(ru)今，橋(qiao)(qiao)基(ji)僅(jin)下沉了5厘米，說明這里(li)的地(di)層(ceng)(ceng)非常適合于(yu)建橋(qiao)(qiao)。

2．趙州橋的(de)(de)(de)砌(qi)置方(fang)法(fa)新穎(ying)、施工修(xiu)(xiu)理方(fang)便。李春就(jiu)地(di)取材，選用附近(jin)州縣生(sheng)產的(de)(de)(de)質地(di)堅硬(ying)的(de)(de)(de)青灰色(se)砂石作(zuo)為(wei)建橋石料，在(zai)石拱砌(qi)置方(fang)法(fa)上，均采用了(le)縱向(xiang)(xiang)（順(shun)橋方(fang)向(xiang)(xiang)）砌(qi)置方(fang)法(fa)，就(jiu)是整(zheng)(zheng)個(ge)大橋是由(you)28道(dao)(dao)各自獨立(li)(li)的(de)(de)(de)拱券(quan)(quan)(quan)沿寬(kuan)度(du)方(fang)向(xiang)(xiang)并列組合而成，拱厚皆為(wei)1.03米，每(mei)券(quan)(quan)(quan)各自獨立(li)(li)、單獨操作(zuo)，相當靈活，每(mei)券(quan)(quan)(quan)砌(qi)完(wan)全(quan)合攏后(hou)就(jiu)成一道(dao)(dao)獨立(li)(li)拼(pin)券(quan)(quan)(quan)，砌(qi)完(wan)一道(dao)(dao)供(gong)券(quan)(quan)(quan)，移(yi)動承擔重(zhong)量的(de)(de)(de)“鷹(ying)架(jia)”，再砌(qi)另一道(dao)(dao)相鄰拱。這種(zhong)砌(qi)法(fa)有很(hen)多優點，它既可以節(jie)省制作(zuo)“鷹(ying)架(jia)”所(suo)用的(de)(de)(de)木(mu)材，便于移(yi)動；同時又利于橋的(de)(de)(de)維修(xiu)(xiu)，一道(dao)(dao)拱券(quan)(quan)(quan)的(de)(de)(de)石塊損壞了(le)，只要嵌(qian)入新石，進行(xing)局部(bu)修(xiu)(xiu)整(zheng)(zheng)就(jiu)行(xing)了(le)，而不必對整(zheng)(zheng)個(ge)橋進行(xing)調整(zheng)(zheng)。

3．在(zai)(zai)保(bao)持大(da)橋穩(wen)定性方面(mian)采取(qu)了(le)(le)許多嚴密(mi)(mi)措(cuo)施。為了(le)(le)加(jia)強(qiang)(qiang)各(ge)道(dao)拱(gong)(gong)(gong)(gong)券(quan)(quan)(quan)(quan)(quan)間(jian)的(de)(de)橫(heng)向(xiang)(xiang)聯(lian)系(xi)，使(shi)(shi)28道(dao)拱(gong)(gong)(gong)(gong)組成一(yi)個(ge)有(you)(you)(you)機整(zheng)體(ti)，連(lian)接緊密(mi)(mi)牢(lao)固(gu)，李春采取(qu)了(le)(le)一(yi)系(xi)列(lie)技術措(cuo)施。1）每一(yi)拱(gong)(gong)(gong)(gong)券(quan)(quan)(quan)(quan)(quan)采用(yong)了(le)(le)下寬(kuan)上(shang)(shang)窄(zhai)、略(lve)有(you)(you)(you)“收(shou)分”的(de)(de)方法，使(shi)(shi)每個(ge)拱(gong)(gong)(gong)(gong)券(quan)(quan)(quan)(quan)(quan)向(xiang)(xiang)里傾斜，相互擠靠(kao)，增(zeng)(zeng)強(qiang)(qiang)其(qi)橫(heng)向(xiang)(xiang)聯(lian)系(xi)，以(yi)防止(zhi)拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)向(xiang)(xiang)外傾倒；在(zai)(zai)橋的(de)(de)寬(kuan)度上(shang)(shang)也采用(yong)了(le)(le)少量“收(shou)分”的(de)(de)辦法，就是從(cong)橋的(de)(de)兩端到橋頂逐漸收(shou)縮寬(kuan)度，從(cong)最(zui)寬(kuan)9.6米收(shou)縮到9米，以(yi)加(jia)強(qiang)(qiang)大(da)橋的(de)(de)穩(wen)定性。2）在(zai)(zai)主券(quan)(quan)(quan)(quan)(quan)上(shang)(shang)均勻沿橋寬(kuan)方向(xiang)(xiang)設置了(le)(le)5個(ge)鐵拉(la)桿，穿過28道(dao)拱(gong)(gong)(gong)(gong)券(quan)(quan)(quan)(quan)(quan)，每個(ge)拉(la)桿的(de)(de)兩端有(you)(you)(you)半(ban)圓形桿頭露在(zai)(zai)石(shi)(shi)(shi)外，以(yi)夾住(zhu)28道(dao)拱(gong)(gong)(gong)(gong)券(quan)(quan)(quan)(quan)(quan)，增(zeng)(zeng)強(qiang)(qiang)其(qi)橫(heng)向(xiang)(xiang)聯(lian)系(xi)。在(zai)(zai)4個(ge)小(xiao)拱(gong)(gong)(gong)(gong)上(shang)(shang)也各(ge)有(you)(you)(you)一(yi)根(gen)鐵拉(la)桿起(qi)同(tong)樣作(zuo)用(yong)。3）在(zai)(zai)靠(kao)外側的(de)(de)幾道(dao)拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)上(shang)(shang)和(he)兩端小(xiao)拱(gong)(gong)(gong)(gong)上(shang)(shang)蓋有(you)(you)(you)護(hu)(hu)拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)一(yi)層，以(yi)保(bao)護(hu)(hu)拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)；在(zai)(zai)護(hu)(hu)拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)的(de)(de)兩側設有(you)(you)(you)勾石(shi)(shi)(shi)6塊，勾住(zhu)主拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)使(shi)(shi)其(qi)連(lian)接牢(lao)固(gu)。4）為了(le)(le)使(shi)(shi)相鄰拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)緊緊貼(tie)合(he)在(zai)(zai)一(yi)起(qi)，在(zai)(zai)兩側外券(quan)(quan)(quan)(quan)(quan)相鄰拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)之間(jian)都穿有(you)(you)(you)起(qi)連(lian)接作(zuo)用(yong)的(de)(de)“腰鐵”，各(ge)道(dao)券(quan)(quan)(quan)(quan)(quan)之間(jian)的(de)(de)相鄰石(shi)(shi)(shi)塊也都在(zai)(zai)拱(gong)(gong)(gong)(gong)背穿有(you)(you)(you)“腰鐵”，把拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)連(lian)鎖起(qi)來(lai)。而(er)且(qie)每塊拱(gong)(gong)(gong)(gong)石(shi)(shi)(shi)的(de)(de)側面(mian)都鑿有(you)(you)(you)細密(mi)(mi)斜紋，以(yi)增(zeng)(zeng)大(da)摩擦力，加(jia)強(qiang)(qiang)各(ge)券(quan)(quan)(quan)(quan)(quan)橫(heng)向(xiang)(xiang)聯(lian)系(xi)。這些(xie)措(cuo)施的(de)(de)采取(qu)使(shi)(shi)整(zheng)個(ge)大(da)橋連(lian)成一(yi)個(ge)緊密(mi)(mi)整(zheng)體(ti)，增(zeng)(zeng)強(qiang)(qiang)了(le)(le)整(zheng)個(ge)大(da)橋的(de)(de)穩(wen)定性和(he)可靠(kao)性。