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1、摘要橋梁是交通運(yùn)輸體系中的樞紐工程,在國(guó)民經(jīng)濟(jì)和社會(huì)生活中擔(dān)當(dāng)著舉足輕重的作用。隨著橋梁使用時(shí)間的延長(zhǎng)和交通運(yùn)輸需求不斷增加,預(yù)應(yīng)力混凝土梁橋由于結(jié)構(gòu)材料的自然老化、車輛荷載的不斷增加、日益惡化的環(huán)境影響以及使用養(yǎng)護(hù)不當(dāng)?shù)纫蛩兀喈?dāng)一部分橋梁不可避免地出現(xiàn)各種各樣的結(jié)構(gòu)損傷和病害,大量在役橋梁承載力不足、老化、破損己影響到橋梁的正常使用,如何合理評(píng)估利用這些橋梁成為國(guó)內(nèi)外十分關(guān)注的問(wèn)題。1.本文從在役預(yù)應(yīng)力混凝土梁橋的風(fēng)險(xiǎn)識(shí)別著手,采用模糊層次分析法對(duì)各風(fēng)險(xiǎn)因素進(jìn)行分析識(shí)別。為了嘗試探討在役橋梁風(fēng)險(xiǎn)事故的發(fā)生的規(guī)律并
2、協(xié)助風(fēng)險(xiǎn)識(shí)別工作,本文開(kāi)發(fā)了橋梁風(fēng)險(xiǎn)事故查詢與預(yù)警系統(tǒng),為在役橋梁風(fēng)險(xiǎn)事故的分析和研究積累資料,進(jìn)行風(fēng)險(xiǎn)預(yù)警。2.依據(jù)我國(guó)橋梁設(shè)計(jì)規(guī)范,建立預(yù)應(yīng)力混凝土梁橋結(jié)構(gòu)的抗彎承載能力極限狀態(tài)方程,結(jié)合已有文獻(xiàn)的統(tǒng)計(jì)參數(shù),采用JC法計(jì)算預(yù)應(yīng)力混凝土梁橋構(gòu)件抗彎承載能力可靠度指標(biāo)和失效概率,利用PNET法計(jì)算結(jié)構(gòu)體系的可靠度指標(biāo)及失效概率。3.將失效概率與以統(tǒng)一貨幣形式計(jì)量的失效后果值相乘得到定量的風(fēng)險(xiǎn)值,根據(jù)風(fēng)險(xiǎn)的概率和風(fēng)險(xiǎn)值大小對(duì)風(fēng)險(xiǎn)進(jìn)行評(píng)級(jí)分類,并構(gòu)建風(fēng)險(xiǎn)矩陣,采用fiLARP法則制定風(fēng)險(xiǎn)接受準(zhǔn)則對(duì)風(fēng)險(xiǎn)值作出評(píng)估。4.以藥
3、湖特大橋?yàn)楣こ瘫尘埃凑毡疚牡姆椒▽?duì)該橋進(jìn)行風(fēng)險(xiǎn)評(píng)估,評(píng)定該橋的風(fēng)險(xiǎn)等級(jí)為三級(jí),表明該橋需要進(jìn)行加固處理。該結(jié)果與按照《公路橋梁技術(shù)狀況評(píng)定標(biāo)準(zhǔn)》評(píng)定的結(jié)果及荷載試驗(yàn)的結(jié)果相一致,證明了本文的風(fēng)險(xiǎn)評(píng)估方法的正確性。同時(shí),針對(duì)技術(shù)狀況標(biāo)準(zhǔn)評(píng)定的不同類別橋梁進(jìn)行風(fēng)險(xiǎn)值計(jì)算,提出不同類別橋梁的風(fēng)險(xiǎn)指標(biāo),為進(jìn)一步對(duì)在役橋梁的風(fēng)險(xiǎn)評(píng)估研究提供參考。關(guān)鍵詞:在役預(yù)應(yīng)力混凝土梁橋;模糊層次分析法;可靠度指標(biāo);橋梁技術(shù)狀況評(píng)定;ALARP法則ABSTRACTBridgeisthekeyprojectoftransportations
4、ystem,andplaysapivotalroleinthenationaleconomicalandsociallife.Withtheincreasingofdemandsoftransportationandextendingofservicetimeofbridge,acertainkindofPCbeambridgeshowvariouskindsofstructuraldamageanddiseasesinevitablyduetOnaturalagingofstructuralmaterials,in
5、creasingofvehicleloads,affectsofdeterioratingenvironments,curingimproperly,andSOon.Lackofload-carryingcapacity,aging,andbreakagehadaffectedthenormalusingofmanyexistingbridges.Hawtoaccessthesebridgeshasbecomeaveryimportantproblemathomeandabroad.1.Thispapersettle
6、sdowntoriskidentifyofPCbeambridge,andtakestheFAHPmethodtofindtheriskfactors.Inordertodiscusstheoccurrencedisciplineofriskeventsofexistingbridgesandgiveassistancetoriskidentify,thispaperdevelopsbridgeriskeventsinquiringandprewarningsystemwhichcanaccumulatesdataf
7、oranalyzingandstudiesonbridgeriskeventsalsocanproceedprewarning.2.Accordingtocodesofbridgedesign,establishequationsofflexuralload-carryingcapacityinultimatestateofstructuresofPCbeambridge,andcombinesstatisticparametersinreferences.JCmethodiSadoptedtocalculatest
8、ructuralreliabilityindexandfailureprobabilityofflexuralload—carryingcapacityofPCbeambridge,andPNETmethodisadoptedtocalculatethereliabilityindexandfailureofthewholebridge.3.T