本文選題：盾構(gòu)隧道　切入點(diǎn)：開挖面穩(wěn)定性　出處：《山東大學(xué)》2016年博士論文　論文類型：學(xué)位論文

【摘要】：今年來,隨著城市建設(shè)的快速發(fā)展,城市規(guī)模不斷擴(kuò)大,城市密集度不斷提高,城市交通逐漸惡化,環(huán)境污染越發(fā)嚴(yán)重,嚴(yán)重制約了經(jīng)濟(jì)和社會(huì)的進(jìn)一步發(fā)展。為緩解地面交通壓力,改善城市交通環(huán)境,促進(jìn)城市的可持續(xù)發(fā)展,城市建設(shè)逐步轉(zhuǎn)變?yōu)榇罅﹂_發(fā)地下空間的全新理念,盾構(gòu)法作為一種較新的施工方式,在城市地下空間的施工中的應(yīng)用也逐漸增加。但隨著盾構(gòu)技術(shù)的發(fā)展以及開挖的要求越來越高,所面臨的問題也越來越多,施工過程中開挖面穩(wěn)定性的預(yù)測和控制非常困難,極易發(fā)生地表沉陷、開挖面突涌水等災(zāi)害事故。據(jù)不完全統(tǒng)計(jì),我國的北京、上海、廣州、南京、深圳等主要城市在地鐵盾構(gòu)隧道建設(shè)中均發(fā)生過重大開挖面失穩(wěn)事故,造成了重大的經(jīng)濟(jì)損失和人員傷亡。針對(duì)地鐵建設(shè)環(huán)境條件復(fù)雜、地層敏感性高、控制標(biāo)準(zhǔn)嚴(yán)苛的特點(diǎn),如何有效的預(yù)測和控制開挖面穩(wěn)定性,成為盾構(gòu)隧道施工的核心問題之一。本文以地鐵隧道土壓平衡盾構(gòu)施工為主要研究對(duì)象,依托濟(jì)南地鐵盾構(gòu)隧道工程,通過室內(nèi)實(shí)驗(yàn)、理論分析、數(shù)值計(jì)算、模型試驗(yàn)和現(xiàn)場試驗(yàn)等手段,深入研究復(fù)合地層盾構(gòu)施工開挖面失穩(wěn)機(jī)理、滲流作用下開挖面失穩(wěn)破壞災(zāi)變演化特性以及失穩(wěn)防治技術(shù)體系,取得了具有一定理論價(jià)值和工程意義的研究成果,主要包括：(1)總結(jié)提出了盾構(gòu)施工工法選型流程,從地層滲透系數(shù)、顆粒級(jí)配、巖土體特性和地下水狀態(tài)等方面對(duì)盾構(gòu)選型適用性進(jìn)行了總結(jié)和研究。開發(fā)了界面友好、人機(jī)交互的盾構(gòu)施工工法軟件系統(tǒng),結(jié)合案例工程,對(duì)盾構(gòu)在復(fù)雜地質(zhì)環(huán)境特別是穿越富水復(fù)合地層的工法選型等施工關(guān)鍵技術(shù)進(jìn)行了深入研究。(2)通過大量開挖面失穩(wěn)導(dǎo)致的地表塌陷和隧道突涌水災(zāi)害的系統(tǒng)收集與整理,分析了災(zāi)害的孕險(xiǎn)環(huán)境和誘發(fā)因子,揭示了典型災(zāi)害源的賦存特征,提出了開挖面失穩(wěn)孕災(zāi)性評(píng)價(jià)的指標(biāo)體系,建立了屬性識(shí)別模型。依托開發(fā)的風(fēng)險(xiǎn)控制軟件系統(tǒng),對(duì)高風(fēng)險(xiǎn)段進(jìn)行動(dòng)態(tài)評(píng)價(jià),提出土壓平衡盾構(gòu)施工開挖面失穩(wěn)的防控措施和應(yīng)急預(yù)案。(3)基于極限分析上限定理,構(gòu)建了三維旋轉(zhuǎn)體優(yōu)化破壞模型,利用開挖面臨界破壞時(shí)外力所做功的功率與土體內(nèi)部耗散功相等的原理,推導(dǎo)了開挖面極限支護(hù)力求解公式,通過MATLAB編程計(jì)算程序,求解土壓平衡盾構(gòu)在均質(zhì)地層和復(fù)合地層開挖面失穩(wěn)臨界支護(hù)壓力。對(duì)于復(fù)合地層,分別分析了覆土層和穿越層兩種工況下隧道埋深、巖土體特性、地下水位等因素對(duì)開挖面穩(wěn)定性的影響,并將計(jì)算結(jié)果與前人提出的經(jīng)典破壞模型得出的結(jié)果進(jìn)行了對(duì)比分析,驗(yàn)證了理論模型的正確性。(4)基于構(gòu)建的三維旋轉(zhuǎn)體優(yōu)化破壞模型,將地下水滲流作用引入到開挖面穩(wěn)定性上限分析中,推導(dǎo)了開挖面滲流力和坍塌土體中的滲流力求解公式,得到了開挖面滲流力與地下水位的關(guān)系,最終求解了滲流作用下復(fù)合地層中開挖面支護(hù)壓力上限解。(5)采用數(shù)值計(jì)算方法對(duì)地下水滲流作用下土壓平衡盾構(gòu)施工力學(xué)過程進(jìn)行了三維數(shù)值模擬,分別研究了盾構(gòu)在均質(zhì)地層施工和復(fù)合地層施工中,不同隧道埋深、巖土體力學(xué)特性、地下水狀態(tài)對(duì)開挖面失穩(wěn)破壞形式、開挖面變形、極限支護(hù)力以及地表變形的影響規(guī)律。(6)為研究地下水滲流作用下,盾構(gòu)隧道開挖面失穩(wěn)過程中開挖面支護(hù)壓力變化規(guī)律和破壞模式,研制了盾構(gòu)掘進(jìn)施工模型試驗(yàn)系統(tǒng)、可視化試驗(yàn)平臺(tái)、防水監(jiān)測自動(dòng)化采集系統(tǒng)。以濟(jì)南地鐵R1線盾構(gòu)隧道穿越灰?guī)r層、砂土層為工程背景,開展了復(fù)合地層開挖面穩(wěn)定性模型試驗(yàn),研究了復(fù)合地層中不同埋深、不同水頭高度下,盾構(gòu)施工開挖面穩(wěn)定性問題,分析了埋深和水頭高度對(duì)開挖面極限支護(hù)壓力、地表沉降、開挖面土體變形規(guī)律的影響,揭示了開挖面失穩(wěn)破壞的演化機(jī)制。
[Abstract]:This year, with the rapid development of city construction, the city continues to expand the scale of city density increasing, city traffic gradually deteriorated, environmental pollution is more serious, seriously restrict the further development of economy and society. In order to alleviate the traffic pressure on the ground, to improve the city traffic environment, promote the sustainable development of the city, city construction gradually transformed into a new concept of development of underground space, the shield method is a new construction method, construction of underground space in the city in the gradually increased. But with the development of shield technology and excavation of the increasingly high demand, facing more and more problems, the prediction and control of excavation face stability in construction process very difficult, prone to surface subsidence, excavation face water inrush and other disasters. According to incomplete statistics, China's Beijing, Shanghai, Guangzhou, Nanjing, Shenzhen and other major city in The construction of metro shield tunnel were happened in the major excavation instability accident, resulting in significant economic losses and casualties. According to the environmental conditions of the subway construction is complex, the formation of high sensitivity and control characteristics of stringent standards, face stability prediction and how to effectively control the excavation, become one of the key problems of shield tunnel construction in Metro. Tunnel of EPB shield construction as the main research object, based on the Ji'nan subway shield tunnel project, through indoor experiments, theoretical analysis, numerical calculation, model test and field test methods, in-depth study of complex strata instability mechanism of shield tunnel excavation, excavation face under seepage failure catastrophe evolution characteristics and loss prevention system of stability technology research achievements, has a certain theoretical value and engineering significance mainly includes: (1) put forward the shield construction method selection process, 浠庡湴灞傛笚閫忕郴鏁，

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