本文選題：盾構(gòu)隧道　切入點(diǎn)：管片襯砌　出處：《西南交通大學(xué)》2014年博士論文

【摘要】：伴隨著大批城市地鐵盾構(gòu)隧道和水下大型鐵路、公路盾構(gòu)隧道的建成,盾構(gòu)隧道的長(zhǎng)期安全穩(wěn)定問題隨之而來。目前盾構(gòu)隧道襯砌結(jié)構(gòu)設(shè)計(jì)理論主要從局部的管片混凝土的強(qiáng)度、混凝土的開裂以及接縫面的強(qiáng)度、接頭的張開等方面進(jìn)行檢算,而對(duì)盾構(gòu)隧道的整體失穩(wěn)破壞問題缺乏考慮。實(shí)際工程中,軟弱地層條件,管片結(jié)構(gòu)材料性能退化以及人類活動(dòng)的影響,比如近接建筑物的施工、抽取地下水等因素都會(huì)對(duì)整個(gè)盾構(gòu)隧道的穩(wěn)定性產(chǎn)生不良影響,而目前缺乏相關(guān)的理論判據(jù),并且目前的相關(guān)研究甚少。論文結(jié)合國家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃)課題“復(fù)雜環(huán)境作用下地下結(jié)構(gòu)的長(zhǎng)期安全性及其預(yù)測(cè)方法”和國家自然科學(xué)基金青年基金“大斷面盾構(gòu)隧道管片接頭力學(xué)行為研究”,主要采用理論分析、相似模型試驗(yàn)和數(shù)值分析等研究手段,對(duì)盾構(gòu)隧道管片襯砌結(jié)構(gòu)的穩(wěn)定性問題進(jìn)行研究,旨在揭示盾構(gòu)隧道管片襯砌結(jié)構(gòu)的失穩(wěn)性態(tài),探明盾構(gòu)隧道管片襯砌結(jié)構(gòu)的失穩(wěn)破壞判定標(biāo)準(zhǔn),主要工作和研究成果如下：1、針對(duì)目前我國存在的典型盾構(gòu)隧道,即一般城市地鐵盾構(gòu)隧道和水下公路或鐵路盾構(gòu)隧道,采用數(shù)值分析的手段,對(duì)外直徑分別為6m級(jí)、10m級(jí)、15m級(jí)的盾構(gòu)隧道管片接頭的抗彎性能進(jìn)行了研究,給出了其盾構(gòu)隧道管片接頭的抗彎剛度設(shè)計(jì)建議取值范圍。2、以外徑10.8m的獅子洋水下鐵路盾構(gòu)隧道為研究對(duì)象,采用數(shù)值分析的手段,探討了接頭抗彎剛度對(duì)管片襯砌結(jié)構(gòu)變形和內(nèi)力的影響規(guī)律,建立了基于接頭抗彎剛度-彎矩-軸力非線性關(guān)系的殼-彈簧管片襯砌力學(xué)計(jì)算模型,探明了與管片結(jié)構(gòu)受力一致的管片接頭抗彎剛度,對(duì)管片接頭的工作性態(tài)有了較準(zhǔn)確的把握,有利于優(yōu)化設(shè)計(jì)3、采用非線性有限元穩(wěn)定性分析方法,分析不同地層條件、不同接頭抗彎剛度、不同拼裝方式下的管片襯砌結(jié)構(gòu)失穩(wěn)力學(xué)特征,探討了不同因素對(duì)盾構(gòu)隧道結(jié)構(gòu)穩(wěn)定性的影響程度和影響規(guī)律。4、采用“盾構(gòu)隧道-土層復(fù)合體模擬試驗(yàn)系統(tǒng)”,針對(duì)標(biāo)準(zhǔn)貫入度≤5的軟弱粘土地層條件,開展了盾構(gòu)隧道管片襯砌結(jié)構(gòu)穩(wěn)定性相似模型試驗(yàn),揭示了接頭抗彎剛度、拼裝方式、管片剛度、地層空洞等不同因素對(duì)管片結(jié)構(gòu)穩(wěn)定性的影響規(guī)律,探明了盾構(gòu)隧道管片結(jié)構(gòu)的失穩(wěn)性態(tài)。通過比較模型試驗(yàn)和數(shù)值分析的結(jié)果,提出了盾構(gòu)隧道管片結(jié)構(gòu)失穩(wěn)破壞判斷的建議。5、采用非線性有限元穩(wěn)定性分析方法,研究特殊條件下的管片襯砌結(jié)構(gòu)穩(wěn)定性,包括局部地層抗力削弱情況、復(fù)合地層條件、地下水位變化以及長(zhǎng)期地下環(huán)境作用引起的結(jié)構(gòu)性能退化等,揭示了不同條件下管片結(jié)構(gòu)的失穩(wěn)機(jī)理和失穩(wěn)性態(tài)。
[Abstract]:With a large number of urban subway shield tunnels and large underwater railways, the construction of highway shield tunnels, At present, the design theory of shield tunnel lining is mainly based on the strength of local segment concrete, the crack of concrete, the strength of joint surface, the opening of joint, and so on. However, the overall instability of shield tunnel is not considered. In actual engineering, the condition of weak stratum, the degradation of material performance of segment structure and the influence of human activity, such as the construction of adjacent buildings, The extraction of groundwater and other factors will have a negative impact on the stability of the whole shield tunnel, but there is no relevant theoretical criterion at present. And there are few related researches at present. The thesis combines with the national key basic research and development plan "the long-term safety of underground structure under complex environment and its prediction method" and the youth of the National Natural Science Foundation of China ("the long-term safety of underground structure under the action of complex environment and its prediction method"). The research on the mechanical behavior of segment joint of large-section shield tunnel is mainly based on theoretical analysis. Similar model test and numerical analysis are used to study the stability of shield tunnel segment lining structure in order to reveal the unstable state of shield tunnel segment lining structure. The main work and research results are as follows: 1. Aiming at the typical shield tunnel existing in our country at present, that is, the general urban subway shield tunnel and the underwater highway or railway shield tunnel, By means of numerical analysis, the bending behavior of shield tunnel segment joints with external diameters of 6m or 10m or 15m respectively is studied. The flexural stiffness of the segment joint of shield tunnel is given in this paper. The suggested value range of bending stiffness of the segment joint of shield tunnel is 0.2. Taking the shield tunnel of Lion-yang underwater railway with the outer diameter of 10.8m as the research object, the method of numerical analysis is adopted. The influence of joint bending stiffness on the deformation and internal force of segment lining structure is discussed, and a mechanical calculation model of shell spring segment lining is established based on the nonlinear relationship between bending stiffness, bending moment and axial force of joint. The bending stiffness of the segment joint which is consistent with the stress on the segment structure is proved, and the working behavior of the segment joint is accurately grasped, which is beneficial to the optimum design 3. The nonlinear finite element stability analysis method is used to analyze the different stratum conditions. The unstable mechanical characteristics of segment lining structure under different joint bending stiffness and different assembling methods, This paper discusses the influence of different factors on the structural stability of shield tunneling. 4. "Shield tunnel-soil complex simulation test system" is adopted to deal with the soft clay formation conditions with standard penetration 鈮，

本文編號(hào)：1655970