本文選題：盾構(gòu)隧道 + 開挖面穩(wěn)定�。� 參考：《浙江大學(xué)》2014年博士論文

【摘要】：為有效解決城市交通擁堵問題,越來越多的城市開始大規(guī)模興建軌道交通。城市軌道交通的區(qū)間隧道大多采用盾構(gòu)法施工,由于施工中時(shí)常遇到工程地質(zhì)和水文地質(zhì)狀況多變、建(構(gòu))筑物及地下管線分布密集等諸多復(fù)雜條件,盾構(gòu)開挖面穩(wěn)定性問題日益突出�；趯�(shí)際工程需求,本文對干砂地層、穩(wěn)態(tài)滲流下飽和砂性土地層(如飽和砂質(zhì)粉土)這兩種典型復(fù)雜條件下盾構(gòu)開挖面穩(wěn)定性問題進(jìn)行了系統(tǒng)深入地研究。主要工作和研究成果如下： (1)采用離散元法較為深入研究了干砂地層盾構(gòu)開挖面穩(wěn)定性問題。發(fā)現(xiàn)失穩(wěn)過程中開挖面支護(hù)力隨位移增大存在“先減小至極限值而后逐漸增大并趨于殘余值”的現(xiàn)象；獲得了當(dāng)隧道埋深比C/D1時(shí)極限支護(hù)力受埋深比影響較小的重要結(jié)論；揭示了典型埋深下(即C/D=2)開挖面漸進(jìn)失穩(wěn)模式；發(fā)現(xiàn)了極限狀態(tài)時(shí),盾構(gòu)拱頂以上失穩(wěn)區(qū)內(nèi)存在顯著的“土拱”效應(yīng),失穩(wěn)區(qū)內(nèi)土體出現(xiàn)“松動(dòng)”現(xiàn)象。 (2)研制了適用于模擬單相土層(如干砂)開挖面失穩(wěn)的離心模型試驗(yàn)裝置,基于該裝置開展了密實(shí)干砂地層開挖面失穩(wěn)離心模型試驗(yàn)。離心試驗(yàn)證實(shí)了離散元研究獲得的開挖面支護(hù)力—位移變化關(guān)系的可靠性,發(fā)現(xiàn)了極限支護(hù)力隨埋深比增大先增加而后基本保持不變的規(guī)律,借助PIV技術(shù)揭示了極限狀態(tài)時(shí)開挖面前方呈現(xiàn)“楔形體—棱柱體”的失穩(wěn)模式,獲得了失穩(wěn)“棱柱體”高度與隧道埋深有關(guān)的重要結(jié)論。 (3)研制了國內(nèi)外首套適用于模擬穩(wěn)態(tài)滲流下盾構(gòu)開挖面失穩(wěn)的離心模型試驗(yàn)裝置,基于該裝置開展了國內(nèi)外首個(gè)穩(wěn)態(tài)滲流下飽和砂質(zhì)粉土地層盾構(gòu)開挖面失穩(wěn)離心模型試驗(yàn)。研究發(fā)現(xiàn)：穩(wěn)態(tài)滲流下,開挖面失穩(wěn)過程中有效支護(hù)力隨位移增大存在“先減小至極限值而后線性增大”的現(xiàn)象；穩(wěn)態(tài)滲流下開挖面極限有效支護(hù)力隨密封艙與遠(yuǎn)場水頭差增大而線性增大；極限狀態(tài)時(shí),開挖面前方呈現(xiàn)“楔形體—棱柱體”失穩(wěn)模式,此時(shí)失穩(wěn)“棱柱體”已經(jīng)發(fā)展到地表,其高度不受隧道埋深比的影響；孔壓沿開挖面向遠(yuǎn)場逐漸增大,當(dāng)距開挖面水平距離大于0.75D后,孔壓幾乎保持不變。 (4)在本文離散元數(shù)值研究及離心模型試驗(yàn)的相關(guān)成果基礎(chǔ)上,圍繞失穩(wěn)模式和“土拱”效應(yīng)兩方面對經(jīng)典“楔形體—棱柱體”極限平衡模型(AnagnostouKovari1996)進(jìn)行了修正,建立了適用于計(jì)算單相無粘性土層(如干砂)、單相粘性-摩擦型土層、穩(wěn)態(tài)滲流時(shí)兩相粘性-摩擦型土層等復(fù)雜條件下開挖面極限支護(hù)力(或極限有效支護(hù)力)的修正“楔形體—棱柱體”極限平衡模型。本文修正“楔形體—棱柱體”理論模型的準(zhǔn)確性得到了筆者開展的離心模型試驗(yàn)的驗(yàn)證,成功應(yīng)用于杭州地鐵1號線九堡東站—下沙西站區(qū)間盾構(gòu)工程。 本文研究有助于提升行業(yè)內(nèi)對復(fù)雜條件下開挖面穩(wěn)定問題的認(rèn)識(shí),為實(shí)際工程中控制盾構(gòu)開挖面穩(wěn)定性提供參考。
[Abstract]:In order to effectively solve the problem of urban traffic congestion, more and more cities have begun to build mass transit in a large scale. Most of the interval tunnels in urban rail transit are constructed by shield method. Because of the complex engineering geology and hydrogeological conditions in the construction, many complex conditions such as construction (construction) and the dense distribution of underground pipelines are often encountered, and the shield excavation is excavated. The problem of surface stability is becoming more and more prominent. Based on the actual engineering requirements, this paper has carried out a systematic and thorough study on the stability of the shield excavation face under two typical complex conditions of dry sand stratum, saturated sandy soil layer (such as saturated sand silt) under steady state seepage.
(1) the problem of stability of shield excavation face in dry sand stratum is studied by the discrete element method. It is found that the support force of the excavation face is reduced to the limit value first and then to the residual value with the increase of the displacement in the process of instability, and the weight of the depth ratio of the limit support force is smaller when the depth ratio of the tunnel depth is C/D1. In order to find out the progressive failure mode of the excavation surface under the typical buried depth (C/D=2), there is a remarkable "soil arch" effect in the instability zone above the shield vault, and the "loosening" phenomenon occurs in the unstable zone.
(2) a centrifugal model test device is developed to simulate the instability of the excavation surface of a single phase soil (such as dry sand). Based on this device, the centrifuge model test of the excavation surface instability in dense dry sand stratum is carried out. The centrifugal test confirms the reliability of the supporting force displacement relation of the excavation face supported by the discrete element method, and finds the limit support force with the depth of the buried depth. According to the law of increasing first and then keeping the same basically, the instability mode of "wedge body prism" in front of the excavation face is revealed with the help of PIV technology, and the important conclusion that the height of unstable "prism" is related to the buried depth of tunnel is obtained.
(3) the first set of centrifuge model test device is developed to simulate the instability of the shield surface under the simulated steady state seepage. Based on this device, the centrifuge model test of the shield excavation surface of the saturated sand powder soil layer under the first steady state seepage is carried out. There is a phenomenon that the displacement increases first to the limit value and then linearly increases, and the ultimate effective support of the excavation face increases linearly with the increase of the gap between the seal and the far field, and the "wedge body" instability model is presented in front of the excavation face, and the unstable "prism" has been developed to the surface at this time. Its height is not affected by the ratio of tunnel depth to depth, and pore pressure increases gradually along the excavation face to the far field. When the horizontal distance from the excavation face is greater than 0.75D, the pore pressure almost remains unchanged.
(4) on the basis of the results of the discrete element numerical study and the centrifugal model test, the classic "wedge prism" limit equilibrium model (AnagnostouKovari1996) is modified around the instability mode and the "soil arch" effect, and a single phase cohesionless soil layer (such as dry sand) and the single phase viscous friction type are established. Under the complicated condition of steady seepage, the limit balance model of the ultimate support force (or the ultimate effective supporting force) is corrected under the complex condition of two phase viscous friction soil layer. The accuracy of this paper is verified by the centrifugal model test carried out by the pen. It is used for shield engineering of Hangzhou Metro Line 1, East Kowloon East Station and Xiasha west station.
This study is helpful to enhance the understanding of the stability of excavation face under complex conditions, and provide reference for controlling the stability of shield excavation face in practical engineering.

【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2014
【分類號】：U455.43

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 魏綱;賀峰;;砂性土中頂管開挖面最小支護(hù)壓力的計(jì)算[J];地下空間與工程學(xué)報(bào);2007年05期

2 胡雯婷;呂璽琳;黃茂松;;盾構(gòu)隧道開挖面極限支護(hù)壓力三維極限平衡解[J];地下空間與工程學(xué)報(bào);2011年05期

3 黎春林;繆林昌;;盾構(gòu)施工滲流場有限元模擬及其對臨近土層的影響分析[J];東南大學(xué)學(xué)報(bào)(自然科學(xué)版);2010年05期

4 邢紀(jì)波,俞良群,張瑞豐,王泳嘉;離散單元法的計(jì)算參數(shù)和求解方法選擇[J];計(jì)算力學(xué)學(xué)報(bào);1999年01期

5 喬金麗;張義同;許春彥;;考慮滲流的盾構(gòu)隧道開挖面穩(wěn)定性分析[J];水文地質(zhì)工程地質(zhì);2009年01期

6 喬金麗;張義同;高健;李艷艷;;強(qiáng)度折減法在盾構(gòu)隧道開挖面穩(wěn)定分析中的應(yīng)用[J];天津大學(xué)學(xué)報(bào);2010年01期

7 黃正榮;朱偉;梁精華;秦建設(shè);;盾構(gòu)法隧道開挖面極限支護(hù)壓力研究[J];土木工程學(xué)報(bào);2006年10期

8 朱偉,秦建設(shè),盧廷浩;砂土中盾構(gòu)開挖面變形與破壞數(shù)值模擬研究[J];巖土工程學(xué)報(bào);2005年08期

9 黃正榮;朱偉;梁精華;秦建設(shè);;淺埋砂土中盾構(gòu)法隧道開挖面極限支護(hù)壓力及穩(wěn)定研究[J];巖土工程學(xué)報(bào);2006年11期

10 高健;張義同;喬金麗;;滲透力對隧道開挖面穩(wěn)定性影響分析[J];巖土工程學(xué)報(bào);2009年10期

相關(guān)博士學(xué)位論文 前1條

1 徐小敏;砂土液化及其判別的微觀機(jī)理研究[D];浙江大學(xué);2012年

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