【摘要】：盾構(gòu)隧道施工將擾動周邊地層,引發(fā)周邊地層應力釋放及調(diào)整,變位地層將導致鄰近建筑物產(chǎn)生不均勻沉降、傾斜、破裂,嚴重時甚至失穩(wěn)坍塌,進而造成重大損失與突出社會矛盾。因此,揭示盾構(gòu)隧道動態(tài)施工對鄰近建筑物工作性狀及其周邊地層變形特性的影響機理,對盾構(gòu)推進過程中施工參數(shù)的合理選取,以及有針對性的對鄰近建筑物進行加固、保護有著重要意義。本文針對盾構(gòu)隧道穿越鄰近側(cè)向既有多層框架結(jié)構(gòu)建筑物施工工況,展開了理論分析、室內(nèi)模型試驗和三維數(shù)值計算,系統(tǒng)分析研究了盾構(gòu)隧道施工對框架結(jié)構(gòu)附加變形、附加內(nèi)力及其周邊地面沉降的影響效應與影響規(guī)律。主要的研究工作及成果如下：(1)基于盾構(gòu)隧道-土體-獨立基礎框架結(jié)構(gòu)建筑物共同作用效應,采用文克爾彈性地基理論,推求得到了盾構(gòu)隧道施工誘發(fā)的獨立基礎多層框架結(jié)構(gòu)建筑物周邊地面沉降的理論計算微分方程及求解表達式,并將理論研究結(jié)果與相應數(shù)值計算、工程實測及室內(nèi)模型試驗結(jié)果進行了對比分析,驗證了該理論研究方法的可行性及其研究結(jié)果的可靠性,并將該理論研究方法進一步擴展應用于分析預測盾構(gòu)施工參數(shù)作用下的框架結(jié)構(gòu)周邊地面沉降。(2)采用自行研制的室內(nèi)模型試驗裝置模擬分析獲得的盾構(gòu)隧道一次開挖完成及不同地層損失率條件下盾構(gòu)隧道動態(tài)開挖導致的天然砂土地面沉降分布曲線特征,以及盾構(gòu)隧道開挖面完全通過后導致的穩(wěn)定砂土地面沉降槽寬度與隧道埋深之比均與已有研究成果基本相符,表明該套可模擬不同地層損失及盾構(gòu)隧道動態(tài)施工的試驗裝置與相應試驗方法的可行性及其試驗結(jié)果的可靠性。(3)針對盾構(gòu)隧道與框架結(jié)構(gòu)建筑物間不同側(cè)向距離、盾構(gòu)隧道與框架結(jié)構(gòu)建筑物間不同斜向夾角、不同建筑基礎形式及不同隧道埋深四種敏感性因素,進行了砂土中盾構(gòu)隧道動態(tài)穿越鄰近側(cè)向框架結(jié)構(gòu)建筑物施工的室內(nèi)模型試驗,明確了各敏感因素對框架結(jié)構(gòu)附加變形、附加應變及其周邊砂土地面沉降的影響效應與影響規(guī)律。(4)針對盾構(gòu)隧道推進過程中所施加的注漿壓力與掌子面推力對多層框架結(jié)構(gòu)建筑物附加變形、附加內(nèi)力及其周邊地面沉降的影響效應與影響規(guī)律,展開了系統(tǒng)的三維數(shù)值分析,提出了盾構(gòu)隧道動態(tài)穿越鄰近側(cè)向框架結(jié)構(gòu)建筑物施工過程中注漿壓力與掌子面推力的合理取值。(5)針對盾構(gòu)隧道鄰近側(cè)向框架結(jié)構(gòu)建筑物施工工況,研究提出了在框架結(jié)構(gòu)建筑物基礎周邊地層進行預先注漿,并驗證了該加固技術(shù)的適用性與實用性,以實現(xiàn)變框架結(jié)構(gòu)建筑物被動加固保護為主動減害。
[Abstract]:The construction of shield tunnel will disturb the surrounding strata and cause the stress release and adjustment of the surrounding strata. The displacement strata will lead to uneven settlement, inclination, rupture and even unstable collapse of adjacent buildings. Thus causing great losses and highlighting social contradictions. Therefore, this paper reveals the influence mechanism of dynamic construction of shield tunnel on the working behavior of adjacent buildings and the deformation characteristics of surrounding strata, the reasonable selection of construction parameters in the course of shield tunneling, and the reinforcement of adjacent buildings. Protection is of great significance. In this paper, the theoretical analysis, indoor model test and 3D numerical calculation are carried out to analyze the construction conditions of shield tunneling through adjacent multi-story frame structure. The additional deformation of shield tunnel to frame structure is studied systematically. The effect and law of the additional internal force and its surrounding land subsidence. The main work and results are as follows: (1) based on the interaction effect of shield tunnel-soil-independent frame structure, Winkler elastic foundation theory is adopted. In this paper, the theoretical differential equation and the solution expression of the ground settlement around the building of multi-story frame structure with independent foundation induced by shield tunneling construction are derived, and the theoretical research results and the corresponding numerical calculation are given. The feasibility of the theoretical research method and the reliability of the research results are verified by comparing and analyzing the engineering measured results and the indoor model test results. Furthermore, the theoretical research method is extended to analyze and predict the ground settlement around the frame structure under the action of shield construction parameters. (2) the shield tunnel obtained by simulation analysis with the self-developed indoor model test device is used to predict the ground subsidence around the frame structure under the action of shield construction parameters. The characteristics of ground subsidence distribution curve of natural sand caused by dynamic excavation of shield tunnel under the condition of the completion of the first excavation of the tunnel and the different loss rates of the stratum. And the ratio of the width of the stable sand settlement trough to the depth of the tunnel caused by the excavation surface of shield tunnel is basically consistent with the existing research results. It shows the feasibility and reliability of the test equipment and corresponding test method for simulating different ground loss and dynamic construction of shield tunnel. (3) aiming at the different lateral distance between shield tunnel and frame structure building, There are four sensitive factors, such as different oblique angle between shield tunnel and frame structure, different building foundation form and different tunnel depth. In this paper, the indoor model test of shield tunneling through adjacent lateral frame structure building in sand is carried out, and the additional deformation of each sensitive factor to the frame structure is determined. The effects of additional strain and surrounding sand settlement on the ground settlement are analyzed. (4) the additional deformation of multi-story frame structure is caused by grouting pressure and face thrust during shield tunneling. The effect and law of the additional internal force and its surrounding land subsidence are analyzed, and the three dimensional numerical analysis of the system is carried out. The reasonable value of grouting pressure and face thrust during the construction process of shield tunnel through adjacent lateral frame structure building is put forward. (5) aiming at the construction condition of shield tunnel adjacent lateral frame structure building, In this paper, pre-grouting in the surrounding strata of frame structure building foundation is proposed, and the applicability and practicability of the reinforcement technique are verified. The passive reinforcement protection of variable frame structure building is regarded as active disaster reduction.
【學位授予單位】：東南大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：U455.43;TU196

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相關(guān)期刊論文 前1條

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本文編號：2371592