【摘要】：隨著經(jīng)濟(jì)社會的發(fā)展和城市化建設(shè)步伐的加快,交通擁堵已經(jīng)成為制約城市和區(qū)域發(fā)展的重要因素,原有的兩車道、三車道公路已經(jīng)無法滿足日益增長交通流量的需要,一部分山區(qū)高速公路和市區(qū)快速路的建設(shè)已經(jīng)進(jìn)入新的發(fā)展時期,與此對應(yīng)的超大斷面隧道的建設(shè)也呈現(xiàn)出快速增多的趨勢。但是國內(nèi)外超大斷面公路隧道的工程實踐尚不多見,既無成熟的施工建設(shè)經(jīng)驗可以借鑒,也無可靠的計算方法可以使用,更無設(shè)計、施工的規(guī)范和標(biāo)準(zhǔn)可參考,僅能依靠為數(shù)不多的簡單的工程類比進(jìn)行分析。本文針對超大斷面公路隧道施工工序受力復(fù)雜、圍巖穩(wěn)定性判別基準(zhǔn)不確定、荷載計算方法不明確以及支護(hù)結(jié)構(gòu)和參數(shù)選取難度較大等研究現(xiàn)狀及難題,通過理論分析、室內(nèi)試驗、模型試驗、數(shù)值模擬以及現(xiàn)場試驗等手段,結(jié)合濟(jì)南東南二環(huán)延長線項目在建港溝隧道工程實際,深入研究了超大斷面隧道施工過程中圍巖空間變形和荷載釋放規(guī)律,并對超大斷面隧道的施工方法比選和凈距優(yōu)化進(jìn)行了詳細(xì)研究,取得了一系列具有理論價值和工程意義的研究成果,主要包括:(1)針對影響隧道圍巖應(yīng)力特征的凈距、矢跨比、側(cè)壓力系數(shù)等因素,分別從應(yīng)力集中度的角度對超大斷面小凈距隧道的圍巖力學(xué)特征進(jìn)行了分析總結(jié)。結(jié)合現(xiàn)有普式壓力理論和公路隧道設(shè)計規(guī)范,對超大斷面小凈距隧道圍巖壓力及荷載模式進(jìn)行了探討,在考慮超大斷面小凈距隧道施工過程中先行洞和后行洞相互影響的前提下,分別進(jìn)行了淺埋情況和深埋情況下的超大斷面小凈距隧道圍巖壓力計算方法和公式的推導(dǎo)。通過公式分析研究可得,超大斷面小凈距隧道內(nèi)側(cè)圍巖與外側(cè)圍巖的壓力呈不對稱的偏壓分布,中夾巖墻豎向圍巖壓力大于隧道外側(cè),先行洞由于受后行洞開挖擾動的影響,偏壓程度較后行洞更加嚴(yán)重。根據(jù)該模式進(jìn)行計算,可以得到更加安全合理的隧道支護(hù)結(jié)構(gòu)設(shè)計參數(shù),對類似工程的設(shè)計具有一定的借鑒意義。(2)開展了工程現(xiàn)場的圍巖動態(tài)分級評價和點荷載試驗,并對白云質(zhì)灰?guī)r開展了室內(nèi)試驗,既對現(xiàn)場施工提供了動態(tài)指導(dǎo),又對模型試驗和數(shù)值模擬圍巖參數(shù)的選擇提供了依據(jù)。借鑒以有相似材料配制經(jīng)驗,在"正交試驗設(shè)計,敏感因素分析"的前提下,進(jìn)行了流-固耦合相似材料的配制,并在模型試驗中成功應(yīng)用。在節(jié)省試驗開支的前提下,研制了厚壁方管組合式試驗臺架和降雨模擬系統(tǒng),構(gòu)建了多元信息實時監(jiān)測和采集系統(tǒng)。利用激光相位測量技術(shù),融合空間動態(tài)坐標(biāo)測量方法與虛擬測量技術(shù),進(jìn)行了適用于模型試驗圍巖變形測量的柔性點云數(shù)據(jù)測量儀的研發(fā),實現(xiàn)了地質(zhì)力學(xué)模型試驗開挖輪廓測量的高自動化、高適應(yīng)性、柔性、非接觸、高效的優(yōu)點,可同時將掃描路徑三維正交分解,通過計算及距離測量自動獲得最佳測量軌跡,可實現(xiàn)對多種隧道模型,多種開挖部形狀的快速精密測量。針對該儀器基于MATLAB進(jìn)行了后處理軟件的開發(fā),可以將柔性點云數(shù)據(jù)測量儀采集的隧道模型點云數(shù)據(jù)進(jìn)行降噪、抽稀、擬合處理,再對比兩次測量數(shù)據(jù)計算隧道的變形量,對隧道模型變形信息進(jìn)行空間可視化的提取。(3)選取依托工程現(xiàn)場有代表性里程段,以此為原型開展了超大斷面隧道淺埋小凈距段施工過程模型試驗研究和復(fù)雜地層超大斷面隧道施工過程力學(xué)模型試驗研究,對超大斷面淺埋小凈距隧道施工過程及降雨入滲對圍巖空間變形的影響規(guī)律進(jìn)行了研究,同時對穿越斷層破碎帶前后不同開挖工法施工下圍巖的空間變形及荷載釋放規(guī)律進(jìn)行了探討。針對模型試驗所選取的工程原型施工段,開展了相應(yīng)數(shù)值模擬試驗研究,通過兩者結(jié)果的相互驗證,增加了結(jié)果的可靠度。其結(jié)果對揭示超大斷面淺埋小凈距隧道施工過程中圍巖空間變形機(jī)制,確保該復(fù)雜地層段的施工安全,保證隧道順利貫通提供了支撐。(4)修正了已有的摩爾-庫倫屈服接近度,并基于彈塑性有限差分?jǐn)?shù)值模擬,進(jìn)行了超大斷面小凈距隧道圍巖穩(wěn)定性影響因素的分析和評價,對不同圍巖等級的隧道給出了合理的施工方案建議。研究了超大斷面小凈距隧道施工力學(xué)特征,對小凈距隧道圍巖變形分布規(guī)律和施工的空間變形效應(yīng)進(jìn)行了分析和探討,建立了超大斷面小凈距隧道合理凈距優(yōu)化準(zhǔn)則,并提出了不同圍巖級別隧道最小凈距的合理取值。(5)依托四車道超大斷面小凈距港溝隧道,對其施工過程中圍巖和支護(hù)結(jié)構(gòu)體系的力學(xué)特點及規(guī)律進(jìn)行了監(jiān)測研究,并對其施工過程中的時空效應(yīng)進(jìn)行了分析總結(jié)。并據(jù)此對依托工程的小凈距段支護(hù)參數(shù)和支護(hù)方案進(jìn)行了優(yōu)化設(shè)計,對提高施工質(zhì)量及進(jìn)度,確保施工安全,保證隧道的順利貫通具有一定的指導(dǎo)意義。
[Abstract]:With the development of economic and social development and the accelerated pace of urbanization, traffic congestion has become an important factor restricting the development of cities and regions. The original two lane and three lane highways have been unable to meet the needs of increasing traffic flow, and the construction of some mountainous expressways and urban expressway has already entered a new development period. The construction of the super large section tunnel is also increasing rapidly. However, the engineering practice of super large section highway tunnel at home and abroad is still few, no mature construction experience can be used for reference, no reliable calculation method can be used, no design, the standard and standard of application can be referred, only can rely on the number of not. Many simple engineering analogies are analyzed. In this paper, the research status and problems of the construction procedure of super large section highway tunnel are complicated, the criterion of stability discrimination of surrounding rock is not definite, the calculation method of load is not clear, and the difficulty of selecting the support structure and parameters is more difficult, through the theoretical analysis, indoor test, model test, numerical simulation and the analysis of the construction process. By means of field test and so on, combining with the project of Ji'nan southeast second ring extension line in the construction of Jian Gang tunnel project, the space deformation and load release law of the surrounding rock during the construction process of the super large section tunnel are deeply studied, and the construction method and net distance optimization of the super large section tunnel are studied in detail, and a series of theoretical values have been obtained. The main achievements of the research are as follows: (1) in view of the factors affecting the stress characteristics of the tunnel surrounding rock, the factors such as the spacing, the vector span ratio, the side pressure coefficient and so on, the mechanical characteristics of the surrounding rock of the super large section small distance tunnel are analyzed and summarized respectively from the angle of stress concentration. The pressure and load mode of large section and small spacing tunnel are discussed. Under the premise of considering the interaction between the first tunnel and the rear row tunnel during the construction process of the super large section and small distance tunnel, the calculation method and formula of the surrounding rock pressure of the tunnel with a small net distance under the shallow burial situation and the deep buried condition are derived respectively. It can be concluded that the pressure of the inner wall rock and the outer surrounding rock of the tunnel with the small spacing of the super large section is asymmetrical, and the pressure of the vertical surrounding rock of the medium wall rock wall is larger than the outside of the tunnel. The deviation degree is more serious because of the influence of the opening and excavation of the tunnel under the influence of the opening and excavation of the tunnel. The design parameters of the tunnel supporting structure are of certain reference significance to the design of similar engineering. (2) the dynamic classification evaluation and the point load test of the surrounding rock of the engineering site are carried out, and the indoor test is carried out on the dolomitic limestone, which not only provides dynamic guidance to the site construction, but also selects the selection of the parameters of the model test and the numerical simulation of the surrounding rock. In the premise of "orthogonal test design, sensitive factor analysis", a flow to solid coupling material was prepared and successfully applied in the model test. On the premise of saving the test expenses, the thick wall square tube assembly test bench and rainfall simulation system were developed, and a multiple letter was constructed. The research and development of a flexible point cloud data measuring instrument, which is suitable for the deformation measurement of the surrounding rock of the model test, has been developed by using the laser phase measurement technology, the spatial dynamic coordinate measurement method and the virtual measurement technology, and the high automation, high adaptability, flexibility and non performance of the excavation contour measurement of the geomechanical model test are realized. With the advantages of contact and high efficiency, the three-dimensional orthogonal decomposition of the scanning path can be obtained at the same time, and the optimal measurement trajectory can be obtained automatically through the calculation and distance measurement. It can realize the rapid and precise measurement of various tunnel models and the shape of various excavations. The flexible point cloud data measuring instrument can be collected by the development of the post processing software based on the MATLAB. The tunnel model point cloud data of the set is de-noising, thinning, fitting and processing, and then comparing the deformation of the tunnel with two measurements, and extracting the spatial visualization of the deformation information of the tunnel model. (3) the representative mileage section of the engineering site is selected as the prototype, so as to open the construction of the shallow distance section of the super large section tunnel for the construction of Guo Chengmo. The model test research and the mechanical model test on the construction process of the super large section tunnel in complex strata are studied. The influence law of the construction process and the rainfall infiltration on the space deformation of the surrounding rock is studied, and the spatial deformation and load release of the surrounding rock under the construction of different excavation methods before and after the crossing fault fracture zone are carried out. According to the prototype construction section selected by the model test, the corresponding numerical simulation test was carried out, and the results were verified by the mutual validation of the two results. The results showed that the deformation mechanism of the surrounding rock in the construction process of the shallow and small distance tunnel in the super large section was revealed, and the application of the complex formation section was ensured. The work safety provides support for the smooth passage of the tunnel. (4) modified the existing mole Kulun yield proximity, and based on the elastoplastic finite difference numerical simulation, the analysis and evaluation of the influence factors of the stability of the surrounding rock of the tunnel with small distance and small spacing are carried out. The reasonable construction proposal is given to the tunnel with different surrounding rock. The mechanical characteristics of the super large section and small distance tunnel construction are analyzed. The distribution law of the surrounding rock deformation and the spatial deformation effect of the small net distance tunnel are analyzed and discussed. The optimization criterion of the reasonable spacing of the tunnel with the small spacing of the super large section is established, and the reasonable distance of the minimum net distance of the tunnel with different surrounding rock grade is put forward. (5) relying on the super break of the four lane. The mechanical characteristics and rules of the surrounding rock and support structure system in the construction process are monitored and studied. The spatio-temporal effect of the construction process is analyzed and summarized. The optimization design is made for the support parameters and support schemes of the small net distance section relying on the project, and the quality and progress of the construction are improved. It is instructive to ensure the safety of construction and ensure the smooth operation of the tunnel.
【學(xué)位授予單位】：山東大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：U456.31
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本文編號：2143398