南水北調(diào)東干渠某標段土壓平衡盾構(gòu)施工關(guān)鍵技術(shù)研究
發(fā)布時間：2018-10-12 08:55
【摘要】：隨著我國城市隧道工程的迅速發(fā)展,土壓平衡盾構(gòu)法以施工速度快、勞動強度低、對環(huán)境影響小、施工經(jīng)濟等優(yōu)點得到了廣泛的應(yīng)用,成為軟土地基隧道施工的首選,并在技術(shù)和經(jīng)濟上取得了良好的效果。但是在土壓平衡盾構(gòu)施工過程中仍然存在著一些問題,如盾構(gòu)機推進速度、推力、艙內(nèi)土壓、刀盤轉(zhuǎn)速、出土量和螺旋輸送機轉(zhuǎn)速間的相互關(guān)系、刀盤阻塞及出土不暢、土倉壓力如何取值才能使掌子面保持平衡、同步注漿壓力與注漿量控制、施工過程中的地層位移等。本文以北京市南水北調(diào)東干渠某標段土壓平衡盾構(gòu)施工為工程背景,對施工過程中開挖渣土改良、掌子面壓力取值和地層位移變化規(guī)律進行了研究。具體研究內(nèi)容及獲得的結(jié)論如下:①渣土改良實驗。設(shè)計了一系列渣土改良室內(nèi)試驗,分別對細中砂和粉質(zhì)粘土進行土體改良優(yōu)化試驗,得到細中砂最佳泡沫注入比為8%,粉質(zhì)粘土的最佳泡沫注入比為30%,并根據(jù)現(xiàn)場混合地層細中砂和粉質(zhì)粘土的體積不同確定最佳泡沫注入比參數(shù)為22%。②掌子面壓力理論計算。運用不同的土倉壓力計算理論,得到優(yōu)化后盾構(gòu)開挖面壓力取值范圍為100-150KPa。③地層位移變化監(jiān)測。對地表位移、土體豎向位移、土體水平位移和盾構(gòu)機實時工作參數(shù)進行了監(jiān)測。得到地層豎向位移變化過程分為三個階段,隆起階段、快速沉降階段、緩慢沉降階段;隧道方向水平位移變化也分為三個階段,先向盾構(gòu)前進方向變化、然后再反方向變化、最后又向盾構(gòu)前進方向變化;盾構(gòu)機總推力、土倉壓力和刀盤扭矩成正相關(guān)關(guān)系,盾構(gòu)參數(shù)的變化對地層位移有著明顯的影響。④地層位移變化數(shù)值模擬。本文運用FLAC3D軟件對實際監(jiān)測段盾構(gòu)施工過程地層位移變化進行數(shù)值模擬計算。模擬得到的地層位移變化規(guī)律與實際位移變化規(guī)律相似。本文的結(jié)論對實際工程具有參考意義,可以為類似地層土壓平衡盾構(gòu)施工提供借鑒。
[Abstract]:With the rapid development of urban tunnel engineering in China, the earth pressure balance shield method has been widely used in the construction of soft ground tunnel with the advantages of fast construction speed, low labor intensity, small environmental impact and construction economy. And achieved good results in technology and economy. However, there are still some problems in the construction of earth pressure balance shield machine, such as the speed of shield machine, the thrust, the earth pressure in the cabin, the rotation speed of the cutter head, the relationship between the unearthed quantity and the rotating speed of the screw conveyor, the blocking of the cutter head and the unobstructed excavations. How to choose the value of soil pressure can keep the balance of face surface, control the grouting pressure and grouting quantity synchronously, and the stratum displacement in the construction process, etc. Based on the soil pressure balance shield tunneling construction in the east trunk canal of the South-to-North Water transfer Project in Beijing, this paper studies the residual soil improvement, the change law of the face pressure and the formation displacement during the construction process. The specific research contents and conclusions are as follows: 1 residual soil improvement experiment. A series of laboratory tests of residual soil improvement were designed, and soil improvement and optimization tests were carried out on fine sand and silty clay, respectively. The optimum foam injection ratio of fine sand is 8 and the best foam injection ratio of silty clay is 30. According to the volume difference of fine sand and silty clay, the optimum foam injection ratio parameter is calculated as 22.2 face pressure theory. By using different calculation theory of soil silo pressure, it is obtained that the pressure range of optimized back-up excavating face is 100-150KPa.3 monitoring of formation displacement. Surface displacement, vertical displacement of soil, horizontal displacement of soil and real time working parameters of shield machine were monitored. The vertical displacement of the stratum is divided into three stages, the uplift stage, the rapid subsidence stage, the slow settlement stage, and the horizontal displacement change in the tunnel direction is also divided into three stages. At last, the total thrust of shield machine, the pressure of earth chamber and the torque of cutter head are positively correlated, and the variation of shield parameters has obvious influence on the formation displacement. 4 numerical simulation of stratum displacement change. In this paper, FLAC3D software is used to simulate and calculate the ground displacement change during shield tunneling in actual monitoring section. The variation law of stratum displacement obtained by simulation is similar to that of actual displacement. The conclusion of this paper is of reference significance for practical engineering and can be used for reference in the construction of earth pressure balance shield machine in similar strata.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U455.43
本文編號：2265533
[Abstract]:With the rapid development of urban tunnel engineering in China, the earth pressure balance shield method has been widely used in the construction of soft ground tunnel with the advantages of fast construction speed, low labor intensity, small environmental impact and construction economy. And achieved good results in technology and economy. However, there are still some problems in the construction of earth pressure balance shield machine, such as the speed of shield machine, the thrust, the earth pressure in the cabin, the rotation speed of the cutter head, the relationship between the unearthed quantity and the rotating speed of the screw conveyor, the blocking of the cutter head and the unobstructed excavations. How to choose the value of soil pressure can keep the balance of face surface, control the grouting pressure and grouting quantity synchronously, and the stratum displacement in the construction process, etc. Based on the soil pressure balance shield tunneling construction in the east trunk canal of the South-to-North Water transfer Project in Beijing, this paper studies the residual soil improvement, the change law of the face pressure and the formation displacement during the construction process. The specific research contents and conclusions are as follows: 1 residual soil improvement experiment. A series of laboratory tests of residual soil improvement were designed, and soil improvement and optimization tests were carried out on fine sand and silty clay, respectively. The optimum foam injection ratio of fine sand is 8 and the best foam injection ratio of silty clay is 30. According to the volume difference of fine sand and silty clay, the optimum foam injection ratio parameter is calculated as 22.2 face pressure theory. By using different calculation theory of soil silo pressure, it is obtained that the pressure range of optimized back-up excavating face is 100-150KPa.3 monitoring of formation displacement. Surface displacement, vertical displacement of soil, horizontal displacement of soil and real time working parameters of shield machine were monitored. The vertical displacement of the stratum is divided into three stages, the uplift stage, the rapid subsidence stage, the slow settlement stage, and the horizontal displacement change in the tunnel direction is also divided into three stages. At last, the total thrust of shield machine, the pressure of earth chamber and the torque of cutter head are positively correlated, and the variation of shield parameters has obvious influence on the formation displacement. 4 numerical simulation of stratum displacement change. In this paper, FLAC3D software is used to simulate and calculate the ground displacement change during shield tunneling in actual monitoring section. The variation law of stratum displacement obtained by simulation is similar to that of actual displacement. The conclusion of this paper is of reference significance for practical engineering and can be used for reference in the construction of earth pressure balance shield machine in similar strata.
【學(xué)位授予單位】：北京工業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：U455.43
【參考文獻】
相關(guān)期刊論文 前1條
1 樂貴平,趙宏偉,周秀普,孟學(xué)文;穿越全斷面礫石層的盾構(gòu)施工[J];現(xiàn)代隧道技術(shù);2001年05期
，本文編號：2265533
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