铁道标准设计
鐵道標準設計
철도표준설계
RAILWAY STANDARD DESIGN
2014年
1期
80-83,84
,共5页
重叠隧道%并行隧道%管幕作用%合理净距%有限差分法
重疊隧道%併行隧道%管幕作用%閤理淨距%有限差分法
중첩수도%병행수도%관막작용%합리정거%유한차분법
overlapped tunnels%parallel tunnels%tube screen effect%reasonable clear distance%finite difference method
以正在建设中的深圳地铁11号线南山至前海湾站小净距重叠区间隧道为研究对象，按先明挖修建桂庙路矩形闭合框架隧道，后进行地铁盾构推进的顺序，采用FLAC有限差分程序对小净距重叠隧道进行弹塑性分析，对多种工况下的围岩位移、夹岩应力、塑性区分布等进行分析，提出矩形闭合框架隧道的管幕作用，其作用影响范围大致沿Mohr.Coulomb模型剪切破坏面(45o+φ/2)的角度，以矩形隧道宽为底边的闭合等腰三角形区域。在此区域内的地下结构均受管幕作用的影响，且距离矩形闭合框架隧道越近管幕作用越明显，在综合考虑了矩形隧道管幕作用和隧道之间近接效应的情况下，确定隧道之间的合理净距。
以正在建設中的深圳地鐵11號線南山至前海灣站小淨距重疊區間隧道為研究對象，按先明挖脩建桂廟路矩形閉閤框架隧道，後進行地鐵盾構推進的順序，採用FLAC有限差分程序對小淨距重疊隧道進行彈塑性分析，對多種工況下的圍巖位移、夾巖應力、塑性區分佈等進行分析，提齣矩形閉閤框架隧道的管幕作用，其作用影響範圍大緻沿Mohr.Coulomb模型剪切破壞麵(45o+φ/2)的角度，以矩形隧道寬為底邊的閉閤等腰三角形區域。在此區域內的地下結構均受管幕作用的影響，且距離矩形閉閤框架隧道越近管幕作用越明顯，在綜閤攷慮瞭矩形隧道管幕作用和隧道之間近接效應的情況下，確定隧道之間的閤理淨距。
이정재건설중적심수지철11호선남산지전해만참소정거중첩구간수도위연구대상，안선명알수건계묘로구형폐합광가수도，후진행지철순구추진적순서，채용FLAC유한차분정서대소정거중첩수도진행탄소성분석，대다충공황하적위암위이、협암응력、소성구분포등진행분석，제출구형폐합광가수도적관막작용，기작용영향범위대치연Mohr.Coulomb모형전절파배면(45o+φ/2)적각도，이구형수도관위저변적폐합등요삼각형구역。재차구역내적지하결구균수관막작용적영향，차거리구형폐합광가수도월근관막작용월명현，재종합고필료구형수도관막작용화수도지간근접효응적정황하，학정수도지간적합리정거。
In this paper, the two overlapped tunnels with short clear distance on Nanshan-Qianhaiwan section of Shenzhen Metro Line Eleven were taken as research object. The two tunnels would be respectively excavated in the order: excavating the rectangular enclosed-frame tunnel along the Guimiao Road by open-cut method first and then excavating the shield tunnel. By using finite difference software FLAC, the elastic-plastic analysis of the overlapped tunnels with short clear distance was carried out under multiple working conditions, including the displacement of the surrounding rock, the stress of the shared rock, the distribution of plastic zone and so on. On this basis, the paper suggested that:there was a tube screen effect in the rectangular enclosed-frame tunnel;and the sphere of the tube screen effect was approximately along a (45o+φ/2) angle of the shearing failure plane of Mohr-Coulomb model, within the range of a enclosed isosceles triangular of which the bottom edge was equal to the width of the rectangular tunnel. The paper also suggested that all the underground structures within above-mentioned range would be influenced by the tube screen; the closer the distance to the rectangular enclosed-frame tunnel, the more obvious the action effect would become. After fully considering the tube screen effect of rectangular tunnel as well as considering the proximity effect of adjacent excavation, the reasonable clear distance between the two tunnels has eventually been determined.
