曲线盾构隧道开挖面极限支护力研究

发布时间：2018-01-07 05:35

本文关键词：曲线盾构隧道开挖面极限支护力研究　出处：《铁道工程学报》2017年09期 　论文类型：期刊论文

【摘要】：研究目的:曲线盾构隧道掘进施工存在巨大安全隐患,受盾构刀盘超挖、盾壳挤压内壁土体和千斤顶不对称推力等因素的影响,致使开挖面前方变形复杂,开挖面稳定性难以控制。基于筒仓理论,本文提出曲面梯度楔形棱柱体开挖面极限平衡模型,推导曲线盾构隧道开挖面极限支护力理论计算公式;进而以济南地铁R1线王府庄至大杨庄区间段曲线盾构隧道为工程背景,探究不同曲率半径下开挖面的变形分布特征,以期为曲线盾构隧道掘进开挖面稳定性提供科学的理论指导。研究结论:(1)曲线盾构隧道开挖面破坏呈现不对称分布,受开挖面偏心支护压力的影响,开挖面前方土体形成曲面梯度楔形棱柱体平衡模型;(2)随着曲率半径的减小,开挖面位移和极限支护压力先增大后减小,且支护压力非常规的按中心支护力进行计算,而是偏向于曲线外侧,其值大于直线盾构隧道;(3)极限支护压力随开挖面土体黏聚力、内摩擦角增大而增大,随两侧破裂角的差值增大先呈现增大趋势,当β132.3°后减小,最后趋于平缓;(4)本研究成果可为曲线盾构隧道施工开挖面稳定性及其支护提供理论指导和科学依据。
[Abstract]:Research purposes: the curve of shield tunneling construction there is a huge security risk, by the shield cutter over excavation, shield wall soil and the effect of extrusion Jack thrust asymmetry and other factors, resulting in front of the excavation face deformation is complex, difficult to control the stability of the excavation face. Based on the theory of silo, this paper surface gradient wedge face limit equilibrium model. Is the curve of shield tunnel excavation face supporting force calculation formula of limit theory; then in Ji'nan Metro Line R1 to Wang Fu Zhuang dayangzhuang interval curve of shield tunnel as the engineering background, explore the different radius of curvature deformation distribution characteristics of the excavation, in order to provide theoretical guidance for the shield tunnel excavation face stability curve. The conclusion of the study: (1) the curve of tunnel face destruction by asymmetrical distribution, bracing pressure of excavation face eccentric, in front of the excavation face soil forming surface Gradient wedge balance model; (2) with the decrease of the curvature radius of the excavation surface displacement and limit support pressure increases first and then decreases, and the support pressure at the center of non conventional supporting force is calculated, but tend to the outer curve, its value is greater than the straight tunnel; (3) limit support pressure with the excavation of soil cohesion increases, the internal friction angle increases, first increases with the increase of the difference between both sides of the rupture angle, when beta 132.3 degrees and then decreases, finally tends to be stable; (4) the results of this study can be for the construction of shield tunnel excavation face stability curve and its support to provide theoretical guidance and scientific basis.

【作者单位】：山东科技大学;济南轨道交通集团有限公司;
【基金】：国家自然科学基金项目(41472280) 山东省自然科学基金项目(ZR2014EEQ028);山东省自然科学基金项目(ZR2017MEE065) 住房城乡建设部科学技术项目(2016-K4-053);住房城乡建设部科技示范工程(2016-S3-008)
【分类号】：U455.43
【正文快照】： 1研究背景随着城市轨道交通的发展以及盾构施工技术的不断完善,盾构施工已成为城市地下空间建设的主流趋势,然而在施工过程中开挖面失稳时有发生,危害巨大,尤其在曲线盾构隧道掘进中开挖面受力复杂,若不及时调整盾构隧道开挖面支护压力,极易引起开挖面失稳、盾构姿态偏移及其

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