侧部松动情况下盾构隧道横向变形特征研究

发布时间：2018-09-09 16:25

【摘要】：邻近隧道的基坑开挖、邻近隧道水土流失或隧道自身的水土流失均可导致隧道周围局部或者大范围的土体松动,并引起已有隧道周围土体应力的变化,以致改变隧道横向受力模式,影响隧道的结构安全.首先对一工程实例进行了详细介绍,在此基础上采用有限元数值方法研究了隧道侧部不同松动角度、不同松动程度下隧道横向承载能力和隧道结构形态的变化模式,揭示了隧道灾害发展过程中隧道管片混凝土应力、接头处螺栓应力以及管片接头张开量等指标达到临界值的先后规律.研究结果表明,隧道侧部松动首先导致隧道腰部接头内侧混凝土受压剥落,隧道竖向收敛值达到0.5%D(D为隧道外径),进而顶部接头螺栓受拉屈服以致断裂.
[Abstract]:Excavation of foundation pit in adjacent tunnel, soil erosion in adjacent tunnel or soil erosion in tunnel itself can result in loosening of soil around the tunnel, and change of soil stress around existing tunnel. As a result, the transverse stress mode of tunnel is changed, and the safety of tunnel structure is affected. At first, an engineering example is introduced in detail. On the basis of this, the variation modes of tunnel lateral bearing capacity and tunnel structure shape under different loosening angles and degrees of loosening are studied by using finite element method. The regularity of tunnel segment concrete stress, bolt stress at the joint and the opening of segment joint in the course of tunnel disaster development are revealed in this paper. The results show that the loosening of the side of the tunnel first results in the compressive spalling of concrete inside the waist joint of the tunnel, the vertical convergence value of the tunnel reaches 0.5D (D is the outer diameter of the tunnel), and the bolt of the top joint is subjected to tensile yield and fracture.
【作者单位】：滨海土木工程结构与安全教育部重点实验室(天津大学);天津大学建筑工程学院;
【基金】：国家自然科学基金重点资助项目(41630641)~~
【分类号】：U455.43

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