膨胀性围岩时高速铁路隧道仰拱的底鼓机理及破坏模式  

Mechanism and Failure Mode of Floor Heave in Tunnel Invert of High Speed Railway under Expansive Surrounding Rock

作　　者：杜明庆[1] 董飞 李奥 曹玺 曾柯涵 周秋爽 DU Mingqing;DONG Fei;LI Ao;CAO Xi;ZENG Kehan;ZHOU Qiushuang(School of Civil Engineering,Qingdao University of Technology,Qingdao Shandong 266033,China;Transportation Planning&Design Division,JSTI Group,Nanjing Jiangsu 210019,China;Tunnel and Underground Engineering Research Center of Ministry of Education,Beijing Jiaotong University,Beijing 100044,China;The First Company of China Eighth Engineering Division LTD,Ji nan Shandong 250100,China)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033 [2]苏交科集团股份有限公司交通规划设计院,江苏南京210019 [3]北京交通大学隧道及地下工程教育部工程研究中心,北京100044 [4]中建八局第一建设有限公司,山东济南250100

出　　处：《中国铁道科学》2019年第6期78-85,共8页China Railway Science

基　　金：国家自然科学基金重点资助项目(51738002);山东省高等学校科技计划项目(J18KA194)

摘　　要：为确定膨胀性围岩时高速铁路隧道仰拱的底鼓机理及破坏模式,从围岩膨胀机理出发,分析膨胀性围岩遇水膨胀后引起的隧道仰拱底鼓破坏模式及过程,推导仰拱各截面弯矩及轴力的计算公式;基于室内模型试验及扩展有限元模拟对膨胀性围岩时仰拱底鼓的基本破坏模式进行研究。结果表明:膨胀性围岩吸水膨胀后产生的膨胀力同时作用于仰拱和围岩,迫使未膨胀围岩裂隙扩展,并提供水分迁移路径,导致未膨胀围岩膨胀;围岩膨胀过程中产生的膨胀力作用于仰拱上,迫使仰拱产生向上的隆起变形;仰拱底鼓属于受弯破坏,中心位置首先出现拉裂缝,随后逐步沿纵向和竖向贯通;最大弯矩出现在仰拱中心位置;仰拱2侧拱脚位置受上部衬砌的限制而隆起变形有限,仰拱中心位置基本处于无约束状态而隆起变形较大,导致仰拱形成W形的隆起破坏模式,故中心位置为仰拱的易损位置,在进行高速铁路隧道仰拱设计时,应重点考虑中心位置的仰拱。In order to determine the failure modes and mechanism of floor heave in the tunnel invert of high speed railway under expansive surrounding rock, based on the expansive mechanism of surrounding rock, the failure mode and process of floor heave in tunnel invert caused by expansive surrounding rock after swelling in water were analyzed, and the formulas for calculating the bending moment and axial force of each section of inverted arch were derived. Based on indoor model test and extended finite element simulation, the basic failure mode of floor heave of inverted arch under expansive surrounding rock was researched. Results showed that the expansive force produced by the water swelling of the expansive surrounding rock simultaneously acted on the inverted arch and the surrounding rock, forced the extension of the cracks in the non-expansive surrounding rock and provided the path of water migration, and resulted in the expansion of the non-expansive surrounding rock. The expansive force generated in the expansion process of surrounding rock acted on the inverted arch and forced the inverted arch to produce upward uplift deformation. The floor heave of inverted arch belonged to bending failure. Tension cracks appeared first in the central position, and then gradually penetrated along the vertical and longitudinal directions. The maximum bending moment occurred in the center of the inverted arch. The arch feet on both sides of inverted arch were confined by the upper lining and the uplift deformation was limited. The center of inverted arch was basically in unconstrained state and the uplift deformation was large, which led to the W-shaped uplift failure mode of inverted arch. Therefore, the center position is the vulnerable position of inverted arch. When designing the inverted arch of high speed railway tunnel, priority should be given to the inverted arch at the central position.

关 键 词：高速铁路隧道 仰拱 膨胀性围岩 底鼓机理 仰拱破坏模式 仰拱内力 

分 类 号：U455[建筑科学—桥梁与隧道工程]