摘要
由于岩溶贯通形态复杂,地下水丰富,对隧道基底局部水压和隧道结构裂缝及层间黏结强度影响较大,易发生隧道道床脱空上浮底鼓现象,危及运营行车安全。将道床上浮情况分为道床横向脱空与纵向脱空两大类,分别开展3种阶段工况下道床在不同水头高度下的上浮量对比分析,结果表明:上浮过程可划分3个阶段:地下水入渗阶段,该阶段仰拱-填充层孔隙水压力降低,道床孔隙水压力增高;黏结失效阶段,临界水头高度与道床板厚度、道床与仰拱填充间黏结强度之间的关联阶段;道床局部上浮脱空阶段,黏结强度对临界水头高度的影响远大于道床板厚度。第一阶段层间黏结良好条件下,上浮水压需要约6.32 MPa;黏结力较弱时,上浮水压仅需66.69 kPa左右。第三阶段横向中部脱空情况下,25 m水头压力下道床层间应力值为1.85 MPa以上,对应最大上浮值为0.22 mm。第三阶段纵向局部脱空情况下,当道床脱空段增大至10 m时,25 m水头压力环下道床最大上浮值为6.83 mm,达到影响行车的上浮阈值8.00 mm。综上可知,隧道道床黏结失效,易诱发道床上浮底鼓。层间增强黏结措施的有效布设,可抑制道床上浮底鼓。建议采用钻孔泄水和补打道床锚杆等应急措施。
Due to the complex form of karst penetration and abundant groundwater,it has a significant impact on the local water pressure at the tunnel base,as well as the structural cracks and interlayer bonding strength of the tunnel.It is easy to cause the phenomenon of tunnel track bed detachment and floating,which endangers the safety of operation and driving.The buoyancy of the track bed was divided into two categories:lateral and vertical void,and a comparative analysis of the buoyancy of the track bed was conducted under different water head heights in three stages of working conditions.The results show that the buoyancy process can be divided into three stages.The first stage is groundwater infiltration stage,during which the pore water pressure of the inverted arch filling layer decreases and the pore water pressure of the track bed increases.The second stage is bonding failure stage,critical water head height and the thickness of the track bed plate.The correlation stage between the bond strength between the roadbed and the inverted arch filling.The third stage is the stage where the track bed partially floats and becomes void,and the influence of bonding strength on the critical water head height is much greater than the thickness of the track bed plate.Under the condition of good interlayer bonding in the first stage,the upward floating water pressure needs to be about 6.32 MPa.When the bonding force is weak,the floating water pressure only needs about 66.69 kPa.In the third stage of lateral central void,the interlayer stress value of the track bed under a 25 m water head pressure is above 1.85 MPa,corresponding to a maximum uplift value of 0.22 mm.In the third stage of longitudinal partial void,when the void section of the track bed increases to 10 m,the maximum floating value of the track bed under the 25 m water head pressure ring is 6.83 mm,reaching the floating threshold of 8.00 mm that affects driving.In summary,it can be seen that the bonding failure of the tunnel track bed can easily cause the bed to flo
作者
杨辉
裴俊豪
朱吉斌
刘宁
YANG Hui;PEI Jun-hao;ZHU Ji-Bin;LIU Ning(First Highway Engineering Group Co.,Ltd.,CCCC,Beijing 100024,China;College of Civil Engineering,Guizhou University,Guiyang 550025,China)
出处
《科学技术与工程》
北大核心
2023年第25期10926-10934,共9页
Science Technology and Engineering
基金
国家自然科学基金地区基金(52168056,52069004)
贵州省科技计划(黔科合支撑[2023]一般423,黔科合支撑[2020]2Y036号)
贵州省交通运输厅科技项目(2021-122-050)。
关键词
岩溶隧道
无砟道床
上浮机制
底鼓特征
黏结强度
数值分析
karst tunnel
ballastless track bed
floating mechanism
characteristics of floor drum
bond strength
numerical analysis
