大跨度多孔箱涵顶进过程基底摩阻力研究  

Research on the Foundation Base Friction Resistance During Jacking of Long-span Porous Box Culvert

作　　者：康军利 KANG Junli(China Railway 24^(th) Bureau Group Co.Ltd.,Beijing Branch,Beijing 102600,China)

机构地区：[1]中铁二十四局集团有限公司北京分公司,北京102600

出　　处：《铁道建筑技术》2021年第4期83-86,共4页Railway Construction Technology

基　　金：中铁二十四局集团有限公司科技研发项目(科研2019-19号)。

摘　　要：本文依托大跨度箱涵下穿京九铁路工程,基于箱涵底板钢筋内力实时监测数据,对箱涵底板所受的摩阻力变化规律进行研究。结果表明:在箱涵顶进过程中,箱涵基底摩阻力沿顶进方向先增大后减小,呈V形分布,峰谷值分别出现在箱涵前端以及中部位置处;箱涵基底摩阻系数随箱涵顶进阶段以及箱涵顶进姿态的变化而改变,以箱涵离开滑板与整体进入线路作为分界点,前、中、后三个阶段的基底摩阻系数分别为0.41、0.59及0.67。同时,受箱涵顶进姿态及相应纠偏措施的影响,基底摩阻系数在各镐次间存在一定程度的波动,峰值达到0.88。基于上述研究,本次工程在总结顶力配置策略的基础上,结合箱涵智能顶力控制系统,在三座箱涵同时顶进的情况下,各轴线偏差均控制在预期指标内。Relying on the large-span box culvert passing under the Beijing-Kowloon Railway project,based on the real-time monitoring data of the internal force of the box culvert bottom plate,the frictional resistance of the box culvert bottom plate is studied,and it is summarized that when the box culvert is jacked,the friction resistance of the box culvert bottom plate increases at first and then decreases along the jacking direction,showing a V-shaped distribution,and the peak force appears at the front of the box culvert,while the valley at the middle.The friction coefficient of the bottom plate will change with the jacking stage and attitude of the box culvert,and taking the box culvert leaving the slide plate and passing through the railway line as the two dividing points,the friction coefficients of the three stages are respectively 0.41,0.59 and0.67.At the same time,affected by the jacking attitude of the box culvert and the corresponding correction measures,the friction coefficient fluctuates to a certain extent under each jacking pick,with a peak value of 0.88.Combined with the above research,on the basis of summarizing the jacking force configuration strategy and adopting the jacking forces smart control system for these three box culverts,the deviation of each axis was controlled within the expected value when the box culverts jacking in the meantime.

关 键 词：箱涵底板内力 基底摩阻力 摩阻系数 智能顶力控制 

分 类 号：U449.5[建筑科学—桥梁与隧道工程]