破碎围岩重载铁路隧道基底结构动力特性现场试验研究  

Field experimental study of basement structural dynamic properties of the heavy-haul railway tunnel in broken surrounding rock

作　　者：李自强 徐湉源[2] 吴秋军 于丽[2] 王明年[2] 王子健[1] LI Zi-qiang1, 2, XU Tian-yuan2, WU Qiu-jun2, YU Li2, WANG Ming-nian2, WANG Zi-jian1(1. School of Civil Engineering and Architecture, Chongqing University of Science ＆ Technology, Chongqing 401331, China; 2. School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, Chin)

机构地区：[1]重庆科技学院建筑工程学院,重庆401331 [2]西南交通大学土木工程学院,四川成都610031

出　　处：《岩土力学》2018年第3期949-956,共8页Rock and Soil Mechanics

基　　金：中国铁路总公司科技研究开发计划课题合同(No.2014G005-A);西南交通大学博士研究生创新基金~~

摘　　要：通过张家口至唐山付营子隧道现场大型激振试验,模拟研究了V级围岩条件下轴重为250、270、300 k N重载列车作用时隧道基底结构压力响应,并提出了各测点动压力在轴重下降时的衰减规律。根据现场实测的压力-时程图,分析了各结构面动压力的横向和竖向传递规律。结果表明:双线隧道重载线路因直接受重载列车荷载作用而使半幅测点动压力均大于客车线路,重载线路轨道下方相应测点在不同轴重作用下的动压力均大于其他测点,对比IV级围岩表面的试验结果得出破碎围岩条件下重载位置的结构和围岩容易出现压力集中,从而引发结构开裂或围岩空洞。列车荷载在基底结构竖向传递过程中先受到道床结构和仰拱填充的缓冲作用,衰减较大,在仰拱结构中衰减较少,以目前的基底结构设计厚度难以满足轴重提升的需求。In this study, dynamic pressure response of base structure of Fu Yingzi tunnel along Zhangjiakou to Tangshan was simulated through field large-scale excitation test under the class V rock conditions when the heavy haul trains with axle weights of 250 k N, 270 k N, and 300 k N passed. Dynamic pressure attenuation values at measuring points were presented when axle weight was reduced. According to the earth pressure time history chart of field measurement, horizontal and vertical distributions of dynamic pressure of the measuring points in each structural plane were analyzed. The results indicate that dynamic pressure of each measuring point in heavy haul line of double line tunnel is greater than passenger train line, and the dynamic pressure of the corresponding measuring points below the railway track under different axle load of heavy haul trains is greater than other measuring points. Stress concentration is found to appear in the structure and surrounding rock at corresponding heave haul position, which is more likely to cause the structure to crack or hole generation in wall rock under the condition of broken rock compared with the test results on the surface of class IV grade surrounding rock. Train load attenuates drastically due to cushioning of the bed structure and inverted arch filling as it vertically transfers, but there is only small attenuation in inverted arch. Current designed basement structure thickness cannot meet the demand of lifting axle load.

关 键 词：重载铁路 基底结构 现场试验 动力响应 

分 类 号：U451.5[建筑科学—桥梁与隧道工程]