摘要
传统的矩形明挖隧道建筑截面适用于跨度较小、回填土较浅的地段,针对兰州中川机场环线明洞填土较高的现状,提出在明挖隧道主体结构设计中引入“梯形拱”顶板,形成了一种特殊的明挖隧道工程:高填方-“梯形拱”明洞。为明确高填土条件下梯形拱明洞顶板上方垂直土压力分布规律,考虑梯形拱跨度大及本身特殊构造的影响,理论推导了高填方梯形拱明洞洞顶垂直土压力的计算方法。在此基础上,通过模型试验和数值模拟对比了拱顶上方特征点(顶板最大垂直土压力和中隔墙上方垂直土压力)的结果,验证了所推导公式的正确性。研究结果表明:随着填土高度的增加,顶板最大垂直土压力和中隔墙上方垂直土压力与土柱压力差值越来越大,且中隔墙上方的垂直土压力始终小于土柱压力,顶板最大垂直土压力恰好相反;梯形拱直顶板和斜顶板交界处出现应力集中,并向交界点两侧扩散,梯形拱直顶板与斜顶板外侧交界处应力比内侧交界处大8.2%,中隔墙位置处土压力比顶板最大垂直土压力少44.4%;填土完成后,顶板最大垂直土压力理论推导值与模型试验误差为5.7%,与数值模拟误差为10.2%;中隔墙上方垂直土压力理论推导值与模型试验误差为4.9%,与数值模拟误差为7.6%。该公式可对高填方梯形拱明洞结构的设计提供参考,后续可以更好地预测该类工程中明洞结构上方土压力的大小,以及确定结构上方填土的最大高度。
The traditional rectangular cut-and-cover tunnel construction cross-section is suitable for smaller spans and shallower backfill.For the current situation of high fill in the cut-and-cover tunnel of Lanzhou Zhongchuan Airport Loop Line,it was proposed to introduce the“trapezoidal arch”roof in the design of the main structure of the cut-and-cover tunnel,which formed a special kind of cut-and-cover tunnel project as the high fill-“trapezoidal arch”cut-and-cover tunnel.In order to study the distribution law of vertical earth pressure above the roof plate of trapezoidal arch open cavern under the condition of high filling,considering the influence of large span of trapezoidal arch and its own special structure,the calculation method of vertical earth pressure at the roof of high filling trapezoidal arch open cavern was deduced.Based on it,the results of the characteristic points above the roof(maximum vertical earth pressure at the roof plate and vertical earth pressure above the diaphragm wall)were compared with those of the model tests and numerical simulation.The correctness of the derived formulae deduced is verified.Specific results are drawn as follows.With the increase of filling height,the difference between the maximum vertical earth pressure of the roof plate and the vertical earth pressure above the diaphragm wall and the theoretical earth pressure is getting bigger and bigger.The vertical earth pressure above the diaphragm wall is always smaller than the theoretical earth pressure.The maximum vertical earth pressure of the roof plate is just the opposite.The stress concentration occurs at the junction of the straight top plate of the trapezoidal arch and the sloped top plate and spreads to the two sides of the junction.The stress at the junction between the straight top plate of the trapezoidal arch and the sloped top plate is bigger than that at the inner one.The stress at the junction of trapezoidal arch straight roof plate and sloping roof plate is 8.2%larger than that at the inner junction.The soil pressure at the position of partition wall is 44.4%smaller than the maximum vertical soil pressure of the roof plate.After the completion of filling,the theoretical derived value of the maximum vertical soil pressure of the roof plate has an error of 5.7%with the model test,and the error is 10.2%with the numerical simulation.The theoretical derived value of the vertical soil pressure over the partition wall has an error of 4.9%with the model test,and the error is 7.6%with the numerical simulation.The error is 7.6%.This formula can provide a reference for the design of high-fill trapezoidal arch open hole structure,and subsequently can better predict the size of the soil pressure above the open hole structure and determine the maximum height of the fill above the structure in this type of project.
作者
禄云华
马莉
李盛
何永泽
张柯
马晓波
LU Yunhua;MA Li;LI Sheng;HE Yongze;ZHANG Ke;MA Xiaobo(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;School of Civil Engineering,Xi’an university of architecture and Technology,Xi’an 710043,China;China Railway Design Group Co.,Ltd.,Tianjin 300000,China;China Railway First Survey and Design Insti Group Co.,Ltd.,Xi’an 710043,China)
出处
《铁道科学与工程学报》
北大核心
2025年第9期4052-4063,共12页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51868041)
甘肃省优秀研究生“创新之星”项目(2025CXZX-657)
甘肃省基础研究创新群体项目(21JR7RA347)。
关键词
高填土
梯形拱明洞
垂直土压力
计算方法
模型试验
high filled
trapezoidal arch cut-and-cover tunnel
vertical earth pressure
calculation methods
model test
