土工基础

›› 2018, Vol. 32 ›› Issue (6): 605-610.

• 工程实录 • 上一篇    下一篇

临线列车振动下黄土隧道围岩振陷力学特性及工程处理措施

霍晓斌1，罗忠明1，杨凡杰2，李 攀2，张王杰2，金韵哲2   

  1. （1.中交隧道工程局有限公司，北京 100000；2.中国科学院武汉岩土力学研究所 岩土力学与工程国家重点实验室， 武汉 430071）
  • 收稿日期:2018-08-10 修回日期:2018-08-29 出版日期:2018-12-20 发布日期:2018-12-21
  • 作者简介:霍晓斌（1991-），男，助理工程师，研究方向为铁路工程建设及施工技术。
  • 基金资助:

    国家自然科学基金（51404240）

Train Vibration Induced Settlement of Tunnel Excavation in Losses

HUO Xiaobin1, LUO Zhongming1， YANG Fanjie2, LI Pan2， ZHANG Wangjie2， JIN Yunzhe2   

  1. (1.Tunnel Engineering Co., Ltd., China Communication Construction Co., Beijing 100000；
    2.State Key Laboratory for Rock and Soil Mechanics, Wuhan Institute of Rock and
    Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071)
  • Received:2018-08-10 Revised:2018-08-29 Online:2018-12-20 Published:2018-12-21

摘要： 振动荷载作用下黄土常易出现坍塌或崩解，在紧邻既有铁路的安家庄黄土隧道施工中，邻近列车振动荷载对其施工安全构成严重威胁。针对安家庄黄土隧道施工期围岩振陷变形问题，首先试验研究了振动荷载下安家庄隧道黄土的力学特性，发现振动荷载会导致黄土的力学性质明显劣化，相较于未振动情况，振动后黄土的压缩模量Es1-2降幅可达73%，粘聚力c降幅可达43.5%，而内摩擦角变化不明显；基于试验结果，计算得出振动荷载下安家庄黄土隧道围岩变形会显著增大，围岩最大变形可达未振动工况下的5倍左右，并确定了围岩的最不利变形部位；在此基础上，采取了加固隧道洞口仰拱支护条件及增加钢管横向临时支撑等工程措施，处理了安家庄黄土隧道洞口端围岩振陷变形问题，确保了隧道洞口端的施工安全，并在后续施工中，采取了调整掌子面距仰拱距离为15~20m以及尽早完成衬砌施工等施工措施，减小了列车振动荷载对隧道施工安全性的影响。

关键词: 隧道工程, 黄土隧道, 力学试验, 数值计算, 处理措施

Abstract: Loess tends to collapse or disintegrate under the cyclic load. Therefore, the operating train load might impose a safety threat to the construction of tunnel in loess soils near the existing rail lines. This paper presents a case history of a tunnel excavation in loess soils of Anjiazhuang Line near an existing rail line. The potential vibration induced settlement in loess soils surrounding the tunnel excavation was evaluated through the site-specific soil property testing. Compared with the original loess soil samples, the compression modulus of samples that subjected to vibration can reduce as much as 73% and the cohesion reduction of 43.5%. The internal friction of vibrated loess soils samples remained unchanged. The evaluation results indicated that the loess soil surrounding the tunnel excavation area can have 5 times greater settlement of the soils that without the vibration at the most unfavorable locations. The preventive measures included supporting the upper portion of the portal and lateral support of inside the excavation. These measures improved the safety of the tunnel excavation in loess soils. In the following excavation, early supporting and lining also played an important role in the successful tunnel excavation in loess soils.

Key words: Tunneling, Tunnel in Loess Soils, Mechanical Tests, Numerical Analysis, Construction Measures