2020·11·Building Construction 2180
大直径盾构隧道下穿城市既有道路沉降分析及预测
王义强 1 岳迎新 2 葛忻声 2
1. 中铁六局集团有限公司 北京 100036;2. 太原理工大学土木工程学院 山西 太原 030024
摘要: 以太原西南环线晋西隧道下穿某城市道路为背景,对大直径盾构隧道下穿城市既有道路时的沉降进行分析与
预测。依据实际施工方案建立FLAC3D仿真模型,分析既有城市道路的弹性模量与路基厚度对路面沉降的影响。结果
表明:城市道路的存在能够更好地约束拱顶上方土体变形,使得路面各点沉降速率差较小,呈现出整体下沉的趋势,
沉降曲线整体上移;路面弹性模量和路基厚度的增大均能使路面最大沉降变小,同时路面弹性模量的增大还可减小
路面各点沉降差;当路面弹性模量为40 MPa时,最大沉降为-3.6 mm,各点沉降差为0.4 mm。结果证明在太原地区
运用Peck公式预测路面沉降是准确可行的,公式中关键参数沉降槽宽度参数介于0.20~0.52之间,地层损失率介于
0.10~0.24之间。
关键词: 盾构隧道;城市既有道路;整体下沉;Peck公式
中图分类号:
T U 99 文献标志码: A 文章编号: 1 004-1 001(2 020)1 1-2 180-0 5 DOI: 1 0.1 4144/j. c nki. jz sg .2 020.1 1.0 48
Settlement Analysis and Prediction of Large Diameter Shield Tunnel
Underpassing Existing Urban Road
WANG Yiqiang 1 YUE Yingxin 2 GE Xinsheng 2
1. Traffic Engineering Branch of China Railway Sixth Group Limited Company, Beijing 100036, China
2. School of Civil Engineering, Taiyuan University of Technology, Taiyuan, Shanxi 030024, China
Abstract: Based on the background that Jinxi tunnel of Taiyuan southwest ring line passes through an urban road, the
settlement of large diameter shield tunnel passing through existing urban road is analyzed and predicted. According
to the actual construction scheme, the FLAC3D simulation model is established to analyze the influence of the elastic
modulus and subgrade thickness of the existing urban road on the pavement settlement. The results show that the
existence of urban road can better restrain the deformation of soil above the arch crown, making the settlement rate
difference of each point of the road surface smaller, showing a trend of overall settlement, and the settlement curve
moves up as a whole; the increase of pavement elastic modulus and subgrade thickness can reduce the maximum
settlement of pavement, and the increase of pavement elastic modulus can also reduce the settlement difference of each
point of the pavement when the modulus is 40 MPa, the maximum settlement is -3.6 mm, and the settlement difference of
each point is 0.4 mm. The results show that it is accurate and feasible to use peck formula to predict pavement settlement
in Taiyuan area. The key parameters in the formula are the width of settlement trough between 0.20 and 0.52, and the
formation loss rate is between 0.10 and 0.24.
Keywords:
s h ie ld tu nnel; e xis tin g u rb an r o ad ; o ve ra ll s u b sid ence; P eck fo rm ula
科学研究 SCIENTIFIC RESEARCH
常 运营,需要研究隧道开挖对既有道路的影响 [1 ]。
目 前,国内外众多学者已经深入研究了盾构隧道下穿
施 工对周围土体及上方既有道路的影响,并取得了较大的
成 果。1969年 ,Peck
[2 ]认 为,地表沉降模式呈沉降槽形式,
且 地表沉降槽与正态分布曲线类似,提出了Peck 公 式。韩
煊 等
[3 ]基 于Peck 公 式结合不同地区地质条件并提出计算公式
参 数的不同取值。Morto n等
[4 ]结 合数值模拟研究隧道下穿既
有 结构物与无结构物两种工况下地层沉降规律,结果发现
下 穿既有结构物时沉降更大。孙文文等
[5 ]依 托青岛地铁下穿
胶 济铁路建立数值模型,研究发现当受到路面交通荷载作
用 时,路基最大沉降是未受交通荷载的73% 。 张鹏等
[6 ]以 隧
道 正交下穿某公
路为背景,认为隧道开挖引起的路面纵向
沉 降规律可以被看作是一条抛物线。侯学渊等
[7 ]考 虑了土体
利
用传统的施工方法进行隧道施工引起的安全问题及
其 对周围环境的影响非常严重,而盾构法是相较最合理有
效 的施工方法。但在盾构隧道开挖过程中会对隧道上方土
体 有一定的扰动,原有土体力学平衡状态被破坏,拱顶上
方 地层发生沉降,进一步引起路面变形,甚至造成路面开
裂 破坏、塌陷
大直径盾构隧道下穿城市既有道路沉降分析及预测(论文).pdf