四车道隧道洞口浅埋偏压段施工力学响应特征分析

Characteristics analysis of construction mechanical response of shallow buried bias section at the entrance of four-lane tunnel

由于四车道隧道断面跨度大且扁平,施工断面多,施工工序繁杂,衬砌结构及围岩受到多次扰动,导致其力学特性较小跨度隧道有明显不同。文章借助有限元分析软件,以仁遵高速公路青山隧道为工程背景,对洞口浅埋偏压段的施工过程进行模拟,研究隧道拱顶沉降、水平收敛和围岩塑性区的分布与发展规律。通过总结与分析计算结果,得到四车道隧道洞口浅埋偏压段施工力学响应特征,并根据其不同的特征提出相应的合理的施工优化措施,以提高施工安全性与隧道工程质量。研究方法及结果可为类似隧道工程设计与施工提供指导与借鉴。

Due to the large-span and flat-section of the four-lane tunnel,which have many construction sections and complicated construction procedures,the lining structure and surrounding rock have been disturbed for many times,resulting in significant differences in mechanical characteristics to the small-span tunnel.In this paper,by using the software of finite element analysis,based on Qingshan tunnel of renzun expressway,the construction process of shallow buried partial pressure section of the entrance was simulated,and the settlement of tunnel vault,horizontal convergence and distribution and development of plastic zone of surrounding rock are studied,by summarizing and analyzing the calculation results,the construction mechanical response characteristics of the shallow buried bias section at the entrance of the four-lane tunnel are obtained,and the corresponding reasonable construction optimization measures are proposed according to the different characteristics,so as to improve the construction safety and tunnel engineering quality.The research methods and results can provide guidance and reference for similar tunnel engineering design and construction.