隧包桥扩大断面衬砌结构受力特性分析

Analysis of Stress Characteristics in the Tunnel Expanded Section of Bridge into Tunnel

在山区高速公路设计中,采用桥隧相接、隧道包桥梁等特殊结构形式通过大高差、陡坡率地段越来越多。拟建渭武高速公路虎家崖隧道出口段地形陡峭,需桥台伸入隧道内,造成隧道洞口段开挖面积大,结构矢跨比较小(0.43)。以该隧道为工程依托,采用地层-结构法对桥梁伸入隧道段落建立数值模型,对隧道扩大断面结构受力特性进行计算分析,并讨论不同施工阶段衬砌结构应力分布特征,对结构设计参数的可靠性进行验证。研究方法和结论对分析大断面隧道衬砌结构的受力特性提供一定的理论支撑,为设计更加经济合理的隧道结构型式提供参考。

The using of the special structures in the highway design in the mountainous area, such as tunnel and bridge linking, bridge surrounded by tunnel etc. passing through the large elevation difference and steep slope areas has become more and more common. For the Hujiaya Tunnel exit section on the proposed Weiyuan -Wudu Expressway, the terrain is very steep, the bridge abutment has to be set in the tunnel which leads to the tunnel excavation area is very large and the rise-span ratio is small （0.43）. This paper is based on the Hujiaya Tunnel, stratum-structure method is used to establish a numerical model for the section, calculation and analysis of the tunnel widening section structure are conducted, the stress of the lining based on the different construction stage of the tunnel is discussed and the reliability of the structural design parameters is verified. The research methods and conclusions have provided a certain theoretical support for the analyzing lining structure stress in the large section tunnel, and provided some reference for designing a more economic and reasonable tunnel structure.