浅埋超大变截面隧道双侧壁导坑施工优化研究  

Construction Optimization Study of Double Sidewall Heading Method for Shallow Buried Oversized Variable Section Tunnel

作　　者：欧剑 OU Jian(China Railway 25th Bureau Group Co.Ltd.,Guangzhou Guangdong 511455,China)

机构地区：[1]中铁二十五局集团有限公司,广东广州511455

出　　处：《铁道建筑技术》2024年第3期120-123,共4页Railway Construction Technology

基　　金：中铁二十五局集团有限公司科技研发计划项目(2020-B-005号)。

摘　　要：轨道交通工程建设中,针对隧道洞身段内出现的超大断面,多采用双侧壁导坑法对其进行施工,但该方法在变截面隧道存在施工工艺转换难度大、开挖难度大、安全隐患大等工程问题,亟需对其进行改进。依托重庆轨道交通24号线一期工程出入段线区间隧道24 m宽大跨度变截面的双侧壁导坑法施工工程,基于该段隧址区域的地质构造特征等因素,分别在导洞先行、核心土支护形式、临时竖向支撑、临时横向支撑等方面进行优化。通过采取上述优化措施,该段隧道开挖及支护施工过程中监控量测及内力监测数据稳定可靠,受力体系稳定,可为类似洞身段大跨度变截面双侧壁导坑施工提供借鉴。In the construction of rail transit engineering,the double sidewall heading method is often used to construct the super-large section in the tunnel body.However,this method has some engineering problems such as dfficult transformation of construction technology,difficult excavation and big security risks in the variable section tunnel,so it is urgent to be improved.This study relies on the construction of double sidewall heading method for the access section interval tunnel with 24 m wide large-span variable section in the first phase of Chongqing Rail Transit Line 24,and based on the geological structure characteristics of the tunnel site area,the optimization is carried out in the aspects of guide tunnel leading,core soil support form,temporary vertical support and temporary lateral support.Through the application of the above optimization measures,the monitoring measurement and internal force monitoring data in the process of tunnel excavation and support construction are stable and reliable,and the force system is stable,which can provide reference for the construction of double sidewall diversion with large span and variable section of similar tunnel body.

关 键 词：双侧壁导坑法 大跨度变截面 导洞先行 核心土支护形式 优化 

分 类 号：U455.4[建筑科学—桥梁与隧道工程]