盾构隧道穿越饱和砂土层的流固耦合分析
FLUID-STRUCTURE INTERACTION ANALYSIS OF SHIELD TUNNELS CROSSING SATURATED SAND LAYERS
高子明1
作者信息
- 1. 中铁二十一局集团轨道交通工程有限公司,济南 250117
- 折叠
摘要
区间盾构穿越砂土层时,因其洞周土层含水量大,导致砂土层的渗透系数较大,极易发生突然涌水、涌砂事故.文中采用有限元方法,分析了饱和渗流作用下,双线盾构隧道贯通后土体及衬砌结构的受力特性.结果表明在左线隧道开挖贯通后,注浆层内水平方向的应力比未注浆区域大,发生挤压流动,带动拱底向上隆起;右线隧道上方地表沉降小于左线隧道;隧道周围土体强度和承载力水平均有所下降.实际施工过程中,应防止衬砌拱顶及拱底处向上的应力过大,应对隧道的不同拱腰处采取相应的加固、支护措施,增大洞口段的支护强度,保证结构的稳定性.
Abstract
During the crossing of sand layers by interval shield tunneling,high water content and significant permea-bility in the sand layers can lead to sudden water influx and sand eruption incidents.This study utilizes the finite ele-ment method to analyze the stress characteristics of the soil and lining structures after the completion of a dual-line shield tunnel under saturated seepage conditions.The results indicate that after the excavation of the left-line tun-nel,the horizontal stress within the grouting layer is greater than in the non-grouted areas,causing extrusion flow and upward arching at the tunnel bottom.Ground settlement above the right-line tunnel is less than that above the left-line tunnel,and the strength and bearing capacity of the surrounding soil decrease.During actual construction,it is essential to prevent excessive upward stress on the lining crown and bottom.Appropriate reinforcement and sup-port measures should be implemented at different arch waist locations to increase the support strength of the portal section,ensuring the stability of the structure.
关键词
盾构隧道/双线隧道/砂土层/流固耦合/力学特性Key words
shield tunnel/dual-line tunnel/sand layer/fluid-structure interaction/mechanical properties引用本文复制引用
出版年
2024
NETL
NSTL
万方数据