火灾中非均匀温场热力耦合隧道管片受力分析  

Internal forces analysis for tunnel segment under fire based on the coupled thermal-mechanical model in non-uniform temperature field

作　　者：崔铁军[1,2] 马云东[2] 

机构地区：[1]辽宁工程技术大学安全科学与工程学院,阜新123000 [2]大连交通大学辽宁省隧道与地下结构工程技术研究中心,大连116028

出　　处：《应用力学学报》2013年第6期936-940,958,共5页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金(51050003);大连市科技计划项目(2011E15SF118)

摘　　要：针对作为地铁隧道主要受力构件的管片在火灾非均匀温度场中产生的复杂的应力分布问题，结合大连地铁201标段盾构隧道工程实例，使用FLAC3D模拟了发生火灾时非均匀温场温度线性升高过程中管片的应力-应变分布和变化特征。根据温度不同材料性质不同的客观事实，在模拟过程中随着温度的升高实时调整材料参数，使模拟结果更加准确。取0℃～1000℃作为温度范围，每升高100℃作为一个特征点进行研究，分别得出了衬砌结构变形分布规律及其应力变化分布规律，进而确定了其在该形式火灾作用下的危险部位。分析结果表明：在火灾温度作用下，盾构隧道管片衬砌的最大水平压力和最大竖直压力分别是初始值的10．5倍和8．9倍，均作用在90°±22．5°范围内的隧道管片上；在300℃时总位移明显增加。本文的研究可为评估盾构隧道在火灾作用下的安全性提供参考依据。Due to the fact that the subway tunnel is underground restricted space, it is difficult for the heat gathered during the fire to be dissipated. The tunnel segment of the shield construction subway is the main bearing structure. In the fire form of convection heat transfer, the non-uniform temperature field is formed and is a temperature gradient field. In this field, segments will produce thermal load, as well as the ground stress load, which make the stress distribution more complex. According to Dalian subway No.201 section tunnel construction practice, in the non-uniform temperature field with temperature linear increase process, FLAC3D is used to simulate the stress distribution and deformation characteristics of the segment. According to the fact that material properties are different in different temperature values, the parameters are adjusted real-timely in the simulation process with temperature rising, so the simulation results obtained are to be more accurate. Finally, the paper finds the deformation distribution and variation rule of stresses distribution, and then finds its damage parts in the fire. Every 100℃ rise is chosen as a feature point for research from 0℃~1000℃.The results show that the maximum horizontal pressure rise faster than the maximum vertical one. The maximum horizontal pressure and maximum vertical pressure are respectively 10.5 and 8.9 times of the initial values, and the positions appear general in the 90°±22.5°of the segment. The total displacement increased significantly after 300℃.

关 键 词：隧道火灾 非均匀温场 热力耦合 FLAC3D 管片受力分析 

分 类 号：TU375.4[建筑科学—结构工程]