火灾高温下盾构衬砌结构试验与力学模型综述

Review of Experiments and Mechanical Models of Shield Lining Structure Exposed to High Temperature

复杂运营环境下自然与人为因素所引发的众多隧道火灾已造成了重大的社会影响和经济损失。火灾已成为威胁隧道安全运营的主要灾害之一,其对隧道衬砌结构会产生严重的损伤乃至破坏。盾构衬砌为装配式结构,接缝多以螺栓连接,火灾高温下易发生管片爆裂和接缝连接薄弱部位受损而诱发的突然破坏;同时,由于盾构隧道周围地层的约束作用有限,其衬砌结构体系受火损坏后垮塌的风险极高。为提高软土地层环境下盾构隧道装配式衬砌结构体系的耐火能力及火灾安全性,本文调研了盾构隧道火灾安全研究现状,对与盾构隧道火灾安全研究相关的试验及理论分析工作做了较为全面的综述,主要包括:火灾高温下盾构隧道衬砌管片力学特性试验与理论分析模型,火灾高温下管片接缝力学特性试验与理论分析模型,火灾高温下盾构衬砌体系力学特性试验与理论分析模型,火灾高温下盾构隧道周围地层力学行为研究。在此基础上,针对大直径盾构隧道的火灾试验,高温引起的盾构衬砌管片材料性能劣化评价及主动式抗火管片的材料设计,火灾高温条件下盾构衬砌结构计算模型精细化这3个核心问题,展望了盾构衬砌受火灾影响的研究方向和思路。

Many tunnel fire incidents in complex operating environment caused by natural and human factors has had a great social impact and spawned a great number of economic losses.As one of the main disasters threatening the safe operation of tunnels,fires may seriously damage the tunnel lining structure and even destroy it.For shield tunnels in the form of assembled structures,the segment joints were connected by bolts.Under the high temperature of fire,the spalling together with sudden collapse induced by the damage in the weak joint section was likely to occur.Whilst due to the limited constraints from the surrounding ground,the failure risk of tunnel lining structure systems is pretty high after fire damage.To improve fire-resistance ability and fire safety of shield lining structures in soft soil,the research status about fire safety of shield tunnels was investigated.The related experiments and theoretical analyses of fire safety of shieldtunnels were discussed and summarized,including the experiments and mechanical models of lining segments in shield tunnels,segment joints and shield lining structure systems in fire and the mechanical behavior of the surrounding soil exposed to high temperature.The Research direction and idea for shield tunnels affected by fire are put forward based on three core problems,namely,large diameter shield tunnel fire experiment,material deterioration evaluation and design of active fire-proof material for shield segments under high temperature,and precision of calculation models.