【作者】 张焱；

【导师】 徐志胜； 廖光煊；

【作者基本信息】 中南大学 ， 消防工程， 2010， 博士

【摘要】 随着社会发展,特长公路隧道出现的越来越多,隧道结构防火是隧道火灾安全工程的一个重要组成部分。国内对于独立排烟道集中排烟方式既无成熟经验又无相应规范,对于其在火灾下及火灾后的安全性关键参数还没有研究,限制了该技术的推广应用。本文在模型隧道大规模热烟试验的基础上,对钢筋混凝土排烟道结构(包括顶隔板和牛腿)和素混凝土隧道衬砌结构的抗火性能进行模型试验研究。通过火灾试验、理论分析和数值模拟等方法,本文取得了研究成果如下：(1)通过对顶隔板试件在HC曲线、900℃恒温、800℃恒温和700℃恒温作用2h的火灾试验研究,得到了高温-荷载耦合作用下顶隔板的温度场分布及挠度变化规律。(2)对受火后的顶隔板承载力损伤特征、损失程度和损伤等级进行了研究,获得了不同工况后的承载力损失与受火温度的非线性关系,经受HC曲线、900℃恒温、800℃恒温和700℃恒温作用2h后剩余承载力分别减少了76%、50%、25%和24%。(3)对在HC升温曲线作用2h时,有(无)防火涂料防护的植筋牛腿结构进行了火灾试验研究,得到了温度场分布及高温反应规律。对受火后牛腿结构承载力损失程度进行了试验研究,得到了剩余承载力变化规律。(4)开展了牛腿植筋高温性能试验研究,获得了牛腿植筋在火灾作用下的温度分布、变形特点及高温后在荷载作用下的变形规律,分析了连接处的安全状态。(5)对在不同受热温度和不同荷载等级下植筋试块的粘结滑移力学性能进行了拉拔试验,测算了常温下、高温自然冷却后、恒温加载植筋试件的极限承载力、极限粘结应力和承载力损失,得到了恒载升温植筋试件破坏的温度和相对滑移量等关键技术参数,总结了高温后和恒温加载植筋试件极限粘结应力和承载力损失的变化规律。(6)在试验研究及理论分析的基础上,通过有限元分析方法对足尺排烟道顶隔板的火安全性进行了数值计算,对火灾后足尺顶隔板结构的损伤等级提出了判断标准和判断方法,对各工况下顶隔板构件的安全性能进行了评定,并提出了加固范围。本研究将填补在特长公路隧道集中排烟道结构抗火性能研究的空白,提高公路隧道火灾防灾救灾水平,对国内特长公路隧道消防工程设计、规范制定、工程的实际应用等也有很大的实际价值和指导意义。更多还原

【Abstract】 With the social development, more and more extra-long highway tunnels appear, it is an important concern to protect tunnel structure from fire in tunnel fire safety engineering. There is no mature experience and corresponding code for centralized smoke exhaust mode in independent smoke shaft by now, which has limited the application of this technique. As there is no research on key safety parameters of independence smoke shaft both in fire and after fire, the application of this technology is limited.Based on the hot somke test of tunnel model, this papper presents the fire resistance of the reinforced concrete structure of independant smoke shaft (including both roof spacer and corbel structure) and plain concrete lining structure by model test. On the basis of fire experiments, theoretical analysis and numerical simulation, a seires of valuable findings are achieved. The main researches are as following:(1) By fire tests of roof spacer under HC standard curve, 900℃,800℃,700℃for 2 hours, the temperature field distribution and deflection varition of roof spacer under coupling of load and temperature is studied.(2) The damage characteristicsm, damage degree and damage grade of variant working conditions after fire are tested, the nonlinear relation between bearing ability of roof spacer and fire temperture is obtained, the residual bearing ability decrease by 76%、50%、25% and 24% respectively.(3) By fire test under HC standard curve for 2 hours, the temperature field distribution and high temperature reaction of corbel structure with (without) fire retardant coatings are obtained. The bearing ability after fire is tested and the declines degree is obtained,(4) The experiments of adhesive steel bar under and after fire are tested, the temperature field distribution, deformation features and deformation law under load after fire are obtained, the safety of the joint is analyzed.(5) The pull-out tests of adhesive steel bar under different temperatures and different load are studied, the ultimate bearing ability, ultimate bond stress and capacity loss under room temperature, natural cooling after high temperature and constant high temperature are analyzed, some key paremeters, such as failure temperature and slided displacement are obtained, the law of ultimate bond stress and capacity loss under and sfter high temperature is obtained.(6) On the basis of test research and theoretical analysis, by using finite element analysis, the evaluation standard and method of damage grade of full-scale roof spacer after fire are carried out, the safety of roof spacer is evaluated, and the strengthening area is proposed.This study will fill in the gap in the field of fire resistance research of extra-long highway tunnels, raise the level of disaster prevention and reduction, also, provide great reference and guiding significance for fire engineering design, code modification and practical application of engineering.更多还原