长大公路隧道防火及降噪技术研究

发布时间：2018-05-25 09:26

本文选题：隧道工程 + 防火及降噪　；参考：《河北工业大学》2015年硕士论文

【摘要】：随着隧道长度、交通密度的增加,隧道发生火灾的潜在威胁在增大,噪音污染也日渐严重。专门针对长大隧道防火和降噪两个方面进行研究,主要内容见以下几个方面:1.通过模拟火灾现场材料表面实际升温曲线,分析了混凝土过火性能影响的三个主要因素(含湿量、强度、骨料),研究结果显示:混凝土受火后的质量损失随着含湿量的升高而增大,含湿量越高,混凝土爆裂越严重;对于混凝土强度等级来说,随着强度的提高,混凝土耐火性变差,质量损失变大;不同骨料混凝土,热稳定性越好的碎石混凝土抗爆裂能力越强,耐火性从好到坏排列顺序为:花岗岩碎石混凝土、玄武岩碎石混凝土、石灰岩碎石混凝土。2.为了提高二衬混凝土的过火性能,采取了一系列措施。将临界含湿量作为混凝土抗爆裂的一个评价指标进行测试,得出防火纤维混凝土爆裂的临界含湿量为79%,均高于其它三种混凝土,抗爆裂性能最好;另外,通过对不同掺量防火纤维混凝土进行过火试验,可以看出,随着纤维掺量的增多,混凝土过火后损伤程度降低;对防火纤维混凝土进行抗渗性测试,得出防火纤维混凝土较普通混凝土抗渗性略有降低;在防火纤维混凝土中掺加粉煤灰,较大程度的提高了混凝土的抗渗性。3.通过测试不同混凝土板侧面温度场以及区域回弹值,可知不同混凝土板侧面温度场基本一致,同一温度场剩余回弹值相差不大,基本呈现随温度的增加,回弹损失值增大的趋势。4.隧道降噪方面,通过对市面上几种常用的吸声材料进行吸声系数测试,试验结果显示,在保证平均吸声系数具有高效能力的基础上,考虑不同频段的吸声效果以及隧道施工的方便性、经济性,初步选取30mm厚无机纤维涂料用于隧道二衬混凝土。5.通过对不同级配不同砂率的露石水泥混凝土进行抗滑、耐磨等使用性能研究,结果表明:砂率为20%,粒径4.75~9.5mm与9.5~13.2mm的集料比例为2:1时,路用性能最好。此配比下的露石水泥混凝土在保证耐磨的前提下,大大提高了路面的抗滑性能,吸声系数也比普通混凝土提高了一倍左右。
[Abstract]:With the increase of tunnel length and traffic density, the potential threat of tunnel fire is increasing, and the noise pollution is becoming more and more serious. Specifically for the long tunnel fire prevention and noise reduction two aspects of the study, the main content of the following several aspects: 1. By simulating the actual heating curve of the material surface in the fire site, three main factors (moisture content, strength) affecting the overfire performance of concrete are analyzed. The research results show that the mass loss of concrete after fire increases with the increase of moisture content, the higher the moisture content, the more serious the concrete burst; for the strength grade of concrete, with the increase of strength, the fire resistance of concrete becomes worse. The better the thermal stability of aggregate concrete is, the stronger the burst resistance of crushed stone concrete is. The order of fire resistance from good to bad is: granite crushed stone concrete, basalt crushed stone concrete, limestone stone crushed stone concrete. The order of fire resistance is: granite crushed stone concrete, basalt crushed stone concrete, limestone crushed stone concrete. A series of measures have been taken to improve the over-fire performance of second-lining concrete. Using critical moisture content as an evaluation index of concrete crack resistance, it is concluded that the critical moisture content of fire-resistant fiber concrete is 79, which is higher than the other three kinds of concrete, and the crack resistance is the best. Through the overfire test of fire-resistant fiber concrete with different content, it can be seen that with the increase of fiber content, the damage degree of concrete after overfire is reduced, and the impermeability of fire-resistant fiber concrete is tested. It is concluded that the impermeability of fire-resistant fiber concrete is slightly lower than that of ordinary concrete, and the anti-permeability of concrete is greatly improved by adding fly ash to the anti-fire fiber concrete. By measuring the temperature field and the regional rebound value of different concrete slabs, it can be seen that the temperature field of different concrete slabs is basically the same, and the residual springback value of the same temperature field is not different, and the residual springback value of the same temperature field is basically increased with the increase of temperature. Springback loss value increase trend. 4. In the aspect of tunnel noise reduction, the sound absorption coefficient of several commonly used sound absorption materials in the market is tested. The experimental results show that, on the basis of ensuring that the average sound absorption coefficient has high efficiency, Considering the sound absorption effect of different frequency bands, the convenience and economy of tunnel construction, the 30mm thick inorganic fiber coating was preliminarily selected for the second lining concrete. 5. In this paper, the anti-sliding and wear-resisting properties of the concrete with different gradation and different sand ratio are studied. The results show that the road performance is the best when the sand ratio is 20 and the aggregate ratio of 4.75~9.5mm to 9.5~13.2mm is 2:1. On the premise of ensuring wear resistance, the anti-slip performance of the concrete under this ratio is greatly improved, and the sound absorption coefficient of the concrete is about twice as high as that of the ordinary concrete.
【学位授予单位】：河北工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U458

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