【作者】 杨玉容；

【导师】 何川；

【作者基本信息】 西南交通大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 随着我国公路建设的快速发展,隧道越来越多地出现在公路交通工程领域里,其洞口废气扩散与窜流问题因其对隧道营运通风及对周围环境密切相关,亦越来越多地受到关注,本论文依托交通部西部交通建设科技项目“公路隧道智能联动控制技术研究”与国家杰出青年基金项目“长大交通隧道建设与营运关键科学问题”等科研项目,采用广泛调研、现场测试、理论分析、综合分析以及系统性数值分析等多种研究手段、结合北碚隧道与中梁山隧道等具体工程,就公路隧道洞口废气扩散形态与窜流影响等相关问题开展了研究,主要研究工作与取得的主要成果如下：1、依据非恒定多因素综合作用下洞口废气浓度分布特点,提出了基于极值的浓度场测试分析方案,依托北碚隧道、中梁山隧道,开展了公路隧道洞口废气浓度扩散的全场现场实测研究,并将全自动烟气分析仪成功应用于中梁山隧道不同测点的同步实测中,获得了多种运营工况、不同洞口地形条件下公路隧道实际运营废气最大浓度影响分布曲线簇以及一系列洞口废气多种成份的同步实测的浓度-时刻曲线簇,并以此为基础,分析了公路隧道洞口废气扩散规律,其扩散特征符合流体流动扩散传输规律、且两种测试方案其测试结果的一致性,印证了基于极值的浓度场测试分析方法具有合理性与可行性。2、根据公路隧道洞口废气扩散进入环境大气的出流特点,结合相关领域的研究分析,率先引入射流理论,并依据气体自由射流自保持状态的相关研究、结合有效模拟复杂地形的网格生成技术,建立了适应于公路隧道洞口废气湍射流扩散数值分析的区域模型；推导选择了相应的多组分气体扩散传输的三维微分数学模型组与适宜的求解方法。3、将基于极值的浓度场测试分析的现场测试与湍射流模拟理论相结合,探讨了一种适应于洞口废气非恒定扩散特点的综合分析方法,提出测试条件下一系列多因素组合影响下的工况组模拟方案,从而将模拟数据与测试数据进行了恰当的比较分析,并针对测试模式下不同自然风速、洞内外不同温差、两洞口不同出口与入口风速等影响因素,系统地探讨了相应工况组的洞口废气的扩散与窜流影响规律,依据现场测试数据,还推导预测了远期不同运营状况下相应洞口处实际废气的最大浓度范围,最后模拟了相应洞口废气窜流状况及出口隧道侧增设挡风壁后废气窜流改善的情况。4、针对洞口结构因素对废气窜流程度的影响开展了系统性的数值分析,首先针对开阔地形的平行隧道洞口从不同横向洞口间距、不同自然风速以及中间设置不同尺寸的挡壁等三个角度开展了影响研究,然后探讨了平行隧道洞口废气窜流影响的相关性研究,并针对特定横向洞口净距,考虑诸如两洞口位置是否纵向错开、在洞口段出口隧道侧、入口隧道侧以及两洞口之间是否有挡壁、以及各挡壁不同的长度与高度等洞口结构因素,采用六因素异水平的正交实验方案系统性地开展了废气窜流影响的模拟研究,最后得出减弱这类隧道废气窜流的有利与不利的洞口段上建结构类型建议。相关的实测数据曲线族,为公路隧道洞口废气扩散影响研究积累了最直接可靠的资料,其测试分析方案与手段亦为非恒定多因素作用下某物理量的测试与评价提供了切实可行的新思路与新途径；适宜的洞口废气湍射流扩散分析区域与求解方法为系统性探讨提供了有效的平台与手段；实测数据与湍射流扩散模拟理论相结合的综合分析研究,为扩散分析提供了相当程度上的可靠性证明；基于实测数据的洞口废气浓度的远期预测以及所探究的减弱平行隧道洞口端废气窜流状况的有利与不利的洞口土建结构类型等,从工程角度方面提出了可供参考的建议。更多还原

【Abstract】 Along with the rapid development of highway engineering, tunnels have increasingly appeared in highway engineering field. Moreover, the problems of tunnel portal exhaust gas diffusing shape and channeling are attracting more and more attentions due to their close relations with tunnel ventilation and environment. Based on the related subjects such as the western transportation construction scientific and technological project of Transportation Department’Highway tunnel intelligent linkage control technology research", the National Science Found for Distinguished Young Scholars of China’key scientific problem of construction and operation for extra-long traffic tunnel’and so on, adopted many methods such as extensive study, field test, theoretical analysis, comprehensive analysis, and systematic numerical analysis, supported by specific projects such as Beibei tunnel and Zhongliangshan Tunnel, some research on highway tunnel portal exhaust gas diffusion shape and channeling problems are carried out in this paper. All the main works and results can be summarized as follows:1. According to the characteristics of concentration distribution of exhaust gas from highway tunnel portal under the comprehensive effect of unsteady multi-factors, the programme and analysis of the concentration distribution testing based on the extremum is put forward. Supported by Beibei Tunnel and Zhongliangshan Tunnel, the research of the whole field test about concentration distribution of exhaust gas from highway tunnel portal is carried out, and the automatic flue gas analyzer is the first applied to the synchronous measurement of the different points of Zhongliangshan Tunnel. A series of curves families of the maximum concentration distribution of the actual operation exhaust gas around of highway tunnel portal are the first obtained for the various operation conditions or terrains, and a series of various ingredients synchronous concentration-time curves families are also obtained firstly. Based on these series of curves families, the diffusion rules of the highway tunnel portal exhaust gas are analyzed, which conform to the ones of fluid flow diffusion transmission. And the concordant results of two kinds of testing plan have mutually proved that it is a reasonable and feasible method of the concentration field test and analysis which based on the extreme.2. According to the flow characteristics of the highway tunnel portal exhaust gas diffusing into the environment atmosphere, combined the analysis of study of the relative field, jet theory is the first introduced, and according to the relevant research on the self-hold state for the gas free jet and combined with the grid generation technique of effective simulation of complex terrain, a suitable regional model of numerical analysis of the turbulent jet spreading is established. And then, the three dimensional differential mathematical model groups and the appropriate solution are deduced or choosed for the corresponding multicomponent gas diffusion transmission.3. Combined the field test of concentration distribution programme and analysis based on the extremum with the simulation theory of turbulent jet together, a comprehensive analysis method adapted to the unsteady diffusion characteristics of tunnel portal exhaust gas is discussed, in which a simulation scheme of a series of working conditions under the functions of multi-factors of the test is put forward, thus resulting in a appropriate comparative analysis between the testing and the simulation data, and in allusion to the different influencing factors in test mode such as natural wind velocity, air flowing temperature difference between outside and inside of tunnel, and the operating wind velocity of both tunnels, the influence rules of the exhaust gas diffusing and channeling around highway tunnel portal are discussed systematically under the corresponding working conditions groups, moreover, on the basis of field test data, under the forward different operation conditions.the maximum concentration range of the corresponding tunnel portal actual exhaust gas is also deduced out,and finally, the corresponding exhaust gas channeling status and the improvement status of the gas channeling under the wind block wall set up on the side of export tunnel are simulated.4. A systematic numerical analysis of the tunnel portal structure factors influencing on the exhaust gas channeling is carried out. Firstly, for the parallel tunnel portal with open terrain, from three angles such as the different transverse spacing of the both tunnel portals, the different natural wind speed, the wind block wall with different size set up in the middle and so on, the impact study of exhaust gas channeling around the portal is carried out. secondly, the correlational study of the influence factors on the parallel tunnel portal exhaust gas channeling is explored, and specially for the tunnel portals with the specific transverse clear distance, consideration of these structure factors such as whether or not the parallel tunnel both portals are longitudinal stagger, whether or not the block wall set up on the side of the exit tunnel, the entrance tunnel and in the middle, different length and height of the block wall and so on, adopting the six factors and different levels orthogonal experiment scheme, the impact researches on the exhause gas channeling around the parallel portal are carried out systematically. Finally, some suggestion on tunnel portal civil structures which are helpful or against to weaken the effect of the parallel portal exhause gas channeling are proposed.The curve families related to the measured data accumulate the most direct and reliable information for the research of the highway tunnel portal exhaust gas diffusing, and the analysis method and means for this testing provides a feasible new idea or a new approach for the testing and evaluation of some physical quantity which is under the action of unsteady multifactor. The suitable analysis regional model and the solving method for the exhaust gas turbulent jet diffuseness of highway tunnel portal provides an effective platform and means for systematic discuss. The integrated analyses method combining the measured data with the simulation theory of the turbulent jet diffusion provide a degree of reliability proof for numerical analysis. The forward prediction based on the measured data of the portal exhaust gas concentration and the favorable or unfavorable civil structure type of highway tunnel portal for the weakening of the exhaust gas channeling are proposed as some engineering suggestions for reference.更多还原