【作者】 刘钊春；

【导师】 柴军瑞；

【作者基本信息】 西安理工大学 ， 水工结构工程， 2010， 硕士

【摘要】 我国隧道施工通风的现状不容乐观。随着隧道掘进速度的加快和长度的增加,施工通风问题已经成为隧道快速施工的“瓶颈”。不论是从施工安全的角度,还是从施工进度及施工经济的角度来看,长大隧道独头掘进施工中的通风散烟问题都是摆在工程设计人员、施工人员和管理人员面前的一个十分重要的问题。本文结合雅砻江两河口1#公路隧道,对压入式通风条件下的独头掘进隧道进行了基本理论计算和数值分析,主要结论和研究成果如下：1)总结了现阶段隧道施工通风中主要应用的几种通风方式,隧道纵向通风所需要的风量计算理论,以及通风中各个环节的布置。针对两河口公路隧道独头掘进的特点,结合总结的理论进行了所需风量的计算,同时较系统地阐述了通风系统的日常管理和维护措施以及安全措施等。2)对于独头掘进隧道而言,掘进距离越长,施工通风难度越大。对整条独头隧道压入式通风条件下,隧道内流场和污染物浓度变化进行了数值分析,此数值分析为隧道实现安全施工提供了合理的理论依据,改变了过去凭经验对施工通风时间范围粗略估计的方法,避免施工不确定因素的干扰,对保证正常的安全生产,提高劳动生产率,推动施工进度的高效进行,具有实际的指导意义。3)通过大型有限元软件ADINA,实现了掘进隧道三维空间内风流结构和有害气体浓度扩散的数值模拟。独头掘进隧道压入式通风属于受限附壁射流,掌子面附近风流形成了射流区,回流区和紊流区三个区间。模拟结果表明,由于涡流对浓度扩散的影响,涡流中心有害气体浓度高,涡流对扩散有明显的滞留作用。工作区间内有害气体浓度随通风时间呈现负指数变化,并通过公式得到了验证。4)为了加快独头掘进隧道压入式通风条件下有害气体的减排速度,对射流风机的摆放位置,风机间距进行了数值模拟。计算分析结果表明,压入式通风条件下,在隧道的回流区中央位置摆放射流风机能够明显加快有害气体的减排速度；射流风机的工作距离为120m左右,在隧道中摆放射流风机时可以以此数据作为参考,减少了安装过程中的盲目性。更多还原

【Abstract】 The status quo of China’s construction about the ventilation can not be optimistic. With the accelerating rate of tunneling and the increasing length of the tunnel,the problem of ventilation has become a "bottleneck." In terms of the safety and the schedule of the construction,or from the economic point of view, the scattered smoke and ventilation problems in the long and large single head tunnel construction, are realistic problems placed before engineering design personnel, project construction and project management personnel. In this paper, according to the Yalong River 1 # highway tunnel,the author try to do the basic theoretical calculations and numerical analysis about single head tunnel construction under the forced ventilation conditions. The main conclusions and findings are as follows:1) Summarize several major applications in the tunnel ventilation construction at the present stage, the calculation theory required in the air flow for the tunnel longitudinal ventilation, and the layout in all aspects of the ventilation. According to the characteristics of single head tunnel construction,combined with the summarized theory,the author makes the calculation of the required air volume, and elaborates the exposition of the ventilation system, the daily management and maintenance measures, and the safety measures in a more systematic way.2)In terms of single head tunnel construction, the longer the distance, the greater the degree of difficulty. The author makes the numerical analysis about the tunnel flow field and pollutant concentration under the forced ventilation conditions. This numerical analysis provides a reasonable theoretical basis for the security of the tunnel construction, changes the rough and empirical estimate ways in the past.Therefore, it has practical significance in avoiding the uncertainty factors of the construction, ensuring the safety of the normal production,improving labor productivity, and promoting the efficient conduct construction progress.3) Achieve the numerical simulation of the wind structure in a three-dimensional space inside the tunnel and the spread of harmful gas concentrations through large-scale finite element software ADINA. Single head tunnel forced ventilation belongs to the limited wall jet fluicids. The working face area makes the formation of the jet airflow area, back area and the turbulent area. The simulation results show that, due to the concentration proliferation effects of eddy current, there are high concentrations of harmful gases in the vortex center, and the eddy current has obvious residual effect on the proliferation. The concentration of harmful gases within the working range has a negative index of changes in ventilation time, and has been verified by the formula.4) In order to speed up the speed of reducing emissions of harmful gases under the forced ventilation conditions,the author makes the the numerical simulation of the jet fans positions and the distances between fans. The calculation results show that, under the forced ventilation conditions, the tunnel jet fans placed in a central location of the recirculation zone can significantly speed up the pace of harmful gas emission reduction; The jet fans working distance is about 120m,which can be used as a reference when we place the tunnel jet fans, thus reducing the blindness during the installation process.更多还原