【作者】 张静；

【导师】 钟登华；

【作者基本信息】 天津大学 ， 工程管理， 2007， 博士

【摘要】 引水隧洞爆破开挖施工过程是极其复杂的,施工方案的优化是一项重要的研究课题。施工期通风问题是制约施工进度的重要因素,需要先进的理论方法对通风过程进行计算分析,以达到制定合理施工组织方案的目的。本文融合水利水电工程科学、系统工程、地理信息系统和计算流体力学等多个交叉学科的先进理论方法与技术,提出了引水隧洞爆破开挖施工期通风CFD数值模拟分析方法和基于通风模拟的施工方案优化技术,主要获得了以下四项研究成果:(1)提出了基于CFD模拟的通风参数确定方法,建立了引水隧洞爆破开挖施工期通风数学模型。采用数学模型解析的方法得到了定量的施工期通风时间参数,克服了传统分析中通风时间参数依据定性工程类比和经验确定的弊端,为施工仿真和施工方案优化提供了理论基础。(2)建立了基于k-ε模型的三维非稳态拟单相流模型及三维非稳态两相流模型。在粉尘扩散模型的动量源项中考虑了相间曳力、升力和虚拟质量力的作用,在CO运移模型的动量方程中考虑了浮力的影响。利用拟单相流模拟粉尘在开挖进尺为50m的引水隧洞内的迁移,其趋势和速度与两相流模型的模拟结果基本一致,通风达标时间也接近。因此,本文采用拟单相流模型对引水隧洞爆破过程中粉尘扩散和CO运移进行模拟,对模型进行了可靠性分析。(3)提出了基于CFD通风数值模拟的施工方案优化技术。在CFD通风数值模拟的基础上,集可视化仿真技术、网络计划分析与优化技术于一体,建立了引水隧洞爆破开挖施工全过程可视化动态仿真模型,为综合分析施工工期、施工强度、交通运输以及各工序之间的相互联系和制约,进而进行施工方案的优化提供了有效的技术手段。(4)以某水电站引水隧洞爆破开挖施工期通风为实例,模拟了不同开挖进尺的引水隧洞施工通风过程,分析了风流、风压、CO浓度分布和粉尘浓度分布规律,并采用数据拟合的方法得到通风时间与开挖进尺之间的关系;基于优化的通风时间,应用仿真技术深入研究了引水隧洞爆破开挖施工仿真与进度优化,获得了合理的施工工期、优化的施工进度以及施工强度等重要参数;对施工方案进行了综合优化分析,有效提高了施工方案的可靠性和合理性。更多还原

【Abstract】 The construction scheme optimization is an important research problem and the construction of the diversion tunnel is extremely complex. Construction ventilation, which is an important restriction factor of construction schedule, needs advanced theory to optimize construction scheme. The theoretical analysis of numerical simulation for the ventilation in the diversion tunnel and optimization of construction sccheme based on the ventilation simulation are presented. It integrates with advanced theories and methods from the hydraulic and hydroelectric engineering science, systems engineering, geographical information system and computational fluid dynamics.In general, the following four achievements are obtained in this dissertation:(1) Determination method of ventilation parameters based on CFD is presented. And the construction ventilation models for diversion tunnel are set up. The quantitative construction ventilation time is obtained by solving mathematical model. It overcomes disadvantages of the qualitative engineering analogy and empirical method of ventilation time. It offers the theoretical basis to construction schedule simulation and construction scheme optimization.(2) The 3-D transient quasi-single phase models and a 3-D two phase flow model are proposed together with k-εequations. The effect of inter-phase drag, lift force and virtual quality force are considered in the momentum source of dust diffusion model. The effect of buoyancy is considered in the momentum equation of the CO transport model. The 3-D dust concentration field in the diversion tunnel with 50m long is simulated using the 3-D quasi-single phase models and a 3-D two phase flow model. The simulated results show that the trend of the dust migration and velocity based on the 3-D transient quasi-single phase models is well in agreement with that based on 3-D two phase flow model. Compared with the two phase flow model and the 3-D transient quasi-single phase models, the time reaching the standard of ventilation is almost the same. Consequently, the dust diffusion in explosion processes of the diversion tunnel is simulated using a 3-D quasi-single phase models. The reliability of the models is analyzed.(3) The optimization of construction scheme based on the numerical simulation of ventilation is presented. Based on the numerical simulation of ventilation, a new method called the visual dynamic simulation technique for construction process is presented, which combines visualization simulation technology, and network plan and optimum technique. It provides powerful technical measures for comprehensive analysis of the interaction and restriction of the construction duration, the intensity of excavation, the traffic of construction site and the construction scheme optimization.(4) The diversion tunnel of a hydropower station is taken as a case. The ventilation in different excavation progresses is simulated. The distributions of the wind velocity, wind pressure, CO concentration and dust concentration are analyzed respectively. Using the data-fitting method, the relation between ventilation time of blasting of the diversion tunnels and excavation progress is established. The construction simulation and schedule optimization are researched based on the optimized ventilation time. The feasible construction period, reasonable construction scheduling and optimized construction intensity are obtained to optimize the construction scheme.更多还原