隧道工程突水机制及对策

为防治隧道工程水害,运用系统分析方法、岩体结构控制理论和岩土优势面理论,研究隧道工程突水机制及其对策。结果表明,充足的水源、顺畅的和足够大的通道是突水必须具备的2个基本条件。水源包括含水层、江河、溶洞和采空区积水、洪水倒灌水、富水优势断裂;通道主要是断裂,断裂包括原生断裂、活化断裂和后生断裂。断裂的富水性、导水性受断裂的时间性、断裂的规模及空间结构、断裂力学性质、断裂两盘的岩性、施工对断裂的扰动程度等因素的综合影响。建立断裂的时间、断裂力学性质、断裂规模、断裂两盘岩性4种优势指标及其量化评价体系。根据优势指标确定某具体隧道工程中断裂的突水等级,对不同等级的突水优势断裂采用不同的工程对策,但对非突水优势断裂必须考虑施工扰动后的活化问题。

Mechanism and Countermeasures of Water-Bursting in Railroad Tunnel Engineering

In order to prevent and treat water-bursting calamity in railroad tunnel engineering,this paper has carried out a study on the mechanism and countermeasures of water-bursting with systems analysis method,rockmass structure controlling theory and rock-soil preferred plane theory. The following conclusions can be drawn.Firstly,ample water source and expedite and large enough channels are essential for water-bursting accidents in railroad tunnel engineering.Water source includes aquiferous layer,river,water-eroded cave,goaf seeper,preferred faults with abundant groundwater.Secondly,the channels of water-bursting are composed of fractures(faults especially) mainly.The fractures include originality fractures,activation fraction and posteriority fracture.The properties of water-bearing and hydraulic conductivity are influenced synthetically by the timeliness of fractures,dimensions and space structure of fractures,mechanics characters of fractures,the lithology of two sides of fractures,disturbance degree of construction to fractures.The preferred indices and the quantization evaluation system are established for the time,mechanical property,scale and the two-side lithology of fractures.Finally,the water-bursting grade of fractures in a railroad tunnel engineering,different countermeasures can be adopted according to different grade water-bursting preferred fractures.The activation water-conduction of non-water-bursting preferred fractures under the disturbance of construction should be taken into account.