拉林铁路罗布穷则泥石流活动特征与灾害防治

Activity Characteristics and Disaster Control of Luobuqiongze Debris Flow in Lasa-Linzhi Railway

研究目的:通过分析罗布穷则泥石流灾害的活动特征及规模,研究其形成与成灾过程,对进一步认识高海拔地区泥石流发育特征具有重要的意义,通过对泥石流的调查分析和研究处理,为类似工程提供借鉴。研究结论:(1)目前沟域内仍残留以沟道物源为主的大量松散物质,在一定降雨条件下仍有爆发泥石流的可能性;(2)罗布穷则爆发的泥石流规模符合50年一遇频率,规模属小型,性质为暴雨诱发型稀性泥石流;(3)沟域内有松散固体物源量18.5×10^(4)m^(3),可能参与泥石流活动的动储量为13.5×10^(4)m^(3),目前该沟仍有爆发泥石流的可能,在50年一遇的暴雨条件下,该沟将爆发泥石流,且有漫流进入右侧DK395+150处沟道并冲出的可能性;(4)对不同降雨频率下罗布穷则沟泥石流的动力学特征进行数值模拟,结果表明,降雨频率为1%的冲出量是2%的1.58倍,是5%的4.96倍,是频率10%时冲出量的2.95倍;(5)结合数值模拟和计算结果,并结合此次泥石流冲出规模,在一定的暴雨条件下,DK395+170处泥石流威胁的范围将为DK395+140~DK395+200段,平均泥深预计可达1.4 m;(6)建议采取明洞加渡槽穿越铁路与公路模式,将DK395+150及DK395+170处泥石流从铁路顶部排导到主河道内;(7)泥石流整治措施对地质条件复杂地区的地质选线及综合治理有良好借鉴作用。

Research purposes:Analyzing the activity characteristics and scale of Luobuqiongze debris flow disasters and studying their formation and disaster processes are of great significance for further understanding the development characteristics of debris flow in high altitude areas.The investigation,analysis,research and treatment of debris flow can provide reference for similar projects.Research conclusions:(1)At present,there are still a large amount of loose material mainly from channel sources in the ditch area,and there is still the possibility of debris flow erupting under certain rainfall conditions.(2)The scale of debris flow erupting in Luobuqiongze is in line with the frequency of once in 50 years.The scale is small,and the nature is torrential rain-induced sparse debris flow.(3)There is a source of loose solids of 18.5×10^(4) m^(3) in the ditch area,and the dynamic reserves that may participate in debris flow activities are 13.5×10^(4) m^(3).There is still a possibility of debris flow erupting in this ditch.Under the conditions of heavy rain once in 50 years,debris flow will erupt in this ditch,and there is the possibility of overflow into the channel at DK395+150 on the right and rush out.(4)Numerical simulation of the dynamic characteristics of debris flow in Luobuqiongze Gully under different rainfall frequencies show that the amount of debris flow at 1%frequency is 1.58 times that of 2%,4.96 times that of 5%,and 2.95 times the amount of punch out at 10%frequency.(5)Combined with the numerical simulation and calculation results,and combined with the scale of this debris flow,under certain heavy rain conditions,the threat range of the debris flow at DK395+170 may be DK395+140~DK395+200.The average mud depth is expected to reach 1.4 m.(6)It is recommended to take the opencut plus aqueduct crossing railway and highway mode to drain the debris flows at DK395+150 and DK395+170 from the top of the railway to the main river.(7)Debris flow regulation measures have a good reference effect on geological line selection and comprehensive control in areas with complex geological conditions.