【摘要】 研究目的:滇西北地区断陷盆地软土分布广、埋深大、种类多、厚度大,通过对该类软土的形成原因和特性进行研究,总结出断陷盆地软土特征及选线原则,为今后类似软土的研究提供借鉴。研究结论:(1)区域地质构造对软土分布的控制表现为:一是新构造运动是软土形成的根本原因,二是区域断裂构造控制断陷盆地软土分布。(2)本区断陷盆地软土具天然含水量高、天然孔隙比大、压缩性高、塑性高、强度低、固结系数小、透水性差、均匀性差等八大特性。(3)软土发育区的地质选线工作总体上应尽量绕避深厚软土,但同时也应考虑工程投资因素,在充分研究区域构造对软土分布的影响下确定选线原则。(4)该研究成果可应用于西南地区活动断裂及软土发育的铁路工程地质勘察。更多还原

【Abstract】 Research purposes: Soft soil is broadly distributed and deep-buried in the northwest region of Yunan province,with many sorts and thick soils.The research was done on the cause of formation and the characteristics of soft soil to summarize the characteristics of the soft soil in fault basin and the principle of geological alignment of railway was presented for providing the reference to the research on similar soft soil.Research conclusions:(1) The control of the regional geological structure on the distribution of the soft soil represents: Firstly,the neotectonics movement is the essential cause of forming for the soft soil.Secondly,the regional fault structure controls the distribution of soft soil in fault basin.(2) The soft soil in this fault basin has eight characteristics.These characteristics include the high natural water content,big crude void rate,strong compressibility,good plasticity,low intensity,low consolidating coefficient,low water permeability and poor homogeneity.(3) The railway alignment in the area of thick soft soil should pass round the area of deep and thick soft soil area based on considering the investment.The alignment principle should be determined on the basis of fully researching the influence of regional structure on the distribution of soft soil.(4) The research result is available for the engineering geological investigation for the railway in the active faults area in the northwest region and in the soft soil developing area.更多还原