Engineering Geological Location Of Zhijin-Nayong Railway

Zhijin-Nayong railway is located in the northwest of Guizhou Province,in the transitional zone between the plateau in the west of Guizhou Province and the mountain plateau in the middle of Guizhou Province.As a whole,the railway is to the northwest direction,which passes through the morphologic region of middle mountains.In that area,the topographic relief is great,the mountain is high,the valley is deep the lithology is various and the geological structure is strong.The unfavorable geology phenomenon in there has many types,wide distribution and large scale.Typical problems include karst,mined out area,dangerous rock and so on.The complicated engineering geological conditions bring a great potential threat to the railway construction and operation.Therefore,it is of great theoretical value and guiding significance to carry out geological route selection for a variety of adverse geological problems encountered in the line.Through the analysis of past experience of railway geological route selection,this paper sums up the main influencing factors of railway line selection.Those are:fault and fold structure,regional topographic features,unfavorable geology of slope,deep water-rich structure,special rock and harmful gas.Based on the engineering geological background of the railway area and from the five points above,the influence factors of the geological route selection of Zhijin-Nayong railway is analyzed.Through the detailed investigation and analysis of the unfavorable geology along the Zhijin-Nayong Railway,the development and distribution characteristics of the bad geology are obtained.Based on the previous principles of railway geological route selection and the example of railway geological survey in representative complex mountainous area,a set of principles of geological route selection are summed up,which is applicable for a variety of unfavorable geology problems alone the railway.The corresponding countermeasures are put forward for mined out area,coal seam gas,karst,dangerous rock,rock pile,landslide and debris flow.That provides the necessary reference for the design and construction of the railway.Based on the principles of the geological route selection of Zhijin-Nayong railway,the four key sections are compared in detail.And finally,the final plan is determined.Based on the study of the geological route selection of Zhijin-Nayong railway,a set of principles of geological route selection are summed up,which is applicable for mountain areas where the bad geological problems are in the dominant position.These results also provide an important reference value for how to solve the similar problems when the railway passing through the similar areas.