On geological engineering control in railway const

On geological engineering control in railway construction projects (2)

2 route selection in mountain crossing areas and geological engineering control of deep buried long tunnels

2.1 existing problems

on the railway extending in line in mountainous areas, it is always inevitable to pass through the watershed. For those railway lines with restrictions on the setting of longitudinal slope lines, the key lies in what measures to overcome the height difference and smoothly pass through the watershed, which is also the biggest technical obstacle in the process of railway construction. In the actual work process, for such terrain, the construction scheme of market tunnel is usually adopted, which can effectively cross the watershed. By shortening the design idea of the line, it can also reduce the elevation of the line, and effectively avoid unnecessary economic losses caused by a large number of line expansion in mountainous slopes and other sections. Both the way of improving the overall technical conditions of the railway and the strategy of improving the engineering geological conditions have their own characteristics

at present, the construction capacity of railway projects in China has been gradually improved. However, for the construction of geological engineering of deep buried long tunnels, there are still the following problems

(1) deformation and failure of surrounding rock. Such geological problems are mainly caused by the collapse of broken rocks, loose layers and rock masses. Usually, under the action of high ground stress, soft rock is more prone to rheological problems, and for hard rock, it will also produce the risk of rock burst

(2) occurrence of water inrush, water leakage and water inrush. It mainly refers to the hazards caused by geological problems such as large-scale karst caves and underground rivers. In the actual work process, it is found that muddy disasters such as water inrush and mud inrush have the greatest impact on railway construction projects

(3) gas explosion will produce many harmful gases, which will also pose the risk of tunnel explosion. In the construction history of railway tunnel, there have been two cases of heavy casualties and losses caused by gas explosion in non coal strata

(4) occurrence of geological disasters such as high temperature, high radioactivity and high earthquake intensity

2.2 solutions

in the actual work process, it is found that it is difficult to solve the above problems, so it is necessary to D. the increase of environmental experiments (high and low temperature experiments) requires the continuous introduction of new technologies and construction concepts in the process of railway route selection and geological exploration, which can be carried out from the following aspects

(1) for mountainous areas with complex terrain and geology, it is necessary to do a good job of analysis and investigation in the primary selection and testing stage, especially the decision-making work of regional geology and address route selection. In all possible route schemes, including the construction scheme of the tunnel crossing the mountains and the largest area through which the leads at both ends pass, the best choice is made in combination with the specific actual situation

find out the geological structure pattern of these areas and the specific characteristics of engineering geological conditions. The analysis and consideration of these elements can effectively control the losses caused by the emergence of geological problems on railway construction. In the process of the first round of scheme comparison and selection, we should focus on the geological perspective and the superiority of the route scheme selection. Try to select schemes with relatively good geological conditions and small scope, so as to ensure that these schemes will not cause more unnecessary troubles and potential safety hazards due to geological decision-making errors. The universal experimental machine for this work adopts microcomputer controlled full digital broadband electro-hydraulic servo valve exhibition, which is also the most important content of Railway Survey and design sequence at present

(2) in terms of the selection of survey methods, we should focus on those mountain crossing areas that involve a large region, which can effectively give full play to the advantages of geological survey. At the same time, during the construction of railway construction projects, we should make full use of various aerospace and aerial remote sensing technologies, and with the help of simulation software, we can effectively improve the overall quality of geological mapping and filling. Make full use of various advanced physical detection technologies, combined with geological surveying and mapping, drilling, pit exploration and other technologies, comprehensively analyze the geology from the perspective of electricity, elasticity, radioactivity and so on, and finally draw a three-dimensional geological exploration map

for example, the Xi'an Ankang line and the Xi'an Nanjing line crossed the Qinling Mountains and Huaihe River area, adopted a comprehensive survey plan, and achieved good results. In addition, for those deep buried long tunnels with complex geology and need to use deep holes to detect the terrain in the survey stage, the horizontal guide and advance construction can be arranged in advance during the preliminary preparation to ensure the accuracy of the geological exploration report. This is better than drilling alone, and can effectively save a lot of money

(3) tunnel engineering geological work should be carried out throughout the construction process of the railway construction project, the exploration and detection of construction geology should be increased, the advance prediction and statistics of construction geology should be done well, and the dynamic design should be implemented through various ways. The investigation and testing of construction geology should be as standard and normative as possible, and the advance prediction should be accurate. Only in this way can we ensure the smooth implementation of railway construction projects. If conditions permit, we should also increase the distance of advance prediction

in recent years, the railway system has successfully developed advanced geophysical exploration methods and advance prediction mechanism, which provides a good guarantee for China's railway construction. For the work of water inrush, water inrush, in-situ stress, ground temperature and other technical difficulties of deep buried long tunnels, we should try our best to strengthen the work of investigation, testing and prediction, and make preparations in advance through various forms. For example, carry out special research on a regular basis, and invite experts and technicians with rich experience in the construction line to explain the work precautions to ensure that the predicted data and information are consistent with the actual situation

3 conclusion

this paper discusses the control of geological engineering in railway construction projects based on the author's experience in the process of practical work. The geological engineering control of railway route selection and slope stability in river valley area, route selection in mountain crossing area and geological engineering control of deep buried long tunnels are introduced respectively. However, due to the limitations of personal knowledge and experience, they have not been able to achieve it. It is hoped that the mold temperature, melt temperature and so on will also change. I hope this paper can attract the extensive attention of scholars