Natural disaster risks and measures for high-speed railroads in our countries

High-speed railways are rapidly developing and becoming widespread, and the preferences of passengers are directed towards those lines where the parameters such as safety and comfort are provided at the top in demanded routes. As a result, the swift return of the investments made has been an effect that enables high-speedrail lines to increase. In this system, which is popular all over the world, it has become more important to take security measures due to the increase in speed caused by development. Safety measures and risk analysis on high-speed railways are more important than conventional lines, because increasing the speed increases the risk of accidents and the severity of accidents. Measures to be taken against the accidents along with the speed increase have come to the forefront and various applications are being made regarding the train operation. Although the main reason for accidents on high-speed railways is considered to be caused by train operation and measures are taken for this, natural disasters in countries with high disaster risks such as Japan are among the most important accident risks in train operation. In this study, natural disaster risk analyses have been carried out according to the regions where the high- speed railway lines constructed and planned in our country, and the measures to be taken against them have been also examined. Ankara-Istanbul and Ankara-Konya in Turkey HSR projects have been implemented. In addition, Ankara-Sivas, Ankara-İzmir and Kayseri-Yerköy high-speed railway lines are being constructed or planned in order to increase the railway share in transportation and the current availability of high-speed railway in our country. These lines, planned and planned, are assigned to various events and disaster numbers belonging to risky areas for the detection of earthquakes, landslides, rock falls, floods and avalanche natural disasters that our country is exposed for natural disaster risks and the disaster risk maps of our country have been utilized. The maps and disaster maps of the constructed high-speed railway line maps, which are constructed and under construction, have been overlapped and it has been clearly defined in which regions the routes are exposed to which natural disasters, however, when comparing the results of the disaster risk / intensity maps of the country, the results of the disasters affected by the number of disaster events in the regions where the HSR lines are located and the results of the affected disasters as a result of these events, and comparing the results on the planned and planned HSR routes, both situations have different disaster risk grades. Accordingly, disaster risk / intensity maps have been found to contain a number of deficiencies, and measures against disasters involving risk on HSR lines have been proposed according to the obtained data. In this study, all the lines in construction stage and planned to be constructed are determined according to the line segments on all natural disasters; on the one hand, in order to determine the effect of natural disasters on HSR lines. According to this, it was determined which natural disasters the HSR lines in various regions were exposed to and the risk ratios were determined according to the sections of each line. When the regions in terms of HSR lines are taken into consideration, accordingly, the most dangerous regions of our country in terms of earthquakes are the North Anatolian Fault Line, the western Anatolian earthquake zone and the earthquake zone of Southeastern Anatolia. In other words, for those sections covering the Marmara, Aegean and Eastern Anatolian Regions, the priority is not yet applied in our country in order to protect the high-speed railways from earthquake disaster. It is recommended to use Urgent Earthquake Disaster Alarm System (UrEDAS). With this system, the effect on the depres- sion HSR lines will be reduced to a certain degree by means of automatically stopped trains, thus avoiding the effects of accidents. Another method that is recommended for earthquakes in terms of HSR lines is strengthening works on art structures such as bridges and viaducts. In terms of landslide, the regions with the highest risk are determined as the Black Sea, Eastern Anatolia and Central Anatolia regions where mountainous and uneven areas are abundant. For landslides, my country firstly recommends Slope Sliding Risk Estimation Method. Thus, in these areas sensitive to both heavy rainfall and landslides where rugged areas are located, the risk of soil slip will be accurately predicted. It is also suggested to install various protective structures in the areas where the lines are located against the landscape. It is also recommended that the Prevention Disaster Alarm System (PreDAS) be introduced to the country so that data transmitted from the monitoring devices via sensors can be displayed at a center via network circuits. Rock falls are most common in the Black Sea and Eastern Anatolia in our country. In order to prevent rolling and slipping against rock falls, it is recommended to fix the rock to the mainland using loose rocks, concrete and rock bolts, which initially have the risk of moving on the slope surface. In addition, protective barrier structures such as wire fences, retaining walls must be constructed to protect railway vehicles from rock fall. It is also recommended to use a detector to detect falling rocks. A self- contained alarm triggers, trains are automatically stopped, and the impact of rock falls on the trains is reduced. The Black Sea region, which is exposed to strong and long-term rainfall, is the most risky area in terms of flooding. For this reason, the drainage systems must be of sufficient capacity. In addition, all drainage systems around the line should be cleaned and precautions should be taken against blockage. The eastern Anatolian region, where large snow masses are located, has been identified as the most dangerous area in terms of avalanche risk. There are no HSR lines in the region; however, the Ankara-Sivas line, which is in the construction phase, has been proposed to apply various structures against the avalanche, assuming the connection with the other lines in Eastern Anatolia in the later periods. It is also recommended that avalanche tunnels be built on the lines to ensure safe passage of vehicles in motion. Curtains around the line should be used so that fine snow that drifts with the wind will not adversely affect train operation. However, it is advisable to spray water with the superstructure irrigation system during heavy snowfall. This ensures that the abdomen gets wet and prevents it from sticking to the train. If there is current on the rail during train operation, this may cause a short circuit and the current may be cut off. For this reason, it is recommended to reduce the train speed as the simplest method during floods and floods. In addition, the air condition must be continuously monitored and the train operation control against flood risk must be ensured. However, sealing membranes should be used in the railway infrastructure. It is suggested that pump stations should be constructed for pumping excess water in the event of flooding near the line, especially in the Eastern Anatolia Region where highly sloped areas dominate. In summary, in this study; In terms of the natural disasters that are underway in our country and planned to be made by HSR lines, the areas with the highest risk that could be involved in the operation were identified. Accordingly, various measures and studies are proposed to prevent accidents due to natural disasters that may occur in the high-speed railways, which are becoming increasingly widespread in our country, by determining the risks of disaster risks in the sections in the lines. In this context, in order to prevent such accidents in our country, technical methods applied in high speed railways in disaster risk countries were examined and suggestions were made for our lines depending on regional risks.