Study on preventive measures for the hottest high-

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Research on preventive measures for high-speed railway accidents

[Abstract] combined with the engineering design process of China's High-speed Railway Guangzhou Shenzhen line (Guangzhou Shenzhen) and Qinhuangdao Shenyang line (Qinhuangdao Shenyang), this paper analyzes the main reasons that may lead to railway accidents: speed control problems, track failures, natural disasters, etc., and puts forward preventive measures for these accident factors. The implementation of these measures plays an important role in reducing the occurrence of railway accidents

1 overview

high speed railway this skill is relatively mature and solid, which is the development direction of modern railway. Foreign high-speed railway has a development history of many years, and China is now in the early stage of high-speed railway research and development. Due to the high speed of high-speed railway, once obstacles suddenly appear in front of the train, it is difficult to take emergency measures to effectively prevent accidents. Therefore, it is very important to fully consider and pay enough attention to the accident prevention system in the process of design, construction and operation management. Guangzhou Shenzhen (Guangzhou Shenzhen) railway is a quasi high-speed railway designed and put into operation for the first time in China; Qinhuangdao Shenyang (Qinhuangdao Shenyang) railway is the first high-speed passenger dedicated railway designed according to the technical standards of high-speed railway in China. Some measures to prevent accidents have been considered in the engineering design of these two lines, such as designing full vertical crossings, setting iron fences on both sides of the railway and other measures. However, systematic research measures have not been put forward for the accident prevention system of high-speed railway. As the possible accident factors of high-speed railway are various, the author puts forward some countermeasures and preventive measures based on the accident factors of speed control system, track fault prevention system, natural disaster accident prevention system and so on

2 speed control system

the running speed of trains is a matter of common concern to passengers and railway workers. The increase of train speed can significantly shorten the journey time. China's railway system has undergone several major speed-up transformations on the existing lines. However, "safety first" and "driving safety" are the prerequisites. Therefore, the improvement of speed or the design of high-speed or quasi high-speed railway should take safety first and passenger comfort as the highest principle, otherwise it is easy to cause traffic accidents. For example, the rollover accident of the "Beijing Qiqihar" express train (T72) at Hui'an station, which obtained the test results and test data of elongation, elongation, stress, strain, etc., was mainly caused by the rollover accident caused by the high speed of the train when entering the turnout. Therefore, with the increase of train speed, the relationship between speed and safety becomes more prominent. It is necessary to study a set of measures of train speed control system to control the speed within the specified speed in different sections and under different conditions

the author believes that the implementation method of the train speed control system is mainly to specify the design speed, inform the driver of the design speed, and abide by the design speed and deceleration principles

2.1 determination of design speed

each railway design line or operation line after speed increase has the maximum design speed of train operation. For example, the maximum design speed of Qinhuangdao Shenyang passenger dedicated line is 200km/h, including flanks and columns, doors, spoilers and seats. Without special speed restrictions, the maximum design speed can be reached, but the speed must be reduced in the following cases:

(1) when approaching the train in front

(2) when entering the station

(3) the radius of track curve is small

(4) poor track maintenance or poor track condition

the "Blue Arrow" EMU with a speed of 200km/h has been officially put into operation on Guangzhou Shenzhen railway on January 8th, 2001, marking the beginning of the construction of high-speed railway in China. Now, the analysis of the train speed control system is carried out under the operating condition of 200km/h. when running at this speed, the braking distance of the train is about 3 km on the horizontal plane and about 4km on the downhill section. If the train is to stop, the stop signal must be displayed before 5 kmg56 km, and the time difference between the driver recognizing the signal and starting braking must be taken into account to determine different braking distances. If the signal is 5 km to 6km away, the train will stop far away from the stop when it enters the area at a slow speed. Therefore, this area is divided into two parts - the first 3 km with a speed of 150km/h and the stop signal in the remaining stages

the speed of 150km/h is selected because the braking distance from 200km/h to 150km/h and from 150km/h to parking is basically the same. Within 3km of displaying the stop signal, its operation steps are as follows:

first display the signal below 30 km/h; Then reduce the vehicle speed to less than 30km/h; The stop signal will be displayed about 100m before the stop

this 3 km is called the taxiing area, and the track circuit is adopted, that is, the track is divided into an interval every 3 km as the conductor of the track circuit. When the train enters the taxiing area, the rail is short circuited by the wheel and axle, which indicates that the train is coming, and the signal of 30km/h is displayed in the next 3km, and 150km/h is displayed in the previous 3km

2.2 method of indicating the specified speed

in the traditional route design, the driver understands the specified speed according to the three color road signs on the roadside: blue line, yellow warning, red stop. When the train approaches the red light, an alarm will sound on the bridge to remind the driver to brake. If the driver does not do so, the train will start the automatic parking system

however, this method is not enough for high-speed railway. Because, first of all, when the train is running at the speed of 200km/h, it is almost impossible for the driver to distinguish the roadside signal; Secondly, because there are many speed limits, it is necessary to develop a set of automatic train control system, mark the specified speed on the dashboard of the bridge, and compare the actual speed with the specified speed. Since the actual speed is connected with the brake device, the brake will be automatically released when the actual speed is reduced to the specified speed

with this system, the control center can understand the location and train number of each train, and can quickly deal with it in case of any error in operation. Each train is equipped with this experimental machine, which is a reliable experimental instrument for colleges and universities to carry out "tribology" teaching and scientific research, so that the driver can contact the dispatcher directly

2.3 speed control system

deceleration control automation shows the characteristics of ATC (automatic train control) system speed control, that is, when the actual speed exceeds the specified speed, it will automatically decelerate to the specified speed, but when accelerating, it is only controlled by the driver, which is the only signal provided by the train. Moreover, the speed change of ATC automatic deceleration control is usually from 200 km/h to 30km/h, and the parking action is operated by the driver

in order to prevent the driver from speeding without slowing down in time, an overspeed protection device is installed 50m before the train stops completely. The stop signal transmitted by the device is received by the receiving antenna, resulting in automatic emergency braking of the train

3 track fault prevention system

when there are obstacles on the track, the train must stop. The obstacle in the way is the train in front, and the train behind will stop automatically through ATC, but when the obstacle is not a train, it cannot be displayed by ATC. As a rule, the driver often looks at the ground in front of him. Once an obstacle is found, he will stop with emergency braking. Moreover, the ground patrolman will report the obstacle to the driver by sending a signal. These methods are not enough for high-speed railway trains. Because of their high speed and long braking distance. Therefore, it is necessary to develop a system to identify obstacles and stop the train immediately

3.1 prevention of track failure

in traditional lines, most track obstacles occur at the intersection of railway and highway. The following preventive measures have been or are being used in some high-speed or quasi high-speed design or speed up reconstruction lines

(1) full grade separation, all railway and highway intersections are designed with full vertical roads

(2) set protective fences to prevent the truck goods from damaging the girder when the road passes under the track; When the road passes on the track, the car can be prevented from overturning

(3) fence the whole line to prevent people from walking inside, and prohibit illegal occupation of the track

3.2 track obstacle detection and train protection

in addition to the above preventive measures, the following methods should be used to deal with line obstacles

3.2.1 fault elimination indicator

in order to find cars or other vehicles breaking into the track, the indicator is installed near any other railway or highway. In case of failure, the device will automatically cut off the circuit and make ATC display the stop signal

3.2.2 emergency disposal when the patrolman finds that the train is dangerous

train protection switches are set every 250 m along the railway for the use of the patrolman. Push this switch in case of emergency, the track circuit will be short circuited, and a D C will display the stop signal

3.2.3 driver's protection of the train

the emergency ground switch installed on the train is controlled by the train driver. By cutting off the power supply of train operation, all nearby trains will stop running

3.2.4 other methods

a solid protector is installed at the front end of the train head, so that the train itself can remove obstacles from the track, such as stones

therefore, adopt facilities and practical methods to prevent cars or stones from falling on the track, and ensure that the foundation slope is more firm to prevent collapse

4 natural disaster accident prevention system

the route selection design in the early stage of railway construction is the fundamental to prevent and reduce railway natural disasters. During route selection, it is necessary to collect the meteorological historical data along the line, conduct field investigation, understand the climate change along the line, try to avoid the more serious frequent sections such as water damage, snow damage, wind damage, fog, etc., and try to choose the route direction parallel to the local main wind direction or at a small intersection angle. In case of natural disasters, it is necessary to adopt rapid and special methods in time. Natural disasters mainly include wind, rain, snow, earthquakes, landslides, landslides, etc. due to the vast territory of China, different regions have different emphasis on natural disasters

4.1 countermeasures for wind disasters

there are few train accidents caused by wind in China, but in areas like southeast and coastal areas where typhoons or monsoons often occur, it is necessary to study wind and train operation and accident prevention measures. Typhoons generally occur in late summer and early autumn, while monsoons occur in late winter and early spring when atmospheric pressure decreases. In most cases, the typhoon speed ranges from 20 m/s to 40 m/s, and in rare cases it can reach 50 m/s. The monsoon speed ranges from 15m/s to 20m/s. There are the following countermeasures to prevent wind damage:

(1) it is necessary to study the allowable safety limit value of the wind speed at which the train will not be overturned by the wind. Moreover, the standard of train running speed is also based on this principle

(2) the relationship between wind speed and train speed should be established to specify the speed at which the train can only travel when the wind speed reaches a certain value. When the wind speed exceeds the allowable safety limit, the train will stop running

(3) establish anemometer in places where strong winds or gales may occur, such as riverbed or mountain tops. The wind speed information is transmitted to the nearest station and automatically recorded

(4) when the wind speed exceeds a certain value, caution, warning and danger signals will be sent out respectively, and the alarm will be sounded at the station and local control center. After receiving these signals, the workers in the control center will instruct act to send signals to the relevant areas and report to the locomotive driver by radio

4.2 dealing with rainstorm and water

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