CN104131500B - A method and device for detecting the compactness of bulk ballasted bed - Google Patents

Abstract

The invention discloses a method and a device for detecting the compactness of a loose ballasted bed, in particular to a new method and device for detecting the compactness of a ballasted bed, by measuring the change of the contact force between the contact plate at the bottom of the sleeper and the ballast The method for judging the compactness of a bulk ballast bed belongs to the technical field of railway engineering ballasted track bed detection; the invention is used in two environments in the field and indoors to solve the problem of measuring the compactness of a bulk ballasted track bed. The main functions that can be realized by the present invention include: detecting the compactness of the ballast bed without destroying the shape of the ballast bed; realizing real-time monitoring of dynamic compactness parameters of the ballasted ballast bed. The beneficial effects that can be realized by the present invention are as follows: the test structure is simple, it is convenient to arrange on the railway site, and it is convenient to operate, which can reduce manual auxiliary work, the test process is not restricted by external environmental factors, and the test work efficiency and accuracy are improved.

Description

A method and device for detecting the compactness of bulk ballasted bed

technical field

The invention relates to a method for detecting the compactness of a bulk ballasted ballast bed and a device for use, which is suitable for detecting the density of a new railway track bed and the compactness of an old line after tamping operations, and is used for judging the compactness of a ballast bed, belonging to railways Technical field of engineering track bed detection.

Background technique

The compactness of the ballast bed refers to the degree to which the particles are arranged and compacted with each other. It is defined as: compactness = volume of solid particles/total volume of granular structures (%). The compactness of the ballast bed is the main parameter to measure the working state and bearing capacity of the ballast bed, and to test the tamping quality of the road maintenance machinery. The traditional on-site measurement methods of compactness include sand filling method and water filling method. The irrigation method is the basic method used by various countries to measure the compactness, and its basic principle is shown in Figure 5; by the formula Get the density of the bed , where , is the volume of water as shown in Figure 5(3) and (5), is the real volume of W ballast in Fig. 5(4). The disadvantages of the irrigation method are that the location of the measuring points is limited, the implementation process is complicated, the accuracy is low, and it is difficult to implement under driving conditions. Another method is to use γ-rays to measure the compactness of the ballast bed, but this method cannot be widely used due to the existence and use of radiation sources. In view of the above reasons, the measurement method of the compactness of the bulk ballast bed is still a difficult problem in the field of railway engineering detection technology.

Contents of the invention

The invention provides an on-site and indoor dual-purpose method for detecting the compactness of a bulk ballasted track bed, which is used for non-destructive testing of the compactness of a bulk ballasted track bed, so as to overcome the defects of low measurement accuracy and difficult implementation of the existing measurement methods.

The specific operation of the method of the present invention is: measure the contact strength value between the bottom of the sleeper and the ballast in 5-10s, calculate the average value of each contact strength value to obtain the contact strength average value , to calculate the average contact intensity with specific measurements difference between ,pass Calculate the difference ratio , take the difference ratio The absolute value of ;when When , it is judged that the compactness of the bulk ballast bed is dense; when , it is judged that the compactness of the bulk ballast bed is generally compact; when When , it is judged that the compactness of the bulk ballast bed is loose; the specific measured value It is the contact strength value measured after the newly built ballast bed reaches a dense state.

The contact strength value refers to the ratio of the contact force between the bottom of the sleeper and the ballast to the contact area.

The method for detecting the compactness of the ballasted ballast bed in bulk can be used for testing the compactness of the ballast bed in an indoor test, and can also be used for monitoring the compactness of the track bed in an outdoor on-site railway track.

Another object of the present invention is to provide a special measuring sleeper for the method of detecting the compactness of loose ballasted ballast beds, which includes a sleeper 1, a mounting bar 2, a mounting seat plate 3, a buffer spacer 4, a pressure sensor 5, and a protection plate 6. Sensor trunking 7, of which 4 installation strips 2 are fixed on the bottom surface of sleeper 1, sensor trunking 7 is installed on installation strip 2, installation seat plate 3 is installed on sensor trunking 7, buffer spacer 4 is set on installation seat plate 3 and the protective plate 6, and the three plates are fixed by bolts, 4-8 pressure sensors 5 are installed in the seat hole of the seat plate 3, and pass through the buffer spacer 4 to contact the protective plate 6, the pressure sensor The signal transmission line of 5 passes to the ballast outside by sensor line groove 7.

The buffer spacer 4 is a polyurethane buffer spacer.

The special measurement sleeper can be arranged in the indoor test device, and can also be arranged in the actual circuit on site.

The special measuring sleeper is in the actual line on site, and its function can replace the ordinary sleeper so as to monitor the compactness of the ballasted bed in the on-site environment.

The pressure sensor 5 is a conventional commercially available standard pressure sensor with strong impact resistance and overload capability.

The steps for using the special-purpose measuring sleeper are:

1) Install special measuring sleepers in the area of the tested railway track bed on new or existing railway lines and arrange signal transmission cables, centrally set the external connection interfaces of cables, and install them in the way that special measuring sleepers and ordinary sleepers are arranged at intervals, each Arrange 3 to 5 special measuring sleepers in the measured area to ensure the contact between the sensor protection plate 6 and the ballast at the bottom of the sleeper; or repeat the above installation steps in the area of the ballasted ballast bed for indoor testing;

2) The newly-built or existing railway lines go through the process of stable operation, actual train trial run, and operation, that is, the train cyclic load loading process is implemented; the bulk ballasted ballast bed in the indoor test is mainly compacted through the simulated cyclic loading test; through the above process, the bulk When the ballasted bed reaches a dense state, the degree of compactness can be tested by the traditional irrigation method or the γ-ray method;

3) At the same time, according to the following steps 4)~9), measure the contact strength value between the bottom of the ordinary sleeper or the special measurement of the contact strength between the bottom protection plate of the sleeper and the ballast within 5-10s and take the average to obtain the specific measurement value As a follow-up measurement reference, the same track bed is usually calibrated once, and the follow-up measurement is carried out after half a year or temporarily adjusted according to the line usage;

4) Before the measurement, connect the dynamic signal testing instrument and the pressure sensor in the special measuring sleeper (or the pressure sensor at the bottom of the ordinary sleeper) through the external interface of the signal transmission cable, and connect the dynamic signal testing instrument and the computer through the data transmission line. The portable mobile power supply is Dynamic signal testing instrument and computer provide power supply;

5) Conduct joint debugging of sensors, dynamic testing instruments, computer software and hardware, and test preparations are ready;

6) The working conditions, test area and load state during the measurement shall be consistent with those used during the measurement in step 3);

7) During measurement, the sensor protection plate 6 is in direct contact with the ballast at the bottom of the pillow, the external load is transmitted to the pressure sensor 5 through the sensor protection plate 6, and the polyurethane buffer spacer 4 plays the role of buffering and reducing impact while ensuring that the sensor protection plate 6 can contact the working surface of the pressure sensor 5;

8) Data collection, the data signal measured by the pressure sensor is transmitted to the computer through the transmission cable, the dynamic signal testing instrument, and the data transmission line, and is analyzed and extracted through the control software. -Contact intensity value within 10s to complete data collection;

9) Data analysis, the average calculation of the obtained 5-10s contact strength value data is obtained ;

10) According to the measured and previously obtained , calculated according to the method of the present invention ,according to The results determine the compactness of the track bed, and then repeat steps 4) to 10) in the above steps to complete the measurement of the compactness of the track bed at different stages of use.

According to the existing railway bulk ballast bed construction standards and ballast bed compactness determination rules, after the bulk ballast bed reaches a dense state after the load cycle loading action, the distance between the bottom of the sleeper and the ballast is measured according to the implementation steps of the method of the present invention. The contact intensity value within 10s is averaged to obtain a specific measurement value , as a reference for subsequent ballast bed compactness measurement.

The present invention has the following beneficial effects:

1. This test method is applicable to both the indoor ballast bed compactness test in the laboratory and the on-site actual line ballast bed compactness measurement. At the same time, it can monitor the ballast bed compactness change in real time;

2. The test process of this detection method is easy to implement and standardize, so the test results are limited by the operator's own operating level, thereby improving the measurement accuracy;

3. The test process is simple and easy to learn, and the analysis process and judgment standards are easy to standardize, so manual assistance can be reduced during the test process, thereby improving test work efficiency;

4. The measurement method and device are not limited by time, place and external natural environmental factors.

5. The special measuring sleeper provided by the present invention has a simple structure, and its external dimensions and basic functions are equivalent to ordinary sleepers, but the sensor structure installed inside it can be used to measure the compactness of ballasted ballast bed in bulk;

6. The special measuring sleeper can be arranged in the indoor test device instead of the ordinary sleeper in the actual line on site, and can also be set in the actual line on site.

Description of drawings

Fig. 1 is the cross-sectional structure schematic diagram of special measuring sleeper of the present invention;

Fig. 2 is the axonometric explosion schematic diagram of the special measuring sleeper of the present invention;

Fig. 3 is the local cross-sectional structure schematic diagram of the special measuring sleeper of the present invention;

Fig. 4 is a schematic diagram of the use state of the special measuring sleeper of the present invention;

Fig. 5 is a schematic diagram of the principle of measuring the compactness of the track bed by the irrigation method of the present invention;

In the figure: 1-sleeper; 2-installation bar; 3-seat plate installation; 4-buffer spacer; 5-pressure sensor; 6-sensor protection plate; 7-sensor trunking; 8-ordinary sleeper; 9-dynamic signal Test instrument; 10-data transmission line; 11-computer; 12-signal transmission line; 13-special measuring sleeper; 14-rail.

detailed description

The patent of the present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the content of the patent of the present invention is not limited to the scope.

Embodiment 1: This bulk ballasted ballast bed density detection method is used as an indoor test ballast bed compactness detection. The test object is a new bulk ballasted ballast bed in the laboratory. The ballast material is ordinary limestone graded ballast. After completion, after 50 10,000 cycles of indoor cyclic loading and compaction, the details are as follows:

By measuring the contact strength value between the protective plate at the bottom of the sleeper and the ballast within 5s, the contact strength value is collected every 0.1s, and the average value of each contact strength value is calculated to obtain the average value of the contact strength , to calculate the average contact intensity with specific measurements difference between ,pass Calculate the difference ratio , take the difference ratio The absolute value of ;The measured results are as follows: measurement time 5s, specific measurement value =45MPa, average contact strength =42.4MPa, =5.78%, 5%<5.78%<10%, so it is judged that the track bed under test is basically dense; the above measurement and analysis process takes 2 hours in total.

In this embodiment, the structure of the special measuring sleeper used for the compactness detection method of the bulk ballasted track bed is shown in Figure 1-4. The special measuring sleeper includes a sleeper 1, a mounting strip 2, a mounting seat plate 3, a polyurethane buffer spacer 4, Pressure sensor 5, protective plate 6, sensor wire slot 7, among which 4 installation strips 2 are fixed on the bottom surface of sleeper 1, sensor wire slot 7 is installed on installation bar 2, installation seat plate 3 is installed on sensor wire slot 7, polyurethane buffer spacer The pad 4 is arranged between the installation seat plate 3 and the protection plate 6, and the three plates are fixed by bolts, and the four pressure sensors 5 are installed in the seat holes of the installation seat plate 3, and pass through the polyurethane buffer spacer 4 and the protection plate. The plate 6 contacts, and the signal transmission line of the pressure sensor 5 passes through the sensor line groove 7 to the outside of the ballast.

The special measurement sleeper is arranged in the indoor test device, and the pressure sensor 5 is an AK-4B pressure sensor.

Install 3 special measurement sleepers in the track bed area of the railway under test, and install them according to the arrangement of special measurement sleepers 13 and ordinary sleepers 8 at intervals; the rail 14 is set above the special measurement sleepers and ordinary sleepers; during measurement, the AK-4B pressure sensor 5 passes The signal transmission line 12 is connected with the DH5923 dynamic signal testing instrument, the sensor protection plate 6 is directly in contact with the ballast, the contact force is transmitted to the pressure sensor 5 through the sensor protection plate 6, and the polyurethane buffer spacer 4 plays the role of buffering and reducing the impact while ensuring transmission. Protection plate 6 can contact the working face of pressure sensor 5; Pressure sensor 5 measures signal and transmits to computer 11 through signal transmission line 12, dynamic signal testing instrument 9, data transmission line 10, and test is as follows as follows:

1) Install special measuring sleepers in the ballasted bed area of the indoor test and arrange the signal transmission cables, and centrally set the external connection interface of the cables, and install them according to the interval between the special measuring sleepers and ordinary sleepers. Each measured area is arranged 3 a special measuring sleeper to ensure contact between the sensor protection plate 6 and the ballast at the bottom of the sleeper;

2) Carry out a cyclic loading test on the ballasted ballast bed of the indoor test to make it reach a compact state, and test its compactness through the traditional irrigation method to be compact;

3) At the same time, according to the following steps 4)~9), measure the contact strength value between the protective plate at the bottom of the special measurement sleeper and the ballast within 5s and take the average to obtain a specific measurement value =45MPa as the follow-up measurement reference, and the follow-up measurement interval is half a year;

4) Before the measurement, connect the dynamic signal testing instrument and the pressure sensor in the special measuring sleeper through the external interface of the signal transmission cable, connect the dynamic signal testing instrument and the computer through the data transmission line, and pass; the portable mobile power supply is provided for the dynamic signal testing instrument and the computer. power supply;

5) Conduct joint debugging of sensors, dynamic testing instruments, computer software and hardware, and test preparations are ready;

6) The working conditions, test area and load state during the measurement shall be consistent with those used during the measurement in step 3);

7) During measurement, the sensor protection plate 6 is in direct contact with the ballast at the bottom of the pillow, the external load is transmitted to the pressure sensor 5 through the sensor protection plate 6, and the polyurethane buffer spacer 4 plays the role of buffering and reducing impact while ensuring that the sensor protection plate 6 can contact the working surface of the pressure sensor 5;

8) Data collection, the data signal measured by the pressure sensor is transmitted to the computer through the transmission cable, the dynamic signal testing instrument, and the data transmission line, and is analyzed and extracted through the control software. -Contact intensity value within 10s to complete data collection;

9) Data analysis, the average calculation of the obtained 5s contact strength value data is obtained =42.4MPa;

10) Follow the above steps 4)~10) to obtain , according to the measured and previously obtained , calculated according to the method of the present invention =5.78%, 5%<5.78%<10%, according to As a result, it was determined that the density of the track bed measured was basically dense; the follow-up density monitoring took half a year as a measurement cycle or adjusted according to the line conditions.

Analysis of test results:

At the same time, the conventional irrigation method is used to detect the above-mentioned bulk ballast bed, and the result is that the ballast bed is basically dense, and the water irrigation method takes 8 hours to measure in total. Compared with the two, the test results of the method of the present invention are basically consistent with the traditional water irrigation method, and the test time is shortened. 1/4 of.

Embodiment 2: This loose body has ballast bed compactness testing method, and this method is used as the track bed compactness monitoring of outdoor on-site railway line, and the test object is the ballast bed of outdoor on-site railway line, and ballast material is ordinary granite graded track bed, built After nearly a year of repeated operation of trains, an average of 20 passenger and freight trains per day are mixed. The details are as follows:

By measuring the contact strength value between the protective plate at the bottom of the sleeper and the ballast within 8s, the contact strength value is collected every 0.1s, and the average value of each contact strength value is calculated to obtain the average value of the contact strength , to calculate the average contact intensity with specific measurements difference between ,pass Calculate the difference ratio , take the difference ratio The absolute value of ;The measured results are as follows: measurement time 5s, specific measurement value =47.5MPa, the average contact strength =44.69MPa, =5.92%, 5%<5.92%<10%, so it is judged that the measured track bed is basically dense; the above measurement and analysis process took a total of 4 hours.

In this embodiment, the special measuring sleeper used for the detection method of compactness of loose ballasted ballast bed includes sleeper 1, installation strip 2, installation seat plate 3, polyurethane buffer spacer 4, pressure sensor 5, protection plate 6, sensor wire slot 7 , wherein four installation strips 2 are fixed on the bottom surface of the sleeper 1, the installation strip 2 is equipped with a sensor wire groove 7, the installation seat plate 3 is installed on the sensor wire groove 7, and the polyurethane buffer spacer 4 is arranged on the installation seat plate 3 and the protection plate 6 Between, and the three boards are fixed by bolt connection, four pressure sensors 5 are installed in the seat hole of the installation seat plate 3, and pass through the polyurethane buffer spacer 4 to contact the protection plate 6, the signal transmission line of the pressure sensor 5 passes through the sensor Line groove 7 leads to ballast outside.

The model of the pressure sensor 5 is DH1003B pressure sensor.

The special measuring sleeper is in the actual line on site, and its function can replace the ordinary sleeper so as to monitor the compactness of the ballasted bed in the on-site environment.

Install 5 special measuring sleepers in the track bed area of the tested railway, and install them according to the interval arrangement between special measuring sleepers and ordinary sleepers; the rails are set above the special measuring sleepers and ordinary sleepers; during measurement, DH1003B pressure sensor 5 communicates with DH5920N through signal transmission line 12 The dynamic signal testing instrument is connected, the sensor protection plate 6 is in direct contact with the ballast, the contact force is transmitted to the pressure sensor 5 through the sensor protection plate 6, and the polyurethane buffer spacer 4 plays the role of buffering and reducing the impact while ensuring that the transmission protection plate 6 can contact To the working surface of the pressure sensor 5; the signal measured by the pressure sensor 5 is transmitted to the computer 11 through the signal transmission line 12, the dynamic signal testing instrument 9, and the data transmission line 10; the test is as follows as follows:

1) Install special measuring sleepers in the track bed area of the tested railway on the newly built outdoor railway line and arrange the signal transmission cables. 5 special measuring sleepers are arranged in the area to ensure the contact between the sensor protection plate 6 and the ballast at the bottom of the sleeper;

2) Carry out real train operation on the newly built railway line, that is, implement the train cyclic load loading process, through the above process, make the loose ballasted track bed reach a dense state; the degree of compactness is tested by the traditional irrigation method;

3) At the same time, according to the following steps 4)~9), measure the contact strength value between the protective plate at the bottom of the special measurement sleeper and the ballast within 8s and take the average to obtain a specific measurement value =47.5MPa as the follow-up measurement reference, and the follow-up measurement interval is half a year;

4) Before the measurement, connect the dynamic signal testing instrument and the pressure sensor in the special measuring sleeper through the external interface of the signal transmission cable, connect the dynamic signal testing instrument and the computer through the data transmission line, and pass; the portable mobile power supply is provided for the dynamic signal testing instrument and the computer. power supply;

5) Conduct joint debugging of sensors, dynamic testing instruments, computer software and hardware, and test preparations are ready;

6) The working conditions, test area and load state during the measurement shall be consistent with those used during the measurement in step 3);

7) During measurement, the sensor protection plate 6 is in direct contact with the ballast at the bottom of the pillow, the external load is transmitted to the pressure sensor 5 through the sensor protection plate 6, and the polyurethane buffer spacer 4 plays the role of buffering and reducing impact while ensuring that the sensor protection plate 6 can contact the working surface of the pressure sensor 5;

8) Data collection, the data signal measured by the pressure sensor is transmitted to the computer through the transmission cable, the dynamic signal testing instrument, and the data transmission line, and is analyzed and extracted through the control software. -Contact intensity value within 10s to complete data collection;

9) Data analysis, the average calculation of the obtained 8s contact strength value data is obtained =44.69MPa;

10) Follow the above steps 4)~10) to obtain , according to the measured and previously obtained , calculated according to the method of the present invention =5.92%, 5%<5.92%<10%, according to As a result, it was determined that the density of the track bed measured was basically dense; the follow-up density monitoring took half a year as a measurement cycle or adjusted according to the line conditions.

Analysis of test results:

At the same time, the conventional irrigation method was used to test the above-mentioned bulk ballast bed, and the result was that the ballast bed was basically dense, and the water irrigation method took a total of 15 hours to measure. Compared with the two, the test result of the method of the present invention is basically the same as that of the traditional irrigation method, and the test time is shortened to nearly 1/4 of the original.

Embodiment 3: This loose body has ballast bed compactness detection method, and this method is used as indoor test ballast bed compactness detection, and test object is that newly-built loose body has ballast bed in laboratory, and ballast material is ordinary granite rock gradation ballast, After completion, it has undergone 1 million cycles of indoor cyclic loading and compaction. The specific methods are as follows:

First place a pressure sensor under the ordinary sleeper. The pressure sensor and its circuit must be protected. By measuring the contact strength value between the bottom of the sleeper and the ballast within 10s, the contact strength value is collected every 0.1s, and the average value of each contact strength value is calculated. Contact Intensity Mean , to calculate the average contact intensity with specific measurements difference between ,pass Calculate the difference ratio , take the difference ratio The absolute value of ;The measured results are as follows: measurement time 10s, specific measurement value =45MPa, average contact strength =43.6MPa, =3.11%, 3.11%<5%, so it is determined that the track bed under test is dense, and the above measurement and analysis process takes 2 hours in total.

At the same time, the conventional irrigation method was used to test the above-mentioned bulk ballast bed, and the result was that the ballast bed was basically dense, and the water irrigation method took a total of 8 hours to measure. Compared with the two, the test result of the method of the present invention is basically the same as that of the traditional irrigation method, and the test time is shortened to 1/4 of the original.

The model of the pressure sensor 5 is AK-3B pressure sensor.

The measurement is carried out as follows:

1) Install the pressure sensor in the ballast bed area of the indoor test bulk and arrange the signal transmission cable, centrally set the external connection interface of the cable, select 4 ordinary sleepers at intervals for each tested area and arrange the pressure sensor at the bottom to ensure the sensor works contact between the surface (protected) and the ballast under the pillow;

2) Carry out a cyclic loading test on the ballasted ballast bed of the indoor test to make it reach a compact state, and test its compactness through the traditional irrigation method to be compact;

3) At the same time, according to the following steps 4)~9), measure the contact strength value between the pressure sensor working surface (protected) and the ballast at the bottom of the ordinary sleeper within 8s and take the average to obtain a specific measurement value =45MPa as the follow-up measurement reference, and the follow-up measurement interval is half a year;

4) Before measurement, connect the dynamic signal testing instrument and the pressure sensor through the external interface of the signal transmission cable, and connect the dynamic signal testing instrument and the computer through the data transmission line; the portable mobile power supply provides power for the dynamic signal testing instrument and the computer;

5) Conduct joint debugging of sensors, dynamic testing instruments, computer software and hardware, and test preparations are ready;

6) The working conditions, test area and load state during the measurement shall be consistent with those used during the measurement in step 3);

7) During measurement, the working surface of the pressure sensor (protected) is in direct contact with the ballast under the pillow, and the external load is transmitted to the pressure sensor through the working surface of the pressure sensor (protected);

8) Data collection, the data signal measured by the pressure sensor is transmitted to the computer through the transmission cable, the dynamic signal tester, and the data transmission line to complete the data collection;

9) Data analysis, the average calculation of the obtained 10s contact strength value data is obtained =43.6MPa;

10) Follow the above steps 4)~10) to obtain , according to the measured and previously obtained , calculated according to the method of the present invention =3.11%, 3.11%<5%, according to As a result, it is determined that the density of the measured track bed is dense; the follow-up density monitoring takes half a year as a measurement cycle or adjusts according to the line conditions.

Claims (3)

1. a prose style free from parallelism ballast track bed compactness inspection method, is characterized in that: measure at least two contact strength values bottom sleeper and between ballast aggregate in 5-10s, the average calculating each contact strength value obtains contact strength average , calculate contact strength average with particular measurement value between difference , pass through calculated difference ratio , get difference ratio thoroughly deserve ; When time, judge that the compaction rate of prose style free from parallelism railway roadbed is as closely knit; When time, judge that the compaction rate of prose style free from parallelism railway roadbed is as generally closely knit; When time, judge that the compaction rate of prose style free from parallelism railway roadbed is as loose; Wherein said particular measurement value for newly-built railway roadbed reach dense state after the contact strength value that records.

2. for the special measurement sleeper of prose style free from parallelism ballast track bed compactness inspection method described in claim 1, it is characterized in that: comprise sleeper (1), mounting bar (2), installation seat plate (3), buffering dottle pin (4), pressure sensor (5), guard shield (6), sensor wire casing (7), article 4, mounting bar (2) is fixed on sleeper (1) bottom surface, sensor wire casing (7) mounting bar (2) is equipped with, installation seat plate (3) is contained on sensor wire casing (7), buffering dottle pin (4) is arranged between installation seat plate (3) and guard shield (6), and three blocks of plates are bolted fixing, 4-8 pressure sensor (5) is installed in the bore of installation seat plate (3), and contact with guard shield (6) through buffering dottle pin (4), the signal transmssion line of pressure sensor (5) passes to ballast aggregate outside by sensor wire casing (7).

3. the special measurement sleeper of prose style free from parallelism ballast track bed compactness inspection method according to claim 2, is characterized in that: buffering dottle pin (4) is polyurethane buffering dottle pin.