TB/T 2897-1998 English PDF (TBT2897-1998)

This Standard specifies the technical requirements, inspection rules and transportation, storage of sub-ballast for ballast bed of railways. This Standard applies to national railways; local railways and industrial enterprise railways may also refer to this Standard.

TB/T 2897-1998
TB
PROFESSIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
Sub-ballast for ballast bed of railways
ISSUED ON. FEBRUARY 24, 1998
IMPLEMENTED ON. SEPTEMBER 1, 1998
Issued by. Ministry of Railways of the People’s Republic of China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 References ... 4
3 Terms ... 4
4 Technical requirements ... 4
5 Inspection rules ... 6
6 Transportation, storage ... 8
Foreword
Sub-ballast is an important part of the ballast bed of railways and is located between the ballast layer of the ballast bed and the surface layer of the subgrade bed. It plays the role of transmitting and distributing the train loads, preventing mutual penetration of top-ballast and surface layer particles of subgrade bed, water seepage transition and antifreeze-and-insulation. In the past, China borrowed the experience of using river sands as sub-ballast from the former Soviet Union. Since there is no material standard, the above-mentioned functions of the sub-ballast cannot be guaranteed and the material source of the sub-ballast is limited. On the basis of reference to the relevant standards such as the sub-ballast material standards of the United States Railway Engineering Association (AREA), Japan railway subgrade bed surface layer (JISA5001 particle size transitional gravel layer) material standards, combining China's national conditions and railway situation, this Standard is developed.
This Standard is proposed by Railway Engineering Research Institute of China Academy of Railway Sciences.
This Standard is under the jurisdiction of Institute of Standard Metrology of National Railway Administration of the People’s Republic of China.
Railway Engineering Research Institute of China Academy of Railway Sciences is responsible for the drafting of this Standard.
Main drafters of this Standard. Zeng Shugu, Zhang Wensheng, Xu Yongxian, Wang Hong, Liu Zengjie.
Sub-ballast for ballast bed of railways
1 Scope
This Standard specifies the technical requirements, inspection rules and transportation, storage of sub-ballast for ballast bed of railways (hereinafter referred to as sub-ballast). This Standard applies to national railways; local railways and industrial enterprise railways may also refer to this Standard.
2 References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below.
TB/T 2140-90 Railway ballast
TB/T 2328.1~18-92 Test method for railway ballast
3 Terms
The plasticity index Ip. the plasticity index is equal to the difference between the liquid limit LL and the plastic limit PL.
Ip = LL - PL
4 Technical requirements
4.1 Sub-ballast material may be taken from natural gravel material, or may be taken from rocks or natural pebbles, gravels by crushing, screening.
4.2 Sub-ballast material’s particle size grading shall comply with the provisions of Table 1, and the particle content of fine aggregate below 0.5 mm sieve that pass through the 0.075 mm sieve shall be less than or equal to 66 %. The matching of the particle size grading of sub-ballast material with the particle size grading of the ballast layer in the ballast bed and the surface layer of the subgrade bed is shown in Figure1. 4.4.4 The mass percentage of clay and other impurities is less than or equal to 0.5 %. 5 Inspection rules
Sub-ballast material shall be subjected to type inspection and production inspection. The type inspection is a ministerial level, and the production inspection is a bureau level.
5.1 Type inspection
5.1.1 When establishing the sub-ballast material mining and processing base, the particle size grading and material property inspection of the finished product shall be carried out by the designated organization of the National Railway Administration of the PRC according to the requirements of 4.2 to 4.4. Approved by the competent department of the National Railway Administration of the PRC and issued sub-ballast mining qualification certificate before production.
5.1.2 Sampling
Divide the mining resource zone by the commissioned mine organization, and develop appropriate mining and processing procedures by the construction organization. In each given resource zone, 400 kg of representative samples are processed according to the developed mining and processing procedures, which is submitted to the designated organization of the National Railway Administration of the PRC for inspection
5.1.3 When the resource zone changes significantly, and the quality of sub-ballast cannot meet the requirements of this Standard, it shall carry out type inspection again. 5.2 Production inspection
5.2.2 According to the requirements of 4.2 to 4.4, the production organization carries out an inspection when every 4 × 104 m3 of sub-ballast are produced. If the annual output is less than 4 × 104 m3, the inspection shall be carried out once a year. 5.2.2 Sampling
Sub-ballast material samples are taken from the finished product discharge port or finished product transport belt. Take four sub-samples at intervals, with each sub- sample weigh about 100 kg and total weight of 400 kg, to send to the inspection department for inspection.
5.2.3 For sub-ballast material’s particle size grading and clay content indicators, in addition to inspect once a week, each production shift shall be monitored by visual inspection. If any problem is found, it shall inspect and handle promptly. Monitoring and inspection results shall be filled in the production diary, as the basis for the