Is code for blanketing material?
4 During widening of bank in case of gauge conversion and rehabilitation of unstable formation, compaction of blanket layer should be minimum 95% of MDD as obtained by Laboratory test as per Heavy Compaction Test (IS: 2720 (part 8) – 1983) or 70% Relative Density for cohesionless soil (IS: 2720 ( Part 14) – 1983).
What is Railway blanket material?
Blanketing material – is a selected well graded soil obtained naturally or by blending two or more soil and placed between sub- grade and ballast in Railway formation.
What type of soil is best suited as subgrade in railway track?
These sand-fiber composite mixed with 25% of moorum by weight of sand may suit best as subgrade material for Railway track having CBR greater than 20%. 2. It can also be noticed that Moorum (25%) and Medium sand (75%) composite is well within the two enveloping curves given in fig.
What is SQ1 soil?
SQ1 (fines >50%), SQ2 (fines: 12 to 50%), SQ3 (fines <12%) Consideration for Blanket thickness (25T) Blanket and its Functions. Blanket is a quality soil between the ballast and the sub-grade with main functions.
What is the full form of Rdso?
Central Standards Office (CSO) and the Railway Testing and Research Centre (RTRC) were integrated into a single unit named Research Designs and Standards Organisation (RDSO) in 1957, under Ministry of Railways at Lucknow.
What is subgrade railway?
In transport engineering, subgrade is the native material underneath a constructed road, pavement or railway track (US: railroad track). It is also called formation level. The term can also refer to imported material that has been used to build an embankment.
Why ballast is used in railway track?
Track ballast forms the trackbed upon which railroad ties (sleepers) are laid. It is used to bear the load from the railroad ties, to facilitate drainage of water, and also to keep down vegetation that might interfere with the track structure. Ballast also holds the track in place as the trains roll over it.
Why the Moorum can be used as a blanketing material for black cotton soil?
Why the moorum can be used as a blanketing material for black cotton soil? Explanation: Moorum prevents percolation of water in formation. This percolated water can lead to softening of formation. Moorum can also be used as initial ballast or sub ballast.
What is the work of RDSO?
RDSO is the sole R&D organisation of Indian Railways and functions as the technical advisor to Railway Board Zonal Railways and Production Units and performs the following important functions : Development of new and improved designs. Development,adoption, absorption of new technology for use on Indian Railways.
How many RDSO are there in India?
32 Directorates
RDSO has 32 Directorates for smooth functioning. All the directorates of RDSO, except Quality Assurance field Units, are located at Lucknow.
What is rail formation?
Formation. The formation (also called subgrade level) is the ground surface prepared to support the track surface. It is the top layer of the extended subsoil. A subgrade protection layer applied to the formation is an integral part of track construction today.
What is GSB in road construction?
Granular Sub-base (GSB) consists of laying and compacting well graded material on prepared sub-grade in accordance with the specifications.: GSB layer is intermediate layer in between Sub-grade and Wet mix macadam. GSB layer is laid in roads and higway works due to its properties .
When did RDSO issue guidelines for earthwork in railway projects?
Geo-technical Engineering Directorate of RDSO had already issued Guidelines for execution of earthwork in Railway projects in year 1970, which were revised subsequently, in year 1978 and 1987. Guidelines for earthwork in conversion projects were also issued in 1995.
How long has RDSO been involved in substructure research?
RDSO has been involved with research and standardization aspects of substructure for the last few decades. Various guidelines have been issued from time to time covering different aspects of track foundation.
What kind of track system does RDSO use?
This calls for a sound track system, both superstructure and substructure. RDSO has been involved with research and standardization aspects of substructure for the last few decades. Various guidelines have been issued from time to time covering different aspects of track foundation.
How big of a fine can a blanket be?
Blanket material should generally conform to following specifications : It should be coarse, granular and well graded. Skip graded material is not permitted. Non-plastic fines (particles of size less than 75 micron) are limited maximum to 12%, whereas plastic fines are limited maximum to 5%.