The Central Railway has found a way to overcome the flooding of tracks at Masjid railway station, which is lower than the ground level. It was decided to lay a 1000 mm diameter RCC pipe by micro-tunnelling method without disturbing rail movement. This method has given good results at the Sandhurst Road station area, where an 1800mm diameter RCC pipe was laid for 425-meter length connecting the west side to the east side across railway tracks.
A meeting was held in coordination with the Municipal Commissioner and Divisional Railway Manager in February 2021, where it was decided to go ahead with the project to prevent flooding of tracks during monsoon. The situation worsens during high-intensity rainfall coupled with high tide, inadequate capacity of the culvert, lower stormwater drainage network carrying capacity.
This project, which covers both the railway and municipal areas, started at the end of April 2021 in coordination with railways. The work in the railway area was completed recently. Work of connection of newly laid RCC pipe with MCGM network is in progress by MCGM, and the same is likely to be completed by this month-end. Stormwater will be bypassed through this newly laid RCC pipe culvert once the whole project is completed, preventing stormwater from coming inside railway premises and eliminating the flooding of tracks. Similar work of micro-tunnelling in coordination with civic authorities has already been successfully completed at Sandhurst road station and the Dadar-Parel area during the monsoon period this year.
Shri Anil Kumar Lahoti, General Manager, Central Railway, said that Micro-tunnelling is a proven technology widely adopted and recently tried, tested and executed at the Sandhurst Road railway station area. The Railway portion micro-tunnelling work at Masjid railway station has been completed in a very short period. This will help prevent waterlogging during the monsoon at Masjid railway station.
The activities carried out include a detailed topographical survey to fix the level of pipe, survey to find out underground obstruction, geological survey by taking bore logs, construction of jacking and receiving pit, aligning and setting up a micro- tunnelling boring machine, casting and testing of 1000mm dia RCC jacking standard pipes, and laying of RCC jacking pipe by micro tunnelling boring machine.
During the execution of work, an old stone British-era masonry duct was encountered in the alignment of the micro tunnelling boring path. Due to hollow stone masonry duct, feed water not coming back as slurry restricting the removal of bored muck through a slurry line to slurry tank. This prevented bored muck in the form of crushed stone pieces getting jammed in a slurry line frequently.
There was a very hard rock encountered in the same alignment. To counter it and lower the time limit to finish the project, special machinery of horizontal directional drilling was deployed to weaken the rock mass by making various sizes of holes in the hard rock mass and ultimately enlarging them to complete the periphery to speed up the work being done.