Contributed by Mr. Rushi Randeria, M.Tech (MIT-WPU, Pune)
As a part of curriculum for M.Tech. Tunnel Engineering at Maharashtra Institute Of Technology World Peace University (MIT WPU), Pune, Maharashtra. Internship was arranged with Mumbai Metro Rail Corporation Ltd. (MMRCL) at Mumbai Metro Line – 3 (MML-3). The students of MIT WPU were allotted different packages at the beginning of internship. As planned by Tunnelling Association Of India young members (TAIym) in association with MIT WPU and Hindustan Construction Company (HCC), young members of the organization were invited for one day site visit to MMRCL MML-3, Package 2 (CSMT to Grant Road) on 12th June 2019. On reaching the site on appointed date we were greeted by HCC officials Mr. Nandan Kumar (Planning Manager), Ms. Pooja Salunkhe (Design Engineer), Mr. Klaus Munz (Technical Consultant – Tunnel & NATM), Mr. Eugene Olenchik (Construction Manager Tunnels). After a brief personal introduction we were served with refreshments.
Thereafter the Safety Engineer gave us a brief information on tunnel safety with a pinch of humor, after finishing with the safety induction we were given Personal Protection Equipments (PPE’s) and were escorted to the shaft entrance by Mr. Nandan. On the way to the shaft entrance Mr. Nandan gave us a detailed information on pre-cast concrete segments such as Various types of segments (Key Segment, Counter Key Segment & universal segment), Structural Properties, Importance & function of gasket & how the segments are laid in curve section of tunnel. On reaching the shaft entrance we were directed to the tunnel portal where we received token as an identity & for record purpose.
Before boarding the electrically powered locomotive Mr. Eugene gave us a brief information on tunnel geometrics, tunnel excavation technique & other technical aspects involved in mining/excavation by dual mode hard rock tunnel boring machine.
On reaching the rear end of the TBM we were directed to the TBM operator’s cabin wherein Mr. Eugene familiarized us with all the controls on the control panel present in the cabin. Thereafter Mr. Nandan gave us in- depth information of how the geological samples are obtained & function of screw- conveyor in open as well as closed mode, thrust jacks & articulation cylinder.
Thereafter were escorted to the rear end of the cutter-head where Mr. Nandan along with Mr. Eugene explained in detail various components & working of Dual mode Hard Rock TBM and the importance of screw conveyor in open & closed mode in TBM.
On our way back to the office Mr. Nandan directed us to the site survey office where we were explained the monitoring techniques used in tunnel & the erection of segments in their position. Thereafter we deposited the PPE’s to the store and were then escorted to the dining area where hot & delicious lunch was served to us. Post lunch we had a power point presentation conducted by Mr. Klaus along with Mr. Nandan on importance of geology in tunnelling, selection of tunnel alignment, selection of TBM based on geology, problems faced in tunnelling & measures to overcome it and other. In the lecture they also shared their personal experience.
This site visit gave me a chance to experience & learn what cannot be gained during lectures or tutorials. One of the first things that I learnt is understanding the importance of safety which is a basic of construction, because of inherent dangers present on site. Furthermore I had in-depth knowledge in working of Dual Mode Hard Rock TBM.
TAI-Young Members 