Pragati Maidan Underground Tunnel

Pragati Maidan Tunnel in Delhi

A Sordid saga of poorly designed and disastrous Construction

Seepage and waterlogging

A gift to the Nation at a cost of about Rs 777 Crores.

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1.Ring road and Mathura road are two very important roads in Delhi connecting to various places/cities in and around Delhi. Prior to the construction of this tunnel, traffic has to take very cumbersome movements, various turns and lot of traffic jams on Ring road and Mathura road. Launched by Prime Minister Narendra Modi in June 2022, this 1.3 km-long tunnel is a part of the Pragati Maidan Integrated Transit Corridor project, built at an initially estimated cost of over Rs 920 crore. The tunnel's construction cost was Rs 777 crore. Length-1.2 Kms First Dead line was-March -2019, Second dead line was- Nov 2021. Third dead line was- Jan 2022. Within two years of inauguration, cracks are showing at Pragati Maidan tunnel.

2.Dogged by waterlogging and seepage since it opened in June 2022, the tunnel, which connects?Mathura Road and India Gate C-Hexagon with Ring Road, has been closed to the public several times for pumping out water and for repairs since 20 Mar 2024.

3.This tunnel was designed and constructed by a leading Construction Company. Since March 24, the Governmental agencies already put up a claim of Rs 500 Crores on the Construction Company and as a consequence of that, the Construction Company also put up a counter Claim of Rs 700 Crores on the Governmental agencies. Both parties are fighting little realising the public hardships and both parties may go to the courts to settle their claims/counterclaims. Who bothers about public money and its sufferings.

4.Since this tunnel was constructed underground without disturbing the traffic touting the big claims about this as? some sort of divine solution. Various turns and u turns were avoided to provide a hassle free traffic from Delhi to UP and vice versa. Since this has been closed, the public is suffering badly due to traffic congestion.

5. This tunnel is basically a two way tunnel and each way is having 3 lanes connecting basically the Mathura Road ?and Ring road without crossing the each way from Ring road and Mathura road. This tunnel is having 18 openings some are two way and ?some are one way by constructing the slopy road leading to the underground tunnel with a purpose to provide a seam less road operations and to avoid the traffic congestion in the construction phase.

6. The essential feature of this tunnel is that ?it was constructed by the Box pushing technique, i.e by casting Reinforced cement concrete rectangular? boxes and? lowering it at certain depth and then pushing it in soil with the help of hydraulic jacks abutting the sold ground supports. When one box was pushed at lead location, the second box ?was placed and pushed similar to the first one and this process is repeated till first box reaches to the other end.

7. It seems highly probable that designers missed some surveys and some design aspects which are as follows;

7.1- Underground water table survey- The Jamuna River is hardly 1400 meters there which is sufficient to raise the water table all around this tunnel. Also the water table if depressed artificially by lowering RCC boxes, it has got two effects that is;

(i) It creates large hydrostatic upward pressure on the box bottom.

(ii) It raises the water table on the sides of the box which creates large lateral pressure on the vertical walls of the box.

7.2- To take care of rainwater, the execution agency provided only road roof covering of about 60 meters on most of the entry points which are quite insufficient to stop the water from going to the tunnel.

7.3-Rainfall data- The behaviour of water flow is very strange that any depressed channel attracts the rainwater making the openings slopy surface as active hydraulic channel. If sufficient data or survey of maximum intensity rainfall was not done, the water entry to the tunnel cannot be stopped.

8.1- Design aspects- Drainage ?To take care of small rainfall, every entry to the tunnel should have been provided by a hump across the road at the start of slopes having sufficient height so that small intensity rainfall water may be stopped which will drain out to the longitudinal channels on either side having sufficient slopes to the outfall ?or by having? suitable pumping arrangements either to storm water mains ?or to a ?nearby low lying areas or to open drains.

8.2- Rainwater arresting- The designers failed to anticipate the rainwater flow the tunnel through openings which is ultimately ?flooding the tunnel. Proper water arresting filters have not been? provided at the entry points on the bottom of RCC Boxes across the road having sufficient sump capacity with auto start/auto stop drainage pumps to the outfall stormwater mains.

8.3-Since the reinforced concrete boxes cannot be pushed in a curvature therefore large number of boxes having small lengths have been used which is involving the large number of joints. In ideal conditions the joints should have been property designed to sustain the water pressure from outside the box either from box bottom or from side vertical members of a RCC boxes. There is only one method by using the sealant which should have three properties;

(i) Sufficient adhesion capacity with concrete.

(ii) Sufficient pressure bearing capacity.

(iii) Should not be prone to crack in damp/water pressure conditions.

(iv) Should not be prone to loss of adhesion with Concrete in the presence of water.

(v) When RCC boxes are in curvature, the joints takes a V shape which makes these joints prone to leakage of water either from bottoms or from sides.

(vi) Since under dynamic loading the concrete joints behave in dynamic motions/vibrations therefore these sealents should have sufficient dynamic strength without cracking.

9. After plugging all the holes, the bottoms and sides will experience large pressure and cracks in the Concrete members sides and bottoms and if that happens then water may enter into concrete members, corrode the reinforcement leading to sudden failure of this underpass.

10. Here the sealent assumes lot of importance therefore designers failed miserably to design and construct drainage arrangements and choice of right type of sealent. However the structures always fail to function due to smaller omission and smaller mistakes only.

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