To facilitate the excavation for the Delhi Main and New Delhi Station and part of the cut and cover tunnel sections, cast in situ diaphragm walls has been constructed by Bauer/L&T Joint Venture with a wall thickness of 800 mm.  The lateral support of the excavated diaphragm walls has been made by providing a temporary struts and at later stage by the permanent tunnel structure.

The diaphragm walls at the Delhi Main Station were constructed for temporary use only while the walls for the New Delhi Station are considered as permanent structure.