NEW DELHI: India will have its own design standards for all civil structures — bridges, elevated sections, tunnels and stations — for the next phase of Bullet train projects with a design speed of 350 kmph rather than following foreign standards.Stepping up preparation for the planning and execution of seven corridors with cumulative length of 4,000-km corridors under “Bharat High Speed Rail Programme”, the bullet train execution agency, NHSRCL, has floated a global tender for preparation of detailed design and standard design for all the permanent components and works of these projects.The NHRSCL said the detailed project report of four corridors out of seven were sanctioned in the past and for the remaining three corridors, surveys are going on. In addition, validation of alignment and pre-tender geotechnical investigation works is also being taken up. “Therefore, to take up such a large volume of work at a fast pace, it is envisaged to adopt the best design and construction practices as adopted in Mumbai-Ahmedabad High Speed Rail corridor with further advancement,” it said.As per the bid document, the Delhi-Varanasi corridor will have an underground station at Jewar airport in Noida and the project will have a 9.4 km tunnel. Similarly, the Bengaluru-Chennai corridor will have three underground stations at Chennai, Whitefield and Baiyappanahalli, and it will have three tunnels with a cumulative length of 15.9 km. Officials said railways are looking at tweaking alignments and to take the high speed connectivity to the core of the cities.The bid specifies that the design must be safe, reliable, comfortable and cost-effective for operation of double track High-Speed Rail at 320 kmph with design speed of 350 kmph with due considerations to the site conditions, including environmental, ground, materials etc.