New Delhi, March 5: Chi has been building helipads and trenches in Doklam but these are not a threat to India, Union Defence Minister Nirmala Sitharaman said on Monday. She said that Chi has been undertaking these construction activities to maintain its troops during the winter and that the troop strengths of both sides have been reduced after the two-and-half-month-long stand-off that ended in August 2017.