its your mistake dost - refer to rail news link here and also the paper Hindu of Dec 2, 2009 for details about blockage & re-routing of trains. its there on 13/12/09 also.
I am reproducing here part of the news item taken out from rail news section, pertaining to your train.
No. 2696 Thiruvananthapuram-Chennai Central Express will go to Egmore. No. 2695 Chennai Central-Thiruvananthapuram will leave from Egmore. On these two days, there will be no change in the suburban operations.
You...
more... can verify from rail news in this website, or through southern railway website where all details are given. its been publicized widely.
in future take care.