The kms on Konkan Rly route is inflated by 40% for the purpose of calculating train fare and hence the avg speed counting is also disturbed. For arriving at the correct kms and correct avg speed, plz divide the kms by 1.4 for correct kms and avg speed by 1.4 for correct speed.
In your case the correct speed will be 82 kmph ( 115 kmph / 1.40).
The website is in the process of doing modifications so as to show correct kms and correct speed.