Is it permissible to combine prayers (Dhuhr and Asr) after their prescribed time due to work circumstances that necessitate traveling a distance of 35 kilometers and commuting for two hours, knowing that work hours extend from 2 p.m. to 10 p.m.?

Leaving the prayer and performing it outside its prescribed time is a grave sin, and a Muslim has no excuse except what has been explicitly exempted by the Shari'ah. Strive to perform Dhuhr prayer at its designated time. You can perform ablution and leave early to pray wherever possible, as the entire earth is a masjid. If that becomes difficult, and you are compelled to delay Dhuhr due to work circumstances, then it is permissible for you to adopt the view of those who permit combining two prayers for a general need. In this case, you would intend to combine it with Asr as a delayed combination (Jama' Ta'khir) and pray both during the time of Asr. However, this should be an exception, undertaken only after making every effort to perform the prayer at its due time.