as per M.O.E regulations the noise level in the public areas should not exced 80 db till 10:00 pm, but any how, you should first go to the site office and inform them verbly or in written notice that you can't sleep or rest during nihgt, after that you can complain to the nearest police station, because if working after 10:00 pm they should have no complain, and in case; they should stop the work.
but did they finish the excavation activities?