A construction project that will bring more shops, housing and parking to downtown Bethesda has entered a new phase — one that may shake windows and rattle the nerves of some in the area.

Blasting — designed to clear dense hard rock on the site of what  used to be a popular parking lot at Woodmont and Bethesda Avenues near the Barnes and Noble — began Dec. 5 and is expected to continue daily for the next two to three months, according to an advisory from Montgomery County officials.

The blasts will occur between 9 a.m. and 3 p.m. with the majority happening between the hours of 10 a.m. and 2 p.m., the county’s advisory said. Most days there will be two blasts a day. A horn — designed to warn workers on the site but audible to others in the vicinity — will sound approximately 15 minutes and five minutes prior to the blast.  The horn will sound again immediately after the blast.

In addition, immediately after the blast, the horn will sound again.

When the project is completed, it is expected to triple the number of parking spaces in the area.