1
general::
Walk the streets, especially in search of employment. For example, He was fired last year and he's been pounding the pavement ever since. A similar usage is pound a beat, meaning "to walk a particular route over and over"; it is nearly always applied to a police officer. [Early 1900s]
American Heritage Idioms
2
general::
Phrase(s): pound the pavement
Fig. to walk through the streets looking for a job. • I spent two months pounding the pavement after the factory I worked for closed. • Hey, Bob. You’d better get busy pounding those nails unless you want to be out pounding the pavement.
McGrawhill's American Idioms And Phrasal Verbs