A major street in San Francisco’s Glen Park neighborhood remained closed for a second day Thursday as city workers dangling from ropes rappelled down an eroding cliffside, clearing out rocks that could break loose in series of storms forecast to slam the Bay Area through the weekend. O’Shaughnessy Boulevard in the Diamond Heights neighborhood is expected to stay closed from Del Vale Avenue to Malta Drive until the evening commute Friday, said Rachel Gordon, a spokeswoman for the Department of Public Works.