City completes improvements to landslide sites
October 30, 2018
The City of Pittsburgh has completed improvements at two landslide sites in the city's southern neighborhoods.
Improvements have been made to two parts of William Street in Mount Washington, one of them above the southern end of the Liberty Tunnel, and Advent Street in Elliott has been remediated and reopened.
The city's Department of Mobility and Infrastructure (DOMI) has been in charge of the landslide work impacting streets citywide. In 2018 alone, the department has responded to 22 landslide events.
In February, a major slide occurred above McArdle Roadway on William Street in Mount Washington. The landslide caused major subsidence and required the closure of William Street from 100 feet after Cola Street to approximately 500 feet above Arlington Avenue.
The slope movement was so great that the segment of roadway will not be restored in the foreseeable future. However, the city's Department of Mobility and Infrastructure (DOMI) has been working to improve the remaining segments of William Street both at the top and the bottom of the slope.
On lower William Street, above Arlington Avenue, DOMI mitigated a mine blowout above the Liberty Tunnel, installing catch basins and crushed limestone French drains to neutralize and handle the acidic mine water runoff.
On upper William Street, the city has been working with neighborhood residents on road widening and drainage issues to improve safety and performance in winter months. DOMI has invested more than $700,000 to address the slope failure including substantial geotechnical investigations, excavation and soil removal work, addressing long standing drainage issues, and rebuilding sidewalks and retaining structures impacted by the widening.
Advent Street in Elliot experienced significant land subsidence requiring the street to be closed in March. DOMI commissioned geotechnical assessments in April and May, and began remediation work in July. Work improvements on Advent included: New guiderail; improved drainage; and, to a rebuilt and resurfaced street.
The street reopened to traffic in September.