The Indiana Department of Transportation is developing plans that represent a fiscal approach for correction of slide conditions along State Road 156 in Ohio and Switzerland Counties. Instead of multi-million-dollar repairs at individual slide sites, INDOT proposes realigning S.R. 156 at two locations 50 to 60 feet away from Ohio River embankments.
State maintenance crews have been securing slopes, building walls, correcting drainage conditions and fixing broken pavement on S.R. 156 for decades.
But when the challenge of active slides goes beyond in-house capabilities, geo-stabilization experts have been contracted to do the work. Oftentimes, “soil nailing” has been employed by specialty crews to stabilize a slide area. A number of long steel shafts are embedded at strategic locations in the embankment, then fitted with mesh to overcoat and hold the slope.
Currently, there are a number of active slides on S.R. 156 along the Ohio River programmed for repair. Geotechnical reports recommend corrective measures beyond soil nailing for several of these slide areas – they call for building drilled pier walls with tie-backs into the embankments.
The estimated cost for drilled pier walls at one 440-foot-wide slide site is $4 million. Combining this designated site with an adjacent 680-foot-wide slide area nearby that has become active, the estimated cost increases to $9.5 million. Another 585-foot-wide slide along S.R. 156 may cost taxpayers over $5 million. And a 344-foot-wide slide site in the same area is estimated at close to $3 million.
In all, cost estimates total more than $16.5 million for correcting S.R. 156 slides using drilled pier walls with tie-backs at these locations between Rising Sun and Patriot:
• 2.95 miles west of the S.R. 56 intersection with S.R 156
• 1.14 miles west of the S.R. 56 intersection
• 0.6 miles west of the intersection
INDOT officials note that these estimates do not include yet-to-be-designated slides in the area which may become active adjacent to sites under consideration for funding.
As a cost alternative – with long-term benefits – the state has identified two segments of S.R. 156 that can be routed away from Ohio River embankments.
Initial plans are being developed to realign a 5,147-foot section of S.R. 156 incorporating two of the designated slide areas along with problem areas. Cost estimates – which include replacement of structurally deficient small drainage structures – are less than $4.5 million.
A second proposed S.R. 156 realignment segment – measuring 4,012 feet in length – has an estimated cost of $3.2 million.
Both realignments would require some acquisition of property for state right-of-way. They also benefit nearby property owners by moderating the grade of the slope to the river.
INDOT officials plan to host a public information meeting this summer to discuss these proposed realignments of S.R. 156 with area residents and businesses.
Realignment of these two segments of S.R. 156 50 to 60 feet away from the Ohio River would preclude embankment slides and road closures such as the one that occurred last July at the site located 2.95 miles west of the S.R. 56 intersection with S.R. 156 in northeast Switzerland County.