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Re: Homeowners having problems with the study
Author: john
Date: 01-16-2017 - 19:50
mook Wrote:
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> The homeowners above the tunnel should, I think,
> welcome the geotech study, as one of them
> apparently does, even if they aren't in love with
> an expensive bike path using it. The ends of the
> tunnel may be plugged, but the rest is still
> there, and given its age and 50 years of
> non-maintenance some of it must be a bit
> precarious by now. Was it concrete-lined or wood?
> A tunnel collapse could propagate upward causing
> building damage. Better to find out about it now
> and, if needed, reconstruct or fully plug the
> tunnel for stability purposes.
The Alto tunnel is all wood lined. It was built to narrow gauge standards and the timber bents began to sink and settle in the late sixties while trains were still running requiring crews to patch it up. A friend and i wear able to climb under the barricade a few years after the last train in 1971. This was on the on the Corte Madera side. We discovered the roof on the tunnel collapsed with a rock the size of a pickup between the rails. We called Market st. and reported the tunnel was collapsing with a house right above it. They downplayed it saying the tracks were abandoned and it was safe. About two weeks later they just happened to inspected it . Then work began to shore it up.They graded a road to the portal and built a wall about 100 feet inside. Then they pumped grout inside for two or thee days nonstop. The people living in the house directly above it reported diesel fumes coming up through their basement.
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> The homeowners above the tunnel should, I think,
> welcome the geotech study, as one of them
> apparently does, even if they aren't in love with
> an expensive bike path using it. The ends of the
> tunnel may be plugged, but the rest is still
> there, and given its age and 50 years of
> non-maintenance some of it must be a bit
> precarious by now. Was it concrete-lined or wood?
> A tunnel collapse could propagate upward causing
> building damage. Better to find out about it now
> and, if needed, reconstruct or fully plug the
> tunnel for stability purposes.
The Alto tunnel is all wood lined. It was built to narrow gauge standards and the timber bents began to sink and settle in the late sixties while trains were still running requiring crews to patch it up. A friend and i wear able to climb under the barricade a few years after the last train in 1971. This was on the on the Corte Madera side. We discovered the roof on the tunnel collapsed with a rock the size of a pickup between the rails. We called Market st. and reported the tunnel was collapsing with a house right above it. They downplayed it saying the tracks were abandoned and it was safe. About two weeks later they just happened to inspected it . Then work began to shore it up.They graded a road to the portal and built a wall about 100 feet inside. Then they pumped grout inside for two or thee days nonstop. The people living in the house directly above it reported diesel fumes coming up through their basement.
