One lane vehicular tunnel under existing railroad tracks
One lane vehicular tunnel under existing railroad tracks
(OP)
Anyone have example projects and/or design guide references or suggested methods of construction? It is through sandy clay type of material. The railroad has to be functional during construction of tunnel.






RE: One lane vehicular tunnel under existing railroad tracks
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
- re-route the railroad to the shoefly
- construct the underpass using open cut method
- re-route back to railroad mainline
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
1) allowable settlement of the tracks and monitoring requirements for it
2) action plan if the tracks do subside
3) how deep to groundwater?
4) type of tunnel to construct ie: concrete box, steel arch, shotcrete lined, other?
5) if you are in expansive clay, will your subgrade expand once you remove the load? If so, how will you mitigate the effect on the railroad above?
6) will grouting be require to stabilize the ground before tunneling? Will grouting be required to fill voids behind the lining?
7) Can you jack a culvert through the embankment instead of constructing a tunnel?
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
i've never had to perform what you're trying but i'm thinking "outside the bun" on this one since i've got a project coming up with a similar situation (at least we can re-route the tracks if needed).
RE: One lane vehicular tunnel under existing railroad tracks
However, geotech investigation and recommendations plus advice from a jacking and tunneling contractor should be number one on your list of things to do before you can select a method...
RE: One lane vehicular tunnel under existing railroad tracks
If settlement is a going to be a problem, a temporary bridge could be slipped under the tracks relatively quickly and the new tunnel then excavated below the bridge. If the temporary bridge is designed as a solid structure you could monitor the track levels and pressure grout or use hydraulic jacks to correct any settlement as you proceed.
Another way would be to just build the side walls of your tunnel first,Which would require minor temporary bridging .When the side walls are ready cut out that section of track excavate a couple of feet and then drop in the new bridge structure complete with rails into the gap that could be done in a few hrs. Then you excavate the rest of the tunnel.
Intrusion Prepakt /marineconcrete.com
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: One lane vehicular tunnel under existing railroad tracks
RE: One lane vehicular tunnel under existing railroad tracks
We adopted a bridge, but it was still a roadway underpass. We had a great subcontractor that had done numerous bridges with "live" operations. That may be an option for you, especially if the geometrics of taking the roadway over the railroad are challenging. They specialize in these types of projects.
PM me and I can send you some project photos and a contact.
RE: One lane vehicular tunnel under existing railroad tracks