Stronghold Engineering’s Rail and Civil division has started work on this joint project between Burlington Northern Santa Fe Railroad (B.N.) and another railroad to increase the track speed on the line running through Portland, Oregon, easing the radius of the merge between B.N. and and the other lines, alleviating the majority of the commuter traffic bottlenecks that currently occur on the B.N. line.
The N Portland JCT Upgrade Project consists of ground stabilization near railroad tracks, in an effort to be able to build a T-Wall on top of the stabilized ground. To stabilize the ground, Stronghold is using deep soil mixing (DSM) techniques, where our crew drills deep into the ground, injects grout, and mixes with the material already in the ground. However, since the ground stabilization is nearby railroad track beds, Stronghold needs to install temporary shoring to ensure that the stability of the track bed is not compromised.
To achieve this, Stronghold’s crew has installed H-piles on both sides of the track bed, and drilled coil rods through the track beds. Our crew then installed lagging into the H-piles, to create temporary walls, somewhat “sandwiching” the track bed in between the two walls. Afterwards, they put up walers on both walls, with the coil rods running through the walers. Using hydraulic pressure jacks attached to the walers and coil rods, Stronghold pulled the coil rods, tightening the tension on the walls, allowing us to safely excavate for the DSM work, without compromising stability.
Once the DSM work is complete and the T-Wall is built, the temporary shoring will be taken down, leaving us with stable ground and a T-Wall. Afterwards, Stronghold will also be building a soldier-pile wall on a different side of the project site, with a chain link fence on top.