Future 295 South to 42 South Ramp

     In my last post I mentioned one of the major pieces of the project that will be part of the fourth contact, the new ramp from 295 South to 42 South. Currently, if you are coming down 295 south you would stay to the right and take the Al-Jo curve to get to 42 south. In the new configuration you will stay to the left and start down the existing ramp that takes you to 76 west towards Philadelphia. This ramp will split off to the left, go under 76 at an angle and come back up on the other side near where the Al-Jo curve currently ends and connect you to 42 south. This picture shows roughly where this ramp will be,

Here is a section of the plans showing that new tunnel.

The first part of this was actually done very early in the project. In this picture you can see the two rows of sheet pile that were installed to form the edges of the ramp.

The latest contract documents give a pretty good summary of how this will be built. It's a pretty complex multi-stage operation. 

In stage 1 the lanes of 76 west will be shifted towards the center median. Permenant sheet pile will be installed on either side of the new tunnel and termporary pile along 76. Shafts will be drilled on either side and concrete support columns poured down to below the level of the finished tunnel. This area will then be excavated but only deep enough to allow for the construction of the new bridge deck. 

In stage 2A, two of the 76 west bound lanes will be shifted to go over this new bridge, the temporary sheet pile removed and reinstalled along the edge of the next to lanes. The whole process from stage 1 will then be repeated between the two sets of lanes. 

In stage 2B the west bound lanes are fully moved over on the newly constructed overpass and then the process is repeated in the area between the east and west bound lanes.

In Stage 3A the east bound lanes are shifter over next to the west bound lanes and againt the process is repeated. 

In Stage 3B the lanes coming from the Al-Jo curve are shifted left and the final section of what will become the tunnel is built. At this point 76 is passing over the future tunnel on a "bridge" that is basically sitting right at ground level. 

The final phase involves digging out under the bridge, pouting the final concrete walls, installing drainage, and pouring the concrete bottom of the tunnel. 

Here is a cutaway view of what the final tunnel will look like.