Advance Planning Studies
TThe structure work for the Railroad SPUI APS involves the demolition of the current I-15 bridges crossing over Railroad and construction of two new bridges with longer lengths (3-span bridges). These new bridges will contain outrigger bents to accommodate the SPUI geometric design below. There will also be new retaining walls added near the new bridge abutments running along the I-15.
A link to the full Railroad SPUI APS file is at the bottom of the page. Listed below are portions of that APS that highlight the structural changes.
This shows the plan view of the Railroad SPUI APS, Railroad is the roadway running up and down and the new I-15 cross over horizontally. The outrigger bents cut across the new bridges and run parallel to Railroad. The outrigger bent columns are labeled with a "1". The new retaining walls are labeled with a "3" and run horizontally with the I-15.
Complete Railroad Elevation View
This is the elevation view of the Railroad SPUI APS, the new I-15 bridge location is shown in green. The dashed red line shows the current existing ground, which will have to excavated to place the retaining walls on both sides near the new abutments.
Eastbound Railroad Elevation View
This is the elevation view highlighting the eastbound side of Railroad. The new I-15 bridge location is on top with its cantilever closed end-backfilled abutment on the left. An outrigger bent column is also shown on the right. The westbound side is a mirror view of the eastbound side in terms of its layout.
Typical Section View
This is a typical section view of the new I-15 bridges. The new bridges include a widening for the ultimate build out of the I-15. The concrete outrigger bent beam runs through the bridges and rests on 3 columns labeled as "4". The bridges will be precast prestressed box girders and are labeled as such in the figure.
The cost estimate of the structure work of adding the retaining walls and the construction of the new I-15 bridges crossing over Railroad Canyon Road and the San Jacinto riverbed for the SPUI alternative is $42 million.
The new northbound I-15 bridge in this design is a precast prestressed box girder bridge with a total length of 367'-3" containing 3 spans of lengths: 104'-9", 178'-0", and 84'-6". The bridge has 2 outrigger bents and has cantilever closed end-backfilled abutments. It has a depth of 8'-7", a width of 74', and a bridge area of 28,100 ft2.
The new southbound I-15 bridge in this design is a precast prestressed box girder bridge with a total length of 347'-6" containing 3 spans of lengths: 93'-9", 178'-1", and 75'-8". The bridge has 2 outrigger bents and has cantilever closed end-backfilled abutments. It has a depth of 8'-7", a width of 74', and a bridge area of 24,700 ft2.
The total retaining wall area in this design is about 4,000 ft2.