Construction of intermodal facility at Stockton, Calif

Railway Track and Structures, Sept, 2003 by Eugene D. Schubel

What happens when a company does careful planning and works closely with local agencies to construct a new world-class facility?

The outcome is Burlington Northern and Santa Fe's intermodal facility, near Stockton, Calif., which recently received a 2002 Regional Excellence Award for innovative use of time treatment for subgrade.

Also in 2002, BNSF was recognized by area agencies as the premier pollution preventer for its efforts. The County of San Joaquin gave BNSF the award, citing improvements in the environmental categories of land, water and air. Besides providing additional wildlife habitat, storm water runoff became controlled traffic congestion and the number of trucks on area highways were reduced.

John Fleming, resident engineer accepted the award on behalf of BNSF. "The project faced many challenges during construction, and during that time the BNSF construction team established great working relationship with all agencies concerned. The project was completed ahead of schedule, under budget and more than 300,000 man-hours worked without a loss-time injury."

The facility, which opened April 2001, has grown in volume with additional parking added at the end of 2002. The initial construction created two 7,70-0foot-long strip tracks, three storage tracks and 900 parking stalls. The design allows for future parking, strip and storage tracks. The facility can handle minimum of 300,000 lifts per year DMJM Harris, Long Beach, Calif., was the designer and construction manager for the project. Kleinfelder, Stockton, Calif., provided the geotechnical support and designed the subgrade.

The civil work was performed by Granite Construction, Stockton, Calif., and BNSF track forces constructed all trackage. The real challenge involved stabilization of native soils before paving materials were applied. A lime-stabilized section 31-inches thick was constructed under the concrete paved loading and unloading areas. The entire lime treating process made it one of the largest lime stabilization projects in the United States, totaling 440,000 cubic yards of treated soil, covering 220 acres.

Drainage features included three retention basins, totaling 46 acres and one million cubic yards of excavation, seven miles of subdrains and six miles of storm drain pipe. The contractor used some creative thinking to overcome environmental and material supply obstacles. One example, the concrete storm drain was not readily available, so a cast-in place approach was used to prevent schedule delays.

Another challenge to timely completion was Weber Slough, which cuts diagonally across the site. This waterway was identified as a habitat for the giant garter snake, a threatened species. From October through April, work could not be performed in this area. The mitigation for the waterway, other wetland impacts and several animal species will be discussed later.

Another creative approach used by the contractor to expedite the concrete box construction in the slough, was to use of rolling steel forms. The bottom slab was prepared first, then movable forms used to construct the walls and top of the boxes in segments. Since the concrete box section consisted of four barrels with a total width of 53 feet and a depth of seven feet, six inches, this structure could not have been easily pre-cast and placed.

The concrete paving for the loading and unloading area was designed to accommodate use of a reach stacker. Although this type of equipment is no currently used, the flexibility to use it in the future was desired. Since expansive clays were the predominate soil type on the site, the deep lime section, previously mentioned, allowed the concrete pavement to be only 13 inches thick. The over all support structure was economically designed and with actual strengths being exceeded, the durability of the pavement section was enhanced.

The paving machine used on the project was only one of four that existed a that time. It was totally-computerized capable of paving a 40-foot-wide section and had special features, such as an automatic dowel bar inserter. This saved the manual labor that is normally used for this step. An onsite batch plant was setup to produce nearly 66,000 cubic yards of concrete that was required.

The mitigation for wetlands and loss of habitat for some animal species resulted in construction of a wetland preserve, which covers 56 acres. Four side pools were created by diverting water from the mitigation channels via diversion channels. A native planting plan was implemented within the preserve along with a temporary drip irrigation system.

Another successful part of the construction was encouraging the contractor to make value-engineering recommendations through the CRIPS, or Cost Reduction Incentive Programs. The savings were shared between BNSF and the contractor Two such recommendations involved changes in the strip track drainage system and the jointing of the concrete pavement.

Gene Schubel, director engineering services, BNSF, was the project manage for the project. "As with any project some mistakes were made and lesson learned to apply to future projects."