Located in the median island in Badillo Street in the City of Covina, the existing vault is a concrete structure with a precast concrete roof system. The vault houses large water valves that tie into Metropolitan Water District’s main feeder line and connects to Suburban Water System’s distribution main which provides potable water to the local community. The existing roof system is comprised of five (5) precast concrete panels with a 3-foot by 3-foot access opening to the surface. The panels were designed with waterproof membranes at the joints, and were meant to be removable for maintenance purposes. However, field operations personnel have indicated that the roof has significant leaking issues and the access hatch is too small for easy egress and ingress of personnel. In addition, the removable panels are not practical for the regular maintenance or replacement of the valves.
Suburban Water Systems desires to replace the concrete roof with a more practical roof that is water tight, has significant openings and hatches for maintenance and replacement of the large valves, as well as access for personnel. The concrete roof needed to support the fill and landscaping in the median. Although the hatches are within a landscape median, all roof including hatches needed to be designed to H20 loading requirements due to the proximity to moving vehicles.
PacRim provided the complete set of construction plans, structural designs and calculations for the new roof structure. The designs included a new 6-foot by 6-foot hatch and a new 6-foot by 7.5-foot access hatch. The plans also included a demolition plan of the existing roof structure, new structural plans of the proposed “roof”, structural details for the concrete reinforcement and connection to the existing vault walls, new hatch and ladder details, sump pump details, and a traffic control plan to close the number 1 lane in each direction on Badillo Street. The new roof was designed in a unique way utilizing a series of concrete beams spaced sufficiently apart to accept the hatches. This unique design eliminated the need for a new roof slab.