MODIFY CABINET FOUNDATIONS -1 DESCRIPTION Where approved by the Engineer, install conduit entrances into existing foundations in accordance with the plans and specifications. Modify existing foundations in accordance with the plans and specifications. -2 MATERIAL Refer to Art icle 1750 -2. -3 CONSTRUCTION METHODS
Install Conduit Entrances into existing cabinet foundations by core drilling foundations to install additional conduit. Maintain a minimum of 3 inches of cover between new conduit and edge of foundation. Maintain minimum clearances of 1 inch from the flange of the base adapter and 2 inches from existing conduits. Avoid damaging e xisting conduit, conductors and anchor bolts. Repair all such damages. Where approved by the Engineer, the foundation may be chipped instead of drilled for conduit entrance. Maintain traffic signal operations while drilling is performed unless approved by the Engineer . Bond new metallic conduit to the equipment ground bus. After installation of conduit, place grout to seal around conduit and return the foundation to normal appearance.
Enlarge existing cabinet foundations to accommodate the new cabinet and/or to provide a maintenance technician pad. Excavate the ground around the existing foundation to a depth sufficient to expose a minimum of 4 inches of the foundation below existing grade. Rough the sides of the existing foundation from the top to a point 4 inches below grade by means of a chisel or other method approved by the Engineer. Wash the sides of the foundation with water pressurized at 50 psi and thoroughly dry with compressed air. Drill holes approximately 12 inches deep on 12 inches centers into the existing foundation. Install # 4 dowels and epoxy into place. Provide dowels of the lengths in Table 1752- 1. TABLE 1752 -1 LENGTH OF DOWEL Foundation Extension Length of Dowel > 16" 24" > 6" and < 16" 17" = 6" 14" Use concrete to install the maintenance technician pad. Form the sides of the modified foundation to a minimum depth of 4 inches below grade. Position forms so that all existing exposed foundation surfaces at or above grade level will be matched. Apply a coating of approved epoxy bonding agent to all exposed roughened concrete surfaces as recommended by the manufacturer.