Custom Blocks Renovation

The Custom Blocks renovation project consisted of two full blocks of buildings, eight individual buildings in all. The improvements to the buildings included a combination of lateral and gravity upgrades, including new steel braced frames and existing floor/roof framing reinforcing.

Design Challenges

One of the largest obstacles was determining how to upgrade the lateral force resisting system of each individual building using ASCE 41, since each building was constructed at a different time and very few existing drawings were available. This required an extensive evaluation of the materials, methods of construction, and an assessment of all existing connections. Several of the foundations for the frames occurred along property lines which required offset footings.

Early investigations of the soil conditions revealed a high ground water level and old fills in an existing creek bed, so micro piles were installed in order to obtain suitable bearing capacity. As the demolition process began, plans started to change and unique details had to be created in order to fit and repair existing issues. Trusses and beams were found to be deficient which required several steel plates and bolts to reinforce them.

The south block was designed to add a catwalk hanging out over the 40-foot tall open space which lead up to a conference room and roof deck. In order to do this, we had to substantially upgrade the trusses and columns supporting the suspended structure. The second level floor space in the south block was completely warped. The intent was to add two inches of concrete to this level to display an exposed finish concrete floor, but due to the warping several spot elevations had to be taken to determine the thickness of concrete required in each area. The added concrete also prompted required structural upgrades to the floor system.