by Eli Moreno August 10, 2019
Old City Hall (OCH) has seen its share of rumbles over the last 125 years, including a few in the magnitude 5 range in the 1930’s and 1940’s as well as a 7.3 magnitude in the Olympia area and the 6.8 magnitude that many of us remember as the Nisqually quake in 2001. None of these have caused significant damage to the brick building or heavy foundation that serves as the base. Since the next 200 years are as important to its safety, our engineering team has undertaken the task of determining the structural safety of the bricks and foundation.
To date, our team of engineers and architects have removed over 200 bricks, individually, across 80 walls on 6 floors. This determines the cohesive strength of the mortar and the porosity of the aged bricks. Keep in mind these bricks are >125 years old!
Furthermore, we are embarking on soil boring which determines the strength of the foundation. The stones in many parts of the wall’s foundation are 8 feet across, which is significantly more than other similar buildings. The OCH founders truly made this Built to Last.
The foundation stones are composed of granite while the overlying limestones’ were carved from a quarry in San Francisco. This quarry remains operational today and we are returning to the site to purchase more stones as replacements for several areas that need reinforcement. At OCH, we are making every effort to maintain the historic significance in all areas of the building. Even deep beneath the surface, as even foundations matter!