Michigan State Capitol Heritage Hall Project
Project summary
Images of the project
Michigan State Capitol Heritage Hall Project
The Michigan State Capitol Heritage Hall Project was a successful and historically significant project that Sixense was honored to work on. After 143 years of dedicated service to state lawmakers and the public, the Michigan State Capitol Building, a splendid National Historic Landmark designed by Elijah E. Myers, underwent major renovations.
These renovations included the construction of the Heritage Hall Visitor Center, a $40M underground expansion serving as a welcoming venue for visitors, and the main entry point for school groups, tourists, and others. Heritage Hall features a 600-person auditorium and conference center with space for historical exhibits.
A key aspect of this project was the creation of a new 10,000-square-foot below-ground central utility plant, which provides year-round heating and cooling to the Capitol building and Heritage Hall using carbon-free geothermal energy. The resilient and energy-efficient MEP systems offer significant life-cycle savings, ensuring the historic Michigan State Capitol thrives for years to come.
Excavation Work
Schnabel, an earth-retention contractor & foundation construction company, was hired for the project to provide temporary and permanent excavation support. The excavation depth-averaged 26 feet, with up to two levels of tiebacks.
A permanent secant wall with tiebacks was chosen to control both horizontal and vertical movements in areas where shoring was needed within the Capitol’s zone of influence. Temporary excavation support, including driven soldier piles, lagging, and tiebacks, was used in all other areas away from the Capitol.
Sixense Monitoring Services
In the midst of the pandemic, Sixense joined the Michigan State Capitol Heritage Hall project to deploy:
- A solar-powered automatic total station was used to continuously monitor twenty-five (25) locations on the Capitol and thirty (30) locations on the permanent and temporary excavation support.
- Three (3) seismographs located in the basement of the Capitol to monitor the vibration from nearby pile driving, secant drilling, and tieback drilling. The seismograph data was continuously monitored as pile driving approached the Capitol to confirm the vibration stayed below a certain threshold. The team closely monitored both vibrations and movements on the Capitol during the drilling process.
Michigan State Capitol Heritage Hall Project Challenges
Sixense navigated the challenges of the ongoing pandemic by implementing innovative solutions and adhering to numerous new safety precautions to comply with state guidelines.
The tieback operation presented its own unique challenges. Tiebacks were installed around an array of newly placed geothermal wells, each of which was field-verified to avoid conflicts. The project also involved two interior corners where tiebacks intersected. Precise drill alignment was essential to weave the tiebacks between the geothermal wells and other adjacent tiebacks. Ultimately, tiebacks were successfully installed without striking any geothermal wells.
Project Completion
The project was completed in September 2020, without exceeding the movement criteria of the Capitol or any of the excavation support, and finishing on time to the satisfaction of our client. The consistent reliability of our data made all of the project stakeholders confident that the existing structures were safe during the works.
The Michigan State Capitol Heritage Hall Project earned an Honor Award Winner in the 2022-2023 ACEC/MW Engineering Excellence Awards Competition, underscoring its success. The improvements have generated significant enthusiasm among Capitol visitors and Michigan residents alike.
