Long-term health monitoring of levee cutoff wall

Researchers: Ruonan Ou, Andrew Yeskoo, Linqing Luo, John Murphy, Yaobin Yang, Kenichi Soga

Client/Owner: US Army Corps of Engineers

Technologies: Distributed Fiber Optic Sensing

USACE reconstructed some levee cutoff walls within the Sacramento River Area during the past two years. The levee cutoff wall is constructed by a mixture of cement, bentonite, and slag, which is a low permeability and high strength material. However, it becomes brittle as well. Under an event of flood or earthquake, the levee may deform due to the external load and the performance of the wall needs to be assessed for its integrity after the event. By embedding an optical fiber sensor into the cutoff wall vertically during construction, the long-term health monitoring of the SCCB cutoff wall at Natomas Reach I started to be conducted from July. 9th, 2020. The curing process was monitored continuously during the first seven days after the SCCB wall construction. Weekly reading is currently taken to measure the final stage of heat dissipation and strain development. The monitoring will continue for years to evaluate the performance of the SCCB wall under the embankment construction, the flooding event, the earthquake event, and the operation of Garden Highway.