Practical Experience with Development and Implementation of Effective Construction Monitoring Plans

摘要

Dams and levees during construction may pose as much, if not more risk, than during normal operation. Michael Baker and the Ohio Department of Natural Resources (ODNR) previously presented on the Ohio statewide Construction Monitoring Plan (CMP) Template, which summarized monitoring, communication, and response protocols during construction. This paper provides valuable insights and updates to CMPs based on actual storm events encountered during recent dam construction projects; including parameters and conditions to be considered in the monitoring of the project, the importance of updating the CMP for changing construction phases as construction advances, and providing clearly-defined communication protocols. CMPs are utilized during construction to determine action levels based on actual or forecasted precipitation quantities, lake levels, and the approved water control plan. Other factors, such as the quantity and quality of information available regarding the condition of the project and the integrity of water control measures and related infrastructure also play a key part in the CMP decision making process. In several recent construction projects, monitoring frequencies were escalated when inspection data was limited or worsening conditions were anticipated such as inclement weather. At one project, site inspections performed during a CMP event revealed the presence of an active seep at the interface of a concrete floodwall and an earthen berm. Through the implementation of the CMP, action levels were elevated, all parties were identified of the problem, and the contractor was directed to perform all necessary remedial efforts to repair the earthen berm. CMPs must be adaptable for all phases of construction, site conditions, and potential failure modes. An example of the adaptation of the CMP to account for multiple phases of construction was represented in a dam construction project that included an initial controlled embankment breach, conveyance of flows through unfinished labyrinth spillway wall sections, and temporary diversion through the completed control tower. Each phase had distinct action levels and potential failure modes that were incorporated in the phase-specific CMP. Communication between the contractor, engineer, owner, and regulator is an extremely important aspect of the CMP. Based on implementation of CMPs on completed projects, the CMP needs to clearly define the method of communication and the template for notifying all stakeholders.