Location: Sunol, CA
Project Partner: Dragados-Flatiron-Sukut JV
Challenge: Plan and execute the foundation drilling and grouting scope in a sequence to avoid delay to the critical path earth work activities.
Overview: Condon-Johnson was contracted to complete the foundation drilling and grouting scope downstream of the existing dam to minimize seepage through the underlying bedrock of the future dam. The grout utilized was a suite of cement-based stable high-mobility grouts with varying viscosities. All injection and permeation testing was monitored and recorded via Condon-Johnson’s custom real-time computer monitoring system.
Results: Through collaborative efforts, the design and construction teams, including the General Contractor, were able to work closely to devise an effective plan to minimize the foundation drilling and grouting scope’s duration on the critical path for the new dam construction. Although some procedures were not typical for dam foundation grouting, the performance goals and traditional grouting requirements were consistently met. Four different types of drill rigs were utilized to overcome the challenging access.