Ground Testing Update: Indicator Piles | January 2020

Dear Neighbor:

As ground improvement testing continues on parking Lot A, the Mission Rock team wanted to provide you with additional insight into the indicator pile program starting on Tuesday, January 21^st (after the Martin Luther King Jr. holiday). You may have noticed the mobilization of equipment on site for the indicator pile program. The purpose of the program is to better refine the overall pile count and the length of steel h-piles that will be needed for each building’s foundation. Similar to other projects in the neighborhood, piles for Mission Rock are designed to reach bedrock.

Each test pile will be made up of three to four segments, approximately 80’ in length. The first two segments are planned to be installed with a vibratory rig which among many advantages helps to reduce noise impacts. Splices between segments are welded once the initial segment is far enough into the ground. The remaining segments (once the vibratory rig can no longer effectively install added length into the ground) will be installed with a diesel impact hammer. During this work you can expect to hear pile driving between 8 a.m. and 5 p.m. on weekdays. While the majority of the impact hammer work for pile testing is planned to be completed at the end of February, the in-place piles will continue to be observed and tested for approximately one month. A noise and vibration consultant works closely with the project team to identify methods to mitigate, monitor, and manage sound and vibration.

Please feel free to direct questions or report observations to the Mission Rock project team via construction hotline (415) 972-1744 or email info@missionrock.com