## [[Risk Action Plan]] ### [[Risk Description|Description]] Due to variable subsurface conditions across the facility site, there is a threat that pile driving operations may encounter obstructions or inadequate bearing capacity at design tip elevations, which may lead to foundation redesign, additional piles, and schedule delays in the structure erection sequence. > [!abstract]- Risk Analysis — Key Assumptions & Current Controls (click to expand) > > **Key Assumptions:** > - Geotechnical investigation borings were performed at a grid spacing of approximately 50 feet; actual subsurface conditions between boring locations are interpolated and carry inherent uncertainty. > - The pile design assumes competent bearing stratum at elevations consistent with boring data; any localized fill, buried utilities, or organics encountered above that elevation could require pile extensions or re-driving. > - The north quadrant of the facility site has fewer borings than the south due to access constraints during the original investigation; this area carries higher subsurface uncertainty. > > **Current Controls:** [[Star Road Engineering]] has prepared a pile installation monitoring plan requiring dynamic load testing (PDA) on a minimum 5% of production piles. [[Wario]] has reviewed the geotechnical report and identified three areas of elevated concern for pre-drilling requirements. [[BUILT RIGHT CONSTRUCTION]]'s pile subcontractor has been briefed on the variable conditions. > [!abstract]- Sources of Information & References (click to expand) > > **Sources:** > - [[EXHIBIT C - General Conditions]] — Differing site conditions clause and contractor notification requirements. > > **Attachments:** > - None ### [[Risk Mitigation Strategy]] REDUCE — [[Wario]] has developed a phased pile driving approach that sequences work from areas with the highest geotechnical confidence (south quadrant, fully investigated) to areas of higher uncertainty (north quadrant), allowing the team to establish actual refusal behavior before committing to production pile installation in the most uncertain zones. Dynamic load testing results from the first 5% of piles will be reviewed within 48 hours and compared against design assumptions; any anomalies will trigger an immediate meeting with [[Star Road Engineering]] to assess whether tip elevations require adjustment before proceeding. A contingency allowance of 15% additional pile quantity has been incorporated into the construction budget per the contract's differing site conditions provisions. ### Possible Additional Actions - Commission supplemental geotechnical borings in the north quadrant prior to commencing pile installation in that area, targeting 25-foot grid spacing to reduce interpolation uncertainty. - Evaluate driven pile pre-drilling requirements at locations where existing underground infrastructure may create obstructions above the design bearing stratum. ### Comments & Recommendations The variable subsurface risk is well-understood but not fully mitigated — the project team should treat initial production pile results as diagnostic data and be prepared to make rapid design decisions. [[Bowser]] should ensure that [[Star Road Engineering]]'s geotechnical engineer of record is available on short notice during the first week of pile driving production to review PDA results and respond to field conditions without delay. ### Status - [ ] [[2026-03-12]] ^status-2026-03-12 - 🟡 **Pile Installation Progress:** South quadrant pile driving is 80% complete — 94 of 118 piles installed, with PDA results indicating bearing capacity within 8% of design assumptions; no tip elevation adjustments required to date. - ⏳ **[[Subsurface Conditions - Geotechnical Report Update|Geotechnical Report Update]]:** Awaiting updated borings from the north quadrant — [[Wario]] has engaged the geotechnical subconsultant, with mobilization scheduled for the week of March 24 and results expected within 10 business days. - [ ] [[2026-02-19]] ^status-2026-02-19 - ⚠️ **Anomaly Detected:** Two piles in the southwest corner of the pump station footprint encountered refusal approximately 4 feet above the design tip elevation, triggering PDA confirmation testing and a geotechnical review by [[Star Road Engineering]]. - 🟡 **Resolution:** [[Star Road Engineering]] confirmed that the early refusal was due to a localized gravel lens — bearing capacity verified by PDA; tip elevations adjusted upward by 3.5 feet for the affected zone, with no net schedule impact. > [!abstract]- Status History (click to expand) > > - [x] [[2025-12-18]] Pile contractor mobilized; test pile program completed in the south quadrant with results confirming bearing stratum within 1 foot of design elevation in all test locations — initial confidence in geotechnical assumptions is high for the south zone. North quadrant supplemental borings not yet authorized. ^status-2025-12-18 > - [x] [[2025-10-01]] Risk identified during constructability review — geotechnical report reviewed by [[Wario]] and flagged for limited boring coverage in north quadrant; pile monitoring plan and PDA requirement added to construction documents by [[Star Road Engineering]]. ^status-2025-10-01