PE review required. Sample illustrative output. Every recommendation here must be reviewed and stamped by a licensed Professional Engineer before use in any bid commitment or construction document.
Phoenix Convention Center Foundation Retrofit
Micropile underpinning · seismic retrofit
Why bid: Project sits squarely in our specialty. Restricted-access interior work with low headroom favors micropile installation over driven alternatives, and the seismic retrofit scope aligns with FHWA design references already in our library.
Existing 1985-era convention center requires foundation underpinning to support a new 4-story east-wing addition and to bring the original structure into compliance with the current Phoenix seismic provisions. Subsurface investigation identifies competent weathered granite at 26-32 ft below ground surface, ideal bond-zone depth for hollow-bar micropiles. Interior installation under 14 ft clearance constrains rig selection. Production rate is the schedule driver — owner has imposed a hard 90-day completion window between trade shows. Critical interface coordination with the existing slab cut-out crew and the MEP rerouting subcontractor will determine whether the schedule holds.
All 14 boring logs confirm SPT N>50 refusal in granitic bedrock at consistent depth. Design capacity of 140 kips/pile is achievable with conservative bond stress assumptions.
Only low-headroom restricted-access rigs (Klemm 802 class) will fit. Mobilization adds a week and a half over open-site installation; production rate drops to ~6 piles/shift.
Hard owner-imposed milestones force 2-crew parallel installation. Casing lead-time on 7-inch Sch 80 is currently 4-6 weeks — order at NTP, no float.
Hollow-bar micropiles, 7-inch O.D. cased, 38 ft typical
Casing lead-time slip blows the trade-show window
HIGHMitigation: Place casing PO at NTP. Lock pricing 60 days. Identify second-source mill before bid.
Existing utilities not located below current slab
MEDIUMMitigation: Vacuum truck pre-excavation at every pile location. Owner to fund as separate line item.
Dust and noise restrictions during evening events
MEDIUMMitigation: Confirm 11pm-5am no-work window in the bid form. Build shift schedule around it before commit.
Existing slab thickness unknown; coring may exceed plan
LOWMitigation: Carry an allowance for 8-inch typical / 14-inch max. Verify with first 4 cores.
Who is responsible for slab cutting and patching at each pile location?
HIGH priorityBid form silent on slab restoration scope. $30-60K swing depending on responsibility.
Is the owner-provided geotech investigation report current as-built?
MEDIUM priorityBorings are dated 2019. Two minor structural revisions since may have invalidated select borings near grid line 7.
Confirm the seismic design category — IBC 2021 vs. 2024?
MEDIUM priorityCited spec references both. SDC D vs. SDC C changes confinement requirements and pile count.
- Restricted-access rig mobilization (low-headroom premium)
- Permanent casing material — 162 piles × 38 ft × 7-inch Sch 80
- Two-crew parallel production schedule to hit 90-day window
- Independent third-party load testing per spec 31 63 26
This is one of three sample analyses.
Bring a real geotech package and we'll run one for you free — no card required.