Galveston Bay Causeway Overpass on SH-146, Harris County, TX. Located in active industrial subsidence corridor.
| NBI Structure Number | TX-0146-0087 |
|---|---|
| Bridge Name | Galveston Bay Causeway Overpass |
| State/County | TX / Harris |
| Year Built | 1978 |
| Structure Type | Prestressed concrete |
| Owner | TxDOT |
| ADT | 34,200 |
| Last Inspection Date | 2025-11-20 |
| Condition Rating | 5 Fair |
| Period (days) | Samples | Mean Displacement (mm) | Max Velocity (mm/yr) | Mean Coherence |
|---|---|---|---|---|
| 36 | 6 | -28.1 | -285.0 | 0.351 |
medium confidence — 6 observations, mean coherence 0.351, uncertainty ±2.4 mm.
| Risk Factor | Weight | Contribution |
|---|---|---|
| Acceleration | 0.14 | 14% |
| Displacement Rate | 0.26 | 26% |
| Criticality | 0.22 | 22% |
| Condition | 0.12 | 12% |
| Geology | 0.16 | 16% |
| Context | 0.10 | 10% |
Active subsidence in industrial corridor. Fair condition (5) but high ADT and ongoing ground movement support proactive preservation funding.
Initiate preservation package design and monitor differential settlement near approach transitions; maintain annual IIJA funding eligibility updates.
| Source | Frames | Date Range | Processing |
|---|---|---|---|
| Sentinel-1 C-band InSAR | F38239 | 2026-01-28 to 2026-03-05 | OPERA DISP-S1 v1.1 (NASA/JPL via ASF) |