The primary emphasis of this manual is placed on the technical procedures for performing precise monitoring surveys in support of the Corps periodic inspection and dam safety programs. General planning criteria, field and office execution procedures, data reduction and adjustment methods, and required accuracy specifications for performing structural deformation surveys are provided. These techniques are applicable to periodic monitoring surveys on earth and rock-fill dams, embankments, and concrete structures. This manual covers both conventional (terrestrial) and satellite (GPS) deformation survey methods used for measuring external movements. This manual does not cover instrumentation required to measure internal loads, stresses, strains, or pressures within a structure–refer to the references at Appendix A for these activities. Example applications on Corps projects are provided at Appendix B (Deformation Surveys of Locks and Dams) and Appendix C (Monitoring Schemes for Concrete Dams).
The manual is intended to be a reference guide for structural deformation surveying, whether performed by in-house hired-labor forces, contracted forces, or combinations thereof. This manual should be directly referenced in the scopes of work for Architect-Engineer (A-E) survey services or other third-party survey services (from U.S. Army Corps of Engineers).
- Deformation survey techniques
- Planning, design and accuracy requirements
- Deformation measurement and alignment instrumentation
- Sources of measurement error and instrument calibrations
- Angle and distance observations – theodolites, total stations and EDM
- Settlement surveys – precise differential leveling observations
- Alignment, deflection & crack measurement surveys
- Monitoring structural deformations using the Global Positioning System
- Pre-analysis and network adjustment
- Relative distance ratio assessment methods
- Analysis and assessment of results
- Data presentation and final reports
Professional Development Hours: 30