Four major criteria to be considered and tested in relation to constructability:
EXCAVATABILITY- How much work will have to be done to remove the soil or rock material?
- How much force will have to be applied to the rock by a mechanical bit, cutter or tool to break it?
- How much explosive energy per cubic metre will be needed to break the rock?
- How much damage will the loosening of soils or the breaking or cutting of rock cause to excavating bits, tools, or cutters?
- How much damage or wear will the transport of loosened or broken soil and rock cause to transportation equipment such as trucks, conveyors and pipelines?
- Will the rock fail before or during removal due to the magnitude of the natural stress field, relative to the rock’s strength properties?
- Will the soil or rock material remaining in place be strong enough to support the slope tunnel, or excavated cavern, or will it have to be artificially strengthened, reinforced or supported?
- What is the strength or yield stress of the rock under slow or sustained loading, by comparison with design values derived from quick laboratory tests?
- How much non-elastic (viscous or plastic) creep deformation will the rock surrounding a tunnel or excavated cavern develop during the life of the project?
- What additional loads will these irresistible deformations cause to the artificial support structures?
- How much swelling pressure will the rock surrounding a tunnel or excavated cavern impose on the artificial support structures during the life of the project?
