rippability

The rippability of an earth (rock) material is a measure of its ability to be excavated with conventional excavation equipment.

In addition, useful information relating to concealed services and mains, archaeological appraisal, rock rippability and corrosivity will be obtained.

The excavatability or rippability of earth materials is evaluated typically by a geophysicist, engineering geologist, or geotechnical engineer.

The rippability of a material is often evaluated by an engineering geologist and/or geophysicist utilizing the seismic refraction equipment (see refraction),.

A refraction seismic survey was conducted to measure compressional-wave seismic velocities to aid in the evaluation of the rippability and/or excavability of the subsurface.

At project feasibility stage sonic logging of open or cored holes drilled from surface can provide a basis for a comprehensive 3D model of rock quality (rippability, blastability), invaluable for feasibility studies and mine design.

A common example of this is bedrock profiling, where GPR may show the detailed transition from overburden to a weathered bedrock, whereas refraction seismic may yield the level and rippability of competent bedrock.

Rippability studies can involve the performance of seismic refraction traverses, the drilling of borings with an air percussion drill rig, the excavation of test trenches with a bulldozer with rippers or backhoe, and by geologic mapping.

An engineering geologist or geophysicist may be called upon to evaluate the excavatability (i.e. rippability) of earth (rock) materials to assess the need for pre-blasting during earthwork construction, as well as associated impacts due to vibration during blasting on projects.

However, marginal rippability occurs for conglomerates at about 4500 feet/second for a D7 ripper, so it would probably be more cost effective to use a D8 or D9 since the velocities of the second layer approach the limits of the D7 ripper.