Driving Into Sloping Rock
When igneous and metamorphosed sedimentary rock formations that have been folded are encountered and when the site is on the arm of an anticline or syncline, solid/sound bearings are difficult to obtain.
When such conditions are encountered the piles (“H” or “PIPE”) must be equipped with a “ROCK INJECTOR” design driving shoe such as:
TITUS “R” Series ROCK INJECTOR POINT (“H” or “PIPE”)
These points can be “chipped” into surfaces dipping up to 50 degrees
Hard Rock: igneous formations of anticlines and synclines – max. 40 degrees
Softer Rock: inclined beds of shale, limestone, corals, sandstone – max. 50 degrees
Other types of driving shoes such as …..Titus “Standard” points, Associated Pile and Fittings “Pruyn” point, the “Hard Bite” point and the “OSLO” point ….. are not designed for these applications. These “Standard” points cannot be properly seated due to sliding or skipping and are deflected as the overburden lateral support is not sufficient to hold the pile and point in place. They may also develop eccentric bending moments and should not be used on bearing surfaces dipping more than 9 degrees
To insure proper alignment and protection for the walls of the pile, only the TITUS ROCK INJECTOR has been tested and proven on surfaces dipping up to 50 degrees.
Seating the Pile: The ultimate bearing capacity of the bedrock is many times the maximum required. Therefore, the main objective is to fix the pile in a firm seat.
This is achieved by immediately reducing the energy at “first refusal” to 10%. The Rock Injector point is then gently “chipped in” by light repeated strokes which are increased by 10% increments to meet full design requirements or “final refusal”. This procedure should be preformed by a qualified and skilled operator and done with care and precision.