Installation of expanded base piles

A driveable pile point assembly comprising a massive precast tip element and a metal sleeve having a cross section substantially smaller than that of said tip element, said sleeve extending into the material of said tip element and tightly encasing a core of the tip element whereby driving forces applied to said core are laterally contained by said tube thereby to provide high-driving capability, and a driving mandrel extending down inside said sleeve and contacting said core encased by said sleeve.

A method of constructing a pile, said method comprising the steps of forming a massive precast pile tip having a driving surface and a metal sleeve of substantially smaller diameter than said tip cast into the material of said tip and extending inwardly thereof and tightly surrounding a core of the material of said tip, applying hammer blows to said driving surface in a region encircled by said sleeve to drive said tip into the earth, and thereafter forming a stem on top of the driven tip.

A method of driving a precast concrete pile tip comprising the step of placing on a surface of the tip to be driven a layer of dry pack grout comprising a mixture of cement sand and water sufficient to cause hydration and curing only when the mixture is subjected to high pressure and thereafter placing a driving mandrel on the layer of grout and driving the tip by applications of driving forces through the mandrel and the layer of grout to the tip.

In combination, a driveable pile point comprising a massive precast tip element and a metal sleeve having a cross section substantially smaller than that of said tip element, an elongated driving mandrel;

• said sleeve extending from within the material of said tip element and tightly encasing a core of the tip element and forming an alignment sleeve for maintaining said tip in proper orientation when driven by hammer blows applied through said mandrel, the lower end of said mandrel fitting closely but loosely within said alignment sleeve.