To easily penetrate a hollow pipe into a hard ground without using special excavator such as an earth auger by adding a simple improvement to a tip of a usually hollow pipe for sand pile development.

A plurality of excavating bits 2 are attached on an inner periphery or an outer periphery of a lower end of a hollow pipe 1 for sand pile development so as to protrude downward. A plurality of nozzles 4 for ejecting high pressure jet water toward a lower direction are arranged on the outer periphery of a lower end of the hollow pipe 1. Accordingly, a hard ground is crushed by bits 2 utilizing vibration of a vibration hammer arranged on a head of the hollow pipe 1, and the hard ground is destroyed and loosened by the high pressure jet water from the nozzles 4 to easily penetrate the hollow pipe 1 into the hard ground.