A method for driving large-diameter pipe piles in rubble-filled soil layers

Abstract

This invention discloses a method for driving large-diameter pipe piles in rubble-filled soil layers, belonging to the field of pile foundation engineering construction. The method employs a casing drilling rig, whose power head can be selectively connected to either a down-the-hole hammer drill or a reaming drill, with double clamps at the top and bottom to hold the casing or pipe pile respectively. During construction, the down-the-hole hammer drill is first used for rock-breaking drilling, simultaneously lowering the steel casing to the design depth to form a temporary retaining wall. After backfilling with rock debris, the steel casing is pulled out. Subsequently, the reaming drill is switched to, and in-situ reaming drilling is performed while simultaneously driving the pipe pile to the design elevation. This method integrates a dust removal and slag removal system to collect the dust and slag discharged from the borehole, uses an electromagnetic vibration pile-pulling tong with sliding rail positioning to retrieve the steel casing, and utilizes a portable measuring device to control the verticality of the driven pile. This invention solves the problems of easy borehole collapse, grout leakage, off-center drilling, and large concrete filling coefficient in traditional rubble-filled soil layers, achieving large-diameter pipe pile driving construction with no mud slurry retaining wall and low pollution.

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