US 4,116,012 AGranted

Method of obtaining sufficient supporting force for a concrete pile sunk into a hole

AssigneeNippon Concrete Industries Co. Ltd.

InventorsNobuyuki Abe, Osamu Watanabe, Koji Nunokawa, Ichiro Tanaka, Masao Manabe

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Abstract

The present invention relates to a process of setting a concrete pile without noise or vibration which is thereby effective to decrease city noises. A concrete pile is sunk into a leading hole substantially concurrently with the progress of the excavation thereof. After the pile has been sunk through a desired distance, another supporting hole is excavated below the pile. A solidifying material, such as cement milk, mortar, or cement concrete including a cement expansion agent of calcium sulfoaluminate system or lime system, is poured into the supporting hole. The solidifying material is expanded within the supporting hole and permeates into the circumferential wall thereof, which is loosened by the excavation, so as to retighten the wall. Therefore, sufficient supporting force can be obtained.

Claims10

Dependent claims

A method for setting a concrete pile and obtaining secure support for the lower end of the pile which comprises:

inserting a screw auger having a bit at the forward end thereof through a hollow concrete pile and rotating said auger and bit to bore a leading hole just below the lower end of said pile, and advancing the pile into the hole until the desired depth is reached;
excavating a hole having a diameter at least as large as the diameter of the pile underneath the lower end of the pile;
completely filling the hole excavated underneath said pile with a cementitious material and rotating said bit so as to mix the cementitiuos material with gravel and debris remaining in the hole after excavation, said cementitious material containing from about 5% to 30% of an expanding agent selected from the group consisting of calcium sulfoaluminate and lime and displaying substantial expansion upon hardening;
withdrawing the auger from the pile, and
seating the pile within the cementitious material by advancing the pile a short distance downwardly into said material to further compact the cementitious material below the lower end of the pile and to obtain a secure support for the pile as the cementitious material expands upon hardening.

2 more elements

A method for setting a concrete pile and obtaining secure support for the lower end of the pile which comprises:

inserting a screw auger having a bit at the forward end thereof through a hollow concrete pile and rotating said auger and bit to bore a leading hole just below the lower end of said pile and advancing the pile into the hole until the desired depth is reached;
excavating a hole having a diameter at least as large as the diameter of the pile underneath the lower end of the pile;
completely filling the hole excavated underneath said pile with a cementitious material and rotating said bit so as to mix the cementitious material with debris remaining in the hole after excavation;
said cementitious material containing an aluminum powder gas generating agent in sufficient amount to cause a substantial expansion of said cementitious material;
emplacing a second cementitious material in the lower portion of said pile in a layer atop said first cementitious material, said second cementitious material having a lower specific gravity and a shorter setting time than said first cementitious material whereby said second cementitious material forms a seal and prevents escape of gas from said first cementitious material thereby causing said first cementitious material to expand within said excavated hole to provide a secure support for the pile, and
withdrawing the auger from the pile before either of said cementitious materials harden.

3 more elements

Dependencies are inferred from the claim text.