Kajima Corporation

Chemical Grouting Company, Ltd.

Chemical Grout Company, Ltd.

Hiroshi Yoshida

Mitsuhiro Shibazaki

Hiroaki Kubo

Shunji Jinbo

Teruo Yahiro

An apparatus for forming a pile having a predetermined pile diameter in a cast-in-place pile includes an agitating apparatus. The agitating apparatus includes a pipe having a longitudinal axis which extends into the ground, and two nozzles are respectively disposed on and supported on the pipe. Each of the plurality of nozzles produces a directional jet flow of liquid. Additionally, an arrangement is provided for supplying liquid under pressure to the two nozzles. The two nozzles are spaced apart a predetermined distance along the longitudinal axis of the pipe, and are oriented such that fluid flow from the two nozzles intersects at a predetermined radial distance from the pipe, so that a cross jet flow is established at the predetermined radial distance to establish an outermost mixing of hardener and settable mixture. A final hardened pile diameter forms at the predetermined radial distance.

Method for controlling a final pile diameter in a cast-in-place of

An apparatus for forming a pile produces a predetermined pile diameter in a cast-in-place pile. The apparatus includes an agitating arrangement which includes a pipe extending longitudinally into the ground, a plurality of agitating blades supported by the pipe for agitating a settable mixture, and a plurality of nozzles respectively disposed on and supported by respective ones of the agitating blades. Each of the plurality of nozzles produces a directional jet flow of liquid. Also, an arrangement is provided for supplying liquid under pressure to each of the plurality of nozzles. At least two of the plurality of nozzles are disposed such that the two nozzles are spaced apart a predetermined distance along the longitudinal direction of the pipe, and are oriented such that fluid flow from the two nozzles intersects, as viewed along the longitudinal axis of the pipe, at a predetermined radial distance from the pipe, forming a cross jet flow at the predetermined radial distance to establish an outermost mixing of hardener and settable mixture, thereby forming a final hardened pile diameter at the predetermined radial distance.

The present invention relates to a consolidating agent injecting apparatus having a nozzle mounted at the end of a pipe. The apparatus is inserted in a guide hole formed in the ground and the nozzle injects a high pressure jet liquid in a radial direction. The injecting direction of the nozzle is downwardly inclined from the horizontal direction within a range from 15 to 45 degrees. The present invention also relates to a ground improving injecting apparatus having first and second nozzles, mounted at the end of a pipe, for injecting a high pressure liquid and a ground improving injection liquid. The first nozzle comprises a plurality of annularly-arranged nozzles. The pipe is inserted into a hole dug in the ground and the high pressure liquid and the ground improving injection liquid are injected from the first and second nozzles. As the pipe is drawn up from under the ground, the ground is dug and grouted and the ground improving injection liquid is injected to form an underground columnar consolidation body and thereby improve the ground. The consolidating agent injecting apparatus and ground improving injection apparatus of the present invention form a consolidation body of a large section area for improvement of the ground, without transitions of the jet streams to turbulent flow.

Consolidating agent injecting apparatus and injecting apparatus for

The present invention relates to a method for improving the ground of a large area. The method comprises the steps of inserting a pipe into a hole previously dug in the ground, injecting a high pressure liquid and a ground improving injection liquid from an injecting apparatus attached to the tip of the pipe, drawing up the pipe, grouting the ground, and injecting the ground improving injection liquid to thereby form an underground columnar consolidation body for improving the ground. The drawing-up operation of the pipe is executed while applying vertical vibration to the pipe. Thus, a consolidation body of a large area for improvement of the ground is obtained without concave and convex portions.

Method of improving ground of large area

The present invention relates to a method of improving the ground of a large section area. A double pipe, having a first nozzle directed in the lateral direction and a second nozzle surrounding the first nozzle, is inserted into a hole dug in the ground. A ground improving agent is injected at high pressure from the first nozzle through one pipe of the double pipe. A reproduced slurry, obtained by reproducing grouted slimes, is injected from the second nozzle through the other pipe of the double pipe at a lower pressure than the pressure of the ground improving agent. While rotating, the double pipe is lifted up from under ground. The ground improving agent, injected at the high pressure, is surrounded by the reproduced slurry injected at the lower pressure. The frictional resistance between the ground improving agent and the sediments is reduced, the arrival distance of the ground improving agent is increased, and the abrasive effect is obtained. Instead of surrounding the first nozzle, the second nozzle can be arranged at a position closer to the first nozzle. Further, a triple pipe, having the first and second nozzles and a third nozzle surrounding the first and second nozzles, can be inserted into the hole dug in the ground. The ground improving agent is injected at high pressure from the first nozzle through a first pipe in the triple pipe. The reproduced slurry, obtained by reproducing the grouted slimes, is injected from the second nozzle through a second pipe in the triple pipe at a lower pressure than the pressure of the ground improving agent. A gas is blown out from the third nozzle through a third pipe in the triple pipe. While rotating, the triple pipe is lifted up from under the ground. Both the ground improving agent injected at the high pressure and the reproduced slurry injected at the lower pressure are surrounded by the gas. This method results in reproduction of the grouted slimes, assurance of the necessary injection amount of the grouting ground improving agent, and suitabloe jet stream dynamic pressure distribution.

Method for improving ground of large section area

This invention concerns with a high pressure grouting process. For lateral cutting of earth in the ground, a high speed core water jet, having its injection velocity equal to at least a half of the sonic one and surrounded by an air ring jet is used. For solidifying the crushed earth, a cement milk is used which is poured separately and at a lower level than that of the air-water combined jet into the space in the ground which space has been formed by the action of the core water jet.

Process for the high-pressure grouting within the earth and apparatus

The method of digging by piercing soil and rock with a jet of liquid discharged at high velocity from a nozzle together with high-velocity air jets discharged from another nozzle arranged concentrically around the liquid nozzle, characterized by the velocity of the air jets being at least half the velocity of sound.

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Tokorozawa, Japan

Hiroshi Yoshida