Mechanism of Cross Jet and Its Application

Hiroshi Yoshida1 and Kunio Saito2

1Chemical Grouting Co., Ltd. 2-2-5, Toranomon, Minato-ku, Tokyo, 105-0001, Japan.

2Research and Development Initiative, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan.


The main feature of cross jet grouting is to eject water from two nozzles attached to the jet monitor pipe. One jet directed upwards at some obliquity is made to meet with another jet directed downwards at a point of some distance from the jet monitor. By arranging the two jets in this way, the redial distance at which the energy of jetting is subsided is fixed, making the circumferential surface of the solidified column smooth, irrespective of existence of thinly stratified deposits of native soils. The mechanism of the cross jet grouting as above is first described briefly and two cases of its application are introduced in which it was used as a starting platform of the shield tunneling.

Keywords: Jet Grouting; shield tunnel; stratified soil deposit.

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