JPS63219728A - Settlement of bottomless well cylinder - Google Patents

Abstract

PURPOSE:To safely and quickly settle a bottomless well cylinder by a method in which gravel is charged into the space between the periphery of a well and the ground and scooped out from window holes provided near the cutting edge of the well to settle the well into the ground by lessening the frictional force of the periphery. CONSTITUTION:Gravel 5 is charged into the space between the periphery of well formed by the cutting edge 7 of the cutter 2 of a bottomless well cylinder 1 and the ground 6. The basal part of the cutter 2 of the well 1 is provided with a number of window holes 3 at given intervals. The gravel 5 is scooped out from the holes 3, whereupon the gravel 5 in the space settles down under the gravity to generate a downward frictional force on the periphery of the well 1, thereby permitting the well 1 to settle down. The bottomless well cylin der 1 can thus be safely settled down without disturbing the surrounding ground.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a construction method for sinking a bottomless well.

[Prior Art] Resistance forces against well sinking include bottom support force and surface friction force.

To reduce the bottom supporting force, simply excavate and remove the ground at the cutting edge, but to reduce the surface friction force, it is necessary to forcibly create an air curtain or water curtain on the outer circumferential surface of the well, or to
Various construction methods have been used, such as the wall flow effect described in Publication No. 3-7723.

However, these do not have the effect of generating negative friction on the outer peripheral surface of the well.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for sinking a bottomless well that can easily sink a well in either a land layer or an underwater layer due to the sedimentation and anti-friction effect of spatial gravel. There is a particular thing.

[Means for Solving the Problems] The means of the present invention is to introduce gravel into the space between the ground and the outer circumferential surface of the well formed by the cutting edge of the well, and to fill the space between the ground and the outer peripheral surface of the well through a plurality of window holes opened near the cutting edge of the well. By scraping out the gravel, the spatial gravel settles due to the action of gravity, and this settling action generates a downward frictional force (negative friction) on the outer circumferential surface of the well, causing the well to sink.

[*Example] Fig. 1 shows the land excavation method, and Fig. 2 shows an example of the underwater method.

In each figure, 1 is a bottomless well, and 2 is a cutting edge 7. Window holes 3 are made at required intervals at the base of the blade mouth 2. 4 is a space formed between the bottomless well 1 and the ground 6 by the cutting edge 7 of the cutting mouth 2, and gravel 5 is put into this space 4.

In the case of FIG. 1, a part of the space gravel 5 is scraped out from the window hole 3 by hand.

As shown in Figure 2, the space gravel 5 is removed from the window hole 3 by a diver underwater.
Either a part of the well is scraped out, or the water in the well is pumped up with a submersible pump 8 and injected onto the space gravel 5. In this way, a downward flow is generated in the space gravel, and water collects at the window hole, and a part of the space gravel flows out due to the flow velocity. The space gravel descends following the scraped out gravel, and negative friction is generated on the outer peripheral surface of the bottomless well 1, promoting the sinking of the well 1.

[Effects of the Invention] According to the present invention, it is possible to safely and quickly promote the sinking of a bottomless well without disturbing the surrounding ground.

[Brief explanation of drawings]

The drawings show an embodiment of the sinking construction method for bottomless wells according to the present invention, and FIG.
Figure 2 is a longitudinal sectional front view showing the underwater tall construction method. 1...bottomless well 2...blade mouth 3...window hole 4...
・Space 5... Space gravel 6... Ground 7... Cutting edge No. i, Figure 2, June 7, 1986

Claims (1)

[Claims] Gravel is poured into the space between the well outer circumferential surface formed by the cutting edge of the well and the ground, and by scraping out the gravel through multiple window holes created near the cutting edge of the well, the space gravel settles under the action of gravity. This sedimentation method generates downward friction (negative friction) on the outer surface of the well, causing the well to sink.