JPH0224419A - Simultaneous backfilling with pile drawing, and pile drawer - Google Patents

Abstract

PURPOSE:To carry out a complete backfilling within a short time and to keep the same level of strength and density of soil as before drawing by filling a backfilling material while drawing a pile together with a casing after driving the casing around the pile. CONSTITUTION:A casing 2 is pierced by a byblow hammer 1 so that an existing pile 4 is inserted into the inside of the casing 2. When a holding device 3 as the tip of the casing 2 reaches below the tip of the pile 4, it holds the lower end of the pile 4. While drawing the casing 2 and pile 4 by a heavy machine on which the byblow hammer 1 is hooking, a backfilling material such as a bentonite motar and the like is discharged to the inside of a hollow section caused by the drawing from a discharge pipe 10 attached to the casing 2 and is filled. A filler is supplied from a plant through a rubber hole 11. The pile 4 is removed from the casing 2 after drawing up to the ground.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a pile-pulling and back-filling method that simultaneously pulls out a pile buried in the ground and simultaneously completes the back-filling of a cavity after the pile is pulled out. Regarding drawing machines.

[Conventional technology]

In general, piles, steel sheet piles, H-beams, etc. buried in temporary construction works such as foundation demolition work of existing structures, bridge foundation work 1 port revetment work, water supply and sewerage work, and earth retaining water stoppage work for electric cable gas management construction work, etc. Pile hammers, vibrating pile drivers, pile pullers, etc. are used to remove large-diameter steel pipes and other special piles. For example, a vibrating pile driver applies vertical vibration to the buried pile while attenuating the frictional resistance with the soil on the side while moving the crane. Methods include pulling out piles using tensile force, or using a pile puller, which uses hydraulic chucks to hold buried piles and multiple pulling cylinders that operate vertically to pull out piles, using a base installed in the ground as a reaction force. It depended on

[Problem to be solved by the invention]

However, with such conventional pile pulling machines and methods, the soil at the construction site is sandy, so the cavity may collapse after being pulled out, or in either case, the pile must be backfilled after being pulled out. As a result, the soil at the location could not be maintained at the same hardness as before the extraction, causing ground subsidence of surrounding roads, tilting of nearby buildings, or subsidence of buried pipes. There have been problems such as various accidents and problems such as damage caused by the retaining wall and loosening of the footing of the retaining wall.

This invention was made in view of these conventional problems, and it improves the strength and density of soil by using a construction method and device that simultaneously pulls out existing buried piles and backfills the area where they were pulled out with backfilling material. The aim is to solve the above problems by maintaining

[Means to solve the problem]

This invention involves driving the casing of a pile extractor into the ground as if inserting an existing pile into the ground, gripping the existing pile with a gripping device provided at the lower end of the casing, and holding the existing pile together with the casing. As an invention of a pile pulling and backfilling method in which a pile is pulled out and backfilling material is discharged from a discharge pipe attached to the casing into the cavity created by the pulling out at the same time as the casing is pulled out, and a device used when carrying out this method, the casing is A hammer part for driving into the pile, a casing held by the hammer part and formed to have a length longer than the entire length of the existing pile, and a discharge extending from the above ground position of the casing along the inside thereof to the lower end of the casing. The pile extractor is made of a pipe, and a gripping device for gripping an existing pile is provided at the lower end of the casing.

[Effect]

Since this invention is configured as described above, when the casing holding the existing pile inside is pulled upward, the discharge pipe attached to the casing is simultaneously For example, a backfilling material made by adding cement liquid to bentonite is discharged and supplied, and the cavity is filled with the backfilling material before a cavity is formed.
It is possible to prevent problems or accidents that occur with conventional construction methods.

〔Example〕

The present invention will be explained below based on the drawings. 1 to 3 are diagrams showing an embodiment of the apparatus according to the present invention, and FIG. 4 is a diagram showing an embodiment of the construction method according to the present invention.

In FIG. 1, ▪ indicates a vibro hammer in this embodiment, and 2 indicates a casing gripped by this hammer 1. At its upper end, this casing 2
As shown in the -1 cross-sectional view of the same figure), it has a rectangular cylindrical shape, and is driven into the ground up to point A at the lower end of this rectangular cylindrical portion 2a. The middle part of the casing is shown as a cross-sectional view (C1) of the casing. 3 is a gripping device attached to the lower end of the casing 2, and in FIG. A pair of hooks 5 for gripping a steel guide frame 3a (in the example, rectangular tube shape) and an existing pile 4.
5. The hook 5 is rotatably supported on a rotation shaft 7 provided on a bracket 6 fixed to the guide frame 3a. A pin-shaped stopper 8 abuts the guide frame 3a from the outside to prevent the hook 5 from recessing further into the interior than shown in FIG. 2(a). 9 is a wire rope for pulling up the hook 5 holding the existing pile 4 in synchronization with the casing 2. Reference numeral 10 denotes a discharge pipe, which is attached from the rectangular tube portion 2a (FIG. 1) of the casing 2 along the corner of the casing 2, and opens at the lower end of the guide frame 3a. Reference numeral 11 denotes a protective piece provided near the opening end of the discharge pipe 10, which prevents earth and sand from entering the discharge pipe when the casing 2 is driven into the soil.

The discharge pipe 10 is connected to a high-pressure rubber hose 11 for supplying backfilling material and jet water on the outside of the rectangular tube portion (FIG. 1).

FIG. 3 shows another embodiment in which a pair of hooks 5.5 are each provided with claw portions 5a, 5a,
The configuration other than this hook is exactly the same as the gripping device shown in FIG. 2. This is the buried pile (existing pile) that should be pulled out.
This is an example in which the user can select the one that is more convenient for each type.

Next, a pile pulling and backfilling method using a pile pulling machine having the above configuration will be explained.

First, as shown in Fig. 4(a), the casing 2 of the pile extractor is held at a position directly above where the existing pile 4 is buried, and the vibro hammer 1 is used to penetrate the resistor 4 into the casing 2 (see Figure 4(a)). Figure (b)). Here, the guide frame 3a of the gripping device 3, which forms the tip of the casing 2, is pushed into the ground first, but at this time, the pair of hooks 5.5 are subjected to earth pressure and are in the position shown by the dotted line in Fig. 2 ta+. becomes. That is, the fourth
In Figure (b), when penetrating the casing, the wire rope is pulled (so that the tip of the hook 5 is attached to the guide frame 3a).
comes into contact with. As a hammer for penetrating the casing 2 into the ground, a vibro hammer that reduces frictional resistance through vibration as in this embodiment or a hydraulic hammer is used for clay ground, and the above-mentioned hammer is used for sandy ground. In addition to a hammer, jet water may also be press-fitted from the discharge pipe 10 in some cases. When the lower end of the gripping device 3 provided on the casing 2 reaches below the tip of the existing pile 4, as shown in FIG.
When the hook 5.5 is pulled up by a heavy machine, the hook 5.5 rotates around the rotation shaft 7 and grips the lower end of the existing pile 4, as shown in FIG. 2(a).

Next, pulling out of the casing 2 is started using a heavy machine that grips the vibro 1, and at the same time, backfilling material such as bentonite mortar is discharged from the discharge pipe 10 into the cavity created by the pulling out to continue filling. Then, when the existing piles 4 have been pulled up to the ground to a certain extent, they are tied together with wires from a separate heavy machine, as shown in Figure 4+d).

Next, when the casing 2 and the existing pile 4 are pulled out to the ground (Fig. 4 (e)), the position that should become the cavity is completely filled with backfilling material, and the existing pile 4 is removed from the casing by a separate heavy machine. This method is then completed ((f) in the same figure).

〔Effect of the invention〕

As explained above, according to the present invention, (11) construction method is simple, so even non-specialists can perform construction; (2)
With conventional construction methods, it was difficult to completely backfill the existing pile removal cavity when the ground was sandy, but with the present invention, complete backfilling is possible by discharging bentonite mortar etc. at the same time as removal. (3) Many effects can be obtained, such as preventing problems and accidents such as ground subsidence of peripheral roads, damage due to subsidence of buried pipes, and slope of adjacent buildings, and (4) shortening construction period and reducing construction costs.

[Brief explanation of the drawing]

FIG. 1(a) is a front view of a pile extractor according to the present invention, and FIG.
) Figure (b) is a cross-sectional view taken along line I-1 in figure (a), figure - is a cross-sectional view taken along line nn in figure ta+, and figure 2 (al is a detail of the gripping device of the pile extractor according to the present invention). Figure 3(b) is a sectional view taken along the line ■-■ in aJ, Figure 3(a) is a detailed view of the gripping device of another embodiment, and figure fb is a The IV sectional view and FIGS. 4(a) to 4(f) are explanatory diagrams of the construction method according to the present invention. 1... Part of hammer, 2... Casing, 3...・Gripping device, 4...Existing pile, 1
0...Discharge pipe. Figure 2 CG) (b)

Claims (2)

[Claims] (1) Drive the casing of a pile puller into the ground as if inserting an existing pile into the ground, grip the existing pile with a gripping device provided at the lower end of the casing,
A method for backfilling piles at the same time as they are pulled out, which is characterized in that the piles are pulled out together with the casing, and at the same time, backfilling material is discharged from a discharge pipe attached to the casing into the cavity created by the pulling out. (2) A hammer part for driving the casing into the ground, a casing held by the hammer part and formed to have a length longer than the entire length of the existing pile, and a part of the casing along the inner side from the above ground position of the casing. A pile extractor comprising a discharge pipe reaching a lower end of a casing, the lower end of the casing being provided with a gripping device for gripping an existing pile.