JPH0615765B2 - Reinforcing material insertion method in deep mixed consolidation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a deep mixed consolidation method for constructing an earth retaining wall or the like in soft ground, and in particular, a reinforcing material is arranged in the mixed consolidation soil. Regarding how to insert.

<< Background of the Invention >> The present inventors have previously developed the following deep mixed consolidation method using a reinforcing material.

As shown in FIG. 7, cement milk, for example, is injected as a solidifying agent into the soil in the columnar region in the soft ground, and the mixture is stirred and mixed.
To form. Although this soil cement column row 10 is solidified with time, a reinforcing material 12 made of, for example, a reinforcing bar is inserted into this column row 10 before solidification.

Here, even if the reinforcing material 12 is randomly inserted, the reinforcing effect is not so large. In order to obtain a large reinforcing effect with the minimum reinforcing material 12, as shown in the figure, if earth pressure acts on the soil cement column 10 in the direction of arrow A, the reinforcing material is applied to the earth pressure acting surface side. 12 are arranged and inserted.

When earth pressure acts on the solidified cement cement column row 10 as shown by arrow A, a tensile force acts on the earth pressure acting surface side and a compressive force acts on the opposite side. Soil cement shows considerable strength against compressive force, but it is weak against tensile force and easily cracks.

Therefore, if the reinforcing material 12 is arranged in the portion where the tensile force acts as described above, a great reinforcing effect can be obtained. However, for that purpose, it is necessary to firmly bond the reinforcing material 12 to the soil cement.

As a result of repeating the construction experiment of the above-mentioned deep mixed consolidation method, it was found that it is very troublesome to insert the reinforcing material in a predetermined position in an orderly manner especially when the column row is deep. Further, if the reinforcing bar 12 is simply inserted into the soil cement column row 10, the bonding force between the reinforcing material and the soil cement is weak, and the reinforcing material 12 does not have the tensile force described above.
Did not show very effective resistance, and the reinforcement effect as expected was not obtained.

«Object of the invention» An object of the present invention is to easily carry out the work of orderly arranging and inserting the reinforcing material at a predetermined position in the mixed solidified soil when carrying out the above-mentioned deep mixed solidified soil construction method. The binding force between the soil and the reinforcing material inserted into it is increased, and when the tensile force acts on the mixed solidified soil, the reinforcing material shows a sufficiently large resistance force, making it easy to construct a strong retaining wall. To be able to do it.

<< Outline of the Invention >> Therefore, in the present invention, first, a plurality of long rods arranged in a straight line or in a fan shape and a plurality of long rods which are laid across in a direction orthogonal to the rods and are fixed to each other. A reinforcing member including a plurality of connecting cross members that are integrated in a state of being arranged in parallel at intervals is provided in advance.

In addition, an insertion jig having a structure that is applied along the longitudinal direction of the reinforcing material and having a grip portion protruding at the upper end is prepared, and the reinforcing material is attached to the insertion jig. At the same time, the reinforcing material is suspended vertically from the vibration type pile driver.

The insertion jig and the reinforcing material suspended in the vibration type pile driver are driven into the mixed solidified soil to a predetermined depth while vibrating through the gripping portion, and then the reinforcing material is removed from the insertion jig. , Pull out while vibrating only the above insertion jig.

<< Embodiment >> FIG. 1 shows a reinforcing member 100 according to a first embodiment of the present invention. Reference numeral 1 is a reinforcing bar as a long bar. Five reinforcing bars 1 are arranged in parallel at predetermined intervals, and the reinforcing bars 1 are integrated by connecting cross members 21, 22, 23, 24.
00 is configured.

The connecting horizontal members 21, 22, 23 are made of short linear reinforcing bars, and short reinforcing bars are laid across in an orthogonal direction with respect to the arrangement of the five reinforcing bars 1, and the intersections with the reinforcing bars are fixed by welding. The connecting cross member 21 is fixed to the upper end side of the arrangement of the reinforcing bars 1, and the connecting cross members 22 and 23 are fixed to the lower end side.

The connecting horizontal members 24 are made of chevron steel, and the valley portions of chevron steel are applied to the lower ends of the five rebars 1 and fixed to each rebar 1 by welding.

Five reinforcing bars 1 by these four connecting cross members 21-24
Are integrated in a predetermined array to form one unitized reinforcing member 100. When this reinforcing material 100 is inserted and disposed at a predetermined position of the soil cement column 10 in the deep consolidation step described above with the reinforcing bar 1 in the vertical direction,
The reinforcing bar 1 corresponds to the reinforcing material 12 in FIG. At this time, since the relative positional relationship of the five reinforcing bars 1 is never disturbed, the arrangement of the reinforcing bars 1 in the soil cement column array 10 becomes extremely orderly.

Further, the connecting horizontal members 21 to 24 act as a fixing plate protruding in the lateral direction with respect to the vertical reinforcing bar 1, and the mechanical coupling force between the soil cement and the reinforcing bar 1 becomes very large. That is, when a tensile force acts on the soil cement column row 10 as described above, the connecting cross members 21 to 24 act extremely effectively like anchors and exert a large force to resist the tensile force. Reinforce column 10 well.

Further, a connecting cross member 24 made of angle steel is fixed to the lower ends of the five rebars 1, and the ridgeline of the angle steel is directed downward.
It has the effect of reducing the force required to insert it.

When inserting the reinforcing material 100 into soil cement, an insertion jig 200 as shown in FIG. 3 is used as an auxiliary tool, and a vibration type pile driver 300 as shown in FIG. 5 is used. The procedure is as shown in FIG.

First, the structure of the insertion jig 200 will be described with reference to FIG. This insertion jig 200 is made of a steel plate, and has a flat rectangular tube 41 that accommodates the reinforcing member 100 having the structure shown in FIG. The grip 42, a guide groove 43 formed in the vertical direction on the center line of the rear surface of the rectangular tube 41, and a plurality of bolts 44 that are detachably screwed into predetermined positions of the rectangular tube 41 are provided.

The vibrating pile driving machine 300 shown in FIG. 5 includes a base machine 61 that travels on soft ground with a caterpillar, a guide post 62 that is vertically attached to the base machine 61 and that is made of H-shaped steel, and a crane wire 64. Vibration unit 63 that is suspended and moves up and down along the guide post 62.
And a guide arm 65 for the insertion jig 200 attached to the lower end portion of the guide post 62.

The operation of driving the reinforcing material 100 is performed as follows. First, the reinforcing material 100 is inserted into the inside of the rectangular tube 41 of the insertion jig 200 from the lower end side, and as shown in FIG.
The connecting horizontal member 24 is placed in such a state that the lower end opening of the rectangular tube 41 is closed. In the stored state, the bolt 44 is screwed into the bolt hole of the rectangular tube 41. Then, the bolt 44 intersects immediately below the connecting cross member 21.

Next, as shown in FIG. 5 and FIG.
The upper end grip portion 42 of the insertion jig 200 in which is set is sandwiched by the chuck of the vibration unit 63 of the vibration type pile driver 300, and the vibration unit 63 is lifted up to a predetermined position.
The insertion jig 200 is suspended from the vibration unit 63. In this suspended state, the reinforcing member 100 inside the insertion jig 200 is suspended within the rectangular tube 41 by the bolts 44 hooking on the connecting cross members 21. Further, the guide groove 43 of the suspended insertion jig 200 is inserted into the vibration type pile driver 3
00 of the guide arm 65.

Then, the base machine 61 is appropriately moved to position the suspended insertion jig 200 at a predetermined position above the soil cement column row 10. Next, as shown in FIG. 6, while vibrating the vibrating unit 63, the vibrating unit 63 is moved downward, and the insertion jig 200 is pressed downward and slid. The pressing force applied to the insertion jig 200 is applied from the lower end of the rectangular tube 41 to the connecting cross member 2.
4, the reinforcing member 100 is also pressed integrally downward. That is, while the reinforcing material 100 is housed in the insertion jig 200, both are embedded in the soil cement column row 10 while vibrating. Here, since the lower end opening of the square tube 41 is almost closed by the connecting cross member 24 made of angle steel, the soil cement hardly enters the square tube 41.

After the insertion jig 200 and the reinforcing material 100 are inserted to a predetermined depth, the bolts 44 attached to the upper portion of the insertion jig 200 are removed, and the square tube 41 and the reinforcing material 100 are unhooked. Then, while vibrating the vibrating unit 63, the unit 63 is pulled up by the wire 64. Then, the insertion jig 200 ascends in the vertical direction together with the vibration unit 63, but since the bolt 44 is removed, the reinforcing material 100 is left in the soil cement column 10. This is the state shown in FIG.

In this way, the reinforcing member 100 in which the five reinforcing bars 1 are integrated in parallel by the connecting cross members 21 to 24 is inserted into the inserting jig 200.
With the use of the vibration type pile driver 300, it can be correctly inserted vertically at a predetermined position. That is, the work of orderly inserting and inserting the reinforcing material in the soil cement casting line 10 can be performed easily and highly efficiently.

FIG. 2 shows a reinforcing member 110 according to the second embodiment of the present invention. In the embodiment shown in FIG. 1, when the five reinforcing bars 1 are viewed in a plan view, the end surfaces of the reinforcing bars 1 are arranged in a straight line. In the embodiment shown in FIG. 2, when the five rebars 1 are viewed in a plan view, the end faces of the rebars 1 are arranged on one arc. That is, the connecting horizontal members 31, 32, 33 made of short reinforcing bars are formed in an arc shape,
The five reinforcing bars 1 are arranged in parallel at a predetermined interval, the connecting cross members 31, 32, 33 are bridged over these, and the intersections of each are welded. Further, the lower end portion of each rebar 1 is bent into a J shape inside the arc. 1a indicates a J-shaped bent portion.

The reason why the reinforcing bars 1 are arranged in an arc shape as shown in FIG. 2 is that the reinforcing bars 1 are arranged in an arc shape in a part of the circular cross section of the soil cement column.

FIG. 4 shows an insertion jig 210 fitted to the reinforcing material 110 shown in FIG. The insertion jig 210 is a circular arc plate 51 applied to the reinforcing member 110, a grip portion 52 that is integrally provided on the upper end of the circular arc plate 51, and is sandwiched by the vibration unit 63, and is perpendicular to the center of the back surface of the circular arc plate 51. The guide groove 53 provided in the direction and the connecting cross member 3 of the reinforcing member 110.
U-bolt 54 for holding 1 and mounting it on arc plate 51
It has and.

When the reinforcing material 110 is attached to the insertion jig 210, the J-shaped bent portion 1a of each reinforcing bar 1 is in the form of embracing the lower end edge of the circular arc plate 51, and the vibrating pile driving machine 300 inserts the insertion jig 200 into the insertion jig 200.
When pushing down, the force is applied from the arc plate 51 to the reinforcing bar 1.
Be transmitted to. When the reinforcing material 110 and the insertion jig 210 are inserted to a predetermined depth, the U bolt 5 is inserted as in the previous embodiment.
When 4 is removed and the insertion jig 210 is vibrated and pulled up, only the reinforcing material 110 remains in the soil cement.

<< Effects of the Invention >> As described in detail above, by carrying out the above-mentioned deep-mixed solidification method using the reinforcing material insertion method according to the present invention,
The work of inserting and arranging a large number of reinforcing materials in order as designed during mixing and consolidation can be performed easily and efficiently. Not only that, the mechanical cross-link between the reinforcing material and the mixed solidified soil becomes extremely strong due to the connecting cross member of the reinforcing material, and in particular, the reinforcing material has an extremely large resistance to the tensile force acting on the solidified soil. Indicates. That is, a good construction result with a large reinforcing effect can be easily obtained, and it becomes easy to construct a soil retaining wall or the like having a large strength in the soft ground.

[Brief description of drawings]

FIG. 1 is a perspective view of a reinforcing member according to a first embodiment of the present invention,
FIG. 2 is a perspective view of the reinforcing material according to the second embodiment, FIG. 3 is a view showing an insertion jig adapted to the reinforcing material of the first embodiment, and FIG. 4 is adapted to the reinforcing material of the second embodiment. The figure which shows an insertion jig, FIG. 5 is a figure which shows the structure of the vibration type pile driver used when implementing the reinforcing material insertion method of this invention, and FIG. 6 is the book which used the said vibration type pile driver. FIG. 7 is a perspective view showing the outline of a state in which the reinforcing material is arranged and inserted in the deep-layer mixed solidified earthing method. 1 ... Reinforcing bar, 21-24 ... Connection horizontal member 110 ... Reinforcing material, 31-33 ... Connection horizontal member 200 ... Insertion jig, 210 ... Insertion jig 300 ... Vibration type pile driver

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kimio Umezu 2-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (56) Reference JP-A-61-229016 (JP, A)

Claims (1)

[Claims] 1. A method of arranging and inserting a reinforcing material at a predetermined position of mixed consolidated soil before consolidation formed in soft ground, comprising a plurality of long rods arranged in a straight line or a fan shape. When,
They are laid across these rods in the orthogonal direction and fixed,
A reinforcing member composed of a plurality of connecting lateral members integrally integrating the rod members arranged in parallel at a predetermined interval is provided in advance, and is composed of a structure applied along the longitudinal direction of the reinforcing member. , Prepare an insertion jig with a gripping part protruding from the upper end, attach the reinforcing material to this insertion jig, and hang the reinforcing material vertically with the insertion jig on a vibrating pile driver. While vibrating the insertion jig and the reinforcing material through the gripping portion, they are driven into the mixed solidified soil to a predetermined depth, then the reinforcing material is removed from the insertion jig, and only the insertion jig is A method for inserting a reinforcing material in a deep mixed solidified earthing method, characterized in that the material is pulled out while vibrating through a grip portion.