JPH0354209B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to the process of replacing the drilling mud in a trench drilled with self-hardening mud while filling it with self-hardening mud. The present invention relates to a method of mixing muddy water and mud water.

(Prior Art) There is a method in which a trench is excavated while being filled with drilling mud for constructing impermeable walls, earth retaining walls, etc., and then the drilling mud in the trench is replaced with self-hardening mud. The self-hardening mud to be replaced is supplied such that the mixing ratio of the curing agent as a component thereof is different between the lower side and the upper side of the groove. That is, self-hardening muddy water prepared to a high concentration is supplied to the lower side of the groove, while self-hardening muddy water prepared to a low concentration is supplied to the upper side. As a result, the self-hardening mud forms a layered structure in the vertical direction inside the groove depending on the concentration of the hardening agent. The self-hardening mud that has been replaced with the drilling mud in this way is then hardened to form a solidified product with different strengths at the upper and lower sides.

Replacing drilling mud with self-hardening mud is usually done by sequentially injecting the self-hardening mud from the bottom of the trench upwards, but at this time, the drilling mud gets caught up in the self-hardening mud. Dispersed in a thin layer in self-hardening mud. For this reason, the self-hardening mud in each layer becomes non-uniform, and there is a problem in that the resulting solidified self-hardening mud has localized portions with low strength and low imperviousness.

In order to solve this problem, for example, it is possible to stir the self-hardening mud after displacement by air blowing. However, when air blow agitation is used, the self-hardening mud in the grooves is entirely stirred and mixed, so it is not possible to create a difference in strength in the solidified product of the self-hardening mud. This also applies to stirring and mixing using a rotatable stirring blade.

(Objective) Therefore, an object of the present invention is to enable the self-hardening mud to be replaced and the drilling mud mixed into the self-hardening mud to be locally mixed.

(Structure) The present invention is characterized in that the vibrating body is vibrated in the self-hardening mud while the self-hardening mud that has replaced the drilling mud in the trench maintains its fluidity.

(Operations and Effects) According to the present invention, the self-hardening mud can be locally mixed around the vibrating body by the vibration of the vibrating body. Thereby, the self-hardening mud and the thin layer of drilling mud mixed therein can be mixed so that the mixing ratio of the hardening agent is not uniform throughout the trench.

Therefore, it is possible to obtain a homogeneous solidified product of self-hardening mud having different strengths on the upper and lower sides.

(Example) Referring to FIGS. 1 and 2, a trench hole 12 is shown that has been excavated while being filled with drilling mud 10.

After excavating the trench hole 12, the drilling mud 10 in the trench hole
is sent via a pipe 14 to a self-hardening mud production plant 16 installed on the ground, where a hardening agent is added and mixed to produce self-hardening mud. The self-hardening slurry produced in plant 16 is
An inverted T-shaped injection pipe 1 that can be moved up and down connected to
8 into the slot 12. in this way,
By returning approximately the same amount of self-hardening mud water to the trench hole 12 as the amount of the drilling mud water 10 sucked up in the trench hole 12,
Collapse of the wall surface of the slot 12 can be prevented.
In this way, the drilling mud 10 is replaced with self-hardening mud throughout the trench hole 12.

As shown in FIG. 3, while the self-hardening mud water 20 moves upward through the injection pipe 18, which is initially located near the bottom of the groove hole 12, it passes through a plurality of injection ports provided on the horizontal bar of the injection pipe 18. It can be supplied into the slot 12 by blowing out from 18a. Since the self-hardening mud 20 has a higher specific gravity than the drilling mud, it
2, but during the injection of self-hardening mud 20,
The drilling mud 10 is rolled into the self-hardening mud 20 at the interface between the two muds (see the arrow). As a result, a large number of the drilling mud 10 is mixed into the self-hardening mud 20 in the form of a thin layer. (See Figure 4).

The self-hardening muddy water 20 is also supplied such that the blending ratio of the curing agent is different between the upper side and the lower side of the slot 12. That is, on the lower side, there is self-hardening mud water 20 with a higher concentration of the curing agent than on the upper side.
is supplied and its concentration is adjusted in said plant 16. Therefore, in the groove hole 12, a plurality of layers (not shown) of self-hardening muddy water 20 having different concentrations of the curing agent are formed in the vertical direction thereof.

To make the self-hardening mud 20 in each layer uniform by mixing the thin layer of mixed drilling mud 10 and the self-hardening mud 20 while substantially maintaining the mixing ratio of the hardening agent in each layer of the self-hardening mud 20. , self-hardening mud 2
0 maintains fluidity, the vibrating body 22 is vibrated in the self-hardening mud 20.

As shown in FIGS. 1, 2, and 4, the vibrating bodies 22 include a plurality of vibrating bodies arranged parallel to each other on both sides of the horizontal bar of the injection tube 18, and a flexible connecting member 24.
It can be used by being connected to the horizontal bar via.

An example of the vibrating body 22 is shown in FIG. This vibrating body 22 is almost similar to a concrete vibrator, and includes a frequency motor 3 having a rotating shaft 30 to which a pair of eccentric weights 28 are fixed within a vibrating cylinder 26.
2 is built-in. The motor 32 is electrically connected via a cord 38 to a frequency converter 36 connected to a power source 34 installed on the ground, and by changing the frequency, the rotational speed of the motor 32 is changed accordingly. You can change the vibration frequency. The vibrating body in this example has a radius of approximately 10 from its center line.
It is set to vibrate in the cm range.

As shown in FIG. 4, the vibrating body 22 moves up inside the slot 12 together with the injection pipe 18 while vibrating, and at this time, the self-hardening mud of each layer is hardly affected by the self-hardening mud of other adjacent layers. The hard mud water 20 and the thin layer of drilling mud water 10a mixed therein can be mixed. As a result, the mixed drilling mud was 10
b is uniformly dispersed in the self-hardening mud water 20. When the vibrating body 22 is raised, the vibration may be made to continue without stopping as described above, or the vibration may be stopped only near the boundary of the self-hardening mud layer.

6 and 7 show an example in which a precast concrete plate 40 is inserted as a structure into the groove hole 12, and then both muddy waters are mixed. Due to the presence of the precast concrete plate 40, the space into which the injection pipe 18 and the vibrating body 22 can be inserted is significantly limited, but the vibrating body 22 in particular can sufficiently exhibit its performance even if it is small, and the shape is suitable for the insertion space. Since it is easy to select the size and size, there is no problem in pouring the self-hardening muddy water 20 and mixing both muddy waters. Moreover, even if the vibrating body 22 comes into contact with the wall surface of the slot hole 12, it hardly scrapes away the ground.

The vibrating bodies 22 placed on both sides of the precast concrete plate 40 vibrate while pulling up the injection pipe 18 in the same manner as described above. This results in
Both muds are mixed uniformly.

In addition, in any of the above examples, the vibrating body 22
Therefore, the raising of the injection pipe 18 can be carried out while supplying the self-hardening muddy water 20 from the injection pipe 18, or after supplying a predetermined amount of the self-hardening muddy water 20 near the bottom of the slot 12. Also,
The vibrating body 22 may be used alone without being attached to the injection tube 18.

The self-hardening muddy water 20 of each layer, which has been uniformly mixed from the bottom to the top of the slot 12 in this way, is then hardened to become a solidified product with different strengths for each layer, and the solidified product has uniform strength and strength in each layer. It will have uniform water impermeability. Therefore, especially
It is ideal for constructing impermeable walls that are subject to large water pressure, earth retaining walls that require high strength, etc., and also allows for thinner wall thickness.

[Brief explanation of drawings]

Figures 1 and 2 are vertical cross-sectional views as seen from the front and side of the trench, and Figure 3 is a vertical cross-sectional view similar to Figure 1, schematically showing the injection situation of self-hardening mud. , FIG. 4 is a vertical sectional view similar to FIG. 1 schematically showing the state during mixing of self-hardening mud, FIG. 5 is a sectional view showing an example of a vibrating body, and FIGS. 6 and 7.
The figure is a longitudinal sectional view of a slot similar to that shown in FIGS. 1 and 2, in an example in which a precast concrete plate is inserted into the slot. 10, 10a, 10b: drilling mud, 12: trench, 18: injection pipe, 20: self-hardening mud, 22: vibrating body.

Claims (1)

[Claims] 1. In the process of replacing the drilling mud in a trench excavated while filling with drilling mud with a plurality of self-hardening mud layers having different blending ratios of hardening agents, the drilling mud mixed into each layer is mixed into each layer. A method for mixing drilling mud and self-hardening mud, comprising vibrating a vibrating body in the self-hardening mud while the self-hardening mud maintains fluidity in order to mix the self-hardening mud with the self-hardening mud.