JPS62215722A - Charging of soil and sand composition into water - Google Patents

Abstract

PURPOSE:To completely prevent the occurrence of muddling of water by a method in which a soil composition formed by mixing soil with a binder with or without a hardener is discharged from a tube into water and also a coagulant is jetted to near the end of the discharge tube. CONSTITUTION:A soil composition 3 containing a binder giving caking power to soil particles and sand grains and also to ensure a given fluidity or a hardener to harden and solidify the soil particles with the binder is supplied by a pump into a discharge tube 1 and discharged from the discharge end 1a to deposit the layer of the composition 3 on the bottom ground (l) under water. Although a suspension layer 4 is formed on the periphery of the discharged position when the grain size of soil is smaller or the discharge speed is high, the suspension layer 4 is coagulated by a coagulant jetted from the end 2a of a coagulant sending pipe 2 and sedimented on the soil composition 3 so deposited to prevent the occurrence of muddling. The prevention measure against muddling when charging the soil composition can be taken at low cost.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method of injecting a soil composition into water, which is used when covering the water bottom with soil and creating an embankment and an artificial island. Concerning methods of preventing pollution.

(Background of the Invention) When constructing an artificial island by covering the bottom of a river, lake, marsh, sea, etc. with earth and embankment, earth and sand are poured into the water. However, with this general sediment, the sediment particles separate and settle in the water, so the coarse particles settle and accumulate first, while the fine particles settle slowly and become suspended in the water.
Because much of the sediment is deposited in the upper layer, the created ground is heterogeneous, and the areas containing many fine particles have a high water content and are extremely soft, and the water quality becomes extremely polluted when soil is added. There was a problem.

Therefore, the present applicant has previously developed a sand and sand composition made by mixing general sand and a binder, or a mixture of these and a hardening agent.

The binder in this sediment composition provides caking properties between the sediment particles,
The curing agent is a material for solidifying earth and sand. Therefore, when this sediment composition is put into water, it does not separate into pieces and settles as a whole, so it is deposited in a very homogeneous state, and there is little water uptake in the water after time. Therefore, it has the advantage of being able to maintain a dense state with little density loss.

(Problems to be Solved by the Invention) However, even with such a sediment composition, the sediment particles may separate when put into water, resulting in water pollution in the vicinity of the crest portion.

The causes of this are (1) when the soil in the sediment composition is fine, (2) when the fluidity of the composition is too low in the mixed state, (3) when the discharge speed is too high, etc. . Therefore, it is sufficient to remove the factors (1), (2), and (3) before putting the product into water, but in reality, it is not possible to completely eliminate all of these factors.

Measures to prevent and cover water pollution include closing off the pouring area;
Pump up the water inside the cofferdam according to the pouring height,
Generally, it is discharged after coagulation and sedimentation treatment, but
This method requires a separate coagulation and sedimentation tank, which is extremely costly, especially in offshore construction.

This invention has been made in view of the above problems, and makes it possible to completely prevent the occurrence of pollution by intensively discussing pollution prevention measures at the discharge end of the discharge tube, which is the source of pollution. The purpose is to

(Means for Solving the Problems) In order to achieve the above object, the present invention provides soil and sand, a binder,
Alternatively, it is characterized in that a sand and sand composition formed by mixing earth and sand, a binder, and a hardening agent is discharged into water from a discharge tube, and a flocculant is spouted near the discharge end.

(Function) The suspended particles flying up near the discharge end will be flocculated and deposited by coming into direct contact with the flocculant.

(Embodiment) FIG. 1 shows a first embodiment of the method of this invention.

In the figure, 1 indicates that the discharge end 1a is at the bottom of the water! The discharge pipe 2 facing 3F is a flocculant pressure-feeding vibrator which is parallel to the outer circumference of the discharge pipe 1 and whose ejection end 2a is located at the periphery of the ejection end 1a.

The earth and sand composition is supplied into the discharge tube 1 by a pressure pump (not shown), and the earth and sand composition 3 is discharged from the discharge end 1a to deposit a layer of the earth and sand composition 3 on the water bottom ground e.

The earth and sand composition 3 includes general earth and sand and a binder that imparts caking properties between the earth and sand particles and ensures a predetermined fluidity, or hardens between the earth and sand, the binder, and the earth and sand particles, It contains a hardening agent that solidifies the earth and sand.

The binder is made of a water-soluble natural, semi-synthetic or synthetic polymer, and has the function of preventing the separation of particles and the incorporation of water through a kind of glue-like substance.

To explain the binder specifically, water-soluble natural polymers include various starches, starches, and funori.

Agar, sodium alginate, molasses, tragonth gum, gum arabic, f-kistrin, levan.

Glue, geladin, casein, collagen, etc. are used.

An example of a water-soluble semi-synthetic polymer is hiscose.

Methylcellulose, ethylcellulose, human oxyedylcellulose, hydroxypropylmethylcellulose,
Carboxymethyl cellulose, soluble starch, carboxymethyl starch, dialdehyde starch, etc. are used.

As the water-soluble synthetic polymer, polyvinyl alcohol, sodium polyacrylate, polyacrylamide, polyethylene oxide, etc. are used.

The hardening agent may be ordinary Portland cement 1-2 blast furnace cement, fly ash cement, other cement materials, lime-based materials such as slaked lime, or Asqual 1-2.
The material is selected from the group consisting of blast furnace slag type materials and blast furnace slag type materials, or a combination thereof.

This type of curing agent has the function of solidifying and stabilizing the soil quality of the earth and sand after being added, and improving its strength.

In addition, the blending ratio of each binder and hardening agent to the soil and sand is determined by taking into account economic efficiency and degree of hardening.
The most preferable values are 1 to 5 parts by weight of the binder and 50 to 300 parts by weight of the curing agent per 00 parts by weight.

Furthermore, these compositions 3 are mixed with water and fed into the discharge end 1a of the discharge pipe 1 in a slurry state, and there is almost no risk of suspension compared to general earth and sand. When the particle size of the material is fine or the discharge speed is high, there is a tl! 3JiM4 is generated. Here, this suspended layer 4 comes into contact with the flocculant spouted from the spouting end 2a of the flocculant-feeding vibrator 2, immediately coagulates, and settles on the sediment composition, thereby preventing pollution. Become.

As for the shape of the ejection end 2a, by providing a large number of fine nozzle parts, the probability of contact with the suspended layer 4 can be increased and contamination can be almost completely prevented.

J3, as the flocculant, a free flocculant such as PAC or sulfuric acid, or a polymer flocculant alone or in a mixture is used.

In this case, for construction work in waters containing salt such as the sea, it is usually sufficient to use only a polymer flocculant.

On the other hand, when used together, it is desirable to pump these flocculants through separate pipes and arrange the vibrator so that the flocculants come into contact first.

Furthermore, it has been confirmed that 1 to 5 g of the polymer flocculant per 1 d of the suspension iiB layer 4 can almost completely prevent water pollution.

Next, FIG. 2 shows a second embodiment of the method of this invention.

In the figure, a suction end 10a of a submersible pump 10 is located at the periphery of a discharge end 1a of a discharge tube 1.

Further, the ejection end 2b of the flocculant pressure-feeding vibrator 2 is connected to the submersible pump 1.
It is located at the suction end 10a of 0.

In the above configuration, by driving the submersible pump 1o while discharging the earth and sand composition 3 from the discharge tube 1, the suspended layer 4 that flies up around the periphery of the discharge end 1a is all sucked into the suction end side of the submersible pump. , At the same time, flocculant pumping vibe 2
The flocculant spouted from the spouting end 2b is also taken into the submersible pump 10 from the suction end 10a. The suspended layer 4 and the flocculant are contacted and mixed in the submersible pump 10, and in this state is discharged from the discharge end 10b of the submersible pump 10.

The discharged suspended layer 4 settles quickly due to the flocculating action of the flocculant, and becomes the bottom of the water! It will be deposited on the IIE.

In this embodiment, since the suspended layer flying up from the discharge end 1a is forcibly sucked in and comes into contact with the flocculant, the
This results in a reliable pollution prevention effect.

(Effects of the Invention) As explained in detail in each of the Examples above, according to the method of the present invention, a separate flocculation and sedimentation tank is required unlike the conventional method in order to completely prevent pollution when the sediment composition is put into water. Since there is no need to install or transport contaminated water to another location, it is possible to implement pollution prevention measures at an extremely low cost when the water is put into the water.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a method of putting the device into water according to the first embodiment of the present invention, and FIG. 2 is an explanatory diagram showing the method of putting the product into water according to the second embodiment of the invention. 1...Discharge pipe 1a...Discharge end 2
...Flocculant pressure-feeding vibrator 2a, 2b...Ejection end 3...Sediment composition Fig. 1 Fig. 2

Claims (1)

[Claims] (1) Discharge a sediment composition formed by mixing soil and a binder, or a soil, a binder, and a hardening agent into water from a discharge tube, and spout a flocculant near the discharge end. A method for introducing a sediment composition into water, characterized by: