JP5954655B2 - Steelmaking slag mixing method for soft soil - Google Patents

Description

  The present invention improves the strength of soft soil by mixing steelmaking slag generated as a by-product in the refining process of steel with soft soil such as dredged soil, before mixing by a mixing means to a predetermined ratio to a certain amount of soft soil. The present invention relates to a steelmaking slag mixing method for soft soil mixed with steelmaking slag.

  Conventionally, steelmaking slag produced as a by-product in the process of steel refining is mixed with soft soil such as dredged soil, and further mixed with mixing means to improve the strength of the soft soil, which can be used as landfill materials at harbors, etc. A method for use as a civil engineering material has been proposed (see, for example, Patent Document 1, paragraph 0035).

  In order to mix steelmaking slag into this soft soil, a certain amount of soft soil is sequentially cut out on a belt conveyor using a pump, hopper, etc., and a certain amount of steelmaking slag is cut from the feeder for each soft soil cut out during the conveyance. Steelmaking slag is added at a predetermined ratio to a certain amount of soft soil introduced into a stirrer such as a mechanical mixer. Then, a method of mixing steelmaking slag into soft soil every predetermined amount by stirring it with a stirrer and forcibly mixing it (conventional method 2) is known.

JP 2009-121167 A

  However, in the conventional method 1 as described above, the work of mixing steelmaking slag into soft soil such as dredged soil can be performed continuously and suitable for large-scale construction, while it is dedicated for the work of mixing steelmaking slag with soft soil. Equipment such as a reclaimer ship (landing ship) is required, and the fleet composition of the work ship becomes large, and there is a problem that the construction cost increases accordingly. Moreover, since a belt conveyor is used, soft soil with a high water content ratio Had the problem of being difficult to adapt.

  On the other hand, in the conventional method 2 as described above, high-quality slag-mixed soil in which steelmaking slag is suitably mixed with soft soil can be obtained, while the work efficiency depends on the ability of the stirrer, so that in the case of large-scale construction. However, there is a problem that a large size or a plurality of stirrers corresponding to it must be used, and the cost increases accordingly.

  Further, when the soft soil 100 and the steelmaking slag 101 are directly put into a storage container 102 such as a hopper of a pneumatic feeding device which is a mixing means at a predetermined ratio without going through the above-described prior mixing process, the mixing is sufficiently performed. Therefore, as shown in FIG. 6, the distribution of the steelmaking slag 101 in the soft soil 100 is biased, and the steelmaking slag 101 may be clogged in the storage container 102 and the like, and may be clogged. There is a possibility that the quality of civil engineering materials such as the above may be deteriorated.

  Therefore, in view of such conventional problems, the present invention has been made for the purpose of providing a steelmaking slag mixing method for soft soil that can be applied to large-scale construction, and can mix steelmaking slag in soft soil in a low-cost and balanced manner. Is.

The feature of the invention described in claim 1 for solving the conventional problems as described above and achieving the intended purpose is that steelmaking slag is mixed at a predetermined ratio into a certain amount of soft soil introduced into a storage container. A method of mixing steelmaking slag with soft soil, wherein the predetermined amount of soft soil is divided into predetermined amounts using a premixed container, and the steelmaking is performed with the predetermined ratio for each of the measured predetermined amounts of soft soil. Adding a predetermined amount of soft soil to which the steelmaking slag has been added in a state where the steelmaking slag is retained on the predetermined amount of soft soil, It is to disperse and mix steelmaking slag.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, a backhoe bucket is used for the pre-mixing container.

The steelmaking slag mixing method for soft soil according to the present invention, as described above, is a steelmaking slag mixing method for soft soil in which steelmaking slag is mixed at a predetermined ratio into a certain amount of soft soil charged into a storage container, The predetermined amount of soft soil was divided into predetermined amounts using a pre-mixed container, and steelmaking slag was added at the predetermined ratio for each of the measured predetermined amounts of soft soil, and the steelmaking slag was added. By dispersing and mixing steelmaking slag in the fixed amount of soft soil by sequentially introducing a predetermined amount of soft soil into the storage container from the premixing container in a state where the steelmaking slag is retained thereon, The distribution of steelmaking slag in soft soil can be made uniform without using premixing equipment such as a reclaimer ship or mechanical mixer, and steelmaking slurries can be efficiently and inexpensively applied to soft soil even in large-scale construction. It can be mixed, to be able to perform the mixing of the soft soil by mixing means with steelmaking slag smoothly and stably. It can also be applied to soft soil with a high water content.

  Further, in the present invention, by using a backhoe bucket in the pre-mixing container, steelmaking slag can be suitably mixed into soft soil due to the mixing action due to the drop energy during the charging operation into the storage container. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view which shows the outline of the state of each process of the steelmaking slag mixing method with respect to the soft soil which concerns on this invention, Comprising: (a) is a soft earth measurement process, (b) is a steelmaking slag addition process, (c) is a storage container. The charging process is shown. It is sectional drawing which shows the outline of the state of the soft soil in which the steelmaking slag was mixed by the method of this invention. It is a side view which shows the outline of the soft soil injection | throwing-in method of case 1 in the effect confirmation test of this invention method. It is a side view which shows the outline of the soft soil injection | throwing-in method of case 2-case 4 same as the above. It is a side view which shows the outline of the soft soil injection | throwing-in method of case 5 and case 6 same as the above. It is sectional drawing which shows the distribution state of the steelmaking slag in a soft soil when a soft soil and steelmaking slag are directly injected into the storage container alternately.

  Next, an embodiment of the steelmaking slag mixing method for soft soil according to the present invention will be described based on the embodiment shown in FIGS. FIG. 1 shows an example of the construction procedure of the method of the present invention. In the figure, reference numeral 1 is an earth transport ship for transporting soft soil such as dredged soil, reference numeral 2 is a slag ship for transporting steelmaking slag, and reference numeral 3 is an air pressure. It is a pneumatic ship equipped with a feeding device 4.

  The pneumatic feeder 4 is an example of a mixing unit that mixes soft soil and steelmaking slag, and steelmaking slag 8 is mixed at a predetermined ratio into a certain amount of soft soil 5 unearthed from the soil carrier 1. The slag-mixed soil is temporarily stored in a storage container 6 such as a hopper, and the slag-mixed soil stored in the storage container 6 is sequentially supplied to the transport pipe 7 and continuously transports high compressed air from the pneumatic feed pipe. The turbulent flow effect caused by the plug flow generated in the transport pipe 7 is caused by moving the slag-mixed soil sent from the storage container 6 into the transport pipe 7 as a large number of plugs sandwiched by the air portion. Thus, the soft soil and the steelmaking slag are agitated and mixed during pneumatic feeding, and the mixed material is continuously supplied to a tremy tube or the like.

  The mixing of the steelmaking slag 8 with the soft soil 5 is carried out in the process of unloading the soft soil 5 from the earth carrier 1 and putting it into the storage container 6, that is, in the preliminary stage of mixing by the mixing means. The steelmaking slag 8 is mixed at a predetermined ratio into a certain amount of soft soil to be introduced so that the ratio of the volume of the steelmaking slag to the volume of the slag-mixed soil is 20 to 35% by volume.

  In addition, the soft soil 5 needs to have sufficient fluidity to move in the transport pipe 7, and the water content is adjusted by pouring water into the unloading portion in the soil carrier 1 as necessary.

  In the steelmaking slag mixing method for soft soil according to the present invention, first, as shown in FIG. 1 (a), a predetermined amount of soft soil is divided into predetermined amounts using a pre-mixing container 9, and then, As shown in FIG. 1 (b), the steelmaking slag 8a is added at a predetermined ratio for each measured predetermined amount of soft soil 5a, and as shown in FIG. A predetermined amount of soft soil 10 to which steelmaking slag has been added is charged into the storage container 6, and the operations shown in FIGS. 1 (a) to 1 (c) are repeated until the soft soil 5 in the storage container 6 reaches a certain amount. The steelmaking slag 8 is mixed into the fixed amount of soft soil 5 at a predetermined ratio by dividing the predetermined amount of soft soil 10 to which the steelmaking slag has been added into the storage container 6 in a plurality of times. .

  For example, a bucket of a backhoe 11 is used as the pre-mixing container 9, and a predetermined amount, that is, an optimum amount of the soft soil 5 per time, is obtained by squeezing the soft soil 5 in the earth transport ship 1 with the bucket 9. It is designed to measure.

  The volume of the premixed container (bucket) 9, that is, the predetermined amount of the soft soil 5 a to be charged is determined based on the ratio of the optimal predetermined amount to the volume of the storage container 6 obtained in advance by experiment, and the ratio is (Predetermined amount / storage container volume) = 0.03 to 0.07.

  On the other hand, in order to add the steelmaking slag 8a at a predetermined ratio to a predetermined amount of soft soil 5a measured using the pre-mixed container 9, a predetermined addition amount to the predetermined amount of soft soil 5a is measured by a measuring means. The measured amount is put on the soft soil 5a in the pre-mixing container 9.

  The weighing means may be a weighing hopper or a feeder that can be discharged for each quantity corresponding to a predetermined ratio, and a weighing container 12 whose volume ratio to the premixed container 9 is the same as the predetermined ratio. May be weighed. In addition, the bucket of the backhoe 13 can be used as the measurement container 12, and in that case, the steelmaking slag 8 in the slag ship 2 can be crushed with the bucket 12 and can be directly put into the premixing container 9.

  Thus, when the steelmaking slag 8a is added at a predetermined ratio for each predetermined amount of soft soil 5a measured using the premixed container 9, and the premixed container 9 is tilted on the storage container 6, the soft soil 5a The steelmaking slag 8a is dropped in the storage container 6 in a state where the steelmaking slag 8a stays thereon, and the steelmaking slag 8a is dispersed in the soft soil 5a by the mixing action by the dropping energy.

  And by repeating the operation | work of Fig.1 (a)-FIG.1 (c), as shown to Fig.2 (a), the steelmaking slag 8a is disperse | distributed by the predetermined ratio to the soft soil 5a in the storage container 6. FIG. By sequentially depositing the mixed lump, as shown in FIG. 2B, the steelmaking slag 8 is distributed at a predetermined ratio and the steelmaking slag 8 is distributed and distributed in a certain amount of soft soil 5. It is mixed.

  In this way, the steelmaking slag 8 is dispersed and distributed in a certain amount of soft soil 5, so that the slag-mixed soil can exhibit suitable fluidity, and storage containers such as hoppers and feeders constituting the mixing means. 6 and the transfer pipe 7 of the pneumatic feeder 4 are not clogged, and the transfer pipe or the like is not easily blocked, and the soft soil 5 and the steelmaking slag 8 can be smoothly mixed by the mixing means.

  In addition, when the steelmaking slag 8 is dispersed and distributed in a certain amount of soft soil 5 stored in the storage container 6, the soft soil 5 and the steelmaking slag 8 are mixed by the mixing means such as the pneumatic feeder 4. Since the mixing means is supplied with slag-mixed soil having a stable blending balance between soft soil and steelmaking slag, a high-quality mixed material can be obtained.

  Furthermore, unlike the above-described conventional example, a special premixing facility such as a reclaimer ship or a stirring device is not required, and steelmaking slag is mixed in the process of unloading the soil from the ship 1 and putting it into the storage container 6. The construction efficiency is good and the construction cost can be reduced.

  In the above-mentioned embodiment, the example in which the method of the present invention is used for the pneumatic feeding method by the pneumatic boat is described. However, the method of the present invention is also applicable to steelmaking slag mixing with soft soil when using other mixing means. can do.

  Next, the experiment conducted in order to confirm the effect of the mixing method of the steelmaking slag with respect to the soft soil based on this invention is demonstrated. In addition, the same code | symbol is attached | subjected and demonstrated to the structure similar to the above-mentioned Example.

This experiment assumes a hopper constituting the pneumatic feeder 4 mounted on the pneumatic vessel 3 as the storage container 6, and inputs the soft soil and steelmaking slag into the storage container 6 or the storage container volume (a certain amount of softness). For each case (case 1 to case 6) having a different ratio of the premixed container volume to the soil), the state of the slag mixed soil is evaluated.
(1) Experimental apparatus The volume of the storage container (hopper) was set to about 1/100 of the hopper of the pneumatic feeding apparatus actually used, and was set to 1.72 cubic meters.
(2) Experimental material Using the soft soil and steelmaking slag shown in (b) and (b) below, slag-mixed soil in the ratio shown in (c) is generated.
(I) Soft soil wet density 1.61 g / cubic centimeter, moisture content 53.4%, liquid limit 53.9%
(B) Steelmaking slag particle size of 25 mm or less, surface dry density 2.95 g / cubic centimeter (c) Slag-mixed soil soft soil: Steelmaking slag = 75:25 (volume ratio)
(3) Experimental method After putting a certain amount of soft soil and steelmaking slag into the storage container (hopper) under the conditions shown in Table 1, slag-containing soil is discharged from the hopper outlet, and slag-containing soil is discharged for each case. Check the condition visually, and collect 10L samples (total 12 samples) 4 times for each discharge period (first half, middle, second half) for each case and measure the wet density of each specimen. At the same time, the steelmaking slag in the soft soil of each specimen is washed out using a 2 mm sieve and then dried to measure its weight.

  As shown in FIG. 3, the case 1 measures a predetermined amount (0.1 cubic meter) of soft soil 5 a with a backhoe bucket 9 and measures it with a hopper 20 each time it is put into a storage container (hopper) 6. The steelmaking slag 8a (0.033 cubic meters) was put into the storage container (hopper) 6 by the belt conveyor 21. In the figure, reference numeral 22 denotes a belt conveyor for transporting the discharged slag-mixed soil, and reference numeral 23 denotes a sample collection container (hereinafter, the same components are given the same reference numerals and description thereof is omitted).

  As shown in FIG. 4, each of the cases 2 to 4 measures the soft soil by a backhoe bucket 9 for each predetermined amount, puts the soft soil 5a into the hopper 6, and the backhoe 13 as a measuring means. A predetermined amount of steelmaking slag 8a was weighed by the bucket 12, and the operation of putting the steelmaking slag 8a into the hopper 6 was alternately performed.

  Case 5 and case 6 are according to the method of the present invention, and a predetermined amount of soft soil 5a is measured using a premixed container (backhoe bucket) 8, and each of the measured soft soil 5a is a measuring means. A predetermined amount of the steelmaking slag 8a measured by the bucket 12 of the backhoe 13 was added, and the soft soil 10 to which the steelmaking slag was added from the pre-mixing container 9 was sequentially put into the storage container (hopper) 6.

  The results of this experiment are shown in Tables 2 and 3. The standard wet density and standard steelmaking slag content of soil mixed with slag are based on the assumption that steelmaking slag is suitably mixed in soft soil based on various conditions such as wet density of soft soil and mixing ratio of steelmaking slag. Under the present experimental conditions, the standard wet density is 2.0 to 2.1 g / cubic centimeter and the standard steelmaking slag content is 0.8 to 1.0 kg / L.

  In Case 1, soft soil was discharged vigorously in the first half, and steelmaking slag was solidified and discharged in the second half. Further, the wet density of each specimen is distributed in the vicinity of 1.7 to 1.8 (g / cubic centimeter) and the steelmaking slag content is concentrated to 0.2 to 0.4 kg / L, respectively. It is distributed outside the standard wet density of 2.0 to 2.1 g / cubic centimeter and the standard steelmaking slag content of 0.8 to 1.0 kg / L. This shows that the steelmaking slag is not properly mixed in the soft soil.

  In Case 2, soft soil was discharged vigorously in the first half, and then after a portion of the soft soil and steelmaking slag were mixed, only steelmaking slag was discharged. In addition, the wet density and the steelmaking slag content of each specimen are distributed outside the standard wet density of 2.0 to 2.1 g / cubic centimeter and the standard steelmaking slag content of 0.8 to 1.0 kg / L under the experimental conditions. It can be seen that the steelmaking slag is not properly mixed in the soft soil.

  In Case 3 and Case 4, the soft soil was discharged first, and then the steelmaking slag and the soft soil were mixed and discharged, but the steelmaking slag was sometimes discharged only. In addition, the amount of steelmaking slag and soft soil discharged separately was smaller in Case 4, that is, in the case where the input amount per time was smaller. Further, the wet density and the content of steelmaking slag vary from sample to sample, and it can be seen that the steelmaking slag is unevenly distributed in the soft soil.

  In case 5 and case 6, the steelmaking slag was dispersed and mixed in soft soil as a whole and discharged. In addition, the wet density and steelmaking slag content of each specimen are also appropriately centered on the standard wet density of 2.0 to 2.1 g / cubic centimeter and the standard steelmaking slag content of 0.8 to 1.0 kg / L under the experimental conditions. It can be seen that the steelmaking slag is evenly distributed in the soft soil and is in a stable mixed state.

  From the above results, as in the case 5 and the case 6 according to the method of the present invention, a predetermined amount of soft soil is weighed separately for each predetermined amount using the premixed container 9, and the measured predetermined amount of soft soil 5a is measured. The method of mixing the steelmaking slag 8 in the soft soil 5 by adding the steelmaking slag 8a at a predetermined ratio every time and sequentially putting the predetermined amount of the soft soil 10 to which the steelmaking slag is added into the storage container 6 is optimal. I found out.

  Moreover, if the volume of the pre-mixed container, that is, the predetermined amount is (predetermined amount / storage container volume) = 0.03 to 0.07 with respect to the storage container volume (1.72 cubic meters), it is stable. It was found that the mixed state was obtained. Therefore, even when an actual pneumatic hopper having a volume exceeding 100 cubic meters is used as a storage container, (predetermined amount / hopper volume) = 0.03 to 0.07 in advance It is considered that steelmaking slag can be mixed in a state of being dispersed and distributed in soft soil by using a container.

DESCRIPTION OF SYMBOLS 1 Earth ship 2 Slag ship 3 Pneumatic ship 4 Pneumatic feeder 5 Soft soil 6 Storage container (hopper)
7 Transport pipe 8 Steelmaking slag 9 Pre-contained container (bucket)
11 Backhoe

Claims (2)

A steelmaking slag mixing method for soft soil in which steelmaking slag is mixed at a predetermined ratio into a certain amount of soft soil charged into a storage container,
The predetermined amount of soft soil was divided into predetermined amounts using a pre-mixed container, and steelmaking slag was added at the predetermined ratio for each of the measured predetermined amounts of soft soil, and the steelmaking slag was added. The steelmaking slag is dispersed and mixed in the predetermined amount of soft soil by sequentially introducing the predetermined amount of soft soil into the storage container from the pre-mixing container in a state where the steelmaking slag is retained on the predetermined amount. Steelmaking slag mixing method for soft soil.   The steelmaking slag mixing method with respect to the soft soil of Claim 1 which uses the bucket of a backhoe for the said premixing container.

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