JPWO2007018033A1 - Mixing device and method for solidifying soft soil - Google Patents

Abstract

A mixing apparatus that can easily mix the additives in the path. A partition plate 53 is provided in the transport pipe 16 for pumping soft soil, and clinker ash is mixed in the transport pipe 16 (in the path) by turbulent flow generated when the soft soil overflows the partition plate 53.

Description

  The present invention mainly relates to an additive mixing apparatus for mixing an additive during solidification processing of soft soil such as dredged soil such as sea areas, rivers, and lakes.

  The present invention mainly relates to a method for solidifying soft soil such as dredged soil such as sea areas, rivers, and lakes.

  In the present invention, the soft soil is one having a water content ratio near the liquid limit and exceeding the liquid limit, for example, having a water content ratio of 80% to 400%.

  Conventionally, as an improvement method for soft ground, a ground improvement method has been developed in which a belt-shaped drain material is inserted into the ground from the surface of the soft ground, and soil pore water in the soft ground is discharged through the drain material. When constructing this kind of construction method on ultra-soft ground with dredged soil, in general, floater type solidification processing boats are floated, and by this, ground improvement treatment such as driving in drain material is performed, but in recent years In Japan, solidified material such as cement milk is added to and mixed with soft landfill such as dredged soil, and the landfill surface is formed using this solidified material-added landfill sand. A method of forming a solidified surface layer on which improved heavy machinery can run has been studied.

Since the construction method for creating this surface solidified layer is carried out for the purpose of ensuring the trafficability of heavy machinery, it is carried out with a relatively low strength as a solidification treatment such as uniaxial compressive strength qu28 = 50 to 200 kN / m ² on the 20th day of material age. There are many cases. This is because, when the drain material is placed in the subsequent ground improvement work, if the strength becomes higher than that, it is difficult to penetrate the mandrel.

  In addition, as a method of mixing an additive such as a solidifying material into the landfill sand, a method of injecting the slurry-like or slurry-like landfill soil pneumatically to the landfill input position and injecting the additive in the middle Has been developed.

  This conventional method of mixing in an additive pipe uses two pressure gauges installed in the transport pipe, in which the slurry-like landfill sand is sandwiched between the air portions, divided into a large number of plugs and moved. For each plug that moves, the volume and the moving speed are measured, and the injection amount of the additive is controlled in accordance with the passage of each plug through the additive injector position (see Patent Document 1).

  In this conventional method, the amount of additive mixture per unit volume (additive mixture ratio) to the sediment slurry is determined in advance according to the properties of the sediment slurry to be used, and it is close to the additive mixture ratio. It is controlled by a computer so that it is injected into each plug.

In the above-described method of forming the surface solidified layer, the landfill soil layer mixed with the solidified material is formed on the soft ground surface layer. The mandrel can be easily penetrated, and the traffic can be secured. Qu28 = 50 kN / m ² When trying to create a strong ground improvement layer, in the indoor blending test, the amount of solidification material added is almost ³⁰ to 40 kg / m ³ in most soft ground, and in the construction process at the site, the mixing accuracy is reduced. Taking into account, the result of the indoor blending test is multiplied by the safety factor, and 1.5 to 2 times the amount of the solidified material is added. When this is performed by the above-described conventional mixing method in the additive pipe, According to the past results, the on-site / indoor strength ratio at the time of poor mixing of solidified material of about ³⁰ to 40 kg / m ³ is 0.1 to 0.3, and an excessive safety factor is necessary for ensuring desired quality. become.

However, if an excessive safety factor is adopted, the target strength of qu28 = 50 kN / m ² can be secured as the minimum strength, but a part with a very high strength is created, and it is difficult to drive the drain material there. The situation that becomes.

  On the other hand, if the indoor blending test results are applied to the site as they are, the overall average strength can achieve the target strength, but there will be a part that does not reach the target strength in part. There arises a problem that safety cannot be maintained.

  Therefore, a technology has been developed that, as an additive, can be used to easily create a surface solidified ground within a certain strength with little variation throughout the entire area by mixing a solidification aid made of an inorganic powder material into a solidification material such as cement. (See Patent Document 2).

  However, considering the predetermined safety factor, it is the same as the prior art in that the amount of cement cannot be significantly reduced.

  On the other hand, the above-described conventional mixing method in the additive material pipe determines the additive mixture ratio by investigating the properties of the sediment slurry fed into the conveying pipe, for example, for each of the transported ship. Therefore, it is assumed that the plug moving in the transport pipe always has a constant moisture content.

  For this reason, the earth and sand inside the ship is always agitated by using a backhoe for unloading so that the water content of the earth and sand slurry fed to the transfer pipe is constant for each plug. There is a problem that requires.

  In addition, even if it is constantly stirred by a backhoe or the like, the water content ratio cannot be kept constant from the beginning to the end of unloading, and the strength after hardening of the landfill soil to be introduced varies, which is necessary over the entire area. There was a problem that it was difficult to obtain a strong landfill.

  As mentioned above, it is difficult to form a low-strength, uniform solidified ground with a small amount of solidified material for soft landfill, especially when the conventional mixing method in the additive pipe is adopted. However, there was a problem that a partial strength difference was increased.

JP-A-11-229428 Japanese Patent Laid-Open No. 2000-3460

  In view of such conventional problems, the present invention easily mixes additives that are high quality inorganic materials such as sandy materials, even when the moisture content fluctuates when solidifying soft soil such as dredged soil. It is an object of the present invention to provide a mixing device that can be used.

  Further, in view of such a conventional problem, the present invention can reduce the amount of the solidifying material to be added and mixed even when the moisture content fluctuates when mainly soft soil such as clay is solidified. Another object of the present invention is to provide a method for solidifying soft soil that can easily obtain a desired strength within a desired range.

  The first aspect of the present invention that solves the above-mentioned problems is that the lightly sandy soil and the inorganic high-quality material such as sandy material are added to the soft soil, and these are not sufficiently mixed in the path for pumping. In the mixing apparatus, a turbulent flow generating means for generating a flow is provided in the path.

  In the first aspect, it is possible to generate a turbulent flow in the soft soil to be pumped and to mix a good quality inorganic material such as a sandy material in the path.

  The second aspect of the present invention that solves the above problem is that the lightly sandy soil and the inorganic high-quality material such as sandy material are added to the soft soil, and these are not sufficiently mixed in the path for pumping. In the mixing apparatus, a jet forming means for generating a flow is provided in the path.

  In the second aspect, it is possible to mix a high quality inorganic material such as a sandy material in the path by generating a jet in the soft soil to be pumped.

  The third aspect of the present invention that solves the above-described problems includes an adding means for adding a powder or liquid solidifying material to a path for pumping both soft soil, lightweight sandy soil, and high quality inorganic material such as sandy material. The mixing apparatus is characterized in that a turbulent flow forming means for generating turbulent flow in both soft soil and a good quality inorganic material fed by adding a solidifying material is provided in a path on the downstream side of the adding means. .

  In the third aspect, it is possible to cause the turbulent flow in both the soft soil to which the solidifying material to be fed and the high quality inorganic material are added, and to mix the high quality inorganic material such as sandy material in the path.

  The fourth aspect of the present invention that solves the above-mentioned problems includes an adding means for adding a powder or liquid solidifying material to a path for pumping both soft soil and lightweight inorganic sand and sandy material. The mixing apparatus is characterized in that a jet forming means for generating jets in both the soft soil to which the solidifying material is added and pumped and a high quality inorganic material are provided in the path on the downstream side of the adding means.

  In a 4th aspect, an inorganic good quality material, such as a sandy material, can be mixed in a path | route by producing a jet in both the soft soil and the inorganic good quality material to which the solidification material to pump is added.

  A fifth aspect of the present invention that solves the above-described problem is an addition means for adding a powder or liquid solidifying material to a path for pumping both soft soil and lightweight high-quality materials such as sandy soil and sandy material. Turbulent flow forming means that generates turbulence in both soft soil that is pumped with the addition of solidification material and lightweight high-quality sandy soil and sandy material, etc. The flow path on the downstream side of the turbulent flow forming means is provided with a jet forming means for generating a jet flow in the soft soil in which the solidification material is added and the turbulent flow is generated, and the light inorganic sand material and the sandy material. It is in the mixing apparatus characterized by having provided in.

  In the fifth aspect, it is possible to generate a turbulent flow and a jet flow in both the soft soil to which the solidifying material to be pumped is added and the inorganic high quality material, and to mix the inorganic high quality material such as sandy material in the path.

  According to a sixth aspect of the present invention, in any one of the first, third, and fifth aspects, the turbulent flow forming means is a partition plate that partitions a part of the lower side of the flow path. Inorganic high quality materials such as sandy soil and sandy material, or high quality inorganic materials such as light sandy soil and sandy material due to turbulent flow generated when overflowing the partition plate with the addition of solid high quality material or solidifying material or / And a solidifying material to be mixed.

  In the sixth aspect, the light sandy soil and the soft soil added with the inorganic high quality material such as sandy material or the solidifying material are mixed in the path by the turbulent flow generated when the partition plate overflows.

  According to a seventh aspect of the present invention, in any one of the second, fourth, and fifth aspects, the jet flow forming means is a plurality of ladder-like plate members arranged in the flow path, and includes soft soil and lightweight sand. Inorganic high-quality materials or solidified materials such as soft soil and lightweight sandy soil and sandy materials due to a jet generated when adding inorganic high-quality materials or solidified materials such as clay and sandy materials and flowing through the gaps between plate materials In a mixing device characterized by being mixed.

  In the seventh aspect, lightweight sandy soil and soft inorganic soil to which a solid high-quality material such as sandy material or a solidifying material is added are mixed in the path by a jet generated when flowing through the gaps in the plate material.

  According to an eighth aspect of the present invention, in any one of the first to seventh aspects, the inorganic high-quality material such as sandy material is at least one inorganic high-quality material selected from clinker ash and granulated slag, The mixing apparatus is characterized in that it is added and mixed in an addition amount that maintains a desired flow value, and is provided in a path in which a solidifying material is added and mixed after an inorganic high quality material is added and mixed. .

  In the eighth aspect, at least one additive selected from clinker ash and granulated slag may be mixed in a route in which a solidified material is added and mixed after an inorganic high quality material such as a sandy material is added and mixed. it can.

  According to a ninth aspect of the present invention, in any one of the third to seventh aspects, the solidifying material is at least one solidifying material selected from cement and cement and fly ash, and maintains a desired strength. The mixing apparatus is characterized by being added and mixed in an added amount of

  In the ninth aspect, a desired solidification strength can be obtained by at least one solidification material selected from cement and fly ash.

  In a tenth aspect of the present invention that solves the above-mentioned problems, a clinker is added in an amount that maintains a desired flow value when soft soil is mixed with light-weight sandy soil and high-quality inorganic materials such as sandy material. A soft soil solidification treatment method comprising adding at least one inorganic high-quality material selected from ash and granulated slag to soft soil and adding and mixing the soft soil in a pumping path.

  In the tenth aspect, when a high quality inorganic material such as clinker ash or granulated slag is added and mixed in the pumping path to the extent that a desired flow value can be obtained, the clinker ash and granulated slag retain moisture in soft soil. In addition, the soil properties can be stabilized and the addition amount of the solidifying material can be reduced without reducing the pumping / conveying property. The addition amount of clinker ash and granulated slag has a moisture content of soft soil. There is no need to change even if it changes.

  The eleventh aspect of the present invention that solves the above-mentioned problems is at least one selected from cement and cement and fly ash at an addition amount that maintains a desired strength when soft soil is solidified with a solidifying material. In the solidifying method for soft soil, the solidifying material is added to the soft soil and added and mixed in the pumping path.

  In the eleventh aspect, a desired solidification strength can be obtained by at least one solidification material selected from cement and cement and fly ash.

  According to a twelfth aspect of the present invention, a lightweight sandy soil and a good quality inorganic material such as a sandy material are mixed with the soft soil by the mixing device according to any one of the first to seventh aspects in the tenth or eleventh aspect. In the method of solidifying soft soil, the mixture is added and mixed in the pressure feeding path.

  In the twelfth aspect, lightweight high quality inorganic materials such as sandy soil and sandy material can be easily mixed in the pumping path.

  According to a thirteenth aspect of the present invention, in any one of the ninth, tenth, eleventh or twelfth aspects, the amount of the inorganic high quality material such as lightweight sandy soil and sandy material is a desired flow value. After determining the ratio to maintain, there is a method for solidifying soft soil characterized in that it is constant regardless of the moisture content of the soft soil.

  In the thirteenth aspect, the amount of inorganic high-quality material such as lightweight sandy soil and sandy material is determined in advance after determining the ratio for maintaining the desired flow value, but the desired blending strength is maintained. Obtainable.

  In a fourteenth aspect of the present invention, in any one of the ninth to thirteenth aspects, the addition amount of the light inorganic sand and sandy material is 10% to 70% by weight. It is in the solidification processing method of the soft soil characterized by the quantity.

  In the fourteenth aspect, the amount of addition can be reduced when a solidifying material is added by adding lightweight high-quality materials such as lightweight sandy soil and sandy material in a predetermined weight ratio.

According to a fifteenth aspect of the present invention, in any one of the ninth to fourteenth aspects, the addition amount of the solidifying material is a total amount of 1000 m ³ of high quality inorganic materials such as soft soil and light sandy soil and sandy material. On the other hand, the present invention resides in a method for solidifying soft soil, which is 30 to 100 kg.

In the fifteenth aspect, desired solidification strength can be obtained by adding the solidification material at a ratio of ³⁰ to 100 kg with respect to the total amount of soft soil and additive material of 1000 m ³ .

A sixteenth aspect of the present invention is the soft soil solidification method according to the fifteenth aspect, wherein the addition amount of the solidifying material is set so that the blending strength is 250 to 100 kN / m ^2. .

  In the sixteenth aspect, a desired solidification strength can be obtained by adding and mixing an inorganic high-quality material such as lightweight sandy soil and sandy material and a solidifying material.

According to a seventeenth aspect of the present invention, in any of the ninth to sixteenth aspects, ³⁰ to 90 kg of fly ash is added as softening aid to a total amount of 1000 m ^{3 of} soft soil and the additive. It is in the solidifying method of soft soil that is characterized.

  In the seventeenth aspect, by further adding fly ash at a predetermined addition amount, desired solidification strength can be maintained more easily and long-term strength increase can be prevented.

  The additive mixing apparatus according to the present invention easily mixes light-weight sandy soil and high-quality inorganic materials such as sandy materials, even when the moisture content fluctuates, mainly when soft soil such as clay is solidified. Can be a mixing device.

  According to the method for solidifying soft soil according to the present invention, clinker ash and granulated slag that are porous and can retain moisture in soft soil such as clay are added to and mixed with soft soil such as clay in the path. By doing so, the soil properties can be stabilized while maintaining light weight and feeding / conveying performance, and the solidified material such as cement to be added can be reduced to obtain a predetermined strength stably. Moreover, the fluidity of the clay can be freely controlled by controlling the amount of clinker ash and granulated slag mixed. Furthermore, in addition to cement and other solidification materials, when fly ash is added and used as a supplement, by selecting the optimal addition ratio that suppresses strength increase over the long term, It is possible to create a low-strength homogeneous improved soil that can be used for future ground improvement work.

It is a figure which shows the outline of an example of the apparatus for enforcing the solidification processing method of this invention. It is a figure which expands and demonstrates a part of FIG. It is a figure which shows the relationship between the addition amount of the additive in the solidification processing method of this invention, and a flow value. It is a figure which shows the relationship between the solidification material addition amount and the intensity | strength after solidification in the solidification processing method of this invention. It is a figure which shows the solidification material addition amount for obtaining the target intensity | strength in FIG. It is a figure which shows the proper mixing ratio of the solidification material corresponding to a moisture content change. It is a figure which shows the time change of the detected pressure of a pressure gauge. It is a figure which shows the relationship between the cement addition amount of Test Example 1, and uniaxial compressive strength. It is a figure which shows the relationship between the elapsed days of Test Example 1, and uniaxial compressive strength. It is a figure which shows the relationship between the fly ash addition amount of Test Example 2, and uniaxial compressive strength. It is a figure which shows the relationship between the fly ash addition amount of Test Example 2, and material age 28 day strength / material age 7 day strength. 1 is a schematic view of a mixing apparatus according to an embodiment of the present invention. It is a schematic block diagram of a turbulent flow formation means. It is a schematic block diagram of a jet flow formation means.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soft soil 10 Earth ship 11 Sand pump 12 Temporary storage tank 13 Earthing pipe 14 Additive material injector 15 γ-ray fine clock 16 Transport pipe 17 Pneumatic feed pipe 18a, 18b Pressure gauge 19 Solidification material injector 20 Injection control means 20a Computer 51 turbulent flow forming means 52 jet forming means 53 partition plate 54 plate material 55 gap 56 flange

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an outline of an example of an apparatus for carrying out the present invention, and FIG. 2 shows an outline of the internal structure of the transport pipe. As shown in the drawing, a sand carrier 11 for transporting soft soil 1 such as high-concentration dredged soil is provided with a sand pump 11 for unloading. An additive injector 13 for adding clinker ash and granulated slag, which are inorganic high-quality materials such as lightweight sandy soil and sandy material, is provided in the middle of the earthpipe 12. Is extended to the temporary storage tank 14. The temporary storage tank 14 temporarily stores the earth and sand slurry that has been unloaded by the sand pump 11 and to which clinker ash or granulated slag has been added. The temporary storage tank 14 is provided with a γ-ray density meter 15 for measuring the density of the sediment slurry, and the starting end of the transfer pipe 16 is communicated with the lower part of the inside. A pneumatic pipe 17 is communicated with the transport pipe 16, a pair of pressure gauges 18 a and 18 b are installed on the downstream side with a small interval in the flow direction, and a solidifying material injector 19 is provided on the downstream side. .

  Using this device, as shown in FIG. 1, clinker ash and granulated slag are added to the soft soil 1 during the pumping, and solidified material is injected and mixed while moving in the transport pipe 16. Then, it is put on a desired soft landfill 21 and deposited on the surface of the soft ground 21 to form a surface solidified ground 22.

  As shown in FIG. 2, the pneumatic feeding pipe 17 intermittently feeds high-pressure air into the transport pipe 16, whereby the sand slurry sent from the temporary storage tank 14 into the transport pipe 16 is removed as an air portion. It is made to move as a large number of plugs S sandwiching A.

  Both pressure gauges 18a and 18b measure in real time the fluctuation and magnitude of the pressure in the pipe as the air portion A and the plug S move in the transport pipe 16.

  The solidifying material injector 19 is provided with an injection nozzle 19a that mixes cement as a solidifying material and, in some cases, fly ash as a solidifying aid, and injects an additive material into a slurry form by adding water. The injection control means 20 using the computer 20a controls the injection timing and the injection amount from the injection nozzle 19a.

  In the soft soil solidification method using such an apparatus, first, the amount of clinker ash or granulated slag to be added from the additive injector 13 is determined in advance. What is necessary is just to determine the addition amount of this clinker ash or granulated slag so that the flow value after ignition may become a desired value. That is, as shown in FIG. 3, the relationship between the amount of clinker ash or granulated slag added and the flow value is determined in advance by investigation. In the case of FIG. 3, when the desired flow value is 1:40, it is 10-30% by weight of the total weight after mixing, and when the desired flow value is 1:15, the total weight About 50% by weight.

  In the present invention, by adding clinker ash or granulated slag in advance and adjusting the flow value to a predetermined range in this way, the amount of solidified material to be added is greatly reduced as shown below. Can do. Also, the amount of clinker ash or granulated slag added does not need to be adjusted even if the water content of the soft soil 1 fluctuates greatly. That is, after the amount of water is determined once, it is added while measuring the water content. There is an advantage that there is no need to adjust the amount. And there exists an effect that the addition amount of a solidification material can be reduced and the ground of desired strength can be obtained stably by this.

In the trial calculation, when adding a solidifying material to a soft soil 1 having a water content of 80% to 400% so that the blending strength is 250 to 100 kN / m ² , it is solidified without adding clinker ash or granulated slag. When the material is added, the addition amount of the solidification material is 80 to 200 kg per rice, whereas when the clinker ash or the granulated slag is added, the addition amount of the solidification material is 30 to 100 kg, preferably 30 to 30 kg. It can be reduced to 90 kg, more preferably about 30 to 60 kg.

  Moreover, in this invention, since a flow value can be freely controlled by adding clinker ash and granulated slag to soft soil, subsequent solidification processing operation can be facilitated.

  On the other hand, the solidifying material to be injected by the solidifying material injector 19 is based on a predetermined formulation, and is mixed uniformly with cement and, in some cases, fly ash using a powder mixer. In addition, it is kneaded and used as a slurry.

  The injection control means 20 controls the additive injection timing and the injection amount for each plug S based on the measurement values obtained by the γ-ray density meter 15 and the two pressure gauges 18a and 18b.

  In the injection control means 20, the water content ratio of the sediment slurry is calculated from the measured value by the γ-ray density meter 15 according to the following soil formulas (1) and (2).

  In the equations (1) and (2), the saturation Sr is 100%, and the soil particle density Gs is obtained in advance by an indoor soil test. The soil particle density is a characteristic soil constant for the soil in the area, and will not change significantly if dredged soil in the same area. Then, the water content ratio w is calculated for each density value (wet unit volume weight γt) obtained by the γ-ray density meter 15.

  On the other hand, in the computer 20a, the solidification material mixing ratio for obtaining a desired target strength corresponding to the change in the water content ratio w is mathematically input, and the above-described calculation formula is based on the additive mixing ratio data. The necessary additive mixing ratio is selected in accordance with the water content ratio obtained in (1), and the amount of solidification material injected by the solidification material injector 19 is controlled.

  As shown in FIG. 4, the solidifying material mixing ratio data is prepared by mixing the additive slurry for each of the samples S1, S2, and S3 with different water content ratios of the soil slurry in several stages. A graph is created by measuring the strength after solidification every time, and as shown in FIG. 5, a graph of the amount of solidified material mixture for obtaining the target strength with respect to the change in the water content is created.

  Furthermore, in order to prevent the shortage of additive when the detected moisture content value is extremely small, and to prevent damage to the device due to excessive addition of additive material per unit time when the moisture content value is extremely large. For a portion outside the expected water content ratio, a graph in which a fixed minimum injection ratio and maximum injection ratio are set is created as shown in FIG.

  Further, from the pressure change value in the transport pipe 16 obtained by the both pressure gauges 18a, 18b, the computer 20a calculates the weight and length (or length) of the plug S when it passes through the additive injection pipe position. Corresponding to the change in the amount of earth and sand slurry, the solidifying material injection amount and the timing at which the solidifying material is injected into each plug S are controlled.

  That is, the computer 20a calculates the weight (or length) of each plug S in the transport pipe 16 based on the peak value p of the pressure curve detected by the pressure gauges 18a and 18b as shown in FIG. The flow rate of each plug S (sediment slurry) is calculated based on the detection time difference t between the peak values p of the two pressure gauges 18a and 18b. The injection amount (or injection time) and injection timing are controlled.

  It has been confirmed by experiments that the pressure rises as each plug S passes through the transport pipe 16, and the tip of the plug S passes through the place where the pressure gauge 18a is installed as shown by the solid line in FIG. At time t0, the measured value of the pressure gauge 18a begins to rise, and at time t1, which is delayed from time t0, the peak value p is detected by the pressure gauge 18a. Then, as indicated by a broken line in FIG. 7, when the same plug S passes through the installation location of the downstream pressure gauge 18b, the peak value of the pressure gauge 18b is reached at a time t2 later than the upstream detection time t1. p is detected.

  Then, the flow velocity v (v = d / t) of the plug S is calculated from the installation interval d of the pressure gauges 18a and 18b and the detection time difference t (t = t2−t1) between the peak values p of the pressure gauges 18a and 18b. From the flow velocity v of the plug S and the distance l between the pressure gauge 18b and the injection nozzle 19a, the time t3 (t3 = 1 / v + t0) at which the tip of the plug S passes the installation location of the injection nozzle 19a is calculated. To do.

  Therefore, when the tips of the multiple plugs S, S... Pass through the injection nozzle 19a, the injection of the solidified material into the transport pipe 16 by the injection nozzle 19a can be started. Even if the intervals of S, S... Are not constant, the solidifying material can be reliably added to each of the plugs S, S... Without supplying the air portions A, A.

  In addition, when the installation interval e of the pressure gauges 18a and 18b is relatively narrow and only one plug S exists between the pressure gauges 18a and 18b, the upstream side pressure gauge 18a detects the same plug S. Immediately after that, since the pressure is detected by the downstream pressure gauge 18b, the detection results of the two pressure gauges 18a and 18b can be easily matched. Further, since the peak value p or waveform detected by the pressure gauges 18a and 18b has a characteristic for each plug S, S..., Two pressure gauges 18a and 18b related to the same plug S are based on the peak value p or waveform. These detection results may be made to correspond.

  It has been confirmed by experiments that the peak value p detected by the pressure gauge 18b is substantially proportional to the weight W of each plug S (W = ap + b (a and b are constants)). The length (volume) of each plug S is proportional to its weight W, and is therefore proportional to the peak value p of the pressure gauge 18b.

  The computer 20a is programmed in advance so that the weight W of each plug S calculated in this way is the solidification material mixing ratio corresponding to the moisture content calculated from the measurement value of the γ-ray density meter 15 described above. The solidification material injection amount is calculated by the calculation formula, and the solidification material injection amount for each plug S from the solidification material injector 19 is controlled.

  The rear end of the plug S passes through the installation position of the injection nozzle 19a by controlling the injection speed of the solidified material by the injection nozzle 19a to be constant and controlling the injection time to be proportional to the peak value p of the pressure gauge 18b. The injection rate of the solidifying material can be adjusted so that the injection time of the additive material just ends, so that even if the plug S is long, the additive material is not biased from the front end to the rear end of the plug S. Can be added evenly.

(Test Example 1)
Next, for soft soil made of clay with a high water content ratio, a test in which clinker ash was added and a solidification material made of cement and, if necessary, a solidification aid made of fly ash was added and mixed for solidification treatment. An example is shown.

In FIG. 8, clinker ash is added at 50% to soft soil (soft soil: clinker ash = 1: 1), and cement is 30, 40, 50, 60 kg relative to the total amount. The uniaxial compressive strength at the age of 14 and 28 days when / m ^{3 is} added and cured in a constant temperature and humidity chamber at 20 ° C. is shown. For comparison, the uniaxial compressive strength on the 28th day of the age when cement is added at 50 or 60 kg / m ³ without adding clinker ash is shown.

Add clinker ash to 50% (soft soil: clinker ash = 1: 1), and add 30kg / m ^{3 of} cement to the total amount of clinker ash. The uniaxial compressive strength on the 14th and 28th days is shown in FIG.

  As shown in FIG. 8, it was confirmed that the addition amount of cement for obtaining a desired strength can be significantly reduced by adding clinker ash.

Moreover, as shown in FIG. 9, it was confirmed that the strength of 250 to 100 kN / m ² which is the management width can be stably obtained even by reducing the amount of cement by adding clinker ash.

(Test Example 2)
In FIGS. 10 and 11, clinker ash is added to soft soil at 50% (soft soil: clinker ash = 1: 1), and cement is 50 kg / m ³ with respect to the total amount. And uniaxial compressive strength of material age 7 when fly ash 40 to 230 kg / m ³ is added, and strength ratio of uniaxial compressive strength of material age 7 days and material age 28 (material strength 28 days strength / material age) 7 days intensity).

As shown in FIG. 10 and FIG. 11, it was known that when fly ash was added together with cement, strength could be obtained from young age, but fly ash was within a predetermined range of ³⁰ to 80 kg / m ^3. When added, it was found that high strength can be obtained from the young age and that long-term strength enhancement can be suppressed.

  Thus, in the solidification processing method of the present invention in which clinker ash is added, by adding a predetermined amount of fly ash together with cement, strength can be secured more stably, and long-term strength increase can also be suppressed. Therefore, the amount of cement can be reduced while further ensuring safety, and high strength that makes it difficult to drive the drain material can be prevented.

  Next, the mixing apparatus will be described with reference to FIGS. FIG. 12 shows an outline of a mixing apparatus according to an embodiment of the present invention, FIG. 13 (a) shows a longitudinal section of the turbulent flow forming means, FIG. 13 (b) shows a transverse section of the turbulent flow forming means, and FIG. FIG. 14A shows a longitudinal section of the jet forming means, and FIG. 14B shows a transverse section of the jet forming means.

  In the illustrated mixing apparatus, soft soil such as dredged soil, clinker ash (light-weight sandy soil and inorganic high-quality materials such as sandy material) and cement are provided in the path of the device shown in FIG. 1 (in the transport pipe 16). , A mixing device for mixing fly ash.

  As shown in FIG. 12, for example, the turbulent flow forming means 51 is provided in the transport pipe 16 on the downstream side of the additive injector 13 and the solidifying material injector 19 (adding means) shown in FIG. A jet forming means 52 is provided on the conveying pipe 16 on the downstream side of the forming means 51.

  As shown in FIG. 13, the turbulent flow forming means 51 is configured by a partition plate 53 fixed to the flange 56 of the transport pipe 16, and the partition plate 53 is a part of the lower side of the flow path (for example, 1/3). ) Part). Soft soil to which clinker ash, cement and fly ash are added and pumped is mixed by turbulent flow generated when the partition plate 53 overflows.

  Therefore, lightweight sandy soil and inorganic high quality materials such as sandy material can be mixed in the transport pipe 16 (in the path) by turbulent flow generated when soft soil overflows the partition plate 53.

  As shown in FIG. 14, the jet forming means 52 includes four ladder-like plate members 54 arranged in the transport pipe 16, and has a configuration in which a jet is generated in the soft soil passing through the gap 55 of the plate member 54. . Soft soil to which clinker ash, cement, and fly ash are added and pumped is mixed by a jet generated when passing through the gap 55 of the plate material 54.

  Therefore, lightweight high quality inorganic materials such as light sandy soil and sandy material can be mixed in the transport pipe 16 (in the path) by a jet generated when soft soil flows through the gap 55 of the plate material 54.

  Note that the mixing device may be provided with either the turbulent flow forming means 51 or the jet forming means 52. Moreover, although the example which provided the turbulent flow formation means 51 and the jet flow formation means 52 in order to mix soft soil with which clinker ash and cement and fly ash were mixed was demonstrated, lightweight sandy soil and sandy material In order to make turbulent flow of soft soil added with clinker ash which is a high quality inorganic material such as turbulent flow in a state where they are not sufficiently mixed, turbulent flow forming means 51 is provided, or soft soil added with clinker ash is sufficient It is also possible to provide the jet forming means 52 for jetting into a state where the mixture is not mixed. That is, the turbulent flow forming means 51 is provided in the uplift pipe 12 between the additive injector 13 for adding clinker ash and granulated slag, which are inorganic high-quality materials such as lightweight sandy soil and sandy material, and the temporary storage tank 14. And / or jet forming means 52 can also be provided.

The present invention mainly relates to a mixing apparatus and a solidification treatment method for additives in soft soil such as dredged soil such as sea areas, rivers, lakes and marshes. It is widely applicable to certain soft soils, for example, those having a water content of 80% to 400%.

Claims (17)

A turbulent flow forming means for generating turbulent flow in a state where these materials are not sufficiently mixed is provided in the path for adding a lightweight sandy soil and sandy material, etc. A mixing device characterized by that. The passage is equipped with jet forming means that generates turbulent flow in a state where they are not sufficiently mixed in the route for adding lightweight high quality sandy soil and sandy material and other inorganic high quality materials to soft soil. A mixing device characterized by. It is equipped with an addition means to add powder or liquid solidifying material to the path for pumping both soft and lightweight sandy soil and high-quality inorganic materials such as sandy materials, and soft soil and inorganic that are pumped with the addition of solidifying material A mixing apparatus comprising a turbulent flow forming means for generating turbulent flow in both high quality materials in a path on the downstream side of the adding means. It is equipped with an addition means to add powder or liquid solidifying material to the path for pumping both soft and lightweight sandy soil and high-quality inorganic materials such as sandy materials, and soft soil and inorganic that are pumped with the addition of solidifying material A mixing apparatus comprising jet forming means for generating jets in both high quality materials in a path on the downstream side of the adding means. A soft soil and an addition means for adding a powdered or liquid solidifying material to a path for pumping both a lightweight sandy soil and a light inorganic sandy material such as a sandy material, and a soft soil to which the solidified material is added and pumped The turbulent flow forming means for generating turbulent flow in both the lightweight sandy soil and the sandy material is provided in the path on the downstream side of the adding means, and the solidification material is added to generate turbulent flow. A mixing apparatus comprising jet forming means for generating a jet in soft high-quality soil, lightweight sandy soil, and high-quality inorganic material such as sandy material, in a path on the downstream side of the turbulent flow forming means. In any of claims 1, 3 or 5
The turbulent flow forming means is a partition plate that divides a part of the lower side of the flow path, and soft soil and light inorganic sand material and solid material such as sandy material are added to overflow the partition plate. A mixing device characterized in that soft soil and inorganic high-quality materials such as lightweight sandy soil and sandy material and / or solidified material are mixed by turbulent flow that is sometimes generated. In any of claims 2, 4 or 5,
The jet forming means is a plurality of ladder-like plates arranged in the flow path, and soft soil and lightweight inorganic sand or sandy materials, such as high quality inorganic materials or solidified materials, are added to flow through the gaps between the plates. A mixing device characterized by mixing soft soil and high quality inorganic material or solidified material such as lightweight sandy soil and sandy material by a jet generated sometimes. In any one of Claims 1-7, an inorganic high quality material, such as a sandy material, is an at least 1 type of inorganic high quality material selected from clinker ash and granulated slag, and the addition used as the ratio which maintains a desired flow value A mixing apparatus, which is added and mixed in an amount, and is provided in a path in which a solidifying material is added and mixed after an inorganic high quality material is added and mixed. The solidification material according to any one of claims 3 to 7, wherein the solidification material is at least one solidification material selected from cement and cement and fly ash, and is added and mixed in an addition amount that maintains a desired strength. Features mixing device. At least one kind of inorganic high quality selected from clinker ash and granulated slag at an addition amount that maintains the desired flow value when mixing soft soil with lightweight high quality inorganic material such as sandy soil and sandy material A method for solidifying soft soil, characterized in that the material is added to soft soil and added and mixed in a pumping route. When soft soil is solidified with a solidifying material, at least one solidifying material selected from cement and cement and fly ash is added to the soft soil in an amount that maintains the desired strength, and is added in the pumping route. A method for solidifying soft soil, comprising mixing. In claim 10 or 11,
A method for solidifying soft soil, comprising adding and mixing lightweight sandy soil and a fine inorganic material such as sandy material in a pumping path of the soft soil by the mixing device according to claim 1. . In claim 9, 10, 11 or 12, the amount of inorganic high-quality material such as lightweight sandy soil and sandy material, after determining the ratio to maintain the desired flow value, the moisture content of the soft soil A method for solidifying soft soil, characterized by being constant regardless. In any one of Claims 9-13, the addition amount of inorganic high quality materials, such as lightweight sandy soil and sandy material, is the quantity used as 10%-70% by weight ratio, Soft soil characterized by the above-mentioned Solidification method. The solidifying material is added according to any one of claims 9 to 14, and the addition amount of the solidifying material is ³⁰ to 100 kg with respect to a total amount of 1000 m ^{3 of} high quality inorganic materials such as soft soil and light sandy soil and sandy material. A method for solidifying soft soil, characterized in that: 16. The method for solidifying soft soil according to claim 15, wherein the addition amount of the solidifying material is set so that the blending strength is 250 to 100 kN / m ² . The method for solidifying soft soil according to any one of claims 9 to 16, wherein fly ash is added as a solidification aid in an amount of ³⁰ to 90 kg with respect to a total amount of 1000 m ^{3 of} soft soil and the additive.

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