JP2017101453A - Water content adjustment method of soil material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water content adjustment method of soil material, which contains a fine grain material and a coarse grain material, capable of efficiently and properly adjusting the water content rate therein.SOLUTION: A water content adjustment method of soil material in an embodiment is a method of adjusting the water content rate in a soil material for manufacturing a soil material M using aground material B which is obtained by excavation. The method of adjusting the water content in a soil material includes the steps of: sorting a ground material B into a fine grain material M1 and a coarse grain material M2 for predetermined period and exposing the same to the atmosphere; mixing the fine grain material M1 and the coarse grain material M2 which have been exposed to the atmosphere for predetermined period; and heating the mixed fine grain material M1 and the coarse grain material M2.SELECTED DRAWING: Figure 6

Description

  The present invention relates to the production of a soil material by a method for adjusting the moisture content of the soil material used for constructing a structure.

  Japanese Patent Application Laid-Open No. 2007-255807 describes a stirring and drying device that dries and stirs solid particulates such as sludge containing moisture, clay, coal, limestone, or slag. This agitation drying apparatus includes an agitation chamber disposed on the upper side and an air blowing chamber disposed on the lower side. A raw material supply port is provided at the upper end of the stirring chamber, and a plurality of paddles rotating around a rod-shaped paddle shaft are arranged inside the stirring chamber. The raw material supplied from the supply port is stirred by a plurality of paddles in the stirring chamber and then discharged from an outlet provided on the side surface of the stirring chamber.

  On the other hand, a gas introduction port for introducing hot gas into the blower chamber is provided at the lower end of the side surface of the blower chamber, and the agitator chamber and the blower chamber are partitioned at the upper end of the blower chamber and the hot gas from below passes therethrough. A gas dispersion plate that can be made to flow is disposed. The hot gas introduced from the gas introduction port passes through the gas dispersion plate and enters the stirring chamber, and dries the raw material stirred in the stirring chamber. Thus, the hot gas introduced for drying the raw material is discharged from the gas discharge port located at the upper end of the stirring chamber.

JP 2007-255807 A

  By the way, a material that does not exist in nature may be used as a soil material used when constructing a structure such as a dam. In such a case, a material obtained by mixing a fine-grained material having a relatively small particle diameter and a coarse-grained material having a larger particle diameter than the fine-grained material may be used as the soil material. When such a soil material is used, it is important to appropriately adjust the mixing ratio and moisture content of the fine and coarse particles.

  In particular, it is important to adjust the moisture content of the fine-grained material and coarse-grained material, and when the fine-grained material and coarse-grained material are used as the soil material, the moisture content of the soil material needs to be close to the optimum moisture content. . Here, the optimal moisture content indicates the moisture content of the soil material that is best compacted when the soil material is compacted by a certain method. When the moisture content of the soil material is close to the optimum moisture content, the density of the soil material can be increased and the soil material can be compacted well, and the quality of the soil material can be increased. Become. In general, the moisture content of fine and coarse particles is often higher than the optimum moisture content, and it may be necessary to reduce the moisture content by drying. Furthermore, when constructing a structure such as a dam, a large amount of soil material is required. Therefore, it is required to efficiently and appropriately adjust the moisture content of fine and coarse particles.

  An object of the present invention is to provide a method for adjusting the moisture content of a soil material that can efficiently and appropriately adjust the moisture content of fine and coarse particles.

  The method for adjusting the moisture content of a soil material according to the present invention is a method for adjusting the moisture content of a soil material for producing a soil material from a ground material obtained by excavation, wherein the soil material is divided into fine and coarse particles. Separately, a step of exposing each of them for a predetermined period, a step of mixing the fine-grained material and the coarse-grained material exposed for a predetermined period of time, and a step of heating the mixed fine-grained material and the coarse-grained material are provided.

  In this method of adjusting the moisture content of the soil material, each of the fine grain material and coarse grain material separated from the ground material is exposed for a predetermined period. At this time, since the particle size of the coarse-grained material is larger than the particle size of the fine-grained material, the coarse-grained material has a larger gap between the particles than the fine-grained material and the air permeability is higher than the fine-grained material. Because it is good, it is easy to dry and moisture content is easy to reduce. Therefore, the moisture content of the coarse-grained material can be particularly reduced at this time by exposing each of the separated fine-grained material and coarse-grained material for a predetermined period. Further, the fine-grained material and the coarse-grained material exposed for a predetermined period are heated in a mixed state. At this time, since the dried coarse-grained material and the fine-grained material are heated in a mixed state, the fine-grained material and the coarse-grained material are dried more efficiently than when only the fine-grained material is heated. be able to. That is, by mixing and heating a fine-grained material to a coarse-grained material that is dry and having a low moisture content, the vaporization of moisture contained in the fine-grained material can be promoted efficiently and appropriately. Therefore, even when a large amount of soil material is required, the moisture content of the fine and coarse particles can be adjusted efficiently and appropriately.

  Moreover, you may perform the above-mentioned classification by classifying a ground material into a fine grain material and a coarse grain material. In this case, since the above-mentioned processing is performed on each of the fine-grained material and coarse-grained material classified by classification, the moisture content of the fine-grained material and coarse-grained material can be adjusted efficiently and appropriately. .

  In addition, after the step of exposing for a predetermined period, a step of comparing the moisture content of the fine-grained material and the moisture content of the coarse-grained material is provided, and in the comparing step, the moisture content of the fine-grained material is equal to or higher than the moisture content of the coarse-grained material. In the case where the water content of the fine-grained material is not equal to or higher than the water content of the coarse-grained material in the step of comparing and performing the step of mixing and heating, the step of heating need not be performed. Good. In this case, the moisture content of the fine-grained material is compared with the moisture content of the coarse-grained material. If the moisture content of the fine-grained material is equal to or higher than the moisture content of the coarse-grained material, a heating step is executed. Thus, when the moisture content of the fine-grained material is high, the soil material as a whole has a large amount of moisture. Therefore, the quality of the soil material can be improved by reducing the moisture content by heating. On the other hand, when the moisture content of the fine-grained material is low, there is little moisture in the entire soil material, so heating is not necessary. Thus, since the moisture content can be compared and the necessity of heating can be determined using the result, the moisture content can be adjusted more appropriately.

  In the heating step, the fine-grained material and the coarse-grained material may be heated while stirring and mixing the fine-grained material and the coarse-grained material. In this case, the fine-grained material and the coarse-grained material are heated while stirring and mixing the fine-grained material and the coarse-grained material, and the vaporization of water contained in the fine-grained material and the coarse-grained material can be promoted by stirring and mixing. Therefore, the moisture content can be reduced efficiently.

  In addition, as a method for suitably exhibiting the above-described effects, specifically, there is a method in which the above-described heating step is a step of applying warm air.

  In addition, the step of mixing the fine-grained material and the coarse-grained material is performed inside the cylindrical body arranged at an inclination. In the step of mixing the fine-grained material and the coarse-grained material, the fine-grained material and the coarse-grained material are While mixing in the cylinder, the fine and coarse particles are moved from the upper side of the cylinder to the lower side, and in the step of applying warm air, the lower part of the cylinder is directed toward the fine and coarse particles in the cylinder. Hot air may be applied. In this case, the mixed fine particle material and coarse particle material are introduced into the cylinder from above, and hot air is applied to the fine particle material and coarse particle material in the cylinder from below the cylinder. Accordingly, fine and coarse particles flow from the upper side to the lower side in the cylinder, and warm air flows from the lower side to the upper side in the cylinder. Therefore, since the relative speed of the warm air with respect to the fine-grained material and the coarse-grained material can be increased, the moisture content by the warm air can be reduced more efficiently.

  ADVANTAGE OF THE INVENTION According to this invention, the moisture content adjustment method of the soil material which can adjust the moisture content of a fine grain material and a coarse grain material efficiently and appropriately can be provided.

It is sectional drawing which shows the rock fill dam constructed | assembled by the soil material obtained with the manufacturing method of the soil material including the moisture content adjusting method of the soil material which concerns on embodiment. It is a graph which shows the relationship between the moisture content in a soil material, and a dry density. It is a side view which shows the soil material manufacturing apparatus which concerns on embodiment. It is an expanded view which shows the inner surface of the cylinder part in the soil material manufacturing apparatus of FIG. It is a figure which shows the state which is stirring and supply of warm air in the inside of the cylinder part of FIG. It is the figure which simplified and showed each apparatus until the soil material shown by FIG. 1 is obtained. It is a flowchart which shows each process of the manufacturing method of the soil material containing the moisture content adjusting method of the soil material which concerns on embodiment. It is a graph which shows the property (particle diameter accumulation curve) of the soil material obtained through each process of FIG.

  Hereinafter, embodiments of a method for producing a soil material including a method for adjusting the moisture content of the soil material according to the present invention will be described with reference to the drawings. The method for adjusting the moisture content of the soil material according to the present invention is not limited to the method for adjusting the moisture content of the soil material of the following embodiment, and can be changed as appropriate. Moreover, in the following description, the same code | symbol is attached | subjected to the element which is the same or it corresponds, and the overlapping description is abbreviate | omitted.

  First, as shown in FIG. 1, the soil material M obtained by the soil material manufacturing method including the moisture content adjusting method according to the present embodiment is, for example, a water-impervious wall of a rock-fill dam D of a central impermeable wall type. Used as W. The rockfill dam D includes the impermeable wall W, a filter layer F located on both sides of the impermeable wall W, and a lock layer R located on both sides of the filter layer F. The water-impervious wall W is a part called a core part, and has a clay shape with high water-imperviousness. The filter layer F is a sand or gravel layer that supports the impermeable wall W from both sides, and the rock layer R is a rock layer that supports the filter layer F from both sides. In the rock fill dam D, high water shielding performance is exhibited in the water shielding wall W, and high stability is ensured by the filter layer F and the rock layer R on the rising surface D1 of the rock fill dam D.

  In the above-described rockfill dam D, the soil material M constituting the water-impervious wall W is required to have high water-blocking performance, and the quality of the soil material M is strictly controlled. As the soil material M, a material that does not exist in nature is used. The soil material M is manufactured by mixing a fine grain material M1 (see FIG. 5) having a relatively small particle diameter and a coarse grain material M2 having a larger particle diameter than the fine grain material M1. Here, for example, the fine particle material M1 indicates a material containing 50% or more of fine particles whose particle size is equal to or smaller than a predetermined value, and the coarse particle material M2 indicates a coarse particle content whose particle size is larger than a predetermined value. Indicates a material containing 50% or more.

  Here, about the fine grain material M1 and the coarse grain material M2, it can obtain | require with the particle size accumulation curve calculated | required by the particle size test (JIS-A-1204) of soil. An example of the particle size accumulation curve is shown in FIG. As shown in FIG. 8, the fine-grained material M1 can also be defined as having a larger passing mass percentage at a predetermined particle size than the coarse-grained material M2. Moreover, it can also obtain | require with the coarse-grain rate calculated | required from the result of the screening which added the new screen sieve to the screen sieve of the magnitude | size prescribed | regulated by a predetermined screening test (JIS-A-1102) and JIS-A-1102. . Further, the fine grain material M1 may be defined as having a lower coarse grain ratio than the coarse grain material M2.

  In the soil material M, it is important that the mixing ratio of the fine grain material M1 and the coarse grain material M2 and the moisture content of the fine grain material M1 and the coarse grain material M2 are appropriately adjusted. Further, as shown in FIG. 2, the moisture content of the soil material M needs to be close to the optimum moisture content Rmax. By bringing the moisture content of the soil material M close to the optimum moisture content Rmax, the dry density of the soil material M (the density of soil particles of the soil material M) can be increased, and the soil material M can be compacted well. It becomes possible to improve the quality as the soil material M.

  Here, as a specific example of bringing the moisture content of the soil material M close to the optimum moisture content Rmax, for example, an example in which the dry density of the soil material M is set to r × Dmax or more is given. Dmax indicates the maximum dry density when the water content is the optimum water content Rmax, and r indicates an arbitrary ratio that is less than 1 and close to 1, for example, 0.9. When the dry density is r × Dmax, the moisture content is Ra slightly smaller than the optimum moisture content Rmax, or Rb slightly larger than the optimum moisture content Rmax, and the moisture content of the soil material M should be Ra above and below Rb. Can be considered.

  Next, the soil material manufacturing apparatus 1 that manufactures the soil material M from the fine-grained material M1 and the coarse-grained material M2 while adjusting the water content will be described with reference to FIG. In this soil material manufacturing apparatus 1, mixing of the fine grain material M1 and the coarse grain material M2 and adjustment of the moisture content of the fine grain material M1 and the coarse grain material M2 are performed. As shown in FIG. 3, the soil material manufacturing apparatus 1 includes hoppers 2a, 2b, and 2c to which fine-grained material M1 and coarse-grained material M2 are supplied, and fine-grained material M1 and coarse-grained material supplied to the hopper 2c. A conveyor 3 that conveys M2 obliquely upward, a mixer 4 that extends obliquely downward from the upper end of the conveyor 3, and a hot air supply device 5 that supplies hot air H to the inside of the mixer 4 from below are provided.

  The hoppers 2a, 2b, and 2c are formed in a funnel shape that gradually increases in diameter toward the top. Each of the hopper 2a and the hopper 2b is supplied with a fine grain material M1 and a coarse grain material M2 having a predetermined ratio. Here, the predetermined ratio is a ratio of the fine-grained material M1 and the coarse-grained material M2 determined in consideration of the water permeability required for the soil material M used as the embankment material of the impermeable wall W. In the present embodiment, the predetermined ratio is, for example, a fine grain material M1: a coarse grain material M2 = 1: 2.

  The soil material manufacturing apparatus 1 further includes moisture content measuring devices 6a and 6b for measuring the moisture content of the fine grain material M1 and the coarse grain material M2 below the hoppers 2a and 2b. Is provided with a moisture content measuring device 6c. The fine-grained material M1 and the coarse-grained material M2 supplied to the hoppers 2a and 2b flow down inside the hoppers 2a and 2b, respectively, and the moisture content measuring devices 6a and 6b respectively contain the fine-grained material M1 and the coarse-grained material M2. The rate is measured.

  The moisture content measuring devices 6a and 6b measure the moisture content of the fine grain material M1 and the coarse grain material M2 passed through the hoppers 2a and 2b. The moisture content measuring devices 6a and 6b are, for example, infrared moisture content measuring devices, which irradiate each of the fine-grained material M1 and the coarse-grained material M2 with infrared rays, and thereby from each of the fine-grained material M1 and the coarse-grained material M2. By detecting the reflected infrared rays, the moisture content of the fine grain material M1 and the coarse grain material M2 is measured in real time. Thus, the moisture content measuring devices 6a and 6b can measure the moisture content of the fine-grained material M1 and the coarse-grained material M2 in a non-contact manner.

  The fine-grained material M1 and the coarse-grained material M2 that have flowed down the hoppers 2a and 2b merge into the hopper 2c, and then, for example, are arranged at a position facing the moisture content measuring device 6c. This moisture content measuring device 6c can measure the moisture content of the fine-grained material M1 and the coarse-grained material M2 in the same manner as the moisture content measuring devices 6a and 6b described above. Note that the number and location of the hoppers 2a, 2b, 2c and the moisture content measuring devices 6a, 6b, 6c are not limited to the above-described examples, and can be changed as appropriate. For example, before being passed through the hoppers 2a and 2b, a moisture content measuring device similar to the moisture content measuring devices 6a, 6b, and 6c may measure the moisture content of the fine-grained material M1 and the coarse-grained material M2.

  The fine-grained material M1 and the coarse-grained material M2 that have passed through the opposite positions of the moisture content measuring device 6c are placed on the lower end portion of the conveyor 3. The conveyor 3 extends obliquely upward from its lower end and conveys the fine grain material M1 and the coarse grain material M2 obliquely upward, and a cover extending along the conveyor body 3a above the conveyor body 3a. 3b and a plurality of column members 3c that support the conveyor body 3a.

  The conveyor main body 3a has the fine grain material M1 and the coarse grain material M2 placed on the upper surface thereof, and conveys the placed fine grain material M1 and coarse grain material M2 obliquely upward. The cover 3b covers the conveyor main body 3a from diagonally above, and protects the fine grain material M1 and the coarse grain material M2 from, for example, rain. By the cover 3b and the conveyor main body 3a, the transport path 3d of the fine-grained material M1 and the coarse-grained material M2 in the conveyor 3 is at least covered at the top and bottom, and has a shape that can easily introduce hot air H described later. It has become. The plurality of column members 3c extend from the conveyor body 3a toward the ground G, and support the conveyor body 3a in an inclined state.

  The mixer 4 has a cylindrical shape as a whole, and a fine grain material M1 and a coarse grain material M2 can be distributed therein. The upper end of the mixer 4 is adjacent to the upper end of the conveyor 3, and the fine grain material M <b> 1 and the coarse grain material M <b> 2 that have moved obliquely upward in the conveyor 3 are supplied into the mixer 4 from above. The mixer 4 includes a cylindrical body 4b formed by connecting five cylindrical portions 4a so as to be rotatable, and a plurality of column members 4c that support the cylindrical body 4b in an inclined state.

  The cylindrical portions 4a of the cylindrical body 4b are connected to each other in the axial direction x (direction extending obliquely), and are rotatable around the axial line. The fine-grained material M1 and the coarse-grained material M2 pass through the inside of each cylindrical portion 4a, and the fine-grained material M1 and the coarse-grained material M2 passing through each cylindrical portion 4a are agitated and mixed by the rotation of each cylindrical portion 4a. Moreover, as FIG. 5 shows, the one cylinder part 4a rotates in the opposite direction of the other cylinder part 4a adjacent to the axial direction x. Specifically, the rotation direction of the cylinder part 4a located at the odd number from the top of the cylinder 4b rotates in the opposite direction to the cylinder part 4a located at the even number from the top. Thus, by rotating one cylinder part 4a in the opposite direction of the other adjacent cylinder parts 4a, it is possible to promote stirring and mixing and homogenization of the fine grain material M1 and the coarse grain material M2 in the cylinder part 4a. It is possible.

  FIG. 4 shows a developed view in which each cylindrical portion 4a is developed. As shown in FIG. 4, the inner surface 4d of each cylindrical portion 4a is provided with a plurality of projecting portions 4e projecting from the inner surface 4d in the out-of-plane direction. Each protrusion 4e is inclined at a predetermined angle θ with respect to the axial direction x of each cylinder 4a. The value of the predetermined angle θ is, for example, 50 ° or more and 80 ° or less, but can be an arbitrary value as long as it is greater than 0 ° and 90 ° or less. Moreover, the inclination direction of the protrusion part 4e in one cylinder part 4a is mutually opposite to the inclination direction of the protrusion part 4e in the other cylinder part 4a adjacent to the axial direction x. As described above, the protrusion 4e is inclined at a predetermined angle θ on the inner surface 4d of each cylindrical portion 4a, whereby the fine-grained material M1 and the coarse-grained material M2 passing through the inner surface 4d and the protruding portion 4e are stirred and mixed. It is possible to further promote homogenization.

  In the mixer 4 configured as shown in FIGS. 3 and 4, the fine grain material M1 and the coarse grain material M2 are introduced into the cylindrical body 4b from above. The fine-grained material M1 and the coarse-grained material M2 introduced into the cylindrical body 4b move downward in the cylindrical body 4b while being stirred and mixed by the rotation of the cylindrical parts 4a and the collision with the protruding parts 4e. Go.

  Moreover, the warm air supply apparatus 5 is arrange | positioned at the lower end of the cylinder 4b. The hot air supply device 5 is mounted, for example, on a work vehicle V including a work table V2 that can be moved up and down by the lift device V1, and is disposed on the work table V2. As described above, the hot air supply device 5 is arranged on the work table V2 on which the work vehicle V can be moved up and down, so that the hot air supply device 5 can be moved to a desired position. The hot air supply device 5 includes a hose portion 5a that is inserted into the cylinder 4b from below, and a fan heater 5b that sends hot air H into the hose portion 5a by, for example, kerosene. Like the hot air H sent from the fan heater 5b, the hot air used in the present embodiment is not a flame like a burner, but assumes a relatively low temperature hot air that can be used as a heater. . The hose portion 5a is made of, for example, vinyl. In addition, the structure of the warm air supply apparatus 5 is not restricted above, It can change suitably.

  As described above, the hot air supply device 5 is disposed on the lower side of the mixer 4, the hose portion 5a of the hot air supply device 5 is inserted into the cylindrical body 4b from below, and the hot air is introduced into the cylindrical body 4b from the hose portion 5a. Supplied. Thereby, as schematically shown in FIG. 5, the fine-grained material M1 and the coarse-grained material M2 are stirred and mixed in the cylindrical body 4b by the rotation of the cylindrical body 4b, and the fine-grained material M1 moving from the top to the bottom. And the warm air H is sprayed from the bottom to the coarse particle material M2.

  Moreover, since the warm air H supplied from the bottom to the cylinder 4b moves obliquely upward along the inner surface 4d of the cylinder 4b, the warm air H flows in the fine particle material M1 and the coarse particle material M2 inside the cylinder 4b. As a result, the fine-grained material M1 and the coarse-grained material M2 are efficiently dried in the cylindrical body 4b and the water content can be reduced. The fine-grained material M1 and the coarse-grained material M2 that are stirred and mixed and dried in the cylindrical body 4b are discharged as a soil material M below the cylindrical body 4b. The discharged soil material M is transported to the site where the rockfill dam D is constructed by a truck or the like and used as the water shielding wall W.

  Next, the manufacturing method which manufactures the soil material M using the soil material manufacturing apparatus 1 is demonstrated, referring FIG.6 and FIG.7. FIG. 6 is a diagram showing each process of the soil material manufacturing apparatus 1 in a simplified manner until the soil material M is obtained. FIG. 7 is an example of a method for manufacturing the soil material M according to the present embodiment. It is a flowchart to show.

  First, as shown in FIGS. 6 and 7, the ground is excavated to form a pile of the ground material B (step S1). And it transfers to step S2 and classifies the fine grain material M1 and the coarse grain material M2 by sieving from the obtained ground material B, and performs the classification with the fine grain material M1 and the coarse grain material M2. At this time, for example, the fine-grained material M1 and the coarse-grained material M2 are separated by performing sieving between the fine-grained material M1 and the coarse-grained material M2 using a grizzly river.

  Next, in step S3, a step of exposing the fine-grained material M1 and the coarse-grained material M2 for a predetermined period of time by executing the fine-grained material M1 and the coarse-grained material M2 respectively in the air is performed. This predetermined period is, for example, one week or more, preferably one month or more and six months or less, and is a period sufficient to dry the fine-grained material M1 and the coarse-grained material M2 to some extent. That is, in step S3, since each of the fine grain material M1 and the coarse grain material M2 is sun-dried, the moisture content of each of the fine grain material M1 and the coarse grain material M2 is reduced to some extent.

  After exposing the fine-grained material M1 and the coarse-grained material M2 for a predetermined period, the moisture content of each of the fine-grained material M1 and the coarse-grained material M2 is measured using the above-described moisture content measuring devices 6a and 6b. The material M1 and the coarse particle material M2 are poured into the hopper 2 of the soil material manufacturing apparatus 1 to start mixing the fine particle material M1 and the coarse particle material M2 (step S4). Note that the moisture content measuring device 6 may measure the moisture content of the fine-grained material M1 and the coarse-grained material M2 with respect to the fine-grained material M1 and the coarse-grained material M2 flowing down by the hopper 2.

  Thereafter, the process proceeds to step S5, and a process of comparing the moisture content of the fine-grained material M1 and the moisture content of the coarse-grained material M2 is performed. In step S5, when it is determined that the moisture content of the fine-grained material M1 is equal to or higher than the moisture content of the coarse-grained material M2, the hot-air supply device is transported after the fine-grained material M1 and the coarse-grained material M2 are conveyed by the conveyor 3. 5 and the stirring and mixing of the fine-grained material M1 and the coarse-grained material M2 by the rotation of the mixer 4 are executed. In this way, a heating step (step of applying warm air) and a mixing step are executed (step S6).

  On the other hand, in Step S5, when it is determined that the moisture content of the fine-grained material M1 is not equal to or higher than the moisture content of the coarse-grained material M2, the fine-grained material M1 and the coarse-grained material M2 are transported by the conveyor 3, Addition to the fine particle material M1 and the coarse particle material M2 and agitation and mixing of the fine particle material M1 and the coarse particle material M2 by the rotation of the mixer 4 are executed (step S7). In step S7, hot air H is not introduced by the hot air supply device 5, but in step S7, it is possible to omit the addition to the fine grain material M1 and the coarse grain material M2.

  By passing through step S6 or step S7 as described above, in the mixer 4, the fine particle material M1 and the coarse particle material M2 are homogenized by stirring and mixing, and the moisture content of the fine particle material M1 and the coarse particle material M2 by drying is reduced. Adjustment is performed at the same time, and a process of bringing the moisture content of the fine-grained material M1 and the coarse-grained material M2 closer to the optimum moisture content Rmax is executed. And in order to make the moisture content of the fine grain material M1 and the coarse grain material M2 approach the optimal moisture content Rmax, the supply amount of the warm air H by the warm air supply device 5 is adjusted. As described above, in the soil material manufacturing apparatus 1, by supplying the fine-grained material M1 and the coarse-grained material M2 into the mixer 4 and supplying the hot air H, a large amount of the fine-grained material M1 and the coarse-grained material M2 are supplied. Can be made uniform and dried at once.

  The fine-grained material M1 and the coarse-grained material M2 that have been homogenized and dried by the mixer 4 as described above are discharged as a soil material M below the mixer 4. And the soil material M discharged | emitted from the mixer 4 is conveyed by the construction site of the rock fill dam D by a truck etc. (step S8), and is used as the impermeable wall W. Thus, a series of processing ends.

  Next, the effect of the soil material moisture content adjusting method according to the present embodiment will be described.

  In the soil material moisture content adjusting method according to the present embodiment, each of the fine-grained material M1 and the coarse-grained material M2 separated from the ground material B is exposed for a predetermined period. At this time, the particle size of the coarse material M2 is larger than the particle size of the fine particle material M1, and therefore the coarse particle material M2 has larger gaps between the particles than the fine particle material M1 when exposed for a predetermined period. Since the surface area in contact with the ventilation is large, the water content is easily reduced. Therefore, by exposing each of the fine-grained material M1 and the coarse-grained material M2 for a predetermined period, the moisture content of the coarse-grained material M2 can be reduced particularly at this time.

  Moreover, the fine grain material M1 and the coarse grain material M2 exposed for a predetermined period are heated by the warm air H of the warm air supply device 5 in a mixed state. At this time, since the dried coarse particle material M2 and the fine particle material M1 are heated in a mixed state, the fine particle material M1 and the coarse particles are more efficiently produced than when only the fine particle material M1 is heated. The material M2 can be dried. That is, by mixing and heating the fine-grained material M1 in the dry coarse-grained material M2, vaporization of the water contained in the fine-grained material M1 can be promoted efficiently and appropriately. Therefore, even when a large amount of soil material M is required, the moisture content of the fine grain material M1 and the coarse grain material M2 can be adjusted efficiently and appropriately.

  In the method for adjusting the moisture content of the soil material according to the present embodiment, the particle size and mixing of the soil material M (the fine grain material M1 and the coarse grain material M2) are performed by introducing the fine grain material M1 and the coarse grain material M2 into the mixer 4. It is also possible to adjust the ratio. For example, as shown in FIG. 8, by mixing the fine-grained material M1 and the coarse-grained material M2 with stirring into the mixer 4, the mixing ratio of the soil material M (particle size of the soil material M) is set to an ideal value (fine particle). (Granular material M1: coarse particle material M2 = 1: 2 calculated value).

  In the soil material moisture content adjusting method according to the present embodiment, as shown in FIGS. 6 and 7, the above-mentioned classification is performed by classifying the ground material B into the fine-grained material M1 and the coarse-grained material M2. ing. Therefore, the fine particles M1 and the coarse particles M2 that have been classified by the classification are subjected to the above-described treatment, so that the moisture content of the fine particles M1 and the coarse particles M2 is adjusted efficiently and appropriately. be able to.

  In addition, after the step of exposing for a predetermined period, a step of comparing the moisture content of the fine-grained material M1 and the moisture content of the coarse-grained material M2 is provided, and in the comparing step, the moisture content of the fine-grained material M1 is the coarse-grained material M2. If the water content of the fine-grained material M1 is not higher than the water content of the coarse-grained material M2, in the step of comparing and performing the heating step, the heating step is not performed. May be.

  Therefore, the moisture content of the fine grain material M1 is compared with the moisture content of the coarse grain material M2, and if the moisture content of the fine grain material M1 is equal to or higher than the moisture content of the coarse grain material M2, the heating step is performed. Run. Thus, when the moisture content of the fine granule material M1 is high, the soil material as a whole often has a lot of moisture, so the quality of the soil material M can be improved by reducing the moisture content by heating. On the other hand, when the moisture content of the fine-grained material M1 is low, it is not necessary to perform heating because the moisture content of the entire soil material is often small. Thus, since the moisture content can be compared and the necessity of heating can be determined using the result, the moisture content can be adjusted more appropriately.

  In the heating step, the fine-grained material M1 and the coarse-grained material M2 are heated while stirring and mixing the fine-grained material M1 and the coarse-grained material M2. Therefore, the fine grain material M1 and the coarse grain material M2 are heated while stirring and mixing the fine grain material M1 and the coarse grain material M2, and the moisture contained in the fine grain material M1 and the coarse grain material M2 is vaporized by stirring and mixing. Since it can be made to promote, a moisture content can be reduced efficiently.

  In addition, the step of mixing the fine-grained material M1 and the coarse-grained material M2 is performed inside the cylindrical body 4b arranged at an inclination, and the step of mixing the fine-grained material M1 and the coarse-grained material M2 While mixing M1 and coarse particle material M2 in cylinder 4b, fine particle material M1 and coarse particle material M2 are moved downward from above cylinder 4b, and in the step of applying hot air, from below cylinder 4b. Hot air H is applied toward the fine-grained material M1 and the coarse-grained material M2 in the cylinder 4b.

  Therefore, the fine-grained material M1 and the coarse-grained material M2 are introduced into the cylindrical body 4b from above, and the fine-grained material M1 and the coarse-grained material M2 in the cylindrical body 4b are supplied with warm air H from below the cylindrical body 4b. Is applied. Therefore, the fine-grained material M1 and the coarse-grained material M2 flow from the upper side to the lower side in the cylinder 4b, and the hot air H flows from the lower side to the upper side in the cylinder 4b. Thereby, since the relative speed of the warm air H with respect to the fine grain material M1 and the coarse grain material M2 can be raised, the water content reduction by the warm air H can be performed more efficiently.

  Furthermore, the soil material M obtained in the process of applying hot air is used as the water-impervious wall W of the rockfill dam D. The water-impervious wall W of the rockfill dam D is required to have high water-impervious performance as described above. And as the soil material M used as the water-impervious wall W, a high-quality material whose water content is appropriately adjusted is required. Therefore, in the method for adjusting the moisture content of the soil material according to the present embodiment, the soil material M obtained through the process of applying hot air as described above can be manufactured, and the soil material M has a moisture content of It is adjusted efficiently and appropriately. Therefore, the high-quality soil material M that can be efficiently manufactured can be used as the water-impervious wall W of the rockfill dam D.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, It deform | transformed in the range which does not change the summary described in each claim, or applied to others It may be a thing. That is, the present invention can be variously modified without changing the gist of each claim.

  For example, in the above-described embodiment, the example in which the hot air supply device 5 applies the hot air H from below the mixer 4 toward the fine grain material M1 and the coarse grain material M2 in the cylindrical body 4b has been described. However, the direction in which the hot air H is applied and the location of the hot air supply device 5 can be changed as appropriate.

  For example, the hot air supply device 5 may be disposed obliquely above the conveyor 3 and the hot air H may be applied from above the conveyor 3 toward the fine grain material M1 and the coarse grain material M2. As described above, even when the hot air H is applied toward the fine-grained material M1 and the coarse-grained material M2 from obliquely above the conveyor 3, the warm-air is applied to the fine-grained material M1 and the coarse-grained material M2 that move obliquely upward. Since the relative speed of H can be increased, the moisture content can be reduced efficiently. As another example, warm air H may be applied toward the fine-grained material M1 and the coarse-grained material M2 from diagonally above the mixer 4, or the fine-grained material M1 and the coarse-grained material M2 from diagonally below the conveyor 3. You may apply the warm air H toward. Further, the means for heating the fine-grained material M1 and the coarse-grained material M2 is not limited to the hot air H, but may be directly heated by a heating means other than the hot air supply device 5, for example, or used in the mixing step. The container to be heated may be heated.

  In the above-described embodiment, as shown in FIG. 6, the fine-grained material M1 and the coarse-grained material M2 are classified from the pile of one ground material B, and the fine-grained material M1 and the coarse-grained material M2 are classified. An example was described. However, even if the excavation place of the fine-grained material M1 and the excavation place of the coarse-grained material M2 are different from each other, the mountain of the fine-grained material M1 and the mountain of the coarse-grained material M2 are each formed in advance. Good. Also, a blend pile in which the fine grain material M1 and the coarse grain material M2 are alternately formed in layers at a predetermined ratio may be formed. The blend pile is sliced obliquely to fine grain material M1 and coarse grain material M1. The granular material M2 may be introduced into the soil material manufacturing apparatus 1. Furthermore, when the fine-grained material M1 and the coarse-grained material M2 are mixed, the fine-grained material M1 that is lacking may be added as necessary.

  Moreover, although the above-mentioned embodiment demonstrated the example which uses the soil material M as the water-impervious wall W of the rock fill dam D, the structure which can apply the soil material M is not limited to the water-impervious wall W of the rock fill dam D. For example, the soil material M may be applied to other structures such as a dike.

  Next, the Example and comparative example which manufactured the soil material M using the soil material manufacturing apparatus 1 and the moisture content adjustment method of a soil material of this embodiment are demonstrated. Here, in this example, the soil material M is used as a material for the embankment material and the mixing ratio of the fine-grained material M1 and the coarse-grained material M2 is set to 1: 2 in consideration of securing the water permeability. did. Since the optimum moisture content Rmax of the soil material M was 18%, the range of the moisture content required for the soil material M mixed at the time of construction was set to 18% or more and 20% or less.

  Moreover, in an Example, immediately after excavating with the ground material B and classifying and obtaining the fine grain material M1 and the coarse grain material M2, the moisture content of the fine grain material M1 is 30% (a), and the coarse grain material M2 The water content of was 27% (b). And after performing the exposure process for a predetermined period and drying the fine-grained material M1 and the coarse-grained material M2 in the sun for two weeks (sunny weather continued), the moisture content of the fine-grained material M1 is 24% (c), coarse The moisture content of the granule M2 was 12% (d).

  Thereafter, the fine-grained material M1 and the coarse-grained material M2 were dried in the sun (relatively fine weather continued), and then the moisture content of the fine-grained material M1 was 27% (e), and the moisture content of the coarse-grained material M2 Was 15% (f), and after exposure to fine-grained material M1 and coarse-grained material M2 for 3 months (sunny weather was repeated), the moisture content of fine-grained material M1 was 30% (g) The moisture content of the material M2 was 18% (h). Thus, it was found that the moisture content of the coarse-grained material M2 can be reduced by separately exposing the fine-grained material M1 and the coarse-grained material M2 for a predetermined period. Similar results were obtained when the fine-grained material M1 and the coarse-grained material M2 were obtained from separate mining sites.

  On the other hand, in the comparative example, the fine-grained material M1 and the coarse-grained material M2 were mixed immediately after excavation to generate mixed soil, and exposed in this state for a predetermined period. Immediately after this, the water content of the mixed soil was 28%. After the mixed soil was dried in the sun for two weeks (sunny weather continued), the moisture content of the mixed soil became 20%, and then the mixed soil was dried in the sun for two months (relatively clear weather continued) The water content of the mixed soil was 22%. And after exposing the mixed soil for 3 months (sunny rainy weather was repeated), the moisture content of the mixed soil became 26%.

  Furthermore, at each time point (a) to (h) in the above-described embodiment, the average moisture content when the fine-grained material M1 and the coarse-grained material M2 are mixed 1: 2 is the first time point ((a). And (b)) 28% (= (30% + 27% × 2) / 3), and 2 weeks later ((c) and (d)) 16% (= (24% + 12% × 2) / 3) 19% (= (27% + 15% × 2) / 3) at 2 months later ((e) and (f)), 22 at 3 months later ((g) and (h)) % (= (30% + 18% × 2) / 3).

  Then, when the fine-grained material M1 and the coarse-grained material M2 having an average moisture content of 22% after 3 months are introduced into the soil material manufacturing apparatus 1 and mixing and drying are promoted, the result is obtained. The water content of the soil material M was reduced by 3% to 19%. Therefore, the moisture content of the obtained soil material M is 18% or more and 20% or less and is within a desired range, and thus it has been found that the required quality is ensured.

  On the other hand, in the comparative example in which only the fine grain material M1 is introduced into the soil material production apparatus 1, only the fine grain material M1 having a moisture content of 30% (g) is introduced into the soil material production apparatus 1. In this case, the water content of the fine grain material M1 was reduced by 5% to 25%. However, the moisture content of the soil material obtained by mixing the fine-grained material M1 and the coarse-grained material M2 at 1: 2 is 20.5% (= (25% + 18% × 2) / 3), which is within the desired range. did not become. Thereby, even if it introduce | transduced only the fine grain material M1 into the soil material manufacturing apparatus 1, it turned out that the required soil material M was not obtained.

  According to the above examples and comparative examples, when the fine-grained material M1 and the coarse-grained material M2 are individually exposed for a predetermined period, and then both the fine-grained material M1 and the coarse-grained material M2 are introduced into the soil material manufacturing apparatus 1, It was confirmed that a high-quality soil material M was obtained.

DESCRIPTION OF SYMBOLS 1 ... Soil material manufacturing apparatus, 2, 2a, 2b, 2c ... Hopper, 3 ... Conveyor, 3a ... Conveyor main body, 3b ... Cover, 3c ... Column member, 4 ... Mixer, 4a ... Cylindrical part, 4b ... Cylindrical body, 4c ... pillar member, 4d ... inner surface, 4e ... projecting part, 5 ... hot air supply device, 5a ... hose part, 5b ... fan heater, 6, 6a, 6b, 6c ... moisture content measuring device, B ... ground material, D ... Rock fill dam, D1 ... rising surface, F ... filter layer, G ... ground, H ... warm air, M ... soil material, M1 ... fine grain material, M2 ... coarse grain material, R ... rock layer, V ... work vehicle, V1 ... lifting device, V2 work bench, W ... water shielding wall, x ... axial direction, θ ... predetermined angle.

Claims (6)

A method for adjusting the moisture content of a soil material to produce a soil material from a ground material obtained by excavation,
Separating the ground material into fine-grained material and coarse-grained material, and exposing each of them for a predetermined period;
Mixing the fine-grained material and the coarse-grained material exposed for the predetermined period;
Heating the mixed fine-grained material and the coarse-grained material;
A method for adjusting the moisture content of a soil material comprising: The classification is performed by classifying the ground material into the fine-grained material and the coarse-grained material,
The method for adjusting the moisture content of the soil material according to claim 1. After the step of exposing for a predetermined period, the step of comparing the moisture content of the fine-grained material and the moisture content of the coarse-grained material,
In the comparing step, when the moisture content of the fine-grained material is equal to or higher than the moisture content of the coarse-grained material, the mixing step and the heating step are executed.
In the comparing step, when the moisture content of the fine-grained material is not equal to or higher than the moisture content of the coarse-grained material, the heating step is not performed.
The method for adjusting the moisture content of a soil material according to claim 1 or 2. In the heating step, the fine grain material and the coarse grain material are heated while stirring and mixing the fine grain material and the coarse grain material.
The moisture content adjustment method of the soil material as described in any one of Claims 1-3. The heating step is a step of applying warm air.
The moisture content adjustment method of the soil material as described in any one of Claims 1-4. The step of mixing the fine-grained material and the coarse-grained material is performed inside a cylindrical body arranged at an inclination,
In the step of mixing the fine-grained material and the coarse-grained material, while the fine-grained material and the coarse-grained material are mixed in the cylinder, the fine-grained material and the coarse-grained material are lowered from above the cylindrical body. Move to
In the step of applying the hot air, the hot air is applied from below the cylindrical body toward the fine-grained material and the coarse-grained material in the cylindrical body,
The method for adjusting the moisture content of the soil material according to claim 5.

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