JP4885088B2 - Compaction soil formation method - Google Patents

Description

  The present invention relates to a method for forming a compacted soil layer made of a ground material on a construction surface.

In the construction in the general civil engineering field, a compacted soil layer is formed by raising and compacting the ground material. In particular, when constructing structures such as radioactive waste disposal sites and highways underground, a compacted soil layer is formed around the structure to serve as a waterproof layer in order to prevent the ingress of groundwater. Is done. As a method of forming a compacted soil layer on the construction surface, the ground material is spread on the construction surface with a hydraulic excavator, bulldozer, etc., spread and then rolled using a rolling roller, etc. A so-called on-site compaction method, which is compacted so that the density is equal to or higher than a predetermined value, is known (see, for example, Patent Document 1). In order to form a compacted soil layer having excellent water-stopping performance or mechanical performance, it is required that the entire compacted soil layer is compacted sufficiently uniformly and at a high density.
JP 2003-10809 A

  By the way, for example, when constructing a compacted soil layer in a limited space such as an underground tunnel, structures such as side walls and struts of underground tunnels, measuring instruments, cables, pipes, etc. are rolled on the construction surface. Hindering traffic. Among areas in the vicinity of such structures, areas that cannot be constructed with a rolling roller must be compacted using a small vibration device such as a rammer or a vibro compactor instead of the rolling roller. Absent. The same applies to a region where it is desired to prevent the earth pressure generated by compaction by the rolling roller from affecting the surrounding structure.

  Compared to the area compacted by a large compacting device, the compacted area is more likely to have a smaller degree of compaction and the water stop performance or mechanical performance tends to be insufficient. There's a problem. In addition, when an operator uses the small vibration device for a long time, there is a concern about the influence of vibration on the human body.

  The present invention has been made in view of such circumstances, and compaction is performed by compacting the ground material to a sufficiently high density even if the region where the compaction operation by the compaction roller cannot be performed is on the construction surface. An object is to provide a compacted soil layer forming method capable of forming a soil layer with high work efficiency.

The compacted soil layer forming method according to the present invention includes a brewing step of squeezing the ground material onto the construction surface, a laying step of laying and leveling the ground material so that the thickness of the ground material is uniform, A compaction step of compacting the ground material with the compaction roller, and the ground material is applied to the spraying area including the non-compressible region of the compaction roller on the construction surface before the brewing step. It is characterized by including a spraying step of spraying to form a spraying construction part having a dry density of 1.5 Mg / m ³ or more .

  The ground material sprayed in the spraying process collides with and adheres to the surface to be sprayed (for example, the construction surface, the surface of the structure, etc.). Therefore, it is necessary to form a spraying construction part in a predetermined area that exhibits a sufficiently high density, uniform and excellent water-stopping performance or mechanical performance without performing compaction using a small vibration device such as a rammer. Can do. Prior to the brewing process, by forming such a spraying construction part in the spraying area including the non-rolling area on the construction surface, it is possible to ensure excellent water-stopping or strength near the structure and the rolling process. In the above, in the region where the compaction by the compaction roller is necessary, the compaction roller can pass through the region without any excess, and the compaction operation can be performed efficiently. In the present invention, the incompressible region refers to a structure that prevents passage of the compaction roller on the construction surface, a region in the vicinity of the wiring or measuring instrument, or a structure that should avoid the influence of earth pressure generated by the compaction. The installation position and its vicinity area.

  In the method of the present invention, it is preferable to determine the shape of the spraying portion in accordance with the shape of the protruding portion that protrudes forward, backward, or laterally from the rolling roller provided in the rolling vehicle. By determining the shape of the spray construction part in this way, the compacted soil layer can be formed with sufficiently high work efficiency regardless of the shape of the rolling compaction vehicle to be used.

  Moreover, in the method of this invention, it is preferable that the upper surface of the spraying construction part of the side contact | abutted with the ground material sprinkled out inclines upwards from a construction surface. If the spraying section has such an inclined surface, for example, when the rolling roller is moving forward toward the inclined surface, the rolling roller can run over the spraying section. As a result, the ground material on the construction surface (excluding the area where rolling is impossible) can be continuously compacted.

  In the method of this invention, it is preferable to further provide the block installation process which arrange | positions the block which consists of ground material in a spraying area | region before a spraying process. Thereby, in the spraying process, the spraying amount of the ground material can be adjusted on the basis of the height of the arranged blocks, and it becomes easy to form a spraying construction part having a desired shape.

  In addition, by arranging a plurality of blocks in the spraying area in advance, even if the sprayed ground material is scattered without adhering to the surface to be sprayed, the ground material is blocked by the surrounding blocks, and in the spraying area. Adhere to. Therefore, the amount of ground material scattering can be reduced, and it becomes easy to spray a predetermined amount of ground material to the spraying region.

  In addition, the compacted soil layer forming method of the present invention includes a brewing step of rolling out the ground material on the construction surface, a spread leveling step of spreading the ground material so that the thickness of the grounded material is uniform, A compacting step of compacting the ground material that has been leveled with a compaction roller, including a structure that prevents the compaction roller from passing on the construction surface and a non-compressible region near the buried object A block laying process for forming a block laying portion by laying a plurality of blocks made of a ground material in the block laying area before the brewing process is provided.

  Prior to the brewing process, blocks with a sufficiently high density and uniform compaction of the ground material are laid down in the block laying area on the construction surface, including the area where the rolling is impossible, so that excellent water-stopping near the structure Alternatively, the strength can be secured, and the rolling roller can pass through the region that needs to be compacted by the rolling roller in the rolling step, so that the rolling operation can be performed efficiently.

  In the method of the present invention, it is preferable that the shape of the block laying portion is determined according to the shape of the protruding portion that protrudes forward, backward, or laterally from the rolling roller provided in the rolling vehicle. By determining the shape of the block laying portion in this manner, the compacted soil layer can be formed with sufficiently high work efficiency regardless of the shape of the rolling compaction vehicle to be used.

  Further, in the method of the present invention, the block laying portion formed by stacking a plurality of blocks is arranged in a staircase pattern so that the block is directed upward from the construction surface on the side in contact with the ground material to be rolled out. It is preferable to have a stepped portion. If the block laying part has such a staircase part, the rolling roller can run above the block laying part in the rolling process, and the rolling roller can set the area on the construction surface. (Excluding) ground material can be compacted continuously.

  ADVANTAGE OF THE INVENTION According to this invention, even if the area | region which cannot implement the rolling operation by a rolling roller exists on a construction surface, the compacting soil layer by which a ground material is compacted with sufficient high density can be formed with high working efficiency.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

(First embodiment)
First, the ground material used for forming the compacted soil layer will be described. Examples of the ground material include gravel, sand, clay, and those obtained by adding cement. In particular, when a compacted soil layer having a role as a water-stopping layer is formed, a water-stopping material containing a solid content containing bentonite and water is used as the ground material.

  The bentonite used for the preparation of the water-stopping material includes those produced from bentonite raw ore. From the viewpoint of obtaining high water-stopping performance, the content of bentonite in the solid content contained in the water-stopping material (based on the solid content) is preferably 95% by mass or more, and more preferably 98% by mass or more. preferable. Furthermore, it is most preferable that the solid content consists essentially of bentonite. When the content of bentonite is less than 95% by mass, the water-stopping performance of the water-stopping layer formed tends to be lower than that of 95% by mass or more.

When the content of bentonite (mass content of solid content) is 95% by mass or more, the water content of the water-stopping material is preferably 15 to 26%, and preferably 17 to 23%. More preferred. When the water content is less than 15%, the adhesion of the water-stopping material becomes insufficient, and the material is likely to be scattered during the spraying operation. On the other hand, when the water content ratio exceeds 26%, the water-stopping material easily adheres to the inside of the nozzle and the like, and it becomes difficult to form a sufficiently high-density water-stopping layer. Here, the water content ratio w (%) of the water-stopping material is defined by the following formula (1). In the formula, W _W is the mass of water contained in the water stop material, W _S is a solid mass such as bentonite and sand contained in the water cutoff material respectively.
w = (W _W / W _S ) × 100 (1)

  Next, the method for forming a compacted soil layer according to the present embodiment will be described with reference to the drawings, taking as an example the case of forming a water stop layer of a radioactive waste disposal site constructed in the ground. For convenience of the drawings, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a cross-sectional view of a radioactive waste disposal site. The radioactive waste disposal site 10 shown in the figure is for geological disposal of radioactive waste. The radioactive waste disposal site 10 has a tunnel 1, and the radioactive waste 2 is buried in the tunnel 1 and discarded. The mine shaft 1 is made of concrete, for example. In the mine shaft 1, a waste body accommodating portion 3 for accommodating the radioactive waste 2 is provided. The radioactive waste 2 is placed in the waste storage unit 3 in a state of being stored in a metal container.

  Around the waste container 3, water-stopping layers 5 a to 5 d made of a water-stopping material containing bentonite are provided. Filling portions 11 to 14 made of concrete, for example, are provided on the outer sides of the water blocking layers 5a to 5d. The water blocking layers 5 a to 5 d provided around the waste container 3 prevent the groundwater from reaching the waste container 3.

  In constructing the radioactive waste disposal site 10 shown in FIG. 1, prior to placing the waste container 3 in the tunnel 1, first, on the bottom surface 1a of the tunnel 1 and on the left and right wall surfaces 1b, 1c. Filling portions 11, 12, and 13 are provided, respectively. The filling part 12 is formed so that the interval between the wall surface 12a of the filling part 12 and the wall surface 3b of the waste body accommodation part 3 is about 1 m when the waste body accommodation part 3 is placed in the tunnel 1. Similarly, the filling portion 13 is formed so that the interval between the wall surface 13a of the filling portion 13 and the wall surface 3c of the waste body accommodation portion 3 is about 1 m when the waste body accommodation portion 3 is placed in the tunnel 1. Is done.

  After forming the filling portions 11 to 13, the water-stopping layer (consolidated soil layer) 5 a is constructed on the upper surface 11 a (hereinafter referred to as “construction surface 11 a”) of the filling portion 11 by the method according to this embodiment. . In addition, the construction surface 11a is provided so that it may become a substantially horizontal surface.

  FIG. 2 is a flowchart of a method for forming the water blocking layer 5a. As shown in the figure, the forming method includes a block installation process in which a plurality of blocks are arranged in the vicinity of the construction surface 11a, and a spraying construction made by spraying a water-stopping material on the area where the plurality of blocks are arranged. A spraying process for forming a portion, a brewing process for squeezing the water-stopping material on the construction surface 11a, a laying-smoothing process for spreading the squeezed water-stopping material so that the thickness is uniform, A compaction step of compacting the water-stopping material that has been compacted with a compaction roller.

  In the block installation process, a plurality of blocks made of a water-stopping material are arranged on the construction surface 11a in a spraying area where spraying is performed in the spraying process described later. FIG. 3 is a perspective view showing a state in the tunnel 1 after the block installation process. As shown in the figure, a water blocking material scattering prevention wall 26 in which a plurality of blocks 25 made of a water blocking material are stacked stepwise is installed at a predetermined interval in the spray region 30 of the construction surface 11a. The water blocking material scattering prevention wall 26 is formed by stacking the blocks 25 so as to be substantially the same as the cross-sectional shape of the spray construction portion 15 to be constructed.

  Prior to the spraying process, the water blocking material scattering prevention wall 26 is provided in the spraying region 30 at a predetermined interval, so that the water blocking material that has been scattered without adhering to the spray target surface in the spraying process can be prevented from scattering. It can be blocked by the wall 26. Thereby, the amount of scattering of a water stop material can be reduced. Moreover, by adjusting the spraying amount of the water-stopping material on the basis of the height of the stacked blocks 25 (the height of the water-stopping material scattering prevention wall 26), the spraying construction part 15 that is sufficiently close to the shape to be constructed is provided. It can be formed efficiently.

  In the spraying process, a water-stopping material is sprayed from the nozzle 9 toward the spraying region 30 shown in FIG. Here, the case where the spray construction part which has substantially the same height as the water stop layer 5a to be constructed is formed will be described as an example. FIG. 4 is a perspective view showing a state on the construction surface 11a after the spraying process, that is, a state in which the spray construction part 15 is formed at the corner of the construction surface 11a.

  Spraying in the spraying process can be performed by so-called wet spraying, and a water-stopping material prepared in advance so as to have a predetermined water content ratio is transferred to the nozzle 9 together with compressed air by the hose 8. The hose 8 preferably has an inner diameter of 5 cm or more.

  It is preferable that the distance between the tip of the nozzle 9 and the construction surface 11a or the surface on which the water-stopping material has already adhered (hereinafter referred to as “surface to be sprayed”) is 500 to 1000 mm. Moreover, it is preferable that a spraying pressure (at the time of steady state) shall be 0.3-0.7 MPa.

  The nozzle 9 has a tapered flow path whose inner diameter is reduced from the proximal end side toward the distal end side. In the spraying process, various shapes of nozzles may be appropriately selected and used according to the water content ratio of the water-stopping material, the pressure of compressed air, the required packing density, and the like. For example, instead of the nozzle 9, a nozzle constituted by a straight pipe having a constant inner diameter may be used. However, it is preferable to use the nozzle 9 which has a taper-shaped flow path from a viewpoint of forming the spray construction part compacted by high density.

The spray construction unit 15 is gradually formed by the sprayed water-stopping material colliding with and adhering to the spray target surface, so that the water-stop material is compacted sufficiently sufficiently and uniformly. In order to ensure good water stopping performance, the packing density of the water stopping material constituting the spray construction section 15 is preferably at 1.5 Mg / ^{m 3} or more dry density, 1.6 mg / ^{m 3} or more More preferably.

  The vicinity of the wall surface 12a is a region where compaction by a compaction roller cannot be performed in a compaction process described later, and a spraying construction portion 15 in which the water-stopping material is compacted uniformly and densely is provided in advance in this region. Thus, it is possible to sufficiently ensure the water stoppage of the region.

  After the spray construction part 15 is also formed in the vicinity of the wall surface 13a, the water stop material carried in by the dump truck is sprinkled on the work surface 11a with a hydraulic excavator or the like (scouring process), Spread with a bulldozer so that the thickness is uniform (laying process).

  In the rolling step, the to-be-rolled layer formed through the spreading step is compacted with a rolling roller. FIG. 5A is a cross-sectional view showing a state on the construction surface 11a after the spreading step, where the spraying construction portion 15 is formed at the corner of the construction surface 11a, and about half the height of the spraying construction portion 15 is shown. A state where the pressed layer 18 is formed by spreading and leveling is shown. FIG. 5B shows a state where the compaction vehicle 20 advances in the direction of the arrow P shown in the figure and the compaction layer 19 formed by compressing the compaction layer 18 is applied.

  FIG. 6A is a side view of the rolling compact vehicle 20, and FIG. 6B is a front view thereof. The rolling vehicle 20 shown in the figure includes a rolling roller 20a on the front side. As shown in FIG. 6, the rolling vehicle 20 has protrusions on the front and side of the rolling roller 20 a. The length A shown in FIG. 6A means the distance between the position of the rotary shaft 20b of the pressure roller 20a and the tip 21a of the front protruding portion 21, and the length B is the contact surface G of the pressure roller 20a. Means the distance between the front end portion 21 and the lower end 21b on the front end 21a side. On the other hand, the length C shown in FIG. 6B means the distance between the side surface 20c of the pressure roller 20a and the tip 22a of the lateral protrusion 22 and the length D is the ground contact surface G of the pressure roller 20a. Means the distance between the protruding portion 22 and the lower end 22b on the tip 22a side.

  Since the rolling compaction vehicle 20 has the front protrusion part 21 which protruded ahead of the compaction roller 20a, as shown in FIG.5 (b), when the rolling compaction vehicle 20 is moving forward toward the wall surface 12a, A region where the rolling roller 20a cannot pass (a region where rolling cannot be performed) exists in the vicinity of 12a. 5 is a region where the distance from the wall surface 12a is within the range of the length A (see FIG. 6A).

  Therefore, it is preferable to form the water stop material spray construction part 15 in the spraying process after taking the lengths A and B of the rolling compact vehicle 20 into consideration. The spraying portion 15 shown in FIG. 5A is formed in consideration of the lengths A and B, and includes a flat surface 15a formed so as to cover at least the non-compressible region 30a, and a covered surface. An inclined surface 15 b is provided on the side in contact with the rolling layer 18. Providing such an inclined surface 15b has the following advantages.

  That is, as the compaction vehicle 20 further moves forward from the state shown in FIG. 5B, the compaction roller 20a can run over the spray construction portion 15 through the inclined surface 15b, so that the compaction by the compaction roller 20a can be performed. In the area that needs to be hardened, the compaction roller 20a can pass through it without leaving any space, and the compaction work can be carried out efficiently.

Incidentally, the inclination of the inclined surface 15b, it is preferable that the slope S less than ₁ calculated by the following formula (2). In the formula, B represents the length B shown in FIG. 6A, and A represents the length A shown in FIG.
S ₁ = B / A (2)

The inclination of the inclined surface 15b by less than the slope S ₁ which is calculated by the equation (2), it is possible to prevent the front protruding portion 21 of the compaction vehicle 20 comes into contact with the blowing construction unit 15.

  From the viewpoint of forming the water-stopping layer 5a having a high water-stopping performance, the water-stopping material is compacted with high density, and then the compaction layer 18 is first compacted without vibrating the rolling roller 20a. Thereafter, the compaction may be further performed while vibrating the rolling roller 20a. In addition, when the density of the pressed layer 18 after the spreading step is insufficient to use the rolling roller 20a, preliminary rolling using a compact rolling roller or the like is applied to the rolling by the rolling roller 20a. You may carry out before pressing.

The series of steps including the brewing step, the spreading step, and the rolling step are repeated until the height of the spray construction portion 15 is substantially the same, and finally the water blocking layer 5a is formed. The filling density of the water-stopping material in the region compacted by the rolling roller 20a is preferably 1.6 Mg / m ³ or more in terms of the dry density.

  Although the case where the rolling compaction vehicle 20 was moving forward toward the wall surface 12a was demonstrated until now, the case where the rolling compaction vehicle 20 passes along the wall surface 12a is demonstrated below. In such a case, the length C and D shown in FIG. 6B are taken into consideration in the spraying process, and the water-stopping material spraying construction part 16 is formed instead of the water-stopping material spraying construction part 15. Is preferred. The spray construction portion 16 shown in FIG. 7A is formed in consideration of the lengths C and D, and includes a flat surface 16a formed so as to cover at least the non-compressible region 30b, and a covered surface. A slope 16b is provided on the side in contact with the rolling layer 18.

The inclination of the inclined surface 16b, it is preferable that the slope S of less than ₂ as calculated by the following formula (3). In the formula, D represents the length D shown in FIG. 6B, and C represents the length C shown in FIG.
S ₂ = D / C (3)

The inclination of the inclined surface 16b by less than the slope S ₂ calculated by Equation (3), it is possible to prevent the lateral extending portion 22 of the compaction vehicle 20 comes into contact with the blowing construction unit 16.

  In addition, when the construction surface 11a has a rectangular shape and four sides are surrounded by standing surfaces, it is efficient to reciprocate the rolling compaction vehicle 20 in the longitudinal direction of the construction surface 11a. Therefore, from the viewpoint of efficiently operating the compaction vehicle 20 by operating the compaction vehicle 20 as described above, the spraying construction portion 16 is formed in the vicinity of the standing surface located on the side of the traveling direction of the compaction vehicle 20. It is preferable to form the spray construction part 15 in the vicinity of the remaining two standing surfaces.

  The waste body accommodating portion 3 is placed so that the water-stopping layer 5a and the bottom surface 3a thus formed are in contact with each other. If the waste body accommodating part 3 is mounted, as shown in FIG. 8, a water stop material is sprayed between the filling part 12 and the waste body accommodating part 3, and the water stop layer 5b is formed. The nozzle 9 is held downward, and the water-stopping material is gradually filled from the lower part to the upper part in the tunnel 1. If the water stop layer 5b is formed between the filling part 12 and the waste body storage part 3, the water stop layer 5c is similarly formed between the filling part 13 and the waste body storage part 3.

  After the water blocking layers 5b and 5c are formed on the wall surfaces 3b and 3c of the waste container 3, the water blocking layer 5d is formed on the upper surface 3d of the waste container 3 in the same manner as the water blocking layers 5b and 5c. . Thereafter, as shown in FIG. 1, a filling portion 14 is formed in a space between the water blocking layer 5 d and the upper wall surface 1 d of the mine shaft 1. The water blocking layers 5 a, 5 b, 5 c, 5 d formed around the waste container 3 prevent the groundwater from reaching the waste container 3.

  The first embodiment of the compacted soil layer forming method according to the present invention has been described above, but the present embodiment may be in the following manner. For example, in the said embodiment, the method of forming the water stop layer 5a by constructing the spray construction part 15 and / or the spray construction part 16 of the same height as the thickness of the water stop layer 5a to be formed in advance is illustrated. However, the height of the spraying construction parts 15 and 16 is set to be lower than the thickness of the water blocking layer 5a to be formed, and a series of processes including a spraying process, a brewing process, a spreading process and a rolling process are repeated as appropriate. Thus, the water blocking layer 5a may be finally formed. A plurality of blocks 25 may be formed on the surface to be sprayed before each spraying step. In this case, instead of stacking the blocks 25 in a step shape, the plurality of blocks 25 are disposed on the surface to be sprayed at predetermined intervals. Should be arranged. By disposing the block 25 on the surface to be sprayed, it is possible to reduce the amount of the water-stopping material scattered.

  Furthermore, in the said embodiment, although a block installation process is implemented before a spraying process, the spraying construction parts 15 and 16 are formed by spraying a water stop material on the corner of the construction surface 11a, without implementing this process. Also good. Moreover, the spraying operation of the water-stopping material may be appropriately performed after the spraying process, and the spraying construction portions 15 and 16 may be expanded according to the shape of the protruding portion of the rolling compact vehicle 20 and the traveling direction thereof.

(Second Embodiment)
Next, a second embodiment of the compacted soil layer forming method of the present invention will be described. In the method according to the second embodiment, instead of the block installation step and the spraying step in the first embodiment, a plurality of blocks 25 made of a water-stopping material are spread in a region (block filling region) equivalent to the spraying region 30. The second embodiment is the same as the first embodiment except that a block laying step for forming a block laying portion is provided. FIG. 9 is a flowchart of this embodiment.

  As shown in FIG. 9, the forming method includes a block laying process in which a plurality of blocks 25 made of a water-stopping material are laid in the block laying region 31 to form a block laying portion 27, and the block laying process is stopped on the construction surface 11a. The brewing process for squeezing out the water material, the laying process for spreading the squeezed water-stopping material so that the thickness of the squeezed water-stopping material is uniform, and the rolling pressure for compacting the laid water-stopping material with a rolling roller A process.

  FIG. 10 is a perspective view showing a state in which the block laying portion 27 is formed on the construction surface 11a. As shown in the figure, the block laying portion 27 has a stepped portion 27a in which the blocks 25 are stacked in a stepped manner upward from the construction surface 11a on the side where the pressed layer 18 is formed. ing. By forming the block laying portion 27 having such a shape in the block laying region 31 equivalent to the spraying region 30, the same effect as that in the case of forming the spraying construction portion 15 can be obtained. The shape of the block laying portion 27 may be determined according to the shape of the protruding portions 21 and 22 of the rolling compact vehicle 20 and the like, similar to the shapes of the spray construction portions 15 and 16.

  In addition, a water stop material may be sprayed on the block laying part 27 formed in the laying process of the block 25, and the shape may be adjusted. For example, the stepped portion 27a may be an inclined surface by spraying a water-stopping material on the stepped portion 27a of the block laying portion 27.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the first and second embodiments. For example, in the said embodiment, the case where the water stop layer of the radioactive waste disposal site 10 by which high water stop performance is requested | required is illustrated, and the content rate (mass standard of solid content) of bentonite is 95 mass% or more. However, solid content with low bentonite content (bentonite content: 5 mass% or more and less than 95 mass%) may be used according to the required performance of the water blocking layer. Examples of components other than bentonite contained in the solid content include sand, earth, and cement. Moreover, when a ground material containing gravel, sand, soil, clay, or cement is compacted in a general compacted soil layer that does not require a water stop function, the method according to the above embodiment may be applied.

  Further, in the block installation process and the block laying process in the first and second embodiments, when the water blocking material scattering prevention wall 26 and the block laying portion 27 are formed, the block 25 is fixed and the water blocking material is blown. You may use together. For example, in the case where the construction surface 11a is not sufficiently flat, before the block 25 is arranged, the water stop material is sprayed on the construction surface 11a in the region, and the surface on which the block 25 is arranged is made flat. It is preferable. By performing such work in advance, it becomes easy to arrange the blocks 25 and to ensure excellent water stop performance. Further, from the viewpoint of improving the adhesion between the adjacent blocks 25, the water blocking material may be sprayed on the arranged blocks 25, and then the blocks 25 may be further stacked.

  Moreover, the area | region which forms a spraying construction part or a block laying part is not restricted to the vicinity of standing surfaces, such as the wall surface 12a. For example, when there is a structure such as a buried object or a support that hinders the passage of the rolling roller 20a on the construction surface 11a, a spray construction part and / or a block laying part may be formed around the structure. In addition, not only the incompressible area in the vicinity of the structure but also the spraying construction part and the block laying part over a certain wide area, so that the compaction roller 20a does not pass in the vicinity of the structure or the embedded object, It is possible to reduce the mechanical load imposed on the structure or the like by the earth pressure generated by the compaction by the rolling roller 20a, and it is possible to sufficiently prevent damage to the structure or the like.

It is sectional drawing of a radioactive waste disposal site. 1 is a flowchart of a first embodiment of a compacted soil layer forming method according to the present invention. It is a perspective view which shows the state on the construction surface after the block installation process which concerns on 1st Embodiment of this invention. It is a perspective view which shows the state on the construction surface after the spraying process which concerns on 1st Embodiment of this invention. (A) is sectional drawing which shows the state on the construction surface after a flooring process, (b) is sectional drawing which shows the state in which the compaction roller is passing on the construction surface on the construction surface. . (A) is a side view of the compaction vehicle used in a compaction process, (b) is a front view of the compaction vehicle. (A) is sectional drawing which shows the state on the construction surface after a flooring process, (b) is sectional drawing which shows the state in which the compaction roller is passing along the standing surface on the construction surface. . It is sectional drawing of the creation process of a radioactive waste disposal site. It is a flowchart of 2nd Embodiment of the compacted soil layer forming method which concerns on this invention. It is a perspective view which shows the state on the construction surface after the block laying process which concerns on 2nd Embodiment of this invention.

Explanation of symbols

5a ... Water stop layer (consolidated soil layer), 11a ... Construction surface, 15, 16 ... Spraying section, 15b, 16b ... Inclined surface, 20 ... Rolling vehicle, 20a ... Rolling roller, 12a ... Wall surface, 25 ... Block 27: Block covering part 30 ... Spraying area 30a, 30b ... Rolling impossible area 31 ... Block covering area

Claims (4)

A brewing process to ground the ground material on the construction surface;
A spread leveling step of spreading the material so that the thickness of the material that has been spread out is uniform;
A rolling process for compacting the spread material with a rolling roller;
In a compacted soil layer forming method comprising:
The material is sprayed before the brewing step on a spraying area including a non-rollable area of the rolling roller on the construction surface to form a spraying construction part having a dry density of 1.5 Mg / m ³ or more. A compacted soil layer forming method comprising a spraying step.   The shape of the spraying construction part is determined according to the shape of a protruding part that protrudes forward, backward, or sideward than the rolling roller provided in the rolling compaction vehicle. Method for forming a compacted soil layer.   3. The compacted soil layer forming method according to claim 1, wherein an upper surface of the spraying construction portion on a side in contact with the material to be sprinkled is inclined upward from the construction surface. 4. . The compacted soil layer formation according to any one of claims 1 to 3, further comprising a block installation step of arranging a plurality of blocks made of the material in the spray region before the spraying step. Method.

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