DETAILED DESCRIPTION OF THE INVENTION

[0023] The invention according to claim 1 provides a method of construction for draining the surface earth of the ground 1, the method comprising the steps of: digging the earth around the ground 1 requiring drainage of the ground 1 to form a waterway 3 around the surface of the ground 1; heaping up a central portion of the ground 1 within the waterway 3 from a peripheral portion of the ground 1 and grading the heaped ground 1 by rolling with a roller to form a foundation bed 2 of the ground 1; covering the whole surface of the foundation bed 2 with corrugated plates of plastics 7 of which surface comprises a continuous corrugated surface in which a number of convex portions 18 and a number of concave portions 19 in the same direction as the convex portions 18 are continuous alternately; laying crushed stones 8 on the corrugated plates of plastics 7; covering the laid crushed stones 8 with the earth to form the surface earth 9, of the ground 1 and causing water permeated into the surface earth 9 of the ground 1 due to rainfall or the like to accumulate into the concave portion 19 of the corrugated plates of plastics 7 and to flow into the waterway 3 from the concave portions 19 of the corrugated plates of plastics 7 to effect draining.

[0024] The invention according to claim 2 provides the method of construction for draining the ground of claim 1 wherein a water permeation mat 10 comprising natural fiber such as coconut nutshell or synthetic coarse and meshed fiber which is laid in place of the crushed stones 8 laid on the corrugated plates of plastics 7.

[0025] The invention according to claim 3 provides the method of construction for draining the ground of claim 1 wherein a water permeation mat 10 is interposed between the corrugated plates of plastics 7 and the crushed stones 8 laid thereon.

[0026] The invention according to claim 4 provides the method of construction for draining the ground of claim 1 wherein a water permeation mat 11 comprising natural fiber such as coconut nutshell or synthetic coarse and meshed fiber which is interposed between the crushed stones 8 laid on the corrugated plates of plastics 7 and the surface earth 9 of the ground 1 laid thereon.

[0027] The invention according to claim 5 provides the method of construction for draining the ground of claim 1 wherein the water permeation mat 10 is interposed between the corrugated plates of plastics 7 and the crushed stones 8 laid thereon, and the water permeation mat 11 is interposed between the crushed stones 8 and the surface earth 9 of the ground 1 laid thereon.

[0028] The invention according to claim 6 provides the method of construction for draining the ground of any one of claims 1 to 5 wherein a water tank 14 is constructed in the underground of the foundation bed 2 of the ground 1 surrounded by the waterway 3, and the waterway 3 in the surroundings of the ground 1 is connected to the water tank 14 for storing water gathered from the surface earth 9 of the ground 1 to the waterway 3.

[0029] The embodiments of the present invention will be explained hereinafter with reference to the drawings. As shown in FIG. 1, the peripheral surface earth of the ground 1 which the method of construction for draining the ground is required is dug, and the concrete ditch block 4 are laid on the dug place to form a waterway 3. A central portion 5 of the surface earth of the ground 1 within the waterway 3 is heaped up higher than a peripheral portion 6, and grading is done by rolling with roller to form a foundation bed 2. The whole surface of the foundation bed 2 formed as described above is covered by connecting a plurality of corrugated plates of plastics 7 comprising an alternate combination of convex portions 18 and concave portions 19 which are put one upon another with the lower end thereof placed on the higher land side piled up the upper end thereof placed on the lower land side, as shown in FIGS. 2A and 2B. In this case, when covering in a manner such that the row direction of the convex portions 18 and the concave portions 19 is in the inclined direction of the foundation bed 2, water gathered in the concave portions 19 flows easily to the downstream. In this case, the corrugated plates of plastics 7 to be used are rectangular, but where the direction is changed from the row direction of the convex portions 18 and the concave portions 19 of the adjacent corrugated plates of plastics 7 adjusting to the inclination of the foundation bed 2, the rectangular corrugated plates of plastics 7 are suitably cut obliquely for use, and as shown in FIG. 2A, the corrugated plates of plastics 7 are placed in contact in the state that the row direction of the convex portions 18 and the concave portions 19 of the connected corrugated plates of plastics 7 is at right angles.

[0030] Next, in the embodiment of the invention according to claim 1, there is provided a method wherein the crushed stones 8 are laid on the corrugated plates of plastics 7 covering the whole surface of the foundation bed 2, and the crushed stones 8 are covered with the surface earth 9 of the ground 1. In this case, the crushed stones 8 having a large diameter are used for the lower part of the layer of the crushed stones so as to prevent the crushed stones 8 from falling down into the concave portions 19 of the corrugated plates of plastics. In this case, as shown in FIG. 4A, when sand stones 12 having a small diameter are used for the upper part of the layer of the crushed stones, it is possible to prevent fine grains of the surface earth 9 of the ground 1 from entering the concave portions due to the presence of the small diameter sand stones 12.

[0031] In the embodiment of the invention according to claim 2, there is provided a method wherein a water permeation mat 10, comprising natural fiber such as coconut nutshell or synthetic fiber and comprising the layered fibers of coarse meshes to a degree that not pass the surface earth 9 of the ground 1 but pass only water, is laid in place of the crushed stones 8 laid on the corrugated plates of plastics 7 in the embodiment of the invention according to claim 1, above of which is covered directly with the surface earth 9 of the ground 1, which construction is shown in FIG. 4B.

[0032] In the embodiment of the invention according to claim 3, there is provided a method wherein as shown in FIG. 4C, the crushed stones 8 are further laid on the water permeation mat 10 which is laid on the corrugated plates of plastics 7 in the embodiment of the invention according to claim 2, and the crushed stones 8 are covered with the surface earth 9 of the ground 1. In this case, since the water permeation mat 10 is present on the lower layer of the crushed stones 8, the crushed stones 8 are not fallen into the concave portions 19 of the corrugated plates of plastics 7. Therefore, its diameter will suffice to be relatively small, but as the crushed stones 8 to be laid, the large-diameter crushed stones 8 may be used for the lower part, and the small-diameter sand stones 12 may be used for the upper part.

[0033] In the embodiment of the invention according to claim 4, there is provided a method wherein as shown in FIG. 5A, the crushed stones 8 are laid on the corrugated plates of plastics 7, a water permeation mat 11 formed of material similar to the water permeation mat 10 is further laid thereon, and the water permeation mat II is covered with the surface earth 9 of the ground 1. Also in this case, as the crushed stones 8 to be laid, the large-diameter crushed stones 8 are used for the lower part, and the small-diameter sand stones 12 are used for the upper part to prevent the crushed stones 8 from falling into the concave portions 19 of the corrugated plates of plastics 7.

[0034] In the embodiment of the invention according to claim 5, there is provided a method wherein the water permeation mat 10 is laid on method of construction for draining the ground covered the foundation bed 2, the crushed stones 8 are laid thereon, and the water permeation mat 11 is laid on the crushed stones 8, which is then covered with the surface earth 9 of the ground 1. This construction is shown FIG. 3 or FIG. 5B. In this case, since the water permeation mat 10 is present under the crushed stones 8, the large-diameter crushed stones 8 can be used.

[0035] As described above, in the ground 1 formed with the draining means by the method of construction for draining the ground of the inventions according to claims 1 to 5, water permeated into the surface earth 9 of the ground due to rainfall or the like is caused to flow into the peripheral waterway 3 from the concave portions 19 of the corrugated plates of plastics 7 laid on the foundation bed 2 to effect draining. In this case, the foundation bed 2 of the ground 1 is covered in its whole surface with the corrugated plates of plastics 7, water such as rainwater is not permeated into the foundation bed 2 passing through the corrugated plates of plastics 7 but is drained quickly to the waterway 3 provided in the periphery from the concave portions 19 of the corrugated plates of plastics 7, and therefore, when the rainfall stops, the ground 1 can be dried in a short period of time and used.

[0036] The crushed stones 8, the water permeation mat 10 and the water permeation mat 11 are used adjusting to the rainfall amount so as not be clogged by the fine-particle earth such as the surface earth 9 of the ground 1. Either the water permeation mat 10 or the water permeation mat 11 is used while being interposed as described above or both of them can be used while being interposed simultaneously.

[0037] In the method of construction for draining the ground 1 or the like described above, the water tank 14 can be provided in the underground of the foundation bed 2 of the ground 1. The waterway 3 around the ground is connected to the water tank 14, and water gathered from the ground surface earth 9 to the waterway 3 is stored in the water tank 14. In this case, a drain 15 is provided in the waterway 3 leading to the water tank 14 so that water may be drained suitably to other places. When water is stored in the water tank 14 provided in the underground of the foundation bed 2 of the ground 1, the function as a sort of dam is given to prevent flood in cities, and further being prepared for the water shortage. Further, water is removed from the water tank 14 to enable utilization for a shelter, preparing for crisis management.

[0038] The corrugated plates of plastics 7 used for the method of construction for draining the ground according to the present invention will be further described. In the corrugated plates of plastics 7, as shown in FIGS. 7 and 8, convex portions 18 are disposed on one side end 16 and the other side end 17 opposite the side end 16, a concave portion 19 extending in the direction parallel with the convex portion 18 is provided adjacent to the convex portion 18, and the convex portion 18 is provided adjacent to the concave portion 19. In this manner, the convex portions 18 and the concave portions 19 are alternately combined to form the corrugated plates of plastics 7 comprising a continuous corrugated surface. FIG. 9 shows the corrugated plates of plastics 7 shown in FIG. 7. FIG. 9A is a plan view where a convex pattern 20 for holding the crushed stones on the upper surface at the concave portions 19 is formed on the convex portion 18, FIG. 9B is a sectional view taken on 9B-9B of FIG. 9A where a non-slip bridge 23 at the inclined surface of the foundation bed 2 is provided on the lower surface of the corrugated plates of plastics 7 at right angles to the row direction of the convex portions 18 and the concave portions 19. One at the left end of the convex portions 18 is concave, in the lower surface thereof, of a hollow portion 21, but another convex portions 18 are all in the form of a solid portion 22. FIG. 9C shows a nail 24 for fastening.

[0039] In the method of construction for draining the ground according to the present invention, adjacent to one corrugated plate of plastics 7 is disposed next corrugated plate of plastics 7, ends of which are put one upon another and connected. That is, the convex portion 18 arranged on one side end 16 of the corrugated plates of plastics 7 is put on the convex portion 18 arranged on the other side end 17 of the other corrugated plate of plastics 7 and connected together. Accordingly, the convex portion 18 on one side end 16 is always concave in section having the hollow portion 21 on the backside as shown in FIG. 7.

[0040] Further, also with respect to both the ends in the row direction and at right angle to the convex portion 18 and the concave portion 19, one end 36 is always concave in section having the hollow portion 21 on the backside of the convex portion 18, and can be put on the other end 37 of another same-shaped corrugated plate of plastics 7 connected in the row direction of the convex portion 18 and the concave portion 19.

[0041] The duplicated end portion of the above said two corrugated plates of plastics 7 is fastened with a nail 24 shown in FIG. 9C so that they are not shifted from each other.

[0042] Further, the upper surface of the convex portion 18 of the corrugated plates of plastics 7 is formed in the whole surface with a convex pattern 20 for holding the crushed stones to the right place in order that the crushed stones 8 laid thereon can be stopped slipping down.

[0043] Furthermore, the corrugated plates of plastics 7 are formed in the backside thereof with a non-slipping crosspiece 23 so as not to be slipped down from the foundation bed 2. The crosspieces 23 may be molded integrally with a corrugated plate of plastics 7. For the purpose of making the non-slipping more effective, the crosspiece 23 is formed so as to be the direction crossing the inclined surface of the foundation bed 2 when the corrugated plates of plastics 7 are laid on the foundation bed 2. Further, the crosspiece 23 also carries out the duty of reinforcing the corrugated plate of plastics 7 and adjusting the thickness thereof, in addition to the non-slipping effect.

[0044] With respect to the back of the convex portion 18 of the corrugated plates of plastics 7, the back of the convex portion 18 of one side end 16 is the hollow portion 21, and the back of all other convex portions 18 is the solid portion 22 in order to withstand the load of the ground. FIG. 7 shows the solid portion 22. However, in case of the corrugated plates of plastics 7 formed of a material capable of withstanding the load, the back of all the convex portions 18 including the convex portion 18 on one side end 16 may be the solid portion 21 as shown in FIG. 8.

[0045] The height of the convex portion 18 of the corrugated plates of plastics 7 may be varied according to the grade of the foundation bed 2 or the water amount to be drained. That is, where there is much water amount to be drained, the height of the convex portion 18 is made high, as a result of which the depth of the concave portion 19 is made deep. For example, as shown in FIG. 10, in the single corrugated plate of plastics 7, the height of the convex portion 18 is made different in left from right adjusting to the grade of the slant of the foundation bed 2, and these corrugated plates of plastics 7 are continuously connected to regulate the drain amount of the whole ground 1.

[0046] In laying the corrugated plates of plastics 7, the end in the direction of the convex portion of the corrugated plates of plastics 7 which is present in the higher place of the foundation bed 2 is put on the end in the direction of the convex portion of the corrugated plates of plastics 7 which is present in the lower place of the foundation bed 2 to thereby prevent running water from the upstream from entering the portion under the lower-side corrugated plates of plastics 7.

[0047] Further, for covering the joint between the two corrugated plates of plastics 7, 7 adjacent to each other, an elongated joining plate of plastics 28 is placed over the joint as shown in FIG. 13. The joining plate of plastics 28 can be folded suitably at a folding line 29, and is formed so that the former may come in contact with and place in close contact with the lower corrugated plates of plastics 7, 7. Further, adjusting to the corrugated surface comprising the convex portions 18 and the concave portions 19 of the lower corrugated plates of plastics 7, 7, the convex portions 18 and the concave portions 19 of the corrugated plates of plastics 7 are provided in the lateral direction as shown in FIG. 13A, the convex portions 18 and the concave portions 19 are provided in the longitudinal direction in the row direction as shown in FIG. 13B, and the convex portions 18 and the concave portions 19 are formed in the oblique direction as shown in FIG. 13C.

[0048] In the corrugated plates of plastics 7 for covering the waterway 3 in the periphery of the ground 1, drain holes 25 comprising through-holes are provided in the bottoms 26 of the concave portions 19 corresponding to the portion of the upper surface of the waterway 3 as shown in FIG. 11A or FIG. 11B, and water flowing from the concave portions 19 is dropped down from the drain holes 25 to the waterway 3 under them.

[0049] Incidentally as shown in FIG. 12A, in the corrugated plates of plastics 7 in which the non-slipping crosspiece 23 is not present on the back thereof, when the drain holes 25 are provided in the bottoms of all the concave portions 19 of the corrugated plates of plastics 7, the corrugated plates of plastics 7 can be wound to form a water permeation tube 27 in which the drain holes 25 are water permeation holes 35, as shown in FIG. 12B.

[0050] Then, as shown in FIG. 14A, when ditches 31 are provided in a net-like form in the ground 1 according to the conventional method, in the draining facility in which a water permeation pipe 33 having a number of water permeation holes 35 bored in a peripheral pipe wall 34 shown in FIG. 14C is laid into the crushed stones 32 crammed into the ditches 31 as shown in FIG. 14B, the water permeation tube 27 having the corrugated plates of plastics 7 wound can be used in place of the water permeation pipe 33 to lay the drainage-ditch net 30 in the ground 1.

[0051] In case of the ground 1 such as a golf course having a large area, the drainage-ditch net 30 as described above is provided in advance in the underground, the water permeation tube 27 is laid in the ditches 31 of the drainage-ditch net 30 and the crushed stones 32 are crammed and the earth is placed thereover to form the foundation bed 2, the crushed stones or the water permeation mat are laid on the foundation bed 2, and are covered with the surface earth to form the method of construction for draining the ground. However, alternatively, the corrugated plates of plastics 7 may be laid on the foundation bed 2 according to the method of construction for draining the ground of the present invention to provide the method of construction for draining the ground.

[0052] The corrugated plates of plastics 7 used in the method of construction for draining the ground of the present invention is removed as waste plastics, when the ground is returned to the original surface earth of the ground or when being reformed, to use it effectively by recycling, and can be used again as raw material of plastics, thus making effective use of resources, and not contaminating the environments.

[0053] As explained above, the present invention provides the method of draining of the ground of preventing water such as rainfall from being permeated into the foundation bed by the corrugated plates of plastics. Therefore, the efficiency of draining the ground is excellent, and the ground can be drained and dried in a very short period of time, and the efficiency of utilization of the ground can be improved. Further, since the water tank is provided in the underground of the ground to enable storage of a huge amount of water, one can deal with emergency, which is one of the excellent merits provided by the present invention.