JPH056604B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Industrial Application Field>> This invention relates to a drain material used in a soft ground improvement method.

<<Conventional technology>> The paper drain method, which is one of the soft ground improvement methods, involves driving a rolled strip of drain material into the ground using a special driving machine to improve the water collection and drainage effect of the drain material. This is a construction method that works to quickly remove moisture contained in the ground and stabilize the ground.

The drain material used in this construction method was
As shown in the figure, a base body 1 is made of a plastic extrusion molded body on which grooves 2 are continuously formed along the longitudinal direction on both sides of the body, and the opening surfaces of the grooves 2 bonded to both sides of the base body 1 are covered. It consists of water permeability 3.

≪Problems to be solved by the invention≫ The problem with the drain material of this structure is that when the drain material is driven into the ground, its strength increases as the ground sinks as water dewaters. ,
In the process of so-called consolidation settlement, the permeable material 3 is pushed into the groove 2 by the soil pressure P as shown by the imaginary line, and the permeable material 3 is pushed into the trench 2 to perform drainage in the longitudinal direction, which is the most important function of the drain material. It is a decline in sexuality.

Another disadvantage of this structure is that the back side of the groove 2 and the water permeable material 3 are fixed by adhesive, so the water permeable area from the surface where the drain material contacts the ground is only 1/2 of the total area. In addition, each groove is connected only in the longitudinal direction, and is not connected in the horizontal direction or the front and back, so if a defect occurs in a certain part of the entire area of the drain material in contact with the ground. The grooves 2 other than those in contact with that surface had no drainage function, and it was not possible for the entire drain material to have a drainage function.

Furthermore, since the base 1 of the drain material is a molded plastic body and is thick, the roll diameter is necessarily large, making transportation etc. inconvenient.

This invention has been developed in view of the above problems, and eliminates the deformation of the permeable material due to earth pressure and the resulting reduction in drainage capacity due to the reduction in the cross-sectional area of the groove. In addition, even if a certain part of the drain material is in contact with soil moisture, the entire drain material can perform the drainage function, and the roll size is small considering its length. The purpose is to make the diameter smaller.

<<Means for Solving the Problems>> In order to achieve the above object, the present invention provides a molded substrate in which longitudinal grooves are continuously formed alternately on both surfaces, and grooves that are bonded to both surfaces of the substrate. In the drain material, each of the grooves is formed in the shape of an internally expanded dovetail groove on one surface of each element constituting the base, and each groove has a dovetail groove shape that expands inwardly on one side of each element constituting the base body, and each groove has a dovetail groove shape at the bottom of each groove. It is characterized by forming cuts that communicate with the bottoms of the grooves and between adjacent grooves on the back surface of the element.

≪Function≫ The internal cross-sectional area of the groove is wide and close to a circular cross-section, so drainage efficiency is high, but since the opening surface in contact with the permeable material is narrow, the amount of deformation of the permeable material due to earth pressure is small, and the cross-sectional area is There is no decrease.

In addition, water is taken into the groove from the back side of the groove through the water permeation holes, and each groove is communicated with each other in the lateral direction, so even if a defect occurs in one location, the drainage function is not significantly degraded.

<<Example>> FIG. 1 is a partially cutaway perspective view of a drain material according to the present invention, and FIG. 2 is a sectional view thereof.

The drain material shown in the figure basically consists of a base 10 on which continuous longitudinal grooves 12 are alternately formed on both sides, as in the conventional case, and a base 10 that is bonded to both sides of the base 10 to form grooves 12 on the opening surfaces of the grooves 12. It consists of a water-permeable material 14 that covers it.

The base body 10 is an extrusion molded body made of vinyl chloride, polypropylene, polyethylene, etc., and each element 1 which is the minimum unit constituting the base body 10
The grooves 12 are formed alternately on the front and back sides in correspondence with the shape of the mold hole of the extrusion molding machine, and each element 10-1 has a cross-sectional shape in which the elements 10-1 are connected in a horizontal row.

The groove 12 is formed in a dovetail groove shape with a small opening surface and a circularly expanding interior depending on the shape of the mold hole. Therefore, the opening surface 12-1 of the groove 12 is very narrow and can have a substantially large cross-sectional area.

Further, each element 10-1 is provided at the bottom of the groove 12.
Water permeable holes 12-2 communicating with the back surface of each element 10-2 are formed at appropriate intervals.
1 has a notch 12-3 on the back surface of the opening surface 12-1 for communicating between adjacent grooves 12 in the same direction.
are formed at appropriate intervals.

This cut 12-3 is the depth of the cut until the bottom of the groove 12 of the element 10-1 is opened, and therefore, one cut 12-3 can be used to cut horizontally and horizontally between the three grooves 12. Connect the front and back sides.

Note that this cut 12-3 also has the function of improving flexibility, and has the advantage of reducing the roll diameter when wound into a roll.

The water permeable hole 12-2 and the notch 12-3 can be formed by continuously pressing or cutting (in the case of the water permeable hole 12-2) while the base body 10 is extruded, or by hot plate (the notch 12-3). 3) on the back side of the element 10-1, it can be made continuously at a predetermined pitch as shown in FIG.

Further, the water-permeable material 14 is made of water-permeable nonwoven fabric, water-permeable paper, or a combination thereof, and may be multilayered in some cases. This is adhered continuously or intermittently along the back surface of the base 10 by heat fusion or adhesive, and the drain material is completed by this adhesion.

In the above configuration, as shown in an enlarged view in Fig. 3, the drain material is pushed underground, and the water permeable material 1
4, since the opening area of the opening surface 12-1 is small, the amount of deformation of the permeable material 14 due to the pressure P is small and does not substantially lead to a reduction in the cross-sectional area of the groove 12. Become something.

Furthermore, the grooves 12 take in water not only from the opening surface 12-1 but also from the water permeable holes 12-2. Furthermore, 1
When one groove 12 overflows, permeable water is taken into the adjacent groove 12 through the notch 12-3 and through the bottom surface of the back side groove 12 of the element 10-1, thereby performing a drainage action. Become.

In the embodiment, the groove has a circular cross-sectional shape, but it goes without saying that it may have another shape as long as the opening is smaller than the inner depth. Further, the grooves may not only be formed alternately on the front and back sides, but may also be formed on one surface.

<<Effects of the Invention>> As explained in detail in the examples above, according to the drain material according to the present invention, it is possible to suppress a decrease in the cross-sectional area due to deformation of the water-permeable material while maintaining a large cross-sectional area of the grooves. Furthermore, the contact area through which water can be drained can be substantially increased by the incisions and the water permeable holes shown in the examples.

In addition, as shown in the example, by making adjacent grooves communicate with each other through cuts, each groove can be fully communicated in the lateral direction and on the back surface, and the grooves may partially overflow or water permeation may occur. It can be used to drain the entire drain material without stopping the drainage function of the groove in a non-contact state. Furthermore, since the flexibility of the drain material is improved by the cuts, the bending radius becomes smaller, and the roll diameter is smaller compared to the length, making transportation etc. easier.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view of the drain material according to the present invention, Fig. 2 is a sectional view of the same, Fig. 3 is an enlarged sectional view of the main part to explain the function, and Fig. 4 is a conventional drain material. It is a sectional view for explaining the action of the material. 10... Base body, 10-1... Neighbor, 12... Groove, 12-1... Opening surface, 12-2... Water permeable hole,
12-3...notch, 14...water permeable material.

Claims (1)

[Scope of Claims] 1. A drain material comprising a molded base in which longitudinal grooves are continuously formed alternately on both sides, and a water-permeable material that is adhered to both sides of the base and covers the opening surfaces of the grooves. , each of the grooves is formed in the shape of a dovetail groove that expands internally on one side of each element constituting the base,
A drain material characterized in that a notch is formed on the back surface of each element to communicate between adjacent grooves and to the bottom of the groove. 2. The drain material according to claim 1, wherein water permeable holes communicating with the bottoms of the grooves are formed at appropriate intervals on the back surface of each of the elements.