JP2772995B2 - Widening civil engineering method using foaming resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a foaming resin for foaming by foaming a foamable resin into a required shape at a widening site in civil engineering work such as widening an inclined wall surface or widening a road in golf course development or the like, thereby simplifying the widening work. Related to widening civil engineering work using resin.

[Prior art]

Attempts have been made in the past to make use of the lightweight properties of the foamed resin to fill in depressions or to make them a part of artificial ground. For example, a foamable resin is molded into a foam block having a predetermined shape at a factory, the foam block is piled up on an original ground to be embanked, and a concrete floor plate, a wall protection material and the like are stretched on the surface layer to finish. Further, a reinforcing material such as a reinforcing bar is arranged inside to improve the structural strength. Here, when the ground is formed by stacking the foam blocks, a gap easily occurs between the foam blocks. Therefore, Japanese Utility Model Application Laid-Open No. 63-81941, Japanese Utility Model Application Laid-Open No. 63-81942, and the like, introduce a method of forming irregularities on the surface of a foam block and engaging the irregularities in order to eliminate the deviation. I have. Further, Japanese Patent Application Laid-Open No. 47-19617 discloses that an unfoamed resin such as urethane, vinyl chloride, and styrene is sprayed on a depression or a roadbed, and then a foaming reaction is performed to fill the depression or the like. I have.

[Problems to be solved by the invention]

However, the method of transporting the foamed block after foaming at the factory to the site and stacking the foamed block in a predetermined shape takes time and effort to transport and handle. For example, a large block of about 2 × 1 × 0.5 m is used as this type of block, but such a large block requires labor for transportation despite its light weight. In addition, the transportation is substantially as if carrying air, and there is much waste. Moreover, as the size of the block becomes larger, a gap is more likely to be formed between the original ground on which the work such as embankment is to be performed and the spread block, so that it is necessary to previously form the original ground. . On the other hand, JP-A-47-1961 in which a foamable resin is foamed on site
Such a problem is solved by the method described in Japanese Patent Application Laid-Open No. 7-74. However, there is no specific teaching in the publication regarding how to expand the expandable resin. By the way, simply foaming a resin often does not have a required contour on a foamed surface after foaming due to uneven foaming or the like. In addition, when foaming is performed at the free interface, the surface strength of the foam is not sufficient, and dents and the like easily occur when a tread pressure is applied. In particular, since the foam of such foamable resin has poor water absorption, in the case of earth widening civil engineering work, water easily accumulates at the boundary surface between the foam and the ground, and the foam is washed away by water pressure. There is a fear. Therefore, an object of the present invention is to form a foam having a required strength obtained by subjecting a widening site to a drainage process.

[Means for Solving the Problems]

For this purpose, the present invention relates to an ejection pipe in which a required amount of foamable resin raw material beads are charged into a mold installed over a ground widening site and penetrated into the ground through the mold in the direction of widening. The raw material beads in the mold are heated and foamed by supplying a heating gas such as steam to the foam, and the foam holding the ejection pipe in the mold is formed in a compressed state to widen the ground. .

[Action]

With such a means, the foam holding the ejection pipe is formed in a compressed state at the widening site in the mold, so that the foam has the required strength. Further, the injection pipe held by the foam penetrates the foam in the widening direction and is driven into the ground, and thus functions as a drain pipe. In addition, the heated gas of the raw material beads is discharged out of the mold or collected by an appropriate means. The surface of the foam formed at the widening site is preferably compacted using topsoil. As the foaming tree used in the present invention, various kinds such as styrene resin, phenol resin, urea resin and urethane resin are commercially available. The foaming temperature of the foamable resin is appropriately determined depending on the type of the resin, usually 70 to 200.
A sufficient foaming reaction can proceed at about ° C.

【Example】

Hereinafter, an embodiment of the present invention applied to widening civil engineering work on an inclined wall surface in a golf course development site will be specifically described with reference to the accompanying drawings. FIG. 1 shows an apparatus used in the present embodiment. A form 1 covering the ground at a site where the ground is widened, an ejection pipe 2 for ejecting steam as a heating gas into the form 1, and steam is supplied to each ejection pipe 2. A hose 3 for distribution, a storage tank 4 for water vapor to which the hose 3 is connected, a pressure pump 6 communicating with the water vapor storage tank 4 via a pressure regulating valve 5, a boiler 7 for supplying water vapor to the pressure pump 6, and the like. Is done. Therefore, first, the formwork 1 is installed so as to cover the widening site of the ground. As shown in FIG. 2, the formwork 1 has a shape covering the top surface, the front surface, and the left and right side surfaces of the widening site, and its flange portion 1a is grounded by appropriate means such as pile driving. Fix it. Here, a large number of small holes 1b for venting steam are provided on the upper surface of the mold 1, and an appropriate number (six in this embodiment) of pipe insertion holes 1c are provided on the front surface thereof at appropriate intervals. At least one of the left and right side walls 1d is configured to be openable and closable by hinge connection, or is configured to be detachable by pin connection or the like. Then, six ejection pipes 2 are inserted into the mold 1 through the pipe insertion holes 1c of the installed mold 1. The jet pipe 2 is provided with a large number of jet holes 2a having a smaller diameter than the raw material beads 8 of the foaming resin on the peripheral surface. Penetrate in the direction. In this case, the injection pipe 2 is inclined so that the inclined wall surface 9 side is slightly higher. The hoses 3 are connected to portions of the injection pipes 2 protruding from the front surface of the mold 1. Next, the side wall 1d is opened in the installed mold 1 and a required amount of the raw material beads 8 are charged, and the side wall 1d is closed and fixed to complete the preparation. After the completion of the preparation, the steam S generated by the boiler 7 is pressurized by the pressurizing pump 6 and adjusted to a predetermined pressure by the pressure adjusting valve 5 and stored in the storage tank 4. Then, the steam S in the storage tank 4 is ejected from the nine ejection pipes 2 into the mold 1 through the hose 3. Here, the input amount of the raw material beads 8 was 90 kg, with the internal volume of the widening site covered by the mold 1 being 3 m ³ . Styrene resin beads having an average particle diameter of 0.9 mm were used as the raw material beads 8. The foaming reaction of the resin beads changes as shown in FIG. 3 depending on the relationship between temperature and time. When the foaming is stopped, the foam expands to a foam having an expansion ratio of about 30 to 45 times, and the density of the foam is about 0.015. g / cm ³ . The temperature of the steam S injected as the heating gas is 10
0 ° C., which was spouted at a flow rate of 0.4 m ³ per minute for 15 minutes. Under such conditions, the raw material beads 8 in the mold 1
Was uniformly heated and foamed as the air in the mold 1 was extruded from the upper small holes 1b and replaced with steam S. At that time, since the foaming volume was regulated by the mold 1, the raw material beads 8 were subjected to a compressive load in the later stage of foaming, and the densely packed foam 10 was formed in the mold 1 without gaps. FIG. 4 shows a foam 10 obtained by removing the mold 1;
Each of the jet pipes 2 is held by the foam body 10 and integrated therewith, and functions as a drain pipe for discharging permeated water on the inclined wall surface 9 side. And the formed foam
10 has a foaming ratio of about 35 times and a density of about 30 kg / m ³
The surface was dense. Here, FIG. 5 is a graph showing the results of an experiment in which the relationship between the density and the compressive stress of the foam formed under various conditions was obtained.
It is a value obtained by measuring a compressive stress value when a compressive strain of 4% is applied to a 50 mm test piece. As is apparent from FIG. 5, the strength of the foam increases as the density increases, and at a density of 30 kg / m ³ , the strength increases by 1.3%.
A compressive strength of about kg / cm ² is obtained. This compressive strength is that the stress generated under the pavement under the normal road load is 0.
Considering that it is 5 kg / cm ² or less, it indicates that the ground having sufficient treading strength has been obtained. In addition, since the compression density of 0.5 kg / cm ² or more can be obtained even when the foam density is 20 kg / m ^3, it is advantageous to reduce the foam density as much as possible when considering raw material consumption and weight reduction. . In the above embodiment, one relatively short foam body 10 is formed along the inclined wall surface 9. However, when a continuous long foam body is obtained, a long form along the inclined wall surface 9 is required. It may be used, and a required number of foams 10 may be sequentially formed in the longitudinal direction.

【The invention's effect】

As described above, according to the present invention, since the foam holding the ejection pipe is formed in a compressed state at the widening site in the mold, the foam has a required strength to withstand tread pressure, and as a ground component material Works well. Also, since the injection pipe held by the foam penetrates the foam in the widening direction and is driven into the ground, it functions as a drainage pipe, and water accumulates at the boundary surface between the ground and the foam. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an explanatory view of one embodiment of the present invention, and is a side view showing a cross section of a widening site together with a device configuration, FIG. 2 is a perspective view of a formwork portion in one embodiment, and FIG. FIG. 4 is a graph showing a foaming reaction of styrene resin beads used in Examples in relation to temperature and time. FIG. 4 is a cross-sectional view of a foam formed by one Example. FIG. 5 is density and compression of foam. It is a graph which shows the relationship with stress. DESCRIPTION OF SYMBOLS 1 ... Mold, 1a ... Flange part, 1b ... Small hole, 1c ... Pipe insertion hole, 1d ... Side wall, 2 ... Spout pipe, 2a ... Spout hole, 3 ... Hose, 4 ... Steam storage tank, 5 ... pressure regulating valve, 6 ... pressure pump, 7 ... boiler, 8 ... raw material beads, 9 ... inclined wall surface, 10 ... foam.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) E02D 17/18 E02D 3/00 E01C 3/00

Claims (1)

(57) [Claims] 1. A required amount of foamable resin raw material beads are charged into a formwork installed over a ground widening site, and water vapor or the like is injected into an ejection pipe that penetrates the formwork in the direction of widening and drives into the ground. A foaming resin characterized in that the raw material beads in the form are heated and foamed by supplying a heated gas of the form, and the foam holding the ejection pipe in the form is formed in a compressed state to widen the ground. Widening civil engineering method using.