JPH045323A - Widening civil engineering work method using foaming resin - Google Patents

Abstract

PURPOSE:To make ground widening possible by foaming resin by placing a required amount of material beads in a mold form, set up in a widening work site, and foaming the material beads by heat through injection pipes driven into the ground and inserted through inside this mold form. CONSTITUTION:A widening device is constituted of a mold form 1 set up in a tilted wall surface 9, plurality of injection pipes 2 and hoses 3, steam storage tank 4, pressure pump 6 and a boiler 7 or the like. The injection pipe 2 is provided with a function for serving also as a water bleed pipe for discharging infiltrating water of the tilted wall surface 9, by driving the injection pipe 2 into the ground through inside the mold form 1 to be held by a foaming unit after it is foamed. Next, the mold form 1 is charged with a beads material 8 of about 90kg per about 3m<3> internal volume, and successively, steam of about 100 deg.C temperature is jetted from the injection pipe 2 for about 15min at a flow rate of about 0.4m<3> per minute. In this way, the foaming unit of holding the injection pipe 2 can be formed in a compressed condition.

Description

[Detailed description of the invention] [Industrial application field]

The present invention provides foaming properties that simplify the widening work by foaming foamable resin into the desired shape at the widening site to form a foam during civil engineering work such as widening sloped walls in golf course development sites and widening roads. Regarding widening civil engineering work using resin.

[Conventional technology]

Attempts have been made to take advantage of the lightweight nature of foamable resins to fill depressions or use them as part of artificial ground. For example, foamable resin is molded into foam blocks of a predetermined shape in a factory, the foam blocks are piled up on the original ground that is to be embanked, and the surface layer is finished with concrete floor plates, wall protection materials, etc. Additionally, reinforcing materials such as reinforcing bars are placed inside to improve structural strength. When forming a foundation by stacking foam blocks, misalignment is likely to occur between the foam blocks. Therefore,
Utility Model Application No. 63-81941, Utility Model Application No. 63-8194
In order to eliminate this misalignment, Patent Publications No. 2 and the like introduce the method of forming irregularities on the surface of the foam block and interlocking the irregularities. Furthermore, Japanese Patent Application Laid-open No. 47-19F317 discloses that after spraying an unfoamed resin such as urethane, vinyl chloride, or styrene onto a depression or roadbed, a foaming reaction is performed to fill the depression. There is.

[Problem to be solved by the invention]

However, the method of transporting foam blocks that have been foamed in a factory to the site and stacking them into a predetermined shape requires time and effort to transport and handle. For example, a large block of about 2XIX 0.5 m is used as this type of block, but such a large block requires manpower to transport, although it is lightweight. Furthermore, the transportation is essentially like transporting air, which is wasteful. Furthermore, as the blocks become larger, gaps are more likely to form between the original ground and the blocks that are to be used for embankment work, so it is necessary to prepare the original ground flat in advance. . On the other hand, Japanese Patent Application Laid-Open No. 47-19 discloses that foamable resin is foamed on-site.
The method described in the F317 publication solves this problem. However, this publication does not specifically teach how to foam the foamable resin. By the way, if the resin is simply foamed, the surface of the foamed product often does not have the required contour due to non-uniform foaming or the like. In addition, when foaming occurs at the free interface,
The surface strength of the foam is insufficient (and dents are likely to occur when treading pressure is applied). In particular, such foamed resin foams have poor water absorption, making them difficult to use for ground widening civil engineering work. In some cases, water tends to accumulate at the interface between the foam and the ground, and there is a risk that the foam will be washed away by water pressure.Therefore, the present invention forms a foam with the required strength that has been treated to drain water at the widening site. The purpose is to

[Means to solve the problem] For this purpose, the present invention provides a blowout pipe in which a required amount of foamed resin raw material beads is put into a formwork installed to cover the ground widening site, and a jet pipe is driven into the ground by penetrating the formwork in the width-widening direction. The material beads in the formwork are heated and foamed by supplying a heated gas such as water vapor to the formwork, and a foam holding an ejection pipe is formed in a compressed state in the formwork to widen the ground. . [For production]

With such means, the foam enclosing the jet pipe is formed in a compressed state at the widening site within the formwork, so that the foam develops the required strength. Furthermore, the injection pipe supported by the foam is driven into the ground through the foam in the width-expanding direction, so it functions as a drain pipe. The heated gas from the raw material beads is discharged out of the mold or recovered by appropriate means. Furthermore, it is preferable that the surface of the foam formed at the widening site be compacted using topsoil. Various foamable resins used in the present invention are commercially available, such as styrene resins, phenol resins, urea resins, and urethane resins. The foaming temperature of the foamable resin is determined appropriately depending on the type of resin, but is usually 70 to 2
A sufficient foaming reaction can proceed at about 00°C.

【Example】

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention applied to civil engineering work to widen a sloped wall in a golf course development site will be described in detail below with reference to the accompanying drawings. Figure 1 shows the equipment used in this example, including a formwork 1 that covers the ground at the site of ground widening, an ejection pipe 2 that ejects water vapor as a heated gas into the formwork 1, and each ejection pipe 2 that injects water vapor into the formwork 1. It consists of a hose 3 for distribution, a water vapor storage tank 4 to which the hose 3 is connected, a pressure pump 6 that communicates with the water vapor storage tank 4 via a pressure regulating valve 5, a boiler 7 that supplies water vapor to the pressure pump 6, etc. be done. Therefore, first, formwork 1 is installed to cover the ground widening site. As shown in Fig. 2, this formwork 1 is shaped to cover the top, front, left and right sides of the widening site, and its flange portion 1a is placed in the ground by appropriate means such as piling. Fix it. Here, a large number of small holes 1b for steam venting are provided on the upper surface of the formwork 1, and an appropriate number (six in this embodiment) of pipe insertion holes 1c are arranged at appropriate intervals on the front surface of the formwork 1.
1d of the left and right side walls (both side walls 1d
It is configured to be able to be opened and closed by a hinge connection, or to be detachable by a pin connection. Then, the six ejection pipes 2 are pushed into the formwork 1 through the pipe insertion holes 1c of the installed formwork 1. This jet pipe 2 is provided with a large number of jet holes 2a on its circumferential surface, each having a smaller diameter than the raw material beads 8 of the foamable resin, and its tip is driven into the inclined wall surface 9 at the widening site to widen the inside of the formwork 1. Penetrate in the direction. In this case, the injection vibrator 2 is inclined so that the inclined wall surface 9 side is slightly higher. Then, each of the hoses 3 is connected to a portion of each ejection vibrator 2 that protrudes from the front surface of the formwork 1. Next, the side wall 1d is opened in the installed formwork 1, a required amount of raw material beads 8 are introduced, and the side wall 1d is closed and fixed to complete the preparation. After the above preparations are completed, the steam S generated by the boiler 7 is pressurized by the pressure pump 6, adjusted to a predetermined pressure by the pressure regulating valve 5, and stored in the storage tank 4. Then, the water vapor S in the storage tank 4 is ejected into the formwork 1 from the nine ejection vibrators 2 via the hose 3. Here, the input amount of the raw material beads 8 was 90 kg, assuming that the internal volume of the widening site covered with the formwork 1 was 3 m3. Moreover, as the raw material beads 8, styrene resin beads with an average particle diameter of 0.9 mm were used. The foaming reaction of these resin beads changes as shown in Figure 3 depending on the relationship between temperature and time.
When foaming is stopped, the foam expands to a foaming ratio of about 30 to 45 times, and the density of the foam is about 0.015 g/cm<3>. The temperature of the water vapor S injected as a heated gas is 10
The temperature was 0°C, and this was ejected for 15 minutes at a flow rate of 0.4 m3 per minute. Under such conditions, the raw material beads 8 in the formwork 1 were uniformly heated and foamed as the air in the formwork 1 was pushed out from the upper small holes 1b and replaced with water vapor S. . At this time, since the foaming volume is regulated by the formwork 1, the raw material beads 8 are subjected to a compressive load in the latter stage of foaming, and the highly dense compressed foam 10 is placed in the formwork 1 without any gaps (formed). FIG. 4 shows the foam 10 obtained by removing the formwork 1,
Each ejection vibrator 2 is held by and integrated with the foam 10, and functions as a drain pipe for discharging permeated water from the inclined wall surface 9 side. The foam 10 thus formed has a foaming ratio of about 35 times and a density of about 3.
It was 0 kg/m3 and the surface was dense. Here, FIG. 5 is a graph showing the experimental results of determining the relationship between the density and compressive stress of foams formed under various conditions.
The compressive stress value was measured when a compressive strain of 4% was applied to a test piece measuring 50 mm by 50 mm. As is clear from FIG. 5, the strength of the foam increases as the density increases, and at a density of 30 kg/m3, a compressive strength of about 1.3 kg/cm2 is obtained. This compressive strength indicates that the ground has sufficient treading strength, considering that the stress generated under the pavement surface under normal traffic loads is 0.5 kg/cm2 or less. It shows. In addition, even if the foaming density is 20kg/m3, it is 0.5kg/cm.
Since a compressive strength of 2 or more can be obtained, it is advantageous to lower the foaming density to the extent possible when considering raw material consumption and weight reduction. relatively short 1
Although it has been shown that the foams 10 are formed in a continuous manner, if a long continuous foam is to be obtained, a long formwork along the inclined wall surface 9 may be used. It may be formed in the direction. [Effects of the Invention] As explained above, according to the present invention, the foam holding the ejection vibrator is formed in a compressed state at the widening site in the formwork, so the foam develops the necessary strength to withstand treading pressure. , it functions well as a ground construction material. In addition, the injection pipe held in the foam is driven into the ground by penetrating the foam in the width direction, so it functions as a drainage pipe and prevents water from accumulating at the interface between the ground and the foam. can be prevented.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention, and is a side view showing the widening site in cross section along with the equipment configuration. FIG. 2 is a perspective view of the formwork portion in one embodiment. A graph showing the foaming reaction of the styrene resin beads used in the example as a function of temperature and time. Figure 4 is a cross-sectional view of a foam formed according to an example. Figure 5 is the density and compression of the foam. It is a graph showing the relationship with stress. DESCRIPTION OF SYMBOLS 1... Formwork, 1a... Flange part, 1b... Small hole, 1c... Vibe insertion hole, 1d... Side wall, 2... Ejection pipe, 2a... Ejection hole, 3 ...Hose, 4...Steam storage tank, 5...Pressure adjustment valve, 6...Pressure pump, 7
...Boiler, 8. Raw material beads, 9.
... Sloped wall surface, 10... Foam. 8 temples (4))

Claims (1)

[Scope of Claims] A required amount of raw material beads of foamable resin are put into a formwork installed to cover the ground widening site, and water vapor is poured into an ejection pipe that penetrates the formwork in the width-widening direction and is driven into the ground. A foaming method characterized by heating and foaming the raw material beads in the mold by supplying a heated gas such as, etc., and forming a compressed foam in which the jet pipe is held in the mold to expand the width of the ground. Widening civil engineering method using resin.