JP3723730B2 - Septic tank equipment and its construction method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the construction methods and purification of tank facilities. More specifically, the present invention relates to a septic tank facility for simple construction that does not require a conventional column mounting process or wall mounting process and its construction method when the septic tank is installed underground such as a garage.
[0002]
[Prior art]
Traditionally, many septic tanks are molded using fiber reinforced plastic (FRP). In particular, it is often molded using an unsaturated polyester resin reinforced with glass fibers.
[0003]
Conventionally, the septic tank is usually buried in the basement next to the house. At that time, in order to make effective use of the land, it is often buried under parking lots. Therefore, it receives the pressure by the vehicle which goes in and out of a parking lot, and this causes the damage of a septic tank. Therefore, in order to reduce or remove the pressure applied to the buried septic tank by a car or the like, as shown in FIGS. 1 and 2, in addition to the slabs on the bottom and top surfaces of the septic tank, the pillars or walls use concrete or the like. Provided.
[0004]
The above conventional construction method will be described in detail with reference to FIG. 1 and FIG. 2. First, a hole for installing the septic tank 1 is dug, a rebar frame is assembled on the dug lower surface, and this is embedded in the lower part. A slab (concrete board) 4 is installed. After the constructed slab is sufficiently cured, the concrete columns 3 (in the case of FIG. 1) in which the reinforcing bar frames are usually placed at the four corners or the concrete walls 6 (in the case of FIG. 2) in which the reinforcing bar frames are put on the four sides are installed. After the support 3 / wall 6 is cured, the septic tank 1 is installed, the soil is backfilled, and finally the upper slab 2 is constructed to the surface position of the septic tank manhole 5. The upper slab 2 is also reinforced with a steel frame. When the surface of the upper slab 2 is further covered with asphalt, the upper surface position of the upper slab is usually lowered by about 50 mm from the highest surface of the septic tank manhole. Recently, a block may be placed instead of asphalt.
[0005]
Here, the pillars often mean pillars installed perpendicular to the ground surface as shown in FIG. 1, but also include those that are not necessarily installed perpendicular to the ground surface, such as braces, The cross section may be a circular triangle or other various shapes in addition to the rectangular shape shown in FIG. Moreover, a wall here refers to the planar support substantially parallel to the side surface of a septic tank, as shown in FIG.
[0006]
The above conventional construction method is only an example, and the slab may lack a reinforcing bar frame, and it is possible to use a material other than concrete as the material. In FIG. However, in actual construction, the number is not constant and may be one or more and may be several or more. Moreover, in FIG. 2, it is represented as a figure surrounded by walls on all four sides, but in actual construction, the number is not constant, and may be one or more and may be several or more. In some cases, the entire surface is not covered, or the entire surface is composed of several walls. Further, the struts are used independently or in combination.
[0007]
However, the conventional construction method requires a column and a wall, and thus has a problem that the installation cost is high and the installation time is long.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a septic tank facility and a construction method that can be constructed at a low cost and in a short period of time without requiring the above-described work of installing columns and walls.
[0009]
[Means for Solving the Problems]
As a result of diligent study on solving this problem, the present inventors have found that if the material used for the septic tank has a yield strength retention rate of a certain level or more against repeated fatigue, this support is not necessary. More specifically, when the septic tank to be used is subjected to repeated fatigue measurements 10,000 times under a load of 1/6 of the initial yield strength, the retention rate is 80% or more of the initial yield strength after repeated fatigue measurements. If the septic tank is made of a material that does not cause problems such as cracking due to repeated use of the septic tank, it will not be subject to repeated septic tank loads without the use of columns and walls. As a result, the present invention was completed .
The septic tank equipment according to claim 1 comprises a lower slab, a septic tank installed on the lower slab, and an upper slab provided so as to face the manhole of the septic tank, and the outer shell of the septic tank is The material is made of a material whose yield strength after repeated fatigue measurement is 80% or more of the initial retention rate when 10,000 times of repeated fatigue measurements are performed under a load that is 1/6 of the initial yield strength . it shall be the features a.
The septic tank according to claim 2 is characterized in that, in the invention according to claim 1, the septic tank has a thickness of a portion of 80% or more of the outer shell of 3 mm or more .
The construction method of the septic tank equipment according to claim 3 is the retention rate of the yield strength after the repeated fatigue measurement is 80% or more of the initial when the repeated fatigue measurement is performed 10,000 times under a load of 1/6 of the initial yield strength. A septic tank that forms an outer shell with a material having a slab is manufactured, a hole is dug in a place where the septic tank is installed, a lower slab is installed on the lower surface, and the septic tank is installed on the lower slab, The soil is backfilled around the septic tank, and the upper slab is provided so as to face the manhole of the septic tank .
Contact name and cyclic fatigue measurements referred to herein, used as a dumbbell type having the same shape as that used for tensile measurement of plastic specimens, tensile repeated using a hydraulic servo-type fatigue tester, repeatedly compressed This is done by applying a load to the specimen. Yield strength is defined as the tensile strength at which permanent set occurs in a tensile test.
[0010]
According to invention of Claim 1, even if it embeds in the underground of a parking lot, the septic tank which has sufficient intensity | strength which a crack does not generate | occur | produce with the weight of a car etc. is obtained. That does not require tank capacity and construction of the column and walls 1 m ³ or more, preferably 1～15M ^3, particularly preferably provided septic tank 1~12m ^3.
According to invention of Claim 2, it is easy to endure deterioration by the oxidation of the surface part of an outer shell .
According to invention of Claim 3, since a septic tank equipment can be constructed without using a support | pillar or a wall, it can construct at low cost in a short time.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described more specifically below. FIG. 3 shows an example of the septic tank of the present invention, in which A is a top view and B is a cross-sectional view taken along line XX of A.
[0012]
The material used for the outer shell of the septic tank of the present invention has a retention rate of 80% or more of the initial yield strength after 10000 repeated fatigue measurements under a load of 1/6 of the initial yield strength. It has been found that a thermoplastic resin or a thermosetting resin may be used as long as the condition is satisfied.
[0013]
Among these, a resin molded by a reaction injection molding method in which a raw material is injected in a liquid state and converted into a resin after the injection can be more preferably used because it can be molded by a relatively small molding machine. Examples of the resin that can be molded by such a reaction injection molding method include polyurethane, nylon 6, and a cyclic olefin crosslinked polymer represented by polydicyclopentadiene. Among these, the most preferable resin is a cyclic olefin cross-linked polymer that has a low viscosity in the raw material liquid, can be molded in a complicated shape, and has excellent mechanical properties.
[0014]
The crosslinked polymer of the cyclic olefin has many double bonds in the chemical structure, and therefore, the surface portion is easily deteriorated by oxidation. Therefore, in consideration of the deterioration due to oxidation, the thickness of 80% or more of the outer shell of the septic tank is preferably 3 mm or more, and more preferably 4 mm or more in the actual production of the septic tank.
[0015]
This cyclic olefin crosslinked polymer is obtained by polymerizing a cyclic olefin with a metathesis catalyst system. As the metathesis polymerizable cyclic olefin, those containing 1 to 2 metathesis polymerizable cycloalkene groups in the molecule are used. A compound having at least one norbornene skeleton in the molecule is preferable. Specific examples thereof include dicyclopentadiene, tricyclopentadiene, cyclopentadiene-methylcyclopentadiene co-dimer, 5-ethylidene norbornene, norbornene, norbornadiene, 5-cyclohexenyl norbornene, 1,4,5,8-dimethano -1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 1,4-methano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethylidene -1,4,5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4-methano-1,4,4a, 5,6 , 7,8,8a-octahydronaphthalene, 1,4,5,8-dimethano-1,4,4a, 5,8,8a-hexahydronaphthalene, ethylenebis (5-norbornene) You can also mix these It is possible to use. In particular, dicyclopentadiene or a mixture containing 50 mol% or more, preferably 70 mol% or more thereof is suitably used. If necessary, a metathesis polymerizable cyclic olefin having a polar group containing different elements such as oxygen and nitrogen can be used as a copolymerization monomer.
[0016]
Molding by reaction injection molding of a cyclic olefin is a metathesis polymerization containing a monomer liquid A (solution A) comprising a metathesis polymerizable cyclic olefin containing a catalyst component of a metathesis polymerization catalyst system and an activator component of a metathesis polymerization catalyst system. The monomer liquid B (solution B) made of a cyclic olefin is mixed, the raw material mixed liquid is poured into a mold, and polymerization and crosslinking reaction are carried out in the mold.
[0017]
The monomer liquid A (solution A) in the cyclic olefin reaction injection molding contains a catalyst component of a metathesis polymerization catalyst system. As such a catalyst component, salts such as halides of metals such as tungsten, rhenium, tantalum, and molybdenum are used, and tungsten compounds are particularly preferable. As such a tungsten compound, tungsten hexahalide, tungsten oxyhalide and the like are preferable, and more specifically, tungsten hexachloride, tungsten oxychloride and the like are preferable. In addition, organic ammonium tungstate can be used. Such a tungsten compound is not preferred because it is known to immediately start cationic polymerization when added directly to the monomer. Therefore, such a tungsten compound is preferably suspended in an inert solvent such as benzene, toluene, chlorobenzene, etc., and solubilized by adding a small amount of an alcohol compound and / or a phenol compound. Further, as described above, in order to prevent undesired polymerization, it is preferable to add about 1 to 5 moles of Lewis base or chelating agent to 1 mole of tungsten compound. Examples of such additives include acetylacetone, acetoacetic acid alkyl esters, tetrahydrofuran, benzonitrile and the like. In the case of using a polar monomer, as described above, it may be a Lewis base itself, and may have an action without adding a compound as described above. As described above, the monomer liquid A (solution A) containing the catalyst component has substantially sufficient stability.
[0018]
On the other hand, the monomer liquid B (solution B) in the molding by the cyclic olefin reaction injection molding method contains an activator component of a metathesis polymerization catalyst system. The activator component is preferably an organometallic compound centered on an alkylated group I-III metal, particularly a tetraalkyltin, alkylaluminum compound, or alkylaluminum halide compound. Examples thereof include diethylaluminum, ethylaluminum dichloride, trioctylaluminum, dioctylaluminum iodide, and tetrabutyltin. The monomer liquid B (solution B) is formed by dissolving the organometallic compound as the activator component in the monomer.
[0019]
Basically, the solution A and the solution B are mixed and injected into a mold to obtain a crosslinked polymer molded product. However, with the above composition, the polymerization reaction starts very quickly. Therefore, curing may occur while it does not sufficiently flow into the molding die, which often causes a problem. Therefore, it is preferable to use an activity regulator. As such a regulator, Lewis bases are generally used, especially ethers, esters, nitriles and the like. Specific examples include ethyl benzoate, butyl ether, diglyme and the like. Such a regulator is generally used by being added to the solution (solution B) side of the component of the activator of the organometallic compound. When a monomer having a Lewis base is used as described above, it can also serve as a regulator.
[0020]
The amount of the metathesis polymerization catalyst system used is, for example, when a tungsten compound is used as the catalyst component, and the ratio of the tungsten compound to the raw material monomer is about 1,000 to 15,000 to 1, preferably 1,500 to 1 to 2,500 on a molar basis. When the alkylaluminum is used as the activator component, the ratio of the aluminum compound to the raw material monomer is about 100: 1 to 10,000: 1, preferably 200: 1 to 1,000 1 is used. Further, as described above, the masking agent and the adjusting agent can be appropriately adjusted according to the amount of the catalyst system used through experiments.
[0021]
In order to improve or maintain the characteristics in practical use, various additives according to the purpose can be further blended in the molded product of the crosslinked polymer. Such additives include elastomers, fillers, reinforcing agents, antioxidants, heat stabilizers, pigments, light stabilizers, UV absorbers, lubricants, antistatic agents, flame retardants, foaming agents, softeners, adhesives. Examples thereof include an imparting agent, a plasticizer, a mold release agent, a deodorant, a fragrance, and a bulking agent, and these can be used alone or in combination of two or more.
[0022]
As a method of addition, it can be mixed in advance with the raw material liquid, mixed as the third liquid immediately before the polymerization, or can be previously filled in the molding die and is more suitable for the kind of additive. A method is selected. In particular, a reinforcing agent such as glass fiber is generally set in a mold and injected with a mixed liquid.
[0023]
In addition, a molded product obtained by a reaction injection molding method of a cyclic olefin can be obtained by adding another polymer in a monomer solution state. As such a polymer additive, an elastomer is effective in increasing the impact resistance of the molded product and adjusting the viscosity of the solution. Examples of elastomers used for this purpose include a wide range of elastomers such as styrene-butadiene-styrene triblock rubber, styrene-isoprene-styrene triblock rubber, polybutadiene, polyisoprene, butyl rubber, ethylene propylene-diene polymer, and nitrile rubber. Can do.
[0024]
Examples of the material of the mold for forming the septic tank molding of the present invention by the reaction injection molding method include casting, thermal spraying of steel, cast or forged aluminum, zinc alloy, etc., electroforming of nickel, copper, and resin, etc. Is mentioned. In addition, the structure of the mold is sufficient because the pressure generated in the mold at the time of molding is several kg / cm ² which is extremely low compared to other molding methods. be able to.
[0025]
If the resin of the present invention is used, it becomes possible to omit the construction method using these columns, the method using the walls and the columns, and the method using the walls. A septic tank facility consisting of burying the soil in the ground can be realized.
Specifically, as shown in FIG. 3, a hole for installing the septic tank 1 is dug, a lower slab 4 is installed on the dug lower surface, the septic tank 1 is installed thereon, the soil is backfilled, and finally The upper slab 2 is constructed up to the surface position of the septic tank manhole 5 . Their to this post, without providing the wall, septic tank equipment consists of buried only septic tank in the ground can be realized.
[0026]
In addition, the construction method which does not require the column mounting or wall mounting according to the present invention is not limited to the case where the septic tank is installed under the parking lot, but in general, the conventional septic tank requires the mounting of the column or wall. Applicable to.
[0027]
For example, when the septic tank is installed in a position away from the house, the embedment depth is deeper than in the case where the septic tank is embedded in a position close to the house where it is normally applied, in order to facilitate the flow of drainage. In such a case, in the buried position, the earth pressure naturally increases according to the depth, and in order to protect the septic tank, it is common to surround the septic tank with a wall. In addition, in consideration of snow loads in heavy snowfall areas, there are cases where construction methods using columns, construction methods using walls, construction methods using columns and walls are used. Furthermore, as a special case, there is a case where a repetitive load or a long-term load is applied to the upper part of the septic tank, not on the ground but on the ground.
[0028]
The present invention can also be applied in these cases. Specifically, when the absolute amount of the long-term load is a stress of 1/4 or less of the yield strength, it is suitable for applying the construction method according to the present invention. Here, the reason why the stress is 1/4 or less of the yield strength is that 1/4 of the yield strength is generally used as a long-term allowable stress from the viewpoint of safety. Therefore, when the period during which the septic tank is used is short, the construction method according to the present invention can be applied without depending on this standard.
[0029]
Hereinafter, the present invention will be described with reference to examples. In addition, an Example is for description and this invention is not necessarily limited to these.
[0030]
【Example】
[Examples 1 to 4]
(1) Molding A sample piece that conforms to the JIS-K7113 plastic tensile test method with a wall thickness of 3 mm was produced by an injection molding method. Moreover, when not producing a test piece directly, a 3 mm flat plate was produced beforehand, and the predetermined test piece was cut out after that. The fiber reinforced FRP flat plate was prepared by using a general-purpose unsaturated polyester hand lay-up, and the SMC flat plate was also a general-purpose type product and was compressed after application. Polydicyclopentadiene was molded by a reaction injection molding method.
[0031]
(2) Fatigue measurement and evaluation The test conditions shown in Table 1 were adopted, and fatigue measurement was repeated 10,000 times at 1/6 the initial yield strength.
[0032]
Table 1
Testing machine: ± 200kgf hydraulic servo type fatigue testing machine Control method: Weight control Waveform: Triangular wave Test temperature: Room temperature Stress ratio: R = 0.1
Test speed: 0.5-2Hz
[0033]
The results are shown in Table 2. Here, only polydicyclopentadiene was maintained at 80% or more.
[0034]
Table 2
Material: Yield strength retention rate Polyvinyl chloride: 70%
FRP: 30%
SMC: 35%
Polydicyclopentadiene: 95%
[0035]
(Monomer solution)
(Preparation of solution A) 28 parts by weight of tungsten hexachloride was added to 80 parts by weight of dry toluene under a nitrogen stream, and then a solution of 1.3 parts by weight of t-butanol dissolved in 1 part by weight of toluene was added and stirred for 1 hour. Next, a solution consisting of 18 parts by weight of nonylphenol and 14 parts by weight of toluene was added and stirred for 5 hours under a nitrogen purge. Further, 14 parts by weight of acetylacetone was added. Stirring was continued overnight while purging by-product hydrogen chloride gas under a nitrogen purge to prepare a polymerization catalyst solution.
[0036]
Subsequently, ethylene-propylene having an ethylene content of 70 mol% with respect to a monomer mixture consisting of 95 parts by weight of purified dicyclopentadiene (purity 99.7% by weight, the same applies hereinafter) and 5 parts by weight of purified ethylidene norbornene (purity 99.5% by weight, the same applies hereinafter) -A monomer solution containing a catalyst component by adding the above polymerization catalyst solution to a solution containing 3 parts by weight of ethylidene norbornene polymer rubber and 2 parts by weight of Etanox 702 as an oxidation stabilizer so that the tungsten content is 0.01 M / liter. (Solution A) was prepared.
[0037]
(Preparation of Solution B) In a solution in which 3 parts by weight of ethylene-propylene-ethylidene norbornene polymer rubber containing 70 mol% of ethylene was dissolved in a monomer mixture consisting of 95 parts by weight of purified dicyclopentadiene and 5 parts by weight of purified ethylidene norbornene, A monomer solution containing an activator component by adding a polymerization activator mixture prepared by mixing at a molar ratio of trioctylaluminum 85, dioctylaluminum iodide 15, and diglyme 100 so that the aluminum content is 0.03 M / liter. B (Solution B) was prepared.
[0038]
(Molding) Heat the aluminum mold for molding to the cavity mold 90 ° C and the core mold 60 ° C, close the mold, and then use this RIM molding machine to mix the same amount of solution A and solution B in the mixing head Were mixed and injected. The mold was opened 3.5 minutes after the liquid injection and filling, and the crosslinked polymer product was taken out. This molding was repeated several times. The size of the obtained crosslinked polymer molded product (manufactured by polydicyclopentadiene) septic tank was an 8-person tank compatible product.
[0039]
(Assembly and construction) The obtained cross-linked polymer molded product (upper tank part and lower tank part) is fixed using bolts, nuts and polyurethane adhesive via flange parts, and further, starting with a partition plate, Materials and fillers were incorporated into test products.
[0040]
(Evaluation) Assuming that it is installed directly under the parking lot, a test septic tank is installed in an iron box, and the gap between the septic tank and the iron box is filled with 3% water-containing No. 6 silica sand. Injected. In order to model the actual pressure of the car, etc., in the septic tank manhole part, it is assumed that 1120kgf load (assuming that one of the rear wheels responsible for 80% of the load of a 2-ton car gets on the manhole) Assuming that the load is applied impactively, 2000kgf * 0.4 (load for one rear wheel) * 1.4 (coefficient for impact) = 1120kgf) was applied and 1 load (1Hz) for 1 second was repeated 10,000 times. . After that, the state of the septic tank that received repeated loads was examined, but no cracks, whitening, water leakage, etc. were found. At the same time, the maximum stress obtained from multiple strain gauges installed at the position where the maximum stress is predicted (such as the septic tank manhole bend) is 69 kgf / mm ^2, which is 1/6 of the initial yield strength. there were.
[0041]
[Comparative Example 1] An 8-person tank septic tank having the same shape as that of Example 4 was prepared except that polydicyclopentadiene was changed to FRP as an outer shell member. As FRP, Mitsui Chemicals R-346 was used, and the glass content was 30% or more.
[0042]
When the same evaluation as in Example 4 was performed, cracks were observed in the bent portion of the septic tank manhole. The maximum stress was less than 1/10 of the initial yield strength.
[0043]
【The invention's effect】
According to invention of Claim 1, even if it embeds in the underground of a parking lot, the septic tank which has sufficient intensity | strength which a crack does not generate | occur | produce with the weight of a car etc. is obtained. That does not require tank capacity and construction of the column and walls 1 m ³ or more, preferably 1～15M ^3, particularly preferably provided septic tank 1~12m ^3.
According to invention of Claim 2, it is easy to endure deterioration by the oxidation of the surface part of an outer shell .
According to invention of Claim 3, since a septic tank equipment can be constructed without using a support | pillar or a wall, it can construct at low cost in a short time.
[Brief description of the drawings]
FIG. 1 shows an example of conventional septic tank construction, in which A is a top view and B is a cross-sectional view taken along line XX of A. FIG.
FIG. 2 shows an example of a conventional septic tank construction, where A is a top view and B is a cross-sectional view taken along line XX of A. FIG.
FIG. 3 shows an example of the septic tank of the present invention, in which A is a top view and B is a cross-sectional view taken along line XX of A. FIG.
[Explanation of symbols]
1 Septic tank 2 Upper slab 3 Support column 4 Lower slab 5 Septic tank manhole 6 Wall

Claims (3)

The lower slab,
A septic tank installed on the lower slab;
It consists of the manhole of the septic tank and the upper slab provided to be in the surface position,
The outer shell of the septic tank is
It is made of a material whose yield strength after repeated fatigue measurement has a retention rate of 80% or more of the initial value when 10000 repeated fatigue measurements are performed under a load 1/6 of the initial yield strength .
Septic tank equipment you, characterized in that. The septic tank has a thickness of 80% or more of the outer shell of 3%. mm That's it
The septic tank equipment according to claim 1. Initial yield strength 1/6 Under the load of 10000 In the case of repeated fatigue measurements, a septic tank that forms an outer shell with a material having a retention rate of 80% or more of the initial yield strength after repeated fatigue measurements is manufactured,
Dig a hole in the septic tank installation location,
Install the lower slab on the dug bottom,
Installing the septic tank on the lower slab,
Backfill the soil around the septic tank,
Provide the upper slab so that it is in the same position as the manhole of the septic tank
The construction method of the septic tank equipment characterized by this.

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