JPH0366793A - Production of re-generated soil and device therefor - Google Patents

Abstract

PURPOSE:To obtain a regenerated soil having uniform grain size and capable of re-utilizing as a road floor material for road, a road ground material, etc., by mixing a slight amount of quick lime and cement into surplus soil after excavation. CONSTITUTION:A housing vessel 2a of surplus soil after excavation and a device 4 for cracking the surplus soil are arranged on carrying course and the path is coupled to a oscillating sieve 5a for forming cracked surplus soil after excavation into desired grain size. Further a proceeding carrying path is coupled to a mixer 8 while arranging a housing vessel 7a for quick lime and a housing vessel 7a for cement above the path and successively a oscillating sieve 5a for giving the desired grain size is provided to provide the regenerated soil 37.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention involves mixing excavated soil with a trace amount of quicklime and cement, or mixing ash waste soil with an appropriate amount of mountain soil, and further adding a trace amount of quicklime and cement. and road subgrade materials by mixing with cement,
The present invention relates to a method for producing recycled soil that can be reused as roadbed material, etc., and an apparatus therefor.

[Conventional technology] Excavated soil generated in various places due to road construction, water supply and sewerage construction, building construction, etc. is classified into clay gravel (GC), clay sand (SC), and clay (CH) according to soil type classification. High water content <
, because the CBR value is low and the plasticity index (hereinafter referred to as PI value) is high, and the grain size etc. is not uniform depending on the excavation location, so conventionally it was used as a backfill material or
Alternatively, quicklime has been mixed in and used as recycled soil by taking advantage of its unique heat-generating and water-absorbing properties, but when mixed with quicklime and used as recycled soil, the quicklime reacts with water and generates a large amount of heat. Therefore, for a certain period of time (from 168 hours)
240 hours) of curing was required, reducing the efficiency of the construction work. In particular, it was not possible to deal with cases where prompt reclamation was required, such as in the case of coastal development. In addition, the ash-like waste soil produced by incinerating a wide variety of garbage has properties similar to excavated soil, and can be dumped in unused land like raw garbage, or hardened into charcoal and used for landfill. However, in order to improve this, the inventor of the present invention developed a method for producing recycled soil, which was first filed in Japanese Patent Application No. 1982-272100, and subsequently published in Jikoe No. 1-16555. This device opened the way to reclaimed soil, but it faced the same problems as with excavated soil. Also,
By mixing quicklime into excavated soil and ash-like waste soil, it is possible to lower the water content ratio, resulting in improvements such as higher CBR values and lower PI values. In order to further increase its suitability as a roadbed material, there has been a strong desire to obtain better values.

[Problems to be Solved by the Invention] Therefore, the present invention shortens the curing period required due to heat generation due to the mixing of quicklime when excavated soil or ash waste soil is used as recycled soil, and The purpose is to obtain recycled soil with better water content ratio, CBR value, and PI value as roadbed material and roadbed material.

[Means for Solving the Problems] That is, the first aspect of the present invention is a method for producing recycled soil by mixing a small amount of quicklime and cement into excavated soil, and the second is a method for producing recycled soil by mixing excavated soil with a small amount of quicklime and cement. This is a method for producing recycled soil in which an appropriate amount of mountain soil is mixed into the soil, and a small amount of quicklime and cement is mixed in to produce recycled soil.The third method is a container for storing excavated soil and a device for crushing the excavated soil. is arranged on the conveyance path, and the conveyance path is connected to a vibrating sieve that makes crushed excavated soil to a desired particle size, and the conveyance path is further connected with a quicklime storage container and a cement storage container above it. This is a recycled soil manufacturing device, which is connected to a mixer, and is further provided with a vibrating sieve to obtain a desired particle size. A device for crushing waste soil is installed on the conveyance route, and the conveyance route is connected to a vibrating sieve that makes the crushed ash waste soil have the desired particle size. This is a recycled soil manufacturing device that is equipped with a storage container, a quicklime storage container, and a cement storage container, connected to a mixer, and further provided with a vibrating sieve to obtain a desired particle size.

[Function] In the present invention configured by the above means, excavated soil is thrown into a hopper-type storage container that is disposed on a conveyance path such as a belt conveyor and has a discharge port at the bottom, and is suitably dumped in a certain amount at a time. It is fed from the discharge port to the conveyance path and is loosened by a subsequent crusher.

The excavated soil thus loosened is passed through a vibrating sieve to select only particles with a particle size of 8011 m or less.

The excavated soil that has been sorted to have a particle size of 80 m or less is transported on a transport route that has a hopper-shaped quicklime storage container and a hopper-shaped cement storage container on the top. A small amount of quicklime from the container,
It is mixed with cement and then falls into the mixer. The excavated soil mixed with quicklime and cement in the mixer is passed through the vibrating sieve again and becomes recycled soil with a particle size of 50 mm or less, which falls and accumulates. The case where ash waste soil is introduced instead of excavated soil is almost the same as the above, but in addition to the above configuration, a mountain soil storage container is provided along with a quicklime storage container and a cement storage container on the conveyance route. A suitable amount of mountain soil of 20% to 50% by weight of the ash waste soil is mixed in from the storage container to adjust the particle size. By using this method and a series of devices, the CBR value, corrected CBR value, and -axial compressive strength can be improved due to the water absorption effect of quicklime and the assimilation effect that hardens the clay content of cement into a sand-like state, compared to when only a small amount of quicklime is added. Due to the synergistic effect of
The time is shortened to ~96 hours, making it even more suitable as road bed material and roadbed material.

“Example” An example will be described below in order to further clarify the gist of the present invention.

The recycled soil manufacturing apparatus will be explained with reference to FIG. The recycled soil manufacturing apparatus P is outdated and consists of the following components.

First, a hopper-type storage container 2a having a discharge port at the bottom is provided on a transport path la provided for transporting leftward in the drawing, and excavated soil or ash-like waste soil 31a is placed in the storage container 2n. is stored at the time of input, and a certain amount is suitably fed onto the conveyance path la from the bottom outlet of the storage container 2a.

A clod crusher 4 is provided on the conveyance route la, and the fed excavation residual soil or ash-like waste soil is loosened.

Further, a conveyance path 1b is provided below the conveyance path 1a, and the conveyance path 1b is designed to convey in a certain direction in the drawing. Below the downstream end of b, a vibration i! i machine 5
a is arranged. The vibrating sieve 5a transfers particles having a particle size of 80 or more to the left side.

The particles 31c having a particle size of 80 mm or less are dropped onto a conveying path 1d provided below the vibrating sieve 5a and designed to be conveyed in a direction in the drawing.

Furthermore, the carrier bodies 31b having a particle diameter of 80 m or more are accumulated on the ground or the like from the trailing end via a conveyance path IC designed to be conveyed to the left in the drawing.

On the conveyance path ld, quicklime 33 is fed in an arbitrary appropriate amount via a quicklime screw feeder 6a within a weight ratio of 2% to 4% relative to the excavated soil or ash waste ±31a. A storage container 7a and a cement storage container 7b configured to feed cement 34 through a cement screw feeder 6a at a weight ratio of 1% to the excavation residue or ash waste 31a are provided, When the raw material to be put into the storage container 2a is ash waste soil, in addition to the above, an appropriate amount of mountain soil is delivered onto the transport route ld via the vibration feeder 9 and the transport route 1g. A container 2b for storing mountain soil 32 is provided for this purpose.

Below the downstream end of the conveyance path 1d, a stabilizer 8 is provided to sufficiently mix the excavated soil or ash waste 31a, the mountain soil 32, quicklime 33, and cement 34, and the mixed soil in which they are mixed is provided. 35 is sorted by the vibration 1i5b provided below the stabilizer 8, and the medium lumps I*36 with a grain size of 50 m+w or larger are transported to the trailing edge through the transport path 1f designed to be transported in a certain direction in the drawing. The reclaimed soil 37, which is accumulated closer to the ground and has a particle size of 5° arm or less, is accumulated below the trailing end by the conveyance path 1e, which is designed to be conveyed to the left.

Next, an example of recycled soil 37 manufactured by the above manufacturing method using the recycled soil manufacturing apparatus P will be described.

The first example was carried out in a certain place in Shizuoka Prefecture, but the soil was classified as clayey gravel (GC) and CBR.
When 3% of quicklime was added to the excavated residual soil with a value of 5.0% and a PI value of it, g, the soil classification was silty gravel (GM).
, CBR value is 62.0%, Shumasa CBR value is 58.2%
, PI value is NP, -axial compressive strength is 13.5 kg/crn
'Met. On the other hand, when 2% quicklime and 1% cement were added to the above excavated soil, the soil classification was silty gravel (G
M), CBR value is 71.2%, corrected CBR value is 62.
4%, PI value is NP, -axial compressive strength is 25.7kg/c
m”, thus, the CBR value, the modified CBR value,
- It was confirmed that the recycled soil had a better axial compressive strength than when only quicklime was added, and was more suitable as a road bed material. Also, only quicklime 3
%, the curing period required was 168 to 240 hours due to the large amount of heat generated by the reaction of quicklime with water;
%, the time could be shortened from 72 hours to 96 hours.

The second example was carried out in Michi Ochi, Shizuoka City, Shizuoka Prefecture,
As a result of adding 2% cement and 1% quicklime to the excavated soil, the soil classification is silt gravel (GM) and the natural moisture content is 13.5%.
The modified soil CBR value was 65.1%, the optimum combined water ratio was 9.7%, and the corrected CBR value was txt, o%, which were values that fully satisfied the restoration standard values associated with Shizuoka City road occupation work. Also,
In the so-called flat plate loading test to find out the magnitude of the bearing capacity of the subgrade, K
,,=20kg/crr? I was able to get a better price than that. In addition, in the so-called on-site density test used to judge the degree of compaction of roadbeds and road bodies, the compaction densities after 4, 6, and 8 compaction cycles were 88.9%, 94.9%, and 9, respectively.
It was a good 6.3%.

[Effects of the invention] As explained in detail above, road construction, water supply and sewage construction,
By mixing a small amount of quicklime and cement into the excavated soil that is generated in various places due to building construction, etc., and by mixing an appropriate amount of mountain soil and a small amount of quicklime and cement into the ash-like waste soil generated from garbage incineration, etc. By doing this, the water absorption effect of quicklime and the assimilation effect of cement have a synergistic effect, resulting in better CB than when only a small amount of quicklime is added.
R value, modified CBR value, -axial compressive strength can be obtained,
Moreover, the method and apparatus for producing recycled soil can shorten the curing period required due to the heat generated by mixing quicklime.

Excavation residual soil and ash waste soil that have been used as backfilling material or for reclamation can be used as recycled soil, so there is no need to dump it, and it can be transported to unused land such as remote mountainous areas for dumping. Not only does it eliminate the need for the labor and expense of waste disposal, it also reduces environmental pollution caused by dumping.
Since the fi, corrected CBR value, and -axial compressive strength are better than conventional recycled soil, it is more suitable for road subgrade materials and roadbed materials, and can be used safely. Also,! I. Faster construction due to shorter development period,
Construction can be carried out.

In addition, by using the manufacturing equipment according to the present invention, recycled soil with a uniform particle size can be obtained, so it can be used with excavated soil and ash-like waste soil with uneven particle sizes, resulting in a more stable product. As mentioned above, the present invention can obtain recycled soil of
I must say that this is a truly excellent invention.

[Brief explanation of drawings]

The drawings show an embodiment of the apparatus for producing recycled soil according to the present invention, and FIG. 1 is a front view showing the main parts of the apparatus. p----1---Recycled soil manufacturing equipment la% lb, lc% ld, le, if% Ig-m
- Transport routes 2a, 2b-m - Storage containers 31a, 31b, 31cm - Excavation residual soil or ash waste soil 32
−−−−−−Ilsan Soil 33−−−−−−Issei Lime 34− − − − − − − Semen
To35------Mixed Soil37------
--1-1± 4-----1--Clod crusher 5a, 5b---Vibration sieve 6a, 6h--
- Screw fie 7 a, 7 b - 11 Storage container 8 ----
--- Stabilizer = 9-111111 Vibration feeder

Claims (4)

[Claims] (1) A method for producing recycled soil, characterized by mixing excavated soil with a small amount of quicklime and cement to obtain recycled soil. (2) A method for producing recycled soil, which comprises mixing an appropriate amount of mountain soil with ash-like waste soil, and further mixing a small amount of quicklime and cement to obtain recycled soil. (3) A storage container for excavated soil and a device for crushing the excavated soil are arranged on a conveyance path, and the conveyance path is connected to a vibrating sieve that makes the crushed excavated soil have a desired particle size, and then continues. The conveyance path is connected to a mixer while a quicklime storage container and a cement storage container are disposed above the conveyance path, and a vibrating sieve is further provided to obtain a desired particle size. Manufacturing equipment. (4) A storage container for ash waste soil and a device for crushing the ash waste soil are arranged on the conveyance path, and the conveyance path is passed through a vibrating sieve to obtain the desired particle size of the crushed ash waste soil. The conveyor path is connected to a mixer while a mountain soil storage container, a quicklime storage container, and a cement storage container are arranged above the conveyance path, and then a vibrating sieve is passed through to obtain the desired particle size. An apparatus for producing recycled soil, characterized by comprising: