JPS601448B2 - Sediment treatment method during road excavation work - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating excavated soil during road excavation work.

For example, in road excavation work that is carried out when installing, replacing, or repairing conduits such as gas pipes, water pipes, and electrical conduit pipes, it is necessary to backfill the excavated area after the work is completed. When excavating an irregular mixture of subgrade soils with different bearing capacity properties, such as low subgrade soil, or high strength subgrade containing a large amount of sand and stones, if the sand is backfilled as it is, the subgrade engineer A large deviation occurs in the strength distribution of the bearing capacity, and the so-called subgrade engineer bearing capacity test value (CBR)
It is called a value.

), the strength becomes uneven, and the ground partially settles, causing damage to buried pipes, undulating asphalt road surfaces, or sinking of the concrete surface layer. For this reason, when backfilling excavated areas in places such as highways where it is necessary to increase the ground strength, the excavated soil is disposed of as a marine landfill base material, and then reused as a new roadbed village. The lower layer was sand or river sand, and the upper layer was crushed stone as a roadbed material, and concrete pavement was applied on top of that.

However, replacing this sand requires a large amount of money, and
The mining of this earth and sand is fraught with social problems such as the destruction of nature and the depletion of civil engineering and construction resources.Furthermore, as it is becoming increasingly difficult to secure disposal sites for the excavated earth and sand, pollution caused by illegal dumping continues to occur. This led to various problems such as not being able to handle the situation. In view of this situation, the method of the present invention uses excavator's sand itself for backfilling, and provides all backfilling locations with the necessary strength as a subgrade material and the necessary clay distribution as a subgrade material, as described above. The aim is to solve all the problems at once. The method for treating earth and sand in road excavation work according to the present invention is to process earth and sand excavated on a road into a first treated material mainly composed of clay, a second treated material mainly composed of sand, and a third treated material mainly composed of stone.
Separate the processed materials and store them separately.
When backfilling the excavated portion of the road, the first and second treated materials are mixed in an appropriate mixing ratio in order to provide the necessary strength as a roadbed material, and the necessary particle size distribution and strength as a roadbed material. A suitable aggregate is mixed in the third treated material in order to provide the third treated material with a mixture of the first and second treated materials in the lower layer and a mixture of the third treated material and bone village in the upper layer. It is characterized by being located in

In other words, although the composition of excavated soil varies greatly depending on the excavation location, the soil excavated over a wide area is divided into the first treated material, the second treated material, and the third treated material, and then the soil is divided into the first treated material, the second treated material, and the third treated material. While blending the first treated product and the second treated product,
If the third treated material and aggregate are mixed in an appropriate ratio for roadbed material, and if such treatment is continued for a long period of time, most of the treated material can be used for backfilling, reducing pollution caused by disposal of excavated soil. In addition, the amount of subgrade material and roadbed material to be replenished can be minimized, making backfilling more economical than conventional methods as a whole. It is now possible to refill the area.

In particular, prior to mixing the first and second treated materials, the first
If the treated material is mixed with an improving agent to improve its strength, it is possible to further increase the strength of the subgrade portion at the backfilling location, and all of the excavated earth and sand can be used for backfilling, thereby achieving the purpose of the present invention. can be achieved in a more advanced state, and the required amount of the improver can be reduced compared to mixing the improver when mixing the two treated products or mixing the improver after mixing the two treated products. economical soil reclamation.

Next, embodiments of the method of the present invention will be described with reference to illustrative drawings.
As shown in Figure 1, the excavated soil e excavated from various road construction sites over a wide area and transported and accumulated in one place is passed through a crusher A that breaks up the large lumps of clay in the sand. B, and is roughly divided into small lump group a, which is mainly composed of clay, sand, and pebbles, and large lump group b, which is mainly composed of asphalt pieces, concrete pieces, and stones.

Supplying the small lump group a to a separation device C that sorts out lumpy clay g, and supplying the lumped clay g to a crusher D,
It is separated into a contracted processed material x mainly composed of clay and a second processed material y mainly composed of pebbles, sand, and soil.

On the other hand, the large lump group b is fed to a specific gravity sorter E to collect sheet-like foreign matter such as synthetic resin and impurities i such as the largest pieces of wood, and crush the stone fraction h. A third processed material z, which is mainly composed of stones, is taken out from the machine F, and the third processed material z and the first and second processed materials x and y are stored separately.

When backfilling the excavated portion of the road, the first
The treated material x and lime e as an example of a subgrade soil bearing capacity strength improver are supplied to a mixer, the first treated material x is subjected to strength improvement, and the first treated material The first treated material Supplying it to a mixer G, thereby regenerating the roadbed material Q having the required particle size distribution, and backfilling by placing the roadbed material P in the lower layer and the roadbed material Q in the upper layer of the excavated area, The surface layer of asphalt or concrete is finished as appropriate.Next, an example of the properties of the roadbed material Q obtained by the above method will be shown.

When the abrasion loss of the third processed material z was measured using a Los Angeles tester, it was all below 35%, with an average of 31%, which fully satisfies the specified standard value of JISA 5001 "Crushed stone for roads". When the particle size of the third treated material z was measured, the results were as shown in the cumulative passage rate table '1} below, and this result also complied with the JIS'A5001 "Crushed stone for roads" mentioned above.
corresponds to more than 13 skins of Crusher Run C-40 or particle size-adjusted crushed stone M-40 specified in
If an appropriate amount of aggregate d is mixed for the 13th side and below, the third treated material z can be reused as crushed stone for roads.

Cumulative penetration rate table (1) Therefore, river sand with the particle size distribution shown in the following cumulative penetration rate table ■ was mixed into the third treated material z as aggregate d, and the following subbase material property table {
1) and {A roadbed material Q was obtained.

Kaeno passing rate table ■ Roadbed material property table 0) [20% sand mixed in the 3rd treatment product] Roadbed material property table ■ [50* in the 3rd treatment product]
'l Sand Mixture] Both of the above-mentioned base course materials Q have the corrected CBR value (
20% or more), and the particle size of the pre-aged grain is JISA
5001 "Crushed stone for roads" falls within the specified range of Kratssharan C-40, and the latter is also a particle size-adjusted crushed stone M-
It falls within the specified range of 40.

In addition, steel slag having a particle size distribution shown in the cumulative passage rate table below was mixed as 20% aggregate d into the third treated material z to obtain the roadbed village Q shown in the following roadbed material property table.

Accumulated Passage Rate Table (3) Roadbed Material Properties Table G) Furthermore, the third treated material z is the screening material shown in the Slave Passage Rate Table '4- below (pongee grains finally obtained in the stone crushing process). was mixed as 20% aggregate d to obtain a subbase material Q as shown in the subbase material property table below.

Transverse Passage Rate Table ■Road Material Properties Table■ All of the above base course villages Q have sufficient corrected CBR values, and the particle size distribution falls within the prescribed range of the Crutsher Run C-40.

Next, another implementation method will be explained with reference to FIG. 2, but the same parts as in the above-mentioned implementation method are given the same reference numerals, and only the changed parts will be described in detail.

That is, the supply of aggregate d to the mixer G is omitted, and a part of the subgrade material P obtained by the metering mixer 1 is used as aggregate to mixer G.
In this way, there is no need to replenish aggregate d, which is more economical, and the regeneration efficiency of excavator sand e can be further improved. More effective backfilling can be performed. Incidentally, the particle size distribution of the above-mentioned subgrade material P is as shown in the cumulative passage rate table below, and the properties of the subgrade village Q obtained by mixing 30% of subgrade material P with the third treated material z. The corrected CBR value is sufficient as shown in the surface of the roadbed village properties below, and the particle size distribution is also within the specified range of Crutshire Run C-40.

Cumulative passing rate table ■ Roadbed material properties table 6) Depending on the properties of the excavated soil e, simply mixing the first treated material x and the second treated material y without adding the improver c can improve the On the other hand, when flooring material P is obtained and it is desirable to add improver c, if improver c is mixed before or after mixing both treated materials Compared to the former method, the required amount of the improvement agent C can be reduced, and the cost of the additive improvement agent accounts for most of the recycling cost of the excavated soil e, making it extremely economical, especially in the former case. is valid

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the method for treating earth and sand in road excavation work according to the present invention, and FIGS. 1 and 2 are flow sheets of different treatment equipment. c: Improver, d: Honemura, x: First treated product, y: Second treated product, z: Third treated product. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1 Separation of earth and sand excavated from a road into a first treated product x mainly composed of clay, a second treated product y mainly composed of sand, and a third treated product z mainly composed of stones. , those processed materials x, y,
z is stored separately, and when backfilling the excavated portion of the road, the first and second treated materials x and y are mixed at an appropriate fusion ratio in order to provide the necessary strength as a roadbed material. In addition, an appropriate aggregate d is mixed into the third treated material z in order to provide the necessary particle size distribution and strength as a roadbed material, and a mixture of the first and second treated materials x and y is added to the lower layer. and a mixture of the third treated material z and the aggregate d is placed in an upper layer. 2. The method according to claim 1, characterized in that, prior to mixing with the second treated material y, a modifier c is mixed into the first treated material x to improve its strength. Method.