JPH03168489A - Burying method of buried pipe - Google Patents

Abstract

PURPOSE:To fix a buried pipe completely by excavating a burying groove to locate a buried pipe, and mixing a binder made by blending 180-240kg cement per 1m<2> excavated soil with CMC, sodium silicate and calcium chloride at a prescribed proportion, with 2.5-5.0% cement in weight to back-fill it as consolidation soil. CONSTITUTION:A burying groove 2 is excavated, and a buried pipe 3 is located inside the groove 2. A binder made by blending 180-240kg cement per 1m<2> excavated soil 4 with 30-40% CMC in weight, 30-35% sodium silicate in weight and 30-35% calcium chloride in weight is mixed with 2.5-5.0% cement in weight to form consolidation soil 5. About 10cm thick consolidation soil 5 is back-filled in groove bottom 2A, and the surface of the groove bottom 2A at both the sides of the buried pipe 3 is completely covered and consolidated to fix the buried pipe 3. Next the excavated soil 4 is back-filled to bury the burying groove 2. The consolidation soil 5 is completely hardened, and it is thus possible to fix the buried pipe completely.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a method for burying underground pipes, and in particular, after burying underground pipes such as sewer pipes, water supply pipes, gas pipes, and utility pipes in a buried trench. This invention relates to a buried construction method that can securely fix the road so that it does not meander due to the buried soil.

[Conventional technology]

Conventionally, when burying sewage pipes under the road surface, as shown in Figure 5, a burial layer 2 is excavated on the road surface 1, sewage pipes 3 are lined up on the bottom 2^, and then the excavation ± 4 is backfilled and compacted. ．． [Problem to be solved by the invention] In the above construction method, the excavated soil 4 is poured into the buried spring 2 from above and backfilled, and the upper part is compacted. However, since the sewer pipe 3 is so-called tubular, Sewer pipe 3 is in contact with 2^
Since it is a part of the circumferential surface of , as shown in Figure 5,
It is unavoidable that a gap 6 is created between the lower part of the sewer pipe 3 and the bottom surface of the groove. In addition, as shown in FIG. 6, since the joint 3A of the sewer pipe 3 protrudes, the body 3B and bottom surface 2A
A gap 6 is also created between them. Therefore, in the conventional method of putting the excavated soil 4 into the buried well 2 and compacting it, the gaps 6 cannot be completely eliminated no matter how compacted the soil is.

Therefore, as rainwater permeates over time, or as people and cars pass by, earth and sand gradually flow into the gap 6, creating a new cavity near the sewer pipe 3. Then, the sewage pipe 3 moves toward the cavity due to vibrations and loads, which causes the sewage pipe 3 to meander, causing the joint to separate and cause water leakage. The problem was that when water leaked, the water washed away the backfilling soil, creating a channel and causing the road surface to cave in.

In order to prevent this, it would be better to fill the gap 6 with earth and sand and compact it, but this would be more time consuming than digging the trench, increase the construction cost, and result in a deficit in competitive bidding. It is also possible to fix the cement with concrete, but if the cement is mixed on-site and supplied from a concrete mixer truck, the cost is high, and this is mainly used by small businesses.
Moreover, it is difficult to make a profit in the sewerage construction industry, where it is extremely difficult to secure employees.

In view of the above-mentioned circumstances, this invention provides a method for burying underground pipes, which can securely fix buried pipes such as sewer pipes by simply adding a small amount of additives to excavated soil and backfilling the burial trench. It was developed for the purpose of [Means for Solving the Problems] In order to solve the above-mentioned problems and achieve the objects, the present invention involves excavating a buried pipe burial trench, arranging the buried pipe in the excavated trench, and removing 1 m' of excavated soil. Cement per unit 180kg ~ 24
0bf and CMC3 0-40 parts by weight Sodium silicate 30-35 parts by weight Calcium chloride 30-35 parts by weight, a certain binder is mixed in an amount of 2.5-5.0% by weight of the amount of cement and solidified. A sewer pipe burying method in which compaction soil is worked out, the compaction soil is backfilled on both sides of the buried pipe, and the excavated soil is backfilled on top of the compaction soil.

A technical measure was taken.

[Effect]

The excavator is discharged when a buried trench in which a buried pipe is buried is excavated, and the soil quality differs depending on the region, but for example, in the Kanto region, it is Kanto-muchi soil. This excavated soil is mixed with cement and a binder in the above ratio, mixed on site and used as consolidation soil to backfill both sides of the buried pipe in the burial trough, and then backfill the excavated soil on top of it. The soil is compacted by the weight of the soil. In this case, add water to the compacting soil to keep it moist as necessary.

The binder has the function of binding excavated soil and cement and rapidly hardening the cement.

That is, C}Ic (carboxymethyl cellulose)
A part of cellulose 10t+ is -011, and it is water-soluble and has high adhesive strength, and it penetrates evenly between cement and excavated soil, and the cellulose molecules bundle together and form a dense arrangement. and create microcrystals (micelles).

Since there are no gaps in which even water molecules can enter the micelles, a cured product with excellent bonding properties is formed. Sodium silicate hydrolyzes into a syrup-like form that penetrates between excavated soil and cement particles, promoting hydrogen bonding and increasing the bond between cement and soil.

Calcium chloride has the effect of rapidly binding the calcareous and silicic substances, which are a part of cement, and hardens the soil for consolidation in a short period of time (about 10 hours).

Therefore, the day after construction is completed, the compacted soil has hardened in the same way as cement concrete, and the buried pipe is completely fixed to the bottom of the trench by gripping it from both sides, so the buried pipe does not move. In addition, since the soil for consolidation completely covers the bottom of the trench where both sides of the buried pipe are open, even if there is a gap below the buried pipe, the excavated soil backfilled above the consolidation site will not flow into the gap. There is no risk of collapse.

[Example 1] A buried sewage pipe 2 (width: approx. 1 mm) is installed as a buried pipe 3 on a road surface 1.
7 m) is excavated using a general method, and the excavated soil 4 is layered on the road surface 1. After installing a sewage pipe (inner diameter 100 CI!
200 kg of cement and 5 kg of binder (CHC,
Sodium silicate. A mixture of equal amounts of calcium chloride) and water 101 were added and kneaded on the road surface 1 using a shovel to form a compacting soil 5. The compacted soil 5 was backfilled into the bottom 2A to a thickness of about 10 AO. As a result, a slight gap 6 was formed below the buried pipe 3, but the bottom 28 sides of the trench bottom 2 at both measuring parts of the buried pipe 3 were completely covered with a layer of compacting soil 5, and the buried pipe 3 was fixed.

Next, the excavated soil 4 was backfilled onto the top of the compacted soil 5 to close off the burial trough 2. When a sample of the compacting soil 5 was left and inspected after 10 hours, it was found that it had hardened and did not lose its shape.

When rubbed against a cement concrete block after 3 days, it was found to have a hardness close to that of cement concrete, with only some scratches.

As a result, it was confirmed that the hardness of the construction area became close to that of cement concrete over time, and that the buried pipe was completely fixed.

In this case, it has been found that if a large amount of water is added to form a paste when making the compacting soil 5, the soil can be sufficiently injected into the gaps 6, and there is no significant difference in hardening time.

[Example 2] The composition in this example is: 2 cement per 1 m' of excavated soil containing waste soil and gravel.
A soil for compaction was prepared by mixing 40 kg of a binder and 5 h of a binder (40% by weight of Ct4C, the other parts being equal parts). This is a formulation for soils that are difficult to coagulate. In Fig. 2, the above-mentioned compacting soil 5 is backfilled in small amounts to approximately 10 layers in the clear bottom 2A of the buried spring 2, and the buried pipe 3 is placed on top of it. The buried pipe 3 was placed on it while it was being formed. Since the soil is soft, the compacted soil 5 is formed to form a foundation, and the compacted soil 5 hardens over time.

[Example 3] 180 kg of cement per lm' of clay excavated soil 4,
Consolidation soil 5 was prepared by adding 2.5% by weight of a binder (30% by weight of CHC and equal amounts of pond) to the cement.

Since clay is viscous, the amount of adhesive CHC was reduced in the binder, and the amount of cement was also reduced.

This soil for consolidation 5 exhibits good hardening regardless of whether it is used in Example 1 or Example 2.

[Example 4] Figure 3 shows Example 4. In this example, a layer of compacting soil 5 was formed below and above the buried pipe 3, and the blending ratio of celnt and binder was the same as Example 1. - According to 2. This embodiment can prevent the buried pipe from sinking, especially in soft ground. The code 7 in the figure indicates asphalt pavement. [Example 5] FIG. 4 does not show Example 5. In this embodiment, a layer of compacted soil 5 was formed to cover the top of the buried pipe 3.
The composition of cement and binder was the same as in Examples 1 and 2.
Number 8 in the figure is mountain sand. This embodiment is suitable when it is desired to use the road surface 1 quickly. In other words, since the mountain sand 8 is laid in the spring bottom 28, the buried pipe 3 can be fixed more quickly. Next, the upper part of the buried pipe 3 is covered with a layer of ±5 for consolidation, so that even if the mountain sand 8 flows, the buried pipe 3 is fixed. Furthermore, since the layer of compacted soil 5 is close to the road surface 1, sufficient compaction can be achieved even when backfilling with excavated soil 4. [Effects of the Invention] As explained above, the present invention has the following excellent effects.

(1) At sewage pipe burying construction sites, compacted soil can be obtained by simply adding cement and a binder to excavated soil and kneading it, and it hardens in a short time by simply backfilling the compacted soil into the trench bottom. , the sewer pipe can be fixed.

(2) Unlike cement concrete, it does not require curing after pouring, and even if it is immediately backfilled, the compacted soil hardens in a short period of time, so it has excellent workability.

(3) Since the soil for consolidation becomes a hardened material with a high degree of hardness in a short period of time, there is no risk that the backfill soil will settle over time after construction and cause the buried pipe to meander.

(4) Since the amount of compacting soil is only needed to fix the buried pipe, the amount of cement and binder is also small, and the construction can be completed without imposing a large burden on cost. be able to.

[Brief explanation of the drawing]

The drawings relate to a real example of the present invention, and FIG. 1 is a front view showing the buried state of the buried pipe in Embodiment 1. Figure 2 is a front view showing the buried state of the buried pipe in Example 2, and Figure 3 is Example 4.
FIG. 4 is a front view of a buried groove showing the fifth embodiment, FIG. 5 is a front view of a conventional example, and FIG. 6 is an open view thereof. 1... Road surface, 2A... trench bottom, 4... excavated soil, 6... gap. 2... Buried clear, 3... Buried pipe, 5... Consolidated soil, Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A buried trench is excavated, a buried pipe is placed in the buried trench, and
180kg to 240kg of cement per 1 m^3 of excavated soil, and a binder consisting of 30 to 40% by weight of CMC, 30 to 35% by weight of sodium silicate, and 30 to 35% by weight of calcium chloride, in an amount of 2.5 to 5.0% by weight of the amount of cement. 1. A method for burying a buried pipe, which comprises: kneading soil for consolidation by mixing the soil for consolidation, backfilling both sides of the buried pipe with the soil for consolidation, and backfilling excavated soil on top of the soil.