JPS5980818A - Earth anchoring work - Google Patents

Abstract

PURPOSE:To increase the frictional resistance between anchor body and the surrounding ground by a method in which an anchor body whose central hollow is filled with a lime-based inorganic compound is formed in an excavated pit and the lime-based inorganic compound is expanded. CONSTITUTION:A thin pipe 3 is inserted into the central hollow of a bundle of tension members 2 for anchor, and a wetted lime-based inorganic compound 4 composed of quick lime, a reaction retarder, and a curing agent, for example, is packed into a pipe 3. The tension members 2 bundle is inserted into a pit excavated by a casing, cement mortar 5, etc., is injected into the pit 1, and while pulling the casing, the cement mortar is pressed from the head of the casing by means of a grout pump. After the drawing of the casing is finished, the compound 3 begins to expand, the surrounding ground of the pit 1 is compared by the expansion pressure, and the frictional resistance between the anchor body and the surrounding ground is increased, thereby fixing the anchor body to the ground.

Description

[Detailed description of the invention] Earth anchors used for mountain anchors generally have a diameter of 90 tons.
The anchor is constructed using a casing of nm to 135 mm, and the anchor is anchored in a compact sand layer or gravel layer. If the anchorage layer of this anchor is deep in the ground, the length of the anchor will become longer.
The cost of constructing an earth anchor would be expensive.

Also, because the tip of the anchor can get stuck in the neighboring property,
Earth anchors may not be usable.

Among the earth anchor construction methods, there is a hole-expanding type anchor that is said to be suitable for hard clay ground, but it is rarely used because it requires a large number of construction steps and is expensive.

The present invention was proposed in order to solve these problems, and includes a horizontally split anchor made of a lime-based inorganic compound in the central cavity of a hole for an earth anchor excavated in the ground. This relates to an earth anchor construction method characterized in that the frictional resistance between the anchor integrally and the surrounding ground is increased by the volume expansion of the lime-based inorganic compound.

In the present invention, as described above, a horizontally split anchor made of a lime-based inorganic compound is created in the central cavity in the hole for the earth anchor that has been excavated in the required ground. The lime-based inorganic compound starts to expand in volume, and the unhardened cement paste and mortar injected into the hole are pressed against the ground surrounding the anchor by the volumetric expansion pressure of the lime-based inorganic compound, and the anchor unit and mortar are pressed against the ground around the anchor. The frictional resistance with the outer circumferential ground increases, and by combining this increased frictional resistance and constructing an anchor with a large surface area, the required pull-out strength can be obtained. Therefore, according to the present invention, a loam layer, a clay layer, a silt layer, a loose sand layer to a medium sand layer, which were not considered to be anchoring ground for an anchor in -V, are used as an anchoring ground for an anchor,
It can constitute an earth anchor. As described above, according to the present invention, the earth anchor can be reliably anchored in relatively shallow ground with simple construction, and the construction period can be shortened.
This can save construction costs.

The present invention will now be explained with reference to the illustrated embodiments.

Using a casing with a diameter of about 250 to 550 mm, drill a hole (1) for an earth anchor with a diameter of 1r = J from the base end to the arrow end on the required drilling board (a). After drilling is completed, the inside of the hole is washed with water to remove slime that has accumulated inside the hole.

PG m twisted string, PCfI as tension material for anchor (2)
Using 114 wire, PC steel bar wire rope, etc., insert a thin-walled pipe (3) made of rubber, gold maple, or plastic into the center cavity of the bundle of tensile material (2) for the anchor. Before inserting the tensile strength (2) into the hole (1) Vr, (for example, a lime-based Kasakura lime 1' in which quicklime is added with a reaction retarder and a hardening agent), Fill with water-absorbing sage vl+ (4).

In this case, it is also possible to assemble a bundle of tension material for anchors around a pipe pre-filled with water absorbing lime-based amorphous compounds.

After filling with water-absorbed lime-based + t'HE H + Compound I as described above, insert the east of the anchoring phase (2) into the drilled hole (1), and open the drilled hole VAX (1). ) and pour cement paste (5) or mortar into it.

The casing is then pulled out, but without pulling it out all at once, the cement paste or mortar in the hole is pressurized from the head of the casing using a two-way Taraud pump. This addition 1f-work k, re-singing pull-out ft
In the middle of the work, divide it into several times and do the following.

When the casing is pulled out, the lime-based inorganic compound (3) at the center of the anchor begins to expand, and the unhardened cement paste in the hole (5B mortar is a lime-based unsalted mortar listed in S++). Due to the volumetric expansion pressure of the compound, it is pressed against the ground around the drilled part (1), and the surrounding ground and plate are pressurized in this way, thereby increasing the *m resistance between the anchor and the surrounding ground. Then, the anchor unit is fixed to the same ground. Fig. 1 shows the earth anchor constructed by the method described above, in which (A) shows the retaining wall and (B) shows the anchor unit.

Next, another example of the method of the present invention will be given.

A hole for the earth anchor is drilled in the required ground in the same way as in the above embodiment, and a thin /ξ rib made of plastic, rubber, or metal is inserted into the central cavity of the hole. Insert the tensile material bundle.

The end of the pipe is closed with a lid. After inserting a bundle of anchor tensile material with a pipe pushed into the central cavity into the drilled hole N+, cement paste or mortar is injected into the drilled hole, and the casing is removed in the same manner as in the previous example. Pull it out.

Once the casing has been pulled out, the pipe is filled with a lime-based inorganic compound that has absorbed water.

Then, this lime-based inorganic compound begins to expand in volume, and the unhardened cement in the drilled area is pressed against the ground around the drilled area by the pressure of the lime-based inorganic compound's volumetric expansion. be done. By pressurizing the surrounding corner disks, the friction resistance between the anchor material and the sigma 11 is increased.

Thus, by increasing the frictional resistance between the anchor and the ground and by increasing the surface area of one anchor, an anchor with a pull-out strength of [,, -%] is constructed at the mountain stop. .

Although the above examples have been described above, the present invention is limited only to such examples. Please do not deviate from the spirit of the invention.
+' [711Pq″T: Uromo Tear 4) with changes to the original construction.

4. [I-plane neck 1, light shark] Figure 1 is the mVgi-plane view of the Yamadome anchor constructed by the method of the present invention, and Figure 2 is the book 3i1. Earth Annex 1- Implementation of Construction Method ←; θ) : ii #I vertical cross-sectional view showing the situation, Figure 3 is the arrow 717- of Figure 2
Figure 111.

Claims (1)

[Claims] A horizontally split anchor unit made of a lime-based inorganic compound is created in the center cavity of the earth anchor hole drilled in the ground, and the volume expansion of the lime-based inorganic compound creates a connection between the anchor unit and the surrounding ground. An earth anchor construction method characterized by increasing frictional resistance.