JP2698511B2 - Ground reinforcement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground strengthening method for strengthening a target ground with an anchor buried in the ground and a consolidation agent injected into the surrounding ground.

[0002]

2. Description of the Related Art Conventionally, a method for stabilizing an unstable ground which has fluidity due to the presence of groundwater, including a ground near a slope or a deep underground, is conventionally drilled in the ground. A method of partially strengthening the ground by inserting rebar into the drilling and injecting mortar, etc., or inserting a tubular body with a bag at the tip into the drilling, and press-fitting the mortar into the bag A typical example is a method in which the surrounding ground is compacted by expanding the ground to give a compressive force to the ground. In each case, the target ground is specified in a limited range.

On the other hand, when a structure is constructed underground at a large depth, for example, the volume of the ground around the structure to be stabilized becomes enormous, so that the water pressure applied to the ground is large. In order to have sufficient strength to resist this and maintain stability, careful construction according to the scale is necessary, but all of the above conventional methods are intended for local ground Then it is hard to be an effective method.

[0004] The most rational method for construction as a strengthening measure for an enormous volume of ground is to inject a non-foaming type cement such as cement milk, water glass or the like or a low foaming type cement such as low-expansion cement. However, there remains a problem that the binder only imparts compressive strength to the ground, and the constructed ground is extremely brittle against tensile and shear forces.

According to a method in which a foamable resin such as polyurethane is used as a consolidating agent, and the foamed resin is injected into the ground and solidified to impart strength to the ground itself, the tensile strength and the shear strength are added to the compressive strength. Although it is possible to impart strength, when the reactivity of the polyurethane solution is lowered and the permeability is increased, the strength of the cured product is significantly reduced due to the presence of groundwater and seawater, and conversely, the reactivity is increased. In this case, the effect of groundwater and seawater is small, but the permeability decreases, and it is impossible to strengthen the large-scale ground alone because the binder solidifies locally.

The present invention has been made in view of the problem encountered when stabilizing the ground under a deep underground, and attempts to newly propose a method for rationally stabilizing a large-scale ground. Is what you do.

[0007]

The main cause of the collapse of the fluid ground is that the ground eventually loses shear resistance. However, in the present invention, the ground in the target ground does not exist. Injecting a foaming or low-foaming consolidation agent to harden the earth and sand, imparting compressive strength to the ground itself, and burying an anchor in the ground, through which a foaming consolidation agent is injected into the ground. And the surrounding ground is strengthened by consolidation to further tighten the anchor anchored by the hardening of the foamable binder, and compressive force is introduced into the ground to provide resistance to tensile and shear forces. The present invention compensates for the weaknesses caused when the above two types of binders are used alone, and effectively strengthens the ground having a huge volume.

[0008] A non-foaming or low-foaming binder is injected into the entire target ground and hardened to consolidate the ground and give it water-tightness and compressive strength.

The anchor is formed of a hollow tube having a tensile strength. When the foaming binder is injected through the inside of the tube, a discharge hole for discharging the binder is formed at the tip or the peripheral surface. You. In the case where the hollow tube itself as an anchor is a synthetic resin pipe having no tensile strength, for example, a tensile material having tensile strength is inserted into the hollow tube or tied to the outside to form the hollow tube. Used as an anchor having tensile strength. In this case, the tension member of the anchor is tensioned as necessary. The anchor is buried in the target ground or through the target ground in its thickness direction.

[0010] The foaming binder is mainly pressed into the interior of the anchor, is discharged into the ground from the discharge hole at the tip or peripheral surface thereof, and is filled into the voids around the anchor at the same time as the ground. It penetrates and foams and hardens. At this time, the ground around the anchor is compacted by the foaming pressure of the foamable binder, and at the same time, the anchor is completely fixed to the ground by the binder that has penetrated into the ground. Here, tension is introduced into the hollow tube anchor itself and the tensile material attached to the anchor, whereby the tensile force of the anchor is transmitted to the ground consolidated by hardening of the binder, compressive force is applied, and tensile force and Resistance to shearing force is provided.

The anchor may be buried in the area to be consolidated before or after injecting the binder. However, in order to prevent infiltration of seawater or groundwater and to improve the workability of burying the anchor, non-foaming or It is appropriate after the injection and curing of the low-foaming binder.

The anchors are arranged at appropriate intervals in the depth direction and the lateral direction of the ground, thereby increasing the adhesion and friction with the earth and sand, and functioning to enhance the effect of the integrity of the ground itself. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing one embodiment.

[0014] The present invention and the target or the ground of interest (hereinafter the target soil) non-foamed system G or solid injection of binding agent 4 ₁ low foaming system, as shown in FIG. 1, effervescent caking agent 4 Injection of ₂ strengthens the consolidation, and thereby imparts tensile strength by anchoring the anchor 1, and further strengthens by the tension of the anchor 1 to stabilize the target ground G against shear force due to water pressure, seismic force, etc. is there.

FIG. 1 shows an embodiment in which the target ground G is the ground around a structure which is assumed to be constructed at a deep underground. Katayuizai 4 ₁ are injected by method, the compressive strength is given a water cut in the ground itself. Katayuizai 4 ₁ Non-foaming system capable ground injection, or low foaming system is not limited to as long as consolidation material, for example cement milk, water glass, low expansion cement or the like is used.

The anchors 1 are arranged radially at an appropriate distance from the height of the target ground G and in the lateral direction as shown in FIGS. 1 and 2 which are plan views thereof, and are arranged in the thickness direction of the target ground G. Is inserted and buried in a hole 7 formed between both ends of the hole. FIG. 3 shows a case where the anchor 1 is buried through the target ground G.

The anchor 1 is basically a hollow tube having a closed end.
1 consists of _zero, but is inserted into pre-drilled drilling in 7,
As shown in FIG. 4, when the blade 2 that closes the end face is connected to the tip, drilling of the drilled hole 7 is performed by the anchor 1 itself, and the hole is buried as it is.

The consolidation agent 4 ₂ effervescent Through the interior of the anchor 1, is injected from the discharge hole 1 _1, which is opened in the front end portion or the peripheral surface, as shown in FIG. 5 in the target ground G. When connecting the blade unit 2 to the tip as in the embodiment shown in FIG. 4 is discharged from the discharge hole 2 _1.

The injection of Katayuizai 4 ₂ the gap between the base portion around the drilling 7 the inner wall of the anchor 1, as shown in FIG. 4, in the blocking element 5 such as a cloth impregnated with foamable resin stock solution This is performed by press-fitting the inside of the anchor 1 with an infusion pump in the closed state. Discharge hole 1 _1, 2 ₁ caking agent 4 ₂ discharged from the filled in 1 around the drilling within 7 anchor, other within the target ground G which is consolidated by Katayuizai 4 _1, as shown in FIG. 3 When the anchor 1 is buried through the target ground G
, And foam and harden as shown in FIGS. Katayuizai 4 surrounding ground anchor 1 by ₂ foaming and curing is enhanced compaction, the anchor 1 is fixed to the ground by the consolidation was 4 ₃ of ground formed by simultaneously penetrating the anticaking agent 4 _2, below tensile force of the anchor 1 is transmitted to the consolidated ground consolidation agent 4 ₁ by the introduction of the tension has been injected into the anchor 1, compressive forces are introduced.

[0020] Katayuizai 4 ₂ effervescent solid Yuizai used has a stock solution properties which can be ground injection may be a caking agent showing a strength necessary for ground consolidation, such as urethane resins, epoxy resins , Phenolic resin and the like are used. Katayuizai 4 ₂ can be used in relatively highly reactive caking agent because it does not require extensive penetration, in which case the need to hardly influenced seawater or underground water.

The anchor 1 is being tensioned according to the situation after curing of Katayuizai 4 _2, 4, when made from a single piece of hollow tube 1 ₀ which is tensioned directly, the embodiment shown in FIG. 5 tension to the anchor 1 by when the tension member 3 to the inside or outside of the hollow tube 1 ₀ are integrated to tension the tension members 3 are introduced as.

[0022] When inserting the tension member 3 to the inside of the hollow tube 1 ₀ As shown in FIG. 5, or although not shown, the hollow tube 1 ₀
When the tension member 3 is tied to the outside of the
Tensile member 3 tension is introduced from the base side of the anchor 1 after curing caking agent 4 _2, tension member 3 is fixed as the base of the anchor 1, that is, the inner peripheral surface 6 of the target ground G. Tip 3 ₁ tensile member 3 is fixed to the distal end of the hollow tube 1 ₀ as shown in FIG. 5, the fixing of the base is done as usual by a nut fixing and wedge fixing the like.

[0023] The above, Katayuizai 4 ₁ injection in addition to the injection of buried and Katayuizai 4 ₂ anchor 1, and the target ground G tensions were subjected anchor 1 on the compressive strength is given It will be compressed in its thickness direction, and will have a high resistance to tensile and shear forces by being placed under this original compressive force.

In the case where only the anchor is installed on the ground as in the conventional anchor method, it is difficult to integrate a plurality of anchors because each anchor behaves independently. Solidified target ground G
Since addition to being inserted in a plurality of sets, consolidated product 4 ₃ Katayuizai 4 ₂ is Deki to penetrate the ground is located inside or outside of the consolidated areas in the anchor 1 the Katayuizai 4 ₂ penetration, not only integrated into the consolidation region by compaction of curing and surrounding ground, the front portion of the consolidated product 4 ₃ against the force to pull out the anchor 1 caused by the earth pressure Located, consolidated material
4 resists the presence of the consolidated body formed by ₁ and furthermore, since this consolidated body covers the entire target ground G, the target ground G has a compressive strength by the consolidated body and a tensile force by the anchor 1. Is provided in a composite form, and becomes an integrated structure extremely strong against external force.

That is, in the present invention, the target ground G is
A consolidation region formed by implantation of 4 _1, so that won Never effects obtained by singly in combination with the anchor 1 was fixed by Katayuizai 4 _2.

[0026]

The present invention is as described above. A non-foaming type or low-foaming type consolidating agent is injected into a target ground to give it a compressive strength, and at the same time, an anchor is inserted into the ground. The foaming binder is injected into the ground through this, and the surrounding ground is strengthened by consolidation, so that the anchor fixed by the hardening of the foaming binder is tensioned, and the compressive force is applied to the ground. In order to give the target ground resistance to tensile and shear forces by introducing
The ground having a huge volume can be effectively strengthened.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is a longitudinal sectional view showing an embodiment in which an anchor is buried through a target ground.

FIG. 4 is a cross-sectional view showing an example of embedding an anchor having a blade portion connected to a distal end.

FIG. 5 is a cross-sectional view showing the anchor when a tensile force is inserted inside the hollow tube.

[Explanation of symbols]

G ...... target the ground, 1 ...... anchor, 1 ₀ ...... hollow tube, 1 ₁ ...
... Discharge hole, 2 ... Blade part, 2 ₁ ... Discharge hole, 3 ... Tension material,
3 ₁ ... tip, 4 ₁ ... non-foaming or low foaming type binder, 4 ₂ ... foaming binder, 4 ₃ ... consolidated product, 5 ... plugging material, 6 ... ... inner peripheral surface of the target ground, 7 ... drilling.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Satake 7-2-35 Higashiogu, Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd. (72) Makio Takahashi 7-35-35 Higashiogu, Arakawa-ku, Tokyo No. Asahi Denka Kogyo Co., Ltd. (56) References JP-A-51-101319 (JP, A) JP-A-52-144109 (JP, A) JP-A-55-31863 (JP, A) JP-A 52-144 80606 (JP, A) JP-A-58-24017 (JP, A) JP-A-6-173578 (JP, A)

Claims (5)

(57) [Claims] 1. A step of injecting a non-foaming or low-foaming consolidating agent into the ground of a target predetermined area, and anchoring a hollow pipe into or through the predetermined area. And burying a plurality of them, and injecting a foaming binder through this anchor, foaming and hardening this binder, and strengthening the ground in the surrounding area in combination with the process of strengthening the ground in the specified area Ground strengthening method characterized by performing. 2. A discharge hole is drilled at a tip or a peripheral surface of the anchor, and a foamable solidifying agent is injected into the ground in a predetermined area from the discharge hole. 1
The ground strengthening method described. 3. The method according to claim 1, wherein the anchor is tensioned to introduce a compressive force into the ground. 4. The method according to claim 1, wherein a tension member is inserted into the inside of the anchor, or the anchor is integrated with the outside to be integrated. 5. The method according to claim 4, wherein the compressive force is introduced into the ground by tensioning the tensile member.