JP3055114B2 - Ground improvement composite injection method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Technical Field of the Invention] The disclosed technology relates to the construction of a ground, etc., in which the ground in the ground is composed of a sand layer, a gravel layer, a cohesive soil layer, etc. The present invention belongs to the field of construction technology for ensuring that the improved material can be reliably injected into a predetermined ground area without the escape of the improved material in the above-mentioned manner.

[0002]

2. Description of the Related Art As is well known, the land is narrow, there are many mountains and forests, and in addition, it approaches a long coastline that has entered complicatedly.
Therefore, in Japan, which has special terrain conditions in which the plains that can be used in industrial areas, urban areas, residential areas, etc. are of course extremely limited, as well as for agricultural and livestock use, the effective use of national land has been extremely long. Therefore, so-called soft ground improvement works such as reclamation, dredging, reclamation, and hardening of shallow shores, rivers, and lake basins are extremely important, and various ground improvement technologies have been researched and developed. Some of the techniques have been put to practical use in various aspects.

Among these, various types of so-called chemical liquid injection methods have been developed in which a rod is inserted into the soft ground through a hole and a chemical liquid as an improving material is injected into a predetermined depth portion. Utilizing this, various aspects are adopted, and these chemical solution injection methods are shown in Table 1 below.
There are various things as shown in.

[Table 1]

[0004] The various chemical solution injection methods shown in Table 1 have conjugate advantages and various disadvantages.
An outer tube that can be used for improving materials such as quick-setting materials and loose-setting materials
The method using double pipes consisting of inner pipes is considered to be an excellent method because of the merit such as selection of gel time, and furthermore, each layer in the ground has a complex alternating layer structure such as sand layer, gravel layer, cohesive soil layer, etc. In the case of a certain aspect, the double pipe rod compound injection method (double phase type) method has recently been used to improve It has been widely used because of its advantage in dealing with groundwater contamination in the ground, etc. Among them, the double pipe rod compound injection method (double phase type) is as shown in the fifth subclassification of Table 1 above. There are five types, such as the Unipack method, the bi-mode method, the multi-riser method, the space grood method, the MT-PGD method, etc. Either suspension-type chemicals or solution-type chemicals are equipped with a special monitor at the tip of the drilling rod. Can be used for construction In addition, since the gel time has a wide range of use from a few seconds to a few tens of minutes, and has flexibility in use, such as being appropriately selectable, the method is a versatile chemical solution injection method, and is widely used. ing.

[0005] A typical bi-mode method among these methods will be briefly described with reference to FIGS. 11, 12 and 13. Switching slide valves 2 and 3 are provided in an outer tube 1 of a drilling rod. The instantaneous binding material and the loose binding material are appropriately and selectively mixed into the water glass for the outer tube 1 and the inner tube 4, and the outer passage between the outer tube 1 and the inner tube 4 and the inner side of the inner tube 4. In the lowering process, the ground is excavated with the help of drilling water to a predetermined depth to form a drilling hole, and in the raising process, the instantaneous bonding material provided at a predetermined position of the outer pipe 1 is provided. The instantaneous binder is discharged from the discharge port 5 into the ground and injected, the sealing layer 7 of the instantaneous binder is formed as shown in FIG. 12, and the slide valve 2 or 3 is switched to be shown in FIG. Similarly, a predetermined loose binder 8 is discharged from the lower loose binder discharge port 6 in the vicinity of the instantaneous binder seal layer 7. Injection is performed to form an improved area 9, and a predetermined gel time of the instantaneous binding material and the loose binding material 8 is used to form a desired solidified region only in the formation region, thereby preventing groundwater contamination and the like. Is being done.

[0006] Switching of the instantaneous binder discharge port 5 and the loose binder discharge port 6 by the slide valves 2 and 3 of the double pipe type rod used in the bi-mode construction method is performed by using the slide valve having an O-ring. This has been achieved in a predetermined manner by interposing a return spring in the sections 2 and 3 and adjusting the balance between the spring force of the return spring and the pressure of the instantaneous binder and the loose binder.

Various specific mechanisms have been developed, each of which has advantages and disadvantages. When a chemical solution is injected into the ground from the upper and lower discharge ports 5, 6 of the monitor, the construction management is required. It is said that it is difficult to perform sufficient control.

[0008]

SUMMARY OF THE INVENTION An object of the invention of this application is to solve the problems of the double-pipe rod compound injection type chemical injection method based on the prior art described above. The cycle of step change is shortened, the structure of the double tube rod is simplified, the operation is speeded up, and the construction And shortening of
To provide an excellent ground improvement combined injection method that can reduce the cost and inject the chemical solution as designed to benefit the civil engineering application field in the construction industry, and a device directly used in the method. Things.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the construction of the invention of the present application, which has the above-mentioned claims and aims at solving the above-mentioned problems, uses a chemical solution injection method such as soft ground improvement. According to the design, it is possible to prevent the groundwater contamination and the like due to the runaway of the chemical solution and the like by performing the optimal discharge injection of the chemical solution to each layer according to the properties of the alternate layers of the plurality of layers in the ground. In order to make it possible to inject the chemical solution, a monitor is installed so that the switching type discharge and injection of the instantaneous binding material and the loose binding material can be performed from the tip of the double tube type rod, and a predetermined static pressure and rotation The rod penetrates into the ground, and at this time, without inserting a check valve into the inner pipe of the rod, drilling water is pumped into the inner pipe and spouted through a bit to assist drilling, Thus, when drilling at a predetermined depth is completed, A predetermined check valve such as a spindle type is put into the pipe, and the inner bottom of the inner pipe is closed, and the outer pipe of the rod and the outer ring-shaped cross section between the inner pipes are pumped by a plant on the ground via a pump. The water glass, the instantaneous binder, and the water glass are supplied under pressure to the passage and the inner passage in the inner tube, respectively, and the upper slide valve interposed between the outer tube and the inner tube slides to slide the outer tube. The outlet of the instantaneous binder formed on the upper side is opened, the outlet of the instantaneous binder formed on the inner pipe is also opened, and the sub-discharge port on the lower part of the inner pipe is closed. It is discharged and injected into the ground of the formation only from the discharge port of the instantaneous binding material on the upper side of
The loose binder and the water glass are mixed and pumped to the inner passage in the inner pipe of the rod, and the upper slide valve lowers the supply pressure of the instantaneous binder by switching the three-way switching valve in the above-ground plant. The slide valve quickly returns due to the decrease in the supply pressure of the instantaneous binder and the urging force of the return spring, and the instantaneous binder returns via the three-way valve due to the decrease in the pressure of the instantaneous binder and the rise of the slide valve by the return spring. Returning to the instantaneous binder tank, the pressure in the outer passage between the outer pipe and the inner pipe is reduced, and in the above-ground plant, the loose binder and water glass are mixed, where the loose binder and water glass are mixed. The pump is pumped to the inner passage of the inner tube of the rod through another pump, the upper slide valve is a return spring, and the outer passage of the cross section between the outer tube and the inner tube is formed by a loose binder on the lower side of the inner tube. The loosening sent to As a result, the discharge port of the instantaneous binder is raised and closed, and the lower slide valve is pushed down against its return spring to open the discharge port of the loose binder outside the outer tube. The loose binder and water glass fed into the inner pipe are pressed out from the lower loose binder discharge port on the lower side of the inner pipe and squirt from the lower loose binder discharge port on the lower side of the inner pipe. Solidifies at the set gel time in the vicinity of the quick-linking material previously injected into the formation concerned, an optimal solidification state appears, no contamination of groundwater, etc., proceed to the next step-up and move the rod as designed Double pipe compound injection is performed, and the return of the upper slide valve is pumped to the low pressure and return spring by returning the instantaneous binder to the instantaneous binder tank in each step, and the feed pressure by the loose binder , The step cycle of each stage is shortened, and The one in which a short discharge injection of the drug solution as designed in construction period at low cost into the ground is taken of technical means to be performed.

[0010]

Next, an embodiment of the invention of this application will be described below with reference to FIGS.

The same parts as those in FIGS. 10 to 12 are described using the same reference numerals.

The illustrated embodiment is an embodiment applied to soft ground improvement work. As shown in FIG. 7, a rod 12 penetrating the ground is connected to a ground plant 1 via a swivel joint 13.
1 through the passages 14 and 15.

In the embodiment shown in FIGS. 1 to 9, the rod 12 has a simple but specially structured monitor 29 'which forms the center of the main part of the invention of this application, and a screw joint 27, 27. The structure has the structure shown in FIG. 1 in detail, and the bi-mode method shown in Table 1 can be adopted. Both the suspension-type solution and the solution-type solution can be used in the ground. The discharge can be selectively injected into the formation and the outer tube 1 can be detected by the monitor 29 '.
′ Is connected and extended to a rod of a predetermined length via a screw joint 27, and an upper portion of the inner pipe of a predetermined diameter is provided on the upper portion thereof through a honeycomb bracket 28 as shown in FIGS. 4 'is mounted on the shaft and the bottom cover 3
0 is provided blindly.

In addition, seats 33, 33 ', 34, 34' having a choke function are provided in a portion of the passage 39 having a ring-shaped cross section between the outer tube 1 'and the inner tube 4', and a lower portion is provided. The other seats 30 ′, 30 ″ are provided in two steps with a predetermined distance therebetween, and the check ball 31 is vertically interposed in a floating state.

[0015] At the tip, the bit 32,
32 are fixedly provided.

In addition, between the seats 33, 33 'in the upper part of the figure, the upper part of a short cylindrical piston type having a donut-shaped cross section which slides with respect to the outer pipe 1' and the inner pipe 4 '. The slide valve 3 ′ has an O-ring 35 ″ as an exterior, and a return spring 35 having a predetermined spring constant is interposed between the slide valve 3 ′ and the seat 33 ′ so as to be movable up and down. The discharge port 5 'of the instantaneous binder of the outer tube 1' and the discharge port 5 '' of the instantaneous binder and the loose binder of the inner tube 4 'can be opened and closed freely.

A discharge port 6 '' for loose binder and a discharge port 6 '' for drilling water are provided at an intermediate portion of the inner pipe 4 'and at a lower end thereof.
Are formed at predetermined intervals in the circumferential direction.

Reference numeral 5 "" denotes a sub-discharge port formed below the discharge port 5 "for the instantaneous and loose binder provided in the inner tube 4.

As shown in FIG. 6, a spindle type check valve 36 is freely inserted into the inside of the inner tube 4 'from an inlet of an upper opening (not shown) on the ground, as shown in FIG. The check valve 36 is set so that the discharge port 6 ″ of the loose binder B ₂ of the inner pipe ₄ ′ and the discharge port 6 ″ ″ of the drilling water can be closed. As shown in FIG. 6, the middle portion has a relatively large diameter portion 36 'and the upper portion has a small diameter portion 36'.
7 and an O-ring 35 ″ is circulated in the tapered portion 38 at the lower portion so that the small-diameter portion 3
6 ″ is integrally extended and fixed.

As shown in FIG. 1, an intermediate portion of the outer tube 1 'is located between the seats 34 and 34' and has a cylindrical lower lower slide valve 2 having a donut-shaped cross section similarly to the upper slide valve 3 '. ′ Is slidably provided on the outer tube 1 ′ and the inner tube 4 ′ via an O-ring 35 ″.
Are freely open and close the loose binding material B ₂ of the discharge port 6 'of the outer tube 1' by the return spring 35 'having a predetermined spring constant is interposed between the'.

[0021] _{Incidentally, W G, B 1, B} 2 are each water glass At a in the figure Madokayuizai, W in show the gradual formation material shows a drilling water, P _1, P ₂ is 2 shows pumps 16 and 19.

In FIG. 7, the ground plant 11 has a passage 14 with respect to the swivel joint 13 of the rod 12.
Pump P ₁ 16 via a three-way changeover valve 20 but is connected
It is connected to, the three-way switching valve 20 and the pump P ₁ 16
The tank 22 of the instantaneous binding material B ₁ is connected in a bypass manner through a passage 21 and is also directly connected to the pump P ₁ 16, and the three-way switching valve 20 is operated manually or , semi-automatically the Madokayui material B ₁ through swivel joint 13 through the pump 16, the outer tube of the rod 12 1 ', and the outer passage 39 between the inner tube 4' and the inner passage of the inner tube 4 '40 It was pumped into, also been to be able to return to the tank 22 of the instantaneous formation material B _1.

[0023] Then, the pump P ₁ 16 is also connected to the tank 24 of the water glass W _G water glass W _G and Madokayui material B ₁
Can be fed to the swivel joint 13 together.

On the other hand, a known line mixer 17 is interposed in the other passage 15 from the swivel joint 13, and a passage 18 is branched from the line mixer 17, and is connected via a pump P ₂ 19. 25 by being a Yuruyuizai B is connected to the _second tank 26 by the moderate binding material B ₂ to be able to feed the inner passage 40 of the inner tube 4 'of the rod 12 via the swivel joint 13 I have.

[0025] Thus, At a terrestrial plant 11, when switching the three-way changeover valve 20 of the passage 14 to the return side Madokayui member B _1, instantaneous sintered material B ₁ represents passageway 1 from the outside passage 39
4,21 returned to Madokayui material tank 22 through, thus, the outer tube 1 'Madokayuizai B ₁ represents the rod 12, and is not pumped into outer passage 39 between the inner tube 4', for the ,
The upper slide valve 3 ′ is not subjected to the pressing force, and is controlled by the urging force of the return spring 35 and the loose binder B ₂ described later.
Due to the pressure-receiving action and the negative-pressure suction action by the feeding, the sheet is forcibly and quickly brought back to the position and orientation shown in FIG.

In the above-mentioned ground improvement composite injection device, when performing soft ground improvement, a suitable driving device is used to apply static pressure to the rod 12 in the axial direction, and also to apply a rotational force to drill a hole to a predetermined depth. Go on.

In this case, as shown in FIG. 1, the spindle type check valve 36 is not inserted into the inner passage 40 of the inner pipe 4 'of the rod 12, and the drilling water W is supplied to the inner pipe 4' of the inner pipe 4 '. When it is fed into the passage 40, it passes from the sub-discharge port 5 '''' through the outer passage 39, re-enters the inner pipe 4 '' from the discharge port 6 '', and ejects the check ball 31 from the discharge port 6 '''' at the tip thereof. It pushes open and squirts into the ground from the bit 32 to assist the drilling, smoothly forms a predetermined drilling, and drills to a predetermined depth.

In this case, it is needless to say that the drilling water W is supplied with a pressure enough to overcome the pressure of the check ball 31 due to the slime up from the tip of the rod 12.

In this manner, the drilling is performed to a predetermined depth, and the rod 12 is stepped up from the depth and pulled up, and the chemical solution is injected in a predetermined manner.

When a spindle type check valve 36 is inserted into the inner passage 40 of the inner tube 4 'from an inlet (not shown) on the ground before the injection of the chemical, the check valve 36 is moved to the bottom cover 30 of the inner tube 4'. , And is set in a predetermined state, thereby closing the drilling water discharge port 6 ″ and the drilling water discharge port 6 ″ ″.

It should be noted that, once drilling is performed, after a predetermined drilling is performed to a set depth, the spindle type check valve 36 is connected to the inner pipe 4 in order to inject a chemical solution into each layer in a step-up manner. It is not necessary to set and reset the spindle type check valve 36 for each step change stage, since it is only necessary to set the spindle type check valve 36 at the inner bottom portion of FIG.

The inner pipe 4 'of the check valve 36
During the charging process into the inner passage 40, the large-diameter portion 36 'of the check valve 36 slides down on the inner surface of the inner pipe 4', possibly resulting in the residual drilling previously supplied. A kind of braking action acts via the resistance of the water, so that a shocking collision with the bottom cover 30 is prevented, and both damages are prevented.

Then, the sand layer, gravel layer,
In order to eject the injection of the chemical solution for the formation of alternating layers of cohesive soil layer, etc., first, appropriate pump P ₁ 1 The three-way switching valve 20
6 and switching set to supply communication to the swivel joint 13 side, the inner passage 40 of the water glass W _G and Madokayui material B ₁ each independently rod 12, and, between the inner tube 4 'and the outer tube 1' And the outer passage 39 having a ring-shaped cross section therebetween.

This state is as shown in FIG.
Madokayui material B ₁ pumped supplied to outer passage 39 between the outer tube 1 'and the inner tube 4' is applying a pressing force to the top of the slide valve 3 ', 8 from the state shown in FIG. 1 Return to the state shown in FIG.
′ To open the instantaneous binder discharge port 5 ′ of the outer tube 1 ′ and also the discharge port 5 ″ of the inner tube 4 ′. Therefore, the outer passage between the outer tube 1 ′ and the inner tube 4 ′ 39 is pumped supply inside passage 40 of the pumping supplied Madokayui material B ₁ inner tube 4 'and the water glass W _G discharge port 5'discharge port 5''
And injected into the ground through the discharge port 5 'to solidify and form the seal layer 7 having a predetermined short gel time similarly to the bi-mode method shown in FIG.

[0035] During this time, water glass W _G which is fed to the inner passage 40 of the inner tube 4 'is prevented from discharging from the discharge port 6''by the check valve 36, therefore, the internal pressure is increased, the high round It is jetted only from the discharge port 5 '' via the discharge port 5 '' via the internal pressure.

Therefore, the lower slide valve 2 '
Receives no pressing action and does not slide down.

[0037] Therefore, after dispensing a predetermined injection amount of Madokayuizai B ₁ in each step, when switched to the passage 21 side to return the ground of the three-way switching valve 20 to the tank 22 of Madokayui material B _1, the upper portion of the The pressing force of the instantaneous binding material B _{1 on} the slide valve 3 ′ is reduced, and the restoring force of the return spring 35 and the forced discharge are combined, so that the slide valve 3 ′ is applied with an upward biasing force, and 4 'and Madokayui material B ₁ represents the three-way switching valve 20 by the target pressure condition of outer passage 39 between the outer tube 1', the instantaneous formation material B ₁ of the tank 2 through the passage 21
2 and is not re-pumped through the passage 14 to the outer passage 39 between the outer tube 1 'and the inner tube 4'.

[0038] Therefore, the passage 15 with the water glass W _G the moderate binding material B ₂ from the tank 26 of Yuruyuizai B ₂ is caused by the operation and the pump P ₁ 16 of the pump P ₁ 19 by actuating the pump P ₂ 19 As shown in FIG. 9, the spindle-type check valve 36 is supplied to the inner passage 40 in the inner pipe 4 '.
Since it has been set in advance, the discharge port 6 ′
, And the hole 6 ′ ″ for cutting water is closed, the internal pressure is increased, and it is ejected from the sub-discharge port 5 ″ ″ into the outer ring-shaped passage 39, whereby the upper part Of the upper slide valve 3 'is smoothly and rapidly raised in cooperation with the elastic pressure of the return spring 35 and the suction force of the negative pressure, and the stroke is raised to the seat 33. , Lower slide valve 2 '
Spring back by the Yuruyuizai B ₂ to be press-fitted from above in the outer ring-shaped passage 39 and the water glass W _G 35 '
To open the loose binder discharge port 6 ', and from the sub discharge port 5''' of the inner pipe 4 'to the outer passage 39.
From the discharge port 6 'a and Yuruyuizai B ₂ water glass W _G is injected earlier in the vicinity of Madokayui material sealing layer 7 that condenses in in the ground in conventional shown in FIG. 13 through Injection is performed in the same manner as in the bi-mode method to solidify the improved region 9 at a predetermined gel time.

[0039] In Thus, for previously injected the Madokayui member B ₁ and the water glass W _G is the already solidified as a sealing layer 7 in a short gel time, Yuruyuizai B ₂ and water glass to be post-injected W _G
Is not infiltrated into the formation and does not contaminate the groundwater as the improved area 9, and solidifies reliably at the gel time as designed.

In this way, as shown in FIG. 13, when the discharge of the predetermined chemical solution into the ground is completed, the next step up is performed to remove the sand layer, the gravel layer, the cohesive soil layer, and the like. sequentially performing double tube rod composite injection Madokayui material B ₁ and Yuruyuizai B ₂ with respect interbedded.

When the injection of the loose binder B2 is completed, the lower slide valve ₂ 'returns to the initial position and posture by the resilient pressure of the return spring 35' before the next injection. also in the cycle, in order to perform injection into above likewise initially Madokayui material B ₁ in the ground, slide valve 3 'of the upper and lower portions, repositioning to the original orientation of the 2' the upper portion of the slide valve 3 ' Need to be performed quickly, but the lower slide valve 2 'need not be performed quickly.

Thus, each sand layer, gravel layer,
When it is not preferable to uniformly perform discharge and injection of a chemical solution when there are a plurality of layers of alternate layers having different properties such as a viscous soil layer, compound injection is performed in a state in which discharge and injection of a chemical solution for each of the formations are adapted to the formation. Can be performed.

The embodiment of the invention of this application is not limited to the above-described embodiments. For example, another three-way switching valve may be provided in the ground plant 11 to reduce the instantaneous binding material B ₁ . connect the negative pressure in the appropriate negative pressure passage in addition to the supply stop by returning to Madokayui material tank 22, the spring back giving negative pressure suction effect in the slide valve, and the press-fitting pressure of Yuruyuizai B ₁ Various modes can be adopted, such as allowing the slide valve to return to the position immediately after each step change of the slide valve.

[0044]

As described above, according to the invention of this application, basically, in a chemical liquid injection method, when a plurality of strata having different properties are alternately formed in the ground,
First, by discharging and injecting the instantaneous binder, and then by performing composite discharge and injection of the loose binder, there is an excellent effect that the chemical solution can be reliably injected with the gel time as designed for each layer in each region. .

Thus, in the invention of this application, a special monitor is provided at the tip of the double-tube type rod so that both the suspension type chemical solution and the solution type chemical solution can be used. In addition, the check valve in the monitor can be a spindle type or ball type, and also a single type.
The versatility can be improved, and an excellent effect that the optimal chemical liquid injection can be performed while alternately switching is achieved.

Further, since the chemical equivalent of the instantaneous binder and the loose binder can be changed and the gel time can be changed for each layer in each region, discharge and injection can be performed. Is played.

Therefore, in the monitor, instead of simply returning the slide valve via the return spring,
In addition to the spring force of the return spring, the supply of the instantaneous binding material is stopped to reduce the supply pressure, so that the spring force of the return spring works effectively, and further, the loose binding material is moved by a slide valve. A spring force is applied to the pressing force generated by press-fitting the lower part of the valve to quickly return the slide valve, and the instantaneously bonded material can be pressurized to smoothly return to the instantaneously bonded material tank. Since the instantaneous binder can be forcibly returned to the instantaneous binder tank, the time required for the step change cycle can be shortened, the construction efficiency can be significantly improved, and the advantages of improved construction accuracy and cost reduction can be achieved. is there.

In this case, by providing a three-way switching valve for the instantaneously bonded material in the above-ground plant so that it can be returned to the instantaneously bonded material tank, the slide valve can be returned very quickly. is there.

According to the invention of this application, there is an excellent effect that the chemical solution can be injected in one step of drilling and subsequent step change, thereby simplifying the construction.

Further, in the device invention, each slide valve is interposed in the passage of the ring-shaped gap between the outer tube and the inner tube to open and close the communication between the discharge port of the inner and outer tubes and the other discharge ports. In addition to the effect of achieving the effect, it is possible to prevent the discharge port of the drilling water from being blocked by the penetration of the slime from the tip of the monitor into the monitor at the time of discharging and injecting the chemical solution.

Since the spindle type check valve can be freely inserted into the inner passage in the inner pipe, there is an effect that the discharge port of the drilling water can be smoothly closed at the time of injection of the chemical solution.

[Brief description of the drawings]

FIG. 1 is an overall schematic sectional view of an embodiment of the apparatus of the present invention, and a sectional view of drilling water supply.

FIG. 2 is a sectional view taken along the line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III of FIG. 1;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is a VV plane view of FIG. 1;

FIG. 6 is a partial sectional side view of the same system.

FIG. 7 is a schematic view of a plant of the same ground improvement composite injection device.

FIG. 8 is a cross-sectional view of injection and discharge of the instantaneously binding material.

FIG. 9 is a cross-sectional view of loose binder injection.

FIG. 10 is a partial sectional view of a monitor according to another embodiment.

FIG. 11 is a schematic sectional view of a bi-mode construction method based on the prior art.

FIG. 12 is a cross-sectional view of discharge and injection of the instantaneous binding material for each formation.

[Explanation of symbols]

39 (cross section ring) outer passageway 40 inner passageway 1'outer tube 4 'in the pipe 5', 5 '' discharge ports B ₁ Madokayuizai B ₂ Yuruyuizai W drilling water 22 Madokayui material tank 16 Pump (P ₁ ) 19 Pump (P2) 20 Three-way switching valve 3 ', _2' Slide valve 35 Return spring 5 "" Sub-discharge port 36 Check valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E02D 3/12

Claims (3)

(57) [Claims] (1) drilling a ground to a predetermined depth through drilling water, then inserting a check valve into the inner pipe from the ground, and then pressing the instantaneously bonded material from a discharge port provided in the outer pipe at a predetermined depth. ejection exit injecting the Madokayui material in該地board through the pump, and then close the loose binding material through the gradual formation material feed pump and change the step Madokayui material in the ground which is discharged injected earlier In the ground improvement composite injection method for discharging and injecting, the instantaneously-bound material for supplying the instantaneously bound material for feeding the outer passage having a ring-shaped cross section between the outer pipe and the inner pipe to a reduced state of the supply pressure is set. Forcibly return to the ground through the three-way switching valve to change the step, and then slowly pump the loose binder through the pump for loose binder pressure delivery to the inner passage in the inner pipe and discharge it to the ground first from the discharge port ground improvement composite Note, characterized in that so as to inject out ejection into the ground in the solidified Madokayui material near Te Method. In soil improvement composite injection device slide valve back is provided with a spring between the inner tube having a wherein ejection outlets corresponding to ejection outlet side set has an outer tube and the discharge opening , Madokayui Zai吐 out <br/> port and the auxiliary discharge port of the lower corresponding to Madokayui material discharge opening of the outer tube is provided on the inner tube, the upper opening and closing the both discharge opening between the outer tube the slide valve is provided, also, discharge opening and the auxiliary discharge port of the lower part corresponding to the gradual formation material discharge opening of the outer tube is provided at a lower portion of the inner tube, the lower slide valve between the inner and outer tubes return a spring is interposed, further soil improvement composite injection apparatus characterized by the lower portion of the discharge opening and the sub-discharge check valve for closing the outlet is freely introduced into the inner tube of the inner tube. 3. The ground improvement composite injection apparatus according to claim 2, wherein said check valve is formed as a spindle type.