KR20190062066A - Soft ground improvement device and that method - Google Patents

Abstract

The present invention relates to a soft ground improvement device to prevent uneven sinking and a construction method thereof. According to the present invention, the soft ground improvement device comprises: an injection means dividing a chemical liquid for forming a solid body into chemical liquids A and B, and including a first supply unit injecting chemical liquid A and a second supply unit injecting chemical liquid B; and an injection pipe discharging the chemical liquid in the ground. Moreover, the construction method comprises a water pumping pipe installation step, a solidification step, a water pumping step, and a sinking step.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a soft ground improvement device,

The present invention relates to a device and method for improving soft ground, and more particularly, to a method for improving the performance of a soft ground by means of a consolidation settlement, a phenomenon in which a soil or embankment sinks due to soil settlement or consolidation caused by drainage of pore water by pressure settlement- (Ground water level - groundwater level - the depth at which the water is leached to reach a certain depth, which is the topmost water surface where the water is retained) at the same time. Minimization of construction cost and formation of high consolidation between upper sand layer and clay layer by grout method and differential settlement - Unconfined settlement - Uneven settlement in various parts of the structure due to subsidence of structure And a method of manufacturing the soft ground improvement device.

In general, Korea is dependent on surface water for most of the domestic water, but surface water is vulnerable to the stability of water supply because it is exposed to weather changes such as drought and water quality accidents. In Korea, which is a water shortage country, the frequency of using underground water in underground rainfall or dry season is increasing. Most of the groundwater is pumped with sand.

For example, in a foreign subway construction site, when groundwater is pumped from a limestone area in the ground, the groundwater in the limestone cavity escapes and the cavity collapses, limiting the groundwater level that is lowered when excavating a certain area.

On the other hand, in the method of promoting the consolidation of clayey soil using the conventional soil pressure or vacuum consolidation, a plurality of circular vertical drains are installed, and then an embankment layer is formed as an upper layer so that consolidation promotion action by dewatering is achieved by the earth pressure .

Generally, soft ground improvement method and apparatus are provided for constructing a water wall in the ground in the construction work of various civil engineering works, or for improving the soft ground when there is a soft ground.

In the conventional construction method, in order to prevent the shear failure due to the load of the large amount of clay soil deposited on the upper part, a small amount of embankment is accumulated step by step, so that the construction is troublesome and long time, It takes a long time for the construction time to be long and the construction cost is high in the vacuum consolidation method which promotes dehydration by operating the vacuum pump while the clay layer is in a vacuum sealed state.

In addition, in the conventional construction method, a plurality of vertical holes are formed in a soft ground in a high deflection state to be improved, and the vertical holes are arranged in any one of triangular, square, polygonal, and circular shapes; The coal fly ash is poured into the vertical hole to form a coal fly ash column in the vertical direction so that when load is applied to the soft foundation, the fly ash is discharged upward through the fly ash drainage column, The dredged fly ash which has been dumped into the landfill coal or coal power plant that has not been subjected to separate separation and sorting process is dredged and then the fly ash mixed with heterogeneous particle size is dropped in water and then sorted by particle size A second step of using a buried fly ash having a particle size that is twice as permeable as that of the soft ground according to the permeability characteristics of the gravel constituting the soft ground undergoing the improvement, which is permeable to the particle size separating apparatus; And a horizontal collecting layer is formed by laying coal fly ash on the soft ground as the upper surface of the coal fly ash column so that the upwardly discharged pore water through the coal fly ash flows in the horizontal direction through the horizontal collecting bed And the third process. However, the above-described drawbacks are not solved, and the utilization of the groundwater and its effect are not considered at all.

As shown in FIG. 1, this type of method is related to a chemical solution injection method (JCM method, CGM method, JS-CGM method) and an apparatus therefor. As a conventional method for ground improvement or underground injection method for forming a water wall, (Grout - cement and water, or a mixture of cement and sand or water, or slicing cement or mortar into cracks in stone stones or buildings) There is a method in which a nozzle for injecting a chemical solution is charged into a rod for injecting a chemical solution and the grouting is performed from the lowermost part of the excavation hole to the upper side while the rod is rising upward.

In the conventional method as described above, there is a problem that the penetration range of the grout becomes uneven because the permeability of the ground is not uniform.

In addition, the conventional method as described above has performed uniform grouting by the experience of the operator without arbitrarily adjusting the curing speed of the grout.

On the other hand, Patent Document 1 relates to a soft ground improvement method and apparatus for constructing a water wall in a ground or improving soft ground, and more particularly, a chemical solution injection method (TCM method, CGM method, JS-CGM method) A conventional grout injection method for ground improvement or a composition of a water wall as a conventional method is to excavate at a certain depth in the ground to load the grout injection rod into the excavation hole to raise the rod from the lowermost portion of the excavation hole and to consolidate the ground. The present invention is characterized in that a chemical liquid discharge nozzle unit having a plurality of discharge ports in a radial direction of a rod is selectively attached to the nozzle unit in accordance with the circumstances of a construction site, By arbitrarily adjusting the strength and hardening speed of the grout, It was equipped with a liquid supply opening and closing device can be routed.

KR 10-0256843 B1

In order to solve the above problems, the present invention provides a pumping well (pumping well), which comprises a pumping pipe inserted into a pumping well and a double pipe for pumping sewage to pumped the pumping water through the pumping well The present invention has as its first object to provide a soft ground improvement device for preventing heterogeneous settlement by forming a solidified body between an upper sand layer and a clay layer through a grout method without the need of installing a separate chemical solution injection rod.

In addition to the use of the above soft ground improvement device, a suitable distance to the soft ground was inserted to insert the water pipe into the pipe, and the groundwater of the wide soft ground was simultaneously reduced to a bundle. Thus, settlement of ground, subsidence The purpose of the soft ground improvement method is to minimize the construction period and construction cost of ground subsidence due to natural settlement due to earthquake or crustal fluctuations and excessive pumping of groundwater. have.

In order to accomplish the above object, the present invention provides a method of manufacturing a semiconductor device having a first supply part for injecting a chemical A solution into an A / B chemical solution for forming a solid solution in a ground of a soft ground, and a second supply part for injecting a B solution, Injection means; And an injection pipe extending from the outer periphery of the pumping pipe inserted into the soft ground to the ground to discharge the chemical solution into the ground by the injection pressure of the injection means connected to the upper end, A plurality of injection passages through which the A / B liquid medicament is respectively moved are formed through the repeatedly formed partition walls, and A / B ejection openings for ejecting the A liquid medicament and the B liquid medicament are formed repeatedly along the outer periphery at the lower end of the injection tube And a soft ground improvement device.

In the method for improving the soft ground using the soft ground improvement device manufactured through the above-described construction, a plurality of pumping pipes having an injection pipe with a double pipe at an appropriate distance as the extent of the solidification formed in the ground of the soft ground Repeatedly tube insertion; A cryogen step of connecting an injection means for feeding and injecting an A / B liquid chemical into the injection tube and discharging the same through the injection tube to form a solid body; A pumping step of pumping water through the plurality of pumping pipes simultaneously to lower the groundwater of the corresponding soft ground to be subjected to consolidation settlement; The solidification of the solidification of the solidification - the solidification of solid matter from the rocks and liquids that are separated from the rocks - solidification of the solidification of the magma into igneous rocks, solidification of sediments into sedimentary rocks (Hereinafter referred to as " lithification action ") in which the upper sand layer and the clay layer are uniformly subdeposited without a differential settlement by the self weight of the groundwater Provide soft ground improvement method.

According to the present invention configured as described above, it is possible to prevent heterogeneous settlement by forming a solidified body between the upper sand layer and the clay layer through the grout method without the need of providing a separate chemical solution injecting rod.

Also, it has the effect of minimizing the construction period and construction cost of ground settlement due to consolidation settlement by lowering the groundwater of wide soft ground to the simultaneous bundle.

1 is a view showing a construction according to a conventional grout method.
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soft ground improvement apparatus.
Fig. 3 and Fig. 4 are views showing examples of installation states of the soft ground improvement apparatus according to the present invention; Fig.
Fig. 5 and Fig. 6 are exemplary sectional views showing a state of use of the soft ground improvement apparatus according to the present invention. Fig.
7 is a flowchart showing a soft ground improvement method according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can readily implement the present invention.

2 to 7, the soft ground improvement apparatus 100 of the present invention is different from the grouting method in which two chemical fluids are simultaneously injected through an injection rod, The pipe 120 is integrally formed and the groundwater in the lower sand layer 230 is pumped through the pumping pipe 110 and the A / B ratio is increased by the injection pressure of the pumping means 130 along the pumping pipe 120 And adopts a partially modified structure so that the formation of the solidification body 140 can be performed on the underground 240 by injecting / discharging it with a chemical liquid.

First, a first supply part 131 for injecting the A liquid medicine into the ground 240 of the soft ground 200 by dividing the liquid chemical for forming the solidification 140 into A / B liquid fluids and a second supply part 131 for injecting the A liquid medicine, (130) having a supply part (133).

Here, the injection means 130 is provided with the same constitution as proposed in Patent Document 1, and the chemical solution is composed of the main material of the solidification material 140 formed in the ground 240, such as cement or mortar The substance is made of the A drug solution, and the B drug solution is constituted by the solid solution or the additive material corresponding to the instant when the A drug solution is solidified in a short time.

The first and second supply units 131 and 133 of the injection means 130 separate and supply the A and B fluids and finally supply the A and B fluids through the A and B discharge ports 123 and 125, They are mixed at the same time as being discharged and cemented in a short period of time to form a solidified body 140.

The injection pipe 130 is connected to the upper end of the suction pipe 110 and is connected to the ground 240 by a double pipe. And an injection tube 120 for discharging the gas.

At this time, it is preferable that the A / B outlet 125 is blown to the lower end of the injection tube 120 along the outer circumference of the injection tube 120 to discharge the A / B liquid medicine.

That is, the injection tube 120 is formed with a plurality of injection passages 121 through which the A / B liquid medicines respectively move through the partition 127 formed repeatedly along the circumferential direction, and the lower end of the injection tube 120 A / B discharge ports 123, 125 for discharging the A liquid medicine and the B liquid medicine are formed repeatedly along the outer periphery.

The first supply part 131 and the second supply part 133 of the injection means 130 are alternately connected to the injection connection part 129 formed at the upper end of the injection tube 120.

If the groundwater layer is sandy soil, the groundwater is pumped down to the well function form when the groundwater is pumped, and the buoyancy is lost in the area where the buoyancy is received.

That is, since the groundwater 250 of the upper sand layer 210 is soft to the ground, the soft ground of the upper sand layer 210 - the clay layer 220 - the lower sand layer 230 is 20 - 30 m lower than the water level Even if the groundwater 250 is dropped, the groundwater 250 can be restored by injecting water or the like to reduce the subsidence of the groundwater.

Here, the lower sand layer 230 is a layer that contains aquifer-water and is capable of discharging a large amount of groundwater because of its high water permeability and storage ability to supply a large amount of water through a canal or fountain. The aquifer is a saturated stratum having a permeability that can supply sufficient groundwater to a canal at a predetermined amount or more. The aquifer may be divided into a free surface aquifer and a pressure aquifer depending on the geological environment. Is developed and water permeability is good.

In the case of a single layer, groundwater is pumped by the intrusion of pumped water, and the groundwater (250) drops from the surface layer to the well function form centering on the pumped water and immediately sinks.

Meanwhile, when the ground water is pumped by inserting the pumping end to the lower sand layer 230 from the upper sand layer 210, the clay layer 220, the lower sand layer 230 and the lower sand layer 230, the clay layer 220 and the lower sand layer 230 The groundwater 250 is reduced in the form of a well function so that the soil between the boundary of the clay layer 220 and the lowered groundwater 250 in the lower sand layer 230 is buoyant.

Accordingly, the clay layer 220 and the sand layer, which are the upper layer of the lower sand layer 230 and the buoyancy of the sand layer, are also lost in the zone where the groundwater 250 is lowered. Thus, in the clay layer 220 and the upper sand layer 210, The pressure acting on a point in the water is the same regardless of the direction, and its size is equal to the product of density, gravitational acceleration and depth of water) is dissipated.

Accordingly, the settlement of the upper sand layer 210 and the lower sand layer 230 occurs immediately due to the elastic deformation, and the settlement settlement due to the volume change due to drainage of the pore water occurs in the clay layer 220 in a time-dependent manner for a long time. Therefore, as described above, the buoyancy in the lower sand layer 230 with the groundwater 250 lowered and the clay layer 220 and the sand layer above the lower sand layer 230 is lost, so that the settlement due to the self weight including the immediate settlement and the consolidation settlement occurs Which is greater than before the groundwater 250 is degraded.

Accordingly, when the groundwater 250 of the lower sand layer 230 is continuously maintained in a lowered state in the lower sand layer 230, the upper sand layer 210 and the clay layer 210 The consolidation is caused by the increase in the weight of the clay layer 220 and the consolidation settlement can be generated in advance before the structure is installed in the surface layer without any further improvement of the clay layer 220.

In addition, since the thickness of each layer of the multi-layer ground is different and the groundwater 250 is lowered by the positive water in the lower sand layer 230 as a well function form, a differential settlement can occur and the structure can not be installed on the surface layer or the existing structure is seriously affected It will be possible.

In order to cope with the unequal settling, in addition to the portion where the hydrostatic pressure at the position adjacent to the existing pumping water is not dissipated, a plurality of pumping chambers penetrate into the lower sand layer 230 to pour the groundwater, thereby inducing the ground consolidation settlement around the pumping chamber. Or by injecting water into the lower sand layer (230) by artificial recharge (artificial recharge - ground water) by minimizing the differential settlement, or by using the ground water by the pumping water by the pumping water, Is a precious water resource with a large amount of water, but it has a slow circulation rate and imbalance between the amphibian and the water causes a disaster such as lowering of water level, salt water intrusion, subsidence of ground, etc. Artificial groundwater is infiltrated into the ground, The groundwater 250 of the lower sand layer 230 is lowered The can prevent and inhibit the consolidation settlement of the ground in accordance with the well function effect.

First, a pipe is inserted from the upper sand layer 210 to the clay layer 220, the lower sand layer 230, and the lower sand layer 230, which are multi-layered ground.

Subsequently, a pump (not shown) is operated on the ground to pumped the groundwater from the lower sand layer 230 so that the groundwater 250 flows from the boundary between the clay layer 220 and the lower sand layer 230, .

The method for improving the soft ground using the soft ground improvement apparatus of the present invention may include a method of improving the soft ground by using the double pipe as the injection pipe 120 at an appropriate distance as the width of the solidification member 140 formed on the ground 240 of the soft ground 200, A plurality of pumping pipes 110 having a plurality of pipes are inserted repeatedly (S100).

The injection tube 130 is connected to the injection tube 120 to inject the A / B liquid medicine into the injection tube 120 and injected to the underground tube 240 to form the solidification body 140. (S200).

This is because when the chemical solution spreads widely in the ground 240, the solidification 140 is cured within a short period of time through solidification.

Then, the water is pumped simultaneously through the plurality of pumping pipes 110 and the groundwater 250 of the soft ground 200 to be compacted is to be lowered (S300).

Finally, the total area of the upper sand layer 210 and the clay layer 220 bonded together through the consolidation of the solidified body 140 by the self weight of the groundwater 250 is uniformly settled without subsidence (S400).

Here, since the clay layer 220 and the lower sand layer 230 have different permeability coefficients, the groundwater 250 is lowered only in the lower sand layer 230.

That is, due to the lowering of the groundwater 250 in the lower sand layer 230, the soil layer between the boundary of the clay layer 220 and the lowered groundwater 250 in the lower sand layer 230 disappears and the groundwater 250 The hydrostatic pressure is dissipated in the lower sand layer 230, the clay layer 220, and the upper sand layer 210 due to the disappearance of the buoyancy in the clay layer 220 and the sand layer, which are the upper layer of the lower sand layer 230,

As a result, when the groundwater 250 of the lower sand layer 230 is kept in a continuously decreased state in the continuous sand layer 230, the larger self weight of the upper sand layer 210 and the clay layer 220 becomes the overburden load surface load, overburden load, overburden load - Generally, the load on the ground or floor. When calculating the side pressure of the earth retaining wall, the load that predicts various loads on the ground surface or the load due to the self weight of earth So that the settlement and settlement settlement in the clay layer 220 occur immediately.

Therefore, it is not necessary to separately fill the upper part of the surface layer, and the weight is larger than that of the embankment, thereby minimizing the time and cost of construction.

In addition, since the groundwater 250 is lowered in the form of a well function by the positive water in the lower sand layer 230, uneven settlement may occur and the structure may not be installed on the surface layer or may seriously affect the existing structure. In addition to a portion where the hydrostatic pressure at the position adjacent to the existing pumping water is not dissipated, a plurality of pumping water penetrates up to the lower sand layer 230 and pumped the groundwater, thereby inducing the ground consolidation settlement around the pumping water, The groundwater is utilized by the pumping water of the groundwater by the pumping water and the water is injected into the lower sand layer 230 by penetrating the injection pond at a position adjacent to the pumping water chamber to lower the groundwater 250 of the lower sand layer 230 And it is possible to suppress the settlement settlement of the ground due to the influence of the well function.

According to the present invention configured as described above, it is possible to prevent the uneven settlement by forming a solidified body between the upper sand layer 210 and the clay layer 220 through a grouting method without providing a separate chemical solution injecting rod have.

The terms and words used in the present specification and claims should not be construed to be limited to ordinary or dictionary terms. It should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Therefore, the configurations shown in the drawings and the embodiments described herein are merely the most preferred embodiments of the present invention, and are not intended to represent all of the technical ideas of the present invention. Therefore, It should be understood that various equivalents and modifications are possible.

100: Soft ground improvement device
110: Pumping pipe
120: injection tube
121: injection passage
123: A outlet
125: B outlet
127:
129: injection connection
130: injection means
131: first supply section
133:
140: solidification
141: Solution
143: A drug solution
145: B drug solution
200: Soft ground
210: upper sand layer
220: clay layer
230: Lower sand layer
240: Underground
250: Groundwater
S100: Installation steps
S200:
S300: positive step
S400:

Claims (3)

A pumping pipe (110) inserted into the soft ground (200);
An injection pipe 120 extending from the outer circumference of the pumping pipe 110 to the ground 240 through a double pipe and discharging the chemical solution to the ground 240 due to the injection pressure of the injection means 130 connected to the upper part; ;
A first supply part 131 connected to the upper part of the injection pipe 120 and dividing the chemical solution for forming the solidification body 140 into the ground 240 of the soft ground 200 by the A / , And a second supply part (133) for injecting the B solution.
The method according to claim 1,
The injection tube 120 is formed with a plurality of injection passages 121 through which the A / B liquid medicines respectively move through the partition 127 formed repeatedly along the circumferential direction. At the lower end of the injection tube 120, And A / B discharge ports (123, 125) for discharging the A solution and the B solution are formed repeatedly.
In the method for improving the soft ground using the soft ground improvement apparatus 100 manufactured through the construction of claim 1,
An installation step of repeatedly tube-inserting a plurality of pumping pipes 110 having a pouring pipe 120 with a double pipe at an appropriate distance as the height of the solidification member 140 formed on the ground 240 of the soft ground 200 S100);
A cementing step (130) for injecting A / B liquid medicine into the injection tube (120) and discharging the same through the injection tube (120) to the underground (240) S200);
(S300) for lowering the groundwater (250) of the soft ground (200) to be consolidated and pumped through the plurality of pumping pipes (110) simultaneously.
The upper sand layer 210 and the clay layer 220 joined together through solidification of the solidified body 140 are ground in a subsidence step in which the total area corresponding to the lowering amount of the groundwater 250 is self- S400). ≪ / RTI >

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