JP2010112028A - Soil bearing capacity enhancement method and device used for the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soil bearing capacity enhancement method for easily and inexpensively enhancing the soil bearing capacity of soft ground without use of a steel pipe pile and a soil cement column, or the like. <P>SOLUTION: A press-fitting member 4 composed of a minor diameter hollow pipe 1 including an injection port 2 for injecting a solidifying milk agent M at a lower end portion thereof, and a plurality of horizontal blades 3 projectively provided at intervals slightly higher in level than the injection port 2 so as to be located at the same height is rotationally pressed into construction ground G, whereby the construction ground G is damaged by the horizontal blade pieces 3 to loosen the construction ground G, and the press-fitting member 4 is rotationally pressed into a predetermined depth of the construction ground G while forming a spiral loosened layer 5. Thereafter, the solidifying milk agent M is injected through the injection port 2 while reversely rotating and pulling up the press-fitting member 4 to charge the solidifying milk agent M to the spiral loosened layer 5, and the solidifying milk agent M is solidified to form an improved part 15. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a ground strength increasing method for enhancing the ground strength of soft ground and an apparatus used for the method.

Conventionally, as a construction method for enhancing the earth bearing capacity of soft ground, a pile placing construction method using a steel pipe pile, a soil cement column or a concrete pile is known. And the thing disclosed by the following patent document 1 is well-known as a ground strength reinforcement method using the said steel pipe pile.

And, the construction method disclosed in Patent Document 1 excavates and stirs the construction ground while injecting the solidified milk agent, mixes and stirs the excavated soil and the solidified milk agent and excavates the cylindrical excavation hole, A steel pipe pile formed by connecting a closing plug with a breakable holding steel rod is embedded in the slurry-like stirring soil, and the lower end surface of the closing plug is grounded to the support layer, thereby hollowing the steel pipe. Fill the inside and outside of the slurry with agitation soil, and then press the upper end surface of the steel pipe pile to break or bend the holding steel rod and fit the plug into the hollow part of the lower end surface of the steel pipe This is a method in which the slurry-like stirring soil is fixed by close fitting.

Japanese Patent Publication No. 5-77809

The method disclosed in Patent Document 1 is a method of mixing and stirring excavated soil and the solidified milk agent while injecting a solidified milk agent, excavating a cylindrical excavation hole, and then connecting a substantially conical plug. The steel pipe pile formed in a fixed manner is embedded in the slurry-like stirring soil in the excavation hole, and the upper end surface of the steel pipe pile is struck to break or bend the holding steel rod, and the plug is placed under the steel pipe. Since it is a method of fitting and fixing to the hollow portion of the end face and fixing the slurry-like stirring soil, it is solidified in the construction ground before being stirred, not after being excavated and stirred by the stirring blade Since the milk agent is injected from the injection port at the tip of the excavator, there is a problem that the solidified milk agent does not penetrate into the construction ground and may not be sufficiently mixed and stirred.

In addition, the construction method disclosed in Patent Document 1 manufactures a steel pipe pile having a blocking plug, conveys the steel pipe pile to a construction site, and further embeds the steel pipe pile in the slurry-like stirring soil. Since the equipment is necessary, the cost is high, and the construction site has a problem that the equipment can be carried in, and the road is necessary, and the construction site and the road cannot be constructed when the road is narrow. .

The present invention has been made to solve the above-mentioned problems, and has a spray port for spraying the solidified milk agent pumped from the pump at the lower end without using a steel pipe pile, and slightly above the spray port. A press-fitting member consisting of a small-diameter hollow tube formed by projecting a plurality of horizontal blade pieces made of metal pieces at the same height position with an interval, without spraying the solidified milk preparation, By rotating and press-fitting to the horizontal wing piece, the construction ground is scratched, and the construction ground is loosened to form a helical unwinding layer and a helical non-unraveling layer. After rotating and press-fitting the member to the construction ground to a predetermined depth, the solidified milk agent is sprayed from the injection port while rotating and pulling out the press-fitting member, and the solidified milk agent is injected into the helical loosening layer and the press-fitted When pulling out parts By filling and solidifying the helical unwinding layer formed, the solid solidified unraveling layer and the spiral non-unraveling layer that was not filled with the solidified milk agent were arranged in layers on the construction ground It is an object of the present invention to provide a ground strength enhancement method and an apparatus used for the method, which are capable of forming an improved area.

In order to solve the above-mentioned problems, the present invention provides the invention according to claim 1, wherein the lower end portion is provided with an injection port for injecting the solidified milk agent pumped from the pump, and a metal piece slightly above the injection port. A press-fitting member consisting of a small-diameter hollow tube formed by projecting a plurality of horizontal blade pieces at the same height position with a gap between them, and rotating press-fitting into the construction ground without spraying the solidified milk preparation Then, the horizontal blade piece continuously damages the construction ground, and loosens the construction ground to form a spiral unraveling layer while rotating the press-fitting member into the construction ground to a predetermined depth. A first step of forming a press-fitting treatment layer in which a spiral loosening layer and a spiral non-unraveling layer are provided in the construction ground, and a press-fitting member is placed on the construction ground to a predetermined depth by the first step. After the press-fitting, the press-fitting member While rotating reversely and pulling out from the press-fit treatment layer, the solidified milk agent is sprayed from the injection port, and the solidified milk agent is reversely rotated through the helical loosening layer formed by the first step and the press-fitting member. When it is pulled out, it is filled with the spiral loosening layer that is formed further, and then the solidified milk agent is solidified, so that the construction ground is not filled with the helical solidified loosening layer and the solidified milk agent. In addition, in the invention of claim 2, a small-diameter enhancement method is provided in which the spiral non-unraveling layer is applied by a second step of forming an improved portion arranged in layers. At the lower end of the hollow tube is provided with an injection port for injecting the solidified milk agent pumped from the pump, and slightly above the injection port, scratching the construction ground, loosening the construction ground, Spiral on the construction ground A press-fitting member formed by projecting a plurality of horizontal wing pieces made of metal pieces at the same height position with a gap to form a loosening layer and a spiral non-unraveling layer in layers. An apparatus for use in the characteristic earth strength enhancement method is provided.

The present invention has an injection port for injecting a solidified milk agent pumped from a pump at a lower end portion, and a press-fitting member composed of a small-diameter hollow tube formed by projecting a horizontal blade piece. By rotating and press-fitting into the construction ground without spraying, the construction ground is scratched by the horizontal blade piece, and the construction ground is loosened to form a spiral unraveling layer and a spiral unraveling layer. While forming, rotationally press-fitted into the construction ground to a predetermined depth, and then, while rotating and pressing the press-fitting member, the solidified milk agent is injected from the injection port, and the solidified milk agent is injected into the spiral shape. Unlike the conventional method using a steel pipe pile, the solidified milk preparation is added after the construction ground is excavated, unlike the conventional construction method using steel pipe piles, by filling the loosening layer and solidifying it. On the horizontal blade Because filling the spiral loosened layers loosened I, fill rate to the helical loosening layer of solidifying milk agent is fast, thus improving site is relatively quickly formed. In addition, in the present invention, since a small-diameter hollow tube is used, large equipment is not required, so that the construction can be performed even when the construction site and the road are narrow. Furthermore, in the present invention, the ground strength of the soft ground can be increased easily and inexpensively without using a steel pipe pile and a soil cement column.

Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the first step in the method of the present invention is a pump P on the lower end of a hollow pipe 1 having a small diameter of about 40 to 60 mm from the construction ground G surface where the earth bearing strength is to be increased. A horizontal wing piece 3 made of a metal piece having a thickness of about 5 to 15 mm and a length of about 15 to 40 cm is provided at a portion slightly above the injection port 2 while jetting the solidified milk preparation M to be pumped from. A press-fitting member 4 (a horizontal wing piece made of two metal pieces is shown in FIG. 1) formed by projecting a plurality of sheets at the same height position with a gap between the solidified milk M The horizontal wing piece 3 is also rotated at the same time without being injected from the injection port 2, so that the rotating horizontal wing piece 3 causes a continuous wound in the spiral manner in the construction ground G. , Loosen the construction ground G, go spirally Rotating and press-fitting while providing the layer 5 and rotating and press-fitting to a preset depth, the construction ground G is not affected by the rotation of the spiral unraveling layer 5 and the horizontal blade piece 3, the construction ground A cylindrical press-fitting treatment layer 7 having the width of the horizontal blade piece 3 is formed, in which a spiral non-unraveling layer 6 that could not be loosened in G is formed in a layered manner.

Although it is not necessary to specifically limit the press-fitting member 4, it is recommended to use a device as shown in FIG. 1 to rotationally press-fit the construction ground G and to inject the solidified milk agent M. That is, one end of a connecting plate 11 that is inserted through a leader 10 erected on the construction ground G so as to move up and down is connected and fixed to the tip of the arm 9 of the heavy construction machine 8 transferred onto the construction ground G. On the other hand, a hydraulic motor 12 is connected and fixed to the upper part of the hollow tube 1, and one end of the hydraulic motor 12 is connected and fixed to the other end of the connecting plate 11. A swivel 14 that pressure-feeds the solidified milk M from the pump P to the hollow tube 1 through the liquid supply hose 13 is connected and fixed to the upper end opening of 1.

Then, while pushing down the connecting plate 11 connected and fixed to the tip of the arm 9 of the construction heavy machine 8 along the leader 10, and rotating the press-fitting member 4 by rotating the hydraulic motor 12, the construction ground When the rotary press-fitting into G is performed, the horizontal blade piece 3 also rotates to scratch the construction ground G in a continuous spiral and loosen the construction ground G. The cylindrical press-fitting treatment layer 7 is formed by rotationally press-fitting the press-fitting member 4 to a predetermined depth while providing the spiral non-unraveling layer 6. The rotational speed of the press-fitting member 4 varies depending on the soil quality of the construction ground G, but it is recommended to rotate at a low speed that does not affect the rotational press-fitting into the construction ground G.

Next, in the second step of the method of the present invention, the press-fitting member 4 is reversely rotated from the press-fitting treatment layer 7 formed by rotating and press-fitting the press-fitting member 4 to a preset depth in the first step (first step). When pulling out while rotating in the direction opposite to the rotation direction of the process), the pump P is operated to inject the solidified milk agent M into the hollow tube 1 at a low pressure, and the solidified milk agent M is injected from the injection port 1. Is injected into the press-fitting treatment layer 7 to be formed by the horizontal blade piece 3 in the first step and further formed by the horizontal blade piece 3 that rotates in reverse as the press-fitting member 4 is pulled out. The spiral loosening layer 5 is filled with the injected solidified milk M. The helical loosening layer 5 has the construction ground G loosened by the horizontal blade 3, so that the solidified milk agent M is easily penetrated and filled, but the helical non-unraveling layer 6 is loose. Therefore, the solidified milk M does not easily penetrate and is hardly filled.

The pressure for injecting the solidified milk M into the hollow tube 1 is not particularly limited, but preferably it is recommended to be a low pressure of about 1.5 to 2.5 MPa. In this case, since the solidified milk agent M is ejected onto the construction ground surface G, it cannot be employed in the present invention.

Then, the press-fitting member 4 is pulled out from the press-fitting treatment layer 7, and then the solidified milk agent M filled in the spiral loosening layer 5 is solidified, so that the helical loosening layer 5 is solidified by the solidified milk agent. The soil particles in the inside are firmly bonded to increase the soil density and form an improved portion 15 that can suppress consolidation settlement.

If the filling of the solidified milk M into the helical loosening layer 5 is not sufficient even after one rotary press-fitting of the press-fitting member 4 and the pulling-out operation of the press-fitting member 4, the solidified milk agent is sufficiently obtained. The operation is repeated a plurality of times until M is filled in the helical loosening layer 5.

Then, as shown in FIG. 3, the helical loosening layer 5 is filled with the solidified milking agent M and the helical solidified loosening layer 5a filled with the solidified milky agent M, as shown in FIG. The improved portion 15 in which the spiral non-unraveling layer 6 that has not been arranged is formed is formed, whereby the ground strength of the soft ground can be enhanced.

According to the state of the construction ground G, the improved portion 15 formed by each of the above steps can be installed by setting in advance the location and number of installations, thereby enhancing the ground strength of the intended construction ground G. it can.

The filling rate of the solidified milk preparation M into the helical loosening layer 5 is about 20 to 40%, preferably about 20 to 40%, although there is an increase or decrease depending on the soil when the volume of the cylindrical press-fitting treatment layer 7 is 100%. About 30% is recommended.

When the helical loosening layer 5 is filled with the solidified milk agent M at the filling ratio of the preferred ratio and the solidified milk agent M is solidified to form the improved portion 15, a load is applied to the improved portion 15 from above. When applied, only the helical non-unraveling layer 6 that is not filled with the solidified milk agent M shrinks, but the solidified helical unraveling layer 5a does not shrink, so the consolidation settlement can be reduced, This prevents uneven settlement.

In this invention construction method, it is a longitudinal cross-sectional view which shows the state which press-fitted the press-fitting member to the construction ground to the set depth. In this invention construction method, it is a longitudinal cross-sectional view which shows the state which is extracting the press-fitting member after carrying out the rotation press-fitting of the press-fitting member to the construction ground to the setting depth. In this invention construction method, it is a longitudinal cross-sectional view which shows the state which formed the improvement site | part in the construction ground.

Explanation of symbols

G Construction ground M Solid milk preparation P Pump 1 Hollow tube 2 Injection port 3 Horizontal blade piece 4 Press-fitting member 5 Helical unwinding layer 5a Helical solidifying unwinding layer 6 Helical non-unraveling layer 7 Press-in processing layer 8 Construction heavy machinery 9 Arm 10 Leader 11 Connecting plate 12 Hydraulic motor 13 Liquid supply hose 14 Swivel 15 Improved part

Claims (2)

The lower end is provided with an injection port for injecting the solidified milk preparation pumped from the pump, and a plurality of horizontal blade pieces made of metal pieces are projected at the same height position with a gap slightly above the injection port. A press-fitting member composed of a small-diameter hollow tube formed and formed, without spraying the solidified milk agent, rotationally press-fitted into the construction ground, and continuously scratching the construction ground with the horizontal blade piece, The construction ground is loosened to form a spiral loosening layer, and the press-fitting member is rotationally press-fitted to the construction ground to a predetermined depth so that a spiral loosening layer and a spiral non-unraveling are formed in the construction ground. A first step of forming a press-fit treatment layer having layers formed therein, and after the press-fitting member is rotationally press-fitted to a construction ground to a predetermined depth by the first step, the press-fitting member is reversely rotated and pulled out from the press-fitting treatment layer. , Solidified from the injection port And spraying the solidified milk agent into the helical loosening layer formed by the first step and the helical loosening layer further formed when the press-fitting member is pulled out in reverse. Then, by improving the solidified milk preparation, the improved site where the spiral solidified loosening layer and the spiral non-freezing layer not filled with the solidified milk preparation are disposed in layers in the construction ground. An earth-strengthening method that is constructed by the second step of forming a slab. At the lower end of the small-diameter hollow tube, an injection port for injecting the solidified milk agent pumped from the pump is provided, and the construction ground is damaged by slightly scratching the construction ground slightly above the injection port. A plurality of horizontal wing pieces made of metal pieces projecting at the same height position with a gap to form a spiral loosening layer and a spiral non-rawing layer on the construction ground. An apparatus used for the earth strength enhancement method characterized by comprising a formed press-fitting member.

Images