KR20050015945A - Method and device for manufacturing of stabilization column in ground - Google Patents

Abstract

PURPOSE: An installation method of a ground stabilization column is provided to install a stabilization column on the ground economically. CONSTITUTION: The installation method of a ground stabilization column comprises the steps of forming a hollow filled with injection materials(17) of an injection materials container(16) through a screw conveyor(12) by pushing out soils when pressing a screw conveyor(12) into the ground(2) through an excavation head(14), penetrating a screw conveyor(12) through the injection materials container(16), supplying injection materials(17) after reaching to the wanted depth of a column, pulling out the screw conveyor(12) and measuring the rotational frequency of the screw conveyor(12) and the transfer of the screw conveyor(12). The Installation apparatus(10) of a ground stabilization column contains a screw conveyor(12) provided with an excavation head(14), an injection materials container(16) penetrated the screw conveyor(12) partially to house injection materials(17), a transfer device(33) forming a hollow on the ground(2) and pressing down or pulling out the screw conveyor(12), a rotary device(31) rotating the screw conveyor(12) to feed injection materials(17) to the hollow, a transfer measuring device measuring the transfer of the screw conveyor(12), and a rotational frequency measuring device measuring the rotational frequency of the screw conveyor(12).

Description

Construction method and device of ground stabilization column {METHOD AND DEVICE FOR MANUFACTURING OF STABILIZATION COLUMN IN GROUND}

The present invention relates to an apparatus and a method for constructing a ground stabilizing column.

In order to stabilize sticky and organic soils with weak bearing capacity, a method of forming a hollow portion by digging a plunger (stamp) into the ground and pushing the surrounding soil is known, and a method of injecting a special injection material into the hollow portion is already known. To facilitate the manufacture of stabilizing columns (posts), a screw conveyor is used to inject the injection into the hollow part. By injecting the injection material into the hollow portion already formed in the excavation process, the hollow support during the construction of the pillar and good compression of the surrounding soil and the pillar material proceed simultaneously.

In general, when the foundation work is not possible on the soft ground and the load must be transferred to the ground of the bearing core, this kind of stabilizing column is constructed. This type of stabilization column is also used to increase the bulk density of the soft ground. The increase in bearing capacity is determined by the strength of the stabilizing column being constructed and the increased compressive force of the surrounding soil. Since these two factors can be highly dependent on the characteristics of the ground, the stabilizing column should be designed in consideration of a suitable high stability factor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a construction apparatus and method for stabilizing columns, which can install the stabilizing columns on the ground very economically.

The object of the invention is achieved through a method comprising the features of claim 1 and an apparatus comprising the features of claim 11.

In the method according to the present invention for manufacturing a ground stabilizing column, by excavating the rotary drive type screw conveyor including the excavation head to the ground to push out the soil and at the same time a hollow portion is formed, the injection material in the injection material container through which the screw conveyor penetrates After filling the hollow through the screw conveyor and reaching the desired column depth, the screw conveyor is drawn off with additional feed material, at least the rotational speed of the screw conveyor and the conveyance of the screw conveyor are measured.

The key of the method according to the invention is to measure the number of revolutions and the conveyance of the screw conveyor for the injection material in the production of so-called CSV pillars. The measured values obtained through the measurement are transferred to the electronic data processing system and output on paper or screen. By evaluating the measured value, it is possible to grasp the characteristics of the perforated soil, the amount of injection material filled in the hollow portion, and the crimp height of the surrounding ground. In particular, the measured values give an indication of the quality and bearing capacity of the fabricated columns, and the data can be used to adjust the safety factors accordingly. This can significantly reduce the over-dimension and thereby increase the production costs of stabilizing columns, i.e. material and working costs, while at the same time achieving improved safety through accurate bearing capacity.

In the present invention, the conveying means the conveying force, the conveying speed, or both required to compress or draw the screw conveyor to or from the ground. In principle, the feed is measured not only at the screw conveyor but also at the time of drawing, and in the latter case the traction force may be measured instead of the pressure for the feed force. Measurements of rotational speed and / or feed are made based on the operating time and / or insertion depth of the screw conveyor.

In particular, by measuring the feed rate based on time and / or depth, it is possible to monitor the continuous and sufficient filling of the filler material to the screw conveyor during pressing into the ground. By completely filling the screw conveyor with the filling material, it is possible to prevent the soil from contacting the spiral of the screw conveyor, and if the soil is in contact with the screw of the screw conveyor, the compression heterogeneity of the filling material, the heterogeneous moisture from the soil sand through the filling material The weakening of the absorption and stabilization pillars can be caused.

By monitoring the rotation speed, it is possible to ensure that the screw conveyor is completely filled with the injection material as it passes through the injection material container. In particular, it is possible to recognize too slow rotations, in which only partial filling or earthwork can reach the spiral. The optimal number of revolutions depends on the spiral height of the screw conveyor and the diameter of the screw conveyor. If the diameter of the drilling head is larger than the diameter of the screw conveyor, the optimum rotational speed is determined according to the size of the drilling head, since the injection amount larger than the capacity of the screw conveyor must be filled with the ground.

By measuring the feed force, it is possible to obtain information on the strength of each ground layer to be drilled. It can be concluded that the screw conveyor is located in the bearing ground, especially when the feed force is increased. Based on this result, the conveyance of the screw conveyor can be stopped. In particular, the result of such a measurement can be advantageously used when the stabilizing column is used as a reinforcing column in the ground having good bearing capacity. The maximum feed force provides information about the normal force that can be transmitted from the stabilizing column to the ground.

Preferably, based on the measured rotational speed, it is possible to determine the sum of the rotations of the screw conveyors in the manufacture of the stabilizing column. These totals provide information on whether a sufficient amount of filler material has been injected into the ground during stabilization columns. Preferably, the total rotation is indicated according to the depth of drilling of the screw conveyor. In this case, a high rotational speed at a slow conveying speed may mean that a locally larger amount of injection material is injected into the ground and the diameter of the pillar is enlarged.

Another embodiment of the method according to the invention is characterized in that the feed drive and / or the rotary drive of the screw conveyor are controlled in accordance with the measured revolutions and / or the measured feed to form a stabilizing column of a particular size. do. This type of control makes it possible to readjust the amount of injected material and the quality of the column depending on the properties of the ground layer currently perforated during the fabrication of the column. Therefore, it is possible to produce a stabilizing column having a constant diameter and a constant pressing force of the injected injection material. The control according to the invention also prevents too large feeds and too slow rotations, which can lead to stabilizing columns of poor quality.

In principle it is possible to measure the number of revolutions and feeds and / or to control the rotary drive and / or the feed drive only when the screw conveyor is pressed into the ground. However, it is preferred that the measurement and / or control be carried out additionally or alternatively even with the drawing of the screw conveyor. The measurement of the feed rate at the time of drawing the screw conveyor shows that a sufficient amount of injection material has been injected into the hollow produced by the screw conveyor. The vertical force in the screw conveyor can be determined by measuring the conveying force at drawing, which can be achieved, for example, by measuring the hydraulic pressure of the hydraulic conveying drive. Through this, it is possible to know the compression ratio of the conveying material, which has an important effect on the compressive strength of the stabilizing column. In particular a low compression ratio or low filling of the injected injection material weakens the compressive strength of the stabilizing column.

In a preferred embodiment of the present invention, the control of the screw conveyor is made such that the speed of rotation is kept almost constant and the feed, in particular the feed rate, is adjustable. Preferably, the number of revolutions that remains substantially constant is represented by the number of revolutions per meter of the stabilizing column. This type of control can be realized very simply. As an alternative to this, it is also possible to control the feed rate to be kept substantially constant and to adjust the rotation speed.

At the time of drawing out of the screw conveyor, it is desirable to control the number of rotations of the screw conveyor per meter of the stabilizing column in such a manner as to adjust the feed speed.

In a preferred embodiment of the method according to the invention, the rotary drive and / or the transfer drive are arranged such that the injection rate of the injection material into the hollow is greater than or equal to the volume change of the formed hollow, which occurs due to the indentation of the screw conveyor into the ground. To control. In this way, sufficient compression of the injection material is achieved and mixing of the soil and injection material can be prevented.

When the screw conveyor is drawn out, the volume change rate (V _hollow ) of the hollow to be secured can be calculated from the feed rate (s) and the cross-sectional area (A) according to the following relationship.

V _Hollow  = s · A

The injection rate (V _material ) of the injection _material passing through the through hole of the drilling head can be estimated by the following relationship.

V _material  = d

Where d is the rotational speed of the screw conveyor and k is the shape factor of the screw conveyor determined according to the spiral shape of the screw conveyor. Thus, in a preferred embodiment of the present invention, control can be made such that the following conditions are met.

| V _hollow | ≤ | V _material |

Alternatively or additionally, it is possible to control the conveying speed to be adjusted as a function of the vertical force and / or the conveying force of the screw conveyor when the screw conveyor is drawn out. By doing so, it is possible to maintain a designated conveying pressure in the hollow portion, whereby uniform compression of the injected injection material can be realized.

Preferably, control is made to inject the same amount of injection material per meter of the advanced stabilizing column into the hollow part. This realizes uniform compression of the injected injection material. In particular, the reduction in the number of revolutions of the screw conveyor in the harder ground can be compensated by slowing down the feed rate.

In another preferred embodiment of the present invention, when the measured conveying force reaches a preset set value, the conveying drive is controlled so that the press-in of the screw conveyor is stopped. Through this, it is possible to accurately construct the stabilizing column on the ground with good supporting force.

In another embodiment of the present invention, the amount of injection material present in the injection material container, in particular the volume and / or weight of the injection material, is additionally measured. Through differential measurement of the amount of injection material in the injection material container, it is possible to more accurately measure the amount and compression of the injection material injected into the ground.

According to the invention, the screw conveyor can be rotated in a suitable way for the filling of the hollow part in drawing and / or indentation. On the one hand, a complete filling of the screw conveyor is achieved through the rotation of the screw conveyor during indentation. On the other hand, this makes it possible to push the injection material into the side wall of the hollow part already during the press-in of the screw conveyor. In particular, it is possible to inject the injection material present in the screw conveyor into the hollow part through the through hole of the drilling head by rotating the screw conveyor during drawing. Preferably, the screw conveyor rotates so that the injection material is transported from the ground surface to the ground, ie from top to bottom, as well as during press-in of the screw conveyor.

The injection material is preferably a dried material such as dry mortar, lime or dry concrete. The strength of these dry materials is enhanced by absorbing moisture in the surrounding ground. In order to fabricate stabilizing columns with very uniform strength properties, it is desirable to moisturize these dry materials when injected into the ground.

In a further preferred embodiment of the method according to the invention, water is fed to the injection material in the hollow, in particular via a nozzle arrangement arranged on the screw conveyor during the extraction of the screw conveyor. By doing so, it is possible to cure the injection material of the stabilizing pillar very quickly and uniformly. Water may be delivered to the nozzle device through a tube disposed in the screw conveyor.

The apparatus according to the invention for producing stabilizing columns in the ground comprises a screw conveyor with an excavation head disposed at an end, an injection vessel for accommodating the injection material, at least partially penetrating the screw conveyor, a screw while forming a hollow in the ground. Transfer drive for indenting or drawing the conveyor, rotary drive for rotating the screw conveyor to feed the feed material into the hollow part, feed force and / or feed speed measuring device for the feed measurement of the screw conveyor, and rotation speed of the screw conveyor It includes a rotation speed measuring device for the measurement. The apparatus is particularly suitable for the implementation of the method described above.

In one embodiment of the device according to the invention, a control device for controlling the rotary drive and / or the transfer drive in accordance with the measured feed and / or measured rotational speed of the screw conveyor to produce a stabilizing column of specific properties is provided. Is mounted. This control is performed in accordance with one of the methods described above. The feed measuring device and the speed measuring device are electrically connected to the control device in a suitable manner.

Preferably the diameter of the drilling head is greater than or equal to the diameter of the screw conveyor. For example, the screw conveyor has a diameter of 100 to 120 mm, in particular 110 mm, and the diameter of the drilling head is 125 mm. Preferably spirals are formed over the entire length of the screw conveyor. There is also at least one through hole in the excavating head which allows the injection material to be transported to the hollow via the excavating head when the screw conveyor is drawn out.

In the following, on the basis of the embodiment shown through the drawings, a detailed description of the present invention will be made. The figure shows a side view of a device according to the invention.

The apparatus 10 for manufacturing a stabilizing column on the ground 2 has a rotationally driven screw conveyor 12 in which an excavation head 14, which can be formed as a starter, is arranged at the lower end. The screw conveyor 12 has a helix 13 over almost all sections and penetrates the box-shaped injection material container 16 filled with the injection material 17. In the illustrated embodiment, the screw conveyor 12 has about a quarter of its total length inserted into the ground 2.

The screw conveyor 12 is rotatably coupled with the rotary drive 31 at its upper end, and the screw conveyor is rotatable through this rotary drive. The rotation drive device 31 is supported by the main column 22 in a form movable through a sliding bed 25. The screw conveyor 12 is supported by a guide 26 in a rotatable form in the cylinder column 22, which guides between the lower end 24 and the sliding bed 25 of the cylinder column 22. It is arranged on the pillar 22 and prevents buckling of the screw conveyor.

The main column 22 is connected to the building vehicle 20 shown as a caterpillar vehicle through a boom 23. The conveying device 33 is coupled to the main column 22 for conveying the screw conveyor 12. The conveying device 33 formed as a step motor is connected to a sliding bed 25 supported in a movable form in the main column 22 through a drive chain or rope not shown in the drawing. The drive chain or rope passes through the main column 21 and the lower end 24 of the main column 22.

The injection material container 16 is fixedly arranged at the lower end 24 of the main column 22 or on the ground surface 3 via the leg 28. A through tube 29 directly connected to the ground surface 3 is disposed at the lower end of the injection material container 16, and a screw conveyor 12 carrying the injection material 17 penetrates the through pipe. At the upper end, the injection material vessel 16 has a bulk hopper 18 for filling the injection material 17 with the injection material vessel 16.

According to the present invention as described above, it is possible to obtain a stabilizing column construction apparatus and method, which can install the stabilizing column very economically on the ground.

1 shows an apparatus according to the invention.

Claims (12)

When the screw conveyor 12 capable of rotation driving is pushed into the ground 2 through the excavation head 14, the soil is pushed out so that the filling material 17 of the filling material container 16 is filled through the screw conveyor 12. A hollow portion is formed, the screw conveyor 12 penetrates the filling material container and draws the screw conveyor 12 continuously supplying the filling material 17 after reaching the desired column depth, and at least the rotation of the screw conveyor 12. The ground (2) stabilization column construction method, the water and the conveyance of the screw conveyor (12) is measured. The method of claim 1, The ground characterized in that the rotary drive 31 and / or the transfer drive 33 of the screw conveyor 12 are controlled in accordance with the measured rotation speed and / or the measured feed in order to produce a stabilizing column of specific characteristics. Stabilization column construction method. The method according to claim 1 or 2, Ground stabilization column construction method characterized in that the measurement and / or control at the time of the press-in and / or pull out of the screw conveyor (12). The method according to claim 2 or 3, A method of constructing a ground stabilizing column, characterized by controlling the screw conveyor (12) to maintain a substantially constant rotational speed and to adjust the feeding, in particular the feeding speed. The method according to any one of claims 2 to 4, Controlling the rotation drive device 31 and / or the feed drive device 33 so that the injection rate of the injection material 17 into the hollow part is greater than or equal to the volume change rate of the hollow part shown by pressing the screw conveyor 12 into the ground. Ground stabilization pillar construction method characterized in that. The method according to any one of claims 2 to 5, A method of constructing a ground stabilizing column, characterized in that for controlling the feed drive device (33) to stop the press-in of the screw conveyor (12) when the measured feed force reaches a predetermined set value. The method according to any one of claims 1 to 6, A method of constructing a ground stabilizing column, characterized by additionally measuring the amount of filler material (17) present in the filler material (16), in particular the volume and / or weight of filler material. The method according to any one of claims 1 to 7, Ground stabilization column construction method characterized in that the screw conveyor (12) rotates for filling the hollow part during indentation and / or drawing. The method according to any one of claims 1 to 8, A ground stabilizing column construction method, characterized in that the injection material (17) is a dry material, such as dry mortar, lime or dry concrete, preferably supplied with moisture prior to injection into the ground (2). The method according to any one of claims 1 to 9, Method for constructing a ground stabilizing column, characterized in that for supplying water to the injection material 17 in the hollow through the nozzle device disposed on the screw conveyor (12) when the screw conveyor (12) is drawn out. A screw conveyor 12 with an excavation head 14 arranged at the end, An injection material container 16 for receiving the injection material 17, at least partially penetrating the screw conveyor 12, A conveying drive 33 capable of pressing or drawing the screw conveyor 12 while forming a hollow in the ground 2, A rotary drive 31 for rotating the screw conveyor 12 to convey the injection material 17 to the hollow part, A conveyance measuring device for conveying measurement of the screw conveyor 12, and A ground (2) stabilized column construction device, comprising a speed measuring device for measuring the speed of the screw conveyor (12), used for the purpose of carrying out the method according to one of the preceding claims. 10). The method of claim 11, Equipped with a control device for controlling the rotary drive 31 and / or the transfer drive 33 in accordance with the measured feed and / or measured rotational speed of the screw conveyor 12 to produce a stabilizing column of specific characteristics. Ground stabilization pillar construction device, characterized in that.