KR102694985B1 - Quality management method of pile with small diameter - Google Patents

Abstract

The present invention relates to a method for managing the quality of small-diameter piles, which enables prediction and management of settlement when design load is applied by installing a measuring section on the top of a small-diameter pile embedded in the ground and then applying a load from a loading section to measure settlement, and which can increase pile bearing capacity by compressing slime at the pile tip when initial load is applied.
The present invention is characterized by comprising the steps of: (a) constructing a plurality of small-diameter piles on the ground; (b) selecting at least one of the plurality of small-diameter piles as a reference pile; (c) applying a design load to the reference pile, and then measuring the settlement according to the load, and creating management reference data according to the measured load-settlement value; (d) placing the measuring unit on the top of the remaining small-diameter piles, excluding the reference pile, as quality management target piles; (e) applying a test load of 5 to 10% of the design load to the quality management target pile by pressurizing the measuring unit main body of the small-diameter pile quality management system with the load unit; (f) measuring the settlement of the quality management target pile by the settlement measuring device of the measuring unit; and (g) calculating and displaying the expected settlement of the quality management target pile when the design load is applied from the management reference data according to the settlement measured when the test load is applied by the monitoring unit of the small-diameter pile quality management system.

Description

{Quality management method of pile with small diameter}

The present invention relates to a method for managing the quality of small-diameter piles, which enables prediction and management of settlement when design load is applied by installing a measuring section on the top of a small-diameter pile embedded in the ground and then applying a load from a loading section to measure settlement, and which can increase pile bearing capacity by compressing slime at the pile tip when initial load is applied.

A pile load test is conducted to determine the size of the load that can be supported within the range of the ultimate load or allowable settlement of a pile embedded in the ground.

Typically, dynamic or static load tests are conducted on approximately 250 units or 1 unit per structure.

The dynamic load test is the most commonly applied test method to determine bearing capacity.

Among the dynamic load test methods, the EOID (End Of Initial Driving) test is a test conducted in parallel with the final driving of a pile. Its purpose is to present construction management standards by measuring the bearing capacity centered on the tip and examining the workability of driving.

Among the dynamic load test methods, the Restrike test is a re-driving test that is conducted after a certain period of time has passed since the completion of the driving. It can confirm the change in bearing capacity over time and is intended to measure the exact bearing capacity of the constructed pile.

Meanwhile, the static load test, which measures the allowable bearing capacity and settlement of a pile by applying an actual load to the pile, is the most reliable method for understanding the behavior of a pile. However, it is difficult to check the change in bearing capacity over time, so it is difficult to use it to manage the quality of constructed piles.

Therefore, in the case of existing PHC piles or steel pipe piles, the quality of the constructed piles is checked by the amount of settlement when the hammer is struck on the entire pile based on the construction management standards confirmed through the dynamic load test (EOID).

In contrast, for small-diameter piles used for reinforcing small and medium-sized buildings or existing structures, only the pile penetration depth is managed during pile construction, and static load tests are conducted only for some piles to confirm the quality, and there is no method for quality control for the entire pile.

KR 10-1017567 B1

In order to solve the above problems, the present invention aims to provide a small-diameter pile quality management method capable of predicting and managing the amount of settlement when a design load is applied to a small-diameter pile and improving the pile bearing capacity.

The present invention according to a preferred embodiment relates to a method for managing the quality of small-diameter piles by a small-diameter pile quality management system, comprising: a main body having a lower socket formed on the lower surface into which the upper end of a small-diameter pile driven into the ground is inserted; a settlement measuring device provided on one side of the main body to measure a distance from the upper surface of the ground; and a load cell provided inside the main body to measure a load transmitted to the small-diameter pile; a loading unit which is pile driving equipment that applies a load to the small-diameter pile by pressing the upper surface of the main body of the measuring unit; and a monitoring unit which receives and displays the measured value measured by the measuring unit; The method comprises: (a) the step of constructing a plurality of small-diameter piles in the ground; (b) the step of selecting at least one of the plurality of small-diameter piles as a reference pile; (c) the step of applying a design load to the reference pile and then measuring the settlement according to the load and creating management reference data according to the measured load-settlement value; (d) the step of installing the measuring unit on the upper end of the remaining small-diameter piles excluding the reference pile as quality management target piles; (e) a step of applying a test load of 5 to 10% of the design load to the quality control target pile by pressurizing the main body of the measuring unit with a load; (f) a step of measuring the settlement of the quality control target pile by a settlement measuring device of the measuring unit; and (g) a step of calculating and displaying the expected settlement of the quality control target pile when the design load is applied from the management reference data according to the settlement measured by the monitoring unit when the test load is applied. The present invention provides a small-diameter pile quality control method characterized by comprising the steps of:

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According to another preferred embodiment, the present invention provides a small-diameter pile quality control method, characterized in that an upper socket is formed on the upper surface of the main body into which the lower end of the lower portion is inserted.

According to another preferred embodiment, the present invention provides a method for managing the quality of a small-diameter pile, characterized in that the lower part comprises a support frame comprising an upper fixing device supported on the lower part of the upper structure and a lower fixing device supported on the upper part of the lower structure, and a pressure member provided on the support frame for pressurizing the main body of the measuring part.

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According to the present invention, the following effects are achieved.

First, by installing a measuring section on the top of a small-diameter pile driven into the ground immediately after the construction of the small-diameter pile and applying a load to the lower portion to measure and output the amount of settlement, it is possible to predict and manage the amount of settlement when the design load is applied, thereby providing a method for managing the quality of small-diameter piles.

Second, a method for managing the quality of small-diameter piles can be provided that can increase pile bearing capacity by compressing the slime at the pile tip by applying an initial load to the lower portion.

FIG. 1 is a drawing illustrating an embodiment of a small diameter file quality management system.
Figure 2 is a perspective view showing a measuring section.
FIG. 3 is a drawing illustrating another embodiment of a small diameter file quality control system.
Figure 4 is a flow chart showing the construction sequence of the small-diameter file quality control method of the present invention.
Figure 5 is a graph showing the load-sinking amount information of the management standard data.

Hereinafter, the present invention will be described in detail with reference to the attached drawings and preferred embodiments.

Figure 1 is a drawing illustrating an embodiment of a small-diameter file quality management system, and Figure 2 is a perspective view illustrating a measuring unit.

As illustrated in FIGS. 1 and 2, the small-diameter pile quality control system is characterized by comprising: a measuring unit (3) comprising a main body (31) formed on the lower surface thereof with a lower socket (311) into which the upper end of a small-diameter pile (2) driven into the ground (1) is inserted; and a settlement measuring device (32) provided on one side of the main body (31) to measure the distance from the upper surface of the ground (1); a loading unit (4) for applying a load to the small-diameter pile (2) by pressing the upper surface of the main body (31) of the measuring unit (3); and a monitoring unit (5) for receiving and displaying the measured value measured by the measuring unit (3).

The present invention provides a method for managing the quality of small-diameter piles, which enables prediction and management of the amount of settlement when a design load is applied to a small-diameter pile (2) and increases the pile bearing capacity.

The above small diameter file quality management system is composed of a measuring unit (3), a loading unit (4), and a monitoring unit (5).

The above small diameter pile quality management system is intended to manage the quality of a small diameter pile (2) immediately after construction of the small diameter pile (2). A measuring unit (3) is installed on the top of a small diameter pile (2) driven into the ground (1), a load is applied, and the amount of settlement is measured and output.

The above measuring unit (3) is composed of a main body (31) and a sinkage measuring device (32).

The above main body (31) has a lower socket (311) formed on the lower surface into which the upper end of a small-diameter pile (2) rooted in the ground (1) is inserted.

In order to place the measuring part (3) on the top of the completed small-diameter pile (2), a lower socket (311) into which the top of the small-diameter pile (2) is inserted is formed on the lower surface of the main body (31) of the measuring part (3).

The above-mentioned settlement measuring device (32) is provided on one side of the main body (31) and measures the distance from the upper surface of the ground (1).

On one side of the main body (31) of the above measuring unit (3), a settlement measuring device (32) is provided to measure the settlement of a small-diameter pile (2) when a load is applied to the pile.

The above settlement measuring device (32) measures the settlement of the pile head by measuring the distance from the upper surface of the ground (1).

The above-mentioned lower part (4) presses the upper surface of the main body (31) of the measuring part (3) to apply a load to the small-diameter pile (2).

The above-mentioned load member (4) is provided on the upper part of the measuring part (3) and applies a load to the small-diameter pile (2) by pressurizing the measuring part (3).

The above-mentioned substructure (4) is to be loaded with only 5 to 10% of the design load immediately after construction of the small-diameter pile (2).

The above monitoring unit (5) receives and displays the measurement values measured by the measuring unit (3).

The amount of sinking measured by the above measuring unit (3) is output by the monitoring unit (5) and displayed on the display unit.

The above monitoring unit (5) may be equipped in the measuring unit (3), or, although not shown in the drawing, may be equipped as a separate device separated from the measuring unit (3).

As described above, in the present invention, quality control of the small-diameter pile (2) is possible by transmitting a loading force to the small-diameter pile (2) constructed by the measuring unit (3) and simultaneously measuring the amount of settlement.

In addition, the pile support capacity can be increased by compressing the slime present at the tip of the small-diameter pile (2) by applying the load of the above-mentioned sub-section (4).

As shown in Fig. 2, a load cell (33) for measuring the load transmitted to the small-diameter pile (2) by the loading of the load member (4) may be provided inside the main body (31).

A load cell (33) that measures the load transmitted to the small-diameter pile (2) by the load applied by the load of the load loader (4) may be provided inside the main body (31) of the above-mentioned measuring unit (3).

Therefore, in the above measuring section (3), not only the amount of settlement of the small-diameter pile (2) but also the size of the load applied can be accurately measured and managed even without separately managing the applied load in the loading section (4).

As shown in Fig. 1, the substructure (4) can be configured as a pile driving device.

The above-mentioned substructure (4) may be a pile driving device used when a small-diameter pile (2) is driven into the ground (1).

Accordingly, the above measuring part (3) is placed on the top of the small-diameter pile (2), and a load can be applied to the small-diameter pile (2) by the own weight and hydraulic pressure of the pile driving equipment that constructed the small-diameter pile (2).

Since the load applied by the above-mentioned substructure (4) is only about 5 to 10% of the design load, sufficient load can be applied using only the pile driving equipment.

As shown in Fig. 2, an upper socket (312) into which the lower part of the lower part (4) is inserted can be formed on the upper surface of the main body (31).

If the above-mentioned sub-assembly (4) is a pile driving device for constructing a small-diameter pile (2), an upper socket (312) into which an auger equipped at the bottom of the pile driving device is inserted can be formed on the upper surface of the main body (31) of the measuring device (3) so that the loading load of the sub-assembly (4) can be smoothly transferred to the measuring device (3).

When a load cell (33) is provided in the above body (31), the load cell (33) can be provided between the upper socket (312) and the lower socket (311) to measure the load transmitted between the lower part (4) and the small-diameter pile (1).

FIG. 3 is a drawing illustrating another embodiment of a small diameter file quality control system.

As shown in Fig. 3, the lower part (4) may be composed of a support frame (41) including an upper fixing device (411) supported on the lower part of the upper structure (6a) and a lower fixing device (412) supported on the upper part of the lower structure (6b), and a pressure member (42) provided on the support frame (41) to pressurize the main body (31) of the measuring part (3).

In remodeling work such as vertical expansion, small-diameter piles (2) are additionally constructed on the foundation of the existing building due to the additional load.

In this case, since small-diameter piles (2) are constructed using small equipment, it is difficult to use pile driving equipment to apply the load.

Therefore, the above-mentioned lower part (4) is composed of a support frame (41) and a pressure member (42), and the support frame (41) is fixed to the upper and lower structures (6a, 6b) of the existing structure. Then, by utilizing the existing structure as a reaction force, the measuring part (3) can be pressurized by the pressure member (42) to apply a load to the small-diameter pile (2).

The above support frame (41) can be composed of an upper fixing device (411) supported on the lower part of an upper structure (6a) such as an upper slab, and a lower fixing device (412) supported on the upper part of a lower structure (6b) such as a foundation plate or lower slab.

The above support frame (41) may be equipped with wheels (43) to facilitate movement and installation of the lower part (4).

The above pressurizing member (42) can be composed of a hydraulic jack, etc.

Figure 4 is a flow chart showing the construction sequence of the small diameter pile quality management method of the present invention, and Figure 5 is a graph showing the load-settlement amount information of the management standard data.

The small-diameter file quality management method of the present invention relates to a method for managing the quality of a small-diameter file using the small-diameter file quality management system described above with reference to FIGS. 1 to 3.

In the small-diameter pile quality control method of the present invention, first, (a) a plurality of small-diameter piles (2) are constructed on the ground (1).

The above small diameter pile (2) is installed to the target depth.

The above small diameter pile (2) is formed so that its head protrudes above the ground (1) or the bottom surface of the structure.

And (b) select at least one of the plurality of small-diameter files (2) as a reference file.

That is, among the multiple small-diameter files (2) that have been constructed, one or more small-diameter files (2) to be the reference file are selected.

Next, (c) after applying the design load to the above reference file, the settlement amount according to the load is measured and management reference data is created based on the measured load-settlement amount value.

Among the above small diameter piles (2), a design load is applied to the reference pile to measure the settlement amount according to the load, and management reference data is created based on the measured load-settlement amount value (Fig. 5).

Thereafter, (d) the measuring part (3) is placed on top of the remaining small-diameter files (2) excluding the reference file as the quality control target file.

Except for the above-mentioned standard file, the remaining small-diameter files (2) become files subject to quality control.

The measuring unit (3) is placed so that the upper part of the small-diameter file (2) is inserted into the lower socket (311) of the measuring unit (3) on the upper part of the quality control target file.

And (e) the main body (31) of the measuring part (3) is pressurized by the load part (4) to apply a test load smaller than the design load to the quality control target file.

In the above step (e), the measuring part (3) is pressurized by the lower part (4) to apply a load to the quality control target file.

At this time, the applied load is a test load that is smaller than the design load.

The above test load can be 5 to 10% of the design load.

When the above test load is less than 5% of the design load, it is difficult to predict the load-settlement trend because no significant settlement occurs.

If the above test load exceeds 10% of the design load, the applied load is excessively large, the equipment burden on the load section (4) is large, and the test time is long.

And (f) the settlement amount of the quality control target file is measured by the settlement amount measuring device (32) of the measuring unit (3).

After completing the test load in step (e) above, the settlement amount of the quality control target pile is measured by the settlement amount measuring device (32) of the measuring unit (3) in step (f).

Finally, (g) the monitoring unit (5) calculates and displays the expected settlement amount when the design load of the quality management target file is applied from the management standard data based on the measured settlement amount when the test load is applied.

That is, the expected settlement amount when the design load of the quality management target file is applied is calculated by referring to the management standard data created in step (c) for the measured test load-settlement amount value.

1: Ground 2: Small diameter pile
3: Measuring section 31: Body
311: Lower socket 312: Upper socket
32: Settlement measuring device 33: Load cell
4: Lower part 41: Support frame
411: Upper fixing device 412: Lower fixing device
42: Pressurized ball 43: Wheel
5: Monitoring section 6a: Superstructure
6b: Substructure

Claims (6)

The present invention relates to a method for managing the quality of small-diameter piles by a small-diameter pile quality management system, comprising: a main body (31) formed on the lower surface with a lower socket (311) into which the upper end of a small-diameter pile (2) driven into the ground (1) is inserted; a settlement measuring device (32) provided on one side of the main body (31) to measure the distance from the upper surface of the ground (1); and a load cell (33) provided inside the main body (31) to measure the load transmitted to the small-diameter pile (2); a loading device (4) which is pile driving equipment that applies a load to the small-diameter pile (2) by pressing the upper surface of the main body (31) of the measuring device (3); and a monitoring device (5) which receives and displays the measured value measured by the measuring device (3);
(a) A step of constructing multiple small-diameter piles (2) on the ground (1);
(b) a step of selecting one or more of the above multiple small-diameter files (2) as a reference file;
(c) a step of applying a design load to the above reference file, measuring the settlement amount according to the load, and creating management reference data according to the measured load-settlement amount value;
(d) a step of placing the measuring part (3) on top of the remaining small-diameter files (2) excluding the reference file as the quality control target file;
(e) a step of applying a test load of 5 to 10% of the design load to the quality control target file by pressurizing the main body (31) of the above measuring unit (3) with the load lower part (4);
(f) a step of measuring the amount of settlement of the quality control target file by the amount of settlement measuring device (32) of the measuring unit (3); and
(g) A small-diameter pile quality management method characterized by comprising: a step of calculating and displaying the expected settlement amount when the design load of the quality management target pile is applied from the management standard data according to the settlement amount measured when the test load is applied by the monitoring unit (5);
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A small diameter pile quality control method characterized in that an upper socket (312) is formed on the upper surface of the main body (31) into which the lower part of the lower part (4) is inserted.
In paragraph 1,
A method for managing the quality of small-diameter piles, characterized in that the above-mentioned substructure (4) is composed of a support frame (41) comprising an upper fixing device (411) supported on the lower part of the upper structure (6a) and a lower fixing device (412) supported on the upper part of the substructure (6b), and a pressurizing member (42) provided on the support frame (41) to pressurize the main body (31) of the measuring unit (3). delete

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