KR102511536B1 - Individual simultaneous tensile system capable of measuring load- displacement, anchor design method and anchor construction management technique therefor - Google Patents

Abstract

The present invention relates to an anchor construction management technique and an individual simultaneous tensile system capable of measuring stand-specific load-displacement and, more particularly, to an anchor construction management technique for ground anchors installed with different strand lengths and an individual simultaneous tensile system capable of measuring stand-specific load-displacement. When an integrated tensile machine is used using wedge seating portions and an individual load gauge, different forces generated in respective strands can be identified, and whether the sum thereof has secured anchoring force required for one ground anchor can be identified. When an individual simultaneous tensile machine is used, respective strands can be tensioned according to predetermined design load, so that even when any tensile machine is used, required design anchoring force can be secured. The individual simultaneous tensile system comprises first individual fixtures (600) through which strands (500) are fastened and which are seated on the bearing plate (410) of an anchor support body (400).

Description

Individual simultaneous tensioning machine system capable of measuring load-displacement and anchor design method and anchor construction management method according to it

The present invention relates to an individual simultaneous tensioner system capable of measuring load-displacement, and an anchor design method and anchor construction management method according thereto. It is about the long-term system, anchor design method and anchor construction management technique.

In the case of a retaining wall or a retaining wall supported by a ground anchor, the ground anchor is drilled into the ground where it can be settled, and the cement grout and the ground anchor anchorage are integrated within the perforation diameter to prevent the anchorage from being pulled out. It is to form a structural system that supports the retaining wall with the tensile force of the constituting strands.

In such a structural system, it is important to construct the anchor anchorage so that it has sufficient frictional resistance with the ground so that it does not pull out, and since each strand constituting the ground anchor has different stretches depending on the magnitude of the applied load, anchoring force is secured. Managing the amount of extension of each strand is also a very important part.

The ground anchor force and anchorage length (i.e., the length of the ground anchor strand) are determined according to the frictional resistance capability of the anchor anchorage and the ground to which the ground anchor is anchored. It will be different. Conventional ground anchors have been developed with design theories and construction methods on the premise that the lengths of all strands constituting one ground anchor are the same, and all current theories and construction methods follow them.

However, in recent years, when the ground on which the ground anchor is anchored is weak and the frictional resistance of the anchorage ground and the anchorage body is weak, when the length of the strand is the same, a large force is required from one anchorage, resulting in insufficient anchoring force There are cases.

In the method of tensioning ground anchors of different lengths constituting one ground anchor, designers sometimes suggest tensioning with individual simultaneous tensioners, but due to difficulties in using individual simultaneous tensioners and lack of supply, etc. The reality is that it is difficult to expect the anchoring force equal to the number of strands used because the strength generated by each anchor body is different from each other because the all-in-one tensioner used for ground anchors with all strands of the same length is used.

When an integral anchorage is used for an integral tensioner, the anchor force generated by each anchor body is different, and the distribution of force during the excavation process has a greater difference, or the load is biased on a certain anchorage, resulting in the ground anchor being pulled out or the strand wire The stability of the retaining wall is greatly reduced due to the phenomenon of fracture. And if anchor bodies of different lengths are tensioned with an integrated tensioner or integrated anchorage, the load is concentrated on the short anchor body, resulting in a drop in anchor strength due to the pull-out of the short anchor body. However, the displacement of the wall of the retaining facility greatly increases in the course of the series, greatly degrading the stability of the retaining facility, and causing great damage to the back structure. In addition, if an integrated load cell is used, it is impossible to know which strand is receiving which load among strands of different lengths, and load management for each strand is not possible. Therefore, an individual load cell must be installed to manage the load of each strand. .

In the case of using an integrated tensioner using a wedge seating part and an individual load gauge, the different forces occurring in each strand can be known, and the sum of them can be used to determine whether the anchoring force required by one ground anchor has been secured. In the case of using individual simultaneous tensioners, it is possible to tension each strand according to the design load determined for each strand, so that the intended purpose of securing the required design anchor force can be achieved regardless of the use of any tensioner.

In order to use detachable anchors with different lengths of strands, problems such as impossibility of construction with anchor support, integrated anchorage, and integrated load system that have been used in the past, the problem of load drifting to an arbitrary anchor due to the change in anchor force during excavation, and all There is a problem in that the stability of the retaining wall cannot be guaranteed because the sum of the strands can be known, but the magnitude of the force supported by each strand cannot be known.

In order to solve this problem, an anchor support having as many holes as the number of strands used in the ground anchor is required. Conventionally, an anchor support having one large hole is used, and all strands constituting the ground anchor are formed through this large hole. It was installed through the wire, and an integral anchorage with holes formed as much as the number of strands was installed on it to support the strands with wedges in the strands in the anchorage.

However, in order to solve the problem in the case of using an integrated anchorage, the wedge anchorage portion must be used for each strand, and when the wedge anchorage unit is installed on the conventional anchor support body with one large hole, the wedge anchorage portion falls into the hole, settlement cannot be formed.

In addition, in the case of a ground anchor composed of several anchor bodies, the length of each anchor body's strand is different, and the size of the load of each strand is different due to the anchored ground condition and ground confining pressure. Only then can the excavation proceed with securing the stability of the retaining wall.

Patent Registration No. 10-1631889 (2016.06.14) Patent Registration No. 10-1677693 (2016.11.14)

In the present invention, when an integral tensioner is used using a wedge mounting portion and an individual load gauge, the different forces generated for each strand can be known, and the sum of them can be used to determine whether the anchoring force required for one ground anchor is secured. In the case of using individual simultaneous tensioners, it is possible to tension each strand according to the design load determined for each strand, so that the intended purpose of securing the required design anchor force can be achieved regardless of the use of any tensioner.

The present invention includes an anchor support 400 in which a pressure plate 410 having a predetermined size is formed on the upper portion, and the pressure plate 410 has a predetermined number of strand passage holes 411 formed thereon;

A strand 500 installed through the pressure plate 410 of the anchor support 400,

A first individual fixture 600 fastened through the strand 500 and seated on the top of the pressure plate 410 of the anchor support 400;

An individual tension plate 700 in which a groove of a predetermined size is formed so that the upper portion of the first individual anchorage 600 is received and fastened;

A strand wire penetrating portion 820 is formed for the strand wire 500 to pass through, and a cylinder seating groove 810 is formed on one side for the cylinder 900 to be seated on, and on the other side, an individual tension plate 700 is accommodated and fastened. An upper tension plate 800 in which tension plate fastening grooves 830 are formed;

A cylinder 900 for tensioning the strand 500 and fastened through the strand 500 and seated on the upper portion of the first individual anchorage 600;

It is located on one side of the upper part of the pressure plate 410 of the anchor support 400, and the number corresponding to the number of the strands 500 is installed, but the reflector 1100 and the pressure plate 410 are installed on one side of each strand 500 A first distance measurement unit 1000, which is a sensor for measuring the distance between

A reflector 1100 positioned above the cylinder 900 but facing the first distance measurement unit 1000;

A load shell 1200 that is fastened through the strand 500 and positioned on top of the reflector 1100,

A second individual anchorage 1300 that is fastened through the strand 500 and is positioned on the upper portion of the load shell 1200 and is formed in various shapes through which each strand 500 can pass through and settle;

One side is connected to the line connected from the load shell 1200 and the first distance measurement unit 1000 to receive and record the load value measured from the load shell 1200 and the distance value measured from the first distance measurement unit 1000 Provides an individual simultaneous tensioner system capable of measuring load-displacement, characterized in that it includes a data log 1500 for the purpose, and an anchor design method and anchor construction management method accordingly.

In the present invention, when an integral tensioner is used using a wedge mounting portion and an individual load gauge, the different forces generated for each strand can be known, and the sum of them can be used to determine whether the anchoring force required for one ground anchor is secured. In the case of using individual simultaneous tensioners, each strand can be tensioned according to the design load determined for each strand, so that the required design anchor force can be secured regardless of the use of any type of anchor.

1 is a view showing the overall appearance of the individual co-tensioner system of the present invention.
2 is an exploded view of the individual co-tensioner system of the present invention.
3 is an exploded view of the first individual fixing tool 600 of the present invention.
4 is a view of an individual tension plate 700 according to the present invention.
5 is a view showing a cross section in which the first individual anchorage 600 of the present invention is fastened to the individual tension plate 700.
6 is a view of the upper tension plate 800 of the present invention.
7 is a cross-sectional side view illustrating a state in which an individual tension plate 700 is fastened to an upper tension plate 800 according to the present invention.
8 to 11 are views for explaining an individual simultaneous tensioner system capable of anchor construction management techniques of the present invention.
12 to 15 are views for explaining the installation sequence of the individual simultaneous tensioner system capable of measuring the load-displacement of each strand of the present invention.
16 relates to a graph shown by measuring the load-displacement of a ground anchor using the individual simultaneous load tension system of the present invention.
17 is a photograph showing how the data log 1500 of the present invention is installed.
18 is a picture showing the screen of the data log 1500 of the present invention.

The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors can properly define the concept of terms in order to explain their invention in the best way. Based on the principle, it should be interpreted as a meaning and concept consistent with the technical idea of the present invention.

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

1 is a view showing the overall appearance of the individual simultaneous tensioning machine system of the present invention. Strand wire 500, first individual anchorage 600, individual tension plate 700, upper tension plate 800, cylinder 900, first distance measurement unit 1000, reflector 1100, load shell 1200 , the second individual anchorage 1300, the second distance measurement unit 1400, and the data log 1500.

2 is an exploded view of the individual co-tensioner system of the present invention, and each component will be described in detail with reference to FIGS. 1 and 2.

The H beams 100 are installed at predetermined intervals in holes drilled in the ground.

The retaining plate 200 is formed in a plate shape of a predetermined size and is located between the H beams 100 installed adjacent to each other at a predetermined interval.

The wale 300 is installed at a predetermined interval in the vertical direction on one side of the H-beam 100.

The anchor support 400 has a pressure plate 410 of a predetermined size formed thereon, and the pressure plate 410 has a predetermined number of wire passage holes 411 formed thereon.

The strand wire passage hole 411 is a hole through which each strand wire 500 passes. As shown in FIG. 12, four strand wire passage holes 411 are formed in the pressure plate 411 so that four strand wires 500 are installed. .

The strand 500 is installed through the pressure plate 410 of the anchor support 400. That is, the strands 500 are formed in a predetermined number so as to individually penetrate through the strand passage holes 411 .

The plurality of strands 500 are installed, but each strand may be installed with the same length or different lengths. Since the present invention is the length of the strand, it is intended to explain design techniques and construction management methods that can be applied when installed with different lengths.

The anchorage 510 is installed at the end of the perforated ground of the strand 500, and each anchorage 510 is installed on each strand 500 to be installed.

The first individual anchorage 600 is fastened through the strand 500 and is seated on the top of the pressure plate 410 of the anchor support 400, and has various forms in which each strand 500 can pass through and settle. can be formed

That is, the first individual anchorage devices 600 are seated on top of the strand wire passage holes 411 formed in a predetermined number in the pressure plate 410 of the anchor support body 400, and each strand 500 individually penetrates and settles. It is built to be able to.

FIG. 3 is an exploded view of the first individual anchorage 600, and the first individual anchorage 600 includes a first wedge seating portion 610 and a first wedge portion 620.

The first wedge seating portion 610 has an accommodation hole corresponding to the outer appearance of the first wedge portion 620 to accommodate the first wedge portion 620 .

The first wedge portion 620 is formed such that its diameter increases from one side to the other.

The individual tension plate 700 is formed with a groove of a predetermined size so that the upper portion of the first individual anchorage 600 is accommodated and fastened.

The individual tension plate 700 can be confirmed through the drawing of FIG. 4, and is configured to include an upper tension plate fastening part 710 and a first individual anchorage fastening step part 720.

The upper tension plate fastening part 710 is for fastening to one side of the upper tension plate 800, and the first individual anchorage fastening step 720 has a step formed on one side of the inner hole so that the first individual anchorage 600 is fastened. will be.

5 is a view showing a cross section in which the first individual anchorage 600 is fastened to the individual tensile plate 700. When the strand is pulled in the direction of the arrow, the first wedge portion 620 of the first individual anchorage 600 moves in the direction of tension. The individual tension plate 700 serves to hold the first wedge portion 620 so that it does not move together along the .

Specifically, the movement of the first wedge portion 620 is restricted due to the first individual anchorage fastening step portion 720 of the individual tension plate 700 .

Referring to FIG. 6, the upper tension plate 800 has a strand wire penetrating portion 820 for passing the strand wire 500, one side is formed with a cylinder seating groove 810 for seating the cylinder 900, and the other side is formed with individual Individual tension plate fastening grooves 830 are formed so that the tension plate 700 is accommodated and fastened thereto.

The individual tension plate fastening grooves 830 of the upper tension plate 800 are formed in a cone shape and have a cross-sectional area decreasing in the direction toward the strand wire penetrating portion 820, so that the strand wire 500 can serve as a guide when tensioned. This is to allow the strand wire 500 to pass through the cylinder 900 well, and to ensure that the individual tension plate 700 is fastened and fixed.

6 (a) shows that the number of cylinder seating grooves 810 is changed according to the number of cylinders 900, and the drawing shows four cylinder seating grooves 810 for seating four cylinders 900.

7 is a cross-sectional side view illustrating a state in which an individual tension plate 700 is fastened to an upper tension plate 800 according to the present invention.

The cylinder 900 is for tensioning the strand 500, and is fastened through the strand 500 and seated on the upper part of the first individual anchorage 600, and is a device that performs linear reciprocating motion and is located within the cylinder 900. The piston rod 910 is formed to perform a linear reciprocating motion, and the strand 500 can be pulled or released due to the linear reciprocating motion of the cylinder 900.

The first distance measuring unit 1000 is located on one side of the upper portion of the pressure plate 410 of the anchor support 400, and a number corresponding to the number of strands 500 is installed, but is installed on one side of each strand 500. .

The first distance measurement unit 1000 is a sensor for measuring the distance between the reflector 1100 and the pressure plate 410, and is intended to measure the displacement of each strand 500.

The first distance measuring unit 1000 is preferably a laser for measuring distance, but other than that, anything capable of measuring distance, such as a tape measure, a string length strain gauge, an encoder, a potentiometer, or an LVDT, may be used.

The reflector 1100 is located above the cylinder 900 and is formed at a position facing the first distance measuring unit 1000 . The reflector 1100 is located above each cylinder 900 and is formed to measure the distance between the first distance measuring unit 1000 and the reflector 1100 .

The load shell 1200 is fastened through the strand 500 and is positioned above the reflector 1100. The load shell 1200 is installed to be connected to each of the strands 500 so as to manage the anchoring force that changes for each anchorage 510 of each strand 500 and re-tension when necessary.

The second individual anchorage 1300 is fastened through the strand 500 and is located on the upper portion of the load shell 1200, and can be formed in various shapes through which each strand 500 can pass through and be anchored. .

The second distance measuring unit 1400 is formed at a position spaced apart from the H-beam 100 by a predetermined interval, and by measuring the distance to the H-beam 100, the displacement of the wall can be confirmed, making it easy to grasp the state of the ground. There are advantages to doing so.

The second distance measurement unit 1400 is preferably a laser for measuring distance, but other than that, anything capable of measuring distance, such as a tape measure, a string length strain gauge, an encoder, a potentiometer, or an LVDT, may be used.

The data log 1500 has one side connected to a line connected from the load shell 1200 and the first distance measurement unit 1000, and the load value measured from the load shell 1200 and the distance measured from the first distance measurement unit 1000 It is for receiving and recording the value (displacement value). In addition, the data log 1500 is characterized in that a load-displacement curve is drawn based on the recorded load value and distance value (displacement value).

17 is a photograph showing a state in which the line 8 connected to the load shell 1200 and the first distance measuring unit 1000 is connected to the data log 1500.

18 is a photograph showing a screen on which measured values are recorded in the data log 1500. The load value (Ton) and displacement value (mm) are displayed, and a load-displacement curve can be drawn based on the displayed information.

In this way, the present invention can know the load acting on each strand through a load gauge or pressure gauge while tensioning the strand, and simultaneously measure the load-displacement by measuring the displacement gauge to draw the load-displacement curve of each anchor strand. It is characterized in that it includes up to the data log.

1 and 2 are diagrams for explaining an individual simultaneous tensioner system capable of anchor construction management techniques of the present invention.

The anchor construction management technique of the present invention is a state in which the H beam 100, the retaining board 200, the wale 300, the anchor support 400, the strand 500, and the first individual anchorage 600 are installed as shown in FIG. Applied in, the anchor construction management technique will be described with reference to FIG.

9 is a view of a first strand 500a and a second strand 500b, which are strands 500 having different lengths, and a first anchorage 510a is formed at the end of the first strand 500a. A second anchorage 510b is formed at the end of the double stranded wire 500b.

The present invention is characterized by improving the design method and the construction management method, unlike the conventional method.

First, the characteristics of the design method are described.

The present invention calculates the design anchor force of the first strand 500a and the second strand 500b having different lengths for the anchorage length actually constituted by each anchor body constituting one ground anchor, It is characterized by obtaining the design anchor force for that length.

The design method for examining the stability of the retaining facility of the present invention is as follows.

The design method of the present invention is based on a typical process, and a detailed description of the typical process is omitted.

The present invention provides a design method in which a load distributing anchor capable of utilizing the permissible limit of the frictional resistance of the ground at various points by varying the length of the strand is separately reviewing the length of the strand of each fixer configured in one ground anchor. Referring to 9, it is described as follows.

① Calculate the design anchor force required for the stability of the retaining wall according to the stability review theory of the general retaining facility.

② Determination of the type and number of strands of strands, distribution of the design anchor force of each anchor body, free field and anchorage field in consideration of the appropriateness of the design anchor force, estimated active surface (6) and anchorage ground (5) Decide. At this time, it is desirable to determine the anchorage by leaving a margin (6) in consideration of the reduction of tension.

③ Calculate the amount of reduction in tension generated when tensioned, considering the strand length of each anchor body and the required force. It is preferable to determine the anchorage length of the anchor body composed of the shortest strands in consideration of the location of the estimated active surface (6) within the minimum anchorage regulations.

④ Review the appropriateness of the type and number of strands required for the final tension of each anchor body, and if necessary, review again from the process of ②.

⑤ Final decision is made on the anchoring place of each anchor body that can exert the initial tension of each anchor body.

(Method 1)

In Fig. 9, the anchor body of the first strand 500a is (A) and the design anchor force is P ₁ . The first anchorage 510a is the anchorage of the anchor body A, and its length is 1 _a . The anchor body of the second strand 500b is (B) and the design anchor force is P ₂ . The second anchorage 510b is the anchorage of the anchor body (B), and its length _is lb. The ultimate circumferential friction resistance of the ground corresponding to the anchorage site of the anchor body (A) is τ _ua and the ultimate circumferential frictional resistance force of the ground corresponding to the anchorage site of the anchor body (B) is τ _ub .

Method 1 is a method that calculates the anchor force in proportion to the length of the anchorage corresponding to each strand and the ultimate frictional resistance. And the total design anchor force is obtained as the sum of the anchor forces P ₁ and P ₂ acting on each strand (design anchor force P=P ₁ +P ₂ ).

The equation for method 1 is as follows.

(Here, FS is a normal safety factor and is different depending on the design standard in case of permanent anchor and temporary anchor.)
(Here, D is a symbol that usually expresses the drilling diameter.)

(Method 2)

In Fig. 9, the anchor body of the first strand 500a is (A) and the design anchor force is P ₁ . The first anchorage 510a is the anchorage of the anchor body A, and its length is 1 _a . The anchor body of the second strand 500b is (B) and the design anchor force is P ₂ . The second anchorage 510b is the anchorage of the anchor body (B), and its length _is lb. The ultimate circumferential friction resistance of the ground corresponding to the anchorage of the anchor body (A) is τ _ua , and the required anchor force of the anchor body (A) is τ _a . And the ultimate circumferential frictional resistance of the ground corresponding to the anchorage of the anchor body (B) is called τ _ub .

Method 2 uses the ultimate circumferential friction resistance τ _ua of the ground of the anchorage as l _a for the anchorage of anchor body (A) corresponding to the anchor force of each anchor body, and the anchorage of anchor body (B) is l _a + l _b , but for _the ultimate frictional resistance at l _a , apply the remaining value after exerting the required anchor force of the anchor body (A), and for the ultimate frictional resistance at lb , use τ _ub of the ground to anchor Calculate P ₁ and P ₂ (design anchor force P=P ₁ +P ₂ ).

The equation for method 2 is as follows.

(Method 3)

The anchor body of the first strand 500a is (A) and the design anchor force is P ₁ . The first anchorage 510a is the anchorage of the anchor body A, and its length is 1 _a . The anchor body of the second strand 500b is (B) and the design anchor force is P ₂ . The second anchorage 510b is the anchorage of the anchor body (B), and its length _is lb. The ultimate circumferential friction resistance of the ground corresponding to the anchorage site of the anchor body (A) is τ _ua and the ultimate circumferential frictional resistance force of the ground corresponding to the anchorage site of the anchor body (B) is τ _ub .

Method 3 uses the application factor α obtained from the pull test to obtain P ₁ corresponding to the anchor body (A), and P ₂ is obtained by subtracting the application factor α from the total increase.

In the case of method 3, the application factor corresponding to the anchor body (A) is set to α, and the value of the application factor α is determined by a pull test.

Through the determined application factor, the design anchor force is obtained as shown in the following formula.

(Method 4)

In FIG. 9, the total anchorage length of the strand 500 is L , and the ultimate peripheral frictional force for the entire anchorage length is τ _u . The anchor body of the first strand 500a is (A) and the design anchor force is P ₁ . The first anchorage 510a is the anchorage of the anchor body A, and its length is 1 _a . The anchor body of the second strand 500b is (B) and the design anchor force is P ₂ . The second anchorage 510b is the anchorage of the anchor body (B), and its length _is lb. The ultimate circumferential friction resistance of the ground corresponding to the anchorage site of the anchor body (A) is τ _ua and the ultimate circumferential frictional resistance force of the ground corresponding to the anchorage site of the anchor body (B) is τ _ub .

Method 4 uses the application factor β obtained from the pull test to obtain P ₂ corresponding to the anchor body (B), and P ₁ is obtained by subtracting _{the anchor length lb} of the anchor body (B) from the total anchorage L .

In the case of method 4, the application factor corresponding to the anchor body (B) is set to β, and the value of the application factor β can be determined by a pull-out test.

Through the determined application factor, the design anchor force is obtained as shown in the following formula.

⑥ Calculate the amount of elongation of each strand for the force corresponding to the initial tension of each anchor body. By presenting the amount of elongation of each strand in this way, it is possible to determine whether each anchor body is anchored in the ground during construction and to know the anchor force exerted by each anchor body, so that the sum of each anchor force is the design anchor force. It can be a criterion for determining whether or not the retaining wall is maintained, so that the next excavation can proceed while checking the stability of the retaining wall.

As described above, the anchor forces P ₁ , P _{2 obtained for each anchor body (A) and (B) and} the amount of elongation of each strand are presented, and construction is performed to confirm them during construction.

The following relates to the construction management method applied to the present invention.

The specific items required for the construction and construction management of a ground anchor composed of several anchor bodies and having different lengths of strands are as follows.

① Anchor support 400 in which strand wire penetration holes 411 are formed in the pressure plate 410 to correspond to the number of strands 500

The anchor support 400 is an anchor support having as many strand passage holes as the number of strands. An anchor having as many strand passage holes as the number of strands by installing or replacing a pressure plate having as many holes as the strands in a conventional anchor support having one large hole. A support may be used.

② An anchorage 510 that is individually settled by installing as many as the number corresponding to the number of strands 500

Since the behavior of each anchor body (strand wire) is different depending on the magnitude of the load exerted by each strand of the anchor force that changes during tension or in the process of excavation, the wedge seating part is used for each strand.

③ Individual load gauges installed at each anchorage

The individual load gauge installed to measure the anchor force exerted by each strand 500 is placed on the top of the support plate with holes through the strand as many as the number of strands, and the anchoring force applied by fixing the strand by installing the wedge seating part on the individual load gauge It is read and managed by construction. In this case, the fixation and load of the strand can be measured by separately manufacturing and installing the wedge seating part and the individual load gauge. In addition, anchorage and load measurement can be performed at the same time by installing an individual load gauge equipped with an anchorage unit in which the anchorage and load gauge are integrated.

④ A construction management method that continuously manages the load using individual load gauges installed as many as the number of strands

After drilling a hole in the location where the ground anchor is to be constructed, inserting the ground anchor, injecting cement milk, and hardening it. When the initial tension is applied, a graph is drawn of the displacement generated by each anchor body's load stage by the length of the strand, and the length of each strand is measured. By managing the volume, it is possible to determine fixation quality of each anchor body.

Determine whether the sum of the loads exerted on each anchor body satisfies the initial tension force or design anchor force suggested by the design.

At the time of initial tension or during excavation, the load read from each individual load system is analyzed, and the anchor body with reduced load or additional tensionable anchor body is re-tensioned to manage the total anchor force to secure more than the design anchor force. Allows you to manage the stability of the wall.

The ground anchor, which is an anchorage with different lengths of strands, has different anchoring force (anchor force) exerted by anchoring for each anchorage, and the amount of extension of the strand is different depending on the anchorage, so the behavior of each anchorage is different. However, in the process of excavation, a settlement must be provided that can respond to this.

Therefore, the anchorage is separately installed for each anchorage, and each component for anchorage required for this is provided. That is, the present invention configures and installs anchorages individually for each strand, and in order to install anchorages individually, the pressure plate 410 is attached to the pressure plate 410 as many as the strands 500, rather than the conventional anchor support with one large hole. It is characterized by constituting the anchor support 400 in which the strand wire passage 411 is formed.

In addition, for ground anchors that have already secured tension in the process of proceeding with the next excavation after setting up anchorages individually, construction management, such as grasping the change in anchor force due to excavation, is required. 10, individual load gauges are installed for each anchorage 510 of each strand 500, as shown in FIG. It is characterized by construction management.

Although FIG. 10 shows five individual settlements, it goes without saying that the number may increase or decrease depending on the work site.

11 shows a state in which the strands are freely bent, and if tension is applied simultaneously, the pulling force for each strand may be different and a problem may occur. There is an advantage.

12 to 15 are views for explaining the installation sequence of the individual simultaneous tensioner system capable of measuring the load-displacement of each strand of the present invention.

In the installation sequence of the individual simultaneous tensioner system of the present invention, after the anchor support 400 and the strand 500 are constructed as shown in FIG. 12, the first individual anchorage 600 is used to fix the strand 500 as shown in FIG. is installed, and the individual tension plate 700, the upper tension plate 800, and the silicon 900 are sequentially installed on the top of the first individual anchorage 600. The installation up to the silicon 900 can be confirmed in FIG. 14 .

15 shows that the first distance measurement unit 1000, the reflector 1100, the load shell 1200, and the second individual anchorage 1300 are sequentially installed.

The following describes the construction management technique with the load-displacement curve that can be obtained with the individual simultaneous tensioner installed in this way.

The present invention is characterized in that whether or not the linearity of the load-displacement curve is secured up to the stage immediately before the pull-out load becomes the construction management criterion rather than the meaning of the upper and lower limits in the load-displacement curve previously used.

16 is a description of the type of load-displacement curve shown by measuring the load-displacement of the ground anchor using the individual simultaneous load tension system of the present invention.

Type of load-displacement curve ①

In the low load stage, it maintains the linearity of the elastic state well, but the displacement tends to increase at the final stage of load. The displacement occurring at the fixing part at a certain load between the load 1.0P _m and 1.2P _m means that the pull-out displacement occurs in addition to the elastic stretch and friction displacement of the strand.

In this load-displacement curve, 1.0P _m is regarded as the ultimate pull-out resistance force, and the value obtained by dividing this value by the safety factor should be regarded as the field design anchor force (modified design anchor force). If there is a need to increase the modified design anchor force, additional Efforts such as installing ground anchors, increasing anchorage, increasing anchorage diameter, and applying pressurized diameter packs are required.

Type of load-displacement curve ②

Up to the load stage of 1.0P _m, the displacement is large, but relatively linear, but the displacement decreases at the 1.2P _m load, which is increased.

This type can be seen as corresponding to the anchorage ground where the frictional displacement is larger in the anchorage than in the displacement up to the load stage of 1.0P _m , and the frictional displacement is rather decreasing at the location of the large load.

In other words, it is a case where the frictional displacement of the ground anchor is large at a low load level, or when the grout of the ground anchor anchorage is in a poor state and then the frictional characteristics between the grout and the ground improve as it is compressed, or a process in which a load of 1.2P _m is transferred to the anchorage part It can be seen that it corresponds to the case where the transition to the better ground began in .

Type of load-displacement curve ③

In all load stages, the elastic state (a state in which only the amount of elastic extension of the strand and the frictional displacement of the fixing part are shown) is well maintained, and no pull-out displacement occurs up to the maximum test load, which corresponds to the type with the best fixing state.

Type of load-displacement curve ④

In the low load stage, it may be judged that the fixing state is relatively poor due to the tendency _that the displacement is biased toward the large displacement or that the displacement occurs rather small compared to the load at the middle stage load (0.4P _m ). Since it is a shape in which linearity (elasticity) is secured overall, it is judged to be a type that can be seen as relatively good in a fixed state.

Type of load-displacement curve ⑤

It shows a curve in which the displacement rapidly increases according to the step of increasing the load, and it can be regarded as an anchored ground with a creep behavior that is highly likely to be pulled out continuously. Grounds with this behavior correspond to weathered soils with high water content, weathered rock grounds, and grounds with many clay and silt components.

If permanent anchors are installed on such ground, care must be taken because they can cause disasters such as continuous loss over a long period of time and eventually leading to large displacement. In other words, it should be judged that a shape showing creep behavior should be paid attention to in case of disaster.

If you want to use it for temporary facilities that require short-term use, you must conduct a creep test and carefully analyze the load-displacement curve to determine the proper size of the working load considering the displacement.

It is desirable to increase the construction anchor force and set the actual anchoring load to a lower value. Therefore, when applying the construction anchor force, do not use the anchoring wedge, apply the tensile load, remove the load, install the anchoring wedge, and then lower the anchoring force. A method of re-tensioning and fixing is preferred.

As such, the present invention analyzes the load and displacement graph obtained from the ground anchor test at the site, and according to the measurement results, it is possible to determine the appropriateness of the load and displacement of the ground anchor, and whether or not the stability of the anchoring state is maintained, thereby securing a safety factor. You can do construction management.

The embodiments described in this specification and the configurations shown in the drawings as described above are merely the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention, so various equivalents and modifications that can replace them It should be understood that there may be examples.

100H beam
200 bands
300 retaining board
400 anchor support
410 acupressure plate
500 strands
600 1st Individual Settlement District
610 First wedge seating part
620 first wedge
700 Individual Tension Plate
800 upper tension plate
810 cylinder seating groove
820 Strand Wire Penetration
830 Individual tension plate fastening part
900 cylinder
910 piston rod
1000 1st distance measuring unit
1100 reflector
1200 loadshell
1300 2nd Individual Settlement District
1310 2nd wedge seating part
1320 second wedge
1400 second distance measuring unit
1500 datalog

Claims (8)

An anchor support 400 in which a pressure plate 410 having a predetermined size is formed on the upper portion, and the pressure plate 410 has a predetermined number of strand passage holes 411 formed therein;
A strand 500 installed through the pressure plate 410 of the anchor support 400,
A first individual fixture 600 fastened through the strand 500 and seated on the top of the pressure plate 410 of the anchor support 400;
An individual tension plate 700 in which a groove of a predetermined size is formed so that the upper portion of the first individual anchorage 600 is received and fastened;
A strand wire penetrating portion 820 is formed for the strand wire 500 to pass through, and a cylinder seating groove 810 is formed on one side for the cylinder 900 to be seated on, and on the other side, an individual tension plate 700 is accommodated and fastened. An upper tension plate 800 in which tension plate fastening grooves 830 are formed;
A cylinder 900 for tensioning the strand 500 and fastened through the strand 500 and seated on the upper portion of the first individual anchorage 600;
It is located on one side of the upper side of the pressure plate 410 of the anchor support 400, and the number corresponding to the number of the strands 500 is installed, but the reflector 1100 and the pressure plate 410 are installed on one side of each strand 500 A first distance measurement unit 1000, which is a sensor for measuring the distance between
A reflector 1100 positioned above the cylinder 900 but facing the first distance measurement unit 1000;
A load shell 1200 that is fastened through the strand 500 and positioned on top of the reflector 1100,
A second individual anchorage 1300, which is fastened through the strand 500 and is positioned on the top of the load shell 1200, and is formed in various shapes through which each strand 500 can penetrate and settle;
One side is connected to the line connected from the load shell 1200 and the first distance measurement unit 1000 to receive and record the load value measured from the load shell 1200 and the distance value measured from the first distance measurement unit 1000 An individual simultaneous tensioner system capable of measuring load-displacement, characterized in that it comprises a data log (1500) for. According to claim 1,
H beams 100 installed at predetermined intervals in holes drilled in the ground;
A retaining plate 200 formed in a plate shape of a predetermined size and located between H beams 100 installed adjacent to each other at a predetermined interval;
A wale 300 installed at a predetermined interval in the vertical direction on one side of the H beam 100,
An individual simultaneous tensioner system capable of measuring load-displacement, characterized in that it includes a second distance measuring unit 1400 formed at a position spaced apart from the H beam 100 on which the anchor support 400 is installed. According to claim 1 or 2,
The data log 1500 is
A load-displacement curve graph is drawn based on the recorded load and distance values,
The load-displacement curve graph is
(1) In the case of a curve that maintains linearity at a low load level and the displacement increases toward the end, it is judged that the pull-out displacement occurs in addition to the elastic stretch and friction displacement of the strand,
(2) In the case of a curve in which the amount of displacement decreases when a predetermined load is applied while maintaining linearity, it is a fixed ground with a large frictional displacement at a low load level, or the grout of the ground anchor fixer is in a poor state and is compressed, causing the grout and the ground It is judged that the frictional property of is improved or the ground transition is made smoothly in the process of transferring a predetermined load to the fixing unit,
(3) If the curved line maintains a certain linearity, it is judged that the fixing state is good,
(4) If one side is a curve in which displacement is less than the load while maintaining linearity, it is judged that the linearity is secured,
(5) In the case of a curve in which the displacement increases as the load increases, it is a shape showing creep behavior and it is to determine that attention should be paid to disasters,
An individual simultaneous tensioner system capable of measuring load-displacement, characterized in that it has an anchor management technique for managing anchors through the load-displacement curve graph.


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