KR100958405B1 - Non-destructive measurement method of pullout resistance in cable structures and device for the same - Google Patents

Abstract

PURPOSE: A pullout resistance measuring method for a cable structure by a non-destructive technique and a measuring system using the same are provided to measure an exact friction force between an object ground and a grout by considering the scale and the natural frequency of a cable which is built in an object ground. CONSTITUTION: A pullout resistance measuring system for a cable structure by a non-destructive technique comprises: a resisting force supplying unit which applies resisting force to a cable structure(4) which is built in an object ground; and a measurement unit which measures the vibration of a cable structure. The resisting force supplying unit comprises: a support stand(20) which is installed in an object ground; a latch for a load loading which is installed in the top portion of the support stand; a weight(11) which hangs on the latch for a load loading; a guide bar(12) which guides an elevation of the weight; an anvil for being struck(10); and a coupler(15).

Description

Non-destructive measurement method of pullout resistance in cable structures and device for the same}

The present invention relates to the measurement of the pull-out resistance of the cable structure, and relates to an economic and stable method for measuring the pull-out resistance of the cable structure using a non-destructive technique.

In general, the principal surface friction of the cable structure (soil nailing, anchor, etc.) to be built on the ground can be said to be the most important resistance element in the design.

In most cases, a pullout test will be performed to reflect principal friction in the design. However, the drawing test is not only time-consuming and expensive, but it is also difficult to secure the stability of the drawn section.

In addition, it can be said to be a limited test because there are limited places to draw. That is, performing the test by drawing directly in the field has a problem that it is difficult not only to guarantee economic efficiency and stability but also to test in large quantities.

In other words, the existing pullout test does not know the main frictional force distribution but only the total pullout resistance. Therefore, the design of the main surface friction is the same throughout the cable structure without considering the fracture stage. There is a problem that can be done.

Therefore, if the frictional force can be estimated by using non-destructive measuring equipment without drawing cable structure, it can not only ensure economic efficiency and stability but also test in large quantities.

Recently, various measurement methods using non-destructive techniques have emerged. Pile driving analyzer (PDI) developed by PDI of USA is one of the most used equipments in the ground field as a device for calculating pile resistance. However, the PDA (Pile Driving Analyzer) is an equipment optimized for pile specifications and it is difficult to apply it to the cable structure installed on the ground.

Therefore, there is an urgent need to develop a method and a device for measuring the resistance to pull resistance using a non-destructive technique that can calculate the exact principal frictional force acting between the ground and the grout in consideration of the size and natural frequency of each cable structure constructed in the ground. That is, the development of a method and apparatus for measuring non-destructive pullout resistance that is optimized to be applied to various cable structures constructed on the target ground is required.

The present invention is to solve the above-mentioned problems of the prior art, to enable more economical and stable measurement of the main surface friction force between the target ground and the cable structure in the cable installed on the target ground using a non-destructive technique The purpose is.

In addition, an object of the present invention is to provide a load-loading device considering the drawing and compression behavior of each cable structure and the navigation method that can maximize the energy efficiency in order to achieve accurate measurement.

In order to achieve the above object, the present invention provides a method for measuring the pullout resistance of a cable structure constructed on the target ground; Applying a driving force to the cable structure, measuring vibrations reflected from the cable structure subjected to the driving force, and analyzing the measured vibrations to measure the resistance between the target ground and the cable structure. Provided is a method of measuring pullout resistance of a cable structure.

At this time, the drag force applied to the cable structure is characterized in that the compression load acting in the compression direction of the cable structure or the draw load acting in the drawing direction of the cable structure.

In addition, the vibration is characterized by being detected by the accelerometer and strain meter as a compression wave or tensile wave.

On the other hand, according to another aspect of the present invention for achieving the above object, and a driving force providing means capable of applying a driving force to the cable structure constructed on the target ground, and the driving force is applied after the driving force is applied to the cable structure An apparatus for measuring pullout resistance of a cable structure is provided, including measuring means for measuring vibration of the applied cable structure.

In the above-described configuration, according to the first embodiment of the anti-force force providing means, the support is installed on the target ground, the load restraining latch provided on the upper end of the support, the weight caught on the load restraining latch, A guide bar installed to guide the lifting and lowering of the weight, a hitting anchor which is fixed to the lower side of the guide bar and receives a load when the weight falls, and transmits a compressive load to the cable structure; It characterized in that it comprises a coupler for engaging.

In the above-described configuration, according to the second embodiment of the anti-force force providing means, the support is installed on the target ground, the pulley is installed on the upper end of the support, the load-carrying latch connected to the connecting line provided on the pulley, A weight connected to the load-carrying clasp, a guide bar for guiding the lifting and lowering of the weight, an anchor for hitting to be fixed to the lower side of the guide bar to receive a load when the weight falls and to transmit a compressive load to the cable structure; And a coupler for engaging the hitting anvil and the cable structure with each other.

In the above-described configuration, according to the third embodiment of the anti-force force providing means, the first support is installed on the target ground, the first pulley provided on the upper end of the first support, and the connection line provided on the first pulley The first weight is connected to, the first guide bar is installed to guide the lifting of the first weight, the first guide bar is provided on the upper end of the first guide bar to avoid receiving a load when the first weight rises to transfer the tensile load to the cable structure A striking anvil, a coupler for coupling the lower end of the first guide bar and the cable structure to each other, a second support provided separately from the first support, a second pulley installed on the upper end of the second support; A second weight connected to the first weight through a connecting line installed in the second pulley and having a greater load than the first weight, and a second guide installed to guide the lifting of the second weight; And, it characterized by configured including a latch for loading so that the second weight to stay on the upper end of the second guide bar.

On the other hand, in the above-described configuration, according to the fourth embodiment of the anti-force force providing means, the support is provided on the target ground, the weight is provided on the upper side of the support, and the load for providing a lifting force to the weight An elastic member, a latch member installed to control the lifting force of the weight due to the elastic force of the load-bearing elastic member, a guide bar installed to guide the lifting of the weight, and fixed to the upper end of the guide bar when the weight is raised It is characterized in that it comprises a hitting anvil for transmitting the tensile load to the cable structure under load, and a coupler for mutually binding the hitting anvil and the cable structure.

In the above-described configuration, the measuring means is characterized by consisting of a strain gauge and an accelerometer selected and installed in accordance with the natural frequency according to the type of cable structure.

In addition, the accelerometer and the strain meter is installed on the hitting anvil, it is characterized in that it may be installed in other parts, such as other guide bar.

The hitting anvil is preferably a T-shaped in cross section, and includes a hitting part and an instrument mounting part, wherein the hitting part performs the function of an anvil receiving a load of a weight, and the instrument mounting part has an accelerometer and a strain gauge mounting space. Characterized in that to provide.

On the other hand, the measuring instrument mounting portion is characterized in that it is provided with a portion that can be connected with the coupler.

And, on the outer peripheral surface of the lower side of the coupler is formed a bolt fastening hole for integral behavior between the nail and the coupler inserted into the nail insertion groove formed in the lower portion of the coupler, the fixing bolt is fastened to the bolt fastening hole.

On the other hand, the coupler and the nail is characterized in that can be combined to be integrally behaved by welding.

And, the load-carrying latch is configured to include a ring coupled to the upper end of the support and provided with an opening in the lower center, and a cross pin installed across the opening below the ring.

As described above, the present invention measures the resistance force between the target ground and the cable structure through the reflected wave that is attached to the strain band and the accelerometer according to the frequency band of each cable and returned by driving. Therefore, the cable structure does not need to be drawn separately from the ground, and it is possible to obtain the pullout resistance through signal analysis by measuring the strain from the signal generated by the simple stroke.

The effects of the present invention can first measure the exact principal surface friction force acting between the target ground and the grout in consideration of the size and natural frequency of each cable structure to be constructed on the target ground.

In addition, the resistance between the cable structure and the target ground can be accurately measured using non-destructive techniques, which not only economically and stably draw resistance can be measured. .

On the other hand, since the present invention is an indirect method of calculating the pull resistance indirectly by vibration measurement by the anti-force force in contrast to the conventional direct pull test, it is possible to evaluate the stability of the target ground in a relatively simple method and low cost compared to the conventional pull method. Compared to the conventional drawing test for experimenting with one cable structure, the measuring method of the present invention has the advantage that the test can be performed on all of the constructed cable structures.

Further, according to the present invention, since the behavior of the target ground and the cable structure can be measured periodically even after the construction of the cable structure is completed, there is an advantage that a real-time measurement system can be provided.

In particular, while the existing direct pull test was able to know only the magnitude of the principal surface friction, the non-destructive test method of the present invention can grasp the distribution of the principal surface friction force can lead to economic design of the cable structure. In other words, the distribution of principal surface friction force and pullout resistance for each position of the cable can be estimated through the program analysis using the data obtained through the strain gauge and the accelerometer.

On the other hand, because the characteristics of materials or scale of the cable structure (soil nailing, anchor, etc.) and the mechanism of behavior with the ground is different, the inherent frequency of each cable structure is different, according to the present invention using a measuring instrument It is possible to determine each natural frequency and to present the application range of the measuring device according to each cable structure.

Hereinafter, the pullout resistance measuring apparatus of the cable structure according to a specific embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Example 1

2A and 2B are diagrams illustrating an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a first embodiment of the present invention, and FIG. 2A illustrates a state before dropping of a weight for compressive load. 2b shows the state after the weight has fallen.

2A and 2B, the drawing resistance measuring apparatus of the cable structure 4 according to the present embodiment is a measuring device through the compressive load, the driving force to the cable structure (4) constructed on the target ground (50) And a measuring means for measuring vibration of the cable structure to which the driving force is applied after the driving force is applied to the cable structure 4.

In the above-described configuration, the drag force providing means, the support 20 is installed on the target ground (50) (see Fig. 1), the load-loading latch 21 is provided on the upper end of the support 20, The weight 11 caught by the load-carrying clamp 21, the guide bar 12 installed to guide the lifting and lowering of the weight 11, and the weight 11 fixed below the guide bar 12. The hitting anvil 10 to transfer the compressive load to the cable structure 4 when the load is dropped, and the coupler 15 for binding the hitting anvil 10 and the cable structure 4 to each other. It is configured to include.

On the other hand, in the above-described configuration, the measuring means is composed of a strain gauge 14 and an accelerometer 13 selected and installed in accordance with the natural frequency according to the type of cable structure, the accelerometer 13 in the present embodiment And the strain gauge 14 is installed in the hitting anvil 10.

At this time, the hitting anvil 10 is preferably a T-shaped in cross-section, the hitting portion 10a of the hitting anvil 10 performs a function of receiving a load of the weight 11, The meter mounting portion 10b of the hitting anvil will provide a space for mounting the accelerometer 13 and the strain gauge 14.

On the other hand, the fastening groove 10d formed in the center of the hitting portion 10a of the hitting anvil is for assembling and coupling with the guide bar 12.

And, the support 20 is made of a tricycle form, the reference numeral 11a is a hang line used to tie the weight.

7A and 7B, the load-carrying latch 21 is coupled to the upper end of the support 20 and has a ring 21a having an opening 210a at the lower center thereof, and the ring 21a. It is configured to include a cross pin (21b) installed across the opening (210a) on the lower side.

The drawing resistance measurement method and its action of the cable structure 4 using the non-destructive method of the present embodiment configured as described above are as follows.

First, as shown in FIG. 2A, the cross pin 21b is pulled out while the weight 11 is hung on the load-carrying clamp 21 so that the opening 210a of the ring 21a is opened. The weight (11) hanging on the free fall down along the guide bar (12).

Since the weight 11 is capable of sufficiently exhibiting the resistance between the target ground 50 and the cable structure 4, when the weight 11 dropped as shown in Figure 2b hit the anvil 10, the impact force is the cable Passed to the structure 4 is excited.

Then, the excited signal is moved toward the anvil 10 connected to the cable structure 4 again, and is reflected from the cable structure 4 in the accelerometer 13 and the strain meter 14 mounted on the anvil 10. The coming vibration is measured, and the measured vibration is analyzed to measure the resistance between the target ground 50 and the cable structure 4.

That is, in the compression test, the weight 11 falls freely downward and strikes the anvil 10, and the excited signal is transferred to the anvil 10, so that the accelerometer 13 and the strain gauge 14 In this embodiment, the anvil 10 is an important element that not only accommodates the driving force but also connects the load-bearing equipment and the cable structure 4 in this embodiment.

Example 2

3A and 3B are diagrams illustrating an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a second embodiment of the present invention. FIG. 3A illustrates a state before dropping of a weight for a compressive load. 3b shows the state after the weight has fallen.

The drawing resistance measuring apparatus of the cable structure according to the present embodiment is a measuring device of yet another structure through a compressive load, and provides a drag force for applying a driving force to the cable structure (4) constructed on the target ground (50) And measuring means for measuring vibration of the cable structure after the hitting force is applied to the cable structure 4.

In this case, the drag force providing means, the support 20 is installed on the target ground 50, the pulley 22 is installed on the upper end of the support 20, and the connection line 23 provided on the pulley 22 Load loading braces 21 to be connected, the weight 11 connected to the loading braces 21, the guide bar 12 for guiding the lifting of the weight 11, and the guide bar 12 The hitting anvil 10 and the hitting anvil 10 and the cable structure 4 which are fixed to the lower side and receive a load upon falling of the weight 11 and transmit a compressive load to the cable structure 4. And a coupler 15 for engaging with each other.

On the other hand, the measuring means is composed of a strain gauge 14 and an accelerometer 13 selected and installed in accordance with the natural frequency according to the type of cable structure, the accelerometer 13 and the strain meter 14 in the present embodiment ) Is installed in the anvil (10).

At this time, the hitting anvil 10 is preferably a T-shaped in cross-section, the hitting portion 10a of the anvil performs a function of receiving a load of the weight 11, the measuring instrument mounting portion 10b of the anvil It provides a space for mounting the accelerometer 13 and the strain gauge 14.

And, the support 20 is made of trivet form.

The action of the apparatus for measuring the pullout resistance of the cable structure using the non-destructive method of the present embodiment configured as described above and the non-destructive measurement method using the same are as follows.

First, as shown in FIG. 3A, when the connection line 23 wound around the winch (not shown) is released and the weight 11 is positioned at the upper end of the guide, the connection line 23 connected to the pulley 22 is released. As shown in FIG. 3B, the weight 11 free falls down along the guide bar 12.

In this case, the weight 11 may exhibit sufficient resistance between the target ground 50 and the cable structure 4. When the dropped weight 11 strikes the hitting anvil 10, the hitting force may be a cable structure ( 4) Be delivered to and excited.

Then, the excited signal is moved toward the anvil 10 connected to the cable structure 4 again, and is reflected from the cable structure 4 in the accelerometer 13 and the strain meter 14 mounted on the anvil 10. The coming vibration is measured, and the measured vibration is analyzed to measure the resistance between the target ground 50 and the cable structure 4.

That is, in the compression test, the weight 11 falls freely downward and strikes the anvil 10, and the excited signal is transferred to the anvil 10 and the accelerometer 13 and the strain gauge 14 As measured in, the anvil 10 is an important element that not only accommodates the driving force in this embodiment, but also connects the load-bearing equipment and the cable structure 4.

Example 3

4A and 4B are diagrams illustrating an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a third embodiment of the present invention, and FIG. 4A illustrates a state before a first weight rise for loading load. 4B shows a state after the first weight is raised.

The drawing resistance measuring device of the cable structure according to the present embodiment is a measuring device through the load load, the drag force providing means that can apply a drag to the cable structure (4) constructed on the target ground 50, the cable And measuring means for measuring vibration of the cable structure 4 to which the driving force is applied after the driving force is applied to the structure 4.

At this time, the drag force providing means, the first support 20a is installed on the target ground 50, the first pulley 22a is installed on the upper end of the first support 20a, and the first pulley 22a A first weight 11a connected to the connection line 23 installed at the first side, a first guide bar 12a installed to guide the lifting and lowering of the first weight 11a, and an upper end of the first guide bar 12a. The hitting anvil 10 which is provided in the first weight (11a) to receive the load when the load rises to the cable structure (4), and the lower end and the cable structure (4) of the first guide bar (12a) ) And a coupler 15 for mutually binding, a second support 20b separately installed outside the installation position of the first support 20a of the target ground 50, and an upper end of the second support 20b. The first drawing 11b is connected to the first weight 11a through a connecting line 23 installed at the second pulley 22b and has a larger load than the first weight 11a. The second weight 11b, the second guide bar 12b installed to guide the lifting of the second weight 11b, and the second weight 11b at the upper end of the second guide bar 12b. It is configured to include a load clamping clamp 21 to be.

In addition, the stopper 18 is preferably provided at the lower side of the first guide part so as to limit the lowering position of the first weight 11a.

On the other hand, the measuring means is composed of a strain gauge 14 and an accelerometer 13 selected and installed in accordance with the natural frequency according to the type of cable structure 4, in the present embodiment the accelerometer 13 and the strain meter 14 is installed in the first guide bar 12a on the lower side of the stopper 18.

In addition, the first support 20a and the second support 20b have a tricycle form.

And, referring to Figure 7, the load-carrying latch 21 is coupled to the upper end of the second support (20b) and the ring 21a is provided with an opening 210a in the lower center, and below the ring (21a) It is configured to include a cross pin 21b installed across the opening 210a.

The action of the apparatus for measuring the pullout resistance of the cable structure using the non-destructive method of the present embodiment configured as described above and the non-destructive measurement method using the same are as follows.

First, as illustrated in FIG. 4A, the cross pin 21b is pulled out while the second weight 11b is caught by the cross pin 21b installed across the opening 210a of the load-carrying clamp 21. When the opening 210a of the ring 21a is opened, the second weight 11b hanging on the ring 21a freely falls down along the second guide bar 12b.

In this case, since the first weight 11a is smaller in weight than the second weight 11b and is connected to the second weight 11b by a connecting line 23, the first weight 11a is the first guide bar. It rises from the lower side to the upper side along 12a.

Therefore, as shown in FIG. 4B, when the first weight 11a rises and strikes the anvil 10, the striking force is transmitted through the first guide bar 12a coupled to the first anvil 10. It is transmitted to the cable structure 4 and is excited.

In addition, the excited signal is transmitted to the lower side of the first guide bar 12a connected to the cable structure 4 again, and the accelerometer 13 and the strain gauge 14 mounted below the first guide bar 12a are connected to the cable. The vibration reflected from the structure 4 is measured, and the measured force is analyzed to measure the resistance force between the target ground 50 and the cable structure 4.

That is, in the present embodiment, when the tension test is applied to the cable structure 4, the second weight 11b freely descends downward, and the first weight 11a connected thereto rises to raise the anvil 10. The excitation signal is transmitted to the accelerometer 13 and the strain gauge 14 to be measured.

Example 4

5A and 5B are diagrams illustrating an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a fourth embodiment of the present invention, and FIG. 5A illustrates a state in which an elastic member is compressed before a weight rise for a compressive load. 5b shows the state after the weight is raised.

The drawing resistance measuring device of the cable structure according to the present embodiment is a measuring device through the load load, the drag force providing means that can apply a drag to the cable structure (4) constructed on the target ground 50, the cable And measuring means for measuring the vibration of the cable structure after the impact is applied to the structure 4.

In this case, the driving force providing means, the support 20 is installed on the target ground 50, the weight 11 is installed on the upper side of the support 20, and providing a lifting force for the weight 11 Lifting and lowering of the load member elastic member 31, the latch member 32 which is installed to control the lifting force of the weight 11 by the elastic force of the load-bearing elastic member 31, A guide bar 12 installed to guide the fixed bar at the upper end of the guide bar 12 and receiving a load when the weight 11 rises to transmit a tensile load to the cable structure 4; In addition, the guide bar 12 is configured to include a coupler (15) for coupling the lower end and the cable structure (4).

On the other hand, the measuring means is composed of a strain gauge 14 and an accelerometer 13 selected and installed in accordance with the natural frequency according to the type of cable structure, the accelerometer 13 and the strain meter 14 in the present embodiment Is installed on the lower end of the guide bar 12.

And, in the present embodiment, the latch member 32 is installed to be slidable in the radial direction on the upper surface of the support 20, the support 20 is made of a trivet form.

The action of the apparatus for measuring the pullout resistance of the cable structure using the non-destructive method of the present embodiment configured as described above and the non-destructive measurement method using the same are as follows.

First, as shown in FIG. 5A, when the latch member 32 installed on the upper surface of the support 20 moves in a radially outward direction while the weight 11 is positioned at the upper end of the guide, the weight 11 is moved. Is released from the restraint of the latch member 32.

Accordingly, the weight 11 rises upward along the guide bar 12 due to the action of the elastic restoring force of the elastic member 31, and is installed at the upper end of the guide bar 12 as shown in FIG. 5B. Anvil 10 will be hit.

And, the weight 11 is that the resistance between the target ground 50 and the cable structure 4 can be sufficiently exhibited, if the raised weight 11 hits the hitting anvil 10, the hitting force is The first guide bar 12a coupled to the anvil 10 is transmitted to the cable structure 4 and is excited.

In addition, the excited signal is transmitted to the lower side of the first guide bar 12a connected to the cable structure 4 again, and the accelerometer 13 and the strain gauge 14 mounted below the first guide bar 12a are connected to the cable. The vibration reflected from the structure 4 is measured, and the measured force is analyzed to measure the resistance force between the target ground 50 and the cable structure 4.

That is, when the non-destructive test is carried out by loading load, the weight 11 rises upward and strikes the anvil 10, and the excitation signal from the cable structure 4 is transferred to the accelerometer 13 and the strain rate. It is measured by the system 14.

As shown in [Example 1] to [Example 4], the load-loading equipment is divided according to the compression and pullout resistance characteristics of each cable structure 4, and the excitation is caused by the impact of the weight 11. Here, the weight 11 should be a size that can sufficiently exhibit the resistance between the target ground 50 and the cable structure (4). When the signal is excited by the weight 11, the signal moves to the cable structure 4 through the hitting anvil 10 as in [Example 1] and [Example 2], or [Example 3]. And a signal moves to the cable structure 4 through the guide bar as in [Example 4].

In the compression test, as shown in FIGS. 2 and 3, the weight 11 falls freely and strikes the anvil 10, and when the pull test is performed, the weight 11 is shown in FIGS. 4 and 5. As such, it is divided into two types according to the condition of the ground to be constructed.

4 is a load-loading device which draws using the weight of the free-falling weight as the driving device for the vertical test, and FIG. 5 uses the restoring force of the elastic member 31 such as a spring when the cable structure is constructed on the inclined ground. The weight 11 is a load-bearing device that draws by hitting the anvil (10).

By means of these four embodiments, the weight 11 strikes the anvil 10 along each guide bar and the compression and tension waves are moved to the cable structure 4 according to each method.

And, since the excited signal is transferred to the part where the measuring means is installed again, the connection structure of the connection part between the site where the measuring means is installed and the cable structure 4 is a very important factor.

If, as in [Example 1] and [Example 2], the measuring instrument mounting portion 10b of the anvil 10 and the nail 41 of the cable structure 4 are not densely connected, or [Example 3] and When the guide bar 12 and the nail 41 of the cable structure 4 are not densely connected as in the fourth embodiment, the attenuation meter 14 may be greatly changed since the attenuation of the excited signal or the measured value may be greatly changed. (B) Joining the site where the measuring means, such as the accelerometer 13, is installed and the cable structure 4 can be made robust and compact.

Meanwhile, a perspective view of the hitting anvil is disclosed in FIG. 6A, wherein the hitting anvil 10 can receive an excited and reflected signal with the hitting portion 10a loaded by the weight 11. Instrument mounting portion 10b on which accelerometer 13 and strain gauge 14 are mounted, and a portion 10c that can be connected to coupler 15 that connects to nail 41 of cable structure 4. .

That is, as mentioned above, the hitting anvil 10 is preferably a T-shaped in cross section, and includes a hitting part 10a and an instrument mounting part 10b, and the hitting part 10a is a weight. (11) serves to receive the load, the instrument mounting portion (10b) is to provide a space for mounting the accelerometer 13 and the strain gauge (14).

In addition, a lower portion of the measuring instrument mounting portion 10b is provided with a portion 10c that may be connected to a threaded coupler, and is screwed into a fastening groove 15a formed on the coupler 15.

On the other hand, Figure 6b is a partial cutaway perspective view of the coupler that binds the nail portion and the guide bar of the cable structure integrally, nail insertion groove 15c formed on the lower side of the coupler 15 on the outer peripheral surface of the lower side of the coupler 15 The bolt fastening hole 15d is formed for the integral operation of the nail 41 and the coupler 15 of the nail structure inserted into the nail structure, and the fixing bolt 16 is fastened to the bolt fastening hole 15d.

In the present invention, since the attenuation problem of the wave may occur at the coupling portion between the coupler 15 and the nail 41, the nail 41 and the coupler 15 are integrally operated by fastening the fixing bolt 16 to the coupler 15. If a stronger bond is required, the integral motion is more reliably made by welding the nail 41 and the coupler 15. In each figure, reference numeral 17 denotes a welded portion of the coupler 15 and the nail 41.

On the other hand, in each embodiment of the present invention, the accelerometer 13 and the strain gauge 14 measures the signal by the excitation and because the natural frequency is different for each type of cable structure to fit each cable structure (4) Use measuring equipment.

In addition, the accelerometer 13 and the strain gauge 14 are attached to two or more at the measuring instrument installation position so as to minimize the eccentricity of the load or measurement error.

The cable structure 4 to be used depends on the target ground 50. Cable structures include soil nailing, anchors, etc., which are used for earthquake construction, and rock bolts, which are mainly used in tunnel construction.

In the case of all the cable structures, since the bulb is formed through the grouting 40, the principal friction is largely determined by the mutual behavior between the grouting 40 and the target ground 50, but with the target ground 50 Due to the different mechanisms of resistance, the distribution of principal frictions measured in each case is different.

In addition, as mentioned above, since the natural frequency is different for each cable structure 4, it is preferable to use measurement equipment in consideration of this.

On the other hand, Figure 7a and 7b is for explaining the structure and operation of the load-carrying latch applied to the above-described embodiment, the load-carrying latch 21 of the present embodiment is coupled to the upper end of the support 20 and in the lower center It includes a ring 21a having an opening 210a and a cross pin 21b installed across the opening 210a under the ring 21a.

And, as shown in the operation, as shown in Figure 7a before pulling out the cross pin (21b) hanger 111a is caught in the hook (21a) weight (11 11 or 4a of FIG. 11b), as shown in FIG. 7b, when the cross pin 21b is pulled out, the hook line 111a can exit the opening 210a of the ring so that the weight falls by its own weight.

On the other hand, Figures 8a and 8b shows another structure and its action of the load-carrying brace of the present invention, the load-carrying brace 21 of the present embodiment and the ring 22a hinged to the upper end of the support 20 and And a cross pin 22b installed to support the end of the ring 21a, and a spring 22c for pressing the cross pin 22a in a direction to be caught by the locking groove 220a at the end of the ring.

In addition, as shown in FIG. 8A, the hook 22a is fixed to the cross pin 22b and the weight (11 of FIG. 2A or 11b of FIG. 4A) is fastened to the hook 22a. In the fixed state, as shown in FIG. 8B, when the spring 22c is pulled in the compression direction, the hook 22a, which is caught on the cross pin 22b, is rotated about the hinge axis by the weight of the weight. As a result, the weight falls.

At this time, the ring (22a) is to take the form that the weight is not caught in the shape of the rotation, so that when the weight of the ring rotates naturally out of the ring.

The present invention configured as described above is to calculate the correct principal surface friction force acting between the target ground 50 and the grout 40 in consideration of the size and natural frequency of each cable structure (4) installed on the target ground (50) Can be.

In addition, according to the present invention, the resistance between the cable structure 4 and the target ground 50 can be accurately measured by using a non-destructive technique, so that the drawing resistance can be measured economically and stably as well as using a non-destructive technique. Therefore, damage to the target ground 50 through the test can also be reduced.

On the other hand, since the present invention is an indirect method of calculating the pull resistance indirectly by measuring the vibration generated by the impact, it is possible to evaluate the stability of the target ground 50 in a relatively simple method and low cost compared to the conventional direct drawing method In addition, unlike the conventional pull-out test for testing one cable structure (4), the measurement method of the present invention has the advantage that more accurate measurements can be made because the test can be performed on all of the constructed cable structures.

In addition, the present invention can measure the behavior of the target ground 50 and the cable structure (4) periodically even after the construction of the cable structure (4) can be equipped with a real-time measurement system.

In particular, while the existing direct drawing test can only know the magnitude of the principal surface friction, the non-destructive test method of the present invention can grasp the distribution pattern of the principal surface friction force can lead to economic design of the cable structure (4) . That is, the data obtained through the strain gauge 14 and the accelerometer 13 can be used to calculate the distribution patterns and pullout resistance of the principal surface friction force for each position of the cable through the program analysis.

For reference, the total principal surface frictional force (RTL) can be expressed as the sum of the dynamic resistance component (R _d ) and the static resistance line segment (R _s ). The force component F (tm) can be measured with a strain gauge, and the velocity component v (tm) can be calculated with an accelerometer.

The dynamic resistance component can be obtained as follows in consideration of the attenuation coefficient.

The static resistance component is a value obtained by subtracting the static resistance component from the total resistance.

For this purpose, the selection of a measuring device considering the size and natural frequency of each cable structure must be preceded, and it is natural for a person skilled in the art that an accurate vibration analysis technique is required for the measured data.

On the other hand, because the characteristics of the material and the scale of the material of each cable structure (soil nailing, anchor, etc.) and the behavior mechanism between the target ground 50 is different, the inherent frequency of each cable structure is different, the present invention According to the can be used to determine the natural frequency of each using a measuring instrument and can present the scope of application of the measuring instrument according to each cable structure.

Although the above description has been described as an example by the embodiment of the present invention, it is not limited to the above embodiment and those skilled in the art will be able to realize that various changes and modifications can be made without departing from the technical spirit of the present invention. .

Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description in the specification but should be defined by the claims.

1 is a cross-sectional view showing a state in which a cable structure to which the non-destructive technique of the present invention is applied

2A and 2B illustrate an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a first embodiment of the present invention.

Figure 2a is a view showing the pre-fall state of the weight for the compressive load

2B is a view showing a state after the weight is dropped.

3A and 3B illustrate an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a second embodiment of the present invention.

Figure 3a is a view showing the pre-fall state of the weight for the compressive load

3B is a view showing a state after the weight is dropped.

4A and 4B illustrate an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a third embodiment of the present invention.

Figure 4a is a view showing the state before the first weight lift for the loading load

Figure 4b is a view showing a state after the first weight is raised

5A and 5B illustrate an apparatus for measuring pullout resistance of a cable structure using a non-destructive technique according to a fourth embodiment of the present invention.

Figure 5a is a view showing the compression state of the elastic member before the weight lift for the compression load

5B is a view showing a state after the weight is raised.

6A illustrates another embodiment of a component according to a first exemplary embodiment of the present invention, and a perspective view showing a case in which the hitting anvil is formed in a T shape and separated from a guide bar.

FIG. 6B is a partial cutaway perspective view of a coupler that engages the nail portion of the cable structure and the guide bar to act integrally; FIG.

7a and 7b is a view for explaining the structure and operation of the load-carrying latch of the present invention

8a and 8b is a view showing another structure and its action of the load-carrying latch of the present invention.

＊ Explanation of symbols for main parts of drawing *

4: cable structure 10: hitting anvil

11: weight 12: information bar

13: accelerometer 14: strain meter

15: Coupler 16: Fixed Bolt

17: welded portion 18: stopper

20: support 21: load bearing latch

22: pulley 23: connecting line

31: elastic member 32: latch member

40: grouting 41: nail

50: Target ground

Claims (17)

delete delete delete delete And a drag force providing means that can apply drag force to the cable structure (4) constructed on the target ground (50), It is composed of a measuring means for measuring the vibration of the cable structure is applied after the driving force is applied to the cable structure (4), The driving force providing means, A support 20 installed on the target ground 50; A load-carrying latch 21 installed at an upper end of the support 20; A weight 11 caught by the load-carrying clamp 21; A guide bar 12 installed to guide the lifting and lowering of the weight 11; A hitting anchor 10 fixed to the lower side of the guide bar 12 to receive a load when the weight 11 falls and to transmit a compressive load to the cable structure 4; Drawing resistance of the cable structure characterized in that it comprises a coupler (15) for binding the hitting anvil (10) and the cable structure (4) mutually. And a drag force providing means that can apply drag force to the cable structure (4) constructed on the target ground (50), It is composed of a measuring means for measuring the vibration of the cable structure is applied after the driving force is applied to the cable structure (4), The driving force providing means, A support 20 installed on the target ground 50; A pulley 22 installed at an upper end of the support 20; A load-carrying latch 21 connected to the connection line 23 installed on the pulley 22; A weight 11 connected to the load-carrying latch 21; A guide bar 12 for guiding the lifting of the weight 11; A hitting anchor 10 fixed to the lower side of the guide bar 12 to receive a load when the weight 11 falls and to transmit a compressive load to the cable structure 4; Drawing resistance of the cable structure characterized in that it comprises a coupler (15) for binding the hitting anvil (10) and the cable structure (4) mutually. And a drag force providing means that can apply drag force to the cable structure (4) constructed on the target ground (50), It is composed of a measuring means for measuring the vibration of the cable structure is applied after the driving force is applied to the cable structure (4), The driving force providing means, A first support 20a installed on the target ground 50; A first pulley 22a installed at an upper end of the first support 20a; A first weight 11a connected to a connection line 23 provided on the first pulley 22a; A first guide bar 12a installed to guide the lifting and lowering of the first weight 11a; A hitting anvil 10 provided at an upper end of the first guide bar 12a to receive a load when the first weight 11a is raised to transmit a tensile load to the cable structure 4; A coupler 15 for binding the lower end of the first guide bar 12a and the cable structure 4 to each other; A second support 20b installed separately from the first support 20a; A second pulley 22b installed at an upper end of the second support 20b; A second weight (11b) connected to the first weight (11a) through a connecting line (23) provided in the second pulley and having a greater load than the first weight (11a); A second guide bar 12b installed to guide the lifting and lowering of the second weight 11b; Drawing resistance resistance measurement device of the cable structure, characterized in that it comprises a load-bearing latch (21) for the second weight (11b) to stay on the upper end of the second guide bar (12b). And a drag force providing means that can apply drag force to the cable structure (4) constructed on the target ground (50), It is composed of a measuring means for measuring the vibration of the cable structure is applied after the driving force is applied to the cable structure (4), The driving force providing means, A support 20 installed on the target ground 50; A weight 11 installed at an upper side of the support 20; A load-bearing elastic member 31 providing a lifting force with respect to the weight 11; A latch member 32 installed to control a lifting force of the weight 11 by the elastic force of the load-bearing elastic member 31; A guide bar 12 installed to guide the lifting and lowering of the weight 11; A hitting anchor 10 which is fixed to the upper end of the guide bar 12 and receives a load when the weight 11 is raised and transmits a tensile load to the cable structure 4; Drawing resistance of the cable structure characterized in that it comprises a coupler (15) for binding the hitting anvil (10) and the cable structure (4) mutually. The measuring means according to any one of claims 5 to 8, Drawing resistance of the cable structure characterized in that it consists of a strain gauge (14) and an accelerometer (13) selected and installed in accordance with the natural frequency according to the type of the cable structure (4). 10. The pullout resistance of the cable structure according to claim 9, wherein at least two accelerometers (13) and strain gauges (14) are attached to the measuring instrument installation position to minimize load eccentricity and measurement errors. Measuring device. The apparatus of claim 10, wherein the accelerometer (13) and the strain gauge (14) are installed in the hitting anvil (10) or the guide bars (12) and (12a). The method of claim 11, The hitting anvil 10, A cable comprising a hitting portion (10a) that serves to receive the load of the weight 11, and a measuring instrument mounting portion (10b) for providing a space for mounting the accelerometer (13) and strain gauge (14) Apparatus for measuring pullout resistance of structures. 13. The method of claim 12, Pulling resistance measuring apparatus of the cable structure, characterized in that the lower portion of the instrument mounting portion (10b) is provided with a portion (10c) for coupling with the coupler (15). The method according to any one of claims 5 to 8, On the outer peripheral surface of the lower side of the coupler 15, a bolt fastening hole 15d for integral action between the nail inserted into the nail insertion groove formed in the lower portion of the coupler 15 and the coupler 15 is formed, and the bolt fastening is formed. Pulling resistance measuring device of the cable structure, characterized in that the fixing bolt 16 is fastened to the ball (15d). The method of claim 14, The coupler 15 and the cable structure 4 is coupled resistance measurement device of the cable structure, characterized in that coupled to each other by welding. The method according to any one of claims 5 to 7, The load-carrying latch 21, It is configured to include a ring 21a coupled to the upper end of the support 20 and provided with an opening 210a at the lower center, and a cross pin 21b installed across the opening 210a under the ring 21a. Drawing resistance measurement device of the cable structure. The method according to any one of claims 5 to 7, The load-carrying latch 21, Ring 22a hinged to the upper end of the support 20, the cross pin 22b installed to support the ring 21a, and the cross pin 22a are caught in the locking groove 220a of the ring. Drawing resistance measurement device of the cable structure characterized in that it comprises a spring (22c) to pressurize with.

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