CN112710565B - Channel on-site shear force experimental device and method for nondestructive concrete - Google Patents

Abstract

The utility model discloses a channel on-site shearing force experiment device and method for nondestructive concrete, which are mainly used for on-site shearing experiments of channels which are installed on concrete in a tunnel and have no stress supporting points. The two displacement sensor fixing blocks are respectively contacted with one ends of the two shearing stress loading blocks. The channel body is used as a stress supporting point for a shear test, and the shear force which can be loaded by external stress support originally is changed into the internal shear force of the system through the rotation and fastening of the force driving force bolt through the effective connection of the driving force bolt, the stress connecting bolt, the shear stress loading block and the rectangular force connecting conversion groove, and then the shear force of the embedded channel or the appearance channel is measured through the force sensor and the displacement sensor.

Description

An on-site shear force test device and test method of a non-destructive concrete channel

technical field

The invention belongs to the technical field of on-site detection of pre-buried channels and externally-mounted channels, and relates to an on-site shear force test device and test method for non-destructive concrete channels, which are specifically used for pre-buried and installed in tunnels. On-site shear test of non-destructive concrete for external hanging channels.

Background technique

At present, channel technology is mainly divided into embedded channel technology and external channel technology. The pre-embedded chute technology refers to pre-embedding C-shaped channel steel in the concrete during the concrete prefabrication process in the tunnel. The external-mounted channel technology refers to the external installation and fixing of the channel on the embedded sleeve or anchor bolt. At the same time, the cables, pipelines, equipment, etc. are fixed on the shield segments by T-bolts.

In actual use, the channel is not only subjected to axial tensile force, but also longitudinal and transverse shear force, due to differences in installation and anchorage under laboratory conditions and field construction conditions. Therefore, in the later stage, it is necessary to conduct on-site inspections on the pre-embedded channels that have been installed in the concrete in the tunnel or the external channels that have been installed in the tunnel.

At present, there are generally two situations in the prefabrication of pre-embedded channels in concrete. One is to pre-embed directly in the segment field and install them in the tunnel together with the segments in the later stage; Cast-in-place installation in concrete inside the tunnel. The external hanging tank is directly installed on the concrete in the tunnel.

In the utility model patent (CN208171764U), a kind of pre-embedded channel shear test device is provided, but this device is to pre-embed the chute sample in the concrete in the laboratory, and only simulates the actual use condition of the pre-embedded channel. The shear force measured by the device cannot represent the actual shear force on the embedded chute of the shield segment on site. And it is not suitable for on-site shearing of external slots.

A utility model patent (CN207779832U) provides a multifunctional pre-buried channel shear force test tool, which only simulates the shear force between the T-bolt and the chute when the T-bolt is fastened in the chute , and did not pre-embed the chute in the concrete.

Invention patent (CN 110132759 A) provides a shearing test device and detection method for the embedded channel on the shield segment. The method and the shearing device are mainly applied to the channel embedded in the shield segment , this method mainly uses the threaded snatch head on the segment as the support point of the reverse force, and this support point is the key to the device being fixedly installed on the segment and providing the reverse force. The core factor of this method is the tube There must be additional counter force anchor points on the chip. Due to stray current, anti-corrosion and aesthetic requirements, the snatch head will be closed after the segment enters the tunnel, so this method is not suitable for the detection of the embedded grooves that have entered the segment installed in the tunnel. In addition, there is no snatch head design on the rectangular tunnel made of concrete cast-in-place, and there is no additional force support point in the tunnel, so this method is not suitable for the shear test of the pre-buried channel in the cast-in-place tunnel. Since the installation position of the external hanging groove is uncertain, this method is also not applicable in the position where there is no reverse force fixed point.

In the prior art, the steel plate is placed on one side of the segment width, and the segment bolt holes and segments are used to fix the steel plate as a counter force. However, the segments that have entered the tunnel have been assembled with the segment It becomes impossible to fix the steel plate with plate bolt holes and segment bolts as a reaction force.

At present, in the interior of the tunnel, it is usually only possible to obtain external force support points by means of mechanical anchor bolts. This method causes additional mechanical damage and damage to the tunnel concrete and reduces its service life. However, under the condition of not destroying the concrete, the existing methods and devices can only complete the on-site testing of the axial tensile bearing capacity of the embedded channel or the external channel, and lack the ability to complete the longitudinal and transverse tests of the embedded channel or the external channel. Method and apparatus for shear capacity. Therefore, there is an urgent need for a method and device that can solve the longitudinal and transverse shear field detection of the pre-buried channel inside the tunnel or the external channel without destroying the concrete.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned existing technical problems, and to provide a shear test method and device for non-destructive concrete field detection of pre-buried channels and external channels in tunnels. This method is low in cost and high in cost performance. It can not only effectively solve the shear test problem of the pre-buried channel and the external channel with no supporting points on the concrete inside the tunnel, but also does not need to use the anchor bolt puller during the test. The test is simple and easy to carry.

The present invention is achieved through the following technical solutions:

An on-site shear force test device for a non-destructive concrete channel is characterized in that it includes two shear force loading blocks, a driving force bolt, a force connection conversion mechanism, a force connection bolt and two shear loads for measuring The displacement sensor for the position change of the force loading block, the two shear force load blocks are fixed on the channel to be detected by T-shaped bolts, and the driving force bolts, the force connection conversion mechanism and the force connection bolts are installed on the two in turn. Between the shear force loading blocks, one end of the driving force bolt is connected with the shear force load block at the corresponding end through thread fit, and the other end is connected with the force connection conversion mechanism through the rotating pair, and the force connection conversion mechanism is connected through the force connection conversion mechanism. The force connection bolt is connected with the shear force loading block at the corresponding end. During the process of twisting the driving force bolt by external force, the relative position of the force connection conversion mechanism at both ends and the shear force load block can be changed, and the force connection conversion Mechanism conversion, changing the tension change between two shear force loading blocks, so as to perform shear force test, a force sensor for detecting the magnitude of the shear force is arranged between the force connection conversion mechanism and the force connection bolt.

Further, the two shear force loading blocks have the same structure, and both include an internally threaded hole and a through hole for mounting on the channel, and the axes of the internally threaded hole and the through hole are perpendicular to each other.

Further, one end of the driving force bolt is provided with an external thread that matches the internal thread hole on the shear force loading block, and the other end is a connecting part connected with the force connection conversion mechanism, and the middle part of the driving force bolt is provided with There is a force receiving part for easy application of external force.

Further, the force-receiving part is a polygonal column coaxial with the driving force bolt.

Further, the force connection conversion mechanism is a rectangular force connection conversion groove, and connection holes are provided at both ends of the rectangular force connection conversion groove, one of the connection holes is connected to the driving force bolt, and the connection on the driving force bolt The part is a cylindrical head whose size is larger than the connecting hole, and the other connecting hole is used to connect with the stressed connecting bolt.

Further, one end of the stress connecting bolt is provided with a rectangular head, and the other end is provided with an external thread. The threaded holes are connected, and the force sensor is a gasket type pressure sensor, and the gasket type pressure sensor is sleeved on the force connecting bolt, and is located between the rectangular head and the inner end of the rectangular force connection conversion groove.

Further, positioning screw holes are provided on the side of the rectangular head, and corresponding fixing holes are provided on the rectangular force connection transition groove.

Further, the rectangular force connection transition tank is composed of four steel plates detachably connected by bolts.

Further, lubricating oil for reducing friction is coated between the cylindrical head of the driving force bolt and the inner end of the rectangular force connection conversion groove.

The pressure sensor and the displacement sensor are respectively connected with the data collector, and the force and displacement data are recorded through the data collector.

A kind of shear experiment method utilizing above-mentioned channel field shear force experiment device, is characterized in that, comprises the following steps:

Step 1. Pass the external threaded end of the driving force bolt through the connecting hole on the rectangular force connection conversion groove and connect it to the internal threaded hole of the shear force loading block;

Step 2. Put the stress connection bolt on the gasket type pressure sensor, then pass through another connection hole on the rectangular force connection conversion groove, and then connect it to the internal thread hole of another shear force loading block;

Step 3. Fix the two shear force loading blocks on a channel to be tested or two adjacent channels through T-shaped bolts;

Step 4. Adjust the stressed connecting bolts and driving force bolts so that the gasket pressure sensor is just zero, and arrange a displacement sensor on the outside of the two shear loaded blocks;

Step 5. Screw the driving force bolt by external force, collect the displacement data of the displacement sensor and the pressure data detected by the gasket pressure sensor, and complete the shearing experiment.

The beneficial effects of the present invention are:

In the present invention, the channel body is used as the supporting point of the shear test force, and through the effective connection of the driving force bolt, the force connecting bolt, the shear force loading block, the rectangular force connection conversion groove, the pressure sensor and the displacement sensor, the The shear force that originally required external force support to be loaded becomes the internal shear force of the system through the force-driven bolt rotation and fastening, and then the embedded channel or external hanging channel is measured through the pressure sensor and displacement sensor installed inside the system Shear force and displacement data for the channel. This method perfectly solves the problem that the pre-buried channel inside the tunnel and the external channel have no supporting points on the concrete and cannot carry out the shear force test. Especially for the cast-in-place pre-buried channel, it becomes possible to conduct field shear test without destroying the concrete.

Description of drawings

Figure 1 is a schematic diagram of the installation of the on-site shear force test device for the longitudinal shear of the embedded channel.

Figure 2 is a schematic diagram of the installation of the on-site shear force test device for the transverse shear of the embedded channel.

Figure 3 is a schematic diagram of the installation of the on-site shear force test device for longitudinal shearing of the external hanging channel.

Figure 4 is a schematic diagram of the installation of the on-site shear force test device for lateral shearing of the external hanging channel.

Fig. 5 is a schematic diagram of a driving force bolt.

Fig. 6 is a schematic diagram of a stressed connecting bolt.

Fig. 7 is a schematic diagram of a rectangular force connection conversion groove.

Fig. 8 is a schematic diagram of a force sensor.

Fig. 9 is a schematic diagram of a loading block under shear force.

1-first shear load block, 101-through hole, 102-internal threaded hole, 103-loading block body, 2-driving force bolt, 201-forced part, 202-external thread head, 203-cylinder Shaped head, 3-rectangular force connection conversion groove, 301-fixing hole, 302-lower connection hole, 303-upper connection hole, 304-rectangular steel plate, 4-force sensor, 401-through hole, 5-forced connection bolt , 501-external thread head, 502-rectangular head, 503-positioning screw hole, 6-displacement sensor, 7-displacement sensor fixing block, 8-data collector, 9-second shear force loading block.

Detailed ways

Referring to the accompanying drawings 1 to 9, a specific embodiment of the present invention is given to further illustrate the method of the present invention.

Example 1

The installation schematic diagram of this method is shown in Fig. 1 (longitudinal shear test of pre-buried channel), a kind of non-destructive concrete channel field shear force test device, including the first shear force loading block 1, driving force bolt 2, rectangular Force connection conversion slot 3 , force sensor 4 , force connecting bolt 5 , second shear force loading block 9 , displacement sensor 6 , displacement sensor fixing block 7 and data collector 8 .

Two shear force loading blocks are fixed on the channel to be detected by T-shaped bolts, as shown in Figure 1, wherein the first shear force load block 1 is fixed on the upper part of the channel to be detected by T-shaped bolts, and the second The shear force loading block 9 is fixed on the lower part of the channel to be detected by T-shaped bolts, and the driving force bolt 2, the rectangular force connection conversion groove 3 and the force connection bolt 5 are installed between the two shear force load blocks in sequence. Between, wherein, the upper end of the driving force bolt 2 is connected with the first shear force loading block 1 through thread fit, the lower end is connected with the upper end of the rectangular force connection conversion groove 3 through a rotating pair, and the lower end of the rectangular force connection conversion groove 3 is connected by the force The connecting bolt 5 is connected with the second shear force loading block 9, and in the process of twisting the driving force bolt 2 by an external force, the relative position of the rectangular force connection conversion groove 3 and the first shear force loading block 1 can be changed. The force connection conversion groove 3 is converted, and the tension change between the first shear force loading block 1 and the second shear force load block 9 is changed, so as to perform a shear force test. The rectangular force connection conversion groove 3 and the force A force sensor 4 for detecting the shear force is arranged between the connecting bolts 5 .

The first shearing force loading block 1 and the second shearing force loading block 9 have exactly the same structure, and the first shearing force loading block 1 is taken as an example, as shown in Figure 9, which includes a rectangular loading block body 103, the front side of the loading block body 103 is provided with a through hole 101 for installing T-shaped bolts, and an internal thread hole 102 is provided on the side perpendicular to this side.

As shown in Figure 5, one end of the driving force bolt 2 has a cylindrical head 203, and the other end head is an external threaded head 202 matched with the internal threaded hole 102 of the shear force loading block. 2 The middle part has a force-receiving part 201 that matches the driving wrench. The force-receiving part 201 can be a polygonal column coaxial with the driving force bolt 2. In this embodiment, it is a hexagonal column. It should be noted that the force-receiving part 201 The size needs to be smaller than the upper connection hole 303 on the rectangular force connection conversion groove 3, so as to pass through the hole.

As shown in Figure 7, the rectangular force connection conversion tank 3 is formed by splicing four rectangular steel plates 304 with bolts, and the upper and lower two short steel plates of the rectangular force connection conversion tank 3 are respectively provided with an upper connection hole 303 and a lower connection hole 302. Two fixing holes 301 are provided on the long steel plate on one side of the rectangular force connection conversion groove 3 for connecting with the positioning screw holes 503 of the force connecting bolt 5 .

As shown in FIG. 8 , the force sensor 4 is a gasket type pressure sensor with a through hole 401 in the middle for the force connecting bolt 5 to pass through.

As shown in Figure 6, one end of the stressed connection bolt 5 has an external thread head 501 matching the shear force loading block, and the other end has a rectangular head 502 matching the internal size of the rectangular force connection conversion groove 3 , the side of the rectangular head 502 is provided with a positioning screw hole 503 corresponding to the fixing hole 301 . The displacement sensor 6 is fixed on the outside of the two shear force loading blocks through the displacement sensor fixing block 7. In this embodiment, there are two displacement sensors 6, which are respectively located on the top of the first shear force load block 1 And the bottom of the second shear force loading block 9, used to detect the displacement of the two shear force load blocks.

As shown in Fig. 1, a method for on-site detection and shearing test of non-destructive concrete in a pre-embedded channel in a tunnel, the pre-embedded channel is a channel C already installed in the concrete inside the tunnel, comprising the following steps:

First, the stressed connecting bolt 5 is passed through the through hole 401 of the force sensor 4, and then the stressed connecting bolt 5 with the force sensor 4 is passed through the lower connecting hole 302 on the rectangular force connection conversion groove 3, and finally the fastening bolt is used to Pass through the fixing hole 301 on the side plate of the rectangular force connection transfer groove 3 and connect and fix it with the positioning screw hole 503 on the force connecting bolt 5 .

The second shear force loading block 9 is connected and fixed with the force connection bolt 5 (the external thread head 501 of the force connection bolt 5 is connected with the internal thread hole of the second shear force load block 9 ).

Pass the external thread head 202 of the driving force bolt 2 through the upper connection hole 303 of the rectangular force connection conversion slot 3 .

The first shear force loading block 1 is connected and fixed with the driving force bolt 2 (the external thread head 202 of the driving force bolt 2 is connected with the internal thread hole 102 of the first shear force loading block 1 ).

As shown in FIG. 1 , the first shearing force loading block 1 and the second shearing force loading block 9 are respectively fixed on the embedded channel C by using T-shaped bolts.

During the test, use the driving wrench to turn the force receiving part 201 on the driving force bolt clockwise, and as the driving force bolt is tightened, the driving force bolt moves in the direction of the first shear force loading block 1, and then the tensile force is converted through the rectangular force connection The groove 3 is transmitted to the stressed connection bolt 5 and the gasket pressure sensor, and the force data is collected by the gasket pressure sensor.

During the test, the first shear force loading block 1 and the second shear force load block 9 are subjected to downward and upward tension respectively, and the displacement sensor 6 collects displacement data. Finally, the displacement sensor 6 and the gasket type pressure sensor transmit the collected data to the data collector 8 .

Embodiment 2: As shown in Figure 2, the installation and implementation steps of the transverse shear test of the embedded channel, the longitudinal shear test and the transverse shear test of the external channel are consistent with embodiment 1, the difference is that the first shear The shearing force loading block 1 and the second shearing force loading block 9 are respectively installed on the two grooves, which will not be repeated here.

It should be noted that the length of the external thread of the driving force bolt 2 and the length of the internal thread of the shear force loading block are sufficient. Test requirements.

It should be noted that lubricating oil should be applied to the side of the cylindrical head 203 of the driving force bolt 2 and the rectangular force connection transition groove 3 to reduce friction.

It should be noted that the rectangular force connection conversion groove 3 must be designed as a rectangle, and the rectangular force connection conversion groove 3 will not rotate when the cylindrical head 203 of the driving force bolt 2 rotates.

It should be noted that the rectangular size of the head of the stressed connecting bolt 5 must be the same as the internal height and width of the rectangular force connecting conversion groove 3. When the cylindrical head 203 of the driving force bolt 2 rotates, the rectangular head of the stressed connecting bolt 5 It fits perfectly with the inner rectangle of the rectangular force connection conversion slot 3 and will not rotate therewith.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications or equivalent replacements of the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all should cover Within the scope of the claims of the present invention.

Claims (7)

1. The utility model provides a on-spot shearing force experimental apparatus of channel of harmless concrete which characterized in that: the device comprises two shearing stress loading blocks, driving force bolts, stress connection conversion mechanisms, stress connection bolts and displacement sensors for measuring position changes of the two shearing stress loading blocks, wherein the two shearing stress loading blocks are fixed on a channel to be detected through T-shaped bolts;

the force-bearing connection conversion mechanism is a rectangular force-bearing connection conversion groove, connecting holes are formed in two ends of the rectangular force-bearing connection conversion groove, one connecting hole is connected with a driving force bolt, a connecting part on the driving force bolt is a cylindrical head with a size larger than that of the connecting hole, and the other connecting hole is used for being connected with the force-bearing connection bolt;

one end of the stress connecting bolt is provided with a rectangular head, the other end of the stress connecting bolt is provided with an external thread, one end of the rectangular head is installed in the rectangular force connecting conversion groove, one end of the external thread is connected with an internal thread hole on the shearing stress loading block, the force sensor is a gasket type pressure sensor, and the gasket type pressure sensor is sleeved on the stress connecting bolt and is positioned between the rectangular head and the inner side end part of the rectangular force connecting conversion groove;

the side face of the rectangular head is provided with a positioning screw hole, and the rectangular force connection conversion groove is provided with a corresponding fixing hole.

2. The channel in situ shear force testing device of claim 1, wherein: the two shearing stress loading blocks have the same structure and comprise an internal threaded hole and a through hole used for being installed on the channel, and the axes of the internal threaded hole and the through hole are mutually perpendicular.

3. The channel in situ shear force testing device of claim 2, wherein: one end of the driving force bolt is provided with external threads matched with the internal thread holes on the shearing stress loading block, the other end of the driving force bolt is a connecting part connected with the stress connection conversion mechanism, and the middle part of the driving force bolt is provided with a stress part for conveniently applying external force.

4. A channel in situ shear force testing device as in claim 3 wherein: the stress part is a polygonal column coaxial with the driving force bolt.

5. The channel in situ shear force testing device of claim 1, wherein: the rectangular force connection conversion groove is formed by detachably connecting four steel plates through bolts.

6. The channel in situ shear force testing device of claim 1, wherein: lubricating oil for reducing friction force is coated between the cylindrical head part of the driving force bolt and the inner side end part of the rectangular force connection conversion groove.

7. A shear test method using the channel in situ shear test device of any of claims 1-6, comprising the steps of:

step 1, connecting an external thread end of a driving force bolt with an internal thread hole of a shearing stress loading block after penetrating through a connecting hole on a rectangular force connection conversion groove;

step 2, sleeving a gasket type pressure sensor on the stressed connecting bolt, penetrating through another connecting hole on the rectangular force connecting conversion groove, and connecting the connecting hole in an internal threaded hole of another shearing stressed loading block;

step 3, fixing two shearing stress loading blocks on one channel to be detected or two adjacent channels through T-shaped bolts;

step 4, adjusting the stress connecting bolts and the driving force bolts to enable the gasket type pressure sensor to be just zero, and respectively arranging a displacement sensor at the outer sides of the two shearing stress loading blocks;

and 5, screwing the driving force bolt through external force, collecting displacement data of the displacement sensor and pressure data detected by the gasket type pressure sensor, and completing a shearing experiment.

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