A shear plate for testing seismic shear waves in rock masses within adits

Abstract

This invention discloses a shear plate for testing seismic shear waves in rock masses within adits, comprising a shear plate body, rubber blocks, strip sandbags, a forward excitation plate, and a reverse excitation plate. The shear plate body is rectangular, with a rectangular groove at the center of its upper surface. A forward excitation plate is installed on one side of the two inner sidewalls opposite the groove, and a reverse excitation plate is installed on the other side. Rubber blocks are fixed to the outer end faces of the shear plate body corresponding to the installation of the forward and reverse excitation plates. Multiple strip sandbags are fixed to the lower surface of the shear plate body, and multiple support grooves are formed on the upper surface of the shear plate body. The internal excitation method compensates for the narrow working space, increases the contact area between the shear plate and the adit wall rock mass, and the highly elastic strip sandbags increase the coupling area between the shear plate and the uneven adit wall rock and soil while ensuring a continuous planar coupling state between the shear plate and the adit wall rock mass, thereby increasing the excitation energy of seismic shear waves within the adit.

Description

Technical Field

[0001] This invention relates to the field of geophysical in-situ testing technology for water conservancy and hydropower engineering, specifically to a shear plate for testing seismic shear waves in rock masses within adits. Background Technology

[0002] In the geological exploration of water conservancy and hydropower projects, exploration adits are a conventional exploration method, widely used for rock mass quality evaluation in key hydraulic structures such as dam sites and underground powerhouses. Seismic shear wave velocity is one of the important parameters for evaluating rock mass quality. Based on the seismic shear and longitudinal wave velocities, Poisson's ratio of the rock mass can be calculated, and based on Poisson's ratio, parameters such as shear modulus and dynamic elastic modulus can be calculated. Therefore, conducting seismic shear wave testing within adits plays a crucial role in evaluating the rock mass quality within adits.

[0003] Lateral hammering of shear plates to excite and pick up seismic shear waves with opposite phases is a commonly used testing method. Existing technology mainly consists of a long strip of wood for the shear plate body and a rake or steel trough below it. Although the rake or steel trough can couple with the adit rock mass, the rake or steel trough is not continuous, resulting in only point or line coupling, and not continuous planar coupling. At the same time, the diameter of a typical exploration adit is about 2.0m, which is narrow and not conducive to lateral hammering at both ends of the shear wave.

[0004] The accuracy of seismic shear wave testing has a significant impact on Poisson's ratio, shear modulus, and dynamic elastic modulus. Theory and practice have shown that how to increase the coupling area between the shear plate and the tunnel wall rock mass while suppressing the P-wave to the greatest extent is a key technical issue for improving interpretation accuracy in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a shear plate that is simple to operate and low in cost for testing seismic shear waves in rock mass inside adits, which compensates for the problem of narrow working space by using an internal excitation method.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a shear plate for testing seismic shear waves in rock mass within an adit, comprising a shear plate body, rubber blocks, strip sandbags, a forward excitation plate, and a reverse excitation plate. The shear plate body is rectangular, with a rectangular groove in the center of the upper surface of the shear plate body. A forward excitation plate is installed on one side of the two inner sidewalls opposite to the groove, and a reverse excitation plate is installed on the other side. Rubber blocks are fixed to the two outer end faces of the shear plate body corresponding to the installation of the forward and reverse excitation plates, and multiple strip sandbags are fixed to the lower surface of the shear plate body. Multiple support grooves are opened on the upper surface of the shear plate body.

[0007] The groove is rectangular and runs in the same direction as the shear plate.

[0008] The thickness of the rubber blocks is the same as the thickness of the shear plate, and the two rubber blocks and the shear plate form a cuboid shape.

[0009] The support groove is formed on the upper surface of the shear plate around the groove, and is a recessed cylindrical groove.

[0010] Both the rubber blocks and the strip-shaped sandbags are elastic.

[0011] The beneficial effects of this invention are as follows: By using an internal excitation method, the problem of narrow working space is compensated for, while maximizing the length of the shear plate, thereby increasing the contact area between the shear plate and the tunnel wall rock mass. Highly elastic strip-shaped sandbags increase the coupling area between the shear plate and the uneven tunnel wall rock and soil, ensuring a continuous planar coupling state between the shear plate and the tunnel wall rock mass. Simultaneously, the sand within the sandbags has a certain suppressive effect on the longitudinal seismic waves generated during the excitation process. High-strength rubber maintains the vertical stability of the shear plate, and during excitation, the rubber contracts, causing instantaneous micro-displacement of the shear plate, thus exciting seismic transverse waves. This invention can increase the excitation energy of seismic transverse waves within the tunnel, thereby improving the accuracy of calculating the Poisson's ratio, shear modulus, and dynamic elastic modulus of the rock mass within the tunnel, providing important basic parameters for rock mass quality evaluation. Attached Figure Description

[0012] Figure 1 This is an upper view of the shear plate used in this invention for testing seismic shear waves in rock mass within an adit.

[0013] Figure 2 This is an external view of the lower part of the shear plate used in this invention for testing seismic shear waves in rock mass within an adit.

[0014] Figure 3 This is a schematic diagram of the working of the shear plate adit sidewall used in this invention for testing seismic shear waves in rock mass within an adit.

[0015] Figure 4 This is a schematic diagram of the working of the shear plate of the adit bottom plate used in this invention for testing seismic shear waves in rock mass within an adit. Detailed Implementation

[0016] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0018] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0019] like Figure 1 , 2 As shown, the shear plate for testing seismic shear waves in rock mass within an adit according to the present invention includes a shear plate body 4, rubber blocks 1, strip sandbags 7, a forward excitation plate 2, and a reverse excitation plate 6. The shear plate body 4 is cuboid in shape, and a rectangular groove 5 is formed in the center of the upper surface of the shear plate body 4. A forward excitation plate 2 is installed on one side of the two inner sidewalls opposite to the groove 5, and a reverse excitation plate 6 is installed on the other side. Rubber blocks 1 are fixed to the two outer end faces of the shear plate body 4 corresponding to the installation of the forward excitation plate 2 and the reverse excitation plate 6, respectively. Multiple strip sandbags 7 are fixed to the lower surface of the shear plate body 4, and multiple support grooves 3 are formed on the upper surface of the shear plate body 4.

[0020] The groove 5 is rectangular and runs in the same direction as the shear plate 4. The thickness of the rubber block 1 is the same as the thickness of the shear plate 4, and the two rubber blocks 1 and the shear plate 4 form a cuboid shape. The support groove 3 is formed on the upper surface of the shear plate 4 around the groove 5, and is a recessed cylindrical groove.

[0021] Both the rubber block 1 and the strip sandbag 7 are elastic.

[0022] Specifically, this invention is used for seismic shear wave excitation in rock masses within adits, and is applied in two ways. The first is seismic shear wave excitation in sidewall rock masses, such as... Figure 3As shown, firstly, the shear plate is lifted and pressed tightly against the rock mass of the adit wall. Then, under artificial lateral pressure, the shear plate is slowly slid down to the bottom of the adit, allowing the strip-shaped, highly elastic sandbags to fully contact the uneven rock mass of the cave wall. At this point, the lower part of the shear plate is supported by high-strength rubber blocks 1. Then, one end of support rods 8 and 9 is fixed to the shear plate support groove 3, and the other end is connected to jacks 10 and 11. The jacks provide lateral pressure to the shear plate. Under the combined action of the bottom rubber plate support and the lateral support, the shear plate is well coupled with the rock mass of the adit wall. Then, a vibratory hammer is used to strike the center of the positive excitation plate 2 and the negative excitation plate 6 in the groove, thereby exciting shear waves with opposite phases. The second case is the excitation of seismic shear waves in the bottom rock mass, which is relatively simpler than the sidewall, such as... Figure 4 As shown, simply place the shear plate flat on the base plate, place loads 12 and 13 on the left and right sides, and then use a vibratory hammer to strike the centers of the forward excitation plate 2 and the reverse excitation plate 6 in the groove, thereby exciting shear waves with opposite phases. This device is simple to operate, low in cost, and reusable. By using internal excitation, it compensates for the problem of narrow working space, while maximizing the length of the shear plate, thereby increasing the contact area between the shear plate and the cave wall rock mass. The high-elasticity strip sandbags increase the coupling area between the shear plate and the uneven cave wall rock and soil, and ensure the continuous planar coupling state between the shear plate and the flat cave wall rock mass. At the same time, the sand in the sandbags has a certain degree of suppression effect on the longitudinal seismic waves generated during the excitation process. The high-strength rubber maintains the vertical stability of the shear plate. During the excitation process, the rubber will shrink accordingly, thereby causing the shear plate to undergo instantaneous micro-displacement, thus exciting the transverse seismic waves. This invention can increase the excitation energy of seismic shear waves within adits, thereby improving the accuracy of calculating the Poisson's ratio, shear modulus, and dynamic elastic modulus of rock masses within adits, providing important basic parameters for rock mass quality evaluation.

[0023] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The patent scope of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A shear plate for testing seismic shear waves in rock mass within an adit, characterized in that, The shear plate (4), rubber blocks (1), strip sandbags (7), forward excitation plate (2) and reverse excitation plate (6) are included. The shear plate (4) is rectangular. A rectangular groove (5) is opened in the center of the upper surface of the shear plate (4). A forward excitation plate (2) is installed on one side of the two inner sidewalls opposite to the groove (5), and a reverse excitation plate (6) is installed on the other side. Rubber blocks (1) are fixed on the two outer end faces of the shear plate (4) corresponding to the installation of the forward excitation plate (2) and the reverse excitation plate (6). Multiple strip sandbags (7) are fixed on the lower surface of the shear plate (4). Multiple support grooves (3) are opened on the upper surface of the shear plate (4).

2. The shear plate for testing seismic shear waves in rock mass within an adit, as described in claim 1, is characterized in that... The groove (5) is rectangular and runs in the same direction as the shear plate (4).

3. The shear plate for testing seismic shear waves in rock mass within an adit, as described in claim 2, is characterized in that... The thickness of the rubber block (1) is the same as the thickness of the shear plate (4), and the two rubber blocks (1) and the shear plate (4) form a cuboid shape.

4. The shear plate for testing seismic shear waves in rock mass within an adit, as described in claim 1, is characterized in that... The support groove (3) is opened on the upper surface of the shear plate body (4) around the groove (5), and is a recessed cylindrical groove.

5. The shear plate for testing seismic shear waves in rock mass within an adit according to claim 1, characterized in that, Both the rubber block (1) and the strip sandbag (7) are elastic.

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