A device for surveying the depth of underground cavities or fissures in karst landforms.

Abstract

This invention relates to the field of karst landform surveying technology, specifically providing a device for surveying the depth of underground cavities or fissures in karst landforms. The aim is to overcome the shortcomings of existing technologies and solve problems such as the pendant component easily getting stuck when falling into the fissure, and the device's adaptability to holes or fissures of different sizes or orientations. The invention comprises several main parts, including a support mechanism with a position adjustment mechanism, a measuring mechanism connected to the support mechanism, and a power mechanism connected to the measuring mechanism. The support mechanism and the position adjustment mechanism enable the device to adapt to holes or fissures of different sizes or orientations. The measuring mechanism uses a pendant component, which is lowered into the hole or fissure via a measuring rope. The power mechanism provides the power to wind and pull the measuring rope.

Description

Technical Field

[0001] This invention relates to the field of karst landform surveying technology, specifically a device for surveying the depth of underground cavities or fissures in karst landforms. Background Technology

[0002] Karst, or karst formation, refers to the geological processes by which water primarily dissolves soluble rocks (carbonate rocks, gypsum, rock salt, etc.), while mechanical processes such as erosion, undercutting, and collapse by flowing water play a secondary role. The resulting landforms are called karst landforms. China's karst landforms are exceptionally widespread and diverse, primarily concentrated in the Yunnan-Guizhou Plateau and southwestern Sichuan. In China, carbonate rocks (such as limestone, dolomite, gypsum, and rock salt)—the material basis for karst landform development—are widely distributed.

[0003] Guizhou Province is located on the slope transitioning from the Yunnan-Guizhou Plateau to the plains. It has a subtropical humid monsoon climate with abundant rainfall, providing the necessary dynamic conditions for karst cave development. In the most recent geological era, the earth's crust underwent intermittent and intense uplift, resulting in extremely rapid surface erosion, denudation, and dissolution. Therefore, Guizhou is dotted with underground caves and rivers, making it one of the regions with the largest number and most diverse types of karst caves in the world, a region where "every mountain has a cave, and every cave is unique."

[0004] For geologists, comprehensively understanding the spatial morphology and distribution of underground cavities and rivers is a demanding yet significant task. Zhou Wenlong et al.'s paper, "Comparative Study of Exploration Data from Qianlong Cave in Guizhou Based on Three Measurement Techniques," points out that karst cave measurement is a special type of underground space measurement. Building upon early traditional hand-drawn measurements of Qianlong Cave in Guizhou, they conducted repeated measurements using paperless measurement technology based on mobile terminals and three-dimensional laser scanning technology. The three types of data were then compared in terms of timeliness, data accuracy and precision, ease of operation, and data storage and processing.

[0005] For underground cavities or fissures, measuring their depth is a crucial task. Existing technicians have proposed several feasible solutions for spatial measurement methods and equipment. For example, Du Yuchao et al. from Shandong University proposed an engineering geological surface fissure depth measuring device (publication number CN115681710A). This solution addresses the issue that when measuring the depth of geological fissures, it's often necessary to manually move the measuring instrument to detect different data in the same direction, leading to poor stability of the measurement results and affecting their accuracy. Their solution primarily addresses this by designing a U-shaped loading frame and its adjustment mechanism. Additionally, Zhao Tongyu et al. from Zhengzhou Guangli Technology Co., Ltd. invented a wheel-type borehole depth measuring instrument and method, mainly for measuring the depth of manually drilled holes. This device uses a wheel frame that rotates with the force applied to the wheel. Instead of restricting the wheel's torsion, an angle sensor obtains the torsion angle in real time. The drilling depth is then calculated by using a trigonometric law sine algorithm to correlate the wheel's displacement with the corresponding wheel frame rotation. However, this solution offers little inspiration for measuring the depth of natural cavities.

[0006] In fact, ultrasonic ranging or laser ranging can be used to measure the depth of most holes or manually drilled boreholes, but each has its drawbacks. First, in complex karst geological conditions, many large geological exploration devices are difficult to carry, and cost is also a significant consideration. Secondly, both ultrasonic ranging and laser devices have limitations in use. For example, ultrasonic waves have a certain diffusion angle, and the transmitted signal and the aftershock signal can cover or interfere with the echo signal. Furthermore, optical sensors have a fatal flaw: they are susceptible to water and dust, making it difficult to guarantee accuracy under complex geological conditions.

[0007] Therefore, manual exploration is sometimes necessary. However, manual exploration can be dangerous, and many holes are too narrow to enter. It is essential to use convenient tools for preliminary, in-depth exploration, such as measuring rods or tools equipped with a plumb bob. Since natural holes or fissures may not develop vertically or in a straight line, some sections may have slopes or obstructions, potentially causing the plumb bob to get stuck and requiring frequent manual pulling, increasing the difficulty of measurement. Furthermore, because the size of hole openings and the width of fissures vary, the exploration tools need to be adaptable to holes or fissures of different sizes and orientations. How to solve these problems is a question that geologists need to consider. Summary of the Invention

[0008] In view of the shortcomings of existing hole depth detection tools, this invention provides a device for surveying the depth of underground cavities or fissures in karst landforms. The purpose is to make up for the deficiencies of the prior art and solve problems such as the pendant component being easily stuck when falling into the fissure and the device being adapted to holes or fissures of different sizes or shapes.

[0009] The present invention achieves its objective by employing the following technical solution:

[0010] A device for surveying the depth of underground cavities or fissures in karst topography comprises several main parts, including a support mechanism, a position adjustment mechanism on the support mechanism, a measuring mechanism connected to the support mechanism, and a power mechanism connected to the measuring mechanism. The support mechanism and position adjustment mechanism enable the device to adapt to holes or fissures of different sizes or orientations. The measuring mechanism employs a pendant component, which is lowered into the hole or fissure via a measuring line. The power mechanism provides the power to wind and pull the measuring line.

[0011] Furthermore, the support mechanism includes a horizontal brace beam, with both ends of the beam connected to the top of an inverted T-shaped bracket. The horizontal brace beam and the T-shaped brackets at both ends constitute an overall support structure resembling a small gantry crane. Following this general concept, the T-shaped bracket can also utilize other construction methods suitable for various terrains, and even the installation of casters could be considered.

[0012] Furthermore, the position adjustment mechanism includes two positioning rings located on the top left and right sides of the cross brace beam, and two hexagonal sliding shafts facing each other at the top of the two T-shaped supports. The two hexagonal sliding shafts are slidably fitted through the two positioning rings. Each positioning ring is equipped with a tightening bolt. Specifically, the cross brace beam has corresponding grooves at its top for the hexagonal sliding shafts to slide through. The advantage of using hexagonal sliding shafts compared to cylindrical sliding shafts is that they prevent rotation within the grooves. The sliding of the hexagonal sliding shafts at both ends within the grooves effectively adjusts the distance between the two T-shaped supports. To ensure the hexagonal sliding shafts are fixed at a certain position, two tightening bolts are provided. Tightening these bolts downwards secures the hexagonal sliding shaft at that position.

[0013] Furthermore, a U-shaped positioning frame is slidably fitted onto the bottom section of the vertical support rod of the T-shaped bracket. Two vertical cones of the positioning frame are inserted through and engaged with the two ends of the horizontal base rod of the T-shaped bracket. A sleeve is located at the top center of the positioning frame, and this sleeve is slidably engaged with the vertical support rod of the T-shaped bracket. A locking bolt is installed on the sleeve. This design facilitates the vertical cones penetrating into the soil or rock to fix the entire device. The positioning frame structure ensures that the cones do not shift or tilt, limiting their position within the frame area and improving overall installation stability. Additionally, this design facilitates the rapid installation and disassembly of the support mechanism. The sleeve facilitates connection and locking with the vertical support rod of the T-shaped bracket, also aiding in the rapid installation and disassembly of the support mechanism.

[0014] In this design, both the power mechanism and the measuring mechanism are located at the bottom of the cross brace beam to facilitate the installation of the power mechanism and the measuring mechanism.

[0015] Furthermore, the bottom of the horizontal support beam is connected to two vertical support rods, and two mounting rings are provided at the bottom ends of the two vertical support rods; the measuring mechanism includes a winding roller rotatably disposed between the two mounting rings, on which a graduated measuring rope is wound, and the first end of the measuring rope is attached to a counterweight ball. The mounting rings are provided to facilitate the installation of the measuring mechanism.

[0016] Furthermore, limit rings are provided at the left and right ends of the winding roller. This design can prevent the measuring wire from detaching from the winding roller or getting tangled during the winding process.

[0017] Furthermore, the bottom of the two mounting rings is provided with two L-shaped lifting rods, and a limiting collar is provided between the two L-shaped lifting rods; the counterweight ball is provided with a U-shaped mounting frame, which engages with the limiting collar when retracted. The limiting collar can prevent the counterweight ball from shaking and moving around when the entire measuring mechanism is transferred, thus avoiding collision deformation and noise.

[0018] Furthermore, the power mechanism includes a motor mounted at the bottom of the crossbeam, with a toothed gear on the motor shaft; one end of the winding roller shaft is connected to a driven gear, which meshes with the toothed gear. Through the toothed gear, the motor can rotate to drive the winding roller to rotate intermittently. This, combined with the falling weight of the counterweight ball, enables intermittent winding and unwinding of the measuring rope, controlling the intermittent up-and-down sliding impact of the counterweight ball to overcome the resistance from the crack, ensuring that the counterweight ball can pull the measuring rope to the bottom of the hole or crack for depth measurement.

[0019] Furthermore, a battery box is clamped between the two support rods, and a battery is installed in the battery box. The battery is electrically connected to the motor. The battery and motor are electrically connected to provide power when electricity is available.

[0020] Furthermore, a rocker arm is connected to one end of the winding roller shaft. The rocker arm is provided to facilitate manual operation in the absence of electricity; it can be of a Z-shaped structure. Beneficial effects

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. The T-shaped bracket of this invention can slide and adjust the support spacing between it in opposite directions, so that the measuring mechanism can be used to measure holes or gaps of different widths, thus expanding the compatibility of the measuring mechanism. When measuring holes or gaps cracked on slopes, the measuring mechanism can be hammered down and fixed to the soil layer of the slope through two positioning frames, so that the measuring mechanism can be used to measure holes or gaps on slopes, further expanding the compatibility of the measuring mechanism. The two locking bolts can tighten and fix the two positioning frames, so that the two positioning frames are kept in the upward sliding idle state.

[0023] 2. In this invention, when the counterweight ball is blocked in a hole or crack during the falling measurement, the motor can be started. Through the toothed gear, the motor can rotate and mesh to drive the winding roller to rotate intermittently. This, combined with the falling weight of the counterweight ball, can realize the intermittent winding and unwinding of the measuring rope, control the intermittent up and down sliding impact of the counterweight ball, break through the blocking resistance from the crack, and ensure that the counterweight ball can pull the measuring rope to the bottom of the hole or crack for depth measurement. Compared with the traditional method of frequently lifting the pendant component manually to create a downward impact to deal with the blocking resistance, it is convenient to use, saves the trouble of frequent manual lifting, and saves time and effort.

[0024] 3. Compared with the traditional method of using a conical counterweight block as a pendant component to pull the measuring rope down by gravity, the counterweight ball of this invention can rotate by friction with the soil layers on both sides of the hole when falling into the hole or crack (especially suitable for inclined soil layers with inclined cracks). This reduces the frictional force of the soil layers in the hole or crack on the pendant component when it falls, and reduces the probability of the counterweight ball and the measuring rope being blocked or stuck in the hole or crack. It is more conducive to the counterweight ball pulling the measuring rope down to the bottom of the hole or crack. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the front structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the rear structure of the present invention;

[0028] Figure 3 This is a schematic diagram of the bottom structure of the present invention;

[0029] Figure 4 This is an enlarged view of the T-shaped bracket of the present invention;

[0030] Figure 5 This is a schematic diagram of the battery mounting location in this invention;

[0031] Figure 6 This is a schematic diagram of the limiting collar of the present invention;

[0032] Figure 7 This is a schematic diagram of the winding roller structure of the present invention;

[0033] Figure 8 This is an enlarged view of the structure of the counterweight suspension ball of the present invention;

[0034] Reference numerals in the attached diagram: 1-Horizontal brace beam; 101-Positioning ring; 102-Vertical support rod; 103-Mounting ring; 104-L-shaped lifting rod; 105-Limiting collar; 2-T-shaped bracket; 201-Hexagonal sliding shaft; 202-Positioning insert frame; 3-Winding roller; 301-Limiting stop ring; 302-Driven gear; 4-Motor; 401-Gear with missing tooth; 5-Counterweight lifting ball; 501-Mounting frame; 6-Battery. Implementation

[0035] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0038] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0039] Furthermore, the terms "installation," "setup," "equipped with," "connection," "linking," and "socketing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] Example. A device for surveying the depth of underground cavities or fissures in karst landforms, first look at... Figure 1 and Figure 2Overall, the equipment includes a cross brace beam 1. Two positioning rings 101 are symmetrically welded to the top left and right sides of the cross brace beam 1. Two T-shaped brackets 2 are symmetrically slidably installed on the two positioning rings 101. The tops of the two T-shaped brackets 2 are supported by two hexagonal sliding shafts 201. The two hexagonal sliding shafts 201 are corresponding to the two positioning rings 101 and slide through them. The tops of the two positioning rings 101 are screwed with two tightening bolts. The two tightening bolts can tighten and fix the two T-shaped brackets 2, so that the two T-shaped brackets 2 are kept in the opposite sliding and unfolding use state.

[0042] Two vertical support rods 102 are symmetrically welded to the bottom of the horizontal support beam 1. Two mounting rings 103 are symmetrically welded to the bottom sections of the two vertical support rods 102. A winding roller 3 is rotatably mounted between the two mounting rings 103. By rotating the winding roller 3 in both directions, the measuring rope can be wound and unwound, controlling the counterweight ball 5 to slide up and down in the crack for measurement. A graduated measuring rope is wound on the winding roller 3, and the first end of the measuring rope is tightly connected to the counterweight ball 5. The structure of the counterweight ball 5 is as follows... Figure 8 As shown.

[0043] like Figure 7 As shown, a Z-shaped rocker arm is welded to the right end of the shaft of winding roller 3. The rocker arm can be used for manual operation in the absence of power. Figure 4 and Figure 5 As shown, a motor 4 is suspended at the bottom left side of the crossbeam 1, and a toothed gear 401 is fitted at the first end of the motor 4's shaft; a battery 6 is supported by screws at the bottom of the middle section of the crossbeam 1, located between the top sections of the two vertical support rods 102, and the battery 6 is electrically connected to the motor 4; two L-shaped suspension rods 104 are symmetrically welded to the bottom of the two mounting rings 103, and a limiting collar 105 is welded between the bottom sections of the two L-shaped suspension rods 104; two limiting retaining rings 301 are symmetrically welded to the winding roller 3, as shown. Figure 7 As shown.

[0044] like Figure 3 and Figure 5 As shown, a U-shaped positioning frame 202 is slidably fitted on the bottom section of the vertical support rod of the two T-shaped brackets 2. The front and rear vertical cones of the positioning frame 202 are inserted and connected to the front and rear ends of the bottom rod of the T-shaped bracket 2. The T-shaped brackets 2 can slide left and right to adjust the support spacing between them, so that the measuring mechanism can be used to measure gaps of different widths, thus expanding the compatibility of the measuring mechanism.

[0045] Among them, such as Figure 4As shown, a rod sleeve is welded to the middle part of the top of the positioning frame 202. A locking bolt is screwed through the rod sleeve and slides with the vertical support rod of the T-shaped bracket 2. When measuring holes or gaps cracked on the slope, the measuring mechanism can be hammered down and fixed to the soil layer of the slope through the two positioning frames 202. This allows the measuring mechanism to be used to measure holes or gaps on the slope, further expanding the compatibility of the measuring mechanism. The two locking bolts can tighten and fix the two positioning frames 202, keeping the two positioning frames 202 in an upward sliding idle state.

[0046] like Figure 5 As shown, a small-diameter driven gear 302 is fitted on the left end of the shaft of the winding roller 3, and the driven gear 302 meshes with the toothed gear 401 for transmission. When the counterweight ball 5 is blocked in the crack during the falling measurement, the motor 4 can be started. Through the toothed gear 401, the motor 4 can rotate and drive the winding roller 3 to rotate intermittently. This, together with the falling gravity of the counterweight ball 5, can realize the intermittent winding and unwinding of the measuring rope, control the intermittent up and down sliding impact of the counterweight ball 5, break through the blocking resistance from the crack, and ensure that the counterweight ball 5 can pull the measuring rope to fall to the bottom of the crack for depth measurement. Compared with the traditional method of frequently lifting the pendant component manually to create a downward impact to deal with the blocking resistance, it is convenient to use, saves the trouble of frequent manual lifting, and saves time and effort.

[0047] like Figure 8 As shown, a U-shaped mounting frame 501 is rotatably mounted on the counterweight ball 5, and the first end of the measuring rope is fastened and fixed together with the mounting frame 501. Compared with the traditional use of a conical counterweight block as a pendant component to pull the measuring rope down by gravity, the counterweight ball 5 can rotate by friction with the soil layers on both sides of the crack when falling into the crack (especially suitable for inclined soil layers with inclined cracks in the crack). This reduces the friction force of the soil layer in the crack on the pendant component when falling, and reduces the probability of the counterweight ball 5 and the measuring rope being blocked and stuck in the crack. It is more conducive to the counterweight ball 5 pulling the measuring rope down to the bottom of the crack.

[0048] When the counterweight ball 5 and the mounting frame 501 slide upward and retract, they are engaged with the limiting collar 105. When the counterweight ball 5 is pulled upward and retracted, it can be inserted into the inside of the limiting collar 105. The limiting collar 105 can prevent the counterweight ball 5 from shaking and moving around when the entire measuring mechanism is transferred, thus avoiding collision deformation and noise.

[0049] like Figure 6As shown, a clamping bolt is screwed through and installed on the rear side of the outer circumference of the right mounting ring 103. The clamping bolt abuts against the right end of the shaft of the winding roller 3. The clamping bolt can tighten and position the winding roller 3, so that the counterweight hanging ball 5 is kept at the height position of the falling measurement and the height position of the upward retraction.

[0050] The specific usage and function of this embodiment: When measuring, the measuring mechanism is supported above the hole or gap. The T-shaped bracket 2 can slide left and right to adjust the support distance between them, so that the measuring mechanism can be used to support holes or gaps of different widths for measurement. Two tightening bolts can tighten and fix the two T-shaped brackets 2, so that the two T-shaped brackets 2 are kept in the state of sliding and unfolding in opposite directions. By rotating the winding roller 3 in both directions, the measuring rope can be wound and unwound. The counterweight ball 5 can be controlled to slide up and down in the hole or gap for measurement. The clamping bolt can tighten the positioning winding roller 3, so that the counterweight ball 5 is kept at the height position of falling measurement and the height position of rising. When measuring holes or gaps that are cracked on the slope, the measuring mechanism can be hammered down and fixed to the soil layer of the slope through the two positioning frames 202.

[0051] When the counterweight ball 5 is blocked in the crack during the falling measurement, the motor 4 can be started. Through the toothed gear 401, the motor 4 can rotate and drive the winding roller 3 to rotate intermittently. This, together with the falling gravity of the counterweight ball 5, can realize the intermittent winding and unwinding of the measuring rope, control the intermittent up and down sliding impact of the counterweight ball 5, break through the blocking resistance from the hole or gap, and ensure that the counterweight ball 5 can pull the measuring rope to fall to the bottom of the hole or gap for depth measurement.

[0052] This device can also be applied to measuring the depth of artificial boreholes and the depth of rivers and lakes.

[0053] This application involves circuits, electronic components, and modules that are all prior art and can be fully implemented by those skilled in the art. The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. Apparatus for surveying the depth of underground cavities or fissures in karst topography, characterised in that: The utility model provides a kind of measuring device, including support mechanism, position adjusting mechanism is equipped on support mechanism, support mechanism connects measuring mechanism, and measuring mechanism connects power mechanism; The support mechanism includes a cross beam (1), and the two ends of the cross beam (1) are respectively connected with the top end of a T-shaped support (2) arranged upside down. The position adjusting mechanism includes two positioning rings (101) arranged on the top left and right parts of the cross beam (1) and two six-sided sliding shafts (201) arranged opposite to the top end of the two T-shaped supports (2), and the two six-sided sliding shafts (201) are slidingly matched with the two positioning rings (101) correspondingly; the positioning ring (101) is provided with a jacking bolt. The bottom of the cross beam (1) is connected with two vertical support rods (102), and the bottom end of the two vertical support rods (102) is provided with two mounting rings (103); the measuring mechanism includes a winding roller (3) rotatably arranged between the two mounting rings (103), and the winding roller (3) is wound with a measuring line with scales; the first end of the measuring line is connected with a counterweight ball (5). The left and right ends of the winding roller (3) are respectively provided with limit stop rings (301). The bottom of the two mounting rings (103) is provided with two L-shaped hangers (104), and a limiting sleeve ring (105) is arranged between the two L-shaped hangers (104); the counterweight ball (5) is provided with an installation frame (501) with a U-shaped structure, and the installation frame (501) is inserted and matched with the limiting sleeve ring (105) when it is retracted. The power mechanism includes a motor (4) arranged at the bottom of the cross beam (1), and a toothless gear (401) is arranged on the rotating shaft of the motor (4); one end of the rotating shaft of the winding roller (3) is connected with a driven gear (302), and the driven gear (302) is arranged in meshing with the toothless gear (401).

2. The apparatus for surveying the depth of underground cavities or fissures of karst topography according to claim 1, characterized in that: The bottom section of the vertical rod of the T-shaped support (2) is slidingly sleeved with a positioning insertion frame (202) with a U-shaped structure, and the two vertical insertion cones of the positioning insertion frame (202) are inserted and matched with the two end parts of the ground-touching horizontal bottom rod of the T-shaped support (2); a rod sleeve is arranged at the top end of the positioning insertion frame (202), and the rod sleeve is slidingly matched with the vertical rod of the T-shaped support (2); the rod sleeve is provided with a locking bolt.

3. The apparatus for surveying the depth of underground cavities or fissures of karst topography according to claim 1, characterized in that: A battery box is clamped between the two support rods (102), and a battery (6) is arranged in the battery box; the battery (6) is electrically connected with the motor (4).

4. The apparatus for surveying the depth of underground cavities or fissures of karst topography according to claim 1, characterized in that: One end of the rotating shaft of the winding roller (3) is connected with a rocker.

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