Measuring device for center hole method field rock mass deformation test

Abstract

The utility model relates to the technical field of rock mass tests on geotechnical engineering sites, and discloses a measuring device for a center hole method site rock mass deformation test, which comprises a fixed support, a measuring rod, an independent air pressure anchoring head, a plurality of synthetic air pressure anchoring heads, an air pump, a collector, a plurality of air inlet pipes and a plurality of signal lines, the independent air pressure anchoring head and the plurality of synthetic air pressure anchoring heads are respectively connected with the air pump through a plurality of air inlet pipes, and the plurality of synthetic air pressure anchoring heads are respectively connected with the collector through a plurality of independent signal lines. According to the utility model, the measuring rod extends into the central hole of the rock mass and is fixed, the plurality of synthetic air pressure anchoring heads are sleeved on the measuring rod in a sliding manner, and the plurality of synthetic air pressure anchoring heads are respectively inflated and expanded to be fixed at different height positions in the central hole; and the plurality of synthetic air pressure anchoring heads are in one-to-one correspondence with the plurality of induction iron cores arranged on the measuring rod to form a plurality of LVDT displacement sensors, so that deformation data of rock masses with different depths can be obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of on-site rock mass testing in geotechnical engineering, in particular to a measuring device for on-site rock mass deformation testing using a center hole method. Background Art

[0002] The study of rock mass deformation properties is an important part of the mechanical properties of engineering rock mass. The center hole deformation test uses the layered elastic modulus calculation method to obtain the modulus of rock mass at different depths through a single test. The test equipment mainly consists of a measuring device composed of an anchor head, a measuring rod and a multi-point displacement meter, and a force transmission and reaction device composed of a flexible pad, a steel plate, a jack and a force transmission column.

[0003] In the prior art, the installation steps of the test equipment for the center hole method deformation test are relatively complicated, and the measuring device and the force transmission and reaction device need to be installed in sequence. In actual operation, the conventional measuring device mainly has the following problems:

[0004] (1) The problem of interference between measuring rods. In the test, it is often necessary to arrange 6 anchor head measuring points within a 2m hole depth. The multi-point displacement meter is connected to 6 anchor heads at different depths in the borehole through 6 measuring rods to measure the deep rock deformation. During the test, the measuring rods often affect each other, resulting in data confusion or large test errors.

[0005] (2) The installation process is complicated. The installation steps of multiple measuring rods and multiple anchor heads in the hole are very complicated, which may easily lead to problems such as confusion in the numbering of measuring rods and anchor heads, and the installation takes a long time;

[0006] (3) High cost of consumables. At present, the main installation method of the anchor head is to fix it inside the borehole through an expansion agent. After the test, the anchor head and the measuring rod are often unable to be removed, becoming disposable consumables, which increases the test cost and makes other testing work impossible in the hole.

[0007] Therefore, in view of the above problems in the prior art, there is an urgent need for a low-cost center hole method deformation test device that can reduce interference between multiple measuring rods, simplify the installation process of in-hole equipment, and has low cost. Utility Model Content

[0008] The utility model aims to provide a measuring device for on-site rock deformation test using the center hole method, so as to solve the problems in the prior art that interference is easily generated between multiple measuring rods, the installation process of in-hole equipment is complicated and the cost is high.

[0009] In order to solve the above technical problems, the utility model specifically provides the following technical solutions:

[0010] A measuring device for a center hole method on-site rock deformation test, comprising a fixed bracket mounted on the rock mass, a measuring rod for extending into a center hole on the rock mass connected to the bottom end of the fixed bracket, an independent pneumatic anchoring head connected to the bottom end of the measuring rod, and a plurality of synthetic pneumatic anchoring heads sleeved on the measuring rod;

[0011] It also includes an air pump and a collector. The independent air pressure anchor head is connected to the air pump through an air inlet pipe, and multiple synthetic air pressure anchor heads are connected to the air pump through multiple air inlet pipes, and multiple synthetic air pressure anchor heads are connected to the collector through multiple independent signal lines.

[0012] As a preferred solution of the utility model, the measuring rod is provided with a plurality of induction cores flush with the outer circumference of the measuring rod, the plurality of induction cores are distributed along the length direction of the measuring rod, and the plurality of induction cores correspond one-to-one with the plurality of synthetic pneumatic anchor heads to form a plurality of LVDT displacement sensors.

[0013] As a preferred solution of the utility model, the synthetic pneumatic anchor head includes an expansion bag, an LVDT induction coil and a wire-passing channel. The LVDT induction coil is arranged at the center position of the expansion bag, and the expansion bag is movably connected to the measuring rod through the LVDT induction coil. The number of the wire-passing channels is two and they are symmetrically distributed on the expansion bag.

[0014] As a preferred solution of the utility model, the expansion bag is connected to an air inlet pipe, the LVDT induction coil is connected to a signal line, the induction core is within the linear range of the LVDT induction coil, and the two wire passing channels are respectively used to pass through multiple air inlet pipes and multiple signal lines.

[0015] As a preferred solution of the utility model, the top center position of the independent pneumatic anchor head is connected to the bottom end of the measuring rod, and the outer sides of the independent pneumatic anchor head and the expansion bag are provided with evenly distributed striped protrusions, and the independent pneumatic anchor head and the expansion bag can be engaged with the center hole when expanded.

[0016] As a preferred solution of the utility model, the air inlet pipe is provided with evenly distributed scale lines.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] The utility model extends a measuring rod into the center hole of the rock mass and fixes it, slides a plurality of synthetic gas pressure anchoring heads on the measuring rod, and inflates and fixes the plurality of synthetic gas pressure anchoring heads at different heights in the center hole respectively. The plurality of synthetic gas pressure anchoring heads correspond one-to-one with the plurality of inductive iron cores arranged on the measuring rod to form a plurality of LVDT displacement sensors. When the rock mass is deformed by pressure, the plurality of synthetic gas pressure anchoring heads at fixed positions will be displaced together, and deformation data of the rock mass at different depths can be obtained through the plurality of LVDT displacement sensors.

[0019] The utility model solves the problem of mutual interference of multiple measuring rods by slidingly sleeved multiple synthetic gas pressure anchoring heads on the same measuring rod, and the multiple synthetic gas pressure anchoring heads are successively passed through the measuring rod and fixed in the central hole of the rock mass, which simplifies the installation process of multiple anchoring heads and multiple measuring rods being connected with each other and placed in the measuring holes. In addition, the synthetic gas pressure anchoring heads are fixed by inflation clamping, and the device can be taken out by releasing the pressure after use, so that it can be reused, which reduces the use cost of the device and ensures the integrity of the borehole. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation of the utility model or the technical solution in the prior art, the following is a brief introduction to the drawings required for the implementation or the prior art description. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0021] Figure 1 It is a schematic diagram of the utility model device and the test force transmission and reaction device as a whole.

[0022] Figure 2 It is a cross-sectional view of the synthetic pneumatic anchoring head of the utility model.

[0023] Figure 3 It is a top view of the synthetic pneumatic anchoring head of the utility model.

[0024] Figure 4 It is a cross-sectional view of the independent pneumatic anchoring head of the utility model.

[0025] Reference numerals:

[0026] 1. Fixed bracket; 2. Measuring rod; 3. Independent pneumatic anchor head; 4. Synthetic pneumatic anchor head; 5. Air pump; 6. Air intake pipe; 7. Collector; 8. Signal line; 9. Induction iron core; 10. Jack; 11. Hydraulic pump; 12. Force transmission column; 13. Steel plate; 14. Flexible pad;

[0027] 401, expansion bag; 402, LVDT induction coil; 403, wire passage. DETAILED DESCRIPTION

[0028] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0029] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0030] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0031] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Embodiment 1

[0033] Combine the following Figures 1 to 4 As shown, the embodiment of the utility model provides a measuring device for a center hole method on-site rock deformation test, comprising a fixed bracket 1 installed on the rock mass, a measuring rod 2 for extending into a center hole on the rock mass is connected to the bottom end of the fixed bracket 1, an independent pneumatic anchor head 3 is connected to the bottom end of the measuring rod 2, and a plurality of synthetic pneumatic anchor heads 4 are sleeved on the measuring rod 2;

[0034] It also includes an air pump 5 and a collector 7. The independent air pressure anchor head 3 is connected to the air pump 5 through an air inlet pipe 6. The multiple synthetic air pressure anchor heads 4 are respectively connected to the air pump 5 through multiple air inlet pipes 6, and the multiple synthetic air pressure anchor heads 4 are respectively connected to the collector 7 through multiple independent signal lines 8.

[0035] The measuring rod 2 is provided with a plurality of inductive cores 9 flush with the outer circumference of the measuring rod 2 . The plurality of inductive cores 9 are distributed along the length direction of the measuring rod 2 . The plurality of inductive cores 9 correspond one-to-one with a plurality of synthetic air pressure anchoring heads 4 to form a plurality of LVDT displacement sensors.

[0036] The utility model extends a measuring rod 2 into the center hole of the rock mass and fixes it, and slides a plurality of synthetic gas pressure anchoring heads 4 on the measuring rod 2, and the plurality of synthetic gas pressure anchoring heads 4 are respectively inflated and fixed at different height positions in the center hole, and the plurality of synthetic gas pressure anchoring heads 4 correspond one-to-one with the plurality of inductive iron cores 9 arranged on the measuring rod 2 to form a plurality of LVDT displacement sensors. When the rock mass is deformed by pressure, the plurality of synthetic gas pressure anchoring heads 4 at fixed positions will be displaced, and deformation data of the rock mass at different depths can be obtained through the plurality of LVDT displacement sensors.

[0037] The utility model solves the problem of mutual interference of multiple measuring rods 2 by slidingly sleeved multiple synthetic gas pressure anchoring heads 4 on the same measuring rod 2, and multiple synthetic gas pressure anchoring heads 4 are successively passed through the measuring rod 2 and fixed in the central hole of the rock mass, which simplifies the installation process of multiple anchoring heads (an independent gas pressure anchoring head 3 and multiple synthetic gas pressure anchoring heads 4) and multiple measuring rods 2 being connected and inserted into the measuring hole. In addition, the synthetic gas pressure anchoring heads 4 are fixed by inflation card engagement, and the device can be taken out by releasing the pressure after use, so that it can be reused, which reduces the use cost of the device and ensures the integrity of the borehole.

[0038] Among them, the synthetic pneumatic anchor head 4 includes an expansion bag 401, an LVDT induction coil 402 and a wire-passing channel 403. The LVDT induction coil 402 is arranged at the center position of the expansion bag 401, and the expansion bag 401 is movably connected to the measuring rod 2 through the LVDT induction coil 402. The number of the wire-passing channels 403 is two and they are symmetrically distributed on the expansion bag 401.

[0039] The expansion bag 401 is connected to an air inlet pipe 6, the LVDT induction coil 402 is connected to a signal line 8, the induction core 9 is within the linear range of the LVDT induction coil 402, and the two wire passages 403 are used to pass through multiple air inlet pipes 6 and multiple signal lines 8 respectively.

[0040] The air inlet pipe 6 is provided with evenly distributed scale lines.

[0041] Specifically, it is necessary to first connect the independent pneumatic anchor head 3 to the bottom end of the measuring rod 2, and extend the independent pneumatic anchor head 3 into the center hole of the rock mass through the measuring rod 2. When the independent pneumatic anchor head 3 is extended to an appropriate depth (this position will not deform under the test stress), gas can be pumped into the air inlet pipe 6 connected to the independent pneumatic anchor head 3 through the air pump 5, so that the independent pneumatic anchor head 3 can be expanded and engaged in the center hole, and the bottom end of the measuring rod 2 is fixed by the independent pneumatic anchor head 3.

[0042] Subsequently, the synthetic gas pressure anchor head 4 is installed, and when multiple synthetic gas pressure anchor heads 4 are extended into the center hole of the rock mass through the measuring rod 2, it is necessary to first place the lowest synthetic gas pressure anchor head 4 into the center hole along the measuring rod 2, and the depth can be determined by the air inlet pipe 6 with scale lines connected to the synthetic gas pressure anchor head 4. When the synthetic gas pressure anchor head 4 is at a predetermined depth, gas can be pumped into the air inlet pipe 6 connected to the synthetic gas pressure anchor head 4 through the air pump 5, so that the expansion bag 401 is enlarged until it is snap-fitted and fixed in the center hole, completing the installation of the synthetic gas pressure anchor head 4, and then following the same steps to sequentially fix the other synthetic gas pressure anchor heads 4 at their respective depths.

[0043] After the in-hole equipment is installed, the measuring rod 2 is connected to the fixing bracket 1 so that the top of the measuring rod 2 is fixed. At this time, the measuring rod 2 is on the central axis of the central hole. In addition, after the test is completed, it is necessary to take out multiple synthetic air pressure anchor heads 4 from high to low, and then take out the independent air pressure anchor head 3 after the multiple synthetic air pressure anchor heads 4 are taken out.

[0044] It is worth noting that the collector 7 can be used to observe whether the LVDT induction coils 402 of multiple synthetic air pressure anchor heads 4 can sense the corresponding induction iron core 9. If the LVDT induction coils 402 of some synthetic air pressure anchor heads 4 fail to sense the induction iron core 9, the air in the expansion bag 401 can be discharged through the air inlet pipe 6, so that the depth of the synthetic air pressure anchor head 4 can be continuously adjusted through the air pipe until the LVDT induction coils 402 of the synthetic air pressure anchor head 4 can sense the corresponding induction iron core 9, and then air can be pumped into the corresponding air inlet pipe 6 again through the air pump, so that the expansion bag 401 is enlarged to fit the center hole.

[0045] Furthermore, the LVDT displacement sensor outputs an electrical signal by moving the rod-shaped armature, which can be converted into displacement. It has the characteristics of simple structure, reliable operation, high sensitivity, wide linear range, and good environmental applicability. The sealed LVDT can be placed in corrosive liquids. Similarly, the above measurement device can also be used in boreholes with water.

[0046] Among them, the top center position of the independent air pressure anchor head 3 is connected to the bottom end of the measuring rod 2, and the outside of the independent air pressure anchor head 3 and the expansion bag 401 are provided with evenly distributed striped protrusions, and the independent air pressure anchor head 3 and the expansion bag 401 can be engaged with the center hole when expanded.

[0047] Embodiment 2

[0048] The above embodiment 1 describes the installation of the measuring device of the test equipment. In order to facilitate a further understanding of the working state of the measuring device of the above embodiment 1 in the central hole of the rock mass, this embodiment is used to illustrate the force transmission and reaction device applicable to the measuring device in the embodiment 1, such as Figure 1As shown, it also includes a reaction force component, which includes a jack 10, the output end of the jack 10 is connected to a fixed base surface above the rock mass, and the jack 10 is connected to a hydraulic pump 11;

[0049] It also includes a force transmission component, which includes a force transmission column 12 for supporting the bottom end of the jack 10, the bottom end of the force transmission column 12 extends to the inner side of the fixed bracket 1 and is connected to a steel plate 13, the bottom end of the steel plate 13 is in contact with the rock mass through a flexible pad 14, the centers of the steel plate 13 and the flexible pad 14 are located directly above the center hole of the rock mass, and through holes are opened on the steel plate 13 and the flexible pad 14 to expose the center hole.

[0050] Specifically, the utility model comprises a plurality of LVDT linear sensors through a plurality of induction cores 9 and LVDT induction coils 402. During the test, hydraulic oil is pumped into the jack 10 through the hydraulic pump 11 of the reaction force assembly, and the upper base surface provides reaction force, so that pressure is applied to the covered rock mass through the force transmission column 12, the steel plate 13 and the flexible pad 14. The rock mass deforms under the action of pressure, and the synthetic pneumatic anchor heads 4 at different positions move downward with the deformation of the rock mass, while the independent pneumatic anchor heads 3 and the bracket 1 at both ends of the measuring rod 2 are arranged outside the pressure influence range. The LVDT induction coil 402 produces relative displacement with the induction core 9, which is transmitted to the collector 7 on the surface in the form of electrical signals, thereby recording deformation data at multiple positions.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A measuring device for a center hole method on-site rock deformation test, comprising a fixed bracket (1) mounted on the rock mass, wherein the bottom end of the fixed bracket (1) is connected to a measuring rod (2) for extending into a center hole on the rock mass, and characterized in that: The bottom end of the measuring rod (2) is connected to an independent pneumatic anchor head (3), and a plurality of synthetic pneumatic anchor heads (4) are sleeved on the measuring rod (2); It also includes an air pump (5) and a collector (7), wherein the independent air pressure anchor head (3) is connected to the air pump (5) via an air inlet pipe (6), and the plurality of synthetic air pressure anchor heads (4) are respectively connected to the air pump (5) via the plurality of air inlet pipes (6), and the plurality of synthetic air pressure anchor heads (4) are respectively connected to the collector (7) via a plurality of independent signal lines (8).

2. A measuring device for on-site rock deformation test using the center hole method according to claim 1, characterized in that: The measuring rod (2) is provided with a plurality of inductive iron cores (9) flush with the outer circumferential surface of the measuring rod (2); the plurality of inductive iron cores (9) are distributed along the length direction of the measuring rod (2); the plurality of inductive iron cores (9) form a plurality of LVDT displacement sensors by corresponding one-to-one with the plurality of synthetic air pressure anchoring heads (4).

3. A measuring device for on-site rock deformation test using the center hole method according to claim 2, characterized in that: The synthetic gas pressure anchor head (4) comprises an expansion bag (401), an LVDT induction coil (402) and a wire-passing channel (403); the LVDT induction coil (402) is arranged at the center of the expansion bag (401), and the expansion bag (401) is movably sleeved on the measuring rod (2) via the LVDT induction coil (402); and the wire-passing channels (403) are two in number and are symmetrically distributed on the expansion bag (401).

4. A measuring device for on-site rock deformation test using the center hole method according to claim 3, characterized in that: The expansion bag (401) is connected to an air intake pipe (6), the LVDT induction coil (402) is connected to a signal line (8), the induction core (9) is within the linear range of the LVDT induction coil (402), and the two wire passages (403) are respectively used to pass through a plurality of air intake pipes (6) and a plurality of signal lines (8).

5. The measuring device for on-site rock deformation test using the center hole method according to claim 3 is characterized in that: The center position of the top end of the independent air pressure anchor head (3) is connected to the bottom end of the measuring rod (2), and the outer sides of the independent air pressure anchor head (3) and the expansion bag (401) are both provided with evenly distributed striped protrusions, and the independent air pressure anchor head (3) and the expansion bag (401) can be engaged with the center hole when expanded.

6. The measuring device for on-site rock deformation test using the center hole method according to claim 1, characterized in that: The air inlet pipe (6) is provided with evenly distributed scale lines.

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