CN212255005U - A seepage test device for rock specimens in tunnels with internal and external water pressure differences - Google Patents

Abstract

The utility model discloses a seepage test device of inside and outside water pressure difference pore rock test piece, including the test piece system, axial loading system, confined pressure loading system, water pressure loading system and controller, axial loading system includes the loading axle, the axial force sensor, a housing, the triaxial chamber, bearing plate and base, the casing bottom is installed on the base through the bearing plate, form the triaxial chamber in the casing, the triaxial intracavity is filled with water, the test piece system is located the middle of triaxial intracavity bottom, the test piece system top is equipped with the loading axle, be equipped with the axial force sensor on the loading axle, the signal output part of axial force sensor links to each other with the controller, confined pressure loading system is connected with the triaxial chamber; the hydraulic loading system is connected with the triaxial chamber. The utility model discloses all parcel has foraminiferous rubber tube inside and outside the rock test piece, and the water pressure difference under the natural state is reached in the self-propelled motion of assurance water that can be fine, reaches inside and outside water pressure balance even, has safe and reliable, respond well characteristics.

Description

A seepage test device for rock specimens in tunnels with internal and external water pressure differences

technical field

The utility model relates to the technical field of engineering geology, in particular to a seepage test device for a rock test piece of a pore channel with an internal and external water pressure difference.

Background technique

Flood in vertical well construction is the most important factor affecting construction progress and quality. In the construction of vertical wells, different water control methods are adopted according to different lithology, different water inflow, and distribution of cracks in different rock formations. The strength characteristics of vertical shafts have always been the frontier and hot topics of rock mechanics research scholars. Usually, the triaxial compression method is used to measure the strength of the rock. The central hole of the upper specimen block enters the center of the fracture surface, and flows out through the fracture surface to form radial flow, without considering the effect of external water pressure. However, in the actual situation, during the stress process of the shaft wall of the vertical shaft, due to the water permeability of the well wall rock itself, when the water pressure inside the well is lower than the external water pressure, the water outside the well can penetrate into the well through the pores of the rock, making the The water pressure reaches a certain balance, which affects the mechanical properties of the rock. Therefore, the conventional specimens cannot comprehensively measure the strength characteristics of the vertical shaft wall of the rock under the three-dimensional stress state, and cannot achieve a better reference value in the actual engineering design and calculation.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned technical problems, the utility model provides a seepage test device for a rock specimen in a pore channel with a simple structure and accurate measurement of the internal and external water pressure difference.

The technical solution of the utility model to solve the above problems is: a seepage test device for a rock test piece of a pore channel with an internal and external water pressure difference, which includes a test piece system, an axial loading system, a confining pressure loading system, a hydraulic loading system and a controller. The axial loading system includes a loading shaft, an axial force sensor, a casing, a triaxial cavity, a pressure bearing plate and a base. The bottom of the casing is mounted on the base through the pressure bearing plate, and a triaxial cavity is formed in the casing. Filled with water, the test piece system is located in the middle of the bottom of the triaxial cavity, the top of the test piece system is provided with a loading shaft, the loading shaft is provided with an axial force sensor, and the signal output end of the axial force sensor is connected to the controller, the said The confining pressure loading system is connected with the triaxial cavity for loading the confining pressure on the test piece system; the hydraulic loading system is connected with the triaxial cavity for loading water pressure on the test piece system.

In the above-mentioned seepage test device for a rock specimen in a channel with a water pressure difference between inside and outside, the specimen system includes an upper backing plate, a lower backing plate, an upper screw, a lower screw, an upper pressure plate with holes, a lower pressure plate with holes, and a rock test piece, A vertical hole is set in the middle of the rock specimen, the lower end of the rock specimen is fixed on the lower backing plate by lower screws, the lower backing plate is installed on the lower pressure plate with holes, the lower pressure plate with holes is installed on the lower rigid pressure plate, and the lower rigid pressure plate is installed On the cushion block in the middle of the bearing plate, the rock specimen is surrounded by an outer rubber tube, and the wall of the inner hole of the rock specimen is wrapped with the inner rubber tube. The upper end is fixed on the upper plate by the upper screw, the upper end of the upper plate is connected with the upper plate with holes, the upper end of the plate with holes is connected with the upper rigid plate, and the upper rigid plate is facing the loading shaft of the axial loading system.

The seepage test device for the above-mentioned internal and external water pressure difference tunnel rock specimens, the center of the outer rubber tube is equipped with a hoop extensometer, one side of the outer rubber tube is provided with an axial extensometer, and the signals of the hoop extensometer and the axial extensometer are The output terminal is connected to the controller.

The seepage test device for the above-mentioned inner and outer water pressure difference tunnel rock specimen, the confining pressure loading system includes a loading water tank, a servo motor, a reducer, a screw transmission pair, a piston, a confining pressure sensor, a control end of the servo motor and a controller Connected, the output shaft of the servo motor is connected to the screw drive pair after the reducer, and the screw drive pair is connected to the piston of the loading water tank. The water outlet of the loading water tank is provided with a confining pressure sensor, and the signal output end of the confining pressure sensor is connected with the controller; The water outlet of the water tank is communicated with the triaxial cavity through a pipeline I, and a valve II is arranged on the pipeline I.

The above-mentioned seepage test device for the rock specimen in the channel of the inner and outer water pressure difference, the hydraulic loading system includes a water pressure box and a voltage stabilizer, and the upper backing plate, the lower backing plate, the upper screw and the lower screw are all open holes, so There is a 7-shaped hole channel I in the middle of the upper pressure plate with holes, and a 7-shaped hole channel II in the middle of the lower pressure plate with holes. One end of Ⅰ is connected, the other end of the 7-shaped channel I is connected to the upper port of the channel through the holes opened by the upper screw and the upper backing plate, and the lower port of the channel is connected to one end of the 7-shaped channel II through the holes opened by the lower backing plate and the lower screw. connected, the other end of the 7-shaped channel II is connected to the voltage stabilizer through the pipeline III.

In the above-mentioned seepage test device for rock specimens in tunnels with water pressure difference, the pipeline II is provided with a flow sensor I, a water pressure gauge I, and a valve I, and the signal output end of the flow sensor I is connected to the controller.

In the seepage test device of the above-mentioned inner and outer water pressure difference tunnel rock specimen, the pipeline III is provided with a flow sensor II, a water pressure gauge II, and a valve III, and the signal output end of the flow sensor II is connected to the controller.

In the above-mentioned seepage test device for a rock specimen in a tunnel with an internal and external water pressure difference, the casing is provided with a number of annular heating rings in the circumferential direction, and a temperature sensor is provided on the heating ring, and the signal output end of the temperature sensor is connected to the controller.

In the above-mentioned seepage test device for a rock specimen in a channel with a water pressure difference between the inside and outside, the rock specimen is a cylinder specimen.

The beneficial effect of the utility model is that: the utility model proposes a method for the actual situation that the water pressure difference in the natural state is generated due to the water permeability of the rock itself and the mutual penetration of the inner and outer water under the stress of the shaft wall in the project. This is a seepage test device for rock specimens with water pressure difference between inside and outside, which has a strong practical reference value. Because the rock specimens are wrapped with rubber tubes with holes inside and outside, it can well ensure the self-movement of water and achieve the natural state. The internal and external water pressure difference, and even the internal and external water pressure balance. It has the characteristics of safety, reliability and good effect.

Description of drawings

FIG. 1 is a schematic structural diagram of the seepage test device of the present invention.

FIG. 2 is a schematic structural diagram of the test piece system in FIG. 1 .

FIG. 3 is a schematic structural diagram of the upper backing plate in FIG. 1 .

FIG. 4 is a schematic structural diagram of the upper screw in FIG. 1 .

FIG. 5 is a schematic structural diagram of the inner rubber tube in FIG. 1 .

FIG. 6 is a schematic structural diagram of the diagram of the middle and outer rubber tubes in FIG. 1 .

Detailed ways

The utility model will be further described below with reference to the accompanying drawings and embodiments.

As shown in FIG. 1 , a seepage test device for a rock specimen in a channel with an internal and external water pressure difference includes a specimen system, an axial loading system, a confining pressure loading system, a hydraulic loading system and a controller 37. The axial loading system The system includes a loading shaft 25, an axial force sensor 23, a casing 33, a triaxial cavity, a pressure bearing plate 34 and a base 35. The bottom of the casing 33 is mounted on the base 35 through the pressure bearing plate 34, and a triaxial cavity is formed in the casing 33. , the triaxial cavity is filled with water, the test piece system is located in the middle of the bottom of the triaxial cavity, the top of the test piece system is provided with a loading shaft 25, which can apply axial force, and the loading shaft 25 is provided with an axial force sensor 23, The signal output end of the axial force sensor 23 is connected with the controller 37 through the data line I15, the confining pressure loading system is connected with the triaxial cavity, and is used to load the confining pressure on the specimen system; the hydraulic loading system is connected with the triaxial cavity Connection for applying hydraulic pressure to the specimen system.

The axial force sensor 23 on the loading shaft 25 detects the magnitude of the force and transmits it to the controller 37. The loading shaft 25 acts on the upper rigid pressure plate 26, and applies an axial force to the rock specimen 30 through the upper pressure plate 47 with holes. .

The test piece system includes an upper backing plate 29, a lower backing plate 28, an upper screw 50, a lower screw 51, an upper pressure plate 47 with holes, a lower pressure plate 48 with holes, and a rock specimen 30. The rock specimen 30 is: A cylindrical specimen with a diameter of 50 mm and a height of 100 mm. A vertical tunnel 42 is set in the middle of the rock specimen 30. The lower end of the rock specimen 30 is fixed on the lower backing plate 28 through the lower screw 51. On the plate 27, the lower rigid pressure plate 27 is installed on the pad 36 in the middle of the pressure-bearing plate 34, the outer rubber tube 38 is wrapped around the rock test piece 30, and the inner rubber tube 39 is wrapped by the hole wall of the hole 42 of the rock test piece 30, Several holes 54 are punched on the outer rubber tube and the rubber tube II. The upper end of the rock specimen 30 is fixed on the upper backing plate 29 by the upper screw 50, the upper end of the upper backing plate 29 is connected with the upper pressure plate 47 with holes, the upper end of the upper pressure plate 47 with holes is connected with the upper rigid pressure plate 26, and the upper rigid pressure plate 26 is facing the loading shaft 25 of the axial loading system. In FIG. 2 , 31 indicates the connection part between the upper screw 50 and the upper backing plate 29 .

The center of the outer rubber tube 38 is equipped with a hoop extensometer 32, the signal output end of the hoop extensometer 32 is connected to the controller 37 through the data line III17, and an axial extensometer 41 is provided on one side of the outer rubber tube 38. The signal output terminal of the extensometer 41 is connected to the controller 37 through the data line IV18.

The confining pressure loading system includes a loading water tank 1, a servo motor 2, a reducer 3, a screw transmission pair 4, a piston 5, and a confining pressure sensor 6. The control end of the servo motor 2 is connected to the controller 37 through the data line VI 20, The output shaft of the servo motor 2 is connected to the screw drive pair 4 through the reducer 3, and the screw drive pair 4 is connected to the piston 5 of the loading water tank 1. The water outlet end of the loading water tank 1 is provided with a confining pressure sensor 6, and the signal output of the confining pressure sensor 6 The end is connected with the controller 37; the water tank port of the loading water tank 1 is communicated with the triaxial cavity through the pipeline I, and the pipeline I is provided with a valve II13.

The triaxial cavity 33 is filled with water, the confining pressure loading is realized by the loading water tank 1, the servo motor 2 rotates according to the command issued by the controller, and the movement of the reducer 3 drives the movement of the screw transmission pair 4 to drive the piston 5 to move linearly to adjust the loading water tank 1. The confining pressure sensor 6 installed at the water outlet of the loading water tank 1 detects the water pressure and transmits it to the controller 37. The controller 37 processes the pressure measurement signal, compares the set pressure data, and then gives a correction signal , so that the applied pressure value is consistent with the set pressure value.

The hydraulic loading system includes a hydraulic box 9 and a voltage stabilizer 40. The upper backing plate 29 and the lower backing plate 28 are perforated and the hole walls are threaded. The upper screw 50 is perforated and the upper end is marked with hexagonal holes. The lower screw 51 is drilled with holes and a hexagonal hole at the lower end. The upper platen with holes 47 has a diameter of 50mm and a height of 40mm. There is a 7-shaped hole I45 in the middle of the platen with holes 47, and a platen with holes 48 in the middle. The diameter is 50mm, the height is 40mm, and a 7-shaped hole II 46 is arranged in the middle of the lower pressure plate 48 with holes. The other end of the zigzag channel I45 is communicated with the upper port of the channel 42 through the holes opened by the upper screw 50 and the upper backing plate 29, and the lower port of the channel 42 is connected to the 7-shaped channel II46 through the holes opened by the lower backing plate 28 and the lower screw 51. One end is connected, and the other end of the 7-shaped hole II 46 is connected with the voltage stabilizer 40 through the pipeline III. The pipeline II is provided with a flow sensor I7, a water pressure gauge I10, and a valve I12. The signal output end of the flow sensor I7 is connected to the controller 37 through a data line VII21. The pipeline III is provided with a flow sensor II8, a water pressure gauge II11, and a valve III14. The signal output end of the flow sensor II8 is connected to the controller 37 through a data line V19.

Connect the pipes and lines of the hydraulic loading system, adjust the outlet air pressure of the hydraulic box 9 to the design value, and adjust the pressure gauge on the pressure regulator 40 to the set value. The high-pressure gas in the hydraulic box 9 passes through the upper belt. The 7-shaped hole I45 of the hole pressure plate 47, the central hole of the cylindrical rock specimen, and the 7-shaped hole II 46 of the lower pressure plate 48 with holes are connected to the regulator 40 to ensure that the water pressure in the central hole of the cylindrical rock specimen is maintained at Settings.

The casing 33 is provided with a plurality of annular heating rings 24 in the circumferential direction. The heating rings 24 are provided with a temperature sensor 22 , and the signal output end of the temperature sensor 22 is connected to the controller 37 through the data line II16 .

A seepage test method for a rock specimen, comprising the following steps:

Step 1: Fabrication of the test piece: The rock test piece 30 is composed of cylindrical rock mass. An electric drill is used to drill the upper and lower surfaces of the penetrating rock test piece 30 with a diameter of 10mm in the center of the cylindrical rock test piece 30 with a height of 100mm and a diameter of 50mm along the radial direction. For the hole 42, the inner rubber tube 39 with a diameter of 9.5mm and a height of 120mm and the outer rubber tube 38 with a diameter of 50.5mm and a height of 150mm are punched with holes 54 with a diameter of 0.1mm, the upper plate 29, the lower plate 28 The outer rubber tube 38 that does not exceed both sides is wrapped externally;

Step 2: Installation of the test piece:

First, place the prepared rock specimen 30 on the pad 36, place the lower pad 28 above the rock specimen 30, and insert the perforated inner rubber tube 39 into the hole 42 of the rock specimen 30, and then Lay the rock specimen 30 flat, and adjust the position of the inner rubber tube 39 to ensure that both ends of the rock specimen 30 have rubber tubes that extend beyond the surface of the rock specimen 30;

Second, place the rock specimen 30 vertically, place the end connected with the lower backing plate 28 on the lower part, place the upper backing plate 29 above the rock specimen 30, and coat the portion of the inner rubber tube 39 beyond the rock specimen 30. Apply glue and stick it on the upper backing plate 29, and then fix the inner rubber tube 39 with the upper screw 50. The upper screw 50 has a hexagonal hole in it, and the upper screw 50 is tightened with a hexagonal screwdriver;

Third, install the upper pressure plate 47 with holes on the upper screws 50, and complete the installation of the lower screws 51 and the lower pressure plate 48 with holes according to the same steps;

Fourth, wrap the outer rubber tube 38 to the ends of the upper backing plate 29 and the lower backing plate 28 at the upper and lower ends of the rock specimen 30, and tie the outer rubber tube 38 with iron wires at the place where the sealing tape is attached to the lower backing plate 28 to ensure the effect. , wrap two circles; use a rubber band to wrap the outer rubber tube 38 around the test piece from bottom to top, and stick the sealing tape on the upper backing plate 29, use iron wire to tie the outer rubber tube 38 tightly, and wrap two circles in the same way, After tying, remove the fixed rubber ring; place the upper rigid platen 26 on the upper platen 47 with holes, place the lower rigid platen 27 on the lower platen 48 with holes, and then place the test piece system on the spacer 36 superior;

Step 3: Loading: The axial loading system and the confining pressure loading system are controlled by the controller 37 to perform axial loading and confining pressure loading on the rock specimen 30, and the axial pressure value and the axial pressure application rate are set in the controller 37, Thus, the application of the confining pressure and the axial pressure to the rock specimen 30 is realized, and the display is used to receive the test data and draw the test image.

Apply confining and axial pressure. Connect the confining pressure to the pipes of the axial pressure system, set the confining pressure to the design value in the controller 37, and apply a certain rate. After the confining pressure is applied, set the axial pressure to the design value in the controller 37, and apply a certain rate. .

Apply water pressure. Connect the pipes and lines of the water pressure loading system, adjust the outlet air pressure of the water pressure tank 9 to the design value, and adjust the pressure gauge on the pressure regulator 40 to the set value at the same time, and the high pressure gas in the water pressure tank 9 passes through the upper The figure-7-shaped channel I45 of the pressure plate 47 with holes, the central channel 42 of the cylindrical rock specimen, and the figure-7-shaped channel II 46 of the lower pressure plate 48 with holes are connected to the voltage stabilizer 40 to ensure the water in the central channel 42 of the cylindrical rock sample. pressure remains at the set value.

Step 4: Determination of rock parameters: the temperature sensor 22, the hoop extensometer 32, the axial extensometer 41, the flow sensor I7, and the flow sensor II8 are used to measure the rock tensile strength value of the rock under the internal and external water pressure difference, and the radial direction of the rock. Deformation, lateral deformation and loading rate.

Set the test temperature. The temperature of the controller 37 is set to 50 ^oC , the heating ring 24 heats the water temperature in the triaxial cavity through heat conduction, and the temperature of the rock specimen 30 is heated to 50 ^oC .

data collection. Keep the axial pressure, confining pressure and temperature unchanged. The entire test lasts for 90 hours. During the test, data such as gas pressure, axial and hoop strain of the specimen, confining pressure, axial pressure and temperature are collected in real time. The sampling interval is 1.0 seconds.

Claims (9)

1. a seepage test device for a tunnel rock specimen with an internal and external water pressure difference, characterized in that: comprising a specimen system, an axial loading system, a confining pressure loading system, a hydraulic loading system and a controller, the axial loading system It includes a loading shaft, an axial force sensor, a casing, a triaxial cavity, a pressure bearing plate and a base. The bottom of the casing is mounted on the base through the pressure bearing plate. A triaxial cavity is formed in the casing, and the triaxial cavity is filled with water. The test piece system is located in the middle of the bottom of the triaxial cavity, the top of the test piece system is provided with a loading shaft, the loading shaft is provided with an axial force sensor, the signal output end of the axial force sensor is connected to the controller, and the confining pressure loading system is connected with the controller. The triaxial cavity is connected for loading the confining pressure on the test piece system; the hydraulic loading system is connected with the triaxial cavity for loading water pressure on the test piece system. 2 . The seepage test device of the rock specimen in the inner and outer water pressure difference according to claim 1 , wherein the specimen system comprises an upper backing plate, a lower backing plate, an upper screw, a lower screw, and an upper belt hole pressure. 3 . plate, lower pressure plate with holes, rock specimens, a vertical hole is set in the middle of the rock specimen, the lower end of the rock specimen is fixed on the lower backing plate by lower screws, the lower backing plate is installed on the lower pressure plate with holes, and the lower pressure plate with holes Installed on the lower rigid pressure plate, the lower rigid pressure plate is installed on the cushion block in the middle of the bearing plate, the rock specimen is surrounded by an outer rubber tube, the hole wall of the inner hole of the rock specimen is wrapped with the inner rubber tube, and the outer rubber tube and Several holes are punched on the hose II. The upper end of the rock specimen is fixed on the upper backing plate by upper screws. The platen faces the loading shaft of the axial loading system. 3. The seepage test device of the rock test piece of the channel rock test piece according to the inner and outer water pressure difference according to claim 2, is characterized in that: the center of the outer rubber tube is provided with a circumferential extensometer, and one side of the outer rubber tube is provided with an axial extensometer , the signal output ends of the hoop extensometer and the axial extensometer are connected to the controller. 4. The seepage test device for the rock specimen in the tunnel with the difference of internal and external water pressure according to claim 1, wherein the confining pressure loading system comprises a loading water tank, a servo motor, a reducer, a screw drive pair, a piston, a confining pressure Sensor, the control end of the servo motor is connected with the controller, the output shaft of the servo motor is connected to the screw drive pair after the reducer, and the screw drive pair is connected with the piston of the loading water tank. The signal output end of the pressure sensor is connected with the controller; the water outlet of the loading water tank is communicated with the triaxial cavity through the pipeline I, and the pipeline I is provided with a valve II. 5 . The seepage test device for the rock test piece of the tunnel with the difference in internal and external water pressure according to claim 2 , wherein the hydraulic loading system comprises a water pressure tank and a voltage stabilizer, and the upper pad and the lower pad , There are holes in the middle of the upper screw and the lower screw. There is a 7-shaped hole channel I in the middle of the upper pressure plate with holes, and a 7-shaped hole channel II in the middle of the lower pressure plate with holes. The water pressure box passes through the pipeline. II is connected with one end of the 7-shaped hole I of the upper platen with holes, and the other end of the 7-shaped hole I is connected with the upper port of the hole through the holes opened by the upper screw and the upper backing plate, and the lower port of the hole passes through the lower backing plate and the lower backing plate. The hole opened by the screw is connected with one end of the 7-shaped hole II, and the other end of the 7-shaped hole II is connected with the voltage stabilizer through the pipeline III. 6. The seepage test device for the rock test piece of the tunnel with the difference of internal and external water pressure according to claim 5, characterized in that: the pipeline II is provided with a flow sensor I, a water pressure gauge I, a valve I, and the signal of the flow sensor I The output terminal is connected to the controller. 7. The seepage test device for the rock specimen of the tunnel with the difference in internal and external water pressure according to claim 5, wherein the pipeline III is provided with a flow sensor II, a water pressure gauge II, a valve III, and the signals of the flow sensor II The output terminal is connected to the controller. 8 . The seepage test device for rock specimens with inner and outer water pressure difference according to claim 5 , wherein the casing is provided with a plurality of annular heating rings in the circumferential direction, and a temperature sensor is arranged on the heating ring, and the signal output of the temperature sensor is provided. 9 . The terminal is connected to the controller. 9 . The seepage test device for a rock specimen in a channel with an internal and external water pressure difference according to claim 5 , wherein the rock specimen is a cylindrical specimen. 10 .

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