Axial loading device without damage to soil body and adaptive to different resonant column instruments

Abstract

The invention discloses a lossless soil axial loading device adaptive to different resonant column instruments, which comprises a counter-force frame, the counter-force frame is mounted on the original structure of the resonant column instrument, a loading airbag mechanism is arranged on the end surface, facing a sample, of the counter-force frame, the loading airbag mechanism is connected with a pressure volume controller through a water pipe, and the pressure volume controller is connected with the counter-force frame. The pressure system controller injects water into the loading air bag mechanism and is controlled by a computer, then different axial pressures are applied to a sample, the device can be compatible with resonant column instruments of different models and is convenient to mount, and meanwhile, axial loading is applied under the function of an original resonant column instrument to perform anisotropic consolidation. And the mechanical properties of the soil body better fitting the actual condition are further obtained.

Description

Technical Field

[0001] The present invention relates to an axial loading device for non-destructive soil bodies and adapted to different resonant column apparatuses. Background Art

[0002] A resonant column apparatus is a commonly used unit test instrument in the field of geotechnical engineering. By changing the vibration frequency, the specimen generates resonance to measure important parameters such as its dynamic elastic modulus and damping ratio. Currently, the resonant column apparatus generally adopts an isotropic consolidation method. However, soil elements in natural soil layers are generally K0 consolidated, that is, in an anisotropic stress state. Compared with the isotropic consolidation method, indexes such as the shear strength and dynamic elastic modulus of the soil under anisotropic consolidation are significantly changed. Therefore, in the resonant column test, if K0 consolidation or different degrees of anisotropic stress states are realized, more realistic soil mechanical properties can be obtained to ensure the safety and reliability of the project.

[0003] Currently, some scholars have proposed a method to achieve anisotropic consolidation in a resonant column. By longitudinally passing a metal rod through the interior of the soil body and applying pressure at the bottom of the rod, the soil sample is subjected to an additional load in the axial direction, thereby achieving anisotropic consolidation. Although this method realizes anisotropic consolidation, it causes damage to the soil structure and directly affects the test structure.

[0004] For another example, the patent application number is: 202311762461.8, and the name is a soil body resonant column test device. The device includes a fixed box body, a first axial force rod, a first driving component, a second driving component, and an exciter. The first axial force rod is slidably arranged inside the fixed box body, and a pressing head is arranged on the top wall of the first axial force rod. A first driving component is arranged inside the fixed box body, and the first driving component is connected to the first axial force rod. A second driving component is arranged on the fixed box body, and a second axial force rod is arranged inside the second driving component. An exciter is detachably arranged at the bottom of the second axial force rod, and an upper pressing head is detachably arranged at the bottom of the exciter. A specimen is arranged between the upper pressing head and the lower pressing head; by connecting the second axial force rod and the exciter, the top of the specimen is fixed. Under the action of the first driving component, the first axial force rod applies an axial force to the specimen to realize the loading of the dynamic load on the specimen. Then, the first axial force rod and the exciter are disassembled, and the exciter is started to perform a resonance test on the specimen.

[0005] The above patent modifies the original loading system of the resonant column apparatus to enable it to achieve an anisotropic stress state without damaging the soil sample. However, this method is relatively complex in design and requires a large modification to the main structure of the resonant column apparatus, resulting in a high promotion cost; and it cannot be conveniently and quickly adapted to different resonant column apparatuses. Summary of the Invention

[0006] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide an axial loading device for non-destructive soil bodies and adaptable to different resonant column apparatuses. This device can be compatible with different models of resonant column apparatuses and is convenient to install. At the same time, axial loading is applied under the original function of the resonant column apparatus for anisotropic consolidation, so as to obtain more realistic soil mechanical properties.

[0007] To achieve the above object, the present invention provides an axial loading device for non-destructive soil bodies and adaptable to different resonant column apparatuses, including a reaction frame. The reaction frame is installed on the original structure of the resonant column apparatus. An end face of the reaction frame facing the specimen is provided with a loading airbag mechanism. The loading airbag mechanism is connected to a pressure-volume controller through a water pipe. The pressure-volume controller injects water into the airbag structure and is controlled by a computer, so as to apply different axial pressures to the specimen.

[0008] Further, the loading airbag mechanism includes an airbag part and a metal sliding part. The airbag part is installed inside the metal sliding part. The metal sliding part includes a fixed shell and a sliding shell vertically slidably connected to the fixed shell. A hemispherical protrusion is provided at the bottom of the sliding shell. The bottom of the airbag part is connected to the inner bottom of the sliding shell. The upper end of the airbag part is connected to the reaction frame, and an opening is provided on the side of the upper end of the airbag part for connection with the water pipe.

[0009] Further, the airbag part includes a rubber membrane. The rubber membrane has a multi-sphere hollow connected structure. The upper opening of the rubber membrane is hermetically connected to a circular stainless steel plate. The circular stainless steel plate is connected to the reaction frame.

[0010] Further, the reaction frame includes four support steel frames. Channels are provided at the bottoms of the four support steel frames. The channels are aligned with the original channels of the resonant column and are fixed to the original structure of the resonant column apparatus by bolts.

[0011] Further, the loading airbag mechanism is also connected to the original data acquisition box of the resonant column apparatus. The data acquisition box is used to collect relevant data information.

[0012] Further, the reaction frame includes a central plate and four groups of adjusting frames connected to the central plate. The adjusting frame includes a horizontal adjusting part and a vertical adjusting part. The horizontal adjusting part is used to adapt to the diameters of different resonant column apparatuses. The vertical adjusting part is used to adapt to the heights of different resonant column apparatuses. A connection end is provided at the bottom of the vertical adjusting part. The connection end is used to be fixed to the original structure of the resonant column apparatus.

[0013] Further, the lateral adjustment part includes a hollow fixed rod. A rectangular through groove is provided at the upper end of the hollow fixed rod, and the rectangular through groove communicates with the inside of the hollow fixed rod. A plurality of locking grooves are provided along the length direction on the side wall of the rectangular through groove. An extended hollow rod is slidably connected to the hollow fixed rod. The extended hollow rod is provided with locking members corresponding to the locking grooves, and the locking members and the corresponding locking grooves fix the extended length of the extended hollow rod.

[0014] Further, a sliding block is provided inside the extended hollow rod. The sliding block is hinged to the vertical adjustment part, and a limiting member is provided at the hinged part of the vertical adjustment part and the sliding block. The limiting member is used to limit the vertical relationship between the vertical adjustment part and the extended hollow rod.

[0015] Further, the locking member includes a convex block. A cavity is provided inside the convex block. A partition is provided in the middle of the cavity. Guide rods are provided on both sides of the partition. A locking block is sleeved on the guide rods. A telescopic spring is provided between the locking block and the partition and the telescopic spring is sleeved on the guide rods. The end face of the locking block facing the inside of the cavity is linked with a button through a Z-shaped frame. The button is arranged on both side edges of the convex block and is slidably connected to the convex block. By pressing the button, the retraction of the locking block is realized, and further the lateral movement of the extended hollow rod is realized.

[0016] Beneficial effects:

[0017] 1. An axial loading device is additionally installed on the original resonant column apparatus in the present invention, and anisotropic consolidation and non-destructive soil tests are carried out together with the original resonant column apparatus; the axial loading device includes a loading airbag mechanism. The loading airbag mechanism is simple in design and low in cost, and can play a role by connecting the pressure volume controller and the data acquisition box in the original equipment; by using the accessories in the original equipment, the axial loading device can ensure the stability and reliability of the applied axial force to the greatest extent.

[0018] 2. The axial loading device in the present application is in point contact with the specimen top cap, so that the specimen can vibrate freely under the anisotropic stress state during the rotational resonance test, and axial static and dynamic loads can also be applied; when it is necessary to carry out a resonance test under an isotropic stress condition, the airbag of the retractable loading airbag mechanism can be disengaged from the specimen top cap.

[0019] 3. The present application also provides a second embodiment to improve the reaction frame. The reaction frame includes a lateral adjustment part and a vertical adjustment part. The lateral adjustment part is used to adapt to the diameters of different resonant column apparatuses, and the vertical adjustment part is used to adapt to the heights of different resonant column apparatuses, so that the axial loading device can be compatible with different types of resonant column equipment and improve the practicability of the axial loading device. Description of the drawings

[0020] Figure 1 Schematic diagram of the axial loading device installed on the resonant column apparatus;

[0021] Figure 2 Schematic perspective view of the axial loading device;

[0022] Figure 3 Schematic front sectional view of the loading airbag mechanism;

[0023] Figure 4 is Figure 2 top view of;

[0024] Figure 5 Schematic view of the unexpanded axial loading device of the second embodiment;

[0025] Figure 6 is Figure 5 expanded schematic view of;

[0026] Figure 7 Schematic view of the locking member;

[0027] Figure 8 Schematic view of the locking member in the pressed state;

[0028] Figure 9 Partial enlarged schematic view of the limiting member.

[0029] Reference numerals: 1, reaction frame; 11, support steel frame; 2, pressure volume controller; 3, computer; 4, data acquisition box; 5, back pressure controller; 6, duct; 7, water pipe; 8, loading airbag mechanism; 81, airbag part; 811, rubber film; 812, circular stainless steel plate; 82, metal sliding part; 821, fixed shell; 822, sliding shell; 823, hemispherical protrusion; 9, center plate; 10, adjusting frame; 101, horizontal adjusting part; 1011, hollow fixed rod; 1012, rectangular through groove; 1013, locking groove; 1014, extended hollow rod; 102, vertical adjusting part; 103, connecting end; 104, sliding block; 105, limiting member; 12, locking member; 121, convex block; 122, cavity; 123, partition; 124, guide rod; 125, locking block; 126, button; 127, Z-shaped frame; 128, spring. Detailed implementation manners

[0030] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, describe in detail the specific implementation manners, structures, features and their effects of the present invention as follows.

[0031] Refer to as Figures 1 - 4As shown in the figure, the present application provides a first embodiment, an axial loading device for a non-destructive soil body and adapted to different resonant column apparatuses, including a reaction frame 1, which is installed on the original support structure of the resonant column apparatus. There are multiple channels 6 on the original support structure of the resonant column apparatus. The reaction frame 1 includes four support steel frames 11. There are channels 6 at the bottoms of all four support steel frames 11. The channels 6 are aligned with the channels 6 on the original support structure of the resonant column apparatus and are fixedly connected by bolts. On the end face of the reaction frame 1 facing the specimen, there is a loading airbag mechanism 8. The loading airbag mechanism 8 is connected to a pressure-volume controller 2 through a water pipe 7 and is controlled by a computer 3, thereby applying different axial pressures to the specimen. The pressure-volume controller 2 is a device that originally exists in the resonant column apparatus and also includes a data acquisition box 4, which is used to collect information of relevant devices. By directly using original accessories such as the pressure-volume control, the stability and reliability of the applied axial force can be maximally ensured.

[0032] Refer to as Figure 3 As shown in the figure, the loading airbag mechanism 8 includes an airbag part 81 and a metal sliding part 82. The airbag part 81 is installed inside the metal sliding part 82. The metal sliding part 82 includes a fixed shell 821 and a sliding shell 822 that is vertically slidably connected to the fixed shell 821. There is a hemispherical protrusion 823 at the bottom of the sliding shell 822, which is made of metal to ensure uniform stress on the specimen. The bottom of the airbag part 81 is connected to the inner bottom of the sliding shell 822. The upper end of the airbag part 81 is connected to the reaction frame 1. There is an opening on the side of the upper end of the airbag part 81 connected to the water pipe 7. During saturated consolidation and related tests, such as saturated consolidation, water is injected into the airbag part 81 through the pressure-volume controller 2. The airbag part 81 expands axially under force, driving the sliding shell 822 to slide relative to the fixed shell 821, so that the hemispherical protrusion 823 contacts the specimen, providing an additional axial pressure to the specimen. At the same time, the air pressure control room of the resonant column apparatus is controlled to inject gas into the confining pressure chamber, so that the air pressure in the confining pressure chamber rises to apply a radial force to the specimen. Another example is during static testing. The water inside the airbag part 81 is drained. At this time, the pressure inside the airbag part 81 is much lower than the external air pressure, and the airbag part 81 contracts, driving the sliding structure to retract and no longer squeezing the specimen. During dynamic testing, controlling the injection of degassed water can achieve cyclic loading. The airbag part 81 includes a rubber membrane 811, which is in a multi-sphere hollow connected structure. The upper end opening of the rubber membrane 811 is hermetically connected to a circular stainless steel plate 812, and the circular stainless steel plate is connected to the reaction frame 1, fully ensuring that the airbag is controlled by the pressure-volume controller 2.

[0033] Refer to as Figures 5 - 9As shown in the figure, the present application also provides a second embodiment, which is basically the same as the first embodiment, except that: the reaction frame 1 includes a central plate 9 and four groups of adjusting frames 10 connected to the central plate 9. The adjusting frame 10 includes a horizontal adjusting part 101 and a vertical adjusting part 102. The horizontal adjusting part 101 is used to adapt to the diameters of different resonant column instruments, and the vertical adjusting part 102 is used to adapt to the heights of different resonant column instruments. A connecting end 103 is provided at the bottom of the vertical adjusting part 102, and the connecting end 103 is used to be fixed on the original structure of the resonant column instrument.

[0034] The horizontal adjusting part 101 includes a hollow fixed rod 1011. A rectangular through groove 1012 is provided at the upper end of the hollow fixed rod 1011 and the rectangular through groove 1012 communicates with the inside of the hollow fixed rod 1011. A plurality of locking grooves 1013 are provided on the side wall of the rectangular through groove 1012 along the length direction. An extended hollow rod 1014 is slidably connected to the hollow fixed rod 1011. A locking member 12 is provided corresponding to the locking groove 1013. The locking member 12 is locked with the corresponding locking groove 1013 to fix the extended length of the extended hollow rod 1014.

[0035] A sliding block 104 is provided inside the extended hollow rod 1014. The sliding block 104 is hinged to the vertical adjusting part 102. A limiting member 105 is provided at the hinged part of the vertical adjusting part 102 and the sliding block 104. The limiting member 105 is used to limit the vertical relationship between the vertical adjusting part 102 and the extended hollow rod 1014.

[0036] The locking member 12 includes a convex block 121. A cavity 122 is provided inside the convex block 121. A partition 123 is provided in the middle of the cavity 122. Guide rods 124 are provided on both sides of the partition 123. A locking block 125 is sleeved on the guide rod 124. A telescopic spring 128 is provided between the locking block 125 and the partition 123 and the telescopic spring 128 is sleeved on the guide rod 124. The end surface of the locking block 125 facing the inside of the cavity 122 is linked with a button 126 through a Z-shaped frame 127. The button 126 is arranged on both side edges of the convex block 121 and is slidably connected to the convex block 121. By pressing the button 126, the retraction of the locking block 125 is realized, and thus the horizontal movement of the extended hollow rod 1014 is realized.

[0037] The above improvement is specifically as follows: As Figures 5 - 9As shown, there are resonance column apparatuses of different models and sizes on the market. Therefore, in order to be compatible with different resonance column apparatuses, the reaction frame 1 of the present application is adjusted, including a central plate 9. The central plate 9 is used to connect with the loading airbag mechanism 8. The central plate 9 is connected with four groups of adjusting frames 10. Each adjusting frame 10 includes a horizontal adjusting part 101 and a vertical adjusting part 102. The horizontal adjusting part 101 includes a hollow fixed rod 1011. The upper end of the hollow fixed rod 1011 is provided with a rectangular through groove 1012, and the rectangular through groove 1012 communicates with the inside of the hollow fixed rod 1011. A plurality of locking grooves 1013 are provided on the side wall of the rectangular through groove 1012 along the length direction. An extended hollow rod 1014 is slidably connected inside the hollow fixed rod 1011. The extended hollow rod 1014 is provided with a locking member 12 corresponding to the locking groove 1013. The locking member 12 includes a convex block 121. A cavity 122 is provided inside the convex block 121. A partition 123 is provided in the middle of the cavity 122. Guide rods 124 are provided on both sides of the partition 123. A locking block 125 is sleeved on the guide rod 124. A telescopic spring 128 is provided between the locking block 125 and the partition 123, and the telescopic spring 128 is sleeved on the guide rod 124. The end face of the locking block 125 facing the cavity 122 is provided with a Z-shaped frame 127. The locking block 125 is linked with the button 126 through the Z-shaped frame 127. When the button 126 is pressed, the Z-shaped frame 127 drives the locking block 125 to retract, so that the extended hollow rod 1014 moves back and forth along the hollow fixed rod 1011, and is adjusted according to the radial diameter of the resonance column apparatus, so that the horizontal adjusting part 101 adapts to the radial direction of the resonance column apparatus. A sliding block 104 is provided inside the extended hollow rod 1014. The sliding block 104 is hinged with the vertical adjusting part 102. A limiting member 105 is provided at the hinged part between the vertical adjusting rod and the sliding block 104. The limiting member 105 is used to limit the vertical relationship between the vertical adjusting part 102 and the extended hollow rod 1014. When storage is needed, the limiting member 105 is released, and the vertical adjusting part 102 is stored inside the extended hollow rod 1014. The limiting member 105 is that the end of the hinge rod at the hinged part is provided with tooth patterns. The sliding block 104 is provided with a horizontal engaging block corresponding to the tooth patterns. The horizontal engaging block meshes with the tooth patterns to limit the swing of the vertical adjusting part 102. Referring to the figure shown, the vertical adjusting member in the present application includes a first vertical rod. A second vertical rod is provided inside the first vertical rod. A lead screw is provided on the first vertical rod to drive the second vertical rod to stretch along the first vertical rod. Or a positioning hole and pin type can be adopted, and any structure that can realize the length change in the vertical direction is applicable. The bottom of the vertical adjusting member is detachably connected with a connecting end 103. The connecting end 103 is a clamping member or a hoop member, which is selected according to the structure settings of different resonance column apparatuses. The clamping member or the hoop member is a prior art and will not be elaborated here.

[0038] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. An axial loading device for non-destructive soil and adapted to different resonant column apparatuses, characterized in that: It includes a reaction frame (1), which is installed on the original structure of the resonant column apparatus. An end face of the reaction frame (1) facing the specimen is provided with a loading airbag mechanism (8). The loading airbag mechanism (8) is connected to a pressure-volume controller (2) through a water pipe (7). The pressure-volume controller (2) injects water into the loading airbag mechanism (8) and is controlled by a computer (3), so as to apply different axial pressures to the specimen.

2. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 1, characterized in that: The loading airbag mechanism (8) includes an airbag part (81) and a metal sliding part (82). The airbag part (81) is installed inside the metal sliding part (82). The metal sliding part (82) includes a fixed shell (821) and a sliding shell (822) vertically slidably connected to the fixed shell (821). A hemispherical protrusion (823) is provided at the bottom of the sliding shell (822). The bottom of the airbag part (81) is connected to the inner bottom of the sliding shell (822). The upper end of the airbag part (81) is connected to the reaction frame (1), and an opening is provided at the upper end side of the airbag part (81) to be connected to the water pipe (7).

3. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 2, characterized in that: The airbag part (81) includes a rubber membrane (811). The rubber membrane (811) has a multi-sphere hollow connected structure. The upper end opening of the rubber membrane (811) is hermetically connected to a circular stainless steel plate (812). The circular stainless steel plate (812) is connected to the reaction frame (1).

4. The axial loading device for adapting different resonance column apparatuses according to claim 3, characterized in that: The reaction frame (1) includes four support steel frames (11). Conduits (6) are provided at the bottoms of the four support steel frames (11). The conduits (6) are aligned with the original conduits (6) of the resonant column and are fixed to the original structure of the resonant column apparatus by bolts.

5. The axial loading device adapted to different resonance column apparatuses according to claim 4, characterized in that: The loading airbag mechanism (8) is also connected to the original data acquisition box (4) of the resonant column apparatus. The data acquisition box (4) is used to collect relevant data information.

6. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 3, characterized in that: The reaction frame (1) includes a central plate (9) and four groups of adjusting frames (10) connected to the central plate (9). The adjusting frame (10) includes a horizontal adjusting part (101) and a vertical adjusting part (102). The horizontal adjusting part (101) is used to adapt to the diameters of different resonant column apparatuses. The vertical adjusting part (102) is used to adapt to the heights of different resonant column apparatuses. A connecting end (103) is provided at the bottom of the vertical adjusting part (102). The connecting end (103) is used to be fixed to the original structure of the resonant column apparatus.

7. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 6, characterized in that: The horizontal adjusting part (101) includes a hollow fixed rod (1011). A rectangular through groove (1012) is provided at the upper end of the hollow fixed rod (1011) and the rectangular through groove (1012) communicates with the inside of the hollow fixed rod (1011). A plurality of locking grooves (1013) are provided along the length direction of the side wall of the rectangular through groove (1012). An extended hollow rod (1014) is slidably connected to the hollow fixed rod (1011). A locking member (12) is provided on the extended hollow rod (1014) corresponding to the locking groove (1013). The locking member (12) is locked with the corresponding locking groove (1013) to fix the extended length of the extended hollow rod (1014).

8. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 7, characterized in that: A sliding block (104) is provided inside the extended hollow rod (1014). The sliding block (104) is hinged to the vertical adjustment part (102). A limiting part (105) is provided at the hinged part of the vertical adjustment part (102) and the sliding block (104). The limiting part (105) is used to limit the vertical relationship between the vertical adjustment part (102) and the extended hollow rod (1014).

9. The non-destructive soil body and axial loading device adapted to different resonant column apparatuses according to claim 8, characterized in that: The locking part (12) includes a convex block (121). A cavity (122) is provided inside the convex block (121). A partition plate (123) is provided in the middle of the cavity (122). Guide rods (124) are provided on both sides of the partition plate (123). The guide rods (124) are sleeved with locking blocks (125). A telescopic spring (128) is provided between the locking block (125) and the partition plate (123), and the telescopic spring (128) is sleeved on the guide rod (124). The end face of the locking block (125) facing the inside of the cavity (122) is linked with a button (126) through a Z-shaped frame (127). The button (126) is arranged on both sides of the convex block (121) and is slidably connected to the convex block (121). By pressing the button (126), the retraction of the locking block (125) is realized, and further the lateral movement of the extended hollow rod (1014) is realized.

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