Contact surface direct shear apparatus capable of controlling pore water pressure

Abstract

The utility model discloses a contact surface direct shear apparatus capable of controlling pore water pressure. The contact surface direct shear apparatus comprises a placement table, a force application mechanism, a pressure chamber, a pressure control mechanism, a longitudinal loading rod and a shear box, the placing table is fixedly connected with the pressure chamber; the interior of the pressure chamber is slidably connected with the lower shear box; the upper shear box and the lower shear box are disconnected; a pushing mechanism and a force measuring mechanism are arranged at two ends of the pressure chamber; the pushing mechanism penetrates through the pressure chamber and is fixedly connected with the lower shear box; the force measuring mechanism is connected with a contact rod which penetrates through the pressure chamber and is fixedly connected with the upper shear box; the bottom of the placing table is fixedly connected with a force application mechanism; two support rods of the force application mechanism are fixedly connected with a force transmission cross beam; the longitudinal loading rod penetrates through the force transmission cross beam and the pressure chamber and is detachably connected with the force transmission cross beam and the pressure chamber; the pressure control mechanism is fixedly connected with the pressure chamber; the pressure chamber is provided with exhaust holes; the structural object surface of the lower shear box is larger than the soil sample surface of the upper shear box, so that the contact area is unchanged; pressure chambers are additionally arranged outside the upper and lower shear boxes, different water pressures are controlled by a pressurizing device, and pore water pressure simulation of the contact surface of a soil sample and a structure is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of geotechnical test equipment, especially to a contact surface direct shear apparatus of controllable pore water pressure. BACKGROUND

[0002] The mechanical test of soil and structure is to evaluate the constitutive relation of the interaction between soil and structure, and the accurate measurement of the stress-strain relation between soil and structure is the key to the design of underground space structure and the prevention and control of disasters, such as the direct shear test of the contact surface of pile-soil, which can provide important parameters for the calculation of pile bearing capacity and pile settlement, and the soil-anchor contact surface test can provide important parameters for the design of retaining structure, and through the mechanical test of soil-structure contact surface, the deformation and stress under actual load can be understood, and the correctness and practicability of the design theory can be verified, so as to ensure the safety and durability of the structure.

[0003] The existing shear strength test device of soil-structure contact surface, such as CN107576580B, discloses a strain control type direct shear apparatus, which comprises an upper shear box, a lower shear box, a water storage box, a normal pressure device, a pressure transmission plate, an upper shear box parallel locking device, a bottom plate, a pusher, a top fixing device and a sensor; the water storage box is slidingly installed on the bottom plate, and the lower shear box is fixed thereon, the upper shear box is horizontally placed on the upper surface of the lower shear box, and the length direction of the two sides is connected with the upper shear box parallel locking device, the pressure transmission plate is installed in the upper shear box, and the normal pressure device is vertically connected thereon; the pusher and the sensor are respectively fixed on the bottom plate on both sides of the water storage box, and are drivingly connected with the lower shear box and the upper shear box through the top fixing device; the lower shear box of the direct shear apparatus in the prior art has a small area of the upper surface of the structure, the contact area is small during the shearing process, and the simulation of different pore water pressures cannot be tested.

[0004] Therefore, the skilled in the art urgently needs to provide a contact surface direct shear apparatus of controllable pore water pressure, which can keep the contact area constant during the shearing process and realize the simulation of different pore water pressures on the soil-structure contact surface. UTILITY MODEL CONTENT

[0005] The utility model aims at providing a contact surface direct shear apparatus of controllable pore water pressure to solve the problems in the prior art.

[0006] The utility model provides a controllable pore water pressure contact surface direct shear apparatus, include: placing platform, forcing mechanism, pressure chamber, pressure control mechanism, longitudinal loading rod and shear box, the shear box includes lower shear box and upper shear box, the placing platform top surface with pressure chamber fixed connection, the pressure chamber inner bottom surface with lower shear box sliding connection, upper shear box passes through bolt with lower shear box detachable connection, the both ends of pressure chamber towards placing platform are provided with push mechanism and force measuring mechanism respectively, push mechanism passes through pressure chamber with lower shear box fixed connection, force measuring mechanism is connected with contact rod, contact rod passes through pressure chamber with upper shear box fixed connection, the bottom surface of placing platform with forcing mechanism fixed connection, the top of two longitudinal support of forcing mechanism fixed connection has force transmission crossbeam, longitudinal loading rod passes through force transmission crossbeam and pressure chamber in proper order, and with force transmission crossbeam and pressure chamber detachable connection, and located in the upper end of upper shear box sample cover, pressure control mechanism with pressure chamber fixed connection, pressure chamber is opened and is provided with exhaust hole.

[0007] Preferably, the pressure chamber includes a pressure cover and a base; the cross section of the pressure cover is rectangular and the bottom surface is open; the bottom end of the pressure cover is detachably connected to the top surface of the base by bolts and is sealed; the longitudinal loading rod passes through the force transmission crossbeam and the pressure cover in sequence, and is detachably connected to the force transmission crossbeam and the pressure cover; the top surface of the base is slidingly connected to the lower shear box; the top surface of the placing platform is fixedly connected to the base; the top surface of the pressure cover is provided with the exhaust hole.

[0008] Preferably, the pressure control mechanism includes a first pipe, a second pipe, a third pipe, a three-way valve, a pore pressure gauge, and a pressurizing device; one end of the first pipe is fixedly connected to the second pipe and the third pipe through the three-way valve; the other end of the first pipe is fixedly connected to the pressure cover through the pressure cover and is close to the top surface of the pressure cover; the other end of the second pipe is a water inlet and outlet; the middle position of the third pipe is fixedly connected to the pore pressure gauge; the other end of the third pipe is fixedly connected to the pressurizing device.

[0009] Preferably, the push mechanism includes a push motor and a push rod; the output end of the push motor is fixedly connected to one end of the push rod; the other end of the push rod is fixedly connected to the lower shear box through the pressure cover; the push rod drives the lower shear box to push towards the force measuring mechanism.

[0010] Preferably, the force measuring mechanism comprises a force ring and a displacement sensor; one end of the contact rod is sequentially fixedly connected with the upper shear box through the force ring and the pressure cover; the other end of the contact rod is fixedly connected with a fixed rod, the fixed rod is fixedly connected with the placing table and is vertical; the fixed rod is fixedly connected with the displacement sensor in the direction of the pressure cover, and the displacement sensor is arranged in the contact rod.

[0011] Preferably, the top surface of the placing table is fixedly connected with a support rod and is vertical; the top surface of the support rod is fixedly connected with the third pipeline.

[0012] Preferably, the force transmission beam and the pressure cover are respectively provided with a first through hole and a second through hole; the first through hole and the second through hole are respectively provided with internal threads; the second through hole is provided with a matching sealing washer; the longitudinal loading rod is provided with external threads matched with the internal threads; the longitudinal loading rod is sequentially threaded through the first through hole and the second through hole and is threadedly connected with the force transmission beam and the pressure cover.

[0013] Preferably, the material of the pressure cover is transparent acrylic or transparent polypropylene or transparent glass.

[0014] Compared with the prior art, the utility model provides a contact surface direct shear apparatus of controllable pore water pressure, has the following beneficial effects:

[0015] 1, the contact surface after filling the structure in the lower shear box is greater than the bottom surface area of the soil sample of the upper shear box, and the contact area can be kept constant during the shearing process, and the test result is more accurate.

[0016] 2, the lower shear box and the upper shear box are provided with a pressure chamber outside, different water pressures can be controlled by using a pressurizing device, and the simulation of different pore water pressures on the contact surface of the soil sample and the structure is realized. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0018] Fig. 1 It is the whole structure schematic diagram of the utility model;

[0019] Fig. 2 It is the force transmission beam and longitudinal loading rod structure schematic diagram of the utility model.

[0020] Wherein: 1 is the placement platform; 2 is the force application mechanism; 3 is the pushing mechanism; 301 is the pushing motor; 302 is the pushing rod; 4 is the pressure chamber; 401 is the pressure cover; 402 is the base; 403 is the exhaust port; 5 is the pressure control mechanism; 501 is the first pipe; 502 is the second pipe; 503 is the third pipe; 504 is the three-way valve; 505 is the orifice pressure gauge; 506 is the pressurizing device; 6 is the lower shear box; 7 is the upper shear box; 701 is the sample cover; 8 is the force measuring mechanism; 801 is the force measuring ring; 802 is the displacement sensor; 9 is the contact rod; 10 is the force transmission beam; 11 is the longitudinal loading rod; 12 is the fixing rod; 13 is the support rod. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figs. 1-2 As shown, a contact surface direct shear apparatus for controllable pore water pressure includes: a placement platform 1, a force application mechanism 2, a pressure chamber 4, a pressure control mechanism 5, a longitudinal loading rod 11, and a shear box; the shear box includes a lower shear box 6 and an upper shear box 7; the top surface of the placement platform 1 is fixedly connected to the pressure chamber 4; the bottom surface of the pressure chamber 4 is slidably connected to the lower shear box 6; the upper shear box 7 is detachably connected to the lower shear box 6 by bolts; a pushing mechanism 3 and a force measuring mechanism 8 are respectively provided at both ends of the pressure chamber 4 facing the placement platform 1; the pushing mechanism 3 passes through the pressure chamber 4 and is fixedly connected to the lower shear box 6. The force measuring mechanism 8 is connected to a contact rod 9, which passes through the pressure chamber 4 and is fixedly connected to the upper shear box 7. The bottom surface of the placement platform 1 is fixedly connected to the force applying mechanism 2, and the top ends of the two longitudinal support rods of the force applying mechanism 2 are fixedly connected to a force transmission beam 10. The longitudinal loading rod 11 passes through the force transmission beam 10 and the pressure chamber 4 in sequence, and is detachably connected to the force transmission beam 10 and the pressure chamber 4, and is located at the upper end of the sample cover 701 of the upper shear box 7. The pressure control mechanism 5 is fixedly connected to the pressure chamber 4. The pressure chamber 4 is provided with an exhaust port 403.

[0024] The utility model discloses, the two longitudinal support rod of forcing mechanism 2 parallelly arranged, and with the transmission beam 10 vertical, when not using, using rubber plug tight sealing prevents pressure relief, exhaust hole 403 is close to the direction of push mechanism 3, longitudinal loading rod 11 gives the sample cover 701 certain force with downward movement, that is, contact or act on the upper end of sample cover 701, push mechanism 3 is used for pushing lower shear box 6, and with pressure chamber 4 seal.

[0025] The utility model discloses, upper shear box 7 is used for packing soil sample, lower shear box 6 is used for packing structure, and the contact surface of soil sample and structure is that upper and lower shear box is out of order, push mechanism 3 applies horizontal thrust, and acts on the lower shear box 6 where structure is, and applies shear stress on the contact surface of soil sample and structure, longitudinal loading rod 11 applies longitudinal pressure to soil sample, pressure chamber 4 fills up with water, and pressure control mechanism 5 is filled up with water with the pressure device 506 pressurization, controls different air pressure through air pressure valve, realizes the setting hydraulic pressure value of applying to the pressure chamber 4 filled up with water after air water pressure conversion, that is, the pore water pressure value on the contact surface, the contact surface after filling structure in lower shear box 6 is greater than the bottom surface area of soil sample of upper shear box 7, and the contact area can be realized constant during shearing, and the test result is more accurate, lower shear box 6 and upper shear box 7 increase pressure chamber 4 outside, and different water pressure can be controlled using pressure device 506, realize the simulation of different pore water pressure on the contact surface of soil sample and structure.

[0026] In one example embodiment, as shown in Figs. 1-2 The pressure chamber 4 includes a pressure cover 401 and a base 402, the cross section of the pressure cover 401 is rectangular and the bottom surface is open, the bottom end of the pressure cover 401 is detachably connected to the top surface of the base 402 by bolts and is sealed, the longitudinal loading rod 11 passes through the transmission beam 10 and the pressure cover 401 in sequence and is detachably connected to the transmission beam 10 and the pressure cover 401, the top surface of the base 402 is slidingly connected to the lower shear box 6, the top surface of the placement table 1 is fixedly connected to the base 402, and the top surface of the pressure cover 401 is provided with the exhaust hole 403.

[0027] In the utility model, the pressure chamber 4 is used to place the contact sample of the soil sample in the upper shear box 7 and the structure in the lower shear box 6 in a sealed container, so as to control the water pressure in the sealed container and realize the simulation of different pore water pressures on the contact surface.

[0028] In one example embodiment, as shown in Figs. 1-2As shown in the pressure control mechanism 5, the first pipe 501, the second pipe 502, the third pipe 503, the three-way valve 504, the hole pressure gauge 505 and the pressure device 506 are fixedly connected; one end of the first pipe 501 is fixedly connected with the second pipe 502 and the third pipe 503 through the three-way valve 504; the other end of the first pipe 501 is fixedly connected with the pressure cover 401 and is close to the top surface of the pressure cover 401; the other end of the second pipe 502 is a water inlet and outlet; the middle position of the third pipe 503 is fixedly connected with the hole pressure gauge 505; the other end of the third pipe 503 is fixedly connected with the pressure device 506.

[0029] In the utility model, the first pipe 501 and the second pipe 502 are parallel with the ground; the third pipe 503 is an L-shaped pipe, one end of which is fixedly connected with the three-way valve 504, and the other end of which is a water inlet and outlet; the water inlet and outlet of the third pipe 503 is tightly sealed by using a rubber plug when not in use to prevent water backflow; the first pipe 501 is sealed by using a sealing ring at the position of the pressure cover 401; the three-way valve 504 can switch the combination and separation of pipes, for example, the first pipe 501 and the third pipe 503 are connected while the second pipe 502 is closed, and the first pipe 501 and the second pipe 502 are connected while the third pipe 503 is closed.

[0030] In one exemplary embodiment, as shown in the pressure control mechanism 5, Figs. 1-2 As shown in the pushing mechanism 3, the pushing motor 301 and the pushing rod 302 are fixedly connected; the output end of the pushing motor 301 is fixedly connected with one end of the pushing rod 302; the other end of the pushing rod 302 is fixedly connected with the lower shear box 6 through the pressure cover 401; the pushing rod 302 drives the lower shear box 6 to push towards the force measuring mechanism 8.

[0031] In the utility model, the pushing rod 302 is sealed by using a sealing ring at the position of the pressure cover 401; the pushing rod 302 keeps the pressure cover 401 in a sealed state when pushing.

[0032] In one exemplary embodiment, as shown in the pressure control mechanism 5, Figs. 1-2 As shown in the force measuring mechanism 8, the force ring 801 and the displacement sensor 802 are fixedly connected; one end of the contact rod 9 is fixedly connected with the upper shear box 7 through the force ring 801 and the pressure cover 401 in sequence; the other end of the contact rod 9 is fixedly connected with the fixed rod 12, the fixed rod 12 is fixedly connected with the placing table 1 and is perpendicular; the fixed rod 12 is fixedly connected with the displacement sensor 802 towards the pressure cover 401, and the displacement sensor 802 is arranged in the contact rod 9.

[0033] In one exemplary embodiment, as shown in the pressure control mechanism 5, Figs. 1-2As shown, the top surface of the placing table 1 is fixedly connected with a support rod 13 which is vertical, and the top surface of the support rod 13 is fixedly connected with the third pipeline 503.

[0034] In the utility model, the support rod 13 is used for supporting the third pipeline 503 so that the structure is more stable.

[0035] In one exemplary embodiment, as shown in the drawings, Figs. 1-2 As shown, the force transmission beam 10 and the pressure cover 401 are respectively provided with a first through hole and a second through hole, the first through hole and the second through hole are respectively provided with internal threads, the second through hole is provided with a matching sealing washer, the longitudinal loading rod 11 is provided with external threads matched with the internal threads, and the longitudinal loading rod 11 is sequentially threaded through the first through hole and the second through hole and is threadedly connected with the force transmission beam 10 and the pressure cover 401.

[0036] In one exemplary embodiment, as shown in the drawings, Figs. 1-2 As shown, the material of the pressure cover 401 is transparent acrylic or transparent polypropylene or transparent glass.

[0037] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0038] The above-described embodiments are only preferred modes of the utility model, and do not limit the scope of the utility model, and various modifications and improvements to the technical scheme of the utility model made by those skilled in the art without departing from the design spirit of the utility model should fall within the protection scope of the utility model claim.

Claims

1. A controlled porosity water pressure face direct shear apparatus, characterized by, Include: The placement platform (1), force mechanism (2), pressure chamber (4), pressure control mechanism (5), longitudinal loading rod (11) and shear box; The shear box includes lower shear box (6) and upper shear box (7); The top surface of the placement platform (1) is fixedly connected with the pressure chamber (4); the inner bottom surface of the pressure chamber (4) is slidably connected with the lower shear box (6); the upper shear box (7) is detachably connected with the lower shear box (6) through bolts; The pressure chamber (4) is provided with a pushing mechanism (3) and a force measuring mechanism (8) at both ends thereof respectively; the pushing mechanism (3) is fixedly connected with the lower shear box (6) through the pressure chamber (4); the force measuring mechanism (8) is connected with a contact rod (9), and the contact rod (9) is fixedly connected with the upper shear box (7) through the pressure chamber (4); The bottom surface of the placement platform (1) is fixedly connected with the force mechanism (2), and the top ends of the two longitudinal supporting rods of the force mechanism (2) are fixedly connected with a force transmission beam (10); The longitudinal loading rod (11) passes through the force transmission beam (10) and the pressure chamber (4) in sequence, and is detachably connected with the force transmission beam (10) and the pressure chamber (4), and is located at the upper end of a sample cover (701) of the upper shear box (7); The pressure control mechanism (5) is fixedly connected with the pressure chamber (4); and the pressure chamber (4) is provided with an exhaust hole (403).

2. The contact surface direct shear apparatus with controllable pore water pressure according to claim 1, characterized in that: The pressure chamber (4) includes a pressure cover (401) and a base (402); The cross section of the pressure cover (401) is rectangular and the bottom surface is open; the bottom end of the pressure cover (401) is detachably connected with the top surface of the base (402) through bolts and is sealed; The longitudinal loading rod (11) passes through the force transmission beam (10) and the pressure cover (401) in sequence, and is detachably connected with the force transmission beam (10) and the pressure cover (401); the top surface of the base (402) is slidably connected with the lower shear box (6); and the top surface of the placement platform (1) is fixedly connected with the base (402); The top surface of the pressure cover (401) is provided with the exhaust hole (403).

3. A contact shear apparatus for controlling pore water pressure according to claim 2, wherein: The pressure control mechanism (5) includes a first pipeline (501), a second pipeline (502), a third pipeline (503), a three-way valve (504), a pore pressure gauge (505), and a pressurizing device (506); One end of the first pipeline (501) is fixedly connected with the second pipeline (502) and the third pipeline (503) through the three-way valve (504); The other end of the first pipeline (501) is fixedly connected with the pressure cover (401) and is close to the top surface of the pressure cover (401); The other end of the second pipeline (502) is a water inlet and outlet; The middle position of the third pipeline (503) is fixedly connected with the pore pressure gauge (505); and the other end of the third pipeline (503) is fixedly connected with the pressurizing device (506).

4. The contact stress direct shear apparatus of claim 2, wherein: The pushing mechanism (3) comprises a pushing motor (301) and a pushing rod (302); One end of the pushing motor (301) is fixedly connected with one end of the pushing rod (302); the other end of the pushing rod (302) is fixedly connected with the lower shear box (6) through the pressure cover (401); The pushing rod (302) drives the lower shear box (6) to push towards the force measuring mechanism (8).

5. The contact stress direct shear apparatus of claim 2, wherein: The force measuring mechanism (8) comprises a force measuring ring (801) and a displacement sensor (802); One end of the contact rod (9) is fixedly connected with the upper shear box (7) through the force measuring ring (801) and the pressure cover (401) in sequence; The other end of the contact rod (9) is fixedly connected with a fixed rod (12), the fixed rod (12) is fixedly connected with the placing table (1) and is perpendicular; The fixed rod (12) is fixedly connected with the displacement sensor (802) towards the pressure cover (401), and the displacement sensor (802) is arranged in the contact rod (9).

6. The contact stress direct shear apparatus of claim 3, wherein: The top surface of the placing table (1) is fixedly connected with a support rod (13) and is perpendicular; the top surface of the support rod (13) is fixedly connected with the third pipeline (503).

7. The contact area direct shear apparatus of controlled pore water pressure according to claim 2, wherein: The force transmission beam (10) and the pressure cover (401) are respectively provided with a first through hole and a second through hole; the first through hole and the second through hole are respectively provided with an internal thread; the second through hole is provided with a matching sealing washer; The longitudinal loading rod (11) is provided with an external thread matched with the internal thread; The longitudinal loading rod (11) is threadedly connected with the force transmission beam (10) and the pressure cover (401) through the first through hole and the second through hole in sequence.

8. The contact area direct shear apparatus of claim 2, wherein: The material of the pressure cover (401) is transparent acrylic or transparent polypropylene or transparent glass.

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