Precast pile side friction resistance testing system

Abstract

The invention provides a precast pile side friction resistance testing system, and relates to the technical field of precast pile side resistance testing, and the precast pile side friction resistance testing system comprises a precast pile body, a driving mechanism and a protection mechanism; the driving mechanism is welded and mounted on the precast pile body; the protection mechanism is mounted on the driving mechanism; the connecting disc is arranged at the bottom of the precast pile body; the bottom of the oil pipe is fixedly connected with the connecting disc; the jack is welded to the bottom of the connecting disc. The pile head is fixedly mounted on an output shaft of the jack; sealing between the connecting disc and the pile head is achieved, and contact between soil and slurry and the jack is reduced or avoided; the problems that a jack is generally exposed for use, soil and slurry are prone to making contact with the jack, corrosion and damage of the jack are prone to being accelerated, and the service life of the jack is shortened are solved. According to the invention, by loading and testing the side friction resistance of the precast pile, the side resistance test of the precast pile after construction is completed is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of prefabricated pile side resistance testing, and more specifically, particularly relates to a prefabricated pile side friction resistance testing system. Background Art

[0002] Precast piles are prefabricated in precast component processing plants, and after curing to reach the designed strength, they are transported to the construction site, driven into the soil with a pile driver, and then the pedestal beam foundation is poured on the top of the pile. Precast piles mainly rely on the friction between the side walls and the rock and soil layers to provide support. Testing the friction resistance between precast piles and soil layers before construction is the most important construction link, which can provide reasonable mechanical parameters for the precast pile design to ensure the stress performance of the precast piles.

[0003] The side resistance test equipment currently in use still has the following problems: the jack is generally used in an exposed manner, which causes soil and mud to easily come into contact with the jack, which easily accelerates the corrosion and damage of the jack and reduces the service life of the jack. Summary of the invention

[0004] The disclosed embodiment relates to a prefabricated pile side friction test system, which has a driving mechanism and a protection mechanism; achieves sealing between the connecting disc and the pile head, reduces or avoids the contact between the soil and mud and the jack; and solves the problem that the soil and mud are easy to contact with the jack.

[0005] In a first aspect of the present disclosure, a precast pile side friction test system is provided, comprising: a precast pile body, a driving mechanism, a protection mechanism, a beam, a displacement sensor and a data acquisition system;

[0006] The prefabricated pile body is a hollow structure; the driving mechanism is welded and installed on the prefabricated pile body; the protection mechanism is installed on the driving mechanism, and the protection mechanism is used to protect the driving mechanism;

[0007] The beam is arranged above the ground; two displacement sensors are provided, and the two displacement sensors are fixedly installed at the bottom of the beam, and the two displacement sensors are located directly above the precast pile body; the data acquisition system is installed on the ground, and the data acquisition system is electrically connected to the two displacement sensors;

[0008] The driving mechanism comprises: a connecting disc, an oil pipe, a jack and a pile head; the connecting disc is arranged at the bottom of the prefabricated pile body; the bottom of the oil pipe is fixedly connected to the connecting disc; the jack is welded to the bottom of the connecting disc; and the pile head is fixedly installed on the output shaft of the jack.

[0009] In at least some embodiments, the protection mechanism includes: a protection ring A, a protection ring B and a mounting plate A; the protection ring A is fixedly mounted on the top of the pile head; the protection ring B is slidably mounted inside the protection ring A, and the top of the protection ring B is in contact with the connecting disc; there are four mounting plates A in total, and the four mounting plates A are fixedly mounted on the inner wall of the protection ring A.

[0010] In at least some embodiments, the protection mechanism also includes: a guide plate B and a circular mounting rod; there are four guide plates B in total, and the four guide plates B are fixedly installed on the inner wall of the protection ring B; there are four circular mounting rods in total, and the four circular mounting rods are fixedly installed on the top of the four mounting plates A, and the four circular mounting rods are also slidably connected to the four guide plates B.

[0011] In at least some embodiments, the protection mechanism also includes: a limit stop ring and a coil spring A; there are four limit stop rings in total, and the four limit stop rings are fixedly installed on the top ends of four circular mounting rods; there are four coil springs A in total, and the four coil springs A are installed on the outside of the four circular mounting rods, and the four coil springs A are located between the four mounting plates A and the four guide plates B.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] 1. In the present invention, when the output shaft of the jack is extended, the precast pile body and the pile head are subjected to force at the same time, and the side resistance of the precast pile body is judged by detecting the moving distance of the precast pile body; the side friction resistance of the precast pile is tested by loading, thereby realizing the side resistance test of the precast pile that has been completed.

[0014] 2. In the present invention, the provision of the protective ring A and the protective ring B realizes the sealing between the connecting disc and the pile head, reduces or avoids the contact between the soil and mud and the jack, plays a protective role, avoids the corrosion or damage of the jack, and improves the service life of the jack; when the output shaft of the jack is extended, the protective ring B can always be in contact with the connecting disc under the action of the four coil springs A, thereby improving the protection effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0016] The drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0017] In the attached picture:

[0018] Figure 1 A three-dimensional structural schematic diagram of the present invention is shown.

[0019] Figure 2 The schematic diagram of the structure of the prefabricated pile body of the present invention is shown.

[0020] Figure 3 The central cutaway structure diagram of the driving mechanism and the protection mechanism of the present invention is shown.

[0021] Figure 4 The schematic diagram of the structure of the driving mechanism of the present invention is shown.

[0022] Figure 5 A partial cross-sectional structural schematic diagram of the protection mechanism of the present invention is shown.

[0023] Figure 6 The present invention is shown Figure 3 Schematic diagram of the local enlarged structure of area A in the middle.

[0024] List of reference numerals:

[0025] 1. Prefabricated pile body;

[0026] 2. Driving mechanism; 201. Connecting disc; 202. Oil pipe; 203. Jack; 204. Pile head;

[0027] 3. Protection mechanism; 301. Protection ring A; 302. Protection ring B; 303. Mounting plate A; 304. Guide plate B; 305. Round mounting rod; 306. Limit stop ring; 307. Coil spring A;

[0028] 4. Beam;

[0029] 5. Displacement sensor;

[0030] 6. Data acquisition system. DETAILED DESCRIPTION

[0031] In order to make the purpose, scheme and advantages of the technical solution of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the drawings of the specific embodiments of the present invention. Unless otherwise specified, the terms used herein have the usual meanings in the art. The same reference numerals in the drawings represent the same components.

[0032] Example: Please refer to Figures 1 to 6 As shown: The present invention provides a precast pile side friction test system, comprising: a precast pile body 1, a driving mechanism 2, a protection mechanism 3, a beam 4, a displacement sensor 5 and a data acquisition system 6;

[0033] The precast pile body 1 is a hollow structure; the driving mechanism 2 is welded and installed on the precast pile body 1; the protection mechanism 3 is installed on the driving mechanism 2, and the protection mechanism 3 is used to protect the driving mechanism 2;

[0034] The beam 4 is arranged above the ground; two displacement sensors 5 are provided, and the two displacement sensors 5 are fixedly installed at the bottom of the beam 4, and the two displacement sensors 5 are located directly above the precast pile body 1; the data acquisition system 6 is installed on the ground, and the data acquisition system 6 is electrically connected to the two displacement sensors 5;

[0035] Its specific function is: because the two displacement sensors 5 are fixedly installed at the bottom of the beam 4, and the two displacement sensors 5 are located directly above the precast pile body 1, the displacement of the precast pile body 1 can be automatically detected, and the displacement data is displayed through the data acquisition system 6, which is convenient for observing the displacement of the precast pile body 1.

[0036] In the present disclosure, Figure 3 and Figure 4 As shown, the driving mechanism 2 includes: a connecting disc 201, an oil pipe 202, a jack 203 and a pile head 204; the connecting disc 201 is arranged at the bottom of the prefabricated pile body 1; the bottom of the oil pipe 202 is fixedly connected to the connecting disc 201; the jack 203 is welded to the bottom of the connecting disc 201 and can be used once; the pile head 204 is fixedly installed on the output shaft of the jack 203;

[0037] Its specific function is as follows: since the jack 203 is welded to the bottom of the connecting disc 201, and the pile head 204 is fixedly installed on the output shaft of the jack 203, when the output shaft of the jack 203 is extended, the precast pile body 1 and the pile head 204 are subjected to force at the same time, and the lateral resistance of the precast pile body 1 is determined by detecting the moving distance of the precast pile body 1; wherein, the jack 203 is connected to an external hydraulic system to realize automatic operation.

[0038] In the present disclosure, Figure 3 , Figure 5 and Figure 6As shown, the protection mechanism 3 includes: a protection ring A301, a protection ring B302 and a mounting plate A303; the protection ring A301 is fixedly mounted on the top of the pile head 204; the protection ring B302 is slidably mounted inside the protection ring A301, and the top of the protection ring B302 is in contact with the connecting disc 201; there are four mounting plates A303, and the four mounting plates A303 are fixedly mounted on the inner wall of the protection ring A301; the protection mechanism 3 also includes: a guide plate B304 and a circular mounting rod 305; there are four guide plates B304, and the four guide plates B304 are fixedly mounted on the inner wall of the protection ring B302; the circular There are four circular mounting rods 305, and the four circular mounting rods 305 are fixedly mounted on the tops of the four mounting plates A303, and the four circular mounting rods 305 are also slidably connected with the four guide plates B304; the protection mechanism 3 also includes: a limit stop ring 306 and a coil spring A307; there are four limit stop rings 306, and the four limit stop rings 306 are fixedly mounted on the tops of the four circular mounting rods 305; there are four coil springs A307, and the four coil springs A307 are mounted on the outside of the four circular mounting rods 305, and the four coil springs A307 are located between the four mounting plates A303 and the four guide plates B304;

[0039] Its specific functions are as follows: since the protective ring A301 is fixedly installed on the top of the pile head 204, and the protective ring B302 is slidably installed inside the protective ring A301, and the top of the protective ring B302 is in contact with the connecting disc 201, the sealing between the connecting disc 201 and the pile head 204 is achieved, reducing or avoiding the contact between the soil and mud and the jack 203, playing a protective role, avoiding the corrosion or damage of the jack 203, and improving the service life of the jack 203; and since the four coil springs A307 are installed on the outside of the four circular mounting rods 305, and the four coil springs A307 are located between the four mounting plates A303 and the four guide plates B304, when the output shaft of the jack 203 is extended, the protective ring B302 can always be in contact with the connecting disc 201 under the action of the four coil springs A307, thereby improving the protection effect;

[0040] The connecting disc 201 is integrated with the prefabricated pile body 1, and a steel bar is connected to one end of the connecting disc, which is prefabricated together with the body.

[0041] When the present invention is used, first, the staff makes the connecting disc 201 contact with the bottom of the precast pile body 1, and then installs the precast pile body 1 in the soil; during the test, after each level of load is applied, the pile top displacement is measured at 5 minutes, 15 minutes, 30 minutes, 45 minutes, and 60 minutes, and the pile top displacement is measured every 30 minutes thereafter; starting from the 30th minute after the graded load is applied, when the displacement increment within each hour does not exceed 0.1mm and occurs twice in succession, it is considered that the precast pile has reached relative stability and the next level of load can be applied; when the output shaft of the jack 203 is extended, the precast pile body 1 and the pile head 204 are subjected to force at the same time, and the lateral resistance of the precast pile body 1 is judged by detecting the moving distance of the precast pile body 1; when the precast pile body 1 does not move and only the pile head 204 moves, This is the maximum lateral resistance of the precast pile body 1; the provision of the protective ring A301 and the protective ring B302 realizes the sealing between the connecting disc 201 and the pile head 204, reduces or avoids the contact between the soil and mud and the jack 203, plays a protective role, avoids the corrosion or damage of the jack 203, and improves the service life of the jack 203; when the output shaft of the jack 203 is extended, the protective ring B302 can always be in contact with the connecting disc 201 under the action of the four spiral springs A307, thereby improving the protective effect; the connecting disc 201 has been prefabricated in the production of the precast pile body 1; the provision of the two displacement sensors 5 can automatically detect the displacement of the precast pile body 1, and the displacement data is displayed through the data acquisition system 6, which is convenient for observing the displacement of the precast pile body 1.

[0042] The test system should be loaded in stages, with the graded load being 1 / 10 of the estimated ultimate frictional resistance, of which the first-stage load is twice the graded load. When, under a certain load level, the displacement of the pile top is greater than 5 times the displacement under the previous load level and the total displacement of the pile top exceeds 40 mm, or the pile top displacement is greater than 2 times the displacement under the previous load level and the precast pile has not reached relative stability after 24 hours, the loading is terminated.

[0043] After the loading operation is completed, unloading is carried out in stages, and the amount of unloading at each stage is twice the graded load during loading; each level of load is maintained for 1 hour, and the displacement of the pile top is measured at 15 minutes, 30 minutes, and 60 minutes, and then unloaded to the next level of load; after unloading to zero, the residual displacement of the pile top is measured for 3 hours, and the measurement time is respectively 15 minutes and 30 minutes, and then every 30 minutes.

[0044] In this article, there are a few points to note:

[0045] 1. The drawings of the embodiments of the present disclosure only involve structures related to the embodiments of the present disclosure, and other structures may refer to general designs.

[0046] 2. In the absence of conflict, the embodiments of the present disclosure and the features therein may be combined with each other to obtain new embodiments.

[0047] The above are only specific embodiments of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present disclosure, which should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A prefabricated pile side friction test system, comprising: Prefabricated pile body (1), driving mechanism (2), protection mechanism (3), beam (4), displacement sensor (5) and data acquisition system (6); The prefabricated pile body (1) is a hollow structure; characterized in that the driving mechanism (2) is welded and installed on the prefabricated pile body (1); the protection mechanism (3) is installed on the driving mechanism (2), and the protection mechanism (3) is used to protect the driving mechanism (2); The beam (4) is arranged above the ground; two displacement sensors (5) are provided, and the two displacement sensors (5) are fixedly installed at the bottom of the beam (4), and the two displacement sensors (5) are located directly above the prefabricated pile body (1); the data acquisition system (6) is installed on the ground, and the data acquisition system (6) is electrically connected to the two displacement sensors (5); The driving mechanism (2) comprises: a connecting disc (201), an oil pipe (202), a jack (203) and a pile head (204); the connecting disc (201) is arranged at the bottom of the prefabricated pile body (1); the bottom of the oil pipe (202) is fixedly connected to the connecting disc (201); the jack (203) is welded to the bottom of the connecting disc (201); and the pile head (204) is fixedly mounted on the output shaft of the jack (203).

2. A precast pile side friction test system according to claim 1, characterized in that: The protection mechanism (3) comprises: a protection ring A (301), a protection ring B (302) and a mounting plate A (303); the protection ring A (301) is fixedly mounted on the top of the pile head (204); the protection ring B (302) is slidably mounted inside the protection ring A (301), and the top of the protection ring B (302) is in contact with the connecting disc (201); and a total of four mounting plates A (303) are provided, and the four mounting plates A (303) are fixedly mounted on the inner wall of the protection ring A (301).

3. A precast pile side friction test system according to claim 2, characterized in that: The protection mechanism (3) further comprises: a guide plate B (304) and a circular mounting rod (305); the guide plates B (304) are provided with four in total, and the four guide plates B (304) are fixedly mounted on the inner wall of the protection ring B (302); the circular mounting rod (305) is provided with four in total, and the four circular mounting rods (305) are fixedly mounted on the top of the four mounting plates A (303), and the four circular mounting rods (305) are also slidably connected to the four guide plates B (304).

4. A precast pile side friction test system according to claim 3, characterized in that: The protection mechanism (3) further comprises: a limit stop ring (306) and a coil spring A (307); a total of four limit stop rings (306) are provided, and the four limit stop rings (306) are fixedly mounted on the top ends of four circular mounting rods (305); a total of four coil springs A (307) are provided, and the four coil springs A (307) are mounted on the outside of the four circular mounting rods (305), and the four coil springs A (307) are located between the four mounting plates A (303) and the four guide plates B (304).

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