CN111119253A - A simple device for testing the pull-out bearing capacity of prefabricated square piles - Google Patents

Abstract

The invention discloses a simple device for detecting the pull-out bearing capacity of a prefabricated square pile. It includes a loading device, an anchoring force transmission device, a reaction force system and a displacement measuring device; the loading device is arranged on the anchoring force transmission device, the anchoring force transmission device is arranged on the reaction force system, the reaction force system is arranged on the natural foundation, and the natural foundation Displacement measuring device is set up, prefabricated square pile is set under the natural foundation, and the surface of the prefabricated square pile is set with a displacement measuring device, which is connected with the anchoring force transmission device; The prefabricated square piles have strong adaptability and will not slant the steel bars to ensure the safety and reliability of the test; due to the lightness of each anchoring device, it can be installed on site without the cooperation of hoisting equipment.

Description

Simple device for detecting uplift bearing capacity of prefabricated square pile

Technical Field

The invention relates to the technical field of foundation foundations, in particular to a simple device for detecting the uplift bearing capacity of a prefabricated square pile.

Background

The basement is acted on by groundwater and has the possibility of floating upward, often resists buoyancy through setting up prefabricated square pile, needs to carry out on-the-spot single pile resistance to plucking bearing capacity to prefabricated square pile and detect. The invention discloses a device for testing the uplift bearing capacity of a fiber-reinforced micro uplift pile in Chinese patent specification CN107816066A, wherein the upper part of a first steel backing plate is connected with a high-strength nut, the lower end of the first steel backing plate is connected with a load sensor, the lower part of the load sensor is connected with a second steel backing plate, and the bottom of the second steel backing plate is connected with a counter-force beam; jack backing plates are placed on two sides of the pile hole, the bottom of the jack is installed in the center of the jack backing plate, the top of the jack is tightly attached to a third steel backing plate, a beam stool is placed on the jack backing plate, and a hoop rib and a fiber rib in the pile hole are connected to form an uplift pile fiber rib cage; the fiber bar lock head and the fiber bar are anchored on the high-strength drawing screw rod of the expanded head, the displacement sensors are symmetrically arranged on two sides of the pile top of the fiber bar micro uplift pile, and the displacement sensors are fixedly arranged on the reference beam; two ends of the reference beam are respectively supported on the buttresses; the device is simple to install, strong in operability, high in safety and reliability, not easy to damage, reusable, low in cost and capable of obtaining larger pulling-resistant bearing capacity. However, it is known that in the conventional single-pile uplift test, the steel bars of the prefabricated square pile are anchored on the steel plate with the holes formed in advance, and the uplift force is applied to the pile by drawing the steel plate, so that the hole formed in the steel plate of the device needs to be consistent with the position of the steel bars of the pile body, the field adaptability is poor, the steel bars are easy to be inclined, and the detection result is influenced.

Disclosure of Invention

Aiming at the prior art, the invention aims to provide a simple device for detecting the uplift bearing capacity of a prefabricated square pile. It has the characteristics of simple structure, convenient assembly, safe and reliable work and the like. The simple device has strong adaptability to prefabricated square piles with different steel bar diameters and steel bar intervals, does not incline the steel bars, and ensures the safety and reliability of the test; the anchoring device is light and convenient, and can be installed on site without the matching of hoisting equipment.

In order to solve the technical problem, the invention provides a simple device for detecting the uplift bearing capacity of a prefabricated square pile. The device comprises a loading device, an anchoring force transmission device, a counterforce system and a displacement measuring device; the loading device is arranged on the anchoring force transmission device, the anchoring force transmission device is arranged on a counterforce system, the counterforce system is arranged on a natural foundation, a displacement measuring device is arranged on the natural foundation, a prefabricated square pile is arranged below the natural foundation, and the surface of the prefabricated square pile is provided with the displacement measuring device which is connected with the anchoring force transmission device; the loading device comprises one or more jacks; the counterforce system comprises buttresses, backing plates and a foundation, the number of the buttresses and the backing plates is two respectively, the two backing plates are placed on the natural foundation, the buttresses are placed on the two backing plates respectively, force transmission steel beams are placed on the two buttresses, jacks are placed on the force transmission steel beams, round backing plates are placed on the jacks, and the two rectangular anchor beams are horizontally placed on the round backing plates; the anchoring force transfer device comprises two rectangular main beams, two rectangular auxiliary beams, four circular buckles, force transfer steel rods, four rectangular anchor beams and two force transfer steel beams, wherein the two rectangular main beams are arranged, the lower ends of the two force transfer steel beams are provided with the rectangular main beam, the rectangular main beam penetrates through tension steel bars of a prefabricated square pile, the rectangular auxiliary beams penetrating through the tension steel bars are orthogonally arranged on the rectangular main beam, the circular buckles are respectively arranged on the rectangular auxiliary beams, the force transfer steel rods penetrate through the rectangular anchor beams and the rectangular main beams, the upper ends and the lower ends of the force transfer steel rods are screwed through bolts, and therefore the rectangular anchor beams and the rectangular main beams are fixedly connected; the displacement measuring device comprises a displacement meter, two magnetic gauge seats, reference piles and reference beams, wherein the number of the displacement meter, the number of the magnetic gauge seats and the number of the reference piles are four respectively, the reference beams are arranged on a natural foundation and are arranged near the prefabricated square piles, and pile soil is arranged around the reference piles; the method comprises the following steps of connecting a displacement meter with a magnetic meter seat, adsorbing the magnetic meter seat on a reference beam, fixing the two ends of the reference beam on a reference pile in a front-back mode, placing a measuring head of the displacement meter on the surface of a prefabricated square pile, recording relative vertical displacement between the prefabricated square pile and the reference beam, and stopping a test until the prefabricated square pile is pulled up to be damaged or the design requirements are met.

Compared with the prior art, the invention has the following beneficial effects: due to the adoption of the structure, when the device is used, the device is used for measuring the displacement through the loading device, the anchoring force transmission device, the counterforce system and the displacement measuring device; the simple device for detecting the uplift bearing capacity of the prefabricated square pile has strong adaptability to the prefabricated square piles with different steel bar diameters and steel bar intervals, does not incline the steel bars, and ensures the safety and reliability of the test; because each anchoring device is light and convenient, the anchoring device can be installed on site without the cooperation of hoisting equipment.

Drawings

FIG. 1 is a schematic sectional view taken along line a-a of FIG. 2 according to the present invention;

FIG. 2 is a schematic top view of the cross-sectional structure of the present invention;

in the figure: the method comprises the following steps of 1-prefabricated square pile, 2-tension steel bar, 3-rectangular anchor beam, 4-bolt, 5-jack, 6-circular base plate, 7-rectangular main beam, 8-rectangular auxiliary beam, 9-circular buckle, 10-pile soil, 11-displacement meter, 12-magnetic gauge stand, 13-reference beam, 14-force transmission steel rod, 15-buttress, 16-base plate, 17-force transmission steel beam and 18-reference pile.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Fig. 1 and 2 show various cross-sectional structural schematics of the present invention. As shown in fig. 1 and 2, the invention provides a simple device for detecting the uplift bearing capacity of a prefabricated square pile 1. The device comprises a loading device, an anchoring force transmission device, a counterforce system and a displacement measuring device; the loading device is arranged on the anchoring force transmission device, the anchoring force transmission device is arranged on the counterforce system, the counterforce system is arranged on a natural foundation, the natural foundation is provided with a displacement measuring device, a prefabricated square pile 1 is arranged below the natural foundation, a plurality of tension steel bars 2 are arranged in the prefabricated square pile 1, and the number of the tension steel bars 2 is preferably four. The surface of the prefabricated square pile 1 is provided with a displacement measuring device which is connected with an anchoring force transmission device; the loading means comprise one or more jacks 5; the counterforce system comprises buttresses 15, backing plates 16 and a foundation, the number of the buttresses 15 and the backing plates 16 is two respectively, the two backing plates 16 are placed on the natural foundation, the buttresses 15 are placed on the two backing plates 16 respectively, force transmission steel beams 17 are placed on the two buttresses 15, jacks 5 are placed on the force transmission steel beams 17, and the jacks 5 are preferably hydraulic jacks 5; a circular base plate 6 is arranged on the jack 5, and two rectangular anchor beams 3 are horizontally arranged on the circular base plate 6; the anchoring force transfer device comprises rectangular main beams 7, rectangular auxiliary beams 8, circular buckles 9, force transfer steel rods 14, rectangular anchor beams 3 and force transfer steel beams 17, the number of the rectangular main beams 7 is two, the number of the rectangular auxiliary beams 8 is two, the number of the circular buckles 9 is four, the number of the force transfer steel rods 14 is four, the number of the rectangular anchor beams 3 is two, each rectangular anchor beam 3 is provided with two force transfer steel beams 17, the lower ends of the two force transfer steel beams 17 are provided with one rectangular main beam 7, the rectangular main beams 7 penetrate through tension steel bars 2 of a prefabricated square pile 1, the rectangular auxiliary beams 8 penetrating through the tension steel bars 2 are orthogonally arranged on the rectangular main beams 7, the circular buckles are respectively placed on the rectangular auxiliary beams 8, the force transfer steel rods 14 penetrate through the rectangular anchor beams 3 and the rectangular main beams 7, and the upper ends and the lower ends of the force transfer steel rods are screwed through bolts 4, so that the rectangular anchor beams 3 are; the displacement measuring device comprises a displacement meter 11, a magnetic gauge stand 12, a reference pile 18 and a reference beam 13, wherein the number of the displacement meter 11, the number of the magnetic gauge stand 12 and the number of the reference pile 18 are four respectively, the number of the reference beams 13 is two, the reference pile 18 is arranged on a natural foundation and is arranged near a prefabricated square pile 1, soil 10 around the pile is arranged around the reference pile 18, the displacement meter 11 is connected with the magnetic gauge stand 12, the magnetic gauge stand 12 is adsorbed on the reference beam 13, the front end and the rear end of the reference beam 13 are fixed on the reference pile 18, a measuring head of the displacement meter 11 is placed on the surface of the prefabricated square pile 1, the relative vertical displacement between the prefabricated square pile 1 and the reference beam 13 is recorded, and the test is terminated until the prefabricated square pile 1 is pulled up and damaged or meets the design requirements. When in use, the device is used for measuring the displacement through a loading device, an anchoring force transmission device, a counterforce system and a displacement measuring device; the simple device for detecting the uplift bearing capacity of the prefabricated square pile 1 has strong adaptability to the prefabricated square piles 1 with different steel bar diameters and steel bar intervals, does not incline the steel bars, and ensures the safety and reliability of the test; because each anchoring device is light and convenient, the anchoring device can be installed on site without the cooperation of hoisting equipment.

While the present invention has been described in detail with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, and various changes and modifications can be made within the knowledge of those skilled in the art.

Claims (5)

1. A simple device for detecting the pull-out bearing capacity of prefabricated square piles, which includes a loading device, an anchoring force-transmitting device, a reaction force system and a displacement measuring device; On the force system, the reaction force system is set on the natural foundation, the displacement measuring device is arranged on the natural foundation, the prefabricated square pile (1) is arranged under the natural foundation, and the displacement measuring device is arranged on the surface of the prefabricated square pile (1), which is related to the anchoring force transmission device. It is characterized in that: the anchoring force transmission device comprises a rectangular main beam (7), a rectangular auxiliary beam (8), a ring buckle (9), a force transmission steel rod (14), a rectangular anchor beam (3), The number of power transmission steel beams (17) is two, the number of rectangular main beams (7) is two, the number of rectangular auxiliary beams (8) is two, the number of ring buckles (9) is four, and the number of power transmission steel rods ( 14) is four, the number of rectangular anchor beams (3) is two, and each rectangular anchor beam (3) is provided with two force-transmitting steel beams (17), two force-transmitting steel beams (17) A rectangular main beam (7) is arranged at the lower end, the rectangular main beam (7) passes through the tensile steel bars (2) of the prefabricated square piles (1), and the rectangular main beam (7) is orthogonally arranged to pass through the tensile steel bars (2). ), circular clips are placed on the rectangular auxiliary beam (8), the force transmission steel rod (14) passes through the rectangular anchor beam (3) and the rectangular main beam (7), and the upper and lower ends By tightening the bolts (4), the rectangular anchor beam (3) and the rectangular main beam (7) are fixedly connected. 2. The simple device for detecting the pull-out bearing capacity of prefabricated square piles according to claim 1, wherein the displacement measuring device comprises a displacement meter (11), a magnetic table base (12), a reference pile (18), The number of reference beams (13), displacement gauges (11), magnetic table bases (12) and reference piles (18) is four respectively, the number of reference beams (13) is two, and the reference piles (18) are located in the natural On the foundation, it is arranged near the prefabricated square pile (1), and the surrounding soil (10) is arranged around the reference pile (18); the displacement meter (11) is connected with the magnetic watch seat (12), and the magnetic watch seat (12) is adsorbed On the reference beam (13), both ends of the reference beam (13) are fixed on the reference pile (18) front and rear, and the displacement meter (11) probe is placed on the surface of the prefabricated square pile (1). 3. The simple device for detecting the pull-out bearing capacity of prefabricated square piles according to claim 1, wherein the reaction force system comprises a buttress (15), a backing plate (16) and a foundation, and the buttress (15) and the number of backing plates (16) are two respectively, two backing plates (16) are placed on the natural foundation, one buttress (15) is placed on both backing plates (16), and one buttress (15) is placed on the two backing plates (15) A power transmission steel beam (17), a jack (5) is placed on the power transmission steel beam (17), a circular backing plate (6) is placed on the jack (5), and two rectangular pieces are placed horizontally on the circular backing plate (6). Anchor beam (3). 4 . The simple device for detecting the pull-out bearing capacity of prefabricated square piles according to claim 3 , wherein the jack ( 5 ) is a hydraulic jack. 5 . 5. The simple device for detecting the pull-out bearing capacity of prefabricated square piles according to claim 1, characterized in that: the prefabricated square piles (1) are provided with several tension bars, and the tension bars of the tension bars (2) are The number is four.

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