Detachable settlement observation device for single pile static load test and installation method

Abstract

The present invention provides a detachable settlement observation device and installation method for a single pile static load test, which belongs to the technical field of foundation pile detection. The detachable settlement observation device for a single pile static load test includes a jack, a jack pad, a displacement point fixing element, a reference pile, a retractable reference beam, a sensor bracket and a sensor. The design of the displacement point fixing element solves the problem of waste of resources and construction period caused by the need to make pile caps or process steel casings, and can realize random sampling, and the engineering detection data is accurate, which greatly improves the quality and safety of the project. The sensor bracket is connected by a plurality of bracket plates, which reduces the weight, reduces the impact on the test results, and solves the problem that the suction force of the magnetic table seat weakens over time. A rubber gasket is arranged on the inner wall of the sensor bracket, which can increase the friction between the retractable reference beam and avoid the problem of sensor sliding due to hydraulic oil splashing. The retractable design of the reference beam is convenient for transportation and carrying.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundation detection, and specifically discloses a detachable settlement observation device for a single pile static load test and an installation method. Background Art

[0002] In the field of engineering construction, most buildings, bridges, and sometimes roads are built with pile foundations. The detection and evaluation of pile bearing capacity is the most important part of engineering quality control. The single pile static load test is a test method for testing the bearing capacity of piles. The principle of this test is to obtain the single pile bearing capacity value by collecting relevant settlement-time-pressure curves. Therefore, the settlement observation device is the most important part of the single pile static load test process.

[0003] The single pile static load test settlement observation device needs to meet the following requirements in accordance with the specifications: ① The measuring plane should be set 200mm below the pile top, and the measuring point should be fixed on the pile body; ② The reference beam needs to be simply supported at one end and fixed at the other end; ③ The fixture and reference beam that fix and support the displacement meter must not be affected by temperature, vibration and other external factors, and shielding measures should be taken when the reference beam is exposed to the sun; ④ The reference pile must meet the relationship with the test pile and the edge of the main pier of the weight platform (the center of the anchor pile), and the distance between them must be greater than 2m and greater than or equal to 4 times the pile diameter (greater than or equal to 3 times the pile diameter with the edge of the main pier of the weight platform).

[0004] At present, the following problems exist in the settlement observation process of single pile static load test: ① During the test, the measuring plane should be set at 200mm below the pile top, and the measuring point should be fixed on the pile body, that is, the pile head needs to be processed before the test, one is to make the pile cap, and the other is to process the steel casing, which has a high production cost, and most of the steel casings are difficult to recycle after the test, resulting in waste. At the same time, the magnetic table base is not firmly adsorbed on the steel casing, and the displacement meter needs to be fixed on the steel casing. The steel plate needs to be welded and placed on the steel casing, which incurs labor and material costs; ② When testing engineering piles, if the pile cap is made in advance, the test will not be random and representative. If random sampling is performed, the pile cap needs to be made after the construction of the engineering pile is completed, which greatly increases the construction period; ③ The magnetic table base has a certain quality. Placing it on the reference beam may affect the test results, and the magnetism will disappear after many uses; ④ Hydraulic oil leakage may cause the magnetic table base and the reference beam to slip, thereby affecting the test results; ⑤ The reference beam is not convenient for transportation. Summary of the invention

[0005] The present application provides a detachable settlement observation device for a single pile static load test and an installation method, which improves the technical problems described in the background technology.

[0006] The detachable settlement observation device for a single pile static load test provided by the present invention comprises a jack, a jack pad, a displacement point fixing element, a reference pile, a retractable reference beam, a sensor bracket and a sensor; the displacement point fixing element comprises a first positioning piece, a second positioning piece, a third positioning piece and a fixing belt I; the second positioning piece is a curved plate, provided with an upper edge and a second connecting edge located below the upper edge, the upper edge and the second connecting edge are both arc-shaped edges, the diameter of the circle where the upper edge and the second connecting edge are located is equal to the diameter of the pile to be tested, and the distance between the upper edge and the second connecting edge is 200 mm; The first positioning piece is a plane plate, provided with a first connecting edge, the first connecting edge is an arc edge, the diameter of the circle where the first connecting edge is located is equal to the diameter of the pile to be measured, and the first connecting edge is rotatably connected to the upper edge of the second positioning piece; the third positioning piece is a plane plate, provided with a third connecting edge, the third connecting edge is an arc edge, the diameter of the circle where the third connecting edge is located is equal to the diameter of the pile to be measured, the third connecting edge is vertically fixedly connected to the second connecting edge of the second positioning piece, and the third positioning piece is located on the outside of the second positioning piece; the fixing belt I is symmetrically arranged on both sides of the second positioning piece, and the first end is connected to the second connecting edge of the second positioning piece. The first and second positioning pieces are connected; multiple displacement point fixing elements are evenly installed on the pile to be tested, the first positioning piece is in contact with the pile top of the pile to be tested, the upper edge and the second connecting edge of the second positioning piece are both in contact with the pile body of the pile to be tested, and the second ends of the fixing belts I of two adjacent displacement point fixing elements are connected to each other; the jack pad is placed on the pile top of the pile to be tested, and the first positioning piece of the multiple displacement point fixing elements is pressed; the jack is installed on the jack pad; two groups of reference piles are symmetrically arranged on both sides of the pile to be tested, and each group of reference piles includes a first reference pile and a second reference pile; the first reference pile includes a pile body and a pile body arranged along the pile body The second reference pile includes a pile body, a plurality of support frames arranged along the pile body, and a fixing belt II installed on the support frame; two retractable reference beams correspond to the two groups of reference piles respectively, the first end of the retractable reference beam is placed on the support frame of the first reference pile, and the second end of the retractable reference beam is placed on the support frame of the second reference pile and fixed by the fixing belt II; the sensor bracket corresponds to the displacement point fixing element one by one, including a bracket frame sleeved on the retractable reference beam and a bracket beam installed on the bracket frame; the sensor is installed on the bracket beam, and the test end is in vertical contact with the third positioning piece.

[0007] In the above-mentioned detachable settlement observation device for single pile static load test, the first positioning piece is a fan-shaped plane plate; the second positioning piece is an arc-shaped curved plate that completely fits the pile body of the pile to be tested, and the second connecting edge is the lower edge; the third positioning piece is a fan-shaped plane plate, and the third connecting edge is the inner edge.

[0008] In the above-mentioned detachable settlement observation device for single pile static load test, the first positioning plate, the second positioning plate and the third positioning plate are steel plates; the first positioning plate and the second positioning plate are rotatably connected through a displacement point hinge; and the second positioning plate and the third positioning plate are welded.

[0009] In the above-mentioned detachable settlement observation device for single pile static load test, the displacement point fixing element also includes a displacement point buckle; the displacement point buckle includes a displacement point clamping port and a displacement point clamping head for plugging in; the second ends of the fixing belt I on both sides of the second positioning piece are respectively provided with a displacement point clamping port and a displacement point clamping head; the fixing belts I of two adjacent displacement point fixing elements are plugged in through the displacement point clamping port and the displacement point clamping head.

[0010] In the above-mentioned detachable settlement observation device for single pile static load test, the retractable reference beam comprises a plurality of rectangular hollow beams which are slidably sleeved in sequence, and two adjacent rectangular hollow beams are connected by bolts.

[0011] In the above-mentioned detachable settlement observation device for single pile static load test, the bracket frame is a rectangular frame adapted to the cross-section of a rectangular hollow beam, and includes a first bracket plate, a second bracket plate, a third bracket plate, a fourth bracket plate, a bracket hinge and a bracket buckle; the first bracket plate and the second bracket plate, the second bracket plate and the third bracket plate, and the third bracket plate and the fourth bracket plate are connected by bracket hinges; the bracket buckle includes a bracket bayonet and a bracket clamp for plugging; the bracket bayonet and the bracket clamp are respectively installed on the first bracket plate and the fourth bracket plate, and the first bracket plate and the fourth bracket plate are connected by plugging the bracket bayonet and the bracket clamp.

[0012] In the above-mentioned detachable settlement observation device for single pile static load test, a rubber gasket is installed on the inner wall of the rectangular frame.

[0013] The installation method of the above-mentioned detachable settlement observation device for single pile static load test comprises the following steps:

[0014] S1, installation of displacement point fixing elements;

[0015] The first positioning piece of the displacement point fixing element is fitted with the pile top of the pile to be measured, the upper edge and the second connecting edge of the second positioning piece are both fitted with the pile body of the pile to be measured, and the second ends of the fixing bands I of two adjacent displacement point fixing elements are connected to each other, so that the displacement point fixing element is fixed on the pile to be measured;

[0016] S2, install the jack plate and jack;

[0017] Place the jack pad on the top of the pile to be tested, press the first positioning pieces of the multiple displacement point fixing elements, and install the jack on the jack pad;

[0018] S3, installing the reference pile and the retractable reference beam;

[0019] The reference pile is driven into the ground according to the specification requirements, and the retractable reference beam is placed in the support frame of the reference pile. The second end of the retractable reference beam is fixed by fixing belt II;

[0020] S4, install the sensor bracket;

[0021] The sensor bracket is fixed on the retractable reference beam at a position corresponding to the displacement point fixing element, and the displacement sensor is installed so that the test end of the displacement sensor is in vertical contact with the third positioning piece.

[0022] Compared with the prior art, the present invention has the following beneficial effects.

[0023] 1. The design of the displacement point fixing element solves the problem of waste of resources and construction period caused by the need to make pile caps or process steel casings. It can realize random sampling, the engineering inspection data is accurate, and the quality and safety of the project are greatly improved.

[0024] 2. The sensor bracket is connected by multiple bracket plates, which reduces the weight, reduces the impact on the test results, and solves the problem of the magnetic base's suction force weakening over time.

[0025] 3. A rubber gasket is set on the inner wall of the sensor bracket to increase the friction between the sensor and the retractable reference beam to avoid the problem of sensor sliding due to hydraulic oil splashing.

[0026] 4. The retractable design of the reference beam makes it easy to transport and carry.

[0027] 5. The present invention has a simple structure, reasonable design and high relative economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a schematic diagram of the installation of a detachable settlement observation device for a single pile static load test;

[0030] Figure 2 It is the installation diagram of the displacement point fixing element;

[0031] Figure 3 It is the structural diagram of the displacement point fixing element;

[0032] Figure 4 is the structural diagram of the first benchmark pile;

[0033] Figure 5 is the structural diagram of the second benchmark pile;

[0034] Figure 6 It is a schematic diagram of the installation of the sensor bracket on the retractable reference beam;

[0035] Figure 7 is a schematic diagram of the connection between the second bracket plate and the third bracket plate;

[0036] Figure 8 is a schematic diagram of the connection between the first bracket plate and the fourth bracket plate;

[0037] Fig. 9 This is the installation front view of the support beam;

[0038] Fig.10 This is a side view of the installation of the support beam;

[0039] Fig.11 This is a schematic diagram of the installation of the sensor fixture;

[0040] Fig.12 A top view of the sensor fixture.

[0041] In the figure: 1- jack; 2- jack pad;

[0042] 3-displacement point fixing element; 3.1-first positioning piece; 3.2-second positioning piece; 3.3-third positioning piece; 3.4-fixing belt I; 3.5-displacement point hinge; 3.6-displacement point buckle;

[0043] 4-reference pile; 4.1-pile body; 4.2-support frame; 4.3-fixing belt II;

[0044] 5-retractable reference beam; 5.1-rectangular hollow beam; 5.2-bolt;

[0045] 6.1- bracket frame; 6.1.1- first bracket plate; 6.1.2- second bracket plate; 6.1.3- third bracket plate; 6.1.4- fourth bracket plate; 6.1.5- bracket hinge; 6.1.6- bracket buckle; 6.1.7- rubber gasket; 6.2- bracket beam;

[0046] 7-Sensor fixture;

[0047] 100-pile to be tested. DETAILED DESCRIPTION

[0048] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] The present embodiment provides a detachable settlement observation device for a single pile static load test, comprising a jack 1, a jack pad 2, a displacement point fixing element 3, a reference pile 4, a retractable reference beam 5, a sensor bracket and a sensor.

[0051] The displacement point fixing element 3 includes a first positioning piece 3.1, a second positioning piece 3.2, a third positioning piece 3.3 and a fixing belt I 3.4; the second positioning piece 3.2 is a curved plate, provided with an upper edge and a second connecting edge located below the upper edge, the upper edge and the second connecting edge are both arcuate edges, the diameter of the circle where the upper edge and the second connecting edge are located is equal to the diameter of the pile 100 to be measured, and the distance between the upper edge and the second connecting edge is 200mm; the first positioning piece 3.1 is a plane plate, provided with a first connecting edge, the first connecting edge is an arcuate edge, the diameter of the circle where the first connecting edge is located is equal to the diameter of the pile 100 to be measured, and the first connecting edge is rotatably connected to the upper edge of the second positioning piece 3.2; the third positioning piece 3.3 is a plane plate, provided with a third connecting edge , the third connecting edge is an arc-shaped edge, the diameter of the circle where the third connecting edge is located is equal to the diameter of the pile 100 to be tested, the third connecting edge is vertically fixedly connected to the second connecting edge of the second positioning piece 3.2, and the third positioning piece 3.3 is located on the outside of the second positioning piece 3.2; the fixing belt I 3.4 is symmetrically arranged on both sides of the second positioning piece 3.2, and the first end is connected to the second positioning piece 3.2; multiple displacement point fixing elements 3 are evenly installed on the pile 100 to be tested, the first positioning piece 3.1 is in contact with the pile top of the pile 100 to be tested, the upper edge and the second connecting edge of the second positioning piece 3.2 are both in contact with the pile body of the pile 100 to be tested, and the second ends of the fixing belts I 3.4 of two adjacent displacement point fixing elements 3 are connected to each other, so that the displacement point fixing element 3 is fixed on the pile 100 to be tested.

[0052] In this embodiment, the first positioning piece 3.1 is a fan-shaped plane plate; the second positioning piece 3.2 is an arc-shaped curved plate that completely fits the pile body of the pile 100 to be tested, and the second connecting edge is the lower edge; the third positioning piece 3.3 is a fan-shaped plane plate, and the third connecting edge is the inner edge. The first positioning piece 3.1, the second positioning piece 3.3, and the third positioning piece 3.3 are steel sheets; the first positioning piece 3.1 and the second positioning piece 3.2 are rotatably connected through a displacement point hinge 3.5; the second positioning piece 3.2 and the third positioning piece 3.3 are welded.

[0053] In this embodiment, the displacement point fixing element 3 also includes a displacement point buckle 3.6; the displacement point buckle 3.6 includes a displacement point buckle port and a displacement point clamping head for plugging in; the second ends of the fixing bands Ⅰ3.4 on both sides of the second positioning piece 3.2 are respectively provided with displacement point buckles and displacement point clamping heads; the fixing bands Ⅰ3.4 of two adjacent displacement point fixing elements 3 are plugged in through the displacement point buckle ports and the displacement point clamping heads.

[0054] The jack plate 2 is placed on the top of the pile 100 to be tested, and presses the first positioning pieces 3.1 of the multiple displacement point fixing elements 3.

[0055] The jack 1 is installed on the jack pad 2.

[0056] Two groups of reference piles 4 are symmetrically arranged on both sides of the pile 100 to be tested, and each group of reference piles 4 includes a first reference pile and a second reference pile; the first reference pile includes a pile body 4.1 and a plurality of support frames 4.2 arranged along the pile body 4.1; the second reference pile includes a pile body 4.1, a plurality of support frames 4.2 arranged along the pile body 4.1 and a fixing belt II 4.3 installed on the support frame 4.2.

[0057] The two retractable reference beams 5 correspond to the two groups of reference piles 4 respectively. The first end of the retractable reference beam 5 is placed on the support frame 4.2 of the first reference pile, and the second end of the retractable reference beam 5 is placed on the support frame 4.2 of the second reference pile and fixed by a fixing belt II 4.3.

[0058] In this embodiment, the telescopic reference beam 5 comprises a plurality of rectangular hollow beams 5.1 which are slidably sleeved in sequence, and two adjacent rectangular hollow beams 5.1 are connected by bolts 5.2.

[0059] The sensor bracket corresponds to the displacement point fixing element 3 one by one, and comprises a bracket frame 6.1 sleeved on the telescopic reference beam 5 and a bracket beam 6.2 mounted on the bracket frame 6.1.

[0060] In this embodiment, the bracket frame 6.1 is a rectangular frame adapted to the cross-section of the rectangular hollow beam 5.1, including a first bracket plate 6.1.1, a second bracket plate 6.1.2, a third bracket plate 6.1.3, a fourth bracket plate 6.1.4, a bracket hinge 6.1.5 and a bracket buckle 6.1.6; the first bracket plate 6.1.1 and the second bracket plate 6.1.2, the second bracket plate 6.1.2 and the third bracket plate 6.1.3, and the third bracket plate 6.1.3 and the fourth bracket plate 6.1.4 are connected by a bracket hinge 6.1.5; the bracket buckle 6.1.6 includes a bracket bayonet and a bracket clamp for plugging; the bracket bayonet and the bracket clamp are respectively installed on the first bracket plate 6.1.1 and the fourth bracket plate 6.1.4, and the first bracket plate 6.1.1 and the fourth bracket plate 6.1.4 are connected by plugging the bracket bayonet and the bracket clamp.

[0061] In this embodiment, a rubber gasket 6.1.7 is installed on the inner wall of the rectangular frame.

[0062] The sensor is mounted on the support beam 6.2, and the test end is in vertical contact with the third positioning piece 3.3.

[0063] Example 2

[0064] This embodiment takes a pile 100 to be tested with a diameter of 800 cm as an example to explain in detail the detachable settlement observation device for a single pile static load test.

[0065] There are four displacement point fixing elements 3. The arc length of the arc edge of the first positioning piece 3.1 is 30 cm, and the cone angle is 30°. The distance between the inner edge and the outer edge of the third positioning piece 3.3 is 10 cm. Two holes are opened on both sides of the second positioning piece 3.2 for connecting the fixing belt I 3.4. The width of the fixing belt I 3.4 is 8 cm.

[0066] The pile body 4.1 is made of angle iron, and a support frame 4.2 is welded every 15 cm on the upper half of the angle iron. The support frame 4.2 includes a right angle frame and a triangular support connecting the right angle frame and the pile body 4.1. The right angle frame is 20 cm long, 5 cm wide and 5 cm high. A hole is opened on the right angle frame of the second reference pile for connecting the fixing belt II 4.3.

[0067] The rectangular hollow beam 5.1 is a square steel with a wall thickness of 5 mm. The cross-sectional size of the smallest square steel is 100 mm × 50 mm. The length of each section of the rectangular hollow beam 5.1 is 6 m. The size difference of the connected square steels is the wall thickness of the square steels to ensure that it can be inserted into the connected square steels.

[0068] The size of the first bracket plate 6.1.1 and the third bracket plate 6.1.3 is 105mm×55mm, and the size of the second bracket plate 6.1.2 and the fourth bracket plate 6.1.4 is 55mm×55mm. They are all made of steel sheets, and the rubber gasket 6.1.7 is bonded to the steel sheet with strong glue. The bracket beam 6.2 is welded with steel columns, including vertical steel columns and horizontal steel columns, wherein the vertical steel column is welded on the second bracket plate 6.1.2 or the fourth bracket plate 6.1.4, and the two ends of the horizontal steel column are flattened and then opened. The first end of the horizontal steel column is sleeved on the vertical steel column and connected by bolts, and the second end is installed with the sensor fixture 7.

[0069] Example 3

[0070] The installation method of the above-mentioned detachable settlement observation device for single pile static load test comprises the following steps:

[0071] S1, installing the displacement point fixing element 3;

[0072] The first positioning piece 3.1 of the displacement point fixing element 3 is fitted with the pile top of the pile 100 to be tested, the upper edge and the second connecting edge of the second positioning piece 3.2 are both fitted with the pile body of the pile 100 to be tested, and the second ends of the fixing belts I 3.4 of two adjacent displacement point fixing elements 3 are connected to each other, so that the displacement point fixing element 3 is fixed on the pile 100 to be tested;

[0073] S2, install jack plate 2 and jack 1;

[0074] Place the jack plate 2 on the top of the pile 100 to be tested, press the first positioning piece 3.1 of the multiple displacement point fixing element 3, and install the jack 1 on the jack plate 2;

[0075] S3, installing the reference pile 4 and the retractable reference beam 5;

[0076] The reference pile 4 is driven into the ground according to the specification requirements, and the retractable reference beam 5 is placed in the support frame 4.2 of the reference pile 4, and the second end of the retractable reference beam 5 is fixed by a fixing belt II 4.3;

[0077] S4, install the sensor bracket;

[0078] The sensor bracket is fixed on the telescopic reference beam 5, the position of which corresponds to the displacement point fixing element 3, and the displacement sensor is installed so that the test end of the displacement sensor is in vertical contact with the third positioning piece 3.3.

[0079] After installation, pre-compression is performed, and after pre-compression, the displacement sensor is readjusted and a pressure test is performed.

[0080] After the test is completed, each component is disassembled and the small components are packed.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A detachable settlement observation device for a single pile static load test, characterized in that: It includes a jack, a jack pad, a displacement point fixing element, a reference pile, a retractable reference beam, a sensor bracket and a sensor; The displacement point fixing element comprises a first positioning piece, a second positioning piece, a third positioning piece and a fixing belt I; The second positioning plate is a curved plate, provided with an upper edge and a second connecting edge located below the upper edge, the upper edge and the second connecting edge are both arc-shaped edges, the diameter of the circle where the upper edge and the second connecting edge are located is equal to the diameter of the pile to be measured, and the distance between the upper edge and the second connecting edge is 200 mm; The first positioning piece is a plane plate, provided with a first connecting edge, the first connecting edge is an arc-shaped edge, the diameter of the circle where the first connecting edge is located is equal to the diameter of the pile to be measured, and the first connecting edge is rotatably connected to the upper edge of the second positioning piece; The third positioning piece is a plane plate, provided with a third connecting edge, the third connecting edge is an arc-shaped edge, the diameter of the circle where the third connecting edge is located is equal to the diameter of the pile to be measured, the third connecting edge is vertically fixedly connected to the second connecting edge of the second positioning piece, and the third positioning piece is located outside the second positioning piece; The fixing belt I is symmetrically arranged on both sides of the second positioning piece, and the first end is connected to the second positioning piece; A plurality of displacement point fixing elements are evenly installed on the pile to be tested, the first positioning piece is fitted with the pile top of the pile to be tested, the upper edge and the second connecting edge of the second positioning piece are both fitted with the pile body of the pile to be tested, and the second ends of the fixing belts I of two adjacent displacement point fixing elements are connected to each other; The jack plate is placed on the top of the pile to be tested, and presses the first positioning piece of the multiple displacement point fixing element; The jack is mounted on a jack plate; Two groups of reference piles are symmetrically arranged on both sides of the pile to be tested, and each group of reference piles includes a first reference pile and a second reference pile; The first reference pile includes a pile body and a plurality of support frames arranged along the pile body; The second reference pile includes a pile body, a plurality of support frames arranged along the pile body, and a fixing belt II installed on the support frames; Two retractable reference beams correspond to the two groups of reference piles respectively, the first end of the retractable reference beam is placed on the support frame of the first reference pile, and the second end of the retractable reference beam is placed on the support frame of the second reference pile and fixed by a fixing belt II; The sensor bracket corresponds to the displacement point fixing element one by one, and includes a bracket frame sleeved on the telescopic reference beam and a bracket beam mounted on the bracket frame; The sensor is mounted on the support beam, and the test end is in vertical contact with the third positioning piece.

2. The detachable settlement observation device for a single pile static load test according to claim 1 is characterized in that: The first positioning piece is a sector-shaped plane plate; The second positioning piece is an arc-shaped curved plate that completely fits the pile body of the pile to be tested, and the second connecting edge is the lower edge; The third positioning piece is a fan-shaped flat plate, and the third connecting edge is an inner edge.

3. The detachable settlement observation device for a single pile static load test according to claim 2 is characterized in that: The first positioning piece, the second positioning piece and the third positioning piece are steel sheets; The first positioning piece and the second positioning piece are rotatably connected via a displacement point hinge; The second positioning piece and the third positioning piece are welded.

4. The detachable settlement observation device for a single pile static load test according to any one of claims 1 to 3, characterized in that: The displacement point fixing element also includes a displacement point buckle; The displacement point buckle comprises a displacement point clamping port and a displacement point clamping head for plugging; The second ends of the fixing bands I on both sides of the second positioning piece are respectively provided with displacement point clamping openings and displacement point clamping heads; The fixing belts I of two adjacent displacement point fixing elements are plugged in through the displacement point clamping opening and the displacement point clamping head.

5. The detachable settlement observation device for single pile static load test according to claim 4 is characterized in that: The telescopic reference beam comprises a plurality of rectangular hollow beams which are slidably sleeved in sequence, and two adjacent rectangular hollow beams are connected by bolts.

6. The detachable settlement observation device for a single pile static load test according to claim 5 is characterized in that: The support frame is a rectangular frame adapted to the cross section of the rectangular hollow beam, and includes a first support plate, a second support plate, a third support plate, a fourth support plate, a support hinge and a support buckle; The first bracket plate and the second bracket plate, the second bracket plate and the third bracket plate, and the third bracket plate and the fourth bracket plate are connected by bracket hinges; The bracket buckle includes a bracket socket and a bracket clamp head for plugging; The bracket bayonet and the bracket clamp are respectively installed on the first bracket plate and the fourth bracket plate, and the first bracket plate and the fourth bracket plate are connected by plugging the bracket bayonet and the bracket clamp.

7. The detachable settlement observation device for a single pile static load test according to claim 6 is characterized in that: The inner wall of the rectangular frame is installed with rubber gaskets.

8. A method for installing the detachable settlement observation device for a single pile static load test according to any one of claims 1 to 7, characterized in that: The steps include: S1, installation of displacement point fixing elements; The first positioning piece of the displacement point fixing element is fitted with the pile top of the pile to be measured, the upper edge and the second connecting edge of the second positioning piece are both fitted with the pile body of the pile to be measured, and the second ends of the fixing bands I of two adjacent displacement point fixing elements are connected to each other, so that the displacement point fixing element is fixed on the pile to be measured; S2, install the jack plate and jack; Place the jack pad on the top of the pile to be tested, press the first positioning pieces of the multiple displacement point fixing elements, and install the jack on the jack pad; S3, installing the reference pile and the retractable reference beam; The reference pile is driven into the ground according to the specification requirements, and the retractable reference beam is placed in the support frame of the reference pile. The second end of the retractable reference beam is fixed by fixing belt II; S4, install the sensor bracket; The sensor bracket is fixed on the retractable reference beam at a position corresponding to the displacement point fixing element, and the displacement sensor is installed so that the test end of the displacement sensor is in vertical contact with the third positioning piece.

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