Counter-force device for static load test

Abstract

A counter-force device for a static load test comprises an anchor pile, a main beam, a secondary beam and a jack. The anchor piles are arranged on two sides of the test pile; a steel cylinder is mounted at the top of the anchor pile; a connecting beam longitudinally penetrates through the steel cylinder; the secondary beams are mounted at the tops of the steel cylinders on two sides of the test pile; the secondary beams and the connecting beams are tied through first tying pieces arranged on the front side and the rear side of the steel cylinder. The jack is mounted at the top of the test pile; the main beam is arranged at the top of the jack, and the two ends of the main beam extend to the positions above the secondary beams on the two sides correspondingly. The main beam and the secondary beams on the two sides are tied through second tying pieces respectively. An adjustable lantern ring is mounted at the lower part of the test pile; displacement meters are arranged on the two sides of the adjustable lantern ring respectively; the displacement meter is supported on the ground and detachably connected with the adjustable lantern ring. The pile foundation static load test device solves the technical problems that a traditional pile foundation static load test device is long in test preparation time and high in cost, potential safety hazards exist, the requirement for a test site is high, the occupied area is large, and the test result is not accurate enough.

Description

Technical Field

[0001] The utility model relates to the technical field of civil engineering component testing, in particular to a reaction force device for static load testing and a testing method thereof. Background Art

[0002] The pile foundation static load test is a technique used in engineering to test the bearing capacity of pile foundations. It is currently the most accurate and reliable test method for determining the ultimate bearing capacity of a single pile. Among the recent related technologies, patent CN117266264A discloses a pile foundation static load test equipment, which includes ballast platform piers on both sides of the test pile, jacks, main beams, secondary beams, ballast platforms and load-bearing adjustment plates, wherein there are two ballast platform piers and they are symmetrically distributed on both sides of the test pile; the jacks are located on the top of the test pile; the main beams are located on the top of the jacks; the secondary beams are erected on the main beams and the ballast platform piers, and the secondary beams are equipped with sensors for detecting vertical loads; the load-bearing adjustment plates are located on the top of the secondary beams and can be stacked with counterweights; patent CN210712977U discloses a pile foundation static load test equipment, which includes a main beam, a secondary beam, a tie rod, an anchor cage and a jack, wherein a jack is provided between the main beam and the test pile; the secondary beam is located above the main beam; both ends of the secondary beam are connected to the anchor cage by tie rods; and the anchor cage is connected to the anchor pile. It can be seen from the above two patent documents that the existing pile foundation static load test mainly includes a weight platform reaction device, an anchor pile beam reaction device, and a ground anchor reaction device. The weight platform reaction device is a pile loading method. Before the test begins, the pile of weights needs to be piled on the load-bearing platform at one time. The test preparation time is long, the cost is high, and there are safety hazards. The ground anchor reaction device has high requirements for the test site and occupies a large area. It is often difficult to achieve uniform distribution of vertical loads on the top of the test pile, which results in inaccurate test results. Utility Model Content

[0003] The purpose of the utility model is to provide a reaction force device for static load test and a test method thereof, in order to solve the technical problems that the traditional pile foundation static load test device has long test preparation time, high cost, potential safety hazards, high requirements for the test site, large occupied area, and often difficult to achieve uniform distribution of vertical load on the top of the test pile, which leads to inaccurate test results.

[0004] In order to achieve the above-mentioned purpose, the present utility model adopts the following technical solutions.

[0005] A reaction force device for a static load test, comprising an anchor pile, a main beam, a secondary beam and a jack; the anchor piles are arranged in two groups on both sides of the test pile; each group of anchor piles is arranged at intervals in the transverse direction; the top of the anchor pile is lower than the top of the test pile; a steel cylinder is installed on the top of the anchor pile; a connecting beam is longitudinally passed through each steel cylinder; there are two secondary beams, which are respectively installed on the top of the steel cylinder on both sides of the test pile; the width of the secondary beam is greater than the diameter of the steel cylinder, and the front side of the secondary beam exceeds the front contour line of the steel cylinder, and the rear side of the secondary beam is The test pile extends beyond the rear contour line of the steel cylinder; the secondary beam and the connecting beam are connected by a first anchor provided on the front and rear sides of the steel cylinder; the jack is installed on the top of the test pile; the main beam is provided on the top of the jack, and the two ends of the main beam extend to the top of the secondary beams on both sides; the main beam and the secondary beams on both sides are connected by a second anchor; an adjustable collar is installed at the lower part of the test pile; displacement meters are provided on both sides of the adjustable collar; the displacement meter is supported on the ground and is detachably connected to the adjustable collar.

[0006] Preferably, an anchor plate is pre-buried at the top of the anchor pile; anchor bars are connected at intervals at the bottom of the anchor plate; the anchor bars are buried in the anchor pile; and the steel tube is welded to the top of the anchor plate.

[0007] Preferably, the two groups of anchor piles are arranged symmetrically about the test pile.

[0008] Preferably, the vertical section of the connecting beam is I-shaped, and vertical steel ribs are arranged at intervals along the longitudinal direction on both sides of the web of the connecting beam and between the upper and lower flange plates.

[0009] Preferably, the first anchor member includes a first tie rod, a first upper anchor plate and a first lower anchor plate; the first upper anchor plate is placed vertically and flatly on the upper surface of the secondary beam, and the first lower anchor plate is arranged vertically at the bottom of the connecting beam; holes are respectively provided on the connecting beam and the secondary beam at positions corresponding to the first tie rod; through holes are respectively provided on the first upper anchor plate and the first lower anchor plate at positions corresponding to the holes; the first tie rod passes through the hole and the through hole, and is fastened with high-strength bolts.

[0010] Preferably, a group of the second anchors are arranged at equal intervals on each side of the test pile, and the second anchors on both sides of the test pile are arranged symmetrically about the test pile; the second anchors include a second tie rod, a second upper anchor plate and a second lower anchor plate; the second upper anchor plate is placed vertically and flatly on the end of the upper surface of the main beam, and the second lower anchor plate is arranged vertically at the bottom of the secondary beam; circular holes are respectively provided on the main beam and the secondary beam at positions corresponding to the second tie rods; through holes are respectively provided on the second upper anchor plate and the second lower anchor plate at positions corresponding to the circular holes; the second tie rod passes through the circular hole and the through hole, and is fastened with high-strength bolts.

[0011] Preferably, the adjustable collar includes an arc-shaped plate and connecting bolts; there are two arc-shaped plates, which are respectively arranged on both sides of the test pile; ear plates are respectively arranged on both sides of each arc-shaped plate; there are two groups of connecting bolts, which respectively connect the ear plates on the corresponding sides of the two arc-shaped plates; horizontal panels for displacement meters to measure displacement are arranged on the tops of the ear plates on both sides; the displacement meters are in contact with the horizontal panels.

[0012] Compared with the prior art, the present invention has the following characteristics and beneficial effects.

[0013] 1. This utility model is based on the improvement of the anchor pile crossbeam reaction device. A displacement meter is set at the bottom of the test pile so that the reading is not affected by the height of the test pile. It is suitable for high-altitude static load tests. Secondary beams are installed on the top of the steel cylinder on both sides of the test pile to provide a stable reaction force for the test pile. For large-tonnage test piles, it can significantly save costs.

[0014] 2. The utility model is quick to install and has efficient load transmission. It realizes load transmission through the main beam and the secondary beam, converts the pulling force of the anchor pile into the vertical load on the top of the test pile, and can provide a stable vertical load for the test pile without processing the weight platform pier or the anchor site, thereby avoiding the limitations of traditional weight reaction devices and anchor reaction devices on site conditions and loading tonnage, and has obvious advantages in narrow and uneven test sites.

[0015] 3. The utility model uses a connector that can be quickly installed and removed to fix the displacement meter to the test pile. The fixing position is located at the bottom of the test pile, so that the reading is no longer affected by the height of the test pile. In addition, the utility model has strong adjustability. The secondary beam can be detachably connected to multiple anchor piles, thereby realizing static load tests of anchor piles of different tonnages. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described in detail below with reference to the accompanying drawings.

[0017] Figure 1 It is a structural schematic diagram of a reaction force device for a static load test of the present utility model.

[0018] Figure 2 It is a schematic diagram of the connection structure between the steel cylinder and the anchor pile in the utility model.

[0019] Figure 3 It is a schematic diagram of the connection structure between the steel tube and the connecting beam in the utility model.

[0020] Figure 4 It is a structural schematic diagram of the connecting beam in the utility model.

[0021] Figure 5 It is a structural schematic diagram of a displacement meter arranged at the bottom of a pilot pile of the utility model.

[0022] Figure numerals: 1 - test pile, 2 - anchor pile, 3 - main beam, 4 - secondary beam, 5 - jack, 6 - first anchor, 6.1 - first tie rod, 6.2 - first upper anchor plate, 6.3 - first lower anchor plate, 7 - second anchor, 7.1 - second tie rod, 7.2 - second upper anchor plate, 7.3 - second lower anchor plate, 8 - anchor plate, 9 - steel cylinder, 10 - adjustable collar, 10.1 - curved plate, 10.1.1 - ear plate, 10.2 - connecting bolt, 10.3 - horizontal panel, 11 - displacement meter, 12 - connecting beam, 13 - steel vertical rib, 14 - anchor bar, 15 - bearing plate. DETAILED DESCRIPTION

[0023] like Figure 1-5 As shown, this static load test reaction device places the displacement meter at the bottom of the test pile 1 through an adjustable collar 10, and each secondary beam 4 is connected to multiple anchor piles. The utility model includes anchor piles 2, main beams 3, secondary beams 4 and jacks 5; there are two groups of anchor piles 2, which are respectively arranged on both sides of the test pile 1; each group of anchor piles 2 is arranged at intervals along the transverse direction; the top of the anchor pile 2 is lower than the top of the test pile 1; a steel cylinder 9 is installed on the top of the anchor pile 2; a connecting beam 12 is longitudinally passed through each steel cylinder 9; there are two secondary beams 4, and the two secondary beams 4 are respectively installed on the top of the steel cylinder 9 on both sides of the test pile 1; the width of the secondary beam 4 is greater than the diameter of the steel cylinder 9, and the front side of the secondary beam 4 exceeds the front contour line of the steel cylinder 9, and the rear side of the secondary beam 4 exceeds the steel cylinder 9. the rear contour line of the pile; the secondary beam 4 and the connecting beam 12 are connected by a first anchor 6 arranged on the front and rear sides of the steel cylinder 9; the jack 5 is installed on the top of the test pile 1; the main beam 3 is arranged on the top of the jack 5, and the two ends of the main beam 3 extend to the top of the secondary beams 4 on both sides; the main beam 3 and the secondary beams 4 on both sides are connected by second anchors 7 respectively; an adjustable collar 10 is installed at the lower part of the test pile 1; displacement meters 11 are respectively provided on both sides of the adjustable collar 10; the displacement meter 11 is supported on the ground and is detachably connected to the adjustable collar 10.

[0024] In this embodiment, an anchor plate 8 is pre-buried at the top of the anchor pile 2; anchor bars 14 are connected at intervals at the bottom of the anchor plate 8; the anchor bars 14 are buried in the anchor pile 2; and the steel tube 9 is welded to the top of the anchor plate 8.

[0025] In this embodiment, the two groups of anchor piles 2 are symmetrically arranged with respect to the test pile 1 .

[0026] In this embodiment, the vertical section of the connecting beam 12 is I-shaped, and steel vertical ribs 13 are provided at intervals along the longitudinal direction on both sides of the web of the connecting beam 12 and between the upper and lower flange plates.

[0027] In this embodiment, the first anchor 6 includes a first tie rod 6.1, a first upper anchor plate 6.2, and a first lower anchor plate 6.3. The first upper anchor plate 6.2 is placed vertically and flatly on the upper surface of the secondary beam 4, and the first lower anchor plate 6.3 is arranged vertically on the bottom of the connecting beam 12. Holes are provided on the connecting beam 12 and the secondary beam 4 at positions corresponding to the first tie rod 6.1. Through holes are provided on the first upper anchor plate 6.2 and the first lower anchor plate 6.3 at positions corresponding to the holes. The first tie rod 6.1 passes through the hole and the through hole and is fastened with high-strength bolts. The bottom of the steel cylinder 9 is welded to the top of the anchor pile 2, so that the anchor pile and the steel cylinder form a structure that can transfer load. Through the connection of the first anchor 6, the steel cylinder 9 and the secondary beam 4 form a structure that can transfer load.

[0028] In this embodiment, a group of second anchors 7 are arranged at equal intervals on each side of the test pile 1, and the second anchors 7 on both sides of the test pile 1 are arranged symmetrically about the test pile 1; the second anchors 7 include a second tie rod 7.1, a second upper anchor plate 7.2 and a second lower anchor plate 7.3; the second upper anchor plate 7.2 is placed vertically and flatly on the end of the upper surface of the main beam 3, and the second lower anchor plate 7.3 is arranged vertically at the bottom of the secondary beam 4; circular holes are respectively provided on the main beam 3 and the secondary beam 4 at positions corresponding to the second tie rods 7.1; through holes are respectively provided on the second upper anchor plate 7.2 and the second lower anchor plate 7.3 at positions corresponding to the circular holes; the second tie rod 7.1 passes through the circular hole and the through hole, and is fastened with high-strength bolts.

[0029] The main beam and the secondary beam are connected to the upper anchor plate through a number of equidistant tie rods, so that a structure capable of transferring loads is formed.

[0030] Of course, in other embodiments, both ends of the main beam 3 exceed the middle of the secondary beam 4 on the corresponding side, and the second anchor 7 connects the main beam 3 and the secondary beam 4 in parallel through the pull rod, so that the main beam 3 and the secondary beam 4 form a structure that can transfer load.

[0031] In this embodiment, the anchor pile 2 and the steel cylinder 9 form a structure that can transfer loads, the steel cylinder 9 and the secondary beam 4 form a structure that can transfer loads, and the secondary beam 4 and the main beam 3 form a structure that can transfer loads. Finally, the anchor pile 2 and the main beam 3 form a structure that can transfer loads.

[0032] In this embodiment, the adjustable collar 10 includes an arc-shaped plate 10.1 and connecting bolts 10.2; there are two arc-shaped plates 10.1, one on each side of the test pile 1; an ear plate 10.1.1 is provided on both sides of each arc-shaped plate 10.1; there are two groups of connecting bolts 10.2, which respectively connect the ear plates 10.1.1 on the corresponding side of the two arc-shaped plates 10.1; a horizontal panel 10.3 for a displacement meter 11 to measure the displacement is provided on the top of the ear plates 10.1.1 on both sides; the displacement meter 11 is in contact with the horizontal panel 10.3.

[0033] In this embodiment, a bearing plate 15 is provided at the bottom of the main beam 3 , at a position corresponding to the jack 5 .

[0034] The test method of the anchor pile crossbeam reaction device for the static load test includes the following steps.

[0035] Step 1: Make a steel cylinder 9 and pass the connecting beam 12 longitudinally through the steel cylinder 9.

[0036] Step 2: prefabricate the anchor pile 2 and connect the steel cylinder 9 to the top of the anchor pile 2.

[0037] Step 3: construct anchor piles 2 at intervals on both sides of the test pile 1.

[0038] Step 4: construct the secondary beam 4 : hoist the two secondary beams above the steel cylinders 9 on top of the two groups of anchor piles 2 respectively, and use the first anchor 6 to tie the secondary beam 4 to the connecting beam 12 .

[0039] Step 5, constructing the main beam 3: hoisting the main beam 3 above the jack 5 on the top of the test pile 1, and using the second anchor 7 to tie the main beam 3 to the secondary beam 4.

[0040] Step six: install an adjustable collar 10 at the bottom of the test pile 1; set displacement meters 11 on both sides of the adjustable collar 10; support the displacement meter 11 on the ground and detachably connect it to the adjustable collar 10.

[0041] Step seven: The main beam 3 is pushed upward by the jack 5. The reaction force generated thereby compresses the test pile 1, causing the test pile 1 to sink.

[0042] Step eight: After the test pile 1 sinks steadily, the reading on the displacement meter 11 is collected to obtain the settlement value of the test pile 1 under a specific load.

[0043] During use of the anchor pile crossbeam reaction device of this embodiment, the top pressure head of the jack 5 applies a load to the bearing plate 15 at the bottom of the main beam 3. The pressure head continuously pushes the main beam 3 upward. Through the connection between the second anchor 7 and the first anchor 6, the anchor pile 2 and the main beam 3 form a structure capable of transferring load. Therefore, the main beam 3 is constrained by the anchor pile 2, which generates a downward load on the pressure head of the jack 5. This load is greater than the load applied by the jack 5 to the main beam 3, thus generating a compressive reaction on the test pile 1, causing the pile to sink. The steel collar fixed to the bottom of the test pile 1 displaces as the test pile settles, and the reading generated by the displacement meter 11 is the settlement of the test pile under the specific load.

[0044] In specific implementation, more anchor piles can be adapted by changing the lengths of the main beam 3 and the secondary beam 4, so that the reaction force device can be applied to static load test piles of larger tonnage.

Claims

1. A reaction force device for static load test, characterized in that: The invention comprises anchor piles (2), main beams (3), secondary beams (4) and jacks (5); the anchor piles (2) are in two groups, which are respectively arranged on both sides of the test pile (1); each group of anchor piles (2) is arranged at intervals in the transverse direction; the top of the anchor pile (2) is lower than the top of the test pile (1); a steel cylinder (9) is installed on the top of the anchor pile (2); a connecting beam (12) is longitudinally passed through each steel cylinder (9); there are two secondary beams (4), which are respectively installed on the top of the steel cylinder (9) on both sides of the test pile (1); the width of the secondary beam (4) is greater than the diameter of the steel cylinder (9), and the front side of the secondary beam (4) exceeds the front contour line of the steel cylinder (9), and the rear side of the secondary beam (4) exceeds the steel cylinder (9). ); the secondary beam (4) and the connecting beam (12) are connected by a first anchor (6) arranged on the front and rear sides of the steel cylinder (9); the jack (5) is installed on the top of the test pile (1); the main beam (3) is arranged on the top of the jack (5), and the two ends of the main beam (3) extend above the secondary beams (4) on both sides; the main beam (3) and the secondary beams (4) on both sides are connected by a second anchor (7); an adjustable collar (10) is installed at the lower part of the test pile (1); displacement meters (11) are respectively provided on both sides of the adjustable collar (10); the displacement meter (11) is supported on the ground and is detachably connected to the adjustable collar (10).

2. The reaction force device for static load test according to claim 1, characterized in that: An anchor plate (8) is pre-buried at the top of the anchor pile (2); anchor bars (14) are connected at intervals at the bottom of the anchor plate (8); the anchor bars (14) are buried in the anchor pile (2); and the steel cylinder (9) is welded to the top of the anchor plate (8).

3. The reaction force device for static load test according to claim 1, characterized in that: The two groups of anchor piles (2) are symmetrically arranged with respect to the test pile (1).

4. The reaction force device for static load test according to claim 1, characterized in that: The vertical section of the connecting beam (12) is in an I-shape, and steel vertical ribs (13) are provided at intervals along the longitudinal direction on both sides of the web of the connecting beam (12) and between the upper and lower flange plates.

5. The reaction force device for static load test according to claim 1, characterized in that: The first anchor member (6) comprises a first tie rod (6.1), a first upper anchor plate (6.2) and a first lower anchor plate (6.3); the first upper anchor plate (6.2) is vertically placed on the upper surface of the secondary beam (4), and the first lower anchor plate (6.3) is vertically arranged on the bottom of the connecting beam (12); holes are respectively provided on the connecting beam (12) and the secondary beam (4) at positions corresponding to the first tie rod (6.1); through holes are respectively provided on the first upper anchor plate (6.2) and the first lower anchor plate (6.3) at positions corresponding to the holes; the first tie rod (6.1) passes through the hole and the through hole and is fastened with high-strength bolts.

6. The reaction force device for static load test according to claim 1, characterized in that: A group of the second anchors (7) are arranged at equal intervals on each side of the test pile (1), and the second anchors (7) on both sides of the test pile (1) are arranged symmetrically with respect to the test pile (1); the second anchors (7) include a second tie rod (7.1), a second upper anchor plate (7.2) and a second lower anchor plate (7.3); the second upper anchor plate (7.2) is vertically placed on the end of the upper surface of the main beam (3), and the second lower anchor plate (7.3) is vertically arranged on the bottom of the secondary beam (4); circular holes are respectively provided on the main beam (3) and the secondary beam (4) at positions corresponding to the second tie rods (7.1); through holes are respectively provided on the second upper anchor plate (7.2) and the second lower anchor plate (7.3) at positions corresponding to the circular holes; the second tie rod (7.1) passes through the circular hole and the through hole and is fastened with high-strength bolts.

7. The reaction force device for static load test according to claim 1, characterized in that: The adjustable collar (10) comprises an arc-shaped plate (10.1) and a connecting bolt (10.2); there are two arc-shaped plates (10.1), which are respectively arranged on both sides of the test pile (1); ear plates (10.1.1) are respectively arranged on both sides of each arc-shaped plate (10.1); there are two groups of connecting bolts (10.2), which respectively connect the ear plates (10.1.1) on the corresponding sides of the two arc-shaped plates (10.1); 10.1.1) A horizontal panel (10.3) is provided on the top for a displacement meter (11) to measure the displacement; the displacement meter (11) is in contact with the horizontal panel (10.3).

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