An anchor pile and reaction secondary beam connection structure, device and method for static load test

Abstract

The present invention discloses a connection structure, device and method for an anchor pile and a reaction secondary beam in a static load test, including an anchor pile and a reaction secondary beam; the anchor pile includes an upper pipe section and a lower pipe section, and a groove is provided on the cross-section of the lower pipe section; both ends of the groove communicate with the opposite side walls of the lower pipe section; the reaction secondary beam is fitted into the groove; the upper pipe section is welded to the cross-section of the lower pipe section to seal the top opening of the groove. The connection structure provides tensile strength through the butt weld between the upper pipe section and the lower pipe section. The restraint effect of the groove on the reaction secondary beam improves the stability of the reaction secondary beam. The circumferential surface contact between the reaction secondary beam and the anchor pile increases the contact stress area between the two, improving the force transmission efficiency and avoiding stress concentration. In particular, the test device using this connection structure can increase the upper limit of the force measurement and obtain more data.

Description

Technical Field

[0001] The present invention belongs to the field of pile foundation engineering, and particularly relates to a connecting structure, device and method for anchor piles and reaction secondary beams in static load tests. Background Art

[0002] A static load test refers to a test method in which vertical pressure, vertical uplift force or horizontal thrust is gradually applied to the top of a pile, and the settlement, uplift displacement or horizontal displacement generated at the top of the pile over time is observed to determine the corresponding vertical compressive bearing capacity, vertical uplift bearing capacity or horizontal bearing capacity of a single pile.

[0003] Since the anchor pile and the reaction secondary beam serve as the support structure of the test device, when the force measuring device applies pressure or tension to the test pile, the combination of the anchor pile and the reaction secondary beam will be subjected to the same reverse force; therefore, it is required that the butt joint of the anchor pile and the reaction secondary beam has high force transmission efficiency, low stress concentration, and high tensile strength.

[0004] In the prior art, the connection method between the anchor pile and the reaction secondary beam is fixed through the anchor pile tie rod and the pin. If the size of the test pile is large and matching large-sized anchor piles and reaction secondary beams, it is very difficult to follow up and match the sizes of the anchor pile tie rod and the pin, resulting in insufficient tensile strength, low force transmission efficiency and stress concentration in the connection method of the anchor pile tie rod and the pin. Therefore, there is an urgent need for a connecting structure for anchor piles and reaction secondary beams that can adapt to large-sized test piles. Summary of the Invention

[0005] The purpose of the present invention is to provide a connecting structure for anchor piles and reaction secondary beams in static load tests, which is applied to the mutual connection of large-diameter anchor piles and reaction secondary beams, can provide a more stable assembly method, improve the tensile strength and force transmission efficiency at the butt joint of the two, and avoid stress concentration at the same time.

[0006] The present invention is realized through the following technical solutions: A connecting structure for anchor piles and reaction secondary beams in static load tests, comprising an anchor pile and a reaction secondary beam; the anchor pile includes an upper pipe section and a lower pipe section, and a groove is provided on the cross-section of the lower pipe section; both ends of the groove communicate with the opposite side walls of the lower pipe section; the reaction secondary beam is fitted into the groove; and the upper pipe section is welded to the cross-section of the lower pipe section to close the top opening of the groove.

[0007] Through the above solution, the present invention at least obtains the following technical effects:

[0008] This solution uses the method of burying the reaction secondary beam inside the anchor pile to enhance the connection strength and stability between the two. First, the anchor pile is cut into an upper pipe section and a lower pipe section, and a groove is excavated axially on the cross-sectional surface of the lower pipe section so that the size of the groove matches the cross-sectional size of the reaction secondary beam. The reaction secondary beam is embedded in the groove, and the part of the reaction secondary beam that exceeds the length of the groove protrudes from the two side walls of the anchor pile. Finally, the upper pipe section is buckled into the cross-sectional surface of the lower pipe section, and the two are re-welded and fixed.

[0009] According to Clause 4.4.4 of GB 50017-2017, "Standard for the Design of Steel Structures," when the steel grade of a steel structure component is Q345, the ultimate tensile strength of the butt weld can be designed to reach 470 MPa. This joint provides sufficient strength to ensure the proper functioning of the reaction system and can replace existing tie rods, latches, and other components. Based on this theory, a larger anchor pile diameter and a longer circumferential butt weld between the upper and lower pipe sections can improve the overall tensile strength of the anchor pile.

[0010] Moreover, since the reaction secondary beam is embedded in the groove, the contact mode between the reaction secondary beam and the anchor pile is surface contact, and the force transmission efficiency between the two is higher under the stress state, thereby avoiding the occurrence of stress concentration.

[0011] Preferably, the upper pipe section and the lower pipe section are two parts cut and separated from the same hollow steel pipe, and the outer diameter and thickness of the two parts are the same.

[0012] Preferably, the upper pipe section and the lower pipe section are reinforced by pouring concrete inside.

[0013] Preferably, a first slope is formed on the edge of the cross-section of the lower pipe section; a second slope is formed on the edge of the cross-section of the upper pipe section; the first slope is symmetrical to the second slope, so as to increase the welding area.

[0014] Preferably, the first slope surface and the second slope surface are symmetrical stepped slope surfaces.

[0015] Preferably, the cross-sectional dimension of the groove is equal to the cross-sectional dimension of the reaction secondary beam.

[0016] Preferably, the anchor pile and the reaction secondary beam are perpendicular to each other.

[0017] The present invention also provides a static load test device, comprising a test main beam, a main beam connecting member, two reaction secondary beams, four anchor piles and a force measuring mechanism; the two ends of any reaction secondary beam are respectively connected to the two anchor piles, the two ends of the test main beam are respectively erected on the top surfaces of the two reaction secondary beams and fixed through the main beam connecting member, the force measuring mechanism is installed on the beam body of the test main beam and is used to detect the test piles; the two reaction secondary beams and the four anchor piles are the anchor piles and reaction secondary beams in the connection structure of the anchor piles and reaction secondary beams of the static load test described in any one of the above schemes.

[0018] Through the above solution, the present invention at least achieves the following technical effects:

[0019] This solution adopts the connection structure between the anchor pile and the reaction secondary beam in the above solution. When using large-diameter anchor piles, by dividing the anchor pile into an upper pipe section and a lower pipe section and then re-welding, the reaction secondary beam is embedded inside the anchor pile to enhance the stability of the reaction secondary beam and avoid shaking. At the same time, the contact area between the reaction secondary beam and the anchor pile is larger, and the stress-bearing area is also larger, which improves the force transmission efficiency and avoids stress concentration. The reaction structure mainly composed of this connection structure has higher tensile strength and stronger stability, enabling the static load test device to have a wider test range, being able to increase the upper limit of the force measurement, and obtaining more data.

[0020] Preferably, the force measurement mechanism is a jack.

[0021] The present invention also provides a test method for a static load test device, including the static load test device in the above solution, and further including the following steps:

[0022] S1: Measure the shape and size of the reaction secondary beam, and respectively mark and cut four anchor piles to form four lower pipe sections and four upper pipe sections;

[0023] S2: Open grooves on the cut surface of each lower pipe section, and make both ends of the grooves penetrate both sides of the lower pipe section;

[0024] S3: Grind the edges of the cut surface of the upper pipe section and the cut surface of the lower pipe section to form symmetric bevels;

[0025] S4: Connect two reaction secondary beams to four lower pipe sections respectively, and embed both ends of each reaction secondary beam into the grooves of two lower pipe sections;

[0026] S5: Cover the cut surfaces of the four upper pipe sections on the cut surfaces of the four lower pipe sections and weld them in place;

[0027] S6: Place the two ends of the test main beam on the top surfaces of two reaction secondary beams respectively, and connect and fix the test main beam to the two reaction secondary beams through main beam connectors;

[0028] S7: Connect the force measurement mechanism between the test main beam and the test pile, and conduct a compressive or tensile test on the test pile and collect data.

[0029] Through the above solution, the present invention at least achieves the following technical effects:

[0030] This solution is a test method for a static load test device, which mainly includes an operation method for the connection structure between the anchor pile and the reaction secondary beam in the static load test. First, cut the anchor pile according to the shape and size of the reaction secondary beam and groove the cut surface of the lower pipe section; then grind the edges of the cut surfaces of the upper and lower pipe sections to form bevels; after embedding the reaction secondary beam into the groove, butt and re-weld and fix the bevels of the upper and lower pipe sections. The operation method of this connection structure can replace the traditional anchor pile tie rod and pin with the strength of the butt weld. When the sizes of the anchor pile tie rod and pin cannot meet the requirements of large-diameter anchor piles, the butt weld can provide better tensile strength and force transmission efficiency than the anchor pile tie rod and pin.

[0031] At the same time, this solution also includes other measurement steps in the static load test, but the force measurement process and principle are too simple and will not be elaborated here.

[0032] The beneficial effects of the present invention are as follows: The butt weld between the upper and lower pipe sections of this connection structure provides tensile strength, the restraint effect of the groove on the reaction secondary beam improves the stability of the reaction secondary beam, the circumferential surface contact between the reaction secondary beam and the anchor pile increases the contact force-bearing area between the two and improves the force transmission efficiency, and avoids the stress concentration phenomenon. In particular, the test device using this connection structure can increase the upper limit of force measurement and obtain more data. Brief Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the overall structure of a static load test device provided by the present invention in an embodiment.

[0034] Figure 2 It is a schematic diagram of the connection structure between the anchor pile and the reaction secondary beam provided by the present invention in an embodiment.

[0035] Figure 3 It is a schematic diagram of the steps of anchor pile cutting and groove opening provided by the present invention in an embodiment.

[0036] Figure 4 It is a schematic diagram of the steps of connecting the anchor pile and the reaction secondary beam provided by the present invention in an embodiment.

[0037] Figure 5 It is a partially enlarged schematic diagram of the local structure where the first slope and the second slope are symmetric smooth inclined slopes provided by the present invention in an embodiment.

[0038] Figure 6 It is a partially enlarged schematic diagram of the local structure where the first slope and the second slope are symmetric stepped surfaces provided by the present invention in an embodiment.

[0039] Legend:

[0040] 1 Anchor pile; 2 Reaction secondary beam; 3 Test main beam; 4 Main beam connecting piece; 5 Force measuring mechanism;

[0041] 11 Upper pipe section; 12 Lower pipe section;

[0042] 41 Main beam tie rod; 42 Connecting beam;

[0043] 111 Second slope surface;

[0044] 121 Groove; 122 First slope surface. Specific implementation mode

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0046] Embodiment 1:

[0047] As Figures 1 - 5 shown, a connection structure between an anchor pile and a reaction secondary beam for a static load test includes an anchor pile 1 and a reaction secondary beam 2; the anchor pile 1 is a hollow steel pipe, which is cut into two parts, an upper pipe section 11 and a lower pipe section 12. A groove 121 is opened on the cross-section of the lower pipe section 12, so that the cross-sectional dimension of the groove 121 is equal to the cross-sectional dimension of the reaction secondary beam 2. The reaction secondary beam 2 is embedded in the groove 121, and the part of the reaction secondary beam 2 longer than the length of the groove 121 protrudes from both sides of the lower pipe section 12. The edges of the cross-section of the upper pipe section 11 and the cross-section of the lower pipe section 12 are polished to form an inclined and smooth first slope surface 122 and a second slope surface 111. The two slope surfaces are symmetrically formed into a butt weld with a triangular cross-section. The upper pipe section 11 and the lower pipe section 12 are reconnected by welding to realize the connection structure of embedding the reaction secondary beam 2 inside the anchor pile 1.

[0048] To further enhance the structural strength of the anchor pile 1, concrete is poured into the hollow steel pipe.

[0049] Since the static load test is to test the compressive and tensile properties of the side-view test pile, and most of them are vertical acting forces, and the connection structure between the reaction secondary beam 2 and the anchor pile 1, as a part of the reaction mechanism that plays a supporting role, needs to maintain the supporting effect on the longitudinal direction to avoid problems of tipping and tilting. Therefore, the anchor pile 1 is usually fixed to the ground and vertically arranged perpendicular to the ground, and the reaction secondary beam 2 is perpendicular to the anchor pile 1 to form a horizontal support structure. In this way, the reaction secondary beam 2 can provide a horizontal support surface for other structures to ensure that the force direction is vertically upward or downward and avoid tilting.

[0050] Embodiment 2:

[0051] As Figure 6As shown, the longer the butt weld length between the upper pipe section 11 and the lower pipe section 12, the greater the tensile strength it can provide. Similarly, appropriately increasing the width of the butt weld can also increase the tensile strength. In Embodiment 1, it is composed of two smooth inclined slopes, forming a butt weld with a triangular cross-section. To further increase the welding volume and enhance the tensile strength, in this embodiment, the first slope 122 and the second slope 111 in Embodiment 1 are replaced with a stepped shape, and the two slopes still remain symmetrical to each other. Other structures in Embodiment 1 remain unchanged.

[0052] The stepped slopes can form narrow seams in the inner layer for connection and fixation, and wide seams in the outer layer for large-area welding, increasing the volume of the welded structure and enhancing the tensile strength between the upper pipe section 11 and the lower pipe section 12.

[0053] Embodiment 3:

[0054] As Figures 1 - 6 shown, this embodiment provides a static load test device adopting the scheme of Embodiment 1 or Embodiment 2. The connection structure of the reaction secondary beam 2 and the anchor pile 1 in Embodiment 1 or Embodiment 2 is added to this embodiment, and the following scheme is obtained:

[0055] It includes a test main beam 3, main beam connectors 4, two reaction secondary beams 2, four anchor piles 1, and a force measuring mechanism 5; the two reaction secondary beams 2 and the four anchor piles 1 form a foundation support framework. The four anchor piles 1 are respectively fixedly installed at the four corners. The two reaction secondary beams 2 are horizontally installed on the four anchor piles 1 in parallel. The two ends of each reaction secondary beam 2 are connected to two anchor piles 1, and the connection method of the reaction secondary beam 2 and the anchor pile 1 is the scheme described in Embodiment 1 or Embodiment 2. The test main beam 3 is placed on the two reaction secondary beams 2 and fixed through the main beam connectors 4. A jack is fixed in the middle section of the main beam as the force measuring mechanism 5, which contacts the test pile to apply pressure or tension.

[0056] Among them, the main beam connector 4 includes four main beam tie rods 41 and four connecting beams 42; the test main beam 3 and the reaction secondary beam 2 are arranged perpendicular to each other in a "cross" shape. The four main beam tie rods 41 are respectively arranged at the four corners of the "cross" structure. Two connecting beams 42 are perpendicular to the test main beam 3 and connected to one end of the four main beam tie rods 41, and the other two connecting beams 42 are perpendicular to the reaction secondary beam 2 and connected to the other end of the four main beam tie rods 41, thus completing the connection and fixation of the test main beam 3 and the reaction secondary beam 2.

[0057] Embodiment 4:

[0058] As Figures 1 - 6 shown, this embodiment provides a test method for a static load test device, including the static load test device described in Embodiment 3, and further includes the following steps:

[0059] Step 1: Measure the shape and dimensions of the reaction secondary beam 2, and separately scribe and cut the four anchor piles 1 to form four lower pipe sections 12 and four upper pipe sections 11;

[0060] Step 2: Open grooves 121 on the cross-section of each lower pipe section 12, and make both ends of the groove 121 penetrate both sides of the lower pipe section 12;

[0061] Step 3: Grind the edges of the cross-section of the upper pipe section 11 and the cross-section of the lower pipe section 12 to form symmetric bevels;

[0062] Step 4: Connect the two reaction secondary beams 2 to the four lower pipe sections 12 respectively. Both ends of each reaction secondary beam 2 are respectively embedded in the grooves 121 of the two lower pipe sections 12;

[0063] Step 5: Cover the four upper pipe sections 11 on the cross-sections of the four lower pipe sections 12 respectively and weld them in place;

[0064] Step 6: Place both ends of the test main beam 3 on the top surfaces of the two reaction secondary beams 2 respectively, and connect and fix the test main beam 3 to the two reaction secondary beams 2 through the main beam connecting member 4;

[0065] Step 7: Connect the force measuring mechanism 5 between the test main beam 3 and the test pile, conduct a compressive or tensile test on the test pile and collect data.

[0066] It is worth mentioning that, as Figure 3 shown, during the actual operation process, to optimize the cutting step of the anchor pile 1, the splitting step of the upper pipe section 11 and the lower pipe section 12 is usually combined with the step of opening the groove 121. That is, after determining the position, shape and size of the groove 121 by scribing, cut the anchor pile 1 at one time, divide the anchor pile 1 into the lower pipe section 12 and the upper pipe section 11 with the part of the groove 121 removed, and then cut off the excess part protruding from the upper pipe section 11. This can simplify the cutting step and improve the experimental efficiency.

[0067] The various technical features in the above embodiments can be combined arbitrarily as long as there is no conflict or contradiction between the features. However, due to space limitations, they are not described one by one.

[0068] The present invention is not limited to the above embodiments. If various modifications or variations of the present invention do not depart from the spirit and scope of the present invention, and if these modifications and variations fall within the scope of the claims of the present invention and equivalent technical scope, then the present invention also intends to include these modifications and changes.

Claims

1. A static load test anchor pile and reaction secondary beam connection structure, characterized by: It includes an anchor pile and a reaction secondary beam; the anchor pile includes an upper pipe section and a lower pipe section, and the cross-sectional surface of the lower pipe section is provided with a groove; the two ends of the groove are connected to the opposite side walls of the lower pipe section; the reaction secondary beam is embedded in the groove; the upper pipe section is welded to the cross-sectional surface of the lower pipe section and the top opening of the groove is closed; the upper pipe section and the lower pipe section are two parts cut and separated from the same hollow steel pipe, and the outer diameter and thickness of the two parts are the same; the anchor pile and the reaction secondary beam are perpendicular to each other.

2. The anchor pile and reaction secondary beam connection structure for static load test according to claim 1 is characterized in that: The upper pipe section and the lower pipe section are reinforced by pouring concrete inside.

3. The anchor pile and reaction secondary beam connection structure for static load test according to claim 1, characterized in that: The edge of the cross-section of the lower pipe section is formed with a first slope; the edge of the cross-section of the upper pipe section is formed with a second slope; the first slope is symmetrical to the second slope, and is used to increase the welding area.

4. The anchor pile and reaction secondary beam connection structure for static load test according to claim 3 is characterized in that: The first slope surface and the second slope surface are symmetrical stepped slope surfaces.

5. The anchor pile and reaction secondary beam connection structure for static load test according to claim 1, characterized in that: The cross-sectional size of the groove is equal to the cross-sectional size of the reaction secondary beam.

6. A static load test device, characterized in that: It includes a test main beam, a main beam connector, two reaction secondary beams, four anchor piles and a force measuring mechanism; the two ends of any reaction secondary beam are respectively connected to the two anchor piles, the two ends of the test main beam are respectively erected on the top surfaces of the two reaction secondary beams and fixed through the main beam connector, and the force measuring mechanism is installed on the beam body of the test main beam and is used to detect the test piles; the two reaction secondary beams and the four anchor piles are the anchor piles and reaction secondary beams in the connection structure of the anchor piles and reaction secondary beams of the static load test as described in any one of claims 1-5.

7. The static load test device according to claim 6, characterized in that: The force measuring mechanism is a jack.

8. A test method for a static load test device, comprising the static load test device according to claim 6 or 7, characterized in that: The following steps are also included: S1: Measure the shape and size of the secondary reaction beam, and mark and cut the four anchor piles to form four lower pipe sections and four upper pipe sections; S2: A groove is formed on the cross-section of each lower pipe section, and the two ends of the groove pass through both sides of the lower pipe section; S3: Grind the cut edge of the upper pipe section and the cut edge of the lower pipe section to form a symmetrical groove; S4: Connect the two reaction secondary beams to the four lower pipe sections respectively, with both ends of each reaction secondary beam embedded in the grooves of the two lower pipe sections respectively; S5: Cover the four upper pipe sections on the cut surfaces of the four lower pipe sections respectively and weld them in place; S6: Place both ends of the test main beam on the top surfaces of the two reaction secondary beams, and connect and fix the test main beam to the two reaction secondary beams through the main beam connectors; S7: Connect the force measuring mechanism between the test main beam and the test pile, perform compression or pullout tests on the test pile and collect data.

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