Large-tonnage horizontal fatigue test loading system and construction method thereof

Abstract

The invention relates to the technical field of civil engineering, and discloses a large-tonnage horizontal fatigue test loading system which comprises a vertical fixed reaction wall and a ground anchor system located in the horizontal direction, and further comprises a reaction supporting device fixed above the ground anchor system and transversely opposite to the fixed reaction wall. The device comprises a vertical assembly and a transverse assembly which are respectively fixed on a ground anchor system, a loading actuator is fixedly arranged on a fixed reaction wall and faces the vertical assembly, and a test model to be tested is arranged between the vertical assembly and the loading actuator. The loading actuator, the fixed reaction wall, the transverse assembly and the vertical assembly jointly provide loading force in the horizontal direction for the test model. By arranging the cast-in-place reaction wall corresponding to the fixed reaction wall, the reaction beam, the steel strand and the loading actuator, a horizontal loading force is provided for the test model together, the large-tonnage horizontal fatigue loading test device is suitable for a large-tonnage horizontal fatigue loading test, the loading capacity is high, and the distortion degree of the adopted test model is small.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a large-tonnage horizontal fatigue test loading system and a construction method thereof. Background Art

[0002] Fatigue failure is one of the major engineering problems faced by civil engineering structures, especially steel structures or steel-concrete structures. Therefore, exploring the fatigue performance and fatigue failure mechanism of the above structures under cyclic loads and avoiding them is the most effective means to ensure that the structures meet the durability requirements.

[0003] With the improvement of infrastructure construction technology and the development of social economy in my country, infrastructure structures are constantly developing in the direction of lightness, complexity and large-scale. At the same time, materials, methods and processes are constantly innovating to adapt to the development of large and complex infrastructure. However, there is often no ready-made experience or specifications for reference in the design and construction of large and complex structures. Therefore, model testing has become the most effective means to explore the mechanical properties of large and complex structures.

[0004] However, for large structures such as cable-stayed bridge main beams, new composite columns of high-rise buildings, and new railway piers that mainly bear axial forces and have relatively small bending moments and shear forces, their geometric dimensions in the direction of force are much larger than their own cross-sectional dimensions, and the axial forces they bear are much larger than conventional structures. How to simulate the mechanical behavior of such structures under fatigue loads is still one of the technical difficulties faced by model tests.

[0005] The existing test equipment and technical level mainly have the following problems:

[0006] (1) The applicability of loading equipment is insufficient. For fatigue model tests, the actuator needs to be installed on a reaction device with greater rigidity, such as a vertical reaction frame or a laboratory fixed reaction wall. The most commonly used method is to perform vertical fatigue loading on the test model with the cooperation of a vertical reaction frame, such as fatigue testing of orthotropic steel bridge decks and railway track systems. However, the height of the vertical reaction frame is usually not large and is affected by the height of the laboratory floor. It is impossible to perform vertical loading on models whose geometric dimensions in the force direction are much larger than the cross-sectional dimensions.

[0007] (2) When vertical loading is applied to a test model whose geometric dimensions in the direction of force are much larger than its own cross-sectional dimensions, the pull-out resistance requirements for the foundation or reaction system are relatively high due to the large fatigue load amplitude on the large structure;

[0008] (3) When a triangular steel frame is used as a horizontal reaction device, the horizontal reaction force provided by the reaction device is limited and the manufacturing cost is high because the contact area between the steel frame and the laboratory floor is small. In addition, the contact area between the steel frame reaction device and the test model is also small, and the connection is unreliable.

[0009] (4) When the required loading force is reduced by using a small-scale model, the distortion of the model will be aggravated, which will greatly reduce the test effect.

[0010] In summary, providing a large-tonnage horizontal fatigue test loading system with high bearing capacity, good applicability, good economy and reliable connection is of great significance for loading large-scale structural test models subjected to large cyclic loads. Summary of the invention

[0011] The purpose of the present invention is to provide a large-tonnage horizontal fatigue test loading system and a construction method thereof. The test loading system has high bearing capacity, good applicability, good economy, and reliable connection, and can perform horizontal loading tests on large structural test models that are subjected to large cyclic loads.

[0012] The present invention provides the following technical solutions:

[0013] On the one hand, the present invention provides a large-tonnage horizontal fatigue test loading system, which includes an upright fixed reaction wall (6) and a ground anchor system (5) fixed to the fixed reaction wall (6) and located in the horizontal direction, and is characterized in that it also includes a reaction support device fixed above the ground anchor system (5) and laterally opposite to the fixed reaction wall (6), and the reaction support device is L-shaped, and includes a vertical component and a horizontal component respectively fixed to the ground anchor system (5), a loading actuator (7) is fixedly arranged on the fixed reaction wall (6) and faces the vertical component, and a test model (1) to be tested is installed between the vertical component and the loading actuator (7), and the loading actuator (7), the fixed reaction wall (6), the horizontal component and the vertical component jointly provide a horizontal loading force for the test model (1).

[0014] According to some embodiments, the vertical component includes a cast-in-place reaction wall (2) fixed above the ground anchor system (5) by second shear bolts (10) and embedded shear devices (11), and a plurality of the second shear bolts (10) are vertically inserted into the cast-in-place reaction wall (2); the embedded shear device (11) is fixedly connected to the bottom of the cast-in-place reaction wall (2) and the ground anchor system (5); the horizontal component includes a reaction beam (3) arranged between the cast-in-place reaction wall (2) and the fixed reaction wall (6), and the reaction beam (3) is fixed to the ground anchor system (5) by a plurality of first shear bolts (4); the reaction beam (3) is integrally cast or fixedly connected to the cast-in-place reaction wall (2); the reaction beam (3) is in contact with the fixed reaction wall (6); the maximum cross-sectional width or height of the reaction beam (3) is less than 1 / 2 of its length dimension.

[0015] In the above embodiments, the contact between the reaction beam and the anchor system can provide interface friction, and the shearing effect of the embedded shearing device provides part of the reaction force for the test model. According to some embodiments, multiple reaction beams can also be arranged to increase the contact area with the anchor system and improve its own bearing capacity.

[0016] According to some embodiments, the transverse assembly comprises a steel strand (9), and the steel strand (9) is arranged between the cast-in-place reaction wall (2) and the fixed reaction wall (6).

[0017] In the above-mentioned embodiment, the steel strand (9) provides a pre-stress for the reaction support device, and the direction of the pre-stress is opposite to the direction of the horizontal thrust applied by the loading actuator (7). Before the test begins, the pre-stress is stored in the reaction beam (3). During the test, the pre-stress can offset part or all of the horizontal thrust applied by the loading actuator (7).

[0018] According to some embodiments, the loading actuator (7) is fixed to the fixed reaction wall (6) via an anchoring device (13), and is fixedly connected to the test model (1) via a loading pad (12).

[0019] In the above-mentioned embodiment, the relative position of the loading actuator (7) and the test model (1) is determined by the characteristics of the internal force applied to the test model (1).

[0020] According to some embodiments, the cast-in-place reaction wall (2) is evenly and vertically provided with a plurality of first holes (2-1) for passing the second shear bolts (10), and is also evenly and horizontally provided with a plurality of transverse holes for passing the steel strands (9); the fixed reaction wall (6) is evenly and horizontally provided with a plurality of second holes (6-1) for fixing the anchoring device (13) or passing the steel strands (9); the ground anchor system (5) is evenly and staggeredly provided with vertical ground anchor holes (5-1) and transverse ground anchor grooves (5-2), and the vertical ground anchor holes (5-1) and the ground anchor grooves (5-2) are aligned with the second holes (6-1).

[0021] According to some embodiments, the steel strands (9) are in one or more bundles.

[0022] According to some embodiments, the reaction beam (3) is selected from a steel beam or a concrete beam. When the reaction beam (3) is selected from a steel beam, the reaction beam (3) is fixedly connected to the cast-in-place reaction wall (2) and can be reused. When the reaction beam (3) is selected from a concrete beam, the reaction beam (3) is cast together with the cast-in-place reaction wall (2) and can be removed together with the cast-in-place reaction wall (2) after the test.

[0023] According to some embodiments, the embedded shear resistor (11) is a solid or welded steel component.

[0024] According to some embodiments, the test model (1) is selected from a steel component, a concrete component or a steel-concrete composite component.

[0025] On the other hand, the present invention also provides a method for constructing the large-tonnage self-balancing test loading system as described above, which comprises the following steps:

[0026] S1: determining the position of the cast-in-place reaction wall (2) and the length of the reaction beam (3) according to the test model (1), the loading actuator (7), the loading pad (12) and the length of the anchoring device (13);

[0027] S2: Determine the installation height of the loading actuator (7) according to the test requirements, install the anchor device (13) on the fixed reaction wall (6) through the anchor bolts (8), and install the loading actuator (7) on the anchor device (13), then adjust the loading actuator (7) to a horizontal state, and then perform preliminary fixing;

[0028] S3: determining the height of the test model (1) from the ground according to the relative height between the test model (1) and the loading actuator (7), installing a bracket supporting the test model (1), and installing the test model (1) on the bracket or setting up a casting template for the test model (1);

[0029] S4: installing the embedded shear device (11) in the vertical anchor hole (5-1) of the anchor system (5), and then installing the second shear bolt (10) in the anchor channel (5-2) of the anchor system (5), so that the second shear bolt (10) is kept in a vertical state and protected and preliminarily fixed, and then installing the formwork and steel bars of the cast-in-place reaction wall (2), and reserving a transverse channel for the steel strand (9) to pass through;

[0030] S5: installing the first shear bolt (4) in the vertical anchor hole (5-1) of the anchor system (5), keeping the first shear bolt (4) in a vertical state and protecting and preliminarily fixing it, and then setting up the template of the reaction beam (3) and tying the steel bars;

[0031] S6: pouring concrete of the reaction beam (3) and the cast-in-place reaction wall (2) and performing curing;

[0032] S7: Passing the steel strand (9) through the cast-in-place reaction wall (2) and the fixed reaction wall (6) in sequence, and installing anchors at both ends of the steel strand (9);

[0033] S8: After the concrete of the reaction beam (3) and the cast-in-place reaction wall (2) reaches a certain strength, the first shear bolt (4), the second shear bolt (10), and the steel strand (9) are tightened in sequence;

[0034] S9: removing the support at the bottom of the test model (1), so that the deadweight of the test model (1) and the effects caused by it are completely borne by the cast-in-place reaction wall (2);

[0035] S10: connecting the loading actuator (7) to the loading pad (12) installed at the front end of the test model (1);

[0036] S11: installing and debugging the instrument, and performing horizontal large-tonnage fatigue test loading and / or static test loading on the test model (1) according to the test plan;

[0037] S12: After loading to a certain number of fatigue times, check the working conditions of the first shear bolt (4), the second shear bolt (10) and the steel strand (9), and if necessary, re-tighten the bolts or re-tension the steel strand.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The large-tonnage horizontal fatigue test loading system provided by the present invention provides a huge horizontal reaction force for the test model by setting a cast-in-place reaction wall, a reaction beam, a steel strand and a loading actuator corresponding to the fixed reaction wall, and is suitable for large-tonnage horizontal fatigue loading tests, has a strong loading capacity, and the test model used has a small degree of distortion. The cross-sectional dimension of the reaction beam is much smaller than the dimension in the length direction, which solves the problems of the inability to load the test model whose geometric dimension in the force direction is much larger than the cross-sectional dimension, insufficient loading capacity and high test cost in the existing test technology.

[0040] The present invention provides a large horizontal resistance for the test model by providing preload, downforce and shear bearing capacity. With the help of the existing reaction equipment in the laboratory, large-tonnage horizontal load loading can be achieved. The invention has strong loading capacity, simple installation, reusable parts, simple operation and good economy. It is suitable for indoor and outdoor horizontal loading model tests and meets the load conditions required by engineering practice and scientific research. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic structural diagram of a large-tonnage horizontal fatigue test loading system provided in an embodiment of the present invention.

[0042] Figure 2 for Figure 1 AA section view.

[0043] Figure 3 for Figure 1 BB cross-sectional view.

[0044] Figure 4 for Figure 1 CC cross-sectional view.

[0045] Figure 5 for Figure 1 DD cross-sectional view.

[0046] Figure 6 A layout diagram of anchor hole grooves for a ground anchor system and a fixed reaction wall provided in an embodiment of the present invention.

[0047] Figure 7 A large-scale drawing of the shear bolts provided in an embodiment of the present invention.

[0048] Figure 8 A large-scale drawing of the steel strand anchoring provided in an embodiment of the present invention.

[0049] In the figure:

[0050] Test model 1; cast-in-place reaction wall 2; first channel 2-1; reaction beam 3; first shear bolt 4; ground anchor system 5; ground anchor vertical anchor hole 5-1; ground anchor channel 5-2; fixed reaction wall 6; second channel 6-1; loading actuator 7; anchor bolt 8; steel strand 9; steel strand anchor pad 9-1; steel strand anchor 9-2; second shear bolt 10; embedded shear device 11; loading pad 12; anchoring device 13. DETAILED DESCRIPTION

[0051] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0052] The present invention will be further described below in conjunction with the accompanying drawings.

[0053] Example 1

[0054] like Figure 1As shown, this embodiment provides a large-tonnage horizontal fatigue test loading system. The test model 1 is a steel-concrete composite specimen. The test model 1 is installed between the cast-in-place reaction wall 2 and the loading actuator 7. The cast-in-place reaction wall 2 is anchored to the existing laboratory ground anchor system 5 through the second shear bolt 10 and the embedded shear device 11. The reaction beam 3 is installed between the cast-in-place reaction wall 2 and the fixed reaction wall 6; the loading actuator 7 is installed between the loading pad 12 and the anchor device 13. The anchor device 13 is anchored to the fixed reaction wall 6 through the anchor bolt 8. The loading pad 12 is installed at the end of the test model 1, and the two ends of multiple steel strands 9 are anchored to the outside of the cast-in-place reaction wall 2 and the fixed reaction wall 6. Figure 2 Two transverse reaction beams 3 are arranged above the anchor system 5. The reaction beams 3 are cast-in-place concrete components. The reaction beams 3 and the cast-in-place reaction wall 2 are cast at the same time to form an integral body. The other end of the reaction beam 3 is in close contact with the fixed reaction wall 6 but not connected. The loading actuator 7 can apply bending moment and axial force to the test model 1 at the same time. The bending moment is obtained by the eccentricity of the axial force.

[0055] Specifically:

[0056] like Figure 1 As shown, the cast-in-place reaction wall 2 is installed on the ground anchor system 5 through a plurality of vertically distributed second shear bolts 10 and embedded shear devices 11, as shown in FIG. Figure 2 A first transverse channel 2-1 is reserved on the cast-in-place reaction wall 2 for the steel strand 9 to pass through.

[0057] like Figure 1 The vertical pressure provided by the multiple rows of vertical second shear bolts 10 can generate huge downward pressure between the cast-in-place reaction wall 2 and the anchor system 5, preventing the cast-in-place reaction wall 2 from overturning under the action of the deadweight of the test model 1, and the friction caused by the downward pressure can prevent sliding between the cast-in-place reaction wall 2 and the anchor system 5.

[0058] like Figure 1 and Figure 3 As shown, the reaction beam 3 is anchored on the ground anchor system 5 by the first shear bolts 4 arranged at equal intervals. The first shear bolts 4 form multi-point constraints on the reaction beam 3, which can prevent the reaction beam 3 from being separated from the ground anchor system 5 and causing instability and damage. At the same time, the vertical pressure provided by the first shear bolts 4 can generate a huge downward pressure between the reaction beam 3 and the ground anchor system 5. The friction caused by the downward pressure is used to prevent sliding between the cast-in-place reaction wall 2 and the ground anchor system 5.

[0059] like Figure 2 The maximum width or height of the cross-sectional area of ​​the reaction beam 3 is less than 1 / 2 of its length dimension. The reaction beam 3 is cast together with the cast-in-place reaction wall 2 and the test model 1, and has good integrity. The design bearing capacity of the reaction beam 3 is equal to the cross-sectional area multiplied by the design strength, and the cross-sectional area is determined according to the tension force of the steel strand 9.

[0060] Before the test, the steel strands 9 will be tensioned, and the tensioning force generated by the steel strands 9 will be borne by the reaction beam 3, thereby ensuring that the net distance between the cast-in-place reaction wall 2 and the laboratory fixed reaction wall 6 remains unchanged.

[0061] The test model 1 is located directly above the anchor system 5, and the net distance between the test model 1 and the reaction beam 3 meets the test requirements, which is convenient for test personnel to install experimental equipment and test equipment.

[0062] like Figure 4 As shown, the fixed reaction wall 6 has a large horizontal stiffness and provides a huge horizontal thrust. A large number of transverse second holes 6-1 are regularly arranged at equal intervals thereon. The second holes 6-1 can be used for anchor bolts 8 or steel strands 9 to pass through for anchoring.

[0063] like Figure 5 and Figure 6 As shown, vertical anchor holes 5-1 and anchor channels 5-2 are arranged at equal intervals and staggered on the anchor system 5, and the plane positions of the vertical anchor holes 5-1 and the anchor channels 5-2 are aligned with the second channel 6-1 on the fixed reaction wall 6.

[0064] like Figure 7 As shown, the first shear bolt 4 and the second shear bolt 10 are both shear bolts, which include a shear screw and a nut and an anchor plate located on the shear screw. The anchor plate can disperse the pressure of the first shear bolt 4 and the second shear bolt 10 to the reaction beam 3 or the cast-in-place reaction wall 2 to prevent excessive local pressure on the concrete.

[0065] like Figure 8 As shown, both sides of the steel strand 9 are anchored between the cast-in-place reaction wall 2 and the fixed reaction wall 6 through steel strand anchor pads and steel strand anchors respectively. The steel strand anchor pads can disperse the pressure of the steel strand 9 to the fixed reaction wall 6 or the cast-in-place reaction wall 2 to prevent excessive local pressure on the concrete.

[0066] In addition, this embodiment also provides a method for constructing the large-tonnage self-balancing test loading system as described above, comprising the following steps:

[0067] S1: determining the position of the cast-in-place reaction wall (2) and the length of the reaction beam (3) according to the test model (1), the loading actuator (7), the loading pad (12) and the length of the anchoring device (13);

[0068] S2: Determine the installation height of the loading actuator (7) according to the test requirements, install the anchor device (13) on the fixed reaction wall (6) through the anchor bolts (8), and install the loading actuator (7) on the anchor device (13), then adjust the loading actuator (7) to a horizontal state, and then perform preliminary fixing;

[0069] S3: determining the height of the test model (1) from the ground according to the relative height between the test model (1) and the loading actuator (7), installing a bracket supporting the test model (1), and installing the test model (1) on the bracket or setting up a casting template for the test model (1);

[0070] S4: installing an embedded shear device (11) in the vertical anchor hole (5-1) of the anchor system (5), and then installing a second shear bolt (10) in the anchor channel (5-2) of the anchor system (5), so that the second shear bolt (10) is kept in a vertical state and protected and preliminarily fixed, and then installing the formwork and steel bars of the cast-in-place reaction wall (2), and reserving a transverse channel for the steel strand (9) to pass through;

[0071] S5: installing the first shear bolt (4) in the vertical anchor hole (5-1) of the anchor system (5), keeping the first shear bolt (4) in a vertical state and protecting and preliminarily fixing it, and then setting up the template of the reaction beam (3) and tying the steel bars;

[0072] S6: pouring concrete of the reaction beam (3) and the cast-in-place reaction wall (2) and performing curing;

[0073] S7: Passing the steel strand (9) through the cast-in-place reaction wall (2) and the fixed reaction wall (6) in sequence, and installing anchors at both ends of the steel strand (9);

[0074] S8: After the concrete of the reaction beam (3) and the cast-in-place reaction wall (2) reaches a certain strength, the first shear bolt (4), the second shear bolt (10), and the steel strand (9) are tightened in sequence;

[0075] S9: removing the support at the bottom of the test model (1), so that the deadweight of the test model (1) and the effects caused by it are completely borne by the cast-in-place reaction wall (2);

[0076] S10: connecting the loading actuator (7) to the loading pad (12) installed at the front end of the test model (1);

[0077] S11: installing and debugging the instrument, and performing horizontal large-tonnage fatigue test loading and / or static test loading on the test model (1) according to the test plan;

[0078] S12: After loading to a certain number of fatigue times, check the working conditions of the first shear bolt (4), the second shear bolt (10) and the steel strand (9), and if necessary, re-tighten the bolts or re-tension the steel strand.

[0079] In addition, there are some additional construction points.

[0080] 1. In the above construction process, the construction points of cast-in-place reaction wall 2 are supplemented as follows:

[0081] The cast-in-place reaction wall 2 is installed on the ground anchor system 5. Its geometric size is much smaller than that of the fixed reaction wall 6 and can be removed after the test is completed.

[0082] The dimension of the cast-in-place reaction wall 2 parallel to the fixed reaction wall 6 is determined according to the cross-sectional size of the test model 1, the dimension perpendicular to the fixed reaction wall 6 is determined according to the anti-overturning force, the height is determined according to the required gap between the test model 1 and the reaction beam 3, and the position is determined according to the model size and the position of the anchor hole on the ground anchor system 5.

[0083] The cast-in-place reaction wall 2 has vertical holes for the second shear bolts 10 to pass through, and horizontal holes for the steel strands 9 to pass through.

[0084] The embedded shearing device 11 needs to be inserted into the reserved anchor hole of the ground anchor system 5 in advance before pouring the cast-in-place reaction wall 2. The embedded shearing device 11 is used to resist the shear force on the contact surface between the cast-in-place reaction wall 2 and the ground anchor system 5.

[0085] After the second shear bolt 10 is tightened, a large downward pressure is provided to the cast-in-place reaction wall 2 , which prevents the test model 1 from overturning under the action of its own weight and generates friction between the cast-in-place reaction wall 2 and the anchor system 5 .

[0086] 2. In the above construction process, the construction points about the reaction beam 3 and the anchor system 5 are supplemented as follows:

[0087] The reaction beam 3 can be a steel beam or a concrete beam. When the reaction beam 3 is a concrete beam, it can be cast together with the cast-in-place reaction wall 2 to form a whole. When the reaction beam 3 is a steel beam, the cast-in-place reaction wall 2 is pre-embedded with bolts at the contact part with the reaction beam 3. The cast-in-place reaction wall 2 and the reaction beam 3 are connected by bolts, and the reaction beam 3 can be reused. The reaction beam 3 is used to bear the tension force generated by the transverse steel strand 9 and maintain the distance between the cast-in-place reaction wall 2 and the fixed reaction wall 6.

[0088] The length of the reaction beam 3 is determined by the distance between the cast-in-place reaction wall 2 and the fixed reaction wall 6. The number of the first shear bolts 4 is determined by the length of the reaction beam 3 and the spacing between the anchor holes on the ground anchor system 5.

[0089] The reaction beam 3 is only in close contact with the fixed reaction wall 6 but not connected thereto, and the reaction beam 3 only applies pressure to the fixed reaction wall 6 .

[0090] The reaction beam 3 is vertically reserved with holes for the first shear bolts 4 to pass through, and the spacing and number of the holes are determined by the spacing of the anchor holes on the ground anchor system 5 .

[0091] Anchor holes and anchor grooves for vertical anchoring are arranged in accordance with rules on the ground anchor system 5. The anchor holes for vertical anchoring can provide a certain amount of horizontal resistance.

[0092] The function of the first shear bolt 4 is to generate downward pressure between the reaction beam 3 and the anchor system 5 after being tightened to prevent the reaction beam 3 from becoming unstable after being compressed. The downward pressure causes friction at the interface between the reaction beam 3 and the anchor system 5.

[0093] The number of transverse steel strands 9 is determined according to the maximum horizontal force applied by the loading actuator 7. After the transverse steel strands 9 are tensioned, a pre-tightening force will be generated between the cast-in-place reaction wall 2, the reaction beam 3 and the fixed reaction wall 6. The pre-tightening force can be used to offset most or all of the horizontal force applied by the loading actuator 7. The first shear bolts 4 and the second shear bolts 10 are initially tightened to generate a small pre-pressure, and then the transverse steel strands 9 are tensioned. After the transverse steel strands 9 are tensioned, the first shear bolts 4 and the second shear bolts 10 are re-tightened into place.

[0094] The test model 1 is placed on the support in the early stage. After the construction of the cast-in-place reaction wall 2 is completed, the second shear bolt 10 is tightened, and then the support under the test model 1 can be removed.

[0095] 3. In the above construction process, the main points about the construction of the fixed reaction wall 6 are supplemented as follows:

[0096] The fixed reaction wall 6 is firmly installed in the test room and can be regarded as a rigid body, which can provide large horizontal and vertical reaction forces. Regularly arranged transverse anchor holes are reserved on it for the anchor bolts 8 and steel strands 9 to pass through.

[0097] The position of the transverse steel strand 9 is determined by the fixed anchor holes on the fixed reaction wall 6 .

[0098] The anchoring device 13 is firmly anchored on the fixed reaction wall 6 by means of anchor bolts 8 , the loading actuator 7 is mounted on the anchoring device 13 by means of bolts, and the fixed reaction wall 6 serves as a fixed reaction support device for the loading actuator 7 .

[0099] The loading actuator 7 is installed between the loading pad 12 and the anchor device 13, and can apply axial or eccentric tension or eccentric pressure to the test model 1. It can perform horizontal fatigue test loading or horizontal static test loading.

[0100] It is suitable for loading test models 1 of various materials and forming reliable connections. When the test model 1 is a steel component, a connecting plate can be embedded in the cast-in-place reaction wall 2, and the test model 1 is installed on the cast-in-place reaction wall 2 through the connecting plate. When the test model 1 is a concrete component or a steel-concrete combined component, the test model 1 is directly cast together with the cast-in-place reaction wall 2 to form a whole.

[0101] The inverted L-shaped device formed by the cast-in-place reaction wall 2 and the reaction beam 3 serves as a reaction support device for the test model 1, and the reaction support device is fixed to the anchor system 5 by the second shear bolt 10, the first shear bolt 4 and the embedded shear device 11. The horizontal force transmitted to the test model 1 by the loading actuator 7 is mainly resisted by the interface friction between the inverted L-shaped device formed by the cast-in-place reaction wall 2 and the reaction beam 3 and the anchor system 5, the preload generated by the steel strand 9, and the embedded shear device 11.

[0102] The number of the second shear bolts 10 is determined by the magnitude of the required friction force and the magnitude of the anti-overturning force.

[0103] Multiple bundles of steel strands 9 can be arranged in the horizontal and vertical directions, and the number of steel strands contained in a single bundle of steel strands 9 is determined by the diameter of the horizontal channel reserved in the fixed reaction wall 6.

[0104] The forces provided by the first shear bolt 4, the second shear bolt 10 and the steel strand 9 all have a large safety reserve, and during the test, they are re-tightened or re-tensioned at regular intervals to maintain their load-bearing state, so as to avoid fatigue loading causing obvious slippage between the inverted L-shaped device formed by the cast-in-place reaction wall 2 and the reaction beam 3 and the anchor system 5.

[0105] The embedded shear device 11 is a solid or welded steel component with a large shear bearing capacity. It can be taken out by dismantling the cast-in-place reaction wall 2 and can be reused many times. The embedded shear device 11 only plays a shearing role when obvious slippage occurs between the inverted L-shaped device formed by the cast-in-place reaction wall 2 and the reaction beam 3 and the ground anchor system 5.

[0106] By adjusting the distance between the cast-in-place reaction wall 2 and the fixed reaction wall 6 , the loading system can be suitable for loading test models 1 of different lengths.

[0107] The height of the test model 1 is determined by the relative position relationship between its free end and the loading actuator 7, the construction requirements and the test requirements. The test model 1 is selected from a variety of structures, such as steel beams, concrete beams, composite beams, etc. The steel beam cannot be cast together with the cast-in-place reaction wall 2, and can only be connected with the embedded steel structure.

[0108] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A large-tonnage horizontal fatigue test loading system, comprising an upright fixed reaction wall (6) and a ground anchor system (5) fixed to the fixed reaction wall (6) and located in a horizontal direction, characterized in that: The invention also comprises a reaction force support device fixed above the anchor system (5) and laterally opposite to the fixed reaction force wall (6); the reaction force support device is L-shaped and comprises a vertical component and a horizontal component respectively fixed to the anchor system (5); a loading actuator (7) is fixedly arranged on the fixed reaction force wall (6) and faces the vertical component; a test model (1) to be tested is installed between the vertical component and the loading actuator (7); the loading actuator (7), the fixed reaction force wall (6), the horizontal component and the vertical component jointly provide a horizontal loading force for the test model (1).

2. The large-tonnage horizontal fatigue test loading system according to claim 1 is characterized in that: The vertical assembly comprises a cast-in-place reaction wall (2) fixed to the top of the ground anchor system (5) by means of second shear bolts (10) and embedded shear devices (11), wherein a plurality of the second shear bolts (10) are vertically inserted into the cast-in-place reaction wall (2); the embedded shear device (11) is fixedly connected to the bottom of the cast-in-place reaction wall (2) and the ground anchor system (5); The transverse component comprises a reaction beam (3) arranged between the cast-in-place reaction wall (2) and the fixed reaction wall (6); the reaction beam (3) is fixed to the ground anchor system (5) via a plurality of first shear bolts (4); the reaction beam (3) is integrally cast or fixedly connected to the cast-in-place reaction wall; the reaction beam (3) is in contact with the fixed reaction wall (6); and the maximum cross-sectional width or height of the reaction beam (3) is less than 1 / 2 of its lengthwise dimension.

3. The large-tonnage horizontal fatigue test loading system according to claim 2 is characterized in that: The transverse component comprises a steel strand (9), and the steel strand (9) is arranged between the cast-in-place reaction wall (2) and the fixed reaction wall (6). The single stranded steel wire (9) comprises a plurality of stranded steel wires of standard sizes, and the number of stranded steel wires contained in the single stranded steel wire (9) is determined by the diameter of the transverse hole reserved in the laboratory fixed reaction wall (6).

4. The large-tonnage horizontal fatigue test loading system according to claim 3 is characterized by: The loading actuator (7) is fixed to the fixed reaction wall (6) via an anchoring device (13), and is fixedly connected to the test model (1) via a loading pad (12).

5. The large-tonnage horizontal fatigue test loading system according to claim 4 is characterized in that: The cast-in-place reaction wall (2) is evenly provided with a plurality of first holes (2-1) vertically for passing the second shear bolts (10), and a plurality of transverse holes for passing the steel strands (9) transversely; The fixed reaction wall (6) is uniformly provided laterally with a plurality of second holes (6-1) for fixing the anchoring device (13) or passing the steel strand (9); The ground anchor system (5) is evenly and alternately provided with vertical ground anchor holes (5-1) and transverse ground anchor grooves (5-2); the vertical ground anchor holes (5-1) and the ground anchor grooves (5-2) are aligned with the second hole (6-1).

6. The large-tonnage horizontal fatigue test loading system according to claim 3 is characterized by: The steel strands (9) are in one bundle or in multiple bundles.

7. The large-tonnage horizontal fatigue test loading system according to claim 2 is characterized in that: The reaction beam (3) is selected from a steel beam or a concrete beam.

8. The large-tonnage horizontal fatigue test loading system according to claim 2 is characterized by: The embedded shear resister (11) is a solid or welded steel component.

9. The large-tonnage horizontal fatigue test loading system according to claim 1, characterized in that: The test model (1) is selected from a steel component, a concrete component or a steel-concrete composite component.

10. A method for constructing a large-tonnage self-balancing test loading system as claimed in claim 5, characterized in that: The steps include: S1: determining the position of the cast-in-place reaction wall (2) and the length of the reaction beam (3) according to the test model (1), the loading actuator (7), the loading pad (12) and the length of the anchoring device (13); S2: Determine the installation height of the loading actuator (7) according to the test requirements, install the anchor device (13) on the fixed reaction wall (6) through the anchor bolts (8), and install the loading actuator (7) on the anchor device (13), then adjust the loading actuator (7) to a horizontal state, and then perform preliminary fixing; S3: determining the height of the test model (1) from the ground according to the relative height between the test model (1) and the loading actuator (7), installing a bracket supporting the test model (1), and installing the test model (1) on the bracket or setting up a casting template for the test model (1); S4: installing the embedded shear device (11) in the vertical anchor hole (5-1) of the anchor system (5), and then installing the second shear bolt (10) in the anchor channel (5-2) of the anchor system (5), so that the second shear bolt (10) is kept in a vertical state and protected and preliminarily fixed, and then installing the formwork and steel bars of the cast-in-place reaction wall (2), and reserving a transverse channel for the steel strand (9) to pass through; S5: installing the first shear bolt (4) in the vertical anchor hole (5-1) of the anchor system (5), keeping the first shear bolt (4) in a vertical state and protecting and preliminarily fixing it, and then setting up the template of the reaction beam (3) and tying the steel bars; S6: pouring concrete of the reaction beam (3) and the cast-in-place reaction wall (2) and performing curing; S7: Passing the steel strand (9) through the cast-in-place reaction wall (2) and the fixed reaction wall (6) in sequence, and installing anchors at both ends of the steel strand (9); S8: After the concrete of the reaction beam (3) and the cast-in-place reaction wall (2) reaches a certain strength, the first shear bolt (4), the second shear bolt (10), and the steel strand (9) are tightened in sequence; S9: removing the support at the bottom of the test model (1), so that the deadweight of the test model (1) and the effects caused by it are completely borne by the cast-in-place reaction wall (2); S10: connecting the loading actuator (7) to the loading pad (12) installed at the front end of the test model (1); S11: installing and debugging the instrument, and performing horizontal large-tonnage fatigue test loading and / or static test loading on the test model (1) according to the test plan; S12: After loading to a certain number of fatigue times, check the working conditions of the first shear bolt (4), the second shear bolt (10) and the steel strand (9), and if necessary, re-tighten the bolts or re-tension the steel strand.

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