A pseudo-static seismic test device for building structures

Abstract

The present invention provides a pseudo-static seismic test device for building structures, including a column cap. The column cap is installed at the top of a column serving as a test piece and is composed of a square main body and four peripheral side plates located on the peripheral sides of the square main body, wherein the four peripheral side plates have the same thickness. The device also includes a plurality of bolts, and the plurality of bolts are all screwed into the column cap from the peripheral side plates in a threaded fit manner. The end of the bolt screwed into the column cap abuts against the side surface of the column or abuts against a steel plate attached to the side surface of the column, so as to fixedly position and connect the column cap with the top end of the column. The horizontal displacement limitation of the column cap is realized by using a horizontal displacement limitation component. The column cap and the horizontal displacement limitation structure of the column are improved, with simple structure, convenient installation, more reasonable force, and no problem of buckling of compression bars.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering building structure test equipment, and particularly relates to a pseudo-static seismic test device for building structures. Background Art

[0002] The pseudo-static test, also known as the low-cycle repeated load test, is a static test that applies multiple reciprocating cyclic actions to building structures or components in the field of civil engineering. In the pseudo-static test, the loading device often includes a reaction wall, a reaction frame, a jack for applying the vertical load of the structure, an electro-hydraulic servo actuator for applying the reciprocating loading and unloading of the structure, and some fixed connection devices. Among them, in order to ensure that the boundary conditions of the columns in the structural test are the same as those in the actual building, the columns generally take the distance between the inflection points of two structural layers, and often a scale-down design is also carried out. A scaled-down component model of the column is used for pseudo-static test research. In order to ensure that only rotation occurs at the top of the column (i.e., the inflection point), in addition to applying axial compression at the top of the column, horizontal supports also need to be set on the sides of the column to limit the horizontal displacement of the column end.

[0003] Currently, when applying the horizontal displacement limit at the column end in the pseudo-static seismic test device, basically steel beams or rigid frames with large weight and volume are used for rigid connection with the column end, which has many inconveniences during the test: (1) The steel beams or rigid frames are large in weight and volume, inconvenient to install and occupy a large space, making the space of the column end connection device narrow and inconvenient for the test personnel to pass through, and also inconvenient for the arrangement of measuring instruments; (2) The connection and installation between the steel beam or rigid frame and the column cap are relatively cumbersome, affecting the test cycle and increasing the test cost; (3) The steel beam or rigid frame, as a compression bar, applies pressure to both sides of the column, and there is a problem of buckling of the compression bar. Summary of the Invention

[0004] Based on the above technical status quo, the purpose of the present invention is to provide a pseudo-static seismic test device for building structures, which improves the column cap and the horizontal displacement limiting structure of the column, has a simple structure, is convenient to install, has a more reasonable force, and does not have the problem of buckling of the compression bar.

[0005] The technical solution adopted by the present invention is as follows: A pseudo-static seismic test device for building structures includes a column cap, which is installed at the top end of a column serving as a test piece. It consists of a square main body and four peripheral side plates located on the peripheral sides of the square main body. The thicknesses of the four peripheral side plates are the same. After the column cap is installed at the top end of the column, there is a certain gap between the side surface of the column top and the inner surface of the peripheral side plate of the column cap, that is, the internal dimension of the column cap is larger than the cross-sectional contour dimension of the column, so that the column cap can be applicable to columns of different sizes; it also includes a plurality of bolts, and the plurality of bolts are all screwed into the inside of the column cap in a threaded fit from the peripheral side plates. The end of the bolt screwed into the column cap abuts against the side surface of the column or abuts against a steel plate attached to the side surface of the column to fixedly position and connect the column cap and the top end of the column; the horizontal displacement limitation of the column cap is realized by using a horizontal displacement limitation component.

[0006] A circular groove is provided on the upper end surface of the square main body of the column cap, and a spherical hinge support is installed in the circular groove. The upper part of the spherical hinge support is connected with a jack connection end plate, and the jack connection end plate is fixedly connected with a jack. The jack is used to apply an axial pressure to fix the column on the reaction frame. The upper end of the jack is installed on the top cross beam of the reaction frame. Specifically, the reaction frame consists of a ground beam pedestal at the bottom, a top cross beam at the upper part, and columns on both sides. The bottom ends of the columns are fixedly installed with the ends of the ground beam pedestal, and the upper ends of the columns are fixedly connected with the ends of the top cross beam. The column is vertically fixedly installed on the ground beam pedestal. A horizontal sliding support is installed below the top cross beam, and the upper end of the jack is fixedly installed on the horizontal sliding support, and the horizontal sliding support is used to adjust the lateral position of the jack.

[0007] A connecting plate is also installed between the jack connection end plate and the spherical hinge support. Square grooves are provided on both the upper and lower surfaces of the connecting plate. The jack connection end plate is accommodated in the square groove on the upper surface of the connecting plate, and the spherical hinge support is accommodated in the square groove on the lower surface of the connecting plate. Limitation is carried out through the coaxial square grooves on the upper and lower surfaces to realize the coaxial connection of the jack connection end plate, the connecting plate and the spherical hinge support, so as to vertically transmit the axial pressure of the jack to the column.

[0008] Further, a plurality of through holes are uniformly distributed on the peripheral side plates, and a nut is fixedly installed at the position corresponding to each through hole. The nut is in threaded fit with the bolt; or, a plurality of threaded holes are uniformly distributed on the peripheral side plates. The threaded holes on the peripheral side plates are in threaded fit with the bolts, and the end of the lead screw is screwed into the column cap in a threaded fit to realize the connection between the column cap and the lead screw.

[0009] The horizontal displacement limiting component includes a lead screw and a tension pre-tightening member. One end of the tension pre-tightening member is threadedly connected to one end of the lead screw, and the other end of the tension pre-tightening member is fixedly connected to the reaction frame of the pseudo-static seismic test device. The other end of the lead screw is fixedly connected to the column cap of the pseudo-static seismic test device. By adjusting the tension pre-tightening member, the horizontal displacement limiting component applies tension between the reaction frame and the column cap. One or more of the same number of the horizontal displacement limiting components can be distributed on both sides of the column cap, and different numbers of horizontal displacement limiting components are selected according to the binding force required by the test to achieve the displacement limitation of the column cap in the horizontal direction.

[0010] The tension pre-tightening member is a type of flower basket structure with axial threaded holes at both ends. One end of the lead screw is threadedly inserted into the threaded hole at one end of the tension pre-tightening member. A short screw rod is threadedly installed in the threaded hole at the other end of the tension pre-tightening member, and the short screw rod is connected to the reaction frame; a pull ring is provided at the end of the short screw rod away from the lead screw, and a rigid rod is installed on the reaction frame, and the rigid rod passes through the inner hole of the pull ring to install and connect the pull ring to the reaction frame.

[0011] The advantages of the technical solution of the present invention are as follows:

[0012] (1) It overcomes the shortcoming of the heavy horizontal restraint support in the existing structural tests. It adopts the design of connecting the column cap with threaded sides to the reaction frame through high-strength lead screws. At the same time, a detachable spherical hinge support is designed at the upper end of the column cap, and nuts (threaded holes) for screwing in high-strength bolts are designed on the side to match columns with different cross-sections, realizing the reusable of the support and the column cap;

[0013] (2) It breaks through the traditional concept limitation, uses the internal tension of the limiting rod to balance the moment transmitted to the column end during pseudo-static loading, thereby realizing the restraint of the horizontal degree of freedom at the column end, and overcoming the problem of buckling of the compression bar when the steel beam or rigid frame applies pressure to both sides of the column as a compression bar;

[0014] (3) It uses lightweight and high-strength materials, the structure is reasonably stressed, and the threaded connection is more convenient for disassembly and assembly, greatly shortening the test period and saving the test cost. It is not only applicable to the low-cycle reciprocating load test of frame joints with beam-end loading, but also can be used in the loading tests of composite structure columns, steel structure trusses, and masonry structures, and has high versatility. Brief Description of the Drawings

[0015] Figure 1 is the overall structural schematic diagram of the pseudo-static seismic test device of the present invention;

[0016] Figure 2 is the structural schematic diagram of the horizontal displacement limiting component of the pseudo-static seismic test device of the present invention;

[0017] Figure 3It is a schematic diagram of the unilateral enlarged state of the horizontal displacement limiting component of the pseudo-static seismic test device of the present invention;

[0018] In the figure: 1. Horizontal sliding support, 2. Reaction frame, 3. Jack, 4. Tensile pre-tightening part, 5. High-strength rigid rod, 6. Locking nut, 7. Lead screw, 8. Column cap, 8-1. Jack connection end plate, 8-2. Spherical hinge support, 8-3. Nut, 8-4. Bolt, 8-5. Connecting plate. Specific implementation mode

[0019] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0020] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. are for simplified description and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "plurality" is two or more.

[0021] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Such as Figure 1As shown in the figure, it is the overall structural schematic diagram of the pseudo-static seismic test device of the present invention. The pseudo-static seismic test device for building structures of the present invention includes a reaction frame 2 serving as a test bench. The reaction frame 2 is composed of a ground beam bench at the bottom, a top cross beam at the upper part, and columns on both sides. The bottom ends of the columns are fixedly installed at the ends of the ground beam bench, and the upper ends of the columns are fixedly connected to the ends of the top cross beam. The column serving as the test piece is vertically fixedly installed on the ground beam bench of the reaction frame 2. A horizontal sliding support 1 is installed below the top cross beam, and a jack 3 is installed through the horizontal sliding support 1. The jack 3 provides a vertically downward pressure, and the horizontal sliding support 1 is used to adjust the lateral position of the jack 3 to correspond to the installation position of the column below.

[0023] The pseudo-static seismic test device further includes a column cap 8. The column cap 8 is installed at the top of the column. In the present invention, the column cap 8 is a cap shell structure composed of steel plates, which is composed of a square main body and four peripheral side plates located on the four side surfaces of the square main body. The thicknesses of the four peripheral side plates are the same. After the column cap is installed at the top of the column, there is a certain gap between the side surface of the column top and the inner surface of the peripheral side plate of the column cap 8, that is, the internal dimension of the column cap 8 is larger than the cross-sectional contour dimension of the column, so that the column cap 8 can be applicable to columns of different sizes. A plurality of through holes are provided on the four peripheral side plates of the column cap 8, and a nut 8-3 is fixedly welded corresponding to each through hole. The bolt 8-4 is screwed into the through hole in cooperation with the nut 8-3 until it abuts against the side surface of the column, so as to fixedly install the column cap 8 at the top of the column. Preferably, a steel plate suitable for the size of the gap is placed in the gap between the inner surface of the peripheral side plate and the side surface of the column top. After the bolt 8-4 is screwed into the column cap 8, it abuts against the steel plate and presses the steel plate against the side surface of the column top to realize the fixed installation of the column cap and the column. In another embodiment, the through holes on the peripheral side plate are opened as threaded holes, and the bolt 8-4 is screwed into the threaded hole in a threaded fit to realize the fixed installation of the column cap and the column, so that the welding work of the nut 8-3 can be omitted.

[0024] A circular groove is provided on the upper end surface of the square main body of the column cap 8. The circular groove is used for positioning and installing a spherical hinge support 8-2. The upper part of the spherical hinge support 8-2 is connected with a jack connection end plate 8-1. The lower end of the jack 3 is fixedly connected with the jack connection end plate 8-1. A connecting plate 8-5 for auxiliary positioning is further installed between the jack connection end plate 8-1 and the spherical hinge support 8-2. Square grooves are provided on both the upper and lower sides of the connecting plate 8-5, and the sizes of the square grooves correspond to the end plate sizes of the jack connection end plate 8-1 and the spherical hinge support 8-2 respectively, that is, the jack connection end plate 8-1 is positioned on the upper end surface of the connecting plate 8-5 through the groove, and the end plate of the spherical hinge support 8-2 is positioned on the lower end surface of the connecting plate 8-5, so that the jack, the jack connection end plate 8-1, the connecting plate 8-5 and the spherical hinge support 8-2 are coaxially connected together by the axial pressure of the jack 3, and horizontal misalignment is ensured not to occur under the action of horizontal load.

[0025] The side of the column cap 8 and the two side columns are provided with horizontal displacement limit components to limit the horizontal displacement of the top of the column. See Figure 2 and Figure 3 , which are respectively the structural schematic diagram of the horizontal displacement limit component of the pseudo-static seismic test device of the present invention and the unilateral enlarged state schematic diagram of the horizontal displacement limit component of the pseudo-static seismic test device of the present invention. The horizontal displacement limit component includes a lead screw 7 and a tension pre-tightening member 4. The tension pre-tightening member 4 is a type of flower basket structure with axial threaded holes at both ends. One end of the tension pre-tightening member 4 is threadedly connected to one end of the lead screw 7, and the other end of the tension pre-tightening member 4 is fixedly connected to the column of the reaction frame 2 through a short screw. The other end of the lead screw 7 is fixedly connected to the side of the column cap 8. When using tools such as crowbars to rotate the tension pre-tightening member 4, the threaded engagement or disengagement of the lead screw 7 and the short screw can be adjusted, and the pre-tightening tension applied by the tension pre-tightening member 4 to the lead screw 7 can be adjusted, so as to rely on the tension of the lead screws 7 on both sides of the column cap 8 to limit the horizontal displacement of the column cap 8. Each lead screw 7 and a tension pre-tightening member 4 cooperate to provide a tension. According to the binding force required for the test, different numbers of lead screws 7 can be selected. In the illustrated embodiment, it shows the situation where four lead screws 7 are installed on each side of the column cap 8 to provide tension. In other embodiments, the tension pre-tightening member 4 can also adopt other structures that can change the total length of the combination of the lead screw 7 and the tension pre-tightening member 4.

[0026] See Figure 3 , a pull ring is provided at the end of the tension pre-tightening member 4, bolt holes are provided on the column of the reaction frame 2, a high-strength rigid rod 5 is installed in the bolt holes of the column, both ends of the high-strength rigid rod 5 are positioned by locking nuts 6, and the high-strength rigid rod 5 passes through the pull ring at the end of the tension pre-tightening member 4 to realize the fixed connection between the horizontal displacement limit component and the reaction frame 2. Specifically, the inner diameter of the pull ring is larger than the diameter of the high-strength rigid rod 5, so that the high-strength rigid rod 5 absolutely does not contact the side close to the column cap 8 in the inner hole of the pull ring, that is, the lead screw 7 provides tension between the column cap 8 and the reaction frame 2, and there will be no pressure caused by the high-strength rigid rod, and there is no problem of buckling of the compression bar that restricts the horizontal displacement of the column cap due to pressure. The structure of the column cap 8 of the present invention can enable the end of the lead screw 7 connected to the column cap 8 to be directly screwed into the threaded hole or nut 8-3 on the circumferential side of the column cap 8 to realize the connection between the lead screw 7 and the column cap 8.

[0027] See Figure 1, like a conventional pseudo-static seismic test device, a middle joint specimen is also provided at the middle position of the column. The two sides of the middle joint specimen are respectively supported and installed on the ground beam pedestal through wire displacement gauges, and measuring tools are installed for the entire seismic test device. This is not related to the main improvement points and inventive concepts of the present invention (i.e., the structure of the column cap and the structure of the horizontal displacement limiting component), so it will not be elaborated here.

[0028] In the technical solution of the present invention, nuts, screws, tension pre-tightening parts 4, pull rings, especially the lead screw 7 and the high-strength rigid rod 5 are all made of high-strength steel materials with resistance to flexure and stretching to meet the mechanical property requirements of the pseudo-static test. The following will be combined with Figures 1-3 The installation and use of the pseudo-static seismic test device of the present invention are further introduced as follows:

[0029] S1: After the test component is hoisted and positioned, install the column cap 8 on the top of the column. At this time, the column cap contacts the upper part of the column, and there is a certain gap on the side. Screw the bolt 8-4 into the nut 8-3 welded on the column cap 8, and place steel plates in the gap between the column and the column cap inside the column cap, so that the bolt 8-4 screwed into the column cap 8 presses it against the column to complete the positioning installation of the column cap 8 and the column, and install all the bolts 8-4. For columns of different test sizes, just change the thickness of the built-in steel plate to firmly connect the column cap 8 and the column through the screwed bolts 8-4.

[0030] S2: Install the spherical hinge bearing 8-2 into the circular groove reserved in the square main body of the column cap. After the jack 3 is connected and the position is adjusted through the horizontal sliding support 1, connect the jack connecting end plate 8-1 to the spherical hinge bearing 8-2, and then use the jack 3 to apply axial pressure to fix the column on the reaction frame 2.

[0031] S3: Connect one end of the lead screw 7 tightly to the column cap 8, connect the other end of the lead screw 7 to the tension pre-tightening part 4, and connect the tension pre-tightening part 4 to the reaction frame 2 through a pull ring in cooperation with the high-strength rigid rod 5. The positions of both ends of the high-strength rigid rod 5 and the reaction frame 2 are fixed by locking nuts 6.

[0032] S4: Use a crowbar to apply a pre-tightening force to the tension pre-tightening part 4 to ensure that sufficient horizontal restraint forces can be received at both ends of the column cap during the test loading process.

[0033] Although the specific implementation manners of the present invention are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solution of the present invention, various equivalent structural or equivalent process modifications or deformations that can be made by those skilled in the art without creative labor, or directly or indirectly applied to other related technical fields, are still within the protection scope of the present invention.

Claims

1. A horizontal displacement limiting component for a pseudo-static seismic test device of a building structure, characterized in that, It includes a lead screw and a tension pre-tightening member. One end of the tension pre-tightening member is in threaded fit connection with one end of the lead screw, and the other end of the tension pre-tightening member is fixedly connected to the reaction frame of the pseudo-static seismic test device. The other end of the lead screw is fixedly connected to the column cap of the pseudo-static seismic test device. By adjusting the tension pre-tightening member, a pre-tightening tension is applied between the reaction frame and the column cap by the horizontal displacement limiting assembly; The tension pre-tightening member is a type of flower basket structure with axial threaded holes provided at both ends. One end of the lead screw is threadedly fitted and extends into the threaded hole at one end of the tension pre-tightening member. A short screw rod is threadedly installed in the threaded hole at the other end of the tension pre-tightening member, and the short screw rod is connected to the reaction frame.

2. The horizontal displacement limiting component according to claim 1, further characterized in that, A pull ring is provided at the end of the short screw rod away from the lead screw. A rigid rod is installed on the reaction frame, and the rigid rod passes through the inner hole of the pull ring to install and connect the pull ring to the reaction frame.

3. A pseudo-static seismic test device for a building structure, including a column cap. The column cap is installed at the top end of a column serving as a test piece. It consists of a square main body and four peripheral side plates located on the four side surfaces of the square main body, and the thicknesses of the four peripheral side plates are the same. It also includes a plurality of bolts. The plurality of bolts are all threadedly screwed into the column cap from the peripheral side plates. The end of the bolt screwed into the column cap abuts against the side surface of the column or abuts against a steel plate attached to the side surface of the column to fixedly position and connect the column cap to the top end of the column. The horizontal displacement limitation of the column cap is achieved by using the horizontal displacement limiting assembly as described in claim 1 or 2.

4. The pseudo-static seismic test device for building structures according to claim 3, further characterized in that, A circular groove is provided on the upper end surface of the square main body of the column cap. A spherical hinge support is installed in the circular groove. An end plate for connecting a jack is connected to the upper part of the spherical hinge support. The end plate for connecting a jack is fixedly connected to the jack. The jack is used to apply an axial pressure to fix the column to the reaction frame.

5. The pseudo-static seismic test device for building structures according to claim 3, further characterized in that, A plurality of through holes are evenly distributed on the peripheral side plates, and a nut is fixedly installed at the position corresponding to each through hole. The nut is in threaded fit with the bolt.

6. The pseudo-static seismic test device for building structures according to claim 3, further characterized in that, A plurality of threaded holes are evenly distributed on the peripheral side plates, and the threaded holes on the peripheral side plates are in threaded fit with the bolts.

7. The pseudo-static seismic test device for building structures according to claim 5 or 6, further characterized in that, The end of the lead screw is threadedly screwed into the column cap to achieve the connection between the column cap and the lead screw.

8. The pseudo-static seismic test device for building structures according to claim 4, further characterized in that, The reaction frame consists of a ground beam pedestal at the bottom, a top cross beam at the upper part, and columns on both sides. The bottom ends of the columns are fixedly installed at the ends of the ground beam pedestal, and the upper ends of the columns are fixedly connected to the ends of the top cross beam. The column is vertically fixedly installed on the ground beam pedestal. A horizontal sliding support is installed below the top cross beam. The upper end of the jack is fixedly installed on the horizontal sliding support, and the horizontal sliding support is used to adjust the lateral position of the jack.

9. The pseudo-static seismic test device for building structures according to claim 4 or 8, further characterized in that, A connecting plate is further installed between the end plate for connecting a jack and the spherical hinge support. Square grooves are provided on both the upper and lower surfaces of the connecting plate. The end plate for connecting a jack is accommodated in the square groove on the upper surface of the connecting plate, and the spherical hinge support is accommodated in the square groove on the lower surface of the connecting plate.

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