A test device and method for field bearing performance test of small and medium span bridges

Abstract

The application discloses a kind of test device and testing method for small and medium span bridge field bearing performance test.It relates to the technical field of bridge engineering, including: counter-force beam, bottom is equipped with lower anchor beam, both ends of lower anchor beam are arranged on counter-force beam by lower anchor beam anchoring device, the top of counter-force beam is provided with support beam, the top of each support beam is equipped with hinged support;Positioning beam is arranged on counter-force beam;Test beam is arranged on hinged support, and loading distribution beam is arranged on test beam;Loading anchoring beam is arranged above loading distribution beam, loading jack is arranged between each loading anchoring beam and loading distribution beam, and both ends of each loading anchoring beam are equipped with loading anchoring beam anchoring device;The fine rolled threaded steel bar is sequentially connected with loading anchoring beam anchoring device, positioning beam anchoring device and lower anchor beam anchoring device.The application is suitable for the device and method for quickly testing the bearing capacity of the old beam to be demolished, the beam to be used after reinforcement and the newly produced beam body on the construction site.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bridge engineering, and more particularly to a test device and a test method for testing the bearing performance of a small and medium span bridge on site. BACKGROUND

[0002] Since the 1990s, precast assembly hollow slab, T-beam and small box girder have been widely used in highway bridges due to their high assembly degree and fast construction speed, and the Ministry of Transport and many provinces have issued general structural design drawings to promote the development of precast assembly concrete bridges. In recent years, the problem of insufficient bearing performance has become increasingly apparent due to the low design load, low construction quality and immature construction technology of the early built assembly hollow slab, T-beam and small box girder. With the continuous advancement of highway reconstruction and expansion projects, the bearing performance of bridges designed according to the old specifications is involved in the problem of bearing performance improvement. In order to determine the specific bearing capacity of the bridges that have been in service for many years, it is necessary to evaluate the bearing capacity of the old beams removed during the reconstruction and expansion process and determine whether they can continue to be used after reinforcement. Similarly, the reinforcement effect of different reinforcement processes also needs to be verified through tests.

[0003] The common test methods at present are to carry out elastic load tests or to transport the removed small span beams to nearby structural laboratories for tests. However, the elastic load test cannot reflect the actual bearing state of the bridge, the laboratory test is greatly limited by transportation conditions, and the transportation cost and risk are increased.

[0004] Therefore, how to provide a test device and a test method for testing the bearing performance of a small and medium span bridge on site, which can fully consider the on-site construction, loading and testing conditions, but will not greatly increase the test cost and can quickly carry out the test, is a problem that needs to be solved by those skilled in the art. SUMMARY

[0005] Therefore, the present application provides a test device and a test method for testing the bearing performance of a small and medium span bridge on site, which can fully consider the on-site construction, loading and testing conditions, but will not greatly increase the test cost and can quickly carry out the test.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A test device for testing the bearing performance of a small and medium span bridge on site, comprising:

[0008] Counterforce beams, two of which are arranged side by side, the bottom of the counterforce beams being provided with lower anchor beams, two of which are arranged at intervals, both ends of each lower anchor beam being arranged below the two counterforce beams through lower anchor beam anchoring devices arranged at both ends of the lower anchor beams, the top of the counterforce beams being provided with support beams, two of which are arranged at intervals, the top of each support beam being provided with a hinged support;

[0009] Positioning beams, two of which are arranged at intervals on the counterforce beams and are pressed between the top surface of the counterforce beams through positioning beam anchoring devices;

[0010] Test beams, which are arranged on the hinged supports and are provided with load distribution beams;

[0011] Loading anchor beams, two of which are arranged at intervals above the load distribution beams, each of which is provided with a loading jack between the loading anchor beam and the load distribution beam, and both ends of each loading anchor beam are provided with loading anchor beam anchoring devices;

[0012] Finely rolled threaded steel bars, which are sequentially connected to the loading anchor beam anchoring devices, the positioning beam anchoring devices and the lower anchor beam anchoring devices.

[0013] Further, the lower anchor beams, the positioning beams and the loading anchor beams are arranged at intervals along the axial direction of the counterforce beams, and the two positioning beams are located between the two support beams along the axial direction of the counterforce beams.

[0014] Further, the lower anchor beam anchoring devices, the positioning beam anchoring devices and the loading anchor beam anchoring devices located on the same side of the counterforce beams are located in the same vertical direction, and the two counterforce beams are located between the two lower anchor beam anchoring devices, the positioning beam anchoring devices and the loading anchor beam anchoring devices.

[0015] Further, the bottom of the counterforce beams is provided with buttresses.

[0016] Further, the finely rolled threaded steel bars can be replaced by prestressed steel bars.

[0017] In another aspect, the application provides a test method for the on-site bearing performance test of a small and medium span bridge, which is based on the above-mentioned test device for the on-site bearing performance test of a small and medium span bridge and specifically includes the following steps:

[0018] Step one: the beams with larger mid-span or higher bearing capacity of single beams in the test section are removed as counterforce beams, in order to fully utilize the prestressed effect in the counterforce beams, two counterforce beams are placed upside down, so that the prestressed steel bars in the counterforce beams are on the tension side;

[0019] Step two: install the lower anchor beam under the counter-force beam, install the loading anchor beam above the test beam, install the loading jack with load sensor below the loading anchor beam, install the loading distribution beam with the same length as the test beam width below the loading jack;

[0020] Install the hinged support at the bottom support point of both ends of the test beam, and set the support beam with the same length as the width of the two counter-force beams below the hinged support, and arrange the support beam on the counter-force beam;

[0021] Step three: set the positioning beam above the counter-force beam, and use the positioning beam anchor device and the lower anchor beam anchor device to keep the finishing rolled threaded steel between them in a tensioned state;

[0022] Step four: lock the upper and lower counter-force beams and the test beam by the finishing rolled threaded steel pulled on the lower counter-force beam and the upper test beam, and apply vertical load by the loading jack above the loading distribution beam until the test beam reaches the ultimate state of bearing capacity and is destroyed.

[0023] Further, the counter-force beam is placed obliquely, the oblique lower end of the cavity in the counter-force beam is sealed with a sealing plate, the oblique upper end of the counter-force beam is sealed with a pouring side plate and a concrete pouring hole is left, the C50 or above strength grade concrete poured in the cavity of the counter-force beam is removed, and after being vibrated and compacted, the test preparation work is started after two weeks of maintenance. When the test preparation is completed and the age of the concrete poured in the cavity reaches the design requirement, the on-site loading test is started.

[0024] According to the technical solution, compared with the prior art, the test device and test method for on-site bearing capacity test of small and medium span bridges are provided, the test beam does not need to be transported to the laboratory for test, the transportation risk is avoided, and the construction procedures such as piling, excavation and steel binding are avoided when the test device is reconstructed on site, the test efficiency is improved, and the device and method are very suitable for rapid test and test of the bearing capacity of the old beam to be demolished, the beam to be reinforced and used again and the newly produced beam body on the construction site, and have good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0026] Fig. 1 The structural schematic diagram of the test device for on-site bearing capacity test of small and medium span bridges provided by the present application is shown in the figure.

[0027] Fig. 2 The side view of the test device for the field bearing performance test of the medium and small span bridge provided by the present application is shown in the figure;

[0028] Fig. 3 The structural schematic diagram of the field filling concrete of the counter-force beam dismantling beam provided by the present application is shown in the figure.

[0029] In the figure, 1 is the counter-force beam, 2 is the lower anchor beam, 3 is the lower anchor beam anchoring device, 4 is the support beam, 5 is the hinged support, 6 is the positioning beam, 7 is the positioning beam anchoring device, 8 is the test beam, 9 is the supporting pier, 10 is the loading distribution beam, 11 is the loading anchoring beam, 12 is the loading jack, 13 is the loading anchoring beam anchoring device, 14 is the finished rolled threaded steel bar, 15 is the concrete, 16 is the blocking plate, 17 is the pouring side baffle, 18 is the concrete pouring hole, and 19 is the inclined supporting pier. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0031] Referring to Figs. 1-3 The embodiment of the present application discloses a test device for the field bearing performance test of a medium and small span bridge, which comprises:

[0032] The counter-force beam 1 is provided in two parallel rows, and the bottom of the counter-force beam 1 is provided with the lower anchor beam 2, which is provided in two parallel rows at intervals for applying the test load. The two ends of each lower anchor beam 2 are arranged below the two counter-force beams 1 through the lower anchor beam anchoring device 3, and the lower anchor beam anchoring device 3 is arranged at the end of the lower anchor beam 2 away from the counter-force beam 1. The top of the counter-force beam 1 is provided with the support beam 4, which is provided in two parallel rows at intervals. The top of each support beam 4 is provided with the hinged support 5.

[0033] The positioning beam 6 is provided in two parallel rows on the counter-force beam 1, and the positioning beam 6 and the top surface of the counter-force beam 1 are pressed tightly through the positioning beam anchoring device 7, so as to prevent the dismantling beam after assembly from being twisted during the test to cause the test failure. The finished rolled threaded steel bar 14 between the positioning beam 6 and the lower anchor beam 2 is kept in a tight state through the tightening of the positioning beam anchoring device 7, so as to enable the two or more counter-force beams 1 to bear the force cooperatively, thereby ensuring that the counter-force beams 1 are in the elastic working state before the test beam 8 is damaged.

[0034] The test beam 8 is arranged on the hinged support 5, and the test beam 8 is provided with the loading distribution beam 10. The loading distribution beam 10 is used to ensure that the test beam 8 body can bear the force uniformly at the loading section.

[0035] The loading anchoring beam 11 is arranged in two spaces above the loading distribution beam 10, and the loading jack 12 is arranged between each loading anchoring beam 11 and the loading distribution beam 10, and the loading anchoring beam anchoring device 13 is arranged at both ends of each loading anchoring beam 11; the test load is applied by the loading jack 12 arranged above the test beam 8, and the load is evenly distributed to the loading section of the test beam 8 by the loading distribution beam 10 arranged below the loading jack 12;

[0036] The finished rolled threaded steel bar 14 is sequentially connected with the loading anchoring beam anchoring device 13, the positioning beam anchoring device 7 and the lower anchoring beam anchoring device 3.

[0037] In the embodiment, the lower anchoring beam 2, the positioning beam 6 and the loading anchoring beam 11 are arranged in two spaces along the axial direction of the counter-force beam 1, and the two positioning beams 6 are located between the two support beams 4 along the axial direction of the counter-force beam 1.

[0038] In the embodiment, the lower anchoring beam anchoring device 3, the positioning beam anchoring device 7 and the loading anchoring beam anchoring device 13 located on the same side of the counter-force beam 1 are arranged in the same vertical direction.

[0039] The anchoring beams are arranged in the same vertical direction, and the two counter-force beams 1 are located between the two lower anchoring beam anchoring devices 3, the positioning beam anchoring devices 7 and the loading anchoring beam anchoring devices 13.

[0040] In the embodiment, the bottom of the counter-force beam 1 is provided with the support pier 9 to support the counter-force beam 1.

[0041] In the embodiment, the finished rolled threaded steel bar 14 can be replaced by a prestressed steel bar.

[0042] On the other hand, the application provides a test method for the field bearing performance test of a small and medium span bridge, which is based on the above-mentioned test device for the field bearing performance test of a small and medium span bridge and specifically includes the following steps:

[0043] Step one: the beam with a larger span or the beam with a higher bearing capacity in the test section is removed as the counter-force beam 1, and in order to fully utilize the prestressed effect in the counter-force beam 1, the two counter-force beams 1 are placed upside down, so that the prestressed steel bars of the counter-force beam 1 are on the tension side;

[0044] Step two: the lower anchoring beam 2 is installed below the counter-force beam 1, the loading anchoring beam 11 is installed above the test beam 8, the loading jack 12 provided with a load sensor is installed below the loading anchoring beam 11, and the loading distribution beam 10 with the same length as the width of the test beam 8 is installed below the loading jack 12;

[0045] Hinge support 5 is installed at the bottom of both ends of test beam 8, and support beam 4 with the same length as the width of two counterforce beams 1 is arranged below hinge support 5 and on counterforce beam 1;

[0046] Step three: positioning beam 6 is arranged above counterforce beam 1, and positioning beam anchoring device 7 is used to keep finishing rolled threaded steel bar 14 between the two in tension;

[0047] Step four: upper and lower counterforce beams 1 and test beam 8 are locked by finishing rolled threaded steel bar 14 pulled above test beam 8 and below counterforce beam 1, vertical load is applied by loading jack 12 above loading distribution beam 10 until test beam 8 reaches the ultimate state of bearing capacity and is destroyed.

[0048] In the embodiment, counterforce beam 1 is placed obliquely, the oblique lower end of the cavity in counterforce beam 1 is sealed with sealing plate 16, the oblique upper end of counterforce beam 1 is sealed with pouring side plate 17 and concrete pouring hole 18 is left for pouring concrete 15, C50 or above strength grade concrete 15 in the cavity of counterforce beam 1 is removed, and after vibration and compaction, curing is carried out for two weeks before starting test preparation, and after test preparation is completed, the age of the concrete 15 in the cavity reaches the design requirement, and the on-site loading test is started.

[0049] In addition, in the embodiment, support pier 9 is arranged at the bottom of counterforce beam 1, and oblique support pier 15 is arranged when counterforce beam 1 is placed obliquely.

[0050] The number of lower anchor beam 2 can also be three or four, and after loading jack 12 is pushed upward, lower anchor beam 2 will abut against the lower edge of counterforce beam 1.

[0051] In view of the problem that the highway widening site does not have the conditions for carrying out bearing capacity test and test of demolished beams or newly built beams, two beams with large span removed in the test section are used as counterforce beams 1, and the two counterforce beams 1 with large span are placed side by side in an inverted manner by taking advantage of the feature that the prestressed steel strands in the middle of the demolished beams are arranged at the beam bottom.

[0052] The beams with large span removed on site are used as counterforce beams 1 in an inverted manner, counterforce beams 1 are anchored by lower anchor beam 2 and loading anchor beam 11, and finishing rolled threaded steel bar 14 is used to apply the pulling load;

[0053] Counterforce beam 1 is at least two or four, and positioning beam 6 and lower anchor beam 2 are used to clamp counterforce beam 1 in order to prevent counterforce beam 1 from being twisted or unstable.

[0054] The various embodiments described in this specification are implemented in a progressive manner, each embodiment focusing on the differences from other embodiments, and the same or similar parts between embodiments can be mutually referred to. For the apparatus disclosed by the embodiments, since it corresponds to the method disclosed by the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0055] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those of ordinary skill in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A test method for field bearing performance test of small and medium span bridges, based on a test device for field bearing performance test of small and medium span bridges, characterized in that, The device comprises: counterforce beams, two of which are arranged side by side, the bottom of the counterforce beams being provided with lower anchor beams, the lower anchor beams being arranged at intervals, the two ends of each lower anchor beam being arranged below the two counterforce beams through lower anchor beam anchoring devices arranged at the two ends of the lower anchor beams, the top of the counterforce beams being provided with support beams arranged at intervals, the top of each support beam being provided with a hinged support; positioning beams arranged at intervals on the counterforce beams and being pressed between the top surface of the counterforce beams through positioning beam anchoring devices; test beams arranged on the hinged supports, the test beams being provided with loading distribution beams; loading anchoring beams arranged at intervals above the loading distribution beams, each loading anchoring beam being provided with a loading jack between the loading distribution beam, and each loading anchoring beam being provided with loading anchoring beam anchoring devices at the two ends thereof; finely rolled threaded steel bars sequentially connecting the loading anchoring beam anchoring devices, the positioning beam anchoring devices and the lower anchor beam anchoring devices; the lower anchor beams, the positioning beams and the loading anchoring beams being arranged at intervals along the axial direction of the counterforce beams, and the two positioning beams being located between the two support beams along the axial direction of the counterforce beams; the lower anchor beam anchoring devices, the positioning beam anchoring devices and the loading anchoring beam anchoring devices located on the same side of the counterforce beams being located in the same vertical direction, and the two counterforce beams being located between the two lower anchor beam anchoring devices, the positioning beam anchoring devices and the loading anchoring beam anchoring devices; the bottom of the counterforce beams being provided with support piers; the finely rolled threaded steel bars being replaceable by prestressed steel bars; the test method specifically comprises the following steps: Step one: the beams with larger midspan or higher single-beam bearing capacity in the test section are taken as counterforce beams, and in order to fully utilize the prestressed effect in the counterforce beams, the two counterforce beams are placed upside down so that the prestressed steel bars in the counterforce beams are on the tension side; Step two: lower anchor beams are installed below the counterforce beams, loading anchoring beams are installed above the test beams, loading jacks provided with load sensors are installed below the loading anchoring beams, and loading distribution beams with the same length as the test beams are installed below the loading jacks; hinged supports are installed at the bottom support points at the two ends of the test beams, support beams with the same length as the two counterforce beams are arranged below the hinged supports, and the support beams are arranged on the counterforce beams; Step three: positioning beams are arranged above the counterforce beams, and the finely rolled threaded steel bars between the positioning beams and the lower anchor beams are kept in a tension state through positioning beam anchoring devices and lower anchor beam anchoring devices; Step four: the upper and lower counterforce beams and the test beams are relatively locked through the finely rolled threaded steel bars pulled below the counterforce beams and above the test beams, vertical loads are applied through the loading jacks above the loading distribution beams, and the test beams reach the ultimate state of bearing capacity and are destroyed. The counterforce beam is placed obliquely, the oblique lower end of the cavity in the counterforce beam is blocked by a blocking plate, the oblique upper end of the counterforce beam is blocked by a pouring side plate and a concrete pouring hole is left, C50 or above strength grade concrete is poured into the cavity of the removed counterforce beam, after being vibrated and compacted, the concrete is maintained for two weeks and then test preparation work is started, when the test preparation is finished and the age of the poured concrete in the cavity reaches the design requirement, the on-site loading test is started.

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