A method for adjusting the casting size of the wedge-shaped block at the bottom of the beam

Abstract

The invention relates to a method for adjusting the casting size of a wedge-shaped block at the bottom of a beam. The method for adjusting the casting size of the wedge-shaped block at the bottom of a beam comprises the following steps: for a precast beam: placing a laser level on the upper surface of a beam-slab precast pedestal, measuring the height △a of a laser projected by the laser level, calculating the center height difference h0+△a between the laser projected by the laser level and the center position of the lower surface of the wedge-shaped block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge-shaped block; using a measuring ruler and a laser level to measure and mark four points on the inner walls of the four corners of a groove reserved on the beam-slab precast pedestal, where the four points have height differences h1+△a, h2+△a, h3+△a, and h4+△a, respectively, from the laser projected by the laser level to the four corners; laying dry sand and pre-buried steel plates in sequence; and then measuring whether the center height difference at the center of the groove meets h0+△a, judging whether it is consistent with the design, ensuring that after laying the dry sand and pre-buried steel plates, the volume in the groove completely matches the designed wedge-shaped block size. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam of the present invention is convenient to operate and has accurate measurement. It can also measure multiple prefabricated beams or cast-in-place beams at the same time, thus saving construction time.

Description

Technical Field

[0001] The invention belongs to the technical field of construction engineering, and particularly relates to a method for adjusting the casting size of a wedge-shaped block at the bottom of a beam. Background Art

[0002] In recent years, prefabricated and cast-in-place prestressed concrete bridges have been particularly widespread, and the problem of bearing damage and replacement has become increasingly serious during later operations. Because bridges achieve longitudinal and transverse slopes through the height difference of the four corners of the wedge-shaped blocks at the bottom of the beam, the bearings must be placed absolutely horizontally to bear the load. However, non-standard control of the wedge blocks during beam-slab construction can result in a poor fit between the contact surface between the beam bottom steel plate and the bearings, resulting in uneven stress on the bearings, biased pressure loss, and localized excessive stress, which can easily cause bearing damage and seriously affect their durability. Therefore, the adjustment accuracy of the longitudinal and transverse slopes of the wedge blocks at the bottom of the beam directly affects the service life of bridge bearings and other structures.

[0003] At present, the commonly used methods for controlling and adjusting the size of the wedge block include: professionally designed and manufactured wedge block adjustment devices, leveling instruments to measure height differences, and wire drawing to adjust height differences. Among them, the professionally designed adjustment device, such as the utility model patent with authorization announcement number CN217053081U, discloses a wedge block bottom mold processing device for the bottom end of a prefabricated beam. The wedge block bottom mold processing device for the bottom end of a prefabricated beam includes four fixing frames, which are respectively fixed on the four corners of the wedge block at the bottom end of the prefabricated beam. The fixing frame includes a fixing body, which includes a first section and a second section vertically connected to the first section, a first reserved screw hole, which is set through one end of the first section, and a first reserved slot, which extends along the direction of the second section; a pair of clamping rails, which are arranged relatively and located below the fixing frame. The clamping rail includes a main body, It has a hollow slide in the direction of the rail extension, two second reserved screw holes, which are respectively provided at both ends of the main body and are provided through the main body, the second reserved screw holes are aligned in the vertical direction with the first reserved screw hole, two second reserved card slots, which are respectively provided at both ends of the main body and are provided in the main body, the second reserved card slots are aligned in the vertical direction with the first reserved card slot; four adjustment screws, the adjustment screws passing through the first and second reserved screw holes; at least one steel ruler, the steel ruler passing through the first and second reserved card slots; and a wooden trowel, the two ends of which are slidably connected to the slide slots of the two main bodies. This prefabricated beam end bottom wedge block bottom mold processing device has a complex structure, cumbersome use, high cost, is easily deformed with repeated use, and can lead to low accuracy over time. The use of a level is complex to operate, has large errors, and is greatly affected by human factors. The wire adjustment accuracy is low, so there is an urgent need to find a simple, convenient, and highly accurate method to control the size of the adjustment wedge block. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for adjusting the casting size of the wedge-shaped block at the bottom of the beam. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam is simple to measure and effectively solves the accuracy of bridge prefabrication and installation.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: a method for adjusting the casting size of the wedge-shaped block at the bottom of the beam, characterized in that it includes the following steps:

[0006] 1) Pre-design the size, orientation, and position of the wedge block at the bottom of the beam. The center height difference of the wedge block is designed to be h0, and the height differences of the four corners of the wedge block are designed to be h1, h2, h3, and h4 respectively. According to the pre-designed size, orientation, and position of the wedge block, a groove with an upper opening corresponding to the wedge block is reserved on the precast pedestal of the beam slab or the bottom form of the cast-in-place beam. The notch of the groove is flush with the position of the wedge block at the bottom of the beam. The depth of the groove is greater than or equal to the maximum design height of the wedge block.

[0007] 2) For precast beams: Place a laser level on the upper surface of the beam-slab precast pedestal, measure the height △a of the laser projected by the laser level, calculate the center height difference h0+△a between the laser projected by the laser level and the center position of the lower surface of the wedge block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge block, use a measuring ruler and a laser level to measure and mark the four points corresponding to the height differences h1+△a, h2+△a, h3+△a, and h4+△a on the inner wall of the four corners of the groove reserved on the beam-slab precast pedestal, and lay dry sand and embedded steel plates in sequence. Then measure whether the center height difference at the center of the groove meets h0+△a, and judge whether it is consistent with the design. Ensure that after laying dry sand and embedded steel plates, the volume in the groove is completely consistent with the designed wedge block size;

[0008] For cast-in-place beams: Place the laser level on the support below the beam bottom formwork, measure the height △a of the laser projected by the laser level, and calculate the height differences △a-h1, △

[0009] a-h2, △a-h3, △a-h4. Use a measuring ruler and a laser level to measure the four points on the inner wall of the four corners of the groove reserved on the bottom formwork of the cast-in-place beam, and the height differences from the laser projection of the laser level to the four corners are △a-h1, △a-h2, △a-h3, and △a-h4, and adjust the bottom formwork of the beam to the corresponding four points so that the volume in the groove is completely consistent with the designed wedge block size.

[0010] Furthermore, after laying dry sand and embedded steel plates in step 2), use a laser level and a measuring ruler to remeasure the dimensions in the groove and compare them with the center height difference h0+△a and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a to ensure that the dimensions of the wedge block and the generated slope error are within the acceptance criteria.

[0011] Furthermore, after adjusting the bottom template of the beam to the corresponding four points as described in step 2), use a laser level and a measuring ruler to remeasure the dimensions in the groove and compare them with the height differences of the four corners △a-h1, △a-h2, △a-h3, and △a-h4 to ensure that the dimensions of the wedge block and the generated slope error are within the acceptance criteria.

[0012] Furthermore, in step 2), the laser level is placed on the beam and slab prefabricated pedestal at a distance of 50 to 100 cm from the groove.

[0013] Furthermore, in step 2), the laser level is placed within 5 cm of the center of the support.

[0014] Furthermore, in step 2), the measuring ruler is a tape measure or a steel ruler.

[0015] Beneficial effects of the present invention:

[0016] The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam of the present invention is convenient to operate and has accurate measurement. It can also measure multiple prefabricated beams or cast-in-place beams at the same time, thus saving construction time.

[0017] The method for adjusting the casting size of the beam bottom wedge block of the present invention uses common tools and has low construction cost, and is easy to promote and use on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the overall operation of adjusting the casting size of the wedge-shaped block at the bottom of a precast beam in the method for adjusting the casting size of the wedge-shaped block at the bottom of a beam in Example 1;

[0019] Figure 2 Schematic front view of the operation of adjusting the casting size of the wedge-shaped block at the bottom of a precast beam in the method for adjusting the casting size of the wedge-shaped block at the bottom of a beam in Example 1;

[0020] Figure 3 Schematic side view of the operation of adjusting the casting size of the wedge-shaped block at the bottom of a precast beam in the method for adjusting the casting size of the wedge-shaped block at the bottom of a beam in Example 1;

[0021] Figure 4 This is a schematic diagram of the overall operation of adjusting the casting size of the wedge-shaped block at the bottom of a cast-in-place beam in the method for adjusting the casting size of the wedge-shaped block at the bottom of a beam in Example 1;

[0022] Figure 5This is a side view schematic diagram of the operation of adjusting the casting size of the wedge-shaped block at the bottom of a cast-in-place beam in the method for adjusting the casting size of the wedge-shaped block at the bottom of a beam in Example 1.

[0023] In the figure: 1. Precast beam pedestal; 2. Groove; 3. Laser level; 4. Laser level projection laser; 5. Cast-in-place beam bottom formwork; 6. Support. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the embodiments of the present invention and the accompanying drawings.

[0025] Example 1

[0026] The method of adjusting the casting size of the wedge block at the bottom of the beam in this embodiment includes the following steps: pre-designing the size of the wedge block, the direction and position of the wedge block at the bottom of the beam, the center height difference of the wedge block being designed to be h0, and the height differences of the four corners of the wedge block being designed to be h1, h2, h3, and h4 respectively; according to the pre-designed size, direction and position of the wedge block, reserving a groove 2 with an upper opening corresponding to the wedge block on the beam slab prefabricated pedestal or the cast-in-place beam bottom form 5, the notch of the groove 2 being flush with the position at the bottom of the beam where the wedge block is set; and the depth of the groove 2 being greater than or equal to the maximum designed height of the wedge block.

[0027] For precast beams: Place the laser level 3 on the upper surface of the beam and slab precast pedestal, with the laser level 3 50 cm away from the groove, measure the height △a of the laser level projected laser 4, calculate the center height difference h0+△a between the laser level projected laser 4 and the center position of the lower surface of the wedge block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge block, use a steel ruler and the laser level 3 to measure the four points corresponding to the height differences h1+△a, h2+△a, h3+△a, and h4+△a on the inner wall of the four corners of the groove 2 reserved on the beam and slab precast pedestal, and mark them. Lay dry sand below the four marked points and compact it to form an inclined plane. The top of the dry sand is flush with the four marked points. Measure whether the center height difference at the center of the groove 2 meets the requirements of h0+△a.

[0028] a. Determine whether it conforms to the design. Then, lay embedded steel bars on the dry sand so that the volume within groove 2 after laying the dry sand and embedded steel bars completely matches the designed wedge size. Use a steel ruler and laser level 3 to remeasure the dimensions within groove 2 and compare them with the center height difference h0+△a and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a to ensure that the wedge size and the resulting slope error are within the acceptance criteria.

[0029] For cast-in-place beams: Place the laser level 3 on the support 6 below the beam bottom formwork, with the laser level 3 within 5 cm of the center of the support 6, and measure the height △a of the laser level projected laser 4. Calculate the four corner height differences △a-h1, △a-h2, △a-h3, and △a-h4 between the laser level projected laser 4 and the four corners of the lower surface of the wedge block. Use a steel ruler and the laser level 3 to measure the four points on the inner wall of the four corners of the groove 2 reserved on the cast-in-place beam bottom formwork 5, which are the height differences from the laser level projected laser 4 to the four corners, and adjust the beam bottom formwork to the corresponding four points so that the volume in the groove 2 is completely consistent with the designed wedge block size. After the beam bottom formwork is adjusted, use the laser level 3 and the steel ruler again to re-measure the size of the groove 2 and the four corner height differences △a-h1, △a-h2, △a-h3, △a-h4.

[0030] Compare a-h4 to ensure that the wedge size and resulting slope error are within the acceptance criteria.

[0031] Example 2

[0032] The method of adjusting the casting size of the wedge-shaped block at the bottom of the beam in this embodiment includes the following steps: pre-designing the size, direction, and position of the wedge-shaped block at the bottom of the beam, wherein the center height difference of the wedge-shaped block is designed to be h0, and the height differences of the four corners of the wedge-shaped block are designed to be h1, h2, h3, and h4, respectively; reserving a groove with an upper opening corresponding to the wedge-shaped block on a prefabricated pedestal for the beam slab or a cast-in-place beam bottom mold according to the pre-designed size, direction, and position of the wedge-shaped block, wherein the notch of the groove is flush with the position at the bottom of the beam where the wedge-shaped block is set; and the depth of the groove is greater than or equal to the maximum designed height of the wedge-shaped block.

[0033] For precast beams: Place a laser level on the upper surface of the beam and slab precast pedestal, 100 cm away from the groove, measure the height △a of the laser projected by the laser level, calculate the center height difference h0+△a between the laser projected by the laser level and the center position of the lower surface of the wedge block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge block, use a steel ruler and a laser level to measure and mark the four points corresponding to the height differences h1+△a, h2+△a, h3+△a, and h4+△a on the inner walls of the four corners of the groove reserved on the beam and slab precast pedestal, lay dry sand below the four marked points and compact it to form a sloped plane, and the top of the dry sand is flush with the four marked points. Measure the center height difference at the center of the groove to see if it meets h0+△a and determine whether it is consistent with the design. Then lay embedded steel bars on the dry sand so that the volume of the groove after laying the dry sand and embedded steel bars is completely consistent with the designed wedge block size. Use a steel ruler and laser level to remeasure the size of the groove and compare it with the center height difference h0+△a and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a to ensure that the wedge block size and the resulting slope error are within the acceptance criteria.

[0034] For cast-in-place beams: Place the laser level on the support below the beam bottom formwork, with the laser level within 5 cm of the support center, measure the height △a of the laser projected by the laser level, and calculate the height differences △a-h1, △a-h2, △a-h3, and △a-h4 between the laser projected by the laser level and the four corners of the lower surface of the wedge block. Use a steel ruler and the laser level to measure the height differences △a-h1, △a-h2, △a-h3, and △a-h4 from the inner wall of the four corners of the groove reserved on the cast-in-place beam bottom formwork.

[0035] Adjust the beam bottom template to the corresponding four points a-h2, △a-h3, and △a-h4, so that the volume in the groove completely matches the designed wedge size. After the beam bottom template is adjusted, use a laser level and steel ruler to remeasure the size of the groove and compare it with the four corner height differences △a-h1, △a-h2, △a-h3, and △a-h4 to ensure that the wedge size and the resulting slope error are within the acceptance criteria.

[0036] Example 3

[0037] The method of adjusting the casting size of the wedge-shaped block at the bottom of the beam in this embodiment includes the following steps: pre-designing the size, direction, and position of the wedge-shaped block at the bottom of the beam, wherein the center height difference of the wedge-shaped block is designed to be h0, and the height differences of the four corners of the wedge-shaped block are designed to be h1, h2, h3, and h4, respectively; reserving a groove with an upper opening corresponding to the wedge-shaped block on a prefabricated pedestal for the beam slab or a cast-in-place beam bottom mold according to the pre-designed size, direction, and position of the wedge-shaped block, wherein the notch of the groove is flush with the position at the bottom of the beam where the wedge-shaped block is set; and the depth of the groove is greater than or equal to the maximum designed height of the wedge-shaped block.

[0038] For precast beams: Place a laser level on the upper surface of the beam and slab precast pedestal, 75 cm away from the groove, measure the height △a of the laser projected by the laser level, calculate the center height difference h0+△a between the laser projected by the laser level and the center position of the lower surface of the wedge block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge block, use a tape measure and a laser level to measure and mark the four points corresponding to the height differences h1+△a, h2+△a, h3+△a, and h4+△a on the inner walls of the four corners of the groove reserved on the beam and slab precast pedestal, lay dry sand below the four marked points and compact it to form a sloped plane, and the top of the dry sand is flush with the four marked points. Measure the center height difference at the center of the groove to see if it meets h0+△a and determine whether it is consistent with the design. Then lay embedded steel bars on the dry sand so that the volume of the groove after laying the dry sand and embedded steel bars is exactly the same as the designed wedge block size. Use a tape measure and laser level to remeasure the size of the groove and compare it with the center height difference h0+△a and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a to ensure that the wedge block size and the resulting slope error are within the acceptance criteria.

[0039] For cast-in-place beams: Place the laser level on the support below the beam bottom formwork, with the laser level within 5 cm of the support center, measure the height △a of the laser projected by the laser level, and calculate the height differences △a-h1, △a-h2, △a-h3, and △a-h4 between the laser projected by the laser level and the four corners of the lower surface of the wedge block. Use a tape measure and the laser level to measure the height differences △a-h1, △a-h2, △a-h3, and △a-h4 from the inner wall of the four corners of the groove reserved on the cast-in-place beam bottom formwork.

[0040] Adjust the beam bottom template to the corresponding four points a-h2, △a-h3, and △a-h4, so that the volume of the groove is completely consistent with the designed wedge size. After the beam bottom template is adjusted, use a laser level and tape measure to re-measure the size of the groove and compare it with the four corner height differences △a-h1, △a-h2, △a-h3, and △a-h4 to ensure that the wedge size and the resulting slope error are within the acceptance criteria.

Claims

1. A method for adjusting the casting size of the wedge-shaped block at the bottom of the beam, characterized in that: The following steps are involved: 1) Pre-design the size, orientation, and position of the wedge block at the bottom of the beam. The center height difference of the wedge block is designed to be h0, and the height differences of the four corners of the wedge block are designed to be h1, h2, h3, and h4 respectively. According to the pre-designed size, orientation, and position of the wedge block, a groove with an upper opening corresponding to the wedge block is reserved on the precast pedestal of the beam slab or the bottom form of the cast-in-place beam. The notch of the groove is flush with the position of the wedge block at the bottom of the beam. The depth of the groove is greater than or equal to the maximum design height of the wedge block. 2) For precast beams: Place a laser level on the upper surface of the beam-slab precast pedestal, measure the height △a of the laser projected by the laser level, calculate the center height difference h0+△a between the laser projected by the laser level and the center position of the lower surface of the wedge block, and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a between the four corners of the lower surface of the wedge block, use a measuring ruler and a laser level to measure and mark the four points corresponding to the height differences h1+△a, h2+△a, h3+△a, and h4+△a on the inner wall of the four corners of the groove reserved on the beam-slab precast pedestal, and lay dry sand and embedded steel plates in sequence. Then measure whether the center height difference at the center of the groove meets h0+△a, and judge whether it is consistent with the design. Ensure that after laying dry sand and embedded steel plates, the volume in the groove is completely consistent with the designed wedge block size; For cast-in-place beams: Place the laser level on the support below the beam bottom formwork, measure the height △a of the laser projected by the laser level, calculate the four corner height differences △a-h1, △a-h2, △a-h3, and △a-h4 between the laser projected by the laser level and the four corners of the lower surface of the wedge block, and use a measuring ruler and a laser level to measure the four points corresponding to the height differences △a-h1, △a-h2, △a-h3, and △a-h4 from the laser projected by the laser level to the four corners on the inner wall of the four corners of the groove reserved on the cast-in-place beam bottom formwork, and adjust the beam bottom formwork to the corresponding four points so that the volume in the groove is completely consistent with the designed wedge block size.

2. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam according to claim 1, characterized in that: After laying dry sand and embedded steel plates in step 2), use a laser level and a measuring ruler to remeasure the dimensions in the groove and compare them with the center height difference h0+△a and the four corner height differences h1+△a, h2+△a, h3+△a, and h4+△a to ensure that the dimensions of the wedge block and the resulting slope error are within the acceptance criteria.

3. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam according to claim 1, characterized in that: After adjusting the beam bottom template to the corresponding four points as described in step 2), use a laser level and a measuring ruler to remeasure the dimensions in the groove and compare them with the four corner height differences △a-h1, △a-h2, △a-h3, and △a-h4 to ensure that the dimensions of the wedge block and the generated slope error are within the acceptance criteria.

4. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam according to claim 1, characterized in that: In step 2), the laser level is placed on the beam and slab prefabricated pedestal at a distance of 50 to 100 cm from the groove.

5. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam according to claim 1, characterized in that: In step 2), the laser level is placed within 5 cm of the center of the support.

6. The method for adjusting the casting size of the wedge-shaped block at the bottom of the beam according to claim 1, characterized in that: In step 2), the measuring ruler is a tape measure or a steel ruler.

Images