Building assembly type prefabricated column auxiliary positioning machine tool and auxiliary construction method thereof

Abstract

The invention relates to assembly type building construction, and provides a building assembly type prefabricated column auxiliary positioning machine tool which comprises a machine tool main frame, a leveling support arranged at the bottom of the machine tool main frame and a bearing mechanism arranged above the machine tool main frame. The machine tool main frame comprises a second support, a first support fixedly connected to one end of the second support and a movable support inserted into the other end of the second support in a sliding mode, and the machine tool main frame is in a groove shape. The two ends of the first support and the two ends of the movable support are each provided with a leveling support. The middle of the first support and the middle of the second support are each provided with a bearing mechanism used for bearing the prefabricated column, and the bearing height of each bearing mechanism is adjustable. The prefabricated column is borne through the bearing piece, positioning butt joint of the prefabricated column and the prefabricated column bearing platform is achieved by controlling the height of the bearing piece in a remote control mode, the laser instrument and the distance sensor are arranged to assist positioning installation, positioning is accurate, construction is convenient and fast, and the labor cost is saved; the movable support is further adopted to adapt to the prefabricated columns of different sizes and can be repeatedly used, and the cost is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of prefabricated building construction, and in particular to a prefabricated building column auxiliary positioning machine and an auxiliary construction method thereof. BACKGROUND

[0002] In prefabricated building construction, the prefabricated column positioning is often hoisted to the designated position by the crane, aligned with the lower prefabricated column pile cap, and finally positioned and installed by manual fine adjustment. Due to the heavy prefabricated column, more manpower is needed, and it is difficult for multiple people to coordinate positioning, which is difficult to ensure accurate positioning. At the same time, in order to align the position, the on-site technical personnel need to spend a long time, and if there is a slight deviation in the alignment process, the positioning needs to be repositioned, which makes the construction process more complicated, time-consuming, and increases the safety risk. In addition, the sling needs to be bound to the component during hoisting by the crane, and the sling needs a long time to recover vertically after moving. If the component adjustment frequency is too high, it will greatly increase the time of component positioning and installation. This also does not fully play the advantages of prefabricated building construction in saving labor and time.

[0003] Some existing researches disclose some auxiliary positioning devices and methods. For example, the utility model patent CN214658956U discloses a prefabricated column hoisting and lowering positioning device, which guides the positioning of the prefabricated component by setting a guide plate. However, the device has the following problems: 1) The device uses pure manual adjustment, which still relies on human eyes for positioning, and the labor cost is high, and the positioning accuracy is insufficient; 2) The device is only suitable for the installation of a prefabricated column of a certain size, and is limited, and has poor applicability and high engineering cost; 3) The degree of automation is low.

[0004] Therefore, the present application proposes a prefabricated column auxiliary positioning machine, which can simply assist the prefabricated column to be quickly and accurately positioned, and has low cost and high degree of automation. SUMMARY

[0005] The present application proposes a prefabricated building column auxiliary positioning machine and an auxiliary construction method thereof to solve the problems in the prior art.

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

[0007] The first aspect of the present application provides a kind of building fabricated column auxiliary positioning machine tool, including machine tool main frame, leveling support being arranged in the bottom of machine tool main frame and receiving mechanism being arranged in the top of machine tool main frame, the machine tool main frame includes second support, first support being fixedly connected in one end of the second support and movable support being slidably inserted in the other end of the second support, and machine tool main frame is in the form of groove;Two ends of the first support and movable support are each provided with a leveling support;The middle part of the first support and second support is each provided with a receiving mechanism for receiving prefabricated column, and the receiving height of the receiving mechanism is adjustable.

[0008] Further, the receiving mechanism includes an electric push rod arranged on the first support or the second support, a receiving member arranged on the movable end of the electric push rod, and a motor electrically connected with the electric push rod.

[0009] Further, the receiving member includes a receiving plate arranged on the movable end of the electric push rod and a limiting plate arranged on the bottom of the receiving plate, and the limiting plate is vertically arranged, and the receiving plate is horizontally arranged and faces the inner side of the machine tool main frame.

[0010] Further, the leveling support includes a positioning plate, a positioning shaft and a support seat are coaxially arranged on the positioning plate, the positioning shaft is fixed, and the support seat can rotate around the positioning shaft, the upper part of the support seat is movably inserted into a insertion hole arranged on the first support or the movable support, and the height of the insertion hole relative to the support seat can be adjusted by rotating the support seat, a positioning bolt is further arranged on the positioning plate to connect with the concrete floor slab, so as to realize the positioning of the leveling support.

[0011] Further, a insertion slot is further arranged on the top of the support seat, a rotating tool is inserted into the insertion hole to the insertion slot, and the support seat can be rotated. Further, a sliding groove is arranged in the inner part of the other end of the second support, a sliding block matched with the sliding groove is arranged on one end of the movable support, the sliding block slides in the sliding groove, the position of the movable support can be adjusted, so that the auxiliary positioning machine tool can be applied to the installation of prefabricated columns with different sizes.

[0012] Further, a laser instrument for monitoring the verticality of the prefabricated column is arranged on each end of the second support, and a distance sensor for monitoring the distance of the prefabricated column relative to the prefabricated column bearing platform is further arranged on the second support or the first support.

[0013] Further, a device box and a display screen are further included, the output end of the device box is connected with the laser instrument and the distance sensor, the output end is connected with the display screen, the device box obtains the verticality data of the prefabricated column and the distance data of the prefabricated column relative to the prefabricated column bearing platform, and after data processing, the signal is transmitted to the display screen to display the numerical value and image, so as to realize the visual operation.

[0014] The second aspect of the present application provides an auxiliary construction method of a building fabricated column auxiliary positioning machine tool, including the following steps:

[0015] 1) Install two auxiliary positioning tools around the prefabricated column cap, so that the first support, the second support and the movable support are installed in place;

[0016] 2) Adjust the leveling support to keep the tool main frame horizontal;

[0017] 3) Hoist the prefabricated column so that the lower end of the prefabricated column abuts the receiving mechanism, and the prefabricated column remains vertical;

[0018] 4) Synchronously adjust the receiving height of each receiving mechanism, and synchronously lower the prefabricated column, so that the lower end of the prefabricated column is aligned and installed with the prefabricated column cap.

[0019] Further, in step 1), the first support and the second support are installed closely to the prefabricated column cap, and the upper surfaces of the first support and the second support are flush with the upper surface of the prefabricated column cap concrete.

[0020] Compared with the prior art, the present application has the following beneficial technical effects:

[0021] 1) The present application uses multiple receiving members to receive the prefabricated column, which is more convenient than positioning the reserved steel bars on the prefabricated column and the steel sleeve on the prefabricated column cap, can achieve rapid and effective precise positioning, and ensures the perpendicularity of the column;

[0022] 2) The present application uses receiving members and remote control electric push rods to control the positioning and docking between the prefabricated column and the prefabricated column cap, which can effectively reduce errors in the operation process, reduce the complexity of positioning and installation, and greatly save labor costs;

[0023] 3) The present application also uses a movable support, which can adjust the position between the two auxiliary positioning tools by adjusting the position of the movable support, forming a space of different cross-sectional sizes, adapting to prefabricated columns of various sizes, not needing to produce multiple models, standardizing production, being reusable, and saving costs;

[0024] 4) The present application also uses a laser instrument to monitor the perpendicularity of the prefabricated column, and a distance sensor to monitor the distance between the prefabricated column and the prefabricated column cap, and adjusts the hoisting state of the prefabricated column in real time according to the monitoring data, to realize automatic and precise installation of the prefabricated column. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 It is a structural schematic view of the auxiliary positioning tool.

[0026] Fig. 2 It is a structural schematic view of the leveling support.

[0027] Fig. 3 It is a schematic view of the auxiliary positioning tool assisting in construction and positioning.

[0028] Fig. 4 The schematic diagram of the auxiliary positioning machine tool assisting the positioning of the prefabricated column.

[0029] Fig. 5 The schematic diagram of the device box structure and signal transmission.

[0030] In the figure: 100-auxiliary positioning machine tool; 110-machine tool main frame; 111-first support; 112-second support; 113-movable support; 114-sliding block; 120-accepting mechanism; 121-accepting piece; 122-electric push rod; 123-motor; 130-leveling support; 131-positioning plate; 132-positioning bolt; 133-positioning shaft; 134-supporting seat; 135-slot; 136-socket; 140-laser instrument; 150-distance sensor; 200-prefabricated column; 201-first reserved steel bar; 300-prefabricated column pile cap; 301-second reserved steel bar; 302-steel sleeve; 400-device box; 401-signal receiver; 402-server; 500-display screen. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0032] Embodiment 1;

[0033] Please see Figs. 1-4 The present embodiment provides an auxiliary positioning machine tool for building prefabricated column, which comprises a machine tool main frame 110, a leveling support 130 arranged at the bottom of the machine tool main frame 110, and an accepting mechanism 120 arranged above the machine tool main frame 110. The machine tool main frame 110 comprises a second support 112, a first support 111 fixedly connected to one end of the second support 112, and a movable support 113 slidingly inserted into the other end of the second support 112. The machine tool main frame is in a groove shape. The first support 111 and the movable support 113 are each provided with a leveling support 130 at both ends. The first support 111 and the second support 112 are each provided with an accepting mechanism 120 in the middle part to accept the prefabricated column. The accepting height of the accepting mechanism 120 is adjustable.

[0034] Specifically, the leveling support 130 comprises a positioning plate 131, a positioning shaft 133 and a support seat 134 are coaxially arranged on the positioning plate 131, the positioning shaft 133 is fixed on the positioning plate 131, the support seat 134 is provided with a positioning groove matched with the positioning shaft 133 at the bottom, the positioning groove at the bottom of the support seat 134 is aligned and installed with the positioning shaft 133, so that the support seat 134 can rotate around the positioning shaft 133; the first support 111 or the movable support 113 is provided with a insertion hole 136, the upper part of the support seat 134 is movably inserted into the insertion hole 136 provided on the first support 111 or the movable support 113, by rotating the support seat 134, the height of the insertion hole 136 relative to the support seat 134 can be adjusted, and the height of the machine tool main frame 110 relative to the support seat 134 is adjusted, the height of the support seat 134 relative to the prefabricated concrete floor is unchanged, so that adjusting the support seat 134 can keep the machine tool main frame 110 horizontal. The movable insertion is inserted in a screwing manner, that is, an internal thread is arranged in the insertion hole 136, an external thread is arranged on the upper part of the support seat 134, the external thread is matched and screwed with the internal thread, and the movable insertion of the support seat 134 in the insertion hole 136 is realized.

[0035] The rotating mode of the support seat 134 is various. Specifically, the top of the support seat 134 is further provided with an insertion groove 135, a rotating tool is inserted into the insertion groove 135 from the insertion hole 136, and the support seat 134 can be rotated. The rotating tool can be a hexagonal wrench, and the insertion groove 135 is a hexagonal counterbore. In addition, in addition to the insertion groove 135, a rotating disc can also be fixedly arranged at the lower part of the support seat 134, the rotating disc is coaxial with the support seat 134 and has an area greater than that of the support seat 134, and anti-skid lines can be arranged on the side surface of the rotating disc.

[0036] Specifically, the positioning plate 131 is further provided with a positioning bolt 132 connected with the prefabricated concrete floor, so as to realize the positioning of the leveling support 130. The prefabricated concrete floor can be provided with an installation hole matched with the positioning bolt 132 in advance. The installation position of the installation hole can be calculated according to the geometric size of the auxiliary positioning machine tool 100 and the geometric size of the prefabricated column 200.

[0037] Specifically, the receiving mechanism 120 includes an electric push rod 122 arranged on the first support 111 or the second support 112, a receiving piece 121 arranged on the movable end of the electric push rod 122, and a motor 123 electrically connected with the electric push rod 122. The motor 123 can be remotely controlled to start and stop through a remote controller. The receiving piece 121 includes a receiving plate 121a and a limiting plate 121b. The limiting plate 121b is arranged vertically and fixedly connected with the movable end of the electric push rod 122, and the receiving plate 121a is arranged horizontally and fixedly connected with the bottom of the limiting plate 121b. The receiving plate 121a is used for supporting the precast column 100, and the limiting plate 121b is used for limiting the position of the lower end of the precast column 100. When two auxiliary positioning machine tools 100 are used in combination, four receiving plates 121a are received in four directions of the lower end of the precast column 100, and four limiting plates 121b form a rectangular space to limit the precast column 100, so as to replace the precise positioning and installation mode of the precast column 100 through the first reserved steel bar 201 arranged thereon and the steel sleeve 302 arranged on the precast column cap 300 in the traditional installation technology, reduce the positioning difficulty, save the labor cost, and improve the positioning accuracy. The upper end of the limiting plate 121b can be arranged to have a certain inclination, and the inclination direction is directed outward of the machine tool main frame 110, so as to guide the receiving of the precast column 200.

[0038] Specifically, the other end of the second support 112 is internally provided with a sliding groove, and one end of the movable support 113 is provided with a sliding block 114 matched with the sliding groove. The sliding block 114 slides in the sliding groove, and the position of the movable support 113 can be adjusted, so that the auxiliary positioning machine tool 100 can be suitable for installation of precast columns 200 of different sizes.

[0039] Specifically, the two ends of the second support 112 are each provided with a laser instrument 140 for monitoring the perpendicularity of the precast column 200. Two auxiliary positioning machine tools 100 have four laser instruments 140, which are respectively located at the four corner portions of the precast column 200. At least one distance sensor 150 is further arranged on the second support 112 or the first support 111 to monitor the distance between the precast column 200 and the precast column cap 300. Since the distance sensor 150 is arranged on the support, and the support is distributed on the outer side of the precast column 200, the distance sensor 150 cannot monitor the precast column 200 vertically. However, if the monitoring direction of the distance sensor 150 is inclined, the distance between the precast column 200 and the precast column cap 300 can be obtained according to the actual monitoring data and the inclination angle of the monitoring direction relative to the vertical direction.

[0040] Specifically, the prefabricated column 200 is generally rectangular in cross-section, so the first support 111 needs to be perpendicular to the second support 112, and the two auxiliary positioning machines 100 are arranged around the prefabricated column 200 to support the prefabricated column 200. The movable support 113 is generally parallel to the first support 111 and can slide along the length direction of the second support 112, so that for each auxiliary positioning machine 100, the machine main frame 110 is in a groove-shaped structure. Limited by the position of the prefabricated column 200, the movable support 113 of one of the auxiliary positioning machines 100 needs to be arranged outside the first support 111 of the other auxiliary positioning machine 100, so as to facilitate the adjustment of the height of the leveling support 130 arranged on the two auxiliary positioning machines 100. The rectangular plane formed by the two groups of first supports 111 and second supports 112 is flush with the upper surface of the prefabricated column cap 300.

[0041] Specifically, the auxiliary positioning machine 100 further comprises a device box 400 and a display screen 500, the device box 400 is provided with a signal receiver 401 and a server 402, the input end of the signal receiver 401 is connected with the laser instrument 140 and the distance sensor 150, the output end is connected with the server 402, and the server 402 is further connected with the display screen 500. The signal receiver 401 can adopt an STC89C52 development board, the original monitoring data of the laser instrument 140 and the distance sensor 150 are read through SPI / I2C and decoded, and then the decoded data are transmitted to the server 402, the server 402 can adopt an STM32F103 server, the server 402 processes the data, calculates the perpendicularity of the prefabricated column 200 and the distance relative to the prefabricated column cap 300, generates dynamic image instructions, and then transmits the dynamic image instructions to the display screen 500 through an HDMI interface, and the display screen 500 can display the numerical value of the specific perpendicularity and distance, or can display a simple model of the prefabricated column 200 and the prefabricated column cap 300, the model comprises a diagram of the perpendicularity of the prefabricated column 200 and a diagram of the distance between the prefabricated column 200 and the prefabricated column cap 300.

[0042] Embodiment 2;

[0043] See Figs. 1-4 The embodiment provides an auxiliary construction method of an auxiliary positioning machine 100 for a building fabricated prefabricated column 200, which comprises the following steps:

[0044] 1) Two auxiliary positioning machines 100 are installed around the cap of the prefabricated column 200, so that the first support 111, the second support 112 and the movable support 113 are installed in place;

[0045] 2) Adjust the leveling support 130 to keep the machine main frame 110 horizontal;

[0046] 3) Hoist the prefabricated column 200 so that the lower end of the prefabricated column 200 abuts against the supporting mechanism 120, and the prefabricated column 200 is kept vertical;

[0047] 4) Synchronously adjust the receiving height of each receiving mechanism 120, and synchronously lower the precast column 200 to align the lower end of the precast column 200 with the precast column 200 bearing platform for installation.

[0048] Specifically, in step 1), before installing the two auxiliary positioning machine tools 100, the positions of the positioning plates 131 and the positioning bolts 132 need to be determined according to parameters such as the geometric dimensions of the auxiliary positioning machine tools 100 and the geometric dimensions of the precast column 200. In particular, bolt mounting holes need to be pre-drilled on the precast concrete floor according to the positions of the positioning bolts 132. When determining the positions of the positioning bolts 132 below the movable supports 113, the construction gap, i.e., the distance between the movable supports 113 and the first supports 111 of the other auxiliary positioning machine tool 100, also needs to be considered to facilitate the adjustment of the height of the leveling supports 130 below the first supports 111.

[0049] Specifically, in step 1), when installing the two auxiliary positioning machine tools 100, the first supports 111 and the second supports 112 are installed in close contact with the precast column bearing platform 300, and the upper surfaces of the first supports 111 and the second supports 112 are flush with the upper surface 11 of the precast column bearing platform 300 concrete.

[0050] Specifically, in step 2), after adjusting the machine tool main frame 110 to be horizontal through the leveling supports 130, the receiving plates 121a are in a horizontal state, the limiting plates 121b are in a vertical state, the four receiving plates 121a are supported at the four positions of the precast column 200, and the four limiting plates 121b limit the precast column 200 at the four positions of the precast column 200; from a spatial perspective, the inner side of the limiting plate 121b corresponds to the outer surface of the precast column 200 and the precast column bearing platform 300, the receiving plate 121a extends a certain width into the cross-sectional range of the precast column 200 and the precast column bearing platform 300, and the extension width of the receiving plate 121a can be 1 / 6-1 / 10 of the width of the precast column 200. The four limiting plates 121b form a larger positioning space, which greatly reduces the difficulty of positioning compared to the positioning of the first reserved steel bar 201 and the steel bar sleeve 302, reduces the construction difficulty, and reduces the labor cost.

[0051] Specifically, in step 3), the display screen 500 can display the specific verticality value of the precast column 200, and the construction technician can observe the above information while monitoring the verticality of the precast column 200 at the four corners of the precast column 200 through the four laser instruments 140 and timely adjusting the verticality to keep the precast column 200 always vertical.

[0052] Specifically, in step 4), the display screen 500 can display the specific distance value of the precast column 200, and the construction technician can observe the above information and simultaneously adjust the extension length of the electric push rod 122 through the remote control, so that the four receiving members 121 are kept synchronous downward movement, and the precast column 200 is also kept synchronous downward movement, and the four receiving members 121 provide a guiding effect for the precast column 200 at this time, guiding the first reserved steel bars 201 on the precast column 200 to move to the steel sleeve 302 arranged on the precast column cap 300, since the positions of the entire device have been accurately calculated, as long as good operation is maintained during the downward movement of the precast column 200, the accurate positioning and installation of the first reserved steel bars 201 and the steel sleeve 302 can be easily realized, and then the connection between the precast column 200 and the precast column cap 300 is realized.

[0053] Specifically, in step 4), when the connection between the precast column 200 and the precast column cap 300 is completed, grouting and consolidation can be performed in the steel sleeve 302, realizing the connection between the first reserved steel bars 20 in the precast column 200 and the second reserved steel bars 301 in the precast column cap 300; then a support is arranged outside the precast column 200 to prevent the precast column 200 from falling down, the auxiliary positioning machine tool 100 is removed or moved to the next precast column cap 300, formwork is arranged outside the connection section between the original precast column 200 and the precast column cap 300, a steel cage is erected, and cast-in-place concrete forms a complete column structure.

[0054] Compared with the prior art, the characteristics of the present application are that the receiving member receives the precast column during hoisting, avoiding the shaking of the precast column during repeated adjustment of the installation position, reducing the number of adjustments; during positioning and installation of the precast column, the receiving member guides the precast column throughout the process without changing the horizontal position and perpendicularity, so that the precast column only keeps vertical movement, the positioning is more accurate, and the number of fine adjustments during positioning of the precast column is reduced compared with the comparative patent CN214658956U; the equipment box and the display screen are used to assist installation, the degree of automation is high, and the labor cost is saved; the machine tool main frame adopts a movable support, which is suitable for precast columns of different sizes, and reduces the manufacturing cost of the auxiliary positioning machine tool.

[0055] The above description is only used to illustrate the technical scheme of the present application and not to limit it, and modifications or replacements of the technical scheme made by other technicians in the field shall be covered in the scope of the claims of the present application as long as they do not deviate from the connotation of the technical scheme of the present application.

Claims

1. An auxiliary positioning tool for prefabricated columns in building assembly, characterized in that: The equipment includes a main frame, a leveling support at the bottom of the main frame, and a receiving mechanism above the main frame. The main frame includes a second support, a first support fixedly connected to one end of the second support, and a movable support slidably inserted into the other end of the second support. The main frame is trough-shaped. A leveling support is provided at each end of the first support and the movable support. A receiving mechanism for receiving precast columns is provided in the middle of the first support and the second support. The receiving height of the receiving mechanism is adjustable.

2. The auxiliary positioning device for prefabricated columns in building assembly according to claim 1, characterized in that: The receiving mechanism includes an electric push rod mounted on a first or second bracket, a receiving component mounted on the movable end of the electric push rod, and a motor electrically connected to the electric push rod.

3. The auxiliary positioning device for prefabricated columns in building assembly according to claim 2, characterized in that: The receiving component includes a receiving plate located at the movable end of the electric push rod and a limiting plate located at the bottom of the receiving plate; the limiting plate is vertically arranged, and the receiving plate is horizontally arranged and faces the inside of the main frame of the machine.

4. The auxiliary positioning device for prefabricated columns in building assembly according to claim 1, characterized in that: The leveling support includes a positioning plate, on which a positioning shaft and a support seat are coaxially arranged. The positioning shaft is fixed and the support seat can rotate around the positioning shaft. The upper part of the support seat is movably inserted into a socket provided on the first bracket or the movable bracket. By rotating the support seat, the height of the socket relative to the support seat can be adjusted. The positioning plate is also provided with positioning bolts to connect with the concrete floor slab to realize the positioning of the leveling support.

5. The auxiliary positioning device for prefabricated columns in building assembly according to claim 4, characterized in that: The top of the support base is also provided with a slot. A rotating tool can be inserted into the slot through the insertion hole to rotate the support base.

6. The auxiliary positioning device for prefabricated columns in building assembly according to claim 1, characterized in that: The other end of the second bracket has a sliding groove inside, and one end of the movable bracket has a slider that matches the sliding groove.

7. The auxiliary positioning device for prefabricated columns in building assembly according to claim 1, characterized in that: The second bracket is equipped with a laser instrument at each end for monitoring the verticality of the precast column, and a distance sensor is also provided on the second bracket or the first bracket for monitoring the distance between the precast column and the precast column support.

8. The auxiliary positioning device for prefabricated columns in building assembly according to claim 7, characterized in that: It also includes an equipment box and a display screen. The output end of the equipment box is connected to a laser and a distance sensor, and the output end is connected to the display screen. The equipment box acquires the verticality data of the precast column and the distance data of the precast column relative to the precast column support. After data processing, the signal is transmitted to the display screen to display the values ​​and images, realizing visual operation.

9. The auxiliary construction method of the auxiliary positioning equipment for prefabricated columns in building assembly according to any one of claims 1-8, characterized in that: Includes the following steps: 1) Install two auxiliary positioning tools around the precast column base to install the first bracket, second bracket, and movable bracket in place; 2) Adjust the leveling supports until the main frame of the machine is level; 3) Hoist the precast column so that the lower end of the precast column abuts against the receiving mechanism, keeping the precast column vertical; 4) Synchronously adjust the bearing height of each bearing mechanism and simultaneously lower the precast column so that the lower end of the precast column is aligned with the precast column support for installation.

10. The auxiliary construction method of the auxiliary positioning tool for prefabricated columns in building assembly according to claim 9, characterized in that: In step 1), the first bracket and the second bracket are installed close to the precast column base, and the upper surfaces of the first bracket and the second bracket are flush with the upper surface of the precast column base concrete.

Images