Damming and masonry construction method

Abstract

The application discloses a weir dam rubble step construction method, which comprises the following steps: preparing a step stone and a supporting positioning device; measuring and lofting to arrange control points and mark points; arranging control lines and positioning areas according to the control points and the mark points; checking and re-measuring; placing the supporting positioning device according to the positioning area and verifying the position; hoisting the step stone to the supporting positioning device and verifying the position; and pouring and forming the top concrete of the weir dam. The weir top step installation construction method can make the step position neat, the axis straight, and the step position fixing synchronous with the concrete pouring of the top of the weir dam, so that the step position fixing is more firm, the integrity and stability of the weir dam are high, and the weir dam is more beautiful and harmonious.

Description

Technical Field

[0001] This invention relates to the field of stepping stone construction technology, specifically to a method for constructing rubble stepping stones for weirs and dams. Background Technology

[0002] Stepping stones are ancient water crossing facilities that are set up at certain intervals in shallow water so that people can step across them. With the development of society, stepping stones are often set on the top of weirs and dams during the construction of water conservancy projects to facilitate passage and to blend them into the surrounding landscape.

[0003] Currently, when installing stepping stones on the top of weirs and dams in water conservancy projects, the main construction method is to use pre-reserved slots or pre-reserved boxes. The principle of both methods is to reserve space in advance according to the size and position of the stepping stones. After the concrete on the top of the weir and dam is poured and solidified, the pre-reserved boxes or slots are processed before the stepping stones are installed.

[0004] However, when using the above method, the reserved slots or boxes cannot be fixed in advance or are inconvenient to fix. During concrete molding, the reserved slots or boxes are easily deformed or displaced by the pressure of the concrete. Since the deformation and displacement of each reserved slot or box are different, and the amount of connecting materials (concrete, adhesive) used between the stepping stones and the reserved slots or boxes is difficult to control, stepping stones installed using this method are prone to inconsistencies in height and horizontal and vertical positions. This results in uneven axes, irregular arrangement, and an unsightly unevenness between the stepping stones after installation. Furthermore, when using the above method, the pouring of the weir crest concrete and the installation and fixing of the stepping stones cannot be carried out simultaneously. It is necessary to wait for the weir crest concrete to be poured and solidified before installing and fixing the stepping stones, which makes the installation difficult, the construction period long, and the overall integrity and stability weak. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for constructing stepping stones for weirs and dams. The method utilizes a support and positioning device made of reinforcing steel bars to support and place the stepping stones. Precise positioning of the support and positioning device is achieved through a layout-based positioning area, and the position of the stepping stones on the support and positioning device is verified using control lines. This ensures accurate positioning, neat arrangement, and straight axis of the stepping stones. Furthermore, the installation and fixing of the stepping stones can be carried out simultaneously with the concrete pouring at the top of the weir and dam, resulting in a more secure fixation, stronger overall integration with the weir and dam, and a more aesthetically pleasing and harmonious appearance.

[0006] To achieve the above objectives, the present invention provides a method for constructing rubble stepping stones for weirs and dams, comprising the following steps:

[0007] (1) In the processing plant, the rough stones are processed into stepping stones of uniform size, and a support and positioning device is made according to the construction drawings. The support and positioning device includes two horizontal fixing frames arranged side by side. The middle of the two horizontal fixing frames is connected to a vertical fixing frame perpendicular to them. The horizontal fixing frame includes a first horizontal steel bar parallel to the horizontal plane and two first vertical steel bars set at both ends of the first horizontal steel bar. The length of the first horizontal steel bar is equal to the length of the stepping stone. Two vertical support steel bars are symmetrically arranged on the first horizontal steel bar. The vertical fixing frame includes a second vertical steel bar parallel to the horizontal plane and two second vertical steel bars set at both ends of the second vertical steel bar. The length of the second vertical steel bar is equal to the width of the stepping stone.

[0008] (2) After the concrete of the bottom panel of the weir is poured and the reinforcement of the weir is tied, the control points and markers of the stepping stones are arranged in sequence according to the construction drawings. The control points are arranged on both sides of the weir according to the longitudinal position of the outer edge of the stepping stone in the row. The markers are arranged at the center of the bottom panel concrete according to the longitudinal and transverse positions of the four vertices of each stepping stone in the row.

[0009] (3) Connect the four markers belonging to the same stepping stone to form a positioning area, and lay out the control line between the control points in the same longitudinal position to form a control line. The elevation of the control line is set within the elevation range of the exposed concrete part of the stepping stone.

[0010] (4) The measurement personnel shall check and remeasure steps (2) and (3);

[0011] (5) Place the support positioning devices on the bottom panel concrete in sequence according to the instructions of the row of positioning areas. After verifying that the position of the support positioning devices is correct, fix the four support steel bars of the support positioning devices to the non-main structure steel bars of the weir.

[0012] (6) Hoist the stepping stones onto the support and positioning device in sequence, and check the placement of the stepping stones in the row through the control line. If it is incorrect, readjust until the position is correct. After the inspection is correct, lay out and install the next row of stepping stones until all the stepping stones are placed.

[0013] (7) Pour the concrete on the top of the weir to the design elevation, vibrate it thoroughly, cover the concrete surface with insulation cotton and sprinkle water to cure it.

[0014] A further technical solution is that the portion of the supporting steel bar extending below the first transverse steel bar is the supporting section, and the height h of the supporting section is set as the difference between the concrete pouring height H of the weir crest and the height h1 of the stepping stone embedded in the concrete.

[0015] A further technical solution is that the height of both the first and second vertical reinforcing bars is set to 1 / 3 to 1 / 2 of the height h1 of the stepping stone embedded in the concrete.

[0016] A further technical solution is that the supporting steel bars and the first transverse steel bars are fixedly connected by tie bars, and the two first transverse steel bars are fixedly connected by several reinforcing steel bars.

[0017] A further technical solution is that, before setting out according to the construction drawings, surveyors set up a total station at the known points and establish a coordinate system, with the length of the weir as the abscissa and the width of the weir as the ordinate. During the setting out, control points are first arranged according to the minimum and / or maximum ordinate of the orthographic projection of the m-th row of stepping stones on the weir. Each group of control points includes two control points Ym and Ym' with the same ordinate, and control points Ym and Ym' are arranged on both sides of the weir. Then, according to the abscissa and ordinate of the four vertices of the orthographic projection of the nth (n = 1, 2, 3...) stepping stone in the m-th row on the weir, four marker points are arranged on the bottom panel concrete. The four marker points are connected in sequence to form the positioning area Zn of the nth stepping stone in that row.

[0018] A further technical solution is to set up vertical poles at the same set of control points Ym and Ym', and pull a nylon line between the two poles as a control line, keeping it straight and taut. After the stepping stone is hoisted onto the support and positioning device, if the control line always stays close to the outer edge of the stepping stone side wall and remains straight, the position is accurate; otherwise, readjust until the position is correct.

[0019] A further technical solution is to set up an infrared ray instrument at control point Ym and make it emit infrared rays to control point Ym' in the same group to form a control line. Place a black baffle facing control point Ym on control point Ym' and draw a marking line on the black baffle, so that the marking line is perpendicular to the ground and extends through control point Ym'. When hoisting the stepping stone onto the support and positioning device, if a red dot always appears on the marking line on the baffle, the position is accurate; otherwise, readjust until the position is correct.

[0020] A further technical solution is to hang plumb lines at the bends at both ends of the longitudinal fixing frame and the two transverse fixing frames when placing the support positioning device. If the entire positioning area is located inside the six plumb lines, the support positioning device is correctly positioned; otherwise, continue adjusting until the position is correct.

[0021] A further technical solution is to cover and protect the exposed concrete portion of the stepping stones with EVA plastic film before pouring concrete.

[0022] A further technical solution is to use a high-frequency vibrator when vibrating the concrete. The vibrator holes are arranged in a quincunx pattern. The vibration time at each position is until the concrete no longer settles significantly, no more air bubbles appear, and the surface begins to slurry. During vibration, the vibrator must not touch the weir reinforcement, embedded parts, or stepping stones. The vertical distance between the vibrator and the weir concrete formwork is not less than 1 / 2 of the effective radius of the vibrator. The displacement distance of the vibrator does not exceed 1.5 times the effective radius of the vibrator.

[0023] The beneficial effects of this invention are:

[0024] The method of this invention uses a support and positioning device made of steel bars. The first transverse steel bar and the first longitudinal steel bar are the same length and width as the stepping stones, respectively, enabling control over the transverse and longitudinal positions of the stepping stones during installation. The height of the support section is the difference between the height of the concrete crest of the weir and the height of the stepping stone embedded in the concrete, facilitating control over the elevation of the stepping stones during installation and achieving precise positioning. Furthermore, by setting the first and second vertical steel bars, not only are the stepping stones protected and fixed when hoisted onto the support and positioning device, acting as a limit to prevent them from falling, but they also act as reinforcing bars embedded in the concrete crest during the pouring of the weir crest, increasing the fixation effect at the bottom of the stepping stones and improving the overall integrity and stability between the stepping stones and the weir.

[0025] This invention utilizes a total station for surveying and layout. Marking points and control points are established at the center and sides of the weir, creating a positioning area for each stepping stone and control lines for verifying the installation position of each row of stepping stones. This ensures the stepping stones are precisely positioned on the top of the weir according to the design drawings, guaranteeing accurate positioning, neat arrangement, and straight axis of the installed stepping stones, resulting in a harmonious and aesthetically pleasing overall structure and excellent construction effect. When installing the support positioning device, it can be quickly placed on the concrete panel at the bottom of the weir according to the markings in the positioning area, and its position can be verified using a plumb line. During stepping stone installation, the control lines allow for rapid position verification. These control lines can be laid out using nylon thread or infrared rays. Nylon thread is convenient and low-cost, while infrared rays are unaffected by wind or weight, resulting in more accurate verification.

[0026] In this invention, the fixing of stepping stones to the weir can be carried out simultaneously with the pouring of concrete on the weir crest. Compared to traditional pre-reserved groove or pre-reserved box methods, the support and positioning device used in this invention offers better stability, is less prone to damage and deformation, and provides more accurate positioning. Furthermore, it achieves integrated cast-in-place construction of the stepping stones and the weir crest, with the bottom of the stepping stones embedded in the weir crest concrete for fixation. This makes the connection between the stepping stones and the weir crest more robust and integral, extending the service life of the stepping stones, reducing construction waiting time, improving construction efficiency, and ensuring the smooth progress of the project. Before pouring the concrete on the weir crest, this invention takes protective measures for the exposed concrete portion of the stepping stones, preserving the overall appearance of the stepping stones and combining aesthetics with practicality.

[0027] The method of this invention is applicable to the installation of stepping stones of various arrangement types, with a wide range of applications, good results, and is economical and practical. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the supporting positioning device;

[0029] Figure 2 This is a side view of the support and positioning device placed on the bottom panel concrete.

[0030] Figure 3 This is a schematic diagram showing the frontal positional relationship of the stepping stones after the concrete is poured on the top of the weir;

[0031] Figure 4 This is a schematic diagram of Example 1 during the layout process;

[0032] Figure 5 This is a schematic diagram of the layout process in Example 2;

[0033] Figure 6 This is another schematic diagram of Example 2 during the layout process;

[0034] Figure 7 This is a schematic diagram showing the effect after the construction of Example 2 is completed.

[0035] In the picture:

[0036] 1. Support and positioning device; 11. Longitudinal fixing frame; 111. Second longitudinal reinforcement; 112. Second vertical reinforcement; 12. Transverse fixing frame; 121. First transverse reinforcement; 122. First vertical reinforcement; 13. Tie bar; 14. Reinforcing reinforcement; 15. Supporting reinforcement; 151. Support section; 152. Protruding section; 2. Bottom panel concrete; 3. Weir crest concrete; 4. Binding reinforcement; 5. Stepping stones; 51. Stepping stone embedded in concrete; 52. Stepping stone exposed in concrete; 6. Control point; 7. Marker point; 8. Control line; 9. Positioning area. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1:

[0039] like Figures 1-4 As shown, a certain weir includes a bottom panel concrete 2 and a weir crest concrete 3. A row of parallel stepping stones 5 are installed on the top surface of the weir crest concrete 3. The construction process of this embodiment is as follows: first, the bottom panel concrete 2 is poured and cured, then the weir reinforcement 4 is tied, and finally the stepping stones 5 and the weir crest concrete 3 are poured on the bottom panel concrete 2.

[0040] The specific steps for constructing stepping stones for weirs and dams are as follows:

[0041] (1) In the processing plant, the rough stones are processed into stepping stones 5. The dimensions of the stepping stones 5 are uniformly 100×40×50cm (length×width×height). According to the construction drawings, the support and positioning device 1 is made. The support and positioning device 1 includes two horizontal fixing frames 12 arranged side by side. The middle of the two horizontal fixing frames 12 is connected to a vertical fixing frame 11 perpendicular to it. The horizontal fixing frame 12 includes a first horizontal steel bar 121 parallel to the horizontal plane and two first vertical steel bars 122 vertically arranged at both ends of the first horizontal steel bar 121. The length of the first horizontal steel bar 121 is equal to the length of the stepping stone 5. The length of the first horizontal steel bar 121 is 100cm. Two vertical support steel bars 15 are symmetrically arranged on the first horizontal steel bar 121. The vertical fixing frame 11 includes a second vertical steel bar 111 parallel to the horizontal plane and two second vertical steel bars 112 vertically arranged at both ends of the second vertical steel bar 111. The length of the second vertical steel bar 111 is equal to the width of the stepping stone 5. The length of the second vertical steel bar 111 is 40cm.

[0042] In manufacturing the support positioning device 1, both the transverse fixing frame 12 and the longitudinal fixing frame 11 are made of a single steel bar, and the two ends of the steel bar are bent to the same side at 90° using a bending machine. The transverse fixing frame 12 is fixed to the longitudinal fixing frame 11 and the supporting steel bar 15 by welding.

[0043] The portion of the supporting reinforcement 15 extending below the first transverse reinforcement 121 is the supporting section 151. The height h of the supporting section 151 is set as the difference between the pouring height H of the concrete 3 at the top of the weir and the height h1 of the stepping stone embedded in the concrete portion 51. Both the pouring height H of the concrete 3 at the top of the weir and the height h1 of the stepping stone embedded in the concrete portion 51 are specified in the construction drawings. By controlling the height of the supporting section 151, the installation height of the stepping stone 5 is precisely determined, ensuring the correct position of the stepping stone 5.

[0044] The portion of the supporting reinforcing bar 15 extending above the first transverse reinforcing bar 121 is a protruding section 152. The height of the protruding section 152 is set to be greater than 1.75 times the diameter of the reinforcing bar to reduce the impact of the bending point of the reinforcing bar.

[0045] The heights of the first vertical reinforcing bar 122 and the second vertical reinforcing bar 112 are both set to 1 / 3 to 1 / 2 of the height h1 of the stepping stone embedded in the concrete part 51. This not only allows them to be embedded in the concrete together with the bottom of the stepping stone 5, which helps to fix the position of the stepping stone 5, but also allows for sufficient concrete protective layer thickness.

[0046] A tie bar 13 is fixedly connected between the supporting steel bar 15 and the first transverse steel bar 121, and a reinforcing steel bar 14 is fixedly connected between the two first transverse steel bars 121. Preferably, the supporting steel bar 15, the reinforcing steel bar 14 and the first transverse steel bar 121 are perpendicularly connected to each other and intersect at a point. By setting the tie bar 13 and the reinforcing steel bar 14, the stability of the support positioning device 1 is improved.

[0047] (2) After the concrete 2 of the bottom panel of the dam is poured and the steel reinforcement 4 of the dam is tied, control points 6 and marker points 7 are arranged in sequence according to the construction drawings. Control points 6 are arranged on both sides of the dam according to the longitudinal position of the outer edge of the stepping stone 5 of the row. Marker points 7 are arranged in the center of the bottom panel concrete 2 according to the longitudinal and transverse positions of the four vertices of each stepping stone 5.

[0048] Before setting out according to the construction drawings, surveyors set up a total station at known points and established a coordinate system, with the length of the weir as the abscissa and the width of the weir as the ordinate. During the setting out, if... Figure 4 As shown, two sets of control points 6 are arranged according to the minimum and maximum values ​​of the longitudinal coordinates of the stepping stones 5 projected onto the weir. The first set of control points is set on both sides of the weir based on the maximum value of the longitudinal coordinates (see...). Figure 4 (Y1 and Y1' in the upper middle row), a set of control points are set on both sides of the weir based on the minimum value of the ordinate (see...). Figure 4 (Y1 and Y1' in the middle and lower rows). Based on the horizontal and vertical coordinates of the four vertices of the orthographic projection of each stepping stone 5 in this row onto the bottom concrete panel 2, mark points 7 are arranged, such as... Figure 4As shown, the four marker points 7 of the first stepping stone 5 are set as A1, B1, C1, and D1 in clockwise order, and then the marker points 7 are arranged for the other stepping stones 5 in the same way. The control points 6 and marker points 7 obtained by the total station are marked with a marker pen or paint.

[0049] (3) Connect the four marker points 7 belonging to the same stepping stone 5 to form a rectangular positioning area 9. The positioning area 9 has the same shape and size as the stepping stone 5. And lay out the control lines 8 between the control points 6 in the same longitudinal position. The elevation of the control lines 8 is set within the elevation range of the exposed concrete part 52 of the stepping stone.

[0050] Using paint or markers, connect the marker points A1, B1, C1, and D1 in sequence to form the rectangular positioning area Z1 of the first stepping stone 5. Similarly, lay out the positioning areas Z2, Z3, and Z4 of the other three stepping stones 5 in the center of the dam.

[0051] Vertical poles are erected at two control points Y1 and Y1' belonging to the same group. A nylon line is stretched between the two poles as a control line 8 and kept straight and taut. The arrangement of the stepping stones in the row is checked by setting up two rows of control lines.

[0052] (4) Professional surveyors use an infrared ray meter to check and retest steps (2) and (3).

[0053] (5) Place the support positioning device 1 on the bottom panel concrete 2 in sequence according to the instructions of the positioning area 9.

[0054] When placing the support positioning device 1, plumb lines are hung at the bends at both ends of the longitudinal fixing frame 11 and the two transverse fixing frames 12 (the bend of the longitudinal fixing frame 11 is the connection between the second longitudinal steel bar 111 and the second vertical steel bar 112, and the bend of the transverse fixing frame 12 is the connection between the first transverse steel bar 121 and the first vertical steel bar 122). If the positioning area 9 is entirely within the six plumb lines, the support positioning device 1 is correctly positioned; otherwise, continue adjusting until the position is correct.

[0055] After the position of the support positioning device 1 is determined, the four support steel bars 15 of the support positioning device 1 are fixedly connected to the non-main structure steel bars of the weir. During fixing, welding, wire binding, or fastener clamping can be used.

[0056] (6) Hoist multiple stepping stones 5 onto the support and positioning device 1 in sequence; and verify the correct placement of the stepping stones by using the control line 8. If the placement is incorrect, readjust until the position is correct. After the inspection is successful, proceed with the layout and installation of the next row of stepping stones until all stepping stones are placed.

[0057] When the stepping stone 5 is hoisted onto the support and positioning device 1 by a crane, if the control line 8 is always close to the outer edge of the side wall of the stepping stone 5 and remains straight, the stepping stone 5 is in the correct position. Otherwise, the support and positioning device 1 or the stepping stone 5 should be readjusted until the position is correct.

[0058] (7) After all the stepping stones 5 are placed, pour the concrete 3 on the top of the weir to the design elevation, vibrate it thoroughly, cover the concrete surface with insulation cotton and sprinkle water to cure it.

[0059] Before pouring concrete, the exposed concrete portion 52 of the stepping stones is covered and protected with EVA plastic film, while the portion 51 embedded in the concrete is left unprotected to ensure that the outer surface of the stepping stones 5 will not be contaminated and its appearance will not be affected when pouring concrete.

[0060] During concrete pouring, concrete mixer trucks are used to transport the concrete to the pouring area at the top of the weir, and a truck-mounted pump is used to vertically deliver the concrete into the formwork. High-frequency vibrators are used for concrete compaction, with the vibrator holes arranged in a quincunx pattern. The vibration time at each location is approximately 20-30 seconds, continuing until the concrete no longer settles significantly, no more air bubbles appear, and the surface begins to show a slurry-like appearance. Vibration operations must be strictly performed according to the operating procedures. During vibration, the vibrator must not touch the weir's reinforcing steel bars 4 or embedded parts, especially the stepping stones 5. The vertical distance between the vibrator and the weir's concrete formwork should not be less than 1 / 2 of the vibrator's effective radius of action, and the displacement distance of the vibrator should not exceed 1.5 times its effective radius of action.

[0061] Example 2:

[0062] like Figures 5-7 As shown, in Example 2, two rows of staggered stepping stones 5 are installed on the top of the same weir as in Example 1. The specific steps for the construction of the stepping stones are as follows:

[0063] (1) In the processing plant, the rough stones are processed into stepping stones 5 of uniform size, and a support and positioning device 1 is made according to the size of the stepping stones 5 and the construction drawings. The structure of the support and positioning device 1 in this embodiment is the same as that in embodiment 1, and will not be described again.

[0064] When manufacturing the support and positioning device 1, both the transverse fixing frame 12 and the longitudinal fixing frame 11 are made of three steel bars. During processing, two short steel bars are vertically welded and fixed to the same side at both ends of the long steel bar. The transverse fixing frame 12 is fixed to the longitudinal fixing frame 11 and the support steel bar 15 by welding.

[0065] (2) After the concrete 2 of the bottom panel of the weir is poured and the reinforcement 4 of the weir is tied, lay out the steps row by row according to the construction drawings (stepping stones arranged on the same straight line are the same row of stepping stones). According to the longitudinal position of the outer edge of the stepping stone 5 in the row, control points 6 are arranged on both sides of the weir. According to the longitudinal and transverse positions of the four vertices of each stepping stone 5 in the row, mark points 7 are arranged at the center of the bottom panel concrete 2.

[0066] Before setting out, surveyors set up a total station at the known points and established a coordinate system, with the length of the weir as the abscissa and the width of the weir as the ordinate. During the setting out, if... Figure 6 As shown, the first stepping stones 5 are laid out. A set of control points is established based on the maximum value of the longitudinal coordinate of the first row of stepping stones 5 projected onto the weir. Two control points 6, Y1 and Y1', are set on both sides of the weir. These control points 6 are marked with a marker or paint. Then, following a left-to-right order, four marker points 7 are established on the bottom panel concrete 2 based on the transverse and longitudinal coordinates of the four vertices of the first row of stepping stones 5 projected onto the weir. These marker points 7 are then marked with a marker or paint.

[0067] (3) Use paint or a marker to connect the four marker points 7 of the first stepping stone 5 in the first row to form the positioning area Z1, and so on, continue to lay out the positioning area Z2 of the second stepping stone 5 in the first row.

[0068] An infrared ray meter is set up at control point Y1 and emits infrared rays towards control point Y1' as control line 8. The elevation of the infrared rays is set within the elevation range of the exposed concrete portion 52 of the stepping stones. A black baffle is placed on control point Y1', and a marking line is drawn on the black baffle, making the marking line perpendicular to the ground and extending through control point Y1'.

[0069] (4) After the first row of stepping stones is laid out, professional surveyors will inspect and remeasure it.

[0070] (5) Then place the support positioning device 1 on the bottom panel concrete 2 according to the instructions of the positioning area 9, and judge whether the placement of the support positioning device 1 is correct by hanging a plumb line. After confirming that the position is correct, fix the support steel bar 15 to the non-main structure steel bar of the weir.

[0071] (6) Hoist multiple stepping stones 5 sequentially onto the support and positioning device 1. During installation, if a red dot consistently appears on the marked line on the baffle, the position is accurate; otherwise, readjust the stepping stones 5 or the support and positioning device 1 until the position is correct. After verification, lay out the second row of stepping stones 5, such as... Figure 7As shown, based on the maximum value of the longitudinal coordinate of the second row of stepping stones projected onto the weir, a set of control points Y2 and Y2' are arranged on both sides of the weir. Then, the marker points 7 of each stepping stone 5 in this row are arranged sequentially from left to right. The subsequent steps of arranging the positioning area 9 and control lines 8 are the same as the arrangement method of the first row of stepping stones 5, and will not be repeated here. In this embodiment, a set of control points 6 are arranged for each row of stepping stones using an infrared ray meter. Since the stepping stones are regular rectangles, arranging at least one set of control lines 8 is sufficient to verify the position of the stepping stones 5. Furthermore, the infrared rays arranged by the infrared ray meter are used as control lines and are not affected by wind or weight, making the verification more accurate.

[0072] (7) Pour concrete to the design elevation at the top of the weir, and after thorough vibration, cover the concrete surface with insulation cotton and sprinkle water for curing. Before pouring concrete, cover the exposed concrete portion of the stepping stones with EVA plastic film for protection.

[0073] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method for constructing stepping stones for weirs and dams, characterized in that, Includes the following steps: (1) In the processing plant, the rough stones are processed into stepping stones of uniform size, and a support and positioning device is made according to the construction drawings. The support and positioning device includes two horizontal fixing frames arranged side by side. The middle of the two horizontal fixing frames is connected to a vertical fixing frame perpendicular to them. The horizontal fixing frame includes a first horizontal steel bar parallel to the horizontal plane and two first vertical steel bars set at both ends of the first horizontal steel bar. The length of the first horizontal steel bar is equal to the length of the stepping stone. Two vertical support steel bars are symmetrically arranged on the first horizontal steel bar. The vertical fixing frame includes a second vertical steel bar parallel to the horizontal plane and two second vertical steel bars set at both ends of the second vertical steel bar. The length of the second vertical steel bar is equal to the width of the stepping stone. (2) After the concrete of the bottom panel of the weir is poured and the reinforcement of the weir is tied, the control points and markers of the stepping stones are arranged in sequence according to the construction drawings. The control points are arranged on both sides of the weir according to the longitudinal position of the outer edge of the stepping stone in the row. The markers are arranged at the center of the bottom panel concrete according to the longitudinal and transverse positions of the four vertices of each stepping stone in the row. (3) Connect the four markers belonging to the same stepping stone to form a positioning area, and lay out the control line between the control points in the same longitudinal position to form a control line. The elevation of the control line is set within the elevation range of the exposed concrete part of the stepping stone. (4) The measurement personnel shall check and remeasure steps (2) and (3); (5) Place the support positioning devices on the bottom panel concrete in sequence according to the instructions of the row of positioning areas. After verifying that the position of the support positioning devices is correct, fix the four support steel bars of the support positioning devices to the non-main structure steel bars of the weir. (6) Hoist the stepping stones onto the support and positioning device in sequence, and check the placement of the stepping stones in the row through the control line. If it is incorrect, readjust until the position is correct. After the inspection is correct, lay out and install the next row of stepping stones until all the stepping stones are placed. (7) Pour the concrete on the top of the weir to the design elevation, vibrate it thoroughly, cover the concrete surface with insulation cotton and sprinkle water to cure it.

2. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, The portion of the supporting reinforcement extending below the first transverse reinforcement is the supporting section. The height h of the supporting section is set as the difference between the concrete pouring height H at the top of the weir and the height h1 of the stepping stone embedded in the concrete.

3. The method for constructing stepping stones for weirs and dams according to claim 2, characterized in that, The heights of the first and second vertical reinforcing bars are both set to 1 / 3 to 1 / 2 of the height h1 of the stepping stone embedded in the concrete.

4. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, Tie bars are fixedly connected between the supporting steel bars and the first transverse steel bars, and several reinforcing steel bars are fixedly connected between the two first transverse steel bars.

5. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, Before setting out according to the construction drawings, the surveyors set up a total station at the known points and established a coordinate system, with the length of the weir as the abscissa and the width of the weir as the ordinate. During the setting out, control points are first arranged according to the minimum and / or maximum ordinate of the orthographic projection of the m-th row of stepping stones on the weir. Each group of control points includes two control points Ym and Ym' with the same ordinate, and control points Ym and Ym' are arranged on both sides of the weir. Then, according to the abscissa and ordinate of the four vertices of the orthographic projection of the nth (n = 1, 2, 3...) stepping stone in the m-th row on the weir, four marker points are arranged on the bottom panel concrete. The four marker points are connected in sequence to form the positioning area Zn of the nth stepping stone in that row.

6. The method for constructing stepping stones for weirs and dams according to claim 5, characterized in that, Vertical poles are set at control points Ym and Ym' in the same set. A nylon line is stretched between the two poles as a control line and kept straight and taut. After the stepping stone is hoisted onto the support and positioning device, if the control line is always close to the outer edge of the stepping stone side wall and remains straight, the position is accurate. Otherwise, readjust until the position is correct.

7. The method for constructing stepping stones for weirs and dams according to claim 5, characterized in that, Set up an infrared ray meter at control point Ym and make it emit infrared rays to control point Ym' in the same group to form a control line. Place a black baffle facing control point Ym' on control point Ym' and draw a marking line on the black baffle, making the marking line perpendicular to the ground and extending through control point Ym'. When hoisting the stepping stone onto the support and positioning device, if a red dot always appears on the marking line on the baffle, the position is accurate; otherwise, readjust until the position is correct.

8. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, When placing the support positioning device, hang plumb lines at the bends at both ends of the longitudinal fixing frame and the two transverse fixing frames. If the entire positioning area is located inside the six plumb lines, the support positioning device is correctly positioned; otherwise, continue adjusting until the position is correct.

9. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, Before pouring concrete, the exposed concrete portions of the stepping stones are covered and protected with EVA plastic film.

10. The method for constructing stepping stones for weirs and dams according to claim 1, characterized in that, When vibrating concrete, a high-frequency vibrator should be used, with the holes of the vibrator arranged in a quincunx pattern. The vibration time at each position should continue until the concrete no longer settles significantly, no more air bubbles appear, and the surface begins to rise to a slurry level. During vibration, the vibrator must not touch the reinforcement bars, embedded parts, or stepping stones of the weir. The vertical distance between the vibrator and the concrete formwork of the weir should not be less than 1 / 2 of the effective radius of the vibrator, and the displacement distance of the vibrator should not exceed 1.5 times the effective radius of the vibrator.

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