Concrete slope protection plate auxiliary laying device and laying method for channel construction

Abstract

The invention discloses an auxiliary laying device and method for a concrete slope protection plate for channel construction, and relates to the auxiliary laying device and method for the concrete slope protection plate. The problems that the labor intensity of workers is high and the safety risk is large in the channel protection building construction process are solved. On the premise that the laying quality of the concrete slope protection plate is guaranteed, damage to a slope surface sand cushion layer is reduced, safety of workers in the slope surface construction process is improved, and potential safety hazards such as slipping, falling injury, clamping injury and bumping of the workers in the construction process are reduced; and the hoisting unit greatly reduces the labor intensity of manual carrying while ensuring the safety. When the slope surface of the channel is laid, an included angle beta is formed between the crossing truss and the axis of the channel, a worker lays the concrete slope protection plate in the direction from the channel bottom to the channel top, and the problem that butt joint cannot be achieved due to staggered stubbles in a segmented construction method is solved; and meanwhile, the problem that butt joints are filled through cast-in-place or precast slab cutting is avoided. The invention belongs to the technical field of concrete slope protection plate laying.

Description

Technical Field

[0001] The invention relates to a concrete slope protection board auxiliary laying device and a laying method, in particular to a concrete slope protection board auxiliary laying device and a laying method for channel construction, belonging to the technical field of concrete slope protection board laying. Background Art

[0002] With the development and construction of irrigation areas by the country, the modernization of irrigation areas is in full swing. In order to facilitate the operation and maintenance of water diversion channels in the later stage, prefabricated concrete slope protection boards are mostly used in the channel protection. Since the existing channels need to maintain normal irrigation water in spring and summer and cannot be cut off, the effective construction period of channel protection is greatly shortened.

[0003] At present, most of the channel protection construction is done by workers using tow hooks to drag the concrete slope protection panels from the stacking position on the top of the channel to the foot of the slope until they are dragged to the designated laying position.

[0004] During the dragging process, the sand cushion layer on the channel slope will be damaged because the dragging method and posture are difficult to control accurately, so the workers' experience is required to be relatively high. In addition, there is a shortage of technical personnel for professionally laying slope protection boards, and the cost of paving a single board is high. Secondly, the weight of a prefabricated board is about 90kg, and manual dragging is inefficient, the labor intensity is high, and it is easy for workers to bump into their hands and feet, posing a great safety risk.

[0005] Accordingly, during the construction of channel protection masonry, the channel is usually divided into several sections, and the sections are laid together. However, the above-mentioned segmented construction method has the following shortcomings:

[0006] Firstly, when laying on the slope of the channel, workers can only lay the row of precast slabs closest to the channel bottom first, and then lay the precast slabs row by row from the channel bottom to the channel top. This method often leads to the gradual accumulation of laying errors of each precast slab when two adjacent work sections are docked, which eventually leads to the precast slabs being misaligned and unable to dock.

[0007] Secondly, gaps need to be reserved between adjacent precast panels. If the gaps are not evenly controlled, the joints between the two adjacent work sections will often be too large. Workers have to pour concrete in the joints to fill them, or cut a precast panel based on the size of the joints and then fill them into the joints.

[0008] In summary, how to propose a concrete slope protection board auxiliary laying device and laying method to address the above technical problems has become an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0009] In view of the above-mentioned deficiencies of the prior art, the present invention provides a concrete slope protection plate auxiliary laying device and laying method for channel construction.

[0010] The technical solution of the present invention is: an auxiliary laying device for concrete slope protection plates for channel construction, comprising a first vertical walking arm, a second vertical walking arm, a cross truss and a lifting unit.

[0011] The height of the second vertical walking arm is greater than that of the first vertical walking arm, and the first vertical walking arm and the second vertical walking arm are respectively vertically installed at two ends of the cross truss.

[0012] The first vertical walking arm and the second vertical walking arm both include a vertical truss and an electric walking crawler, and the vertical truss is connected to the electric walking crawler through a steering mechanism.

[0013] The lifting unit includes slide rails, electric hoists and scissor-type slope protection plate clamps.

[0014] The slide rail is fixed to the lower surface of the cross truss, the electric hoist is installed on the slide rail, and the electric hoist can move along the length direction of the slide rail, and the scissor-type slope protection plate clamp is connected with the sling on the electric hoist.

[0015] Furthermore, the steering mechanism includes a steering motor, a planetary gear and an internal gear turntable bearing.

[0016] A driving gear is installed on the output shaft of the steering motor, the steering motor is fixedly connected to the vertical truss, the vertical truss is fixedly connected to the inner ring of the internal gear turntable bearing, and the outer ring of the internal gear turntable bearing is fixedly connected to the frame of the electric walking crawler.

[0017] The planetary gear is rotatably connected to the frame of the electric walking crawler, and the planetary gear is arranged between the driving gear and the inner ring of the internal gear turntable bearing, and the inner ring of the internal gear turntable bearing and the driving gear are both meshed with the planetary gear.

[0018] The present invention also provides a method for laying a concrete slope protection plate for channel construction, which is specifically carried out in the following steps:

[0019] Step 1: Lay the channel bottom

[0020] Step 11: The second vertical walking arm is arranged at the bottom of the channel, and the first vertical walking arm is arranged at the top of the channel, and the cross truss is ensured to be parallel to the horizontal plane;

[0021] Step 1 and 2: The first vertical walking arm and the second vertical walking arm move along the length direction of the channel at the same time, the lifting unit lifts the concrete slope protection board to the designated position at the bottom of the channel, and the workers lay the concrete slope protection board along the length direction of the channel;

[0022] Step 2: Lay the slope of the channel

[0023] Step 21: The first vertical walking arm and the second vertical walking arm move in opposite directions relative to each other. At the same time, the steering mechanism is started, and the steering mechanism and the electric walking crawler are coordinated to form an angle β between the cross truss and the axis of the channel;

[0024] Step 22: The first vertical walking arm and the second vertical walking arm move along the length direction of the channel at the same time, the lifting unit lifts the concrete slope protection board to the designated position on the slope, and the workers lay the concrete slope protection board in the direction from the bottom of the channel to the top of the channel.

[0025] Compared with the prior art, the present invention has the following effects:

[0026] 1. The present invention reduces the damage to the sand cushion layer on the slope while ensuring the quality of laying the concrete slope protection board, and is also beneficial to improving the safety of workers during slope construction, reducing safety hazards such as slips, falls, pinches, and bumps during construction; the lifting unit 400 greatly reduces the labor intensity of manual handling while ensuring safety, thereby reducing labor cost consumption.

[0027] 2. The present invention is easy to operate. When laying the channel bottom, the present invention moves along the length direction of the channel, and workers lay the concrete slope protection plates along the length direction of the channel.

[0028] When laying the slope of the channel, the cross truss 300 forms an angle β with the axis of the channel, and then the first vertical walking arm 100 and the second vertical walking arm 200 move along the length direction of the channel at the same time, and the lifting unit 400 lifts the concrete slope protection board to the specified position of the slope, and the workers lay the concrete slope protection board in the direction from the bottom of the channel to the top of the channel. With this arrangement, the present invention realizes construction from one end of the channel to the other end, avoiding the problem of segmented construction method that cannot be connected due to misalignment; at the same time, it avoids the problem of on-site casting or cutting of prefabricated panels to fill the joints, saving time and reducing construction waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is an axonometric view of the present invention;

[0030] Figure 2 is an axonometric view of the steering mechanism 510 of the present invention;

[0031] Figure 3 is an axonometric view of the hoisting unit 400 of the present invention;

[0032] Figure 4 It is a front view of the scissor-type slope protection plate clamp 430 of the present invention;

[0033] Figure 5 It is a schematic diagram of the present invention when laying a slope.

[0034] In the figure: 100, first vertical walking arm; 200, second vertical walking arm; 300, cross truss; 400, lifting unit; 410, slide rail; 420, electric hoist; 430, scissor-type slope protection plate clamp; 431, first clamping arm; 432, second clamping arm; 432-1, handle; 433, support rod; 434, first transmission arm; 435, second transmission arm; 436, third transmission arm; 437, fourth transmission arm; 438, fifth transmission arm; 439, sixth transmission arm; 500, electric walking crawler; 510, steering mechanism; 511, steering motor; 512, internal gear turntable bearing; 513, driving gear; 514, planetary gear. DETAILED DESCRIPTION

[0035] In order to make the purpose, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0036] Specific implementation method 1: Combination Figures 1 to 4 The present embodiment is described below. The present embodiment is a concrete slope protection board auxiliary laying device for channel construction, which includes a first vertical walking arm 100 , a second vertical walking arm 200 , a cross truss 300 and a hoisting unit 400 .

[0037] The height of the second vertical traveling arm 200 is greater than that of the first vertical traveling arm 100 , and the first vertical traveling arm 100 and the second vertical traveling arm 200 are respectively vertically installed at two ends of the cross truss 300 .

[0038] The first vertical walking arm 100 and the second vertical walking arm 200 both include a vertical truss and an electric walking track 500 , and the vertical truss is connected to the electric walking track 500 via a steering mechanism 510 .

[0039] The lifting unit 400 includes a slide rail 410 , an electric hoist 420 and a scissor-type slope protection plate clamp 430 .

[0040] The slide rail 410 is fixed to the lower surface of the cross truss 300 , the electric hoist 420 is installed on the slide rail 410 , and the electric hoist 420 can move along the length direction of the slide rail 410 , and the scissor-type slope protection plate clamp 430 is connected to the sling on the electric hoist 420 .

[0041] Furthermore, the electric hoist 420 is a CD type electric hoist.

[0042] Specific implementation method 2: Combination Figure 1 to Figure 2 The present embodiment will be described. In the present embodiment, the steering mechanism 510 includes a steering motor 511 , a planetary gear 514 , and an internal gear type turntable bearing 512 .

[0043] A driving gear 513 is installed on the output shaft of the steering motor 511 . The steering motor 511 is fixedly connected to the vertical truss. The vertical truss is fixedly connected to the inner ring of the internal gear turntable bearing 512 . The outer ring of the internal gear turntable bearing 512 is fixedly connected to the frame of the electric walking crawler 500 .

[0044] The planetary gear 514 is rotatably connected to the frame of the electric walking crawler 500. Further, a pin is fixed to the frame of the electric walking crawler 500, and the planetary gear 514 is mounted on the pin to realize the rotatable connection between the planetary gear 514 and the frame of the electric walking crawler 500.

[0045] The planetary gear 514 is disposed between the driving gear 513 and the inner ring of the internal gear type turntable bearing 512 , and both the inner ring of the internal gear type turntable bearing 512 and the driving gear 513 are meshed with the planetary gear 514 .

[0046] Other components and connection relationships are the same as those in the first specific implementation method.

[0047] Specific implementation method three: Combination Figure 1 , Figure 3 and Figure 4 To illustrate this embodiment, in this embodiment, the scissor-type slope protection plate clamp 430 includes a first clamp arm 431, a second clamp arm 432, a support rod 433, a scissor-type clamp arm unit, a third transmission arm 436, a fourth transmission arm 437, a fifth transmission arm 438 and a sixth transmission arm 439.

[0048] The first clamping arm 431 and the second clamping arm 432 are symmetrically arranged, and two ends of the support rod 433 are hinged to the first clamping arm 431 and the second clamping arm 432 respectively.

[0049] The scissor-type clamping arm unit includes a first transmission arm 434 and a second transmission arm 435 , and the first transmission arm 434 and the second transmission arm 435 are arranged in an X shape.

[0050] Both ends of the fifth transmission arm 438 are hinged to the sling and the third transmission arm 436 respectively.

[0051] Both ends of the sixth transmission arm 439 are hinged to the sling and the fourth transmission arm 437 respectively.

[0052] Two ends of the first transmission arm 434 are hinged to the first clamping arm 431 and the fourth transmission arm 437 respectively.

[0053] Two ends of the second transmission arm 435 are hinged to the second clamping arm 432 and the third transmission arm 436 respectively.

[0054] The other components and connection relationships are the same as those in the first or second specific implementation.

[0055] Specific implementation method four: Combination Figure 1 and Figure 3 To explain this embodiment, in this embodiment, the first clamp arm 431 and the second clamp arm 432 both include a clamping claw, a connecting arm and a pin shaft.

[0056] One end of the connecting arm is fixedly connected to the clamping claw, and the other end of the connecting arm is hinged to the pin shaft.

[0057] The first transmission arm 434 is fixedly connected to a pin on the first clamping arm 431 , and the second transmission arm 435 is fixedly connected to a pin on the second clamping arm 432 .

[0058] Two ends of the support rod 433 are hinged to the connecting arm on the first clamping arm 431 and the connecting arm on the second clamping arm 432 respectively.

[0059] The other components and connection relationships are the same as those of the first, second or third specific implementation modes.

[0060] Specific implementation method five: Combination Figure 1 and Figure 3 The present embodiment is described. In the present embodiment, the slide rail 410 and the cross truss 300 are connected by welding.

[0061] Furthermore, the slide rail 410 is an H-shaped steel.

[0062] Furthermore, the clamping claw is an angle steel.

[0063] The other components and connection relationships are the same as those of the first, second, third or fourth specific implementation modes.

[0064] Specific implementation method six: Combination Figure 3 and Figure 4 To explain this embodiment, in this embodiment, a handle 432 - 1 is installed on the second clamp arm 432 . Furthermore, the handle 432 - 1 is fixedly connected to the pin of the second clamp arm 432 .

[0065] The other components and connection relationships are the same as those of the first, second, third, fourth or fifth specific implementation modes.

[0066] Specific implementation method seven: Combination Figure 1 This embodiment further includes a remote controller and a controller. The electric hoist 420, the electric walking crawler 500 and the steering motor 511 are all electrically connected to the controller, and the remote controller sends a control signal to the controller, thereby realizing remote control of the present invention.

[0067] The other components and connection relationships are the same as those of the first, second, third, fourth, fifth or sixth specific embodiments.

[0068] Specific implementation method eight: Combination Figures 1 to 5 The present embodiment is described. A method for laying a concrete slope protection plate for channel construction in the present embodiment is carried out according to the following steps:

[0069] Step 1: Lay the channel bottom

[0070] Step 11: The second vertical walking arm 200 is arranged at the bottom of the channel, and the first vertical walking arm 100 is arranged at the top of the channel, and the cross truss 300 is ensured to be parallel to the horizontal plane;

[0071] Step 1 and 2: The first vertical walking arm 100 and the second vertical walking arm 200 move along the length direction of the channel at the same time, the hoisting unit 400 hoists the concrete slope protection board to the designated position at the bottom of the channel, and the workers lay the concrete slope protection board along the length direction of the channel;

[0072] Step 2: Lay the slope of the channel

[0073] Step 21: The first vertical walking arm 100 and the second vertical walking arm 200 move in opposite directions. At the same time, the steering mechanism 510 is started. Through the cooperation between the steering mechanism 510 and the electric walking crawler 500, an angle β is generated between the cross truss 300 and the axis of the channel.

[0074] Step 22: The first vertical walking arm 100 and the second vertical walking arm 200 move along the length direction of the channel at the same time, the lifting unit 400 lifts the concrete slope protection board to the designated position on the slope, and the workers lay the concrete slope protection board in the direction from the bottom of the channel to the top of the channel.

[0075] In this embodiment, when a single unit of the present invention is used for construction, the present invention first moves forward along the channel to lay the channel bottom, and then moves backward along the channel to lay the slope surface, then removes the cross truss 300, and moves the first vertical walking arm 100 to the top of the channel on the other side, and finally reconnects the two ends of the cross truss 300 with the first vertical walking arm 100 and the second vertical walking arm 200, and then lays the remaining channel bottom and slope surface according to the above construction method.

[0076] When two machines of the present invention are used for construction, the two machines are arranged side by side front and back and move forward at the same time, and the channel bottom and two slope surfaces can be paved by "advancing first and then retreating" along the length direction of the channel.

[0077] The other components and connection relationships are the same as those of the first, second, third, fourth, fifth, sixth or seventh specific embodiments.

[0078] How it works

[0079] Combination Figures 1 to 5 The working principle of the present invention is described:

[0080] The height of the second vertical walking arm 200 is greater than that of the first vertical walking arm 100, and the first vertical walking arm 100 and the second vertical walking arm 200 are respectively vertically installed at both ends of the cross truss 300. In this arrangement, during construction at the construction site, the first vertical walking arm 100 is placed on the top of the channel, and the second vertical walking arm 200 is placed on the bottom of the channel.

[0081] The electric walking track 500 has a strong load-bearing capacity and a large contact area with the ground at the construction site, which reduces the pressure. The steering mechanism 510 can drive the present invention to turn. Therefore, the cooperation between the electric walking track 500 and the steering mechanism 510 can drive the present invention to move to different positions of the channel, thereby achieving different angles β between the cross-truss 300 and the length direction of the channel. At the same time, the electric hoist 420 moves along the length direction of the slide rail 410, which can achieve continuous laying of concrete slope protection boards in the channel.

[0082] The steering principle of the steering mechanism 510 is as follows:

[0083] The outer ring of the internal gear turntable bearing 512 is fixedly connected to the frame of the electric walking crawler 500 , the vertical truss is fixedly connected to the inner ring of the internal gear turntable bearing 512 , the steering motor 511 is fixedly connected to the vertical truss, and a driving gear 513 is installed on the output shaft of the steering motor 511 .

[0084] The planetary gear 514 is rotationally connected to the frame of the electric walking crawler 500 , and the planetary gear 514 is arranged between the driving gear 513 and the inner ring of the internal gear turntable bearing 512 , and the inner ring of the internal gear turntable bearing 512 and the driving gear 513 are both meshed with the planetary gear 514 .

[0085] When the output shaft of the steering motor 511 rotates, it drives the driving gear 513 to rotate together. The driving gear 513 transmits power to the planetary gear 514. When the planetary gear 514 rotates, it also revolves around the axis of the steering motor 511. Therefore, when the planetary gear 514 revolves, it drives the electric walking track 500 to deflect at an angle relative to the vertical truss, thereby realizing the steering of the electric walking track 500 during driving.

[0086] The principle of the scissor type slope protection plate clamp 430 to clamp or release the concrete slope protection plate is as follows:

[0087] When clamping the precast concrete slope protection board, the handle 432-1 on the second clamping arm 432 is moved to rotate the second clamping arm 432 (or the first clamping arm 431) around the hinge between the second clamping arm 432 and the support rod 433, so that the pin shaft on the second clamping arm 432 and the pin shaft on the first clamping arm 431 are relatively close to each other, so that the concrete slope protection board can be embedded in the clamping claws of the first clamping arm 431 and the second clamping arm 432.

[0088] Then the electric hoist 420 slowly tightens the sling, and the hinges of the fifth transmission arm 438, the sixth transmission arm 439, the first transmission arm 434 and the second transmission arm 435 rotate relative to each other, forcing the pin on the second clamping arm 432 to move relatively away from the pin on the first clamping arm 431, and the claws on the first clamping arm 431 and the second clamping arm 432 tightly clamp the concrete slope protection board. As the sling continues to be tightened, the concrete slope protection board is lifted upward.

[0089] The present invention has been disclosed as above in the form of a preferred embodiment, but it is not intended to limit the present invention. Any simple modification, equivalent changes and modifications made to the above implementation cases by any professional and technical personnel who do not deviate from the content of the technical solution of the present invention and based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A concrete slope protection board auxiliary laying device for channel construction, characterized in that: It comprises a first vertical walking arm (100), a second vertical walking arm (200), a cross truss (300) and a hoisting unit (400); The height of the second vertical walking arm (200) is greater than the height of the first vertical walking arm (100), and the first vertical walking arm (100) and the second vertical walking arm (200) are respectively vertically installed at two ends of the cross truss (300); The first vertical walking arm (100) and the second vertical walking arm (200) both comprise a vertical truss and an electric walking crawler (500), and the vertical truss is connected to the electric walking crawler (500) via a steering mechanism (510); The lifting unit (400) comprises a slide rail (410), an electric hoist (420) and a scissor-type slope protection plate clamp (430); The slide rail (410) is fixedly connected to the lower surface of the cross truss (300), the electric hoist (420) is installed on the slide rail (410), and the electric hoist (420) can move along the length direction of the slide rail (410), and the scissor-type slope protection plate clamp (430) is connected to the sling on the electric hoist (420).

2. The device for auxiliary laying of concrete slope protection plates for channel construction according to claim 1 is characterized in that: The steering mechanism (510) comprises a steering motor (511), a planetary gear (514) and an internal gear turntable bearing (512); A driving gear (513) is installed on the output shaft of the steering motor (511), the steering motor (511) is fixedly connected to the vertical truss, the vertical truss is fixedly connected to the inner ring of the internal gear turntable bearing (512), and the outer ring of the internal gear turntable bearing (512) is fixedly connected to the frame of the electric walking crawler (500); The planetary gear (514) is rotatably connected to the frame of the electric walking crawler (500), and the planetary gear (514) is arranged between the driving gear (513) and the inner ring of the internal gear turntable bearing (512), and the inner ring of the internal gear turntable bearing (512) and the driving gear (513) are both meshed with the planetary gear (514).

3. The auxiliary laying device for concrete slope protection plate for channel construction according to claim 1 is characterized by: The scissor-type slope protection plate clamp (430) comprises a first clamping arm (431), a second clamping arm (432), a support rod (433), a scissor-type clamping arm unit, a third transmission arm (436), a fourth transmission arm (437), a fifth transmission arm (438) and a sixth transmission arm (439); The first clamping arm (431) and the second clamping arm (432) are symmetrically arranged, and two ends of the support rod (433) are hinged to the first clamping arm (431) and the second clamping arm (432) respectively; The scissor-type clamping arm unit comprises a first transmission arm (434) and a second transmission arm (435); Two ends of the fifth transmission arm (438) are respectively hinged to the sling and the third transmission arm (436); Two ends of the sixth transmission arm (439) are respectively hinged to the sling and the fourth transmission arm (437); Two ends of the first transmission arm (434) are respectively hinged to the first clamping arm (431) and the fourth transmission arm (437); Two ends of the second transmission arm (435) are respectively hinged to the second clamping arm (432) and the third transmission arm (436).

4. The auxiliary laying device for concrete slope protection plate for channel construction according to claim 3 is characterized in that: The first clamping arm (431) and the second clamping arm (432) both comprise a clamping claw, a connecting arm and a pin shaft; One end of the connecting arm is fixedly connected to the clamping claw, and the other end of the connecting arm is hinged to the pin shaft; The first transmission arm (434) is fixedly connected to a pin on the first clamping arm (431), and the second transmission arm (435) is fixedly connected to a pin on the second clamping arm (432); The two ends of the support rod (433) are respectively hinged to the connecting arm on the first clamping arm (431) and the connecting arm on the second clamping arm (432).

5. The device for auxiliary laying of concrete slope protection plates for channel construction according to claim 3 is characterized in that: A handle (432-1) is mounted on the second clamping arm (432).

6. The device for auxiliary laying of concrete slope protection plates for channel construction according to claim 1, characterized in that: The slide rail (410) is connected to the cross truss (300) by welding.

7. The device for auxiliary laying of concrete slope protection plates for channel construction according to claim 1 is characterized in that: The slide rail (410) is an H-shaped steel.

8. The device for auxiliary laying of concrete slope protection plates for channel construction according to claim 4 is characterized in that: The clamping claw is an angle steel.

9. A method for laying concrete slope protection slabs for channel construction using the auxiliary laying device according to any one of claims 1 to 8, characterized in that: The method is specifically carried out in the following steps: Step 1: Lay the channel bottom Step 11: The second vertical walking arm (200) is arranged at the bottom of the channel, and the first vertical walking arm (100) is arranged at the top of the channel, and the cross truss (300) is ensured to be parallel to the horizontal plane; Step 12: The first vertical walking arm (100) and the second vertical walking arm (200) move along the length direction of the channel at the same time, the lifting unit (400) lifts the concrete slope protection board to a designated position at the bottom of the channel, and the workers lay the concrete slope protection board along the length direction of the channel; Step 2: Lay the slope of the channel Step 21: The first vertical walking arm (100) and the second vertical walking arm (200) move in opposite directions relative to each other. At the same time, the steering mechanism (510) is started. Through the cooperation between the steering mechanism (510) and the electric walking crawler (500), an angle β is generated between the cross truss (300) and the axis of the channel. Step 22: The first vertical walking arm (100) and the second vertical walking arm (200) move along the length direction of the channel at the same time, the lifting unit (400) lifts the concrete slope protection board to the designated position on the slope, and the workers lay the concrete slope protection board in the direction from the bottom of the channel to the top of the channel.

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