An overlapping box for drilling drainage holes in a dam

Abstract

The present invention discloses an overlapping box for drilling drainage holes in a dam, which comprises a drainage hole arranged in a concrete block, an upper protective cover and a lower protective cover covering above the drainage hole, and the lower protective cover is located inside the upper protective cover; both the upper protective cover and the lower protective cover are fixed on the concrete block. Through the cooperative structure of the upper protective cover and the lower protective cover, the present invention forms a protective space above the drainage hole in the previous cast concrete block, and at the same time provides an overlapping foundation for the next cast concrete block. The drainage hole in the next concrete block can be communicated with the drainage hole in the previous concrete block by drilling the overlapping box below, realizing the segmented implementation of the drainage hole along with the cast concrete layer, avoiding the problem of hole inclination control caused by deep drilling and avoiding the influence of pre-buried drainage pipes on the construction of the roller compacted concrete dam; the structure of the present invention is simple, easy to implement, and convenient for pre-buried construction, and can effectively reduce the consumption of manpower and material resources.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic construction, in particular to a lap joint box used for drilling drainage holes in dams. Background Art

[0002] The drainage holes of the dam are vertical pipes used to discharge water seepage from the dam body. The drainage holes can lower the position of the dam body's infiltration line and reduce the seepage pressure. Gravity dams and arch dams are generally equipped with dam body drainage pipes. The dam body drainage position is located on the upstream side of the dam, penetrating through the corridors of each layer in the dam, and up to the vertical drainage hole curtain near the dam top or the overflow weir top. The spacing between single-row drainage holes is generally about 3m. The drainage holes are generally formed by drilling holes from the upper gallery to the lower gallery or drilling upward holes, or using pre-buried drainage blind pipes.

[0003] When drilling holes, in order to control the verticality of the drainage holes and make the drainage holes penetrate through at the designed positions in the lower gallery or in the reserved grooves, the construction party needs to adopt strict measures to control the hole positions and hole inclinations during the construction of the drainage holes. At present, the measures for controlling the hole inclination and the bottom outlet of the drainage holes during the drilling construction of the drainage holes include: 1. Strictly control the accuracy of measurement and setting out. Before the drilling rig is in place and before drilling starts after the drilling rig is in place, it is necessary to use an inclinometer azimuth on-site calibrator and combine it with a total station to accurately check the hole position and azimuth angle; 2. When installing the drilling tool, ensure that the axis of the drilling tool coincides with the designed hole axis, and the center of the drill bit coincides with the hole position point; 3. To ensure that the drilling of the drainage holes meets the hole inclination requirements, it is necessary to fix the drilling rig. The four corners of the drilling rig are fixed with expansion bolts for ground anchoring. During the drilling process, it is necessary to regularly check the tightening degree of the fasteners of the drilling rig. If looseness is found, it must be tightened again; 4. During the drilling process, if a reinforced concrete section is encountered, the drilling rig needs to be lifted to replace the diamond drill bit for drilling. After drilling through the steel bar layer, replace the conventional drill bit; 5. Adopt an anti-inclination drilling tool of "drilling rig limit + hole mouth limit device + hard alloy centralizer + spiral drill pipe"; 6. During the drilling process, in the first 20m, control is carried out every 2 - 5m of drilling. After 20m, measure the hole inclination in time every 5 - 10m, master the drilling trajectory in real time and adjust the parameters of the whipstock accordingly. The first initial inspection is about 20m deep in the hole, and then self-inspect every 5m or so of drilling. According to the different situations of the drilling hole inclination, adjust the parameters of the whipstock in real time; 7. Reserve 0.5m for the drainage holes according to the designed hole depth, and conduct inspections on the bottom positions of the drainage holes. If the bottom position of the hole is within the reserved groove in the gallery, replace the XY-2 geological drilling rig and continue drilling. After passing through the steel mesh, penetrate through the final hole in the reserved groove; if the bottom position of the hole deviates from the range of the reserved groove in the gallery, according to the bottom position of the hole, use an opener in the gallery to drill upward from the curved surface of the reserved groove to connect with the drainage hole; 8. Although various measures for controlling the hole inclination are taken during the construction of the drainage holes, it is still impossible to ensure that each drainage hole penetrates through in the reserved groove. After the hydraulic anchor drilling rig drills to 0.5m away from the designed hole depth, detect the bottom position of the hole, and replace the geological drilling rig or the opener to complete the final hole. In order to detect the bottom position of the drainage hole, methods such as geological radar scanning the bottom position of the hole, metal detector detecting the bottom position of the drill pipe hole, using a three-dimensional digital electronic compass and gyroscope to measure the drilling trajectory, and ultrasonic hole bottom positioning are adopted during the construction to determine the bottom position of the hole. Finally, determine the bottom position of the drainage hole according to the ultrasonic detection results.

[0004] It can be seen that in order to ensure that the hole inclination of the drainage holes meets the requirements and the bottom outlet of the holes can be exposed in the reserved groove on the specified side wall of the gallery, strict control means must be adopted during the above construction process, and various geophysical exploration methods are used. The control means can be achieved by unconventional construction techniques, which have very high requirements for the construction method, are time-consuming and laborious, and have high input costs for each item, and are difficult to achieve in general projects. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a lapping box for drilling drainage holes in a dam, which facilitates the implementation of drainage holes in sections with the pouring layer and can reduce the difficulty of controlling the hole deviation of the drainage holes.

[0006] The technical solution adopted by the present invention to solve the above technical problem is: a lapping box for drilling drainage holes in a dam, including a drainage hole arranged in a concrete block, an upper protective cover and a lower protective cover covering above the drainage hole, the lower protective cover is located inside the upper protective cover; both the upper protective cover and the lower protective cover are fixed on the concrete block.

[0007] Furthermore: it also includes a fixing ring, the fixing ring is arranged around the outer periphery of the hole opening of the drainage hole and is fixedly connected with the concrete block; both the upper protective cover and the lower protective cover are fixedly connected with the fixing ring.

[0008] Furthermore: the fixing ring is anchored on the concrete block through anchor bars.

[0009] Furthermore: it also includes a plurality of anchor bar fixing holes arranged along the circumference of the fixing ring, and fixing holes corresponding to the anchor bar fixing holes one by one are provided on the concrete block; the fixing ring is fixed on the concrete block through L-shaped anchor bars or U-shaped anchor bars.

[0010] Furthermore: the number of the anchor bar fixing holes is four, and the four anchor bar fixing holes are evenly arranged along the circumference of the fixing ring; the aperture of the anchor bar fixing holes is 40mm.

[0011] Furthermore: the fixing ring is a steel fixing ring, and the upper protective cover and the lower protective cover are welded to the fixing ring.

[0012] Furthermore: the thickness of the fixing ring is 1 - 2mm, the outer ring diameter of the fixing ring is 650mm, the inner ring diameter is 450mm, and the width of the fixing ring is 100mm; the width of the part of the fixing ring located outside the upper protective cover is 75mm, and the width of the part of the fixing ring located inside the upper protective cover is 25mm.

[0013] Furthermore: both the upper protective cover and the lower protective cover are elliptical protective covers; the length of the major semi-axis of the upper protective cover is 250mm, and the length of the minor semi-axis is 125mm; the length of the major semi-axis of the lower protective cover is 250mm, and the length of the minor semi-axis is 50mm.

[0014] Furthermore: the lower protective cover is a mesh structure composed of a plurality of steel bars arranged in a staggered manner.

[0015] Furthermore: the mesh size on the mesh structure is smaller than the aperture of the drainage hole.

[0016] The beneficial effects of the present invention are as follows: Through the cooperative structure of the upper protective cover and the lower protective cover, the present invention forms a protective space above the drainage hole on the previous cast concrete block, and at the same time provides a lapping foundation for the next cast concrete block. The drainage hole on the next concrete block can be connected to the drainage hole on the previous concrete block by drilling the lapping box below, so that the drainage hole can be conveniently and accurately implemented in segments with the cast concrete layer, avoiding the problem of hole inclination control caused by deep drilling and the influence of pre-buried drainage pipes on the construction of roller-compacted concrete dams. The structure of the present invention is simple, easy to implement, and convenient for pre-buried construction, which can effectively reduce the consumption of manpower and material resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a top view of the present invention;

[0018] Figure 2 is Figure 1 a cross-sectional view taken along line A-A in

[0019] The reference numerals in the figures are: 100 - concrete block, 200 - drainage hole, 300 - upper protective cover, 400 - lower protective cover, 500 - fixing ring, 510 - anchor bar fixing hole, 600 - anchor bar. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] For the convenience of understanding the present invention, the present invention will be further described below with reference to the accompanying drawings.

[0021] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "front", "rear", "left", "right", "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0022] Such as Figure 1 and Figure 2As shown in the figure, a lapping box for drilling drainage holes in a dam disclosed by the present invention includes an upper protective cover 300 and a lower protective cover 400. The upper protective cover 300 and the lower protective cover 400 are stacked vertically and cover the upper part of the drainage hole 200 provided in the concrete block 100, forming a protection and lapping structure above the drainage hole 200. The principle of controlling the hole inclination of the drainage hole 200 by using the lapping box for drilling drainage holes in a dam of the present invention is as follows: the one-time drilling construction of the drainage hole in the prior art is improved to be a segmented construction carried out along with the multi-layer pouring construction of the concrete, and then the drainage holes are connected by drilling the lapping boxes between the concrete layers respectively. By using the lapping box for drilling drainage holes in a dam of the present invention, the construction problems encountered in the one-time deep drilling construction can be completely avoided, the construction difficulty of the dam drainage holes is greatly reduced, and the effective control of the hole inclination of the drainage holes is realized.

[0023] Specifically, both the upper protective cover 300 and the lower protective cover 400 in the present invention are of an oval protective cover structure. The upper protective cover 300 is processed and formed by using a non-removable formwork material or other materials that can be penetrated by a drill. The upper protective cover 300 needs to bear the load during the pouring process of the upper concrete block. Therefore, the oval protective cover structure can effectively disperse the pressure exerted by the upper concrete block and improve the bearing capacity of the upper protective cover 300. The lower protective cover 400 is of a mesh structure composed of multiple staggered steel bars. It is preferably to use anti-corrosion steel bars for the steel bars; the main function of the lower protective cover 400 is to protect the lower drainage hole 200 to prevent large concrete slag bodies passing through the upper protective cover 300 from falling into the drainage hole 200 of the lower concrete block and blocking the drainage hole 200 during the drilling work of the drainage hole 200 of the upper concrete block; therefore, the lower protective cover 400 is built with steel bars to improve the overall bearing capacity and strength, and the mesh size on the mesh structure of the lower protective cover 400 needs to be set to be smaller than the aperture of the drainage hole 200.

[0024] Considering the actual aperture size of the drainage hole 200 and the protection range of the lapping box during the dam construction, in the present invention, the major semi-axis length of the upper protective cover 300 is set to 250 mm, and the minor semi-axis length of the upper protective cover 300 is set to 125 mm; the major semi-axis length of the lower protective cover 400 is set to 250 mm, and the minor semi-axis length of the lower protective cover 400 is set to 50 mm. The size of the upper protective cover 300 meets the requirements that when the height of the upper poured concrete block ≤ 10 m, the allowable hole position deviation is within 5 cm and the hole bottom deviation of the drilling is within 15 cm when using a conventional drilling device to drill the upper concrete block, and still can penetrate the upper protective cover 300 to connect with the drainage hole in the lower concrete block; making the lapping box more adaptable to the actual construction requirements.

[0025] Specifically, in the present invention, the upper protective cover 300 and the lower protective cover 400 are fixed on the concrete block 100 through the fixing ring 500. As Figure 1 and Figure 2 shown, the fixing ring 500 is a circular ring structure with an inner ring diameter larger than the aperture diameter of the drainage hole 200, and the edges of the upper protective cover 300 and the lower protective cover 400 are bent to form a circular ring edge on the upper protective cover 300 and the lower protective cover 400 that fits the fixing ring 500. The outer ring diameter of the fixing ring 500 is larger than the outer diameter of the edges of the upper protective cover 300 and the lower protective cover 400; when installing the lapping box, after fixing the circular ring edges of the upper protective cover 300 and the lower protective cover 400 on the fixing ring 500, the fixing ring 500 is arranged around the outer periphery of the orifice of the drainage hole 200 and fixedly connected to the concrete block 100. The fixing ring 500 is made of a steel fixing ring, and the upper protective cover 300 and the lower protective cover 400 are welded to the fixing ring 500. According to the set dimensions of the upper protective cover 300 and the lower protective cover 400, the thickness of the fixing ring 500 is set to 1 - 2 mm, the outer ring diameter of the fixing ring 500 is 650 mm, the inner ring diameter is 450 mm, and the width of the fixing ring 500 is 100 mm; the width of the part of the fixing ring 500 located outside the upper protective cover 300 is 75 mm, and the width of the part of the fixing ring 500 located inside the upper protective cover 300 is 25 mm.

[0026] As Figure 1 and Figure 2 shown, in the present invention, the fixing ring 500 is anchored on the concrete block 100 through the anchor bars 600. Specifically, a plurality of anchor bar fixing holes 510 are provided on the fixing ring 500, and at the same time, fixing holes corresponding to the anchor bar fixing holes 510 one by one are drilled on the concrete block 100. The fixing ring 500 is placed on the surface of the concrete block 100 in a fitting manner and the anchor bar fixing holes 510 on the fixing ring 500 are aligned with the fixing holes on the concrete block 100, and then the anchor bars 600 are passed through the anchor bar fixing holes 510 and inserted into the fixing holes, and the anchor bars 600 are bent into an L shape or a U shape to fix the anchor bars 600 on the concrete block 100.

[0027] Furthermore, in order to improve the uniformity of force, the number of the anchor bar fixing holes 510 can be set to four, and the four anchor bar fixing holes 510 are evenly distributed along the circumference of the fixing ring 500. The diameter of the anchor bars 600 is 22 - 32 mm, and the aperture diameter of the fixing holes on the concrete block 100 is 40 mm.

[0028] When constructing the dam drainage hole using a lapping box for dam drainage hole drilling of the present invention, the construction is carried out according to the following steps:

[0029] Step 1. Customize or make the upper protective cover 300 according to the construction dimensions. The upper protective cover 300 is processed from formwork-free materials or other materials that can be penetrated by a drill. After forming, the bearing capacity of the upper protective cover 300 is ≥ 5 MPa.

[0030] Step 2. Customize or make the lower protective cover 400 according to the construction dimensions. Use anti-rust steel wire mesh with a diameter of 6 mm to lap into a grid structure with a spacing of 50 mm, or use other similar grid meshes.

[0031] Step 3. Customize or make the fixing ring 500 according to the construction dimensions using steel plates, and process anchor bar fixing holes 510 on the fixing ring 500.

[0032] Step 4. Weld the lower protective cover 400 to the fixing ring 500, then cover the upper protective cover 300 above the lower protective cover 400, and fully weld the upper protective cover 300 along the edge of the upper protective cover 300 to the fixing ring 500, and detect the strength of the welding part. If there is no strength detection condition, the full weld seam height should be controlled not less than 3 mm.

[0033] Step 5. Cover the processed lap box above the drain hole 200, align the center point of the drain hole 200 with the center point position of the upper protective cover 300. After making a drilling mark on the concrete block 100, remove the lap box. Drill fixing holes on the concrete block 100. The diameter of the fixing holes is not less than 40 mm, and the depth of the fixing holes is not less than 55 cm. After drilling, rinse it clean to ensure that the thickness of the sediment at the bottom of the hole is less than 5 cm. Inject cement mortar into the fixing holes. The height of the cement mortar should be such that the cement mortar is just flush with the hole position of the fixing hole after the anchor bar 600 is inserted. The strength of the cement mortar after setting is not lower than the strength of the concrete block 100.

[0034] Step 6. Align the anchor bar fixing holes 510 on the fixing ring 500 of the lap box with the grouted fixing holes, and insert the pre-prepared anchor bar 600. The length of the anchor bar 600 buried in the concrete block 100 is 50 cm, and the length of the exposed bent part of the anchor bar 600 is 20 cm. After the cement mortar has finally set, check whether the fixing holes are filled. If there is a cavity formed by the settlement of the cement mortar at the hole opening, the cavity needs to be replenished.

[0035] Step 7. After the cement mortar has finally set, weld the anchor bar 600 to the fixing ring 500.

[0036] Step 8: Before normal construction, conduct test inspections on the bearing capacity and anchoring process of the lapping box to ensure that the lapping box will not be damaged or displaced due to vibration or rolling during construction; after verifying through tests that the bearing capacity of the lapping box meets the requirements and the anchoring process of the lapping box is feasible, then conduct normal material feeding, leveling, rolling or vibration, and observe whether the lapping box deforms or displaces during construction.

Claims

1. A lapping box for drilling drainage holes in a dam, comprising a drainage hole (200) provided in a concrete block (100), characterized in that: It includes an upper protective cover (300) and a lower protective cover (400) covering above the drain hole (200), and the lower protective cover (400) is located inside the upper protective cover (300); both the upper protective cover (300) and the lower protective cover (400) are fixed on the concrete block (100); It further includes a fixing ring (500), the fixing ring (500) is arranged around the outer periphery of the orifice of the drain hole (200) and is fixedly connected with the concrete block (100); both the upper protective cover (300) and the lower protective cover (400) are fixedly connected with the fixing ring (500); the fixing ring (500) is anchored on the concrete block (100) through anchor bars (600); it further includes a plurality of anchor bar fixing holes (510) arranged along the circumference of the fixing ring (500), and the concrete block (100) is provided with fixing holes corresponding to the anchor bar fixing holes (510) one by one; the fixing ring (500) is fixed on the concrete block (100) through L-shaped anchor bars or U-shaped anchor bars; the number of the anchor bar fixing holes (510) is four, and the four anchor bar fixing holes (510) are evenly arranged along the circumference of the fixing ring (500); The aperture of the anchor bar fixing hole (510) is 40 mm; the fixing ring (500) is a steel fixing ring, and the upper protective cover (300) and the lower protective cover (400) are welded to the fixing ring (500); the thickness of the fixing ring (500) is 1 - 2 mm, the outer ring diameter of the fixing ring (500) is 650 mm, the inner ring diameter is 450 mm, and the width of the fixing ring (500) is 100 mm; the width of the part of the fixing ring (500) located outside the upper protective cover (300) is 75 mm, and the width of the part of the fixing ring (500) located inside the upper protective cover (300) is 25 mm; both the upper protective cover (300) and the lower protective cover (400) are oval protective covers; the length of the major semi-axis of the upper protective cover (300) is 250 mm, and the length of the minor semi-axis of the upper protective cover (300) is 125 mm; the length of the major semi-axis of the lower protective cover (400) is 250 mm, and the length of the minor semi-axis of the lower protective cover (400) is 50 mm; The lower protective cover (400) is a mesh structure composed of a plurality of steel bars arranged in a staggered manner; the mesh size on the mesh structure is smaller than the aperture of the drain hole (200).

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