A precast drainage cavity crown structure for a drainage gallery

Abstract

The present invention discloses a precast drainage cavity crown arch structure for a drainage gallery, which comprises multiple crown arch structures arranged on the top of the drainage gallery and arranged and connected in sequence along the length direction of the drainage gallery; a drainage cavity and a reserved drainage hole communicated with the drainage cavity are arranged in the crown arch structure, the reserved drainage hole is vertically arranged above the drainage ditch of the drainage gallery, and the drainage cavities of adjacent crown arch structures are communicated. The present invention can not only quickly realize the rapid positioning of the drainage holes of the dam body on the drainage gallery, and can connect the drainage holes with the drainage ditch of the drainage gallery without complex control means for accurate positioning, ensuring the smooth discharge of the seepage water of the dam drainage holes, but also can serve as a permanent structure on the top of the drainage gallery to play a role in support and protection.

Description

Technical Field

[0001] The invention relates to the technical field of hydropower and water conservancy engineering, in particular to a prefabricated drainage cavity top arch structure of a drainage gallery. Background Art

[0002] The drainage holes of the dam are vertical pipes used to discharge the seepage inside 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 vertical drainage hole curtains of each layer of the corridor inside the dam, up to the vicinity of the dam top or the overflow weir top. The spacing between single rows of 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 by using pre-buried drainage blind pipes. Generally, the drainage holes are connected to the drainage pipes inside and outside the corridor at the upstream arch angle of the drainage corridor. The seepage water is discharged into the drainage funnel of the external drainage pipe through the drainage holes and then enters the upstream drainage ditch.

[0003] When drilling holes, the positions of drainage holes exposed in the drainage corridor are rather messy, and some drainage holes may even be exposed on the downstream side of the drainage corridor, resulting in a messy arrangement of drainage pipes in the drainage corridor. In order to expose the drainage holes at the designed position of the drainage corridor, some projects adopt the method of exposing them in the reserved grooves set upstream. The reserved grooves are covered with buckle plates, which can achieve a certain covering effect. However, the control measures required for drilling holes to be exposed in the reserved grooves are still very complicated. The drainage hole outlet of a certain project is designed in the reserved groove of the upstream side wall of the corridor. The projection size of the reserved groove is 1.00m (width) × 1.25m~1.50m (height), the groove depth is 0.30m, and the minimum distance between the designed hole bottom and the edge of the reserved groove is 0.45m~0.50m. The appearance quality of the hole bottom in this part needs to be guaranteed to reduce the degree of tearing damage during drilling, so the drilling accuracy of the drainage holes is required to be high. In addition to taking strict measures to control the hole inclination during the drilling process, the bottom of the hole is scanned by geological radar, the bottom of the drill pipe is detected by metal detectors, the drilling trajectory is measured by three-dimensional digital electronic compass and gyroscope, and ultrasonic bottom positioning is used to determine the exit position of the hole. Finally, according to the results of ultrasonic detection, it was determined that the bottom of the drainage hole can come out of the reserved groove. With the cooperation of strict process detection measures, the exit position of the hole is controlled within 1.00m along the corridor and 0.30m vertically in the corridor. However, the control process is extremely complex and requires very high construction methods. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a prefabricated drainage cavity top arch structure for a drainage gallery, which is convenient for positioning the drainage holes and can reduce the drilling error of the drainage holes.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows: A precast drainage cavity crown arch structure for a drainage gallery, comprising multiple crown arch structures arranged and connected in sequence along the length direction of the drainage gallery at the top of the drainage gallery; a drainage cavity and a reserved drainage hole communicating with the drainage cavity are provided in the crown arch structure, the reserved drainage hole is vertically arranged above the drainage ditch of the drainage gallery, and the drainage cavities of adjacent crown arch structures are communicated.

[0006] Furthermore: The crown arch structure is surrounded by an upper load-bearing plate at the top of the crown arch structure, an arc-shaped plate at the top of the gallery at the bottom of the crown arch structure, and a pressure-bearing support plate on both sides of the crown arch structure.

[0007] Furthermore: The outer side surfaces of the pressure-bearing support plates are all slopes, and the thickness of the pressure-bearing support plates gradually increases from the top to the bottom of the pressure-bearing support plates.

[0008] Furthermore: The width of the crown arch structure is greater than the width of the drainage gallery, and the width of the drainage cavity is greater than or equal to the width of the drainage gallery.

[0009] Furthermore: The drainage cavity is composed of an upstream cavity and a downstream cavity communicating with each other; the upstream cavity and the downstream cavity are connected by at least one communication cavity arranged between the upstream cavity and the downstream cavity; the upstream cavity communicates with the reserved drainage hole.

[0010] Furthermore: A middle support structure is provided between the upstream cavity and the downstream cavity, the middle support structure is vertically fixed between the upper load-bearing plate and the arc-shaped plate at the top of the gallery, and the middle support structure, the upper load-bearing plate and the arc-shaped plate at the top of the gallery are of an integral structure.

[0011] Furthermore: The bottom of the upstream cavity is provided with an arc surface matching the arc-shaped plate at the top of the gallery, and the bottom surface of the upstream cavity is a slope inclined downward from around the reserved drainage hole towards the reserved drainage hole, and the slope of the slope ≥ 5%.

[0012] Furthermore: It also includes a lifting ring, and the lifting ring is fixed on the top surface of the upper load-bearing plate of the crown arch structure.

[0013] Furthermore: It also includes a positioning groove provided on the crown arch structure, and adjacent crown arch structures on the drainage gallery are aligned with each other through the positioning groove.

[0014] The beneficial effects of the present invention are as follows: By providing a crown arch structure with a drainage cavity at the top of the drainage gallery as the drainage outlet of the dam body's water outlet holes in the drainage gallery, during the drilling construction of the drainage holes, it is only necessary to drill through the top of the crown arch structure until it is connected to the drainage cavity to complete the final hole drilling of the drainage holes. The seepage water in the drainage holes can enter the reserved drainage holes through the drainage cavity and then be discharged into the drainage ditch of the drainage gallery. The present invention can not only quickly realize the rapid positioning of the dam body's drainage holes on the drainage gallery, connect the drainage holes with the drainage ditch of the drainage gallery without the need for complex control means for accurate positioning, ensure the smooth discharge of the seepage water from the dam drainage holes, but also serve as a permanent structure at the top of the drainage gallery to play a supporting and protective role. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a front sectional view of the present invention;

[0016] Figure 2 is a top view of the present invention;

[0017] Figure 3 is Figure 2 the sectional view at A-A in

[0018] Figure 4 is Figure 2 the sectional view at B-B in

[0019] The labels in the figure are: 100 - drainage gallery, 110 - drainage ditch, 200 - drainage cavity, 210 - upstream cavity, 220 - downstream cavity, 230 - connecting cavity, 300 - reserved drainage hole, 410 - upper load-bearing plate, 420 - arc-shaped plate at the top of the gallery, 430 - pressure-bearing support plate, 440 - middle support structure, 500 - lifting ring, 600 - positioning groove. DETAILED DESCRIPTION OF THE INVENTION

[0020] For the convenience of understanding the present invention, the present invention will be further described below in conjunction with the drawings and embodiments.

[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 to the present invention.

[0022] Such as Figure 1As shown in the figure, a prefabricated drainage cavity crown arch structure for a drainage gallery disclosed by the present invention includes a crown arch structure arranged at the top of the drainage gallery 100. The number of the crown arch structures is multiple. Multiple sections of the crown arch structures are fixed at the top of the drainage gallery 100 and arranged in sequence along the length direction of the drainage gallery 100. A drainage cavity 200 and reserved drainage holes 300 are arranged in the crown arch structure. The reserved drainage holes 300 are communicated with the drainage cavity 200 and the reserved drainage holes 300 are located above the drainage ditch 110 in the drainage gallery 100. The reserved drainage holes 300 can be connected with the drainage ditch 110 through an externally hung drainage pipe. Multiple sections of the crown arch structures at the top of the drainage gallery 100 are connected in sequence so that the drainage cavities 200 in each crown arch structure are communicated with each other. The prefabricated length of a single section of the crown arch structure is adjusted according to the actual engineering requirements to ensure that it is consistent with the drainage hole spacing length of the dam drainage curtain. After the crown arch structure described in the present invention is arranged at the top of the drainage gallery 100, when constructing the drainage holes of the dam body above the drainage gallery 100, a drill can be directly used to drill a hole from the top of the crown arch structure to the drainage cavity 200. When the hole is drilled to be communicated with the drainage cavity 200, the final hole of the drainage hole is completed. Then, the drainage holes of the dam body can be directly communicated with the drainage ditch 110 in the drainage gallery 100 through the drainage cavity 200 and the reserved drainage holes 300. The seepage water of the drainage holes of the dam body can be discharged into the drainage ditch 110 in the drainage gallery 100 through the drainage cavity 200 and the reserved drainage holes 300. After adopting the prefabricated drainage cavity crown arch structure for the drainage gallery of the present invention, since the drainage cavity 200 and the reserved drainage holes 300 are arranged in the crown arch structure for water diversion and water collection, when constructing the drainage holes of the dam body, it is not necessary to adopt a variety of control methods to accurately position the drainage holes, thereby simplifying the control means for positioning the drainage hole outlet, avoiding deflecting the drainage hole outlet within the drilling error azimuth so that the drainage holes appear at different positions in the drainage gallery 100, ensuring that the drainage holes can be smoothly connected to the drainage ditch 110, and at the same time, avoiding affecting the drainage effect and the appearance of the drainage gallery 100 due to the messy arrangement of the drainage pipes of the drainage holes in the drainage gallery 100.

[0023] In order to facilitate the docking of multiple sections of the crown arch structure, a positioning groove 600 can be arranged on the crown arch structure. The specific setting position and shape of the positioning groove 600 are not limited. When docking multiple sections of the crown arch structure, it is only necessary to align the positioning grooves 600 on adjacent crown arch structures to quickly complete the positioning of the crown arch structure.

[0024] Specifically, such as Figure 1As shown, the arch structure of the present invention is composed of an upper load-bearing plate 410, a gallery top arc plate 420 and a pressure support plate 430. Among them, the upper load-bearing plate 410 is located at the top of the arch structure; the gallery top arc plate 420 is an arc plate structure protruding upward at the top of the drainage gallery 100, and the gallery top arc plate 420 is located at the bottom of the arch structure; two pressure support plates 430 are respectively located on both sides of the arch structure. The cavity formed by the upper load-bearing plate 410, the gallery top arc plate 420 and the pressure support plate 430 is the drainage cavity 200.

[0025] Furthermore, the outer side surfaces of the pressure-bearing support plate 430 are all sloped surfaces, and the thickness of the pressure-bearing support plate 430 gradually increases from the top of the pressure-bearing support plate 430 to the bottom of the pressure-bearing support plate 430; because the outer side surface of the pressure-bearing support plate 430 is in direct contact with the water flow and needs to withstand the scouring force of the water flow, setting the outer side surface of the pressure-bearing support plate 430 as a slope can play a role in dispersing the scouring force of the water flow. Taking the actual construction requirements as an example, the upper load-bearing plate 410 is a reinforced concrete structure, the thickness of the upper load-bearing plate 410 is ≥25cm, the top thickness of the pressure-bearing support plate 430 is ≥25cm, and the bottom thickness of the pressure-bearing support plate 430 is ≥40cm. The width of the top arch structure is greater than the width of the drainage corridor 100, and the width of the drainage cavity 200 is greater than or equal to the width of the drainage corridor 100.

[0026] like Figure 1 As shown, the drainage cavity 200 in the present invention is composed of an upstream cavity 210 and a downstream cavity 220 connected to each other. The upstream cavity 210 is located on the side of the top arch structure close to the upstream of the water flow, and the downstream cavity 220 is located on the side of the top arch structure close to the downstream of the water flow. Figure 1 , Figure 3 and Figure 4 As shown, a connecting cavity 230 is provided between the upstream cavity 210 and the downstream cavity 220, and the upstream cavity 210 and the downstream cavity 220 are connected through the connecting cavity 230. The number and specific size of the connecting cavity 230 are set according to actual construction requirements; the height of the connecting cavity 230 is 25 cm, and the length of the connecting cavity 230 is 100 cm.

[0027] Specifically, when two or more connecting cavities 230 are used, adjacent connecting cavities 230 are separated by a middle support structure 440. Figures 1 to 3As shown in the figure, the middle support structure 440 is a support structure arranged between the upstream cavity 210 and the downstream cavity 220. The middle support structure 440 is vertically fixed between the upper load-bearing plate 410 and the arched plate 420 at the top of the corridor. The middle support structure 440, the upper load-bearing plate 410 and the arched plate 420 at the top of the corridor are set as an integral structure to improve the overall strength of the crown arch structure. The height of the middle support structure 440 is 25 cm, the width is 20 cm, and the length is 50 cm.

[0028] As Figure 1 shown in the figure, in order to facilitate the diversion of the seepage water from the drainage holes in the dam body, the upstream cavity 210 in the present invention is set as a cavity structure similar to a triangle. The bottom of the upstream cavity 210 is provided with an arc surface matching the arched plate 420 at the top of the corridor. The water flow entering the drainage cavity 200 through the drainage holes in the dam body can flow into the reserved drainage hole 300 along the bottom arc surface of the upstream cavity 210. And, as Figure 4 shown in the figure, the bottom surface of the upstream cavity 210 is set as a slope that slopes downward from the periphery of the reserved drainage hole 300 towards the reserved drainage hole 300, and the slope of the slope ≥ 5%.

[0029] As Figures 1 to 4 shown in the figure, a lifting ring 500 can also be added to the top of the crown arch structure. The lifting ring 500 is fixed on the top surface of the upper load-bearing plate 410 of the crown arch structure. By setting the lifting ring 500, it is convenient to carry out hoisting during the prefabrication construction process of the crown arch structure.

[0030] When constructing the prefabricated drainage cavity crown arch structure of the drainage corridor disclosed in the present invention, the construction is carried out according to the following steps:

[0031] Step 1: Prefabricate the crown arch structure in the prefabrication factory at the construction site. First, make a mold, and then bind the steel bars to assemble the basic skeleton of the crown arch structure. The configured steel bars need to meet the hoisting requirements of the crown arch structure, as well as the self-weight of the upper concrete pouring layer and the construction load requirements of the construction machinery and equipment. The diameter of the steel bars is calculated according to the actual size of the drainage corridor 100. The diameter of the steel bars configured for the crown arch structure with a span ≤ 3.5 m is not less than 16 mm, and the row spacing between the steel bars is 15 - 20 cm. The concrete strength grade of the poured crown arch structure should be the same as that of the concrete partition of the dam. Then, embed the lifting ring 500. The lifting ring 500 is made of grade I steel bars to meet the load requirements during the hoisting process. Combine and close the formwork, and carry out the pouring of concrete. Demold and cure according to the requirements of the concrete construction specifications. The curing time is not less than 28 days. After curing, it is ready for use.

[0032] Step 2: Hoist the prefabricated crown arch structure to the top of the drainage gallery 100. After the positioning grooves 600 of each section of the crown arch structure are aligned with each other, install the crown arch structure. Drill holes at a distance of 0.5 m on both sides of the crown arch structure to install the limit anchor bars. The diameter of the limit anchor bars shall not be less than 25 mm, the depth of the limit anchor bars embedded in the concrete shall not be less than 0.5 m, and the exposed length of the limit anchor bars shall not be less than 0.3 m.

[0033] Step 3: Embed a drain pipe at the reserved drain hole 300 of the crown arch structure. The exposed length of the drain pipe shall meet the access requirements of the drain funnel.

[0034] Step 4: Tie the steel bars around the drainage gallery 100 according to the design requirements.

[0035] Step 5: Pour the concrete construction layer at the top of the drainage gallery 100.

[0036] Step 6: Drill drain holes on the crown arch structure according to the project requirements until the drainage cavity 200 is connected. After the drill penetrates the upper load-bearing plate 410 of the crown arch structure, the drain hole drilling is completed. After the completion of the hole, pour water from the drain hole orifice to check the drainage condition of the drain hole to determine whether the drill hole is connected to the drainage cavity 200, and record the positions of the outlets of the drain holes corresponding to each drill hole in the drainage gallery 100 for later detection and judgment of the seepage condition of each part of the dam body.

Claims

1. A precast drainage cavity crown arch structure for a drainage corridor, characterized in that: It includes multiple top arch structures arranged on the top of the drainage corridor (100), and the top arch structures are arranged in sequence along the length direction of the drainage corridor and are connected to each other; a drainage cavity (200) and a reserved drainage hole (300) communicated with the drainage cavity (200) are provided in the top arch structure, the reserved drainage hole (300) is vertically arranged above the drainage ditch (110) of the drainage corridor (100), and the drainage cavities (200) of adjacent top arch structures are communicated; The top arch structure is surrounded by an upper load-bearing plate (410) located at the top of the top arch structure, a top arc plate (420) of the corridor located at the bottom of the top arch structure, and pressure-bearing support plates (430) located on both sides of the top arch structure; the outer sides of the pressure-bearing support plates (430) are all slopes, and the thickness of the pressure-bearing support plates (430) gradually increases from the top to the bottom of the pressure-bearing support plates (430); the width of the top arch structure is greater than the width of the drainage corridor (100), and the width of the drainage cavity (200) is greater than or equal to the width of the drainage corridor (100); the drainage cavity (200) is composed of an upstream cavity (210) and a downstream cavity (220) communicated; the upstream cavity (210) and the downstream cavity (220) are connected through at least one communication cavity (230) arranged between the upstream cavity (210) and the downstream cavity (220); the upstream cavity (210) is communicated with the reserved drainage hole (300); A middle support structure (440) is provided between the upstream cavity (210) and the downstream cavity (220), the middle support structure (440) is vertically fixed between the upper load-bearing plate (410) and the top arc plate (420) of the corridor, and the middle support structure (440) and the upper load-bearing plate (410) and the top arc plate (420) of the corridor are of an integral structure; the bottom of the upstream cavity (210) is provided with an arc surface matching the top arc plate (420) of the corridor, and the bottom surface of the upstream cavity (210) is a slope inclined downward from around the reserved drainage hole (300) towards the reserved drainage hole (300), and the slope of the slope ≥5%; It also includes a positioning groove (600) arranged on the top arch structure, and adjacent top arch structures on the drainage corridor (100) are aligned with each other through the positioning groove (600).

2. The precast drainage cavity crown arch structure of a drainage corridor according to claim 1, characterized in that: It also includes a lifting ring (500), and the lifting ring (500) is fixed on the top surface of the upper load-bearing plate (410) of the top arch structure.

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