Drainage and exhaust structure for underground buried pipe backfill concrete pouring
By setting up drainage and exhaust bolts and drainage and exhaust structures with drainage bolts and permeable air -breathable templates within the bottom of the pressure of the stress steel pipe, the problem of deficiency between concrete and steel pipes is solved, and the close combination of concrete and steel pipes is achieved. Efficiency and reduction of costs.
Patent Information
- Application Number
- CN202420885137.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-26
- Publication Date
- 2025-01-24
- Estimated Expiration
- 2034-04-26
AI Technical Summary
In water conservancy and hydropower projects, closed air and bubbles are easily formed between the pressure steel pipes and concrete, resulting in the backfill concrete and the steel pipe walls that cannot be closely combined, forming de-emphasis defects. There is uncertainty in traditional contact grouting methods and drilling holes to damage the pipe walls. , problems such as large pressure fluctuations.
A drainage and exhaust structure is adopted, including setting drainage exhaust bolts within 120 ° at the bottom of the pressure steel pipe, and wrapped the water permeable template cloth around the bolt and the screw end. Wastewater and exhaust gas can be discharged in time.
Through the drainage and exhaust structure, the concrete is closely combined with the steel pipe, avoiding the deficiency of the air, reducing the grouting work, improving construction progress, and reducing construction investment.
Smart Images
Figure CN222390443U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to concrete engineering in the fields of water conservancy and hydropower engineering, and in particular to a drainage and exhaust structure used for pouring backfill concrete for underground buried pipes. Background Art
[0002] In water conservancy and hydropower projects, when the tunnel of the water transmission system adopts an underground pipe structure, concrete is used to fill the space between the pressure steel pipe wall and the surrounding rock so that the internal water pressure is borne by the surrounding rock and the external water head acting on the outer wall of the steel pipe is reduced. During the backfill concrete pouring process between the pressure steel pipe and the surrounding rock, it is easy to form a closed air between the backfilled concrete and the steel pipe wall within the 120° range at the bottom of the pressure steel pipe, and the bubbles generated by the concrete vibration float up and gather near the outer wall of the steel pipe, resulting in the backfilled concrete and the steel pipe wall not being able to be tightly combined, resulting in a void. At present, the design and construction of contact grouting are required for the void defects. Generally, the cavity area between the steel pipe and the concrete in the tunnel is first inspected and counted, and then the gap between the steel pipe and the concrete in the tunnel exceeds the design allowable value or the hollow area has a greater impact on the safe operation of the steel pipe. The grouting drilling adopts a magnetic base electric drill. Each independent hollow area has no less than 2 holes, the drilling hole diameter is not less than 12mm, the grouting pressure is 0.1~0.2Mpa, and the grouting is accepted after acceptance. Round steel is driven into the drilled hole to seal it and fully welded at the hole opening to ensure that the steel pipe wall is tightly combined with the concrete and the drilled hole is sealed and leak-proof.
[0003] In general, during the manufacturing process of penstocks, backfill grouting holes and consolidation grouting holes are arranged according to the design requirements, and grouting plugs are arranged on the holes. During the backfill concrete construction, in order to prevent the concrete slurry from flowing into the tunnel from the grouting holes and polluting the protective film and grouting holes on the steel pipes, the grouting plugs are installed on the grouting holes, and the grouting holes are in a closed state. When backfilling or consolidation grouting is performed, the grouting plugs are removed for grouting. After the grouting is completed, the grouting plugs are installed again and welded to the steel pipes. The following problems exist in the traditional concrete pouring, penstock degassing inspection and contact grouting:
[0004] (1) The location where the pressure steel pipe and concrete are hollow is uncertain. When using the "knocking method" to check and determine the hollow area, experienced construction personnel are required, and the calculated area is inaccurate.
[0005] (2) The grouting holes arranged on the pressure steel pipe cannot meet the requirements of contact grouting. Contact grouting requires drilling holes on the steel pipe wall as needed. At least two holes need to be drilled for each location that requires contact grouting. Drilling will damage the protective coating on the inner and outer surfaces of the pipe wall, causing the steel pipe to rust easily and be difficult to repair.
[0006] (3) The grouting pressure required for contact grouting is relatively low. Improper operation will cause large pressure fluctuations, which will cause the steel pipe wall to bulge and deform.
[0007] (4) Especially for high-strength steel, sealing the hole in the steel pipe wall can easily cause stress concentration in the steel pipe or weld cracks.
[0008] In the process of engineering design, the defects of hollowing out between concrete and steel pipes and the stress concentration and damage of steel pipes caused by grouting should be avoided as much as possible. Especially for high-strength steel pipes with high water head, the steel plate drilling method should be used with caution for contact grouting construction. Therefore, in order to improve the quality of backfill concrete at the bottom of the pressure steel pipe and avoid hollowing out between concrete and steel pipes, a drainage and exhaust structure is proposed, which can timely discharge the wastewater and waste gas between concrete and steel pipes during the backfill concrete pouring process to ensure that the concrete and steel pipes are tightly combined. Utility Model Content
[0009] The purpose of the utility model is to provide a drainage and exhaust structure for backfilling concrete pouring of underground buried pipes. When the bottom of the pressure steel pipe is backfilled with concrete within a range of 120°, the utility model can ensure that the concrete and the steel pipe are tightly combined, avoid the gap between the concrete and the steel pipe, reduce contact grouting work, improve construction progress, and reduce construction investment.
[0010] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:
[0011] A drainage and exhaust structure for backfill concrete pouring of underground buried pipes, comprising drainage and exhaust bolts, which are arranged at intervals on grouting holes within a 120° range at the bottom of a pressure steel pipe, and the surrounding areas and threaded ends of the drainage and exhaust bolts are wrapped with a water-permeable and breathable template cloth, and the water-permeable and breathable template cloth is bound with two binding wires.
[0012] Preferably, the spacing between the grouting holes is 2 to 3 m.
[0013] Preferably, the center of the drain and exhaust bolt is a circular hollow structure.
[0014] Preferably, the drainage and exhaust bolts are installed into the grouting holes from the water-facing side of the pressure steel pipe, so that the threads are located in the grouting holes on the steel pipe reinforcement plate, and the screw heads are located in the grouting holes on the pipe wall of the pressure steel pipe.
[0015] Preferably, the thread diameter is smaller than the hole diameter of the reinforcing plate, the thread length is greater than the thickness of the steel pipe reinforcing plate, and the screw head length is greater than the thickness of the pressure steel pipe wall.
[0016] Preferably, the minimum size of the water-permeable and air-permeable template cloth can wrap the drainage and exhaust bolts.
[0017] The beneficial effect of the utility model is that when the bottom of the pressure steel pipe is backfilled with concrete within a range of 120°, the utility model can ensure that the concrete and the steel pipe are closely combined, avoid the gap between the concrete and the steel pipe, reduce contact grouting work, improve construction progress, and reduce construction investment. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a cross-sectional view of an underground buried pipe structure of a water conveyance tunnel to which the utility model is applied.
[0019] Figure 2 It is a longitudinal section view of the underground buried pipe structure of the water conveyance tunnel applied by the utility model.
[0020] Figure 3 yes Figure 2 Detailed drawing of part A (detailed drawing of drainage and exhaust structure installation).
[0021] Figure 4 It is a detailed structural diagram of the drainage and exhaust bolt of the utility model.
[0022] Figure 5 It is a cross-sectional view of the thread of the utility model.
[0023] Figure 6 It is a cross-sectional view of the screw head of the utility model.
[0024] In the figure: 1. Penstock; 1a. Water-facing surface of penstock; 1b. Back-water surface of penstock; 2. Backfill concrete; 3. 120° easy-to-slip zone at the bottom of the tunnel; 4. Grouting hole; 5. Water-permeable and breathable formwork cloth; 6. Drainage and exhaust bolts; 7. Binding wire; 8. Thread; 9. Screw head; 10. Hollow structure; 11. Steel pipe reinforcement plate; 12. Welding seam; 13. Water flow direction; The diameter of the hole in the penstock wall; The aperture of the reinforcement plate; is the diameter of the hollow structure; is the thread diameter of the bolt; is the diameter of the inscribed circle of the screw head 9; t1 is the thickness of the pressure steel pipe wall; t2 is the thickness of the steel pipe reinforcement plate; L1 is the distance that the bolt protrudes from the inner wall of the pressure steel pipe; L2 is the length of the thread; L3 is the length of the screw head; and L4 is the length of the bolt. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings of the utility model.
[0026] like Figure 1-Figure 6As shown, the underground buried pipe is a pressure steel pipe buried in the rock mass, with concrete filled between the steel pipe and the surrounding rock. The transverse direction is the circular diameter length direction of the pressure steel pipe 1, and the longitudinal direction is the length direction perpendicular to the transverse direction.
[0027] A drainage and exhaust structure for backfill concrete pouring of underground buried pipes comprises a water-permeable and breathable template cloth 5, drainage and exhaust bolts 6 and binding wires 7.
[0028] The surface of the pressure steel pipe 1 in contact with water is the water-facing surface 1a of the pressure steel pipe, and the surface of the pressure steel pipe 1 in contact with concrete is the water-repelling surface 1b of the pressure steel pipe. The steel pipe reinforcement plate 11 is fixed around each grouting hole 4 of the pressure steel pipe 1 by a weld 4, and the hollow part in the middle of the pressure steel pipe 1 and the steel pipe reinforcement plate 11 is the grouting hole 4.
[0029] The drainage and exhaust bolts 6 are installed at intervals on the grouting holes 4 within a range of 120° at the bottom of the pressure steel pipe 1. The spacing between the grouting holes 4 is determined according to the design, and is generally 2 to 3 meters. The drainage and exhaust bolts 6 are surrounded by a water-permeable and breathable template cloth 5 and the ends of the threads 8 are wrapped and tied with two binding wires 7. The ends of the screw heads 9 are not wrapped with the water-permeable and breathable template cloth 5.
[0030] The drain and exhaust bolt 6 includes a thread 8 and a screw head 9. The center of the drain and exhaust bolt 6 is a circular hollow structure 10 for draining and exhausting. The screw head 9 of the bolt has a hexagonal outer contour for installing the drain and exhaust bolt 6. The thread 8 has a circular outer contour for fixing the drain and exhaust bolt 6 on the steel pipe reinforcement plate 11.
[0031] The grouting hole 11 includes two parts: a grouting hole on the wall of the pressure steel pipe 1 and a grouting hole on the steel pipe reinforcement plate 11. The drainage and exhaust bolt 6 is installed from the water-facing surface 1a side of the pressure steel pipe to the grouting hole 4. The screw head 9 of the drainage and exhaust bolt 6 is rotated with a wrench so that the thread 8 is fixed in the grouting hole on the steel pipe reinforcement plate 11, and the screw head 9 is fixed in the grouting hole on the wall of the pressure steel pipe 1.
[0032] The diameter of thread 8 is smaller than the opening diameter of the reinforcement plate The length of the thread 8 is greater than the thickness of the steel pipe reinforcement plate 11, and the length of the screw head 9 is greater than the thickness of the pressure steel pipe wall.
[0033] Size Description: The diameter of the hole in the penstock wall, D1 = D2 + 20 mm; The diameter of the hole for the reinforcement plate is determined according to the requirements of the grouting hole 4, generally 50mm; is the diameter of the hollow structure 10, which is 20 mm to 30 mm; is the diameter of the thread 8, D4 = D2-4mm; is the diameter of the inscribed circle of the hexagonal screw head, D5=D4; t1 is the thickness of the pressure steel pipe wall; t2 is the thickness of the steel pipe reinforcement plate; L1 is the distance that the bolt protrudes from the inner wall of the pressure steel pipe, which is 20mm~30mm; L2 is the length of the thread, L2=t2+2~3 pitches; L3 is the length of the screw head, L3=t1+L1; L4 is the length of the bolt, L4=L2+L3.
[0034] The water-permeable and breathable template cloth 5 has a thickness of 2 mm, and the minimum size of the cutting should be able to wrap the drainage and exhaust bolts 6. The binding wire 7 uses a 0.9 mm diameter iron wire to fix the water-permeable and breathable template cloth 5.
[0035] The entire processing and installation process of the utility model is as follows:
[0036] (1) Processing of drainage and exhaust structures
[0037] The drainage and exhaust structure includes three parts. The first part is the drainage and exhaust bolt 6, which is made of Q235 steel. The center of the drainage and exhaust bolt 6 is a circular hollow structure 10, and the diameter of the hollow structure 10 is D3. The thread 8 of the drainage and exhaust bolt 6 has a circular outer contour, a length of L2, and an outer diameter of D4. The screw head 9 of the drainage and exhaust bolt 6 has a hexagonal outer contour, a length of L3, and an inscribed circle diameter of D5. Figures 2 to 4 and "Dimension Description" for processing. The processing quantity is the number of all grouting holes 4 within the planned casting length of the tunnel and within the 120° range of the bottom of the pressure steel pipe (one for each hole), and 3 to 5 more are added as spares; the specifications of the drainage and exhaust template cloth 5 meet the requirements of the specification "Permeable template cloth for concrete engineering" (JT / T736). The thickness of the permeable and breathable template cloth 5 is 2mm, and the minimum cutting size should be able to wrap the drainage and exhaust bolts 6; the binding wire 7 uses a 0.9mm diameter iron wire. After processing the drainage and exhaust bolts 6 and cutting the permeable and breathable template cloth 5, wrap the surroundings of the drainage and exhaust bolts 6 and the ends of the threads 8 with the permeable and breathable template cloth 5, and tie them with two binding wires 7. The ends of the screw heads 9 are not wrapped with the permeable and breathable template cloth 5.
[0038] (II) Installation
[0039] Before pouring backfill concrete on the outside of the tunnel penstock 1, remove the sealing plugs installed on all the grouting holes 4 within a 120° range at the bottom of the penstock 1 from the water-facing surface 1a of the penstock, and use a wrench to rotate the screw head 9 of the drainage and exhaust bolt 6 to install this drainage and exhaust structure into the grouting hole 4 from which the sealing plugs have been removed, ensuring that the threads 8 of each drainage and exhaust structure are fixed in the steel pipe reinforcement plate 11 around each grouting hole 4 of the penstock 1.
[0040] (III) Concrete pouring
[0041] The outer side of the penstock 1 is backfilled with concrete. During the pouring, the waste water flowing out of the hollow structure 10 of the drainage and exhaust bolts 6 is cleaned in time to ensure that the water-facing surface 1a of the penstock is not polluted.
[0042] (IV) 6 hours after the backfill concrete pouring at the bottom of the penstock 1 is completed, the drainage and exhaust structure is dismantled.
[0043] (V) Check the integrity of the water-permeable and breathable template cloth 5 of the drainage and exhaust structure and the threads 8 of the drainage and exhaust bolts 6. If the threads 8 of the drainage and exhaust bolts 6 and the wrapped water-permeable and breathable template cloth 5 are not damaged, they can continue to be recycled. If the threads 8 of the drainage and exhaust bolts 6 are damaged or the water-permeable and breathable template cloth 5 wrapped at the end is lost, it cannot be used, and the damaged drainage and exhaust bolts 6 or water-permeable and breathable template cloth 5 should be replaced.
Claims
1. A drainage and exhaust structure for pouring concrete for backfilling underground pipes, characterized in that: It includes drainage and exhaust bolts, which are arranged at intervals on grouting holes within a range of 120° at the bottom of the pressure steel pipe. The surrounding areas and threaded ends of the drainage and exhaust bolts are wrapped with a water-permeable and breathable template cloth, and the water-permeable and breathable template cloth is tied with two binding wires.
2. The drainage and exhaust structure for underground pipe backfill concrete pouring according to claim 1 is characterized in that: The spacing between the grouting holes is 2 to 3 m.
3. The drainage and exhaust structure for underground pipe backfill concrete pouring according to claim 1 is characterized in that: The center of the drain and exhaust bolt is a circular hollow structure.
4. The drainage and exhaust structure for underground pipe backfill concrete pouring according to claim 1 is characterized in that: The drainage and exhaust bolts are installed into the grouting holes from the water-facing side of the pressure steel pipe, so that the threads are located in the grouting holes on the steel pipe reinforcement plate, and the screw heads are located in the grouting holes on the pipe wall of the pressure steel pipe.
5. The drainage and exhaust structure for underground pipe backfill concrete pouring according to claim 4 is characterized in that: The thread diameter is smaller than the hole diameter of the reinforcing plate, the thread length is greater than the thickness of the steel pipe reinforcing plate, and the screw head length is greater than the thickness of the pressure steel pipe wall.
6. The drainage and exhaust structure for underground pipe backfill concrete pouring according to claim 1 is characterized in that: The minimum size of the water-permeable and air-permeable template cloth can wrap the drainage and exhaust bolts.