Winter construction method for curtain grouting in alpine region

Abstract

The invention discloses an alpine region curtain grouting winter construction method, which comprises the following steps of pipeline heat preservation, drilling grouting platform and heat preservation shed platform erection, hot water slurry preparation and slurry temperature measurement, through the whole set of technical measures, the stability of the temperature and the performance of the slurry is ensured, and the curtain grouting construction quality is further ensured. And reference and guidance are provided for follow-up curtain grouting construction under the cold weather condition in winter in high-altitude and alpine regions.

Description

Technical Field

[0001] The present invention relates to the technical field of building structure engineering, and particularly relates to a method for winter construction of curtain grouting in alpine regions. Background Art

[0002] In building construction, the anti-seepage curtain of the dam foundation includes the riverbed foundation curtain, the main curtain and the overlapping curtain in the grouting adits on the left and right bank slopes, and the curtain in the triangular area of the bank slope cover foundation. Usually, the "orifice closed, from top to bottom, in-hole circulation" grouting method is adopted for curtain grouting. High quality requirements for curtain grouting are necessary to ensure the quality requirements of the anti-seepage curtain of the dam foundation. The quality of curtain grouting plays an irreplaceable role in the service life of water conservancy and hydropower projects, and the winter construction technology of curtain grouting will directly affect the construction quality of the grouting project. In the prior art, when grouting construction is carried out in alpine or low-temperature environments, the common technical problem faced is that the temperature of the cement slurry cannot reach the design and specification requirements. Summary of the Invention

[0003] The main object of the present invention is to provide a method for winter construction of curtain grouting in alpine regions, aiming to solve the technical problem that it is difficult for the temperature of the cement slurry to reach the design value during grouting construction in alpine regions in the prior art. Winter grouting construction is realized by means of heat preservation combined with heating, so that the temperature of the cement slurry meets the design value requirements. While ensuring the grouting quality, construction can also be carried out in winter in alpine regions, ensuring the construction period and construction quality.

[0004] A method for winter construction of curtain grouting in alpine regions includes the following steps: (1) Erection of drilling and grouting platforms: According to the construction design parameters, a plurality of drilling and grouting platforms are respectively erected in the construction areas of the triangular area curtains on the left and right bank slopes of the dam; (2) Erection of heat preservation shed platforms on the drilling and grouting platforms: On the top, the side close to the clay core wall, and the upstream and downstream sides of each drilling and grouting platform, a framework is formed by overlapping the second cross bars, the second vertical bars and the second scissors braces. The outside of the framework is covered with a PVC heat preservation tarpaulin. Wooden templates are installed on the top and around the outside of the PVC heat preservation tarpaulin. Then, a PVC heat preservation tarpaulin is covered on the outside of the wooden templates, and the outermost tarpaulin is fixed with wooden strip press bars; The adjacent tarpaulins are connected by magic tapes; Heat preservation protection is carried out on the drilling and grouting platforms, grouting stations and transfer stations; (3) Arrangement of drilling equipment, pulp making equipment and heating equipment; Installation of drainage, power supply and water supply systems; (4) Pipeline heat preservation: All the slurry supply pipelines and water supply pipelines in the bank slope curtain construction area are heat-preserved. All the slurry supply pipelines and water supply pipelines are wrapped with polyethylene rubber and plastic heat preservation cotton, and are firmly tied with iron wires after being completely wrapped; (5) Drilling operations are carried out on the drilling and grouting platforms according to the construction design requirements; (6) Pulp preparation: Use hot water for pulp preparation to make the pulp temperature reach the design requirements; (7) Grouting construction: Before grouting, first wash the holes to be grouted with hot water, and then according to the construction design requirements, pour the slurry prepared in step (6) into the holes through the slurry transported in the heat preservation pipeline in step (4) to complete the grouting construction.

[0005] A further technical solution is that in step (1), the platform part of the drilling and grouting platform is supported by the cross-connection of the first cross bar and the first vertical bar. The distance between the first vertical bar and the first cross bar is 1.5m, and the first scissors brace is provided; the drilling operation platforms are connected in a stepped manner.

[0006] A further technical solution is that in step (2), the second vertical bar of the heat preservation shed platform is overlapped and fixed with the first vertical bar of the drilling and grouting platform, and the overlapping length is not less than 1m; the side of the top of the heat preservation shed platform close to the slope surface is connected to the first vertical bar of the previous drilling and grouting platform, and the top is encrypted with pipe racks, with a spacing of 1m; the thickness of the wooden formwork is 10-15mm; the specification of the wooden strip pressing strip is 20mm×50mm.

[0007] A further technical solution is that the heat preservation method of the drilling and grouting platform is the same as the erection method of the PVC heat preservation tarpaulin in step (2), and the heat preservation methods of the grouting station and the transfer station are the same as the erection method of the heat preservation shed platform in step (2).

[0008] A further technical solution is that a slope ladder is provided on the slope, and the ladder pedals are made of corrugated anti-slip steel plates; a safety passage is erected between the slope ladder and each drilling and grouting platform; the safety passage is fully covered with wooden boards and tied firmly, and a 1.2m high protective railing is installed on the air side, and a 12mm thick wooden formwork is used for enclosure.

[0009] A further technical solution is to monitor the water temperature and slurry temperature of the centralized pulp preparation station, grouting operation platform and drilling operation platform respectively; use a mercury thermometer for detection, and at the same time use an infrared thermometer for calibration; the hot water temperature is between 25°C and 40°C; the slurry temperature is maintained between 5°C and 40°C.

[0010] A further technical solution is that in step (3), a separate heating power supply system is set up: including a main distribution box and a leakage protector, laying a power cable to connect the heating equipment for power supply.

[0011] A further technical solution is that step (7) is arranged for construction during the daytime.

[0012] The beneficial effects of the present invention: The present invention adopts the overall scheme of "external enclosure, internal heating, hot water hole washing, hot water slurry preparation, pipeline heat preservation, and platform heat preservation" for construction. Moreover, the construction process flow is set as: pipeline heat preservation → erection of the drilling and grouting platform and the heat preservation shed platform → hot water slurry preparation → slurry temperature measurement. Through this set of technical measures, the slurry temperature and performance are ensured to be stable, further guaranteeing the construction quality of curtain grouting. After adopting winter construction measures, the construction quality of the curtain grouting project of the Lianghekou Hydropower Station generally meets the specification and design requirements. At the same time, it effectively guarantees the continuous construction of curtain grouting projects in alpine regions in winter, laying a solid foundation for the impoundment and power generation of the Lianghekou Hydropower Station on schedule. Meanwhile, it provides reference and guidance for subsequent curtain grouting construction under cold climate conditions in high-altitude and alpine regions in China. Brief Description of the Drawings

[0013] Figure 1 It is a schematic diagram of the curtain construction area in the triangular regions on the left and right bank slopes of the dam of the present invention; Figure 2 It is a schematic diagram of the curtain construction area of a slope bank; Figure 3 It is a schematic diagram of the drilling and grouting platform and the heat preservation shed platform in the curtain construction area. Detailed Description of the Preferred Embodiment

[0014] Now, the present invention will be further described in detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0015] In the description of the present invention, it should be noted that, as terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the invention.

[0016] In the description of the present invention, it should be noted that, unless otherwise clearly specified and defined, as terms such as "installation", "connection", "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0017] In the present invention, in the winter construction method of curtain grouting in alpine regions, the specific construction steps it includes are as follows: (1) Erection of Drilling and Grouting Platforms: According to the construction design parameters, multiple drilling and grouting platforms are erected respectively in the curtain construction areas of the triangular zones on the left and right bank slopes of the dam. The drilling and grouting platforms are connected in a stepped manner. Among them, the platform part of the drilling and grouting platform is supported by the cross-connection of the second horizontal bars and the second vertical bars. The distances between the second vertical bars and the second horizontal bars are both 1.5 m, and second cross braces are provided. In one embodiment, the length × width × height of each drilling and grouting platform = 8 m × 10 m × 7 m, and the horizontal projection area is 80 m 2 . Moreover, bank slope ladders are provided on the left and right bank slopes of the dam, and the ladder treads are made of corrugated anti-slip steel plates. In addition, safety passages are erected between the bank slope ladders and each drilling and grouting platform; the safety passages are fully covered with wooden boards and tied firmly. Protective railings with a height of 1.2 m are installed on the air side, and the air side is enclosed with 12-mm-thick wooden formwork.

[0018] (2) Erection of Insulation Shed Platforms on Drilling and Grouting Platforms: On the top, the side close to the clay core wall, and the upstream and downstream sides of each drilling and grouting platform, frames are formed by the lap joint of the first horizontal bars, the first vertical bars, and the first cross braces. Among them, the second vertical bars of the insulation shed platform are lap-jointed and fixed with the first vertical bars of the drilling and grouting platform, and the lap length is not less than 1 m. The side close to the slope on the top is connected to the first vertical bars of the previous drilling and grouting platform, and the top is encrypted with pipe racks at a spacing of 1 m; the outside of the frame is covered with PVC insulation tarpaulins, and wooden formwork is installed on the top and all around the outside of the PVC insulation tarpaulins. In one embodiment, the thickness of the wooden formwork is 10 - 15 mm. Then, PVC insulation tarpaulins are covered on the outside of the wooden formwork, and the outermost tarpaulins are fixed with wooden strip presses. The specifications of the wooden strip presses are 20 mm × 50 mm; adjacent tarpaulins are connected with magic tapes.

[0019] (3) Another insulation shed platform is erected for both the grouting station and the transfer station; the erection method of this another insulation shed platform is the same as that of the insulation shed platform erected on the drilling and grouting platform. PVC insulation tarpaulins are erected on the drilling and grouting platform, and the erection method of the PVC insulation tarpaulins is the same as that of the double-layer insulation tarpaulins on the insulation shed platform.

[0020] (4) Drilling equipment, pulp-making equipment, heating equipment, etc. are respectively arranged on the left and right bank slopes of the dam; (5) Drainage, power supply, and water supply systems are respectively installed on the left and right bank slopes of the dam; among them, a heated power supply system is separately set up on the left and right bank slopes of the dam: including a main distribution box and a leakage protector, and a power cable is laid to connect the heating equipment for power supply.

[0021] (6) Pipeline Insulation: All slurry supply pipelines and water supply pipelines in the curtain construction area of the bank slope are insulated. The above-mentioned all slurry supply pipelines and water supply pipelines are wrapped with polyethylene rubber and plastic insulation cotton, and are firmly tied with iron wires after being completely wrapped; (7) Drilling operations are carried out on the drilling and grouting platform according to the construction design requirements.

[0022] (8) Prepare slurry: Use hot water to prepare slurry to make the slurry temperature reach the design requirements.

[0023] (9) Temperature control: Monitor the water temperature and slurry temperature of the centralized slurry preparation station and the drilling and grouting platform respectively; Use a mercury thermometer for detection and calibrate with an infrared thermometer at the same time.

[0024] (10) Grouting construction: Before grouting, first wash the holes to be grouted with hot water, and then according to the construction design requirements, pour the slurry prepared in steps (8) and (9) into the holes through the slurry transported in the heat preservation pipeline in step (6) to complete the grouting construction. Among them, try to arrange the grouting construction during the period with higher daytime temperature.

[0025] In this construction method, the hot water temperature is between 25°C and 40°C, and the slurry temperature is maintained between 5°C and 40°C.

[0026] A specific construction case is described in detail below.

[0027] As Figures 1 - 3 shown in the embodiment, it is a schematic diagram of the dam curtain grouting construction of the Lianghekou Hydropower Station. Figure 1 It is a schematic diagram of the curtain construction area in the triangular areas on the left and right banks of the dam. Among them, there are two drilling and grouting platforms 3 in Unit 18 of the left bank triangular area 1 of the dam, and three drilling and grouting platforms 3 in Unit 19 of the left bank triangular area 1 of the dam. There are two drilling and grouting platforms in Unit 18 of the right bank triangular area 2 of the dam, and two drilling and grouting platforms in Unit 19 of the right bank triangular area 2 of the dam. These drilling and grouting platforms are arranged in a stepped manner, that is, in a stepped setting. Heat preservation shed platforms 4 are built on all the drilling and grouting platforms 3.

[0028] As Figure 3As shown in the figure, the platform part 37 of the drilling and grouting platform 3 is supported by the cross-connection of the first horizontal bar 31 and the first vertical bar 32. The spacing between the first vertical bar 32 and the first horizontal bar 31 is 1.5 m, and the first diagonal brace 33 is provided to connect the first horizontal bar 31 and the first vertical bar 32. On the slope 11, there is also a slope bottom-sweeping bar 34, and the slope bottom-sweeping bar 34 is fixed on the slope 11 through the connecting wall members 35 arranged at intervals thereon. Among them, one end of the connecting wall member 35 is fixed on the slope bottom-sweeping bar 34, and the rest is buried in the concrete of the slope 11 for fixation. In one embodiment, the connecting wall member 35 is a steel bar, and the steel bar is welded and fixed to the slope bottom-sweeping bar 34. The spacing of the connecting wall members 35 arranged on the slope bottom-sweeping bar 34 is usually set between 1 - 2 m. The first vertical bar 32 is fixed on the slope bottom-sweeping bar 34, and a vertical bar limiting rib 36 is provided at the bottom of each first vertical bar 32. The vertical bar limiting rib 36 is drilled and inserted into the concrete of the slope 11 for fixation. In one embodiment, the bottom of the first vertical bar 32 is welded and fixed to the vertical bar limiting rib 36. The length × width × height of each drilling and grouting platform 3 in the curtain construction area of the triangular areas on the left and right bank slopes of the dam at Lianghekou is 8 m × 10 m × 7 m, and the horizontal projection area is 80 m 2 . In addition, a bank slope ladder 5 is provided near the side of the drilling and grouting platform on the left and right bank slopes of the dam. Among them, the ladder treads are made of patterned anti-slip steel plates. And a safety passage 6 is built between the bank slope ladder 5 and each drilling and grouting platform; the safety passage 6 is fully covered with wooden boards and tied firmly. A protective railing with a height of 1.2 m is installed on the air-facing side, and a 12-mm-thick wooden formwork is used for enclosure.

[0029] Similarly, as Figure 3 shown, the heat preservation shed platform 4 is built on the drilling and grouting platform 3. Specifically, on the top, the side near the clay core wall, and the upstream and downstream sides of each drilling and grouting platform 3, a framework is formed by overlapping the second horizontal bar 41, the second vertical bar 42, and the second diagonal brace 43. Among them, the second vertical bar 42 of the heat preservation shed platform is overlapped and fixed with the first vertical bar 32 of the drilling and grouting platform, and the overlapping length is not less than 1 m. The side of the top of the second vertical bar 42 near the slope is connected to the first vertical bar 32 of the previous drilling and grouting platform, and the top is encrypted with a pipe 44, with a spacing of 1 m; the outside of the framework is covered with a PVC heat preservation tarpaulin, and wooden formworks are installed on the top and all around the outside of the PVC heat preservation tarpaulin. In one embodiment, the thickness of the wooden formwork is 10 - 15 mm. Then, a PVC heat preservation tarpaulin is covered on the outside of the wooden formwork, and the outermost tarpaulin is fixed with a wooden strip pressing bar. The specification of the wooden strip pressing bar is 20 mm × 50 mm; the adjacent tarpaulins are connected with magic tapes. The length × width × height of the heat preservation shed platform 4 on the drilling and grouting platform 3 is 8 m × 10 m × 7 m.

[0030] As Figure 2As shown in the figure, there are also grouting stations and transfer stations etc. at the tops of the left and right banks of the dam. Another insulation shed platform 7 is also erected on the same grouting stations and transfer stations. The erection method of another insulation shed platform 7 is the same as that of the insulation shed platform 4 on the drilling and grouting platform 3. First, the framework is erected, and then the PVC insulation tarpaulin is covered. Wooden formworks are installed on the top and all around the outside of the PVC insulation tarpaulin. Then, the PVC insulation tarpaulin is covered on the outside of the wooden formworks, and the outermost tarpaulin is fixed with wooden strip batten. There is a PVC insulation tarpaulin erected on the drilling and grouting platform 3, and the erection method of the PVC insulation tarpaulin is the same as that of the double-layer insulation tarpaulin on the insulation shed platform 4.

[0031] Drilling equipment, pulp making equipment, heating equipment etc. are respectively arranged on the left and right bank slopes of the dam, and drainage, power supply and water supply systems are respectively installed; among them, a heated power supply system is respectively set up on the left and right bank slopes of the dam: including installing 1 main distribution box with a size of 800mm×1000mm and 1 leakage protector of 630A, and laying a 3×150+2×95 power cable with a length of 200m, which is specially responsible for the power supply of the heating equipment.

[0032] All the slurry supply pipelines and water supply pipelines in the curtain construction area of the bank slope are insulated. The specific operation is that all the slurry supply pipelines and water supply pipelines are wrapped with polyethylene rubber and plastic insulation cotton, and after being completely wrapped, they are tied firmly with iron wire.

[0033] According to the construction design requirements, drilling operations are carried out on the drilling and grouting platform. Of course, this step can also be completed before the erection of the insulation shed platform.

[0034] Hot water is used for slurry mixing, and the water temperature and slurry temperature are continuously detected during the slurry mixing and grouting processes to ensure that the slurry temperature reaches the design requirements. During the construction of the dam body of the Lianghekou Hydropower Station, the hot water temperature is between 25℃ and 40℃, and the slurry temperature is kept between 5℃ and 40℃. During the temperature monitoring, mercury thermometers are used for detection, and at the same time, infrared thermometers are used for calibration. The double detection ensures the accuracy of the temperature.

[0035] After the construction method of the present invention is adopted in the Lianghekou Hydropower Station, it effectively guarantees the effective operation time of the curtain grouting in the winter construction of the slope triangular area on the critical line of the Lianghekou Hydropower Station. The critical line of the overall dam construction is effectively guaranteed. At the same time, the overall construction quality of the curtain grouting in the triangular area meets the design and specification requirements. Through the third-party seepage monitoring, the overall construction quality of the curtain grouting is continuously reliable. The curtain of the dam slope triangular area ensures the completion of the overall grouting construction task on time by taking scientific and effective winter construction measures, and also creates good conditions for the continuous filling construction of the lower dam core wall. Since the grouting project of the Lianghekou Hydropower Station has been carried out normally throughout the year, there has been no shutdown due to the decrease in temperature, effectively guaranteeing the effective operation time of the curtain grouting in the winter construction of the slope triangular area on the critical line of the Lianghekou Hydropower Station. At the same time, the construction quality of the curtain is strongly supported, and it also provides a reliable guarantee for the Lianghekou Hydropower Station to be put into operation and generate electricity on schedule.

[0036] Enlightened by the ideal embodiments of the present invention as described above, through the above description, relevant staff can completely make various changes and modifications within the scope not deviating from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A winter construction method for curtain grouting in alpine regions, characterized in that, It includes the following steps: (1) Erection of drilling and grouting platforms: According to the construction design parameters, multiple drilling and grouting platforms are respectively erected in the curtain construction areas of the triangular zones on the left and right bank slopes of the dam; (2) Erection of heat preservation shed platforms on the drilling and grouting platforms: On the top, the side close to the clay core wall, and the upstream and downstream sides of each drilling and grouting platform, a framework is formed by overlapping the second cross bars, second vertical bars and second scissors braces. The outside of the framework is covered with PVC heat preservation tarpaulin. Wooden formworks are installed on the top and around the outside of the PVC heat preservation tarpaulin. Then, PVC heat preservation tarpaulin is covered on the outside of the wooden formworks, and the outermost tarpaulin is fixed with wooden strip pressing bars; The adjacent tarpaulins are connected with magic tapes; Heat preservation protection is carried out on the drilling and grouting platforms, grouting stations and transfer stations; (3) Arrangement of drilling equipment, pulp making equipment and heating equipment; Installation of drainage, power supply and water supply systems; (4) Pipeline heat preservation: All slurry supply pipelines and water supply pipelines in the curtain construction area of the bank slope are heat-preserved. All the slurry supply pipelines and water supply pipelines are wrapped with polyethylene rubber and plastic heat preservation cotton, and are firmly tied with iron wires after being completely wrapped; (5) Drilling operations are carried out on the drilling and grouting platforms according to the construction design requirements; (6) Pulp preparation: Hot water is used for pulp preparation to make the temperature of the slurry reach the design requirements; (7) Grouting construction: Before grouting, the holes to be grouted are washed with hot water. Then, according to the construction design requirements, the slurry prepared in step (6) is poured into the holes through the slurry transported in the heat-preserved pipeline in step (4) to complete the grouting construction.

2. The winter construction method of curtain grouting in alpine regions according to claim 1, characterized in that, In step (1), the platform part of the drilling and grouting platform is supported by the cross-connection of the first cross bars and the first vertical bars. The distances between the first vertical bars and the first cross bars are both 1.5 m and the first scissors braces are provided; The drilling operation platforms are connected in a stepped manner.

3. A winter construction method for curtain grouting in alpine regions according to claim 2, characterized in that, In step (2), the second vertical bars of the heat preservation shed platform are overlapped and fixed with the first vertical bars of the drilling and grouting platform, and the overlapping length is not less than 1 m; The side of the top of the heat preservation shed platform close to the slope surface of the bank is connected with the first vertical bar of the previous drilling and grouting platform, and the top is encrypted with pipe racks with a spacing of 1 m; The thickness of the wooden formwork is 10 - 15 mm; The specifications of the wooden strip pressing bars are 20 mm × 50 mm.

4. A winter construction method for curtain grouting in alpine regions according to claim 3, characterized in that The heat preservation method of the drilling and grouting platform is the same as the erection method of the PVC heat preservation tarpaulin in step (2), and the heat preservation methods of the grouting station and the transfer station are the same as the erection method of the heat preservation shed platform in step (2).

5. A winter construction method for curtain grouting in alpine regions according to claim 2, characterized in that, There are bank slope ladders on the bank slope, and the ladder pedals are made of corrugated anti-slip steel plates; A safety passage is erected between the bank slope ladder and each drilling and grouting platform; The safety passage is fully covered with wooden boards and tied firmly, and a 1.2 m high protective railing is installed on the air side and enclosed with a 12 mm thick wooden formwork.

6. A winter construction method for curtain grouting in alpine regions according to claim 1, characterized in that, The water temperature and slurry temperature of the centralized pulp making station, grouting operation platform and drilling operation platform are monitored respectively; A mercury thermometer is used for detection, and an infrared thermometer is used for calibration at the same time; The hot water temperature is between 25°C and 40°C; The temperature of the slurry is kept between 5°C and 40°C.

7. A winter construction method for curtain grouting in alpine regions according to claim 6, characterized in that, In step (3), a separate heated power supply system is set up: including a main distribution box and a leakage protector, and a power cable is laid to connect the heating equipment for power supply.

8. A winter construction method for curtain grouting in alpine regions according to claim 1, characterized in that, Step (7) is arranged for construction during the daytime period.

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