Freeze-thaw resisting canal constructed based on prestressed steel bars and construction technology

Abstract

The invention discloses an anti-freezing and thawing water channel constructed based on prestressed steel bars and a construction process. A water channel main body is connected into a whole through mortise and tenon connecting structures arranged between water channel units; each water channel unit is provided with prestressed steel bars; and the prestressed reinforcement completely penetrates through the whole section of water channel. In the actual operation environment, especially in the northern area, the frost heaving phenomenon in winter can generate strong stress resistance to the canal, and the prestress generated by the prestressed steel bars can exactly and effectively offset the stress resistance, so that the occurrence probability of canal cracks is greatly reduced, the service life is prolonged, and the damage resistance is enhanced. On the aspect of drainage function optimization, accumulated water at the bottom of the water channel can be drained timely and rapidly through the drainage pipeline laid at the bottom of the water channel and the pipelines on the two sides, and the water level is effectively lowered. In the freezing and thawing cycle process in the north, the canal is not prone to serious structural damage such as displacement and collapse, and the stability and durability of the canal are improved.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy engineering, and in particular to a freeze-thaw resistant water channel constructed based on prestressed steel bars and a construction process. Background Art

[0002] In the scope of water conservancy projects in the cold northern regions, the construction and maintenance of freeze-thaw resistant canals are caught in a very unique and complex background environment. With the continuous changes in the global climate, the frequency and intensity of extreme cold weather are on the rise, which undoubtedly makes the freeze-thaw problem of canals more severe and eye-catching. In cold regions, the temperature frequently drops below freezing point. Once the water in the canal freezes, it will expand in volume, exerting strong pressure on the canal structure. When this pressure changes periodically, that is, when it undergoes a freeze-thaw cycle, the concrete or masonry structure used in ordinary canals is prone to cracks, looseness, and even collapse, which has an extremely adverse and serious impact on the water conveyance efficiency and structural stability of the canal.

[0003] The design concept of traditional canals mostly focuses on the water transportation function, and there are great deficiencies in their adaptability to the special environment of cold regions. Its construction materials and construction techniques are difficult to effectively resist the frequent freeze-thaw effects. With the complexity and changeability of the climate, the scope of cold regions continues to expand, and the degree of freeze-thaw damage to canals continues to increase, which will not only cause the loss of precious water resources and greatly reduce the transportation efficiency, but also lead to rising maintenance costs. In addition, the conventional steel bar configuration of traditional canals has obvious limitations in resisting freeze-thaw stress and cannot meet the actual needs of its long-term and efficient operation.

[0004] Therefore, the full development of canals with excellent and efficient anti-freeze and thaw performance has become a core key issue that urgently needs to be solved in the field of water conservancy engineering. This requires us to comprehensively consider many key factors such as the material's own characteristics, structural design optimization plans, and the effective application of new protection technologies, so as to ensure that the canals can achieve long-term and stable operation under low temperature conditions. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a freeze-thaw resistant canal and construction process constructed based on prestressed steel bars. The device uses prestressed steel bars to make the canal, which increases the stress resistance of the canal.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] The freeze-thaw resistant canal constructed based on prestressed steel bars provided by the present invention comprises a canal main body, wherein the canal main body comprises a plurality of canal unit sections, and flexible connection structures are arranged between the canal units, through which the various canal units are connected into a whole; the canal units are prefabricated concrete parts provided with prestressed steel bars; the prestressed steel bars are arranged along the laying direction of the canal units.

[0008] Furthermore, the flexible connection structure arranged on the end faces between the water channel units is a mortise and tenon connection structure; the mortise and tenon connection structure adopts a double trapezoidal mortise and tenon groove or a double trapezoidal mortise and tenon head.

[0009] Furthermore, a drainage structure is provided at the lower part of the water channel unit, and the drainage structure is used to drain the accumulated water at the bottom of the water channel.

[0010] Furthermore, the drainage structure includes a drainage pipe and a guide channel; the drainage pipe is laid in the middle of the bottom of the canal; the guide pipe runs through the drainage pipe horizontally along the drainage pipe, and is used to guide the accumulated water at the bottom of the canal into the drainage pipe.

[0011] Furthermore, the drainage pipe includes a main drainage pipe and secondary drainage pipes arranged on both sides of the main drainage pipe; the secondary drainage pipes are arranged at the same height on both sides of the main drainage pipe, and the diameter of the middle main drainage pipe is slightly larger than the diameter of the secondary drainage pipe; the secondary drainage pipe is arranged obliquely to guide the accumulated water on both sides into the main drainage pipe; the diameter of the guide pipe is the same as that of the secondary drainage pipe; the guide pipes are arranged at intervals on both sides of the drainage pipe;

[0012] Furthermore, the outer layer of the drainage pipe is provided with a thin layer of water-permeable material.

[0013] Furthermore, the drain pipe is provided with a plurality of water-permeable channels, and the water-permeable channels are used to allow accumulated water to enter the drain pipe.

[0014] Furthermore, the concrete in the water channel unit adopts modified concrete, wherein the modified concrete selects silicate cement as the base material, and is mixed with slag powder in an appropriate amount, while the water-cement ratio is strictly controlled within 0.45, and denitrifying bacteria are added to the recycled aggregate.

[0015] The freeze-thaw resistant canal construction process based on prestressed steel bars provided by the present invention comprises the following steps:

[0016] S1: Prepare the canal construction materials according to the design requirements;

[0017] S2: Carry out earth excavation for canal foundation according to design requirements;

[0018] S3: Produce a water channel unit with modified concrete mix according to design requirements;

[0019] S4: Set up drainage structure according to design requirements;

[0020] S5: Lay the canal units on the drainage structure in sequence according to the canal design requirements.

[0021] Further, the water channel unit is manufactured according to the following steps:

[0022] S31: obtaining silicate cement as a base material, adding an appropriate amount of slag powder, controlling the water-cement ratio within 0.45, and adding denitrifying bacteria to obtain recycled aggregate;

[0023] S32: Add the recycled aggregate into a concrete mixer according to the high performance concrete mix ratio, first mix the dry material evenly, then add water and a water reducing agent to mix to obtain concrete; the concrete mix ratio is set in the following manner:

[0024] Cement: mineral powder or fly ash: sand: gravel: water reducing agent: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4);

[0025] S33: pouring the mixed concrete into the channel formwork where the steel bars are located, and performing a tamping operation;

[0026] S34: Timely maintenance after pouring;

[0027] S35: According to the tensioning control force and tensioning sequence required by the design, prestress is applied to the prestressed steel bars one by one or one bundle at a time. During the operation, the elongation value of the steel bars is measured synchronously and compared with the theoretical value until the requirement is met. Finally, the anchoring operation is performed to obtain the channel unit.

[0028] The beneficial effects of the present invention are:

[0029] The anti-freeze-thaw canal based on prestressed steel bars provided by the present invention is constructed based on the prestressed steel bars. Compared with the traditional canal, it has many innovative designs. In terms of structural assembly, the canal wall is modularized and divided into several sections according to the construction requirements. These modules can be prefabricated in the factory and then transported to the site for assembly, just like assembling a canal. Figure 1 This design makes it easy to repair and replace damaged parts, and can be flexibly combined under different terrain conditions. If the canal needs to be expanded, just add the corresponding modules.

[0030] In terms of structural reinforcement, prestressed steel bars were added, which run through the entire section of the canal. In the actual operating environment, especially in the northern region, the frost heave phenomenon in winter will produce strong stress resistance on the canal, and the prestress generated by the prestressed steel bars can effectively offset this part of the stress resistance; the bottom of the canal is an arched structure, which is more advantageous than the traditional flat-bottomed canal in terms of bearing soil pressure and water pressure. It can disperse the pressure to the supporting structures on both sides, reducing the pressure on the bottom, and the internal space of the arched structure is relatively large, which is convenient for inspection and maintenance personnel to move inside; the canal wall modules are connected using a special mortise and tenon structure and TPE material to resist the pressure transmitted from the bottom of the arch, thereby greatly reducing the probability of cracks in the canal, extending the service life, and enhancing the ability to resist damage.

[0031] In terms of drainage function optimization, three drainage pipes are carefully laid vertically in the middle of the bottom of the canal. The pipes on both sides are located at the same height. The diameter of the middle pipe is slightly thicker than that of the pipes on both sides, and it is tilted downward at a certain slight angle. In addition, a horizontal pipe is laid at the bottom of the canal and runs through the three vertical pipes. The aperture is the same as that of the two vertical outer pipes, which plays a diversion role. The pipe material is plastic corrugated pipe (HDPE corrugated pipe), which is light, corrosion-resistant, easy to transport and install. The corrugated structure inside this material can provide expansion space, and its smooth pipe wall can reduce water flow resistance and improve water delivery efficiency. It is particularly suitable for areas with strong soil corrosion. These pipes are properly wrapped with geotextiles, and many small holes are evenly distributed on the pipes. Geotextile is a synthetic fiber fabric with good water permeability. Geotextile can be wrapped on the outside of the drainage pipe to play a dual role of filtering and drainage. It allows water to pass smoothly, while blocking impurities such as sediment from entering the pipe, preventing soil particles from clogging the pipe, extending the service life of the pipe, and ensuring the normal operation of the drainage system. In this way, the accumulated water at the bottom of the canal can be drained away promptly and quickly, effectively lowering the water level. During the freeze-thaw cycle in the north, the canal is less likely to suffer serious structural damage such as displacement and collapse, thus improving the stability and durability of the canal.

[0032] In addition, there have been breakthroughs in drainage. Considering the significant damage that groundwater may cause to the channel bed, drainage pipes are innovatively laid under the gravel cushion layer to absorb gravel and groundwater in a timely manner, thereby effectively reducing common problems such as cracks and deformation caused by freeze-thaw cycles, comprehensively improving the performance and service life of the water channel, and providing a solid and reliable guarantee for the stable operation of water conservancy projects in complex environments.

[0033] For the key part of the canal connection, the present invention uses TPE material and mortise and tenon structure for connection. TPE material has both the elasticity of rubber and the processing characteristics of plastic. It can be made into canal parts of various shapes through processes such as injection molding or extrusion. For example, in some canal connections or curved parts that require complex shapes, TPE materials can be well formed. And the expansion and contraction rate of TPE materials can be adjusted according to the specific formula to adapt to different environmental requirements. Its weather resistance is also relatively good, and it can maintain good physical properties under different climatic conditions. With its excellent sealing performance, it can effectively prevent water leakage, and the mortise and tenon structure has a strong bite force and can withstand greater pressure. This feature plays a vital role in alleviating the freeze-thaw cycle phenomenon of the canal in extremely cold weather, effectively avoiding a series of freeze-thaw damage problems caused by leakage, and further improving the overall freeze-thaw resistance of the canal.

[0034] At the same time, we have carried out in-depth development and extension in dealing with the settlement problem. By using prestressed steel bars combined with mortise and tenon structures to tighten each section of the canal, the integrity and stability of the canal structure have been significantly enhanced. In response to extreme weather conditions in the north, bold innovations have been carried out in the field of freeze-thaw protection from both material and structure aspects.

[0035] From the perspective of material selection, there is an extreme shortage of high-performance, environmentally friendly materials suitable for canal construction in cold regions, and traditional antifreeze additives may also cause pollution and damage to the soil and water environment.

[0036] From the perspective of construction technology, there was a lack of refined standards and quality control systems specifically formulated for cold environments, which caused many canals to have the seeds of freeze-thaw hazards in the early stages of construction. Furthermore, the geographical and geological conditions in cold regions are complex and diverse. In some areas, the groundwater level is high and the soil is extremely frost-heavy, which further increases the potential risk of freeze-thaw damage to the canals. At the same time, it also greatly increases the difficulty of the design and construction process, posing a continuous and severe challenge to the performance and stability of existing freeze-thaw-resistant canals.

[0037] The concrete mix ratio is deeply optimized, and high-performance antifreeze admixtures, polymer emulsion mortar, high-strength fiber, etc. are added to comprehensively improve the inherent antifreeze and crack resistance and self-repair ability of concrete; prestressed steel bars and mortise and tenon structures are cleverly used to strengthen the integrity and density of the canal structure, thereby effectively improving the antifreeze-thaw performance of concrete; drainage technology is reasonably used to efficiently drain groundwater and accumulated water in a timely manner, thereby minimizing the serious damage to the canal structure caused by water freezing and expansion in a low-temperature environment; the connection technology is cleverly used to connect the various canal modules to extend the service life of the canal. The organic and comprehensive application of these technologies has laid a solid and reliable foundation for the in-depth research and development and successful construction of new antifreeze-thaw canals. Its core purpose is to properly solve the problem of canal freezing damage in cold areas, comprehensively improve the reliability and service life of water conservancy facilities, and provide strong technical support and solid guarantee for water conservancy projects in cold northern areas.

[0038] The canal has excellent structural integrity and high density, and its advantages are significant. On the one hand, it can effectively deal with the settlement problem that is very easy to occur in the cold climate conditions in the north, and on the other hand, it can effectively ensure the water tightness between the sections of the canal. At the same time, by cleverly adding drainage pipes, the irreversible damage to the canal bed caused by the freeze-thaw cycle has been successfully reduced, thereby comprehensively improving the stability and durability of the canal in harsh environments.

[0039] The modular water channel of the present invention can be prefabricated in a factory and then transported to the site for assembly. Figure 1 This design facilitates the repair and replacement of damaged parts, and can be flexibly combined under different terrain conditions. If the canal needs to be expanded, just add the corresponding modules. For some temporary irrigation canals or canals used for drainage in disaster relief, this modular design can be quickly built and dismantled, improving efficiency.

[0040] The modified concrete of the present invention has excellent impermeability, can effectively reduce the loss of water resources and ensure the water conveyance efficiency of the canal; its good frost resistance enables the canal to maintain structural stability in cold areas or in winter, avoiding cracking and peeling of concrete due to freeze-thaw cycles, thereby extending the service life of the canal; its strong wear resistance can resist long-term scouring of water flow and abrasion of solid particles such as mud and sand carried in the water; its excellent corrosion resistance can resist erosion and damage to the canal structure by chemicals, microorganisms, etc. in the water.

[0041] The prestress of the prestressed steel bar of the present invention can effectively offset part or all of the tensile stress that the canal may bear during use, greatly enhance the tensile strength of the canal structure, and significantly reduce the possibility of cracks caused by tensile stress on concrete, thereby improving the anti-seepage performance of the canal, avoiding leakage loss of water resources, and ensuring water delivery efficiency. From the perspective of structural stability, it can make the structure more stable, better resist interference from external factors such as water flow impact, soil side pressure, and temperature changes, reduce the risk of structural deformation or even damage, greatly extend the service life of the canal, and reduce maintenance and reconstruction costs.

[0042] The drainage pipe of the present invention can quickly remove water from the bottom of the canal, reduce water retention time, and reduce the risk of damage such as leakage and collapse of the canal due to long-term water accumulation. In addition, in the winter in the north, the thermal conductivity of the drier soil is relatively small. The drainage pipe can slow down the transfer of heat, make the soil temperature at the bottom of the canal relatively stable, and reduce the frequency and intensity of freeze-thaw.

[0043] The TPE material of the present invention has excellent elasticity and deformation ability, and can effectively adapt to the deformation of the canal connection caused by temperature change, foundation settlement or water pressure, tightly fit the gap, prevent leakage, ensure the water tightness of the canal, reduce the loss and waste of water resources, and ensure water delivery efficiency. Its good aging resistance can maintain a stable water-stopping effect under long-term sunlight, humid environment and various water erosion, greatly extending the waterproof life of the canal connection and reducing the cost of frequent maintenance and replacement.

[0044] The mortise and tenon connection structure of the present invention is tight, and can withstand greater pressure and weight through the precise fit between the tenon and the mortise, and is not prone to the situation where a section of the water channel becomes loose or falls off, causing damage to the overall structure, and can effectively extend the service life. In addition, the mortise and tenon structure has outstanding seismic performance. It is a flexible connection, and there is a certain gap between the mortise and tenon. It is not a completely rigid connection, and has a certain expansion margin and flexibility. When an earthquake occurs, the water channel can absorb part of the impact energy brought by the seismic wave through the deformation of the mortise and tenon connection, thereby reducing the damage to the water channel as a whole by the earthquake, and achieving "shaking without dispersing, shaking without falling". After the earthquake, the special structure of the mortise and tenon can automatically return to its original position to a certain extent, reducing the difficulty and cost of post-disaster repair.

[0045] The geotextile of the present invention is a synthetic fiber fabric with good water permeability. The geotextile can be wrapped around the outside of the drainage pipe to play a dual role of filtering and drainage. It allows water to pass smoothly while blocking impurities such as silt from entering the pipe. It is an important auxiliary material in the drainage system of the dam, which can prevent soil particles from clogging the pipe, extend the service life of the pipe, and ensure the normal operation of the drainage system.

[0046] Compared with the traditional flat-bottomed canal, the canal bottom arch structure of the present invention has more advantages in bearing soil pressure and water pressure. It can disperse the pressure to the supporting structures on both sides, reducing the pressure on the bottom, and the internal space of the arch structure is relatively large, which is convenient for inspection and maintenance personnel to move inside.

[0047] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for explanation.

[0049] Figure 1 This is a cross-sectional view of a freeze-thaw resistant canal.

[0050] Figure 2 This is a side view of the freeze-thaw resistant canal model.

[0051] Figure 3 This is an oblique cross-sectional view of a freeze-thaw resistant canal.

[0052] Figure 4 This is the overall effect diagram of the freeze-thaw resistant canal.

[0053] Figure 5 This is a thin layer diagram of the permeable material of the drainage pipe at the bottom of the canal.

[0054] Figure 6 Schematic diagram of the permeable pores in the drainage pipe at the bottom of the canal.

[0055] Figure 7 Schematic diagram of the connection materials for the canal module.

[0056] Figure 8 This is a schematic diagram of the mortise and tenon structure details.

[0057] Fig. 9 It is a freeze-thaw resistant canal construction technology based on prestressed steel bars.

[0058] In the figure, 1 represents prestressed steel bars, 2 represents mortise and tenon connection structure, 3 represents drainage structure, 31 represents main drainage pipe, 32 represents secondary drainage pipe, 33 represents diversion pipe; 4 represents geotextile, 5 represents permeable pores, 6 represents TPE material, and 7 represents mortise. DETAILED DESCRIPTION

[0059] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0060] Example 1

[0061] like Figure 1 and Figure 2 As shown, the freeze-thaw resistant canal constructed based on prestressed steel bars provided in this embodiment includes a canal body;

[0062] The water channel body includes a plurality of water channel units, and a connecting structure is provided between the water channel units, and the water channel units are connected into a whole through the connecting structure; the connecting structure in this embodiment adopts a flexible connecting structure;

[0063] The cross section of each water channel unit is an open-top water trough with an arched bottom structure; the water channel unit is a prefabricated concrete part provided with prestressed steel bars; the prestressed steel bars are provided along the laying direction of the water channel unit; Figure 3 and Figure 4 shown.

[0064] The flexible connection structure provided on the end surface between the water channel units is a mortise and tenon connection structure; the mortise and tenon connection structure includes a double trapezoidal mortise and tenon groove, a double trapezoidal mortise and tenon head; and a mortise hole formed, such as Figure 7 and Figure 8 shown.

[0065] A drainage structure is provided at the bottom of the water channel unit, and the drainage structure is used to drain the accumulated water at the bottom of the water channel;

[0066] The drainage structure includes a drainage pipe and a diversion channel; the drainage pipe is laid in the middle of the bottom of the canal; the diversion pipe runs through the drainage pipe horizontally along the drainage pipe, and is used to guide the accumulated water at the bottom of the canal into the drainage pipe;

[0067] The drainage pipe includes a main drainage pipe and secondary drainage pipes arranged on both sides of the main drainage pipe; the secondary drainage pipes are arranged at the same height on both sides of the main drainage pipe, and the diameter of the middle main drainage pipe is slightly larger than that of the secondary drainage pipe; the secondary drainage pipe is arranged obliquely to guide the accumulated water on both sides into the main drainage pipe; the diameter of the guide pipe is the same as that of the secondary drainage pipe; the guide pipes are arranged at intervals on both sides of the drainage pipe;

[0068] The outer layer of the drainage pipe is provided with a thin layer of geotextile water-permeable material; Figure 5 shown.

[0069] The drain pipe is provided with a plurality of water-permeable channels, and the water-permeable channels are used to allow the accumulated water to enter the drain pipe; Figure 6 shown.

[0070] A rubber water stop is arranged between each of the water channel units, and the rubber water stop is arranged along the cross-section side of the water channel unit, and the rubber water stop is arranged on the outer side and the inner side of the cross-section of the water channel unit respectively;

[0071] Each water channel unit includes a bottom module and a side module; the side modules are symmetrically and obliquely arranged on both sides of the bottom module to form a water channel with an open top in cross section; the side modules are inclined at an angle of 20 to 40 degrees relative to the vertical direction;

[0072] The raw materials of the canal unit in this embodiment are modified concrete, and silicate cement is carefully selected as the basic material, and slag powder is appropriately mixed. At the same time, the water-cement ratio is strictly controlled within 0.45, and denitrifying bacteria are innovatively added to the recycled aggregate. The product structure generated by silicate cement during the hydration reaction presents a relatively dense characteristic, which can significantly improve the frost resistance of concrete; slag powder has high activity, and when interacting with other components, it can promote the formation of a denser and stronger structure; and a reasonable and accurate water-cement ratio setting is conducive to reducing the porosity of concrete, thereby improving its density; the unique role of denitrifying bacteria is that it can effectively prevent water from entering the pores, reduce the absorption of free water in the concrete, and can produce calcium carbonate crystals, which can gradually fill the gaps, greatly enhancing the ability of concrete to resist water freezing expansion. Through the all-round optimization and innovative combination of raw materials, the antifreeze performance of concrete is effectively improved from the fundamental source, laying a solid foundation for the stable operation of the canal in a cold environment.

[0073] Among them, in the common emulsion mortar ratio for protecting the inner wall of the canal, the polymer emulsion: cement: sand = 0.2:1:2.5 can be used. Cement usually uses ordinary Portland cement with a strength grade of 42.5, and sand can use medium sand with a fineness modulus between 2.3-3.0. Such mortar has good workability and crack resistance, and can effectively prevent leakage and cracking of the canal wall. At the same time, in order to improve the working performance of the mortar, an appropriate amount of admixtures, such as cellulose ether, can also be added. The addition amount is generally 0.05%-0.1% of the cement mass, which can improve the water retention and construction workability of the mortar.

[0074] The mix ratio (mass ratio) of high-performance concrete (used for large or important canal structures) is cement: mineral powder (or fly ash): sand: gravel: water reducer: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4).

[0075] Mineral powder or fly ash can improve the performance and durability of concrete. Water reducer can reduce the water-cement ratio and improve the strength and durability of concrete. The fiber volume ratio is generally 0.5%-2% (total concrete volume), and the dosage of antifreeze agent is generally 5%-15%.

[0076] First, carefully select silicate cement as the base material, add an appropriate amount of slag powder, strictly control the water-cement ratio within 0.45, and add denitrifying bacteria to the recycled aggregate. Add these materials to the concrete mixer according to the high-performance concrete ratio (cement: mineral powder (or fly ash): sand: gravel: water reducer: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4), first mix the dry materials evenly, then add water and water reducer and mix. The mixing time meets the specification requirements to ensure the uniformity and workability of the concrete. Among them, the amount of water reducer is usually expressed as a percentage of the cement mass. The calculation formula is: m 减水剂 =m 水泥 ×p, where m 减水剂 is the mass of water reducing agent (kg), m 水泥 is the mass of cement in concrete (kg), and p is the amount of water reducer (expressed as a decimal). For example, in high-performance concrete (cement: mineral powder (or fly ash): sand: gravel: water reducer: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4)), if the amount of cement is 300kg and the amount of water reducer is 2%, then the mass of the water reducer is 6kg. The mixed concrete is transported to the construction site by a transport vehicle, poured into the channel formwork, and poured and vibrated in layers according to the size of the structure. The vibration is combined with an inserted vibrator and a flat vibrator to ensure compaction. Pay attention to protecting the position of the steel bars during pouring. After pouring is completed, timely maintenance methods such as covering with plastic film and sprinkling water to retain moisture are adopted. The maintenance time is determined according to the strength growth requirements and environmental conditions, and is generally not less than 7 days. By optimizing the combination of raw materials and standardizing the operation of each process, the frost resistance of concrete can be improved to ensure the stable operation of the channel in a cold environment.

[0077] The canal structure provided in this embodiment uses prestressed steel bars and mortise and tenon structures. This measure brings multiple positive effects. On the one hand, the bite force of the mortise and tenon structure is used for embedding, which effectively reduces the construction difficulty and greatly reduces the construction time, significantly improving the efficiency of engineering construction; on the other hand, the prestress generated by the prestressed steel bars can accurately offset part of the stress resistance caused by frost heave, greatly enhancing the integrity and density of the canal structure, reducing the infiltration of water, thereby effectively reducing the frequency and degree of damage of the freeze-thaw cycle phenomenon, and ensuring the long-term stability of the canal structure.

[0078] During the construction of prestressed steel bars, firstly, the steel bars are accurately cut and bent according to the design drawings, and the processing size and shape are strictly controlled, while paying attention to protecting the surface of the steel bars from damage. Then, on the treated foundation cushion or existing concrete structure, the prestressed steel bars are accurately installed according to the spacing and position given in the design, and reliable connection methods such as binding and welding are used to ensure the stability of the steel skeleton. When the strength of the concrete structure reaches the specified proportion of the design strength (usually 75% and above), according to the tensioning control force and tensioning sequence required by the design, professional tensioning equipment is used to apply prestress to the prestressed steel bars one by one or one bundle at a time. During the operation, the elongation value of the steel bars is accurately measured simultaneously and compared with the theoretical value in detail to control the error within the allowable range. Finally, the anchoring operation is properly performed, thereby effectively ensuring the reliable application of prestress and the stability of the structure.

[0079] The drainage structure provided in this embodiment includes three drainage pipes carefully laid in the middle of the bottom of the canal, the pipes on both sides are located at the same height, the diameter of the middle pipe is slightly thicker than the pipes on both sides, and it is tilted downward at a certain slight angle. In addition, a horizontal pipe is laid at the bottom of the canal and runs through three vertical pipes, and the aperture is the same as that of the two vertical outer pipes, which plays a diversion role. The pipe is densely covered with small holes, and the outside of the pipe is tightly wrapped with permeable materials. The laying of drainage pipes is of great significance. On the one hand, it can drain the accumulated water at the bottom of the canal in a timely and rapid manner, effectively reduce the serious damage caused to the canal structure by the freezing and expansion of water in a low temperature environment, and significantly reduce the possibility of cracks, deformation and other problems caused by freeze-thaw cycles; on the other hand, the drainage pipe can also regulate the temperature of the soil around the canal to a certain extent, and further optimize the external environment of the canal. In addition, timely discharge of accumulated water and lowering of the water level can effectively reduce the pressure on the canal structure, so that the canal is not prone to structural damage such as displacement and collapse during the freeze-thaw process, effectively extending the service life and cycle of the canal, and ensuring that it always maintains a good performance state during long-term operation.

[0080] In this embodiment, rubber waterstops are precisely installed at the joints of each section of the canal. With its good elastic properties and excellent water-stopping ability, rubber waterstops can flexibly adapt to the deformation of concrete structures caused by temperature fluctuations, foundation settlement and other complex factors, and can still maintain good sealing after deformation, effectively preventing water leakage, successfully solving the problem of water resource loss, and significantly improving the efficiency of water transportation, ensuring the efficient and stable operation of the canal water delivery function.

[0081] Example 2

[0082] like Fig. 9 As shown, the freeze-thaw resistant canal construction process based on prestressed steel bars provided in this embodiment includes the following steps:

[0083] S1: Prepare the construction materials of the water channel according to the design requirements, mainly silicate cement, slag powder, ordinary silicate cement (for emulsion mortar), medium sand, gravel, polymer emulsion, cellulose ether, water reducer, denitrifying bacteria, antifreeze agent (determine the specific type and dosage according to environmental requirements) and prestressed steel bars, etc.;

[0084] S2: Carry out earth excavation for canal foundation according to design requirements;

[0085] S3: A water channel unit with a modified concrete mix ratio is manufactured according to the design requirements, and the stirred emulsion mortar is evenly applied on the inner wall of the water channel in a layered manner;

[0086] S4: Set up drainage structure according to design requirements and lay drainage pipes wrapped with geotextiles under the channel bottom;

[0087] S5: According to the canal design requirements, the canal units are laid on the drainage structure in sequence, and the mortise and tenon structure and TPE materials are used to connect the canal sections to ensure the sealing of the canal.

[0088] The water channel unit in this embodiment is manufactured according to the following steps:

[0089] S31: obtaining silicate cement as a basic material, adding an appropriate amount of slag powder, controlling the water-cement ratio within 0.45, and adding denitrifying bacteria to obtain recycled aggregate;

[0090] S32: Add the recycled aggregate into a concrete mixer according to the high-performance concrete mix ratio, first mix the dry material evenly, then add water and a water reducing agent to mix to obtain concrete; the concrete mix ratio is set in the following manner:

[0091] Cement: mineral powder or fly ash: sand: gravel: water reducing agent: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4);

[0092] S33: pouring the mixed concrete into the channel formwork where the steel bars are located, and performing a tamping operation;

[0093] S34: Timely maintenance after pouring;

[0094] S35: According to the tensioning control force and tensioning sequence required by the design, prestress is applied to the prestressed steel bars one by one or one bundle at a time. During the operation, the elongation value of the steel bars is measured synchronously and compared with the theoretical value until the requirement is met. Finally, the anchoring operation is performed to obtain the channel unit.

[0095] The specific process of the freeze-thaw resistant canal construction process based on prestressed steel bars provided in this embodiment is described in detail below:

[0096] First, according to the design requirements, materials such as Portland cement, slag powder, ordinary Portland cement (for emulsion mortar), medium sand, gravel, polymer emulsion, cellulose ether, water reducer, denitrifying bacteria, antifreeze (determine the specific type and dosage according to environmental requirements) and prestressed steel bars are purchased. Ensure that the quality of the materials meets the relevant standards and conduct inspections and retests on important materials such as cement and steel. According to the ratio requirements of modified concrete and emulsion mortar, accurately calculate the amount of each material, and do a good job of storing and preserving the materials to prevent moisture and deterioration. Clear the debris and obstacles at the construction site, level the site, and provide good working conditions for the construction of the canal. According to the design direction and size of the canal, measure and lay out the lines, determine the center line and boundary line of the canal, and set control piles and leveling points to facilitate measurement and control during construction. Equipped with mechanical equipment such as concrete mixers, mortar mixers, transport vehicles, vibrating equipment (such as inserted vibrators, flat vibrators), steel bar processing equipment (such as steel bar cutting machines, bending machines, electric welders), tensioning equipment (used for tensioning prestressed steel bars), etc., and carry out debugging and maintenance to ensure that the equipment performs well and operates normally.

[0097] Then, excavate the earthwork of the canal foundation according to the design requirements, and use a combination of mechanical excavation and manual finishing to ensure that the base elevation, size and slope meet the design requirements. During the excavation process, pay attention to protecting the stability of the surrounding soil and avoid over-excavation or disturbing the original soil of the base. In case of weak foundation, the foundation should be treated according to the design requirements, such as replacement and compaction. After the base is accepted, lay the foundation cushion. The cushion material can be selected according to the design, such as plain concrete cushion or sand and gravel cushion. For the plain concrete cushion, pour it according to the construction process of ordinary concrete, vibrate it to make it dense, smooth the surface, and maintain it to ensure that the strength and flatness of the cushion meet the subsequent construction requirements.

[0098] Secondly, according to the requirements of the design drawings, the prestressed steel bars are processed by cutting, bending and other operations. Ensure that the length and bending angle of the steel bars meet the design dimensions. During the processing, pay attention to protecting the surface of the steel bars to avoid defects such as scratches and rust. Install prestressed steel bars on the foundation cushion or the poured concrete structure according to the designed spacing and position. Use connection methods such as binding and welding to ensure the firmness and stability of the steel skeleton. During the installation of the steel bars, pay attention to reserving the position and structure of the tensioning end and the anchoring end for subsequent prestressing and anchoring. After the concrete structure reaches a certain proportion of the design strength (such as more than 75%), the prestressed steel bars are tensioned. Determine the tensioning control force and tensioning sequence according to the design requirements, use tensioning equipment to tension the prestressed steel bars one by one or one bundle by one, and measure the elongation value of the steel bars at the same time, and compare it with the theoretical elongation value to control the tensioning error within the allowable range. After the tensioning is completed, anchor the prestressed steel bars to ensure the effective application of prestress.

[0099] Thirdly, according to the ratio requirements of modified concrete, materials such as silicate cement, slag powder, sand, gravel, water, water reducer and recycled aggregate containing denitrifying bacteria are added to the concrete mixer for mixing. First, mix the dry materials evenly, then add water and admixtures. The mixing time should meet the requirements of relevant specifications to ensure the uniformity and workability of the concrete. Pour the concrete into the canal formwork and pour it according to a certain pouring sequence and layer thickness. For larger canals, layered pouring and layered vibration can be adopted. The thickness of each layer should not exceed 1.25 times the effective radius of the vibrator. When vibrating, a combination of an inserted vibrator and a flat vibrator is used to ensure that the concrete is vibrated densely to avoid leakage and over-vibration. During the pouring process, pay attention to protecting the position and shape of the prestressed steel bars to prevent the steel bars from shifting. After the concrete is poured, it should be maintained in time. Covering with plastic film, sprinkling water to keep it moist, and other maintenance methods can be adopted. The maintenance time is determined according to the strength growth requirements of the concrete and environmental conditions, and is generally not less than 7 days. During the curing period, keep the concrete surface moist to prevent cracks due to water loss.

[0100] Furthermore, the processed drainage pipes (surface covered with geotextile material) are combined and laid on the soil foundation, covered with a certain thickness of fill, and each channel unit is assembled and fixed together using mortise and tenon structure and TPE material to ensure the stability and sealing of the channel.

[0101] Finally, according to the ratio requirement of polymer emulsion: cement: sand = 0.2:1:2.5, ordinary Portland cement (grade 42.5), medium sand and polymer emulsion are added to the mortar mixer and stirred. At the same time, 0.05%-0.1% cellulose ether of cement mass is added as needed, and stirred evenly to make the mortar have good workability and water retention. After the concrete of the main structure of the canal reaches a certain strength, the stirred emulsion mortar is evenly applied to the inner wall of the canal. The layered application method is adopted, and the thickness of each layer is controlled within an appropriate range. Generally, the thickness of each layer does not exceed 10mm. During the application process, attention should be paid to compaction and smoothing to ensure that the mortar is firmly bonded to the concrete base, the surface is flat and smooth, and there are no defects such as cracks and hollows. After each layer of mortar is applied, proper maintenance should be carried out according to environmental conditions. For example, water can be sprinkled appropriately in a dry environment to prevent the mortar from losing water and cracking prematurely.

[0102] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A freeze-thaw resistant canal constructed based on prestressed steel bars, comprising a canal body, characterized in that: The water channel body comprises a plurality of water channel units, and a flexible connection structure is arranged between the water channel units, through which the various water channel units are connected into a whole; the water channel units are prefabricated concrete parts provided with prestressed steel bars; the prestressed steel bars are arranged along the laying direction of the water channel units.

2. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The flexible connection structure arranged on the end surfaces between the water channel units is a mortise and tenon connection structure; the mortise and tenon connection structure adopts a double trapezoidal mortise and tenon groove or a double trapezoidal mortise and tenon head.

3. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: A drainage structure is arranged at the lower part of the water channel unit, and the drainage structure is used to drain the accumulated water at the bottom of the water channel.

4. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The drainage structure includes a drainage pipe and a guide channel; the drainage pipe is laid in the middle of the bottom of the canal; the guide pipe runs through the drainage pipe horizontally along the drainage pipe to guide the accumulated water at the bottom of the canal into the drainage pipe.

5. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The drain pipe includes a main drain pipe and secondary drain pipes arranged on both sides of the main drain pipe; the secondary drain pipes are arranged at the same height on both sides of the main drain pipe, and the diameter of the middle main drain pipe is slightly larger than the diameter of the secondary drain pipe; the secondary drain pipe is arranged at an angle to guide the accumulated water on both sides into the main drain pipe; the diameter of the guide pipe is the same as that of the secondary drain pipe; the guide pipes are arranged at intervals on both sides of the drain pipe.

6. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The outer layer of the drainage pipe is provided with a thin layer of water-permeable material.

7. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The drain pipe is provided with a plurality of water-permeable channels, and the water-permeable channels are used to allow accumulated water to enter the drain pipe.

8. The freeze-thaw resistant canal constructed based on prestressed steel bars according to claim 1, characterized in that: The concrete in the water channel unit adopts modified concrete, wherein silicate cement is selected as the basic material, and slag powder is mixed in an appropriate amount, while the water-cement ratio is strictly controlled within 0.45, and denitrifying bacteria are added to the recycled aggregate.

9. The freeze-thaw resistant canal construction process based on prestressed steel bars is characterized by: The following steps are involved: S1: Prepare the canal construction materials according to the design requirements; S2: Carry out earth excavation for canal foundation according to design requirements; S3: Produce a water channel unit with modified concrete mix according to design requirements; S4: Set up drainage structure according to design requirements; S5: Lay the canal units on the drainage structure in sequence according to the canal design requirements.

10. The freeze-thaw resistant canal construction process based on prestressed steel bars as claimed in claim 9, characterized in that: The water channel unit is manufactured according to the following steps: S31: obtaining silicate cement as a base material, adding an appropriate amount of slag powder, controlling the water-cement ratio within 0.45, and adding denitrifying bacteria to obtain recycled aggregate; S32: Add the recycled aggregate into a concrete mixer according to the high performance concrete mix ratio, first mix the dry material evenly, then add water and a water reducing agent to mix to obtain concrete; the concrete mix ratio is set in the following manner: Cement: mineral powder or fly ash: sand: gravel: water reducing agent: water = 1: (0.2-0.3): (1.2-1.8): (2.5-3.2): (0.01-0.03): (0.3-0.4); S33: pouring the mixed concrete into the channel formwork where the steel bars are located, and performing a tamping operation; S34: Timely maintenance after pouring; S35: According to the tensioning control force and tensioning sequence required by the design, prestress is applied to the prestressed steel bars one by one or one bundle at a time. During the operation, the elongation value of the steel bars is measured synchronously and compared with the theoretical value until the requirement is met. Finally, the anchoring operation is performed to obtain the channel unit.

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