Flexible composite anti-seepage thin wall system and construction method thereof

Abstract

The invention discloses a flexible composite anti-seepage thin wall system and a construction method thereof. The flexible composite anti-seepage thin wall system comprises a solidified soil anti-seepage thin wall, an omega-shaped core material capable of being assembled, an omega-shaped core material vertical fusion assembling sleeve, a nose-shaped positioning clamping piece and an omega-shaped core material concave connector bottom protection sleeve. The thin wall is formed at the middle position of the dike body by adopting vertical cutting in combination with spraying and stirring of the curing agent slurry, then the vertical anti-seepage core material capable of being spliced is implanted in the middle position in the thin wall, and the thin wall is bonded with the anti-seepage core material to form a whole after being cured, so that a flexible composite anti-seepage thin wall structure is formed at the middle position of the dike. The structure has the advantages of being good in flexibility, high in structural toughness, high in deformation adaptability, reliable in seepage prevention, low in investment, convenient to construct and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of underground impervious wall engineering, and particularly relates to a flexible composite impervious thin wall system with low elastic modulus, strong deformation adaptability, coordinated work between impervious core material and solidified soil, and good wall-forming effect, and a construction method thereof. Background Art

[0002] An impervious wall is a common impervious structure in water retaining buildings such as clay core rock-fill dams and earth flood control dikes. It is an indispensable structure in the impervious of sluice foundations on deep overburden layers and the cut-off wall for seepage monitoring behind a river blocking dam. It is also often used in the construction of construction cofferdams and temporary foundation pit enclosures. Common types of impervious walls include: a) concrete impervious wall, b) high-pressure jet grouting impervious wall, c) cement mixing impervious wall, d) plastic steel sheet pile impervious wall, e) clay sleeve well, f) gravel foundation curtain grouting impervious wall, etc.

[0003] The existing impervious wall technologies are already very mature. Each type of impervious wall has its own characteristics. Although it is feasible to solve problems in actual use, there is still great room for improvement if both safety and reliability and economic rationality are to be considered.

[0004] Problems existing in the existing common impervious walls are as follows: a) Concrete impervious wall: In a pervious foundation, a rotary drilling or percussion continuous hole-forming and grooving is adopted, and then concrete is poured in the groove hole. Concrete in each groove hole is poured once to form a wall segment, and multiple wall segments are connected and spliced through a water-stop structure to form a complete impervious wall. The redundant slurry for wall stability needs to be recycled and treated through a slurry pit. The concrete impervious wall includes a normal concrete impervious wall and a plastic concrete impervious wall. The existing normal concrete impervious wall and plastic concrete impervious wall both have problems such as large construction disturbance, high cost, too high stiffness, poor deformation adaptability, complex construction technology, and high requirements for segmented joint treatment.

[0005] b) High-pressure jet grouting impervious wall: A hollow drill rod with a diameter of 75 mm to 130 mm is inserted into a pervious foundation, and then a high-pressure pump with a pressure of 20 to 40 Mpa is used to spray cement slurry or chemical slurry at a high speed through a nozzle with a diameter of 2 mm to 3 mm on the side wall below the hollow drill rod, forming a jet with concentrated energy. The cement slurry or chemical slurry is pressed into the pervious soil body and fully mixed with it to form a single cement-soil pile with a diameter of about 0.6 to 1.2 m, high strength, and low permeability. Adjacent piles are overlapped and interlocked with each other by 10 to 20 cm to form a continuous impervious wall. The high-pressure jet grouting impervious wall has the following deficiencies: When there are soil layers such as sand and gravel in the foundation soil, its construction quality is difficult to guarantee, its durability is not high, the impervious quality of a single-row impervious wall is difficult to guarantee, the cost of a multi-row impervious wall is relatively high, especially the construction disturbance is large, and there are problems such as it is difficult to meet the design wall thickness requirement when the jet grouting pressure is small, and the foundation soil is easily extruded when the jet grouting pressure is too large.

[0006] c) Cement mixing impervious wall: It uses an inverted "T"-shaped mixing mechanical drill rod to insert into the soil layer for deep mixing. At the same time, cement slurry or dry cement powder is injected into the mixed soil layer. The drill bit rotates horizontally in a spiral up-and-down motion to cut the soil and mix it with the cement slurry. The cement reacts chemically with the reinforced soil layer to form a dense cement soil body. The diameter of a single cement mixing pile is 60 cm to 120 cm, and multiple mixing piles are overlapped by 10 to 20 cm according to the design to form an integral impervious wall. The following are the deficiencies of the cement mixing impervious wall: It is difficult to control the deep vertical biting accuracy. The deep impervious wall often leaks due to vertical deviation, making it difficult to bite each other. The durability of the cement soil is low. It is difficult to ensure the impervious quality of a single-row impervious wall. The cost of a multi-row impervious wall is high. The construction load of the three-axis is large, which has a great impact on the overall stability and disturbance of the dike or dam. Currently, the cement mixing impervious wall is commonly used in soft soil foundations such as silty clay foundations with relatively low strength, and is not applicable to sandy gravel layers or soil layers containing large-sized boulders.

[0007] d) Plastic steel sheet pile impervious wall: It uses a hammering or hydraulic device to directly press the plastic steel sheet piles into the soil and overlap and bite each other to form an impervious wall. It is commonly used for vertical impervious reinforcement in soft foundation sluice stations and other buildings when there is a problem of settlement and separation from the foundation soil under the rigid constraint of bored piles. However, it is completely impossible to press into hard soil layers such as sandy gravel layers and soil layers containing large-sized boulders. The following are the deficiencies of the plastic steel sheet pile impervious wall: The applicable range of the stratum is small, and it is only applicable to the impervious treatment of soft soil foundations such as silt and silty clay with relatively low strength, and is not applicable to the impervious reinforcement of hard soil layers such as sandy gravel layers and soil layers containing large-sized boulders. It is difficult to drive and insert during construction, and the construction equipment has a large disturbance.

[0008] e) Clay sleeve well impervious wall: It is an impervious technology that forms a continuous underground impervious barrier by drilling wells, backfilling low-permeability clay, and ramming. That is, using a grab-type well-drilling machine to vertically drill wells within the seepage range of the dike or earth-rock dam, and then using clay to backfill and ram in layers. Each well is overlapped with a certain range, and they bite each other by about 20 cm to form a continuous clay impervious wall. The following are the deficiencies of the clay sleeve well impervious wall: The applicable range of the stratum is small, and it is not applicable to the impervious reinforcement of permeable sandy gravel layers. It must be constructed at a depth above the groundwater level, and the construction depth is limited. At the same time, due to the preciousness of current agricultural land resources and the serious shortage of clay resources, the clay sleeve well impervious wall is generally rarely used at present.

[0009] f) Gravel foundation curtain grouting impervious wall: The principle of the gravel foundation curtain grouting impervious wall is similar to that of the high-pressure jet grouting impervious wall. It has poor stratum adaptability and also has the disadvantages of difficult construction quality control, large disturbance, low durability of the cement soil, difficult to ensure the impervious quality of a single-row impervious wall, and relatively high cost of a multi-row impervious wall.

[0010] The Chinese invention patent "A construction device and construction method for an in-situ deformable cut-off curtain in strata (CN115059106 A)" proposes a similar construction device. However, the thickness of the wall formed by this device is very large, more than 80 cm, resulting in huge investment. Moreover, the main function of the vertical reinforcing bars in the in-situ deformable cut-off curtain described in this invention is to increase the stiffness of the deformable cut-off curtain and ensure that the cut-off curtain will not break due to the deformation of the free face in the mining area. The reinforcing bars are in the shape of "king" characters, and their functions are similar to the tensile load-bearing and bending resistance functions of steel bars in ordinary concrete. The reinforcing bars do not overlap with each other and do not have the function of preventing seepage. This invention patent (CN115059106 A) has the fatal defect problem of seepage in the cement soil wall due to the cracking, bending deformation cracks of the cement soil wall and local construction unevenness, and it is difficult to be widely applied in the long-distance linear dike anti-seepage reinforcement project on a large scale.

[0011] Therefore, to meet the requirements of popularization and application in most dike projects, it is very necessary to develop a new type of anti-seepage wall system and its construction method with low investment, good anti-seepage effect and fast and efficient construction. Summary of the Invention

[0012] To solve the problems existing in the prior art, the present invention provides a flexible composite anti-seepage thin wall system and its construction method, that is, at the middle position of the dike body, a thin wall is formed by combining up-and-down cutting and spraying a curing agent slurry for stirring, and then spliceable vertical anti-seepage core materials are implanted in the middle position of the thin wall. After the thin wall is cured, it is bonded with the anti-seepage core materials to form an integral body, so as to form a flexible composite anti-seepage thin wall structure at the middle position of the dike. It has the advantages of good flexibility, strong structural toughness, strong deformation adaptability, reliable anti-seepage, low investment and convenient construction.

[0013] To achieve the above object, the present invention adopts the following technical solutions: A flexible composite anti-seepage thin wall system, comprising a flexible composite anti-seepage thin wall, construction equipment and a dike. The flexible composite anti-seepage thin wall is arranged inside the dike, and during the construction process, the construction equipment is arranged on the top surface of the dike crest and the top surface of the flexible composite anti-seepage thin wall; the flexible composite anti-seepage thin wall includes a solidified soil anti-seepage thin wall, a spliceable Ω-shaped core material, and a nose-shaped positioning card. The solidified soil anti-seepage thin wall is arranged inside the middle dike body, the spliceable Ω-shaped core material is arranged in the middle of the solidified soil anti-seepage thin wall, and a nose-shaped positioning card is arranged at the middle position of the bottom of the spliceable Ω-shaped core material to play a role in centering control of the spliceable Ω-shaped core material; The prefabricated Ω-shaped core material is composed of a core web, core adhesion convex bodies, core flanges, female core joints and male core joints; the core adhesion convex bodies are arranged at intervals on the inner and outer side surfaces of the core web to increase the bonding force between the prefabricated Ω-shaped core material and the solidified soil anti-seepage thin wall; core flanges that can adapt to deformation are provided at both the left and right ends of the core web, and female core joints and male core joints are respectively provided at the ends of the core flanges, forming an integrated structure similar to the shape of the Greek letter Ω; the prefabricated Ω-shaped core materials are spliced with each other by engaging the adjacent female core joints and male core joints in the horizontal direction along the top of the dike, so as to form an anti-seepage structure that continuously extends in the horizontal direction along the top of the dike.

[0014] Furthermore, the prefabricated Ω-shaped core material is formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials; the vertical fusion splicing sleeve for the Ω-shaped core material, the nose-shaped positioning card and the bottom protection sleeve for the concave interface of the Ω-shaped core material are also formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials; the prefabricated Ω-shaped core materials are spliced vertically by the vertical fusion splicing sleeve for the Ω-shaped core material. The upper and lower prefabricated Ω-shaped core materials to be spliced and the vertical fusion splicing sleeve for the Ω-shaped core material are heated by external heat sources such as ultrasonic vibration to reach the molten state, and under the action of external pressure and cooling, uniform and reliable hot melt weld seams are formed.

[0015] Furthermore, a bottom protection sleeve for the concave interface of the Ω-shaped core material is sleeved at the bottom of the side of the prefabricated Ω-shaped core material with a female core joint, which plays a role in preventing coarse particles from embedding and blocking.

[0016] Furthermore, the nose-shaped positioning card is composed of a socket-type nose-shaped card slot, card positioning wings and arc-shaped positioning sliding ends; card positioning wings are respectively provided on both side surfaces of the socket-type nose-shaped card slot, and arc-shaped positioning sliding ends are provided at the ends of the card positioning wings. The socket-type nose-shaped card slot is inserted and connected to the middle position at the bottom of the core web. The prefabricated Ω-shaped core material is centered inside the solidified soil anti-seepage thin wall through the nose-shaped positioning card, and the bottom of the prefabricated Ω-shaped core material smoothly rubs against the side wall of the solidified soil anti-seepage thin wall through the arc-shaped positioning sliding ends to achieve the purpose of smooth sinking.

[0017] Furthermore, the construction equipment is assembled by a cutting, spraying and mixing device, a core-inserting device, a control device, a power device and a traveling device; the cutting, spraying and mixing device is arranged at the middle position of the traveling device, the control device is arranged on the top surface of the traveling device, the core-inserting device is arranged at the tail position of the traveling device, and the power device is arranged on the road behind the inner side of the dike to reduce the load on the construction equipment and the underlying soft foundation dike. The power device is connected to the control device through a cable, and the control device is connected to the cutting, spraying and mixing device, the traveling device and the core-inserting device through data lines and controls their orderly operation. Both the cutting, spraying and mixing device and the core-inserting device have functions of intelligent leveling in the front-back, up-down and rotational directions to ensure that when the working surface of the construction equipment, i.e., the top surface of the dike body structure, is uneven, the automatic verticality control requirements for the construction of the solidified soil anti-seepage thin wall by the cutting, spraying and mixing device and the constructible Ω-shaped core material by the core-inserting device are realized; the dike includes a dike body structure, a pervious soft foundation, a relatively impervious foundation, a dike top protection structure and a dike end connection structure; the relatively impervious foundation, the pervious soft foundation and the dike body structure are arranged from bottom to top in sequence, the dike top protection structure is arranged on the top surface of the dike body structure, and the dike end connection structure is connected to the side surface of one end of the dike body structure; during the construction process, the cutting, spraying and mixing device penetrates through the dike body structure, the pervious soft foundation and the relatively impervious foundation respectively and is arranged inside them. During the construction process, the cutting, spraying and mixing device cuts the dike body structure, the pervious soft foundation and the relatively impervious foundation respectively, and at the same time sprays and mixes to form the solidified soil anti-seepage thin wall.

[0018] The construction method of a flexible composite anti-seepage thin wall system of the present invention includes the following steps: S1. Construction preparation, assembling the construction equipment, preparing the curing agent slurry, producing the constructible Ω-shaped core material and accessories; S2. Leveling the cutting, spraying and mixing device and sinking it into the dike body; S3. The construction equipment slowly advances, the cutting, spraying and mixing device is leveled and corrected in real time, and cutting into the wall, spraying and mixing are carried out; S4. The construction equipment stops, the core-inserting device is leveled, and the constructible Ω-shaped core material is inserted. At the same time, the cutting, spraying and mixing device carries out mixing; S5. Repeat step S3 and step S4, enter the next construction cycle operation until the construction of all the flexible composite anti-seepage thin walls is completed; S6. Construct the dike top protection structure and the dike end connection structure.

[0019] Further, in step S1, the curing agent in the curing agent slurry is prepared by mixing cement, ground granulated blast-furnace slag, water reducer and retarder in a certain proportion, and the water-binder ratio of the curing agent slurry is 0.4:1 to 0.5:1; the assembled Ω-shaped core material has an outer shape structure similar to the Greek letter Ω, and the assembled Ω-shaped core material is formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials; the vertical fusion assembly sleeve, nose-shaped positioning card and concave interface bottom protection sleeve of the Ω-shaped core material of the accessory are also formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials.

[0020] Further, in step S2, when the construction operation platform on the top surface of the dike body structure is uneven, the cutting and grouting mixing device is leveled intelligently back and forth, up and down and rotationally, and sinks to the top of the relatively impervious foundation. During the sinking process of the cutting and grouting mixing device, it penetrates through the dike body structure, pervious soft foundation and relatively impervious foundation respectively. The cutting and grouting mixing device can be set with more than two and is spliced up and down by anchor bolts. The sinking depth is controlled by the standard of effectively truncating the anti-seepage channels of the dike body and the dike foundation to ensure the anti-seepage safety requirements of the dike.

[0021] Further, in step S3, the construction equipment moves forward slowly, and at the same time, the cutting and grouting mixing device is leveled and corrected in real time to avoid tilting under the interference of external forces. At the same time, the cutting and grouting mixing device rotates up and down to cut the dike body structure and the pervious soft foundation, and uses the soil body itself for in-situ retaining wall protection. The cutting and grouting mixing device injects the prepared curing agent slurry into the cut soil at high pressure. The admixture amount of the curing agent is generally low, controlled within the range of 5% to 15% by mass ratio. Specifically, the control principle is to appropriately and rapidly increase the 28-day unconfined compressive strength of the cured soil anti-seepage thin wall to 0.1 to 0.5 Mpa. The high-pressure grouting pressure range of the curing agent slurry is 0.2 to 0.8 Mpa. The cutting and grouting mixing device stirs up and down to form a fluidized state cured soil anti-seepage thin wall in the initial stage of construction. The up and down rotation speed of the cutting and grouting mixing device needs to be reasonably controlled. Specifically, it is necessary to not only meet the uniformity of up and down rotation and stirring, but also ensure the overall construction work efficiency; at the same time, the construction equipment moves forward slowly along the axis direction of the dike top, and the forward speed is 5 to 20 m / hr.

[0022] Further, in step S4, the construction equipment is stationary. The core-inserting device can be assembled by intelligent leveling in the front-back, up-down, and rotational directions. The nose-shaped positioning card is sleeved into the middle position of the bottom surface of the assembled Ω-shaped core material, and the bottom protection sleeve of the concave interface of the Ω-shaped core material is sleeved at the bottom of the female-shaped joint of the core material to prevent its cavity from being blocked by coarse particles in the foundation soil. Then, the core-inserting device at the tail of the construction equipment is used to vertically press the assembled Ω-shaped core material into the middle position inside the fluidized state solidified soil anti-seepage thin wall at the initial stage of construction. The male-shaped joint of the core material of the assembled Ω-shaped core material is snapped into the female-shaped joint of the already inserted core material, and the two ends of the assembled Ω-shaped core material are mutually engaged and spliced. When the depth of the bottom surface of the pervious soft foundation in the dike exceeds 15 - 20 m, limited by transportation requirements, the one-time forming length of the assembled Ω-shaped core material is limited. It is necessary to use the vertical fusion assembly sleeve of the Ω-shaped core material to perform vertical fusion splicing on the assembled Ω-shaped core material. The width of the fusion splicing is not less than 50 cm. The hot fusion welds formed by the assembled Ω-shaped core material and the vertical fusion assembly sleeve of the Ω-shaped core material need to be arranged in a staggered joint, that is, the hot fusion welds formed by adjacent assembled Ω-shaped core materials and the vertical fusion assembly sleeve of the Ω-shaped core material need to be arranged at different depths, and the depth difference range needs to meet 1 m - 5 m. Moreover, the hot fusion welds formed by the assembled Ω-shaped core material and the vertical fusion assembly sleeve of the Ω-shaped core material should be arranged in the soil layer with relatively weaker permeability as much as possible. The assembled Ω-shaped core material smoothly and vertically sinks to the design depth along the two side walls of the solidified soil anti-seepage thin wall and jointly acts with the solidified soil anti-seepage thin wall to form a flexible composite anti-seepage thin wall. In step S4, the cutting and slurry spraying and stirring device at the front end of the construction equipment continuously operates up and down to ensure the uniformity of the solidified soil anti-seepage thin wall.

[0023] Further, in step S6, after the construction of the flexible composite anti-seepage thin wall is completed, the anchor bolts connecting the cutting and slurry spraying and stirring device up and down are disassembled, and the cutting and slurry spraying and stirring device is lifted out of the dike in sections, disassembled, and the assembled components of the construction equipment are withdrawn. At the same time, after the solidified soil anti-seepage thin wall in the flexible composite anti-seepage thin wall reaches the 28-day design strength, the designed unconfined compressive strength range is 0.1 - 0.5 Mpa. For the end boundary of the flexible composite anti-seepage thin wall and the anti-seepage thorn wall of the adjacent building, an external wrapping anti-seepage connection protection is adopted with clay anti-seepage material outside the connection structure at the end of the dike. The external wrapping thickness is not less than 1.0 m, and the permeability coefficient of the clay anti-seepage material is not greater than 1×10 -5 cm / s to avoid lateral seepage around. The top of the flexible composite anti-seepage thin wall is protected by the dike top protection structure. The dike top protection structure is backfilled with 30 cm - 50 cm thick clay, and an asphalt pavement structure is laid on the clay backfill to prevent the dike top load from causing fracturing damage to the flexible composite anti-seepage thin wall.

[0024] Furthermore, to ensure perfect adhesion between the flexible composite anti-seepage thin wall and the assembled Ω-shaped core material, it is recommended that the single-arch height of the assembled Ω-shaped core material be controlled within 25% - 40% of the thickness of the flexible composite anti-seepage thin wall 1. This can not only ensure that the outside of the assembled Ω-shaped core material is wrapped by a flexible composite anti-seepage thin wall with sufficient thickness, improving the durability of the assembled Ω-shaped core material such as anti-aging, but also ensure that the assembled Ω-shaped core material itself has a certain flexural rigidity, which is beneficial to the downward pressure stability during construction, ensuring safety and saving materials to optimize the project investment.

[0025] Furthermore, the thickness range of the flexible composite anti-seepage thin wall is 35 cm - 50 cm, the single-width of the assembled Ω-shaped core material is 60 cm - 80 cm, the single-arch height of the assembled Ω-shaped core material is 10 cm - 20 cm, the single-length of the assembled Ω-shaped core material is 5 m - 17 m, and the thickness of the core material web is 6 mm - 12 mm.

[0026] Furthermore, through a large number of experimental research and calculations, the empirical formula for the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall in this invention is: (1) Where: is the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall, with the unit of cm / s; is the total correction coefficient considering the influence of complex factors such as the dosage of on-site cement and other curing agents and the actual soil layer complexity in the flexible composite anti-seepage thin wall; is the thickness of the web of the assembled Ω-shaped core material, with the unit of cm; is the thickness of the flexible composite anti-seepage thin wall, with the unit of cm. In this invention, the thickness range is 35 cm - 50 cm; is the average horizontal permeability coefficient of the solidified soil anti-seepage thin wall in the flexible composite anti-seepage thin wall itself, with the unit of cm / s; is the horizontal permeability coefficient of the assembled Ω-shaped core material itself, with the unit of cm / s; is the influence coefficient for reducing the horizontal permeability coefficient of the assembled Ω-shaped core material itself due to the splicing of the core material's female joints and male joints in the horizontal direction; Among them, the permeability coefficient of the solidified soil anti-seepage thin wall in the flexible composite anti-seepage thin wall k 固化土 is not only related to the distribution of the foundation soil layer, but also related to the dosage of the curing agent during the process of cutting and mixing to form the wall. Through a large number of experimental research and calculations, the empirical formula can be used: (2) Wherein: They are respectively the thickness of the first layer of the embankment body structure, the thickness of the second layer of soil with pervious and weak foundation, and the thickness of the third layer of relatively impervious foundation after cutting, mixing and solidifying in the embankment, with the unit of m; They are respectively the horizontal permeability coefficients of the first layer of the embankment body structure, the pervious and weak foundation, and the third layer of relatively impervious foundation in the embankment after cutting, mixing and solidifying respectively, with the unit of cm / s; It represents the total thickness of the flexible composite anti-seepage thin wall, with the unit of m.

[0027] Through comparative analysis, the following deficiencies exist in a device for constructing an in-situ deformable water cut-off curtain in a Chinese invention patent (CN115059106 A): a) In the invention patent (CN115059106 A), the vertical moving mechanism and the cutting mechanism are located on one side of the whole device, with a large eccentricity. It is necessary to use the counterweight of the power mechanism and the grouting mechanism on the other side for counter-pressure balance. Otherwise, the whole device is at risk of eccentric tipping. Therefore, according to the actual engineering experience in the domestic and foreign civil engineering fields at present, the overall weight of the device in the invention patent (CN115059106 A) is generally very heavy. For example, for the CMD950 crawler-type TRD trench cutter of Fawu Heavy Industry, which is similar to the invention patent (CN115059106 A) in the market, its wall thickness is generally greater than 70 cm, and the mass of the whole set of device reaches 2300 kN. When the trench depth is greater, considering factors such as the greater self-weight resistance of the deep soil, the longer cutting tool, the greater counter-pressure configuration load, and the higher power requirements, the overall weight of the equipment will be even greater.

[0028] b) In the invention patent (CN115059106 A), when there are uneven terrains such as pits and depressions on the construction site plane, it lacks the function of automatically leveling the whole equipment. During each fixed-point construction, it is necessary to first carry out manual terrain leveling to ensure that the cutting mechanism keeps vertical cutting. And there are certain errors in manual leveling. For example, the manual flatness error is generally about 1% - 5%. When the cutting depth is 20 m, the displacement error at the deepest part of the trench will be 20 m × 2% = 0.4 m, with a large error. This is also the reason why the wall thickness in the invention patent (CN115059106 A) is generally greater than 80 cm and it is difficult to achieve a thin wall of 35 cm - 50 cm. When the equipment leveling is not in place, it will seriously affect the deep water cut-off effect of the water cut-off curtain in the invention patent (CN115059106 A).

[0029] c) In the steel bar inserting mechanism of the invention patent (CN115059106 A), there is also a lack of precise verticality control function. Similarly, when the cutting depth of the cut-off wall is deeper, it is very easy for the steel bars to tilt, resulting in the bottom of the steel bars deviating or even protruding beyond the range of the cut-off curtain, thus destroying the overall anti-seepage effect of the cut-off curtain.

[0030] d) In the cut-off curtain of the invention patent (CN115059106 A), the core anti-seepage function is the cement soil itself. However, in actual engineering, the cement soil wall is prone to cracking, bending deformation cracks, and local construction unevenness, etc., which may lead to the failure of the anti-seepage function of the cement soil wall.

[0031] In view of the above deficiencies in the invention patent (CN115059106 A), the innovations of the present invention compared with it are as follows: a) In the present invention, both the cutting, spraying and mixing device and the core planting device are arranged in a centered and symmetrical manner, avoiding the problem of large eccentricity arrangement that requires counterweight to maintain balance. At the same time, the total weight of the equipment is also greatly optimized, saving a large amount of equipment costs. The total weight of the construction equipment of the present invention is only about 500 KN, which is greatly optimized by 78.3% compared with the weight of 2300 kN of the similar equipment in the invention patent (CN115059106 A).

[0032] b) In the present invention, the control device can avoid the large error problem of the cut-off curtain at the deep layer through multi-dimensional intelligent leveling functions such as front-back, up-down, and rotation.

[0033] c) In the present invention, the core planting device can also avoid the phenomenon that the bottom of the steel bar deviates or even protrudes beyond the range of the cut-off curtain through multi-dimensional intelligent leveling functions such as front-back, up-down, and rotation. At the same time, the present invention innovatively adopts a splicable Ω-shaped core material, and by inserting a nose-shaped positioning card at the bottom, the centered arrangement of the splicable Ω-shaped core material can be easily realized.

[0034] d) The core anti-seepage structure of the present invention is a splicable Ω-shaped core material. The main function of the solidified soil anti-seepage thin wall is to break the original soil layer into a fluidized state so that the splicable Ω-shaped core material can be easily inserted into it. The anti-seepage function of the solidified soil anti-seepage thin wall itself is very small or even completely negligible.

[0035] The beneficial effects of the present invention are: 1. Good flexibility, strong structural toughness, and strong deformation adaptability. The anti-seepage core material of the flexible composite anti-seepage thin wall of the present invention can be made by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials, or other engineering materials with high strength and strong deformation ability. The anti-seepage core material has certain flexibility and good water-proof and anti-seepage effect. The solidified soil is low-content solidified soil, and the mass ratio of its cement and other curing agent content is 5% to 15%, which is half of that of general cement mixing piles or even less. The elastic modulus of the solidified soil anti-seepage thin wall is generally 10 to 30 MPa, which is much smaller than the elastic modulus of low elastic modulus concrete of 2000 to 2500 MPa. It has good flexibility and strong deformation adaptability. At the same time, the flexible composite anti-seepage thin wall of the present invention is formed by in-situ crushing and mixing up and down to form composite solidified soil. Its structural toughness is better than that of single soil layer solidified soil. Therefore, compared with the existing anti-seepage wall, the flexible composite anti-seepage thin wall of the present invention has the remarkable characteristics of good flexibility, strong structural toughness, and strong deformation adaptability.

[0036] 2. The anti-seepage core material and the solidified soil work together to achieve good anti-seepage effect, high reliability and good durability. The flexible composite anti-seepage thin wall of the present invention is solidified into a wall by cutting up and down, crushing and stirring in situ. It can cut and crush large particles such as sand and gravel layers that are difficult for high-pressure rotary spray anti-seepage walls and plastic steel sheet pile anti-seepage walls to adapt to in situ, and use the soil itself for in-situ wall protection; at the same time, it uses the up and down saw-type layered thin layer in-situ cutting, crushing and in-situ mixing technology to overcome the problems of existing cement mixing anti-seepage walls due to excessive mixing resistance of deep hard soil; the present invention can be constructed continuously and uninterruptedly, avoiding the problem that ordinary concrete anti-seepage walls must be divided into construction joints, and can be perfectly integrated with the original soil of the embankment. At the same time, in the initial construction stage of the flexible composite anti-seepage thin wall, it is in a fluid plastic state, which is not only beneficial to the anti-seepage core material Vertical implantation facilitates the interlocking and continuous splicing of the anti-seepage core materials. The fine particles of solidified soil in a fluidized state densely fill the tiny gaps at the interface of the core materials. Once the wall solidifies, it forms a complete flexible composite anti-seepage thin wall. The core material adhesion-enhancing protrusions on the web of the anti-seepage core material achieve a strong and perfect bond with the solidified soil, ensuring that the core material and solidified soil form a single unit and work together seamlessly. Furthermore, the solidified soil surrounding the core material significantly enhances its corrosion and aging resistance. The flexible composite anti-seepage thin wall allows for continuous and uninterrupted construction, resolving the challenges of existing embankment anti-seepage walls, such as high-pressure jet grouting piles, which suffer from vertical deviations, resulting in non-closure of deep-layer anti-seepage layers and joints in concrete wall construction. This invention overcomes the critical flaws of the invention patent (CN115059106 A) in cement-soil walls, which suffer from cracking, bending deformation cracks, and localized construction unevenness, leading to seepage in cement-soil walls. It offers superior anti-seepage effectiveness compared to the present invention. Therefore, the flexible composite anti-seepage thin wall of the present invention has advantages such as better anti-seepage effect, higher reliability and better durability than general anti-seepage walls.

[0037] 3. Thin wall, low investment, and convenient construction. The thickness of the flexible composite anti-seepage thin wall of the present invention can be controlled between 35 cm and 50 cm, which is thinner than the existing anti-seepage walls of dikes, such as the single-row high-pressure jet grouting pile with a thickness of 80 cm and the double-row with a thickness of 140 cm. Compared with the 80 cm thickness in the invention patent (CN115059106 A), the thickness of the flexible composite anti-seepage thin wall of the present invention is reduced by 56.3% - 37.5%, greatly saving the project investment and having significant advantages in long-distance dike linear projects; at the same time, the flexible composite anti-seepage thin wall of the present invention uses up-and-down cutting and crushing, and in-situ mixing and curing to form a wall, and its construction method is convenient and fast, with high construction efficiency and reliability.

[0038] 4. Low cement content, less waste mud, and high environmental protection. The cement content of the solidified soil anti-seepage thin wall in the present invention is generally low, that is, the mass ratio of the cement and other curing agents is 5% - 15%, which is half or even less than that of the general cement mixing pile anti-seepage wall, and also less than the 20% - 40% dosage of the curing agent in the cut-off curtain grouting in the invention patent (CN115059106 A), saving more than 50% of the cement and other curing agents. Its main function is to cut and crush the hard soil layer in-situ to facilitate the quick insertion of the assembled Ω-shaped core material into the anti-seepage soil body. The main purpose of the low content of cement and other curing agents is to quickly restore the strength of the plastic anti-seepage thin wall to that before the original soil body during the initial stage of construction; at the same time, the low content of cement and other curing agents will greatly reduce the problem of mud overflow, and its waste mud is reduced by more than 70% compared with the waste mud of the bored cast-in-place pile anti-seepage wall and the cement mixing pile anti-seepage wall, with better environmental protection effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is the flow chart of the construction method of the present invention; Figure 2 is the plan layout diagram of the system of the present invention; Figure 3 is Figure 2 the A - A cross-sectional view during the construction period; Figure 4 is Figure 2 the B - B cross-sectional view during the construction period; Figure 5 is Figure 2 the A - A cross-sectional view during the operation period; Figure 6 is Figure 5 the C - C cross-sectional view of Figure 7 is Figure 6 the three-dimensional detailed drawing of the assembled Ω-shaped core material of Figure 8 is Figure 7 the three-dimensional detailed drawing of the bottom positioning card of the Ω-shaped core material in Figure 9 is Figure 7Three-dimensional detail drawing of the bottom protective sleeve of the concave interface of the Ω-shaped core material in the middle.

[0040] In the figure: 1 - Flexible composite anti-seepage thin wall; 2 - Construction equipment; 3 - Dike; 11 - Solidified soil anti-seepage thin wall; 12 - Assemblable Ω-shaped core material; 13 - Vertical fusion assembly sleeve for Ω-shaped core material; 14 - Nose-shaped positioning card; 15 - Bottom protective sleeve for the concave interface of the Ω-shaped core material; 121 - Core material web; 122 - Core material tackifying convex body; 123 - Core material flange; 124 - Female joint of core material; 125 - Male joint of core material; 141 - Socket nose-shaped card slot; 142 - Card positioning wing; 143 - Arc-shaped positioning sliding end; 21 - Cutting, spraying and stirring device; 22 - Core planting device; 23 - Control device; 24 - Power device; 25 - Traveling device; 31 - Dike body structure; 32 - Permeable soft foundation; 33 - Relatively impermeable foundation; 34 - Dike top protection structure; 35 - Dike end connection structure. Specific implementation mode

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work shall fall within the scope of protection of the present invention.

[0042] The present invention provides a flexible composite anti-seepage thin wall system and a construction method thereof. The method of the present invention is applicable to the anti-seepage reinforcement design and construction in the technical field of underground anti-seepage wall engineering such as dikes and earth-rock dams.

[0043] As Figures 2 to 5 shown, a flexible composite anti-seepage thin wall system of the present invention includes a flexible composite anti-seepage thin wall 1, construction equipment 2 and a dike. The flexible composite anti-seepage thin wall 1 is arranged inside the dike, and during the construction process, the construction equipment 2 is arranged on the top surface of the dike top and the top surface of the flexible composite anti-seepage thin wall 1; the flexible composite anti-seepage thin wall 1 includes a solidified soil anti-seepage thin wall, an assemblable Ω-shaped core material, and a nose-shaped positioning card. The solidified soil anti-seepage thin wall is arranged inside the middle dike body, the assemblable Ω-shaped core material is arranged in the middle inside the solidified soil anti-seepage thin wall, and a nose-shaped positioning card is arranged at the middle position of the bottom of the assemblable Ω-shaped core material to play a role in centering control of the assemblable Ω-shaped core material; As Figures 6 to 9As shown in the figure, the assembled Ω-shaped core material is composed of a core material web, core material adhesion-promoting convex bodies, core material flanges, a female core material joint, and a male core material joint; the core material adhesion-promoting convex bodies are arranged at intervals on the inner and outer side surfaces of the core material web to increase the bonding force between the assembled Ω-shaped core material and the solidified soil impervious thin wall. Core material flanges that can adapt to deformation are provided at both the left and right ends of the core material web. The ends of the core material flanges are respectively provided with a female core material joint and a male core material joint, forming an integrated structure similar to the shape of the Greek letter Ω; the assembled Ω-shaped core materials are spliced with each other by engaging the adjacent female core material joints and male core material joints in the horizontal direction along the top of the dike, thereby forming an impervious structure that continuously extends in the horizontal direction along the top of the dike.

[0044] Furthermore, the assembled Ω-shaped core material is formed by mixing and extruding polyvinyl chloride (PVC) resin and a reinforcing material. The reinforcing material is glass fiber; the vertical fusion assembly sleeve for the Ω-shaped core material, the nose-shaped positioning card, and the bottom protection sleeve for the concave interface of the Ω-shaped core material are also formed by mixing and extruding polyvinyl chloride (PVC) resin and a reinforcing material, and the reinforcing material is also glass fiber; the assembled Ω-shaped core materials are spliced vertically by hot melting through the vertical fusion assembly sleeve for the Ω-shaped core material. By heating the two assembled Ω-shaped core materials to be spliced and the vertical fusion assembly sleeve for the Ω-shaped core material with external heat sources such as ultrasonic vibration, they are brought to a molten state, and under the action of external pressure and cooling, a uniform and reliable hot melt weld seam is formed.

[0045] Furthermore, a bottom protection sleeve for the concave interface of the Ω-shaped core material is sleeved at the bottom of the side of the assembled Ω-shaped core material with the female core material joint, which plays a role in preventing coarse particles from being embedded and blocked.

[0046] Furthermore, the nose-shaped positioning card is composed of a socket-type nose-shaped card slot, card positioning wings, and an arc-shaped positioning sliding end; card positioning wings are respectively provided on both side surfaces of the socket-type nose-shaped card slot, and an arc-shaped positioning sliding end is provided at the end of the card positioning wings. The socket-type nose-shaped card slot is connected to the middle position at the bottom of the core material web in a socket manner. The assembled Ω-shaped core material passes through the nose-shaped positioning card to achieve the purpose of arranging the assembled Ω-shaped core material in the middle of the solidified soil impervious thin wall. The bottom of the assembled Ω-shaped core material smoothly rubs against the side wall of the solidified soil impervious thin wall through the arc-shaped positioning sliding end to achieve the purpose of smooth sinking.

[0047] As Figure 2 、 Figure 3 and Figure 4As shown in the figure, the construction equipment 2 is assembled by a cutting, spraying and stirring device 21, a core planting device 22, a control device 23, a power device 24 and a traveling device 25. Among them, the cutting, spraying and stirring device 21 is arranged at the middle position of the traveling device 25, the control device 23 is arranged on the top surface of the traveling device 25, the core planting device 22 is arranged at the tail position of the traveling device 25, and the power device 24 is arranged on the road behind the inner side of the dike 3 to reduce the load on the construction equipment 2 and the underlying soft foundation dike 3. The power device 24 is connected to the control device 23 through a cable, and the control device 23 is connected to the cutting, spraying and stirring device 21, the traveling device 25 and the core planting device 22 through data lines and controls their orderly operation. Both the cutting, spraying and stirring device 21 and the core planting device 22 have the functions of intelligent leveling in the front-back, up-down and rotational directions to ensure that when the working surface of the construction equipment 2, that is, the top surface of the dike body structure 31, is uneven, the cutting, spraying and stirring device 21 can achieve the automatic control requirement of the verticality of the construction of the solidified soil anti-seepage thin wall 11, and the core planting device 22 can achieve the automatic control requirement of the verticality of the construction of the assembled Ω-shaped core material 12. The dike 3 includes a dike body structure 31, a permeable soft foundation 32, a relatively impermeable foundation 33, a dike top protection structure 34 and a dike end connection structure 35. The relatively impermeable foundation 33, the permeable soft foundation 32 and the dike body structure 31 are arranged from bottom to top in sequence. The dike top protection structure 34 is arranged on the top surface of the dike body structure 31, and the dike end connection structure 35 is connected to the side surface of one end of the dike body structure 31. During the construction process, the cutting, spraying and stirring device 21 penetrates through the dike body structure 31, the permeable soft foundation 32 and the relatively impermeable foundation 33 respectively and is arranged inside them. During the construction process, the cutting, spraying and stirring device 21 cuts and breaks the dike body structure 31, the permeable soft foundation 32 and the relatively impermeable foundation 33 respectively, and at the same time sprays and stirs to form a solidified soil anti-seepage thin wall 11. The solidified soil anti-seepage thin wall 11 is a thin wall with a wall thickness of 35 cm to 50 cm. The solidified soil anti-seepage thin wall 11 is in a fluidized state at the initial stage of construction, so that the assembled Ω-shaped core material 12 can be easily inserted into the solidified soil anti-seepage thin wall 11 and sink to its bottom.

[0048] The cutting, spraying and stirring device 21 is internally equipped with a high-precision electronic level. The vertical deviation of the cutting, spraying and stirring device 21 in the vertical direction is displayed in real time through the high-precision electronic level, and the cutting, spraying and stirring device 21 is controlled in real time through the control device 23, and real-time front-back, up-down and rotational control adjustments are realized. The core planting device 22 is internally equipped with a high-precision electronic level. The vertical deviation of the core planting device 22 in the vertical direction is displayed in real time through the high-precision electronic level, and the core planting device 22 is controlled in real time through the control device 23, and real-time front-back, up-down and rotational control adjustments are realized.

[0049] There are two or more solidified soil anti-seepage thin walls 11, assembled Ω-shaped core materials 12, Ω-shaped core vertical fusion assembly sleeves 13, nose-shaped positioning cards 14 and Ω-shaped core concave interface bottom protection sleeves 15.

[0050] As Figure 1 shown, a construction method of a flexible composite anti-seepage thin wall system of the present invention includes the following steps: S1. Construction preparation, assembling construction equipment, preparing curing agent slurry, and producing assembled Ω-shaped core materials and accessories; S2. Leveling the cutting and grouting mixing device and sinking it into the embankment body; S3. The construction equipment advances slowly, the cutting and grouting mixing device is leveled and corrected in real time, and cutting into the wall, grouting, and mixing are carried out; S4. The construction equipment is stationary, the core implanting device is leveled, and the assembled Ω-shaped core material is implanted. At the same time, the cutting and grouting mixing device performs mixing; S5. Repeat step S3 and step S4, enter the next construction cycle operation until the construction of all flexible composite anti-seepage thin walls is completed; S6. Construct the embankment top protection structure and the embankment end connection structure.

[0051] In step S1, the curing agent in the curing agent slurry is made by mixing cement, ground granulated blast-furnace slag, water-reducing agent and retarder according to a certain ratio. Among them, the mixing ratio range of cement, ground granulated blast-furnace slag, water-reducing agent and retarder by mass ratio is 60% - 90%, 34% - 8%, 3% - 1% and 3% - 1%. The water-binder ratio of the curing agent slurry is 0.4:1 - 0.5:1; the assembled Ω-shaped core material 12 has an outer shape structure close to the shape of the Greek letter Ω. The assembled Ω-shaped core material 22 is formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials; the accessories, namely, the vertical fusion assembly sleeve 13 of the Ω-shaped core material, the nose-shaped positioning card 14 and the bottom protection sleeve 15 of the concave interface of the Ω-shaped core material, are also formed by mixing and extruding polyvinyl chloride (PVC) resin and reinforcing materials.

[0052] In step S2, when the construction operation platform on the top surface of the embankment body structure 31 is uneven, a high-precision electronic level is configured inside the cutting and grouting mixing device 21. The vertical deviation of the cutting and grouting mixing device 21 in the vertical direction is displayed in real time through the high-precision electronic level, and the cutting and grouting mixing device 21 is controlled in real time through the control device 23 and real-time front-back, up-down and rotation control adjustments are realized; the cutting and grouting mixing device 21 sinks from the embankment top to the top of the relatively impermeable foundation 33. During the sinking process of the cutting and grouting mixing device 21, it penetrates through the embankment body structure 31, the pervious soft foundation 32 and the relatively impermeable foundation 33 respectively. The cutting and grouting mixing device 21 can be spliced up and down by two or more modules through anchor bolts. The sinking depth is controlled by the standard of effectively cutting off the anti-seepage channels of the embankment body and the embankment foundation of the embankment 3 to ensure the anti-seepage safety requirements of the embankment 3.

[0053] In step S3, the construction equipment travels slowly while the cutting, spraying and mixing device 21 is leveled and corrected in real time to prevent the cutting, spraying and mixing device 21 from tilting under external interference. At the same time, the cutting, spraying and mixing device 21 operates up and down to cut the embankment structure 31 and the pervious soft foundation 32, and uses the soil itself for in-situ wall protection. The cutting, spraying and mixing device 21 injects the prepared curing agent slurry into the cut soil under high pressure. The incorporation amount of the curing agent is generally low, controlled within the range of 5% - 15% by mass ratio. Specifically, the control principle is to appropriately and rapidly increase the unconfined compressive strength of the 28-day cured soil impervious thin wall 11 to 0.1 - 0.5 Mpa. The high-pressure grouting pressure range of the curing agent slurry is 0.2 - 0.8 Mpa. The cutting, spraying and mixing device 21 stirs up and down to form the flowable state cured soil impervious thin wall 11 at the initial stage of construction. The up and down operation speed of the cutting, spraying and mixing device 21 needs to be reasonably controlled. Specifically, it is necessary to not only meet the uniformity of up and down operation and stirring, but also ensure the overall construction work efficiency. At the same time, the construction equipment 2 slowly advances along the axis direction of the embankment top of the dike 3 at a speed of 5 - 20 m / hr.

[0054] In step S4, the construction equipment 2 is stationary. The core-inserting device 22 is internally equipped with a high-precision electronic level. The vertical deviation of the core-inserting device 22 in the vertical direction is displayed in real time through the high-precision electronic level, and the core-inserting device 22 is controlled in real time by the control device 23 to achieve real-time front-back, up-down, and rotation control adjustments. The middle position at the bottom of the assembled Ω-shaped core material 12 is sleeved with a nose-shaped positioning card 14, and the bottom protection sleeve 15 of the concave interface of the Ω-shaped core material is sleeved at the bottom of the female joint 124 of the core material to prevent its cavity from being blocked by coarse particles in the foundation soil. Then, the core-inserting device 22 at the tail of the construction equipment 2 is used to vertically press the assembled Ω-shaped core material 12 into the middle position inside the fluid plastic state solidified soil anti-seepage thin wall 11 at the initial stage of construction. The male joint 125 of the core material of the assembled Ω-shaped core material 12 is inserted into the female joint 124 of the implanted core material. The two ends of the assembled Ω-shaped core material 12 are spliced by interlocking. When the depth of the bottom surface of the pervious soft foundation 32 in the dike 3 exceeds 15m to 30m, due to transportation requirements, the one-time forming length of the assembled Ω-shaped core material 12 is limited, and the vertically fused assembly sleeve 13 of the Ω-shaped core material is required to perform up-down fusion splicing on the assembled Ω-shaped core material 12. The width of the fusion splicing is not less than 50cm. The hot fusion weld formed by the assembled Ω-shaped core material 12 and the vertically fused assembly sleeve 13 of the Ω-shaped core material needs to be arranged in a staggered joint, that is, the hot fusion welds formed by adjacent assembled Ω-shaped core materials 12 and the vertically fused assembly sleeve 13 of the Ω-shaped core material need to be arranged at different depths, and the depth difference range needs to meet 1m to 5m. Moreover, the hot fusion weld formed by the assembled Ω-shaped core material 12 and the vertically fused assembly sleeve 13 of the Ω-shaped core material should be arranged in the soil layer with relatively weak water permeability as much as possible. The assembled Ω-shaped core material 12 smoothly and vertically sinks to the design depth along the two side walls of the solidified soil anti-seepage thin wall 11 and jointly acts with the solidified soil anti-seepage thin wall 11 to form a flexible composite anti-seepage thin wall 1. In step S4, at the same time, the cutting, spraying, and stirring device 21 at the front end of the construction equipment 2 continuously operates up and down to ensure the uniformity of the solidified soil anti-seepage thin wall 11.

[0055] In step S6, after the construction of the flexible composite anti-seepage thin wall 1 is completed, the anchor bolts connecting the cutting, spraying, and stirring device 21 up and down are disassembled, and the cutting, spraying, and stirring device 21 is lifted out of the dike 3 in sections, and each assembled component of the construction equipment 2 is disassembled and evacuated. At the same time, after the solidified soil anti-seepage thin wall 11 in the flexible composite anti-seepage thin wall 1 reaches the 28-day design strength (the range of the unconfined compressive strength is 0.1 to 0.5 Mpa), the boundary at the end of the flexible composite anti-seepage thin wall 1 and the anti-seepage thorn wall of the adjacent building are protected by the clay anti-seepage material in an external wrapping manner through the dike end connection structure 35. The external wrapping thickness is not less than 1.0m, and the permeability coefficient of the clay anti-seepage material is not greater than 1×10 -5cm / s to avoid lateral seepage around; the top of the flexible composite impervious thin wall 1 is protected by the embankment top protection structure 34. The embankment top protection structure 34 is backfilled with 30 cm to 50 cm thick clay, and an asphalt pavement structure is laid on the clay backfill to avoid fracturing damage to the flexible composite impervious thin wall 1 caused by the embankment top load.

[0056] The thickness range of the flexible composite impervious thin wall 1 is 35 cm to 50 cm. The single-width range of the assembled Ω-shaped core material 12 is 60 cm to 80 cm. The single-arch height range of the assembled Ω-shaped core material (12) is 10 cm to 20 cm. The single length of the assembled Ω-shaped core material 12 is 5 m to 17 m. The web thickness range of the core material web 121 is 6 mm to 12 mm.

[0057] In order to ensure perfect adhesion between the flexible composite impervious thin wall 1 and the assembled Ω-shaped core material 12, it is recommended that the single-arch height of the assembled Ω-shaped core material 12 be controlled at 25% to 40% of the thickness of the flexible composite impervious thin wall 1. This can not only ensure that there is a sufficient thickness of the flexible composite impervious thin wall 1 outside the assembled Ω-shaped core material 12 to improve the durability such as anti-aging of the assembled Ω-shaped core material 12, but also ensure that the assembled Ω-shaped core material 12 itself has a certain flexural stiffness and is beneficial to the downward pressure stability during construction, which can ensure safety and save materials to optimize the project investment.

[0058] Through a large number of experimental studies and calculations, the empirical formula for the comprehensive permeability coefficient of the flexible composite impervious thin wall 1 in the present invention is: (1) Where: is the comprehensive permeability coefficient of the flexible composite impervious thin wall 1, with the unit of cm / s; is the total correction coefficient considering the influence of complex factors such as the admixture amount of on-site cement and other curing agents and the actual soil layer complexity in the flexible composite impervious thin wall 1; is the thickness of the web of the assembled Ω-shaped core material 12, with the unit of cm; is the thickness of the flexible composite impervious thin wall 1, with the unit of cm. In the present invention, the thickness range is 35 cm to 50 cm; is the average horizontal permeability coefficient of the solidified soil impervious thin wall 11 in the flexible composite impervious thin wall 1 itself, with the unit of cm / s; is the horizontal permeability coefficient of the assembled Ω-shaped core material 12 itself, with the unit of cm / s; is the influence coefficient of the reduction of the horizontal permeability coefficient of the assembled Ω-shaped core material 12 due to the splicing of the female joint 124 and male joint 125 of the core material in the horizontal direction; where the permeability coefficient of the solidified soil impervious thin wall 11 in the flexible composite impervious thin wall 1 k 固化土 is not only related to the distribution of the foundation soil layer, but also related to the dosage of the curing agent during the process of cutting and mixing to form the wall. After many large-scale experimental studies and calculations, the empirical formula can be used: (2) where: are the thicknesses of the first-layer soil embankment structure 31, the second-layer soil pervious soft foundation 32, and the third-layer soil relatively impervious foundation 33 in the dike 3 after cutting, mixing, and solidification, with the unit of m; are the horizontal permeability coefficients of the first-layer soil embankment structure 31, the pervious soft foundation 32, and the third-layer soil relatively impervious foundation 33 in the dike 3 after cutting, mixing, and solidification, respectively, with the unit of cm / s; is the total thickness of the flexible composite impervious thin wall 1, with the unit of m.

[0059] Example 1 is as follows:

[0060] As Figure 5 shown, the thickness of the first-layer soil embankment structure 31 in the dike 3 is , and its horizontal permeability coefficient after cutting, mixing, and solidification is ; the thickness of the second-layer soil pervious soft foundation 32 is , and its horizontal permeability coefficient after cutting, mixing, and solidification is ; the thickness of the third-layer soil relatively impervious foundation 33 after cutting, mixing, and solidification is , and its horizontal permeability coefficient after cutting, mixing, and solidification is ; The thickness of the flexible composite impervious thin wall 1:

[0061] Therefore, the actual designed length of the assembled Ω-shaped core material 12 is 14 m, and it can be formed in one construction without splicing up and down.

[0062] Then, according to the formula, the permeability coefficient of the solidified soil impervious thin wall 11 in the flexible composite impervious thin wall 1 is:

[0063] As Figure 7 shown, it represents the thickness of the flexible composite impervious thin wall 1, and the thickness of the web of the assembled Ω-shaped core material 12 is , the horizontal permeability coefficient of the assembled Ω-shaped core material 12 itself , the influence coefficient of the reduction of the horizontal permeability coefficient of the assembled Ω-shaped core material 12 due to the splicing of the horizontal core material female joint 124 and the core material male joint 125, etc. , the total correction coefficient considering the complex factors such as the content of on-site cement and other curing agents and the complexity of the actual soil layer in the flexible composite impervious thin wall 1 , then according to the formula, the comprehensive permeability coefficient of the flexible composite impervious thin wall 1 is:

[0064] Example 2 is as follows:

[0065] As Figure 5 shown, the thickness of the first layer of the earth embankment body structure 31 in the dike 3 is , and its horizontal permeability coefficient after cutting, mixing and curing is ; the thickness of the second layer of the pervious soft foundation 32 of the soil is , and its horizontal permeability coefficient after cutting, mixing and curing is ; the thickness of the third layer of the relatively impervious foundation 33 of the soil after cutting, mixing and curing is , and its horizontal permeability coefficient after cutting, mixing and curing is ; The thickness of the flexible composite impervious thin wall 1:

[0066] Therefore, the total length of the assembled Ω-shaped core material 12 is 22 m, and it cannot be formed by one-time production. Two typical specifications of 10 m and 12 m can be combined vertically and spliced by hot melting. The height of the Ω-shaped core vertical fusion assembly sleeve 13 is 0.6 m.

[0067] Then according to the formula, the permeability coefficient of the solidified soil impervious thin wall 11 in the flexible composite impervious thin wall 1 is:

[0068] As Figure 7 shown, it represents the thickness of the flexible composite impervious thin wall 1 , the thickness of the web of the assembled Ω-shaped core material 12 is , the horizontal permeability coefficient of the assembled Ω-shaped core material 12 itself , the influence coefficient of the reduction of the horizontal permeability coefficient of the assembled Ω-shaped core material 12 due to the splicing of the horizontal core material female joint 124 and the core material male joint 125 and the influence of vertical hot melting splicing , the total correction coefficient considering the complex factors such as the content of on-site cement and other curing agents and the complexity of the actual soil layer in the flexible composite impervious thin wall 1 , then according to the formula, the comprehensive permeability coefficient of the flexible composite impervious thin wall 1 is:

[0069] From the calculations of the above examples, it can be seen that after the flexible composite anti-seepage thin wall system of the present invention is adopted in the levee 3 in Example 1, the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall 1 , is much smaller than the horizontal permeability coefficient after cutting, mixing and solidifying the pervious soft foundation 32 in the levee 3 . This further verifies that the core anti-seepage structure in the flexible composite anti-seepage thin wall system of the present invention is the assembled Ω-shaped core material 12, and the anti-seepage effect of the solidified soil anti-seepage thin wall 11 is very small or even negligible. The main function of the solidified soil anti-seepage thin wall 11 is to cut and break large granular bodies such as cobblestone layers in-situ and use the soil itself for in-situ wall protection; in Example 2, the remaining parameters are the same as those in Example 1, only the thickness of the pervious soft foundation 32 of the second layer of soil is increased from 7 m in Example 1 to 15 m. At the same time, the assembled Ω-shaped core material 12 needs to be spliced by hot melting with two upper and lower pieces combined. By calculating the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall 1 in Example 2 , it is larger than the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall 1 in Example 1 . This also conforms to the engineering practice experience. The calculation results and accuracy can meet the requirements of engineering practice applications, and it has the advantages of good anti-seepage effect, high reliability, good durability, thin wall, low investment and convenient construction, etc.

[0070] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A flexible composite anti-seepage thin wall system, characterized in that: It includes a flexible composite anti-seepage thin wall, construction equipment and a dike. The flexible composite anti-seepage thin wall is arranged inside the dike, and during the construction process, the construction equipment is arranged on the top surface of the dike crest and the top surface of the flexible composite anti-seepage thin wall. The flexible composite anti-seepage thin wall includes a solidified soil anti-seepage thin wall, a spliceable Ω-shaped core material, and a nose-shaped positioning card. The solidified soil anti-seepage thin wall is arranged inside the middle body of the dike. The spliceable Ω-shaped core material is arranged in the middle inside the solidified soil anti-seepage thin wall. A nose-shaped positioning card is arranged at the middle position of the bottom of the spliceable Ω-shaped core material to play a role in centering control of the spliceable Ω-shaped core material. The spliceable Ω-shaped core material is composed of a core material web, core material adhesion-enhancing convex bodies, core material flanges, a core material female joint, and a core material male joint. The core material adhesion-enhancing convex bodies are arranged at intervals on the inner and outer side surfaces of the core material web to increase the bonding force between the spliceable Ω-shaped core material and the solidified soil anti-seepage thin wall. Core material flanges capable of adapting to deformation are provided at both the left and right ends of the core material web. Core material female joints and core material male joints are respectively provided at the ends of the core material flanges, forming an integrated structure similar to the shape of the Greek letter Ω. The spliceable Ω-shaped core materials are spliced with each other by adjacent core material female joints and core material male joints in the horizontal direction along the dike crest, thereby forming a continuously extending anti-seepage structure in the horizontal direction along the dike crest.

2. The flexible composite anti-seepage thin wall system according to claim 1, characterized in that: The spliceable Ω-shaped core material is formed by mixing and extrusion molding of polyvinyl chloride (PVC) resin and reinforcing materials. The vertical fusion splicing sleeve of the Ω-shaped core material, the nose-shaped positioning card, and the bottom protection sleeve of the Ω-shaped core material concave interface are formed by mixing and extrusion molding of polyvinyl chloride (PVC) resin and reinforcing materials. The spliceable Ω-shaped core materials are spliced vertically through the vertical fusion splicing sleeve of the Ω-shaped core material. The upper and lower spliceable Ω-shaped core materials to be spliced and the vertical fusion splicing sleeve of the Ω-shaped core material are heated by external ultrasonic vibration to make them reach the molten state, and under the action of external pressure and cooling, a uniform and reliable hot melt weld seam is formed. A bottom protection sleeve of the Ω-shaped core material concave interface is sleeved at the bottom of one side of the spliceable Ω-shaped core material with a core material female joint to play a role in preventing coarse particles from embedding and blocking.

3. The flexible composite anti-seepage thin wall system according to claim 1, characterized in that: The nose-shaped positioning card is composed of a socket-type nose-shaped card slot, card positioning wings, and an arc-shaped positioning sliding end. Card positioning wings are respectively provided on both side surfaces of the socket-type nose-shaped card slot, and an arc-shaped positioning sliding end is provided at the end of the card positioning wings. The socket-type nose-shaped card slot is connected to the middle position of the bottom of the core material web in a socket manner. The spliceable Ω-shaped core material is centered inside the solidified soil anti-seepage thin wall through the nose-shaped positioning card, and the bottom of the spliceable Ω-shaped core material smoothly rubs against the side wall of the solidified soil anti-seepage thin wall through the arc-shaped positioning sliding end to sink smoothly.

4. The flexible composite anti-seepage thin wall system according to claim 1, characterized in that: The construction equipment is assembled by a cutting, spraying and mixing device, a core planting device, a control device, a power device and a traveling device; the cutting, spraying and mixing device is arranged at the middle position of the traveling device, the control device is arranged on the top surface of the traveling device, the core planting device is arranged at the tail position of the traveling device, and the power device is arranged on the road behind the inner side of the dike to reduce the load on the construction equipment and the underlying soft foundation dike. The power device is connected to the control device through a cable, and the control device is connected to the cutting, spraying and mixing device, the traveling device and the core planting device through data lines and controls their orderly operation. Both the cutting, spraying and mixing device and the core planting device have functions of intelligent leveling in the front-back, up-down and rotational directions, so as to ensure that under the condition that the working surface of the construction equipment, that is, the top surface of the dike body structure, is uneven, the automatic control requirements for the verticality of the cutting, spraying and mixing device for constructing the solidified soil anti-seepage thin wall and the core planting device for constructing the assembled Ω-shaped core material are realized; the dike includes a dike body structure, a pervious soft foundation, a relatively impervious foundation, a dike top protection structure and a dike end connection structure; The relatively impervious foundation, the pervious soft foundation and the dike body structure are arranged from bottom to top in sequence. The dike top protection structure is arranged on the top surface of the dike body structure, and the dike end connection structure is connected to the side surface of one end of the dike body structure; during the construction process, the cutting, spraying and mixing device penetrates through the dike body structure, the pervious soft foundation and the relatively impervious foundation respectively and is arranged inside them. During the construction process, the cutting, spraying and mixing device cuts the dike body structure, the pervious soft foundation and the relatively impervious foundation respectively, and at the same time sprays and mixes to form the solidified soil anti-seepage thin wall.

5. The construction method of the flexible composite anti-seepage thin wall system according to any one of claims 1 to 4, characterized in that: It includes the following steps: S1. Construction preparation, assembling the construction equipment, preparing the curing agent slurry, producing the assembled Ω-shaped core material and accessories; S2. Leveling the cutting, spraying and mixing device and sinking it into the dike body; S3. The construction equipment slowly advances, the cutting, spraying and mixing device is leveled and corrected in real time, and cutting into the wall, spraying and mixing are carried out; S4. The construction equipment stops, the core planting device is leveled, and the assembled Ω-shaped core material is implanted. At the same time, the cutting, spraying and mixing device is stirred; S5. Repeat step S3 and step S4, enter the next construction cycle operation until the construction of the entire flexible composite anti-seepage thin wall is completed; S6. Construct the dike top protection structure and the dike end connection structure.

6. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: In step S1, the curing agent in the curing agent slurry is made by mixing cement, ground granulated blast-furnace slag, water-reducing agent and retarder in a certain ratio, and the water-binder ratio of the curing agent slurry is 0.4:1 to 0.5:1; the assembled Ω-shaped core material is an outer shape structure similar to the Greek letter Ω, and the assembled Ω-shaped core material is manufactured by mixing and extrusion molding of polyvinyl chloride (PVC) resin and reinforcing materials; the accessories, namely the vertical fusion assembly sleeve of the Ω-shaped core material, the nose-shaped positioning card and the bottom protection sleeve of the concave interface of the Ω-shaped core material, are also manufactured by mixing and extrusion molding of polyvinyl chloride (PVC) resin and reinforcing materials.

7. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: In step S2, when the construction operation platform on the top surface of the embankment structure is uneven, the cutting and grouting mixing device is leveled intelligently in the front-back, up-down, and rotational directions and sinks to the top of the relatively impervious foundation. During the sinking process of the cutting and grouting mixing device, it penetrates through the embankment structure, the pervious soft foundation, and the relatively impervious foundation respectively. The cutting and grouting mixing device is provided with more than two and is spliced up and down by anchor bolts. The sinking depth is controlled by the standard of effectively truncating the anti-seepage channels of the embankment body and the embankment foundation to ensure the anti-seepage safety requirements of the embankment.

8. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: In step S3, the construction equipment moves forward slowly, and at the same time, the cutting and grouting mixing device is leveled and corrected in real time to avoid the inclination of the cutting and grouting mixing device under the interference of external forces. At the same time, the cutting and grouting mixing device rotates up and down to cut the embankment structure and the pervious soft foundation, and uses the soil itself for in-situ retaining wall protection. The cutting and grouting mixing device injects the prepared curing agent slurry into the cut soil under high pressure. The admixture amount of the curing agent is controlled within the range of 5% - 15% by mass ratio. Specifically, the control principle is to increase the 28-day unconfined compressive strength of the solidified soil anti-seepage thin wall to 0.1 - 0.5 Mpa. The high-pressure grouting pressure range of the curing agent slurry is 0.2 - 0.8 Mpa. The cutting and grouting mixing device stirs up and down to form a fluidized solidified soil anti-seepage thin wall at the initial stage of construction. The up and down rotation speed of the cutting and grouting mixing device needs to be reasonably controlled. Specifically, it is necessary to not only meet the uniformity of up and down rotation stirring but also ensure the overall construction work efficiency. At the same time, the construction equipment moves forward slowly along the axis direction of the embankment top, and the forward speed is 5 - 20 m / hr.

9. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: In step S4, the construction equipment is stationary. The core-inserting device can be assembled by intelligent leveling in the front-back, up-down, and rotational directions. The nose-shaped positioning card can be sleeved into the middle position of the bottom surface of the Ω-shaped core material that can be assembled. The concave interface bottom protection sleeve of the Ω-shaped core material can be sleeved at the bottom of the female-shaped joint of the core material to prevent the cavity from being blocked by coarse particles in the foundation soil. Then, the core-inserting device at the tail of the construction equipment is used to vertically press the Ω-shaped core material that can be assembled into the middle position inside the fluidized state solidified soil anti-seepage thin wall at the initial stage of construction. The male-shaped joint of the core material of the Ω-shaped core material that can be assembled is snapped into the female-shaped joint of the implanted core material. The two ends of the Ω-shaped core material that can be assembled are spliced by interlocking. When the depth of the bottom surface of the pervious soft foundation in the dike exceeds 15 - 20 m, due to transportation requirements, the one-time forming length of the Ω-shaped core material that can be assembled is limited. It is necessary to use the vertical fusion assembly sleeve of the Ω-shaped core material to perform vertical fusion splicing on the Ω-shaped core material that can be assembled. The width of the fusion splicing is not less than 50 cm. The hot melt joints formed by the Ω-shaped core material that can be assembled and the vertical fusion assembly sleeve of the Ω-shaped core material need to be arranged in a staggered joint, that is, the hot melt joints formed by adjacent Ω-shaped core materials that can be assembled and the vertical fusion assembly sleeve of the Ω-shaped core material need to be arranged at different depths. The depth difference range needs to meet 1 m - 5 m, and the hot melt joints formed by the Ω-shaped core material that can be assembled and the vertical fusion assembly sleeve of the Ω-shaped core material should be arranged in the soil layer with relatively weak water permeability as much as possible. The Ω-shaped core material that can be assembled smoothly and vertically sinks to the design depth along the two side walls of the solidified soil anti-seepage thin wall and jointly acts with the solidified soil anti-seepage thin wall to form a flexible composite anti-seepage thin wall. In step S4, at the same time, the cutting and grouting mixing device at the front end of the construction equipment continuously operates up and down to ensure the uniformity of the solidified soil anti-seepage thin wall.

10. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: In step S6, after the construction of the flexible composite anti-seepage thin wall is completed, the anchor bolts connecting the upper and lower parts of the cutting and grouting mixing device are disassembled, and the cutting and grouting mixing device is lifted out of the dike in sections, and each assembled component of the construction equipment is disassembled and evacuated; at the same time, after the solidified soil anti-seepage thin wall in the flexible composite anti-seepage thin wall reaches the designed strength of 28 days, the designed unconfined compressive strength range is 0.1~0.5 Mpa. For the end boundary of the flexible composite anti-seepage thin wall and the anti-seepage spur wall of the adjacent building, an outer wrapping type anti-seepage connection protection is adopted with clay anti-seepage material outside the connection structure at the end of the dike, and its outer wrapping thickness is not less than 1.0 m, and the permeability coefficient of the clay anti-seepage material is not greater than 1×10 -5 cm / s to avoid lateral seepage around; The top of the flexible composite anti-seepage thin wall is protected by the dike top protection structure. The dike top protection structure is backfilled with 30 cm - 50 cm thick clay, and an asphalt pavement structure is laid on the clay backfill to prevent the dike top load from causing fracturing damage to the flexible composite anti-seepage thin wall.

11. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: The single-arch height of the Ω-shaped core material that can be assembled is controlled at 25% - 40% of the thickness of the flexible composite anti-seepage thin wall 1 to ensure that the flexible composite anti-seepage thin wall and the Ω-shaped core material that can be assembled are completely bonded to each other. It not only ensures that there is a sufficient thickness of the flexible composite anti-seepage thin wall outside the Ω-shaped core material that can be assembled to improve the anti-aging durability of the Ω-shaped core material that can be assembled, but also ensures that the Ω-shaped core material that can be assembled itself has a certain bending stiffness and is beneficial to the downward pressure stability during construction.

12. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: The thickness range of the flexible composite anti-seepage thin wall is 35 cm - 50 cm, the single-width of the Ω-shaped core material that can be assembled is 60 cm - 80 cm, the single-arch height of the Ω-shaped core material that can be assembled is 10 cm - 20 cm, the single-length of the Ω-shaped core material that can be assembled is 5 m - 17 m, and the thickness of the core material web is 6 mm - 12 mm.

13. The construction method of the flexible composite anti-seepage thin wall system according to claim 5, characterized in that: The empirical formula for calculating the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall is: （1） Where: is the comprehensive permeability coefficient of the flexible composite anti-seepage thin wall, with the unit of cm / s; To consider the total correction factor in the flexible composite impervious thin wall due to the influence of the on-site cement curing agent dosage and the actual soil layer complexity factors; is the thickness of the web of the collapsible Ω-shaped core material, in cm; is the thickness of the flexible composite anti-seepage thin wall, with the unit of cm, and the thickness range is 35 cm to 50 cm; is the average horizontal permeability coefficient of the solidified soil impervious thin wall of the flexible composite impervious thin wall, with the unit of cm / s; is the horizontal permeability coefficient of the assembled Ω-shaped core material, with the unit of cm / s; is the influence coefficient of the reduction of the horizontal permeability coefficient of the spliceable Ω-shaped core material under the influence of the splicing of the female-shaped joint and the male-shaped joint of the core material in the horizontal direction; Among them, the permeability coefficient of the solidified soil impervious thin wall in the flexible composite impervious thin wall k 固化土 is not only related to the distribution of the foundation soil layer, but also related to the dosage of the curing agent during the process of cutting and mixing to form the wall. After a large number of experimental studies and calculations, the empirical formula is adopted: (2) Where: They are the thicknesses of the first layer of embankment structure, the second layer of soil with perviousness and soft foundation, and the thickness after cutting, mixing and solidifying of the relatively impervious foundation of the third layer of soil, with the unit of m; They are the horizontal permeability coefficients after cutting, mixing and solidifying the first earthen dike body structure, the pervious soft foundation and the relatively impervious third-layer soil foundation in the dike, with the unit of cm / s; is the total thickness of the flexible composite anti-seepage thin wall, with the unit of m.

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