265results about How to "Avoid water seepage" patented technology

The invention relates to a structure and a construction method of a cast-in-style welded steel frame composite concrete shear wall. The structure comprises an indoor concrete layer, an outdoor concrete layer and a wire frame insulation sandwich board. The wire frane insulation sandwich board is coated between the indoor concrete layer and the outdoor concrete layer. At least two rectangular and groove-typed cantilever holes are arranged at the top of the sandwich board, and each cantilever hole is provided with a U-shaped cantilever anchor bar which penetrates through the sandwich board and a floor slab to be fixedly connected with the floor slab. The construction method includes site preparation work, binding of load-bearing steel bars of a wall body and edge member steel bars, custom processing of the sandwich boards, installation of the sandwich boards, pavement of template positioning pieces and wall bushings, fixation of water and electric pipes inside the wall body, binding of ordinary blocks on both sides of the wall body steel bars, erecting of the templates, pouring of the concrete, removing of the templates and concrete curing. Since a series of composite wall construction methods are adopted, problems existing in the prior art are solved, and a composite heat preservation technology is improved.

A job practice of which center island is done in sequence and partial skirts done inversely, comprising the following steps : set up exterior-protected construction, purlin and steel upright columns around the foundation ditch; dig on basin pattern for the first time to the depths to structural plane of purlin, earthwork are unified dig beneath the designed to the surrounding medium plate in the foundation ditch, pour the surrounding medium plate; dig for the second time with basin pattern downwards from the position of foundation ditch medium plate to the bottom of the designed foundation ditch, pour the center island plate; after the center island plate meets the maintenance time request of plate, construct in sequence to close the medium plate, setting fetching holes; then use medium plate for support system, construct criss-cross structural upper plate and plates in inverse zones. This construction method is convenient, save labor force and resources, improves the progress of the project, shorten the construction period.

The present invention relates to a kind of highly antibacterial gas permeable film, it is the PE antibacterial gas permeable film formed by the modified porous graphene composite antibacterial material evenly distributed in it in PE matrix material, and its component and parts by weight are as follows: PE 40-70 parts 0.5-10 parts of modified porous graphene antibacterial masterbatch; 28-55 parts of inorganic filler; 0.5-5 parts of auxiliary agent A. Wherein, the modified porous graphene masterbatch is made of 5-60 parts of carrier resin, 1-12 parts of modified porous graphene antibacterial powder, auxiliary agent B, and is extruded and granulated by screw after blending. The pores of porous graphene are loaded with antibacterial plant extracts, or antibacterial plant extracts and antibacterial materials prepared by loading organic rare earth salts, wherein the antibacterial plant extracts are such as camellia oil, tea polyphenols, and aloe oil. Porous graphene is one or both of porous graphene oxide and porous reduced graphene, and the inorganic filler is CaCO3 or / and Na2SO4.

The invention relates to a production technology of a composite material for a yacht, comprising the following steps: firstly using a padding-bonding all-in-one machine to pad a mesh cloth layer with a PVC resin-pasting adhesive and drying and preheating; then synchronously bonding the mesh cloth layer with an ink-jet printing film layer and a surface film layer at 190-200 DEG C, wherein the ink-jet printing film layer is arranged between the mesh cloth layer and the surface film layer; bonding the other side surface of the mesh cloth layer with a bottom film layer; and finally cooling to mold, and trimming and reeling to obtain the composite material for the yacht. According to the invention, by preferred formula of the surface film layer, a transparent elastic film with excellent performance is obtained; by using the PVC resin-pasting adhesive, the peeling strength, tearing strength, handle resilience and other physical properties are good; by completing the bonding of the multiple film layers and the mesh film layer in one step, the damage to the PVC film layer caused by multi-time heating and cooling is reduced, and the product performance is raised.

The invention discloses an I-shaped water retaining dam for a ground-water reservoir in coal mine. The I-shaped water retaining dam is located between coal pillar dam bodies so as to be used for isolating the ground-water reservoir from corresponding coal roadways. The I-shaped water retaining dam comprises an upper flange, a web plate and a lower flange from top to bottom, the vertical face of adam body is in an I shape, the upper flange stretches into a roadway roof, the two ends of the web plate are embedded into the coal pillar dam bodies, and the lower flange stretches into a bottom plate. Because the I-shaped water retaining dam is located in an underground coal rock bed roadway, the surrounding rock stress acting on the I-shaped water retaining dam is relatively complicated, the phenomenon of water-seepage of a weak part on the upper portion of a traditional I-shaped water retaining dam is effectively overcome, the punching stress of the dam body to the bottom plate of the roadway is reduced, the stability of the dam body and the overall stability are improved, and the requirements for water storage and the safety performance of the ground-water reservoir in the coal mine are met.

The invention relates to a finger-shaped connector of an aramid fiber conveying belt and a preparation method of the finger-shaped connector. The preparation method comprises the following steps: stripping coverage glue, cleaning residual glue, cutting finger shapes, coating mucilage, splicing the finger shapes, forming and coating glue, reinforcing by a fabric layer, covering glue, and sulfurizing a specimen, thereby obtaining the finger-shaped connector on the aramid fiber conveying belt. According to the invention, the problems of extraction, edge wrapping, water seepage, glue failure of seams and the like of the connector of the conveying belt in the dynamic running process are solved; a certain gap is reserved in splicing the finger shapes so as to guarantee that the pasting glue can seep fully toward the finger shapes, the extraction force is increased, the stress uniformity is improved, and the phenomena of extraction and cracking which are caused by stress uniformity are prevented; the length of the stripped coverage glue is greater than the length of each finger by 5cm, and the connector glue and the coverage glue are lapped into an oblique slope, so that the phenomenon of water seepage of a framework material because of glue failure of the seam is prevented, and the service life of the connector of the aramid fiber conveying belt is prolonged greatly.

The invention discloses a rail-traveling type hydraulic ditch cable trench trolley formwork system. The system comprises a hydraulic system, a traveling system, a steel formwork system, a truss, a screw rod, vertical sliding shoes, a horizontal sliding shoe, a limit lever and rails, wherein the hydraulic system comprises a horizontal oil cylinder and vertical oil cylinders; the traveling system comprises a driving wheel and a driven wheel; the steel formwork system comprises a concrete pouring cavity formed by a ditch steel formwork, a cable trench steel formwork, an outside steel formwork and a seal end steel formwork, the ditch steel formwork, the cable trench steel formwork and the horizontal sliding shoe are in pin joint through the vertical sliding shoes and realize stretching and retracting through the vertical oil cylinders arranged at two ends, the horizontal sliding shoe is connected with the truss and realizes horizontal stretching and retracting through the horizontal oil cylinder arranged at the top, and the outside steel formwork and the truss are in pin joint through the screw rod and realize stretching and retracting through the horizontal oil cylinder arranged on the side surface. According to the rail-traveling type hydraulic ditch cable trench trolley formwork system, the construction quality and the construction efficiency are effectively improved, and the construction cost is reduced.

The invention belongs to the technical field of power facilities and particularly relates to a fireproof power cable trench. The fireproof power cable trench comprises multiple trench bodies; each trench body comprises a bottom plate, side baffles and a cover plate; one accommodating cavity and multiple discharge ports are arranged in the side baffles and on the cover plate; the discharge ports are located at the inner side of the cable trench; the accommodating cavity and the multiple discharge ports are communicated; the accommodating cavity is internally provided with a fireproof material;and the discharge port is provided with a plugging mechanism. Through improving the structure of the trench body, the accommodating cavity with the fireproof material is arranged in the side baffles and the cover plate, self extinguishing is carried out while waiting for rescue, and secondary fault of a power device is avoided.

The invention discloses a strong-upper anti-seepage water retaining dam of an underground reservoir of a coal mine, which is positioned between coal pillar dam bodies to isolate the underground reservoir and a corresponding coal roadway, wherein a dam body comprises a main dam and a strong-upper part, the strong-upper part is formed by extending at least a length of S1 towards the underground reservoir based on the thickness of the main dam, the extended S1 part also forms a first anti-seepage part, the strong-upper part is embedded into the coal pillar dam bodies on both sides, the upper endsof the storing-upper part and main dam are embedded into surrounding rock of the roof of the roadway, and the lower ends of the main dam and the strong-upper part are embedded into the surrounding rock of the floor of the roadway. As the water retaining dam is positioned in the underground coal rock stratum roadway and is subjected to complex surrounding rock stress, the water retaining dam effectively overcomes the phenomena of weak upper parts at two sides of the roadway of a prior water retaining dam and easy water seepage, and also reduces the local pressure of the dam body to the coal pillar dam bodies at two ends of the roadway, the stability of the dam body and the whole body is improved, and the water storage and safety requirements of the underground reservoir of the coal mine are met.

The invention provides a water tank. The water tank comprises a shell, a water storage chamber arranged in the shell, and a water outlet connected with the outside, also comprises a driving part connected with the shell, a water diversion mechanism connecting the driving part is arranged between the water storage chamber and the water outlet, and the driving part drives by friction with the groundwhen the water tank is driven by the cleaning device, the water diversion mechanism driven by the movement of the driving part achieves to lead the water in the water storage cavity to the water outlet. The water tank utilizes the motion produced by the friction between the driving part mounted on the water tank and the ground to provide the driving force and drive the water diversion mechanism,so as to control the flow out and stop of the water, and prevent the leakage of the water tank or the seepage phenomenon caused by the long time stationary.

The invention discloses a prefabricated assembled bridge deck plate dry joint connection structure and an implementation method and belongs to the field of bridge engineering. The prefabricated assembled bridge deck plate dry joint connection structure comprises prefabricated assembled type bridge deck plates, a top reserved pre-stressing hole channel, a top pre-stressing tendon, a top anchorage device, a top spacer, a bottom reserved pre-stressing hole channel, a bottom pre-stressing tendon, a bottom anchorage device, a bottom spacer and a water stop. The top pre-stressing tendon and the bottom pre-stressing tendon are stretched by mounting the spacers and the anchorage devices, so that top parts and bottom parts of the adjacent prefabricated bridge deck plates are connected together. Inaddition, the bottom reserved pre-stressing hole channel, the bottom pre-stressing tendon, the bottom anchorage device and the bottom spacer can be replaced with a bottom embedded part, a bottom steelplate and nuts; the bottom steel plate is fixed by mounting the nuts so as to reduce the workload for stretching the pre-stressing tendons. According to the prefabricated assembled bridge deck platedry joint connection structure and the implementation method disclosed by the invention, the design is simple, the cast-in-place concrete is not needed, the mounting is convenient and rapid, the construction of the full prefabricated bridge is implemented, and the structure has the characteristics of being repairable, and easy to replace and update.

The invention discloses a tube well used for unwatering and pressure-reducing drainage. The tube well comprises a well pipe comprising a precipitation tube, a pressure-reducing water filtering tube, a pressure-reducing well wall tube, an unwatering water filtering tube and an unwatering well wall tube which are sequentially arranged from bottom to top in a penetrating mode, and the joint of the pressure-reducing well wall tube and the unwatering water filtering tube forms a lower pressure-reducing well pipe and an upper unwatering well pipe through a seal board in a partitioning mode. The seal board is provided with a natural flow pipe comprising a water inlet pipe section and a water outlet pipe section, the water inlet pipe section is provided with a water inlet, the water outlet pipe section is sequentially provided with a plurality of water outlet pipe section bodies in the axial direction, each water outlet pipe section body is provided with a side wall water outlet and an upper water outlet, and the side wall water outlets and the upper water outlets are of opening and closing structures. The tube well simplifies drainage procedures, increases the drainage success probability, reduces engineering costs, accelerates the construction progress, increases the deep foundation pit excavation safety coefficient, and simplifies capping work. The invention further discloses a drainage method using the tube well.

The invention discloses an I-type rib-reinforcing and seepage-preventing water retaining dam for a coal mine underground reservoir. The I-type rib-reinforcing and seepage-preventing water retaining dam is located between coal pillar dam bodies on left and right sides of a roadway and used for isolating the underground reservoir from the roadway and blocking a water source in the underground reservoir. A dam body of the I-type rib-reinforcing and seepage-preventing water retaining dam comprises an upper wing plate, a web and a lower wing plate from top to bottom sequentially, wherein the vertical section, perpendicular to the dam surface, of the dam body is I-type; the dam body of the I-type rib-reinforcing and seepage-preventing water retaining dam further comprises reinforced rib parts located on left and right sides of the web, and each reinforced rib part comprises a first seepage preventing part which is formed by extending to one side of the underground reservoir by at least S1 length on the basis of the thickness of the web. The water retaining dam is located in an underground coal seam roadway and receives complicated surrounding rock stress, so that through the adoption ofthe water retaining dam, local instability and failure and water seepage due to overhigh local stress of the coal pillar dam bodies can be reduced, the defect that two rib parts of the roadway of thetraditional water retaining dam are weak and prone to water seepage is overcome effectively, and the requirement for water storage and safety of the coal mine underground reservoir are met.

The invention relates to an impermeable structure applied to a concrete pressure container, which belongs to the technical field of solid engine test, and comprises a concrete wall, steel embedded parts, a steel plate and a glass fiber reinforced plastic coating, wherein the concrete wall is arranged on the outermost layer of the impermeable structure, the steel embedded parts are arranged in the concrete wall, the steel embedded parts are connected with a prestressed steel bar in concrete, the steel plate is adjacent to the concrete wall and is closely attached to the concrete wall after being welded with the steel embedded parts, and the glass fiber reinforced plastic coating is uniformly coated on the outer layer of the steel plate. The impermeable structure is simple in construction process, easy to realize, applicable to the concrete pressure container under the pressure lower than 0.4MPa, and water in the concrete pressure container can be prevented from permeating outwards via the wall.

The invention discloses a hidden type floor prevention system which comprises a main trough body (1), a water baffle (2), a power system and an auxiliary supporting structure, wherein guide rails (3) are arranged on the left and right sides of the main trough body (1); a water drainage slot (5) is formed in the lower portion of the main trough body (1); a horizontal protection plate (9) is arranged on the upper end surface of the water baffle (2); the power system comprises an electric hoist (10) and a manual winch (11); the auxiliary supporting structure comprises vertically arranged supporting rods (16) and horizontally arranged puller bolts (17); the supporting rods (16) are provided with threaded holes (18); and the puller bolts (17) penetrate through the threaded holes and then are in contact with the water baffle (2). By simultaneously arrangement of the electric hoist and the manual winch, the automation property of the hidden type floor prevention system is effectively improved; and furthermore, by additional arrangement of the auxiliary supporting device on the inner side of the water baffle, the flood prevention performance of the hidden type floor prevention system is effectively improved.

The invention discloses a vacuum fluorescent float which comprises a fluorescent float body and a lead. The fluorescent float body is hollow, a vacuum cavity is formed, and hydrogen is injected into the vacuum cavity. Two ends of the fluorescent float body are respectively closed by I-shaped end caps. The lead is folded to be two units successively passing through the two I-shaped end caps. The I-shaped end caps are prepared by elastic rubber and plastic materials. The fluorescent float body is prepared by rigid plastic. The fluorescent float is designed to be hollow with the tow ends closed by the I-shaped end caps, leakproofness is excellent, interior water seepage can be effectively prevented, and the vacuum fluorescent float is simple and reasonable in structure, large in buoyancy, good in visibility, and convenient to make and use.

The invention relates to the technical field of machine tool-related equipment, in particular to a device for cleaning sediments in a machine tool water tank. The device includes a support frame, a water tank is fixedly connected to the inner side of the support frame, a chip removal mechanism is arranged on the inner side of the water tank, a top plate fixedly connected with the support frame isarranged on the upper side of the water tank, and a purification mechanism for collecting the sediments is arranged at the top of the top plate. According to the device for cleaning the sediments in the machine tool water tank, a scraping plate is arranged, the up and down movement of the scraping plate can be used for scraping down the sediments attached to the tank wall, and the sediments can beconveniently collected; a crushing blade is arranged to crush impurities scraped from the tank wall to avoid the pipe blockage due to the excessive volume of the impurities, and the stability of thepurification process is ensured; a spraying pipe is arranged to wash the scraping plate and the tank wall by using the purified water, and the device can clean up the sediments more thoroughly; and the purification mechanism is arranged, the sediments in the water tank can be collected, and the sediments in the water tank can be automatically cleaned without removing other parts installed on the water tank.

The invention relates to a cast-in-place concrete floor punching pipe seal template device and a using method. The device comprises angle steel frames (3), wooden templates (5) and a round steel pulling rod (4). The device is characterized in that the two angle steel frames (3) are oppositely arranged, two ends of the angle steel frames (3) are connected with each other through the round steel pulling rod (4), the wooden templates (5) are boards with semicircle notches, the two wooden templates (5) which are horizontally arranged in a butt joint mode are clamped between the two angle steel frames (3), the wooden templates (5) are clamped and fixed at the lower end of a concrete reserved hole through the angle steel frames (3), and the wooden templates can be disassembled to be used circularly after being used. The cast-in-place concrete floor punching pipe seal template device is simple in structure, convenient to install, applicable to seal cast concrete of pipes with different diameters, quick to disassemble and capable of being used circularly.

The invention belongs to deep sea overline transportation and linkage projects, and relates to a deep see immersed type tunnel based on a rigidity carrier. A traditional seabed tunnel, a flume and a bridge are combined and improved, and the immersed type tunnel high in rigidity and capable of being spliced and dismounted is formed. A segment splicing method is adopted in a pipe of the immersed type tunnel, the pipe is embedded in a supporting flume, the pipe can be replaced or dismounted in the later period through a connector at a port of a segment of the tunnel pipe and is transported to the land in a floating mode to be repaired. Water seepage of the tunnel pipe is avoided through a gate at the port of the segment of the tunnel pipe when the part of pipe is dismounted and maintained. Thus, the deep see immersed type tunnel based on the rigidity carrier adapts to deep sea and has high spanning capability through increasing of the structural carrier rigidity and has the dismounting and replacing functions.

The invention provides a guide rail device, and is applied to cast-in-place concrete of a sloping roof. The guide rail device comprises a sloping roof formwork, plate bottom steel bars, plate surface steel bars, a guiding guide rail, a guide rail support and cushion blocks. The plate bottom steel bars are laid on the sloping roof formwork. The multiple cushion blocks are arranged between the plate bottom steel bars and the sloping roof formwork. The plate surface steel bars are arranged on the upper portion of the plate bottom steel bars. The plate surface steel bars are fixed on the plate bottom steel bars through a bracket. The guiding guide rail is placed on the upper portion of the plate surface steel bars. The guiding guide rail is fixed on the plate bottom steel bars or / and the plate surface steel bars through the guide rail support. The elevation of the guiding guide rail is the elevation of the concrete surface. The invention further relates to a construction method of controlling slope and thickness of the sloping roof. According to the construction method of controlling the slope and thickness of the sloping roof and the guide rail device, the roof forming quality can be guaranteed, rework and secondary leveling are avoided, the construction period, material cost and labor cost are saved, and the construction difficulty is reduced; and the phenomenon of seepage of roofing is avoided, and the loss to an owner is not caused.

The invention discloses a water-proof construction method for connected nodes of a foundation slab and a ground wall in a composite surround system, and relates to the technical field of underground engineering water-proof construction. The water-proof construction method aims at the problems that the interface of a new concrete structure and an old concrete structure and the chiseled portion of a bored cast-in-place pile are prone to forming underground water seepage path, and the construction quality of the foundation slab is influenced. The water-proof construction method comprises that 1, a sunken portion is dug on the edge of a foundation pit, a concrete base layer is constructed, a first geosynthetic clay liner is laid to the bored cast-in-place pile, and closing up is carried out; 2, the foundation slab to be poured and a reinforcing steel bar bracket to be turned downwards are erected and bond, and a space on the edge of the foundation slab to be poured is reserved; the foundation slab is poured, and the bracket is turned downwards; 3, the portions, over the bottom elevation of the foundation slab, of the bored cast-in-place pile and a high-pressure jet grouting pile are chiseled away, and a depth D is dug downwards along the bottom elevation of the foundation slab continuously; a base layer is poured on the chiseled portion and coated by a second geosynthetic clay liner, and closing up is carried out; and 4, after a pouring belt is poured, the pouring belt and the foundation slab are fixedly connected into a whole.

The invention discloses a construction method of a water-borne non-curing coating and coiled composite waterproof system. The construction method comprises the following steps: S1, spraying a water-borne non-curing coating on a base material layer; S2, pasting a waterproof coiled material on the surface of the coating of the S1. According to the construction method of the water-borne non-curing coating and coiled composite waterproof system, firstly spraying the water-borne non-curing coating on the base material surface, forming a whole waterproof layer with no joint on the surface of the base material, and then directly bonding the waterproof coiled material on an upper end of the water-borne non-curing coating by using adhesion property of the water-borne non-curing coating, so as to increase the rigidity of the waterproof system. Compared with the prior art, no heat treatment is needed in the construction process, and the dry and humidity degree of the construction surface is not required, so that cold construction and construction in rainy day can be realized.

The invention discloses a water-cooling electric reactor which comprises three groups of windings, an iron core, cooling pipelines and water distributors, wherein the windings are wound on the iron core; the cooling pipelines are positioned in the windings; the pipe joints of the cooling pipelines are positioned below the windings; the water distributors are positioned at the two ends of the electric reactor; two joints are arranged on the water distributors; the joints are connected with the cooling pipelines respectively; and coil ending rows and coil starting rows are also arranged on the windings. According to the water-cooling electric reactor, the pipe joints of the cooling pipelines are arranged below the windings, and the water distributors are arranged on the two sides of the electric reactor, so that the pipe joints can be prevented from leaking water; and the stable and safe running of the water-cooling electric reactor is guaranteed, and the water-cooling electric reactor is strong in practicality.

The invention provides a prefabricated composite wallboard and a preparation method thereof. The prefabricated composite wallboard includes a first decorative protective layer, a reinforcing layer, asecond decorative protective layer, a vacuum insulation board layer and a structural layer which are sequentially attached; the first decorative protective layer and the second decorative protective layer are a mortar layer, the reinforcing layer is a high-strength fiber gridding cloth or a steel wire mesh sheet, and the structural layer is a reinforced concrete layer. According to the prefabricated composite wallboard and the preparation method thereof, the first decorative protective layer, the reinforcing layer, the second decorative protective layer, the vacuum insulation board layer and the structural layer are connected into a whole through connecting pieces, and the five layers of materials adopt strengths and avoid weaknesses, so that the integrated effects of lightness and thinness, high thermal insulation, fire protection, high strength, and high thermal performance are achieved. The prefabricated composite wallboard is more convenient to transport and install, the utilization of the building area is improved, and the problem that existing wallboards cannot integrate fire prevention, thermal insulation, lightness and thinness, and load bearing is solved.

The invention discloses a method for making a closed composite partition wall board, and solves the problems that circuits and switch sockets are inconvenient to lay out and wood plastic boards are unfit for being used as the partition wall boards for the conventional partition wall board. The method comprises the steps as follows: making raw materials of a closed composite partition wall board housing; carrying out extrusion molding on the closed composite partition wall board housing; and filling insulated materials into the closed composite partition wall board housing. The flame retarding level reaches the A1 level; the wood plastic housing is in the B1 level; the integrated housing avoids the defects of cracking, water seepage, dropping and the like; the wood plastic housing is good in waterproof and moistureproof performance and is not deformed and degenerated after being soaked with water; a cement foam board is not shrunk when meeting water, so that the insulation performance is not influenced; the strength is higher, so that the composite board is not deformed when being slightly hit; and the composite board is light in weight and simple, convenient and quick in construction.

The invention relates to the technical field of building mortar preparations, and concretely relates to a preparation method of a polymer composite water-proof mortar. The preparation method of the polymer composite water-proof mortar comprises the following steps: firstly, natural river sand and glass fiber are used as filling materials to improve the mechanical properties of the mortar, orange peel juice and rose essential oil are decomposed to produce a large number of lipophilic ester groups and aromatic hydrocarbon groups under the function of microbes, and the lipophilic groups are introduced onto the surface of a mixed powder through microbes, so that the compatibility of an inorganic mixed powder with a polymer is improved, and the anti-permeable strength of the mortar is improved.According to the polymer composite water-proof mortar, the excellent water-resistant properties of silica sol and organic siloxane are fully used to improve the water-proof property of the mortar, besides the polymeric matrix contains abundant silicon hydroxyl groups, and the silicon hydroxyl groups and silicon hydroxyl groups on the surface of the modified mixed powder undergo a reaction under the effect of a heating power to form Si-O-Si bonds with extreme big bond energy, so as to improve the internal bonding strength of the mortar, and further improve the mechanical properties of the water-proof mortar, thereby, the polymer composite water-proof mortar has a broad application prospect.

The invention discloses a box type water retaining dam for a coal mine underground reservoir. The box type water retaining dam is located between coal pillar dam bodies on the left side and the rightside of a roadway and used for isolating the underground reservoir and the roadway and blocking a water source in the underground reservoir. The box type water retaining dam comprises a main dam bodyand water retaining wings, wherein the main dam body is of a box type structure, the left side and the right side of the main dam body are embedded in the coal pillar dam bodies on the two sides, thetop of the main dam body is embedded in roadway roof surrounding rock, and the bottom of the main dam body is embedded in roadway bottom plate surrounding rock; and the water retaining wings compriseside wings, the side wings are connected with the left side and the right side of the main dam body and arranged along at least the whole height range of the main dam body, the side wings are embeddedinto the coal pillar dam bodies on the two sides to a certain depth, and thus side wing seepage prevention areas are formed. The box type water retaining dam can reduce crippling and water seepage caused by excessive local stress of the surrounding rock at the same time, adjusts differential settlement, prevents the surrounding rock from being softened due to water entering, and ensures the stability and safety of the dam bodies.

The invention provides a construction method and a permanent support system of a shallow-buried and underground-excavated large-span tunnel, and belongs to the technical field of tunnel engineering construction. The construction method of the shallow-buried and underground-excavated large-span tunnel comprises the steps of construction preparation, pipe jacking operation, reinforced concrete pouring operation, water stopping and waterproofing operation, tunnel excavation and water guiding and waterproofing operation. According to the construction method of the shallow-buried and underground-excavated large-span tunnel, a pipe curtain system structure is reserved in a tunnel structure, so that the pipe curtain system structure forms a supporting and permanent integrated design and construction structure, construction operations such as temporary supporting, steel pipe cutting, stand column welding and reinforcing mesh binding are greatly reduced, the construction workloads can be reduced, the construction period can be shortened, meanwhile, by arranging a water guide waterproof mechanism, underground water which permeates accidentally is discharged out of the tunnel, and the water seepage phenomenon is avoided.

An automatic line drawing tool of a neodymium iron boron permanent magnet is characterized by comprising a distance-adjustable transmission guide rail, a pressing wheel and a line drawing pen. The distance-adjustable transmission guide rail is used for containing and conveying the neodymium iron boron permanent magnet; the pressing wheel is used for flattening a neodymium iron boron permanent magnet strip; the line drawing pen is provided with a line drawing intensity adjusting mechanism. A motor is adopted to drive the automatic line drawing tool of the neodymium iron boron permanent magnet to automatically draw a line, labor is saved, and the efficiency is improved. The line drawing pen is inclined by a certain angle to be mounted, abrasion of the line drawing pen is reduced, the line drawing pen is pressed on the neodymium iron boron permanent magnet strip by means of the gravity of the pen and a line drawing intensity adjusting rod, and the height of the line drawing pen does not need to be repeatedly adjusted; the pressing wheel is arranged, so that the neodymium iron boron permanent magnet strip is flattened, and the line breaking condition is avoided. A compressed air nozzle is arranged, so that a drawn line can be rapidly blown dry, and the water seepage situation is avoided.