49results about How to "Controllable duration" patented technology

The invention discloses a voltage-dip generator used for wind power generation. The voltage-dip generator comprises a host computer, a data collecting card, an IGBT driving and protecting circuit, two IGBT bilateral switches, a booster, a voltage Hall sensor, a current Hall sensor and a wind turbine generator. Three-phase voltage signals and three-phase current signals output by the voltage-dip generator are obtained by the voltage Hall sensor and the current Hall sensor; the three-phase voltage signals and the three-phase current signals output by the voltage-dip generator are acquired by the data collecting card and transmitted to the host computer; the host computer outputs voltage-dip signals and restores instruction signals to the IGBT driving and protecting circuit through the data collecting card, and leads the two IGBT bilateral switches to conduct alternately; and the voltage output by the voltage-dip generator is switched over between a primary side and a secondary side of the booster, thereby simulating various symmetrical and unsymmetrical network voltage dip faults. The voltage-dip generator has the characteristics of simple operation, high reliability, good real-time performance, etc., and is suitable for performance test and research of the wind turbine generator when in network voltage faults.

The invention relates to an operation synthesis tester for an ultrahigh voltage direct current converter valve, which comprises a 12-pulse wave converter loop, a high voltage loop and a large current loop which are connected two by two, wherein the ultrahigh voltage loop provides a reverse restore voltage and a positive voltage for a valve to be tested; the large current loop provides a large current for flowing the valve to be tested; the 12-pulse wave converter loop provides high voltage, fault overcurrent and direct current intermittent current needed by the valve to be tested. Compared with the prior art, the operation synthesis tester for the ultrahigh voltage direct current converter valve has the advantages of good equivalence, wide applicable range, good economy, high test precision and the like.

The invention provides a red envelope rain issuing method, system and apparatus, and a computer readable storage medium. The method comprises the steps of transferring an amount of an issuer account corresponding to an issuer to a red envelope pool according to red envelope rain setting information; and forming red envelope rain by red envelopes in the red envelope pool, and performing display inreceivers in a preset time based on target interfaces according to the red envelope rain setting information, thereby enabling the receivers to obtain the red envelopes based on the red envelope rain.According to the method provided by the invention, the red envelopes in the red envelope pool form the red envelope rain according to the preset red envelope rain setting information and are displayed in the target interfaces where the receivers are located, so that the receivers obtain the red envelopes in the red envelope rain displayed in the interfaces in the preset time; and, the duration ofthe red envelope rain is controllable, so that the interactivity between the issuer and the receivers is strong, the red envelope issuing enthusiasm of the issuer is greatly improved, and the user experience and the entertainment are enhanced.

The invention discloses a prefabricated assembly type water tank and an assembly method, and belongs to the field of liquid storage tanks. The prefabricated assembled type water tank comprises a watertank bottom plate and prefabricated components arranged on the water tank bottom plate, wherein the prefabricated components comprise the plurality of groups of L-shaped components arranged on the water tank bottom plate and the vertical plate-type components arranged between the transversely adjacent L-shaped components; and connecting bolts are arranged between the L-shaped components and the vertical plate-type components. The prefabricated assembled type water tank absorbs the advantages of the assembly type construction technology to form a modular, standard and large-scale production technology and a standard assembling technology, under the condition of meeting a certain degree of strength, durability and stability, the construction period is shortened to the maximum extent, the construction efficiency is improved, the ecological environment is protected, and the noise pollution of a construction site is reduced; and meanwhile, the construction efficiency of the pre-drilling engineering is improved, and the problem that the construction period of the pre-drilling engineering is short for a long time is solved.

The invention relates to the technical field of manufacturing of refrigeration equipment and particularly relates to a multi-functional modular combined cold box. The multi-functional modular combinedcold box provided by the invention comprises a box body module, tail end modules and a cold source module; the box body module is connected with at least one tail end module; each tail end module isconnected with the cold source module; the box body module is used for providing a low-temperature storage space or a low-temperature operation space; each tail end module comprises a plurality of secondary functional modules and is used for providing heat exchange conditions for a low-temperature environment; the cold source module is used for providing cold source supply for each tail end module; and a control module is used for harmonizing the secondary functional modules of all tail end modules so as to provide one or a plurality of functions including temperature regulation, humidity regulation and air regulation. The cold box formed by adopting the three modules realizes standard production, is low in manufacturing cost and short in installation period, can guarantee the quality, andis also beneficial for realizing flexible switching between different functions such as quick freezing, quick precooling, cooling, cold storage of cooled materials, cold storage of frozen materials,air-regulated cold storage and low-temperature production environment.

The invention discloses a steel cantilever combined bridge deck slab widening and reconstruction structure and a construction method thereof and aims at solving the problem existing in widening of a traditional box beam. The steel cantilever combined bridge deck slab widening and reconstruction structure comprises an original box beam and widening parts symmetrically arranged on two sides of the original box beam and is characterized in that each widening part comprises a steel cantilever, a steel bottom die, a steel guardrail and cast concrete, wherein the steel cantilever is a welding steel member of a triangular open web type structure, the steel cantilever is connected with the original box beam through an anchor bolt, and the steel bottom die is fixed to the steel cantilever, is provided with the cast concrete and form effective PBL key connection. The original box beam structure is fully utilized, and second phase dead load increase of the structure is small (only about 10% of an original structure), so that the lower portion and a foundation of an original bridge can be directly utilized, and the reconstruction project amount is remarkably decreased.

The invention relates to a construction method for a fabricated enclosing wall. The construction method comprises the following steps that S1, materials are conveyed, specifically, prefabricated columns and prefabricated wallboards are conveyed to a construction site; S2, an enclosing wall foundation is manufactured, specifically, steel bar formworks are mounted and concrete is poured on the construction site, and thus the enclosing wall foundation is completed; S3, the prefabricated columns are mounted, specifically, before mounting, column position cross lines are snapped according to the size of a drawing, preformed holes are treated, the bottoms of the preformed holes are leveled through fine aggregate concrete according to the set mounting height, the prefabricated columns are mounted, and the positions of the prefabricated columns are adjusted; S4, the prefabricated wallboards are mounted, specifically, before mounting, the surface of the enclosing wall foundation is leveled, and the prefabricated wallboards are hoisted and fixed; S5, enclosing wall copings are mounted, specifically, the prefabricated wallboard coping and the prefabricated column coping are mounted respectively; and S6, seams are treated, specifically, seams between the prefabricated wallboards and corresponding prefabricated column grooves are filled. Compared with the prior art, the construction method for the fabricated enclosing wall has the advantages that material waste is avoided, manpower is saved, the time is saved, the cost is controllable.

The invention relates to a novel construction method for closing traffic in a short time. The novel construction method comprises the following steps that the normal road traffic is closed, the closed road serves as a temporary construction site, and enclosure structures, water sealing systems and bracket stand column piles are constructed in the temporary construction site; the soil is excavated to the bottom elevation of a structural top board on the ground of the temporary construction site, rainfall systems are reserved, a formwork is laid, the structural top board is finished, and a pouring structure is reserved; according to the roadbed requirement, the soil is refilled on the structural top board, and normal traffic is recovered through compaction layer by layer. Monitoring points are arranged outside a pit, the rainfall systems are started for rainfall, an excavator enters the underground to excavate soil from passage inlets and outlets in the two sides of the road, and informatization construction is made according to monitored data. The construction of a structural bottom board, structural side walls and structural pillar main body structures is finished. The novel construction method can ensure the completion of self engineering, achieves improvement of the road surface traffic, and can carry out comprehensive improvement by combination with the program conditions of a municipal pipeline.

The invention provides a bathroom fabricated chassis which comprises a waterproof integral bottom plate, a skeleton, a surface floor and a plurality of pipelines. The waterproof integral bottom plateis a flat plate, and the flat plate is provided with pipeline mounting grooves. The skeleton is installed on the waterproof integral bottom plate, the surface floor is fixed on the skeleton by adjusting bolts, and the surface floor is provided with three ports for installing a toilet, a hand washing sink and a floor drain separately. The multiple pipelines are installed in the pipeline mounting grooves, one ends of the pipelines are connected to water outlets of the toilet, the hand washing sink and the floor drain, and the other ends of the pipelines are connected to a drainage stand pipe ofa bathroom. The chassis is a fabricated integral chassis, the pipelines used can be separated from a structural floor or the wall, and therefore the problems of the drainage of the same layer, smell of the floor drain of the bathroom and leakage can be solved. In addition, partial components of the bathroom fabricated chassis are produced in a standardized mode, on-site assembly is carried out, and the construction is convenient; and after installation, the fabricated chassis does not occupy space and is waterproof and reliable.

The invention provides a construction method for entering a hole in a vertical shaft directly above a main line of a subway section, and belongs to the field of urban rail transit construction. The construction method for entering the hole in the vertical shaft directly above the main line of the subway section comprises the following procedures of construction of a vertical shaft locking wellheadring beam, installation of hoisting equipment, excavation of earthwork and stonework, borehole wall supporting, horsehead door treatment, temporary pilot tunnel construction, middle pilot tunnel construction and left line excavation-expansion section construction. The construction method is used for effectively restraining the impact of vertical shaft excavation on the surrounding residents, shops and unit environment and ensuring construction safety and construction period.

The invention relates to systems used for enabling LNG pipelines to cross over a dam and construction methods of the systems, wherein one of the systems used for enabling LNG pipelines to cross over the dam and suitable for a soil, stone-built or concrete dam comprises a box culvert, slopes, LNG pipelines, an electric tracer heating system, a cushion layer and a waterproof layer, wherein the box culvert is stacked at the top of the dam; the slopes are arranged at two sides of the box culvert; the LNG pipelines cross over the box culvert and pass through the dam; the electric tracer heating system is arranged between the top of the dam and a bottom plate of the box culvert; the cushion layer is arranged between the electric tracer heating system and the bottom plate of the box culvert; and the waterproof layer is arranged at the outer side of the box culvert. The other system used for enabling LNG pipelines to cross over the dam and suitable for a soil dam comprises a box culvert, LNG pipelines, an electric tracer heating system, a cushion layer and a waterproof layer, wherein the box culvert is arranged in the dam and passes through the dam; the LNG pipelines cross over the box culvert and pass through the dam; the electric tracer heating system is arranged between a soil body inside the dam and a bottom plate of the box culvert; the cushion layer is arranged between the electric tracer heating system and the bottom plate of the box culvert; and the waterproof layer is arranged at the outer side of the box culvert. The invention also provides another system used for enabling LNG pipelines to cross over the dam and suitable for a soil dam, wherein the system comprises the LNG pipelines directly cross over the inside of the dam and waterproof cushions for wrapping the outer parts of the LNG pipelines.

The invention provides a mouse control method and application thereof, and the method comprises the steps: building a selection table P of an initial DPI value of a mouse, recognizing the type of a real-time program D0, responding to the mouse in real time, on a host, selecting a DPI value matched with the type of the program from the selection table P, and setting the DPI value as the initial DPI value of the mouse. According to the method, the mouse DPI values can be primarily selected according to the program types, the selection efficiency is high, the calculation amount can be remarkably reduced, and the primarily selected mouse DPI values which are relatively adaptive can be provided for different types of programs. After primary selection, the mouse DPI value is adjusted for the first time and more than one time of subsequent adjustment to complete adjustment of the mouse DPI value, so that the mouse DPI value can be further matched with a corresponding program type, and compared with the method of selecting the DPI value by adopting an optimal iteration algorithm and the like in the prior art, the calculation amount can be remarkably reduced, the workload of a host is reduced, and crash of the host or occupation of a large number of computing resources is avoided, and the adjustment duration is short.

The invention provides a high-temperature steam curing construction method for a prefabricated bridge deck of a UHPC steel-concrete composite beam without coarse aggregate. The method comprises the following steps that 10, steel bars are blanked and machined, specifically, the steel bars are machined and distributed in a centralized mode in a factory; 20, a mold is installed, specifically, a formwork of the bridge deck is installed, and the formwork comprises a bottom mold, a transverse side mold and a longitudinal side mold; 30, the steel bars and embedded parts are installed, specifically, an upper layer of steel bar net and a lower layer of steel bar net which are arranged in a spaced mode are installed on the formwork through the steel bars, and the embedded parts are installed on the formwork; and 40, concrete is mixed, specifically, a premix package with the concrete prefabricated and an additive and steel fiber formula package are included, and the premix package and the formula package are put into a stirrer till the concrete is mixed and discharged out of a station. According to the high-temperature steam curing construction method for the prefabricated bridge deck of the UHPC steel-concrete composite beam without the coarse aggregate, the self-weight load of the structure can be reduced, the design is lighter and more economical, and the common problem of cracking of the bridge deck and the like can be well solved.

The invention belongs to the technical field of water conservancy construction, and relates to a construction method for reconstructing a cofferdam anti-seepage system in an immersed tube tunnel. The construction method comprises the steps that remaining sand-filled long pipe bags and a river bed after an original primary cofferdam is destroyed by rush of river are adopted as a base, and stones are thrown at two sides of the base to form an inner side riprap cofferdam body and an outer side riprap cofferdam body; the space between the inner side riprap cofferdam body and the outer outside riprap cofferdam body is filled with clay to form a first-level clay cofferdam body, the inner side riprap cofferdam body, the outer side riprap cofferdam body and the first-level clay cofferdam body form an earth-rock cofferdam, and after the construction of the earth-rock cofferdam, a second-level clay cofferdam body is constructed above the earth-rock cofferdam through filling; and plastic concrete drilling occlusion piles are constructed in the middle part of the first-level clay cofferdam body as the anti-seepage system of the earth-rock cofferdam. According to the construction method, the cofferdam can be quickly reconstructed on the basis of the remaining sand-filled long pipe bags and the river bed remaining after the original primary cofferdam is destroyed by rush of river, the stable earth-rock cofferdam and the anti-seepage system thereof are formed, and remaining civil engineering in the cofferdam is guaranteed to reach the construction condition of no-water operation.

The invention discloses a construction device for existing pile foundation pile connection in soil. The position of an existing pile foundation and the standard height of a pile top and the height ofa pile top super-filled concrete are determined;the soil is excavated by manual hole digging, and a bricking protection wall is set up; a super-filled part of the existing pile foundation is excavated,the super-filled part is subjected to laitance breaking, a fresh and compact concrete is broken, and it is ensured that the exposure length of a main rib of the existing pile foundation meets the requirements; the end of a manual hole diggingpile adopts an enlarged head form; a steel reinforcing cage of a pile adding part is laid down and welded with the main rib of the existing pile foundation;the concrete of the pile adding part is poured and fully vibrated and compacted. The device solves the construction problem of the existing pile foundation pile connection underground. Compared with atraditional treatment method, the device can reduce the large area of earth excavation, earthwork backfilling and concrete pouring,greatly form the protection for the foundation soil, be safe and reliable, and reduce construction costs.

The invention discloses a construction device for pile splicing of an existing pile foundation in soil. The position of the existing pile foundation and the pile top elevation are determined, and thepile top exceeds the concrete placing height; a manual hole digging manner is adopted to carry out soil excavating, and a brick shaft lining is arranged; excavating to the placing exceeding portion ofthe existing pile foundation is achieved, laitance breaking of the placing exceeding portion is achieved, breaking is carried out until the fresh dense concrete is achieved, and it is ensured that the main rib length exposing of the existing pie foundation meets the requirement; the bit expansion type is adopted in the manual hole digging pile end; a pile supplementing portion steel reinforcementcage is put down, and is welded with the existing pile foundation main ribs; the pile supplementing portion concrete is poured and is sufficiently subject to compaction vibration. The device solves the construction problem of pile splicing of the existing pile foundation below the ground, compared with the traditional treatment method, the large-area soil excavating, earthwork backfilling and concrete pouring amount can be reduced, the protection for the foundation soil can be greatly formed, safety and reliability are achieved, and the construction cost is reduced.

The invention discloses a BIM technology-based power transformation and distribution station deepening design process and process. The process comprises the following steps: s1, delivering a seal version construction drawing to an electromechanical engineering general contracting unit for signing and filing; s2, determining local power supply bureau requirements and consultation confirmation; s3, determining the model of electromechanical equipment and civil engineering conditions; s4, establishing a power transformation and distribution station model and carrying out deepened design; s5, verifying the power transformation and distribution station deepened design model and performing engineering quantity statistics; s6, performing power transformation and distribution station engineering construction acceptance. According to the invention, the whole process of the power transformation and distribution station machine room is controlled from the management perspective of an engineering construction unit and a construction general contract unit, and the whole process of the power transformation and distribution station machine room is managed; According to the method, new technologies and new methods are utilized, and new management and control measures are mainly taken for deepening a design process, an information feedback process, main nodes, key areas, a deepening scheme, cost control, quality supervision and the like; so that wrong construction modes such as noise, miscellaneous, mess, pollution, waste and reworking in conventional power transformation and distribution station construction are solved.

The invention provides a double-curvature saddle-shaped plate compression molding tooling applied to the technical field of double-curvature saddle-shaped plates for ships. The double-curvature saddle-shaped plate compression molding tooling comprises an upper die (1) and a lower die (2); the upper die (1) comprises an upper die base plate (3), a plurality of upper die transverse partition plates (4) and a plurality of upper die longitudinal partition plates (5); and the lower die (2) comprises a lower die base plate (10), a plurality of lower die transverse partition plates (11) and a plurality of lower die longitudinal partition plates (12). The double-curvature saddle-shaped plate pressing forming tooling provided by the invention is simple in structure, pressing forming of the double-curvature saddle-shaped plate can be conveniently and rapidly achieved, the quality of pressed finished products is effectively guaranteed, the tooling manufacturing time is shortened, the expenditure is reduced, the machining difficulty is reduced, labor intensity is reduced, energy consumption is saved, and construction period is controlled.

The invention relates to a cable tunnel structure of a power transmission line, in particular to a bolt splicing axis bendable all-prefabricated splicing open excavated cable tunnel. The cable tunnelis structurally characterized in that the cable tunnel is formed by splicing a plurality of cable prefabricated tunnel sections and comprises the standard tunnel section and the bending tunnel sections; each cable prefabricated tunnel section comprises a concentric-square-shaped tunnel body, a grounding system and a support system; each support system comprises a groove type component and suspension arm transverse supports; the groove type components are embedded and distributed in the sidewalls of the concentric-square-shaped tunnel bodies; the suspension arm transverse supports are fixedly connected with the corresponding groove type components through bolts; each grounding system comprises an outer grounding steel ring, an inner grounding ring and connecting parts connecting the outer grounding steel ring with the inner grounding ring; the inner grounding rings are connected with the groove type components embedded in the support systems; each concentric-square-shaped tunnel body comprises a cable erection space composed of the suspension arm transverse supports and a walking maintenance channel; every two adjacent cable prefabricated tunnel sections are connected through double-end bending bolts. The cable tunnel structure has the advantages that the workload of field construction is greatly reduced; the construction quality is improved; the cable tunnel structure is convenient and fast to use and is hardly affected by weather; the construction period is controlled easily; the operation cycle is short.

The invention discloses a home decoration design construction system based on BIM, and relates to the technical field of buildings, and the technical scheme is that the home decoration design construction system comprises a main control module, and a design module, a supplier library module and a manual module which are connected with the main control module and form an information path; the design module is an online 3D design module, and the BIM building module is used as the presentation form of the home decoration design model. The beneficial effects of the invention are that: according tothe scheme, the design and construction problems of customers in the home decoration process can be practically solved; the material price can be reduced through centralized supply of suppliers, seamless link from real estate project development to home decoration can be achieved through the design associated with the BIM model, a personal-to-personal order sending mode can be achieved through amanual order placing management system, and the intermediate link control cost is reduced. Uncontrollable intermediate links can be reduced through a full-flow control mode according to the flow, theconstruction period is controllable on the whole, the construction cost is controllable, and the quality is controllable.

The invention discloses an easy-to-replace LNG (liquefied natural gas) storage tank shock isolation cushion and a replacement method thereof. The shock isolation cushion comprises a shock isolation cushion body, a shock isolation cushion upper padding plate and a shock isolation cushion lower padding plate; the shock isolation cushion upper padding plate is arranged on the upper portion of the shock isolation cushion body, and the shock isolation cushion lower padding plate is arranged on the lower portion of the shock isolation cushion body; the shock isolation cushion upper padding plate is connected with an upper flange through upper fastening bolts, and the shock isolation cushion lower padding plate is connected with a lower flange through lower fastening bolts; the upper fastening bolts or the lower fastening bolts are bolts capable of being unscrewed; upper flange bolts are arranged on the upper plate and used for being connected with an LNG storage tank bearing platform; lower flange bolts are arranged on the lower flange and used for being connected with an LNG storage tank pile foundation. When the LNG storage tank shock isolation cushion is replaced, the padding plates need not to be jacked by a jack, cracks are avoided, and disturbance of the structure is guaranteed to the utmost degree.

The invention provides a high-pressure rapid inflation and deflation system. The high-pressure rapid inflation and deflation system comprises a tank body, the two ends of the tank body are provided with an inflation head and a deflation head respectively and sealed through O-shaped sealing rings, and the inflation head, the tank body and the deflation head are all made of high-strength steel. According to the high-pressure rapid inflation and deflation system, the functional requirements for storing inert gases such as nitrogen, carbon dioxide and argon and rapidly inflating and deflating are met, and the blank of a non-welding forming high-pressure gas cylinder structure design method is filled up; the tank body, the deflation head and the inflation head are made of high-strength steel materials and form a closed container together with a manual stop valve and an ejector rod, so that the light weight of the high-pressure rapid inflation and deflation system is realized on the premise of ensuring the safety; and the tank body is connected with the deflation head and the inflation head in a fastening mode through threads and then fastened through an upper fixing plate, a lower fixing plate and a threaded rod, and the performance requirements for air tightness, safety, reliability and accuracy are met in a spherical sealing and sealing ring sealing mode.

The invention discloses a wall net combination structure with prevention and early warning functions of karst collapse. The wall net combination structure comprises a plurality of box-like structuralretaining walls (1), synthetic material nets (2) and early warning units (3), wherein fillers connected with the box-like structural retaining walls on the two sides is arranged between every two oppositely arranged box-like structural retaining walls (1); the two ends of each synthetic material net (2) are arranged in the space between every two oppositely arranged box-like structural retaining walls (1) and buried in the corresponding fillers; the synthetic material nets (2), the fillers and the box-like structural retaining walls (1) together form a stress structure; and each early warningunit (3) comprises a wire net arranged at the top of the corresponding synthetic material net (2) and used for synchronizing the corresponding synthetic material net (2) and a warning structure. The invention further discloses a construction method of the wall net combination structure with prevention and early warning functions of karst collapse. The construction cost is reduced, and meanwhile the roles of prevention and early warning of karst collapse are played.

The invention discloses tubular pile joint annular welding equipment capable of automatically identifying and compensating welding seams, which comprises a steel belt guide rail, the steel belt guide rail is connected into an annular structure through a quick clamping lock, a plurality of groups of clamping components are mounted on the steel belt guide rail, and the clamping components are used for clamping and connecting the steel belt guide rail to a tubular pile joint; a driving assembly is installed on the steel belt guide rail and annularly moves along the steel belt guide rail, and a welding assembly used for welding a pipe pile connector is installed at the lower end of the driving assembly. By means of the method, pipe pile welding work can be completed quickly and efficiently, the welding time is shortened by 50%, it is ensured that the whole construction period is controllable, wrap angle welding and multi-layer and multi-pass welding can be achieved through welding program control, and it is ensured that the welding process is controllable and the welding seam quality is good and stable.

The invention discloses a voltage-dip generator used for wind power generation. The voltage-dip generator comprises a host computer, a data collecting card, an IGBT driving and protecting circuit, two IGBT bilateral switches, a booster, a voltage Hall sensor, a current Hall sensor and a wind turbine generator. Three-phase voltage signals and three-phase current signals output by the voltage-dip generator are obtained by the voltage Hall sensor and the current Hall sensor; the three-phase voltage signals and the three-phase current signals output by the voltage-dip generator are acquired by the data collecting card and transmitted to the host computer; the host computer outputs voltage-dip signals and restores instruction signals to the IGBT driving and protecting circuit through the data collecting card, and leads the two IGBT bilateral switches to conduct alternately; and the voltage output by the voltage-dip generator is switched over between a primary side and a secondary side of the booster, thereby simulating various symmetrical and unsymmetrical network voltage dip faults. The voltage-dip generator has the characteristics of simple operation, high reliability, good real-timeperformance, etc., and is suitable for performance test and research of the wind turbine generator when in network voltage faults.

The invention relates to systems used for enabling LNG pipelines to cross over a dam and construction methods of the systems, wherein one of the systems used for enabling LNG pipelines to cross over the dam and suitable for a soil, stone-built or concrete dam comprises a box culvert, slopes, LNG pipelines, an electric tracer heating system, a cushion layer and a waterproof layer, wherein the box culvert is stacked at the top of the dam; the slopes are arranged at two sides of the box culvert; the LNG pipelines cross over the box culvert and pass through the dam; the electric tracer heating system is arranged between the top of the dam and a bottom plate of the box culvert; the cushion layer is arranged between the electric tracer heating system and the bottom plate of the box culvert; and the waterproof layer is arranged at the outer side of the box culvert. The other system used for enabling LNG pipelines to cross over the dam and suitable for a soil dam comprises a box culvert, LNG pipelines, an electric tracer heating system, a cushion layer and a waterproof layer, wherein the box culvert is arranged in the dam and passes through the dam; the LNG pipelines cross over the box culvert and pass through the dam; the electric tracer heating system is arranged between a soil body inside the dam and a bottom plate of the box culvert; the cushion layer is arranged between the electric tracer heating system and the bottom plate of the box culvert; and the waterproof layer is arranged at the outer side of the box culvert. The invention also provides another system used for enabling LNG pipelines to cross over the dam and suitable for a soil dam, wherein the system comprises the LNG pipelines directly cross over the inside of the dam and waterproof cushions for wrapping the outer parts of the LNG pipelines.

The invention relates to the field of water-rich deep sand layer waterproof curtain type ultra-deep foundation pit leakage pressure precipitation construction, in particular to a stepped rapid precipitation method which is a new precipitation concept and is successfully implemented in Shenyang north station of Shenyang subway line IV. According to the method, special medium-coarse sand high-water-permeability geological waterproof curtain type foundation pit leakage pressure dewatering construction serves as the background, and the defects that conventional dewatering is large in power consumption and slow in dewatering are overcome. Firstly, the funnel surface forming time of the conventional single-row layout dewatering well is long; secondly, according to traditional precipitation, precipitation wells need to be opened at the same time through the group well effect, and power consumption is large; thirdly, precipitation construction in the construction process of foundation pit operation becomes a constraint factor of the foundation pit operation to a great extent; fourthly, the water level of the dewatering well automatically controls a water pump start-stop system, the water level outside the foundation pit is automatically controlled, and accurate dewatering is achieved. The method solves the problems that after the precipitation well is constructed, the speed is high, energy consumption is low, and the construction progress is limited by the water level effectively.

The invention belongs to the technical field of water conservancy construction, and relates to a construction method for reconstructing a cofferdam anti-seepage system in an immersed tube tunnel. The construction method comprises the steps that remaining sand-filled long pipe bags and a river bed after an original primary cofferdam is destroyed by rush of river are adopted as a base, and stones are thrown at two sides of the base to form an inner side riprap cofferdam body and an outer side riprap cofferdam body; the space between the inner side riprap cofferdam body and the outer outside riprap cofferdam body is filled with clay to form a first-level clay cofferdam body, the inner side riprap cofferdam body, the outer side riprap cofferdam body and the first-level clay cofferdam body form an earth-rock cofferdam, and after the construction of the earth-rock cofferdam, a second-level clay cofferdam body is constructed above the earth-rock cofferdam through filling; and plastic concrete drilling occlusion piles are constructed in the middle part of the first-level clay cofferdam body as the anti-seepage system of the earth-rock cofferdam. According to the construction method, the cofferdam can be quickly reconstructed on the basis of the remaining sand-filled long pipe bags and the river bed remaining after the original primary cofferdam is destroyed by rush of river, the stable earth-rock cofferdam and the anti-seepage system thereof are formed, and remaining civil engineering in the cofferdam is guaranteed to reach the construction condition of no-water operation.