425 results about "River section" patented technology

The invention discloses a pollution source diffusion early-warning method based on a water quality on-line monitoring system. The method comprises the following steps of S01, monitoring water quality current situation of each monitoring station in an area in real time through the water quality on-line monitoring system; S02, confirming a pollution source being warned; S03, acquiring real-time monitoring data of excessive pollutants at the monitoring station where the pollution source is located; S04, selecting a river where the station is located to simulate a terminal; S05, inputting relevant parameters of a river section to be simulated; S06, calculating a one-dimensional steady-state water quality model; S07, rendering a pollutant concentration gradient for the simulated river section and carrying out early-warning information judgment. The one-dimensional steady-state model applied by the invention is independent of specific riverway geographic information and terrain parameters, only relates to hydrologic condition flux and flow velocity of riverways, can be automatically modeled according to GIS (Geographic Information System) information, and is strong in universality.

The invention relates to a method for constructing a deep pool and a shoal in a straight river channel. In the method, a spur dike is arranged on the left bank side of the straight river channel, a bank slope on the opposite bank of the spur dike is protected by riprap, a diving guide wall is arranged on the left and right banks of the downstream side of the spur dike respectively, the discharge cross section of the river channel is shortened by the spur dike to increase the flow rate of water flow, the bottom of a river bed of a river reach between the diving guide walls on the downstream side of the spur dike is continuously scoured to naturally form the deep pool, and a dead water area or slow flow water area formed between the diving guide wall and the river bank becomes the shoal through long-term deposition. The method has the advantages that: the deep pool is naturally formed and becomes a rest place for aquatic organisms such as fishes and the like, and can become a shelter for the aquatic organisms such as the fishes and the like in a flood period; plants can be planted on the shoal, and the shoal can become an organism habitat different from the deep pool; and the complexity of a river channel structure and water conservation condition diversity can be increased or repaired, and river biodiversity, population composition and rare species conservation are facilitated.

The invention discloses a construction method of a flat shoal flow prediction model based on joint control of upstream-downstream borders over a lower reach. The construction method specifically comprises the steps of adopting a one-dimensional hydrodynamic model to calculate and study a water level-flow relation curve of each fixed section in the reach; determining flat shoal flow in each section according to flat shoal elevation in each fixed section; adopting a method based on the combination of geometric average of logarithmic transformation and weighted average of section spacing to calculate the flat shoal flow of reach dimension; analyzing a response relationship of the flat shoal flow adjustment on an upstream water-sediment condition and downstream water level change, and constructing the prediction model based on joint control of the upstream-downstream borders over the lower reach. According to the construction method of the flat shoal flow prediction model based on joint control of the upstream-downstream borders over the lower reach, the calculated and obtained flat shoal flow of reach dimension is capable of better describing the flow passing capacity of the whole reach, and thus the flat shoal flow is more representative; the constructed flat shoal flow prediction model is capable of well reflecting the variation trend of the flat shoal flow along with the upstream water-sediment condition when the downstream water level changes sharply, and thus the constructed flat shoal flow prediction model has a guidance significance in the flood prevention and riverway management.

The invention relates to a flood combined probability analysis method and an application thereof based on Copula. The flood analysis method is aimed at providing a flood control construction basis for tidal river reach, and mirroring functions of affecting overflowing of flood facilities and characteristic quantity of regulation and storage capacity through creation of a joint probability distribution function about sea level, rainfall peak and subrainfall so that reliable basis is provided for anti-flood construction.

The invention discloses a river critical levee section washing safety analysis and bank slope stability judgment method. The method comprises the steps of 1, generating a data set used for constructing a two-dimensional river channel water / sand model; 2, setting model calculation parameters and definite solution conditions according to river reach parameters in the research area, and constructing a two-dimensional water / sand numerical simulation model of the research area; step 3, setting various working conditions according to sand coming conditions under different flood conditions, simulating river water / sand transportation and river bed silt flushing of a research area by utilizing a two-dimensional water / sand numerical model, analyzing dangerous river beds before and after flood based on a simulation result, and respectively calculating river dangerous bank slope river bed depth flushing distance and river lateral erosion distance; and step 4, constructing a finite element model for seepage-stability analysis of the bank slope of the critical levee section, and quantitatively researching the relationship between each factor and the bank slope stability safety coefficient. According to the method, the stability of the riverway dangerous work bank slope under the action of water flow flushing is studied, and a quantitative means is provided for critical levee section stability evaluation.

The invention provides a coupling analysis method for a one-dimensional mathematical model and two-dimensional mathematical model of river way outburst flood. After corresponding data is collected, adyke breach outflux inundated area and a river way section obviously influenced by dyke breach outflux are first dispersed by using a quadrilateral or triangular unstructured grid, and other river sections adopt one-dimensional cross-section data generalization. The one-dimensional model is solved by adopting a classical Presimann implicit format, the two-dimensional model is solved by adopting aGodunov format with a shock capturing ability. In order to avoid numerical oscillation, mass conservation and momentum conservation of the connection portion between the one-dimensional mathematical model and the two-dimensional mathematical model are ensured; according to the coupling analysis method for the one-dimensional mathematical model and two-dimensional mathematical model of river way outburst flood, provided connection portion is a transition region, one-dimensional model calculation and two-dimensional model calculation are both conducted in the transition region. After the dyke breach is started, the dyke breach outflux inundated area and a river way two-dimensional computing area automatically become an integrated two-dimensional computing area, and the calculation of dyke breach outflux process is completed by the two-dimensional model. The processing method can fully consider the hydrodynamic response process inside and outside the river way on the dyke breach, the numerical simulation precision of the dyke breach outflux process is improved, and the shortcoming in a traditional method is overcome that only a weir formula is adopted to calculate the dyke breach outflux process, so that the momentum exchange inside and outside the river way can not be considered.

The invention relates to a method for monitoring river runoff through a remote-sensing hydrologic station. The method comprises the steps of 1, selecting key fluvial sections lacking measuring stationareas; 2, conducting low-altitude remote sensing retrieval on the information of the fluvial sections lacking the measuring station areas; conducting real-time drone control flight on monitoring points of the fluvial sections selected in step 1, preprocessing the obtained data, extracting earth surface information, obtaining the longitudinal section gradient, the cross section area and the watersurface width of the fluvial sections on this basis, combining ground water level monitoring and underwater topographic surveying and mapping, and utilizing a manning formula for deduction to solve the flow of the monitored section. The method has the advantages that satellite remote sensing and low-altitude remote sensing are coupled, each other's advantages are complemented, and the blank of thelack of hydrologic data is filled up; during emergency management, the real-time river channel segment width is obtained, the river runoff is calculated, the river runoff data is reported in real time, and the runoff monitoring precision is smaller than 8%; the problem that hydrometric stations of an arid region are scarce, and cannot handle flood, water pollution and other emergency events is solved.

The invention discloses a drawing and coding method for large-scale complex river network massive fine regular grids of a river basin. The method comprises the steps of S1, identifying structure layers and boundary range layers of a river basin water system body; S2, obtaining river reaches of rivers of a river basin water system segment by segment; S3, drawing two-dimensional regular grids of the rivers and coding the grids in the rivers; S4, carrying out two-dimensional compilation on the two-dimensional regular grids, thereby obtaining an integrated grid; S5, carrying out one-dimensional compilation on the integrated regular grid; and S6, establishing one-dimensional grid relationships. According to the method, on the basis of an existing massive regular grid method and tool, the large-scale massive grids are increased, reduced and coarsened simply and effectively, the grids are drawn once and can be used for life, and the data support is provided for calculation of values based on the regular grids.

The invention discloses a non-contact flow measurement method for measuring a high flood based on the flow velocity of representative vertical line points. The method includes the following steps of (1) determining the positions of one or more vertical lines according to river section data, and using a radar flow velocity meter to measure the flow velocity of a river surface point below a measured vertical line; (2) calculating the flow velocities V1-Vp (the surface point flow velocity of P vertical lines) of the surface points of multiple vertical lines according to the surface point flow velocity of the measured vertical line; (3) conducting arithmetic average on the section surface point flow velocity of the multiple vertical lines, and obtaining the average flow velocity Vsur of the river surface; according to the empirical formula of hydraulics, making the average flow velocity of the river surface multiplied by the surface velocity coefficient lambda to obtain the average flow velocity Vave of the section; (4) according to the river section data, obtaining the river water passing section area corresponding to the set water depth, and making the area multiplied by the average flow velocity of the section to obtain a river flow value. The method can calculate the flow of artificial and natural rivers quickly, conveniently and accurately, and is especially suitable for unattended heavy rain, high flood and other complex disastrous environments.

The invention discloses a rasterization-based method of determining a river surface source pollution load in a plain river network area. According to the method, based on a rasterization technology and a GIS spatial overlay analysis function, a confluence weight factor is calculated with a ratio of a river section area to a shortest distance between a grid and a surrounding rive as a weight, and aconfluent area range of each river and utilization area of corresponding type of land are determined. The method comprises specific steps of drawing a river network polygon, calculating area rasterization and performing spatial operation, calculating the confluence weight factor, determining a flow direction of the surface source pollution, dividing a confluent area of the surface source pollution, calculating use areas of different types of land, calculating a pollution load per unit area, and calculating the river surface source pollution load. The method determines the surface source pollution confluent area reflecting characteristics of water systems of the plain river network area, making it easier to determine a boundary of a confluent area of the area and being easy to promote anduse in calculation of pollution load of areas with the same water system characteristics.

The invention discloses a comprehensive fish concentrated transportation platform and a method for preventing a hydropower station from stopping fish from sailing upstream. The method comprises the following steps: according to the phenomena that tail water drainage of the hydropower station has attraction to the sailing-upstream fish in the river sections under a dam, and the tail water with higher flow rate forms a barrier to prevent fish from sailing upstream, a fish attracting passage is newly built at the downstream area of the forefront position, that the fish sails upstream to reach, ofthe downstream of the tail water; related fish attracting measures, observation apparatuses and lifting transferring facilities are additionally arranged in the passage to realize the purposes of attracting, observing and transferring fish under the dam; and then, the fish is transferred to a river sections of a reservoir area on the dam for release through an automobile, so that the obstructingaction to the sailing upstream of the fish under the dam from the dam is slowed down.

A construction method for a river beach pool ecological purification system relates to a river ecological repairing technology. The technical scheme is that a crooked river channel is adopted as a construction area, one section in the construction area is a river section with the river bend central angle as 90-160 degrees and is provided with more than two bent portions, and the linear length of the construction area is 5-7 times as large as the average width of a main river channel at the river section. The method is characterized in that bend tops of the turning positions at the upper end and the lower end of the river channel in the construction area are dug for 50cm-2m downwards to build a deep pool, earthwork obtained through digging of the deep pool is used for constructing a shallow beach at the center of the river channel of a straight section between the two bent portions of the river channel in the construction area and on the side close to a convex bank at the turning positions of the river channel in the construction area, the shallow beach is 10cm-50cm higher than the original river bottom to form a river island or a river bank beach, large rocks with the specification of 30-80cm are piled on the upstream face of the constructed shallow beach, and a fish channel with the recessed depth as 20-50cm is constructed at the center of the river channel at the downstream of the constructed river island. The method is used for pollution regulation and ecological repairing of rivers.

The invention discloses a river section water quality monitoring system. The river section water quality monitoring system comprises a bank control base station and a monitoring box, wherein a sampling device, a water quality monitoring device and an underwater control device are arranged in the monitoring box; the sampling device is connected with the water quality monitoring device which is connected with the underwater control device, a balance stabilizing device is arranged at the upper part of the monitoring box, and a lifting control device is arranged at the lower part of the monitoring box. A river section water quality monitoring method comprises steps of (1) building the bank control base station; (2) mounting cables; (3) controlling the monitoring box to reach a river section monitoring point; (4) monitoring the river section water quality. The river section water quality monitoring system is simple in structure, high in pertinence, high in automation degree and convenient to operate; with adoption of the method, the water quality condition of the river section can be monitored in real time, the accuracy is high, information is pushed actively and remotely, remote control is realized, the water quality condition is known by a worker conveniently at any time, and the labor intensity is reduced, so that the working efficiency is increased and the economic cost is reduced.

The invention discloses an alluvial river bank collapse early warning method. Aiming at collapse of a binary structure bank of an alluvial river under long-term action of water flow, the position of bank collapse can be forecasted early; meanwhile, rolling forecast can be continuously performed by utilizing the characteristics that river section data is relatively easily acquired and more forecasting times are present, and the forecast accuracy is improved. The method comprises the following steps of: determining a river bank stability index, forecasting river bed deposition and erosion change and performing early warning and judgment on the bank collapse. By using the bank slope stability index determining and judging standard, comparing with a forecast slope and combining with a gradingjudgment index system, the position of a dangerous bank section can be early warned, and technical support is provided for dike maintenance and management.

The invention relates to the technical field of hydroelectric engineering ecological dispatching, and discloses a cascade power station ecological dispatching system suitable for producing drifting egg fishes, which is used for providing appropriate hydrological process conditions for drifting egg fish breeding and reducing the influence of cascade reservoir operation on the drifting egg fish breeding process. The method is based on the water level of a fish spawn spawning site and a fish spawn drifting river section; change in indicators such as flow, the upstream step is matched with the downstream step to adjust the water level of the fish spawning site and the fish egg drifting river section. Through the cooperative use of engineering measures and non-engineering measures, appropriatehydrodynamic process conditions are provided for the breeding of the fishes laying the drifting eggs, and the influence of the operation of the cascade reservoir on the breeding process of the fisheslaying the drifting eggs is reduced. The method is suitable for the ecological dispatching of the cascade power station nearby living fishes with drifting eggs.

The invention provides a river ecological flow determining method with the benthos diversity as a target. By means of the method, the research methods of ecological water requirements are enriched, and meanwhile, the ecological flow determining method with benthos as indicator organisms is provided. The method comprises the steps that river segment selection is researched; the benthos in a river segment are researched and ecological environment elements are inspected on site; the type of a benthos habitat and the characteristic parameter threshold value of the benthos habitat are determined; the optimal type of the benthos habitat which maintain the benthos diverse is determined; the fluvial geomorphology measurement of the river segment is researched; a two-dimensional hydrodynamics modelis constructed; the benthos habitat of the river segment is simulated in different flows; the optimal flow for maintaining the benthos diverse is determined. The method has the advantages that the ecological flow which enables the benthos diversity to be highest can be very accurately obtained, and the problem that by means of a general ecological flow determining method, the result cannot reflect the actual demands of aquatic organisms is solved.

The invention relates to a river section degradation evaluation method, which effectively solves the problems that the evaluation excessively depends on data, the compatibility is complicated and the accuracy and efficiency of the evaluation are affected. The method comprises the following steps: establishing river section degradation evaluation elements and indexes, performing in-situ monitoring, carrying out water quality chemical index analysis and biological authentication for a collected sample, determining a weight of criterion layer evaluation elements for the river degradation by utilizing the level analysis characteristic value method, determining a sub-weight for each representative evaluation index of the criterion layer evaluation elements by utilizing a variance method, and obtaining an absolute weight of each index by considering the weight of the criterion layer evaluation elements; evaluating the river section degradation situation according to each evaluation index absolute weight and a matter-element model, calculating a correlation function and correlation degree, and obtaining the degradation degree of the river section according to the evaluation standard. The method is novel and unique, easy to operate and use, good in effect and capable of accurately evaluating the river section degradation and instructing the river governing and ecological restoration.

The invention provides a method for determining a dynamic water quality target of an urban river section, which belongs to the field of water environment treatment. The method provided by the invention comprises the steps that a an indicator framework system which affects the determining of the water quality target of the urban river section is established; b an analytic hierarchy process is usedto judge the importance of indicators and analyze and calculate the weights of the indicators; c graded quantitative evaluation is carried out individual evaluation indicators; and d a weighted average method is used to calculate the comprehensive score of an indicator set to determine high, medium and low water quality target levels. According to the invention, a conventional method for determining the water quality target of an urban river based on functional requirements is optimized; a watershed manager can formulate the water quality target of the river according to hydrological and hydraulic conditions, water quality conditions, functional needs and other different characteristics of the river, so that the target determination is more reasonable and feasible; and the method can be used by urban river health evaluation, ecological evaluation, water environment carrying capacity evaluation and other evaluations for reference, and has good versatility.

The invention relates to the technical field of water resource monitoring, in particular to a water environment pollution analysis system based on big data, comprising: an acquisition unit for acquiring river basic data and pollution source data; the division unit that is used for carrying out river reach division on the river; the modeling unit that is used for establishing a pollutant tracing relationship and a monitoring section water quality response relationship; the analysis unit that is used for performing pollution source structure analysis on each water outlet of each control unit according to the internal and external source contribution analysis and the pollution source type contribution analysis, and analyzing the contribution rate of the pollution source to the water quality of the monitoring section; and the output unit that is used for outputting an analysis result. According to the invention, the monitoring section is taken as the core, the pollution source causing themonitoring section can be analyzed, the pollution source with relatively large contribution degree to the river section water quality in the river is locked, and the technical problem that when an existing method is used for coping with sudden pollution sources, pollution source checking and tracing work cannot be effectively carried out in time is solved.

The invention discloses a non-contact river surface velocity measurement based regression calculation method for an instantaneous flow rate. According to the method, river multipoint surface flow velocities Vi and a river level height H are measured simultaneously through a non-contact method, a river section area S is obtained according to the river level height H, S is a function of H, that is, S=(S)H, a river surface average flow velocity is obtained according to river multipoint surface flow velocities Vi as following, and then a formula that M=K*Vs*S is used for calculating a river section instantaneous flow rate, wherein Vs is the river surface average flow velocity, and S is the river section area obtained according to the river level height. By the aid of the method, the instantaneous flow rate of a river can be calculated through surface flow velocities, river levels and section data provided by a non-contact velocity measurement technology, the proximity of the data obtained through non-contact measurements to data obtained through manual measurements is high, the error is small, and non-contact measurements can completely substitute for manual measurements.

The invention discloses a river phase relation suitable for a runoff tidal estuary area and derivation method thereof. The method is characterized by comprising the following steps: S1, primarily deriving the river phase relation by combining the O'Brien method with the Douguoren method; S2, establishing a current mathematic model according to the actually measured data of the river, and solving the current mathematic model by use of a finite volume method; S3, selecting a river area only under the runoff effect, and fitting the river phase relation of the runoff river area; S4, selecting the engineering river area of the representative upstream runoff flow; S5, dividing the river area into a certain number of cross sections, equally dividing the river width of each cross section into several, and calculating through the river phase relation of the runoff river area fitted in the step S3; and S6, respectively calculating the average wetted area A and QT falling of the river area in the step S4 by use of the current mathematic model in the step S2. The river phase relation disclosed by the invention has extremely high precision when qualitatively and quantitatively describing the relation of a river power condition and the channel morphology at the runoff tidal estuary area.

The invention provides a river health comprehensive characterization and evaluation system covering three scales of river basin, river corridor and habitat and combining points, lines and surfaces against the problem that the existing river health characterization and evaluation are largely focused on the single river corridor scale with the ignorance of the internal relations between a river and the river basin and the habitat, and the river health comprehensive characterization and evaluation system applies the multi-index integrated method, respectively determines the river comprehensive health and the health level in each scale and identifies main factors limiting the river health state. The method fully considers the multi-scale integration of the river and the characteristics of close links among the scales and fully considers an interference source of the river and the river, thereby being capable of rapidly and accurately identifying the main limiting factors of the river health while determining the health scales of different river sections of the same river or the health scales of different rivers in the same ecological region, having the advantages of intuitive result expression, convenient application and the like and providing a definite method basis for the river comprehensive management.

The invention relates to a coupling method and system for a one-dimensional hydrodynamic model and a two-dimensional hydrodynamic model. The method comprises steps that the one-dimensional hydrodynamic model is constructed; wherein the one-dimensional hydrodynamic model comprises a one-dimensional river network water flow mathematical model; a two-dimensional hydrodynamic model is constructed to simulate two-dimensional shallow water flow of an earth surface; and according to the one-dimensional hydrodynamic model and the two-dimensional hydrodynamic model, a corresponding one-dimensional andtwo-dimensional hydrodynamic model coupling mode is carried out for various river section forms. According to the method, a one-dimensional and two-dimensional coupled hydrodynamic model is adopted, the influence of urban buildings, trees and other plants on flood propagation can be fully considered, and hydrodynamic models of different scales and different dimensions are coupled according to theone-dimensional flow characteristics of a river channel and the two-dimensional flow characteristics of a lake; and flood influence degree and range simulation and prediction under different flood frequencies are carried out. The urban water regime situation can be perceived, the water level information is collected in combination with an upstream sensing instrument, and the aims of reducing the discharge peak flow and achieving flood recycling are achieved in combination with gate dam dispatching.

The invention relates to the technical field of water conservancy research, in particular to a tree-shaped river network cascade reservoir hydrodynamic water quality and sediment coupling simulation method and system, and aims to solve the problem of integrity and reliability of river channel terrain sections and control line hydrological station data. After the cascade reservoirs are added, how to solve the problem of joint solution of the river network and the cascade reservoirs is solved, and a Western River midstream river network overall hydrodynamic simulation calculation platform integrating a cascade reservoir scheduling mode and a one-dimensional river network hydrodynamic model is established by relying on latest actually-measured water depth topographic data of the main and branch river channels. Model calculation is based on a one-dimensional Cherry View South Range. a calculation sequence for establishing a model from four levels of a river network, a sub-river network, ariver channel and nodes is provided. The river network and the cascade reservoirs are generalized. The river network and the cascade reservoirs are connected into a whole through the transmission relation of the water conservancy project scheduling mode and the external boundary conditions. All river segments are connected into a calculation whole, synchronous real-time simulation and calculationare achieved, and the research means of river network cascade reservoir scheduling is enriched.

The invention discloses a simulative nature river course water purification system. A river section is based on the trapezoidal compound section, multiple segments of filler purification regions are arranged at two sides in a main channel in a staggered manner so as to form sub-channels meandering on a plane, and the height of the filler purification region is higher than the low water level of the river; the filler purification region is filled with ripraps, broken stones and surface fillers from the bottom to the top; and a riprap banket is arranged between each two segments of filler purification regions. The simulative nature river course water purification system provides diversified habitat environments while strengthening the self cleaning capacity of the river and improving the river water environment quality, and plays an active role in repairing the biological diversity recovery of the stream segment. The simulative nature river course water purification system has the following remarkable advantages that the system operates in a passive unpowered manner, can improve the flow state, has no influence on the flood discharge of the main stream in the flood season, and has the advantages in multiple aspects, such as excellent water purification and ecological restoration effect and so on, especially, the system is suitable for the small rivers with low sediment amount and low flow velocity, or the scenic rivers.

The invention relates to a developing and governing method for a sandy wide channel canal / shoal / pool. A narrow river channel is formed by two main dikes (new flood dikes) which are constructed between the prior flood dikes at two sides of a sandy channel segment along the riverway trend, and large dams are constructed at the upstream and the downstream. A water supply and sand diversion canal is constructed at the inside or outside of at least one of the main dikes in the narrow river channel. A conveyance and navigation canal is constructed outside one or two sides of the narrow river channel. The conveyance and navigation canal is adjacent to the water supply and sand diversion canal or the conveyance and navigation canal, or the conveyance and navigation canal is a split type. The bottomland and the pool surrounded by the diking are changed from the shoal area between the main dike or canal dike and the prior flood dikes. The bottomland can be a permanent site for living, production, construction and development. The long-term reserved pool is capable of storing water resource and supplying water in non-flood season, storing floodwater and replenishing dryness in flood season, and detaining and storing the flood. The developing and governing method for the sandy wide channel canal / shoal / pool effectively prevents from flood, treats and uses slit, ensures the security in flood prevention, and supplies enough rinsing water source; the water service cost is low, and the method is capable of developing and utilizing the resources such as hydraulic power, shipping, and tourism, etc. in the channel segment, and the method has a positive meaning in improving environment.

The invention belongs to the field of bridge measurement and design, and provides a measuring and controlling method of the maximal scouring depth of a bridge abutment. The method comprises the following steps of: firstly designing a bridge abutment scouring experiment scheme, and then analyzing the shifting bed experiment result, wherein aiming at that during the specific flood process, the bridge abutment scouring depth has great relationship with the maximal unit discharge of the flood peak at the bridge site, the river bed gradient as well as the particle size composition of the river bed, the bridge abutment is in the increase trend as the unit discharge and the river bed gradient, and is in decrease trend as the river bed particle size. The partial scouring depth around the bridge abutment by adopting the multi-parameter correlation analysis is subjected to formula fitting, thereby obtaining the fitting formula of the bridge abutment scouring depth. The obtained fitting formula is high in pertinence and suitable for the built bridge culvert of a high-gradient gravel-cobble river reach, the relevant coefficient of the fitting formula is high, and the problems that the existing formula for calculating the partial scouring depth of the bridge abutment is not suitable for the high-gradient gravel-cobble river reach and is unreasonable in calculation are solved.

The invention relates to a construction method of an erosion-preventing large-diameter bored pile. The method is characterized in that in the construction method, a movable large-rigidity guide rack is used to control steel casing perpendicularity, an erosion-preventing protecting layer comprises a lower-layer cement grouting body, a middle-layer film bag sand-filling body and upper-layer stone riprap; the movable large-rigidity guide rack comprises a section steel truss, a pushing adjusting device, a moving guide rail, a movable pulley, a traction device and the like;a sectional machining and a field butt joint is adopted for the sinking process, and the sinking process uses the large-rigidity guide rack to position the steel casing, control the perpendicularity of the steel casing and correct the steel casing; high-pressure grouting is performed in certain depth range of a riverbed through a reserved grouting pipe to form a cement grouting body protecting layer after the bored pile is constructed, and a riprap erosion-preventing layer is constructed after a whole pile group is constructed. By the method, the erosion-preventing large-diameter bored pile can be fast constructed in river sections with rapid flows and severe erosion effects, high construction quality is achieved, and good technological and economic benefits are achieved.

The invention discloses a river dredging method. The method comprises the following steps of: step S1, setting a first cofferdam to the river section, and extracting the water in the first cofferdam;step S2, cleaning the muck in the river; step S3, discharging the sludge in the river. The method disclosed by the invention comprises: firstly, setting a first cofferdam to the river section, and extracting the water in the first cofferdam; next, cleaning the muck in the river; finally, discharging the sludge in the river. The method disclosed by the invention can discharge the sludge in the river, and solve the problem of clogging of the river.