Coastal drainage board structure and construction method therefor

Abstract

The present invention discloses a coastal drainage board structure comprising: a water conveying board body arranged above a sand cushion layer and provided with multiple through holes, wherein a cavity is arranged in water conveying board body and is lowered from left to right, an insertion hole with an elastic clamping member and communicated with a cavity is formed beside through hole, ,water conveying board body is provided with a water conveying hole communicated with cavity and water pump, a water retaining structure is arranged between insertion hole and through hole; multiple composite drainage boards whose top inserting into cavity and bottom penetrating into a coastal soft soil foundation layer are arranged below water conveying board body, and comprise a drainage board core and coating wrapping; a pressing member comprising right—angle and T—shaped pressing boards. The invention is unnecessary to arrange multiple pipeline joints, short and long pipelines, saving cost.

Description

TECHNICAL FIELD The present invention relates to the technical eld of coastal construction. More particularly, the present invention relates to a coastal drainage board structure and a construction method therefor. BACKGROUND The construction environment of coastal engineering projects is relatively poor, and the foundation in coastal engineering construction is mostly soft soil foundation. In the construction process, it is necessary to reinforce the soft soil foundation to improve the foundation. The reinforcement methods comprise a traditional packed drain well reinforcement method and a plastic drainage board reinforcement method. The plastic drainage board method is an underwater soft soil foundation treatment method that has emerged since 1980s, and compared with the traditional packed drain well reinforcement method, it has the advantages of light mass, strong toughness, high strength, uniform specications, smooth drainage, low costs, high construction efciency, and the like. At present, the construction by the plastic drainage board method comprises that: a plastic drainage board penetrates into a casing of a board insertion machine, a lower end of the plastic drainage board exposed from the casing is locked by a specially-made bayonet at a lower end of the casing, an upper end of the plastic drainage board is tensioned at the same time to be in a taut state so as to be further straightened vertically, the casing of the board insertion machine is moved to make the casing and a board insertion position vertically align with a preset position, the specially-made bayonet at the lower end of the casing of the board insertion machine is slowly lifted to be automatically opened, then the plastic drainage board is left and inserted into a preset soft soil foundation, the upper end of the plastic drainage board is cut to expose a part in about 20 cm length from a sand cushion layer, and nally, the plastic drainage board in a relative position is connected with a plurality of pipelines through pipeline joints to form a water conveying pipeline until the pipeline is connected to a water collection tank or a water pump. However, because the plastic drainage boards are arranged in many places on the soft soil foundation, and pipeline joints and pipelines between all plastic drainage pipes are nally connected, it is necessary to arrange a plurality of pipeline joints and a plurality of short pipelines to form a long pipeline between every two rows of plastic drainage boards, and each long pipeline is connected with one water pump for pumping water. This operation requires articial construction, thus consuming time and labor. For example, the patent with the application number 2015208617090 discloses a direct-drainage differential vacuum degree pre- pressing foundation treatment structure, which consists of a sealing system, a vacuum treatment system and a soft soil foundation treatment system, wherein the sealing system comprises a sealing membrane and a geotextile; the vacuum treatment system comprises a sand cushion layer, a lter pipe and a vacuum pump; and the soft soil foundation treatment system comprises a soft soil foundation, a drainage board, an interlocking geogrid and a curtain wall. The geotextile is divided into upper, middle and lower layers, and covers the sand cushion layer; and the drainage board is connected with the lter pipe through a connecting pipe, and the lter pipe is horizontally arranged in the sand cushion layer and connected with a vacuum pump through a main pipe. In this patent, the drainage board is connected with the lter pipe through the connecting pipe, and the lter pipe is horizontally arranged in the sand cushion layer and connected with the vacuum pump through the main pipe. The construction of this structure consumes a lot of manpower and material resources. SUMMARY One objective of the present invention is to solve at least the above problem, and to provide at least the advantages that will be described hereinafter. Another objective of the present invention is to provide a coastal drainage board structure, wherein a water conveying board body is arranged on a sand cushion layer, bottom ends of a plurality of composite drainage boards penetrate through a plurality of through holes in the water conveying board body to be inserted into a coastal soft soil foundation layer, and top ends of the composite drainage boards are inserted into insertion holes to be communicated with a cavity for water drainage and conveyance, so as to avoid the problem that each drainage pipe needs to be connected through a plurality of pipeline joints and a plurality of short pipeline and a long pipeline is formed between every two rows of plastic drainage board traditionally, and each long pipeline is connected with a water pump for pumping water, thus consuming time and labor. In order to achieve these objectives and other advantages according to the present invention, a coastal drainage board structure is provided, which comprises: a water conveying board body, which is arranged above a sand cushion layer, wherein a plurality of through holes penetrating through the sand cushion layer are arranged in the water conveying board body at intervals, an insertion hole is formed on one side beside each through hole, an elastic clamping member is arranged around an inner side of each insertion hole, a cavity is arranged in the water conveying board body, each insertion hole is communicated with the cavity, a bottom portion of the cavity is gradually lowered in a stepped manner from a left side to a right side of the water conveying board body, the right side of the water conveying board body is provided with a water conveying hole which is communicated with the cavity, the water conveying hole is communicated with a water pump through a water conveying pipe, a water retaining structure is arranged between each insertion hole and a bottom portion of each through hole, and the water retaining structure is arranged around the bottom portion of each through hole; a plurality of composite drainage boards, which are arranged below the water conveying board body, wherein each composite drainage board comprises a drainage board core and a coating, the drainage board core comprises a plurality of drainage pipes, the coating wraps an outer periphery of the plurality of drainage pipes, a top end of each composite drainage board penetrates through the sand cushion layer and each corresponding through hole, and extends into the cavity through the insertion hole, a bottom end of each composite drainage board vertically penetrates into a coastal soft soil foundation layer, so that water in the coastal soft soil foundation layer is drained into the cavity through the plurality of drainage pipes, and the top and bottom ends of each composite drainage board are both unsealed; and a pressing member, which comprises a pair of right-angle pressing boards and a T-shaped pressing board, wherein a top portion of each right-angle pressing board is pressed on two adjacent edges of the water conveying board body, a bottom portion of the right-angle pressing plate is inserted into the coastal soft soil foundation layer by closely abutting against the water conveying board body, two ends of a horizontal portion of the T-shaped pressing board are xed on opposite edges of the pair of right-angle pressing boards by bolts, and a vertical portion of the Tshaped pressing board is xed on the water conveying board body. Preferably, the plurality of drainage pipes comprise: a plurality of concave drainage pipes, which are arranged in a middle portion of the drainage board core, wherein a cross section of each concave drainage pipe is in a concave structure, and upper and lower ends are open; a pair of linear drainage pipes, which are symmetrically arranged on two sides of the plurality of concave drainage pipes; and a pair of cross-shaped drainage pipe groups, which are symmetrically arranged on two sides of the pair of linear drainage pipes, wherein each cross-shaped drainage pipe group comprises a plurality of crossshaped drainage pipes with vertical portions connected end to end from top to bottom, one end of a horizontal portion of each crossshaped drainage pipe is communicated with the coastal soft soil foundation layer, and the other end of the horizontal portion is communicated with an adjacent linear drainage pipe; wherein, the concave drainage pipe and the linear drainage pipe, and adjacent concave drainage pipes are connected by exible connecting members, and the coating wraps around an outer periphery of the plurality of concave drainage pipes, the pair of linear drainage pipes and the pair of cross-shaped drainage pipe groups, so that the plurality of drainage pipes and the coating form an integral structure, so as to form the composite drainage board. Preferably, each drainage board core further comprises: a pair of mud-retaining and waterpermeable members, which are arranged on two sides of the drainage board core and connected with the plurality of crossshaped drainage pipes to cover one end of the horizontal portion of each cross-shaped drainage pipe, so as to avoid soft soil of the coastal soft soil foundation layer from blocking the cross-shaped drainage pipe. Preferably, bottom ends of one pair of crossshaped drainage pipe groups, one pair of linear drainage pipes and the plurality of concave drainage pipes are all provided with water- permeable membranes. Preferably, the water conveying board body is further provided with an exhaust hole, which is communicated with an air pump through an exhaust valve. Preferably, a top portion of the T-shaped pressing board is provided with a load layer, the load layer is a concrete layer, and the concrete layer has a thickness of 80 cm. The present invention is further realized by a construction method for the coastal drainage board structure, and the construction method for the coastal drainage board structure comprises the following steps: rst step: laying the sand cushion layer on the coastal soft soil foundation layer to make a thickness of the sand cushion layer reach 50 cm, and laying the water conveying board body on the sand cushion layer; second step: allowing the composite drainage board to penetrate into the casing from a casing opening of a board insertion machine, xing a bottom end of the composite drainage board on a pin at a bottom portion of the casing, tensioning the composite drainage board at the same time, aligning the board insertion machine with one through hole, driving the composite drainage board to be vertically and downwardly inserted towards the coastal soft soil foundation layer to reach a design depth through the casing, upwardly pulling out the casing, leaving the composite drainage board in coastal soft soil by a pressure of the coastal soft soil, cutting off a top end of the composite drainage board to expose 15 cm of the sand cushion layer, inserting the top end of the composite drainage board into the insertion hole corresponding to the through hole, clamping the composite drainage board with the elastic clamping member, and repeating the above operations until all the through holes in the water conveying board body are inserted with the composite drainage boards, wherein a verticality of the board insertion machine is not greater than 1.5%; third step: xing one pair of right-angle pressing boards around the water conveying board body, pressing a top portion of each rightangle pressing board on two adjacent edges of the water conveying board body, xing the right-angle pressing boards on the water conveying board body by bolts, tightly attaching a bottom portion of each right-angle pressing board to the water conveying board body to be inserted into the coastal soft soil foundation layer, xing the vertical portion of the Tshaped pressing board by a bolt in a central position of the water conveying board body, and xing the horizontal portion of the Tshaped pressing board by bolts on opposite edges of the pair of right-angle pressing boards; fourth step: arranging the load layer on the top portion of the T-shaped pressing board, wherein a length of the load layer is the same as that of the horizontal portion of the T-shaped pressing board; and fth step: communicating the water conveying hole in the water conveying board body with the water pump through the water conveying pipe, and communicating the exhaust hole in the water conveying board body with the air pump through an exhaust pipeline and the exhaust valve. The present invention comprises at least the following benecial effects: 1. In the coastal drainage board structure of the present invention, the water conveying board body is arranged on the sand cushion layer, the bottom ends of the plurality of composite drainage boards penetrate through the plurality of through holes in the water conveying board body to be inserted into the coastal soft soil foundation layer, and the top ends of the composite drainage boards are inserted into the insertion holes to be communicated with the cavity for water drainage and conveyance, so as to avoid the problem that each drainage pipe needs to be connected through a plurality of pipeline joints and a plurality of short pipeline and a long pipeline is formed between every two rows of plastic drainage board traditionally, and each long pipeline is connected with a water pump for pumping water, thus consuming time and labor. 2. In the coastal drainage board structure of the present invention, the drainage board core of the composite drainage board are provided with the cross-shaped drainage pipes on two sides and theconcave drainage pipes in the middle, which can not only improve the water permeability and water passing capacity of composite drainage pipes in horizontal and vertical directions, but also improve the compression resistance of the composite drainage board. 3. In the coastal drainage board structure of the present invention, the composite drainage board is provided with the mud-retaining and water-permeable members on two side and the water-permeable membranes at the bottom ends, so as to avoid soil of the coastal soft soil foundation layer from blocking the drainage pipe to affect the water permeability and water passing capacity. 4. In the coastal drainage board structure of the present invention, the pressing member and the load layer are provided to improve a bearing capacity of the coastal soft soil foundation layer, accelerate the drainage consolidation of the coastal soft soil foundation layer, and shorten consolidation time, thus improving the construction efciency. Other advantages, objectives and features of the present invention will be partially reected by the following description, and will be partially understood by those skilled in the art through researching and practicing the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural diagram of a coastal drainage board structure in one technical solution of the present invention; FIG. 2 is a schematic structural diagram of a drainage board core in one technical solution of the present invention; FIG. 3 is a schematic structural diagram of a water conveying board body in one technical solution of the present invention; FIG. 4 is a transverse crosssectional view in a position of a through hole in the water conveying board body in another technical solution of the present invention; FIG. 5 is a longitudinal cross-sectional view in the position of the through hole in the water conveying board body in another technical solution of the present invention; and FIG. 6 is a schematic structural diagram of a crossshaped drainage pipe group in another technical solution of the present invention. Reference numerals: 1 refers to water conveying board body, 100 refers to through hole, 110 refers to insertion hole, 120 refers to cavity, 130 refers to water conveying hole, 140 refers to exhaust hole, 2 refers to sand cushion layer, 3 refers to composite drainage board, 300 refers to drainage board core, 301 refers to cross-shaped drainage pipe group, 302 refers to linear drainage pipe, 303 refers to concave drainage pipe, 305 refers to mud-retaining and water- permeable member, 306 refers to water-permeable membrane, 307 refers to exible connecting member, 308 refers to cross-shaped drainage pipe, 4 refers to pressing member, 400 refers to rightangle pressing board, 410 refers to Tshaped pressing board, 5 refers to exhaust valve, 6 refers to air pump, 7 refers to load layer, and 8 refers to water retaining structure. DETAILED DESCRIPTION The present invention is further described in detail hereinafter with reference to the drawings, so that those skilled in the art can implement according to the specication. It should be understood that the terms such as "having," "including," and "comprising" as used herein do not exclude the presence or addition of one or more other elements or combinations thereof. As shown in FIG. 1 to FIG. 5, the present invention provides a coastal drainage board structure, which comprises: a water conveying board body 1, which is arranged above a sand cushion layer 2, wherein a plurality of through holes 100 penetrating through the sand cushion layer 2 are arranged in the water conveying board body 1 at intervals, an insertion hole 110 is formed on one side beside each through hole 100, an elastic clamping member is arranged around an inner side of each insertion hole 110, a cavity 120 is arranged in the water conveying board body 1, each insertion hole 110 is communicated with the cavity 120, a bottom portion of the cavity 120 is gradually lowered in a stepped manner from a left side to a right side of the water conveying board body 1, the right side of the water conveying board body 1 is provided with a water conveying hole 130 which is communicated with the cavity 120, the water conveying hole 130 is communicated with a water pump through a water conveying pipe, a water retaining structure 8 is arranged between each insertion hole 110 and a bottom portion of each through hole 100, and the water retaining structure 8 is arranged around the bottom portion of each through hole 100; a plurality of composite drainage boards 3, which are arranged below the water conveying board body 1, wherein each composite drainage board 3 comprises a drainage board core 300 and a coating, the drainage board core 300 comprises a plurality of drainage pipes, the coating wraps an outer periphery of the plurality of drainage pipes, a top end of each composite drainage board 3 penetrates through the sand cushion layer 2 and each corresponding through hole 100, and extends into the cavity 120 through the insertion hole 110, a bottom end of each composite drainage board 3 vertically penetrates into a coastal soft soil foundation layer, so that water in the coastal soft soil foundation layer is drained into the cavity 120 through the plurality of drainage pipes, and the top and bottom ends of each composite drainage board 3 are both unsealed; and a pressing member 4, which comprises a pair of right-angle pressing boards 400 and a T- shaped pressing board 410, wherein a top portion of each right-angle pressing board 400 is pressed on two adjacent edges of the water conveying board body 1, a bottom portion of the right-angle pressing board is closely attached to the water conveying board body 1 to be inserted into the coastal soft soil foundation layer, two ends of a horizontal portion of the Tshaped pressing board 410 are xed on opposite edges of the pair of right-angle pressing boards 400 by bolts, and a vertical portion of the T-shaped pressing board is xed on the water conveying board body 1. In the above technical solution, the coastal drainage board structure comprises the water conveying board body 1, the plurality of composite drainage boards 3 and the pressing member 4, the bottom portion of each composite drainage board 3 correspondingly penetrates through one through hole 100 in the water conveying board body 1 and then is vertically and downwardly inserted into the coastal soft soil foundation layer, and the top portion of the composite drainage board is inserted into the insertion hole 110 to be communicated with the cavity 120. The top and bottom ends of each composite drainage board 3 are both unsealed, so that the composite drainage board has good drainage performance and water permeability, thus forming a plurality of good drainage channels in the coastal soft soil foundation layer. A pressure on the sand cushion layer 2 is continuously increased, so that one part of water in the coastal soft soil foundation layer is drained into the cavity 120 through the plurality of composite drainage boards 3, and the other part of the water is drained by absorption through the sand cushion layer 2, thus accelerating the drainage consolidation of the coastal soft soil foundation layer and improving a bearing capacity of the coastal soft soil foundation layer. This technical solution avoids the problem that each drainage pipe needs to be connected through a plurality of pipeline joints and a plurality of short pipeline and a long pipeline is formed between every two rows of plastic drainage board traditionally, and each long pipeline is connected with a water pump for pumping water, thus consuming a lot of materials and consuming time and labor. The water conveying board body 1 may be made of a pressureresistant plastic material, such as a rigid PVC board structure made of polyvinyl chloride, the water conveying board body 1 is a hollow cubic structure, andeach edge of the water conveying board body 1 has a board thickness of 20-30 mm. According to the requirements of pressure resistance, multiple layers of rigid PVC boards, such as two or three layers, may be arranged on each edge of the water conveying board body 1. The plurality of through holes 100 are formed in the water conveying board body 1 at intervals, each through hole 100 penetrates through the sand cushion layer 2 from the top portion of the water conveying board body 1, the insertion hole 110 is formed on one side beside each through hole 100, the water retaining structure 8 is arranged between each insertion hole 110 and the bottom portion of each through hole 100, and the water retaining structure 8 is arranged around the bottom portion of each through hole 100. The water retaining structure 8 may also be made of a pressureresistant plastic material, which is the same material as the water conveying board body 1, and the water retaining structure is arranged around the bottom portion of each through hole 100, so as to avoid water drained from the composite drainage board 3 from owing out of the water conveying board body 1 through the through hole 100, so that the water drained from the composite drainage board 3 enters the cavity 120. Because the cavity 120 is lowered from left to right, the water automatically ows into the water conveying hole from the left side of the cavity 120, and then is pumped out of the cavity through the water conveying pipe. The drainage board core 300 is a plastic structure made of a rigid polyvinyl chloride or polypropylene material, and the coating is a ber structure, which does not affect the drainage performance of the drainage board core 300, but can play a role in retaining soil. During the construction, a site is cleaned rst, garbage and other sundries are removed, and a settlement observation apparatus is photographed for horizontal displacement and settlement observation. The sand cushion layer 2 is laid to make a thickness of the sand cushion layer reach 50 cm and then leveled, wherein the sand cushion layer is made of coarse gravel sand, and has a bearing capacity of 240 KPa and a silt content less than 4%, and the water conveying board body 1 is laid on the sand cushion layer 2. The composite drainage board 3 penetrates into the casing from a casing opening of a board insertion machine, a bottom end of the composite drainage board 3 is xed on a pin at a bottom portion of the casing, the composite drainage board 3 is tensioned at the same time, the board insertion machine is aligned with one through hole 100, the composite drainage board 3 is driven to be vertically and downwardly inserted towards the coastal soft soil foundation layer through the casing, a vibration hammer is started to drive the composite drainage board according to a driving speed controlled at 10 m / min until the composite drainage board reaches a design depth, the casing is upwardly pulled out, the pin at the bottom portion of the casing may be automatically opened, the composite drainage board 3 is left in coastal soft soil by a pressure of the coastal soft soil, a top end of the composite drainage board 3 is cut off to expose 15 cm of the sand cushion layer 2, the top end of the composite drainage board 3 is inserted into the insertion hole 110 corresponding to the through hole 100, the composite drainage board is clamped with the elastic clamping member, and the above operations are repeated until all the through holes 100 in the water conveying board body 1 are inserted with the composite drainage boards 3, wherein a verticality of the board insertion machine is not greater than 1.5%. One pair of right-angle pressing boards 400 are xed around the water conveying board body 1, a top portion of each rightangle pressing board 400 is pressed on two adjacent edges of the water conveying board body 1, the right-angle pressing boards are xed on the water conveying board body 1 by bolts, a bottom portion of each right angle pressing board 400 is tightly attached to the water conveying board body 1 to be inserted into the coastal soft soil foundation layer, the vertical portion of the Tshaped pressing board 410 is xed by a bolt in a central position of the water conveying board body 1, and the horizontal portion of the T-shaped pressing board 410 is xed by bolts on opposite edges of the pair of right-angle pressing boards 400. The water conveying hole 130 in the water conveying board body 1 is communicated with the water pump through the water conveying pipe. The pair of right-angle pressing boards 400 and the Tshaped pressing board 410 are made of reinforced concrete. In another technical solution, the plurality of drainage pipes comprise: a plurality of concave drainage pipes 303, which are arranged in a middle portion of the drainage board core 300, wherein a cross section of each concave drainage pipe 303 is in a concave structure, and upper and lower ends are open; a pair of linear drainage pipes 302, which are symmetrically arranged on two sides of the plurality of concave drainage pipes 303; and a pair of cross-shaped drainage pipe groups 301, which are symmetrically arranged on two sides of the pair of linear drainage pipes 302, wherein each crossshaped drainage pipe group 301 comprises a plurality of crossshaped drainage pipes 308 with vertical portions connected end to end from top to bottom, one end of a horizontal portion of each cross-shaped drainage pipe 308 is communicated with the coastal soft soil foundation layer, and the other end of the horizontal portion is communicated with an adjacent linear drainage pipe 302; wherein, the concave drainage pipe 303 and the linear drainage pipe 302, and adjacent concave drainage pipes 303 are connected by exible connecting members 307, and the coating wraps around an outer periphery of the plurality of concave drainage pipes 303, the pair of linear drainage pipes 302 and the pair of cross-shaped drainage pipe groups 301, so that the plurality of drainage pipes and the coating form an integral structure, so as to form the composite drainage board 3. In the above technical solution, the drainage board core 300 is provided with the cross shaped drainage pipe groups 301 on two sides and the concave drainage pipes 303 in the middle, and each crossshaped drainage pipe group 301 comprises the plurality of cross-shaped drainage pipes 308 from top to bottom. One end of the horizontal portion of the cross-shaped drainage pipe 308 is communicated with the coastal soft soil foundation layer, and the other end of the horizontal portion is communicated with the adjacent linear drainage pipe 302, so that the formed composite drainage board 3 can not only drain water owing in a vertical direction of the coastal soft soil foundation layer, but also drain water owing in a horizontal direction of the coastal soft soil foundation layer through the horizontal portions of the plurality of cross-shaped drainage pipes 308, thus improving the water permeability and water passing capacity of composite drainage pipes in horizontal and vertical directions. The plurality of concave drainage pipes are arranged in the middle, which cooperate with the cross-shaped drainage pipe groups 301 on two sides, so as to improve horizontal and vertical pressure resistance of the composite drainage board. The concave drainage pipe 303, the linear drainage pipe 302, the cross-shaped drainage pipe group 301 and the drainage board core 300 are all plastic structures made of a specially treated rigid polyvinyl chloride or polypropylene material, and the formed composite drainage board 3 has a vertical water permeability higher than 30X103mm3 / s and a horizontal water permeability higher than 10X103mm3 / s. In another technical solution, each drainage board core 300 further comprises: a pair of mudretaining and water-permeable members 305, which are arranged on two sides of the drainage board core 300 and connected with one pair of cross-shaped drainage pipes 301 to cover one end of the horizontal portion of each cross-shaped drainage pipe 308, so as to avoid soft soil of the coastal soft soil foundation layer from blocking the cross-shaped drainage pipe 308. In the above technical solution, the mud-retaining and waterpermeable members 305 are arranged on two sides of the drainage board core 300 of the composite drainage board 3 to cover one end of the horizontal portion of each crossshaped drainage pipe 308, so as to avoid the soil of the coastal soft soil foundation layer from blocking the cross-shaped drainage pipe 308 to affect the water permeability and water passing capacity, wherein the mud-retaining and water- permeable member 305 is a mudretaining and water-permeable structure made of a propylene or polyester material, which is stuck at one ends of the horizontal portions of the crossshaped drainage pipes 308 and covers one ends of the horizontal portions of the plurality of cross shaped drainage pipes 308. In another technical solution, bottom ends of one pair of cross-shaped drainage pipe groups 301, one pair of linear drainage pipes 302 and the plurality of concave drainage pipes 303 are all provided with water-permeable membranes 306. In the above technical solution, the bottom portions of the plurality of drainage pipes are provided with the water-permeable membranes 306, so as to avoid the soil of the coastal soft soil foundation layer from blocking the drainage pipes to affect the water permeability and water passing capacity. The waterpermeable membrane 306 is made of a synthetic material of water permeable geotextile, with an elongation at break of 30-60%. In the above technical solution, the water conveying board body 1 is further provided with an exhaust hole, which is communicated with an air pump 6 through an exhaust valve 5. In the above technical solution, in order to increase a consolidation speed of the coastal soft soil foundation layer and shorten a construction period, the exhaust valve 5 may be opened, and the cavity 120 may be vacuumized by the air pump 6, so that water in the coastal soft soil foundation layer is quickly drained into the cavity 120 through the composite drainage board 3, thus accelerating the settlement and consolidation of the coastal soft soil foundation layer. If the consolidation is not accelerated by vacuumizing, it is only necessary to close the exhaust valve 5. In another technical solution, a top portion of the Tshaped pressing board 410 is provided with a load layer 7, the load layer 7 is a concrete layer, and the concrete layer has a thickness of 80 cm. In the above technical solution, the top portion of the Tshaped pressing board 410 is provided with the load layer 7, which improves a bearing capacity of the coastal soft soil foundation layer, accelerates the drainage consolidation of the coastal soft soil foundation layer, and shortens consolidation time, thus improving the construction efciency. This technical solution may further comprise the following technical details to better realize the technical effects. A construction method for the coastal drainage board structure comprises the following steps: rst step: laying the sand cushion layer 2 on the coastal soft soil foundation layer to make a thickness of the sand cushion layer reach 50 cm, and laying the water conveying board body 1 on the sand cushion layer 2; second step: allowing the composite drainage board 3 to penetrate into the casing from a casing opening of a board insertion machine, xing a bottom end of the composite drainage board 3 on a pin at a bottom portion of the casing, tensioning the composite drainage board 3 at the same time, aligning the board insertion machine with one through hole, driving the composite drainage board 3 to be vertically and downwardly inserted towards the coastal soft soil foundation layer to reach a design depth through the casing, upwardly pulling out the casing, leaving the composite drainage board 3 in coastal soft soil by a pressure of the coastal soft soil, cutting off a top end of the composite drainage board 3 to expose 15 cm of the sand cushion layer 2, inserting the top end of the composite drainage board 3 into the insertion hole 110 corresponding to the through hole 100, clamping the composite drainage board with the elastic clamping member, and repeating the above operations until all the through holes 100 in the water conveying board body 1 are inserted with the composite drainage boards 3, wherein a verticality of the board insertion machine is not greater than 1.5%; third step: xing one pair of right-angle pressing boards 400 around the water conveying board body 1, pressing a top portion of each right-angle pressing board 400 on two adjacent edges of the water conveying board body 1, xing the rightangle pressing boards on the water conveying board body 1 by bolts, tightly attaching a bottom portion of each right-angle pressing board 400 to the water conveying board body 1 to be inserted into the coastal soft soil foundation layer, xing the vertical portion of the Tshaped pressing board 410 by a bolt in a central position of the water conveying board body 1, and xing the horizontal portion of the T- shaped pressing board 410 by bolts on opposite edges of the pair of right-angle pressing boards 400; fourth step: arranging the load layer 7 on the top portion of the Tshaped pressing board 410, wherein a length of the load layer 7 is the same as that of the horizontal portion of the T- shaped pressing board 410; and fth step: communicating the water conveying hole 130 in the water conveying board body 1 with the water pump through the water conveying pipe, and communicating the exhaust hole in the water conveying board body 1 with the air pump 6 through an exhaust pipeline and the exhaust valve 5. In the above technical solution, the bottom portion of the composite drainage board 3 correspondingly penetrates through one through hole 100 in the water conveying board body 1, and then is vertically and downwardly inserted into the coastal soft soil foundation layer, and the top portion of the composite drainage board is inserted into the insertion hole 110 to be communicated with the cavity 120, so that a plurality of good drainage channels are formed in the coastal soft soil foundation layer. The right-angle pressing boards 400 and the Tshaped pressing board 410 are pressed on the water conveying board body 1, and the load layer 7 is arranged on the T-shaped pressing board 410, so that a pressure on the water conveying board body 1 is continuously increased, so as to improve the bearing capacity of the coastal soft soil foundation layer, accelerate the quick drainage of water in the coastal soft soil foundation layer from the composite drainage board 3, accelerate the drainage consolidation of the coastal soft soil foundation layer, and shorten the consolidation time, thus improving the construction efciency. Meanwhile, the exhaust hole is opened by the exhaust valve 5, and the cavity 120 is vacuumized by the air pump 6, so as to further increase a drainage rate of the composite drainage board 3 and accelerate the drainage consolidation of the coastal soft soil foundation layer. The water drained into the cavity 120 is pumped from the water conveying hole 130 by the water pump, and then is used for other construction or drained into a water collection tank around the construction. In the second step, it is necessary to strictly control to avoid a pulling-up phenomenon of the composite drainage board and controla pullingup length to be not greater than 4% of a total insertion length. The settlement and displacement caused by the drainage consolidation of the coastal soft soil foundation layer after pressing and loading should be observed regularly through the settlement apparatus, and measurement and control data formed by observation should be analyzed to optimize the construction technology. The equipment quantity and the processing scale described herein are used to simplify the description of the present invention. The application, modication and variation of the coastal drainage board structure of the present invention are obvious to those skilled in the art. Although the implementation of the present invention has been disclosed above, it is not limited to the applications listed in the specication and the embodiments, and can be fully applied to various elds suitable for the present invention, and additional modications can be easily implemented by those skilled in the art. Therefore, the present invention is not limited to the specic details and illustrations shown and described herein without departing from the general concept dened by the claims and the equivalent scope.

Claims

1. Coastal drainage plate structure, comprising: a water transport plate body, which is placed above a sand cushion layer, whereby a multitude of passage holes penetrating through the sand cushion layer at intervals in the water transport plate body are fitted, with a insertion hole is formed, with an elastic clamping member fitted around an inner side of each insertion hole, wherein a cavity is provided in the water transport plate body, wherein each insertion hole is communicated with the cavity, with a bottom portion of the cavity is gradually lowered step by step from a left side to a right side of the water transport plate body, where the right side of the water transport plate body is provided of a water conveyance hole communicated with the cavity, the water conveyance hole is communicated with a water pump via a water transport pipe, whereby a water retention structure is provided between each insertion hole and a bottom portion of each through hole, and where the water retention structure is provided around the bottom part of each passage hole; a multitude of composite drainage plates, which are located under the water transport plate body applied, each composite drainage plate comprising a drainage plate core and a coating, wherein the drainage plate core comprises a plurality of drainage pipes, wherein the coating comprises a outer periphery of the plurality of drainage pipes, with an upper end of each composite drainage plate through the sand cushion layer and each corresponding passage hole penetrates and extends through the insertion hole into the cavity, with a lower end of each composite drainage plate penetrates vertically into a coastal soft soil foundation layer, so that water in the coastal soft soil foundation layer is drained by the multitude of drainage pipes in the cavity drained, and where the upper and lower ends of each composite drainage plate are both are not sealed; and a press member, which includes a pair of rectangular press plates and a T-shaped press plate, where an upper portion of each rectangular press plate rests on two adjacent edges of the water transport plate body is pressed a lower portion of the rectangular press plate is inserted into the coastal soft soil foundation layer by pressing against the to connect a water transport plate body, where two ends of a horizontal section of the T-shaped press plate are attached by means of bolts to opposite edges of the pair of rectangular press plates, and where a vertical portion of the T-shaped press plate is attached to the water transport plate body.

2. A coastal drainage plate structure according to claim 1, characterized in that the plurality of drainage pipes include: a multitude of concave drainage pipes, which are located in a central portion of the drainage plate core are provided, with a cross-section of each concave drainage pipe has a concave structure and the upper and lower ends are open; a pair of linear drainage pipes, which are symmetrically arranged on two sides of the multitude of concave drainage pipes; and a pair of cross-shaped drainage pipe groups, which are symmetrical on two sides of the pair linear drainage pipes are installed, with each cross-shaped drainage pipe group of top to bottom comprises a multitude of cross-shaped drainage pipes, of which vertical parts are connected end to end, with one end of a horizontal section each cross-shaped drainage pipe communicates with the coastal soft soil foundation layer, and the other end of the horizontal section is communicated with a adjacent linear drainage pipe; where the concave drainage pipe and the linear drainage pipe and the adjacent concave Drainage pipes are connected by flexible connecting members, and where the coating is a outer periphery of the plurality of concave drainage pipes, the pair of linear drainage pipes and encloses the pair of cross-shaped drainage pipe groups, so that the plurality of drainage pipes and the coating forms an integral structure, to form the composite drainage plate.

3. Coastal drainage plate structure according to claim 2, characterised in that each drainage plate core further includes: and a pair of mud-retaining and water-permeable members, which are located on two sides of the drainage plate core are fitted and connected to the multitude of cross-shaped drainage pipes around one end of the horizontal portion of each cross-shaped drainage pipe to cover, to prevent soft soil from the coastal soft soil foundation layer from cross-shaped drainage pipe is blocked.

4. Coastal drainage plate structure according to claim 3, characterised in that the lower ends of one pair of cross-shaped drainage pipe groups, of one pair of linear drainage pipes and of the multitude of concave drainage pipes all are provided with water-permeable membranes.

5. Coastal drainage plate structure according to claim 4, characterized in that it water transport plate body is further provided with an outlet hole, which is communicated with an air pump through an exhaust valve.

6. Coastal drainage plate structure according to claim 5, characterized in that an upper part of the T-shaped press plate is provided with a load layer, whereby the load layer a concrete layer, where the concrete layer has a thickness of 80 cm.

7. Construction method for the coastal drainage plate structure according to claim 6, comprising the following steps: first step: laying the sand cushion layer on the coastal soft soil foundation layer so that the sand cushion layer reaches a thickness of 50 cm, and the laying of the water transport site body on the sand cushion layer; second step: allowing the composite drainage plate to fit into a casing of a to penetrate the casing opening of a plate insertion machine, attaching a bottom end of the composite drainage plate on a pin at a bottom portion of the casing, tensioning the composite drainage plate at the same time, aligning the single-hole plate feeding machine, driving the composite drainage plate through the sheath to be inserted vertically and downwards towards the coastal soft soil foundation layer to achieve a design depth, the upward extension of the casing, the leaving of the composition drainage plate in coastal soft soil by a pressure of the coastal soft soil, cutting off an upper end of the composite drainage plate at 15 cm of the sand cushion layer to be exposed, inserting the upper end of the composite drainage plate in the insertion hole corresponding to the passage hole, the clamping the composite drainage plate with the elastic clamping member and repeating the above operations until all passage holes in the water transport plate body are inserted with the composition drainage plates, whereby a verticality of the plate insertion machine is not greater than 1.5%; third step: attaching one pair of rectangular press plates around the water transport plate body, pressing an upper portion of each rectangular press plate on two adjacent edges of the water transport plate body, fastening by means of bolts of the rectangular press plates on the water transport plate body, inserting a lower portion of each rectangular press plate into the coastal soft soil foundation layer by to connect the water transport plate body, fixing the vertical part of the T-shaped press plate secured in a central position by means of bolts water transport plate body, and the attachment of the horizontal portion of the T-shaped press plate by means of bolts on opposite edges of the pair of rectangular press plates; fourth step: applying the tax layer to the top part of the T-shaped press plate, where the length of the load layer is the same as that of the horizontal part of the T-shaped press plate; and fifth step: communicating the water transport hole in the water transport plate body the water pump through the water transport pipe, and communicating the outlet hole in the water transport plate body with the air pump via an exhaust pipeline and the exhaust valve.