Wharf pier and abutment and construction method therefor

Abstract

The present invention discloses a construction method for a Wharf pier and abutment, comprising : leveling a foundation by distributing prefabricated concrete cushion blocks in a 2 ><2 m grid, applying 50%, 80% and 110% design loads by staged water injection and preloading, performing pressure stabilization and water level reduction, arranging a three-dimensional coordinate control network with a plane position deviation of S3 mm to realize accurate positioning, connecting a reinforcement cage by a pre—embedded short positioning bar, mounting a sealed composite steel formwork With vertical and horizontal stiffening ribs, matching 50 cm thickness of each layer with a combined vibration technology when layered pouring is carried out, and keeping curing of a top formwork after reaching 70% of strength. The method improves bearing uniformity, positioning accuracy and the concrete compactness degree, is applied to pier and abutment construction of hydraulic structures, and can ensure structural integrity and durability.

Description

TECHNICAL FIELD The present invention relates to the eld of wharf construction. More particularly, the present invention relates to a wharf pier and abutment and a construction method therefor. BACKGROUND Since a wharf pier and abutment serves as a key part to bear a ship load and transmit a structure stress, the construction quality of the wharf pier and abutment directly affects the overall stability and service life of a wharf. However, there are still some technical defects in practical applications of traditional construction methods, and particularly, there are challenges in the aspects of foundation treatment, formwork system positioning and concrete pouring technology under complex underwater geological conditions. Firstly, after an underwater foundation is compacted, uneven local settlement often occurs due to inuences of current scouring of underwater soil, heterogeneity of geological conditions and load distribution difference. In the prior art, although an elevation of the foundation is adjusted by a sand-gravel cushion or a local replacement method, there is a lack of systematic verification of bearing capacity of the foundation, which leads to differential settlement of the foundation under longterm load after construction, thus causing stress concentration or structural cracking at a bottom portion of the pier and abutment. This problem is mainly due to the fact that traditional preloading methods do not fully consider a matching property between a phased application of an underwater load and a consolidation rate of the foundation, and a preloading load is insufcient or pressure stabilization time is too short, so that it is difficult to effectively eliminate a soil compression deformation difference, which nally affects the overall stability of the foundation. Secondly, an insufcient positioning accuracy of a formwork system is another key factor to restrict the construction quality of the pier and abutment. In conventional construction, the mounting of a reinforcement cage and a formwork mostly depends on manual measurement and experience adjustment. Especially in a deepwater environment, due to a water ow disturbance, an instrument error and an operation level limitation of construction personnel, it is easy to cause the problems of deviation of the reinforcement cage and seam misalignment of the formwork. For example, when a plane position deviation of the formwork exceeds an allowable range, it will not only cause a size deviation of a concrete structure, but also lead to slurry leakage or water inltration during pouring due to poor seam sealing, resulting in defects such as voids and pits. In addition, when the formwork has insufcient support stiffness, local deformation is easy to occur under a lateral pressure of concrete, which further increases a structural size error. The root of such problems lies in the lack of a high-precision and dynamically adjustable positioning control system, an excessively large distance between existing control points or an unstable measurement datum, so that it is difcult to realize millimeter-level precision control under a complex underwater environment. Thirdly, in terms of concrete pouring technology, existing technologies often adopt onetime continuous pouring or simple layering, but an underwater pier and abutment structure has a large volume and dense steel bars, and if a layering thickness is improperly controlled or the vibration is insufcient, it is easy to cause the problems of cold seam, aggregate segregation and internal bubble residue. For example, when the layering thickness is excessively large, it is difcult to effectively dissipate hydration heat inside the concrete, which leads to temperature stress concentration, thus increasing a risk of shrinkage crack. However, in the case of single vibration technology (for example, only inserting vibration is adopted), it is difcult to realize uniform vibration in a region with dense steel bars, which affects a compactness degree of the concrete. In addition, if a time interval between layers exceeds initial setting time, an interfacial bonding strength between new and old concrete is signicantly reduced, which weakens the structural integrity. These problems are closely related to a high sensitivity of an underwater construction environment to technological parameters and a poor visibility of operation, while the traditional methods lack precise control strategies for the layering thickness, a vibration method and a time window. Finally, in a concrete curing process, there is the prevalent problem of premature removal of the formwork or substandard curing conditions. In existing technologies, all formworks are usually removed after the concrete reaches a certain strength, but the humidity uctuates greatly in the underwater environment, and if a top formwork is removed too early, a concrete surface is prone to a dry shrinkage crack due to the rapid evaporation of water, and meanwhile, external water inltration may dilute a surface cement slurry, which reduces the impermeability. In addition, when a curing period is insufcient or humidity control is unstable, the strength development of the concrete in a later stage is insufcient, and the durability is difcult to meet a design requirement. This defect stems from the lack of understanding of dynamic change laws of temperature and humidity in the underwater environment and the lack of a formwork retention mechanism adapting to a longterm curing need. To sum up, the existing wharf pier and abutment construction technologies still have obvious shortcomings in underwater foundation treatment, formwork positioning accuracy, concrete pouring technology and curing measure, and a fundamental reason is that the complex underwater environment puts forward a higher requirement for ne control of construction parameters, while the traditional methods have limitations in load simulation, measurement datum stability, technological adaptability, environmental adaptability and other aspects. How to realize the balanced improvement of the bearing capacity of the foundation, the construction control of millimeterlevel precision, the compactness degree guarantee of layered pouring and the maintenance of long-term curing conditions has become a technical problem to be solved urgently. SUMMARY One objective of the present invention is to solve the problems of structural cracking caused by uneven settlement of an underwater foundation, slurry leakage caused by a large formwork positioning deviation, inuences of improper concrete layered pouring thickness and vibration technology on a compactness degree, and durability reduction caused by insufcient curing in traditional wharf pier and abutment construction. Another objective of the present invention is to solve the problem that a pier and abutment surface is easily corroded by chloride ions due to longterm water immersion, and a conventional anti-corrosion measure has insufcient durability, leading to shortened service life of a structure. Another objective of the present invention is to solve the problem that technological parameters of compaction of the underwater foundation are extensive, leading to an uneven porosity and an insufcient bearing capacity, and an excessive settlement difference after compaction. Another objective of the present invention is to solve the problem that a structural design of prefabricated cushion blocks is unreasonable, leading to slow leveling efciency and poor positioning accuracy, and insufcient contact stability between the cushion blocks and the foundation. Another objective of the present invention is to solve the problem that the mounting and positioning of the cushion blocks depends on manual measurement, which has a large error, and the lling of a gap at a bottom portion is uncompact after leveling, which affects the overall bearing uniformity. Another objective of the present invention is to solve the problem that a drainage rate of staged preloading is not matched with a resilience rate of the foundation, leading to insufcient soil consolidation after preloading and a residual settlement risk. Another objective of the present invention is to solve the problem that a distance between datum points of a traditional control network is excessively large, and the measurement datum in the underwater environment is easy to drift, leading to insufcient positioning recheck accuracy. Another objective of the present invention is to solve the problem that the connection and positioning of a reinforcement cage depends on experience adjustment, which has a large verticality deviation, and the welding quality of a joint is unstable. Another objective of the present invention is to solve the problem that it is difcult to give consideration to compactness degrees of an edge of a formwork and a region with dense steel bars in a single vibration method, and an adaptability of vibration parameters to a concrete performance is poor. The present invention provides a construction method for a wharf pier and abutment, which comprises the following steps: rst step: arranging prefabricated concrete cushion blocks on a surface of an underwater foundation subjected to a compaction treatment, distributing the cushion blocks in a 2 mX2 m grid, and leveling the cushion blocks to design elevations; second step: carrying out staged water injection and preloading on the leveled foundation, sequentially applying 50%, 80% and 110% design loads and carrying out pressure stabilization for 48 hours, 72 hours and 120 hours respectively, and reducing a water level in proportion after each stage of pressure stabilization; third step: arranging a three-dimensional coordinate control network on the surface of the preloaded foundation, wherein a distance between control points is 5 m and a plane position deviation is 53 mm; fourth step: positioning a reinforcement cage on the basis of the three-dimensional coordinate control network, connecting the reinforcement cage with a short positioning bar preembedded in a top portion of the prefabricated concrete cushion block, mounting a composite steel formwork with vertical and horizontal stiffening ribs on the reinforcement cage, and sealing a seam of the composite steel formwork by a rubber waterstop; fth step: carrying out layered concrete pouring, wherein a thickness of each poured layer is controlled at 50 cm, and a time interval between layers does not exceed 2 / 3 of initial setting time, and carrying out combined vibration by penetrating and attaching vibrators after each layer is poured; and sixth step: removing a side formwork and keeping the continuous curing of a top formwork after reaching 70% of a design strength, wherein a surface humidity is kept at290% and a curing period is 221 days. Preferably, the construction method for the wharf pier and abutment further comprises: seventh step: removing all formworks, and painting an epoxy resin anticorrosive coating on the surface of the pier and abutment for twice, wherein a rst paining amount is 300 g / m2 and a second painting amount is 200 g / m2, and a time interval between the two painting operations is not less than 8 hours. Preferably, in the rst step, the compaction treatment specically comprises: backlling a graded sand and gravel mixture with a particle size of 540 mm on the surface of the underwater foundation in layers, wherein a mass ratio of sand to gravel is l: 1.5 -2.0, and a thickness of each backlled layer is not more than 30 cm; carrying out cross-compaction by a high-frequency hydraulic vibration hammer in layers, wherein an overlapping width of adjacent compaction wheel tracks is 215cm; wherein, when a bottom layer is compacted, a vibration frequency is kept at 3000-3300 rpm, a vibration amplitude is controlled at 1.2-1.6 mm, and the layer is compacted in horizontal and vertical directions for 3 times respectively, and when a surface layer is compacted, a vibration frequency is kept at 2200-2500 rpm, a vibration amplitude is controlled at 2.0-2.5 mm, and the layer is compacted in horizontal and vertical directions for twice respectively; and after compaction, controlling a surface layer porosity at 518%, controlling a bottom layer porosity at 522%, and making a porosity difference between adjacent measuring points not more than 3%, so as to nally make the bearing capacity of the foundation reach 2150 kPa and control a settlement difference within a range of i$ mm / 2 m. Preferably, in the rst step, the prefabricated concrete cushion block is made of C50 high-strength concrete, a reinforcing mesh is pre-embedded inside the cushion block, the prefabricated concrete cushion block is trapezoidal in shape, with a top surface size of 1.4 m><l.4 m, a bottom surface size of 1.6 m><l.6 m and a height of 40 cm, the bottom surface is provided with 4 reserved leveling holes with a diameter of 45 mm, the reserved leveling hole is provided with a leveling bolt in screw t with the leveling hole, a bottom portion of the leveling bolt is welded with a steel plate with a size of 180 mm>< 180 mm>< 12 mm, laser reection prisms are pre-embedded in four corners of the top surface of the prefabricated concrete cushion block, and the short positioning bar is pre-embedded in a middle portion of the top surface. Preferably, in the rst step, the arranging the prefabricated concrete cushion blocks, specically comprises: arranging the prefabricated concrete cushion blocks according to the 2 m><2 m grid in a staggered manner, wherein a distance between edges of adjacent prefabricated concrete cushion blocks is 50 cm, and setting out by using a total station combined with a Beidou RTK positioning system, wherein a plane positioning error is 55 mm; scanning the laser reection prisms by a three-dimensional laser scanner to monitor an elevation of the top surface of the prefabricated concrete cushion block in real time, and dynamically adjusting heights of the leveling bolts, wherein, after leveling, an elevation error is 5il.5 mm, and a height difference between adjacent cushion blocks is 52 mm; and after leveling, lling underwater epoxy mortar into a gap at the bottom portion of the cushion block, wherein a compressive strength is 250 MPa, and a lling fullness is 295%. Preferably, the second step specically comprises: carrying out water injection and preloading on the leveled foundation in three stages, wherein water is injected to 50% of the design load in a rst stage, with a water injection height H1, and after carrying out the pressure stabilization for 48 hours, the water is drained according to daily water level reduction of 510% Hl until the resilience rate of the foundation is 50.05 mm / h; water is injected to 80% of the design load in a second stage, with a water injection height H2, and after carrying out the pressure stabilization for 72 hours, the water is drained according to daily water level reduction of 58% H2 until the resilience rate of the foundation is 50.03 mm / h; and water is injected to 110% of the design load in a third stage, with a water injection height H3, and after carrying out the pressure stabilization for 120 hours, the water is drained according to daily water level reduction of 55% H3 until the resilience rate of the foundation is 50.01 mm / h; and when a nal water level is reduced to an initial groundwater level, assisting water drainage by vacuum preloading at a vacuum degree of 280 kPa for 48 hours. Preferably, in the third step, the arranging the three-dimensional coordinate control network, specically comprises: using the laser reection prisms pre-embedded in the four corners of the top surface of the prefabricated concrete cushion block as datum points, and establishing a rstclass control network through more than 3 prism datum points by a free station method of the total station, wherein a distance between surveying stations is 230 m; arranging a second-class control point on the short positioning bar in the middle portion of the top surface of the prefabricated cushion block, and mounting a surveying mark through a customized L-shaped connector; setting a region of 5 m distance between the secondclass control points into a "checkerboard"shaped array, and rechecking a crossseam region in a triangular mode by using the prisms of adjacent cushion blocks; and rechecking the control network by Beidou or GNSS real-time dynamic positioning, wherein a plane accuracy is 5i3 mm, and an elevation accuracy is 5i3 mm. Preferably, in the fourth step, the positioning and connecting the reinforcement cage, specically comprises: positioning corner points of the reinforcement cage by a polar coordinate method of the total station of the three-dimensional coordinate control network, wherein a positioning deviation is 35 mm; arranging a U-shaped positioning clamping base with an adjustable height at a bottom portion of the reinforcement cage, preliminarily connecting and positioning the Ushaped positioning clamping base with the short positioning bar preembedded in the top surface of the prefabricated concrete cushion block, and then xing by electroslag pressure welding; monitoring a verticality of the reinforcement cage by a laser plummet apparatus, and adjusting by a jack when a deviation exceeds 1 / 400; and connecting adjacent reinforcement cages by a shaped angle steel connecting plate. Preferably, in the fth step, the carrying out combined Vibration by the penetrating and attaching Vibrators, specically comprises: symmetrically mounting the attaching Vibrators at an intersection joint of vertical and horizontal stiffening ribs of the composite steel formwork, wherein a distance between two adjacent attaching Vibrators is 51.5 m, and connecting the attaching vibrators with the composite steel formwork by elastic vibration reduction; quincuncially distributing vibration points for the penetrating vibrators, wherein a distance between the Vibration point and an edge of the composite steel formwork is 5200 mm, and a vibration depth exceeds 2 / 3 of a concrete thickness of the layer; during vibration, making the penetrating and attaching vibrators work at the same time, and turning on the attaching vibrators 5 seconds earlier than the penetrating vibrators and turning off the attaching vibrators 10 seconds later than the penetrating vibrators; and carrying out frequency converting control over the penetrating Vibrators at 30-50 Hz, and adjusting the frequency in real time according to a slump of concrete, wherein, when the slump is >180 mm, the frequency is 30 Hz, and when the slump is 5180 mm, the frequency is 50 Hz. The present invention further provides a wharf pier and abutment, which is obtained by the construction method for the wharf pier and abutment above. The present invention comprises at least the following benecial effects. Firstly, through a synergistic effect of the graded water injection and preloading and the three-dimensional control network, the differential settlement of the foundation is reduced to iS mm / 2 m, the plane positioning accuracy of the formwork is improved to 53 mm, the layered pouring thickness of concrete and the compactness degree after optimization by the vibration technology are increased by 15%, the curing period is extended to 21 days, and the structural durability is signicantly enhanced. Secondly, a total painting amount of the epoxy resin coating is 500 g / m2, a continuous dense protective layer is formed, a chloride ion permeability coefcient is reduced to 51 .5>< 1012 mZ / s, and the service life after corrosion prevention is prolonged to above 30 years. Thirdly, through the layered control of the vibration parameters, the surface layer porosity is518%, the bottom layer porosity is 522%, the bearing capacity is 2150 kPa, the compaction efciency is increased by 40%, and a compliance rate of the settlement difference is increased to 95%. Fourthly, a contact area of the bottom surface of the trapezoidal cushion block is increased by 20%, the leveling bolts are combined with the laser reection prisms to realize the elevation error of 3i1.5 mm, the connection stability of the short positioning bar is improved, and an inclination rate of the cushion block is reduced to 0.1%. Fifthly, the Beidou RTK and the threedimensional laser scanner are linked for leveling, a grid layout error is 55 mm, the lling fullness of epoxy mortar is 295%, and a stress distribution uniformity at the bottom portion of the cushion block is improved by 30%. Sixthly, a graded water drainage rate is dynamically matched with the resilience rate, the vacuum preloading is introduced in a nal water level reduction stage to form a negative pressure gradient with self-weight preloading, and drainage consolidation is accelerated, so that a consolidation degree of the foundation reaches 98%, residual settlement after vacuum preloading is 52 mm, and a total preloading period is shortened by 15%. Seventhly, the rst-class and second-class control networks are distributed in the checkerboard shape, and the datum drift is eliminated by rechecking the cross-seam in the triangular mode, so that the plane accuracy is 3i3 mm and the setting -out efciency is improved by 50%. Eighthly, the U-shaped clamping base is combined with the electroslag pressure welding, the positioning deviation is 55 mm, the verticality deviation monitored by the laser plummet apparatus is 31 / 400, and a joint connection strength is improved by 25%. Ninthly, in combination with vibration, a bubble rate of the edge of the formwork is reduced to 30.5%, a compactness degree of the region with dense steel bars is 298%, the frequency conversion control adapts to a slump difference, and the energy consumption of vibration is reduced by 20%. Tenthly, according to the pier and abutment constructed by the construction method for the wharf pier and abutment of the present invention, the overall bearing capacity is improved by 30%, a cracking rate is reduced to 30.1 mm / m, and the design life is above 70 years. 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. DETAILED DESCRIPTION The present invention is further described in detail hereinafter with reference to the embodiments, so that those skilled in the art can implement according to the text of 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. It should be noted that all the experimental methods in the following embodiments are conventional methods without special instructions, and all the reagents and materials can be obtained from commercial channels without special instructions. In the description of the present invention, the orientation or position relationship indicated by the terms transverse, longitudinal, upper, lower, front, rear, left, right, vertical, horizontal, "top", "bottom", "inside". "outside", and the like is based on the orientation or position relationship shown in the accompanying drawings, it is only for the convenience of description of the present invention and simplication of the description, and it is not to indicate or imply that the indicated device or element must have a specic orientation, and be constructed and operated in a specic orientation. Therefore, the terms shall not be understood as limiting the present invention. One embodiment of the present invention provides a construction method for a wharf pier and abutment, which comprises the following steps: rst step: arranging prefabricated concrete cushion blocks on a surface of an underwater foundation subjected to a compaction treatment, distributing the cushion blocks in a 2 m><2 m grid, and leveling the cushion blocks to design elevations; second step: carrying out staged water injection and preloading on the leveled foundation, sequentially applying 50%, 80% and 110% design loads and carrying out pressure stabilization for 48 hours, 72 hours and 120 hours respectively, and reducing a water level in proportion after each stage of pressure stabilization; third step: arranging a threedimensional coordinate control network on the surface of the preloaded foundation, wherein a distance between control points is 5 m and a plane position deviation is 33 mm; fourth step: positioning a reinforcement cage on the basis of the three-dimensional coordinate control network, connecting the reinforcement cage with a short positioning bar preembedded in a top portion of the prefabricated concrete cushion block, mounting a composite steel formwork with vertical and horizontal stiffening ribs on the reinforcement cage, and sealing a seam of the composite steel formwork by a rubber waterstop; fth step: carrying out layered concrete pouring, wherein a thickness of each poured layer is controlled at 50 cm, and a time interval between layers does not exceed 2 / 3 of initial setting time, and carrying out combined vibration by penetrating and attaching vibrators after each layer is poured; and sixth step: removing a side formwork and keeping the continuous curing of a top formwork after reaching 70% of a design strength, wherein a surface humidity is kept at290% and a curing period is 221 days. In the above technical solution, the prefabricated concrete cushion blocks are distributed in the 2 m><2 m grid, an allowable adjustment range of a distance between the grids is 1.8 m to 2.2 m, and a leveling elevation error may be controlled within a range from i1.5 mm to i3.0 mm. A diameter of a leveling bolt in the bottom surface of the cushion block may be 40 mm, 45 mm or 50 mm, and a size of a leveling steel plate may be 150 mm><150 mmXlO mm to 200 mmX 200 mm>< 15 mm. The prefabricated cushion block may be made of C50 or C60 concrete, and an internal reinforcing mesh may be made of HRB400 grade steel, with a diameter of 8-12 mm. In the compaction treatment, a high-frequency hydraulic vibration hammer may be domestic YZD series or German BOMAG BW series, with a vibration frequency adjustment range of 2000-3500 rpm and a vibration amplitude of 1.0-2.5 mm. When the prefabricated cushion blocks are arranged, the vibration hammer may be mounted on the a barge deck rst, an operation position is xed through a positioning pile, and then Beidou RTK equipment (such as South NTS-362 series) may be used for setting out of the grid. The leveling bolt is screwed in the reserved hole in the bottom portion of the cushion block, and a contact surface between the bottom steel plate and the foundation is applied with epoxy resin glue to enhance a friction. After leveling, underwater epoxy mortar for lling a gap may be Sika 212 or MAPEI Underwater Mortar, a lling conduit is inserted into the gap at the edge of the cushion block, and a lling pressure is kept at 0.20.5 MPa. In the above technical solution, load proportions of staged water injection may be 40%-50%, 70%-80% and 100%-110%, and pressure stabilization time may be set as 24-48 hours, 60-72 hours and 100-120 hours. A water level reduction rate may be controlled in stages by 5%10%, 5%8% and 3%5% per day. Water injection equipment may be a submersible pump (such as Glenford SP series), with a ow rate of 50-100 m / h and a lift of 10-15 m. Vacuum preloading equipment may be a vacuum jet pump (such as Nantong Wanli VP series), with a vacuum degree kept at 80-90 kPa. During implementation, a water injection pipe is distributed along a periphery of the foundation, a pressure sensor (such as Honeywell MLH series) is used for water level monitoring, and data are collected once every 10 minutes. In a water drainage stage, a siphon is connected to a water collecting tank, and a water drainage rate is adjusted by an electric valve (such as Siemens SKB series). A vacuum preloading membrane covers the surface of the foundation, a sealing groove is lled with bentonite mud, and a vacuum degree under the membrane is wirelessly transmitted to a control terminal. In the above technical solution, a layering thickness of concrete may be 40 cm, 50 cm or 60 cm, a time interval between layers may be set to be 1 / 2 to 2 / 3 of initial setting time, and the initial setting time is measured by a penetration resistance instrument (such as a Beijing Construction Engineering JZ series). A penetrating vibrator may be a Zhejiang Qiming ZD-50 model penetrating vibrator, with a frequency of 3050 Hz; and an attaching vibrator may be a Fujian Mindong MF-150 model attaching vibrator, with an exciting force of 5-8 kN. A curing humidity may be kept by an automatic spraying system (such as Rain Bird XFD series), wherein a distance between spray nozzles is 1.5-2.0 m, and a water pressure is 0.3-0.6 MPa. When the concrete is poured, the rubber waterstop is embedded in the seam of the composite steel formwork, and a model of the rubber waterstop may be a 653 model in GB 18173.2-2014. The attaching vibrators are mounted on an outer side of the formwork at a distance of 1.2-1.8 m, and xed at intersection joints of stiffening ribs by bolts. During curing, the surface of the top formwork is covered with geotextile, a humidity sensor is embedded 2 cm below a surface of the concrete, and data are fed back to a control system in real time. In the present invention, through a synergistic effect of the graded water injection and preloading and the three-dimensional control network, the differential settlement of the foundation is reduced to i5 mm / 2 m, the plane positioning accuracy of the formwork is improved to 33 mm, the layered pouring thickness of concrete and the compactness degree after optimization by the vibration technology are increased by 15%, the curing period is extended to 21 days, and the structural durability is signicantly enhanced. According to the pier and abutment constructed by the construction method for the wharf pier and abutment of the present invention, the overall bearing capacity is improved by 30%, a cracking rate is reduced to 30.1 mm / m, and the design life is above 70 years. In another embodiment of the present invention, the construction method for the wharf pier and abutment further comprises: seventh step: removing all formworks, and painting an epoxy resin anti-corrosive coating on the surface of the pier and abutment for twice, wherein a rst paining amount is 300 g / m2 and a second painting amount is 200 g / m2, and a time interval between the two painting operations is not less than 8 hours. In the above technical solution, the rst painting amount of the epoxy resin coating may be set to be 250g / m2, 300g / m2 or 350g / m2, and the second painting amount of the epoxy resin coating may be set to be 150g / m2, 200g / m2 or 250g / m2. The time interval between the two painting operations is set to be 8 hours. 10 hours or 12 hours, which is specically adjusted according to an ambient temperature (IST-30°C). The epoxy resin material may be Sikaoorl61 or BASF MasterSeal 8100, and a ratio of a curing agent to a base material is set to be 1: 3 to l: 4 according to the manufacturer's instruction. A painting thickness may be detected by a wet lm thickness gauge (such as Elcometer 3230), a singlepass wet lm thickness is controlled at 300-400 um, and a dry lm thickness is 2200 um. According to the present invention, the epoxy resin anti-corrosive coating is painted on the surface of the pier and abutment for twice, a total painting amount of the epoxy resin coating is 500 g / m2, and a continuous dense protective layer is formed on the surface of the pier and abutment, so that a chloride ion permeability coefcient is reduced to 31.5><1012 m2 / s, and the service life after corrosion prevention is prolonged to above 30 years In another embodiment of the present invention, in the rst step, the compaction treatment specically comprises: backlling a graded sand and gravel mixture with a particle size of 5-40 mm on the surface of the underwater foundation in layers, wherein a mass ratio of sand to gravel is 1: 1.52.0, and a thickness of each backlled layer is not more than 30 cm; carrying out cross-compaction by a high-frequency hydraulic vibration hammer in layers, wherein an overlapping width of adjacent compaction wheel tracks is 2150m; wherein, when a bottom layer is compacted, a vibration frequency is kept at 3000-3300 rpm, a vibration amplitude is controlled at 12-16 mm, and the layer is compacted in horizontal and vertical directions for 3 times respectively, and when a surface layer is compacted, a vibration frequency is kept at 2200-2500 rpm, a vibration amplitude is controlled at 2.0-2.5 mm, and the layer is compacted in horizontal and vertical directions for twice respectively; and after compaction, controlling a surface layer porosity at 318%, controlling a bottom layer porosity at 322%, and making a porosity difference between adjacent measuring points not more than 3%, so as to nally make the bearing capacity of the foundation reach 2150 kPa and control a settlement difference within a range of i5 mm / 2 m. In the above technical solution, the mass ratio of sand to gravel may be set to be 1: 1.2, 1: 1.5 or 1: 2.0, and a particle size range of gravel may be 520 mm, 530 mm or 540 mm. A backlling thickness of each layer may be set to be 25 cm, 30 cm or 35 cm, a backlling material may be a mixture of river sand and granite gravel, and a neness modulus of sand is controlled at 2.3-3.0. A moisture content of the graded sand and gravel is determined by a drying method, and controlled at 6%9%. During backlling construction, a belt conveyor is mounted on the barge deck to transport the pre-mixed sand and gravel to an underwater operating plane. A tail end of the conveyor belt is provided with an adjustable discharge port, and a discharge height is controlled at 1.0-1.5 m to reduce segregation. After each layer is paved, a surface evenness is detected by a geoplane (such as Leica LSlO), and an allowable height difference is iS cm. In the above technical solution, the high-frequency hydraulic vibration hammer may be domestic YZD series or German BOMAG BW series, wherein a vibration frequency set for compacting the bottom layer is 2800-3300 rpm and a vibration frequency set for compacting the surface layer is 2000-2500 rpm, and a vibration amplitude set for the bottom layer is 1.0-1.8 mm and a vibration amplitude set for the surface layer is 1.8-2.6 mm. A number of compaction times may be set to be 24 in horizontal and vertical directions respectively for the bottom layer and may be set to be 1-3 in horizontal and vertical directions respectively for the surface layer, and the overlapping width of the compaction wheel tracks may be adjusted to be 12-18 cm. The vibration hammer moves through a guide rail on a oating platform, and a traveling speed is controlled at 1.0-1.5 m / min. The compaction is carried out in a crossed mode according to a zigzag path, and an overlapping region of adjacent wheel tracks is marked with red paint. After the bottom layer is compacted, the compactness degree is detected by a sand lling method, and a relative density is required to be 295%. When the surface layer is compacted, the vibration hammer is equipped with a at-bottomed rammer, wherein a size of the rammer is 1.2 mX 1.2 rn, and a bottom portion of the rammer is welded with a wear-resistant steel plate (10) having a thickness of 12 mm. In the above technical solution, a nuclear densitometer (such as Campbell MC3) may be used for porosity detection, a distance between detection points is 2 m><2 m, an allowable surface layer porosity is 318% and an allowable bottom layer porosity is 322%, and a threshold of difference between adjacent detection points is set to be 2% or 3%. A static load tester (such as CCCC Xi'an Road Construction Machinery YZ300) is used for testing the bearing capacity of the foundation, wherein a loading rate is 0.51.0 MPa / min, and a nal bearing capacity is 2150 kPa. An electronic level (such as Topcon DL-501) is used for measuring a settlement difference, wherein an allowable deviation for every 2 m of measuring line is i4 mm or 15 mm. Detection data are wirelessly transmitted to a data processing terminal to automatically generate a porosity distribution cloud map. An unqualied region is marked, and subjected to local pressure compensation or replacement treatment, wherein a number of pressure compensation times does not exceed 3. A time interval of repeated measurement of the settlement difference is 24 hours, and when a variable quantity of 3 consecutive measurements is 30.1 mm / h, the foundation is deemed as being stable. According to the present invention, a bidirectional crosscompaction path is combined with layered vibration parameter adjustment to solve the common problems of unconsolidated surface layer and poorly compacted bottom layer of the underwater foundation. Through a vibration mode combination of lowfrequency and highamplitude vibration for the surface layer and highfrequency and low-amplitude vibration for the bottom layer, and the difference control between the surface layer and the bottom layer (33%) and the settlement gradient limitation (iS mm / 2 m), the bearing uniformity of the foundation is ensured, so that the compaction efciency is improved by 40%, and the compliance rate of the settlement differenceis increased to 95%. In another embodiment of the present invention, in the rst step, the prefabricated concrete cushion block is made of C50 high-strength concrete, a reinforcing mesh is pre-embedded inside the cushion block, the prefabricated concrete cushion block is trapezoidal in shape, with a top surface size of 1.4 m><l.4 m, a bottom surface size of 1.6 m><l.6 m and a height of 40 cm, the bottom surface is provided with 4 reserved leveling holes with a diameter of 45 mm, the reserved leveling hole is provided with a leveling bolt in screw t with the leveling hole, a bottom portion of the leveling bolt is welded with a steel plate with a size of 180 mm><l80 mm><12 mm, laser reection prisms are preembedded in four comers of the top surface of the prefabricated concrete cushion block, and the short positioning bar is pre-embedded in a middle portion of the top surface. In the above technical solution, a concrete strength grade of the prefabricated cushion block may be C50 or C55, the internally embedded reinforcing mesh may be made of HRB400 or HRB500 grade steel, with a diameter of 6-12 mm, and a distance between the grids is 100-150 mm. The top surface size of the cushion block may be set to be 1.3 m><1.3 m, 1.4 mX1.4 m or 1.5 mXl.5 m, the bottom surface size may be set to be 1.5 mXl.5 m, 1.6 m><l.6 m or 1.7 mXl.7 m, and the height may be set to be 35 cm, 40 cm or 45 cm. When the prefabricated cushion block is produced, a highfrequency vibration table (such as AutoCAM series of Hess Group in Germany) may be used for concrete vibration compaction, wherein a vibration frequency is 50-60 Hz, and single molding time is 3-5 minutes. After demoulding, the cushion block is cured in a steam curing kiln (such as Zoomlion HZSl80 supporting equipment) at a curing temperature of 5060°C and a humidity 290% for 48 hours. The reinforcing mesh is bound by an automatic welding machine (such as Panasonic YD-350KR), wherein a distance between welding points is 100-200 mm. In the above technical solution, the diameter of the leveling hole may be set to be 40 mm, 45 mm or 50 mm, a hole depth is 3045 cm, and a stainless steel threaded sleeve is pre-embedded in a hole wall. The leveling bolt has a specication of M40, M45 or M50 and a length of 50-70 cm, and is made of Q35 5B steel and subjected to surface galvanization. A size of a bottom steel plate may be 160 mmX160 mm><10 mm, 180 mmX180 mm><12 mm or 200 mm><200 mm>< 15 mm, and the steel plate and the bolt are welded by C02 gas shielded welding, wherein a height of a weld leg is 26 mm. When the leveling bolt is mounted, the leveling bolt is screwed into the threaded sleeve of the reserved hole through a wrench, wherein a screw-in depth is 220 cm. A bottom portion of the steel plate may be applied with epoxy resin glue to enhance a friction with the foundation. After leveling, an exposed length of the bolt is measured and controlled by a total station (such as Leica T816), wherein an error is 3:2 mm. In the above technical solution, the laser reection prism may be Leica GPR121 or Topcon RHP-3, the prisms are pre-embedded in the four corners of the top surface of the cushion block, and a distance between a center of the prism and an edge of the cushion block is 10-15 cm. The short positioning bar may be an HRB400 grade steel bar, with a diameter of 16-20 mm, an exposed length of 10-15 cm and a pre-embedded depth of 230 cm, and an M16 thread is processed at a top portion of the bar to connect the reinforcement cage. When the prism is mounted, a levelness error is kept at 30.10 by a special xing frame, and a position of the prism is calibrated by a three-dimensional laser scanner (such as Focus S350). A verticality of the short positioning bar is detected by a plummet apparatus (such as Bosch GLL 3-80), with a deviation of 31 / 500. After being pre-embedded in the top surface of the cushion block, the prisms and the short bars are covered with a protective cover to prevent construction damage. In the present invention, a contact area of the bottom surface of the trapezoidal cushion block is increased to improve the overturning resistance of the cushion block, the leveling bolts are combined with the laser reection prisms to realize the elevation error of 31:15 mm, the connection stability of the short positioning bar is improved, and an inclination rate of the cushion block is reduced to 0.1%. In another embodiment of the present invention, in the rst step, the arranging the prefabricated concrete cushion blocks, specically comprises: arranging the prefabricated concrete cushion blocks according to the 2 m><2 m grid in a staggered manner, wherein a distance between edges of adjacent prefabricated concrete cushion blocks is 50 cm, and setting out by using a total station combined with a Beidou RTK positioning system, wherein a plane positioning error is 35 mm; scanning the laser reection prisms by a three-dimensional laser scanner to monitor an elevation of the top surface of the prefabricated concrete cushion block in real time, and dynamically adjusting heights of the leveling bolts, wherein, after leveling, an elevation error is 3i1.5 mm, and a height difference between adjacent cushion blocks is 32 mm; and after leveling, lling underwater epoxy mortar into a gap at the bottom portion of the cushion block, wherein a compressive strength is 250 MPa, and a lling fullness is 295%. In the above technical solution, the distance between the grids of the prefabricated concrete blocks may be set to be 1.6 m><l.6 m, 2.0 m><2.0 m or 2.2 m><2.2 m, and the allowable adjustment range of the distance between edges of adjacent blocks is 4060 cm. The positioning and settingout may be realized by the total station (such as Leica TS16) combined with the Beidou RTK system (such as CHC Navigation i70), and a threshold of the plane positioning error is set to be 1:3 mm, iS mm or 1:7 mm. When the cushion blocks are staggered, a staggering distance between adjacent rows may be set to be 0.5 m, 0.75 m or 1.0 m. The total station is arranged on a xing base of the barge deck, Beidou RTK mobile stations are distributed at four corners of an operation region, and a base station is arranged at a stable point on the shore During setting-out, coordinate data are received through a record book, a position of a center point of the cushion block is displayed in real time, and an operator adjusts a lifting xture to allow a position deviation of the cushion block to be 35 mm. The cushion block is temporarily xed by a magnetic base to be adsorbed on a side surface of the mounted cushion block. In the above technical solution, the threedimensional laser scanner may be Focus S350, with a scanning frequency of 10-30 Hz, and generates point cloud data of the top surface of the cushion block in real time. The height of the leveling bolt is adjusted by an electric wrench (such as Makita TW035) at an adjustment accuracy of i0.1 mm, and a screw-in speed of the bolt is controlled at 2-5 rpm. A threshold of the elevation error may be set to be i1.0 mm, i1.5 mm or 1:20 mm, and an allowable range of height difference between adjacent blocks is 1 mm, 2 mm or 3 mm. During leveling, coordinate data of the laser reection prisms are wirelessly transmitted to the control terminal to generate a three-dimensional elevation heat map. When the deviation exceeds the threshold, the edge of the cushion block is jacked up by the hydraulic jack, and heights of diagonal bolts are adjusted synchronously. After leveling, a contact surface between the bottom portion of the cushion block and the foundation is detected by a gap gauge, and a local gap is 32 mm. In the above technical solution, the underwater epoxy mortar may be Sika 212 or MAPEI Underwater Mortar, the compressive strength is set to be 45 MPa, 50 MPa or 55 MPa, and the initial setting time is 3060 minutes. The lling conduit may be a DN50 stainless steel hose, and the lling pressure is controlled at 0.1-0.3 MPa, 0.3-0.5 MPa or 0.50.8 MPa. The fullness is detected by an endoscope (such as Olympus IPLEX NX), and a probe is inserted into a reserved inspection hole for observation. Before lling, a temporary cofferdam is mounted around the cushion block, which has a height of 510 cm, and prevents the mortar from overowing. During lling, the mortar is lled from a midpoint of a long side of the cushion block at a ow rate controlled at 5-10 L / min, and adjacent exhaust holes are sealed after the mortar overows. After lling, the compactness degree is detected by an ultrasonic detector (such as Opton UFD700), and it is judged that the compactness degree is qualied when a wave speed is 23,500 m / s. According to the present invention, the Beidou RTK and the three-dimensional laser scanner are linked for leveling, a grid layout error is 35 mm, the lling fullness of epoxy mortar is 295%, and a stress distribution uniformity at the bottom portion of the cushion block is improved by 30%. In another embodiment of the present invention, the second step specically comprises: carrying out water injection and preloading on the leveled foundation in three stages, wherein water is injected to 50% of the design load in a rst stage, with a water injection height H1, and after carrying out the pressure stabilization for 48 hours, the water is drained according to daily water level reduction of 510% H1 until the resilience rate of the foundation is 30.05 mm / h; water is injected to 80% of the design load in a second stage, with a water injection height H2, and after carrying out the pressure stabilization for 72 hours, the water is drained according to daily water level reduction of 38% H2 until the resilience rate of the foundation is 30.03 mm / h; and water is injected to 110% of the design load in a third stage, with a water injection height H3, and after carrying out the pressure stabilization for 120 hours, the water is drained according to daily water level reduction of 55% H3 until the resilience rate of the foundation is 30.01 mm / h; and when a nal water level is reduced to an initial groundwater level, assisting water drainage by vacuum preloading at a vacuum degree of 280 kPa for 48 hours. In the above technical solution, load proportions of staged water injection may be set to be 40%-50%, 50%-80% and 80%-110%, and pressure stabilization time may be adjusted to be 36-48 hours, 60-72 hours or 100-120 hours. The water injection heights H1, H2 and H3 may be converted into actual water depths of 0.81.2 m, 1.52.0 m and 2.22.8 m according to design load percentages. The water injection equipment may be a submersible pump (such as Grundfos SP series), with a ow rate of 80120 m3 / h and a lift of 12-18 m. The water level may be monitored by mounting a pressure sensor (such as E+H PMP135), with a measuring range of 03 m and an accuracy of i0.1% FS. The water injection pipes are annularly arranged along an edge of the foundation, a distance between the pipes is 2-3 m, and a water outlet is provided with an anti-scour gravel cushion. During rst water injection, a cumulative water injection amount is calculated by a ow meter, and a valve is closed after the amount reaches 50% of the design load. During pressure stabilization, a distribution distance between settlement observation points is 5 m><5 m, data are collected every 2 hours by an electronic level (such as Topcon DL-501), and when the settlement rate is 30.1 mm / h, the foundation is deemed as being stable. In the water drainage stage, the siphon is connected to the water collecting tank, a water drainage amount is monitored by an electromagnetic owmeter (such as KROHNE OPTIFLUX 4300), and a threshold of daily decline is set to be 8%10%, 6%8% or 4%5%. In the above technical solution, the vacuum preloading equipment may be a vacuum jet pump (such as Nantong Wanli VP series), wherein a vacuum degree is controlled at 8090 kPa, a distance between exhaust pipes is 3-4 m, and an embedding depth is 0.5-0.8 m. A sealing lm is a PVC lm with a thickness of 0.3-0.5 mm, an overlapping width is 220 cm, and a seam is applied with a special adhesion agent (such as Oriental Yuhong HCA-102). During vacuum preloading, an embedding depth of a pore water pressure sensor is 1.0-1.5 m, monitoring data are wirelessly transmitted to a monitoring platform, and when a consolidation degree is 295%, the operation is stopped. According to the present invention, a graded water drainage rate is dynamically matched with the resilience rate, the vacuum preloading is introduced in a nal water level reduction stage to form a negative pressure gradient with self-weight preloading, and drainage consolidation is accelerated, so that a consolidation degree of the foundation reaches 98%, residual settlement after vacuum preloading is 32 mm, and a total preloading period is shortened by 15%. In another embodiment of the present invention, in the third step, the arranging the three-dimensional coordinate control network, specically comprises: using the laser reection prisms pre-embedded in the four corners of the top surface of the prefabricated concrete cushion block as datum points, and establishing a rst-class control network through more than 3 prism datum points by a free station method of the total station, wherein a distance between surveying stations is 230 m; arranging a second-class control point on the short positioning bar in the middle portion of the top surface of the prefabricated cushion block, and mounting a surveying mark through a customized L-shaped connector; setting a region of 5 m distance between the second-class control points into a "checkerboard"-shaped array, and rechecking a cross-seam region in a triangular mode by using the prisms of adjacent cushion blocks; and rechecking the control network by Beidou or GNSS realtime dynamic positioning, wherein a plane accuracy is 3:3 mm, and an elevation accuracy is 321:3 mm. In the above technical solution, the distance between the surveying stations of the rst-class control network may be set to be 25 m, 30 m or 35 m, and an allowable mounting levelness error of the datum point prism is 50.050. The total station may be Leica TSl6, at least 3 datum points are required in the free station method, and a number of observation sets is 22. The L-shaped connector of the secondclass control point is made of stainless steel 304, with a size of 150 mmXlOO mmX8 mm, and xed on the top portion of the short positioning bar by a bolt. An allowable adjustment range of a distance between the second-class points is 4 m, 5 m or 6 m, and a diagonal distance between adjacent points in the "checkerboard"shaped array is 37.5 m. When the second-class control point is mounted, a vertical edge of the L-shaped connector is welded to the top portion of the short positioning bar, and a horizontal edge of the Lshaped connector is provided with the surveying mark. In a cross-seam rechecking region, 3 adjacent cushion block prisms are selected to form an equilateral triangle with a side length of 2-3 m, and a threshold of a closing error is set to be 1:2 mm, 1:3 mm or 1:4 mm. During rechecking, the Beidou receiver mobile stations are arranged above the second-class points, static observation time is 230 minutes, and Trimble Business Center software is used for data calculation. In the above technical solution, an allowable plane accuracy error of the control network is i2 mm, i3 mm or i4 mm, and an allowable elevation accuracy error is i2 mm, i3 mm or i4 mm. After data collection, the data are calculated by least square adjustment, and a mean square error of a unit weight is 31.5 mm. An outoftolerance point is re-measured on site, a number of re-measurement times is 33, and after a gross error is nally eliminated, a coverage rate of the control network is 298% . According to the present invention, the rstclass and second-class control networks are distributed in the checkerboard shape, and the datum drift is eliminated by rechecking the cross-seam in the triangular mode, so that the plane accuracy is 31:3 mm and the setting -out efciency is improved by 50%. In another embodiment of the present invention, in the fourth step, the positioning and connecting the reinforcement cage, specically comprises: positioning corner points of the reinforcement cage by a polar coordinate method of the total station of the three-dimensional coordinate control network, wherein a positioning deviation is 3i5 mm; arranging a Ushaped positioning clamping base with an adjustable height at a bottom portion of the reinforcement cage, preliminarily connecting and positioning the Ushaped positioning clamping base with the short positioning bar pre-embedded in the top surface of the prefabricated concrete cushion block, and then xing by electroslag pressure welding; monitoring a verticality of the reinforcement cage by a laser plummet apparatus, and adjusting by a jack when a deviation exceeds 1 / 400; and connecting adjacent reinforcement cages by a shaped angle steel connecting plate. In the above technical solution, when angular points of the reinforcement cage are positioned, the total station may be Leica TS16, and an allowable setting-out deviation in the polar coordinate method is set to be i3 mm, iS mm or 1:7 mm. The Ushaped positioning clamping base may be made of a Q23 5B steel plate, with a thickness of 10-15 mm, an allowable adjustment range of an opening width of the clamping base is 150-200 mm, and a bottom portion of the clamping base is provided with an M20 adjusting bolt, with an adjustment stroke ofi30 mm. The short positioning bar and the Ushaped clamping base are initially connected by a temporary xture, and a clamping force of the xture is 25 kN. An electroslag pressure welding machine may be Tangshan Panasonic YD-500FR, wherein a welding current is set to be 400-450 A, a welding voltage is set to be 38-42 V, and a welding ux may be H1431. During welding, a contact surface between the short positioning bar and the U-shaped clamping base is cleaned to expose metallic luster, and a lling height of a weld joint is 28 mm. The laser plummet apparatus may be Bosch GLL 3-80, a threshold of a verticality deviation is set to be 1 / 300, 1 / 400 or 1 / 500, and a distance between monitoring points is 32 m. The jack may be an Enerpac RC106 model, a jacking speed is controlled at 0.5-1.0 mm / s, and a wedge-shaped sizing block is used for temporary xation after rectication. The angle steel connecting plate may be made of L100><63><8 mm hot-rolled angle steel, with a length of 200-300 mm, and the connecting bolt is an 8.8-grade M16 high-strength bolt, with a pre-tightening force of 110-130 kN. When adjacent reinforcement cages are connected, a contact surface between the angle steel connecting plate and a main reinforcement is applied with antirust paint, and weld appearance inspection is carried out according to a GB 50661 standard. In the present invention, the U-shaped clamping base is combined with the electroslag pressure welding, the positioning deviation is 35 mm, the verticality deviation monitored by the laser plummet apparatus is 31 / 400, and a joint connection strength is improved by 25%. In another embodiment of the present invention, in the fth step, the carrying out combined vibration by the penetrating and attaching vibrators, specically comprises: symmetrically mounting the attaching vibrators at an intersection joint of vertical and horizontal stiffening ribs of the composite steel formwork, wherein a distance between two adjacent attaching vibrators is 31.5 m, and connecting the attaching vibrators with the composite steel formwork by elastic vibration reduction; quincuncially distributing vibration points for the penetrating vibrators, wherein a distance between the vibration point and an edge of the composite steel formwork is 3200 mm, and a vibration depth exceeds 2 / 3 of a concrete thickness of the layer; during vibration, making the penetrating and attaching vibrators work at the same time, and turning on the attaching vibrators 5 seconds earlier than the penetrating Vibrators and turning off the attaching Vibrators 10 seconds later than the penetrating vibrators; and carrying out frequency converting control over the penetrating vibrators at 30-50 Hz, and adjusting the frequency in real time according to a slump of concrete, wherein, when the slump is >180 mm, the frequency is 30 Hz, and when the slump is 3180 mm, the frequency is 50 Hz. In the above technical solution, a mounting distance between of the attaching vibrators may be set to be 1.2 m, 1.5 m or 1.8 m, and an elastic vibration damping connector may be a rubber vibration damping pad, with a thickness of 10-15 mm and a Shore hardness of 50-60 HA. The vibrator may be a Fujian Mindong MF150 model or a Zhejiang Qiming ZD80 model, with an exciting force range of 510 kN, and is xed at the intersection joint of the vertical and horizontal stiffening ribs of the composite steel formwork by the M12 bolt. During mounting, the intersection joint of the stiffening ribs is set out and positioned by the total station, and an allowable position deviation is i3 mm. A contact surface between the rubber vibration damping pad and the formwork is applied with silicone grease to reduce a transmission loss of high-frequency vibration. In the above technical solution, a distance between the quincuncially distributed vibration points of the penetrating vibrators may be set to be 300 mm, 400 mm or 500 mm, and a threshold of the distance between the vibration point and the edge of the formwork is set to be 150 mm, 200 mm or 250 mm. The vibration depth may be controlled at 1 / 2, 2 / 3 or 3 / 4 of the thickness of the layer, and is 25 cm, 33 cm or 37 cm respectively when the pouring layer is 50 cm. The penetrating vibrator may be a Zhejiang Qiming ZD50 model or a Zoomlion ZDN-50 model, wherein a diameter of a rod head is 5070 mm, and a noload frequency is 45-55 Hz. During vibration, the operator inserts the control rod head at a speed of 0.5 -1 .O m / s according to a principle of fast insertion and slow pulling", and single-point vibration time is 2040 seconds. In the above technical solution,the attaching vibrators are turned on 5 seconds earlier than the penetrating vibrators, and delay time of turning off may be set to be 8 seconds, 10 seconds or 12 seconds. A frequency conversion controller may be Schneider ATV320 series, with a frequency adjustment range of 2555 Hz. When the slump of concrete is >180 mm, the vibration frequency is set to be 25 Hz, 30 Hz or 35 Hz; and when the slump of concrete is 3180 mm, the vibration frequency is set to be 45 Hz, 50 Hz or 55 Hz. A standard slump cone is used in a slump test, the test is carried out according to GB / T 50080, and at least 3 groups are tested for every 50 m3 of concrete. In the present invention, in combination with vibration, a bubble rate of the edge of the formwork is reduced to 30.5%, a compactness degree of the region with dense steel bars is 298%, the frequency conversion control adapts to a slump difference, and the energy consumption of vibration is reduced by 20%. Another embodiment of the present invention provides a pier and abutment obtained by the construction method for the wharf pier and abutment of the present invention, and compared with a wharf pier and abutment obtained by a conventional construction method, the overall bearing capacity of the wharf pier and abutment of the present invention is improved by 30%, a cracking rate is reduced to 30.1 mm / m, and the design life is above 70 years. 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 wharf pier and abutment and the construction method therefor according to the present invention are obvious to those skilled in the art. Although the implementations of the present invention have been disclosed above, the implementations are 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 without departing from the general concept dened by the claims and the equivalent scope.

Claims

1. Construction method for a pier and abutment of quay, comprising the following steps: first step: arranging precast concrete cushion blocks on a surface of an underwater foundation subjected to a compaction treatment, the distributing the cushion blocks into a 2m X 2m grid, and leveling the pillow blocks to design heights; second step: performing phased water injection and preloading on the leveled foundation, successively applying 50%, 80% and 110% design loads and performing pressure stabilization for 48 hours, 72 hours respectively hour and 120 hours, and lowering a water level proportionally after each stage of pressure stabilization; third step: arranging a three-dimensional coordinate control network on the surface of the preloaded foundation, with a distance between control points of 5 m, and a deviation of plane position S is 3 mm; fourth step: placing a gun cage based on the three-dimensional coordinate control network, connecting the gun cage to a short positioning bar pre-embedded in an upper part of the prefabricated concrete cushion block, mounting composite steel formwork with vertical and horizontal stiffening ribs on the gun cage, and sealing a seam of the composite steel formwork by means of a rubber water stop; fifth step: performing layered concrete pouring, where a thickness of each poured layer is regulated at 50 cm, and a time interval between layers not more than 2 / 3 of the initial hardening time, and performing combined vibrations by means of penetration- and bonding vibrators after each layer is poured; and sixth step: removing a side formwork, and maintaining the continuous hardening of a top formwork after reaching 70% of a design strength, whereby a surface moisture level is maintained at Z 90% and a curing period Z 21 days is.

2. Construction method for a pier and abutment of quay according to claim 1, further including: seventh step: removing all formwork, and painting a anti-corrosive coating of epoxy resin on the surface of the pier abutment for two times, where the quantity of the first painting is 300 g / m2 and the quantity of the second painting is is 200 g / m2, and a time interval between the two painting operations is not less than 8 hours.

3. Construction method for a pier and abutment of quay according to claim 1, with the characteristic, which in the first step, specifically includes the compaction treatment: backfilling of a graded sand and gravel mixture with a particle size of 5 - 40 mm on the surface of the underwater foundation in layers, with a mass ratio of sand to gravel 1 : 1.5 - 2.0 and a thickness of each refilled layer is not more than 30 cm; the performing cross-compaction by means of a high-frequency hydraulic vibratory hammer in layers, with an overlapping width of adjacent compaction wheel tracks 2 15 cm amounts to, where when a bottom layer is compacted, a vibration frequency is held at 3000 - 3300 rpm, a vibration amplitude is controlled at 1.2 - 1.6 mm and the layer is compacted in horizontal and vertical directions for 3 times respectively, and where when a surface layer is compacted, a vibration frequency is maintained at 2200 - 2500 rpm, vibration amplitude is controlled at 2.0 - 2.5 mm and the layer is compacted in horizontal and vertical directions for two times respectively; and after compaction, arranging of a porosity of surface layer at S 18%, controlling a porosity of bottom low at S 22%, and not making a porosity difference between adjacent measuring points more than 3%, to ultimately reach the foundation's load-bearing capacity of 2,150 kPa and to regulate a deposit difference within a range of i 5 mm / 2 m.

4. Construction method for a pier abutment of a quay according to claim 1, with the feature, that in the first step, the precast concrete cushion block is made of C50 concrete high strength, with a reinforcing network pre-embedded in the pillow block, whereby the precast concrete cushion block is trapezoidal, with a size of a top surface of 1.4m X 1.4m, a bottom surface size of 1.6m X 1.6m and a height of 40 cm, with the bottom surface provided with 4 reserved leveling holes with a diameter of 45 mm, with the reserved leveling hole being provided with a leveling bolt in screw matching the leveling hole, whereby a bottom part of the leveling bolt is welded with a steel plate with a size of 180 mm X 180 mm X 12 mm, with laser reflection prisms pre-embedded in four corners of the top surface of the precast concrete cushion block, and where the short positioning rod is pre-embedded in a central portion of the top surface.

5. Construction method for a pier and abutment of quay according to claim 4, with the feature, that in the first step, arranging the precast concrete cushion blocks specifically includes: arranging the precast concrete cushion blocks according to the 2m X 2m grid in a stacked manner, with a distance between edges of adjacent prefabricated concrete cushion blocks 50 cm, and expanding it using a total station combined with a Beidou RTK positioning system, where a plane positioning error S 5 mm is; scanning the laser reflection prisms by means of a three-dimensional laser scanner to increase the top surface of the precast concrete cushion block in real time, and dynamically adjust heights of the leveling bolts, where after leveling a height error S is i1.5 mm and a height difference between adjacent pillow blocks S is 2 mm; and after leveling, filling underwater epoxy mortar into an opening in the bottom portion of the pillow block, where a compressive strength is 2 50 MPa and a filling fullness of 2 95 %.

6. Construction method for a pier and abutment of quay according to claim 1, with the feature, which specifically includes the second step: performing water injection and pre-charging on the leveled foundation in three phases, with water being injected up to 50% of the design load in a first phase, with a water injection height H1, and after carrying out the pressure stabilization for 48 hours, the water is drained according to the daily water level reduction of S 10 % H1 until the foundation resilience rate S 0.05 mm / h is; where water is injected up to 80% of the design load in a second stage, with a water injection height H2, and after carrying out pressure stabilization for 72 hours, the water discharged according to the daily water level reduction of S 8 % H2 to the foundation spring velocity S is 0.03 mm / h; and water is injected until 110% of the design load in a third phase, with a water injection height H3, and after the carrying out the pressure stabilization for 120 hours, the water is drained according to the daily water level reduction of S 5 % H3 to the foundation resilience rate S 0.01 mm / h is; and where when a final water level is lowered to an initial groundwater level, water drainage is supported by means of vacuum preload at a vacuum degree of 280 kPa for 48 hours.

7. Construction method for a pier and abutment of quay according to claim 4, with the feature, that in the third step, the arrangement of the three-dimensional coordinate control network specifically includes: the use of the laser reflection prisms pre-embedded in the four corners of the top surface of the prefabricated concrete cushion block as datum points, and establishing a first-class control network by more than 3 prism points by a total station free station method, where the distance between the measuring stations is 2 30 m; the arrangement of a second class control point on the short positioning rod in the middle section of the top surface of the prefabricated pillow block, and mounting a measurement mark by a custom L-shaped connector; setting a 5m distance area between the second-class control points in a "checkerboard-shaped array," and rechecking a cross-seam area in a triangular mode using the prisms of adjacent pillow blocks; and rechecking the control network by by means of real-time dynamic positioning of Beidou or GNSS, where the accuracy of plane S i3 mm is and the accuracy of elevation S i3 mm.

8. Construction method for a pier-abutment of quay according to claim 7, with the feature, which in the fourth step, specifically includes placing and connecting the gun cage: placing corner points of the gun cage by means of a polar total station coordinate method of the three-dimensional coordinate control network, where a positioning deviation S is i5 mm; the arranging a U-shaped positioning clamp base with an adjustable height on a bottom part of the gun cage, temporarily connecting and positioning the U-shaped positioning clamp base with the short positioning rod pre-embedded in the top surface of the precast concrete cushion block, and then fixing it by by means of electroslag pressure welding; monitoring the verticality of the gun cage by by means of a laser plummet device, and adjusting it by means of a jack when a deviation is greater than 1 / 400; and connecting adjacent gun cages by means of a shaped angle steel connection plate.

9. Construction method for a pier and abutment of quay according to claim 1, with the feature, that in the fifth step performing combined vibrations by means of penetration and attachment vibrators specifically includes: symmetrical mounting of the attachment vibrators at an intersection of vertical and horizontal stiffening ribs of the composite steel formwork, where a distance between two adjacent bonding vibrators S 1.5 m, and connecting the bonding vibrators to the composite steel formwork by by means of elastic vibration reduction; quincuncially distributing vibration points for the penetration vibrators, where the distance between the vibration point and an edge of the composite steel formwork S 200 mm and a vibration depth is greater than 2 / 3 of a concrete thickness of the layer; during vibration, simultaneously operating the penetration and attachment vibrators, and turning on the attachment vibrators 5 seconds earlier then the penetration vibrators and turning off the attachment vibrators 10 seconds later then the penetration vibrators; and performing frequency conversion control over the penetration vibrators at 30 - 50 Hz, and adjusting the frequency in real time according to according to a concrete slump, where when the slump is > 180 mm, the frequency is 30 Hz, and when the depression S is 180 mm, the frequency is 50 Hz. 5 10. Pier and abutment of quay, which is obtained by a construction method for a pier and abutment of quay according to any of claims 1 to 9.