Construction process for densely-arranged piles

Abstract

The present invention provides a construction process for densely-arranged piles, the construction process comprising the following steps: constructing a protective barrier along the periphery of a backwater in a design drawing, wherein the backwater is specifically formed by several densely-arranged piles; the several densely-arranged piles being provided with lifting lugs at the tops and being bundled at the lower portions, and the several densely-arranged piles being hoisted sequentially in the manner of firstly bundling the piles and then hoisting same; performing pile sinking by means of sequentially driving the piles until the sinking of all the densely-arranged piles is completed, wherein the clear distance between adjacent densely-arranged piles is 80-200 mm; and using rib plates to form flexible pouring cavities between the adjacent densely-arranged piles, and in the flexible pouring cavities, using fine aggregate concrete to complete cavity pouring between the adjacent densely-arranged piles, so that the several densely arranged piles form an integral breakwater wave-blocking structure. The present invention is mainly used for the construction of densely-arranged piles having a relatively small pile spacing, and thus the method of combining flexible pouring cavities with the pouring of fine aggregate concrete is used to achieve the blockage between adjacent densely-arranged piles.

Description

Construction technology of densely packed piles Technical Field

[0001] The invention relates to the technical field of breakwaters formed by using densely packed piles on docks, and in particular to a construction process of densely packed piles. Background Art

[0002] In the prior art, when closely packed piles are used to form a breakwater, the distances between the piles are relatively large. Therefore, most piles are directly hoisted and sunk by setting lifting lugs at a certain distance from the top and bottom of the piles. However, when the distance between adjacent piles is small, the lifting lugs set at a certain distance from the bottom of the piles will make it impossible to sink adjacent steel piles.

[0003] Furthermore, the traditional pile-based breakwater wave-blocking structure is achieved by welding locking joints on the densely packed piles, and then "biting" the locking joints of adjacent densely packed piles to each other, so that the densely packed piles form an overall force-bearing wave-blocking structure, thereby reducing the waves in the area behind the densely packed piles.

[0004] Summary of the Invention

[0005] The purpose of the present invention is to provide a construction process for closely spaced piles, which aims to lift piles by means of lifting ears in combination with bundled piles, and by means of ribs forming flexible pouring cavities, etc., which not only realizes the sinking of piles with small spacing, but also eliminates mutual constraints between the ribs of adjacent closely spaced piles, thereby improving the pile sinking efficiency. After the pouring is completed, the flexible cavity and the closely spaced piles form an overall wave-blocking structure with a good wave-blocking effect.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions.

[0007] The construction process of densely packed piles includes the following steps:

[0008] Along the perimeter of the breakwater in the design drawings, a fence is constructed for protection. The breakwater is specifically formed by a number of closely spaced piles.

[0009] Using the lifting lugs set on the top and the piles tied at the bottom, several closely spaced piles are lifted in sequence in the manner of first tying the piles and then lifting them;

[0010] Sink the piles in a sequential manner until all closely spaced piles are sunk, with a net distance of 80-200mm between adjacent closely spaced piles;

[0011] A flexible pouring cavity is formed between adjacent closely spaced piles by using ribs, and fine stone concrete is poured into the flexible pouring cavity to complete the cavity pouring between adjacent closely spaced piles, so that several closely spaced piles form an integral breakwater wave-blocking structure.

[0012] A plurality of closely spaced piles are located on the same horizontal line, or are vertically arranged on two sides of a right angle to form the breakwater.

[0013] Furthermore, when a plurality of closely spaced piles are arranged at right angles, the ribs at the corners are triangular plates, and a pouring cavity is formed between the triangular plates.

[0014] Furthermore, the length of the densely packed piles is 40-50m, and the depth of the densely packed piles submerged in water is 25m-35m.

[0015] Furthermore, the lifting lug is arranged at a position 2m or 5m downward from the top of the densely packed pile, and the lifting lug is cut off when the densely packed pile is 1-2m away from the top of the adjacent densely packed pile during the pile sinking process.

[0016] Furthermore, the ribs are arranged at the middle and upper parts of the densely packed piles, and the length of the ribs is greater than the difference between the pile top elevation and the mud surface elevation.

[0017] Furthermore, between adjacent closely spaced piles, the ribs parallel to each other and the closely spaced piles form a flexible perfusion cavity with an escape gap, and the length of the flexible perfusion cavity along the circumferential direction is greater than the length of the gap between the closely spaced piles.

[0018] Furthermore, at least two staggered avoidance gaps are provided in the same flexible grouting cavity, and the rotation angle of the pile body during the close-packed pile driving is less than 10°.

[0019] Furthermore, it also includes a longitudinal beam located at the top of the breakwater, and steel bars are arranged in the flexible pouring cavity along a direction perpendicular to the longitudinal beam.

[0020] Furthermore, the method further includes forming a civil engineering mold bag placed in a flexible pouring cavity, wherein the pouring speed of the flexible pouring cavity during pouring is 1m 3 / h-2m 3 / h.

[0021] The beneficial effects of the present invention are as follows:

[0022] Firstly, in the present invention, for the lifting of densely packed piles, a lifting device is used to lift the piles, and the lifting ears at the top of the piles are used as the lifting points. The bottom of the piles are directly tied up with two circles along the circumference of the densely packed piles. Combined with the actual weight of the piles, the length of the steel wire rope used for tying the piles is not less than 28 meters, and the diameter should be not less than 34 mm.

[0023] Secondly, in the present invention, there is no mutual constraint between the ribs between adjacent closely spaced piles, and the pile sinking efficiency is high; the deviation of the pile sinking can be flexibly dealt with; the full-length mold bag concrete is poured into the cavity between the ribs to form an integral force-bearing structure with the closely spaced piles, which has a good wave-blocking effect and is convenient to construct.

[0024] Thirdly, in the present invention, compared with the traditional mutually interlocking cavity type closely spaced pile wave-blocking structure, the new breakwater wave-blocking structure is easy to construct and can flexibly solve problems such as pile displacement, providing a new idea for the design of pile-based breakwater wave-blocking structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a flow chart of a construction process for closely spaced piles according to the present invention;

[0026] FIG2 is a schematic plan view of the flexible perfusion chamber provided by the present invention;

[0027] FIG3 is a schematic plan view of a rib plate according to the prior art proposed by the present invention;

[0028] FIG4 is a second schematic plan view of the rib plate in the prior art proposed by the present invention;

[0029] FIG5 is a third schematic plan view of a wave-blocking structure in the prior art proposed by the present invention;

[0030] FIG6 is a schematic plan view of the wave-blocking structure of the present invention;

[0031] In the figure: 100, closely spaced piles; 200, flexible grouting chamber; 300, ribs; 400, wave breakers. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in this field based on these embodiments are all within the scope of protection of the present invention.

[0033] Referring to Figures 1-2, the construction method of the present invention is applied to a certain confidential project. Specifically, the project mainly includes a 3km pier, a 500m pile-foundation breakwater, two 15,000t berths, channel and harbor dredging, onshore facilities, and transportation process pipelines and ancillary equipment.

[0034] In the embodiment, the berth and the breakwater are combined into a whole, the upper layer of the breakwater is the driving lane and the process pipeline platform, and the upper and lower layers are Cast-in-place piers; berths are arranged along the longitudinal axis of the breakwater; the breakwater is partially widened at the berths, and the pier platform is connected to the roadway. Steel pipe dense pile 100 and The piles consist of 100 closely spaced piles with a spacing of 100mm, topped with cast-in-place reinforced concrete. These piles are protected by riprap, measuring 15.3m wide and 1.1m thick. The entire project involves 260 closely spaced steel piles, each 2m in diameter and ranging in length from 41 to 48m, for the new wave-blocking structure.

[0035] In this embodiment, the bill of quantities of the densely packed piles 100 is shown in Table 1.

[0036] Table 1

[0037] In this embodiment, a plurality of closely spaced piles 100 form a horizontal line or an L-shaped planar layout to form a breakwater.

[0038] In this embodiment, geological survey reports indicate that the area within approximately 15 meters below the seabed is composed of loose sandy silt soil with an N value of less than 4; the depth between 15 and 35 meters is composed of a medium-hard sand layer and a hard gray soil layer with a value of 5 less than N less than 50; and the depth above 35 meters is composed of a hard soil layer with an N value of more than 50. For the entire pile sinking process, there are problems such as a complex construction environment, strong winds, and high waves. Furthermore, during the monsoon season, the sea surface surges are large, and most of them are long waves. Optical cables and natural gas pipelines are also located near the construction area, significantly impacting the operation of large marine equipment such as pile-driving vessels, resulting in a short effective operation time. Traditional pile-based breakwater wave-blocking structures are constructed by welding locking joints on closely spaced piles 100, and then "interlocking" the locking joints of adjacent closely spaced piles 100, so that the closely spaced piles 100 form an integrally stressed wave-blocking structure, thereby reducing waves in the area behind the closely spaced piles 100. However, this type of breakwater structure has mutual constraints between the locks, requiring high pile driving accuracy; the locks are deformed; the locks are pulled against each other, causing the locks to become unwelded; and after the piles are driven, the direction of the pile axis deviates significantly from the design.

[0039] Since the spacing between the closely spaced piles 100 is relatively small in this embodiment, the only construction method available is the use of rectangular I-shaped ribs 300 and bagged concrete. Specifically, a full-length bag is placed in the rectangular cavity formed between the ribs 300, and concrete is poured into the bag to form a new wave-blocking structure.

[0040] The I-shaped ribs 300 of the present invention eliminate mutual constraints between the ribs 300, improving pile driving efficiency and flexibly addressing pile deviation. The cavities between the ribs 300 are filled with full-length formwork bags, forming a single, integral load-bearing structure with the closely spaced piles 100, providing excellent wave-blocking effectiveness and facilitating construction. This solution, while maintaining a constant 100mm spacing between the closely spaced piles, is based on the excellent durability and anti-seepage properties of the formwork bags.

[0041] In the present invention, the specific construction process of the mold bag concrete is: construction preparation → lowering the mold bag and the guide tube → mixing the mold bag concrete → pouring the mold bag concrete → inserting the steel bar → cutting off the excess mold bag.

[0042] In this embodiment, the specific pile sinking process is as follows:

[0043] (1) Piling and transportation

[0044] The dense piles 100 are stacked in 3 layers when they are dropped on the barge. Because there are ribs 300 on both sides of the dense piles 100, wooden planks should be placed on the bottom, upper and lower layers, and between adjacent dense piles on the same layer for support and blocking before the dense piles are dropped on the barge to avoid direct collision between iron and iron.

[0045] Since the verticality deviation requirement is high when sinking 100 densely packed piles, an inclinometer will be installed on the ship to make real-time adjustments based on the readings to accurately control its verticality.

[0046] Temporary reinforcement of densely packed piles 100 and inclined top piles: After the densely packed piles 100 and inclined piles are sunk, in order to ensure the stability of the pile body, steel sections are welded in time as temporary supports.

[0047] (2) Closely spaced piles 100 hanging piles

[0048] The 100 closely spaced piles with a diameter of 2 meters for the breakwater are lifted at two points. The positions of the lifting lugs are set in accordance with the on-site construction requirements to facilitate the lifting of piles and the cutting of the lifting lugs. For piles shorter than 45 meters, a pair of lifting lugs are set 3 meters below the top of the piles, and for piles 48 meters long, a pair of lifting lugs are set 5 meters below the top of the piles. As the net spacing between adjacent closely spaced piles at the bottom of the piles is only 10 cm, designing lifting lugs will make it impossible to sink adjacent steel piles, so no lifting lugs are set and the piles are bundled.

[0049] Close-packed piles 100 are suspended using wire ropes, with lugs at the top serving as the lifting point. Ties are secured to the base of the pile. The wire ropes used for tying should be at least 28 meters long and 34 mm in diameter. In practice, close-packed piles can be 40-50 meters long and submerged in water at depths of 25 to 35 meters. For example, a 40-meter steel pipe pile can be submerged to a depth of 28 meters.

[0050] (3) Pile stabilization and pile sinking

[0051] When the pile gripper was modified, the position of the steel pipe pile rib 300 was taken into consideration. During the pile stabilization process, the rib 300 would not hit the pile gripper of the piling vessel, allowing it to enter the mud smoothly. The pile stabilization depth was 20m below the mud surface.

[0052] The order of pile sinking is from tugboat berth → berth 2 → berth 1. During the pile sinking process, when the lifting lug of the steel pile is more than 1 meter away from the top of the adjacent closely spaced piles 100, the lifting lug should be cut off before continuing to sink the pile to the design elevation.

[0053] In this embodiment, the length of the rib is 13m, and after the pile is sunk, the rib is about 1m deep into the mud. The specific length is determined according to the project situation, and the specific length is the pile top elevation minus the mud surface elevation, and then 1m is added to get the rib length.

[0054] (4) Stop hammer

[0055] The pile tip should reach the design elevation. The penetration of the last set of 10 hammer blows should be used for verification. When the hammer capacity is not less than 9 t.m, the penetration should not exceed 3 mm per blow.

[0056] In this embodiment, the ribs 300 on the close-packed piles 100 and the geotextile mold bag are used to form a flexible grouting cavity 200, which is then poured to achieve the blockage between the ribs of two close-packed piles 100. In this embodiment, between adjacent close-packed piles 100, the ribs 300 and the close-packed piles 100, which are parallel to each other, form a flexible grouting cavity with an avoidance gap. The length of the flexible grouting cavity along the circumferential direction is greater than the length of the gap between the close-packed piles. In this embodiment, the size of the flexible grouting cavity formed by the ribs is 168mm×100mm. That is, the cross-section of the flexible grouting cavity is a rectangle, with the spacing between the two close-packed piles as the width and the spacing between the ribs as the length.

[0057] In this embodiment, the spacing between adjacent closely packed piles is 80-200 mm. In the specific calculation, L is the net distance between piles, which is 80 mm to 200 mm, l is the gap spacing from the rib to the adjacent closely packed piles, which is 0-50 mm, and t is the width of the rib, which is Ll.

[0058] In this embodiment, at least two staggered avoidance gaps are provided in the same flexible pouring cavity. That is, one end of the rib is fixedly connected to the dense pile, and the other end is suspended. In order to avoid collision between the ribs, the rotation angle of the pile body during the dense pile driving is less than 10°.

[0059] In this embodiment, SIka215 is used, which is a type of fine stone concrete with a maximum aggregate size of 6 mm. During pouring, Sika is mixed using a small mixer, and the mix ratio is strictly in accordance with the Sika specification sheet. Sika: water = 25 kg: 4.2 L is prepared.

[0060] Sika pouring is carried out using segmented detachable steel conduits. After pouring 75kg of Sika, a section of the conduit can be lifted and removed, and the bottom of the conduit is always kept buried in the Sika concrete at a depth of not less than 300mm. After 7 cycles, the Sika form bag in a single pouring cavity can be poured to the top of the pile. After the pouring is completed, the Sika form bag should be 10cm higher than the top of the pile to allow the Sika form bag to reserve a certain amount of settlement before the longitudinal beam is poured.

[0061] In this embodiment, the open lock of the dense pile 100 is changed into a closed cavity, and the V-shaped special-shaped rib is optimized to an I-shaped rib 300. The cavity between the ribs 300 is filled with SIKA 215 fine stone concrete using geotextile bags. Two one-meter-long Steel bars, the steel bars extend into the longitudinal beam 0.5m.

[0062] During construction, the mud surface elevation in the area of ​​100 densely packed piles is -9.5m, and the top elevation of the steel pipe piles is +2.8m. It is planned to make a 14m long geotextile mold bag, and the mold bag material must comply with the design requirements; the casting cavity formed between the ribs of 100 densely packed piles is 168mm*100mm in size and has a circumference of approximately 540mm. The customized circumference of the mold bag should be appropriately larger than the casting cavity. In this embodiment, 590mm (casting cavity circumference + 2 times the gap distance) is taken. In addition, the cavity at the corner of the 100 densely packed piles is larger, and a 2.35m circumference mold bag is arranged separately.

[0063] The 100-lock grouting of densely packed piles must be carried out after the pile core is cast. The plan is to first install the mold bag into the cavity, manually check and adjust the position and status of the geotechnical mold bag to ensure that it is not knotted or twisted, and then insert the grouting steel conduit into the cavity section by section. The conduit should extend to the bottom of the mold bag. SIKA215 fine stone concrete is used for mold bag grouting. A single 25kg bag of Sika215 can be poured to a height of 0.8 meters. Considering a single cavity of 13.5 meters, a total of 17 bags of fine stone concrete are required. The fine stone concrete is mixed on-site using a small mixer and poured manually with steel conduits. The steel conduits used for grouting are 5cm in diameter and each section is 1.5 meters long. The upper and lower adjacent conduits are connected by threaded sleeves. Before pouring, use a fixed steel frame to assemble a hand hoist to lower the conduit section by section. During pouring, lift and remove the conduit section by section according to the pouring volume, and always keep the bottom of the conduit at least 300mm above the Sika surface. Pour to 10cm above the top of the pile. After the pouring is completed, insert two steel bars with a length of 1 meter and a diameter of 10mm. After the Sika age is full for 1 day, cut off the excess mold bag above the Sika top.

[0064] In this embodiment, longitudinal beams are used to form a barrier, enclosing several closely packed piles 100 (the longitudinal beams are located on top of the closely packed piles 100, and a cover is installed on the closely packed piles 100 to form an integral load-bearing structure). Rebar is placed in the cavity, perpendicular to the longitudinal beams, and extends 500mm into the longitudinal beams. This is to strengthen the connection between the bagged concrete and the longitudinal beams and prevent the bagged concrete from settling later. Specifically, two 10mm diameter and 1m long steel bars are placed in the flexible pouring cavity. The steel bars extend 500mm into the cavity and the longitudinal beams, respectively. This ensures a better connection between the cavity structure and the longitudinal beams after pouring, preventing the cavity structure from settling.

[0065] For the vertically set right angles, in order to ensure that the perfusion cavity is filled densely, at the corners, the ribs 300 are set as two triangular ribs 300, and the ribs 300 are filled with filling material. The gap in the mold bag at the corner is large, and the mold bag is slightly larger to block the ribs 300.

[0066] In this embodiment, when pouring in the pouring cavity, the concrete of a single pouring cavity is about 0.23m 3 , the pouring speed should be strictly controlled within 1m 3 / h-2m 3In the present invention, the pouring speed is related to the pouring volume of a single cavity, the diameter of the conduit, etc. Specifically, if the speed is too slow, it is inconvenient to lift the conduit and the continuity of concrete pouring is poor; if the speed is too fast, it will affect the quality of concrete pouring.

[0067] Pile collision analysis and proposed measures

[0068] Analysis of the design drawings revealed that the key and most challenging aspect of this project's underwater pile sinking was the construction of 100 closely spaced piles. These piles consisted of 2000mm Φ steel pipes, ranging in length from 41m to 48m. These straight piles were arranged along a single axis, with a 10cm spacing between adjacent piles. Furthermore, 300 30cm-long ribs were welded to both sides of each pile, extending 13m downward from the top.

[0069] A feasibility analysis of pile sinking construction was conducted based on the structure and plane position of the densely packed piles 100, combined with the performance of our company's piling vessel, on-site geology, wind and wave conditions, etc.

[0070] I. Angle calculation when two adjacent pile ribs rotate 300 degrees and collide:

[0071] According to measurement and analysis, when the pile body does not twist, the distance from the edge of the rib 300 to the edge of the adjacent rib 300 is 100 mm. When two adjacent piles rotate 9 degrees relative to each other, the rib 300 will hit the rib 300 of the adjacent closely spaced pile 100.

[0072] In order to ensure the planar position of each pile rib 300, the position of the rib 300 is strictly controlled when the steel pipe pile is made, and a 20mm wide white line is sprayed from just below the bottom of the 13-meter-long rib 300 to 13 meters upward from the bottom of the pile to facilitate the observation of the rotation of the pile body during the pile installation process to avoid collision between adjacent ribs 300.

[0073] II. Analysis of pile collision when two adjacent piles are offset

[0074] When the pile foundations of two adjacent closely spaced piles 100 have a front-to-back relative displacement of 168 mm or a left-to-right relative displacement of 25 mm, the pile ribs 300 will collide.

[0075] After the sinking of the plurality of closely spaced piles 100, cavity pouring is performed as follows:

[0076] After the design change, the open lock of the dense pile 100 is changed to a closed cavity, and the conventional rib 300 is optimized to an I-shaped rib 300. At this time, the two ribs 300 are connected to the dense pile 100 at one end and the other end is not connected. Then, the cavity between the ribs 300 is filled with SIKA 215 fine stone concrete using geotextile bags and two one-meter-long and diameter ribs are placed on the top. Steel bars, the steel bars extend into the longitudinal beam 0.5m.

[0077] The original design was a conventional open-type breakwater, using a combination of ear-shaped ribs and 4.8-meter-high wave-breaking panels. This structure has now been replaced with a new wave-breaking structure consisting of I-shaped ribs and bagged fine stone concrete. Consider adding additional illustrations.

[0078] During construction, the mud surface elevation in the area of ​​100 densely packed piles is -9.5m, and the top elevation of the steel pipe piles is +2.8m. It is planned to make a 14m long geotextile mold bag, and the mold bag material must comply with the design requirements; the casting cavity formed between the ribs of 100 densely packed piles has a size of 168mm*100mm and a circumference of about 540mm. The customized circumference of the mold bag should be appropriately larger than the casting cavity. In this embodiment, 580mm is taken. In addition, the cavity at the corner of 100 densely packed piles is larger, and a separate mold bag with a circumference of 2.35m is arranged.

[0079] The 100 lock-joint grouting of densely packed piles needs to be carried out after the pile core is poured. It is planned to install the mold bag into the cavity first, and manually check and adjust the position and status of the geotechnical mold bag to ensure that it is not knotted or twisted. Then, the grouting steel conduit is inserted into the cavity section by section, and the conduit should extend to the bottom of the mold bag. SIKA215 fine stone concrete is used for mold bag grouting. A single 25kg bag of sika215 can be poured to a height of 0.8 meters. Considering a single cavity of 13.5 meters, a total of 17 bags of fine stone concrete are required. Fine stone concrete is mixed on-site using a small mixer, and a grouting machine pressure pump or manual grouting is used. During grouting, a 5cm diameter threaded steel conduit is extended below the grouting surface. The conduit is 1.5 meters long per section, and the upper and lower adjacent conduits are connected by threaded sleeves. Before grouting, use a fixed steel frame to assemble a hand hoist to lower the conduit section by section. During grouting, lift and remove the conduit section by section according to the amount of grouting, and always keep the bottom of the conduit at least 300mm above the Sika surface. Grouting must be done to 10cm above the top of the pile. After grouting is completed, insert two steel bars with a length of 1 meter and a diameter of 10mm. After the Sika age is one day, cut off the excess mold bag above the top of the Sika.

[0080] Compared with the traditional 100 interlocking cavity-type closely spaced pile wave-blocking structure, the new breakwater wave-blocking structure with 300 I-type ribs + Sika215 bagged concrete is easy to construct and can flexibly solve problems such as pile displacement. It provides a new idea for pile-based breakwater wave-blocking structures, has been unanimously recognized by the owner and design unit, and has established a good brand image for the applicant in the market.

[0081] Referring to Figures 3-4, the common pile-based breakwater wave-blocking structures in the prior art include the close-packed pile lock type and the close-packed pile hollow type. The former forms an integrally stressed wave-blocking structure by "biting" the locks between adjacent close-packed piles and the close-packed piles. The advantage is that it has a good wave-blocking effect. The disadvantage is that the pile sinking process is relatively cumbersome. During the pile sinking process, the locks of the close-packed steel piles will be deformed, resulting in the next adjacent close-packed steel pile unable to be sunk to the designed elevation; the locks pull each other, resulting in problems such as lock desoldering and lock deformation, and very high requirements for pile sinking accuracy; the latter forms a wave-blocking structure by welding special-shaped ribs on the close-packed piles and the front wave-blocking plate 400. The advantage is that the close-packed piles are easy to sink; the disadvantage is that the wave-blocking effect cannot be comparable to the former, and the installation of the wave-blocking plate 400 is complicated, which affects the construction progress of the upper structure.

[0082] In the present invention, specifically in a certain part of the confidential project, referring to Figure 5, the original design adopts an 'ear-shaped' rib plate + wave-breaking board 400 hollow wave-breaking structure, the densely packed piles are 2-meter diameter steel piles, a total of 260, and the wave-breaking board 400256 pieces are 4.8 meters high, 2.08 meters wide, and 0.5 meters thick. Since the project is located in an unprotected area in the open sea, and the monsoon period is from the end of October to the middle of March of the following year, the sea surface surges during the monsoon period, and most of them are long waves, which have a great impact on the operation of large ship machinery and equipment such as pile driving ships, resulting in a short effective operation time. Obviously, this structural form is not the optimal wave-breaking structure for this project, so the inventors continued their research and changed the dense pile ribs from "ear" type to "I" type. At this time, the number of 2-meter diameter dense steel piles selected after the change is still 260, and the dense pile ribs are changed to "I" type. After the adjacent dense pile ribs are sunk, a rectangular cavity with a length of 160 mm and a width of 100 mm is formed. A full-length geotextile mold bag with a length of 14 meters and a cross-sectional circumference of 550 mm (from the mud surface to the pile top) is placed in the cavity, and the mold bag concrete is poured into the mold bag. The wave breakers 400 are eliminated to form a new wave-breaking structure.

[0083] There is no mutual constraint between the ribs of the new wave-breaking structure, and the pile driving efficiency is high; when the pile driving is offset, it can be flexibly adjusted; full-length formwork bag concrete is poured in the cavity between the ribs, forming an overall force-bearing structure with the densely packed piles, which has a good wave-breaking effect and is easy to construct. It can be applied to all densely packed pile wave-breaking structures and has good practicality and promotion value.

[0084] In this embodiment, the bagged concrete is applied to the wave-blocking structure of the hydraulic wharf, which is innovative and forward-looking. It also provides a new idea for the development of the densely packed pile wave-blocking structure and further enriches the wave-blocking structure form.

[0085] In the present invention, SAP-2000 software was also used to establish a stress model for close-packed piles before and after optimization, and the internal forces on the piles were calculated. To further verify this, stress simulations were performed on the ear-shaped ribs before and after the modification, and then a statistical table comparing the internal forces of the piles with the ear-shaped and straight ribs was obtained, as shown in Table 1.

[0086] Table 1 Comparison statistics of pile internal forces

[0087] Table 1 shows that the internal forces on the densely packed piles increased after the change. However, the maximum pullout capacity of the densely packed piles is 7000 kN, and the maximum bending capacity is 21645 kN.m, which can pass the internal force calculation.

[0088] In order to further study the rib strength and weld height, relevant research was conducted and Table 2 and Table 3 were obtained.

[0089] Table 2 Rib strength calculation table

[0090] Conclusion: The ribs are made of S355 material, and the design value of bending tensile stress is 305 MPa. The strength meets the requirements.

[0091] Table 3 Calculation of weld height

[0092] Conclusion: The weld height of 14mm meets the requirements.

[0093] The efficiency of densely packed piles was basically the same before and after the change. The installation of wave-breaking boards was considered to be 3 piles per day, and the monthly effective working days were 22 days (taking into account the influence of wind and waves). There were 2 parallel construction work surfaces, and 256 piles required a total of 256 / (22*3)*30 / 2=59 days. The construction was carried out on the bagged concrete construction platform, and the monthly effective working days were 30 days. 10 to 12 piles per day, 2 parallel construction work surfaces, and 259 bags of concrete only needed 13 days to complete. The overall construction period was shortened by at least 46 days.

[0094] The installation of wave breakers is carried out on two parallel working surfaces, equipped with a flatbed truck, a flatbed barge, a 75t crawler crane and a material barge.

[0095] Table 4 Unit: Ringgit

[0096] The construction cost was saved by 3.448 million ringgit, about 5.4 million yuan, with good economic benefits.

[0097] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0098] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0099] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. The construction process of close-packed piles is characterized by: The following steps are involved: Along the periphery of the breakwater in the design drawings, a fence is constructed for protection, and the breakwater is specifically formed by a number of closely spaced piles; Using the lifting lugs set at the top and the piles tied at the bottom, several closely spaced piles are lifted in sequence in the manner of first tying the piles and then lifting them; Sink the piles in a sequential manner until all the closely spaced piles are sunk, with a clear distance of 80-200mm between adjacent closely spaced piles; A flexible pouring cavity is formed between adjacent closely spaced piles by using ribs, and fine stone concrete is poured into the flexible pouring cavity to complete the cavity pouring between adjacent closely spaced piles, so that a plurality of closely spaced piles form an integral breakwater wave-blocking structure.

2. The construction process of close-packed piles according to claim 1, characterized in that: A plurality of closely spaced piles are located on the same horizontal line, or are vertically arranged on two sides of a right angle to form the breakwater.

3. The construction process of close-packed piles according to claim 2, characterized in that: When a plurality of closely spaced piles are arranged at right angles, the rib plates at the corners are triangular plates, and a pouring cavity is formed between the triangular plates.

4. The construction process of close-packed piles according to claim 1, characterized in that: The length of the close-spaced piles is 40-50 m, and the depth of the close-spaced piles submerged in water is 25 m to 35 m.

5. The construction process of close-packed piles according to claim 4, characterized in that: The lifting lug is arranged at a position 2m or 5m downward from the top of the densely spaced pile, and the lifting lug is cut off when the densely spaced pile is 1-2m away from the top of the adjacent densely spaced pile during the pile sinking process.

6. The construction process of close-packed piles according to claim 4, characterized in that: The rib plate is arranged at the middle and upper part of the close-packed piles, and the length of the rib plate is greater than the difference between the pile top elevation and the mud surface elevation.

7. The construction process of close-packed piles according to claim 1, characterized in that: Between adjacent closely spaced piles, the ribs parallel to each other and the closely spaced piles form a flexible perfusion cavity with an escape gap, and the length of the flexible perfusion cavity along the circumferential direction is greater than the length of the gap between the closely spaced piles.

8. The construction process of close-packed piles according to claim 7, characterized in that: At least two offset avoidance gaps are provided in the same flexible pouring cavity, and the rotation angle of the pile body in the close-packed pile driving is less than 10°.

9. The construction process of close-packed piles according to claim 1, characterized in that: It also includes a longitudinal beam located at the top of the breakwater, and steel bars are arranged in the flexible pouring cavity along a direction perpendicular to the longitudinal beam.

10. The construction process of close-packed piles according to claim 1, characterized in that: The invention also includes forming a civil engineering mold bag placed in a flexible perfusion cavity, wherein the perfusion speed of the flexible perfusion cavity during perfusion is 1m 3 / h-2m 3 / h.

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