Construction method of hydraulic wharf using prefabricated blocks

Abstract

The application discloses a kind of hydraulic wharf construction methods of application prefabricated block, belong to hydraulic wharf construction technical field.The construction method includes: excavating foundation trench and retaining original underwater rock;Toward foundation trench throw fill stone material and form stone cushion layer;Survey obtains the shape and position data of underwater rock;Design prefabricated block arrangement scheme and divide target, standard prefabricated block, set assembly groove on the bottom surface of target prefabricated block;After prefabricating various prefabricated blocks in factory, hoist in place, make underwater rock embed assembly groove and pour grouting material to construct groove foundation;Stack upper prefabricated block and lay load plate to form wharf main body.The present application relies on natural rock embedding fixed position, cancels reef blasting and whole base flattening process, simplifies construction process;Meanwhile, using prefabricated block dense arrangement to form foundation, can inhibit uneven settlement, improve the integrity and service stability of foundation, reduce construction cost, improve the overall construction efficiency of wharf.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic wharf construction technology, and particularly relates to a hydraulic wharf construction method using precast blocks. Background Technology

[0002] Nearshore hydraulic wharves are mostly located in shallow waters. After the foundation trench is excavated, the bottom of the trench often contains various types of hard rock, with uneven rock surfaces, local rock protrusions, and an overall irregular topography. Wharf construction follows the process of foundation trench excavation, foundation laying within the trench, and then constructing the main structure layer by layer based on the foundation. Traditional methods generally involve first blasting away the protruding rock at the bottom of the trench, then leveling and smoothing the entire bottom of the trench, followed by building a construction platform to carry out foundation construction and the construction of the superstructure.

[0003] Low water levels in shallow waters make it difficult for conventional blasting equipment to be deployed, allowing operations only during brief high-tide windows, resulting in low efficiency. Constructing temporary offshore platforms is difficult and costly, and on-site construction is easily affected by hydrological and meteorological factors such as wind, waves, and currents, which can significantly delay the construction schedule. Furthermore, blasting and leveling operations cannot completely eliminate unevenness in the trench bottom, resulting in poor foundation flatness. This leads to uneven stress distribution and insufficient fit after subsequent assembly of foundation components, making the wharf susceptible to uneven foundation settlement, slippage, and tilting during long-term use, posing a significant structural safety risk. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, one aspect of this application proposes a construction method for a hydraulic wharf using precast blocks, the method comprising: Excavate the foundation trench, preserving the original underwater rocks during the excavation process; Stones are thrown into the trench to cover the rocks at the bottom of the water. The stones are then compacted and leveled to form a stone cushion layer. The geomorphology of the foundation trench was surveyed to obtain the location and dimensions of the underwater rocks within the trench; Based on the dimensions of the foundation trench and the specifications of the precast blocks, design a layout scheme for the precast blocks within the foundation trench; Based on the location and dimensions of the underwater rocks in the trench, the target precast blocks are located and determined in the layout scheme, and an assembly groove that matches the underwater rocks is designed on the bottom surface of the target precast blocks. Prefabricate the target prefabricated block and the remaining standard prefabricated blocks; The crane vessel places each prefabricated block into the foundation trench according to the arrangement plan, so that the underwater rock is embedded in the assembly groove of the target prefabricated block, and fills the gap between the assembly groove and the underwater rock with grouting material to form the foundation in the trench. Precast blocks are stacked on top of the existing foundation in the trench, and load-bearing slabs are laid to form the main body of the wharf.

[0006] The technical solution utilizes a crane vessel to lay and stack prefabricated blocks to construct the wharf, eliminating the need for temporary offshore construction platforms and directly reducing the difficulty and cost of construction in shallow water areas. Assembly grooves adapted to the underwater rock are created on the bottom surface of the target prefabricated blocks, eliminating the need for blasting reefs and leveling the entire trench bottom, thus removing the blasting window limitation, shortening the construction period, and improving construction efficiency. The prefabricated blocks are laid in one go to form the foundation within the trench, with a naturally flat top surface. Simultaneously, the natural underwater rock embedded in the grooves forms a rigid, fixed support, structurally preventing base undulations and localized voids. This ensures that the subsequent superstructure is subjected to uniform stress and has a dense contact, effectively solving the problems of uneven foundation settlement, slippage, and tilting during long-term wharf use, and improving overall stability and service safety.

[0007] In some embodiments, during the process of the crane vessel placing the prefabricated blocks into the trench according to the layout plan, the prefabricated blocks are placed row by row from the roadside to the waterside of the trench, including: Place a row of precast blocks on the bottom of the foundation trench; The adjacent row of prefabricated blocks is temporarily stacked on top of the previously placed row of prefabricated blocks, and left to stand for a set time. The adjacent row of precast blocks is placed on the bottom of the foundation trench and arranged adjacent to the previous row of precast blocks; Repeat the above steps, advancing row by row from the roadside to the waterside, until all prefabricated blocks have been placed.

[0008] In the technical solution, the next row of precast blocks is temporarily stacked on top of the precast blocks that have already been placed. By surcharge preloading, the precast blocks that have been placed earlier are further compacted and stabilized, reducing displacement caused by subsequent construction disturbances. This ensures that the benchmark is stable and the alignment is accurate when each row is in place, controlling cumulative errors and overall deformation from the source and improving the accuracy of foundation forming. At the same time, a sequential stacking and placement method is adopted, utilizing the stacking and static time for cross-operation to reduce the overall waiting time and maintain high construction efficiency while ensuring stability.

[0009] In some embodiments, during the process of the crane ship placing each precast block into the foundation trench according to the arrangement plan, when a row of standard precast blocks on the side of the target precast block near the water are temporarily stacked with precast blocks, grouting material is filled into the gap between the assembly groove of the target precast block and the bottom rock.

[0010] In this technical solution, grouting is carried out after a row of standard precast blocks near the water side of the target precast block is temporarily stacked. At this time, the target precast block has been compacted and effectively limited laterally by adjacent blocks, and the whole is in a stable and fixed state. The gap between the assembly groove and the bottom rock remains stable and without displacement or deformation. After the grout is injected, it can accurately fill the gap and solidify, firmly locking the target precast block in the designed position. At the same time, the row of precast blocks stacked above the water side can form a natural retaining structure, effectively reducing the impact and disturbance of tides and water flow on the target precast block, preventing the target precast block from shifting or shaking during the grouting process. In addition, the stable external environment can ensure that the grouting pipeline is always accurately aligned with the target area, avoiding the pipeline from falling off or shifting due to water flow, fundamentally eliminating problems such as grout leakage and grouting interruption, ensuring continuous and controllable grouting operation, full and dense gap filling, and significantly improving the reliability of rock-embedded connection and overall construction quality.

[0011] In some embodiments, after the last row of prefabricated blocks is lowered to the bottom of the foundation trench and positioned, a row of upper prefabricated blocks is stacked on top of the placed last row of prefabricated blocks and left to stand for a set time. After a set set time, the settlement of the row of precast blocks that have been placed is measured.

[0012] In this technical solution, after the first row of precast blocks in the foundation layer of the trench is placed, another row of precast blocks is used for temporary surcharge compaction and settlement testing. This allows for direct verification of the settlement of the precast blocks in that row during the foundation construction phase, enabling timely detection and correction of settlement anomalies and preventing problems from accumulating in subsequent processes. Compared to waiting until the entire foundation layer in the trench is completed and then inspecting the foundation settlement for abnormalities during the construction of the superstructure, this approach allows for earlier identification of potential problems and a shorter problem-solving cycle. Furthermore, combining the compaction and settlement testing of the foundation in the trench with the placement of the precast blocks in the upper layer makes the connection between foundation construction and superstructure construction smoother, reduces process intervals, and effectively improves overall construction efficiency.

[0013] In some embodiments, during the process of the crane vessel placing each prefabricated block into the trench according to the arrangement scheme, the prefabricated blocks are placed row by row from the road side to the water side of the trench. If a target precast block is included in a row of precast blocks to be placed, the target precast block is placed first, and then the remaining standard precast blocks in the row are placed sequentially to one or both sides of the target precast block as a reference.

[0014] In the technical solution, when placing each row of precast blocks, the target precast block is positioned first, and then standard precast blocks are laid out sequentially to one or both sides based on it. The target precast block, which is precisely fitted with the rock at the bottom of the water, serves as the positioning reference, avoiding cumulative deviations caused by unidirectional laying from one end and preventing misalignment between the rock mass and the groove. The target precast block is stably positioned and reliably fitted. Using it as a reference, the other precast blocks are laid out, which can ensure that the entire row is aligned, the spacing is uniform, the side walls of each block are tightly fitted, and the force transmission is continuous. At the same time, it reduces repeated adjustments caused by unstable reference, improves installation efficiency, makes the overall layout of the foundation in the trench neat and the force balanced, and enhances the collaborative bearing capacity of the foundation.

[0015] In some embodiments, when searching for and determining the target precast blocks in the layout scheme, if the number of target precast blocks corresponding to the same underwater rock is greater than or equal to three, the layout scheme of the precast blocks in the trench is adjusted so that the number of target precast blocks corresponding to the same underwater rock is one or two.

[0016] In the technical solution, the number of target prefabricated blocks corresponding to the same underwater rock is limited to one or two. A small number of grooves can completely cover and adapt to the shape of the rock mass, avoiding the rock mass being shared by too many prefabricated blocks, and preventing the grooves from being opened at the corners of the blocks or horizontally penetrating the block body. This avoids local stress concentration in the blocks, weakening the structural strength, ensuring that the force on a single target prefabricated block is reasonable and the structure is intact, maintaining its own strength and stability. At the same time, it ensures that the fit between the rock mass and the grooves is reliable, improving the overall load-bearing safety of the rock-embedded foundation.

[0017] In some embodiments, when designing an assembly groove on the bottom surface of the target precast block to fit the underwater rock, grouting holes and drainage holes are further designed on the target precast block. The grouting hole and the drainage hole are both connected to the assembly groove and extend vertically upward through the target precast block; the grouting hole is vertically aligned with the edge of the underwater rock, and the drainage hole is vertically aligned with the apex of the underwater rock.

[0018] In the technical solution, grouting holes and drainage holes are set on the target precast blocks, which are connected to the assembly grooves and are vertically connected. The grouting holes are aligned with the rock edges and the drainage holes are aligned with the rock apex. During grouting, grout can be injected from the edges and drained simultaneously from the apex, so as to remove water accumulated in the gap between the groove and the rock in time and avoid water retention affecting the setting strength of the grout. At the same time, the drainage holes can be inserted into the vibrator to vibrate the grout in the gap, eliminate internal voids, make the grout filling more compact, significantly improve the bonding strength and overall embedment of the rock and the precast blocks. The vertically connected channels also facilitate on-site construction operations, reduce grouting dead corners, effectively enhance the reliability of the rock embedment connection, and ensure the long-term load-bearing stability of the foundation.

[0019] In some embodiments, when designing grouting holes and drainage holes for target precast blocks, if there are multiple adjacent target precast blocks, the multiple adjacent target precast blocks are integrated into a target block group, and a grouting hole and a drainage hole are set in the target block group.

[0020] In this technical solution, multiple adjacent precast blocks are merged into a single unit and share a set of grouting and drainage holes. This avoids drilling holes for each block individually, reducing the number of precast component processing steps and lowering production costs. Simultaneously, the shared ducts allow the assembly grooves of adjacent blocks to be joined together, enabling synchronized drainage and grouting. This ensures uniform grout filling and consistent density within each gap, preventing differences in filling due to segmented construction. Furthermore, the shared drainage holes allow for unified vibration of the overall gaps, enhancing the integrity and synergy of the connection between adjacent precast blocks, preventing localized voids or uneven stress, and further improving the overall stability and ease of construction of the rock-embedded foundation.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic flowchart illustrating a construction method for a hydraulic wharf using prefabricated blocks according to an embodiment of this application. Figure 2 This is a schematic diagram of the construction status after step S2 is performed in the hydraulic wharf construction method using prefabricated blocks according to the embodiments of this application. Figure 3 This is a schematic diagram of the layout scheme after step S4 of the hydraulic wharf construction method using precast blocks according to the embodiments of this application. Figure 4 This is a schematic diagram of the structure of the target precast block in the hydraulic wharf construction method using precast blocks according to the embodiments of this application; Figure 5 This is a schematic diagram of the construction state of step S7 in the hydraulic wharf construction method using precast blocks according to the embodiments of this application. Figure 1 ; Figure 6 This is a schematic diagram of the construction state of step S7 in the hydraulic wharf construction method using precast blocks according to the embodiments of this application. Figure 2 .

[0023] In the diagram: 1. Foundation trench; 2. Bottom rock; 3. Stone cushion layer; 4. Precast block; 41. Target precast block; 42. Standard precast block; 401. Grouting hole; 402. Drainage hole; 5. Assembly groove; 6. Grouting material. Detailed Implementation

[0024] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0025] In this application's embodiments, prefixes such as "first" and "second" are used merely to distinguish different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. Furthermore, in the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0026] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0027] In the embodiments provided in this application, it should be understood that the disclosed systems and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system.

[0028] It should be noted that, as an important water transport infrastructure in nearshore waters, a hydraulic wharf is mainly used for ship berthing, cargo loading and unloading, and personnel embarkation and disembarkation. Its overall structure typically consists of three parts: the underwater foundation, the superstructure, and ancillary facilities. The underwater foundation is the core load-bearing part of the wharf, generally located at the bottom of the foundation trench, directly resting on rock or treated ground, bearing all loads from the superstructure and ships and cargo. The superstructure includes walls, breast walls, load-bearing plates, and surface layers, forming the working platform at the wharf's front and transferring loads to the underwater foundation. Ancillary facilities include fenders, mooring bollards, and drainage systems, ensuring the safety of ship berthing and the normal operation of the wharf.

[0029] In existing technologies, after the excavation of the foundation trench for a hydraulic wharf is completed, some hard, natural reefs that are difficult to completely remove often remain on the bottom of the water. These reefs form local protrusions at the bottom of the foundation trench, with varying heights and irregular shapes. The stones subsequently dumped can only cover the area around the reefs, and cannot completely wrap or flatten the protruding reefs, making it difficult to make the bottom of the foundation trench flat and resulting in poor overall flatness.

[0030] To eliminate the adverse effects of protruding reefs on foundation construction, conventional construction methods typically employ underwater blasting to remove and level the reefs. However, wharf foundation trenches are mostly located in shallow near-shore waters with consistently shallow depths. Conventional blasting equipment is large and has a deep draft, making it difficult to directly access the site for blasting operations. Operations can only be carried out briefly during high tide when the water depth temporarily increases to meet the equipment's draft requirements, and then must be urgently evacuated before low tide, resulting in extremely short and fragmented working windows. To completely remove the protruding reefs and achieve the designed levelness, it is often necessary to repeatedly utilize multiple high and low tide cycles for blasting and gradual clearing, significantly extending the construction period and resulting in extremely low overall construction efficiency.

[0031] Furthermore, even after multiple blasting operations, the top surface of the remaining reefs is still difficult to achieve an ideal flatness, often exhibiting height differences, localized pits, or protruding edges. When the underwater foundation structure is placed at the bottom of the trench, the limited contact area and insufficient fit with the top surface of the reef prevent it from obtaining uniform and continuous support. This easily leads to local tilting and stress imbalance in the underwater foundation structure, which can further cause uneven settlement after long-term operation. In severe cases, foundation slippage and displacement may even occur, directly threatening the overall stability and service safety of the wharf foundation structure. This can further transmit to the upper walls, breast walls, surface layers, and other main structures, causing structural cracking, deformation, or even overall instability and failure.

[0032] Furthermore, in the traditional construction process of hydraulic wharves, it is usually necessary to erect large temporary offshore construction platforms in the waters surrounding the foundation trench to serve as a support for the placement of underwater foundation structures and subsequent pouring or assembly of superstructures. However, the construction environment for temporary offshore construction platforms is complex, requiring them to cope with multiple hydrological and meteorological influences such as wind, waves, currents, and tides, making construction extremely difficult and resulting in high material and construction costs. At the same time, the entire process of platform erection and subsequent construction is susceptible to interference from sudden winds, waves, strong currents, and other severe weather, frequently leading to construction interruptions and delays, further increasing construction costs and project risks.

[0033] To address the above problems, this application provides a construction method for hydraulic wharves using prefabricated blocks.

[0034] Figure 1 This is a schematic flowchart illustrating a construction method for a hydraulic wharf using prefabricated blocks, as provided in this embodiment. The method includes the following steps.

[0035] S1. Excavate the foundation trench 1, and retain the original underwater rocks 2 during the excavation process.

[0036] Specifically, using excavation equipment, the work area was demarcated according to the wharf design outline. Strict adherence to the predetermined excavation depth and boundary specifications was maintained, and the soil, loose gravel, and silt were removed layer by layer from the trench. During the excavation, only the soft surface layer was removed, and operations avoided touching or scraping the hard, original underwater rock mass, preserving the original appearance of the natural rock mass within trench 1. After trench 1 was excavated and formed, the underwater rock 2 maintained its original distribution.

[0037] S2. Throw stones into the trench 1 so that the stones cover the rocks 2 at the bottom of the water. Then compact and level the stones to form a stone cushion layer 3.

[0038] Specifically, see Figure 2 The qualified stones are loaded onto the rock-throwing vessel, which then sails to the construction area above the foundation trench 1. Based on the overall outline of the foundation trench 1 and the actual distribution of the underwater rocks 2, the vessel flexibly adjusts its working position, sequentially throwing stones into the area around the bottom of the trench around the underwater rocks 2, ensuring the stones evenly fill the gaps between the rock mass and the sidewalls of the foundation trench 1. After the stones are placed in place, underwater compaction equipment is used to pound and compact the filling layer. Then, underwater leveling equipment is used to repeatedly push and smooth the surface of the stone cushion layer 3, calibrating the overall elevation, eliminating surface unevenness, and finally forming a dense, flat stone cushion layer 3.

[0039] It should be noted that there is usually a certain height difference between the top surface of the stone cushion layer 3 and the top of the foundation trench 1. The top of the underwater rock 2 is higher than the top surface of the stone cushion layer 3 and is raised in the foundation trench 1.

[0040] S3. Conduct a survey of the topography of trench 1 to obtain the location and dimensions of the underwater rock 2 within trench 1.

[0041] In practice, a combination of multibeam sonar and manual underwater surveying was used to conduct the survey. First, the multibeam sonar was mounted on a survey vessel, which smoothly traversed the entire area of ​​trench 1, scanning and collecting underwater topographic data to initially pinpoint the locations of various underwater rocks 2 within trench 1. Subsequently, divers were dispatched to the corresponding underwater areas for on-site verification, accurately confirming the actual shape of the underwater rock mass. During the survey, the length, width, and height parameters of each rock were measured, and all data were comprehensively summarized to accurately determine the distribution location and dimensions of the rocks within trench 1.

[0042] S4. Based on the dimensions of the foundation trench 1 and the specifications of the precast blocks 4, design the arrangement scheme of the precast blocks 4 in the foundation trench 1.

[0043] Specifically, see Figure 4Based on the overall planar design dimensions of the foundation trench 1 as indicated in the construction design drawings of the hydraulic wharf, and combined with the standard external dimensions of the precast blocks 4, the overall layout planning and design of the precast blocks 4 were carried out. The precast blocks 4 typically adopt a cubic structure with a regular and uniform shape. The foundation trench 1 usually has a regular rectangular outline on the horizontal plane, with overall regularity and clear boundaries, providing a good foundation for the standardized layout of the precast blocks 4.

[0044] During the layout design process, the rectangular outer contour of the foundation trench 1 is used as the overall benchmark. Combined with the standard dimensions of the length and width of each precast block 4, the maximum number of precast blocks 4 that can be laid out in the length and width directions of the foundation trench 1 is precisely calculated. The layout scheme adopts a maximized close-packing design, using a multi-column, multi-row matrix arrangement. All adjacent precast blocks 4 have their sidewalls tightly against each other without gaps, maximizing the filling of the internal working area of ​​the foundation trench 1. Due to the modular matching limitation between the overall dimensions of the foundation trench 1 and the standard dimensions of the individual precast blocks 4, after the layout is completed, a small gap is usually left between the outermost precast block 4 and the sidewall of the foundation trench 1, without the need for forced contact with the trench wall.

[0045] S5. Based on the location and dimensions of the underwater rock 2 in the trench 1, locate and determine the target precast block 41 in the layout scheme, and design an assembly groove 5 on the bottom surface of the target precast block 41 that is compatible with the underwater rock 2.

[0046] Specifically, the precise distribution location and three-dimensional dimensions (length, width, and height) of the underwater rocks 2 inside the trench 1 obtained from step S3 are retrieved and compared one by one with the matrix arrangement scheme of the prefabricated blocks 4 proposed in step S4. Based on the planar coordinates of each protruding underwater rock 2 within the trench 1, the range of the prefabricated blocks 4 covering it is precisely compared: if a single underwater rock mass corresponds to only one prefabricated block 4, then that block is designated as the target prefabricated block 41; if the planar coverage of the underwater rock mass is large and overlaps with the positions of multiple prefabricated blocks 4 in the arrangement scheme, then all prefabricated blocks 4 in the overlapping areas are uniformly designated as target prefabricated blocks 41, and the prefabricated blocks 4 in other regular positions are designated as standard prefabricated blocks 42, maintaining the standard cubic structure unchanged.

[0047] Subsequently, based on the measured maximum length, width, and height dimensions of the underwater rock 2, the structural design of the assembly groove 5 was carried out. The assembly groove 5 adopts a standardized cubic internal cavity structure according to the maximum three-dimensional dimensions of the rock mass, eliminating the need for irregular shape adaptation to the rock mass's irregular contours, ensuring that the overall internal space of the assembly groove 5 can completely accommodate the protruding rock mass. When the underwater rock mass corresponds to only one target prefabricated block 41, the assembly groove 5 is placed at the bottom of that target prefabricated block 41; when the underwater rock mass corresponds to multiple target prefabricated blocks 41, the assembly groove 5 is distributed to the bottom of each target prefabricated block 41 as needed.

[0048] S6. Prefabricate the target prefabricated block 41 and the remaining standard prefabricated blocks 42.

[0049] Specifically, based on the aforementioned layout scheme and the design parameters of the assembly groove 5 of the target prefabricated block 41, the factory prefabrication production of all prefabricated blocks 4 is carried out uniformly.

[0050] According to the structural type, the precast blocks 4 are divided into two categories: standard precast blocks 42 and target precast blocks 41, which are poured and processed in batches. The conventional cube blocks without grooves are standard precast blocks 42, and the blocks with cube assembly grooves 5 at the bottom are target precast blocks 41.

[0051] Before prefabrication, steel templates are customized according to the design dimensions. Standard prefabricated block 42 is processed using an integral closed cubic template. For target prefabricated block 41, according to the preset cubic assembly groove 5 size, a pre-embedded mold is preset at the bottom of the corresponding template to accurately reserve a regular cubic groove cavity, ensuring that the groove size, depth and outline meet the design requirements and avoiding the prefabrication construction difficulties caused by irregular structures.

[0052] After the formwork is erected and passes inspection, the reinforcing steel cage is tied strictly according to the specifications in the construction drawings. The spacing of the reinforcing bars, the thickness of the protective layer, and the lap length are controlled to ensure that the overall rigidity and strength of the cage meet the underwater foundation bearing requirements. After the reinforcing steel is laid out and passes the concealed acceptance inspection, the pouring process begins. Subsequently, concrete of the design grade is used for layered pouring and compaction to eliminate quality defects such as honeycomb, pitting, and voids. After pouring, static curing, demolding, and grinding are carried out according to specifications. The external dimensions, flatness, and structural strength of all precast blocks 4 are controlled to ensure that the standard precast blocks 42 are regular in shape and uniform in size, and that the grooves of the target precast blocks 41 are accurately formed without deformation deviation. The quality and specifications of all precast components meet the underwater installation construction standards. After acceptance, they are classified and stacked for later use.

[0053] S7. The crane ship places each precast block 4 into the foundation trench 1 according to the arrangement plan, so that the underwater rock 2 is embedded into the assembly groove 5 of the target precast block 41, and fills the gap between the assembly groove 5 and the underwater rock 2 with grout 6 to form the foundation in the trench.

[0054] Specifically, see Figures 5 to 6According to the arrangement plan of the precast blocks 4 and the hoisting operation sequence, the crane vessel, equipped with a lifting device, hoisted the precast blocks 4 into place one by one. Before the hoisting operation, the elevation and flatness of the top surface of the stone cushion layer 3 in the foundation trench 1 were checked to confirm that there was no debris accumulation in the foundation trench 1. Then, the crane vessel arrived at the construction area and maintained the stability of the vessel position by dynamic positioning. The precast blocks 4 were hoisted using special lifting devices. The standard precast blocks 42 and the target precast blocks 41 were hoisted one by one to the corresponding positions above the foundation trench 1 according to the arrangement plan and slowly lowered into place. During the lowering process, underwater sonar monitoring and underwater verification by divers are used to adjust the attitude and lowering position of the blocks in real time to ensure that the assembly groove 5 at the bottom of the target precast block 41 is precisely aligned with the underwater rock 2 in the foundation trench 1, so that the rock is completely embedded in the groove. The standard precast blocks 42 are placed tightly in sequence according to the close arrangement requirements, with the side walls of adjacent precast blocks 4 closely attached and arranged without gaps, forming a continuous matrix structure. After all precast blocks 4 are placed in place and their positions are verified to be satisfactory, high-strength grout 6 (compressive strength typically greater than or equal to 60 MPa) is injected or gravity-fed into the assembly groove 5 through grouting channels pre-installed in the precast blocks 4 to fill the gap between the groove and the rock. This allows the grout 6 to solidify, firmly bonding the precast blocks 41 and the rock 2 together, enhancing the overall embedding effect and stress stability. Simultaneously, the gaps between the outer precast blocks 4 and the sidewalls of the trench 1 can be filled according to design requirements. The precast block layer laid at the bottom of the trench 1 according to the above-mentioned arrangement constitutes the trench foundation. After all the grout 6 has cured and reached the required structural strength, the precast blocks 4, together with the stone cushion layer 3 and the embedded structure of the rock 2 in the trench 1, form a strong and uniformly stressed underwater foundation, completing the construction of the trench foundation.

[0055] S8. Stack the upper layer of precast blocks on the foundation inside the trench, lay load-bearing slabs, and construct the main body of the wharf.

[0056] Specifically, after the structural strength of the foundation within the trench reaches the design requirements, the layered stacking construction of the superstructure begins. Using the precast block layer laid in step S7 (i.e., the foundation within the trench) as the bottom layer, and following the layered design elevation and vertical layout plan of the main wharf structure, the upper-layer precast blocks are sequentially lifted by a crane vessel and stacked layer by layer, row by row, on the top surface of the foundation within the trench from bottom to top. During the stacking process, the alignment of the central axis of each layer of blocks is strictly controlled to ensure that the contact surfaces between the upper and lower layers of precast blocks 4 are flat and tightly fitted, forming a continuous and regular vertical force transmission path. Adjacent precast blocks 4 in the same layer are also closely fitted together, forming a matrix arrangement aligned with the lower structure to ensure uniform stress distribution and good coordination of the overall structure. The above lifting, alignment, and stacking procedures are repeated, laying the upper-layer precast blocks upwards layer by layer until the top layer of the upper-layer precast blocks reaches the design elevation above the water surface. After all the upper-layer precast blocks are stacked and the elevation is verified to be qualified, a load plate is uniformly laid on the top surface of the top layer of precast blocks. The load plate is tightly attached to the top surface of the top layer of precast blocks 4. Cast-in-place concrete slabs or precast reinforced concrete slabs can be used according to design requirements. After the laying is completed, the structural joints are sealed so that each layer of precast blocks 4 and the load plate form an integral load-bearing structure, and finally a complete wharf main structure is constructed.

[0057] In this embodiment, the construction method relies on a crane vessel to directly complete the hoisting and stacking of the underwater prefabricated blocks 4 and the main structure of the wharf. The direct operation mode on the water eliminates the need for the erection and dismantling of temporary offshore construction platforms, which is necessary for traditional shallow sea wharf construction. This simplifies the offshore operation process from the source of construction technology, significantly reduces the input of offshore auxiliary construction components, equipment and manpower, effectively reduces the construction difficulty under complex hydrological conditions in shallow water areas, and reduces the overall construction cost. This construction method targets the naturally protruding underwater rock 2 within the trench 1. It employs an adaptive structure by creating cubic assembly grooves 5 on the bottom surface of the target precast blocks 41. These grooves accommodate the natural protruding rock mass. This structural adaptation replaces the traditional blasting and trench bottom leveling process, completely avoiding approval restrictions, hydrological window constraints, and the time lost due to blasting debris removal. This significantly reduces the trench 1 foundation pretreatment period while preserving the original high-strength bearing characteristics of the natural underwater rock 2, preventing disturbance and damage to the surrounding soil and rock structure during blasting. This significantly improves construction efficiency and safety. Furthermore, this method uses a dense arrangement of standardized precast blocks 4 to form an integral trench foundation. The neatly assembled cubic precast components naturally form a flat, continuous, and high-precision upper load-bearing surface, eliminating the need for additional manual leveling and ensuring tight contact and uniform stress distribution of the stacked upper structure. After the underwater rock 2 is embedded in the bottom groove of the target precast block 41, it can form a multi-point rigid embedded support structure, which directly transmits the vertical load of the upper multi-layer precast blocks 4 and the main body of the wharf to the natural hard rock mass. This completely solves the stress defects caused by uneven compaction, local weak interlayers, and base protrusion and voids in the traditional artificial leveling pad layer. It fundamentally suppresses the problems of uneven settlement, overall slippage, and structural tilt that occur during the long-term service of the wharf foundation, and greatly improves the integrity, stability and long-term service safety performance of the overall wharf structure.

[0058] See Figures 5 to 6 In one embodiment of this application, during the process of the crane vessel placing each prefabricated block 4 into the foundation trench 1 according to the arrangement scheme, the prefabricated blocks 4 are placed row by row from the roadside to the waterside of the foundation trench 1, including: Place a row of precast blocks 4 on the bottom surface of the foundation trench 1; The adjacent row of prefabricated blocks 4 is temporarily stacked on top of the previously placed row of prefabricated blocks 4, and left to stand for a set time. The adjacent row of precast blocks 4 is placed on the bottom surface of the foundation trench 1 and arranged adjacent to the previous row of precast blocks 4; Repeat the above steps, advancing row by row from the roadside to the waterside, until all prefabricated blocks 4 are placed.

[0059] Specifically, the placement of precast blocks 4 proceeds row by row along the roadside of the foundation trench 1 towards the waterside, with the roadside being the side closest to the land and the waterside being the side furthest from the land. First, the first row of precast blocks 4 is hoisted and lowered one by one, smoothly placed on the stone cushion layer 3 at the landside end of the foundation trench 1, ensuring that the blocks in the same row are tightly fitted together to form a stable arrangement unit. Then, the next row of precast blocks 4 is hoisted and lowered one by one, temporarily stacking each precast block 4 on top of its corresponding precast block 4 in the first row, and left to stand for a set time. Once the postures of the upper and lower precast blocks 4 have stabilized, the next row of precast blocks 4 is lowered one by one onto the stone cushion layer 3 at the bottom of the foundation trench 1, ensuring tight contact with the precast blocks 4 in the first row.

[0060] The process of stacking, stabilizing, and placing the precast blocks 4 one by one is repeated in a cycle to complete the placement of each subsequent row of precast blocks 4. The process continues to advance from the roadside to the waterside until all the precast blocks 4 at the bottom of the foundation trench 1 are in place.

[0061] It should be noted that if the precast blocks 4 are directly lowered underwater onto the bottom of the foundation trench 1, the components lack temporary fixing constraints and are easily affected by water flow, waves, and water turbulence, resulting in slippage, displacement, or even overturning. This makes it difficult for the first-placed precast blocks 4 to form a stable arrangement benchmark. When subsequent precast blocks 4 are aligned and placed based on the first-placed precast blocks 4, there will be no reliable reference, which can easily lead to problems such as misalignment, uneven gaps, and non-straight lines. Repeated underwater adjustments and corrections will be labor-intensive and inefficient. Furthermore, the foundation in the trench after formation is prone to local stress concentration and uneven stress due to insufficient arrangement accuracy, which will affect the overall structural stability and long-term service performance of the wharf.

[0062] In this embodiment, by temporarily stacking the next row of precast blocks 4 on top of the already positioned precast blocks 4, the self-weight of the precast blocks 4 is used to form an active surcharge preloading effect: when the subsequent precast blocks 4 are temporarily stacked on top of the previous row of precast blocks 4, their self-weight load will be evenly transferred to the already positioned precast blocks 4 and the foundation 1 cushion layer (stone cushion layer 3) below through the contact interface, causing the cushion layer material to be further compacted and compacted in a short time, and at the same time compacting the small gaps between the already positioned precast blocks 4 and the cushion layer, greatly improving the fit between the pre-arranged units and the base, so that the placed precast blocks 4 form a more stable stress state on the cushion layer, significantly enhancing their resistance to water flow erosion, wave disturbance and slippage, and avoiding displacement of the precast blocks 4 used as the arrangement reference due to water flow impact and hoisting disturbance during subsequent construction.

[0063] Based on this, when each row of precast blocks 4 is in place, the previous row of blocks that has been stabilized by preloading is used as a rigid and reliable reference benchmark. The alignment accuracy of subsequent blocks is no longer affected by the shaking or offset of the precast blocks 4 that have been placed in the previous stage. This enables high-precision lateral contact and positioning, controls the alignment deviation of a single row from the source, avoids the accumulation of errors, overall deformation and linear deviation caused by unstable benchmarks in traditional construction, effectively ensures the regularity and uniformity of the overall layout of the foundation in the trench, reduces local gaps and misalignment defects, and greatly improves the foundation forming accuracy.

[0064] Furthermore, this "row-by-row stacking and placement" assembly line operation mode enables process overlap and time reuse: while the next row of blocks is hoisted and stabilized, the previous row of blocks is further stabilized under continuous loading. There is no need to set up a separate settling process to wait for the benchmark to stabilize. The stacking and settling time is used to achieve cross-operation. Under the premise of ensuring construction stability and forming quality, the overall ineffective waiting time is reduced, which effectively improves the continuity and overall efficiency of underwater construction.

[0065] Ultimately, the formed trench foundation not only has high layout accuracy and straight lines, but also has tight fit between each row of precast blocks 4 and uniform stress distribution. Structurally, it avoids the hidden dangers of local stress concentration and uneven stress distribution, providing a high-precision and high-stability foundation for the subsequent stacking construction of multiple layers of precast blocks 4 on the upper part, and significantly improving the stability and long-term service performance of the overall wharf structure.

[0066] See Figure 5 In one embodiment of this application, during the process of the crane ship placing each prefabricated block 4 into the foundation trench 1 according to the arrangement scheme, when a row of standard prefabricated blocks 42 on the side of the target prefabricated block 41 near the water side are temporarily stacked with prefabricated blocks 4, grouting material 6 is filled into the gap between the assembly groove 5 of the target prefabricated block 41 and the bottom rock 2.

[0067] It should be noted that when grout 6 is injected directly into the gap between the assembly groove 5 of the target precast block 41 and the underwater rock 2, the grout 6 supply equipment above the water surface needs to be connected to the grouting channel on the target precast block 41 through a pipeline. Under the action of water flow, the pipeline is prone to large-scale shaking, which can cause the connection between the pipeline and the grouting channel to loosen or fall off, making it impossible for the grout to be accurately delivered into the gap between the groove and the rock. In addition, when the pipeline connection is disconnected after the grout 6 is filled, the water flow can easily directly fill the grouting channel, washing away and diluting the grout 6 that has not yet solidified, causing grout loss and insufficient strength, and making it impossible to form a reliable embedded support structure.

[0068] During the placement of precast blocks 4, the timing of grouting operations for the target precast blocks 41 was optimized: while the crane ship was placing each precast block 4 into the foundation trench 1 according to the arrangement plan, it was necessary to wait until a whole row of standard precast blocks 42 on the side of the target precast blocks 41 away from the land was in place and a row of precast blocks 4 was temporarily stacked on top of them before connecting the pipeline of the grouting material 6 supply equipment to the grouting channel of the target precast blocks 41 and performing the process of filling the gap between the mounting groove 5 and the underwater rock 2 with grouting material 6.

[0069] In this embodiment of the application, the following effect can be achieved by setting the grouting process of the target precast block 41 after all the standard precast blocks 42 on the side away from the land have been placed and a row of precast blocks 4 have been temporarily stacked.

[0070] First, the structure of the precast blocks 4, which are placed and stacked on the side away from the land, is stable and can provide reliable lateral ballast for the target precast block 41. At the same time, the friction generated by the contact surface of the components forms a vertical constraint effect, which effectively offsets the impact force generated during the injection of grout 6 and weakens the upward pushing force on the target precast block 41 after the grout fills the gap. This effectively limits the target precast block 41 from floating, shifting, or shaking, ensuring that the positioning accuracy of the components is not affected by the grouting construction, and providing a stable and accurate working benchmark for the subsequent stacking construction of the superstructure.

[0071] Secondly, the stacked precast blocks 4 arranged on the side away from the land, being in a shallow water area, can usually be exposed above the water surface, forming a natural protective shield structure on the outside of the target precast block 41. This prevents the water flow from directly scouring the target precast block 41, avoids pipe swaying caused by water flow disturbance, maintains a stable connection between the delivery pipe and the grouting channel, and ensures that the grouting material 6 can be smoothly injected into the preset gap.

[0072] In addition, after the grouting operation is completed and the pipeline connection is disconnected, the shielding and protection effect of the outer stacked precast blocks 4 can prevent water from flowing into the grouting channel, avoid the grout material 6 that has not yet solidified from being washed away by the water flow, and ensure that the grout material 6 can be fully solidified and cured in the gap between the assembly groove 5 and the underwater rock 2, forming a rigid embedded support structure with qualified strength and reliable performance, so that the target precast block 41 and the underwater rock 2 are firmly fixed as a whole, effectively improving the overall anti-slip and anti-overturning ability of the wharf foundation.

[0073] The grouting construction sequence is fully compatible with the sequential stacking and placement of precast blocks, allowing for simultaneous grouting operations during the static and stable period of the outer precast blocks 4. This enables cross-coordination of different processes and efficient reuse of time, eliminating the need for additional construction time. While ensuring overall construction efficiency, it comprehensively improves the quality of underwater grouting construction and the bonding effect of components, fundamentally avoiding problems such as foundation slippage and uneven settlement caused by grouting defects, and further enhancing the overall structural strength and long-term service safety and stability of the wharf foundation.

[0074] In one embodiment of this application, after the last row of prefabricated blocks 4 is placed on the bottom surface of the foundation trench 1, a row of upper prefabricated blocks is stacked on top of the placed last row of prefabricated blocks 4 and left to stand for a set time. After a set set time, the settlement of the row of precast blocks 4 that have been placed is measured.

[0075] It should be noted that after the precast blocks 4 are directly placed on the bottom surface of the foundation trench 1 to complete the bottom layer arrangement, although the precast blocks 4 forming the foundation of the trench are in place, the stone cushion layer 3 is affected by underwater construction disturbance, and gaps and loose areas still remain inside. At the same time, each row of precast blocks 4 only relies on its own weight to achieve initial stability, without overall compaction. If the superstructure is stacked immediately after the bottom blocks are laid, it is impossible to accurately determine the density of the stone cushion layer 3, nor can it predict subsequent settlement changes, making it difficult to detect hidden quality problems such as insufficient compaction, voids at the bottom of components, and uneven settlement in advance. If the upper layer of precast blocks is stacked in this state, the base cushion layer is very prone to secondary compression settlement, causing deviations in the settlement values ​​of various parts of the foundation, which in turn leads to problems such as local tilting of the foundation, unbalanced stress distribution, and cracking and damage of component joints. This not only increases the cost and difficulty of later maintenance and repair of the wharf, but also significantly reduces the service life of the structure and reduces the overall service safety factor.

[0076] The finishing pressure stabilization and settlement detection procedures after the bottom precast blocks 4 are laid are optimized to adapt to the construction process of overall row-by-row placement. The work object is the bottom precast blocks 4 that have been completely laid inside the foundation trench 1. The specific construction steps are as follows: After the construction personnel have completed the placement of all the bottom precast blocks 4 along the roadside to the waterside, and the last row of precast blocks 4 is smoothly lowered to the bottom surface of the foundation trench 1, accurately aligned and closely arranged with the adjacent precast blocks 4, a crane ship lifts a whole row of upper precast blocks and stacks the whole row of upper precast blocks on the top surface of the last row of bottom precast blocks 4 that have been placed.

[0077] Throughout the entire process of loading the upper precast blocks onto the bottom last row of precast blocks 4, and temporarily loading the previous row of precast blocks 4 onto the previous row of precast blocks 4, it is crucial to ensure a one-to-one correspondence and precise overlap between the upper and lower precast blocks 4, ensuring complete contact between the upper and lower components and preventing any undesirable conditions such as component suspension, offset, or skewing. After the loading operation is completed, the static stabilization stage begins. The required static stabilization time is typically set according to the process standards, and under normal working conditions, the set time is 24 hours. During the static stabilization period, relying on the self-weight of the upper precast blocks 4, continuous vertical pressure is applied to the lower precast blocks 4 and the stone cushion layer 3 of the bottom foundation trench 1, gradually compressing and closing the internal pores of the cushion layer, eliminating loose and unlaid areas of the cushion layer, achieving secondary compaction of the base cushion layer, and releasing the potential settlement of the cushion layer in advance.

[0078] After the stacked precast blocks 4 in a single row have been left to stand for the preset time, construction personnel use underwater detection equipment and high-precision underwater rangefinders, along with divers for on-site underwater verification, to conduct specialized settlement testing on all precast blocks 4 in that row. Real-time elevation data of the top surface of each individual precast block 4 is collected and compared with its initial placement elevation to accurately calculate the actual settlement value of each precast block 4. The measured settlement data is compared with the design threshold to evaluate the compaction of the base layer and the stability of the foundation. When the settlement of all precast blocks 4 in the row is within the design allowable range (less than or equal to 5mm), it is determined that the base layer in this area is sufficiently compacted and the overall foundation is stable. Subsequent stacking of multiple layers of precast blocks can then be carried out on top of these blocks. If the settlement of any precast block 4 in the row exceeds the specified threshold (greater than 5mm), it is determined that the foundation has insufficient compaction. The bottom precast block 4 with excessive settlement, as well as the precast blocks 4 temporarily stacked on top of it, are then removed. Subsequently, based on the extent of the excessive settlement, a stone base layer 3 of appropriate thickness is added at the corresponding location. After the addition is completed, the bottom precast blocks 4 are repositioned, and the upper precast blocks are stacked again for static stabilization. After static stabilization, the settlement data is re-measured, and this process is repeated until the settlement indicators meet the construction specifications.

[0079] In this embodiment, after the single row of precast foundation blocks 4 is placed, another row of precast blocks 4 is immediately used for temporary surcharge compaction and settlement testing, achieving phased verification of the settlement status from the perspective of construction sequence. Relying on the self-weight of the upper blocks to form a vertical load, the pores of the cushion layer are forced to compress and shrink in advance, releasing the compressible deformation of the soil. This allows the settlement characteristics of the single row of precast blocks 4 to be fully manifested during the foundation construction stage, directly reflecting the actual settlement performance of individual blocks and the entire row of blocks. It enables the immediate identification of abnormal problems such as excessive local settlement and uneven compaction of the cushion layer, facilitating timely rectification and correction, preventing the accumulation of single construction defects, and avoiding the continuation of hidden dangers to subsequent stacking operations.

[0080] This segmented inspection method differs from the traditional approach of verifying settlement only after the entire floor is completed. Traditional methods often rely on applying loads to the superstructure to check foundation settlement, resulting in late defect detection. This solution moves the inspection process forward, allowing for hazard identification during the single-row foundation forming stage. This significantly advances problem detection, ensures precise anomaly location, and enables simultaneous on-site rectification, significantly reducing the time required for fault handling and lowering the probability of later structural deformation and stress imbalance from the outset.

[0081] This process integrates foundation pre-compaction, settlement quality testing, and the installation of upper components. The surcharge stabilization step serves as both a foundation reinforcement method and a preparatory step for upper construction. The processes are closely linked and seamlessly transitioned, eliminating the need for a separate, pre-defined interval for foundation static acceptance and reducing time losses caused by fragmented construction. This ensures that each row of foundation components possesses uniform and stable load-bearing capacity, solidifying the overall structural foundation, while also allowing for the orderly stacking of foundations and upper blocks. Under strict quality control, this effectively improves the overall efficiency of on-site construction.

[0082] In one embodiment of this application, during the process of the crane ship placing each prefabricated block 4 into the foundation trench 1 according to the arrangement scheme, the prefabricated blocks 4 are placed row by row from the road side to the water side of the foundation trench 1. If a target prefabricated block 41 is included in a row of prefabricated blocks 4 to be placed, the target prefabricated block 41 is placed first, and then the remaining standard prefabricated blocks 42 in the row are placed sequentially to one or both sides of the target prefabricated block 41 as a reference.

[0083] It should be noted that if the precast blocks 4 in a single row are placed sequentially from one end of the row to the other, the placement error of each precast block 4 will accumulate along the layout direction due to factors such as underwater positioning operation deviation and water disturbance. When construction reaches the position of the target precast block 41, the accumulated error will cause the alignment of the assembly groove 5 of the target precast block 41 with the underwater rock 2 to be offset, resulting in the underwater rock 2 not being able to be completely embedded in the assembly groove 5. Consequently, the target precast block 41 may be forcibly lifted by the rock, resulting in the precast block 4 being tilted in place and suspended at the bottom. This not only damages the flatness of the single row of precast blocks 4, but also causes abnormal stress on the precast blocks 4 and loose adhesion, making it impossible to carry out subsequent grouting operations normally, which seriously affects the foundation forming quality and structural stability.

[0084] When the crane vessel is carrying out the hoisting and placement of precast blocks 4 according to the preset layout plan, for each row of precast blocks 4 to be placed, the component composition is checked first. If the row includes the target precast block 41, the conventional sequential placement process is adjusted: first, the crane vessel hoists the target precast block 41 to the design position, accurately completes the alignment, lowering and fixing, and ensures that the assembly groove 5 of the target precast block 41 is accurately aligned with the underwater rock 2, so that the underwater rock 2 is completely embedded in the groove. The target precast block 41 is placed stably on the stone pad layer 3 at the bottom of the foundation trench 1, without being lifted, suspended or tilted.

[0085] Using the precast block 41 already in place as the core positioning benchmark for the entire row, and based on the site layout requirements, if the target precast block 41 is located at one end of the row of precast blocks 4, the remaining standard precast blocks 42 in this row are hoisted and placed sequentially, starting from one side of the target precast block 41; if the target precast block 41 is not located at one end of the row of precast blocks 4, the remaining standard precast blocks 42 in this row are hoisted and placed sequentially, starting from both sides. When placing the standard precast blocks 42, the adjacent precast blocks 4 already in place are used as a reference, and each block is precisely aligned and tightly fitted until the layout of all precast blocks 4 in the current row is completed. After the current row of precast blocks 4 is placed, the work continues from the roadside to the waterside to carry out the placement of subsequent rows of precast blocks 4, until all the precast blocks 4 at the bottom layer of the foundation trench 1 are placed in place.

[0086] In this embodiment, by prioritizing the placement of the target prefabricated block 41 and using it as the baseline for the entire row, the problem of error accumulation caused by sequential placement is avoided from the root. First, prioritizing the positioning and placement of the target prefabricated block 41 can directly ensure that its assembly groove 5 is precisely matched with the underwater rock 2, allowing the rock to be smoothly embedded in the groove. This completely avoids problems such as components being lifted by the rock, the bottom being suspended, and the posture being skewed caused by accumulated errors in the early stage, ensuring that the positioning state of the target prefabricated block 41 is compliant and creating good working conditions for the subsequent grouting process.

[0087] Secondly, the arrangement work is carried out with the precast block 41 with precise positioning as the center: if a single-sided arrangement mode is adopted, the reference component can be used to accurately position it in one direction; if a double-sided arrangement mode is adopted, the assembly error generated by the placement can be dispersed to the left and right sides of the row, preventing the error from unidirectionally accumulating and avoiding the overall shift of the entire row of precast blocks 4 relative to the design arrangement scheme in a single direction. This fundamentally ensures that the arrangement position of a single row of precast blocks 4 is accurate, the line is straight, and the gaps between adjacent components are uniform.

[0088] Meanwhile, the orderly arrangement of components without abnormal lifting or suspension defects ensures uniform stress transfer between the precast blocks 4 and the base, as well as between components, improving the overall density and structural integrity of the foundation within the trench and reducing the risk of uneven settlement and localized stress concentration later on. The entire process is adapted to the on-site flow construction rhythm, solving alignment problems and controlling construction quality while reducing the workload of underwater rework and correction, thus balancing construction accuracy and work efficiency.

[0089] In one embodiment of this application, when searching for and determining the target precast block 41 in the layout scheme, if the number of target precast blocks 41 corresponding to the same underwater rock 2 is greater than or equal to three, the layout scheme of the precast blocks 4 in the trench 1 is adjusted so that the number of target precast blocks 41 corresponding to the same underwater rock 2 is one or two.

[0090] It should be noted that in step S2, after filling the trench 1 with stones and constructing the stone cushion layer 3, the lower part of the natural underwater rock 2, which was originally directly exposed inside the trench 1, will be partially covered by the filled stones. As a result, the external dimensions of the remaining exposed area of ​​the underwater rock 2 are reduced, and at least one of its horizontal length and width is smaller than the horizontal dimensions of the precast block 4; therefore, under normal design conditions, it is not necessary to lay the assembly groove 5 on the entire bottom surface of the precast block 4.

[0091] Furthermore, during the layout design phase, if a single underwater rock 2 corresponds to three or more target prefabricated blocks 41, it will typically lead to two types of structural defects: Firstly, when the underwater rock 2 is located at the central intersection of four prefabricated blocks 4, the corresponding mounting groove 5 needs to be split into four different prefabricated blocks 4, that is, a partial groove structure is arranged in the corner area of ​​each prefabricated block 4. This design will cause the bottom surface of the prefabricated block 4 to form a missing corner structure, causing the effective contact area between the prefabricated block 4 and the stone pad 3 to be biased to one side of the component, and the vertical support point will be shifted accordingly, breaking the force balance of the component and greatly increasing the probability of tilting and instability of the prefabricated block 4 during underwater placement and static pressure stabilization.

[0092] Secondly, when the underwater rock 2 penetrates multiple precast blocks 4 along a single straight line, the assembly groove 5 of some target precast blocks 41 will cross the bottom surface of the component, causing only the two sides of the bottom of the precast block 4 to be able to contact the stone pad layer 3 of the foundation trench 1. This type of structure will cause too much missing base material at the bottom of the precast block 4, and the overall structural strength will be greatly reduced. When bearing the load pressure of the upper precast block 4 and the external water load, it is very easy to produce stress cracking, damage and other defects, which seriously affect the service life of the foundation components and the overall construction quality.

[0093] Before officially commencing the underwater placement of precast blocks 4, preliminary verification and scheme optimization were conducted based on the topography of the foundation trench 1, the distribution of underwater rocks 2, and the arrangement plan of precast blocks 4. First, technicians compared the layout design drawings with the underwater topographic survey data, clarifying the correspondence between each rock location and the target precast blocks 41, and verifying the number of target precast blocks 41 matched for each underwater rock 2. If the verification results showed that the number of target precast blocks 41 corresponding to a single underwater rock 2 was greater than or equal to three, the overall arrangement plan of precast blocks 4 within the foundation trench 1 was immediately adjusted.

[0094] Because the foundation trench 1 in the layout scheme is not completely filled with precast blocks 4, there is ample space between the outer precast blocks 4 and the sidewalls of the foundation trench 1, allowing for horizontal displacement adjustment of the layout scheme. Two translation methods can be used to optimize the layout: one is to translate the entire layout scheme along any direction in the horizontal XY plane; the other is to adjust the position of a single row of precast blocks 4 individually, in which case translation is only possible along the length of the row. Through these displacement adjustment methods, the number of target precast blocks 41 corresponding to a single underwater rock 2 can be adjusted to one or two.

[0095] It should be noted that in nearshore waters suitable for wharf construction, the number of underwater rocks is relatively small and their individual sizes are generally small. After the foundation trench 1 is excavated, there are usually only one or two underwater rocks 2 inside. If the initial layout plan has three or more target precast blocks 41 corresponding to underwater rocks 2, the layout should be adjusted according to the above translation method to ensure that the number of target precast blocks 41 matched by each underwater rock 2 is controlled within one or two ranges.

[0096] After the layout plan is adjusted and confirmed to be correct, the crane vessel can carry out the hoisting, alignment and placement of the precast blocks 4 row by row from the roadside to the waterside according to the optimized plan, ensuring that each underwater rock 2 is only fitted and positioned with one or two target precast blocks 41. Subsequently, supporting construction procedures such as surcharge stabilization, settlement detection and gap grouting are carried out in sequence.

[0097] In this embodiment, the component layout is optimized through a translational arrangement scheme, controlling the number of target precast blocks 41 corresponding to a single underwater rock 2 to one or two. This avoids the situation where a single rock simultaneously connects to too many precast blocks 4 from the design source, and eliminates unreasonable structural forms such as the assembly groove 5 being split into the corners of multiple precast blocks 4 or the groove running across the bottom surface of the precast blocks 4. This effectively solves the problems of bottom support misalignment and stress imbalance of the precast blocks 4, preventing tilting and instability during the placement and stacking of the precast blocks 4. It also prevents defects such as excessive missing base material at the bottom of the precast blocks 4 and reduced overall strength, significantly reducing the risk of cracking and damage to the precast blocks 4 under the action of upper loads, and ensuring the structural integrity and load-bearing capacity of the components themselves.

[0098] Only a small number of target precast blocks 41 are matched with a single underwater rock 2, which greatly reduces the construction difficulty of aligning and fitting multiple precast blocks 4 at the same time. It avoids problems such as the precast blocks 4 being lifted up and the bottom being suspended due to mismatch between the groove and the rock, so that each target precast block 41 can be placed stably, effectively improving the positioning accuracy and construction quality of underwater placement operations.

[0099] This optimization method utilizes the reserved space within the foundation trench 1 to perform overall or single-row translation adjustments without altering the structure or shape of the prefabricated blocks 4. The adjustment method is simple and easy to implement, and does not increase the cost of component processing. Simultaneously, after layout optimization, the distribution of the interlocking force system between each prefabricated block 4 and the underwater rock 2 is more rational, which can disperse the single-point bearing pressure, prevent damage to the underwater rock 2 due to concentrated loads, and further improve the overall structural stability and long-term service performance of the foundation trench 1.

[0100] See Figures 4 to 6 In one embodiment of this application, when the bottom surface of the target precast block 41 is designed with an assembly groove 5 that is adapted to the underwater rock 2, a grouting hole 401 and a drainage hole 402 are further designed in the target precast block 41. The grouting hole 401 and the drainage hole 402 are both connected to the assembly groove 5 and penetrate the target precast block 41 vertically upwards; the grouting hole 401 is vertically aligned with the edge of the underwater rock 2, and the drainage hole 402 is vertically aligned with the top of the underwater rock 2.

[0101] It should be noted that if the target precast block 41 is only provided with grouting holes 401 as grouting channels, the water and air accumulated in the narrow, enclosed gap formed by the assembly groove 5 and the underwater rock 2 cannot be discharged smoothly and in a timely manner during grouting operations. This can easily lead to the formation of air masses and water accumulation areas inside the groove, resulting in incomplete filling of the grouting material 6 and quality defects such as voids and interlayers. In addition, if the grouting holes 401 are positioned directly opposite the center of the underwater rock 2, the grouting material 6 will diffuse and flow from the center outwards, easily causing insufficient grout supply at the far end of the gap and weak filling at the edges. These problems will directly reduce the bonding and anchoring performance of the grouting layer, resulting in insufficient bonding strength between the target precast block 41 and the underwater rock 2 and a decrease in the overall anti-slip capability. At the same time, it will cause uneven local stress on the foundation, making the structure prone to settlement displacement, component loosening, and other defects during long-term service, seriously affecting the underwater foundation forming quality and overall structural stability.

[0102] Vertically penetrating grouting holes 401 and drainage holes 402 are added to the target precast block 41. Both grouting holes 401 and drainage holes 402 vertically penetrate the upper surface of the target precast block 41, and the bottom ends of both holes are directly connected to the inner cavity of the bottom mounting groove 5. The top openings are exposed on the top surface of the precast block 4, facilitating the connection of construction equipment and the ventilation and drainage. The grouting hole 401 is vertically aligned with the edge of the underwater rock 2, and the drainage hole 402 is vertically aligned with the highest point of the underwater rock 2.

[0103] During the actual grouting operation, the construction personnel connect the grouting material 6 supply equipment pipeline to the grouting hole 401 on the top surface of the precast block 4. The high-pressure grouting material 6 is transported along the channel to the edge of the underwater rock 2 within the assembly groove 5. Because the edge of the underwater rock 2 is a low-lying area with gaps, the grouting material 6 first flows around the outer periphery of the rock, and then gradually spreads and fills the rock from the edge towards the top in an orderly manner. Throughout the entire process of injecting and filling the grouting material 6, the construction personnel can insert a vibrator through the top drainage hole 402 to perform layered vibration of the grouting material 6 inside the groove, breaking air bubbles inside the grout and promoting uniform flow and dense filling of the grouting material 6. Simultaneously, the grouting operation squeezes and expels the water and air accumulated in the groove. The displaced water and air are discharged upwards to the outside of the precast block 4 through the drainage hole 402. Workers can visually judge the filling status inside the gap by observing the outflow status of the drainage hole 402: when pure grout 6 continuously flows out of the drainage hole 402 without air bubbles or clear water, it can be determined that the gap between the assembly groove 5 and the bottom rock 2 has been filled tightly, and then the vibrator is removed and the grouting operation is terminated. After grouting is completed, each hole can be sealed to maintain the effective filling of the grout 6.

[0104] In this embodiment, a dual-hole structure with grouting hole 401 and drainage hole 402 is adopted, which overcomes the shortcomings of traditional single-hole grouting with poor air venting and drainage. During the grouting operation, the high-level drainage hole 402 is used to promptly discharge the air and water trapped inside the groove, completely avoiding quality defects such as grouting voids and interlayers caused by sealed air pockets and water dead corners. This ensures that the grouting material 6 can completely fill all gaps between the assembly groove 5 and the bottom rock 2, significantly improving the fullness of grouting filling.

[0105] With targeted and differentiated hole placement, grouting hole 401 is aligned with the low-lying area of ​​the rock edge for grouting, and drainage hole 402 is aligned with the highest point of the rock for venting and drainage. This allows the grout to flow in an orderly manner from the edge to the highest point, effectively solving the problems of insufficient material supply at the far end and weak edge filling caused by traditional center grouting. It is suitable for grouting operations in the gaps of irregular underwater rocks.

[0106] The drainage hole 402 serves as a working channel, and a vibrator is inserted during grouting to assist in compacting the grout. On the one hand, this can break up air bubbles inside the grout, further expel residual air in the gaps, and avoid local void defects; on the other hand, it can reduce the viscosity of the grout material 6, improve the fluidity of the grout, alleviate the phenomenon of grout accumulation and segregation, and promote the grout material 6 to fully cover all corners of the gaps, thereby improving the overall compactness of the grouting from two levels.

[0107] The drainage hole 402 has multiple functions, including ventilation, drainage, and vibration operation channel. It does not require the addition of a special operation hole or modification of the overall structure of the precast block 4. This simplifies the design of component openings, reduces the processing cost of precast components, and simplifies the underwater construction process. At the same time, the staff can directly observe the outflow medium of the drainage hole 402, quickly determine the grouting fullness, reduce the difficulty of underwater quality inspection, and reduce the frequency of rework.

[0108] After being vibrated and compacted, the grouting layer can solidify the target precast block 41 and the underwater rock 2 into a whole in all directions, uniformly transfer vertical and horizontal loads, greatly improve the anti-slip and anti-overturning ability of the target precast block 41, strengthen the overall integrity of the foundation, avoid the defects such as component loosening, uneven settlement, and local displacement caused by insufficient grouting, significantly improve the overall forming quality of the underwater foundation, and ensure the long-term service stability of the wharf foundation.

[0109] In one embodiment of this application, when designing grouting holes 401 and drainage holes 402 in the target precast block 41, if there are multiple adjacent target precast blocks 41, the multiple adjacent target precast blocks 41 are integrated into a target block group, and a grouting hole 401 and a drainage hole 402 are set in the target block group.

[0110] It should be noted that for multiple adjacent precast blocks 41 on site, if the design is still based on the method of independently setting grouting holes 401 and drainage holes 402 for each individual component, it will result in an excessive number of ducts and a messy layout. On the one hand, opening a large number of ducts will weaken the main structure of the precast block 41 and increase the risk of strength reduction in the component; on the other hand, grouting each block individually requires repeated connection of pipelines and switching of work points, which is cumbersome, frequent, and time-consuming and inefficient for underwater construction. At the same time, independent grouting of adjacent components is prone to grout cross-flow and uneven pressure, making it difficult to uniformly control the grouting flow and pressure, which can easily lead to inconsistent filling density between components, affecting the overall consolidation effect and stress uniformity.

[0111] To optimize the layout of the ducts for multiple adjacent precast target blocks 41, based on the pre-reserved assembly groove 5 on the bottom surface of the target precast block 41 that is compatible with the underwater rock 2, the grouting holes 401 and drainage holes 402 are planned in a unified manner according to the component layout.

[0112] First, the precast blocks 4 within the foundation trench 1 are divided into zones. Multiple target precast blocks 41 that are adjacent to each other and arranged side by side are integrated into a target block group. For each target block group, instead of individually opening grouting holes 401 and drainage holes 402 for each precast block 4 within the group, only one grouting hole 401 and one drainage hole 402 are uniformly set for the whole group. The grouting hole 401 and drainage hole 402 are both vertically connected to the corresponding precast block 4 within the target block group. The mounting groove 5 at the bottom of the hole has an opening at the top that protrudes from the top surface of the component, facilitating the connection of grouting equipment and the discharge of gas and water. It can also serve as the working channel for the vibrator.

[0113] During on-site construction, the grouting material 6 supply equipment pipeline is connected to the common grouting hole 401 of the target block group. The high-pressure grouting material 6 is synchronously delivered through the common channel to the gaps between each target precast block 41 and the underwater rock 2 within the group. The grouting material 6 gradually fills the gaps according to the preset flow direction. The accumulated water and air in the gaps are collected and discharged outward from the common drainage hole 402. During the grouting process, a vibrator can also be inserted through the drainage hole 402 to vibrate the grouting material 6 in each group's gaps. When pure grouting material 6 continues to flow out of the drainage hole 402 without air bubbles or clear water, and it is determined that all gaps within the entire target block group are filled densely, grouting is stopped.

[0114] In this embodiment, adjacent precast blocks 41 are integrated into a block group and share a set of grouting holes 401 and drainage holes 402. This significantly reduces the overall number of openings, minimizes the weakening effect of openings on the structure of the precast blocks 4, and ensures the structural strength and integrity of the target precast blocks 41. By adopting a group-shared channel model, grouting operations for multiple adjacent components can be completed with a single set of equipment and a single connection. This eliminates the repetitive steps of disassembling and assembling pipelines and switching work points, simplifies the underwater construction process, and significantly improves the overall efficiency of the grouting operation. The shared channels allow for unified control of grouting pressure and slurry flow, ensuring consistent grouting conditions in the gaps between the assembly grooves 5 within the group. This effectively avoids problems such as slurry cross-flow and excessive differences in filling density between adjacent components, ensuring uniform and consistent consolidation quality between all target precast blocks 41 and the underwater rock 2 within the group, resulting in more balanced force transmission. With fewer ducts, the amount of work required for sealing the ducts is reduced, which also reduces the risk of water seepage and grout leakage caused by poor sealing of the ducts, further improving the seepage prevention performance and long-term reliability of the underwater foundation.

[0115] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0116] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A construction method for a hydraulic wharf using precast blocks, characterized in that, The method includes: Excavate the foundation trench, preserving the original underwater rocks during the excavation process; Stones are thrown into the trench to cover the rocks at the bottom of the water. The stones are then compacted and leveled to form a stone cushion layer. The geomorphology of the foundation trench was surveyed to obtain the location and dimensions of the underwater rocks within the trench; Based on the dimensions of the foundation trench and the specifications of the precast blocks, design a layout scheme for the precast blocks within the foundation trench; Based on the location and dimensions of the underwater rocks in the trench, the target precast blocks are located and determined in the layout scheme, and an assembly groove that matches the underwater rocks is designed on the bottom surface of the target precast blocks. Prefabricate the target prefabricated block and the remaining standard prefabricated blocks; The crane vessel places each prefabricated block into the foundation trench according to the arrangement plan, so that the underwater rock is embedded in the assembly groove of the target prefabricated block, and fills the gap between the assembly groove and the underwater rock with grouting material to form the foundation in the trench. Precast blocks are stacked on top of the existing foundation in the trench, and load-bearing slabs are laid to form the main body of the wharf.

2. The construction method for a hydraulic wharf using precast blocks according to claim 1, characterized in that, During the process of the crane vessel placing the precast blocks into the foundation trench according to the layout plan, the precast blocks are placed row by row from the road side to the water side of the foundation trench, including: Place a row of precast blocks on the bottom of the foundation trench; The adjacent row of prefabricated blocks is temporarily stacked on top of the previously placed row of prefabricated blocks, and left to stand for a set time. The adjacent row of precast blocks is placed on the bottom of the foundation trench and arranged adjacent to the previous row of precast blocks; Repeat the above steps, advancing row by row from the roadside to the waterside, until all prefabricated blocks have been placed.

3. The construction method for a hydraulic wharf using precast blocks according to claim 2, characterized in that, During the process of the crane vessel placing each precast block into the foundation trench according to the arrangement plan, when a row of standard precast blocks on the side of the target precast block closest to the water are temporarily stacked with precast blocks, grouting material is filled into the gap between the assembly groove of the target precast block and the bottom rock.

4. The construction method for a hydraulic wharf using precast blocks according to claim 2, characterized in that, After the last row of precast blocks is lowered to the bottom of the foundation trench and positioned, a row of upper-layer precast blocks is stacked on top of the last row of precast blocks that has been placed, and left to stand for a set time. After a set set time, the settlement of the row of precast blocks that have been placed is measured.

5. The construction method for a hydraulic wharf using precast blocks according to claim 1, characterized in that, During the process of the crane vessel placing each prefabricated block into the foundation trench according to the arrangement plan, the prefabricated blocks are placed row by row from the road side to the water side of the foundation trench. If a target precast block is included in a row of precast blocks to be placed, the target precast block is placed first, and then the remaining standard precast blocks in the row are placed sequentially to one or both sides of the target precast block as a reference.

6. The construction method for a hydraulic wharf using precast blocks according to claim 1, characterized in that, When searching for and determining the target precast blocks in the layout scheme, if the number of target precast blocks corresponding to the same underwater rock is greater than or equal to three, the layout scheme of the precast blocks in the trench is adjusted so that the number of target precast blocks corresponding to the same underwater rock is one or two.

7. The construction method for a hydraulic wharf using precast blocks according to claim 1, characterized in that, When designing an assembly groove on the bottom surface of the target precast block to fit the underwater rock, further design grouting holes and drainage holes on the target precast block. The grouting hole and the drainage hole are both connected to the assembly groove and extend vertically upward through the target precast block; the grouting hole is vertically aligned with the edge of the underwater rock, and the drainage hole is vertically aligned with the apex of the underwater rock.

8. The construction method for a hydraulic wharf using precast blocks according to claim 7, characterized in that, When designing grouting holes and drainage holes for target precast blocks, if there are multiple adjacent target precast blocks, these multiple adjacent target precast blocks are integrated into a target block group, and a grouting hole and a drainage hole are set in the target block group.

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