H-shaped steel beam lattice support unbonded prestress assembly road and construction method

Abstract

The invention relates to the technical field of fabricated roads, in particular to an H-shaped steel beam lattice supporting unbonded prestress fabricated road and a construction method, a process method is optimized, and structural design and key technology research work of an H-shaped steel beam lattice supporting system modular fabricated road are implemented. The overall technical scheme follows the principles of H-shaped steel beam lattice type supporting, cast-in-place conversion section reinforcing joints, efficient hoisting of integrated prefabricated shear wallboards with curbstone beams, L-shaped steel hanging beams assisting in steel bar mesh in place, cross arrangement of longitudinal and transverse unbonded prestressed tendons, multi-hole-site high-pressure grouting and comprehensive pavement of asphalt surface layers, and engineering practice is combined. Research and development and application of a new technology are enhanced, a new technology system is constructed, a technical standard is expected to be formed, and reliable technical support is provided for high-quality development of the technical field of road engineering in China for industry reference.

Description

Technical Field

[0001] The present invention relates to the technical field of prefabricated roads, and particularly to an H-shaped steel beam lattice-supported unbonded prestressed prefabricated road and a construction method thereof. Background Technique

[0002] The prefabricated road construction technology is an important innovation direction in the global transportation infrastructure construction field in recent years. Through the construction mode of modular design, factory prefabrication and on-site rapid assembly, it is reshaping the traditional road construction process. This technical system reconstructs the entire life cycle of road engineering with industrial thinking, and promotes the transformation of transportation infrastructure towards high efficiency, environmental protection and sustainability through the deep integration of standardized component production, intelligent management platform and green construction concept. From the technical characteristics, prefabricated roads use precast concrete or composite material components as basic units, and form a road structure with sufficient bearing capacity by optimizing the connection structure and stress system. In practical applications, prefabricated roads demonstrate multi-dimensional application values. Despite the significant advantages, the popularization of prefabricated roads still faces challenges such as imperfect standard systems, relatively high initial costs, and insufficient industrial coordination. In the future, it requires the triple drive of policy guidance, technological innovation and market demand: establishing a national technical standard system, cultivating a professional industrial worker team, and reducing marginal costs through large-scale application. With the advancement of new urbanization construction, the prefabricated road construction technology will become the key grasp for the low-carbon transformation of transportation infrastructure, and promote the industry to develop towards a higher dimension of intelligent manufacturing and green construction. The present invention is the research and application result of the 2023 Nantong Science and Technology Plan Project undertaken by the team of Gao Luheng from Jiangsu Vocational and Technical College of Engineering: Research on Key Technologies for the Construction of Prefabricated Roads (PFR Technical System). It is expected to form a relatively mature new structure, new process and new method for prefabricated road construction, and jointly make efforts for the application of new assembly construction technologies in the field of prefabricated roads in China, innovate structural design, optimize construction technology, and make certain contributions to the high-quality development of the prefabricated road structure construction field in China. Summary of the Invention

[0003] The purpose of the present invention is to provide an H-shaped steel beam lattice-supported unbonded prestressed prefabricated road and a construction method thereof to solve the problems raised in the background technique.

[0004] To achieve the above object, the present invention provides the following technical solution: A lattice-supported unbonded prestressed assembled road with H-shaped steel beams, including H-shaped steel beams, precast shear wall panels integrated with curb beams, L-shaped steel lifting beams, steel mesh sheets, prestressing tendons, cast-in-place concrete layers, and asphalt surface layers; the H-shaped steel beams are fixed on the underlying cushion through embedded anchor bolts, and the H-shaped steel beams are arranged longitudinally and transversely along the road alignment, presenting an overall lattice form; a funnel-shaped reserved hole is provided on the upper flange of the H-shaped steel beam, and the L-shaped steel lifting beam is fixed on the upper flange of the H-shaped steel beam by anchor bolts. A number of U-shaped grooves are provided on the short limb of the L-shaped steel lifting beam, and the steel mesh sheet is placed in the U-shaped grooves; circular perforations are provided on the web of the H-shaped steel beam, and the prestressing tendons pass through the circular perforations on the web of the H-shaped steel beam, and both ends of the prestressing tendons are anchored at the web of the H-shaped steel beam; precast shear wall panels integrated with curb beams are provided above adjacent two H-shaped steel beams, and grouting holes and slurry overflow holes are provided on the precast shear wall panels integrated with curb beams; a cast-in-place concrete layer is poured inside the cavity formed by the H-shaped steel beams, the precast shear wall panels integrated with curb beams, and the foundation soil layer. There is asphalt glue in the joint between adjacent two precast shear wall panels integrated with curb beams, and an asphalt surface layer is provided above the precast shear wall panels integrated with curb beams.

[0005] The present invention also discloses a construction method for a lattice-supported unbonded prestressed assembled road with H-shaped steel beams. The construction process flow includes foundation trench excavation, pouring cushion concrete --- hoisting and fixing of longitudinal and transverse H-shaped steel beams --- laying of unbonded prestressing tendons --- on-site installation of L-shaped steel lifting beams --- segmental and lattice-structured interval hoisting of steel mesh sheets and fixed connection --- segmental and lattice-structured interval pouring of cast-in-place concrete layers, cast-in-place conversion section treatment --- segmental and lattice-structured interval hoisting of precast shear wall panels integrated with curb beams --- pouring of joint asphalt glue --- high-pressure grouting --- tensioning, anchoring, and sealing treatment of unbonded prestressing tendons --- post-treatment of foundation trench, and overall paving of asphalt surface layer.

[0006] Preferably, the specific technical solution content is as follows:

[0007] Step S1: Foundation trench excavation, pouring cushion concrete:

[0008] According to the construction plan, a total station is used to conduct overall measurement and setting out of the road alignment, and flow construction is carried out in sections, with each construction section controlled within 200m - 300m; First, excavate the foundation trenches of the H-shaped steel beam lattice support systems in each section of the site. In order to improve the local compressive strength of the foundation soil layer at the lower part of the foundation trench, the excavation depth of the foundation trench can be appropriately increased by 150mm - 200mm. After the foundation trench is excavated, a mixture of crushed stone, coarse sand, slag, fly ash, and cement is used for paving and rolling reinforcement according to a certain ratio, and then a layer of cement slurry is paved on the upper part of the mixture reinforcement layer for further solidification treatment; The excavation width of the foundation trench should be 300mm - 400mm larger than the width of the flange plate of the H-shaped steel beam, the cushion width is not less than 500mm, the cushion thickness is 120mm, the cushion concrete strength is not less than C30, and a steel mesh is provided inside the cushion; In order to meet the accurate on-site hoisting and positioning of the H-shaped steel beam during the subsequent construction process, the embedded work of anchor bolts needs to be carried out according to the hoisting positions of the corresponding H-shaped steel beams before the cushion concrete is poured. The adjacent two embedded anchor bolts are fixed with a perforated steel sheet. The bolt hole positions on the perforated steel sheet correspond to the positions of the embedded anchor bolts of the same position in the cushion, and the embedded positions of the anchor bolts also correspond one by one to the installation hole positions on the H-shaped steel beam to be hoisted. The maximum error of the plane position of the anchor bolts does not exceed 2mm, and the length of the anchor bolts should also meet the requirements of hoisting, positioning, and fixing of the H-shaped steel beam;

[0009] Step S2: Hoisting and fixing of longitudinal and transverse H-shaped steel beams:

[0010] After the cushion concrete of the foundation trench is poured and cured, and the positions of the embedded anchor bolts of the same position and the positional relationship between the anchor bolts of adjacent spans are accurately checked and found to be correct, the hoisting and fixing of the longitudinal and transverse H-shaped steel beams can be carried out; The on-site hoisting of the longitudinal and transverse H-shaped steel beams adopts the technical scheme of "sectional hoisting, flow operation, first hoisting the longitudinal H-shaped steel beams, and then hoisting the transverse H-shaped steel beams, using the longitudinal H-shaped steel beams to control the road structure dimensions and the transverse H-shaped steel beams to control the structure hoisting errors". The on-site hoisting of the longitudinal and transverse H-shaped steel beams is carried out strictly in accordance with the construction organization arrangement, fixed immediately after hoisting, tightened one by one with the anchor bolts, and strictly control the bottom elevation of the longitudinal and transverse H-shaped steel beams, that is, the top elevation of the cushion. Before on-site hoisting, the top elevation of the cushion at the hoisting position of the H-shaped steel beam to be hoisted should be rechecked, and the maximum error of the top elevation of the cushion is controlled within -3mm; At the intersection of the longitudinal H-shaped steel beam and the transverse H-shaped steel beam, an additional sealing steel plate with a reserved hole is set at the end of the transverse H-shaped steel beam and is bolted and fixed to the web of the longitudinal H-shaped steel beam. Moreover, the end of the transverse H-shaped steel beam adopts a variable cross-section design. The variable cross-section width at the end of the transverse H-shaped steel beam remains unchanged, and its height is 3mm - 5mm smaller than the height of the web of the longitudinal H-shaped steel beam. The size of the additional sealing steel plate with a reserved hole is the same as the variable cross-section of the transverse H-shaped steel beam, and the thickness is not less than 16mm; After the on-site hoisting and fixing of the longitudinal and transverse H-shaped steel beams are completed, sectional process acceptance work is carried out and acceptance records are left;

[0011] Step S3: Laying of unbonded prestressed tendons:

[0012] The lattice road structure support system is formed by hoisting the H-shaped steel beams in both longitudinal and transverse directions. After the longitudinal and transverse H-shaped steel beams are hoisted and fixed, the unbonded prestressed tendons in each module can be laid in sections, and the fixation of the prestressed tendons should be done well. In order to better improve the modular assembly construction quality and later maintenance of the road structure, at least 3 unbonded prestressed tendons should be set in each lattice support area. Each unbonded prestressed tendon passes through the reserved holes on the webs of the corresponding H-shaped steel beams and is temporarily fixed on the webs of the H-shaped steel beams at both ends. Using the unbonded prestressed technology, as semi-finished products, the unbonded prestressed tendons first pass through the reserved holes on the web of the middle H-shaped steel beam, then the linear trend of the unbonded prestressed tendons in the structure is erected and fixed, and finally the two ends of the unbonded prestressed tendons pass through the reserved holes on the webs of the two end H-shaped steel beams respectively and are temporarily fixed to wait for the subsequent tensioning and anchoring of the prestressed tendons. For the cast-in-situ conversion section joints of the special-shaped crossroads at the road corners, the horizontal prestressed tendons of the cast-in-situ conversion section joints of the special-shaped crossroads are arranged horizontally on site, and the longitudinal prestressed tendons are arranged crosswise. The number of prestressed tendons is also not less than 4. The prestressed tendons shall not collide with other steel bars in the cast-in-situ conversion section. Before implementation, BIM technology is used for in-depth design and dynamic construction simulation.

[0013] Step S4: On-site installation of L-shaped steel hanging beams:

[0014] In order to improve the overall bearing capacity of the road structure, a single-layer steel mesh is provided inside the road structure, and the four sides of the steel mesh are placed in the U-shaped grooves of the L-shaped steel hanging beams. As the support points of the single-layer steel mesh, the on-site installation of the L-shaped steel hanging beams should have sufficient strength and stiffness. The L-shaped steel hanging beams are suspended and fixed to the inner side of the upper flange of the H-shaped steel beams through anchor bolts, and a funnel-shaped anchor bolt perforation is provided at the upper flange of the H-shaped steel beams. The L-shaped steel hanging beams are fixed one by one on site. In order not to affect the positioning work of the integrated precast shear wall with road curb beams on the upper part of the H-shaped steel beams in the subsequent process, the top of the L-shaped steel hanging beams after being suspended and fixed by anchor bolts should not exceed the top surface of the anchor bolt perforations at the upper flange of the H-shaped steel beams. The anchor bolts are locked with nuts inside the funnel-shaped anchor bolt perforations, and each fixed hole position is sealed with anti-corrosion grease inside.

[0015] Step S5: Hoist the steel mesh in sections and lattice intervals and fix and connect them:

[0016] After the L-shaped steel suspension beam is installed on site, the work of hoisting the steel mesh sheets section by section and grid by grid can be carried out; each steel mesh sheet on site is first fabricated and formed in the PC factory or at the project site. The spacing between the distributed steel bars of each steel mesh sheet is strictly in accordance with the requirements of the drawings. Each steel mesh sheet is fabricated and formed modularly, and is directly hoisted and fixedly connected as a finished product on site; the spacing between the distributed steel bars is the same as the spacing of the U-shaped grooves on the L-shaped steel suspension beam. After each steel mesh sheet is formed, it is directly hoisted and supported in the U-shaped grooves of the L-shaped steel suspension beam. The distributed steel bars are successively placed inside the U-shaped grooves. The middle of the steel mesh sheet is supported by a trapezoidal steel support, and the end is fixed to the L-shaped steel suspension beam by spot welding; during the process of hoisting and fixedly connecting the steel mesh sheets section by section and grid by grid, the unbonded prestressed tendons that have been laid shall not be disturbed, and the acceptance work of the concealed works of the steel bars in each section shall be done well, and acceptance records shall be kept;

[0017] Step S6: Pour the cast-in-place concrete layer section by section and grid by grid, and deal with the cast-in-place conversion section:

[0018] According to the construction plan, organize flowing water construction. After the installation of the steel mesh sheets is completed, pour the cast-in-place concrete layer section by section and grid by grid. The pouring height of the cast-in-place concrete layer shall be based on the upper flange of the H-shaped steel beam, and it is advisable to pour to 30 mm - 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, and the cast-in-place concrete layer covers the steel mesh sheets; the cast-in-place concrete layer is poured in one go, using slightly expanded and low-shrinkage fine aggregate concrete, and the concrete strength grade is not lower than C30, and no construction joints are left. Strengthen the concrete pouring and vibration work at the H-shaped steel beams around each grid section; for the treatment of the cast-in-place conversion sections set on site, the width of each cast-in-place conversion section is preferably 2000 mm - 3000 mm. The extended stressed steel bars of the integrated precast shear wall panels with road curbs at both ends of the cast-in-place conversion section are successively connected and grouted using steel sleeves. The cutting length of the extended stressed steel bars should meet the design width requirements of the cast-in-place conversion section and the connection structure requirements of the steel sleeves. And the L-shaped steel suspension beam at the cast-in-place conversion section should be arranged continuously. The steel mesh sheets and the extended stressed steel bars are connected to form a double-layer and double-direction steel mesh at the cast-in-place conversion section, effectively strengthening the bearing effect of the assembled road structure system; for the trapezoidal cast-in-place conversion section set at the road corner, an irregular cross-road cast-in-place conversion section node is formed. After the concrete of the first construction section in each direction at the road intersection corner is poured and cured for more than 7 days, the concrete at the irregular cross-road cast-in-place conversion section node can be poured, and it is also poured in one go. The concrete strength at the irregular cross-road cast-in-place conversion section node should be increased by one grade;

[0019] Step S7: Hoist the integrated precast shear wall panels with road curbs section by section and grid by grid:

[0020] According to the technical solution, organize the flow construction. After the cast-in-place concrete layer is poured in each segmented and grid-structured area, including the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, strengthen the maintenance of the concrete; after the bottom elevation of the integrated precast shear wall panel with a curb beam is accurately rechecked and the hoisting is in place, the hoisting work of the integrated precast shear wall panel with a curb beam in the segmented and grid-structured area can be carried out; before hoisting the integrated precast shear wall panel with a curb beam, each precast component should be numbered, especially the integrated precast shear wall panel with a curb beam that needs to reserve grouting holes and overflow holes at the ends of each grid-structured area should be numbered and marked. When necessary, draw a plan layout of the precast components for segmented hoisting and do a good job in the technical disclosure of the hoisting work; for the hoisting of two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, special attention should be paid to protecting the extended stressed steel bars of the two adjacent integrated precast shear wall panels with a curb beam at the conversion section. From the perspective of structural design, after the hoisting of the two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, the extended stressed steel bars need to be connected by sleeve grouting one by one, with 100% sleeve grouting connection, and then the secondary concrete of the cast-in-place conversion section is poured, and the relevant concealed works acceptance is done;

[0021] Step S8: Pour asphalt glue into the board joints:

[0022] After hoisting the integrated precast shear wall panel with a curb beam in the segmented and grid-structured area, it is necessary to fill the gap between two adjacent integrated precast shear wall panels with a curb beam. The gap filling is carried out by the method of pouring asphalt glue at one time after adding reinforcing steel bars. The added reinforcing steel bars are not less than 1 Φ12 grade III steel bars; the gap filling between two adjacent integrated precast shear wall panels with a curb beam provides greater energy consumption or temperature deformation resistance for the subsequent traffic. That is, in the above process, each integrated precast shear wall panel with a curb beam is fixedly connected to the H-shaped steel beam below at one end and hinged connected to the middle H-shaped steel beam at the other end, meeting the load-bearing requirements of the overall road structure; before pouring the asphalt glue into the board joints between two adjacent integrated precast shear wall panels with a curb beam on site, it is necessary to clean the board joints. Each board joint is cleaned one by one with a high-pressure air gun, and there should be no large and hard stones or other objects stuck inside the board joints. During the treatment process, special personnel are assigned to be responsible for pouring the asphalt glue into the board joints to ensure that there is no debris in each board joint and reinforcing steel bars are added, and do a good job in the process acceptance and keep the acceptance records;

[0023] Step S9: High-pressure grouting:

[0024] Since the cast-in-place concrete layer is poured 30 mm to 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, after the precast shear wall panel integrated with the curb beam is hoisted between the segmented and grid-structured areas, there will be a cavity with a thickness of the upper flange of the H-shaped steel beam + 30 mm to 50 mm between the cast-in-place concrete layer and the precast shear wall panel integrated with the curb beam; according to the technical solution, after the precast shear wall panel integrated with the curb beam is hoisted and positioned between the segmented and grid-structured areas, the high-pressure grouting process can be carried out. Before high-pressure grouting, the transverse joints between adjacent precast shear wall panels integrated with the curb beam should be sealed with sealant strips, and the sealant strips should be torn off after the grouting is completed to complete the grouting operation; there are grouting holes and overflow holes on the precast shear wall panels at the corners of each grid-structured area. During the on-site construction process, high-pressure grouting is carried out simultaneously on 3 of the grouting holes, and the operation stops after the overflow holes start to discharge slurry. High-strength, slightly expanding and low-shrinking grouting material should be used for on-site high-pressure grouting, and the secondary pressurization method should be used for supplementary grouting to improve the grouting fullness; for the high-pressure grouting work in the grid-structured areas around the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road, it should be ensured that the concrete pouring of the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road is completed first, and then the high-pressure grouting of the surrounding grid-structured areas is carried out;

[0025] Step S10: Unbonded prestressed tendon tensioning, anchoring and end sealing treatment:

[0026] After the high-pressure grouting of the precast shear wall panel integrated with the curb beam is completed and cured for at least 7 days, the unbonded prestressed tendons can be tensioned and anchored; in order to enhance the local concrete compressive strength at the end of the H-shaped steel beam web where the prestressed tendons are anchored, during the layout of the unbonded prestressed tendons, steel sleeves are set at the perforated parts of the H-shaped steel beam web. The steel sleeves pass through the reserved holes on the H-shaped steel beam web, and the unbonded prestressed tendons directly pass through the steel sleeves. Spiral steel bars are also provided outside the steel sleeves to enhance the local compressive strength of the concrete at the anchorage end of the unbonded prestressed tendons; the prestressed tendons are tensioned symmetrically with a 1.03σcom over-tensioning. During on-site construction, taking the cast-in-place transition section as the reference, the unbonded prestressed tendons near the cast-in-place transition section are tensioned first, from near to far, symmetrically; the unbonded prestressed technology does not require the setting of prestressed tendon ducts and duct grouting, and the anchorage end can be reliably sealed; considering the special requirements of the working face for prestressed tendon tensioning, for the tensioning and anchoring of prestressed tendons at the nodes of the cast-in-place transition section of the special-shaped intersection road, the unbonded post-tensioning technical solution is implemented, and one-end tensioning is adopted uniformly, and tensioning and anchoring are carried out simultaneously;

[0027] Step S11: Post-treatment of the foundation trench and full paving of the asphalt surface layer:

[0028] Perform flow operation and repeat steps S1 to S10 until the construction of the road main structure is completely finished; for the gaps between the H-shaped steel beams at both ends of the road and the foundation trenches, according to the technical solution, fill them with fine aggregate concrete instead of earth backfill. The strength of the fine aggregate concrete used for the foundation trench backfill shall not be lower than C20, and it shall be poured in one go without construction joints left. After the construction of the main structure is completed, the asphalt surface course can be fully paved according to the road alignment and the elevation of the road top surface, and the project acceptance and filing can be organized.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: The overall technical solution of the present invention follows the principle of "H-shaped steel beam lattice support, cast-in-place conversion section to strengthen nodes, efficient hoisting of integrated precast shear wall panels with curb beams, L-shaped steel lifting beams to assist the placement of steel mesh sheets, cross-layout of longitudinal and transverse unbonded prestressing tendons, multi-hole high-pressure grouting, and full paving of asphalt surface course". Combining with engineering practice, it strengthens the research and development and application of new technologies, constructs a new technology system, in order to form technical standards, provides reliable technical support for the high-quality development of the road engineering technology field in China for the industry to refer to. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the structural schematic diagram of the road of the present invention;

[0031] Figure 2 is the schematic diagram of the cast-in-place conversion section;

[0032] Figure 3 is Figure 1 the structural schematic diagram of the L-shaped steel lifting beam in

[0033] Figure 4 is the node structure schematic diagram of the cast-in-place conversion section of the special-shaped cross road;

[0034] Figure 5 is the construction process flow chart of the present invention;

[0035] Reference numerals: H-shaped steel beam 1, anchor bolt 2, cushion 3, anchor bolt 4, L-shaped steel lifting beam 5, U-shaped groove 6, steel mesh sheet 7, prestressing tendon 8, integrated precast shear wall panel with curb beam 9, grouting hole 10, slurry overflow hole 11, asphalt surface course 12, asphalt glue 13. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] In the embodiment of the present invention, a road with H-shaped steel beam lattice support and unbonded prestress assembly is disclosed. Its overall structure mainly includes an H-shaped steel beam 1, an integrated precast shear wall panel with curb beam 9, an L-shaped steel lifting beam 5, a steel mesh sheet 7, a prestressing tendon 8, a cast-in-place concrete layer, and an asphalt surface course, as Figure 1As shown in the figure. The H-shaped steel beam 1 is fixed on the cushion layer 3 below it through embedded anchor bolts 2. The H-shaped steel beams 1 are arranged longitudinally and transversely along the road alignment, and are distributed in a lattice form as a whole. A funnel-shaped reserved hole is provided on the upper flange of the H-shaped steel beam 1. The L-shaped steel hanging beam 5 is fixed on the upper flange of the H-shaped steel beam 1 by anchor bolts 4. Refer to Figure 3 , a number of U-shaped grooves 6 are provided on the short limb of the L-shaped steel hanging beam 5, and the steel mesh 7 is placed in the U-shaped grooves 6 on the short limb of the L-shaped steel hanging beam 5. Circular perforations are provided on the web of the H-shaped steel beam 1, and the prestressed tendons 8 pass through the circular perforations on the web of the H-shaped steel beam 1, and both ends of the prestressed tendons 8 are anchored at the web of the H-shaped steel beam 1. An integrated precast shear wall panel 9 with a kerb beam is provided above adjacent two H-shaped steel beams 1. Grouting holes 10 and overflow holes 11 are provided on the integrated precast shear wall panel 9 with a kerb beam. A cast-in-place concrete layer is poured inside the cavity surrounded by the H-shaped steel beam 1, the integrated precast shear wall panel 9 with a kerb beam and the foundation soil layer. An asphalt adhesive 13 is provided in the joint between adjacent two integrated precast shear wall panels 9 with a kerb beam. An asphalt surface layer 12 is provided above the integrated precast shear wall panel with a kerb beam.

[0037] Refer to Figure 5 As shown in the figure, the construction method of the above assembled road is as follows: The construction process flow includes foundation trench excavation, pouring cushion concrete --- hoisting and fixing of longitudinal and transverse H-shaped steel beams --- laying of unbonded prestressed tendons --- on-site installation of L-shaped steel hanging beams --- hoisting and fixing connection of steel mesh in sections and lattice-structured intervals --- pouring of cast-in-place concrete layer in sections and lattice-structured intervals, treatment of cast-in-place transition sections --- hoisting of integrated precast shear wall panels with kerb beams in sections and lattice-structured intervals --- pouring of joint asphalt adhesive --- high-pressure grouting --- tensioning, anchoring and sealing treatment of unbonded prestressed tendons --- post-treatment of foundation trench, and overall paving of asphalt surface layer.

[0038] The key technical solution content of this construction process flow is as follows:

[0039] Step S1: Foundation trench excavation, pouring cushion concrete

[0040] According to the construction plan, the road line type is measured and laid out as a whole using a total station, and the road is constructed in sections, with each construction section controlled at 200m to 300m. First, the foundation trench of each section of the H-beam lattice support system on site is excavated. In order to improve the local compressive strength of the foundation soil layer under the foundation trench, the excavation depth of the foundation trench can be appropriately increased by 150mm to 200mm. After the foundation trench is excavated, crushed stone, coarse sand, slag, fly ash and cement are mixed in a certain proportion for paving and rolling reinforcement, and then a layer of cement slurry is laid on the upper part of the mixed material reinforcement layer for further solidification. The excavation width of the foundation trench should be 300mm to 400mm larger than the width of the H-beam flange plate, the cushion width should not be less than 500mm, the cushion thickness should be 120mm, the cushion concrete strength should not be less than C30, and a steel mesh should be provided inside the cushion. In order to meet the requirements of accurate on-site hoisting and positioning of H-beams during subsequent construction, anchor bolts must be pre-buried according to the corresponding H-beam hoisting position before pouring the cushion concrete. Two adjacent anchor bolts are pre-buried and fixed with perforated steel sheets. The positions of the bolt holes on the perforated steel sheets correspond to the positions of the pre-buried anchor bolts in the cushion, and the pre-buried positions of the anchor bolts correspond to the positions of the mounting holes on the H-beams to be hoisted. The maximum error of the plane position of the anchor bolts shall not exceed 2mm, and the length of the anchor bolts shall also meet the requirements of hoisting, positioning and fixing of the H-beams.

[0041] Step S2: Lifting and fixing of vertical and horizontal bidirectional H-beams

[0042] After the concrete pouring of the foundation trench cushion layer is completed, the maintenance is strengthened, and the position of the embedded anchor bolts in the same position and the position relationship between the anchor bolts of the adjacent spans are accurately checked, the vertical and horizontal bidirectional H-beams can be hoisted and fixed. The vertical and horizontal bidirectional H-beams hoisting on site adopts the technical scheme of "segmented hoisting, flow operation, first hoisting the longitudinal H-beams, then hoisting the transverse H-beams, using the longitudinal H-beams to control the road structure size, and using the transverse H-beams to control the structural hoisting error". The vertical and horizontal bidirectional H-beams are hoisted on site strictly in accordance with the construction organization arrangement, and are fixed as they are hoisted. They are tightened one by one with anchor bolts, and the bottom elevation of the vertical and horizontal bidirectional H-beams (i.e. the elevation of the top surface of the cushion layer) is strictly controlled. Before hoisting on site, the elevation of the top of the cushion layer where the H-beams to be hoisted are in place should be reviewed, and the maximum error of the top elevation of the cushion layer should be controlled within -3mm. At the junction of the longitudinal H-beam and the transverse H-beam, an additional sealing steel plate with a reserved hole is set at the end of the transverse H-beam and fixed to the web of the longitudinal H-beam by bolts. The end of the transverse H-beam adopts a variable section design. The width of the variable section at the end of the transverse H-beam remains unchanged, and its height is 3mm to 5mm smaller than the height of the web of the longitudinal H-beam. The size of the additional sealing steel plate with a reserved hole is the same as the variable section of the transverse H-beam, and the thickness is not less than 16mm. After the vertical and horizontal bidirectional H-beam is hoisted and fixed on site, the process acceptance work is carried out in sections, and the acceptance records are kept.

[0043] Step S3: Laying of unbonded prestressed tendons

[0044] The lattice-type road structure support system is formed by hoisting the H-shaped steel beams in both longitudinal and transverse directions. After the longitudinal and transverse H-shaped steel beams are hoisted and fixed, the unbonded prestressed tendons in each module can be laid in sections, and the fixing work of the prestressed tendons should be done well. In order to better improve the modular assembly construction quality and later maintenance of the road structure, at least 3 unbonded prestressed tendons are arranged in each lattice support area. Each unbonded prestressed tendon passes through the reserved holes on the webs of the corresponding H-shaped steel beams and is temporarily fixed on the webs of the H-shaped steel beams at both ends. Using the unbonded prestressed technology, as semi-finished products, the unbonded prestressed tendons first pass through the reserved holes on the web of the middle H-shaped steel beam, and then the linear alignment of the unbonded prestressed tendons in the structure is erected and fixed. Finally, the two ends of the unbonded prestressed tendons pass through the reserved holes on the webs of the two end H-shaped steel beams respectively and are temporarily fixed to wait for the subsequent tensioning and anchoring of the prestressed tendons. For the cast-in-situ transition section joints of the special-shaped intersection roads set at the road corners (such as Figure 4 shown), the transverse prestressed tendons of the cast-in-situ transition section joints of the special-shaped intersection roads are arranged horizontally on site, and the longitudinal prestressed tendons are arranged crosswise. The number of prestressed tendons is also not less than 4. The prestressed tendons shall not collide with other steel bars in the cast-in-situ transition section. Before implementation, BIM technology is used for detailed design and dynamic construction simulation.

[0045] Step S4: On-site installation of L-shaped steel lifting beams

[0046] In order to improve the overall bearing capacity of the road structure, a single-layer steel mesh is provided inside the road structure, and the four sides of the steel mesh are placed in the U-shaped grooves of the L-shaped steel lifting beams. As the support points of the single-layer steel mesh, the on-site installation of the L-shaped steel lifting beams should have sufficient strength and stiffness. The L-shaped steel lifting beams are suspended and fixed to the inner side of the upper flange of the H-shaped steel beams through anchor bolts, and a funnel-shaped anchor bolt perforation is provided at the upper flange of the H-shaped steel beams. The L-shaped steel lifting beams are fixed one by one on site. In order not to affect the positioning work of the integrated precast shear wall panel with the road curb beam on the upper part of the H-shaped steel beam in the subsequent process, the top of the L-shaped steel lifting beam after being suspended and fixed by the anchor bolts should not exceed the top surface of the anchor bolt perforation at the upper flange of the H-shaped steel beam. The anchor bolts are locked with nuts inside the funnel-shaped anchor bolt perforation, and each fixed hole position is sealed with anti-corrosion grease.

[0047] Step S5: Hoisting, fixing and connecting the steel mesh in sections and lattice intervals

[0048] After the L-shaped steel suspension beam is installed on-site, the work of hoisting the steel mesh sheets one by one in each segmented and grid-structured area can be carried out. Each steel mesh sheet on-site is first fabricated and formed in the PC factory or the project site. The spacing between the distributed steel bars of each steel mesh sheet is strictly implemented according to the drawing requirements. Each steel mesh sheet is fabricated and formed modularly, and directly hoisted and fixedly connected as a finished product on-site. The spacing between the distributed steel bars is the same as the spacing of the U-shaped grooves on the L-shaped steel suspension beam. After each steel mesh sheet is formed, it is directly hoisted and supported in the U-shaped grooves of the L-shaped steel suspension beam. The distributed steel bars are successively placed inside the U-shaped grooves. The middle of the steel mesh sheet is supported by trapezoidal steel brackets, and the ends are fixed to the L-shaped steel suspension beam by spot welding. During the process of hoisting and fixedly connecting the steel mesh sheets in each segmented and grid-structured area, the unbonded prestressed tendons that have been laid should not be disturbed, and the acceptance work of the steel bar concealed works in each section should be done well, with acceptance records kept.

[0049] Step S6: Pour the cast-in-place concrete layer in each segmented and grid-structured area, and deal with the cast-in-place conversion section

[0050] According to the construction plan, organize flow construction. After the installation of the steel mesh sheets is completed, pour the cast-in-place concrete layer in each segmented and grid-structured area. The pouring height of the cast-in-place concrete layer is based on the upper flange of the H-shaped steel beam, and it is advisable to pour to 30 mm - 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, and the cast-in-place concrete layer covers the steel mesh sheets. The cast-in-place concrete layer is poured in one go, using slightly expanded and low-shrinkage fine aggregate concrete, and the concrete strength grade is not lower than C30, and no construction joints are left. Strengthen the concrete pouring and vibration work at the H-shaped steel beams around each grid-structured area. For the treatment of the cast-in-place conversion sections set on-site (as shown in Figure 2 ), the width of each cast-in-place conversion section is preferably 2000 mm - 3000 mm. The stressed steel bars extending out of the precast shear wall panels integrated with the curb beams at both ends of the cast-in-place conversion section are successively connected and grouted using steel sleeves. The cut-off length of the stressed steel bars extending out should meet the design width requirements of the cast-in-place conversion section and the connection structure requirements of the steel sleeves. And the L-shaped steel suspension beam at the cast-in-place conversion section should be laid continuously. The steel mesh sheets and the stressed steel bars extending out are connected to form a double-layer and double-direction steel mesh at the cast-in-place conversion section, effectively strengthening the bearing effect of the assembled road structure system. For the trapezoidal cast-in-place conversion section set at the road corner, an irregular cross-road cast-in-place conversion section node is formed (as shown in Figure 4 ), after the concrete in the first construction section in all directions at the road intersection corner is poured and cured for more than 7 days, the concrete at the irregular cross-road cast-in-place conversion section node can be poured, and it is also poured in one go. The concrete strength at the irregular cross-road cast-in-place conversion section node should be increased by one grade.

[0051] Step S7: Hoist the precast shear wall panels integrated with the curb beams in each segmented and grid-structured area

[0052] According to the technical solution, organize the flow construction. After the cast-in-place concrete layer is poured in each segmented and grid-structured area, including the cast-in-place conversion section (as shown in Figure 2 ), and the node of the cast-in-place conversion section of the special-shaped crossroad (as shown in Figure 4 ), strengthen the curing of the concrete. After the bottom elevation of the integrated precast shear wall panel with a curb beam in each segmented and grid-structured area is accurately rechecked and verified, the hoisting work of the integrated precast shear wall panel with a curb beam in each segmented and grid-structured area can be carried out. Before hoisting the integrated precast shear wall panel with a curb beam, each precast component should be numbered. In particular, the integrated precast shear wall panel with a curb beam that needs to reserve grouting holes and overflow holes at the ends of each grid-structured area should be numbered and marked. When necessary, draw the plane layout diagram of the precast components for segmented hoisting, and do a good job in the technical disclosure of the hoisting work types. For the hoisting of two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the node of the cast-in-place conversion section of the special-shaped crossroad, special attention should be paid to protecting the extended stressed steel bars of the two adjacent integrated precast shear wall panels with a curb beam at the conversion section. From the perspective of structural design, after the hoisting of the two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the node of the cast-in-place conversion section of the special-shaped crossroad, the extended stressed steel bars also need to be connected by sleeve grouting one by one, with 100% of the sleeves grouted, and then the secondary concrete of the cast-in-place conversion section is poured, and relevant concealed works acceptance is done.

[0053] Step S8: Pour asphalt glue into the board joints

[0054] After hoisting the integrated precast shear wall panel with a curb beam in each segmented and grid-structured area, it is necessary to fill the gaps between two adjacent integrated precast shear wall panels with a curb beam. The method of adding additional reinforcing bars and then pouring asphalt glue at one time is used for joint filling. The additional reinforcing bars added are not less than 1 Φ12 grade III reinforcing bars. The joint filling between two adjacent integrated precast shear wall panels with a curb beam provides greater energy consumption or resistance to temperature deformation for subsequent traffic. That is, in the above-mentioned process, each integrated precast shear wall panel with a curb beam is fixedly connected to the H-shaped steel beam below at the end, and the other end is hinged to the middle H-shaped steel beam, meeting the requirements of the overall road structure load-bearing. Before pouring the asphalt glue for the board joints between two adjacent integrated precast shear wall panels with a curb beam on-site, it is necessary to clean the board joints. Use a high-pressure air gun to clean each board joint one by one, and there should be no large and hard stones or other objects stuck inside the board joints. During the treatment process, there should be dedicated personnel responsible for pouring the asphalt glue for the board joints to ensure that there is no debris in each board joint and additional reinforcing bars are added, do a good job in the process acceptance, and keep acceptance records.

[0055] Step S9: High-pressure grouting

[0056] Since the cast-in-place concrete layer is poured 30 mm to 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, after the precast shear wall panel integrated with the kerb beam is hoisted in the segmented and grid-structured areas, there will be a cavity with a thickness of the upper flange of the H-shaped steel beam + 30 mm to 50 mm between the cast-in-place concrete layer and the precast shear wall panel integrated with the kerb beam. According to the technical solution, after the precast shear wall panel integrated with the kerb beam is hoisted and positioned in the segmented and grid-structured areas, the high-pressure grouting process can be carried out. Before high-pressure grouting, the transverse joints between adjacent precast shear wall panels integrated with the kerb beam should be sealed with sealing strips, and the strips should be torn off after grouting to complete the grouting operation. Grouting holes and overflow holes are provided on the precast shear wall panels at the corners of each grid-structured area. During the on-site construction process, high-pressure grouting is carried out simultaneously on 3 of the grouting holes, and the operation stops after the overflow holes start to discharge slurry. High-strength, slightly expanding and low-shrinking grouting material should be used for on-site high-pressure grouting, and the secondary pressurization method should be used for supplementary grouting to improve the grouting fullness. For the high-pressure grouting work in the grid-structured areas around the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road, the concrete pouring of the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road should be completed first, and then the high-pressure grouting of the surrounding grid-structured areas should be carried out.

[0057] Step S10: Unbonded prestressed tendon tensioning, anchoring and end sealing treatment

[0058] After the high-pressure grouting of the precast shear wall panel integrated with the kerb beam is completed and cured for at least 7 days, the unbonded prestressed tendons can be tensioned and anchored. In order to strengthen the local concrete compressive strength at the anchorage of the prestressed tendons at the end of the H-shaped steel beam web, during the layout of the unbonded prestressed tendons, a steel sleeve is set at the perforated part of the H-shaped steel beam web. The steel sleeve passes through the reserved hole on the H-shaped steel beam web, and the unbonded prestressed tendon directly passes through the steel sleeve. A spiral steel bar is also provided outside the steel sleeve to enhance the local compressive strength of the concrete at the anchorage end of the unbonded prestressed tendon. The prestressed tendons are tensioned symmetrically with a 1.03σcom over-tensioning. During on-site construction, taking the cast-in-place transition section as the reference, the unbonded prestressed tendons near the cast-in-place transition section are tensioned first, from near to far, symmetrically. The unbonded prestressed technology does not require the setting of prestressed tendon ducts and duct grouting, and the anchorage end can be reliably sealed. Considering the special requirements for the working face of the prestressed tendon tensioning, for the tensioning and anchoring of the prestressed tendons at the nodes of the cast-in-place transition section of the special-shaped intersection road, the unbonded post-tensioning technical solution is implemented, and one-end tensioning is adopted uniformly, with tensioning and anchoring carried out simultaneously.

[0059] Step S11: Post-treatment of the foundation trench and full paving of the asphalt surface layer

[0060] The flow operation repeats steps S1 to S10 until the construction of the road main structure is completely finished. For the gaps between the H-shaped steel beams at both ends of the road and the foundation trenches, according to the technical solution, fine aggregate concrete is used for filling, and earth backfill is not allowed. The strength of the fine aggregate concrete used for the foundation trench backfill is not lower than C20, and it is poured in one go without construction joints. After the main structure construction is completed, the asphalt surface course can be fully paved according to the road alignment and the road top surface elevation, and the project acceptance and filing are organized.

[0061] In summary, the overall technical solution of the present invention follows the principle of "H-shaped steel beam lattice support, cast-in-place conversion section to strengthen nodes, integrated precast shear wall panels with kerb beams for efficient hoisting, L-shaped steel lifting beams to assist the reinforcement mesh in place, cross-layout of longitudinal and transverse unbonded prestressing tendons, multi-hole high-pressure grouting, and full paving of asphalt surface course". Combining with engineering practice, it strengthens the research and development and application of new technologies, constructs a new technology system, in order to form technical standards, provides reliable technical support for the high-quality development of the road engineering technology field in China for the industry to reference.

[0062] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A grid-supported unbonded prestressed assembled road with H-shaped steel beams, characterized in that: It includes H-shaped steel beams, integrated precast shear wall panels with curb beams, L-shaped steel lifting beams, steel mesh sheets, prestressed tendons, cast-in-place concrete layers, and asphalt surface layers; the H-shaped steel beams are fixed to the underlying cushion through embedded anchor bolts, and the H-shaped steel beams are arranged longitudinally and transversely along the road alignment, presenting an overall lattice form; funnel-shaped reserved holes are provided on the upper flange of the H-shaped steel beams, and the L-shaped steel lifting beams are fixed to the upper flange of the H-shaped steel beams by anchor bolts. A number of U-shaped grooves are provided on the short limbs of the L-shaped steel lifting beams, and the steel mesh sheets are placed in the U-shaped grooves; circular perforations are provided on the webs of the H-shaped steel beams, and the prestressed tendons pass through the circular perforations on the webs of the H-shaped steel beams, and both ends of the prestressed tendons are anchored at the webs of the H-shaped steel beams; integrated precast shear wall panels with curb beams are provided above adjacent two H-shaped steel beams, and grouting holes and slurry overflow holes are provided on the integrated precast shear wall panels with curb beams; a cast-in-place concrete layer is poured inside the cavity surrounded by the H-shaped steel beams, the integrated precast shear wall panels with curb beams, and the foundation soil layer. There is asphalt glue in the joint between adjacent two integrated precast shear wall panels with curb beams, and an asphalt surface layer is provided above the integrated precast shear wall panels with curb beams.

2. A construction method for a non-bonded prestressed assembled road with a lattice support of an H-shaped steel beam, characterized in that: The construction process flow includes foundation trench excavation, pouring cushion concrete --- hoisting and fixing of longitudinal and transverse H-shaped steel beams --- laying of unbonded prestressed tendons --- on-site installation of L-shaped steel lifting beams --- hoisting and fixed connection of steel mesh sheets in segmented and lattice-structured intervals --- pouring of cast-in-place concrete layers in segmented and lattice-structured intervals, treatment of cast-in-place conversion sections --- hoisting of integrated precast shear wall panels with curb beams in segmented and lattice-structured intervals --- pouring of asphalt glue in the joints --- high-pressure grouting --- tensioning, anchoring, and sealing treatment of unbonded prestressed tendons --- post-treatment of the foundation trench, overall paving of the asphalt surface layer.

3. The construction method according to claim 2, wherein: The specific technical solution content is as follows: Step S1: Foundation trench excavation, pouring cushion concrete: According to the construction plan, a total station is used to conduct overall measurement and setting out of the road alignment, and construction is carried out in a sectional flow manner, with each construction section controlled within 200m to 300m; First, the foundation trenches of the H-shaped steel beam lattice support systems in each section of the site are excavated. In order to improve the local compressive strength of the foundation soil layer at the lower part of the foundation trench, the excavation depth of the foundation trench can be appropriately increased by 150mm to 200mm. After the foundation trench is excavated, a mixture of gravel, coarse sand, slag, fly ash and cement is used for paving and compaction reinforcement in accordance with a certain ratio, and then a layer of cement slurry is paved on the upper part of the mixture reinforcement layer for further solidification treatment; The excavation width of the foundation trench should be 300mm to 400mm larger than the width of the flange plate of the H-shaped steel beam, the cushion width is not less than 500mm, the cushion thickness is 120mm, the cushion concrete strength is not less than C30, and a steel mesh is provided inside the cushion; In order to meet the accurate on-site hoisting and positioning of the H-shaped steel beam during the subsequent construction process, the embedding work of anchor bolts needs to be carried out in accordance with the hoisting positions of the corresponding H-shaped steel beams before the cushion concrete is poured. The adjacent two embedded anchor bolts are fixed with a perforated steel sheet. The bolt hole positions on the perforated steel sheet correspond to the positions of the embedded anchor bolts of the same position in the cushion, and the embedded positions of the anchor bolts also correspond one by one to the installation hole positions on the H-shaped steel beam to be hoisted. The maximum error in the plane position of the anchor bolts does not exceed 2mm, and the length of the anchor bolts should also meet the requirements for the hoisting, positioning and fixing of the H-shaped steel beam; Step S2: Hoisting and fixing of longitudinal and transverse H-shaped steel beams: After the cushion concrete of the foundation trench is poured and cured, and the positions of the embedded anchor bolts of the same position and the positional relationship between the anchor bolts of adjacent spans are accurately checked and found to be correct, the hoisting and fixing of the longitudinal and transverse H-shaped steel beams can be carried out; The on-site hoisting of the longitudinal and transverse H-shaped steel beams adopts the technical scheme of "sectional hoisting, flow operation, first hoisting the longitudinal H-shaped steel beams, and then hoisting the transverse H-shaped steel beams, controlling the road structure dimensions with the longitudinal H-shaped steel beams and controlling the hoisting errors of the structure with the transverse H-shaped steel beams". The on-site hoisting of the longitudinal and transverse H-shaped steel beams is carried out strictly in accordance with the construction organization arrangement, fixed immediately after hoisting, tightened one by one with anchor bolts, and strictly control the bottom installation elevation of the longitudinal and transverse H-shaped steel beams, that is, the top elevation of the cushion. Before on-site hoisting, the top elevation of the cushion at the hoisting position of the H-shaped steel beam to be hoisted should be rechecked, and the maximum error in the top elevation of the cushion is controlled within -3mm; At the intersection of the longitudinal H-shaped steel beam and the transverse H-shaped steel beam, an additional sealing steel plate with a reserved hole is arranged at the end of the transverse H-shaped steel beam and is bolted and fixed to the web of the longitudinal H-shaped steel beam. Moreover, the end of the transverse H-shaped steel beam adopts a variable cross-section design. The variable cross-section width of the end of the transverse H-shaped steel beam remains unchanged, and its height is 3mm to 5mm smaller than the height of the web of the longitudinal H-shaped steel beam. The size of the additional sealing steel plate with a reserved hole is the same as that of the variable cross-section of the transverse H-shaped steel beam, and the thickness is not less than 16mm; After the on-site hoisting and fixing of the longitudinal and transverse H-shaped steel beams are completed, the process acceptance work is carried out section by section, and acceptance records are left; Step S3: Laying of unbonded prestressed tendons: The lattice road structure support system is formed by hoisting the H-shaped steel beams in both horizontal and vertical directions. After the horizontal and vertical H-shaped steel beams are hoisted and fixed, the unbonded prestressed tendons in each module can be laid in sections, and the fixation of the prestressed tendons should be well done. In order to better improve the modular assembly construction quality and later maintenance of the road structure, at least 3 unbonded prestressed tendons are arranged in each lattice support area. Each unbonded prestressed tendon passes through the reserved holes on the webs of the corresponding H-shaped steel beams and is temporarily fixed on the webs of the H-shaped steel beams at both ends. Using the unbonded prestressed technology, the unbonded prestressed tendons are semi-finished products. First, the unbonded prestressed tendons are passed through the reserved holes on the web of the middle H-shaped steel beam, and then the linear alignment of the unbonded prestressed tendons in the structure is erected and fixed. Finally, the two ends of the unbonded prestressed tendons are respectively passed through the reserved holes on the webs of the two end H-shaped steel beams and temporarily fixed to wait for the subsequent tensioning and anchoring of the prestressed tendons. For the cast-in-place conversion section joints of the special-shaped crossroads at the road corners, the transverse prestressed tendons of the cast-in-place conversion section joints of the special-shaped crossroads are arranged horizontally on site, and the longitudinal prestressed tendons are arranged crosswise. The number of prestressed tendons is also not less than 4. The prestressed tendons shall not collide with other steel bars in the cast-in-place conversion section. Before implementation, BIM technology is used for detailed design and dynamic construction simulation. Step S4: On-site installation of the L-shaped steel lifting beam: To improve the overall load-bearing capacity of the road structure, a single-layer steel mesh is provided inside the road structure, and the four sides of the steel mesh are placed in the U-shaped grooves of the L-shaped steel lifting beams. The L-shaped steel lifting beams serve as the support points for the single-layer steel mesh. Therefore, the on-site installation of the L-shaped steel lifting beams should have sufficient strength and stiffness. The L-shaped steel lifting beams are suspended and fixed to the inner side of the upper flange of the H-shaped steel beam by anchor bolts, and a funnel-shaped anchor bolt perforation is provided at the upper flange of the H-shaped steel beam. The L-shaped steel lifting beams are fixed one by one on site. In order not to affect the positioning of the integrated precast shear wall panel with the road curb beam on the upper part of the H-shaped steel beam in the subsequent process, the top of the L-shaped steel lifting beam after being suspended and fixed by the anchor bolts should not exceed the top surface of the anchor bolt perforation at the upper flange of the H-shaped steel beam. Nuts are used to lock the anchor bolts inside the funnel-shaped anchor bolt perforation, and each fixed hole position is sealed with anti-corrosion grease inside. Step S5: Hoist the steel mesh in sections and by lattice intervals and fix the connection: After the L-shaped steel hanging beam is installed on site, the work of hoisting the steel mesh sheets section by section and grid by grid can be carried out; each steel mesh sheet on site is first fabricated and formed in the PC factory or at the project site. The spacing between the distribution steel bars of each steel mesh sheet is strictly implemented in accordance with the drawing requirements. Each steel mesh sheet is fabricated and formed modularly, and directly hoisted and fixedly connected as a finished product on site; the spacing between the distribution steel bars is the same as the U-shaped groove spacing on the L-shaped steel hanging beam. After each steel mesh sheet is formed, it is directly hoisted and supported in the U-shaped groove of the L-shaped steel hanging beam. The distribution steel bars are successively placed inside the U-shaped groove. The middle of the steel mesh sheet is supported by a trapezoidal steel support, and the end is fixed to the L-shaped steel hanging beam by spot welding; during the process of hoisting and fixedly connecting the steel mesh sheets section by section and grid by grid, the unbonded prestressed tendons that have been laid should not be disturbed, and the acceptance work of the concealed steel works in each section should be done well, and acceptance records should be kept; Step S6: Pour the cast-in-place concrete layer section by section and grid by grid, and deal with the cast-in-place conversion section: According to the construction plan, organize flow construction. After the installation of the steel mesh sheets is completed, pour the cast-in-place concrete layer section by section and grid by grid. The pouring height of the cast-in-place concrete layer is based on the upper flange of the H-shaped steel beam, and it is advisable to pour to 30 mm - 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, and the cast-in-place concrete layer covers the steel mesh sheets; the cast-in-place concrete layer is poured in one go, using slightly expanded low-shrinkage fine aggregate concrete, and the concrete strength grade is not lower than C30, and no construction joints are left. Strengthen the concrete pouring and vibration work at the H-shaped steel beams around each grid section; for the treatment of the cast-in-place conversion sections set on site, the width of each cast-in-place conversion section is preferably 2000 mm - 3000 mm. The stressed steel bars extending out of the precast shear wall panels integrated with the kerb beams at both ends of the cast-in-place conversion section are successively connected and grouted using steel sleeves. The cutting length of the stressed steel bars extending out should meet the design width requirements of the cast-in-place conversion section and the connection structure requirements of the steel sleeves. And the L-shaped steel hanging beam at the cast-in-place conversion section should be arranged in a continuous length. The steel mesh sheets and the stressed steel bars extending out are connected to form a double-layer and double-direction steel mesh at the cast-in-place conversion section, effectively strengthening the bearing effect of the assembled road structure system; for the trapezoidal cast-in-place conversion section set at the road corner, an irregular cross-road cast-in-place conversion section node is formed. After the concrete in the first construction section in each direction at the road intersection corner is poured and cured for more than 7 days, the concrete at the irregular cross-road cast-in-place conversion section node can be poured, and it is also poured in one go. The concrete strength at the irregular cross-road cast-in-place conversion section node should be increased by one grade; Step S7: Hoist the precast shear wall panels integrated with the kerb beams section by section and grid by grid: According to the technical solution, organize the flowing water construction. After the cast-in-place concrete layer is poured in each segmented and grid-structured area, including the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, strengthen the maintenance of the concrete; after the bottom elevation of the integrated precast shear wall panel with a curb beam is correctly checked and hoisted in place in each segmented and grid-structured area, the hoisting work of the integrated precast shear wall panel with a curb beam in the segmented and grid-structured area can be carried out; before hoisting the integrated precast shear wall panel with a curb beam, each precast component should be numbered, especially the integrated precast shear wall panel with a curb beam that needs to reserve grouting holes and overflow holes at the ends of each grid-structured area should be numbered and marked. When necessary, draw the plane layout diagram of the precast components for segmented hoisting and do a good job in the technical disclosure of the hoisting work types; for the hoisting of two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, special attention should be paid to protecting the extended stressed steel bars of the two adjacent integrated precast shear wall panels with a curb beam at the conversion section. From the perspective of structural design, after the hoisting of the two adjacent integrated precast shear wall panels with a curb beam at the cast-in-place conversion section and the nodes of the cast-in-place conversion section of the special-shaped intersection road, the extended stressed steel bars need to be connected by sleeve grouting one by one, with 100% of the sleeves grouted and connected, and then the secondary concrete of the cast-in-place conversion section is poured, and the relevant concealed works acceptance is done; Step S8: Pour asphalt glue into the board joints: After hoisting the integrated precast shear wall panel with a curb beam in the segmented and grid-structured area, it is necessary to fill the gaps between two adjacent integrated precast shear wall panels with a curb beam. The gap filling is carried out by the method of adding reinforcing steel bars and then pouring asphalt glue at one time. The added reinforcing steel bars shall not be less than 1 Φ12 grade III steel bars; the gap filling between two adjacent integrated precast shear wall panels with a curb beam provides greater energy consumption or anti-temperature deformation effect for the subsequent traffic. That is, in the above process, each integrated precast shear wall panel with a curb beam is fixedly connected to the H-shaped steel beam below it at the end, and the other end is hinged at the middle H-shaped steel beam, meeting the load-bearing requirements of the overall road structure; before pouring the asphalt glue into the board joints between two adjacent integrated precast shear wall panels on site, the board joints need to be cleaned. Each board joint is cleaned one by one with a high-pressure air gun, and there should be no large and hard stones or other objects stuck inside the board joints. During the treatment process, there should be special personnel responsible for pouring the asphalt glue into the board joints to ensure that there is no debris in each board joint and reinforcing steel bars are added, do a good job in the process acceptance, and keep the acceptance records; Step S9: High-pressure grouting: Since the cast-in-place concrete layer is poured 30 mm to 50 mm below the bottom surface of the upper flange of the H-shaped steel beam, after the precast shear wall panel integrated with the curb beam is hoisted in the segmented and grid-structured areas, there will be a cavity with a thickness of the upper flange of the H-shaped steel beam + 30 mm to 50 mm between the cast-in-place concrete layer and the precast shear wall panel integrated with the curb beam; According to the technical solution, after the precast shear wall panel integrated with the curb beam is hoisted and positioned in the segmented and grid-structured areas, the high-pressure grouting process can be carried out. Before high-pressure grouting, the transverse joints between adjacent precast shear wall panels integrated with the curb beam should be sealed with sealing strips, and the strips should be torn off after grouting to complete the grouting operation; Grouting holes and overflow holes are provided on the precast shear wall panels at the corners of each grid-structured area. During the on-site construction process, 3 of the grouting holes are simultaneously grouted under high pressure, and the operation stops after the overflow holes start to discharge slurry. High-strength, slightly expanding and low-shrinking grouting material should be used for on-site high-pressure grouting, and the secondary pressurization method should be used for supplementary grouting to improve the grouting fullness; For the high-pressure grouting work in the grid-structured areas around the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road, it should be ensured that the concrete pouring of the cast-in-place transition section and the nodes of the cast-in-place transition section of the special-shaped intersection road is completed first, and then the high-pressure grouting of the surrounding grid-structured areas is carried out; Step S10: Unbonded prestressed tendon tensioning, anchoring and end sealing treatment: After the high-pressure grouting of the precast shear wall panel integrated with the curb beam is completed and cured for at least 7 days, the unbonded prestressed tendons can be tensioned and anchored; In order to enhance the local concrete compressive strength at the anchorage of the prestressed tendons at the end of the H-shaped steel beam web, during the laying of the unbonded prestressed tendons, a steel sleeve is set at the perforated part of the H-shaped steel beam web. The steel sleeve passes through the reserved hole on the H-shaped steel beam web, and the unbonded prestressed tendon directly passes through the steel sleeve. A spiral steel bar is also provided outside the steel sleeve to enhance the local compressive strength of the concrete at the anchorage end of the unbonded prestressed tendon; The prestressed tendons are tensioned symmetrically with an over-tensioning of 1.03σcom. During on-site construction, taking the cast-in-place transition section as the reference, the unbonded prestressed tendons near the cast-in-place transition section are tensioned first, from near to far, symmetrically; The unbonded prestressed technology does not require the setting of prestressed tendon ducts and duct grouting, and the anchorage end can be reliably sealed; Considering the special requirements of the working surface for prestressed tendon tensioning, for the tensioning and anchoring of prestressed tendons at the nodes of the cast-in-place transition section of the special-shaped intersection road, the unbonded post-tensioning technical solution is implemented, and one-end tensioning is adopted uniformly, with tensioning and anchoring carried out simultaneously; Step S11: Post-treatment of the foundation trench and full paving of the asphalt surface layer: Carry out sequential construction and repeat steps S1 to S10 until the construction of the road main structure is completed; For the gaps between the H-shaped steel beams at both ends of the road and the foundation trench, according to the technical solution, fine aggregate concrete should be used for filling, and earth backfilling is not allowed. The strength of the fine aggregate concrete used for foundation trench backfilling should not be lower than C20, and it should be poured in one go without construction joints; After the construction of the main structure is completed, the full paving of the asphalt surface layer can be carried out according to the road alignment and the road top elevation, and the project acceptance and filing can be organized.

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