Deep foundation pit assembled modular steel trestle and installation method

Abstract

The application provides a deep foundation pit assembled modular steel trestle and a mounting method, relates to the field of urban renewal deep foundation pits or groove engineering, and comprises an upper module, a head bottom module and a tail bottom module which are horizontally distributed, a middle module which is installed in multiple groups and has a triangular prism module installed on the top surface, and a slope bottom triangular prism module which is gradually lowered in height from the upper module to the top of the slope bottom triangular prism module and has an inclined top surface which is inclined downward from the upper module to the tail bottom module. The head bottom module and the upper module are vertically distributed to solve the technical problems that the existing prefabricated plates are mainly laid by sliding, the steel trestle lacks lateral fixation, and the transport vehicle is prone to side slipping during transportation along the slope.

Description

Technical Field

[0001] This invention relates to the field of deep foundation pit / trench engineering in urban renewal, and particularly to a prefabricated modular steel trestle bridge for deep foundation pits and its installation method. Background Technology

[0002] In the field of foundation pit engineering, traditional deep foundation pit engineering uses reserved ramps or sloping earth to form a foundation pit transportation channel. This often results in excessively large slopes and smooth slope surfaces, which can easily lead to safety accidents in rainy or snowy weather. At the same time, the presence of reserved ramps means that the foundation pit support or anti-seepage wall cannot be completely sealed, which can cause groundwater seepage or foundation pit collapse.

[0003] The existing technology adopts CN202211222421.X, which describes an inclined steel trestle bridge and its construction method for soil extraction in large deep foundation pits. Soil extraction is carried out by using an inclined steel trestle bridge. By disassembling the bridge deck system into several prefabricated panels, the installation of the bridge deck system can be achieved simply by assembling them on the construction site.

[0004] However, the following problems exist:

[0005] 1) The existing main construction is the sliding laying of precast slabs, and there is a lack of laterally fixed steel trestle bridges; 2) When transporting along the slope, the transport vehicle is prone to side slippage.

[0006] Therefore, it is necessary to develop a modular and rapid assembly method for steel trestle bridges to complete the excavation of large-area foundation pits. Summary of the Invention

[0007] The purpose of this invention is to design an installation method for a modular steel trestle bridge for deep foundation pits. The method involves prefabricating the structure in a factory, transporting it to the site for assembly and connection, and forming a vertical transportation channel for deep foundation pits, which facilitates the entry and exit of muck trucks.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A modular steel trestle bridge for deep foundation pits:

[0010] The upper module has a patterned steel panel on top;

[0011] The end bottom module and the end bottom module are horizontally distributed;

[0012] The middle module is equipped with multiple sets of triangular prism modules, including the top, middle, and bottom modules, and the upper module. The height of these modules gradually decreases from the top to the bottom module, and the top and bottom modules are inclined. The inclination direction is from the upper module towards the bottom module at the tail end.

[0013] The middle bottom module group is divided into multiple groups located between the end bottom module and the end bottom module; the middle bottom module group, the end bottom module and the end bottom module are used to support the middle module; the end bottom module and the upper module are vertically distributed;

[0014] The upper module, middle module, end bottom module, middle bottom module group, and end bottom module are all hexahedral frame structures, and adjacent modules are connected by mounting connectors.

[0015] In a further technical solution, the upper module includes an upper column and a connecting beam. The upper column and the connecting beam are welded together and connected end to end to form a hexahedral structure. Connectors are installed at both the upper and lower ends of the upper module. The top connector is connected to the patterned steel panel, and the bottom connector is connected to the corresponding middle module.

[0016] The central module includes a central column and a second connecting beam. The central column and the second connecting beam are welded together and connected end to end to form a hexahedral structure. Connectors are installed at the top and bottom ends and at least one side of the central module.

[0017] In a further technical solution, the middle bottom module group includes a bottom column and a connecting beam three. The bottom column and the connecting beam three are welded together and connected end to end to form a hexahedral structure. Connectors are installed on both sides and the top of the middle bottom module group.

[0018] The middle bottom module group includes middle bottom module one, middle bottom module two, middle bottom module three and middle bottom module four, and is arranged from the end bottom module to the end bottom module.

[0019] In a further technical solution, the connector includes a module top connecting plate, a module bottom connecting plate, and a connecting steel plate, with reserved bolt holes provided on the connecting steel plate; high-strength bolts can be detachably installed in the reserved bolt holes;

[0020] The top and bottom connecting plates of the module are respectively installed at the top and bottom ends of the corresponding module; both the top and bottom connecting plates of the module are provided with reserved bolt holes;

[0021] The upper module, middle module, and bottom middle module group are all equipped with cross-shaped module supports on their sides;

[0022] In the vertical direction, the top or bottom connecting plates of adjacent modules are connected to the connecting steel plate by installing high-strength bolts in the reserved bolt holes;

[0023] It also includes bolts, which connect adjacent modules in the horizontal direction.

[0024] In a further technical solution, the connecting steel plate has two rows of reserved bolt holes symmetrically distributed on both sides of its length, and the number of reserved bolt holes on one side is the same as that on the top connecting plate of the module; the connecting steel plate is sandwiched between the top connecting plate of the middle module and the bottom connecting plate of the upper module, or between the bottom connecting plate of the middle module and the top connecting plate of the middle bottom module group.

[0025] In a further technical solution, the slope top triangular prism module includes triangular prism columns, triangular prism beams, and triangular prism diagonal purlins, forming a triangular prism structure;

[0026] Multiple sets of triangular prism columns are installed, with inter-column support beams between them;

[0027] Multiple sets of triangular beams are installed, with bottom beams supporting the inter-beam configuration.

[0028] At the connection between the triangular column and the triangular beam, a triangular diagonal brace is installed facing the triangular purlin; a central beam and a central column are installed on the triangular diagonal brace, and are respectively connected to the triangular beam and the triangular column.

[0029] In a further technical solution, ramp slabs are laid on the triangular prism purlins, and anti-slip strips are welded at fixed intervals along the inclined surface of the ramp slabs;

[0030] The sloping top triangular prism module is connected at the bottom of the triangular prism column using high-strength bolts, and the upper or middle module is connected to the top of the lower module by bolts and angle steel.

[0031] The three triangular prism modules in the middle of the slope (Module 1, Module 2, and Module 3) and the triangular prism module at the bottom of the slope have the same structure as the triangular prism module at the top of the slope, but their dimensions and top slope are not exactly the same.

[0032] A further technical solution also includes a lateral protective frame, which is located on the side of the steel trestle bridge;

[0033] The lateral protective frame includes side pull plates and support components. The side pull plates are connected to the upper module, the middle module, and the middle bottom module group, respectively. The support components include support rods with foot braces at the bottom and a fixing plate at the top. The fixing plate is detachably connected to the side pull plates.

[0034] A plug is installed on the side of the fixed plate facing the steel trestle. The plug passes through the steel trestle laterally and abuts against the support module for support. A grouting port is opened on the plug and a grout outlet is provided at the end.

[0035] When the steel trestle is installed on the side wall of the foundation pit, the insert is inserted into the side wall of the foundation pit and the insert is filled with concrete slurry.

[0036] In a further technical solution, multiple sets of position holes are opened on the ramp plate, and the multiple sets of position holes are evenly distributed; a hinge plate is installed in the triangular prism module one in the slope, and the top of the hinge plate is hinged to the triangular prism column; a plug-in column is opened on the side of the hinge plate facing the ramp plate, and the top end of the plug-in column is rounded.

[0037] An airbag is installed inside the triangular prism module 1 in the slope, and a connecting block 1 and a connecting block 2 are respectively set on the airbag; a strip groove 1 is opened on the back of the hinge plate, and the connecting block 1 is constrained to slide within the strip groove 1;

[0038] An inclined push assembly block is installed inside the triangular prism module 1 in the slope. The inclined push assembly block includes an upper block and a lower block. The lower block is fixedly connected to the bottom beam support. An inclined groove is opened on the lower block. The inclined groove is parallel to the ramp slab. The inclined groove is set with an opening on one side.

[0039] A sliding block is provided on the side of the upper block facing the lower block, and the sliding block slides in the inclined groove;

[0040] A vertical groove is provided on the side of the upper block facing the airbag, and the connecting block two is constrained within the vertical groove.

[0041] A method for installing a prefabricated modular steel trestle bridge in a deep foundation pit includes the following steps:

[0042] Step 1: First, prepare a special construction plan for the foundation pit excavation; after the foundation pit support is completed, drill the permanent engineering cast-in-place pile holes and put the lattice column into the pile hole along with the cast-in-place pile reinforcement cage; then, pour the pile foundation concrete, and when the concrete strength reaches more than 70% of the design strength, excavate the foundation pit soil in symmetrical layers and areas to avoid damaging the pile body during the excavation.

[0043] Step 2: Based on the depth of the foundation pit, design the slope of the trestle bridge reasonably to ensure that dump trucks can freely enter and exit the foundation pit;

[0044] A perforated end plate is welded to the top of the lattice column to facilitate the connection of the longitudinal and transverse steel beams. High-strength bolts are used for the connection. After re-measuring the elevation of the top of the lattice column, the longitudinal and transverse steel beams are installed on the top of the pile below the location of the steel trestle.

[0045] Step 3: Using a truck crane, lift the multiple sets of modules as described in claim 1 column by column from the top of the pit slope to the bottom. The modules in the same column should be installed from bottom to top. The specific installation is as follows:

[0046] A. The end bottom module, middle bottom module one, middle bottom module two, middle bottom module three, middle bottom module four, bottom transition module, end bottom module, middle module, upper module, slope top triangular prism module, slope middle triangular prism module one, slope middle triangular prism module two, slope middle triangular prism module three, and slope bottom triangular prism module are all prefabricated and assembled in the factory;

[0047] B. On-site lifting and installation: First, lift the end bottom module to the longitudinal steel beam at the top of the lattice column. The flange of the longitudinal steel beam has reserved holes. Use connecting steel plates to insert between the end bottom module and the longitudinal steel beam, and use high-strength bolts to connect the three.

[0048] Then, the middle bottom module 1, middle bottom module 2, middle bottom module 3, middle bottom module 4, bottom transition module, and end bottom module are lifted and installed one by one from one end to the other.

[0049] C. After the bottom modules are installed, the middle modules are lifted and installed row by row in the previous order. Connecting steel plates are used to connect the bottom of adjacent modules, and then bolts and perforated angle steel are used to fasten the adjacent modules together to form an integral structure.

[0050] D. After completing the installation of the middle and lower modules according to the design slope of the steel trestle bridge, hoist and install the upper module, the triangular prism module at the top of the slope, the triangular prism module 1 in the middle of the slope, the triangular prism module 2 in the middle of the slope, the triangular prism module 3 in the middle of the slope, and the triangular prism module at the bottom of the slope. Use bolts and perforated angle steel to fix the bottom triangular prism beam to the module below. Use bolts and perforated angle steel to connect the columns of adjacent modules to form a whole. In this way, a steel trestle bridge passage that can freely enter and exit the foundation pit is formed, which is convenient for large dump trucks to move around.

[0051] Step 4. Finally, symmetrically excavate the foundation pit. After the foundation pit excavation is completed and the foundation and underground main structure construction is finished, dismantle each module, lattice column and longitudinal and transverse steel beams row by row from top to bottom to achieve standardized reuse.

[0052] Beneficial effects:

[0053] 1. The modular system of this invention is prefabricated in the factory and dry-connected on site, which can greatly reduce labor intensity, reduce carbon emissions and protect the environment, and enable reuse.

[0054] 2. This invention achieves the erection of a steel trestle bridge by setting up multiple interconnected modules. Multiple sets of hexahedral frame modules and triangular prism modules form an inclined transport surface, which is beneficial for the design standards of steel trestle bridges under different foundation pit standards. Laying ramp slabs and anti-slip strips on the surface enables the transport vehicle to bear the load and increases friction, thus improving transport efficiency.

[0055] 3. This invention achieves lateral stability by connecting multiple modules with a lateral protective frame, and provides bottom support through multiple support rods, which are detachably connected to the pit floor via foot braces. Internally, a filling cylinder is poured to connect to the sidewall of the pit and securely presses down on the multiple modules, thus lowering the center of gravity.

[0056] 4. This invention utilizes an inclined upper block that slides down the inclined groove along with a sliding block, continuously compressing the airbag. This causes the airbag to abut against the hinge plate, forcing the hinge plate's insertion pin into the positioning hole, thus achieving a surface friction effect on the ramp plate. As the gas in the airbag decreases, the upper block continues to compress, ensuring a low-cost friction effect through a non-electric structure. Furthermore, when the hinge plate needs to be replaced, the gas in the airbag can be released, allowing the hinge plate to disengage from the positioning hole before replacement. Attached Figure Description

[0057] Figure 1 This is a structural schematic diagram of an installation method for a prefabricated modular steel trestle bridge in a deep foundation pit, as proposed in this invention.

[0058] Figure 2 This is a schematic diagram showing the vertical connection between the upper and lower modules proposed in this invention.

[0059] Figure 3 This is a schematic diagram showing the connection between adjacent middle modules proposed in this invention;

[0060] Figure 4 This is a schematic diagram of the perforated connecting steel plate proposed in this invention;

[0061] Figure 5 This is a schematic diagram of the slope-top triangular prism module structure proposed in this invention;

[0062] Figure 6 A schematic diagram of the structure for laying ramp slabs on the surface of the steel trestle bridge according to the present invention;

[0063] Figure 7 This is a schematic diagram of the steel trestle bridge of the present invention inside the foundation pit;

[0064] Figure 8 This is a schematic diagram showing the connection between the middle module and a group of modules in the middle bottom module group of the present invention;

[0065] Figure 9 This is a schematic diagram of the first type of the slope triangular prism module of the present invention;

[0066] Figure 10 This is a schematic diagram of the lateral protective frame of another type of steel trestle bridge according to the present invention;

[0067] Figure 11 This is a schematic diagram of the insert's structure;

[0068] Figure 12 This is a structural diagram of another type of triangular prism module in the slope according to the present invention;

[0069] Figure 13 This is a side view of the triangular prism module one of the present invention.

[0070] Figure 14 This is a schematic diagram of the hinge plate of the present invention;

[0071] Figure 15 This is a schematic diagram of the airbag structure;

[0072] Figure 16 This is a schematic diagram of the upper block of the present invention;

[0073] Figure 17 This is a schematic diagram of the structure of the lower block of the present invention.

[0074] In the diagram: 1. Upper module; 2. Middle module; 3. Upper column; 6. Middle bottom module one; 7. Middle bottom module two; 8. Middle bottom module three; 9. Middle bottom module four; 10. Bottom transition module; 11. End bottom module;

[0075] 12. Triangular prism module for the slope top; 13. Ramp slab; 14. Anti-slip strip;

[0076] 15. Triangular prism module 1 in the middle of the slope; 16. Triangular prism module 2 in the middle of the slope; 17. Triangular prism module 3 in the middle of the slope; 18. Triangular prism module at the bottom of the slope; 19. Top connecting plate of the module; 20. Reserved bolt holes; 21. Bottom connecting plate of the module; 22. Module support;

[0077] 23. Connecting steel plate; 24. Triangular prism diagonal purlin; 25. Triangular prism column; 26. Inter-column support beam; 28. Triangular prism crossbeam; 29. ​​Triangular prism diagonal brace; 30. Bottom beam support; 31. Middle column; 32. Middle crossbeam;

[0078] 33. Patterned steel panel; 34. End and bottom module; 35. Bottom column; 36. Middle column;

[0079] 5. Lateral protective frame; 51. Side tie plate; 52. Support rod; 53. Foot brace; 54. Fixing plate; 55. Insert cylinder; 551. Grouting port; 552. Grout outlet;

[0080] 131. Position hole; 41. Hinge plate; 42. Insert post; 43. Airbag; 44. Upper block; 45. Lower block;

[0081] 431. Connecting block one; 432. Connecting block two; 441. Sliding block; 442. Vertical groove; 451. Inclined groove. Detailed Implementation

[0082] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0083] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0084] Example 1

[0085] Reference Figure 1-9 As shown, this is one embodiment of the present invention, a method for installing a prefabricated modular steel trestle bridge in a deep foundation pit, comprising:

[0086] The upper module 1 is a hexahedral frame structure formed by welding the upper column 3 and the small cross-section H-shaped connecting beam from one end to the other. The top is welded with a patterned steel panel 33, and the bottom is connected to the middle module 2 by high-strength bolts through the connecting steel plate 23.

[0087] like Figure 2 As shown, the upper column 3 is a square steel tube with a certain diameter and thick wall. The upper part is welded to the horizontal connecting beam at the top of the module, and the lower part is welded to the horizontal connecting beam at the bottom of the module. The module support 22 is welded between the two upper columns 3.

[0088] The module support 22 consists of two intersecting angle steels that form the central support structure of the frame. The two ends of the support are welded to the node plates at the beam and column joints of the module, respectively.

[0089] like Figure 6 As shown, the patterned steel panel 33 is a rolled steel plate of a certain thickness with decorative patterns. It is welded as a whole to the top of the upper module 1, and its perimeter is welded to the horizontal crossbeam at the top of the upper module 1 with fillet welds.

[0090] like Figure 2 and 3 As shown, the middle module 2 is a hexahedral frame structure formed by welding two small-section H-shaped connecting beams end to end, consisting of a central column 36 and two connecting beams. It is connected to the lower module via connecting steel plates 23 using high-strength bolts. Figure 1 As shown, the top surface of the upper middle module 2 in the middle position is connected to the slope top triangular prism module 12, the middle slope triangular prism module 15, the middle slope triangular prism module 2 16, the middle slope triangular prism module 3 17, and the slope bottom triangular prism module 18, respectively.

[0091] like Figure 1 and 2 As shown, the top connecting plate 19 of the module has a certain thickness and is distributed at the top of the four corner steel columns of the steel frame module. The connecting plate has pre-drilled bolt holes 20. By using high-strength bolts, the upper module 1 is vertically connected to the middle module 2, the middle module 2 is vertically connected to the end bottom module 34, the middle module 2 is vertically connected to the end bottom module 34, the middle module 2 is vertically connected to the middle bottom module 1 6, the middle module 2 is vertically connected to the middle bottom module 2 7, the middle module 2 is vertically connected to the middle bottom module 3 8, the middle module 2 is vertically connected to the middle bottom module 4 9, the middle module 2 is vertically connected to the bottom transition module 10, and the upper module 1 is vertically connected to the end bottom module 11.

[0092] like Figure 4 As shown, the connecting steel plate 23 is a rectangular steel plate of a certain thickness, with two rows of bolt holes symmetrically distributed on both sides of its length. The number of bolt holes on one side is the same as that on the top connecting plate 19 of the module. The connecting steel plate 23 is sandwiched between the bottom connecting plate 21 of the upper module and the top connecting plate 19 of the middle module 2, and between the bottom connecting plate 21 of the middle module and the top connecting plate 19 of the middle bottom module group or the end bottom module 34. By using the connecting steel plate 23 with reserved bolt holes 20, the left and right modules are bundled together, as shown. Figure 3 As shown;

[0093] The module bottom connecting plate 21 has a certain thickness and is distributed at the bottom of the four corner steel columns of the steel frame module. The module bottom connecting plate 21 is provided with bolt holes. By using high-strength bolts, the upper module 1 is vertically connected to the middle module 2, the middle module 2 is vertically connected to the end side bottom module 34, the middle module 2 is vertically connected to the end bottom module 34, the middle module 2 is vertically connected to the middle bottom module 1-6, the middle module 2 is vertically connected to the middle bottom module 2-7, the middle module 2 is vertically connected to the middle bottom module 3-8, the middle module 2 is vertically connected to the middle bottom module 4-9, the middle module 2 is vertically connected to the bottom transition module 10, and the upper module 1 is vertically connected to the end bottom module 11.

[0094] like Figure 5 As shown, the triangular prism module 12 at the top of the slope includes triangular prism columns 25, triangular prism beams 28 and their hypotenuses, inter-column support beams 26, triangular prism diagonal braces 29, bottom beam supports 30, central columns 31, and central beams 32. Triangular prism diagonal purlins are welded at regular intervals along the triangular hypotenuses of the upper and lower bottom surfaces. The steel purlins have a square steel tube cross-section. Ramp slabs 13 are welded and laid on the triangular prism diagonal purlins. Anti-slip strips 14 are welded at regular intervals along the slope of the ramp slabs 13. The bottom of the triangular prism module 12 at the top of the slope is connected to the upper module 1 and the middle module 2.

[0095] The ramp slab 13 is a patterned steel plate of a certain thickness, which is welded to the steel frame of the triangular prism module 12 at the top of the ramp, and has a certain strength and rigidity.

[0096] Anti-slip strips 14 are distributed at certain intervals along the slope of ramp 13, and their horizontal length is the same as the width of ramp 13.

[0097] The intercolumn support beam 26 is a square steel tube with a certain wall thickness, which is horizontally distributed in the middle position between two triangular columns 25, and its two ends are welded to the triangular columns 25.

[0098] The triangular prism diagonal brace 29 is a square steel tube with a certain wall thickness, distributed diagonally, with one end welded and both ends welded to the triangular prism column 25;

[0099] The bottom beam support 30 is a square steel pipe with a certain wall thickness, with both ends welded between the triangular beams 28, and distributed horizontally;

[0100] The triangular beam 28 is a square steel tube with a certain wall thickness. One end is welded to the bottom surface of the steel purlin below the ramp slab 13, and the other end is welded to the bottom side of the triangular column 25.

[0101] The central column 31 is a square steel pipe with a certain wall thickness. The upper end is welded to the bottom surface of the steel purlin below the ramp slab 13, and the lower end is welded to the triangular beam 28.

[0102] Triangular prism module 15 in the slope is welded with triangular prism purlins at regular intervals along the slope. The purlins are also square steel tubes. Ramp slabs 13 are welded and laid on the triangular prism purlins, and anti-slip strips 14 are welded at regular intervals along the slope of the ramp slabs 13. The bottom of the triangular prism module 12 at the top of the slope is connected to the upper module 1 and the middle module 2.

[0103] The slope triangular prism module 216, the slope triangular prism module 317, and the slope bottom triangular prism module 18 have the same structure as the slope triangular prism module 115, but their dimensions are not exactly the same.

[0104] like Figure 8 As shown, the middle bottom module group includes a bottom column 35 and a connecting beam three. The bottom column 35 and the connecting beam three are welded together and connected end to end to form a hexahedral structure. Connectors are installed on both sides and the top of the middle bottom module group. The middle bottom module group includes a middle bottom module one 6, a middle bottom module two 7, a middle bottom module three 8 and a middle bottom module four 9, and are arranged from the end bottom module 34 toward the end bottom module 11.

[0105] Step 1: First, prepare a special construction plan for the foundation pit excavation; after the foundation pit support is completed, drill the permanent engineering cast-in-place pile holes and put the lattice column into the pile hole along with the cast-in-place pile reinforcement cage; then, pour the pile foundation concrete, and when the concrete strength reaches more than 70% of the design strength, excavate the foundation pit soil in symmetrical layers and areas to avoid damaging the pile body during the excavation.

[0106] like Figure 7As shown in step 2, the slope of the trestle bridge should be reasonably designed according to the depth of the foundation pit to ensure that the dump trucks can freely enter and exit the foundation pit.

[0107] A perforated end plate is welded to the top of the lattice column to facilitate the connection of the longitudinal and transverse steel beams. High-strength bolts are used for the connection. After re-measuring the elevation of the top of the lattice column, the longitudinal and transverse steel beams are installed on the top of the pile below the location of the steel trestle.

[0108] Step 3: Using a truck crane, lift the multiple sets of modules as described in claim 1 column by column from the top of the pit slope to the bottom. The modules in the same column should be installed from bottom to top. The specific installation is as follows:

[0109] A. End bottom module 34, middle bottom module 1 6, middle bottom module 2 7, middle bottom module 3 8, middle bottom module 4 9, bottom transition module 10, end bottom module 11, middle module 2, upper module 1, slope top triangular prism module 12, slope middle triangular prism module 15, slope middle triangular prism module 2 16, slope middle triangular prism module 3 17, and slope bottom triangular prism module 18 are all prefabricated and assembled in the factory;

[0110] B. On-site lifting and installation: First, lift the end bottom module 34 to the longitudinal steel beam at the top of the lattice column. The flange of the longitudinal steel beam has a reserved hole. Use connecting steel plate 23 to insert between the end bottom module 34 and the longitudinal steel beam, and use high-strength bolts to connect the three.

[0111] Then, the middle bottom module 16, middle bottom module 27, middle bottom module 38, middle bottom module 49, bottom transition module 10, and end bottom module 11 are lifted and installed one by one from one end to the other.

[0112] C. After the bottom module is installed, the middle module 2 is lifted and installed row by row in the previous order. The bottom of the adjacent modules is connected by connecting steel plates 23, and the adjacent modules are fastened together with bolts and perforated angle steel to form an integral structure.

[0113] D. After completing the installation of the middle and lower modules according to the design slope of the steel trestle bridge, hoist and install the upper module 1, the top slope triangular prism module 12, the middle slope triangular prism module one 15, the middle slope triangular prism module two 16, the middle slope triangular prism module three 17, and the bottom slope triangular prism module 18. Use bolts and perforated angle steel to fix the bottom triangular prism beam 28 to the module below; use bolts and perforated angle steel to connect the columns of adjacent modules to form a whole; in this way, a steel trestle bridge passage that can freely enter and exit the foundation pit is formed, which is convenient for large muck trucks to move around;

[0114] Step 4. Finally, symmetrically excavate the foundation pit. After the foundation pit excavation is completed and the foundation and underground main structure construction is finished, dismantle each module, lattice column and longitudinal and transverse steel beams row by row from top to bottom to achieve standardized reuse.

[0115] At the top of the upper module 1 at the left end and the middle part, there are respectively a slope top triangular prism module 12, a slope middle triangular prism module one 15, a slope middle triangular prism module two 16, a slope middle triangular prism module three 17, and a slope bottom triangular prism module 18 to reduce the slope of the entire slope.

[0116] like Figure 6 As shown, the ramp slab 13 is a steel plate of a certain thickness, with sufficient strength and rigidity. The bottom surface is welded to the inclined steel purlins of the triangular prism module in the middle or bottom of the slope, and anti-slip strips 14 are welded on it at certain intervals to prevent the dump truck from sliding on the slope in rainy weather.

[0117] The triangular prism module 12 at the top of the slope is connected to the bottom of the triangular prism column 25 using high-strength bolts, and is connected along the height range using bolts and angle steel. At the same time, bolts and perforated angle steel are used to connect the triangular prism beam 28 to the top steel beam of the upper module 1 or the middle module 2 below, forming an integral structure to prevent lateral displacement.

[0118] The triangular prism module 15 in the slope is connected to the bottom of the triangular prism column 25 using high-strength bolts, and bolts are used in conjunction with angle steel to connect it along the height range. At the same time, bolts are used in conjunction with perforated angle steel to connect the triangular prism beam 28 to the top steel beam of the upper module 1 or the middle module 2 below, forming an integral structure to prevent lateral displacement.

[0119] The triangular prism module 216 in the slope is connected to the bottom of the triangular prism column 25 using high-strength bolts, and bolts are used in conjunction with angle steel to connect it along the height range. At the same time, bolts are used in conjunction with perforated angle steel to connect the triangular prism beam 28 to the top steel beam of the upper module 1 or the middle module 2 below, forming an integral structure to prevent lateral displacement.

[0120] The triangular prism module 317 in the slope is connected to the bottom of the triangular prism column 25 using high-strength bolts, and bolts are used in conjunction with angle steel to connect it along the height range. At the same time, bolts are used in conjunction with perforated angle steel to connect the triangular prism beam 28 to the top steel beam of the upper module 1 or the middle module 2 below, forming an integral structure to prevent lateral displacement.

[0121] The triangular prism module 18 at the bottom of the slope is connected to the bottom of the triangular prism column 25 using high-strength bolts, and is connected along the height range using bolts and angle steel. At the same time, bolts and perforated angle steel are used to connect the triangular prism beam 28 to the top steel beam of the upper module 1 or the middle module 2 below, forming an integral structure to prevent lateral displacement.

[0122] If the top of the module above the bottom module 11 at the end of the ramp is uneven and the vehicle jumps due to the large slope, a triangular prism module can be used for buffering.

[0123] This invention achieves the erection of steel trestle bridges by setting up multiple interconnected modular steel trestle bridges. Multiple sets of hexahedral frame modules and triangular prism modules form an inclined transport surface, which is beneficial for the design standards of steel trestle bridges under different foundation pit standards. Laying ramp slabs and anti-slip strips on the surface enables the transport vehicle to bear the load and increases friction, thus improving transport efficiency.

[0124] Example 2

[0125] like Figure 10 and 11 As shown, another embodiment of the present invention is provided, which, based on embodiment 1, further includes a lateral protective frame 5, which is located on the side of the steel trestle bridge.

[0126] like Figure 10 As shown, the lateral protective frame 5 includes a side pull plate 51 and a support assembly. The side pull plate 51 is connected to the upper module 1, the middle module 2 and the middle bottom module group respectively. The support assembly includes a support rod 52. The bottom of the support rod 52 is provided with a foot support 53 and the top is installed with a fixing plate 54. The fixing plate 54 is detachably connected to the side pull plate 51.

[0127] like Figure 11 As shown, a plug 55 is installed on the side of the fixed plate 54 facing the steel trestle. The plug 55 passes through the steel trestle and abuts against the support module support 22. The plug 55 has a grouting port 551 and a pointed end. The surface is provided with multiple grout outlets 552. A sealing ring is provided to fit the surface of the foundation pit to prevent grouting from splashing outward.

[0128] When the steel trestle is installed on the side wall of the foundation pit, the insert 55 is inserted into the side wall of the foundation pit, and the insert 55 is filled with concrete grout. Figure 7 The ends of the steel trestle bridge are attached to the sidewalls of the foundation pit. Therefore, the insert is designed to be bent, and the insert can press down on the module supports 22 of multiple modules to achieve the effects of pressing down and bearing and lateral positioning.

[0129] This invention achieves lateral stability by connecting multiple modules with a lateral protective frame, and provides bottom support through multiple support rods. The base is detachably connected to the pit floor via foot braces. Internally, a filling cylinder is poured to connect to the sidewalls of the pit and securely presses down on the multiple modules, thus lowering the center of gravity.

[0130] Example 3

[0131] like Figure 12-17As shown, in another embodiment of the present invention, based on embodiment 2, the ramp slab 13 has multiple sets of position holes 131, such as... Figure 12 As shown, multiple sets of position holes 131 are evenly distributed; a hinge plate 41 is installed inside the triangular prism module 15 in the slope, and the top of the hinge plate 41 is hinged to the triangular prism column 25; a plug-in post 42 is provided on the side of the hinge plate 41 facing the ramp slab, and the top end of the plug-in post 42 is rounded, as shown. Figure 14 As shown;

[0132] like Figure 13 As shown, an airbag 43 is installed inside the triangular prism module 15 in the slope. Connecting block 43 is provided with connecting block 431 and connecting block 432 respectively. Figure 15 As shown; a strip-shaped groove is provided on the back of the hinge plate 41, and the connecting block 431 is constrained to slide within the strip-shaped groove;

[0133] like Figure 13 As shown, a sloping push assembly block is installed inside the triangular prism module 15 in the slope. The sloping push assembly block includes an upper block 44 and a lower block 45. The lower block 45 is fixedly connected to the bottom beam support 30. A sloping groove 451 is formed on the lower block 45, such as... Figure 17 As shown, the inclined groove 451 is parallel to the ramp slab 13; the inclined groove 451 is set with an opening on one side.

[0134] like Figure 16 As shown, a sliding block 441 is provided on the side of the upper block 44 facing the lower block 45, and the sliding block 441 slides in the inclined groove 451; a vertical groove 442 is provided on the side of the upper block 44 facing the airbag 43, and the connecting block 432 is constrained in the vertical groove 442.

[0135] This invention utilizes an inclined upper block that slides down a ramp groove along with a sliding block, continuously compressing the airbag. This causes the airbag to abut against a hinge plate, forcing the hinge plate's insertion pin into the positioning hole, thus achieving a surface friction effect on the ramp. As the gas in the airbag decreases, the upper block continues to compress, ensuring a low-cost friction effect through a non-electric structure. Furthermore, when the hinge plate needs replacement, the gas in the airbag can be released, allowing the hinge plate to disengage from the positioning hole before replacement.

Claims

1. A modular prefabricated steel trestle bridge for deep foundation pits, characterized in that: The upper module (1) is topped with a patterned steel panel (33). The end bottom module (34) and the end bottom module (11) are horizontally distributed; The middle module (2) is equipped with multiple sets of slope top triangular prism modules (12), slope middle triangular prism module one (15), slope middle triangular prism module two (16), slope middle triangular prism module three (17), slope bottom triangular prism module (18) and upper module (1) respectively. The height gradually decreases from the top of the upper module (1), slope top triangular prism module (12), slope middle triangular prism module one (15), slope middle triangular prism module two (16), slope middle triangular prism module three (17) and slope bottom triangular prism module (18), and the top surface is inclined, with the inclination direction from the upper module (1) towards the tail bottom module (11) and downward. The middle bottom module group is divided into multiple groups located between the end bottom module (34) and the end bottom module (11); the middle bottom module group, the end bottom module (34) and the end bottom module (11) are used to support the middle module (2); the end bottom module (34) and the upper module (1) are vertically distributed; The upper module (1), middle module (2), end bottom module (34), middle bottom module group, and end bottom module (11) are all hexahedral frame structures and adjacent modules are connected by installation connectors.

2. The prefabricated modular steel trestle bridge for deep foundation pits according to claim 1, characterized in that, The upper module (1) includes an upper column (3) and a connecting beam. The upper column (3) and the connecting beam are welded together and connected end to end to form a hexahedral structure. The upper module (1) has connectors installed at both the top and bottom. The top connector is connected to the patterned steel panel (33), and the bottom connector is connected to the corresponding middle module (2). The middle module (2) includes a central column (36) and a connecting beam 2. The central column (36) and the connecting beam 2 are welded together and connected end to end to form a hexahedral structure. Connectors are installed at the upper and lower ends and at least one side of the middle module (1).

3. The prefabricated modular steel trestle bridge for deep foundation pits according to claim 2, characterized in that, The middle bottom module group includes a bottom column (35) and a connecting beam three. The bottom column (35) and the connecting beam three are welded together and connected end to end to form a hexahedral structure. Connectors are installed on both sides and the top of the middle bottom module group. The middle bottom module group includes middle bottom module one (6), middle bottom module two (7), middle bottom module three (8) and middle bottom module four (9), and is arranged from the end bottom module (34) toward the end bottom module (11).

4. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 2, characterized in that, The connector includes a module top connecting plate (19), a module bottom connecting plate (21), and a connecting steel plate (23). The connecting steel plate (23) has a reserved bolt hole (20). A high-strength bolt can be detachably installed in the reserved bolt hole (20). The top connecting plate (19) and the bottom connecting plate (21) of the module are respectively installed at the top and bottom ends of the corresponding module; both the top connecting plate (19) and the bottom connecting plate (21) of the module are provided with reserved bolt holes (20). The upper module (1), the middle module (2) and the middle bottom module group are all equipped with cross-shaped module supports (22) on the sides. In the vertical direction, the top connecting plate (19) or bottom connecting plate (21) of the adjacent modules are connected to the connecting steel plate (23) by installing high-strength bolts in the reserved bolt holes (20); It also includes bolts, which connect adjacent modules in the horizontal direction.

5. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 4, characterized in that, The connecting steel plate (23) has two rows of reserved bolt holes (20) symmetrically distributed on both sides of its length. The number of reserved bolt holes (20) on one side is the same as that on the top connecting plate (19) of the module. The connecting steel plate (23) is sandwiched between the top connecting plate (19) of the middle module and the bottom connecting plate (21) of the upper module, or between the bottom connecting plate (21) of the middle module and the top connecting plate (19) of the middle bottom module group.

6. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 4, characterized in that, The slope top triangular module (12) includes a triangular column (25), a triangular beam (28), and a triangular purlin (24), forming a triangular structure; Multiple sets of triangular prism columns (25) are provided and inter-column support beams (26) are installed between them. Multiple sets of triangular prism crossbeams (28) are provided, with bottom beam supports (30) installed between them. At the connection between the triangular column (25) and the triangular beam (28), a triangular diagonal brace (29) is provided facing the triangular purlin (24); a central beam (32) and a central column (31) are respectively installed on the triangular diagonal brace (29), and the triangular beam (28) and the triangular column (25) are respectively connected.

7. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 6, characterized in that, A ramp slab (13) is laid on the triangular prism purlin, and anti-slip strips (14) are welded at a fixed distance along the inclined surface of the ramp slab (13). The slope-top triangular prism module (12) is connected to the bottom of the triangular prism column (25) using high-strength bolts, and the upper module (1) or middle module (2) below is connected to the top of the lower module (1) or middle module (2) by bolts and angle steel. The slope triangular prism module one (15), slope triangular prism module two (16), slope triangular prism module three (17), and the slope bottom triangular prism module (18) have the same structure as the slope top triangular prism module (12), but their dimensions and top slope are not exactly the same.

8. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 7, characterized in that, It also includes a lateral guardrail (5), which is located on the side of the steel trestle bridge; The lateral protective frame (5) includes a side pull plate (51) and a support assembly. The side pull plate (51) is connected to the upper module (1), the middle module (2) and the middle bottom module group respectively. The support assembly includes a support rod (52). The bottom of the support rod (52) is provided with a foot support (53) and the top is equipped with a fixing plate (54). The fixing plate (54) is detachably connected to the side pull plate (51). A plug (55) is installed on the side of the fixed plate (54) facing the steel trestle. The plug (55) passes through the steel trestle and abuts against the support module support (22). A grouting port (551) is opened on the plug (55), and a grout outlet (552) is provided at the end. When the steel trestle is installed on the side wall of the foundation pit, the insert (55) is inserted into the side wall of the foundation pit and the insert (55) is filled with concrete slurry.

9. A prefabricated modular steel trestle bridge for deep foundation pits according to claim 8, characterized in that, The ramp plate (13) has multiple sets of position holes (131) evenly distributed; a hinge plate (41) is installed in the triangular prism module (15) in the middle of the ramp, and the top of the hinge plate (41) is hinged to the triangular prism column (25); a plug-in column (42) is provided on the side of the hinge plate (41) facing the ramp plate, and the top end of the plug-in column (42) is rounded. An airbag (43) is installed inside the triangular prism module 1 (15) in the slope. A connecting block 1 (431) and a connecting block 2 (432) are respectively provided on the airbag (43). A strip groove 1 is opened on the back of the hinge plate (41), and the connecting block 1 (431) is constrained to slide in the strip groove 1. An inclined push assembly block is installed in the triangular prism module 1 (15) in the slope. The inclined push assembly block includes an upper block (44) and a lower block (45). The lower block (45) is fixedly connected to the bottom beam support (30). An inclined groove (451) is opened on the lower block (45). The inclined groove (451) is parallel to the ramp slab (13). The inclined groove (451) is set with an opening on one side. A sliding block (441) is provided on the side of the upper block (44) facing the lower block (45), and the sliding block (441) slides in the inclined groove (451); The upper block (44) has a vertical groove (442) on the side facing the airbag (43), and the connecting block two (432) is constrained in the vertical groove (442).

10. A method for installing a prefabricated modular steel trestle bridge in a deep foundation pit, characterized in that, Includes the following steps: Step 1: First, prepare a special construction plan for the foundation pit excavation; after the foundation pit support is completed, drill the permanent engineering cast-in-place pile holes and put the lattice column into the pile hole along with the cast-in-place pile reinforcement cage; then, pour the pile foundation concrete, and when the concrete strength reaches more than 70% of the design strength, excavate the foundation pit soil in symmetrical layers and areas to avoid damaging the pile body during the excavation. Step 2: Based on the depth of the foundation pit, design the slope of the trestle bridge reasonably to ensure that dump trucks can freely enter and exit the foundation pit; A perforated end plate is welded to the top of the lattice column to facilitate the connection of the longitudinal and transverse steel beams. High-strength bolts are used for the connection. After re-measuring the elevation of the top of the lattice column, the longitudinal and transverse steel beams are installed on the top of the pile below the location of the steel trestle. Step 3: Using a truck crane, lift the multiple sets of modules as described in claim 1 column by column from the top of the pit slope to the bottom. The modules in the same column should be installed from bottom to top. The specific installation is as follows: A. The end bottom module (34), middle bottom module one (6), middle bottom module two (7), middle bottom module three (8), middle bottom module four (9), bottom transition module (10), end bottom module (11), middle module (2), upper module (1), and slope top triangular prism module (12), slope middle triangular prism module one (15), slope middle triangular prism module two (16), slope middle triangular prism module three (17), and slope bottom triangular prism module (18) are all prefabricated and assembled in the factory; B. On-site hoisting and installation: First, hoist the end bottom module (34) to the longitudinal steel beam at the top of the lattice column. The flange of the longitudinal steel beam is provided with a reserved hole. Use a connecting steel plate (23) to insert between the end bottom module (34) and the longitudinal steel beam, and use high-strength bolts to connect the three together. Then, the middle bottom module 1 (6), middle bottom module 2 (7), middle bottom module 3 (8), middle bottom module 4 (9), bottom transition module (10), and end bottom module (11) are lifted and installed one by one from one end to the other. C. After the bottom module is installed, the middle module (2) is lifted and installed row by row in the previous order. The bottom of the adjacent modules is connected by connecting steel plates (23), and the adjacent modules are fastened together with bolts and perforated angle steel to form an integral structure. D. After completing the installation of the middle and lower modules according to the design slope of the steel trestle bridge, the upper module (1), the top triangular prism module (12), the middle triangular prism module one (15), the middle triangular prism module two (16), the middle triangular prism module three (17), and the bottom triangular prism module (18) are hoisted and installed. The bottom triangular beam (28) is fixed to the module below by bolts and perforated angle steel. The triangular columns (25) are connected to the columns of adjacent modules by bolts and perforated angle steel to form a whole. In this way, a steel trestle bridge passage that can freely enter and exit the foundation pit is formed, which is convenient for large slag trucks to move. Step 4. Finally, symmetrically excavate the foundation pit. After the foundation pit excavation is completed and the foundation and underground main structure construction is finished, dismantle each module, lattice column and longitudinal and transverse steel beams row by row from top to bottom to achieve standardized reuse.

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