All-steel assembly type barrier-free foundation pit supporting structure and construction method

Abstract

The invention discloses an all-steel assembly type barrier-free foundation pit supporting structure and a construction method, and the all-steel assembly type barrier-free foundation pit supporting structure comprises an assembly type steel plate combined steel pipe pile module, a combined type steel crown beam module, a compensation type steel pipe diagonal bracing module and a steel pipe diagonal bracing anchoring module, the compensation type steel pipe diagonal bracing module is connected with the assembly type steel plate combined steel pipe pile module in a matched mode and used for providing diagonal supporting force for the assembly type steel plate combined steel pipe pile module. The steel pipe inclined strut anchoring module is connected with the compensation type steel pipe inclined strut module and the assembly type steel plate combined steel pipe pile module in a matched mode and used for anchoring inclined supporting of the compensation type steel pipe inclined strut module on the assembly type steel plate combined steel pipe pile module. On the premise of ensuring the overall stress of the enclosure structure, the green construction level and the component recovery rate of the enclosure structure are effectively improved, the labor force is saved, and the working efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and in particular to an all-steel assembled barrier-free foundation pit support structure and a construction method. Background Art

[0002] With the acceleration of urbanization, urban construction land has become increasingly tight, which has prompted the intensive development of urban buildings. Large-scale comprehensive multifunctional building complexes have continued to emerge, and the corresponding foundation pits have gradually deepened and expanded in area, especially in coastal soft soil areas.

[0003] For deep foundation pits with extremely large areas and complex shapes, the use of traditional internal support structural systems is costly and difficult to construct. Therefore, in recent years, a number of new unsupported support technologies suitable for ultra-large foundation pits have emerged, such as "double-row piles + steel pipe diagonal bracing combined support structure", "vertical piles + inclined piles combined support structure", etc. The pile types mainly include cast-in-place piles, precast piles, etc., which realize the excavation and structural construction conditions without internal support in the pit, save the construction and removal of temporary supports inside the foundation pit, and effectively shorten the foundation pit excavation time.

[0004] Although the green construction level of unsupported support technology can be improved through SMW piles and steel pipe piles, cast-in-place reinforced concrete crown beams are still required to connect the retaining piles into a whole. After the construction of the main underground structure is completed, the crown beams need to be removed to recover the inserted steel sections, steel pipe piles and steel sheet piles of the SMW piles.

[0005] It can be seen that how to effectively improve the green construction level and component recovery rate of enclosure structures is a problem that needs to be solved in this field. Summary of the Invention

[0006] In view of the above-mentioned technical problems existing in the existing new type of unsupported support technology, the purpose of the present invention is to provide an all-steel assembled barrier-free foundation pit support structure, which can effectively improve the green construction level and component recovery rate of the enclosure structure. On this basis, this scheme also provides a construction method of the all-steel assembled barrier-free foundation pit support structure, which effectively overcomes the problems existing in the existing technology.

[0007] In order to achieve the above-mentioned objectives, the present invention provides an all-steel assembled barrier-free foundation pit support structure, including an assembled steel plate combined steel pipe pile module, a assembled steel crown beam module, a compensating steel pipe diagonal brace module and a steel pipe diagonal brace anchoring module. The combined steel crown beam module is cooperated and connected with the assembled steel plate combined steel pipe pile module, which is used to provide axial and normal constraints to the assembled steel plate combined steel pipe pile module. The compensating steel pipe diagonal brace module is cooperated and connected with the assembled steel plate combined steel pipe pile module to provide diagonal support force to the assembled steel plate combined steel pipe pile module. The steel pipe diagonal brace anchoring module is respectively cooperated and connected with the compensating steel pipe diagonal brace module and the assembled steel plate combined steel pipe pile module to anchor the compensating steel pipe diagonal brace module to provide diagonal support to the assembled steel plate combined steel pipe pile module.

[0008] Furthermore, the assembled steel plate combined steel pipe pile module includes a first steel pipe supporting pile unit, a second steel pipe supporting pile unit and a baffle unit, wherein the first steel pipe supporting pile unit and the second steel pipe supporting pile unit are symmetrically arranged, and the baffle unit is assembled and connected to the first steel pipe supporting pile unit;

[0009] The first steel pipe support pile unit includes a plurality of first steel pipe support piles, which are symmetrically arranged according to the required spacing, and a first arc-shaped stirrup is provided at the top of the first steel pipe support pile for connecting with the combined steel crown beam module. The second steel pipe support pile unit includes a plurality of second steel pipe support piles, which are arranged at intervals corresponding to the first steel pipe support piles and are arranged on the same axis as the oppositely arranged first steel pipe support piles. A second arc-shaped stirrup is provided at the top of the second steel pipe support pile for connecting with the combined steel crown beam module.

[0010] Furthermore, two symmetrically arranged C-shaped steel guide rail slots are provided on the first steel pipe support piles, and the C-shaped steel guide rail slots between two adjacent first steel pipe support piles are used to lower the baffle unit to provide axial and normal constraints for the baffle unit.

[0011] Furthermore, the baffle unit includes a first baffle and a plurality of second baffles, and the first baffle and the plurality of second baffles are arranged in sequence;

[0012] The first baffle is a guide baffle, and both ends of the first baffle are provided with T-shaped limiters, which are used to engage with the C-shaped steel guide rail slide groove of the steel pipe support pile to limit the first baffle. The upper end of the guide baffle is concave and the lower end is wedge-shaped, and the concave end is embedded with a waterproof strip;

[0013] The second baffle is a standard baffle with a concave upper end and a convex lower end, and a waterproof rubber strip is embedded in the concave end.

[0014] Furthermore, auxiliary tooling is provided on both sides of the first baffle, and the auxiliary tooling is two groups of frames welded by a number of horizontal steel grooves and a number of vertical steel grooves, and are symmetrically arranged on both sides of the baffle assembly. The lower part of each group of frames has a number of connecting holes for installation on the first baffle; the lower end of each group of frames of the auxiliary tooling is provided with a water outlet trough, and the water outlet trough is inclined inward to ensure that the high-pressure water line is sprayed to the bottom of the baffle; the inner corner of the vertical channel steel is provided with a seamless steel pipe, and the water outlet trough is connected to the external boosting equipment through the seamless steel pipe welded to the inner corner of the vertical channel steel. When the external boosting equipment is turned on, the water outlet trough sprays the high-pressure water line to cut the soil under the first baffle to reduce the downward pressure resistance.

[0015] Furthermore, the combined steel crown beam module includes a first H-shaped steel box beam, a second H-shaped steel box beam and a hoop assembly. The first H-shaped steel box beam and the second H-shaped steel box beam are symmetrically arranged on the periphery of the first steel pipe support pile and the second steel pipe support pile respectively. The hoop assembly is symmetrically arranged on the first H-shaped steel box beam and the second H-shaped steel box beam and is matched with the matching steel plate combined steel pipe pile module.

[0016] Furthermore, a modular connecting beam module is provided between the first steel pipe supporting column and the corresponding second steel pipe supporting column to connect them to form an overall structural system.

[0017] Furthermore, the compensating steel pipe brace module includes a first section of steel pipe brace and a second section of steel pipe brace, the first section of steel pipe brace is covered with a layer of transition steel pipe, and the second section of steel pipe brace is inserted into the transition steel pipe of the first section of steel pipe brace and fixed.

[0018] Furthermore, the steel pipe diagonal brace anchoring module is composed of two groups of symmetrically arranged diagonal brace limiters, a third H-shaped steel box girder, a fourth H-shaped steel box girder and a fourth hoop assembly;

[0019] The two fourth hoop assemblies are arranged above the prefabricated steel plate combined steel pipe pile module, and the bent ear plates of the two fourth hoop assemblies are connected to form an annular hoop structure for clamping the prefabricated steel plate combined steel pipe pile module. The third H-shaped steel box girder and the fourth H-shaped steel box girder are symmetrically arranged in two groups and are respectively connected to the fourth hoop assemblies; the diagonal brace limiter is arranged on the compensating steel pipe diagonal brace module, and the diagonal brace limiter includes a first diagonal brace limiter assembly and a second diagonal brace limiter assembly; the first diagonal brace limiter assembly includes a first arc-shaped notch steel plate and a first square rod, the first square rod is located below the first arc-shaped notch steel plate, forming a lower steel pipe diagonal brace limiter, which is arranged at the lower part of the third H-shaped steel box girder and the fourth H-shaped steel box girder; the second diagonal brace limiter assembly includes a second arc-shaped notch steel plate and a second square rod, the second square rod is located above the second arc-shaped notch steel plate, forming an upper steel pipe diagonal brace limiter, which is arranged at the upper part of the third H-shaped steel box girder and the fourth H-shaped steel box girder.

[0020] In order to achieve the above-mentioned object, the present invention provides a construction method of an all-steel assembled barrier-free foundation pit support structure. The construction method of the all-steel assembled barrier-free foundation pit support structure is implemented based on the all-steel assembled barrier-free foundation pit support structure. The construction method of the all-steel assembled barrier-free foundation pit support structure comprises the following steps:

[0021] Step 1: After completing construction preparation and pile position setting, insert the first steel pipe support pile of the front row and the adjacent second steel pipe support pile into the soil, and control the verticality of the pile body to meet the design requirements;

[0022] Step 2: Set the auxiliary tooling on both sides of the guided baffle and press it between the adjacent steel pipe support piles. Then, embed the standard baffle into the installed guided baffle. Press down the auxiliary tooling to drive the baffle to move down along the C-shaped steel guide rail slide of the adjacent steel pipe support piles. Simultaneously turn on the external booster equipment to spray high-pressure water from the outlet trough to cut the soil under the guided baffle to reduce the downward pressure resistance. Pause the booster equipment and install other standard baffles in sequence as needed. Pause the booster equipment after installing the standard baffle.

[0023] Step 3: After the pile sinking construction of the adjacent third steel pipe support pile is completed, repeat step 2 to finally complete the front row pile construction;

[0024] Step 4: After the front row pile construction is completed, repeat operation 1 to carry out the rear row pile construction;

[0025] Step 5: To reduce the risk of water leakage from the front row piles, after the rear row piles are constructed, a chain trencher can be used to cut the soil between the front and rear rows of piles and simultaneously grout the soil to form a shallow chain mixing wall. A dewatering well can also be added between the shallow chain mixing wall and the front row piles.

[0026] Step 6: Install the first H-shaped steel box girder and the second H-shaped steel box girder respectively, and install the hoop assemblies on the first H-shaped steel box girder and the second H-shaped steel box girder, so that the arc-shaped stirrups at the top of the steel pipe support piles are respectively embedded in the embedding grooves of the hoop;

[0027] Step 7: After completing the installation of the modular steel crown beams for the front and rear rows of piles according to step 6, install the modular connecting beams to form the front and rear rows of piles into a whole;

[0028] Step 8: Level the soil area between the front and rear rows of piles to provide construction space for the installation of the combined steel crown beam; then, insert the compensating steel pipe brace obliquely, and use high-pressure grouting to squeeze the annular bag at the bottom end of the completed compensating steel pipe brace out of the annular bag bin and form a grouting expansion end at the end of the compensating steel pipe brace to increase the end resistance of the compensating steel pipe brace;

[0029] Step 9: According to the relative relationship of the elevations of the arc-shaped stirrups at the top of the rear row of steel pipe support piles, the third H-shaped steel box girder and the fourth H-shaped steel box girder, and the diagonal bracing limiter, the position of the lower steel pipe diagonal bracing limiter on the compensating steel pipe diagonal bracing is determined. Then, the third H-shaped steel box girder and the fourth H-shaped steel box girder are hoisted to the lower steel pipe diagonal bracing limiter and connected to the hoop assembly respectively; then, two diagonal bracing limiters are symmetrically welded on the second section of the steel pipe diagonal bracing to form an upper steel pipe diagonal bracing limiter; finally, the upper steel pipe diagonal bracing limiter and the lower steel pipe diagonal bracing limiter are fixed to the third H-shaped steel box girder and the fourth H-shaped steel box girder respectively;

[0030] Step 10: Install the axial force compensation device of the compensating steel pipe brace, then remove the fixing bolts of the transition steel pipe of the first section of the steel pipe brace and the second section of the steel pipe brace, manually adjust the axial force compensation device so that it acts on the transition steel pipe of the first section of the steel pipe brace and the second section of the steel pipe brace, and then adjust the axial force compensation device to the automatic control state;

[0031] Step 11: Carry out dewatering construction to the designed water level, and then carry out earth excavation.

[0032] The all-steel assembled barrier-free foundation pit support structure and construction method provided by the present invention effectively improve the green construction level and component recovery rate of the enclosure structure while ensuring the overall stress of the enclosure structure, saving labor and improving work efficiency, thereby helping the transformation and upgrading of the construction industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0034] Figure 1 This is a top view of the structure of the all-steel assembled barrier-free foundation pit support structure of the present invention without using compensating steel pipe diagonal braces;

[0035] Figure 2 This is a top view of the structure of the assembled steel plate combined steel pipe pile in this all-steel assembled barrier-free foundation pit support structure;

[0036] Figure 3 This is a top view of the structure of the auxiliary tooling in this all-steel assembled barrier-free foundation pit support structure;

[0037] Figure 4 This is the structural front view of the all-steel assembled barrier-free foundation pit support structure without the use of compensating steel pipe diagonal bracing;

[0038] Figure 5 This is a structural diagram of the first hoop in this all-steel assembled barrier-free foundation pit support structure;

[0039] Figure 6 This is a structural diagram of the second hoop in this all-steel assembled barrier-free foundation pit support structure;

[0040] Figure 7 This is a structural diagram of the third hoop in this all-steel assembled barrier-free foundation pit support structure;

[0041] Figure 8 This is a structural front view of the all-steel assembled barrier-free foundation pit support structure using compensating steel pipe diagonal bracing of the present invention;

[0042] Figure 9 This is a top view of the structure of the all-steel assembled barrier-free foundation pit support structure using compensating steel pipe diagonal bracing of the present invention;

[0043] Figure 10 This is a schematic diagram of the compensating steel pipe diagonal bracing structure in this all-steel assembled barrier-free foundation pit support structure;

[0044] Figure 11 It is a top view of the compensating steel pipe diagonal brace, combined steel crown beam, and rear row piles of the present invention.

[0045] Figure 12 It is a side view of the compensating steel pipe diagonal brace, combined steel crown beam and rear row piles of the present invention.

[0046] The following is a description of the components in the accompanying drawings:

[0047] 1. Prefabricated steel plate combined steel pipe pile module 2. Combined steel crown beam module 3. Modular connecting beam module 4. Compensating steel pipe diagonal brace module 5. Steel pipe diagonal brace anchor module

[0048] 11. First steel pipe support pile unit 111. First steel pipe support pile 112. C-shaped steel guide rail chute 113. First annular bagging compartment 114. First high-pressure grouting steel pipe 12. Second steel pipe support pile unit 121. Second steel pipe support pile 13. Baffle unit 131. First baffle 132. Second baffle 1311. Bolt hole 1312. T-shaped limiter 14. Auxiliary tooling 141. Horizontal steel trough 142. Vertical steel trough 143. Seamless steel pipe

[0049] 21. First H-beam 22. Second H-beam 23. First hoop assembly 24. Second hoop assembly 25. Third hoop assembly 231. First hoop plate 232. First bent ear plate 233. First stiffening rib plate 241. Second hoop plate 242. Second bent ear plate 243. Second stiffening rib plate 244. First stiffening web plate 245. First butt plate 251. Third hoop plate 252. Third bent ear plate 253. Third stiffening rib plate 254. Second stiffening web plate 255. Second butt plate 256. First H-beam 257. Reinforced angle plate

[0050] 41. First section of steel pipe diagonal brace 411. Second annular bag compartment 412. Second high-pressure grouting steel pipe 42. Second section of steel pipe diagonal brace 43. Transition steel pipe 431. Light hole 432. Window 433. Reinforcement rod

[0051] 51. Third H-shaped steel beam 52. Fourth H-shaped steel beam 53. First arc-shaped notched steel plate 54. First square rod 55. Fourth hoop assembly. DETAILED DESCRIPTION

[0052] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0053] To address the aforementioned technical issues with existing new unsupported support technologies, the present invention provides an all-steel, prefabricated, barrier-free foundation pit support structure. While ensuring the overall load-bearing capacity of the retaining structure, it effectively improves the green construction level and component recovery rate of the retaining structure, saving labor and improving work efficiency, thereby facilitating the transformation and upgrading of the construction industry. Furthermore, this solution also provides a construction method for the all-steel, prefabricated, barrier-free foundation pit support structure, effectively overcoming the problems existing in the existing technology.

[0054] See also Figure 1 and Figure 9 The all-steel assembled barrier-free foundation pit support structure provided by the present invention includes an assembled steel plate combined steel pipe pile module 1, a combined steel crown beam module 2, a modular connecting beam module 3, a compensating steel pipe diagonal brace module 4 and a steel pipe diagonal brace anchor module 5.

[0055] See also Figure 1 The assembled steel plate combined steel pipe pile module 1 includes a first steel pipe support pile unit 11, a second steel pipe support pile unit 12 and a baffle unit 13. In this solution, the first steel pipe support pile unit 11 serves as a front row column, and the second steel pipe support pile unit 12 serves as a rear row column. They are generally used as the front row piles of the all-steel assembled barrier-free foundation pit support structure, and the rear row piles generally only use steel pipe support piles.

[0056] The first steel pipe support pile unit 11 includes a plurality of first steel pipe support piles 111, which are symmetrically arranged according to the required spacing and inserted into the soil. The second steel pipe support pile unit 12 includes a plurality of second steel pipe support piles 121, which are arranged at intervals corresponding to the first steel pipe support piles 111 and are arranged on the same axis as the oppositely arranged first steel pipe support piles 111.

[0057] Among them, see Figure 4In the case where the vertical bearing capacity of the steel pipe support pile needs to be improved, this solution sets a first annular bag warehouse 113 at the end of the first steel pipe support pile 111 for temporary storage of the annular bag. The annular bag is connected to the external grouting equipment through a first high-pressure grouting steel pipe 114. High-pressure grouting will squeeze the annular bag out of the first annular bag warehouse 113 and form a grouting expansion end at the end of the first steel pipe support pile 111, which is used to improve the end resistance of the first steel pipe support pile 111.

[0058] Further, see Figure 2 C-shaped steel guide rail grooves 112 are symmetrically provided on both sides of each first steel pipe support pile 111. The C-shaped steel guide rail grooves 112 between two adjacent first steel pipe support piles 111 are used to lower the baffle unit 13 to provide axial and normal constraints for the baffle unit 13.

[0059] In addition, a certain number of two C-shaped steel guide rail slots 112 arranged at right angles need to be provided for the setting of the right-angle turns of the front row piles. If other angle turns are encountered, steel pipe support piles can be temporarily customized according to actual conditions.

[0060] See also Figure 4 The baffle unit 13 adopts a modular design. The baffle unit 13 includes a first baffle 131 and a plurality of second baffles 132. The first baffle 131 and the plurality of second baffles 132 are arranged in sequence.

[0061] See also Figure 2 The first baffle 131 is a guide baffle, and T-shaped limiters 1312 are respectively provided at both ends of the first baffle 131, which are used to engage with the C-shaped steel guide rail groove 112 of the steel pipe support pile to limit the first baffle 131.

[0062] The guide baffle is preferably a steel structural member with a concave upper end and a wedge-shaped lower end. The concave portion has a waterproof rubber strip embedded therein, and bolts are welded inside and outside the concave portion for installing the auxiliary tooling 14 .

[0063] See also Figure 3 and Figure 4 The auxiliary tooling 14 is composed of two sets of frames connected by a number of horizontal steel grooves 141 and a number of vertical steel grooves 142, and is symmetrically arranged on both sides of the first baffle 131. There are a number of bolt holes 1311 at the bottom of each set of frames for installation on the guided baffle. The auxiliary tooling 14 can be extended according to needs.

[0064] The lower end of each frame of the auxiliary tooling 14 is provided with a water outlet trough, which is inclined inward by 5 degrees to ensure that the high-pressure water line is sprayed below the baffle unit 13. A seamless steel pipe 143 is provided at the inner corner of the vertical channel steel 142. The water outlet trough is connected to the external supercharging equipment through the seamless steel pipe 143 welded to the inner corner of the vertical channel steel 142. When the external supercharging equipment is turned on, the water outlet trough sprays the high-pressure water line to cut the soil below the guide baffle to reduce the downward pressure resistance.

[0065] In addition, when the auxiliary tooling 14 is extended, the seamless steel pipe 143 can be extended synchronously through the threaded straight-through.

[0066] The second baffle 132 is a standard baffle, which is preferably a steel structural member, a high-strength aluminum alloy component, a high-strength wear-resistant composite material component, etc. The upper end of the second baffle 132 is concave and the lower end is convex, and the concave end is embedded with a waterproof rubber strip.

[0067] When the first steel pipe support pile 111 is installed, first install the auxiliary tooling 14 on the inner and outer sides of the guide baffle 131, and press it between the C-shaped steel guide rail slide grooves 112 of the adjacent steel pipe support piles, then embed the convex end of the first standard baffle 132 into the concave end of the installed guide baffle 131, and press the auxiliary tooling 14 downward to drive the baffle to move downward along the C-shaped steel guide rail 112 slide groove of the adjacent steel pipe support pile, and simultaneously turn on the external boosting equipment to make the water outlet spray high-pressure water line to cut the soil under the guide baffle 131 to reduce the downward pressure resistance, and install other standard baffles 132 in sequence as needed, and suspend the boosting equipment when installing the standard baffle 132.

[0068] Furthermore, a first arc-shaped stirrup is provided at the top of the first steel pipe supporting pile 111 for embedding into the embedding groove in the combined steel crown beam module to improve its vertical restraint force.

[0069] Secondly, a second arc-shaped stirrup is welded to the top of the second steel pipe supporting pile 121 to be embedded in the embedded groove of the combined steel crown beam module to improve its vertical restraint force.

[0070] See also Figure 1 The combined steel crown beam module 2 includes a first H-shaped steel box beam 21, a second H-shaped steel box beam 22 and a hoop unit.

[0071] The first H-shaped steel box girder 21 and the second H-shaped steel box girder 22 are symmetrically arranged on the periphery of the first steel pipe supporting pile 111 and the second steel pipe supporting pile respectively.

[0072] The first H-shaped steel box girder 21 and the second H-shaped steel box girder 22 in this solution are preferably first H-shaped steels, and light holes are reserved on the two second flange plates of the first H-shaped steel and sleeves are welded to form first through holes for connection with the hoop unit by setting connecting parts.

[0073] Here, the number and relative positions of each group of first through-holes correspond to the light holes reserved on the hoop unit, and the setting of the spacing between each group of first through-holes depends on the spacing of the assembled steel plate combined steel pipe pile modules 1.

[0074] Furthermore, the hoop unit is used to fasten the first steel pipe support column 111 and the second steel pipe support column 121 , and the hoop unit includes a first hoop assembly 23 , a second hoop assembly 24 and a third hoop assembly 25 .

[0075] Among them, see Figure 6 The first hoop assembly 23 is Ω-shaped as a whole, and is composed of a first hoop plate assembly 231 and a first bent ear plate 232. The first hoop plate 231 is formed by bending a cast iron component or a thick steel plate. The first hoop plate 231 is semicircular and has an embedded groove.

[0076] The first bent ear plates 232 are disposed at both ends of the first hoop plate 231 , and the first bent ear plates 232 are provided with a plurality of light holes.

[0077] A first stiffening rib plate 233 is preferably added to the intersection area between the first bent ear plate 232 and the first hoop plate 231 to enhance the overall rigidity.

[0078] See also Figure 7 The second hoop 24 includes a second hoop plate 241 , a second bent ear plate 242 , a second stiffening rib plate 243 , a first stiffening web plate 244 and a first docking plate 245 .

[0079] Among them, the composition and connection structure of the second hoop plate 241, the second bent ear plate 242 and the second stiffening rib plate 243 are the same as those of the first hoop plate 231, the first bent ear plate 232 and the first stiffening rib plate 233, and will not be described in detail here.

[0080] The first butt joint plate 245 is arranged in cooperation with the second hoop plate 241 . A plurality of bolt holes or light holes are reserved on the first butt joint plate 245 for connection with the first through hole group on the first H-shaped steel box girder 21 .

[0081] A first stiffening web 244 is preferably provided between the first butt joint 245 plate and the second hoop plate 241 on the second hoop 24 to enhance the overall rigidity.

[0082] See also Figure 8 The third hoop 25 includes a third hoop plate 252 , a third bent ear plate 252 , a third stiffening rib plate 253 , a second stiffening web plate 254 , a second butt joint plate 255 and a first H-shaped steel 256 .

[0083] Among them, the composition and connection structure of the third hoop plate 252, the third bent ear plate 252, the third stiffening rib plate 253, the second stiffening web plate 254 and the second docking plate 255 are the same as those of the first hoop plate 231, the first bent ear plate 232 and the first stiffening rib plate 233, and will not be described in detail here.

[0084] The first H-shaped steel 256 is arranged on the second docking plate 255. One end of the first H-shaped steel 256 is welded to the second docking plate 255, and the other end is welded with a steel plate as a first closing plate. The first closing plate is fully welded to the upper and lower flange plates and web plates of the first H-shaped steel 256. A number of light holes are reserved on the first closing plate for connecting the modular connecting beam modules.

[0085] A reinforcing angle plate 257 is preferably welded at the intersection of the first cover plate and the web of the first H-shaped steel 256 to increase the rigidity of the first cover plate.

[0086] The reserved light hole of the first bent ear plate 232 of the first clamp assembly is aligned with the reserved light hole of the second bent ear plate 242 of the second clamp assembly and connected, so that the first clamp assembly 23 and the second clamp assembly 24 can form an annular clamp structure, and the first docking plate 245 of the second clamp assembly 24 is connected to the first H-shaped steel beam 21, and the first steel pipe support column 111 is embedded in the embedding groove of the first clamp assembly 23 and the second clamp assembly 24 to clamp the first steel pipe support column pile 111.

[0087] The second bent ear plate 242 of the second clamp assembly 24 is connected to the reserved light hole on the third bent ear plate 252 of the third clamp assembly 25 to form an annular clamp structure. The first docking plate 245 of the second clamp assembly 24 is connected to the first H-shaped steel beam 21 and the second H-shaped steel beam 22, and the first steel pipe support column 111 and the second steel pipe support column 121 are embedded in the embedding groove of the second clamp assembly 24 and the third clamp assembly 25 to clamp the first steel pipe support column pile 111 and the second steel pipe support column pile 121 arranged on the same axis.

[0088] The first steel pipe support pile unit 11 and the second steel pipe support pile unit 12 formed by the above solution can form an integral system by setting a modular connecting beam module 3 between the rear column and the front column. For details, see Figure 1 .

[0089] Furthermore, the modular connecting beam module 3 is arranged between the first steel pipe support column 111 and the second steel pipe support column 121 on the same axis, and its two ends are respectively connected to the first H-shaped steel on the third clamp set on the first steel pipe support column 111 and the second steel pipe support column 121, connecting the first steel pipe support pile unit 11 and the second steel pipe support pile unit 12 to form an integral system.

[0090] The modular connecting beam module 3 in this solution is a second H-shaped steel. It is preferred that steel plates are welded at both ends of the second H-shaped steel as a second closing plate. The two flange plates and the web of the second H-shaped steel are fully welded. Several light holes are reserved on the second closing plate 2 for connecting with the light holes on the first H-shaped steel on the third clamp assembly.

[0091] In this solution, it is preferred to weld a reinforcing angle plate at the intersection of the second cover plate and the H-shaped steel web to increase the rigidity of the second cover plate.

[0092] Further, see Figure 8 and Figure 9 The compensating steel pipe diagonal bracing module 4 is used to improve the diagonal supporting force of the assembled steel plate combined steel pipe pile module 1, which is arranged on the second steel pipe support column 121, wherein the compensating steel pipe diagonal bracing module 4 includes a first section of steel pipe diagonal bracing 41 and a second section of steel pipe diagonal bracing 42.

[0093] Among them, see Figure 10 A second annular bag warehouse 411 is provided at the lower end of the first section of the steel pipe diagonal brace 41 for temporary storage of the annular bag. The annular bag is connected to the external grouting equipment through a second high-pressure grouting steel pipe 422. High-pressure grouting will cause the annular bag to be squeezed out of the second annular bag warehouse 411 and form a grouting expansion end at the end of the compensating steel pipe diagonal brace, which is used to increase the end resistance of the compensating steel pipe diagonal brace.

[0094] The upper end of the first section of the steel pipe diagonal brace 41 is preferably sealed and reinforced with a double-layer steel plate, and a light hole is reserved on the sealing plate for the high-pressure grouting steel pipe to pass through.

[0095] A layer of transition steel pipe 43 is placed on the outer cover of the first section of steel pipe diagonal brace 41 and fully welded. In addition, a plurality of light holes 431 are reserved on the upper half of the transition steel pipe 43 .

[0096] The lower end of the second section steel pipe diagonal brace 42 is preferably sealed and reinforced with a double-layer steel plate, and a light hole is reserved for the high-pressure grouting steel pipe to pass through. In addition, a number of bolt holes are reserved at the lower end of the second section steel pipe diagonal brace 42. The second section steel pipe diagonal brace 42 is inserted into the transition steel pipe of the first section steel pipe diagonal brace 41, and the light hole 431 on the transition steel pipe 43 is aligned with the bolt hole of the second section steel pipe diagonal brace 42, and fixed with bolts. It is necessary to ensure that the intersection area between the two is preferably not less than 1.0m to ensure the reliability of the connection between the first section steel pipe diagonal brace 41 and the second section steel pipe diagonal brace 42.

[0097] It should be noted here that during the foundation pit excavation stage, an axial force compensation device can be installed according to the deformation of the surrounding structure. If an axial force compensation device needs to be installed, a local window 432 is made on the transition steel pipe 43 to facilitate the installation of the axial force compensation device, and reinforcing rods 433 are fully welded around the window area.

[0098] The axial force compensation device integrates a jack, a hydraulic pump, an axial force self-servo wireless control system, and a power supply. It can independently realize intelligent control of the axial force and displacement. It has its own intellectual property patent sources (ZL201922176236.1, CN202211387716.2, CN2024106305810, etc.). The specific structure and working principle of the axial force compensation device installed here are well known to those skilled in the art, so they will not be described in detail here.

[0099] Further, see Figure 9 The steel pipe diagonal brace anchoring module 5 is arranged on the second steel pipe support column 121 and is used to anchor the compensating steel pipe diagonal brace module 4. The steel pipe diagonal brace anchoring module 5 consists of two groups of symmetrically arranged diagonal brace limiters, a third H-shaped steel box beam 51, a fourth H-shaped steel box beam 52 and a fourth hoop assembly 55.

[0100] See also Figure 12 The two fourth hoop assemblies 55 are arranged above the second H-shaped steel beam 22, and the bent ear plates of the two fourth hoop assemblies 55 are connected to form an annular hoop structure for clamping the second steel pipe support column 121 above the second H-shaped steel beam 22.

[0101] The structure of the fourth clamp assembly 55 is the same as that of the second clamp assembly 24 , and will not be described in detail here.

[0102] The third H-shaped steel box girder 51 and the fourth H-shaped steel box girder 52 are symmetrically arranged and are respectively connected to the first docking plate 245 of the hoop assembly 25 by bolts.

[0103] Here, the third H-shaped steel box girder 51 and the fourth H-shaped steel box girder 52 are preferably both composed of third H-shaped steel, and the two flange plates of the third H-shaped steel are closed by setting steel plates as third closing plates, and both are fully welded.

[0104] Light holes are reserved in the closing plates on both sides of the third H-shaped steel and the web in the middle, and sleeves are welded to form second through holes; the number and relative positions of each group of second through holes correspond to the light holes reserved on the docking plate of the fourth clamp assembly 55, and are used to connect with the docking plate of the fourth clamp assembly 55. The setting of the spacing between each group of second through hole groups depends on the spacing between the rear row of steel pipe support piles.

[0105] In addition, light holes are reserved on the two flange plates of the third H-shaped steel, and sleeves are welded to form third through holes 3. The third through holes are used to connect with the diagonal bracing limiters. The spacing between each group of third through holes depends on the spacing of the compensating steel pipe diagonal braces.

[0106] Further, see Figure 11The diagonal brace limiting member is welded to the second section of the steel pipe diagonal brace 42 of the compensating steel pipe diagonal brace module, and the diagonal brace limiting member includes a first diagonal brace limiting component and a second diagonal brace limiting component.

[0107] The first diagonal bracing limiting assembly includes a first arc-shaped notched steel plate 53 and a first square rod 54 . The first square rod 53 is located below the first arc-shaped notched steel plate 54 and serves as a lower steel pipe diagonal bracing limiting member.

[0108] The second diagonal brace limit assembly includes a second arc-shaped notch steel plate and a second square rod. The second square rod is located above the second arc-shaped notch steel plate and serves as an upper steel pipe diagonal brace limiter. The structure of the second arc-shaped notch steel plate and the second square rod here is the same as the structure of the above-mentioned first arc-shaped notch steel plate 53 and the first square rod 54, so they will not be described in detail here.

[0109] The notch structure and size of the steel plate with arc notch are pre-processed in the factory according to the inclination angle of the compensating steel pipe brace, and the dimensional deviation caused by on-site construction errors should be taken into account.

[0110] See also Figure 12 , a first diagonal brace limiter is symmetrically welded on the second section of the compensating steel tube diagonal brace 42 as a lower steel tube diagonal brace limiter, wherein the first square steel rod 54 is located below the first arc-shaped notched steel plate 53; then the third H-shaped steel box girder 51 and the fourth H-shaped steel box girder 52 are hoisted to the lower steel tube diagonal brace limiter, and the third H-shaped steel box girder 51 and the fourth H-shaped steel box girder 52 are respectively bolted to the docking plate of the fourth clamp assembly 55; then the second diagonal brace limiter is symmetrically welded on the second section of the steel tube diagonal brace 42 to form an upper steel tube diagonal brace limiter, wherein the second square steel rod is located above the second arc-shaped notched steel plate; finally, the upper steel tube diagonal brace limiter and the lower steel tube diagonal brace limiter are respectively fixed to the third H-shaped steel box girder 51 and the fourth H-shaped steel box girder 52 by tension bolts.

[0111] The all-steel assembled barrier-free foundation pit support structure formed by the above scheme also provides a construction method of the all-steel assembled barrier-free foundation pit support structure. The construction method of the all-steel assembled barrier-free foundation pit support structure includes the following steps:

[0112] Step 1: After completing construction preparation and pile position setting out, insert the first steel pipe support pile 111 of the front row and the adjacent second steel pipe support pile 121 into the soil, and control the verticality of the pile body to meet the design requirements.

[0113] For example, static pressure pile driving or vibration pile driving can be used to sequentially insert the first steel pipe support pile of the front row and the adjacent second steel pipe support pile into the soil.

[0114] Secondly, if the soil layer is a clay layer or a fine sand layer, drilling construction can be used.

[0115] Step 2: Install auxiliary fixtures on both sides of the guide baffles 131 and press them between adjacent first steel pipe support piles 111. Then, insert the first standard baffle 132 into the installed guide baffles 131. Press down on the auxiliary fixture 14 to move the baffles downward along the C-shaped steel guide rails 112 of the adjacent steel pipe support piles. Simultaneously, activate the external pressurization equipment, causing the outlet trough to spray high-pressure water to cut the soil below the guide baffles 131, reducing downward pressure resistance. Pause the pressurization equipment, and install additional standard baffles 132 as needed. Pause the pressurization equipment after installing the standard baffles.

[0116] Step 3: After the pile sinking construction of the adjacent third first steel pipe support pile 111 is completed, repeat step 2 to finally complete the front row pile construction.

[0117] Step 4: After the construction of the front row of piles is completed, repeat operation 1 to carry out the construction of the rear row of piles.

[0118] Step 5: To reduce the risk of water leakage in the front row of piles, after the construction of the rear row of piles is completed, a chain trencher can be used to cut the soil in the soil area between the front and rear rows of piles and simultaneously grouting can be performed to form a shallow chain mixing wall, and a dewatering well can be added between the shallow chain mixing wall and the front row of piles.

[0119] Step 6: Install the first H-shaped steel box girder 21 and the second H-shaped steel box girder 22 respectively, and install hoop assemblies on the first H-shaped steel box girder 21 and the second H-shaped steel box girder 22 so that the arc-shaped stirrups at the top of the first steel pipe support pile are respectively embedded in the embedding grooves of the hoop.

[0120] Specifically, first, on the steel pipe support piles 111 in the front row of piles that are on the same axis as the rear row of piles, and on the steel pipe support piles 112 of the rear row of piles, an annular hoop formed by connecting the second hoop assembly 24 and the third hoop assembly 25 is installed, so that the arc-shaped stirrups at the top of the front and rear rows of steel pipe support piles are respectively embedded in the embedded grooves of the hoop plate, and rubber sheets are padded; on the front row of steel pipe support piles 111 that are not on the same axis as the rear row of piles, an annular hoop formed by connecting the first hoop assembly 23 and the second hoop assembly 24 is installed, so that the arc-shaped stirrups at the top of the front row of steel pipe support piles 111 are respectively embedded in the embedded grooves of the hoop, and rubber sheets are padded; the first H-shaped steel box girder 21 and the second H-shaped steel box girder 22 are respectively installed, and the first through hole is aligned with the light hole reserved on the first docking plate 245 of the second hoop assembly and connected.

[0121] Step 7: After completing the installation of the combined steel crown beams for the front and rear rows of piles according to step 6, install the modular connecting beam 3 to form the front and rear rows of piles into a whole.

[0122] Step 8: Level the soil area between the front and rear rows of piles to provide construction space for the installation of the combined steel crown beam; then insert the compensating steel pipe brace obliquely, and use high-pressure grouting to squeeze out the annular bag at the bottom end of the completed compensating steel pipe brace from the annular bag bin and form a grouting expansion end at the end of the compensating steel pipe brace to increase the end resistance of the compensating steel pipe brace.

[0123] Specifically, the soil area between the front and rear rows of piles is leveled to provide construction space for the installation of the combined steel crown beam. Next, an oblique borehole is constructed for the compensating steel pipe brace. The borehole length must be less than the insertion length of the compensating steel pipe brace. After the borehole is completed, the second section of the compensating steel pipe brace 42 is bolted to the transition steel pipe 43 of the first section of the compensating steel pipe brace 41. The compensating steel pipe brace is then obliquely inserted. High-pressure grouting is then used to squeeze the annular bag at the bottom end of the completed compensating steel pipe brace out of the annular bag bin and form a grouting expansion end at the end of the compensating steel pipe brace, thereby increasing the end resistance of the compensating steel pipe brace.

[0124] Step 9: Based on the relative elevations of the curved stirrups at the top of the rear row steel pipe support piles, the third and fourth H-shaped steel box girders 51 and 52, and the diagonal brace stoppers, determine the position of the lower steel pipe diagonal brace stoppers on the compensating steel pipe diagonal brace. The third and fourth H-shaped steel box girders 51 and 52 are then hoisted and lowered to the lower steel pipe diagonal brace stoppers, where they are bolted to the docking plates of the fourth clamp assembly 55. Two diagonal brace stoppers are then symmetrically welded to the second section of steel pipe diagonal brace 42 to form the upper steel pipe diagonal brace stoppers. Finally, the upper and lower steel pipe diagonal brace stoppers are secured to the third and fourth H-shaped steel box girders 51 and 52, respectively, using tension bolts.

[0125] Step 10: Install the axial force compensation device of the compensating steel pipe diagonal brace, then remove the fixing bolts of the transition steel pipe 43 of the first section steel pipe brace 41 and the second section steel pipe brace 42, manually adjust the axial force compensation device so that it acts on the transition steel pipe of the first section steel pipe brace 41 and the second section steel pipe brace 42, and then adjust the axial force compensation device to the automatic control state.

[0126] Step 11: Carry out dewatering construction to the designed water level, and then carry out earth excavation.

[0127] The all-steel prefabricated barrier-free foundation pit support structure and construction method composed of the above-mentioned scheme effectively improves the green construction level and component recovery rate of the enclosure structure while ensuring the overall stress of the enclosure structure, saving labor and improving work efficiency, and helping the transformation and upgrading of the construction industry.

[0128] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. An all-steel assembled barrier-free foundation pit support structure, characterized in that: It includes an assembled steel plate combined steel pipe pile module, a assembled steel crown beam module, a compensating steel pipe diagonal brace module and a steel pipe diagonal brace anchoring module. The combined steel crown beam module is matched with the assembled steel plate combined steel pipe pile module to provide axial and normal restraint forces for the assembled steel plate combined steel pipe pile module. The compensating steel pipe diagonal brace module is matched with the assembled steel plate combined steel pipe pile module to provide diagonal support forces for the assembled steel plate combined steel pipe pile module. The steel pipe diagonal brace anchoring module is respectively matched with the compensating steel pipe diagonal brace module and the assembled steel plate combined steel pipe pile module to anchor the compensating steel pipe diagonal brace module to provide diagonal support for the assembled steel plate combined steel pipe pile module.

2. The all-steel assembled barrier-free foundation pit support structure according to claim 1, characterized in that: The assembled steel plate combined steel pipe pile module includes a first steel pipe supporting pile unit, a second steel pipe supporting pile unit and a baffle unit. The first steel pipe supporting pile unit and the second steel pipe supporting pile unit are symmetrically arranged, and the baffle unit is assembled and connected to the first steel pipe supporting pile unit. The first steel pipe support pile unit includes a plurality of first steel pipe support piles, which are symmetrically arranged according to the required spacing, and a first arc-shaped stirrup is provided at the top of the first steel pipe support pile for connecting with the combined steel crown beam module. The second steel pipe support pile unit includes a plurality of second steel pipe support piles, which are arranged at intervals corresponding to the first steel pipe support piles and are arranged on the same axis as the oppositely arranged first steel pipe support piles. A second arc-shaped stirrup is provided at the top of the second steel pipe support pile for connecting with the combined steel crown beam module.

3. The all-steel assembled barrier-free foundation pit support structure according to claim 2, characterized in that: Two symmetrically arranged C-shaped steel guide rail slots are provided on the first steel pipe support piles, and the C-shaped steel guide rail slots between two adjacent first steel pipe support piles are used to lower the baffle unit to provide axial and normal constraints for the baffle unit.

4. The all-steel assembled barrier-free foundation pit support structure according to claim 3, characterized in that: The baffle unit includes a first baffle and a plurality of second baffles, wherein the first baffle and the plurality of second baffles are arranged in sequence; The first baffle is a guide baffle, and both ends of the first baffle are provided with T-shaped limiters, which are used to engage with the C-shaped steel guide rail slide groove of the steel pipe support pile to limit the first baffle. The upper end of the guide baffle is concave and the lower end is wedge-shaped, and the concave end is embedded with a waterproof strip; The second baffle is a standard baffle with a concave upper end and a convex lower end, and a waterproof rubber strip is embedded in the concave end.

5. The all-steel assembled barrier-free foundation pit support structure according to claim 4, characterized in that: Auxiliary tooling is provided on both sides of the first baffle, and the auxiliary tooling is two groups of frames welded by several horizontal steel grooves and several vertical steel grooves, and are symmetrically arranged on both sides of the baffle assembly. The lower part of each group of frames has several connecting holes for installation on the first baffle; the lower end of each group of frames of the auxiliary tooling is provided with a water outlet trough, and the water outlet trough is inclined inward to ensure that the high-pressure water line is sprayed to the bottom of the baffle; the inner corner of the vertical channel steel is provided with a seamless steel pipe, and the water outlet trough is connected to the external boosting equipment through the seamless steel pipe welded to the inner corner of the vertical channel steel. When the external boosting equipment is turned on, the water outlet trough sprays the high-pressure water line to cut the soil under the first baffle to reduce the downward pressure resistance.

6. The all-steel assembled barrier-free foundation pit support structure according to claim 2, characterized in that: The combined steel crown beam module includes a first H-shaped steel box beam, a second H-shaped steel box beam and a hoop assembly. The first H-shaped steel box beam and the second H-shaped steel box beam are symmetrically arranged on the periphery of the first steel pipe support pile and the second steel pipe support pile respectively. The hoop assembly is symmetrically arranged on the first H-shaped steel box beam and the second H-shaped steel box beam and is matched with the matching steel plate combined steel pipe pile module.

7. The all-steel assembled barrier-free foundation pit support structure according to claim 6, characterized in that: A modular connecting beam module is provided between the first steel pipe supporting column and the corresponding second steel pipe supporting column to connect them to form an overall structural system.

8. The all-steel assembled barrier-free foundation pit support structure according to claim 1, characterized in that: The compensating steel pipe brace module includes a first section of steel pipe brace and a second section of steel pipe brace. The first section of steel pipe brace is covered with a layer of transition steel pipe, and the second section of steel pipe brace is inserted into the transition steel pipe of the first section of steel pipe brace and fixed.

9. The all-steel assembled barrier-free foundation pit support structure according to claim 1, characterized in that: The steel pipe diagonal brace anchoring module consists of two sets of symmetrically arranged diagonal brace limiters, a third H-shaped steel box girder, a fourth H-shaped steel box girder and a fourth hoop assembly; The two fourth hoop assemblies are arranged above the prefabricated steel plate combined steel pipe pile module, and the bent ear plates of the two fourth hoop assemblies are connected to form an annular hoop structure for clamping the prefabricated steel plate combined steel pipe pile module. The third H-shaped steel box girder and the fourth H-shaped steel box girder are symmetrically arranged in two groups and are respectively connected to the fourth hoop assemblies; the diagonal brace limiter is arranged on the compensating steel pipe diagonal brace module, and the diagonal brace limiter includes a first diagonal brace limiter assembly and a second diagonal brace limiter assembly; the first diagonal brace limiter assembly includes a first arc-shaped notch steel plate and a first square rod, the first square rod is located below the first arc-shaped notch steel plate, forming a lower steel pipe diagonal brace limiter, which is arranged at the lower part of the third H-shaped steel box girder and the fourth H-shaped steel box girder; the second diagonal brace limiter assembly includes a second arc-shaped notch steel plate and a second square rod, the second square rod is located above the second arc-shaped notch steel plate, forming an upper steel pipe diagonal brace limiter, which is arranged at the upper part of the third H-shaped steel box girder and the fourth H-shaped steel box girder.

10. A construction method of an all-steel assembled barrier-free foundation pit support structure, characterized in that: The construction method of the all-steel assembled barrier-free foundation pit support structure is implemented based on the all-steel assembled barrier-free foundation pit support structure described in claims 1 to 9 above, and the construction method of the all-steel assembled barrier-free foundation pit support structure comprises the following steps: Step 1: After completing construction preparation and pile position setting, insert the first steel pipe support pile of the front row and the adjacent second steel pipe support pile into the soil, and control the verticality of the pile body to meet the design requirements; Step 2: Set the auxiliary tooling on both sides of the guided baffle and press it between the adjacent steel pipe support piles. Then, embed the standard baffle into the installed guided baffle. Press down the auxiliary tooling to drive the baffle to move down along the C-shaped steel guide rail slide of the adjacent steel pipe support piles. Simultaneously turn on the external booster equipment to spray high-pressure water from the outlet trough to cut the soil under the guided baffle to reduce the downward pressure resistance. Pause the booster equipment and install other standard baffles in sequence as needed. Pause the booster equipment after installing the standard baffle. Step 3: After the pile sinking construction of the adjacent third steel pipe support pile is completed, repeat step 2 to finally complete the front row pile construction; Step 4: After the front row pile construction is completed, repeat operation 1 to carry out the rear row pile construction; Step 5: To reduce the risk of water leakage from the front row piles, after the rear row piles are constructed, a chain trencher can be used to cut the soil between the front and rear rows of piles and simultaneously grout the soil to form a shallow chain mixing wall. A dewatering well can also be added between the shallow chain mixing wall and the front row piles. Step 6: Install the first H-shaped steel box girder and the second H-shaped steel box girder respectively, and install the hoop assemblies on the first H-shaped steel box girder and the second H-shaped steel box girder, so that the arc-shaped stirrups at the top of the steel pipe support piles are respectively embedded in the embedding grooves of the hoop; Step 7: After completing the installation of the modular steel crown beams for the front and rear rows of piles according to step 6, install the modular connecting beams to form the front and rear rows of piles into a whole; Step 8: Level the soil area between the front and rear rows of piles to provide construction space for the installation of the combined steel crown beam; then, insert the compensating steel pipe brace obliquely, and use high-pressure grouting to squeeze the annular bag at the bottom end of the completed compensating steel pipe brace out of the annular bag bin and form a grouting expansion end at the end of the compensating steel pipe brace to increase the end resistance of the compensating steel pipe brace; Step 9: According to the relative relationship of the elevations of the arc-shaped stirrups at the top of the rear row of steel pipe support piles, the third H-shaped steel box girder and the fourth H-shaped steel box girder, and the diagonal bracing limiter, the position of the lower steel pipe diagonal bracing limiter on the compensating steel pipe diagonal bracing is determined. Then, the third H-shaped steel box girder and the fourth H-shaped steel box girder are hoisted to the lower steel pipe diagonal bracing limiter and connected to the hoop assembly respectively; then, two diagonal bracing limiters are symmetrically welded on the second section of the steel pipe diagonal bracing to form an upper steel pipe diagonal bracing limiter; finally, the upper steel pipe diagonal bracing limiter and the lower steel pipe diagonal bracing limiter are fixed to the third H-shaped steel box girder and the fourth H-shaped steel box girder respectively; Step 10: Install the axial force compensation device of the compensating steel pipe brace, then remove the fixing bolts of the transition steel pipe of the first section of the steel pipe brace and the second section of the steel pipe brace, manually adjust the axial force compensation device so that it acts on the transition steel pipe of the first section of the steel pipe brace and the second section of the steel pipe brace, and then adjust the axial force compensation device to the automatic control state; Step 11: Carry out dewatering construction to the designed water level, and then carry out earth excavation.

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