Assembling type steel lattice stand column for foundation pit supporting and construction method of assembling type steel lattice stand column

Abstract

The invention relates to an assembled steel lattice stand column for foundation pit supporting and a construction method thereof.The assembled steel lattice stand column for foundation pit supporting comprises a top fixing joint, standard joints, floor conversion joints, supporting beam conversion joints and permanent embedding joints, the standard joints are arranged on all floors of a basement, and the floor conversion joints are arranged on floors of all the floors of the basement in a penetrating mode; supporting beam conversion joints are correspondingly arranged on the supporting beams between every two adjacent layers of the basement in a penetrating mode, top fixing joints are correspondingly embedded in the supporting beams on the top of the basement, permanent embedding joints are embedded in stand column piles of the basement, supporting tables are arranged on the top fixing joints and the supporting beam conversion joints, and the supporting beams are supported on the corresponding supporting tables. The method has the beneficial effects that after construction of a basement structure is completed, except for the permanent embedded sections, the other sections of the steel lattice stand column can be dismounted without damage, the dismounting mode is simple, the dismounting efficiency is high, the repeated utilization rate of the steel lattice stand column can be greatly increased, and the material cost is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building engineering, in particular to a kind of assembled steel lattice column for foundation pit support and its construction method. BACKGROUND

[0002] Steel lattice column is the most commonly used column structure of deep foundation pit horizontal support structure. The traditional steel lattice column is integrally welded from top to bottom, and after the completion of the basement structure construction, it is removed by cutting the steel lattice column, which not only has great difficulty in removal, low efficiency, low reusability of steel lattice column, but also increases the cost of materials. In addition, the traditional steel lattice column penetrates the floor by reserving a hole at the floor and then pouring it. With the removal of the support and support beam, the compression and bending length of the steel lattice column will gradually increase. Under the condition of larger basement height, the overall instability of the steel lattice column may occur due to the excessive compression and bending length of the steel lattice column, causing safety hazards of foundation pit, or higher model steel lattice column is used, which greatly increases the cost. SUMMARY

[0003] The present application aims to overcome the shortcomings of the prior art and provide an assembled steel lattice column for foundation pit support and its construction method, which can solve the problems of traditional steel lattice column integrally welded, such as great difficulty in removal, low efficiency, low reusability and high material cost.

[0004] The object of the present application is achieved by the following technical solutions:

[0005] An assembled steel lattice column for foundation pit support, comprising a top fixed section, a standard section, a floor conversion section, a support beam conversion section and a permanent embedded section. Each floor of the basement is provided with a standard section. The floor conversion section is provided on each floor of the basement. The support beam conversion section is provided on the support beam between the adjacent two floors of the basement. The standard section, the support beam conversion section and the floor conversion section between the adjacent two floors of the basement are connected in sequence from top to bottom by connecting steel plates and fastening components. The top fixed section is embedded on the support beam at the top of the basement. The top fixed section, the floor conversion section at the top floor of the basement and the standard section at the top floor of the basement are connected in sequence from top to bottom by connecting steel plates and fastening components. The permanent embedded section is embedded on the column pile of the basement. The permanent embedded section and the standard section at the bottom floor of the basement are connected by connecting steel plates and fastening components. The top fixed section and the support beam conversion section are each provided with a support platform, and the support beam is supported on the corresponding support platform.

[0006] Further, the permanent embedded section, the standard section, the support beam conversion section, the floor conversion section and the top fixed section each comprise four L-shaped angle steels arranged symmetrically in pairs. The adjacent two L-shaped angle steels in the permanent embedded section and the standard section are connected by a detachable connecting plate.

[0007] Further, the L-shaped angle steel end is provided with a first connecting hole, the connecting steel plate is provided with a second connecting hole, and the L-shaped angle steel is detachably connected with the connecting steel plate through the fastening assembly, the first connecting hole and the second connecting hole.

[0008] Further, the support table comprises a first fixed plate, a second fixed plate, a stiffening rib and a support plate, one end of the first fixed plate is vertically welded to one end of the bottom surface of the second fixed plate, the stiffening rib is vertically welded to the bottom surface of the second fixed plate and is vertically welded with the plate surface of the first fixed plate, the support plate is anchored to the top surface of the second fixed plate, the first fixed plate is detachably connected with the L-shaped angle steel, and the support beam is supported on the support plate.

[0009] Further, based on the above-mentioned assembled steel lattice column for foundation pit support, the application further provides a construction method of the assembled steel lattice column for foundation pit support, comprising the following steps:

[0010] The number and length of each connecting assembly of the steel lattice column structure are determined according to the basement structure, and each connecting assembly of the steel lattice column structure is selected through finite element simulation, and then each connecting assembly of the steel lattice column structure is spliced into the steel lattice column structure;

[0011] After the column pile of the basement is poured, the steel lattice column structure is sunk to make the lower end of the permanent embedded section embedded in the column pile, and the sinking depth of the steel lattice column structure is controlled by using the long-distance laser positioning control method;

[0012] The construction positions of each layer of support beams of the basement are excavated in the basement pit from top to bottom, and the soil pits for accommodating the support tables are excavated at the bottom of the construction positions of each layer of support beams, the support tables are installed on the top fixed sections and the support beam conversion sections, and the support tables are wrapped with foam paper on the top fixed sections and the support beam conversion sections, each layer of support beams is constructed from top to bottom, the top of the top fixed section is embedded in the corresponding support beam, the support beam conversion section penetrates through the corresponding support beam, and the support table supports the corresponding support beam;

[0013] The construction position of the basement bottom plate is excavated in the basement pit, then the bottom plate is constructed, the reserved post-cast hole is arranged at the permanent embedded section, the connecting joint between the permanent embedded section and the standard section is exposed, and the standard section above the permanent embedded section is removed without damage in the later period;

[0014] The foam paper is wrapped on the floor conversion section, each layer of floor of the basement is constructed from bottom to top at the floor construction position below each layer of support beam, and the floor conversion section penetrates through the corresponding floor, after the construction of each layer of floor of the basement is completed and the floor concrete reaches the age strength, the support beams are removed layer by layer, and the load of the support beam is transferred to the floor;

[0015] The connecting steel plate and fastening assembly between the basement top floor slab conversion joint and the top fixed joint are removed, then the top fixed joint is removed, then the basement floor slab conversion joint, the standard joint and the support beam conversion joint are removed in sequence from top to bottom, and the reserved post-cast hole formed on the bottom plate and the post-cast hole formed on the floor slab are repaired.

[0016] Further, the sinking depth of the steel lattice column structure is controlled by using a long-distance laser positioning control method, including the following steps:

[0017] A laser instrument and a fixed scale are respectively erected on opposite sides of the foundation pit area, the laser instrument is erected on a base with a known elevation, during the sinking process of the steel lattice column structure, horizontal laser is emitted by the laser instrument, the horizontal laser is calibrated and the elevation of the horizontal laser is determined by the fixed scale, and the sinking depth of the steel lattice column structure is controlled by moving the scale according to the elevation of the horizontal laser.

[0018] Further, when the floor slab conversion joint, the standard joint and the support beam conversion joint of each floor of the basement are removed, the following steps are included:

[0019] The connecting steel plate and fastening assembly between the floor slab conversion joint and the standard joint are removed, the L-shaped angle steel of the floor slab conversion joint is not pulled out, the suspension rod is anchored on the top of the standard joint, then the connecting steel plate and fastening assembly at the lower end of the support beam conversion joint are removed, then the L-shaped angle steel of the floor slab conversion joint is pulled out, and the standard joint and the support beam conversion joint are placed together in a preset direction by supporting the suspension rod by a forklift;

[0020] Further, when the reserved post-cast hole formed on the bottom plate and the post-cast hole formed on the floor slab are repaired, the following steps are included:

[0021] The bottom surface of the reserved post-cast hole on the flush bottom plate is cut, the protruding steel lattice column structure is cut off, the surface of the reserved post-cast hole on the bottom plate is roughened and cleaned, then the reserved post-cast hole on the bottom plate is filled by pouring repair concrete into the reserved post-cast hole on the bottom plate;

[0022] A baffle is arranged at the bottom of the post-cast hole on the floor slab, then the post-cast hole on the floor slab is filled by pouring repair cement mortar into the post-cast hole on the floor slab.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] The assembled steel lattice column for foundation pit support of the present application is detachably connected between each segment through the connecting steel plate and the fastening assembly, after the basement structure construction is completed, the remaining segments of the steel lattice column can be removed without damage except for the permanent embedded segment, the removal method is simple, the removal efficiency is high, the reusability of the steel lattice column can be greatly improved, and the material cost is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A schematic diagram of an overall structure of a steel lattice support structure in the present application;

[0026] Figure 2 A schematic diagram of another overall structure of a steel lattice support structure in the present application;

[0027] Figure 3 A schematic diagram of a structure at A in Figure 2

[0028] Figure 4 A schematic diagram of a structure at B in Figure 2

[0029] Figure 5 A schematic diagram of a structure of a permanent embedded joint in the present application;

[0030] Figure 6 A schematic diagram of a structure of a standard joint in the present application;

[0031] Figure 7 A schematic diagram of a structure of a floor transfer joint in the present application;

[0032] Figure 8 A schematic diagram of a structure of a support beam transfer joint in the present application;

[0033] Figure 9 A schematic diagram of a structure of a top fixed joint in the present application;

[0034] Figure 10 A schematic diagram of a cross-sectional structure in the direction of C-C in Figure 9

[0035] A schematic diagram of a cross-sectional structure in the direction of D-D in Figure 11 Figure 9 A schematic diagram of a structure of a connecting steel plate in the present application;

[0036] Figure 12 A schematic diagram of a structure at E in

[0037] Figure 13 Figure 12

[0038] Figure 14 A schematic diagram of a construction process of a steel lattice support structure in the present application;

[0039] Figure 15 A schematic diagram of earthwork excavation of a first support beam in the present application;

[0040] Figure 16 A schematic diagram of construction of a basement support beam in the present application;

[0041] Figure 17 ​​​​​A basement floor construction schematic diagram in the present application;

[0042] Figure 18 A sinking control schematic diagram of the steel lattice support structure in the present application;

[0043] Figure 19 A demolition schematic diagram of the steel lattice support structure in the present application;

[0044] Figure 20 A repair schematic diagram of the basement floor and the basement bottom plate in the present application;

[0045] Figure 21 A structure front view schematic diagram of the support platform in the present application;

[0046] Figure 22 A structure bottom view schematic diagram of the support platform in the present application;

[0047] Figure 23 A Figure 21 A sectional structure schematic diagram in F-F direction.

[0048] 101, support beam; 101a, first deep ground; 101b, soil pit; 102, floor; 102a, repair cement mortar; 103, bottom plate; 103a, reserved post-cast hole; 103b, repair concrete; 104, column pile; 105, foundation pit bottom surface; 2, steel lattice column structure; 201, permanently buried joint; 202, standard joint; 202a, hanging rod; 203, floor conversion joint; 204, support beam conversion joint; 205, top fixed joint; 206, support platform; 206a, first fixed plate; 206b, second fixed plate; 206c, stiffening rib; 206d, support plate; 206e, third bolt hole; 206f, third bolt hole reinforcing convex; 206g, fourth bolt hole; 207, foam paper; 3, connecting steel plate; 4, high-strength bolt; 401, first bolt hole; 401a, first bolt hole reinforcing convex; 402, second bolt hole; 402a, second bolt hole reinforcing convex; 5, L-shaped angle steel; 6, add-on plate; 701, laser instrument; 702, base; 703, fixed scale; 704, horizontal laser line; 705, moving scale. DETAILED DESCRIPTION

[0049] The present application will be further described below in conjunction with the drawings, but the protection scope of the present application is not limited to the following description.

[0050] As Figures 1-13 , Figures 16-17As shown, a kind of assembled steel lattice column for foundation pit support is used for foundation pit support, including top fixed node 205, standard node 202, floor conversion node 203, support beam conversion node 204, permanent buried node 201.Every floor of basement is equipped with standard node 202, and floor conversion node 203 is penetrated on the floor 102 of every floor of basement, and support beam conversion node 204 is penetrated on the support beam 101 between adjacent two floors of basement, and standard node 202, support beam conversion node 204 and floor conversion node 203 between adjacent two floors of basement are sequentially detachably connected by connecting steel plate 3 and fastening assembly from top to bottom, and top fixed node 205 is correspondingly buried on the support beam 101 of the top of basement, and top fixed node 205, floor conversion node 203 of the top floor of basement, standard node 202 of the top floor of basement are sequentially detachably connected by connecting steel plate 3 and fastening assembly from top to bottom, and permanent buried node 201 is buried on the column pile 104 of basement, and permanent buried node 201 and standard node 202 of the bottom floor of basement are detachably connected by connecting steel plate 3 and fastening assembly, and support platform 206 is equipped on top fixed node 205 and support beam conversion node 204, and support beam 101 is supported on corresponding support platform 206.

[0051] Permanent buried node 201 and standard node 202 all include four L-shaped angle steels 5 and add-on plate 6 detachably connected between adjacent two L-shaped angle steels 5, and floor conversion node 203 and top fixed node 205 all include four L-shaped angle steels 5.

[0052] Permanent buried node 201, standard node 202, floor conversion node 203 and top fixed node 205 are sequentially spliced by connecting steel plate 3 and fastening assembly.

[0053] Among them, four L-shaped angle steels 5 are symmetrically arranged two by two, and adjacent two L-shaped angle steels 5 have a certain interval.

[0054] In the embodiments of the application, permanent buried node 201 and standard node 202 are detachably connected by connecting steel plate and fastening assembly, standard node 202 and floor conversion node 203 are detachably connected by connecting steel plate 3 and fastening assembly, floor conversion node 203 and top fixed node 205 are detachably connected by connecting steel plate 3 and fastening assembly, and fastening assembly is high-strength bolt 4.

[0055] Four L-shaped angle steels 5 of permanent buried node 201 are connected by add-on plate 6 to form permanent buried node 201. Figure 5 As shown, the length l1 of permanent buried node 201 includes insertion column pile depth l 11 And buried basement floor length l 12 According to insertion column pile depth requirement and basement thickness, the length of permanent buried node 201 can be selected as one of 4m, 6m and 8m, and insertion column pile depth K is a safety factor, taking 2.0-2.5, N is the vertical bearing capacity of the steel lattice column structure, unit is N, f c is the design value of the axial compressive strength of concrete, unit is N / mm 2 , A is the cross-sectional area of the steel lattice column structure, unit is mm 2 , L is the perimeter of the cross section of the steel lattice column structure, unit is mm, σ is the design value of the tensile strength of concrete, unit is N / mm 2 .

[0056] Four L-shaped angle steels 5 of the standard section 202 are connected by the connecting plate 6 to form the standard section 202. As shown in Figure 6 , the length l2 of the first standard section 202 includes two connecting sections l 21 and a standard section l 22 , which can be selected from 1200mm, 1500mm, 1800mm, 2100mm and 2400mm according to the floor height.

[0057] As shown in Figure 7 , the floor conversion section 203 is formed by four L-shaped angle steels 5. The length l3 of the floor conversion section 203 includes two connecting sections l 31 and a floor conversion section l 32 , which can be set to a fixed length of 600mm.

[0058] As shown in Figure 9 , the top fixed section 205 is formed by four L-shaped angle steels 5. The length l5 of the top fixed section 205 includes a connecting section l 51 , a support platform section l 52 and a fixed section l 53 , which can be set to a fixed length of 900mm.

[0059] The L-shaped angle steel used to make the permanent embedded section 201, the standard section 202, the floor conversion section 203 and the top fixed section 205 can be selected from one of the types L120mm×12mm, L140mm×14mm, L160mm×16mm and L180mm×18mm, and the steel strength grade can be selected as Q235B or Q345B.

[0060] The cross-sectional dimension of the permanent embedded section 201, the standard section 202, the floor conversion section 203 and the top fixed section 205 can be one of 420mm, 440mm and 460mm. Correspondingly, the connecting steel plate and the connecting plate 6 of the permanent embedded section 201 and the standard section 202 can be selected from one of the sizes 400mm×300mm×12mm, 420mm×300mm×12mm and 440mm×300mm×12mm.

[0061] For basements with a single floor, the prefabricated steel lattice columns for foundation pit support are assembled sequentially from a permanently embedded section 201, a standard section 202, a floor slab transition section 203, and a top fixed section 205.

[0062] In the embodiments of this application, the segments of the prefabricated steel lattice column for foundation pit support are detachably connected by connecting steel plates 3 and fastening components. After the basement structure is completed, except for the permanently embedded segments, the remaining segments of the prefabricated steel lattice column for foundation pit support can be dismantled without damage. The dismantling method is simple and efficient, which can greatly improve the reusability of the steel lattice column structure and effectively reduce material costs.

[0063] For basement floors with multiple floors, the number of standard sections 202 is greater than or equal to 2. The prefabricated steel lattice column for foundation pit support also includes at least one support beam transfer section 204. The number of support beam transfer sections 204 is one less than the number of standard sections 202. The support beam transfer section 204 includes four L-shaped angle steels 5.

[0064] A floor slab transition section and a support beam transition section 204 are sequentially spliced ​​together between two adjacent standard sections via connecting steel plates 3 and fastening components.

[0065] In this embodiment of the application, when the number of standard sections 202 is equal to 2, such as Figure 2 As shown, the prefabricated steel lattice column for foundation pit support is assembled sequentially from a permanently embedded section 201, a standard section 202, a floor slab transfer section 203, a support beam transfer section 204, and a top fixed section 205. This type of column is suitable for basements with two floors. The sum of the lengths of the standard section 202, floor slab transfer section 203, and support beam transfer section 204 equals the height of the second basement level. The sum of the lengths of the standard section 202, floor slab transfer section 203, and top fixed section 205 equals the height of the first basement level.

[0066] The permanently embedded section 201 is detachably connected to the standard section 202 via connecting steel plate 3 and fastening components. The standard section 202 is detachably connected to the floor slab transition section 203 via connecting steel plate 3 and fastening components. The floor slab transition section 203 is detachably connected to the support beam transition section 204 via connecting steel plate 3 and fastening components. Figure 3 As shown, the support beam transition section 204 and the standard section 205 are detachably connected via connecting steel plate 3 and fastening components, as follows: Figure 4 As shown, the floor transition section 203 and the top fixed section 205 are detachably connected by a connecting steel plate 3 and a fastening assembly.

[0067] When the number of standard sections 202 is equal to 3, the assembled steel lattice column for foundation pit support is assembled in sequence by one permanent embedded section 201, one standard section 202, one floor conversion section 203, one support beam conversion section 204, one standard section 202, one floor conversion section 203, one support beam conversion section 204, one standard section 202, one floor conversion section 203 and one top fixed section 205, which is suitable for the case that the basement floor is 3 floors. Among them, the sum of the lengths of the standard section 202, the floor conversion section 203 and the support beam conversion section 204 is the height of the negative three basement floor. The sum of the lengths of the standard section 202, the floor conversion section 203 and the support beam conversion section 204 is the height of the negative two basement floor. The sum of the lengths of the standard section 202, the floor conversion section 203 and the top fixed section 205 is the height of the negative one basement floor.

[0068] When the number of standard sections 202 is greater than 3, reference can be made to the above-mentioned cases where the number of standard sections 202 is 2 or 3, which will not be repeated here.

[0069] As shown in Figure 8 , the support beam conversion section 204 is formed by four L-shaped angle steels 5. The length l4 of the support beam conversion section 204 includes two connecting sections l 41 , a support platform section l 42 and a support beam conversion section l 43 , which can be set to a fixed length of 1500mm.

[0070] The L-shaped angle steel used to make the support beam conversion section 204 can be selected from one of the following types: L120mmx12mm, L140mmx14mm, L160mmx16mm and L180mmx18mm, and the steel strength grade can be selected from Q235B or Q345B. The cross-sectional dimension of the support beam conversion section 204 can be one of 420mm, 440mm and 460mm.

[0071] In one embodiment, the top of the L-shaped angle steel 5 of the permanent embedded section 201, the top and bottom of the L-shaped angle steel 5 of the standard section 202, the top and bottom of the L-shaped angle steel 5 of the floor conversion section 203 and the bottom of the L-shaped angle steel 5 of the top fixed section 205 are provided with first connecting holes, and the connecting steel plate is provided with second connecting holes corresponding to the first connecting holes;

[0072] The fastening assembly passes through the second connecting holes and the first connecting holes to sequentially splice the permanent embedded section 201, the standard section 202, the floor conversion section 203 and the top fixed section 205.

[0073] Among them, the first connecting hole includes but is not limited to a bolt hole and a bolt hole, and the second connecting hole includes but is not limited to a rivet hole. Correspondingly, the fastening assembly can be a bolt or a rivet.

[0074] In the embodiment of the present application, as shown in Figure 5 The upper end of the L-shaped angle steel 5 of the permanent embedded section 201 is provided with a first bolt hole 401 for anchoring and connecting the steel plate, and the lower end can not be provided with a bolt hole. As shown in Figure 6 The two ends of the L-shaped angle steel 5 of the standard section 202 are symmetrically provided with first bolt holes 401 for anchoring and connecting the steel plate.

[0075] As shown in Figure 7 The two ends of the L-shaped angle steel 5 of the floor transfer section 203 are symmetrically provided with first bolt holes 401 for anchoring and connecting the steel plate; as shown in Figure 9 The lower end of the L-shaped angle steel 5 of the top fixing section 205 is provided with a first bolt hole 401 for anchoring and connecting the steel plate.

[0076] In the embodiment of the present application, the permanent embedded section 201, the standard section 202, the floor transfer section 203 and the top fixing section 205 are firmly spliced into the steel lattice column structure 2 by bolts, which pass through the connecting holes of the connecting steel plate and the L-shaped angle steel 5 in turn, and the nuts are tightened.

[0077] In one embodiment, the top of the L-shaped angle steel 5 of the permanent embedded section 201, the top and bottom of the L-shaped angle steel 5 of the standard section 202, the top and bottom of the L-shaped angle steel 5 of the floor transfer section 203, the top and bottom of the L-shaped angle steel 5 of the support beam transfer section 204, and the bottom of the L-shaped angle steel 5 of the top fixing section 205 are provided with first connecting holes, and the connecting steel plate is provided with second connecting holes corresponding to the first connecting holes.

[0078] The fastening assembly passes through the second connecting holes and the first connecting holes to splice the permanent embedded section 201, at least one standard section 202, at least one floor transfer section 203, at least one support beam transfer section 204 and the top fixing section 205 in turn.

[0079] In the embodiment of the present application, as shown in Figure 5 The upper end of the L-shaped angle steel 5 of the permanent embedded section 201 is provided with a first bolt hole 401 for anchoring and connecting the steel plate 3, and the lower end can not be provided with a bolt hole. As shown in Figure 6 The two ends of the L-shaped angle steel 5 of the standard section 202 are symmetrically provided with first bolt holes 401 for anchoring and connecting the steel plate 3.

[0080] As shown in Figure 7 , Figure 8 The two ends of the L-shaped angle steel 5 of the floor transfer section 203 and the support beam transfer section 204 are symmetrically provided with first bolt holes 401 for anchoring and connecting the steel plate 3. As shown in Figure 9 The lower end of the L-shaped angle steel 5 of the top fixing section 205 is provided with a first bolt hole 401 for anchoring and connecting the steel plate 3.

[0081] The bolt passes through the connecting steel plate and the connecting hole of the L-shaped angle steel in sequence, and the nut is tightened, so that the permanent buried section 201, the standard section 202, the floor conversion section 203, the support beam conversion section 204 and the top fixed section 205 are firmly spliced into the steel lattice column structure 2.

[0082] In an optional embodiment, a bolt hole reinforcing protrusion can be arranged on the inner side of the bolt hole of the L-shaped angle steel 5. Taking the top fixed section 205 as an example, the bottom of the top fixed section 205 is connected with the top of the floor conversion section 203 through the connecting steel plate, the bolt and the nut. Therefore, as shown in the figure, a first bolt hole reinforcing protrusion 401a can be arranged on the inner side of the first bolt hole 401 of the L-shaped angle steel 5 corresponding to the connecting section of the top fixed section 205. Figure 10 Figure 8 、 Figure 12 As shown in the figure, a support platform needs to be installed on the top fixed section 205. Therefore, as shown in the figure, a first bolt hole reinforcing protrusion 401a can be arranged on the inner side of the first bolt hole 401 of the L-shaped angle steel 5 corresponding to the support platform section of the top fixed section 205. Figure 11

[0083] By arranging the first bolt hole reinforcing protrusion 401a on the inner side of the bolt hole of the L-shaped angle steel 5, the connection of each section of the steel lattice column structure 2 through the connecting steel plate and the bolt and the nut is more firm.

[0084] In an optional embodiment, as shown in the figure, the connecting steel plate 3 is provided with a second bolt hole 402 corresponding to each section, as shown in the figure, the second bolt hole 402 can be provided with a second bolt hole reinforcing protrusion 402a on the outer side. Figure 12 Figure 13 By arranging the second bolt hole reinforcing protrusion 402a on the outer side of the second bolt hole 402 of the connecting steel plate 3, the connection of each section of the steel lattice column structure through the connecting steel plate and the bolt and the nut is more firm.

[0085] By arranging the second bolt hole reinforcing protrusion 402a on the outer side of the second bolt hole 402 of the connecting steel plate 3, the connection of each section of the steel lattice column structure through the connecting steel plate and the bolt and the nut is more firm.

[0086] As shown in the figure, when the assembled steel lattice column for foundation pit support is constructed, the following steps are included: Figures 1-20

[0087] (1) According to the structure of the basement, the number and length of each connecting component of the steel lattice column structure 2 are determined, and each connecting component of the steel lattice column structure 2 is selected by finite element simulation, and then each connecting component of the steel lattice column structure 2 is spliced into the steel lattice column structure 2.

[0088] ​​​​(2) After the column pile 104 of the basement is poured, the steel lattice column structure is sunk to make the lower end of the permanent embedded section 201 embedded in the column pile 104, and the sinking depth of the steel lattice column structure is controlled by using the long-distance laser positioning control method.

[0089] More specifically, when the long-distance laser positioning control method is used to control the sinking depth of the steel lattice column structure, a laser instrument 701 and a fixed scale 703 are respectively erected on the opposite two sides of the foundation pit area, the laser instrument 701 is erected on a base 702 with a known elevation, and during the sinking process of the steel lattice column structure 2, a horizontal laser line 704 is emitted by the laser instrument 701, the horizontal laser line 704 is calibrated and the elevation of the horizontal laser line 704 is determined by the fixed scale 703, and according to the elevation of the horizontal laser line 704, the sinking depth of the steel lattice column structure 2 is controlled by moving the scale 705.

[0090] (3) The construction positions of the basement support beams 101 of each layer are excavated in the basement foundation pit from top to bottom, and the soil pits 101b for accommodating the support tables 206 are excavated at the bottom of the construction positions of the support beams 101 of each layer, the support tables 206 are installed on the top fixed sections 205 and the support beam conversion sections 204, and the foam paper 207 is wrapped outside the top fixed sections 205 and the support beam conversion sections 204, the support beams 101 of each layer are constructed in turn from top to bottom, and the top of the top fixed section 205 is embedded in the corresponding support beam 101, the support beam conversion section 204 penetrates through the corresponding support beam 101, and the support table 206 supports the corresponding support beam 101.

[0091] (4) The construction position of the basement floor 103 is excavated in the basement foundation pit, then the floor 103 is constructed, the reserved post-cast hole 103a is provided at the permanent embedded section 201, and the connecting joint between the permanent embedded section 201 and the standard section 202 is exposed, so that the standard section 202 above the permanent embedded section 201 can be removed without damage in the later period.

[0092] (5) The foam paper 207 is wrapped on the floor conversion section 203, the basement floors 102 of each layer are constructed in turn from bottom to top at the floor construction positions below the support beams 101 of each layer, and the floor conversion section 203 penetrates through the corresponding floor 102, after the construction of the basement floor 102 of each layer is completed and the concrete of the floor 102 reaches the age strength, the basement support beams 101 are removed layer by layer, and the load of the support beams 101 is transferred to the floor 102.

[0093] (6) remove the connecting steel plate 3 and fastening assembly between the basement top floor slab conversion node 203 and the top fixed node 205, then remove the top fixed node 205, and then sequentially remove the basement floor slab conversion node 203, the standard node 202 and the support beam conversion node 204 from top to bottom, and repair the reserved post-cast hole 103a formed on the bottom plate 103 and the post-cast hole formed on the floor slab 102.

[0094] More specifically, when removing the basement floor slab conversion node 203, the standard node 202 and the support beam conversion node 204, the connecting steel plate 3 and the fastening assembly between the floor slab conversion node 203 and the standard node 202 are removed, the L-shaped angle steel 5 of the floor slab conversion node 203 is not pulled out, the suspension rod 202a is anchored on the top of the standard node 202, then the connecting steel plate 3 and the fastening assembly at the lower end of the support beam conversion node 204 are removed, then the L-shaped angle steel 5 of the floor slab conversion node 203 is pulled out, and the standard node 202 and the support beam conversion node 204 are placed in the preset direction together by supporting the suspension rod 202a with a forklift

[0095] When repairing the reserved post-cast hole 103a formed on the bottom plate 103 and the post-cast hole formed on the floor slab 102, the bottom surface of the reserved post-cast hole 103a on the bottom plate 103 is leveled, the protruding steel lattice column structure 2 is cut off, the surface of the reserved post-cast hole 103a on the bottom plate is roughened and cleaned, then the reserved post-cast hole 103a on the bottom plate 103 is filled with repair concrete 103b, and the reserved post-cast hole 103a on the bottom plate 103 is filled; a baffle is arranged at the bottom of the post-cast hole on the floor slab 102, and then the post-cast hole on the floor slab 102 is filled with repair cement mortar 102a to fill the post-cast hole on the floor slab 102.

[0096] As shown in Figure 14 For the case of a one-story basement, the construction method of the assembled steel lattice column structure for supporting the foundation pit comprises the following steps:

[0097] S10, determine the length and number of each segment of the steel lattice column structure according to the position of the support beam, the position of the floor slab, the position of the basement bottom plate, the position of the foundation pit ground, the embedded column depth of the steel lattice column structure, and the height of the basement floor, determine the type and size of the related components of the steel lattice column structure through finite element simulation, and produce or transport all segments and related components from the previous construction site in the factory, assemble all segments and related components, and obtain the steel lattice column structure 2.

[0098] Among them, all segments and related components produced or transported from the previous construction site in the factory need to be pre-assembled to ensure that the assembly precision and the size of the structure after assembly meet the requirements.

[0099] In the embodiments of the present application, the determination of the type and size of the related components of the steel lattice column structure is to simulate the most unfavorable working condition of the foundation pit support and earth excavation by using commercial finite element software to obtain the maximum axial force, shear force and moment at the intersection node of the steel lattice column structure and the support beam; the type of the steel lattice column structure and the support table is selected according to the maximum axial force, shear force and moment at the node, and the high-strength bolts 4 and bolt hole sizes for anchoring and connecting the components are designed; for specific design and calculation, refer to the Code for Design of Steel Structures GB 50017.

[0100] For the case of a one-story basement, the steel lattice column structure is assembled by a permanent embedded section 201, a standard section 202, a floor transfer section 203 and a top fixed section 205 in sequence.

[0101] S20, after the column pile concrete pouring is completed, the steel lattice column structure is sunk into the column pile, and the bottom of the permanent embedded section 201 is embedded into the column pile.

[0102] The column pile is a kind of pile structure buried underground, which mainly functions to transmit the load generated by the foundation pit support structure to the ground to ensure the stability and safety of the building.

[0103] In the embodiments of the present application, the construction of the column pile generally includes the steps of drilling, hole cleaning, placing the reinforcement cage, pouring concrete, etc. Before the column pile concrete solidifies, the assembled steel lattice column structure is sunk into the column pile, and the bottom of the permanent embedded section 201 is embedded into the column pile.

[0104] S30, excavate to the bottom surface elevation of the first support beam at the position of the first support beam, excavate a pit for installing the support table below the first support beam and at the top fixed section, install the support table on the top fixed section, wrap the top fixed section with foam paper 207, perform formwork, tie the reinforcement and pour concrete on the ground at the bottom surface elevation of the first support beam to form the first support beam, and embed the top of the top fixed section into the first support beam; the position of the first support beam is the highest support beam position among the plurality of support beam positions.

[0105] The formwork is a preparation work before concrete pouring, which aims to form a concrete pouring space and ensure that the concrete has the correct shape and size during pouring and hardening. Specifically, the formwork includes the operations of measurement and line laying, formwork installation and formwork fixing.

[0106] The reinforcement is the main part of the concrete structure that bears the tensile force, and the reinforcement tying is an important step to ensure the strength of the structure.

[0107] The concrete pouring is to pour the concrete material into the formwork to form a concrete structure with a specific shape and size.

[0108] In the embodiments of the present application, as shown in Figure 1 , Figure 15 A pit 101b is dug below the first deep ground 101a and close to the position of the top fixed node. A support table is installed on the top fixed node, which is used to support the first support beam. The top fixed node is wrapped with foam paper 207, which facilitates the removal of the top fixed node in the later stage.

[0109] S40, excavate to the bottom surface elevation of the basement floor at the position of the basement floor, bind the steel bars on the ground surface at the ground elevation of the basement floor, and pour concrete to form the basement floor 103. A reserved post-cast hole 103a is provided at the permanent embedded node 201, and the connecting joint between the permanent embedded node 201 and the standard node 202 is exposed, so that the standard node 202 above the permanent embedded node 201 can be removed without damage in the later stage.

[0110] The top of the permanent embedded node 201 is below the upper surface of the basement floor 103, and the part below the top is located in the column pile.

[0111] In the embodiments of the present application, the over-poured concrete of the column pile 104 is removed at a position 200-300 mm above the bottom surface 105 of the foundation pit. A box-shaped formwork with a size of 800 mm x 800 mm x 350 mm is made at a position 200-300 mm below the upper surface elevation of the basement floor 103 of the steel lattice column structure 2, so that a reserved post-cast hole 103a with a depth of 200-300 mm is reserved at the position of the steel lattice column structure 2 when the basement floor 103 is poured with concrete, so that the standard node 202 above the permanent embedded node 201 can be removed without damage in the later stage.

[0112] S50, after the concrete of the basement floor 103 hardens to reach the age strength, the foam paper 207 is wrapped outside the floor transfer node penetrating the basement floor. Formwork is erected, steel bars are bound, and concrete is poured at the positions between the corresponding basement structural columns, beams, basement floor, and basement floor and maintenance structure to form the basement floor and support structure, and the floor transfer node 203 penetrates the basement floor. After the concrete reaches the age strength, the support beam above the basement floor is removed, and the load of the support beam is transferred to the first basement floor.

[0113] In the embodiments of the present application, as shown in Figure 1 Formwork is erected, steel bars are bound, and concrete is poured at the positions between the basement structural columns, beams, first basement floor, and first basement floor and maintenance structure to obtain the basement floor 102.

[0114] According to the embodiment of the application, the first support beam, the basement floor and the first basement floor are sequentially constructed, then the first support beam is removed, the support force provided by the support beam is converted into the support force provided by the basement floor, the top end fixing node, the floor conversion node 203 and the standard node 202 of the steel lattice column are gradually removed, the hole is repaired, and the construction of the first basement floor is completed.

[0115] For the case of a two-story basement, the construction method of the assembled steel lattice column for foundation pit support comprises the following steps:

[0116] S100, according to the position of the support beam, the position of the floor, the position of the basement floor, the position of the foundation pit ground, the embedded depth of the steel lattice column structure into the column pile and the height of the basement floor, the length and number of each segment of the steel lattice column structure are determined, the type and size of the related components of the steel lattice column structure are determined through finite element simulation, and all segments and related components are produced in the factory or transported from the previous construction site, all segments and related components are assembled to obtain the steel lattice column structure.

[0117] In the embodiment of the application, step S100 can refer to step S10, which will not be repeated here.

[0118] For the case of a two-story basement, the steel lattice column structure is assembled by a permanently embedded node 201, a standard node 202, a floor conversion node 203, a support beam conversion node 204 and a top fixing node.

[0119] S200, after the column pile concrete pouring is completed, the steel lattice column structure is sunk into the column pile, and the bottom of the permanently embedded node 201 is embedded into the column pile;

[0120] In the embodiment of the application, step S200 can refer to step S20, which will not be repeated here.

[0121] S300, as shown in Figure 15 , Figure 16 , the first support beam position is excavated to the bottom surface elevation of the first support beam, a pit for installing a support table is excavated below the first support beam and at the top fixing node, the support table is installed on the top fixing node, the top fixing node is wrapped with foam paper 207, formwork is erected, steel bars are bound and concrete is poured on the ground at the bottom surface elevation of the first support beam to form the first support beam, and the top of the top fixing node is embedded in the first support beam; the first support beam position is the support beam position with the maximum height among the plurality of support beam positions.

[0122] In the embodiment of the application, step S300 can refer to step S30, which will not be repeated here.

[0123] S400, as shown in Figure 15 , Figure 16As shown, the excavation process involves removing soil and rock from the foundation pit down to the top surface of the second support beam, then excavating downwards from the location of the first support beam to the bottom elevation of the second support beam. A pit is then dug at the transition section of the support beam to install the support platform. The support platform is installed on the transition section of the support beam, and foam paper 207 is wrapped around the transition section of the support beam that passes through it. Formwork is then erected, steel bars are tied, and concrete is poured at the bottom elevation of the second support beam to form the second support beam, allowing the transition section to pass through the second support beam. The location of the second support beam is the support beam whose height is only less than that of the first support beam among multiple support beam locations.

[0124] In this embodiment of the application, a support platform is installed on the support beam transition section 204. The support platform is used to support the second support beam. Foam paper 207 is wrapped around the support beam transition section 204 to facilitate the removal of the support beam transition section 204 later.

[0125] S500. Continue to excavate the soil and rock in the foundation pit until the bottom surface of the basement floor slab is at the elevation. Tie steel bars and pour concrete on the ground at the elevation of the basement floor slab to form the basement floor slab 103, so that the top of the permanent embedded section 201 is embedded in the basement floor slab 103.

[0126] In the embodiments of this application, step S500 can refer to step S40, and will not be repeated here.

[0127] S600, such as Figure 17 As shown, the basement structure construction, support replacement, and support removal are carried out. Foam paper 207 is wrapped around the floor slab transfer joint that penetrates the first basement floor slab. Formwork is erected, reinforcing bars are tied, and concrete is poured at the corresponding basement structural columns, beams, the first basement floor slab, and the locations between the first basement floor slab and the maintenance structure to form the first basement floor slab and the support structure. The floor slab transfer joint 203 penetrates the first basement floor slab. After the concrete reaches its required strength, the support beams above the first basement floor slab are removed, transferring the load of the support beams to the first basement floor slab.

[0128] In the embodiments of this application, step S600 can refer to step S50, and will not be repeated here.

[0129] S700, such as Figure 17As shown, the foam paper 207 is wrapped outside the second basement floor position corresponding floor transition section 203, and the formwork is erected, the steel bars are tied and the concrete is poured at the position between the corresponding basement structure column, beam, second basement floor and the maintenance structure, the second basement floor is formed, and the second floor transition section 203 penetrates through the second basement floor; after the concrete reaches the age strength, the support beam above the second basement floor is removed, and the load of the support beam is transferred to the second basement floor; the second basement floor position is the basement floor position with a height only greater than that of the first basement floor position among the plurality of basement floor positions.

[0130] In the embodiment of the present application, as shown in Figure 2 The second basement floor is obtained by erecting the formwork, tying the steel bars and pouring the concrete at the second basement floor position.

[0131] By applying the embodiment of the present application, the first support beam, the second support beam, the basement floor, the first basement floor and the second basement floor are sequentially constructed, wherein after the construction of the first basement floor is completed, the support beam above the floor is removed, the load of the support beam is transferred to the first basement floor, and then the second basement floor is constructed; after the construction of the second basement floor is completed, the support beam above the floor is removed, and the load of the support beam is transferred to the second basement floor.

[0132] Finally, the top end fixed section of the steel lattice column is gradually removed, the hole is repaired, and the construction of the basement floor is completed.

[0133] For the case of a three-story or more basement, the specific construction process can refer to steps S100-S700, and the support force provided by the support beam is converted into the support force provided by the basement floor in sequence according to the order of the support beam, the basement floor and the basement floor, the support beam and the top end fixed section of the steel lattice column are gradually removed, the hole is repaired, and the construction of the multi-story basement floor is completed.

[0134] After step S10, the following step S101 is further included:

[0135] S101, a laser instrument and a fixed scale are respectively erected on the opposite two sides of the foundation pit area, the laser instrument is erected on the base, and during the sinking process of the steel lattice column structure, the horizontal laser is emitted by the laser instrument, the horizontal laser is calibrated and the elevation of the horizontal laser is determined by the fixed scale, the sinking depth of the steel lattice column structure 2 is controlled by moving the scale according to the elevation of the horizontal laser, and the bottom of the permanent embedded section 201 is inserted into the column pile.

[0136] In the embodiment of the present application, as shown in Figure 18As shown, the sinking depth of the steel lattice column structure 2 adopts a long-distance laser positioning control method. Specifically, the laser instrument 701 is erected on the base 702 with a known elevation, a horizontal laser line 704 is emitted by the laser instrument 701, the horizontal laser line 704 is calibrated and the elevation of the horizontal laser line 704 is determined by the fixed scale 703, the sinking depth of the steel lattice column structure 2 is controlled by the moving scale 705 according to the elevation of the horizontal laser line 704, the precise control of the sinking depth of the steel lattice column structure in the pit area is realized, and compared with the existing theodolite control, the operation is more convenient, and the construction difficulty of the sinking depth control of the steel lattice column structure is greatly simplified.

[0137] After step S50, steps S51-S52 are further included:

[0138] S51, after the first supporting beam is removed, the connecting steel plate 3 and the fastening assembly between the top of the first floor slab conversion section 203 and the bottom of the top fixed section 205 are removed to remove the top fixed section 205;

[0139] S52, the connecting steel plate 3 and the fastening assembly between the bottom of the first floor slab conversion section 203 and the top of the standard section 202 are removed, the L-shaped angle steel 5 of the first floor slab conversion section 203 is not pulled out, the hanging rod 202a is anchored on the gusset plate 6 at the top of the standard section 202, and the standard section 202 is placed in the preset direction by supporting the hanging rod 202a with a forklift to remove the first floor slab conversion section 203 and the standard section 202.

[0140] In the embodiment of the present application, the connection position of the standard section 202 and the floor slab conversion section 203 avoids the first basement floor, the connection position of the floor slab conversion section 203 and the top fixed section 205 avoids the first basement floor, and the top fixed section 205, the floor slab conversion section 203 and the standard section 202 are removed in turn from top to bottom, so that the standard section 202, the floor slab conversion section 203 and the top fixed section 205 are removed without damage.

[0141] In one embodiment, after the step of placing the standard section 202 in the preset direction by supporting the hanging rod 202a with a forklift to remove the first floor slab conversion section 203 and the standard section 202 in step S52, steps S521-S522 are further included:

[0142] S521, the bottom surface of the reserved post-cast hole 103a of the basement floor 103 is leveled, the steel lattice column structure protruding part is cut off, the surface of the reserved post-cast hole 103a of the basement floor 103 is roughened and cleaned, and the repair concrete 103b of the basement floor is poured again to fill the reserved post-cast hole 103a of the basement floor 103;

[0143] S522, setting a baffle under the post-poured hole of the steel lattice column structure penetrating the first basement floor, pouring repair cement mortar 102a above the first basement floor to fill the post-poured hole of the first basement floor.

[0144] In the embodiment of the present application, as shown in Figure 20 pouring repair concrete 103b on the basement floor and pouring repair cement mortar 102a above the first basement floor.

[0145] By filling the reserved post-poured hole of the basement floor and the post-poured hole of the first basement floor, the integrity and stability of the basement structure can be ensured, and the destruction or safety accidents of the basement structure caused by holes can be prevented.

[0146] After step S700, steps S710-S730 are further included as follows:

[0147] S710, after all the support beams are removed, the connecting steel plate 3 and the fastening assembly between the top of the first floor conversion section 203 and the bottom of the top fixed section 205 are removed to remove the top fixed section 205;

[0148] S720, the connecting steel plate 3 and the fastening assembly between the bottom of the first floor conversion section 203 and the top of the standard section 202 are removed, the L-shaped angle steel 5 of the first floor conversion section 203 is not pulled out, the hanging rod 202a is anchored on the top of the standard section 202, the connecting steel plate 3 and the fastening assembly between the bottom of the support beam conversion section 204 and the top of the second floor conversion section 203 are removed, the L-shaped angle steel 5 of the first floor conversion section 203 is pulled out, and the standard section 202 is placed in the preset direction by supporting the hanging rod 202a with a forklift to remove the first floor conversion section 203, the standard section 202 and the support beam conversion section 204;

[0149] S730, the second support beam is removed, after the second support beam is removed, the connecting steel plate 3 and the fastening assembly between the bottom of the second floor conversion section 203 and the top of the standard section 202 are removed, the L-shaped angle steel 5 of the second floor conversion section 203 is not pulled out, the hanging rod 202a is anchored on the top of the standard section 202, and the standard section 202 is placed in the preset direction by supporting the hanging rod 202a with a forklift to remove the second floor conversion section 203 and the standard section 202.

[0150] In the embodiment of the present application, as shown in Figure 19As shown, after all the support beams are removed, the steel lattice column structure is removed from top to bottom in sequence. First, the high-strength bolts 4 connecting the first floor slab conversion section 203 upper end and the connecting steel plate are removed, then the top fixing section 205 is removed, and then the high-strength bolts 4 connecting the first floor slab conversion section 203 lower end and the connecting steel plate 3 are removed. At this time, the L-shaped angle steel 5 of the first floor slab conversion section 203 is not pulled out, and is used as a support for the removal of the lower standard section 202 and the support beam conversion section 204. Then, the standard section 202 and the support beam conversion section 204 are removed as a whole. First, the suspension rod 202a is anchored at the upper end of the standard section 202, then the high-strength bolts 4 connecting the lower end of the support beam conversion section and the connecting steel plate 3 are removed, then the high-strength bolts 4 connecting the standard section 202 and the support beam conversion section and the floor slab conversion section 203 on the opposite side of the floor slab are removed, the L-shaped angle steel 5 of the first floor slab conversion section 203 is pulled out, the standard section 202 and the support beam conversion section 204 are placed in the preset direction by supporting the suspension rod 202a with a forklift, and the safe removal of the first floor slab conversion section 203, the standard section 202 and the support beam conversion section 204 is realized. In turn, until the lowermost standard section 202 is removed, the other sections except the permanent embedded section 201 can be removed without damage and reused. Compared with the traditional gas cutting steel lattice column structure removal construction method, the removal efficiency is high, and dangerous devices such as gas cutting are not needed, which greatly improves the safety of the removal of the steel lattice column structure.

[0151] In one embodiment, after the step of placing the standard section 202 and the floor slab conversion section 203 in the preset direction by supporting the suspension rod 202a with a forklift to remove the second floor slab conversion section 203 and the standard section 202 in step S730, the steps S731-S732 are further included.

[0152] S731, the bottom surface of the reserved post-cast hole 103a of the basement floor is leveled, the protruding part of the steel lattice column structure is cut off, the surface of the reserved post-cast hole 103a of the basement floor is roughened and cleaned, and then the repair concrete 103b of the basement floor is poured to fill the reserved post-cast hole 103a of the basement floor.

[0153] S732, a baffle is arranged below the post-cast hole of the steel lattice column structure penetrating the first basement floor and the second basement floor, repair cement mortar 102a is poured above the first basement floor and the second basement floor, and the post-cast hole of the first basement floor and the second basement floor is filled.

[0154] In the embodiments of the present application, as shown, Figure 20 the repair concrete 103b is poured on the basement floor, the repair cement mortar 102a is poured above the first basement floor, and the repair cement mortar 102a is poured above the second basement floor.

[0155] By filling the reserved post-cast hole of the basement floor 103, the post-cast hole of the first basement floor and the post-cast hole of the second basement floor, the integrity and stability of the basement structure can be ensured, and the basement structure damage or safety accident caused by the hole can be prevented.

[0156] In one embodiment, as shown in Figures 21-23 The first fixed plate 206a is vertically welded at one end of the bottom surface of the second fixed plate 206b, the stiffening rib 206c is vertically welded to the first fixed plate 206a and welded to the bottom surface of the second fixed plate 206b, and the support plate 206d is anchored to the top surface of the second fixed plate 206b. The first fixed plate 206a is detachably connected with the L-shaped angle steel 5, and the support beam 101 is supported on the support plate 206d.

[0157] More specifically, the first fixed plate 206a and the second fixed plate 206b are welded and connected at the short side, the stiffening rib 206c is welded to the second fixed plate 206b and is vertically welded and connected with the first fixed plate 206a; the support plate 206d is arranged above the second fixed plate 206b and is anchored and connected with the second fixed plate 206b through bolts; the third bolt hole 206e for anchoring the support plate 206d is arranged on the second fixed plate 206b at one side of the stiffening rib 206c, the fourth bolt hole 206g corresponding to the second fixed plate 206b is arranged on the support plate 206d, and the third bolt hole 206e for anchoring the support platform 206 on the support beam conversion joint 204 and the top fixed joint 205 is arranged on the first fixed plate 206a at the other side of the stiffening rib 206c; the third bolt hole 206e is provided with a third bolt hole reinforcing convex body 206f at one side of the stiffening rib 206c; the support plate 206d is provided with a buried nut buried hole 206h at the bolt hole.

[0158] In the embodiments of the present application, through the cooperation of the first fixed plate 206a, the second fixed plate 206b, the stiffening rib 206c and the support plate 206d, the support platform 206 installed on the top fixed joint 205 can support the first support beam 101, and the support platform installed on the support beam conversion joint 204 can support the second support beam 101.

[0159] The steel lattice column structure is divided into five types of standard segments, namely, a permanently buried section 201, a standard section 202, a floor conversion section 203, a support beam conversion section 204, and a top fixed section 205, according to the characteristics of the steel lattice column structure crossing the support beam 101, the floor 102, and the column pile 104. The high-strength bolts 4 are used to connect between the segments, and the connection nodes avoid the support beam 101, the floor 102, and the column pile 104. After the completion of the basement structure construction and the removal of the support beam 101, all the segments except the permanently buried section 201 can be removed without damage, greatly improving the reusability of the steel lattice column structure and effectively reducing the material cost. The floor conversion section 203 adopts a combination of four L-shaped angle steels and connecting steel plates, and the L-shaped angle steel 5 is wrapped with foam paper 207 at the floor. No hole needs to be reserved during floor pouring, and the steel lattice column structure is integrally poured with the floor. The overall compression and bending length of the steel lattice column structure will not be greatly increased due to the removal of the support beam, effectively avoiding the instability of the supporting structure caused by the increase of the compression and bending length in the traditional construction method or the increase of the cost caused by the selection of larger steel lattice column structure.

[0160] The bolt hole is provided with a reinforcing convex body, which can ensure that the bolt hole is designed according to the required bearing capacity, and ensure that the high-strength bolt 4 connection node between the segments has sufficient bearing capacity. In addition, the bearing capacity requirement of the high-strength bolt 4 connection node between the segments is 1.5 times or more than the vertical bearing capacity of the steel lattice column structure, and the high-strength bolt 4 connection node between the segments has sufficient strength and damage resistance, which can ensure that the high-strength bolt 4 connection node can be recycled for a sufficient number of times without failure, and can be reused multiple times. The sinking depth of the steel lattice column structure 2 adopts a long-distance laser positioning control method. The laser instrument is used to control the sinking depth of the steel lattice column structure in the foundation pit. Compared with the traditional theodolite control, the operation is more convenient, and the construction difficulty of the sinking depth control of the steel lattice column structure is greatly simplified.

[0161] The high-strength bolts 4 connecting the lower end of the floor conversion joint 203 and the steel plate are removed, at this time, the L-shaped angle steel of the floor conversion joint 203 is not pulled out, serving as a support for the removal of the lower standard joint 202 and the support beam conversion joint 204, then the standard joint 202 and the support beam conversion joint 204 are removed as a whole, the hanging rod 202a is anchored on the upper end of the standard joint 202, then the high-strength bolts 4 connecting the lower end of the support beam conversion joint and the steel plate are removed, then the high-strength bolts 4 connecting the floor conversion joint 203 and the steel plate on the upside of the floor conversion joint 203 are removed, the L-shaped angle steel 5 of the floor conversion joint 203 is pulled out, the standard joint 202 and the support beam conversion joint 204 are placed upside down in a predetermined direction by supporting the hanging rod 202a with a forklift, and the safe removal of the floor conversion joint 203, the standard joint 202 and the support beam conversion joint 204 is realized. Compared with the traditional gas cutting steel lattice column structure removal construction method, the application not only has high removal efficiency, but also does not need to use dangerous devices such as gas cutting, greatly improving the safety of the removal of the steel lattice column structure.

[0162] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences, modifications, replacements and variations of the embodiments, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A bolted steel lattice column for use in excavation support, characterized by: The basement is provided with the standard section (202) on each floor, the floor conversion section (203) is arranged on the floor (102) of each floor of the basement, the support beam conversion section (204) is arranged on the support beam (101) between the adjacent two floors of the basement, the standard section (202), the support beam conversion section (204) and the floor conversion section (203) between the adjacent two floors of the basement are sequentially detachably connected through the connecting steel plate (3) and the fastening assembly, the top fixed section (205) is arranged on the support beam (101) at the top of the basement, the top fixed section (205), the floor conversion section (203) of the top floor of the basement and the standard section (202) of the top floor of the basement are sequentially detachably connected through the connecting steel plate (3) and the fastening assembly, the permanent embedded section (201) is embedded on the column pile (104) of the basement, the permanent embedded section (201) and the standard section (202) of the bottom floor of the basement are detachably connected through the connecting steel plate (3) and the fastening assembly, the support platform (206) is arranged on the top fixed section (205) and the support beam conversion section (204), and the support beam (101) is supported on the corresponding support platform (206).

2. The bolted steel tubular sheeting pile of claim 1, wherein: The permanent embedded section (201), the standard section (202), the support beam conversion section (204), the floor conversion section (203) and the top fixed section (205) all comprise four L-shaped angle steels (5) arranged in pairs of symmetry, and the two adjacent L-shaped angle steels (5) in the permanent embedded section (201) and the standard section (202) are detachably connected through the added plate (6).

3. The bolted steel tubular sheeting pile of claim 2, wherein: The end of the L-shaped angle steel (5) is provided with a first connecting hole, the connecting steel plate (3) is provided with a second connecting hole, and the L-shaped angle steel (5) is detachably connected with the connecting steel plate (3) through the fastening assembly, the first connecting hole and the second connecting hole.

4. The construction method of the assembled steel latticed column for foundation pit support according to claim 2, characterized in that: The support platform (206) comprises a first fixed plate (206a), a second fixed plate (206b), a stiffening rib (206c) and a support plate (206d), one end of the first fixed plate (206a) is vertically welded to one end of the bottom surface of the second fixed plate (206b), the stiffening rib (206c) is vertically welded to the bottom surface of the second fixed plate (206b) and is vertically welded to the plate surface of the first fixed plate (206a), the support plate (206d) is anchored to the top surface of the second fixed plate (206b), the first fixed plate (206a) is detachably connected with the L-shaped angle steel (5), and the support beam (101) is supported on the support plate (206d).

5. A method of constructing a steel lattice column for a foundation pit support, characterized by, The method comprises the following steps: According to the structure of the basement, the number and length of each connecting assembly of the steel lattice column structure (2) are determined, each connecting assembly of the steel lattice column structure (2) is selected through finite element simulation, and then each connecting assembly of the steel lattice column structure (2) is spliced into the steel lattice column structure (2); After the column pile (104) of the basement is poured, the steel lattice column structure is sunk to make the lower end of the permanent embedded joint (201) embedded in the column pile (104), and the sinking depth of the steel lattice column structure is controlled by using a long-distance laser positioning control method; In the basement pit, the construction positions of the support beams (101) of each layer of the basement are excavated from top to bottom in sequence, and the soil pits (101b) for accommodating the support tables (206) are excavated at the bottom of the construction positions of the support beams (101) of each layer, the support tables (206) are installed on the top fixed joints (205) and the support beam conversion joints (204), and the foam paper (207) is wrapped outside the top fixed joints (205) and the support beam conversion joints (204), the support beams (101) of each layer are constructed from top to bottom in sequence, and the top of the top fixed joint (205) is embedded in the corresponding support beam (101), the support beam conversion joint (204) penetrates through the corresponding support beam (101), and the support table (206) supports the corresponding support beam (101); In the basement pit, the construction position of the basement bottom plate (103) is excavated, then the bottom plate (103) is constructed, and the reserved post-cast hole (103a) is arranged at the permanent embedded joint (201), and the connecting joint between the permanent embedded joint (201) and the standard joint (202) is exposed, so that the standard joint (202) above the permanent embedded joint (201) can be removed without damage in the later period; The foam paper (207) is wrapped on the floor conversion joint (203), the floors (102) of each layer of the basement are constructed from bottom to top in sequence at the construction position of the floor (102) below the support beam (101), and the floor conversion joint (203) penetrates through the corresponding floor (102), after the construction of each layer of the basement floor (102) is completed and the floor (102) concrete reaches the age strength, the basement support beam (101) is removed layer by layer, and the load of the support beam (101) is transferred to the floor (102); The connecting steel plate (3) and the fastening assembly between the top fixed joint (205) and the floor conversion joint (203) of the top layer of the basement are removed, then the top fixed joint (205) is removed, then the floor conversion joint (203), the standard joint (202) and the support beam conversion joint (204) of each layer of the basement are removed from top to bottom in sequence, and the reserved post-cast hole (103a) formed on the bottom plate (103) and the post-cast hole formed on the floor (102) after removal are repaired.

6. The construction method of the assembled steel lattice column for the foundation pit support according to claim 5, characterized in that, The long-distance laser positioning control method is used to control the sinking depth of the steel lattice column structure, which comprises the following steps: A laser instrument (701) and a fixed scale (703) are respectively erected on the opposite sides of the foundation pit area, the laser instrument (701) is erected on a pedestal (702) with known elevation, during the sinking process of the steel lattice column structure (2), the laser instrument (701) emits a horizontal laser line (704), the fixed scale (703) is used to calibrate the horizontal laser line (704) and determine the elevation of the horizontal laser line (704), according to the elevation of the horizontal laser line (704), the sinking depth of the steel lattice column structure (2) is controlled by moving the scale (705).

7. The construction method of the assembled steel lattice column for the foundation pit support according to claim 5, characterized in that, When the floor transfer joint (203), the standard joint (202) and the support beam transfer joint (204) of each floor of the basement are demolished, the following steps are included: The connecting steel plate (3) and the fastening assembly between the floor transfer joint (203) and the standard joint (202) are removed, the L-shaped angle steel (5) of the floor transfer joint (203) is not pulled out, the suspension rod (202a) is anchored on the top of the standard joint (202), then the connecting steel plate (3) and the fastening assembly at the lower end of the support beam transfer joint (204) are removed, then the L-shaped angle steel (5) of the floor transfer joint (203) is pulled out, and the standard joint (202) and the support beam transfer joint (204) are placed together in the preset direction by supporting the suspension rod (202a) with a forklift.

8. The construction method of the assembled steel lattice column for the foundation pit support according to claim 5, characterized in that, When the reserved post-cast hole (103a) formed on the bottom plate (103) and the post-cast hole formed on the floor (102) are repaired, the following steps are included: The bottom surface of the reserved post-cast hole (103a) on the flush floor is cut off, the protruding steel lattice column structure (2) is removed, the surface of the reserved post-cast hole (103a) on the floor is chiseled and cleaned, then the repair concrete (103b) is poured into the reserved post-cast hole (103a) on the floor, and the reserved post-cast hole (103a) on the floor is filled flat; A baffle is arranged at the bottom of the post-cast hole on the floor (102), then the repair cement mortar (102a) is poured into the post-cast hole on the floor (102), and the post-cast hole on the floor (102) is filled flat.

Images