Urban river channel steel dam construction diversion canal foundation pit supporting system

Abstract

The utility model discloses a diversion canal foundation pit supporting system for urban river channel steel dam construction. The problems that in the prior art, a diversion canal supporting mode is complex, a foundation pit is deep, the distance is large, and cost is high are solved. The urban river channel steel dam construction diversion canal foundation pit supporting system comprises a diversion supporting structure, an opposite-pulling structure and a slope protection structure, the supporting structure comprises a plurality of steel sheet piles and steel pipe piles, and the steel sheet piles are close to one side of a steel dam and are arranged in the extension direction of a diversion canal. The steel pipe piles are sequentially arranged on the outer side slope of the diversion canal in the extension direction of the diversion canal, the opposite-pull structures are connected to the steel pipe piles and the corresponding steel sheet piles, the slope protection structure comprises a reinforcing mesh arranged on the slope surface of the diversion canal, and the reinforcing mesh is fixed through anchor rods. According to the supporting system, the steel sheet piles and the steel pipe piles are combined, and on the premise that the supporting problem in the process of manufacturing the diversion canal in steel dam construction is solved, the water retaining property, the seepage-proofing performance and the rigidity of the supporting structure can be improved, and the cost can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of steel dam foundation pit support and diversion construction, in particular to a diversion channel foundation pit support system for steel dam construction of urban rivers. Background Art

[0002] Steel dams can achieve rapid switching between discharge and water storage functions through rapid opening and closing operations. They not only meet the requirements of landscape ecological water level interception in urban rivers during the non-flood season, but also do not affect the flood discharge requirements of rivers during the flood season. At the same time, they have beautiful shapes and adapt to the surrounding urban environment. They have been widely used in urban rivers in recent years.

[0003] During the construction of urban river steel dams, due to the deep excavation of foundation pits and diversion channels, the use of slope excavation technology has the following disadvantages: 1. The foundation pits and diversion channels are deep, the excavation size is large, and the cost of earth transportation is high; 2. The large excavation depth makes precipitation difficult, and precipitation can easily cause over-exploitation of groundwater and subsidence of the surrounding ground, posing a great safety hazard; 3. Construction sites in urban areas are limited, and many places do not have the site conditions for full slope excavation. Utility Model Content

[0004] In view of the deficiencies in the above-mentioned background technology, the utility model proposes a diversion channel foundation pit support system for urban river steel dam construction, which solves the problems in the prior art of conventional slope excavation due to the deep foundation pit and large excavation distance, great safety hazards, high costs, and limited construction sites in some urban areas, which do not have the site conditions for all slope excavation.

[0005] The technical solution of the utility model is achieved in this way:

[0006] A diversion channel foundation pit support system for steel dam construction in an urban river includes a diversion support structure, a tension structure and a slope protection structure. The support structure includes a plurality of steel sheet piles and steel pipe piles. The steel pipe piles have high rigidity, low cost and are easy to construct. The steel sheet piles are arranged on one side of the steel dam and along the extension direction of the diversion channel. The steel pipe piles are arranged on the outer side slope of the diversion channel in sequence along the extension direction of the diversion channel. The steel sheet piles and steel pipe piles are arranged on both sides of the diversion channel relatively to facilitate the arrangement of the tension structure. Because the steel sheet piles are supported by the diversion channel, the exposed length is too long and the lateral pressure is too large. Therefore, the steel pipe piles are used to ensure the force balance. The tension structure is connected to the steel pipe piles and the corresponding steel sheet piles, which strengthens the balance and stability of the support structure. The slope protection structure includes a steel mesh arranged on the slope of the diversion channel. The steel mesh is fixed by anchor rods. The anchor rods ensure the stability of the slope body, and the steel mesh prevents the slope from sliding.

[0007] Furthermore, the tension structure includes a tie rod and a cross beam, and the cross beam is respectively arranged on the outside of the top of the steel sheet pile and the outside of the top of the steel pipe pile, the space between the steel sheet pile and the steel pipe pile is the inner side of the diversion channel, and the direction away from the diversion channel on the steel sheet pile and the steel pipe pile is the outer side. The cross beam connects all the steel sheet piles or steel pipe piles into a whole. When the tension structure is set, the whole is stressed and the force is balanced, which improves the anti-extrusion and bearing capacity of the support structure. The two ends of the tie rod pass through the steel sheet pile and the steel pipe pile respectively and are fixedly connected to the corresponding cross beam to form a tension, thereby ensuring the stability and balance of the support structure.

[0008] Furthermore, the crossbeam includes a triangular bracket, a double I-beam and a steel pad, the triangular bracket is provided with a double I-beam, the double I-beam supports the support structure to form a whole, and improves the supporting force of the support structure. The outer side of the double I-beam is connected by a steel pad, which is used to fix the double I-beam and strengthen the support of the double I-beam.

[0009] Furthermore, the double I-beam includes an I-beam I and an I-beam II arranged in parallel, and the I-beam I is arranged above the I-beam II, which strengthens the bearing capacity of the crossbeam. The reserved gap between the I-beam I and the I-beam II forms a channel for the tie rod to pass through, which facilitates the tie rod to pass through the crossbeam and strengthens the fastening effect of the tie rod on the double I-beam.

[0010] Furthermore, the tie rod passes through the steel pad through the channel, and a double nut is provided on the outer side of the steel pad, and the double nut is threadedly connected with the tie rod. The tie rod tightens the steel pad through the double nut, thereby fixing the double-jointed I-beam. This is conducive to the crossbeam supporting and bearing the steel sheet pile and the steel pipe pile. The anti-extrusion and bearing capacity of the supporting structure are enhanced.

[0011] Furthermore, the pull rod is a threaded steel bar, and an external thread is provided at the end of the threaded steel bar, which facilitates the threaded connection between the double nut and the pull rod, thereby improving the tightening effect of the pull rod.

[0012] Furthermore, the triangular bracket is welded or bolted to the steel pipe piles and the corresponding steel sheet piles, which is beneficial to the installation of the cross beam and convenient for construction.

[0013] Furthermore, in the support structure, the steel pipe piles are arranged in groups of two, and each group is driven at a certain distance and at the same height as the steel sheet piles. According to calculations, the steel pipe piles are driven at a certain distance to achieve the balance of the lateral force of the steel sheet piles.

[0014] Furthermore, the steel sheet piles are Larsen steel sheet piles, which further improves the anti-seepage performance and strengthens the supporting capacity of the supporting structure.

[0015] Furthermore, an anti-seepage geotextile is laid at the bottom of the diversion channel, and a bottom protection concrete layer is poured on the anti-seepage geotextile to prevent the open channel river water from seeping into the steel dam foundation pit and affecting the steel dam structure construction.

[0016] The beneficial effects of the utility model are as follows: the support system involved in the utility model combines steel sheet piles and steel pipe piles, and adopts a slope excavation method. On the premise of solving the support problem in the diversion channel during steel dam construction, it can not only improve the water-retaining property, anti-seepage performance and rigidity of the support structure, but also reduce costs, which is more economical and reasonable, and the construction progress is faster. By setting a support structure, steel sheet piles and steel pipe piles are combined, the excavation distance of the diversion channel foundation pit is reduced, safety is improved, and costs are reduced. By setting a tension structure, the steel sheet piles and steel pipe piles are subjected to overall force, the balance and stability of the support structure are enhanced, and the slope distance is reduced. By setting a slope protection structure, the slope body is strengthened to prevent the slope from sliding. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0019] Figure 2 This is a schematic diagram of the beam structure of the utility model;

[0020] 1. Steel sheet piles; 2. Steel pipe piles; 3. Pull rods; 4. Waist beams; 401. Triangular brackets; 402. Steel pads; 403. I-beams Ⅰ; 404. I-beams Ⅱ; 5. Double nuts; 6. Steel mesh; 7. Anchor rods; 8. Bottom concrete layer; 9. Anti-seepage geotextile. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0022] Embodiment 1, as Figure 1As shown, in this embodiment, a foundation pit support system for diversion channel of urban river steel dam construction includes a diversion support structure, a tension structure and a slope protection structure. The support structure includes a plurality of steel sheet piles 1 and steel pipe piles 2. The steel pipe piles 2 have high rigidity, low cost and are easy to construct. The steel sheet piles 1 are arranged on one side of the steel dam and along the extension direction of the diversion channel. The steel sheet piles 1 are constructed by a crawler crane equipped with a vibrating hammer to insert and drive the steel sheet piles one by one. The verticality of each steel sheet pile 1 should be always controlled with a hammer ball and adjusted in time. The adjustment tools mainly include jacks, wooden wedges, etc. During the insertion and driving process, the construction points of "inserting piles straight, correcting them when dispersed, and adjusting and closing them" should be observed. The steel pipe piles 2 are arranged on the outer slope of the diversion channel in sequence along the extension direction of the diversion channel, and are constructed by crawler cranes and vibrating hammers. After the steel pipe piles 2 enter the soil layer under their own gravity and the vibrating hammer, the plane position of the steel pipe piles 2 is re-measured and set. After meeting the requirements, the vibrating hammer is started to vibrate the steel pipe piles 2 into the soil. The steel sheet piles 1 and the steel pipe piles 2 are arranged on both sides of the diversion channel to facilitate the setting of the tension structure. Because the steel sheet piles 1 are too exposed due to the diversion channel support, the lateral pressure is too large, so the steel pipe piles 2 are used to ensure the force balance. The tension structure is connected to the steel pipe piles 2 and the corresponding steel sheet piles 1, which enhances the balance and stability of the support structure. The slope protection structure includes a steel mesh 6 arranged on the slope of the diversion channel. The steel mesh 6 is fixed by anchor rods 7. The anchor rods 7 ensure the stability of the slope, and the steel mesh 6 prevents the slope from sliding.

[0023] Specifically, the outside of the diversion channel is sloped with a slope of 1:1, and the slope surface is sprayed with mesh. The concrete strength grade is C20, the thickness is 80mm, and the steel mesh 6 is made of 8mm diameter round steel with a spacing of 200×200mm. The anchor rod 7 is arranged in a plum blossom shape with a length of 1000mm and a diameter of 14mm for the third-grade threaded steel to fix the steel mesh 6. After the diversion channel is sloped, the steel mesh 6 is immediately sprayed with concrete to prevent the slope from being exposed to rain or freezing. The mesh spray protection is applied layer by layer from top to bottom, and the slope surface is set with a diameter of 8cm. The drainage holes are arranged in a plum blossom shape with a spacing of 2m.

[0024] On the basis of the above-mentioned embodiment, as a preferred embodiment, the tension structure includes a tie rod 3 and a cross beam 4, and the cross beam 4 is respectively arranged on the outer side of the top of the steel sheet pile 1 and the outer side of the top of the steel pipe pile 2, the space between the steel sheet pile 1 and the steel pipe pile 2 is the inner side of the diversion channel, and the direction away from the diversion channel on the steel sheet pile 1 and the steel pipe pile 2 is the outer side. The cross beam 4 connects all the steel sheet piles 1 or steel pipe piles 2 into a whole, and the whole is stressed and balanced during tension, which improves the anti-extrusion and bearing capacity of the support structure. The two ends of the tie rod 3 respectively penetrate the steel sheet pile 1 and the steel pipe pile 2 and are fixedly connected to the corresponding cross beam 4 to form a tension, thereby ensuring the stability and balance of the support structure.

[0025] Based on the above implementation, as a preferred implementation, Figure 2As shown, the crossbeam 4 includes a triangular bracket 401, a double-jointed I-beam and a steel pad 402. The triangular bracket 401 is welded with channel steel, and a double-jointed I-beam is arranged on the triangular bracket 401. Before installing the double-jointed I-beam, the triangular bracket 401 is welded on the outer wall of the steel sheet pile 1 according to the determined elevation position. When installing the triangular bracket 401, measures must be taken to ensure that the top surfaces of all triangular brackets 401 are located on the same horizontal plane. The double-jointed I-beam supports the supporting structure to form a whole, thereby improving the supporting force of the supporting structure. The outer side of the double-jointed I-beam is connected by a 2 cm thick steel pad 402, which is used to fix the double-jointed I-beam and strengthen the support of the double-jointed I-beam.

[0026] Based on the above implementation, as a preferred implementation, Figure 2 As shown, the double-jointed I-beam includes an I-beam Ⅰ403 and an I-beam Ⅱ404 arranged in parallel, and both the I-beam Ⅰ403 and the I-beam Ⅱ404 are 2I40 I-beams. The I-beam Ⅰ403 is arranged above the I-beam Ⅱ404, which strengthens the bearing capacity of the crossbeam 4. The reserved gap between the I-beam Ⅰ403 and the I-beam Ⅱ404 forms a channel for the tie rod 3 to pass through, and the tie rod 3 passes through the channel, which facilitates the tie rod 3 to penetrate the crossbeam 4, thereby strengthening the fastening effect of the tie rod 3 on the double-jointed I-beam.

[0027] Based on the above implementation, as a preferred implementation, Figure 2 As shown, the tie rod 3 passes through the steel pad 402 through the channel, and a double nut 5 is provided on the outer side of the steel pad 402, and the double nut 5 is threadedly connected with the tie rod 3. The tie rod 3 tightens the steel pad 402 through the double nut, thereby fixing the double-jointed I-beam. This is beneficial for the crossbeam 4 to support and carry the steel sheet pile 1 and the steel pipe pile 2. The anti-extrusion and bearing capacity of the supporting structure are enhanced.

[0028] On the basis of the above-mentioned embodiment, as a preferred embodiment, the tie rod 3 is a 32 mm finely rolled threaded steel bar, and the end of the threaded steel bar is provided with an external thread, which facilitates the threaded connection between the double nut 5 and the tie rod 3. The double nut 5 is tightened with a wrench before excavation, thereby improving the tightening effect of the tie rod 3.

[0029] On the basis of the above implementation, as a preferred implementation, in order to prevent excessive pressure during the excavation of the dam body from affecting the construction safety in the cofferdam, two steel pipe piles 2 are driven side by side every 3m on the outer slope of the diversion channel, with the same height as the steel sheet piles 1. The total length of the steel pipe piles 2 is 16.8m, and the anchor depth in the soil is 15m. According to calculations, the steel pipe piles 2 are driven at intervals of 3m to achieve the lateral force balance of the steel sheet piles 1.

[0030] Example 2 is further optimized on the basis of Example 1. In this example, in order to prevent the open channel river water from infiltrating into the steel dam foundation pit and affecting the steel dam structure construction. An impermeable geotextile 9 is laid at the bottom of the diversion channel, and a 10 cm thick C20 concrete is poured on the geotextile. After the excavation is completed, the impermeable geotextile 9 is laid. When laying the impermeable geotextile 9, it is important to ensure that the longitudinal overlap is not less than 1m long. Construct the concrete cushion layer according to the design requirements within the specified time, pour in sections, strictly control the top surface elevation during construction, and compact it with a flat vibrator to ensure a smooth and clean surface without honeycomb cracks.

[0031] Embodiment 3 is further optimized on the basis of embodiment 1. In this embodiment, the steel sheet pile 1 is a Larsen IV type water-stop steel pad, which further improves the anti-seepage performance and strengthens the support capacity of the support structure.

[0032] Embodiment 4 is further optimized on the basis of embodiment 1. In this embodiment, the triangular bracket 401 is bolted to the steel pipe pile 2 and the corresponding steel sheet pile 1, which is beneficial to the installation of the cross beam 4 and convenient for construction.

[0033] The specific construction of the diversion channel foundation pit support system for urban river steel dam construction is as follows:

[0034] 1. Excavation of diversion channel slope

[0035] The first diversion channel was excavated to the design flood level in the non-flood season (91.0m) to provide a construction working surface for the steel sheet piles 1 and steel pipe piles 2 inside the diversion open channel.

[0036] The diversion channel earthwork excavation is carried out in a vertical section, horizontal layer, and full section excavation from top to bottom. Each layer of drainage ditch is always 3m deep ahead of the excavated soil layer to ensure water-free earthwork excavation. The earthwork excavation is carried out in layers and sections from top to bottom, and the excavation layer is controlled at 3.0m. For the same section and the same excavation layer, the excavation is carried out from the middle to both sides of the diversion channel. The earthwork excavation is carried out by excavator, the layer thickness does not exceed 3m, and it is transported by 15-20t dump trucks.

[0037] Diversion channel slope protection

[0038] The slopes of the diversion channel are all protected by mesh spraying, with a concrete strength grade of C20 and a thickness of 80mm. The steel mesh 6 is made of 8mm diameter round steel with a spacing of 200×200mm. The anchor rod 7 is a three-level threaded steel with a length of 1000mm and a diameter of 14mm arranged in a plum blossom shape to fix the steel mesh. After the diversion channel is brushed, the steel mesh spraying concrete protection is immediately carried out to prevent the slope from being exposed to rain or freezing. The mesh spraying protection is applied layer by layer from top to bottom. The slope surface is set with a diameter of 8cm. The drainage holes are arranged in a plum blossom shape with a spacing of 2m.

[0039] Steel sheet pile construction inside diversion channel

[0040] The construction of steel sheet pile 1 adopts the construction scheme of inserting and driving one by one with crawler crane and vibrating hammer. In order to ensure the accurate insertion and driving of each steel sheet pile 1, the position of the first steel sheet pile 1 is selected at the center of the horizontal bridge. Before inserting and driving, a limit frame is set on the upper and lower sides of the guide frame, and the size is 1cm larger than each side of the steel sheet pile 1. When inserting and driving, the back of the steel sheet pile 1 is close to the guide frame, and the hook is slowly lowered while inserting. At this time, the instrument (total station) is used to observe in two mutually perpendicular directions to ensure that the steel sheet pile 1 is inserted and inserted straight. After the first steel sheet pile 1 is determined to be qualified through testing, the steel sheet pile 1 is inserted symmetrically on both sides based on the first steel sheet pile 1. During the entire steel sheet pile 1 construction process, each steel sheet pile 1 is inserted and driven to the designed position at the beginning. During the entire construction process, the verticality of each steel sheet pile 1 should be always controlled with a hammer ball, and timely adjusted. The adjustment tools mainly include jacks, wooden wedges, guide chains, etc. During the driving process, the key construction points of "inserting piles straight, correcting them when scattered, and adjusting and closing them" must be observed.

[0041] Steel pipe pile construction

[0042] Positioning is performed based on the center plane coordinates of the steel pipe pile 2 calculated before construction. Crawler cranes and vibratory hammers are used for construction. After the steel pipe pile 2 enters the soil layer under its own gravity and the vibratory hammer, the plane position of the steel pipe pile 2 is re-measured and set. When the requirements are met, the vibratory hammer is started to vibrate the steel pipe pile 2 in. During the vibration pile sinking process, technicians use a total station and a hammer ball to observe the verticality of the pipe pile in the longitudinal and transverse directions, and direct the crawler crane to swing back and forth and left and right to adjust the verticality of the steel pipe pile 2. When the steel pipe pile 2 enters the soil 2 to 3 meters, and its plane position and verticality basically do not change, the hook can be released to allow the steel pipe pile 2 to continue to be vibrated in under the action of the vibratory hammer. When the top of the first section of the steel pipe pile 2 is about 1.5 meters above the ground, stop vibrating and remove the vibratory hammer to extend the steel pipe pile 2.

[0043] Fence construction

[0044] After the construction of the steel sheet pile 1 is completed, a support is installed 0.5m below the top of the steel sheet pile 1 to prevent excessive pressure during the excavation of the dam body from affecting the construction safety in the cofferdam. Two steel pipe piles 2 are set side by side every 3m on the outer slope of the diversion channel. The steel pipe pile 2 is a 630 steel pipe with the same height as the steel sheet pile 1. The total length of the steel pipe pile 2 is 16.8m, and the depth of the anchor in the soil is 15m. A triangular bracket 401 is welded on the outside of the steel pipe pile 2. The bracket is made of channel steel. The double-piece I-beam is installed on the triangular bracket 401. The double-piece I-beam is 2I40 I-beam. Before installing the double-piece I-beam, the triangular bracket is welded on the outer wall of the steel sheet pile 1 according to the determined elevation position. When installing the triangular bracket 401, measures must be taken to ensure that the top surface is on the same horizontal plane. Then install the double-piece I-beam. The tie rod 3 is a 32mm fine-rolled threaded steel. One end of the tie rod 3 is fixed to the outside of the double-piece I-beam, and one end of the tie rod 3 is fixed to the outside of the steel pipe pile. Install a 2 cm thick steel plate on the tie rod 3 on the outside of the double I-beam on the steel pipe pile 2, and then install the double nut 5. Use a wrench to tighten the double nut 5 before excavation.

[0045] Diversion channel base construction

[0046] In order to prevent the water from the diversion channel from seeping into the foundation pit of the steel dam and affecting the construction of the steel dam structure. An impermeable geotextile 9 is laid at the bottom of the diversion channel, and 10cm thick C20 concrete is poured on the geotextile. After the excavation is completed, the impermeable geotextile 9 is laid. When laying the impermeable geotextile 9, pay attention to the longitudinal overlap of not less than 1m. Construct the concrete cushion layer 8 according to the design requirements within the specified time, pour in sections, strictly control the top surface elevation during construction, and compact it with a flat vibrator to ensure that the surface is smooth and clean without honeycomb cracks.

[0047] Foundation pit excavation

[0048] The excavation of the foundation pit adopts a combination of mechanical excavation and manual finishing. The excavation elevation should be strictly controlled, and the excavation depth of each layer should be controlled to 2-2.5m. Mechanical excavation uses a backhoe excavator. Parts that cannot be excavated by the local excavator can be excavated manually. When the elevation is about 30cm from the bottom of the pit, manual slope repair and flat bottom should be used to prevent disturbance of the base soil layer.

[0049] Removal of enclosures, steel sheet piles and steel pipe piles

[0050] When pulling out the steel sheet pile 1, first clamp the head of the steel sheet pile 1 with a vibrating hammer and vibrate it for 1 to 2 minutes to loosen the soil around the steel sheet pile 1 and produce "liquefaction" to reduce the friction of the soil on the pile. Then slowly vibrate and pull it upwards. Pay attention to the load of the pile driver when pulling out the pile. If it is difficult or impossible to pull it out, stop pulling the pile. You can first inject a little downwards and then pull it up. Repeat this process until the pile is pulled out (the removal of the steel pipe pile 2 is similar). Attention should be paid to the following during the removal work:

[0051] The removal of the steel sheet pile 1 is carried out in the opposite manner to the insertion and driving construction procedure. After the earthwork is backfilled, the upper support is removed.

[0052] The steel sheet pile 1 is first removed from the downstream direction and then symmetrically removed to the upstream direction, using a vibrating hammer and a crane. During the removal process, attention must be paid to construction safety at all times.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A diversion channel foundation pit support system for urban river steel dam construction, characterized by: The invention comprises a diversion support structure, a tension structure and a slope protection structure. The support structure comprises a plurality of steel sheet piles (1) and steel pipe piles (2). The steel sheet piles (1) are arranged on one side of a steel dam and along the extension direction of a diversion channel. The steel pipe piles (2) are arranged in sequence on the outer side slope of the diversion channel along the extension direction of the diversion channel. The tension structure is connected to the steel pipe piles (2) and the corresponding steel sheet piles (1). The slope protection structure comprises a steel mesh (6) arranged on the slope surface of the diversion channel. The steel mesh (6) is fixed by anchor rods (7).

2. The diversion channel foundation pit support system for urban river steel dam construction according to claim 1 is characterized by: The tension structure comprises a tension rod (3) and a cross beam (4), wherein the cross beam (4) is respectively arranged on the outside of the top of the steel sheet pile (1) and the outside of the top of the steel pipe pile (2), and the two ends of the tension rod (3) respectively penetrate the steel sheet pile (1) and the steel pipe pile (2) and are fixedly connected to the corresponding cross beam (4).

3. The diversion channel foundation pit support system for urban river steel dam construction according to claim 2 is characterized by: The crossbeam (4) comprises a triangular bracket (401), a double-jointed I-beam and a steel backing plate (402); the triangular bracket (401) is provided with a double-jointed I-beam, and the outer sides of the double-jointed I-beam are connected via the steel backing plate (402).

4. The diversion channel foundation pit support system for urban river steel dam construction according to claim 3 is characterized by: The double I-beam comprises an I-beam I (403) and an I-beam II (404) arranged in parallel, the I-beam I (403) being arranged above the I-beam II (404), and a gap reserved between the I-beam I (403) and the I-beam II (404) forming a channel for the pull rod (3) to pass through.

5. The diversion channel foundation pit support system for urban river steel dam construction according to claim 4 is characterized by: The pull rod (3) passes through the steel backing plate (402) through a channel, and a double nut (5) is provided on the outer side of the steel backing plate (402), and the double nut (5) is threadedly connected to the pull rod (3).

6. The diversion channel foundation pit support system for urban river steel dam construction according to claim 5 is characterized by: The pull rod (3) is a threaded steel bar, and the end of the threaded steel bar is provided with an external thread.

7. The diversion channel foundation pit support system for urban river steel dam construction according to claim 3 is characterized by: The triangular bracket (401) is welded or bolted to the steel pipe pile (2) and the corresponding steel sheet pile (1).

8. The diversion channel foundation pit support system for urban river steel dam construction according to claim 1 is characterized by: In the support structure, two steel pipe piles (2) form a group, and each group is driven at a certain distance and has the same height as the steel sheet piles (1).

9. The diversion channel foundation pit support system for urban river steel dam construction according to claim 1 is characterized by: The steel sheet piles (1) are Larsen steel sheet piles.

10. The diversion channel foundation pit support system for urban river steel dam construction according to claim 1 is characterized by: An anti-seepage geotextile (9) is laid on the base of the diversion channel, and a bottom protection concrete layer (8) is poured on the anti-seepage geotextile (9).

Images