Steel dam deep foundation pit supporting system of urban river close to existing gas pipeline

Abstract

The utility model discloses a deep foundation pit supporting system of an urban river channel steel dam close to an existing gas pipeline, which comprises a supporting structure, a waist beam and a side slope protection structure, the supporting structure comprises a plurality of steel pipe piles and anchor rods, and the steel pipe piles are arranged at certain intervals along the extension direction of a foundation pit. The anchor rods are arranged at the interval of every two adjacent steel pipe piles in the extending direction of the foundation pit, and the waist beams are arranged on the steel pipe piles and connected with the anchor rods at the same height. The slope protection structure comprises a reinforcing mesh arranged on the slope surface of the slope, and the reinforcing mesh is fixed through positioning ribs. And a concrete layer is poured on the reinforcing mesh. According to the supporting structure, the steel pipe piles and the anchor rods are combined, the steel pipe piles and the anchor rods are connected into a whole through the arrangement of the waist beams, the whole supporting structure is stressed in a balanced mode, and the extrusion resistance and the bearing capacity of the supporting structure are improved. The slope surface is prevented from sliding off by arranging the reinforcing mesh, and construction safety is guaranteed. By pouring the concrete layer, collapse caused by rainwater due to the fact that the excavation face is exposed for a long time is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of water conservancy foundation pit construction, in particular to a deep foundation pit support system for a steel dam in an urban river channel close to an existing gas pipeline. Background Art

[0002] In the city center, the site is often small, the distance between adjacent buildings is close, and various underground pipelines are intricate. The excavation of deep foundation pits must ensure the safety of surrounding buildings (pipelines) and meet the normal construction of the project. During the construction process, we summarized a construction method of steel pipe piles and anchor rods.

[0003] During the excavation of deep foundation pits, the pit wall cannot maintain its own stability and cannot form a supporting working surface. Slope excavation or steel sheet pile support technology is usually used during foundation pit excavation construction.

[0004] The following disadvantages exist when using slope excavation technology for deep foundation pits: 1. The presence of pipelines in the surrounding area can easily cause stress deformation and settlement of the pipelines, affecting their service life and safety; 2. Slope excavation requires temporary reinforcement and protection measures for surrounding pipelines, increasing construction costs; 3. The amount of backfill is large, and landslides are prone to occur due to soaking in the rainy season; 4. It has a greater impact on the surrounding environment (buildings).

[0005] There are the following disadvantages when using steel sheet pile support construction technology for deep foundation pits: 1. Steel sheet pile support for deep foundation pits requires support; 2. The river channel of water conservancy projects is generally wide, and the support length is long when using counter-bracing measures, and measures such as lattice columns need to be added in the middle, which is expensive; 3. Too long support can easily lead to excessive deformation, affecting the safety and stability of the foundation pit. Utility Model Content

[0006] In view of the deficiencies in the above-mentioned background technology, the utility model proposes a deep foundation pit support system for a steel dam in an urban river near an existing gas pipeline, which solves the problems in the prior art that the steel dam foundation pit is generally deep and the river channel is generally wide, the support length is long using counter-bracing measures, and lattice columns need to be added in the middle, which is expensive. At the same time, temporary reinforcement measures for the gas sub-high pressure pipeline are also required, the construction cost is high, and there are safety hazards in the excavation of the gas sub-high pressure pipeline.

[0007] The technical solution of the utility model is achieved in this way:

[0008] A deep foundation pit support system for a steel dam in a city river near an existing gas pipeline includes a support structure, a waist beam and a slope protection structure. The support structure includes a plurality of steel pipe piles and anchor rods. The steel pipe piles are arranged at a certain distance along the extension direction of the foundation pit. The anchor rods are arranged at the interval between two adjacent steel pipe piles along the extension direction of the foundation pit. The waist beam is arranged on the steel pipe piles and connected to the anchor rods at the same height. The slope protection structure includes a steel mesh arranged on the slope surface, and the steel mesh is fixed by positioning bars. A concrete layer is poured on the steel mesh. The support structure combines steel pipe piles and anchor rods, and utilizes the advantage of the large rigidity of the steel pipe pile structure itself. The anchor rods replace the support, simplifying the construction process and accelerating the construction progress. The steel pipe piles and anchor rods are connected as a whole by the setting of the waist beam, so that the support structure is stressed as a whole and the stress is balanced, thereby improving the anti-extrusion and bearing capacity of the support structure. The steel mesh is arranged to prevent the slope surface from sliding and ensure construction safety. By pouring the concrete layer, the excavation surface is prevented from being exposed for too long and collapsing due to the influence of rainwater.

[0009] Furthermore, the anchor rods are inserted into the foundation pit soil at an angle of 15° to reinforce the support for the side walls of the foundation pit, ensure the stability of the soil, and improve the supporting capacity of the support structure.

[0010] Furthermore, the waist beam includes a triangular bracket, a double I-beam and a steel pad. The triangular bracket is arranged on the upper part of the steel pipe pile and close to the inner side of the foundation pit. The double I-beam is arranged on the triangular bracket through a wedge block, and the double I-beam spans at least two steel pipe piles. The wedge block is fixedly connected to the upper part of the triangular bracket. The double I-beam is parallel to the inclined anchor rod through the setting of the wedge block, thereby strengthening the supporting force of the double I-beam on the supporting structure. A steel pad spanning at least two steel pipe piles is provided on the outer side of the double I-beam, which is used to fix the double I-beam and strengthen the support of the double I-beam. Specifically, the double I-beam and the steel pad can be spliced ​​in multiple sections so that they span all the steel pipe piles along the extension direction of the foundation pit.

[0011] Furthermore, the double-jointed I-beam includes an I-beam I and an I-beam II, and the I-beam I is arranged above the I-beam II, thereby enhancing the bearing capacity of the waist beam. The reserved gap between the I-beam I and the I-beam II forms a channel for the anchor rod to pass through, which facilitates the anchor rod to pass through the double-jointed I-beam and enhances the anchor rod's fastening effect on the double-jointed I-beam.

[0012] Furthermore, the double-jointed I-beam and the steel plate cross the steel pipe pile and are connected to the anchor rod. The anchor rod penetrates the steel plate through the channel of the double-jointed I-beam. Double nuts are provided on the outer side of the steel plate corresponding to the anchor rod. The anchor rod is threadedly connected to the double nuts. The anchor rod tightens the steel plate through the double nuts to fix the double-jointed I-beam. This is beneficial for the waist beam to support and carry the steel pipe pile. The anti-extrusion and bearing capacity of the support structure are enhanced.

[0013] Furthermore, the anchor rod is a HRB400 steel bar, and the end of the steel bar is provided with an external thread, which facilitates the threaded connection between the double nut and the anchor rod, thereby improving the stabilizing effect of the anchor rod on the steel pipe pile.

[0014] Furthermore, the triangular bracket is welded or bolted to the inner side wall of the steel pipe pile, which is conducive to the installation of the waist beam and convenient for construction. The wedge block is a right-angled triangle structure with a vertex angle of 15°, which is the same as the inclination angle of the anchor rod, so that the double-jointed I-beam is arranged parallel to the anchor rod, which strengthens the fastening effect of the anchor rod on the double-jointed I-beam and improves the bearing capacity of the waist beam on the supporting structure.

[0015] Furthermore, the steel pipe piles are 630×10 mm spiral pipes. According to calculations, the steel pipe piles can be inserted below the slope at intervals of 80 cm to meet the slope support requirements. The intervals can be adjusted according to different foundation pit depths, which simplifies the construction process and speeds up the construction progress.

[0016] Furthermore, drainage holes are provided on the slope surface of the side slope, and the drainage holes are spaced at a certain distance and arranged in a plum blossom shape to prevent water from accumulating on the side slope and affecting the construction.

[0017] Furthermore, the steel pipe piles are arranged in rows, and a steel pipe pile construction platform is constructed between the lower side slope and the steel pipe pile row. The steel pipe pile construction platform is arranged between the lower side slope and the steel pipe pile row along the extension direction of the foundation pit. The steel pipe piles are driven in through the steel pipe pile construction platform, which facilitates the construction and speeds up the construction progress.

[0018] The beneficial effects of the utility model are:

[0019] The utility model adopts a support system of "steel pipe pile support + anchor rod" in the upper part and a support system of "steel pipe pile support + anchor rod" in the lower part. This support system reduces the distance of slope excavation and avoids the gas pipeline from being exposed to the outside world. Compared with traditional slope excavation and steel sheet pile support, it reduces the construction safety risk and achieves good economic and social benefits. The support structure combines steel pipe piles and anchor rods. The steel pipe pile structure itself has the advantage of high rigidity. Anchor rods replace supports, which reduces construction costs, simplifies construction technology, and speeds up construction progress. The steel pipe piles and anchor rods are connected as a whole by the setting of waist beams, so that the support structure is stressed as a whole and the force is balanced, which improves the anti-extrusion and bearing capacity of the support structure. The steel mesh is set to prevent the slope surface from sliding and ensure construction safety. By pouring a concrete layer, the excavation surface is prevented from being exposed for too long and causing collapse due to rain. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1 It is a side structural schematic diagram of the utility model;

[0022] Figure 2 This is a schematic diagram of the waist beam structure of the utility model;

[0023] 1. Steel pipe piles; 2. Anchor rods; 3. Waist beams; 301. Triangular brackets; 302. Wedge blocks; 303. I-beams I; 304. I-beams II; 305. Steel pads; 4. Steel mesh; 5. Positioning ribs; 6. Double nuts; 7. Concrete layer; 8. Steel pipe pile construction platform. DETAILED DESCRIPTION

[0024] 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.

[0025] Embodiment 1, as Figure 1 As shown, in this embodiment, a deep foundation pit support system of a steel dam in an urban river near an existing gas pipeline includes a support structure, a waist beam 3 and a slope protection structure. The support structure includes a plurality of steel pipe piles 1 and anchor rods 2. The steel pipe piles 1 are 630×10mm spiral pipes. The steel pipe piles 1 are inserted below the slope at intervals of 80cm along the extension direction of the foundation pit. Anchor rods are drilled between two adjacent steel pipe piles 1. The anchor hole diameter is 120mm. The anchor rod 2 is a 25mmHRB400 steel bar. The anchor rod 2 is arranged at the interval between two adjacent steel pipe piles 1 along the extension direction of the foundation pit. The waist beam 3 is arranged on the upper part of the side wall of the steel pipe pile 1 close to the inner side of the foundation pit and is connected to the anchor rod 2. The slope protection structure includes a steel mesh 4 arranged on the slope surface. The steel mesh 4 is made of 8mm diameter round steel with a spacing of 200×200mm. The steel mesh 4 is fixed by the positioning ribs 5. The positioning ribs 5 are made of grade 3 threaded steel bars with a length of 1000 mm and a diameter of 14 mm and are arranged in a plum blossom shape to fix the steel mesh. After the positioning ribs 5 are manufactured and installed, a concrete layer 7 is sprayed on the steel mesh 4 to the required thickness according to the design requirements.

[0026] Based on the above implementation, as a preferred implementation, the anchor rod is inserted into the foundation pit soil at an angle of 15° to strengthen the support for the side wall of the foundation pit.

[0027] Based on the above implementation, as a preferred implementation, Figure 2 As shown, the waist beam 3 includes a triangular bracket 301, a double-piece I-beam and a steel pad 305. The triangular bracket 301 is welded 0.8m below the top of the steel pipe pile. In order to connect the double-piece I-beam with the anchor rod 2, the setting height of the triangular bracket 301 can be adjusted as needed. The triangular bracket 301 is spliced ​​with 14b channel steel. The double-piece I-beam is installed on the triangular bracket 301, and the double-piece I-beam spans at least two steel pipe piles 1. A wedge block 302 is welded on the upper part of the triangular bracket 301 and on the inner side of the double-piece I-beam. The wedge block 302 is a right-angled triangle structure with a vertex angle of 15°, which is the same as the inclination angle of the anchor rod, so that the double-piece I-beam is arranged parallel to the anchor rod, which strengthens the fastening effect of the anchor rod on the double-piece I-beam. The outer side of the double-piece I-beam is provided with a steel pad 305 spanning at least two steel pipe piles 1. The double-jointed I-beam and steel pad 305 are joined in multiple sections so as to span across all the steel pipe piles 1 in the direction in which the foundation pit extends.

[0028] On the basis of the above-mentioned embodiment, as a preferred embodiment, the double-jointed I-beam includes I-beam I 303 and I-beam II 304, and both I-beam I 303 and I-beam II 304 are 2I40 I-beams. I-beam I 303 is arranged above I-beam II 304 to strengthen the bearing capacity of the waist beam. The reserved gap between I-beam I 303 and I-beam II 304 forms a channel for the anchor rod 2 to pass through, so that the anchor rod 2 passes through the double-jointed I-beam across the steel pipe pile 1.

[0029] On the basis of the above-mentioned embodiment, as a preferred embodiment, the anchor rod 2 penetrates the steel plate 305 across the steel pipe pile 1 through a channel composed of double I-beams, and a double nut is provided on the outer side of the steel plate 305 corresponding to the anchor rod 2. The anchor rod 2 is an HRB400 steel bar, and the end of the steel bar is provided with an external thread, so that the anchor rod 2 is threadedly connected with the double nut 6.

[0030] Embodiment 2 is further optimized on the basis of embodiment 1. In this embodiment, the triangular bracket 301 is bolted to the inner side wall of the steel pipe pile 1, which is beneficial to the installation of the waist beam 3 and convenient for construction.

[0031] Embodiment 3 is further optimized on the basis of Embodiment 1. In this embodiment, drainage holes with a diameter of 8 cm are arranged on the slope surface of the slope, with a spacing of 2 m and arranged in a plum blossom shape.

[0032] Embodiment 4 is further optimized on the basis of embodiment 1. In this embodiment, the steel pipe piles 1 are arranged in rows to form steel pipe pile rows, and a steel pipe pile construction platform 8 is constructed between the lower part of the slope and the steel pipe pile row. The steel pipe pile construction platform 8 is arranged between the lower part of the slope and the steel pipe pile row along the extension direction of the foundation pit. Before the piling construction, the site is leveled and three connections are made, obstacles on the piling foundation are handled, and rainwater drainage ditches need to be set up during cleaning and leveling.

[0033] The specific construction of a deep foundation pit support system for a steel dam in an urban river near an existing gas pipeline is as follows:

[0034] Step 1, upper slope; excavate the foundation pit by slope excavation, excavate section by section and layer by layer, and after the excavation length and depth are reached, use an excavator to initially shape the slope, and then use manual trimming to make the slope straight, flat and beautiful. Pay attention to controlling the elevation during excavation; pay attention to observing the slope during excavation, and there should be a dedicated person to direct the excavation of the foundation pit.

[0035] Step 2: Slope spraying anchor; after excavation and slope brushing, in order to prevent the excavation surface from being exposed for too long and causing collapse due to rain, the initial spraying of concrete with a thickness of 40mm is immediately carried out to seal the soil layer. The slope surface is protected by mesh spraying, with a concrete strength grade of C20 and a thickness of 80mm. The steel mesh 4 uses 8mm diameter round steel with a spacing of 200×200mm. The positioning bar 5 uses a third-grade threaded steel with a length of 1000mm and a diameter of 14mm and is arranged in a plum blossom shape to fix the steel mesh. Immediately after brushing the slope, the steel mesh 4 is sprayed with concrete 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 drainage hole with a diameter of 8cm, with a spacing of 2m and arranged in a plum blossom shape. After the positioning bar 5 is manufactured and installed, a concrete layer 7 is sprayed on the steel mesh 4 to the required thickness according to the design requirements.

[0036] Step three, the construction of the steel pipe pile construction platform 8; before the piling construction, the site is leveled, obstacles on the piling foundation are handled, and rainwater drainage ditches are set during cleaning and leveling.

[0037] Step 4: Steel pipe pile 1 is inserted and driven; positioning is performed according to the center plane coordinates of steel pipe pile 1 calculated before construction. Steel pipe pile 1 is set below the slope along the extension direction of the foundation pit. Steel pipe pile 1 adopts 630×10mm spiral pipe, and the spacing of steel pipe piles is set at 80cm. After calculation, an interval of 80cm can meet the requirements of slope support. The spacing distance is adjusted according to different foundation pit depths. After the steel pipe pile 1 enters the soil layer under its own gravity and the vibrating hammer, the plane position of the steel pipe pile 1 is re-measured and set. After meeting the requirements, the vibrating hammer is started to vibrate the steel pipe pile 1. During the vibration pile sinking process, the technicians use the total station and hammer ball to observe the verticality of the steel pipe pile 1 in the longitudinal and transverse directions, and command the crawler crane to swing forward and backward and left and right to adjust the verticality of the steel pipe pile 1. When the steel pipe pile 1 enters the soil 2~3m, its plane position and verticality will basically not change, and the hook can be loosened to allow the steel pipe pile 1 to continue to vibrate under the action of the vibrating hammer. When the top of the first section of the steel pipe pile 1 is about 1.5m above the ground, the vibration is stopped and the vibrating hammer is removed to extend the steel pipe pile 1.

[0038] Step 5, drilling of anchor rods 2; anchor holes are set at the intervals of steel pipe piles 1, with an anchor hole diameter of 120 mm. According to the design plan and soil geological conditions, soil nailing is performed using a total station, level, steel tape measure, etc. to determine the elevation and spacing of anchor rods 2, determine the hole positions, and make marks. The allowable deviation of the anchor hole spacing is ±15 mm, the inclination and horizontal angle errors of the drilled holes are controlled within 1°, and the hole slope does not exceed 1 / 100.

[0039] Step 6, installation of anchor rod 2; strictly follow the calculation book and drawings, drill holes at the intervals of steel pipe piles 1 to make anchor rod 2. Anchor rod 2 is made of 25mmHRB400 steel bars. It should be straightened and derusted before use. The end of anchor rod 2 is threaded with a threading machine and matched with double nuts 6. Anchor rod 2 positioner is constructed according to the drawing, and the spacing between anchor rod positioners is 1m. When placing, the rod body should be prevented from twisting, pressing and bending. The grouting pipe is placed in the hole together with anchor rod 2. The grouting pipe should be inserted to 250mm~500mm from the bottom of the hole. To ensure full grouting, a grout plug and exhaust pipe are set at the hole mouth. Anchor rod 2 clamps the steel pad through double nuts 6 to fix the waist beam 3.

[0040] Step 7, grouting of anchor 2; grouting uses pure cement slurry with a water-cement ratio of 0.45-0.50, and the cement uses P.O42.5 ordinary Portland cement, and the cement strength grade shall not be less than 30MPa. After grouting, maintenance should be carried out, and anchor 2 should be locked when the slurry strength reaches 70% of the design strength. Grouting of anchor 2 adopts the bottom grouting method until fresh slurry overflows from the orifice. It is strictly forbidden to extract grouting or grouting at the orifice. If the slurry surface at the orifice falls back, the bottom of the hole should be pressed and slurried 2 to 3 times within 30 minutes to ensure that the orifice is full of slurry.

[0041] The free section of the anchor rod 2 is protected before grouting. To prevent cement slurry from being injected into the free section during grouting, an elastically expandable grout stopper is provided in the free section to achieve elastic separation between the free section and the anchoring section.

[0042] Step eight, installation of waist beam 3; after the grouting strength of anchor rod 2 reaches 70% of the design strength, install waist beam 3 0.8m below the top of steel pipe pile 1, which is consistent with the height of anchor rod 2. This is to prevent excessive pressure during foundation pit excavation from affecting the construction safety in the cofferdam. A triangular bracket 301 is welded on the outside of steel pipe pile 1. Triangular bracket 301 is made of channel steel, and double I-beams are installed on the bracket. A 15° wedge block is welded on the inner side of the double I-beam close to the triangular bracket 301 and located on the triangular bracket 301. The double I-beam is installed on the triangular bracket 301 through a wedge block 302, and a 2cm thick steel pad 305 is installed on the outside of the double I-beam.

[0043] The double-jointed I-beams include I-beams Ⅰ303 and I-beams Ⅱ304. Both I-beams Ⅰ303 and I-beams Ⅱ304 are I40 I-beams. I-beams Ⅰ303 are arranged above I-beams Ⅱ304, which strengthens the bearing capacity of the waist beam 3. The reserved gap between I-beams Ⅰ303 and I-beams Ⅱ304 forms a channel for the anchor rod 2 to pass through, which facilitates the anchor rod 2 to penetrate the double-jointed I-beams and strengthens the fastening effect of the anchor rod 2 on the double-jointed I-beams. The height of the waist beam 3 is consistent with that of the anchor rod 2, and the anchor rod 2 penetrates the steel pad 305 through the channel.

[0044] Double nuts 6 are installed outside the steel pad 305 and at the anchor rod 2. Double nuts 6 can be tightened with anchor rod 2 using a wrench. The height of the waist beam 3 is consistent with that of the anchor rod 2, so that the anchor rod 2 can pass through the passage of the double cross steel and penetrate the steel pad 305. The waist beam 3 forms the steel pipe pile 1 and the anchor rod 2 into a whole, so that the support structure is stressed as a whole and the stress is balanced, which improves the anti-extrusion and bearing capacity of the support structure.

[0045] Step 9: Excavation of foundation pit: The excavation of 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 bottom leveling should be adopted to prevent disturbance of the base soil layer.

[0046] 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 deep foundation pit support system for a steel dam in an urban river adjacent to an existing gas pipeline, characterized in that: The invention comprises a supporting structure, a waist beam (3) and a slope protection structure, wherein the supporting structure comprises a plurality of steel pipe piles (1) and anchor rods (2), wherein the steel pipe piles (1) are arranged at a certain distance along the extension direction of the foundation pit, and the anchor rods (2) are arranged at the interval between two adjacent steel pipe piles (1) along the extension direction of the foundation pit, and the waist beam (3) is arranged on the steel pipe piles (1) and connected to the anchor rods (2), and the slope protection structure comprises a steel mesh (4) arranged on the slope surface, wherein the steel mesh (4) is fixed by positioning ribs (5), and a concrete layer (7) is poured on the steel mesh (4).

2. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 1 is characterized by: The anchor rod (2) is inserted into the foundation pit soil at an angle of 15°.

3. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 1 is characterized by: The waist beam (3) comprises a triangular bracket (301), a double-jointed I-beam and a steel pad (305); the triangular bracket (301) is arranged on the inner upper part of the steel pipe pile (1); the double-jointed I-beam is arranged on the triangular bracket (301) via a wedge block (302); the double-jointed I-beam spans at least two steel pipe piles (1); the wedge block (302) is fixedly connected to the upper part of the triangular bracket (301); and the steel pad (305) is arranged on the outer side of the double-jointed I-beam.

4. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 3 is characterized by: The double-jointed I-beam comprises an I-beam I (303) and an I-beam II (304), wherein the I-beam I (303) is arranged above the I-beam II (304), and a gap reserved between the I-beam I (303) and the I-beam II (304) forms a channel for the anchor rod (2) to pass through.

5. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 4 is characterized by: The anchor rod (2) penetrates the steel backing plate (305) through the channel, and a double nut is provided on the outer side of the steel backing plate (305) at a position corresponding to the anchor rod (2), and the anchor rod (2) is threadedly connected to the double nut (6).

6. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 5 is characterized by: The anchor rod (2) is an HRB400 steel bar, and the end of the steel bar is provided with an external thread.

7. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 3 is characterized by: The triangular bracket (301) is welded or bolted to the inner side wall of the steel pipe pile (1), and the wedge block (302) is a right-angled triangle structure with a vertex angle of 15°.

8. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 1 is characterized by: The steel pipe piles (1) are inserted below the slope at intervals of 80 cm, and the steel pipe piles (1) are 630×10 mm spiral pipes.

9. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 1 is characterized by: Drain holes are provided on the slope surface of the slope, and the drainage holes are arranged at a certain distance.

10. The deep foundation pit support system for steel dams in urban rivers near existing gas pipelines according to claim 1 is characterized by: The steel pipe piles (1) are arranged in rows to form a steel pipe pile row, and a steel pipe pile construction platform (8) is constructed below the slope and between the steel pipe pile rows.

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