A fully steel combined inclined strut support system and method

Abstract

The present invention provides a fully steel combined inclined strut support system and method, which adopts steel retaining piles, hoop-type steel combined ring beams, umbrella-shaped expansion mechanisms and steel advanced inclined struts. The steel retaining piles are composed of a plurality of steel pipe piles and water-stop steel sheet piles. Each hoop-type steel combined ring beam is sleeved on each steel pipe pile, and adjacent steel combined ring beams are connected into a whole. The umbrella-shaped expansion mechanism is arranged at the lower end of the steel advanced inclined strut. The umbrella-shaped expansion mechanism presents a contracted state under natural conditions. After the lower end of the steel advanced inclined strut reaches a certain depth in the soil body, the umbrella-shaped expansion mechanism expands under the action of soil resistance. The upper end of the steel advanced inclined strut is connected to the corresponding hoop-type steel combined ring beam. By adding the umbrella-shaped expansion mechanism, the supporting force of the steel advanced inclined strut in the shallow soil layer can be improved, and the length of the steel advanced inclined strut pile can be shortened. By adopting the hoop-type steel combined ring beam, the connection between the retaining body and the steel advanced inclined strut can be quickly realized, and the overall force of the support system can be realized.

Description

Technical Field

[0001] The present invention belongs to the field of sub-projects, and particularly relates to a fully steel combined inclined strut support system and method. Background Art

[0002] For a foundation pit with a shallow excavation depth (h≤7m), when the area of the foundation pit is large or the distance between the foundation pit boundary line and the land use red line is insufficient and a gravity dam and double-row pile retaining cannot be used, generally, an inclined throw strut support scheme is adopted, combined with the construction method of a central island. The conventional inclined throw strut scheme can save the engineering quantity and cost of the struts and columns, facilitate large-area excavation, improve the soil excavation efficiency, and save the construction period. However, this method also has some disadvantages, such as complex construction procedures, a rather cumbersome construction process, difficult excavation of the soil left beside the pit, the need for secondary pouring of the floor slab, and the risk of leakage after cutting the main building floor slab.

[0003] In view of the above disadvantages, a self-stabilizing foundation pit support structure system using steel advanced inclined strut piles instead of inclined throw struts has emerged on the market. Different from the construction procedure of the inclined throw strut scheme where the soil in the middle of the foundation pit is first excavated and the inclined throw struts are constructed after the floor slab is poured and cured to the design strength, the steel advanced inclined strut can be driven into the soil before the foundation pit is excavated by using special construction equipment, and together with the retaining structure, a force-bearing support system is formed, thus avoiding secondary pouring of the foundation floor slab. At present, the commonly used steel advanced inclined struts generally adopt small-diameter steel pipe piles combined with post-grouting to form a combined steel pipe pile reinforcement body, or directly adopt precast reinforced concrete rectangular piles. In the soft soil area of Shanghai, there is a relatively thick soft soil layer in the shallow part, and the side resistance and end resistance of the steel advanced inclined strut are weak, and it cannot provide sufficient support force in the shallow soil layer. Therefore, the steel advanced inclined strut needs to enter the deep soil layer, the pile body is long, the construction difficulty and project cost are high. At the same time, the connection between the steel advanced inclined strut and the retaining structure adopts a cast-in-place reinforced concrete ring beam, which requires binding of steel bars and curing of concrete, the construction procedure is relatively complex, the construction period is long, and finally a lot of waste concrete is generated, which is not environmentally friendly. Summary of the Invention

[0004] In view of the problems that the steel advanced inclined strut cannot provide sufficient support force in the shallow soil layer and the construction period of the cast-in-place reinforced concrete ring beam is relatively long, the present invention proposes a high-load-bearing fully steel combined steel advanced inclined strut support system that can be quickly constructed, which can improve the support force of the steel advanced inclined strut in the shallow soil layer, shorten the length of the steel advanced inclined strut pile, quickly realize the connection between the retaining structure and the steel advanced inclined strut by using a hoop-type steel combined ring beam, and realize the overall force-bearing of the support system.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] A fully steel combined inclined strut support system, comprising steel retaining piles, hoop-type steel combined ring beams, umbrella-shaped expansion mechanisms, and steel advanced inclined struts. The steel retaining piles are composed of a number of steel pipe piles and water-stop steel sheet piles, which are alternately driven in sequence. The adjacent steel pipe piles are connected by water-stop steel sheet piles to play a water-stop role. The top of the steel pipe piles is higher than the top surface of the hoop-type steel combined ring beam, and the top of the water-stop steel sheet piles is flush with the bottom surface of the hoop-type steel combined ring beam. Each hoop-type steel combined ring beam is sleeved on each steel pipe pile, and the adjacent steel combined ring beams are connected into a whole. The umbrella-shaped expansion mechanism is arranged at the lower end of the steel advanced inclined strut. The umbrella-shaped expansion mechanism is in a contracted state in the natural state. After the lower end of the steel advanced inclined strut reaches a certain depth in the soil, the umbrella-shaped expansion mechanism expands under the action of soil resistance. The upper end of the steel advanced inclined strut is connected to the corresponding hoop-type steel combined ring beam.

[0007] Preferably, in the above-mentioned fully steel combined inclined strut support system, the umbrella-shaped expansion mechanism includes an upper end plate, a lower end plate, a number of main rods, a number of auxiliary rods, a high-strength flexible membrane, a number of tension springs, and a pile cap. Both the lower end plate and the lower end plate are circular rings. The upper end plate is fixedly sleeved on the outer wall of the steel advanced inclined strut. The lower end plate is sleeved on the outside of the steel advanced inclined strut. The pile cap is fixedly arranged at the lower end of the steel advanced inclined strut. The lower end plate is located between the upper end plate and the pile cap, and the lower end plate can move axially along the steel advanced inclined strut. The number of main rods is arranged radially along the periphery of the upper end plate, and the upper ends of the main rods are respectively hinged to the upper end plate. One end of each auxiliary rod is respectively hinged to the middle of the corresponding main rod, and the other end of each auxiliary rod is respectively hinged to the lower end plate. The high-strength flexible membrane covers the main rods. The number of tension springs is evenly arranged on the lower end plate. The two ends of the tension spring are respectively connected to the lower end plate and the pile cap. The number of tension springs pull down the lower end plate so that the main rods are in a contracted state before and at the initial stage of the steel advanced inclined strut entering the soil. When the soil resistance received by the combination of the main rods and the high-strength flexible membrane exceeds the tension of the tension springs after the steel advanced inclined strut is driven into the soil to a certain depth, the main rods are pushed open by the soil resistance, causing the umbrella-shaped expansion mechanism to expand.

[0008] The working principle of the umbrella-shaped expansion mechanism: By evenly distributing tension springs on the lower end plate, the spring tension plays a locking mechanism role before and at the initial stage of the steel advanced inclined strut entering the soil, making the main rods and the high-strength flexible membrane in a contracted state. When the soil resistance received by the combination of the main rods and the high-strength flexible membrane exceeds the tension of the tension springs, the main rods are pushed open by the soil resistance, and the angle becomes larger and larger until it reaches a predetermined state, so as to achieve the purpose of improving the bearing capacity of the steel advanced inclined strut.

[0009] Preferably, in the above all-steel combined inclined strut support system, the umbrella-shaped expansion mechanism further includes a plurality of reinforcing rib plates. One side of each reinforcing rib plate is welded to the upper end plate respectively, and the other side is welded to the steel advanced inclined strut respectively. The plurality of reinforcing rib plates are arranged at equal intervals along the outer periphery of the steel advanced inclined strut, playing a role in enhancing the bearing capacity of the upper end plate.

[0010] Preferably, in the above all-steel combined inclined strut support system, the pile cap includes a disc part and a conical part. The upper surface of the disc part is fixedly arranged at the lower end of the steel advanced inclined strut, and the conical part is fixedly arranged on the lower surface of the disc part. The disc part is coaxially and fixedly connected to the conical part and the steel advanced inclined strut respectively. The tip of the conical part is arranged away from the disc part. The outer diameter of the disc part is 3 - 5 cm larger than the outer diameters of the upper end part and the lower end part. The pile cap is connected to the steel advanced inclined strut by welding. Its main function is to reduce the gap between the main rod and the outer wall of the steel advanced inclined strut, avoid the premature opening of the main rod, and at the same time, play a role in fixing the tension spring.

[0011] Preferably, in the above all-steel combined inclined strut support system, the top of the steel pipe pile is higher than the top surface of the hoop-type steel combined circular beam, and the top of the water-stop steel sheet pile is flush with the bottom surface of the hoop-type steel combined circular beam.

[0012] Preferably, in the above all-steel combined inclined strut support system, the hoop-type steel combined circular beam adopts a hoop-type box structure. The hoop-type steel combined circular beam is arranged along the foundation pit edge line, and adjacent hoop-type steel combined circular beams are connected into a whole by high-strength bolts. The hoop-type steel combined circular beam includes an outer shell, an inner shell and a plurality of connecting pieces. The outer shell is formed by welding four rectangular steel plates into a box structure. The inner shell is a circular pipe into which the steel pipe pile can extend. The inner diameter of the inner shell is slightly larger than the outer diameter of the steel pipe pile. The inner shell and the outer shell are welded and connected into a whole by a plurality of connecting pieces. The plurality of connecting pieces are evenly arranged in a radial pattern on the outer peripheral surface of the inner shell. The connecting pieces are made of steel plates. The hoop-type steel combined circular beam with the above structure not only makes the installation and connection of the hoop-type steel combined circular beam itself very convenient, but also facilitates the rapid and efficient connection of the steel advanced inclined strut and the steel retaining pile, realizes the rapid formation of a complete support system, and effectively improves the construction safety and construction efficiency.

[0013] An all-steel combined inclined strut support method adopts the above all-steel combined inclined strut support system, and the method includes the following steps:

[0014] Step 1, construct the steel retaining pile, and the steel retaining pile includes a steel pipe pile and a water-stop steel sheet. The steel pipe pile and the water-stop steel sheet pile are driven alternately.

[0015] Step 2, drive the steel advanced inclined strut. After the lower end of the steel advanced inclined strut reaches a certain depth, the umbrella-shaped expansion mechanism expands to a predetermined state.

[0016] Step 3: Sleeved the hoop - type steel combined girder on the top of the corresponding steel pipe pile. The top of the steel pipe pile is higher than the top surface of the hoop - type steel combined girder, and the top of the water - stop steel sheet pile is flush with the bottom surface of the hoop - type steel combined girder. Adjacent hoop - type steel combined girders are connected into a whole by high - strength bolts.

[0017] Step 4: Weld the upper end of the steel advanced inclined strut to the hoop - type steel combined girder to form a complete support system, achieving the purpose of rapidly increasing the support force.

[0018] Preferably, in the above - mentioned all - steel combined inclined strut support method, the umbrella - type expansion mechanism includes an upper end plate, a lower end plate, a number of main rods, a number of auxiliary rods, a high - strength flexible membrane, a number of tension springs and a pile cap. Both the lower end plate and the upper end plate are circular - ring - shaped. The upper end plate is fixedly sleeved on the outer wall of the steel advanced inclined strut, the lower end plate is sleeved on the outside of the steel advanced inclined strut, the pile cap is fixedly arranged at the lower end of the steel advanced inclined strut, the lower end plate is located between the upper end plate and the pile cap, and the lower end plate can move axially along the steel advanced inclined strut; the number of main rods are arranged radially along the perimeter of the upper end plate, and the upper ends of the main rods are respectively hinged to the upper end plate; one end of each auxiliary rod is respectively hinged to the middle of the corresponding main rod, and the other end of each auxiliary rod is respectively hinged to the lower end plate. The high - strength flexible membrane covers the main rods; the number of tension springs are evenly arranged on the lower end plate, and both ends of the tension springs are respectively connected to the lower end plate and the pile cap. The number of tension springs pull down the lower end plate so that the main rods are in a contracted state before and at the initial stage of the steel advanced inclined strut entering the soil. When the soil resistance received by the combination of the main rods and the high - strength flexible membrane exceeds the tension of the tension springs after the steel advanced inclined strut is driven into the soil to a certain depth, the main rods are pushed open by the soil resistance, causing the umbrella - type expansion mechanism to expand.

[0019] Preferably, in the above - mentioned all - steel combined inclined strut support method, the umbrella - type expansion mechanism further includes a number of reinforcing rib plates. One side of each reinforcing rib plate is respectively welded to the upper end plate, and the other side is respectively welded to the steel advanced inclined strut. The number of reinforcing rib plates are arranged at equal intervals along the outer periphery of the steel advanced inclined strut, playing a role in enhancing the bearing capacity of the upper end plate.

[0020] Preferably, in the above all-steel combined inclined strut support method, the pile cap includes a disc part and a conical part. The upper surface of the disc part is fixedly arranged at the lower end of the steel advanced inclined strut. The conical part is fixedly arranged on the lower surface of the disc part. The disc part is coaxially and fixedly connected to the conical part and the steel advanced inclined strut respectively. The tip of the conical part is arranged away from the disc part. The outer diameter of the disc part is 3-5 cm larger than the outer diameters of the upper end and the lower end. The pile cap and the steel advanced inclined strut are connected by welding. The main function is to reduce the gap between the main rod and the outer wall of the steel advanced inclined strut, avoid the premature opening of the main rod, and at the same time, play a role in fixing the tension spring.

[0021] Preferably, in the above all-steel combined inclined strut support method, the top of the steel pipe pile is higher than the top surface of the hoop-type steel combined circular beam, and the top of the water-stop steel sheet pile is flush with the bottom surface of the hoop-type steel combined circular beam.

[0022] Preferably, in the above all-steel combined inclined strut support method, the hoop-type steel combined circular beam adopts a hoop-type box structure. The hoop-type steel combined circular beam is arranged along the foundation pit edge. Adjacent hoop-type steel combined circular beams are connected into a whole by high-strength bolts. The hoop-type steel combined circular beam includes an outer shell, an inner shell and several connecting pieces. The outer shell is formed by welding four rectangular steel plates into a box structure. The inner shell is a circular pipe into which the steel pipe pile can extend. The inner diameter of the inner shell is slightly larger than the outer diameter of the steel pipe pile. The inner shell and the outer shell are welded and connected into a whole by several connecting pieces. The several connecting pieces are evenly arranged in a radial pattern on the outer peripheral surface of the inner shell. The connecting pieces are made of steel plates. The hoop-type steel combined circular beam with the above structure not only makes the installation and connection of the hoop-type steel combined circular beam itself very convenient, but also facilitates the rapid and efficient connection of the steel advanced inclined strut and the steel retaining pile, realizes the rapid formation of a complete support system, and effectively improves the construction safety and construction efficiency.

[0023] It can be seen from the above disclosed technical solutions that, compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] In summary, a fully steel combined inclined strut support system and method provided by the present invention adopt steel retaining piles, sleeve-type steel combined ring beams, umbrella-shaped expansion mechanisms and steel advanced inclined struts. The steel retaining piles are composed of a number of steel pipe piles and water-stop steel sheet piles, and the steel pipe piles and water-stop steel sheet piles are alternately driven in sequence. The top of the steel pipe pile is higher than the top surface of the sleeve-type steel combined ring beam, and the top of the water-stop steel sheet pile is flush with the bottom surface of the sleeve-type steel combined ring beam. Each sleeve-type steel combined ring beam is sleeved on each steel pipe pile, and adjacent steel combined ring beams are connected into a whole. The umbrella-shaped expansion mechanism is arranged at the lower end of the steel advanced inclined strut. The umbrella-shaped expansion mechanism is in a contracted state under natural conditions. After the lower end of the steel advanced inclined strut reaches a certain depth in the soil, the umbrella-shaped expansion mechanism expands under the action of soil resistance. The upper end of the steel advanced inclined strut is connected to the corresponding sleeve-type steel combined ring beam. By adding an umbrella-shaped expansion mechanism, the supporting force of the steel advanced inclined strut in the shallow soil layer can be improved, and the length of the steel advanced inclined strut pile can be shortened. By adopting the sleeve-type steel combined ring beam, the connection between the retaining body and the steel advanced inclined strut can be quickly realized, and the overall force of the support system can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a front elevation structural schematic diagram of a fully steel combined inclined strut support system.

[0026] Figure 2 is a plan structural schematic diagram of a fully steel combined inclined strut support system.

[0027] Figure 3 is a structural schematic diagram when the umbrella-shaped expansion mechanism is in a contracted state.

[0028] Figure 4 is a structural schematic diagram when the umbrella-shaped expansion mechanism is in an expanded state

[0029] Figure 5 is Figure 4 top view of.

[0030] In the figure: 1 - steel retaining pile, 11 - steel pipe pile, 12 - water-stop steel sheet pile, 2 - sleeve-type steel combined ring beam, 21 - outer shell, 22 - inner shell, 23 - connecting piece, 24 - high-strength bolt, 3 - umbrella-shaped expansion mechanism, 31 - upper end plate, 32 - lower end plate, 33 - main rod, 34 - auxiliary rod, 35 - high-strength flexible membrane, 36 - tension spring, 37 - pile cap, 38 - reinforcing rib plate, 4 - steel advanced inclined strut. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. The technical content and features of the present invention will be described in detail below by way of the enumerated embodiments in conjunction with the accompanying drawings. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. For the sake of convenience of description, the "upper" and "lower" described below are in the same direction as the upper and lower of the accompanying drawings, but this should not be a limitation to the technical solution of the present invention.

[0032] Please refer to Figures 1 to 5 , this embodiment discloses a fully steel combined inclined strut support system, including a steel retaining pile 1, a hoop-type steel combined ring beam 2, an umbrella-shaped expansion mechanism 3 and a steel advanced inclined strut 4. The steel retaining pile 1 is composed of a number of steel pipe piles 11 and water-stop steel sheet piles 12, and the steel pipe piles 11 and the water-stop steel sheet piles 12 are driven in turn alternately. The top end of the steel pipe pile 11 is higher than the top surface of the hoop-type steel combined ring beam 2, and the top end of the water-stop steel sheet pile 12 is flush with the bottom surface of the hoop-type steel combined ring beam 2. Each hoop-type steel combined ring beam 2 is sleeved on each steel pipe pile 11, and adjacent steel combined ring beams are connected into a whole. The umbrella-shaped expansion mechanism 3 is arranged at the lower end of the steel advanced inclined strut 4. The umbrella-shaped expansion mechanism 3 is in a contracted state in the natural state. After the lower end of the steel advanced inclined strut 4 reaches a certain depth in the soil, the umbrella-shaped expansion mechanism 3 expands under the action of soil resistance. The upper end of the steel advanced inclined strut 4 is connected to the corresponding hoop-type steel combined ring beam 2.

[0033] A fully steel combined inclined strut support system and method provided by the present invention can effectively improve the supporting force of the steel advanced inclined strut 4 in the shallow soil layer and shorten the pile length of the steel advanced inclined strut 4 by adding the umbrella-shaped expansion mechanism 3, which is in a contracted state in the natural state and expands under the action of soil resistance after the lower end of the steel advanced inclined strut 4 reaches a certain depth in the soil. By using the hoop-type steel combined ring beam 2, the steel retaining pile 1 and the steel advanced inclined strut 4, the rapid connection of the steel retaining pile 1 and the steel advanced inclined strut 4 can be realized, the overall force of the support system can be quickly realized, the construction safety and construction efficiency can be improved, and the problems that the steel advanced inclined strut 4 cannot provide sufficient supporting force in the shallow soil layer and the construction period of the cast-in-place reinforced concrete ring beam is relatively long are effectively solved.

[0034] Preferably, in the above all-steel combined inclined strut support system, the umbrella-shaped expansion mechanism 3 includes an upper end plate 31, a lower end plate 32, a plurality of main rods 33, a plurality of auxiliary rods 34, a high-strength flexible film 35, a plurality of tension springs 36 and a pile cap 37. Both the lower end plate 32 and the lower end plate 32 are circular rings. The upper end plate 31 is fixedly sleeved on the outer wall of the steel advanced inclined strut 4. The lower end plate 32 is sleeved outside the steel advanced inclined strut 4. The pile cap 37 is fixedly arranged at the lower end of the steel advanced inclined strut 4. The lower end plate 32 is located between the upper end plate 31 and the pile cap 37, and the lower end plate 32 can move axially along the steel advanced inclined strut 4. The plurality of main rods 33 are arranged radially along the periphery of the upper end plate 31, and the upper ends of the main rods 33 are respectively hinged to the upper end plate 31. One end of each auxiliary rod 34 is respectively hinged to the middle of the corresponding main rod 33, and the other end of each auxiliary rod 34 is respectively hinged to the lower end plate 32. The high-strength flexible film 35 covers the main rods 33. The plurality of tension springs 36 are evenly arranged on the lower end plate 32. The two ends of each tension spring 36 are respectively connected to the lower end plate 32 and the pile cap 37. The plurality of tension springs 36 pull down the lower end plate 32 so that the main rods 33 are in a contracted state before and at the initial stage of the steel advanced inclined strut 4 entering the soil. When the soil resistance received by the combination of the main rods 33 and the high-strength flexible film 35 exceeds the tension of the tension springs 36 after the steel advanced inclined strut 4 is driven into the soil to a certain depth, the main rods 33 are pushed open by the soil resistance, causing the umbrella-shaped expansion mechanism to expand. The auxiliary rods 34 are mainly used to expand the angle of the main rods 33. The pile cap 37 is welded to the steel advanced inclined strut 4, and its main function is to reduce the gap between the main rods 33 and the outer wall of the steel advanced inclined strut 4, prevent the main rods 33 from opening prematurely, and at the same time, play a role in fixing the tension springs 36.

[0035] Preferably, in the above all-steel combined inclined strut support system, the high-strength flexible film 35 is any one of PTFE film (i.e., polytetrafluoroethylene film), geotextile woven fabric, and polypropylene high-strength geotextile.

[0036] Preferably, in the above all-steel combined inclined strut support system, the umbrella-shaped expansion mechanism 3 further includes a plurality of reinforcing rib plates 38. One side of each reinforcing rib plate 38 is respectively welded to the upper end plate 31, and the other side is respectively welded to the steel advanced inclined strut 4. The plurality of reinforcing rib plates 38 are arranged at equal intervals along the outer periphery of the steel advanced inclined strut 4, and can play a role in enhancing the bearing capacity of the upper end plate 31.

[0037] Preferably, in the above all-steel combined inclined strut support system, the pile cap 37 includes a disc portion and a conical portion. The upper surface of the disc portion is fixedly arranged at the lower end of the steel advanced inclined strut 4. The conical portion is fixedly arranged on the lower surface of the disc portion. The disc portion is coaxially and fixedly connected to the conical portion and the steel advanced inclined strut 4 respectively. The tip of the conical portion is arranged away from the disc portion. The outer diameters of the upper end and the lower end are equal. The outer diameter of the disc portion is 3-5 cm larger than the outer diameters of the upper end and the lower end. The pile cap 37 and the steel advanced inclined strut 4 are connected by welding. With the above structure and connection method, the main function is to reduce the gap between the main rod 33 and the outer wall of the steel advanced inclined strut 4, avoid the premature opening of the main rod 33, and at the same time, play a role in fixing the tension spring 36.

[0038] Preferably, in the above all-steel combined inclined strut support system, the main rod 33 includes two structures up and down. The two structures up and down are connected by bolts and are in the form of pasting or bundling or intermediate clamping, so that the high-strength flexible film 35 is clamped between adjacent main rods 33.

[0039] Preferably, in the above all-steel combined inclined strut support system, the hoop-type steel combined circular beam 2 adopts a hoop-type box structure. The hoop-type steel combined circular beam 2 is arranged along the foundation pit edge line. Adjacent hoop-type steel combined circular beams 2 are connected into a whole by high-strength bolts 24. The hoop-type steel combined circular beam 2 includes a housing 21, an inner housing 22 and a plurality of connecting pieces 23. The housing 21 is welded into a box structure by four rectangular steel plates. The inner housing 22 is a circular tube into which the steel pipe pile 11 can extend. The inner diameter of the inner housing 22 is slightly larger than the outer diameter of the steel pipe pile 11. The inner housing 22 and the housing 21 are welded and connected into a whole by a plurality of connecting pieces 23. The plurality of connecting pieces 23 are evenly arranged in a radial manner on the outer peripheral surface of the inner housing 22. The connecting pieces 23 are made of steel plates. The hoop-type steel combined circular beam 2 with the above structure not only makes the installation and connection of the hoop-type steel combined circular beam 2 itself very convenient, but also facilitates the rapid and efficient connection of the steel advanced inclined strut 4 and the steel retaining pile 1, realizes the rapid formation of a complete support system, and effectively improves the construction safety and construction efficiency.

[0040] Please continue to refer to Figures 1 to 5 This invention also discloses an all-steel combined inclined strut support method, which adopts the above all-steel combined inclined strut support system. The method includes the following steps:

[0041] Step 1, construct the steel retaining pile 1. The steel retaining pile 1 includes a steel pipe pile 11 and a water-stop steel plate. The steel pipe pile 11 and the water-stop steel plate pile 12 are alternately driven.

[0042] Step 2, drive the steel advanced inclined strut 4. After the lower end of the steel advanced inclined strut 4 reaches a certain depth, the umbrella-type expansion mechanism 3 expands to a predetermined state.

[0043] Step 3: Sleeving the hoop - type steel composite ring beam 2 on the top of the corresponding steel pipe pile 11. The top end of the steel pipe pile 11 is higher than the top surface of the hoop - type steel composite ring beam 2, and the top end of the water - stop steel sheet pile 12 is flush with the bottom surface of the hoop - type steel composite ring beam 2. Adjacent hoop - type steel composite ring beams 2 are connected into a whole by high - strength bolts 24.

[0044] Step 4: Welding the upper end of the steel advanced inclined strut 4 to the hoop - type steel composite ring beam 2 to form a complete support system, achieving the purpose of rapidly increasing the support force.

[0045] A full - steel composite inclined strut support method provided by the present invention, by adding an umbrella - type expansion mechanism 3, the umbrella - type expansion mechanism 3 is in a contracted state under natural conditions. After the lower end of the steel advanced inclined strut 4 reaches a certain depth in the soil, the umbrella - type expansion mechanism 3 expands under the action of soil resistance, so as to effectively improve the supporting force of the steel advanced inclined strut 4 in the shallow soil layer and shorten the pile length of the steel advanced inclined strut 4; by adopting the hoop - type steel composite ring beam 2, the steel retaining pile 1 and the steel advanced inclined strut 4, the rapid connection of the steel retaining pile 1 and the steel advanced inclined strut 4 can be realized, the overall force of the support system can be rapidly realized, the construction safety and construction efficiency are improved, and the problems that the steel advanced inclined strut 4 cannot provide sufficient supporting force in the shallow soil layer and the construction period of the cast - in - place reinforced concrete ring beam is relatively long are effectively solved.

[0046] Preferably, in the above all-steel combined inclined strut support method, the umbrella-shaped expansion mechanism 3 includes an upper end plate 31, a lower end plate 32, a plurality of main rods 33, a plurality of auxiliary rods 34, a high-strength flexible membrane 35, a plurality of tension springs 36, and a pile cap 37. Both the lower end plate 32 and the lower end plate 32 are circular. The upper end plate 31 is fixedly sleeved on the outer wall of the steel advanced inclined strut 4. The lower end plate 32 is sleeved on the outside of the steel advanced inclined strut 4. The pile cap 37 is fixedly arranged at the lower end of the steel advanced inclined strut 4. The lower end plate 32 is located between the upper end plate 31 and the pile cap 37, and the lower end plate 32 can move axially along the steel advanced inclined strut 4. The plurality of main rods 33 are arranged radially around the periphery of the upper end plate 31, and the upper ends of the main rods 33 are respectively hinged to the upper end plate 31. One end of each auxiliary rod 34 is respectively hinged to the middle of the corresponding main rod 33, and the other end of each auxiliary rod 34 is respectively hinged to the lower end plate 32. The high-strength flexible membrane 35 covers the main rods 33. The plurality of tension springs 36 are evenly arranged on the lower end plate 32, and both ends of each tension spring 36 are respectively connected to the lower end plate 32 and the pile cap 37. The plurality of tension springs 36 pull down the lower end plate 32 so that the main rods 33 are in a contracted state before and at the initial stage of the steel advanced inclined strut 4 entering the soil. When the soil resistance received by the combination of the main rods 33 and the high-strength flexible membrane 35 exceeds the tension of the tension springs 36 after the steel advanced inclined strut 4 is driven into the soil to a certain depth, the main rods 33 are pushed open by the soil resistance, causing the umbrella-shaped expansion mechanism 3 to expand. The auxiliary rods 34 are mainly used to expand the angle of the main rods 33. The pile cap 37 is welded to the steel advanced inclined strut 4, and its main function is to reduce the gap between the main rods 33 and the outer wall of the steel advanced inclined strut 4, prevent the main rods 33 from opening prematurely, and at the same time, play a role in fixing the tension springs 36.

[0047] Preferably, in the above all-steel combined inclined strut support method, the umbrella-shaped expansion mechanism 3 further includes a plurality of reinforcing rib plates 38. One side of each reinforcing rib plate 38 is respectively welded to the upper end plate 31, and the other side is respectively welded to the steel advanced inclined strut 4. The plurality of reinforcing rib plates 38 are arranged at equal intervals along the outer periphery of the steel advanced inclined strut 4, playing a role in enhancing the bearing capacity of the upper end plate 31.

[0048] Preferably, in the above-mentioned all-steel combined inclined strut support method, the pile cap 37 includes a disc part and a conical part. The upper surface of the disc part is fixedly arranged at the lower end of the steel advanced inclined strut 4. The conical part is fixedly arranged on the lower surface of the disc part. The disc part is coaxially and fixedly connected to the conical part and the steel advanced inclined strut 4 respectively. The tip of the conical part is arranged away from the disc part. The outer diameter of the disc part is 3-5 cm larger than the outer diameters of the upper end and the lower end. The pile cap 37 and the steel advanced inclined strut 4 are connected by welding. The main function is to reduce the gap between the main rod 33 and the outer wall of the steel advanced inclined strut 4, avoid the premature opening of the main rod 33, and at the same time, play a role in fixing the tension spring 36.

[0049] Preferably, in the above-mentioned all-steel combined inclined strut support method, the main rod 33 includes two structures up and down. The two structures up and down are connected by bolts and are in the form of pasting or binding or intermediate clamping, so that the high-strength flexible film 35 is clamped between adjacent main rods 33.

[0050] Preferably, in the above-mentioned all-steel combined inclined strut support method, the hoop-type steel combined ring beam 2 adopts a hoop-type box structure. The hoop-type steel combined ring beam 2 is arranged along the foundation pit side line. Adjacent hoop-type steel combined ring beams 2 are connected into a whole by high-strength bolts 24. The hoop-type steel combined ring beam 2 includes an outer shell 21, an inner shell 22 and a number of connecting pieces 23. The outer shell 21 is welded by four rectangular steel plates into a box structure. The inner shell 22 is a circular tube that can allow the steel pipe pile 11 to extend into. The inner diameter of the inner shell 22 is slightly larger than the outer diameter of the steel pipe pile 11. The inner shell 22 and the outer shell 21 are welded and connected into a whole by a number of connecting pieces 23. The number of connecting pieces 23 is evenly arranged in a radial pattern on the outer peripheral surface of the inner shell 22. The connecting pieces 23 are made of steel plates. The hoop-type steel combined ring beam 2 with the above structure not only makes the installation and connection of the hoop-type steel combined ring beam 2 itself very convenient, but also facilitates the rapid and efficient connection of the steel advanced inclined strut 4 and the steel retaining pile 1, realizes the rapid formation of a complete support system, and effectively improves the construction safety and construction efficiency.

[0051] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the field of the present invention according to the above disclosure shall fall within the protection scope of the claims.

Claims

1. An all-steel combined diagonal bracing support system, characterized in that: The invention comprises steel retaining piles, a sleeve-type steel composite ring beam, an umbrella-shaped expansion mechanism and a steel advanced diagonal brace. The steel retaining piles are composed of a plurality of steel pipe piles and water-stop steel sheet piles. The steel pipe piles and the water-stop steel sheet piles are driven in turn and alternately. The top of the steel pipe pile is higher than the top surface of the sleeve-type steel composite ring beam. The top of the water-stop steel sheet pile is flush with the bottom surface of the sleeve-type steel composite ring beam. Each sleeve-type steel composite ring beam is sleeved on each steel pipe pile. Adjacent steel composite ring beams are connected as a whole. The umbrella-shaped expansion mechanism is arranged on the steel The lower end of the steel advanced diagonal brace is connected to the umbrella-shaped expansion mechanism, which is in a contracted state in a natural state. After the lower end of the steel advanced diagonal brace reaches a certain depth of the soil, the umbrella-shaped expansion mechanism expands under the action of soil resistance. The upper end of the steel advanced diagonal brace is connected to the corresponding sleeve-type steel composite ring beam. The umbrella-shaped expansion mechanism includes an upper end plate, a lower end plate, a plurality of main rods, a plurality of auxiliary rods, a high-strength flexible membrane, a plurality of tension springs and a pile cap. The lower end plate and the lower end plate are both annular. The upper end plate is fixedly sleeved on the steel The lower end plate is sleeved on the outer wall of the steel advance diagonal brace, the pile cap is fixedly arranged on the lower end of the steel advance diagonal brace, the lower end plate is located between the upper end plate and the pile cap, and the lower end plate can move along the axial direction of the steel advance diagonal brace; the plurality of main rods are radially arranged along the periphery of the upper end plate, and the upper ends of the main rods are respectively hinged to the upper end plates; one end of the auxiliary rod is respectively hinged to the middle part of the corresponding main rod, and the other end of the auxiliary rod is respectively hinged to the lower end plate. The high-strength flexible membrane covers the main rod; the plurality of tension springs are evenly arranged on the lower end plate, and the two ends of the tension springs are respectively connected to the lower end plate and the pile cap. The plurality of tension springs pull down the lower end plate so that the main rod is in a contracted state before the steel advance diagonal brace is driven into the soil and in the initial stage of burying the steel advance diagonal brace. When the steel advance diagonal brace is driven into the soil to a certain depth, the soil resistance of the main rod and the high-strength flexible membrane assembly exceeds the tension of the tension springs, and the main rod is opened by the soil resistance, so that the umbrella-shaped expansion mechanism expands.

2. The all-steel combined diagonal bracing support system according to claim 1, characterized in that: The umbrella-shaped expansion mechanism also includes a plurality of reinforcing ribs, one side of which is welded to the upper end plate, and the other side is welded to the steel advance diagonal brace. The plurality of reinforcing ribs are arranged at equal intervals along the outer circumference of the steel advance diagonal brace.

3. The all-steel combined diagonal bracing support system according to claim 1 is characterized in that: The pile cap includes a disc portion and a cone portion, the upper surface of the disc portion is fixedly arranged on the lower end of the steel advance diagonal brace, and the cone portion is fixedly arranged on the lower surface of the disc portion, the disc portion is coaxially fixedly connected to the cone portion and the steel advance diagonal brace respectively, the cone tip of the cone portion is arranged away from the disc portion, and the outer diameter of the disc portion is 3 to 5 cm larger than the outer diameters of the upper end and the lower end.

4. The all-steel combined diagonal bracing support system according to claim 1, characterized in that: The hoop-type steel composite ring beam adopts a hoop-type box-type structure. The hoop-type steel composite ring beam is arranged along the edge of the foundation pit. Adjacent hoop-type steel composite ring beams are connected into a whole by high-strength bolts. The hoop-type steel composite ring beam includes an outer shell, an inner shell and a plurality of connecting parts. The outer shell is a box-type structure welded by four rectangular steel plates. The inner shell is a circular tube that can allow steel pipe piles to extend into. The inner shell and the outer shell are welded and connected as a whole by a plurality of connecting parts. The plurality of connecting parts are radially and evenly arranged on the outer circumferential surface of the inner shell. The connecting parts are made of steel plates.

5. An all-steel combined diagonal bracing support method, characterized in that: Using the all-steel combined diagonal bracing system as claimed in claim 1, the method comprises the following steps: Step 1, constructing steel retaining piles, wherein the steel retaining piles include steel pipe piles and water-stopping steel sheets, and the steel pipe piles and water-stopping steel sheet piles are driven in alternately; Step 2, driving in a steel advance diagonal brace, and after the lower end of the steel advance diagonal brace reaches a certain depth, the umbrella-shaped expansion mechanism expands to a predetermined state; Step 3, sleeve the sleeve-type steel composite ring beam on the top of the corresponding steel pipe pile, the top of the steel pipe pile is higher than the top surface of the sleeve-type steel composite ring beam, the top of the water-stop steel sheet pile is flush with the bottom surface of the sleeve-type steel composite ring beam, and the adjacent sleeve-type steel composite ring beams are connected into a whole with high-strength bolts; Step 4, welding the upper end of the steel advance diagonal brace to the sleeve-type steel composite ring beam to form a complete support system, thereby achieving the purpose of rapidly increasing the support force.

6. The all-steel combined diagonal bracing support method according to claim 5, characterized in that: The umbrella-shaped expansion mechanism also includes a plurality of reinforcing ribs, one side of which is welded to the upper end plate, and the other side is welded to the steel advance diagonal brace. The plurality of reinforcing ribs are arranged at equal intervals along the outer circumference of the steel advance diagonal brace.

7. The all-steel combined diagonal bracing support method according to claim 5, characterized in that: The pile cap includes a disc portion and a cone portion, the upper surface of the disc portion is fixedly arranged on the lower end of the steel advance diagonal brace, and the cone portion is fixedly arranged on the lower surface of the disc portion, the disc portion is coaxially fixedly connected to the cone portion and the steel advance diagonal brace respectively, the cone tip of the cone portion is arranged away from the disc portion, and the outer diameter of the disc portion is 3 to 5 cm larger than the outer diameters of the upper end and the lower end.

8. The all-steel combined diagonal bracing support method according to claim 5, characterized in that: The hoop-type steel composite ring beam adopts a hoop-type box-type structure. The hoop-type steel composite ring beam is arranged along the edge of the foundation pit. Adjacent hoop-type steel composite ring beams are connected into a whole by high-strength bolts. The hoop-type steel composite ring beam includes an outer shell, an inner shell and a plurality of connecting parts. The outer shell is a box-type structure welded by four rectangular steel plates. The inner shell is a circular tube that can allow steel pipe piles to extend into. The inner shell and the outer shell are welded and connected as a whole by a plurality of connecting parts. The plurality of connecting parts are radially and evenly arranged on the outer circumferential surface of the inner shell. The connecting parts are made of steel plates.

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