Deep foundation pit concrete support inclined steel latticed column reinforcing structure

Abstract

The utility model relates to the field of deep foundation pit supporting, in particular to an inclined steel latticed column reinforcing structure of a deep foundation pit concrete support. The structural system comprises an inclined steel latticed column with the upper end integrally poured with a first-layer concrete supporting beam and the lower end fixedly connected with a foundation pile; the upper end of the newly-added steel stand column is fixedly connected with the first-layer concrete supporting beam, and the lower end of the newly-added steel stand column is fixedly connected with the thickened reinforcement cushion layer foundation; the newly-added steel stand columns and the inclined steel latticed columns are welded and connected into a whole through the steel batten plates. The diagonal bracing steel beams are arranged between the first-layer concrete supporting beams and the second-layer concrete supporting beams and between the second-layer concrete supporting beams and the thickened reinforced cushion layer foundations, the upper ends of the diagonal bracing steel beams are connected with the steel batten plates on the steel latticed columns in a welded mode, and the lower ends of the diagonal bracing steel beams are fixedly connected with the second-layer concrete supporting beams and the thickened reinforced cushion layer foundations. The reinforcing structure has the advantages of being large in rigidity, high in stability, convenient to construct, capable of saving construction cost and construction period and the like.

Description

Technical Field

[0001] This utility model relates to the field of deep foundation pit support, and in particular to a reinforced structure for inclined steel lattice columns supported by concrete in deep foundation pits. Background Technology

[0002] With the development and utilization of urban underground space in my country, the depth of foundation pits is increasing. The surrounding environment of foundation pits is often complex, with buildings, underground pipelines, and other issues. In addition, various regions have successively issued regulations prohibiting anchor bolts from exceeding the planning boundary. For deep foundation pits with two or more basement levels and poor soil conditions, the conventional approach is to install internal supports and steel lattice columns to control the stability and deformation of the foundation pit and protect the safety of the surrounding environment. The steel lattice columns mainly bear the vertical load from the upper part and are an important component of the support system. Due to construction reasons and deviations in on-site verticality control, the steel lattice columns are prone to tilting, exceeding the design requirements, and having large eccentricity, which reduces the bearing capacity and endangers the safety of the foundation pit. For tilted steel lattice columns whose verticality does not meet the design requirements, it is crucial to quickly and effectively reinforce them to ensure the safety of the foundation pit.

[0003] The commonly used structural reinforcement techniques for inclined steel lattice columns include the following:

[0004] (1) A new steel lattice column is to be reconstructed next to the inclined steel lattice column to replace the inclined steel lattice column. Since it was found on site that part of the earthwork had been excavated when the steel lattice column was inclined, this technology requires the reconstruction of the foundation piles under the steel lattice column. The pile driving machinery needs to enter the site twice and carry out construction in the pit. The construction period is long, the cost is high, and the construction is difficult.

[0005] (2) Enclosing the inclined steel lattice column with a larger steel lattice column and filling it with concrete to form a whole has the following problems: If the inclined steel lattice column is long and has a large inclination, the outer steel lattice column is large, which makes the overall construction inconvenient and affects the construction of the basement. Since the gap between the inclined steel lattice column and the newly added outer steel lattice column is small, the concrete cannot be vibrated and the concrete filling is not dense, which affects the bearing capacity. During the construction of the basement floor slab, the floor slab reinforcement needs to pass through the steel lattice column. The large size of the outer steel lattice column will make it difficult for the basement floor slab reinforcement to pass through. At the same time, the concrete inside the steel lattice column needs to be removed, which makes the process complicated and delays the construction period.

[0006] (3) Adding oblique steel beams or horizontal steel beams between the inclined steel lattice column and the adjacent steel lattice column increases the integrity of the inclined steel lattice column and the adjacent steel lattice column. This technology does not directly reinforce the inclined steel lattice column, and the bearing capacity of the inclined steel lattice column is not significantly improved. It is suitable for reinforcing steel lattice columns with relatively slight inclination, but not suitable for steel lattice columns with severe inclination. Utility Model Content

[0007] Purpose of this utility model: This utility model mainly solves the technical problem of reinforcing inclined steel lattice columns with concrete supports in existing deep foundation pit projects. It proposes a reinforcement structure for inclined steel lattice columns with concrete supports in deep foundation pits. By adding steel columns to the outside of the inclined steel lattice columns, and connecting the new steel columns with the inclined lattice columns by welding steel gusset plates to form an integral whole, the stress-bearing area of ​​the steel lattice columns is increased, and the eccentric stress on the steel lattice columns is reduced. Diagonal bracing steel beams are set on the outside of the inclined steel lattice columns and the outside of the new steel columns, respectively. The diagonal bracing steel beams share part of the vertical force of the inclined steel lattice columns, improve the bearing capacity of the inclined steel lattice columns, thereby ensuring the safety of the foundation pit and avoiding foundation pit accidents. At the same time, the on-site construction is simple, which greatly saves project costs and construction time.

[0008] To solve the above-mentioned technical problems, the present invention is as follows:

[0009] A deep foundation pit concrete-supported inclined steel lattice column reinforcement structure includes:

[0010] The inclined steel lattice column has a verticality exceeding the normal threshold.

[0011] The foundation piles for the inclined steel lattice column are connected at their upper ends to the lower ends of the inclined steel lattice column.

[0012] The first concrete layer is set at the top of the inclined steel lattice column and is fixedly connected to the inclined steel lattice column;

[0013] The second concrete layer is located in the middle of the inclined steel lattice column;

[0014] A thickened reinforced cushion layer foundation is installed at the top of the inclined steel lattice column foundation piles;

[0015] The base slab cushion layer is placed above the thickened reinforced cushion layer foundation and is poured simultaneously with the thickened reinforced cushion layer foundation.

[0016] The newly added steel column is perpendicular to the horizontal direction and is fixedly connected to the inclined steel lattice column as a whole. The upper end of the newly added steel column is fixedly connected to the first concrete layer, and the lower end is fixedly connected to the thickened reinforced pad foundation.

[0017] Two symmetrically arranged first-layer diagonal steel beams are placed between the first-layer concrete layer and the second-layer concrete layer. One of the first-layer diagonal steel beams is fixedly connected at both ends to the newly added steel column and the second-layer concrete layer, respectively. The other first-layer diagonal steel beam is fixedly connected at both ends to the inclined steel lattice column and the second-layer concrete layer, respectively.

[0018] Two symmetrically arranged second-layer diagonal steel beams are positioned between the second-layer concrete layer and the thickened reinforced foundation. One of the second-layer diagonal steel beams is fixedly connected at both ends to the newly added steel column and the thickened reinforced foundation, respectively, while the other second-layer diagonal steel beam is fixedly connected at both ends to the inclined steel lattice column and the thickened reinforced foundation, respectively.

[0019] Preferably, the upper end of the inclined steel lattice column foundation pile is integrally cast and solidified with the lower end of the inclined steel lattice column.

[0020] Preferably, the upper end of the inclined steel lattice column is integrally cast and solidified with the first layer of concrete support beam.

[0021] Preferably, the upper end of the newly added steel column is fixedly connected to the first layer support beam through a steel pad and embedded reinforcing bars; the lower end of the newly added steel column is fixedly connected to the thickened reinforced foundation through a pre-embedded steel plate and pre-embedded reinforcing bars.

[0022] Preferably, the thickness of the reinforced foundation layer is greater than that of the bottom slab foundation layer, and it is reinforced with steel bars.

[0023] Preferably, the inclined steel lattice column foundation pile is a bored cast-in-place pile.

[0024] Preferably, the inclined steel lattice column is formed by welding the angle steel of four inclined steel lattice columns to four steel gusset plates; the newly added steel column is formed by welding the angle steel of two newly added steel columns to three newly added steel gusset plates; the newly added steel column and the inclined steel lattice column are fixedly connected as a whole by welding. Beneficial effects: By adding steel columns to the outside of the inclined steel lattice column and welding them together to form a whole, the load-bearing area of ​​the inclined steel lattice column is increased, the eccentricity is reduced, and the stiffness and stability of the inclined steel lattice column are improved; the lower end of the newly added steel lattice column is provided with a thickened reinforced pad foundation to improve the bearing capacity; two diagonal bracing steel beams are installed on the outside of the newly added steel column and the inclined steel lattice column, and the number of diagonal bracing steel beam layers is set according to the number of concrete support layers. The diagonal bracing steel beams can share the vertical force of the inclined steel lattice column, further improving the bearing capacity of the inclined steel column, and solving the shortcomings and defects of the current technology. This reinforcement structure has the advantages of high stiffness, high stability, convenient construction, and cost and time savings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a deep foundation pit concrete-supported inclined steel lattice column reinforcement structure.

[0026] Figure 2 It is a horizontal projection diagram of the connection between the newly added steel columns and the inclined steel lattice columns;

[0027] Figure 3 This is a front projection view of the connection between the newly added steel column and the thickened reinforced foundation layer;

[0028] Figure 4 It is a horizontal projection diagram of the connection between the newly added steel column and the thickened reinforced foundation layer;

[0029] In the diagram: 10. Inclined steel lattice column foundation pile; 20. Inclined steel lattice column; 201. Steel gusset plate on the inclined steel lattice column; 202. Angle steel on the inclined steel lattice column; 30. First-layer concrete support beam; 40. Newly added steel column; 401. Steel gusset plate on the newly added steel column; 402. Angle steel on the newly added steel column; 50. First-layer diagonal bracing steel beam; 60. Second-layer concrete support beam; 70. Thickened reinforced foundation pad; 80. Bottom slab pad; 90. Second-layer diagonal bracing steel beam; 100. Embedded reinforcing steel; 110. Embedded steel plate. Detailed Implementation

[0030] The present invention will be further explained in detail below with reference to the accompanying drawings. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications to the present invention by those skilled in the art (including but not limited to the number of concrete support layers, the number of inclined steel beam layers, the form of steel columns, etc.) will fall within the scope defined by the appended claims.

[0031] refer to Figure 1-4 As shown, this utility model provides a reinforced structure for inclined steel lattice columns supported by concrete in deep foundation pits:

[0032] in Figure 1 This is a schematic diagram of a deep foundation pit concrete-supported inclined steel lattice column reinforcement structure. Figure 2 It is a horizontal projection diagram of the connection between the newly added steel columns and the inclined steel lattice columns; Figure 3 This is a front projection view of the connection between the newly added steel column and the thickened reinforced foundation layer; Figure 4 This is a horizontal projection diagram of the connection between the newly added steel column and the thickened reinforced pad foundation; the structural system of this utility model includes: inclined steel lattice column foundation pile 10, inclined steel lattice column 20, first layer concrete support beam 30, newly added steel column 40, first layer inclined bracing steel beam 50, second layer concrete support beam 60, thickened reinforced pad foundation 70, bottom slab pad 80, and second layer inclined bracing steel beam 90.

[0033] The upper end of the inclined steel lattice column foundation pile 10 is integrally cast and fixedly connected to the lower end of the inclined steel lattice column 20; the upper end of the inclined steel lattice column 20 is integrally cast and fixedly connected to the first layer concrete support beam 30; the upper end of the newly added steel column 40 is fixedly connected to the first layer support beam through steel pads and embedded reinforcing bars, and the lower end of the newly added steel column 40 is fixedly connected to the thickened reinforced pad foundation 70 through embedded steel plates 110 and embedded reinforcing bars 100; the first layer inclined bracing steel beam 50 is symmetrically arranged between the first layer concrete support beam 30 and the second layer concrete support beam 60; the second layer inclined bracing steel beam 90 is symmetrically arranged between the second layer concrete support beam 60 and the thickened reinforced pad foundation 70.

[0034] The inclined steel lattice column foundation pile 10 is a bored cast-in-place pile;

[0035] The inclined steel lattice column 20 is an integral part formed by welding the angle steel 202 of the four inclined steel lattice columns and the steel gusset plates 201 of the four inclined steel lattice columns. After the first layer of concrete support beam 30 is poured, the earthwork is excavated to the position of the second layer of concrete support beam 60. Before the concrete of the second layer of support beam 60 is poured, the inclination is measured on site and the verticality is not met after design calculation, resulting in the lattice column bearing capacity being insufficient to meet the safety requirements of the specifications.

[0036] The newly added steel column 40 is a whole formed by welding two newly added steel column upper angle steels 402 and three newly added steel column upper steel gusset plates 401; the newly added steel column upper angle steels 402 are of the same type as the upper angle steels 202 of the inclined steel lattice column; the three newly added steel column upper steel gusset plates 401 are of the same type as the upper steel gusset plates 201 of the inclined steel lattice column, and their size is determined on site according to the degree of inclination;

[0037] The first layer of diagonal bracing steel beam 50 consists of two diagonal bracing steel beams. One of the diagonal bracing steel beams is set outside the newly added steel column 40, with its upper end welded to the steel gusset plate 401 on the newly added steel column, and its lower end fixedly connected to the second layer support beam 60 through a pre-embedded steel plate 110 and a pre-embedded reinforcing bar 100. The other diagonal bracing steel beam is set outside the inclined steel lattice column 20, with its upper end welded to the steel gusset plate 201 on the inclined steel lattice column 20, and its lower end fixedly connected to the second layer support beam 60 through a pre-embedded steel plate 110 and a pre-embedded reinforcing bar 100.

[0038] The second layer of diagonal bracing steel beam 90 consists of two diagonal bracing steel beams. One of the diagonal bracing steel beams is set outside the newly added steel column 40, with its upper end welded to the steel gusset plate 401 on the newly added steel column, and its lower end fixedly connected to the thickened reinforced pad foundation 70 through the embedded steel plate 110 and the embedded steel bar 100. The other diagonal bracing steel beam is set outside the inclined steel lattice column 20, with its upper end welded to the steel gusset plate 201 on the inclined steel lattice column 20, and its lower end fixedly connected to the thickened reinforced pad foundation 70 through the embedded steel plate 110 and the embedded steel bar 100.

[0039] The thickened reinforced cushion foundation 70 is set on top of the inclined steel lattice column foundation pile 10 and is poured at the same time as the bottom slab cushion 80. The thickness of the thickened reinforced cushion foundation 70 is greater than that of the bottom slab cushion 80, and it is reinforced with steel bars to improve the bearing capacity of the foundation.

[0040] The specific construction steps are as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown,

[0041] S1. First, the inclined steel lattice column foundation pile 10 is constructed by drilling machinery. Before the concrete of the inclined steel lattice column foundation pile 10 is poured, the inclined steel lattice column 20 is lowered to the design elevation. The concrete of the inclined steel lattice column foundation pile 10 is poured so that the upper end of the inclined steel lattice column foundation pile 10 and the lower end of the inclined steel lattice column 20 form an integral and solid connection.

[0042] S2, the earthwork is excavated to the bottom 30 of the first layer of concrete support beam, the first layer of concrete support beam 30 is constructed, the upper end of the inclined steel lattice column 20 is anchored into the first layer of concrete support beam 30, and the whole is poured with concrete to consolidate and connect.

[0043] S3, earthwork excavation to the bottom of the second layer concrete support beam 60, on-site measurement of the verticality of the inclined steel lattice column 20 and after design verification to see if the bearing capacity meets the safety requirements of the specification.

[0044] S4, Reinforce the inclined steel lattice column 20 that does not meet the safety requirements of the specification. Construct a new steel column 40 on the outside of the inclined steel lattice column 20. The new steel column 40 is welded to the inclined steel lattice column 20 to form an integral whole through steel gusset plates. The upper end of the new steel column 40 is fixedly connected to the first layer concrete support beam 30 through steel pads and embedded steel bars. The lower end passes through the bottom of the first layer support beam so that the new steel column 40 can be welded and lengthened.

[0045] S5, construct the second layer of concrete support beam 60, and pre-embed steel plate 110 and pre-embed steel bar 100 in the second layer of concrete support beam 60.

[0046] S6, construct the first layer of inclined steel beams 50;

[0047] S7, earthwork excavation to the bottom of the foundation slab cushion layer 80 and the thickened reinforced cushion layer foundation 70;

[0048] S8, the newly added steel column 40 between the second layer concrete support beam 60 and the thickened reinforced foundation 70 is extended by welding to the newly added steel column 40 above.

[0049] S9, construction base slab cushion layer 80, thickened reinforced cushion layer foundation 70;

[0050] S10, construct the second layer of inclined steel beams 90.

[0051] This addresses the problems in existing inclined steel lattice column reinforcement technologies, such as high construction difficulty, high cost, long construction period, complicated procedures, impact on basement construction, no significant improvement in the bearing capacity of the inclined steel lattice column after reinforcement, and insufficient stiffness and stability.

Claims

1. A reinforced structure for inclined steel lattice columns supported by concrete in deep foundation pits, characterized in that, include: The inclined steel lattice column has a verticality exceeding the normal threshold. The foundation piles for the inclined steel lattice column are connected at their upper ends to the lower ends of the inclined steel lattice column. The first concrete layer is set at the top of the inclined steel lattice column and is fixedly connected to the inclined steel lattice column; The second concrete layer is located in the middle of the inclined steel lattice column; A thickened reinforced cushion layer foundation is installed at the top of the inclined steel lattice column foundation piles; The base slab cushion layer is placed above the thickened reinforced cushion layer foundation and is poured simultaneously with the thickened reinforced cushion layer foundation. The newly added steel column is perpendicular to the horizontal direction and is fixedly connected to the inclined steel lattice column as a whole. The upper end of the newly added steel column is fixedly connected to the first concrete layer, and the lower end is fixedly connected to the thickened reinforced pad foundation. Two symmetrically arranged first-layer diagonal steel beams are placed between the first-layer concrete layer and the second-layer concrete layer. One of the first-layer diagonal steel beams is fixedly connected at both ends to the newly added steel column and the second-layer concrete layer, respectively. The other first-layer diagonal steel beam is fixedly connected at both ends to the inclined steel lattice column and the second-layer concrete layer, respectively. Two symmetrically arranged second-layer diagonal steel beams are positioned between the second-layer concrete layer and the thickened reinforced foundation. One of the second-layer diagonal steel beams is fixedly connected at both ends to the newly added steel column and the thickened reinforced foundation, respectively, while the other second-layer diagonal steel beam is fixedly connected at both ends to the inclined steel lattice column and the thickened reinforced foundation, respectively.

2. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The upper end of the inclined steel lattice column foundation pile is integrally cast and solidified with the lower end of the inclined steel lattice column.

3. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The upper end of the inclined steel lattice column is integrally cast and solidified with the first layer of concrete support beam.

4. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The upper end of the newly added steel column is fixedly connected to the first layer of support beam through steel pads and embedded steel bars; the lower end of the newly added steel column is fixedly connected to the thickened reinforced foundation through embedded steel plates and embedded steel bars.

5. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The thickness of the reinforced foundation pad is greater than that of the bottom slab pad, and it is reinforced with steel bars.

6. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The inclined steel lattice column foundation piles are bored cast-in-place piles.

7. The deep foundation pit concrete-supported inclined steel lattice column reinforcement structure according to claim 1, characterized in that, The inclined steel lattice column is formed by welding the angle steel of four inclined steel lattice columns and the steel gusset plates of four inclined steel lattice columns; the newly added steel column is formed by welding the angle steel of two newly added steel columns and the steel gusset plates of three newly added steel columns; the newly added steel column and the inclined steel lattice column are fixedly connected as a whole by welding.

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