A ring frame support enclosure system that can also serve as a retaining wall and its construction method

Abstract

The present invention discloses a ring frame support enclosure system that can also serve as a retaining wall, including a retaining structure arranged around a foundation pit to bear the lateral load of the foundation pit, and a concrete support structure arranged inside the retaining structure to balance the lateral load on the retaining structure; the concrete support structure includes ring frame beams arranged on both sides of the retaining structure, and a concrete waist beam for connecting the ring frame beams, the concrete waist beam is arranged close to the retaining structure; and a support member is arranged inside the concrete support structure. The present invention also discloses a construction method of a ring frame support enclosure system that can also serve as a retaining wall. The present invention not only has high engineering applicability, high structural reliability and safety, but also has fewer construction steps and good economy.

Description

Technical Field

[0001] The invention belongs to the technical field of supporting structures, and in particular relates to a ring frame supporting enclosure system which can also serve as a retaining wall and a construction method thereof. Background Art

[0002] With the rapid development of urban rail transit, the construction sequence of subway stations continues to increase, and the location of subway stations has gradually increased from the early extension under the existing urban roads to the location under the planned roads and within the plots. Since the planned roads have not been implemented (the plots have not been developed), in the construction areas with hilly and mountainous landforms, there are large height differences in the construction sites, and a large amount of excavation is required to level the site to a uniform elevation, resulting in large project investment and low feasibility.

[0003] The existing technologies commonly used to deal with this situation are: when the height difference around the foundation pit is large (>5m), add a retaining structure (buttress retaining wall, pile anchor structure, etc.); when the height difference around the foundation pit is small (≤5m), add a retaining structure (cantilever retaining wall) on the foundation pit retaining structure; carry out overall earthwork excavation and excavate the entire site to the site elevation. Using these methods, there will be the following problems:

[0004] 1. When the existing technology adopts a separate retaining structure, such as a buttress retaining wall, it is necessary to cut the slope and excavate the retaining wall working surface during the construction phase, and then implement the retaining wall; the soil behind the wall needs to be backfilled during the use phase, which is complicated and requires a large investment in the project; the retaining structure is separated from the surrounding structure, resulting in a height difference in the site, which affects the access and use of the circular driveway and large equipment (shield machine). If a pile-anchor structure is used, it is necessary to stay as far away from the proposed surrounding structure as possible during the construction phase to ensure the width of the passive earth pressure zone of the embedded section of the pile body, thereby maintaining the overall stability of the retaining pile. The setting of the anchor cable (rod) is greatly restricted by the formation conditions. For example, when the stable rock (soil) layer is buried deep, the length of the anchor cable (rod) will be too long, the project safety is low, and the project investment is large; during the use phase, the anchor cable (rod) is an underground pollutant, which has a great impact on the construction site and surrounding plots. It needs to be recovered or excavated after use, resulting in an increase in project investment, otherwise it does not meet the requirements of green projects.

[0005] 2. When the existing technology uses a retaining structure on the enclosure structure, such as a cantilever retaining wall, it is necessary to cut the slope and excavate the retaining wall working surface during the construction phase, and then implement the retaining wall; the soil behind the wall needs to be backfilled during the use phase, and the process is complicated. Since the cantilever retaining wall structure should not exceed 5m, it is not suitable for sites with large height differences, and its engineering adaptability is poor.

[0006] 3. When the existing technology adopts overall earth excavation, if the entire site is excavated to the site elevation, the amount of excavated earth is large and the abandoned earth needs to be transported to a unified area, resulting in a long construction period and large project investment; if there are existing buildings within the required range of the site and they are not included in the demolition range, the plan cannot be implemented and the project has poor adaptability. Summary of the invention

[0007] In order to overcome the above-mentioned technical defects, the first purpose of the present invention is to provide a ring frame support enclosure system that can also serve as a retaining wall. Its retaining structure can be adjusted according to site conditions and has high engineering applicability. The concrete support structure adopts a ring frame structure, which is convenient for the construction of large equipment such as shield machines and has high structural reliability and safety.

[0008] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0009] A ring frame support enclosure system that can also serve as a retaining wall, comprising a retaining structure arranged around a foundation pit to bear the lateral load of the foundation pit, and a concrete support structure arranged inside the retaining structure to balance the lateral load on the retaining structure;

[0010] The concrete supporting structure comprises ring frame beams respectively arranged on both sides of the retaining structure, and a concrete waist beam used to connect the ring frame beams, wherein the concrete waist beam is arranged close to the retaining structure; and a supporting member is arranged in the concrete supporting structure.

[0011] Furthermore, a steel center column is provided through the concrete supporting structures.

[0012] Furthermore, the supporting structure includes a plurality of concrete straight supports for connecting the concrete waist beam; the steel center column is arranged on the concrete straight supports.

[0013] Furthermore, a concrete diagonal brace is provided on the concrete vertical brace close to the ring frame beam, and the two ends of the concrete diagonal brace are respectively provided on the ring frame beam and the concrete waist beam; a rib brace is provided on the concrete vertical brace without the concrete diagonal brace, and the two ends of the rib brace are respectively provided on the concrete vertical brace and the concrete waist beam.

[0014] Furthermore, the supporting structure also includes a connecting beam for connecting the concrete straight support; the connecting beam is arranged at the connection between the concrete straight support and the steel center column, and both ends of the connecting beam are respectively arranged on the ring frame beam.

[0015] Furthermore, the concrete straight supports are vertically arranged on the concrete waist beam; and the steel center column is vertically arranged in the middle of the concrete straight supports.

[0016] Furthermore, the ring frame beam includes a plurality of rectangular structures, and the plurality of rectangular structures are sequentially connected to form a rectangular frame.

[0017] Furthermore, the retaining structure is a bored pile, and a cap beam is provided on the top of the bored pile.

[0018] Furthermore, a shear bench is provided between the concrete waist beam and the bored piles to ensure the integrity of the force transmission system of the enclosure system.

[0019] In order to overcome the above-mentioned technical defects, the second purpose of the present invention is to provide a construction method for a ring frame support enclosure system that can also serve as a retaining wall. The retaining structure can be implemented as a whole at one time, and the concrete support structure can be erected according to the standard foundation pit excavation. When the foundation pit is backfilled, the thickness of the top plate can be effectively reduced. The construction steps are few, the project is highly feasible and economical.

[0020] In order to solve the above problems, the present invention is implemented according to the following technical solutions:

[0021] A construction method of a ring frame support enclosure system that can also serve as a retaining wall comprises the following steps:

[0022] S1. Plan a construction site according to the site conditions, ensure the feasibility of the construction loop, material stacking, and material processing site, reduce earth excavation in the site, and design the retaining structure and the concrete support structure according to the planned construction site; and level the site according to the planned construction site and construct the retaining structure;

[0023] S2. When the distance between the field floor and the proposed top layer exceeds 5m, excavate earth to the first support elevation to ensure that the distance between the field floor and the first support elevation does not exceed 5m, and add the first concrete support structure; if the distance between the field floor and the top layer does not exceed 5m, do not add the first concrete support structure;

[0024] S3, after the first concrete support structure reaches the support strength, excavate the earthwork to the second support elevation, and implement the second concrete support structure as the top layer;

[0025] S4, after the second concrete support structure reaches the support strength, excavate the earthwork to the third support elevation, and implement the third support structure as the middle layer;

[0026] S5, repeating step S4, adding the supporting structure according to the required number of layers, and each additional supporting structure adds one more layer;

[0027] S6, excavating the earthwork to the bottom of the foundation pit, applying a cushion layer, a waterproof layer, and a bottom plate of the lowest layer, and removing the supporting structure from bottom to top in sequence, while applying the waterproof layer, structure, and middle plate or top plate of the side wall of the layer;

[0028] S7. Use the first and second concrete support structures to hoist the equipment, then seal the hoisting holes and the holes of the first and second concrete support structures in turn, and backfill the earth between the top plate and the ground in layers from bottom to top.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention provides a ring frame support enclosure system that can also serve as a retaining wall. The ring frame support enclosure system that can also serve as a retaining wall is provided around the foundation pit to bear the lateral load of the foundation pit. The retaining structure can be adjusted according to the site conditions, and a ramp can be appropriately provided to ensure the reasonable layout of the construction site and the circular driveway. A concrete support structure is provided inside the retaining structure, and the concrete support structure adopts a ring frame structure, which is convenient for the construction of large equipment such as shield machines. The ring frame support enclosure system that can also serve as a retaining wall described in the present invention not only has high engineering applicability, but also has high structural reliability and safety.

[0031] (2) The construction method of the ring frame support enclosure system that can also serve as a retaining wall described in the present invention is that the retaining structure can be implemented as a whole at one time, and then the concrete support structure can be erected according to the standard foundation pit excavation. When the foundation pit is backfilled, the concrete support structure can be used to form a layered partition, which effectively reduces the thickness of the top plate. It not only has fewer construction steps, but also has high project feasibility and good economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0033] Figure 1 It is a front cross-sectional view of the ring frame support enclosure system which can also serve as a retaining wall according to the present invention;

[0034] Figure 2 It is a side cross-sectional view of the ring frame support enclosure system which can also serve as a retaining wall according to the present invention;

[0035] Figure 3 It is a plan view of the concrete support structure described in the first section of the present invention;

[0036] Figure 4 The plan view of the second concrete support structure of the present invention;

[0037] Figure 5 The invention discloses an anti-shear bench arranged on the concrete waist beam.

[0038] Marking Description:

[0039] 1. Retaining structure; 11. Bored piles; 12. Crown beam; 2. Concrete supporting structure; 21. Ring frame beam; 211. Rectangular structure; 22. Concrete waist beam; 23. Support member; 231. Concrete vertical support; 232. Concrete diagonal support; 233. Rib support; 234. Connecting beam; 3. Support structure; 4. Steel center column; 5. Shear bench; 6. High part of the construction site; 7. Low part of the construction site; 8. Bottom of foundation pit; 9. Bottom of bored piles. DETAILED DESCRIPTION

[0040] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0041] Example 1

[0042] This embodiment discloses a ring frame support enclosure system that can also serve as a retaining wall. Figure 1-5 As shown, it includes a retaining structure 1 arranged around the foundation pit for bearing the lateral load of the foundation pit, and a concrete supporting structure 2 arranged inside the retaining structure 1 for balancing the lateral load borne by the retaining structure 1;

[0043] The concrete support structure 2 includes ring frame beams 21 respectively arranged on both sides of the retaining structure 1, and a concrete waist beam 22 for connecting the ring frame beams 21, and the concrete waist beam 22 is arranged close to the retaining structure 1; a support member 23 is arranged in the concrete support structure 2.

[0044] In this embodiment, a steel center column 4 is provided through the concrete support structure 2; the provision of the steel center column 4 can reduce the span of a large-span support.

[0045] In this embodiment, the ring frame beam 21 includes a plurality of rectangular structures 211, and the plurality of rectangular structures 211 are sequentially connected to form a rectangular frame; the supporting member 23 includes a plurality of concrete straight supports 231 for connecting the concrete waist beam 22; the steel center column 4 is arranged on the concrete straight supports 231;

[0046] A concrete diagonal brace 232 is provided on the concrete straight brace 231 close to the ring frame beam 21, and the two ends of the concrete diagonal brace 232 are respectively provided on the ring frame beam 21 and the concrete waist beam 22; a rib brace 233 is provided on the concrete straight brace 231 without the concrete diagonal brace 232, and the two ends of the rib brace 233 are respectively provided on the concrete straight brace 231 and the concrete waist beam 22.

[0047] The structural design of the ring frame beam 21 and the supporting member 23 allows the active earth pressure on the side of the retaining structure 1 to be transmitted to the concrete waist beam 22 and the retaining structure 1 around it through the rectangular structure 211 of the ring frame beam 21 and the concrete diagonal brace 232, forming a balance between the vertical load and the active earth pressure of the retaining structure 1 around the concrete waist beam 22, thereby increasing the stability of the entire enclosure system; and the structural design of the ring frame beam 21 facilitates the construction of large equipment such as shield machines.

[0048] In this embodiment, the support member 23 further includes a connecting beam 234 for connecting the concrete straight support 231; the connecting beam 234 is arranged at the connection between the concrete straight support 231 and the steel center column 4, and both ends of the connecting beam 234 are respectively arranged on the ring frame beam 21. The structural design of the connecting beam 234 can connect a single concrete straight support 231 to increase the overall structural stability.

[0049] In this embodiment, the concrete braces 231 are vertically arranged on the concrete waist beam 22; the steel center column 4 is vertically arranged in the middle of the concrete braces 231. The structural design of the concrete braces 231 and the steel center column 4 makes the overall structure more stable.

[0050] In this embodiment, the retaining structure 1 is a bored pile 11; a cap beam 12 is provided on the top of the bored pile 11; a shear bench 5 is provided between the concrete waist beam 22 and the bored pile 11 to ensure the integrity of the force transmission system of the retaining system; specifically, the bored piles 11 are all constructed on the ground of the yard, formed once to below the bottom of the foundation pit 8, until the bottom of the bored pile 9, the pile head is chiseled out, and a cap beam 12 is applied on the top of the pile, and the entire yard (from the high point 6 of the construction yard to the low point 7 of the construction yard) is flush with the top of the cap beam 12 to ensure the availability of the site around the excavated foundation pit (within the enclosure).

[0051] Based on the above structural design, this embodiment takes a deep foundation pit of a two-story underground station of a city rail transit as an example, in which bored piles 11 are used as retaining structure 1. There is a height difference of 6.5m between the end of the station and the standard section. There are 7 2-6-story natural foundation houses within 5.2-19.2m from the top of the slope to the foundation pit of the subway station. The retaining structure 1 at the end of the subway station needs to be raised to the ground, and the first concrete support structure 2 is added so that the distance between the field ground and the first support elevation does not exceed 5m. The specific construction steps are as follows:

[0052] S1. Plan a construction site according to the site conditions, ensure the feasibility of the construction loop, material stacking, and material processing site, minimize the excavation of the site, and design the retaining structure 1 and the concrete support structure 2 according to the planned construction site; and level the site according to the planned construction site, and then carry out the construction of bored piles 11 and steel center columns 4;

[0053] Specifically, the soil on the upper part of the plane from the high part 6 of the construction site to the low part 7 of the construction site is excavated, and the bored pile 11 is formed once to below the bottom 8 of the foundation pit and to the bottom 9 of the bored pile, and the pile head is chiseled off, and a cap beam 12 is constructed on the top of the bored pile 11;

[0054] S2, excavate earth to the first support elevation, ensure that the distance between the ground and the first support elevation does not exceed 5m, construct the first concrete support structure 2, and set a shear bench 5 between the concrete waist beam 22 and the bored pile 11, such as Figure 3 , 5 As shown;

[0055] S3, after the first concrete support structure 2 reaches the support strength, excavate the earth to the second support elevation, implement the second concrete support structure 2 as the top layer, and set the shear bench 5 between the concrete waist beam 22 and the bored pile 11, as shown in FIG. Figure 4 , 5 As shown;

[0056] S4, after the second concrete support structure 2 reaches the support strength, excavate the earth to the third support elevation, implement the third support structure 3 as the middle layer of the two-story underground station, and set up shear benches;

[0057] S5. After the third support structure 3 reaches the support strength, excavate the earth to the fourth support elevation, implement the fourth support structure 3 as the bottom floor of the two-story underground station, and set up shear benches;

[0058] S6, excavate earth to the bottom of the foundation pit 8, construct the cushion layer, waterproof layer, and the bottom plate of the second underground floor; remove the fourth supporting structure 3, construct the side wall waterproof layer, structure, and station middle plate of the second underground floor; remove the third supporting structure 3, construct the side wall waterproof layer, structure, and station top plate of the first underground floor;

[0059] S7. Use the station structure and the first and second concrete support structures 2 to hoist the equipment, then seal the station hoisting holes and the holes of the first and second concrete support structures 2 in turn, and backfill the earth in layers from the station roof to the second concrete support structure 2, from the second concrete support structure 2 to the first concrete support structure 2, and from the first concrete support structure 2 to the ground.

[0060] Example 2

[0061] This embodiment discloses a ring frame support enclosure system that can also serve as a retaining wall. Its retaining structure 1 and concrete support structure 2 are the same as those in Embodiment 1. The difference between its construction method and that in Embodiment 1 is that:

[0062] The distance between the field ground and the top layer is no more than 5m, and in step S2, there is no need to add the first concrete support structure 2.

[0063] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A construction method for a ring frame support enclosure system that can also serve as a retaining wall, characterized in that: It includes a retaining structure arranged around the foundation pit to bear the lateral load of the foundation pit, and a concrete support structure arranged inside the retaining structure to balance the lateral load borne by the retaining structure; The concrete support structure comprises ring frame beams respectively arranged on both sides of the retaining structure, and a concrete waist beam for connecting the ring frame beams, wherein the concrete waist beam is arranged close to the retaining structure; a support member is arranged in the concrete support structure; A steel center column is provided between the concrete support structures; The supporting member comprises a plurality of concrete vertical supports for connecting the concrete waist beam; the steel center column is arranged on the concrete vertical supports; The support member further comprises a connecting beam for connecting the concrete straight support; the connecting beam is arranged at the connection between the concrete straight support and the steel center column, and the two ends of the connecting beam are respectively arranged on the ring frame beam; The concrete supports are vertically arranged on the concrete waist beams; the steel center column is vertically arranged in the middle of the concrete supports; The ring frame beam comprises a plurality of rectangular structures, and the plurality of rectangular structures are sequentially connected to form a rectangular frame; The construction method of the ring frame support enclosure system that can also serve as a retaining wall, wherein the construction of the underground two-story station includes the following steps: S1. Plan a construction site according to the site conditions, ensure the feasibility of the construction loop, material stacking, and material processing site, reduce earth excavation in the site, and design the retaining structure and the concrete support structure according to the planned construction site; and level the site according to the planned construction site and construct the retaining structure; S2. When the distance between the field floor and the proposed top layer exceeds 5m, excavate earth to the first support elevation to ensure that the distance between the field floor and the first support elevation does not exceed 5m, and add the first concrete support structure; if the distance between the field floor and the top layer does not exceed 5m, do not add the first concrete support structure; S3, after the first concrete support structure reaches the support strength, excavate the earthwork to the second support elevation, and implement the second concrete support structure as the top layer; S4, after the second concrete support structure reaches the support strength, excavate the earthwork to the third support elevation, and implement the third support structure as the middle layer; S5, repeating step S4, adding the supporting structure according to the required number of floors, and adding one more floor for each additional supporting structure, that is, after the third supporting structure reaches the supporting strength, excavating earth to the fourth supporting elevation, and implementing the fourth supporting structure as the bottom floor of the two-story underground station; S6, excavating the earthwork to the bottom of the foundation pit, applying a cushion layer, a waterproof layer, and a bottom plate of the lowest layer, and removing the supporting structure from bottom to top in sequence, while applying the waterproof layer, structure, and middle plate or top plate of the side wall of the layer; S7. Use the first and second concrete support structures to hoist the equipment, then seal the hoisting holes and the holes of the first and second concrete support structures in turn, and backfill the earth between the top plate and the ground in layers from bottom to top.

2. The construction method of the ring frame support enclosure system that can also serve as a retaining wall according to claim 1 is characterized in that: A concrete diagonal brace is provided on the concrete vertical brace close to the ring frame beam, and the two ends of the concrete diagonal brace are respectively provided on the ring frame beam and the concrete waist beam; a rib brace is provided on the concrete vertical brace without the concrete diagonal brace, and the two ends of the rib brace are respectively provided on the concrete vertical brace and the concrete waist beam.

3. The construction method of the ring frame support enclosure system that can also serve as a retaining wall according to any one of claims 1 to 2, characterized in that: The retaining structure is a bored pile, and a cap beam is arranged on the top of the bored pile.

4. The construction method of the ring frame support enclosure system that can also serve as a retaining wall according to claim 3 is characterized in that: An anti-shear bench is arranged between the concrete waist beam and the bored piles to ensure the integrity of the force transmission system of the enclosure system.

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