A double-row core soil steel plate device constructed by retreat method

Abstract

The present invention discloses a double-row core soil steel plate device constructed by a retreat method, which relates to the technical field of construction engineering. The key point of the technical solution is to improve the double-row steel sheet pile support structure into a ring-shaped modular support unit. When the support area of ​​a single support unit is small, only the outer ring steel sheet pile and the inner ring steel sheet pile can provide stable support, and there is no need to add auxiliary support inside the outer ring steel sheet pile and the inner ring steel sheet pile, which can effectively reduce the impact of the auxiliary support inside the outer ring steel sheet pile and the inner ring steel sheet pile on the subsequent structural construction. In addition, the present invention sets a soil layer and sand pile that are easy to construct and low in cost between the inner ring steel sheet pile and the outer ring steel sheet pile, so that the stress of the soil around the inner ring steel sheet pile and the outer ring steel sheet pile is effectively dispersed, reducing the possibility of stress concentration around the inner ring steel sheet pile and the outer ring steel sheet pile, and reducing the risk of deformation of the inner ring steel sheet pile and the outer ring steel sheet pile.

Description

Technical Field

[0001] The invention relates to the technical field of construction engineering, and more particularly to a double-row core soil steel plate device constructed by a retreat method. Background Art

[0002] With the rapid development of the national economy, urban land is in short supply. In addition to extending to the sky, construction and transportation projects are also developing towards deep underground space. The comprehensive utilization of underground space has become increasingly important, and has become one of the key issues restricting the rapid development of urban construction. The application of deep foundation pits is becoming more and more extensive. Deep foundation pits refer to projects with an excavation depth of 5 meters or more; or projects with a depth of less than 5 meters, but with particularly complex geological conditions, surrounding environment, and underground pipelines.

[0003] In some projects, foundation pit work needs to be carried out near existing buildings. There is an invisible "building red line" between the foundation pit to be constructed and the existing buildings, which directly affects the lateral thrust during the construction process and is related to the safe use of the existing buildings.

[0004] Chinese patent CN102444132A provides a relay-type double-row steel sheet pile underwater deep foundation pit support structure, which includes a double-row steel sheet pile external enclosure structure and an internal horizontal support structure. The double-row steel sheet pile external enclosure structure includes mutually parallel outer steel sheet piles and inner steel sheet piles, and the top of the outer steel sheet pile is higher than the inner steel sheet pile; a filling wall is filled between the outer steel sheet pile and the inner steel sheet pile, and the lower part of the filling wall is clay and the upper part is concrete.

[0005] The above structure adopts the principle of thin-wall strong support. It has a double-row steel sheet pile support structure with a low inner side and a high outer side outside the deep foundation pit, and a combined system of multiple horizontal support beams inside. The structure is safe and solves the problem that steel sheet piles cannot be used in foundation pits with larger depths. It also solves the problem that the application depth of double-layer steel sheet piles is limited due to parallel arrangement, and breaks through the limitation that the application depth of steel sheet piles is shallow in deep foundation pits.

[0006] In the above structure, the filling wall is made of clay and concrete, and the construction process is complicated, time-consuming and costly. Summary of the invention

[0007] In view of the problem that in the existing deep foundation pit double-row steel sheet pile support structure, the filling wall is made of clay and concrete, the construction process is complicated, time-consuming and costly, the purpose of the present invention is to provide a double-row core soil steel plate device constructed by the retreat method, which includes at least one support unit, and the support unit includes an outer ring steel sheet pile, an inner ring steel sheet pile, a soil layer and a sand pile.

[0008] The inner circle steel sheet piles and the outer circle steel sheet piles are both arranged vertically, and the outer circle steel sheet piles are located outside the inner circle steel sheet piles. The space between the inner circle steel sheet piles and the outer circle steel sheet piles is filled with a soil layer (13), and a plurality of vertical holes are arranged on the soil layer around the inner circle steel sheet piles, and each vertical hole is filled with sand to form a sand pile, and the porosity of the sand is greater than the porosity of the soil layer.

[0009] When there are multiple support units, the outer ring steel sheet piles of each support unit have at least one side parallel to the outer ring steel sheet piles of other support units.

[0010] The present invention is further configured such that: the top end of the outer ring steel sheet pile is higher than the top end of the inner ring steel sheet pile, or the top end of the outer ring steel sheet pile is flush with the top end of the inner ring steel sheet pile.

[0011] The present invention is further configured such that the bottom end of the outer ring steel sheet pile is lower than the bottom end of the inner ring steel sheet pile.

[0012] The present invention is further configured such that: the bottom end of the sand pile is lower than the bottom end of the inner ring steel sheet pile.

[0013] The present invention is further configured as follows: the horizontal cross-section of the inner ring steel sheet pile and the horizontal cross-section of the outer ring steel sheet pile are both rectangular.

[0014] The present invention is further configured as follows: a plurality of the support units are provided, all the support units are arranged horizontally and linearly, and the outer ring steel sheet piles of two adjacent support units are connected.

[0015] The present invention is further configured as follows: it also includes linear support steel sheet piles, two of the linear support steel sheet piles are arranged, all support units are located between the two linear support steel sheet piles, and the length directions of the two linear support steel sheet piles are parallel to the horizontal linear arrangement direction of all support units.

[0016] The present invention is further configured as follows: the supporting unit also includes a surrounding purlin, and a circle of surrounding purlins is fixed to the inner top of the inner circle of steel sheet piles.

[0017] The present invention is further configured as follows: the supporting unit further comprises a support beam, and two ends of the support beam are respectively fixedly connected to different inner sides of the surrounding purlin. At least one support beam is provided.

[0018] The present invention is further configured as follows: the support unit further includes a grouting layer, and both inner and outer sides of the outer ring steel sheet piles have a grouting layer.

[0019] In summary, the present invention has the following beneficial effects compared to the prior art: the present invention improves the double-row steel sheet pile support structure into a ring-shaped modular support unit. When the support area of ​​a single support unit is small, the outer ring steel sheet piles and the inner ring steel sheet piles alone can provide stable support, without the need to add auxiliary supports on the inner side of the outer ring steel sheet piles and the inner ring steel sheet piles, which can effectively reduce the impact of the auxiliary supports on the inner side of the outer ring steel sheet piles and the inner ring steel sheet piles on the subsequent structural construction. In addition, the present invention sets a soil layer and sand piles that are easy to construct and low in cost between the inner ring steel sheet piles and the outer ring steel sheet piles, so that the stress of the soil around the inner ring steel sheet piles and the outer ring steel sheet piles is effectively dispersed, reducing the possibility of stress concentration around the inner ring steel sheet piles and the outer ring steel sheet piles, and reducing the risk of deformation of the inner ring steel sheet piles and the outer ring steel sheet piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A top view of an embodiment;

[0021] Figure 2 A cross-sectional view showing the support unit.

[0022] In the figure: 1. Support unit; 11. Outer circle steel sheet piles; 12. Inner circle steel sheet piles; 13. Soil layer; 14. Sand piles; 15. Purlin; 16. Support beam; 2. Linear support steel sheet piles; 3. Existing buildings. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention, and all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the invention.

[0024] It should be noted that the directions or positional relationships indicated by terms such as “center”, “up”, “down”, “horizontal”, “left”, “right”, “front”, “back”, “lateral” and “longitudinal” are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0025] Example

[0026] like Figure 1-2 As shown, it is the basic structure of a preferred embodiment of the present invention. This embodiment provides a double-row core soil steel plate device constructed by the retreat method, which includes at least one support unit 1, and the support unit 1 includes an outer circle steel sheet pile 11, an inner circle steel sheet pile 12, a soil layer 13 and a sand pile 14.

[0027] In this embodiment, the inner ring steel sheet piles 12 and the outer ring steel sheet piles 11 are both arranged vertically, and the outer ring steel sheet piles 11 are located outside the inner ring steel sheet piles 12. In this embodiment, the double-row steel sheet pile support structure is symmetrically arranged on both sides of the construction area, and is improved into a ring-shaped modular support unit 1. The construction personnel select the support area of ​​a single support unit 1, the horizontal cross-sectional shape of a single support unit 1, and the number of support units 1 in the construction area according to the size and shape of the construction area. In this embodiment, the horizontal cross-sections of the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12 in each support unit 1 are polygonal. In the outer ring steel sheet piles 11, each side wall can provide auxiliary support for its two adjacent side walls; in the inner ring steel sheet piles 12, each side wall can provide auxiliary support for its two adjacent side walls; when the support area of ​​a single support unit 1 is small, the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12 alone can provide stable support, and there is no need to add auxiliary support on the inner side of the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12, which can effectively reduce the impact of the auxiliary support arranged on the inner side of the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12 on subsequent structural construction.

[0028] On this basis, in this embodiment, a soil layer 13 is set between the inner steel sheet pile 12 and the outer steel sheet pile 11. When the inner steel sheet pile 12 and the outer steel sheet pile 11 are anchored into the soil, the soil cut by the inner steel sheet pile 12 and the outer steel sheet pile 11 will naturally form a soil layer 13 between the inner steel sheet pile 12 and the outer steel sheet pile 11, without the need for additional filling. Compared with the existing filling wall made of concrete and clay, the operation is simple and the cost is low. The formation of the soil layer 13 can ensure that there is always a gap between the inner steel sheet pile 12 and the outer steel sheet pile 11, so that the stress of the soil around the inner steel sheet pile 12 and the outer steel sheet pile 11 is effectively dispersed, reducing the possibility of stress concentration around the inner steel sheet pile 12 and the outer steel sheet pile 11.

[0029] In this embodiment, the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12 have the same shape but different sizes, and the longitudinal center line of the outer ring steel sheet piles 11 and the longitudinal center line of the inner ring steel sheet piles 12 are collinear, so that the thickness of the soil layer 13 at various locations in the horizontal direction is basically consistent, thereby improving the uniformity of the auxiliary support provided by the outer ring steel sheet piles 11 to the inner ring steel sheet piles 12.

[0030] Furthermore, in this embodiment, a plurality of vertical holes are arranged around the inner steel sheet pile 12 on the soil layer 13, and each vertical hole is filled with sand to form a sand pile 14, and the porosity of the sand is greater than that of the soil layer 13. The outer steel sheet pile 11 is allowed to deform, and by utilizing the maximum deformation allowed by the existing building 3 and the outer steel sheet pile 11 itself, unloading based on the vertical holes and the sand pile 14 can be achieved, reducing the possibility of load transfer to the inner steel sheet pile 12. The sand pile 14 is easy to construct and low in cost. At the same time, the sand pile 14 can also serve as a drainage channel, reducing the moisture in the soil and improving the stability of the soil.

[0031] Furthermore, when there are multiple support units 1, at least one side of the outer ring steel sheet piles 11 of each support unit 1 is parallel to the outer ring steel sheet piles 11 of other support units 1. When constructing the device, different support units 1 can be constructed in sequence, and the support unit 1 constructed first and the original soil structure as a whole provide support for the support unit 1 constructed later.

[0032] Furthermore, the top of the outer steel sheet pile 11 is higher than the top of the inner steel sheet pile 12, or the top of the outer steel sheet pile 11 is flush with the top of the inner steel sheet pile 12, so as to reduce the lateral pressure on the top of the inner steel sheet pile 12 and improve the structural stability and reliability of the top of the inner steel sheet pile 12. In this embodiment, the top of the outer steel sheet pile 11 is higher than the top of the inner steel sheet pile 12.

[0033] Furthermore, the bottom end of the outer ring steel sheet pile 11 is lower than the bottom end of the inner ring steel sheet pile 12, so as to increase the depth of the entire support unit 1, improve the support unit 1's resistance to lateral soil pressure, reduce the possibility of soil deformation and displacement, and improve the stability, safety and reliability of the support unit 1.

[0034] Furthermore, the bottom end of the sand pile 14 is lower than the bottom end of the inner ring steel sheet pile 12 to reduce the lateral pressure on the inner ring steel sheet pile 12 at all height positions, thereby improving the protective effect of the sand pile 14 on the inner ring steel sheet pile 12 .

[0035] Furthermore, in this embodiment, the horizontal cross-section of the inner ring steel sheet pile 12 and the horizontal cross-section of the outer ring steel sheet pile 11 are both rectangular, so as to facilitate the assembly of multiple support units 1.

[0036] Furthermore, the support unit 1 also includes a purlin 15 , and a circle of purlin 15 is fixed to the inner top of the inner circle steel sheet pile 12 to enhance the structural stability and reliability of the top of the inner circle steel sheet pile 12 .

[0037] Furthermore, the support unit 1 also includes a support beam 16, and the two ends of the support beam 16 are respectively fixedly connected to different inner sides of the purlin 15. At least one support beam 16 is provided. In this embodiment, the support beam 16 is horizontal. In addition, in this embodiment, the support beam 16 is divided into two types, one support beam 16 is a cross brace, and the two ends of the cross brace are respectively fixedly connected to two parallel sides of the purlin 15; in this embodiment, one cross brace is provided. Another support beam 16 is an oblique brace, and the two ends of the oblique brace are respectively fixedly connected to two sides corresponding to the same angle of the purlin 15. In this embodiment, an oblique brace is fixed at each angle of the purlin 15.

[0038] In this embodiment, a plurality of support units 1 are provided, all support units 1 are arranged horizontally and linearly, and the outer ring steel sheet piles 11 of two adjacent support units 1 are connected. When installing the device, a support unit 1 is first constructed in the soil near the existing building 3, and then the support unit 1 is used as a basis to retreat in a horizontal linear direction away from the existing building 3, and the remaining support units 1 are constructed in sequence.

[0039] Furthermore, the present embodiment also includes a linear support steel sheet pile 2, wherein two linear support steel sheet piles 2 are provided, and all support units 1 are located between the two linear support steel sheet piles 2, and the length directions of the two linear support steel sheet piles 2 are parallel to the horizontal linear arrangement direction of all support units 1, and all support units 1 can obtain auxiliary support force from the linear support steel sheet piles 2, thereby further improving the stability and reliability of the entire device.

[0040] Furthermore, the support unit 1 also includes a grouting layer, and both the inner and outer sides of the outer ring steel sheet piles 11 have grouting layers. The grouting layer is the last part of the single support unit 1 to be constructed. The completed support unit 1 and the original soil structure are regarded as a whole. During construction, there is often a certain gap between the outer ring steel sheet piles 11 of the support unit 1 and the whole. This gap is filled by grouting on the inner and outer sides of the outer ring steel sheet piles 11. The grouting layer finally formed will tightly connect the inner and outer sides of the outer ring steel sheet piles 11 with the whole, further improving the structural stability and reliability of the whole. The grouting layer is not shown in the figure.

[0041] In this embodiment, all structures except the sand piles 14 and the soil layer 13 can be prefabricated to improve construction efficiency.

[0042] The construction method of a single support unit 1 is:

[0043] First, the outer ring steel sheet piles 11 are constructed on the soil, the soil inside the outer ring steel sheet piles 11 is excavated to a certain depth, and then the inner ring steel sheet piles 12 are constructed on the soil inside the outer ring steel sheet piles 11. Subsequently, the soil layer 13 between the outer ring steel sheet piles 11 and the inner ring steel sheet piles 12 is vertically drilled, and the drilled vertical holes are backfilled with sand to form sand piles 14. Then, the soil inside the inner ring steel sheet piles 12 is excavated to the set foundation surface, and the surrounding purlins 15 and support beams 16 are installed inside the inner ring steel sheet piles 12. Finally, grouting is performed on both sides of the outer ring steel sheet piles 11 to fill the gaps between the support unit 1, the soil structure and the existing building 3 structure, so that the support unit 1, the soil structure and the existing building 3 structure are firmly connected.

[0044] In summary, the present embodiment improves the double-row steel sheet pile support structure into a ring-shaped modular support unit 1. When the support area of ​​a single support unit 1 is small, the outer ring steel sheet pile 11 and the inner ring steel sheet pile 12 alone can provide stable support, and there is no need to add auxiliary support inside the outer ring steel sheet pile 11 and the inner ring steel sheet pile 12, which can effectively reduce the impact of the auxiliary support inside the outer ring steel sheet pile 11 and the inner ring steel sheet pile 12 on the subsequent structural construction. In addition, the present embodiment sets an easy-to-construct, low-cost soil layer 13 and sand piles 14 between the inner ring steel sheet pile 12 and the outer ring steel sheet pile 11, so that the stress of the soil around the inner ring steel sheet pile 12 and the outer ring steel sheet pile 11 is effectively dispersed, reducing the possibility of stress concentration around the inner ring steel sheet pile 12 and the outer ring steel sheet pile 11, and reducing the risk of deformation of the inner ring steel sheet pile 12 and the outer ring steel sheet pile 11.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A double-row core soil steel plate device constructed by retreat method, characterized in that: The invention comprises at least one supporting unit (1), wherein the supporting unit (1) comprises an outer ring steel sheet pile (11), an inner ring steel sheet pile (12), a soil layer (13) and a sand pile (14); the inner ring steel sheet pile (12) and the outer ring steel sheet pile (11) are both arranged vertically, and the outer ring steel sheet pile (11) is located outside the inner ring steel sheet pile (12); the space between the inner ring steel sheet pile (12) and the outer ring steel sheet pile (11) is filled with a soil layer (13), a plurality of vertical holes are arranged on the soil layer (13) around the inner ring steel sheet pile (12), and each vertical hole is filled with sand to form a sand pile (14), and the porosity of the sand is greater than the porosity of the soil layer (13); The top of the outer ring steel sheet pile (11) is higher than the top of the inner ring steel sheet pile (12), or the top of the outer ring steel sheet pile (11) is flush with the top of the inner ring steel sheet pile (12); The bottom end of the outer ring steel sheet pile (11) is lower than the bottom end of the inner ring steel sheet pile (12); The bottom end of the sand pile (14) is lower than the bottom end of the inner ring steel sheet pile (12); When there are multiple support units (1), the outer ring steel sheet piles (11) of each support unit (1) have at least one side parallel to the outer ring steel sheet piles (11) of other support units (1); First, construct an outer circle of steel sheet piles on the soil, dig the soil inside the outer circle of steel sheet piles to a certain depth, and then construct an inner circle of steel sheet piles on the soil inside the outer circle of steel sheet piles; then vertically drill holes in the soil layer between the outer circle of steel sheet piles and the inner circle of steel sheet piles, and backfill the drilled vertical holes with sand to form sand piles; then dig the soil inside the inner circle of steel sheet piles to the set foundation surface, and install purlins and support beams on the inside of the inner circle of steel sheet piles; finally, grouting is performed on both sides of the outer circle of steel sheet piles to fill the gaps between the support unit, soil structure and existing building structure, so that the support unit, soil structure and existing building structure are firmly connected.

2. The device for constructing double-row core soil steel plates by retreat method according to claim 1 is characterized in that: The horizontal cross-section of the inner ring steel sheet pile (12) and the horizontal cross-section of the outer ring steel sheet pile (11) are both rectangular.

3. The device for constructing double-row core soil steel plates by retreat method according to claim 2 is characterized in that: A plurality of the support units (1) are provided, all the support units (1) are arranged horizontally and linearly, and the outer ring steel sheet piles (11) of two adjacent support units (1) are connected.

4. The device for constructing double-row core soil steel plates by retreat method according to claim 3 is characterized in that: It also includes linear support steel sheet piles (2), wherein two linear support steel sheet piles (2) are provided, and all support units (1) are located between the two linear support steel sheet piles (2), and the length directions of the two linear support steel sheet piles (2) are parallel to the horizontal linear arrangement direction of all support units (1).

5. A device for constructing double-row core soil steel plates by retreating method according to any one of claims 1 to 4, characterized in that: The support unit (1) further comprises a surrounding purlin (15), and a circle of surrounding purlin (15) is fixed to the inner top of the inner circle steel sheet piles (12).

6. The device for constructing double-row core soil steel plates by retreat method according to claim 5 is characterized in that: The support unit (1) further comprises a support beam (16), the two ends of which are respectively fixedly connected to different inner side surfaces of the surrounding purlin (15); at least one support beam (16) is provided.

7. A device for constructing double-row core soil steel plates by retreating method according to any one of claims 1 to 4, characterized in that: The support unit (1) further comprises a grouting layer, and both the inner and outer sides of the outer ring steel sheet pile (11) have a grouting layer.

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