Sandy foundation pit slope back pressure anchor-free supporting structure

Abstract

The utility model discloses a sandy foundation pit side slope back pressure anchor-free supporting structure which comprises a foundation pit side slope surface, a hanging net concrete spraying layer and a back pressure sand bag layer, a water retaining table and a sand bag cushion layer are arranged at the top and the bottom of a foundation pit side slope respectively, and the foundation pit side slope surface comprises a first slope surface section, a platform section and a second slope surface section. The first slope section is provided with an upper-layer supporting assembly used for supporting the back pressure sand bag layer, and the second slope section is provided with a lower-layer supporting assembly used for supporting the back pressure sand bag layer. The foundation pit supporting structure is reasonable in structural design, a traditional soil nailing wall foundation pit supporting mode is replaced by a new process that the sand bags are used for carrying out back pressure on the foundation pit slope and the dead weight characteristic of the sand bags and the side pressure of the slope are mutually counteracted, the stability of the slope is guaranteed, material input is saved, the construction period is shortened, and the construction efficiency is improved. The supporting assemblies are additionally arranged at the bottoms of the sand bags to prevent the sand bags from displacing and sliding off, gaps between the back pressure sand bags are filled with mortar, and the integrity of the back pressure sand bags is improved.

Description

Technical Field

[0001] This utility model belongs to the field of foundation pit slope protection technology, specifically relating to a sandy foundation pit slope counterpressure anchor-free support structure. Background Technology

[0002] Slope protection technology is primarily a technique used in civil engineering construction to support and protect the surrounding environment. It is a crucial measure for improving the quality and safety of foundation pit construction in civil engineering projects. It also ensures the stability of the soil around the foundation pit while providing sufficient space for basement construction, a necessary condition for both earthwork excavation and basement construction. When slope excavation of the foundation pit is difficult, support structures such as anti-slide piles and soil nailing walls can be used. However, for projects with limited timeframes and site constraints, such as single-story underground sandy foundation pits (around 7 meters deep), traditional anti-slide piles and soil nailing walls result in longer construction periods and higher costs. They also present numerous management challenges for owners and contractors in terms of limited space, construction time, and cost.

[0003] Therefore, it is necessary to propose a sandy foundation pit slope counterpressure anchor-free support structure that can significantly shorten the construction cycle. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a sandy foundation pit slope counter-pressure anchor-free support structure that addresses the shortcomings of the prior art. Its structure is rationally designed and utilizes sandbags to counter-pressure the foundation pit slope. This new process, which uses the self-weight characteristics of the sandbags to offset the lateral pressure of the slope, replaces the traditional soil nailing wall foundation pit support mode. This ensures slope stability, saves material input, and shortens the construction period. Support components are added to the bottom of the sandbags to prevent displacement and slippage. Mortar is used to fill the gaps between the counter-pressure sandbags, increasing the overall integrity of the counter-pressure sandbags and further improving the waterproofing capacity of the slope concrete layer.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a sandy foundation pit slope counter-pressure anchor-free support structure, characterized in that: it includes a foundation pit slope surface and a wire mesh sprayed concrete layer and a counter-pressure sandbag layer arranged sequentially on the foundation pit slope surface, a water-retaining platform is set at the top of the foundation pit slope, and a sandbag cushion layer is set at the bottom of the foundation pit slope.

[0006] The foundation pit slope includes a first slope section, a platform section and a second slope section arranged sequentially from top to bottom. The first slope section is provided with an upper support component for supporting the counter-pressure sandbag layer, and the second slope section is provided with a lower support component for supporting the counter-pressure sandbag layer.

[0007] The counter-pressure sandbag layer includes an inner sandbag layer laid close to the slope surface of the foundation pit and a multi-layered covering sandbag layer set outside the inner sandbag layer. The inner sandbag layer includes a first sandbag layer stacked on the upper support component, a second sandbag layer stacked between the platform section and the upper support component, a third sandbag layer stacked on the lower support component, and a fourth sandbag layer stacked between the lower support component and the sandbag pad layer. The first and second sandbag layers are both laid close to the first slope section, and the third and fourth sandbag layers are both laid close to the second slope section.

[0008] The above-mentioned sandy foundation pit slope counterpressure anchor-free support structure is characterized in that: the first sandbag layer, the second sandbag layer, the third sandbag layer, the fourth sandbag layer and the cover sandbag layer all include multiple rows of sandbag groups arranged sequentially from top to bottom, and multiple sandbags in adjacent rows of the sandbag groups are arranged alternately.

[0009] The above-mentioned sandy foundation pit slope counterpressure anchor-free support structure is characterized in that: the gaps between each sandbag in the counterpressure sandbag layer and the gap between the counterpressure sandbag layer and the wire mesh shotcrete layer are all filled with mortar.

[0010] The above-mentioned sandy foundation pit slope counterpressure anchor-free support structure is characterized in that: the third sandbag layer overlaps with the first sandbag layer, the top height of the multiple layers of covered sandbags gradually decreases from the inside to the outside, the innermost layer of covered sandbags overlaps with the second sandbag layer, and the top of the next innermost layer of covered sandbags is higher than the top of the platform section.

[0011] The above-mentioned sandy foundation pit slope counterpressure anchor-free support structure is characterized in that: the upper support component and the lower support component each include multiple inclined rods arranged sequentially along the width direction of the foundation pit slope surface and transverse supports connected to the multiple inclined rods, the transverse supports being parallel to the foundation pit slope surface, and the inclined rods being vertically inserted into the foundation pit slope surface.

[0012] The above-mentioned sandy foundation pit slope counterpressure anchor-free support structure is characterized in that: a plurality of vertical rods are inserted at the bottom of the foundation pit slope to support the lower counterpressure sandbag layer, and the vertical rods are arranged close to the outermost covering sandbag layer.

[0013] This utility model has the following advantages compared with the prior art:

[0014] 1. This utility model uses a layer of counter-pressure sandbags to counter-pressure the slope of the foundation pit, avoiding the waiting time for grouting to solidify as is done with traditional soil nailing. It can quickly seal the original soil structure within the slope, effectively saving construction time and reducing the area occupied. The sandbags used do not need to be removed during the subsequent backfilling operation, which can speed up the construction period and meet the engineering quality requirements. At the same time, it can also effectively prevent rainwater from damaging the slope and ensure the stability of the foundation pit slope.

[0015] 2. By constructing the first slope section, the platform section, and the second slope section as the foundation pit slope, this utility model can achieve uniform matching of gravity and soil internal forces at different height positions of the slope, thereby effectively reducing the possibility of foundation pit slope collapse.

[0016] 3. This utility model sets up upper and lower support components on the first and second slope sections respectively, and combines them with the platform section to effectively support the sandbags, thereby facilitating the layered excavation of the foundation pit. This not only solves the problems of short-term support and continuous excavation, but also shortens the exposure time of the excavated foundation pit slope, improves the cost-effectiveness of the foundation pit support project, and meets the requirements of current green construction.

[0017] In summary, this utility model has a reasonable structural design. By using sandbags to counter-pressure the foundation pit slope, and utilizing the self-weight characteristics of the sandbags to offset the lateral pressure of the slope, it replaces the traditional soil nailing wall foundation pit support mode, ensuring the stability of the slope, saving material input, and shortening the construction period. The addition of support components at the bottom of the sandbags prevents the sandbags from shifting and slipping. The use of mortar to fill the gaps between the counter-pressure sandbags increases the integrity of the counter-pressure sandbags and further improves the waterproofing ability of the slope concrete layer.

[0018] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a schematic diagram of the structure after the first layer of sandbags is stacked.

[0021] Figure 3 This is a schematic diagram of the structure after the second sandbag layer of this utility model is stacked.

[0022] Figure 4 This is a schematic diagram of the structure after the third sandbag layer of this utility model is stacked.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1—Water-retaining platform; 21—First slope section; 22—Platform section;

[0025] 23—Second slope section; 3—Wire mesh and shotcrete layer; 41—First sandbag layer;

[0026] 42—Second sandbag layer; 43—Third sandbag layer; 44—Fourth sandbag layer;

[0027] 45—Covered sandbag layer; 5—Horizontal support; 6—Angled insert rod;

[0028] 7—Vertical insertion rod; 8—Mortar filling layer; 9—Sandbag pad layer. Detailed Implementation

[0029] like Figure 1 As shown, this utility model includes a foundation pit slope surface and a wire mesh sprayed concrete layer 3 and a counter-pressure sandbag layer sequentially arranged on the foundation pit slope surface. A water-blocking platform 1 is provided at the top of the foundation pit slope, and a sandbag cushion layer 9 is provided at the bottom of the foundation pit slope.

[0030] The foundation pit slope includes a first slope section 21, a platform section 22 and a second slope section 23 arranged sequentially from top to bottom. The first slope section 21 is provided with an upper support component for supporting the counter-pressure sandbag layer, and the second slope section 23 is provided with a lower support component for supporting the counter-pressure sandbag layer.

[0031] The counter-pressure sandbag layer includes an inner sandbag layer laid close to the slope surface of the foundation pit and a multi-layered covering sandbag layer 45 disposed outside the inner sandbag layer. The inner sandbag layer includes a first sandbag layer 41 stacked on the upper support component, a second sandbag layer 42 stacked between the platform section 22 and the upper support component, a third sandbag layer 43 stacked on the lower support component, and a fourth sandbag layer 44 stacked between the lower support component and the sandbag pad layer 9. The first sandbag layer 41 and the second sandbag layer 42 are both laid close to the first slope section 21, and the third sandbag layer 43 and the fourth sandbag layer 44 are both laid close to the second slope section 23.

[0032] In this embodiment, the first sandbag layer 41, the second sandbag layer 42, the third sandbag layer 43, the fourth sandbag layer 44 and the covering sandbag layer 45 each include multiple rows of sandbag groups arranged sequentially from top to bottom, and multiple sandbags in adjacent rows of the sandbag groups are arranged alternately.

[0033] In this embodiment, mortar filling layers 8 are provided for the gaps between the sandbags in the counter-pressure sandbag layer and the gap between the counter-pressure sandbag layer and the wire mesh sprayed concrete layer 3.

[0034] In actual use, by setting the mortar filling layer 8, the counterpressure sandbag layer can form an effective overall pressure layer, which is optimized and improved compared to the uneven stress surface of the soil nail, and the reliability of preventing rainwater from seeping into the slope soil layer is higher.

[0035] In this embodiment, the third sandbag layer 43 overlaps with the first sandbag layer 41, the top height of the multiple layers of covered sandbag layers 45 gradually decreases from the inside to the outside, the innermost layer of covered sandbag layer 45 overlaps with the second sandbag layer 42, and the top of the next innermost layer of covered sandbag layer 45 is higher than the top of the platform section 22.

[0036] In this embodiment, both the upper support assembly and the lower support assembly include multiple inclined rods 6 arranged sequentially along the width direction of the foundation pit slope and a transverse support 5 connected to the multiple inclined rods 6. The transverse support 5 is parallel to the foundation pit slope, and the inclined rods 6 are vertically inserted into the foundation pit slope.

[0037] In this embodiment, a plurality of vertical rods 7 are inserted at the bottom of the foundation pit slope to support the lower counter-pressure sandbag layer, and the vertical rods 7 are arranged close to the outermost covering sandbag layer 45.

[0038] In actual use, by setting up a layer of counter-pressure sandbags to counter-pressure the slope of the foundation pit, the waiting time for the grouting of traditional soil nail support is avoided, which effectively saves the construction period and can occupy less site area. The sandbags used do not need to be removed during the later backfilling operation, which can speed up the construction period and meet the engineering quality requirements. At the same time, it can also effectively prevent rainwater from damaging the slope and ensure the stability of the foundation pit slope.

[0039] It should be noted that by making the first slope section 21, the platform section 22, and the second slope section 23 constitute the foundation pit slope, gravity and soil internal forces can be uniformly matched at different height positions of the slope, thereby effectively reducing the possibility of foundation pit slope collapse.

[0040] In practice, upper and lower support components are set on the first slope section 21 and the second slope section 23 respectively, and the sandbags are effectively supported by the platform section 22. This facilitates the layered excavation of the foundation pit, which solves the problems of short-term support and continuous excavation, shortens the exposure time of the excavated foundation pit slope, improves the cost-effectiveness of the foundation pit support project, and meets the requirements of current green construction.

[0041] In practice, after the foundation pit is excavated, the bottom of the slope is compacted and leveled, and a plain concrete cushion layer of not less than 60mm thick is added as a sandbag cushion layer 9 to ensure that the sandbag foundation is flat and the compaction meets the requirements.

[0042] In actual construction, sandbags are first made and their stacking method is determined. The sandbags are made of non-weatherable and environmentally friendly fiber cloth bags, and the sand and soil excavated on site are used to fill and seal the bags. Then, according to the critical slope ratio design value of the foundation pit slope, the foundation pit is excavated in layers. During the layering, the foundation pit is excavated in four layers according to the positions of platform section 22, upper support components, and lower support components. After the first layer of excavation is completed, the slope is manually repaired. Loose soil on the slope is manually compacted or removed to obtain the upper part of the first slope section 21. In the first excavated slope section 21, wire mesh is installed and shotcrete is applied. A 300mm high water-retaining platform 1 is constructed above the pit. Sandbags are supported using scrap timber, with a cross-section of not less than 40mm*60mm. One end is sharpened to serve as a wedge 6, which is vertically wedged into the slope of the pit, with an exposed length of approximately 0.35m and a wedging depth of not less than 1.5 times the exposed length. Two rows of longitudinal square timber are then installed on the wedge 6 as transverse supports 5. A layer of sandbags is then stacked along the slope on the transverse supports 5 to form the first sandbag layer 41. Figure 2 As shown; then continue excavating the second layer to obtain the complete first slope section 21 and platform section 22. Wire mesh is installed on the excavated slope and platform sections of the second layer, and shotcrete is applied. From platform section 22 upwards along the slope, a layer of sandbags is piled to form the second sandbag layer 42, as shown. Figure 3 As shown; continue excavating downwards to the third layer, and spray concrete onto the slope surface with mesh, install lower support components, and stack a layer of sandbags along the slope surface on the lower support components to form a third sandbag layer 43, so that the third sandbag layer 43 overlaps with the second sandbag layer 42, as shown. Figure 4 As shown; continue to excavate the fourth layer downwards to obtain the complete second slope section 23, and spray concrete with mesh on the slope, and construct the sandbag cushion layer 9. On the sandbag cushion layer 9, stack a layer of sandbags along the slope to form the fourth sandbag layer 44.

[0043] To prevent sandbags from slipping or shifting, a row of vertical inserts 7 is added to the bottom of the foundation pit according to the lateral pressure design requirements at different heights. These vertical inserts 7 are made from scrap timber, with a cross-section of not less than 40mm x 60mm. One end is sharpened and vertically wedged into the foundation at the bottom of the pit. Then, multiple layers of sandbags 45 are continuously stacked from bottom to top. Figure 1 As shown; when stacking sandbags, sandbags in the same row should be stacked simultaneously, with staggered placement between rows and overlapping left and right, and the stack should be compacted to ensure the overall structural integrity of the sandbags. The openings of the stacked sandbags should face inwards (towards the slope) and should be tightly against the slope. Gaps should be filled tightly with dry mortar. The outer sides of the sandbags should be flat, with a uniform slope that meets the requirements.

[0044] In addition, when stacking sandbags, the quality of the stacking should be ensured, with a flat surface, dense stacking, and uniform slope. During construction, slope stability monitoring should be strengthened to prevent slope deformation from causing the support structure to collapse. To ensure the stability of the sandbag support structure and the slope, and to prevent slope instability caused by heavy rain and erosion, the slope should be covered with waterproof tarpaulins to ensure safe construction.

[0045] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the present utility model. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A sandy foundation pit slope counterpressure anchor-free support structure, characterized in that: It includes the slope surface of the foundation pit and the mesh sprayed concrete layer (3) and the counter-pressure sandbag layer set sequentially on the slope surface of the foundation pit. A water-blocking platform (1) is set at the top of the foundation pit slope, and a sandbag cushion layer (9) is set at the bottom of the foundation pit slope. The foundation pit slope includes a first slope section (21), a platform section (22), and a second slope section (23) arranged from top to bottom. The first slope section (21) is provided with an upper support component for supporting the counter-pressure sandbag layer, and the second slope section (23) is provided with a lower support component for supporting the counter-pressure sandbag layer. The counter-pressure sandbag layer includes an inner sandbag layer laid close to the slope surface of the foundation pit and a multi-layer covering sandbag layer (45) set outside the inner sandbag layer. The inner sandbag layer includes a first sandbag layer (41) stacked on the upper support component, a second sandbag layer (42) stacked between the platform section (22) and the upper support component, a third sandbag layer (43) stacked on the lower support component, and a fourth sandbag layer (44) stacked between the lower support component and the sandbag pad layer (9). The first sandbag layer (41) and the second sandbag layer (42) are both laid close to the first slope section (21), and the third sandbag layer (43) and the fourth sandbag layer (44) are both laid close to the second slope section (23).

2. The sandy foundation pit slope counter-pressure anchor-free support structure according to claim 1, characterized in that: The first sandbag layer (41), the second sandbag layer (42), the third sandbag layer (43), the fourth sandbag layer (44) and the covering sandbag layer (45) all include multiple rows of sandbag groups arranged sequentially from top to bottom, with multiple sandbags in adjacent rows of the sandbag groups arranged alternately.

3. The sandy foundation pit slope counter-pressure anchor-free support structure according to claim 1, characterized in that: The gaps between the sandbags in the counter-pressure sandbag layer and the gap between the counter-pressure sandbag layer and the shotcrete layer (3) are all filled with mortar (8).

4. The sandy foundation pit slope counter-pressure anchor-free support structure according to claim 1, characterized in that: The third sandbag layer (43) overlaps with the first sandbag layer (41). The top height of the multiple layers of covered sandbag layers (45) gradually decreases from the inside to the outside. The innermost layer of covered sandbag layer (45) overlaps with the second sandbag layer (42). The top of the next innermost layer of covered sandbag layer (45) is higher than the top of the platform section (22).

5. The sandy foundation pit slope counter-pressure anchor-free support structure according to claim 1, characterized in that: Both the upper and lower support components include multiple inclined rods (6) arranged sequentially along the width direction of the foundation pit slope and a transverse support (5) connected to the multiple inclined rods (6). The transverse support (5) is parallel to the foundation pit slope, and the inclined rods (6) are inserted vertically into the foundation pit slope.

6. The sandy foundation pit slope counter-pressure anchor-free support structure according to claim 1, characterized in that: Multiple vertical rods (7) are inserted at the bottom of the foundation pit slope to support the lower counter-pressure sandbag layer. The vertical rods (7) are arranged close to the outermost covering sandbag layer (45).

Images