Plate wall foundation in-situ reinforcing structure capable of reducing excavation depth
By adjusting the excavation surface to the original backfill area and designing a stepped new reinforcement foundation, the high cost and safety hazards caused by the excavation depth in the existing technology were solved, and the construction efficiency and quality were improved.
Patent Information
- Application Number
- CN202520307251.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-25
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-02-25
AI Technical Summary
When constructing an existing in-situ reinforcement system for reinforced concrete slab wall foundations indoors, deep excavation to the base of the slab wall is required, resulting in high project costs, high construction costs, and potential safety and quality hazards.
An in-situ reinforcement structure for the slab wall foundation with reduced excavation depth is adopted, which includes the original reinforced concrete raft foundation, backfill soil, foundation cushion layer and newly added reinforcement foundation. By adjusting the excavation surface to the original backfill soil range, a stepped new reinforcement foundation is designed, and tie bars are set in the foundation to enhance the bearing capacity.
This significantly reduces the amount of earthwork excavation and backfilling, shortens the construction period, lowers costs, improves construction safety and quality, and meets seismic performance requirements.
Smart Images
Figure CN223838118U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of in-situ reinforcement and renovation, and in particular, it is an in-situ reinforcement structure for slab wall foundations that reduces excavation depth. Background Technology
[0002] The existing in-situ reinforcement system for reinforced concrete slab wall foundations requires the following steps during construction: First, excavation of the earthwork around the original structural wall is necessary, starting from the indoor ground level and removing all backfill soil. A portion of the original reinforced concrete raft foundation is then excavated until the base of the slab wall is exposed, forming an excavation surface. Next, above the excavation surface, new reinforcement foundations are constructed around the base of the slab wall. New reinforcement walls are then constructed on both sides of the slab wall above these new foundations. Finally, secondary backfilling is carried out around the new reinforcement foundations and walls above the excavation surface, with the excavation depth extending to the base of the slab wall.
[0003] The existing technology has the following problems:
[0004] I. Foundation reinforcement construction is mostly carried out indoors. Due to the limitations of room height, width, and depth in old residential areas and student dormitories, only small machinery or even manual labor can be used for earthwork excavation and backfilling. As a result, the cost of indoor earthwork projects is higher per cubic meter than that of conventional earthwork projects. This cost difference increases proportionally with the increase of excavation depth and area. At this time, the cost of measures to ensure safety and quality will also increase, and the corresponding construction period and cost will also rise accordingly.
[0005] Second, due to the limitations and influences of indoor space and terrain, there are significant safety and construction quality risks associated with large-scale excavation and backfilling between the base of the wall panel and the raft foundation to the depth required by the design. Utility Model Content
[0006] The purpose of this utility model is to provide an in-situ reinforcement structure for slab wall foundations that reduces excavation depth. This addresses the technical problem that existing in-situ reinforcement systems for indoor reinforced concrete slab wall foundations require excavation to the root of the slab wall, resulting in high project costs and construction expenses. It also addresses the significant safety and construction quality risks associated with large-scale excavation and backfilling.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] An in-situ reinforcement structure for a slab wall foundation that reduces excavation depth includes a reinforced concrete raft foundation, backfill, a foundation pad, and a newly added reinforcement foundation. The backfill includes original backfill and secondary backfill.
[0009] The original reinforced concrete raft foundation was covered with the original backfill soil. The excavation face was located on the surface of the original backfill soil, and a foundation pad was placed on top of the original backfill soil. The newly added foundation was located on top of the foundation pad and below the indoor ground level.
[0010] The in-situ reinforcement structure for the slab wall foundation includes the original structural wall and the newly added reinforcement wall. The base of the original structural wall is embedded in the original reinforced concrete raft foundation. The original backfill soil, foundation pad, and newly added reinforcement foundation are arranged sequentially from bottom to top around the outer side of the original structural wall along its height direction.
[0011] Two new reinforced walls are added, located on both sides of the original structural walls and connected to the upper side of the new reinforced foundation. The secondary backfill soil is backfilled above the foundation pad and below the indoor ground level, and is set around the outer side of the new reinforced foundation and the outer side of the bottom of the new reinforced wall.
[0012] Each newly added solid wall consists of wall concrete and a new wall steel mesh. New wall tie bars that pass through the original structural wall are provided between the new wall steel meshes on the left and right sides.
[0013] The newly added foundation includes foundation concrete, the cross-section of which is stepped, including a wide section of the lower step and a narrow section of the upper step, both of which have rectangular cross-sections.
[0014] The newly added solid foundation also includes foundation reinforcement, which includes foundation reinforcing bars. The foundation reinforcing bars include vertical sections and horizontal bends at the base. The vertical sections are formed by extending downwards from the newly added wall steel mesh to the bottom of the width section. The horizontal bends at the base are formed by continuing to bend outwards horizontally from the bottom end of the vertical sections and extending to the outer edge of the width section.
[0015] The foundation reinforcement consists of horizontal reinforcement and longitudinal reinforcement. The horizontal reinforcement is fixedly connected to the longitudinal reinforcement. The horizontal reinforcement is spaced along the longitudinal reinforcement and is divided into vertical horizontal reinforcement and bent horizontal reinforcement according to its position.
[0016] The basic reinforcement also includes basic tie bars, which are set within the vertical range and fixedly connected to the vertical.
[0017] The foundation tie bars include step tie bars, which pass through the original structural wall and are set at the step positions of the wide and narrow parts of the newly added solid foundation. The two ends of the step tie bars are exposed in the original structural wall and are fixedly connected to the vertical horizontal load-bearing bars on the left and right sides.
[0018] The reinforced concrete ring beam is located within the original structural walls and below the interior floor level.
[0019] The basic tie bars also include ring beam tie bars, which are fixedly connected to the reinforced concrete ring beam and are set at the position where the narrow part overlaps with the reinforced concrete ring beam. The outer ends of the ring beam tie bars are exposed outside the reinforced concrete ring beam and are fixedly connected to the vertical horizontal reinforcing bars on the left and right sides.
[0020] The fixed connection between the tie bars of the ring beam and the reinforced concrete ring beam is either through-hole reinforcement bars that penetrate the reinforced concrete ring beam or non-penetrating reinforcement bars that are installed.
[0021] The foundation concrete and the wall concrete are cast as a single unit.
[0022] Compared with the prior art, this utility model has the following features and beneficial effects:
[0023] This invention eliminates the old solution that requires the excavation depth to reach the root of the slab wall. The old solution requires an earthwork excavation depth of up to 1.6m, and also requires the destruction and excavation of part of the original reinforced concrete raft foundation, which makes construction very difficult.
[0024] This utility model adjusts the excavation surface by raising it to the original backfill area, eliminating the need to excavate to the base of the slab wall. Excavation only needs to be done from the indoor ground level to 0.6m, retaining a portion of the original backfill without excavation, thus reducing earthwork excavation of the original backfill. A foundation pad is constructed on the original backfill, followed by a new reinforced foundation. The structure and connection method of the new reinforced foundation have been designed. The new reinforced foundation is designed as a stepped structure, and its footprint is increased compared to the old design. Two layers of tie bars are installed within the foundation: one layer is placed at the weakest point of the foundation step, and the other layer is fixed using the existing ring beam, enhancing the bearing capacity of the new reinforced foundation. After raising the elevation of the new reinforced foundation, the compressive bearing capacity of the wall still embedded in the original raft foundation, the bearing capacity at the bottom of the foundation, and the seismic performance of the wall were verified, and all requirements were met.
[0025] This utility model reduces the excavation depth of the foundation for reinforced concrete slab wall reinforcement, significantly reducing the amount of earthwork excavation and backfilling during the construction of reinforced concrete slab wall foundations. It also significantly shortens the construction period for earthwork excavation and backfilling in foundation reinforcement, and greatly reduces the cost of earthwork sub-projects. Therefore, it can ensure the safety of foundation pit earthwork excavation operations affected by indoor space and terrain, and also ensure the backfill quality of the base layer used as the ground decoration layer. It improves the efficiency of indoor earthwork operations and ensures that the seismic fortification intensity and structural stress of the structure meet the current national standards and requirements.
[0026] This utility model provides a cost-reduction and efficiency-enhancing solution for in-situ reinforcement projects of indoor wall foundations that are limited by floor height, bay width, and depth, which suffer from long construction periods and high costs in earthwork engineering. It is particularly valuable for projects with strict requirements on construction period and cost. Attached Figure Description
[0027] The present invention will now be described in further detail with reference to the accompanying drawings.
[0028] Figure 1 This is a schematic diagram of the existing technology.
[0029] Figure 2 This is a schematic diagram of the structure of this utility model.
[0030] Figure 3 yes Figure 2 A magnified view of a portion of the image.
[0031] Figure reference numerals: 1 - Original reinforced concrete raft foundation; 2 - Backfill soil; 21 - Original backfill soil; 22 - Secondary backfill soil; 3 - Foundation pad; 4 - Foundation reinforcement; 41 - Vertical section; 42 - Horizontal bend in the base; 43 - Horizontal reinforcement; 431 - Vertical horizontal reinforcement; 432 - Horizontal reinforcement in the bend; 44 - Longitudinal reinforcement; 5 - Foundation tie bar; 51 - Step tie bar; 52 - Ring beam tie bar; 6 - Newly added solid foundation; 61 - Wide section; 62 - Narrow section; 7 - Indoor ground; 8 - Reinforced concrete ring beam; 9 - Original structural wall; 10 - Newly added solid wall; 101 - Newly added wall reinforcement mesh; 102 - Newly added wall tie bar; 103 - Wall concrete; 11 - Excavation face. Detailed Implementation
[0032] See Figure 1 As shown, the original design is an in-situ reinforcement system for reinforced concrete slab wall foundations. During construction, the artificial earthwork around the original structural wall 9 is first excavated, starting from the indoor ground level 7 and moving downwards. All backfill soil is removed, and a portion of the original reinforced concrete raft foundation 1 is excavated until the root of the slab wall is exposed, forming an excavation surface 11. Then, above the excavation surface 11, new reinforcement foundations 6 are constructed around the root of the slab wall. Next, new reinforcement walls 10 are constructed on both sides of the slab wall above the new reinforcement foundations 6. Subsequently, secondary backfilling 22 is carried out above the excavation surface 11, around the new reinforcement foundations 6 and the new reinforcement walls 10, until the indoor ground level 7 is reached. In the existing technology, the excavation surface 11 needs to reach the root of the slab wall, which can be up to 1.6m deep relative to the indoor ground level 7. This results in high project costs and construction expenses, and the large-scale excavation and backfilling pose significant safety and construction quality risks.
[0033] See Figure 2-3 As shown, an in-situ reinforcement structure for a slab wall foundation with reduced excavation depth is disclosed, comprising a reinforced concrete raft foundation 1, backfill soil 2, foundation cushion layer 3, and a newly reinforced foundation 6. The backfill soil 2 includes original backfill soil 21 and secondary backfill soil 22. The reserved thickness H of the original backfill soil 21 is 150mm-200mm.
[0034] The original reinforced concrete raft foundation 1 is covered with the original backfill soil 21. The excavation face 11 is located on the surface of the original backfill soil 21. The original backfill soil 21 is covered with the foundation cushion layer 3. The newly added solid foundation 6 is located on the upper side of the foundation cushion layer 3 and below the indoor ground level 7.
[0035] In this utility model, the depth of the excavation surface 11 is 0.6m below the indoor ground level 7, the width a of the foundation pad 3 is 600mm, the thickness b is 100mm, and the foundation pad is constructed using C20 plain concrete.
[0036] The in-situ reinforcement structure of the slab foundation also includes the original structural wall 9 and the newly added reinforcement wall 10. The root of the original structural wall 9 is embedded in the original reinforced concrete raft foundation 1. The original backfill soil 21, the foundation pad 3 and the newly added reinforcement foundation 6 are arranged around the outside of the original structural wall 9 from bottom to top along the height direction of the original structural wall 9.
[0037] Two new reinforced walls 10 are added, located on both sides of the original structural wall 9 and connected to the upper side of the newly added reinforced foundation 6. The secondary backfill soil 22 is backfilled above the foundation pad 3 and below the indoor ground 7, and is set around the outer side of the newly added reinforced foundation 6 and the outer side of the bottom of the newly added reinforced wall 10.
[0038] Each newly added solid wall 10 includes wall concrete 103 and newly added wall steel mesh 101. New wall tie bars 102 that pass through the original structural wall 9 are provided between the newly added wall steel mesh 101 on the left and right sides.
[0039] The newly added solid foundation 6 includes foundation concrete, the cross-section of which is stepped, including a wide portion 61 of the lower step and a narrow portion 62 of the upper step, both of which have rectangular cross-sections.
[0040] In this utility model, the width c of the wide part 61 is 500mm and the thickness d is 200mm, the width e of the narrow part is 200mm and the thickness f is 200mm, and the distance g between the top surface of the narrow part and the indoor floor 7 is 100mm.
[0041] The newly added solid foundation 6 also includes foundation reinforcement, which includes foundation reinforcing bars 4. The foundation reinforcing bars include a vertical part 41 and a base horizontal bend part 42. The vertical part 41 is formed by the newly added wall steel mesh 101 extending downward to the bottom of the width part 61. The base horizontal bend part 42 is formed by the bottom end of the vertical part 41 continuing to bend outward horizontally and extending to the outer edge of the width part 61.
[0042] The foundation reinforcing bar 4 consists of horizontal reinforcing bars 43 and longitudinal reinforcing bars 44. The horizontal reinforcing bars 43 and the longitudinal reinforcing bars 44 are fixedly connected. The horizontal reinforcing bars 43 are arranged at intervals along the longitudinal reinforcing bars 44. According to their arrangement, they are divided into vertical horizontal reinforcing bars 431 and bent horizontal reinforcing bars 432.
[0043] The basic reinforcement also includes basic tie bars 5, which are set within the vertical part 41 and fixedly connected to the vertical part 41.
[0044] The basic tie bar 5 includes a step tie bar 51, which passes through the original structural wall 9 and is set at the step position of the wide part 61 and narrow part 62 of the newly added solid foundation 6. The two ends of the step tie bar 51 are exposed in the original structural wall 9 and are fixedly connected to the vertical horizontal stress bars 431 on the left and right sides.
[0045] The reinforced concrete ring beam 8 is located within the original structural wall 9 and below the indoor floor 7. The distance h between the top surface of the reinforced concrete ring beam 8 and the indoor floor 7 is 60mm.
[0046] The basic tie bar 5 also includes a ring beam tie bar 52, which is fixedly connected to the reinforced concrete ring beam 8 and is set at the position where the narrow part 62 overlaps with the reinforced concrete ring beam 8. The outer end of the ring beam tie bar 52 protrudes from the reinforced concrete ring beam 8 and is fixedly connected to the vertical horizontal reinforcing bars 431 on the left and right sides.
[0047] The fixed connection between the ring beam tie bar 52 and the reinforced concrete ring beam 8 is either a through-hole reinforcement bar penetrating the reinforced concrete ring beam 8 or a non-through-hole anchor bar. In this embodiment, the fixed connection between the ring beam tie bar 52 and the reinforced concrete ring beam 8 is a through-hole reinforcement bar penetrating the reinforced concrete ring beam 8.
[0048] The foundation concrete and the wall concrete 103 are cast as a single unit.
[0049] The specific construction steps for this in-situ reinforcement method for slab wall foundations that reduces excavation depth are as follows:
[0050] Step 1: Design the dimensions of each component, and then excavate downwards from the indoor ground level 7 until the depth is -0.6m. When excavating to this position, leave the original backfill soil 21 with a thickness of 150mm-200mm.
[0051] Step 2: The top surface of the original backfill soil 21 is the bottom elevation of the foundation cushion layer 3. After the foundation trench is inspected and accepted by the construction, survey, design, supervision and construction parties, the foundation cushion layer 3 is poured on the original backfill soil 21.
[0052] Step 3: At the designed location, tie the double-layer foundation tie bar 5, step tie bar 51 and ring beam tie bar 52 above the foundation pad 3.
[0053] Step 4: At the designed location, tie the newly added wall reinforcement mesh 101 and newly added wall tie bars 102 of the newly added solid wall 10 on the outside of the original structural wall above the foundation pad 3. Tie the newly added wall reinforcement mesh 101 to the reinforcement in the original structural wall as one piece. Bend the bottom of the newly added wall reinforcement mesh 101 to form the foundation main reinforcement 4 in the foundation reinforcement. Then fix the foundation tie bars 5 to the vertical part 41 of the foundation main reinforcement 4.
[0054] Step 5: After the reinforcement binding is completed and passes inspection, the formwork is erected. After the reinforcement binding and formwork pass inspection, the wall concrete 103 and foundation concrete are poured together.
[0055] Step six: After the concrete has cured to the required strength, the secondary backfill soil above the foundation will be constructed. After the backfill soil and compaction reach the required compaction strength, the surface layer of the ground will be constructed.
Claims
1. An in-situ reinforcement structure for slab wall foundations that reduces excavation depth, characterized in that: It includes the original reinforced concrete raft foundation (1), backfill (2), foundation cushion (3) and newly added solid foundation (6). The backfill (2) includes the original backfill (21) and the secondary backfill (22). The original reinforced concrete raft foundation (1) is covered with the original backfill soil (21). The excavation face (11) is located on the surface of the original backfill soil (21). The original backfill soil (21) is covered with the foundation cushion layer (3). The newly added solid foundation (6) is located on the upper side of the foundation cushion layer (3) and below the indoor ground level (7). The in-situ reinforcement structure of the slab foundation also includes the original structural wall (9) and the newly added reinforcement wall (10). The root of the original structural wall (9) is embedded in the original reinforced concrete raft foundation (1). The original backfill soil (21), the foundation pad (3) and the newly added reinforcement foundation (6) are arranged from bottom to top around the outside of the original structural wall (9) along the height direction of the original structural wall (9). Two new solid walls (10) are installed on both sides of the original structural wall (9) and connected to the upper side of the new solid foundation (6). The secondary backfill soil (22) is backfilled above the foundation cushion (3) and below the indoor ground (7). At the same time, it is set around the outer side of the new solid foundation (6) and the bottom outer side of the new solid wall (10).
2. The in-situ reinforcement structure for reducing excavation depth of the slab wall foundation according to claim 1, characterized in that: Each newly added solid wall (10) includes wall concrete (103) and newly added wall steel mesh (101), and newly added wall tie bars (102) passing through the original structural wall (9) are provided between the newly added wall steel mesh (101) on the left and right sides.
3. The in-situ reinforcement structure for reducing excavation depth of the slab wall foundation according to claim 2, characterized in that: The newly added solid foundation (6) includes foundation concrete, the cross-section of which is stepped, including a wide part (61) of the lower step and a narrow part (62) of the upper step, both of which have rectangular cross-sections.
4. The in-situ reinforcement structure for reducing excavation depth of the slab wall foundation according to claim 3, characterized in that: The newly added solid foundation (6) also includes foundation reinforcement, which includes foundation reinforcing bars (4). The foundation reinforcing bars include a vertical part (41) and a base horizontal bend (42). The vertical part (41) is formed by the newly added wall steel mesh (101) extending downward to the bottom of the width part (61). The base horizontal bend (42) is formed by the bottom end of the vertical part (41) continuing to bend outward horizontally and extending to the outer edge of the width part (61).
5. The in-situ reinforcement structure for reducing excavation depth of the slab wall foundation according to claim 4, characterized in that: The foundation reinforcing bars (4) consist of horizontal reinforcing bars (43) and longitudinal reinforcing bars (44). The horizontal reinforcing bars (43) and longitudinal reinforcing bars (44) are fixedly connected. The horizontal reinforcing bars (43) are spaced along the longitudinal reinforcing bars (44) and are divided into vertical horizontal reinforcing bars (431) and bent horizontal reinforcing bars (432) according to their positions.
6. The in-situ reinforcement structure for reducing excavation depth of a slab wall foundation according to claim 5, characterized in that: The basic reinforcement also includes basic tie bars (5), which are set within the vertical part (41) and fixedly connected to the vertical part (41).
7. The in-situ reinforcement structure for reducing excavation depth of a slab wall foundation according to claim 6, characterized in that: The basic tie bar (5) includes a step tie bar (51). The step tie bar (51) passes through the original structural wall (9) and is set at the step position of the wide part (61) and narrow part (62) of the newly added solid foundation (6). The two ends of the step tie bar (51) are exposed in the original structural wall (9) and are fixedly connected to the vertical horizontal reinforcing bars (431) on the left and right sides.
8. The in-situ reinforcement structure for reducing excavation depth of a slab wall foundation according to claim 6, characterized in that: The reinforced concrete ring beam (8) is located inside the original structural wall (9) and below the indoor floor (7). The basic tie bar (5) also includes the ring beam tie bar (52), which is fixedly connected to the reinforced concrete ring beam (8) and set at the position where the narrow part (62) overlaps with the reinforced concrete ring beam (8). The outer end of the ring beam tie bar (52) protrudes from the reinforced concrete ring beam (8) and is fixedly connected to the vertical horizontal reinforcing bars (431) on the left and right sides.
9. The in-situ reinforcement structure for reducing excavation depth of a slab wall foundation according to claim 8, characterized in that: The fixed connection between the tie bar (52) of the ring beam and the reinforced concrete ring beam (8) is either through-hole reinforcement through the reinforced concrete ring beam (8) or non-through-hole anchoring.
10. The in-situ reinforcement structure for reducing excavation depth of a slab wall foundation according to claim 3, characterized in that: The foundation concrete and the wall concrete (103) are cast as a single unit.