Foundation pit slope supporting and reinforcing method

Abstract

The invention relates to a foundation pit slope supporting and reinforcing method. The foundation pit slope supporting and reinforcing method comprises the following steps that S1, a foundation pit is constructed and finished; s2, anchoring the side slope; s3, net hanging and concrete spraying; s4, piling and pouring; s5, laying a reinforcing mesh; s6, laying a template; and S7, concrete pouring. Through the multi-layer collaborative process of foundation pit finishing, side slope anchoring, net hanging and concrete spraying, piling and pouring, reinforcing mesh laying, formwork supporting and concrete pouring, an overall reinforcing system from surface layer erosion resistance to deep layer tensile resistance is formed. Key technologies such as T-shaped anchor rod plum blossom distribution, steel mesh-pile body reserved steel bar binding and segmented concrete curing are adopted, the strength and the severe environment resistance of the supporting structure are remarkably improved, and the supporting structure is suitable for foundation pit engineering under complex geological conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of foundation pits, and in particular relates to a foundation pit slope support and reinforcement method. Background Art

[0002] Foundation pit support is a key measure to ensure the safety of underground structure construction and the surrounding environment. Among them, the most commonly used support and reinforcement method for foundation pit slopes is spray anchor support. During the construction of spray anchor support, it is first necessary to anchor the steel bars on the slope of the foundation pit, and then lay the steel mesh on the slope, and tie the laid steel mesh and steel bars with steel wire, and finally spray concrete on the surface of the steel mesh. However, the current spray concrete reinforcement strength is low and is easily damaged under severe weather or external force impact, resulting in an increased risk of foundation pit collapse. In addition, a single spray concrete layer lacks deep and lateral coordinated reinforcement, and it is difficult to meet the stability requirements under complex geological conditions. Therefore, there is an urgent need for a foundation pit support reinforcement method that can significantly improve the anti-destruction ability and service life of the support structure. Summary of the Invention

[0003] The main purpose of the present invention is to propose a foundation pit slope support and reinforcement method, which can effectively solve the problems in the background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0005] A foundation pit slope support and reinforcement method comprises the following steps:

[0006] S1. Foundation pit construction and finishing: After the foundation pit is completed, the bottom of the foundation pit and the side slopes are trimmed and compacted to provide a flat and stable slope foundation for subsequent steps;

[0007] S2. Slope anchoring: After the slope of the foundation pit is trimmed, the drilling positions are determined at equal intervals on the upper part of the slope. The drilling operation is then carried out in sequence. Then, "T"-shaped anchor rods are placed inside the drilled holes. The outer ends of the "T"-shaped anchor rods are exposed to the pre-connected steel bars. Grouting work is then carried out. After grouting, the grouting is allowed to solidify.

[0008] S3. Hanging mesh and spraying concrete: After the slurry solidifies, lay the steel mesh on the slope surface of the foundation pit. Tie the steel mesh and the exposed part of the "T"-shaped anchor rod to prevent the steel mesh from falling. Then spray concrete on the surface of the steel mesh and wait for the sprayed concrete to solidify.

[0009] S4. Piling and pouring: After the sprayed concrete treatment, the pile driver drills multiple holes in the sprayed concrete area, then places prefabricated steel bars inside the holes, and then pours concrete to form the pile body, with steel bars reserved at the top of the pile;

[0010] S5. Laying of steel mesh: After the pile is formed, the steel bars are laid towards the slope of the foundation pit. The steel bars are arranged in a cross shape and supported by concrete pads. After the laying is completed, the bottom of the steel bars are tied to the steel bars reserved at the top of the pile;

[0011] S6. Formwork laying: Set up formwork around the steel mesh to provide a closed space for concrete pouring and prevent leakage;

[0012] S7. Concrete pouring: After the formwork is fixed, concrete can be poured into it. The poured structural parts need to be watered and cured for at least 7 days, and the formwork will be removed after the strength reaches 75%.

[0013] Preferably, in step S2, when drilling holes in the slope of the foundation pit, the drilling positions can be confirmed by staking out in a plum blossom-shaped distribution to disperse stress and enhance anchoring density.

[0014] Preferably, in step S3, the concrete is sprayed evenly onto the slope of the foundation pit, with a spraying thickness of 5-15 cm and a strength of not less than 15 MPa. The spraying is carried out in two steps, from bottom to top.

[0015] Preferably, in step S4, when the prefabricated steel bar frame is placed inside the filling hole, 30-40 cm is reserved on the upper part of the prefabricated steel bar frame.

[0016] Preferably, in step S4, the holes need to be cleaned before pouring the concrete to prevent soil from mixing into the interior of the concrete. During the pouring, the interior of the hole needs to be vibrated.

[0017] Preferably, in step S5, the steel bars are supported by concrete pads so that the height of the steel bars exceeds 1 cm, and the concrete pads are laid in a plum blossom shape at the intersection of the two groups of steel bars.

[0018] Preferably, in step S6, the bottom of the template is plugged in and fixed to avoid the bottom of the template from skipping, and the top is reinforced with steel pipe diagonal braces to prevent the template from deformation.

[0019] Preferably, in step S7, when pouring concrete, the concrete is poured in batches and sections. After pouring one section, the concrete needs to be sorted, vibrated, and smoothed. Then, the concrete is covered and cured before pouring the next section.

[0020] The present invention provides a foundation pit slope support and reinforcement method, which has the following beneficial effects:

[0021] This invention utilizes a multi-layered, coordinated process involving pit finishing, slope anchoring, mesh spraying, piling and pouring, steel mesh installation, formwork support, and concrete pouring to create a comprehensive reinforcement system that provides both surface erosion resistance and deep-seated tensile strength. Key technologies, such as a "T"-shaped anchor bolt pattern, pre-reinforced steel mesh-pile binding, and segmented concrete curing, significantly enhance the support structure's strength and resistance to harsh environments, making it suitable for pit projects located in complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a construction step diagram of the foundation pit support and reinforcement method of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the present invention.

[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate directions or positional relationships 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, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0027] Example

[0028] Reference Figure 1 , a foundation pit slope support and reinforcement method, comprising the following steps:

[0029] S1. Foundation pit construction and finishing: After the foundation pit is completed, the bottom of the foundation pit and the side slopes are trimmed and compacted to provide a flat and stable slope foundation for subsequent steps;

[0030] Specifically, large machinery is used to carry out excavation work at the foundation pit location to form the foundation pit, and then a tamping machine is used to compact and level the bottom of the foundation pit, and then the slope of the foundation pit is trimmed and compacted to make the slope of the foundation pit in a flat state.

[0031] A laser measuring instrument can be used to perform laser positioning on the upper and bottom parts of the foundation pit respectively, and then the upper and bottom parts of the foundation pit can be trimmed according to the laser measuring line. After the bottom and upper sides of the foundation pit are trimmed, the slopes can be trimmed using a level instrument to ensure the angle and flatness of the slopes.

[0032] S2. Slope anchoring: After the slope of the foundation pit is trimmed, the drilling positions are determined at equal intervals on the upper part of the slope. The drilling operation is then carried out in sequence. Then, "T"-shaped anchor rods are placed inside the drilled holes. The outer ends of the "T"-shaped anchor rods are exposed to the pre-connected steel bars. Grouting work is then carried out. After grouting, the grouting is allowed to solidify.

[0033] When drilling holes on the slope of the foundation pit, the drilling position can be confirmed by staking out in a plum blossom-shaped distribution to disperse stress and enhance anchoring density. A steel pipe rack platform is set up to drill holes according to the inclination angle of the slope of the foundation pit and the "T"-shaped anchor rod. The "T"-shaped anchor rod is then pushed into the borehole, and the pre-connected steel bars are exposed at the outer end of the "T"-shaped anchor rod. Grouting is then performed on the drilling position.

[0034] S3. Hanging mesh and spraying concrete: After the slurry solidifies, lay the steel mesh on the slope surface of the foundation pit. Tie the steel mesh and the exposed part of the "T"-shaped anchor rod to prevent the steel mesh from falling. Then spray concrete on the surface of the steel mesh and wait for the sprayed concrete to solidify.

[0035] Spray the concrete evenly onto the slope of the foundation pit. The spraying thickness is 5-15 cm and the strength should be no less than 15Mpa. The spraying should be carried out in two times, from bottom to top. The spraying effect should be flat and dense, without exposed reinforcement and hollowing.

[0036] S4. Piling and pouring: After the sprayed concrete treatment, the pile driver drills multiple holes in the sprayed concrete area, then places prefabricated steel bars inside the holes, and then pours concrete to form the pile body, with steel bars reserved at the top of the pile;

[0037] When the prefabricated steel frame is placed inside the filling hole, 30-40CM should be reserved on the upper part of the prefabricated steel frame;

[0038] Before pouring concrete, the holes need to be cleaned to prevent soil from mixing into the concrete. When pouring, the inside of the hole needs to be vibrated to prevent the concrete from breaking.

[0039] S5. Laying of steel mesh: After the pile is formed, the steel bars are laid towards the slope of the foundation pit. The steel bars are arranged in a cross shape and supported by concrete pads. After the laying is completed, the bottom of the steel bars are tied to the steel bars reserved at the top of the pile;

[0040] The steel bars are supported by concrete pads so that the height of the steel bars exceeds 1CM. The concrete pads are laid in a plum blossom shape at the intersection of two groups of steel bars. The piles can support the bottom of the steel bars, thereby effectively improving the overall strength of the steel bars during laying, making it easier to fix and tie the bottom of the steel bars.

[0041] S6. Formwork laying: Set up formwork around the steel mesh to provide a closed space for concrete pouring and prevent leakage;

[0042] The bottom of the formwork is plugged in and fixed to avoid the bottom of the formwork from skipping, and the top is reinforced with steel pipe diagonal braces to prevent the formwork from deformation.

[0043] S7. Concrete pouring: After the formwork is fixed, concrete can be poured into it. The poured structural parts need to be watered and cured for at least 7 days, and the formwork will be removed after the strength reaches 75%.

[0044] When pouring concrete, it is poured in batches and sections. After pouring one section, the concrete needs to be sorted, vibrated, and smoothed. Then, the concrete is covered and cured before pouring the next section to avoid concrete landslides.

[0045] This invention utilizes a multi-layered, coordinated process involving pit finishing, slope anchoring, mesh spraying, piling and pouring, steel mesh installation, formwork support, and concrete pouring to create a comprehensive reinforcement system that provides both surface erosion resistance and deep-seated tensile strength. Key technologies, such as a "T"-shaped anchor bolt pattern, pre-reinforced steel mesh-pile binding, and segmented concrete curing, significantly enhance the support structure's strength and resistance to harsh environments, making it suitable for pit projects located in complex geological conditions.

[0046] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A foundation pit slope support and reinforcement method, characterized in that: The following steps are involved: S1. Foundation pit construction and finishing: After the foundation pit is completed, the bottom of the foundation pit and the side slopes are trimmed and compacted to provide a flat and stable slope foundation for subsequent steps; S2. Slope anchoring: After the slope of the foundation pit is trimmed, the drilling positions are confirmed at equal intervals on the upper part of the slope. The drilling operation is carried out in sequence. Then, "T"-shaped anchor rods are placed inside the drilled holes. The outer ends of the "T"-shaped anchor rods are exposed to the pre-connected steel bars. Grouting work is then carried out. After grouting, the grouting is allowed to solidify. S3. Hanging mesh and spraying concrete: After the slurry solidifies, lay a steel mesh on the slope surface of the foundation pit. Tie the steel mesh and the exposed part of the "T"-shaped anchor rod to prevent the steel mesh from falling. Then spray concrete on the surface of the steel mesh and wait for the sprayed concrete to solidify. S4. Piling and pouring: After the sprayed concrete treatment, the pile driver drills multiple holes in the sprayed concrete area, then places prefabricated steel bars inside the holes, and then pours concrete to form the pile body, with steel bars reserved at the top of the pile; S5. Laying of steel mesh: After the pile is formed, the steel bars are laid towards the slope of the foundation pit. The steel bars are arranged in a cross shape and supported by concrete pads. After the laying is completed, the bottom of the steel bars are tied to the steel bars reserved at the top of the pile; S6. Formwork laying: Set up formwork around the steel mesh to provide a closed space for concrete pouring and prevent leakage; S7. Concrete pouring: After the formwork is fixed, concrete can be poured into it. The poured structural parts need to be watered and cured for at least 7 days, and the formwork will be removed after the strength reaches 75%.

2. A foundation pit slope support and reinforcement method according to claim 1, characterized in that: In step S2, when drilling holes on the slope of the foundation pit, the drilling positions can be confirmed by staking out in a plum blossom-shaped distribution to disperse stress and enhance anchoring density.

3. The foundation pit slope support and reinforcement method according to claim 1, characterized in that: In step S3, concrete is sprayed evenly onto the slope of the foundation pit, with a spraying thickness of 5-15 cm and a strength of no less than 15 MPa. The spraying is carried out in two steps, from bottom to top.

4. A foundation pit slope support and reinforcement method according to claim 1, characterized in that: In step S4, when the prefabricated steel bar frame is placed inside the filling hole, 30-40 cm should be reserved on the upper part of the prefabricated steel bar frame.

5. The method for supporting and reinforcing a foundation pit slope according to claim 1, characterized in that: In step S4, the holes need to be cleaned before pouring concrete to prevent soil from mixing into the interior of the concrete. During pouring, the interior of the hole needs to be vibrated.

6. The method for supporting and reinforcing a foundation pit slope according to claim 1, characterized in that: In step S5, the steel bars are supported by concrete pads so that the height of the steel bars exceeds 1 cm. The concrete pads are laid in a plum blossom shape at the intersection of the two groups of steel bars.

7. The method for supporting and reinforcing a foundation pit slope according to claim 1, characterized in that: In step S6, the bottom of the template is plugged in and fixed to avoid the bottom of the template from skipping, and the top is reinforced with steel pipe diagonal braces to prevent the template from deformation.

8. The method for supporting and reinforcing a foundation pit slope according to claim 1, characterized in that: In step S7, when pouring concrete, the concrete is poured in batches and sections. After pouring one section, the concrete needs to be sorted, vibrated, and smoothed. Then, the concrete is covered and cured before pouring the next section.

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