Mini-type steel pipe pile foundation for earth-rock backfill side slope

Abstract

The utility model discloses a miniature steel pipe pile foundation for an earth-rock backfill side slope. The miniature steel pipe pile foundation is arranged above an earth-rock backfill area and is supported and fixed in a rock area; the miniature steel pipe pile foundation comprises miniature steel pipe piles and a structural foundation, the miniature steel pipe piles are vertically arranged side by side, and the tops of the miniature steel pipe piles in each group and the structural foundation formed through pouring are fixedly connected into a whole. Each group of miniature steel pipe piles is formed by casting steel pipes, reinforcing steel bar bundles and non-shrinkage mortar on site; wherein the steel bar bundle penetrates through the steel pipe and is consolidated through non-shrinkage mortar poured in the steel pipe on site, the bottom of the steel pipe and the bottom of the steel bar bundle extend into original rock to be fixed, and the top of the steel pipe and the top of the steel bar bundle are consolidated with a structural foundation formed through pouring; the structure foundation is a horizontal platform foundation formed through cast-in-place. Holes are formed in the wall of the steel pipe pile, the steel pipe pile and the periphery are fixedly connected to form a stable structure after grouting, the requirements for foundation bearing and upper load stress can be met, large-area excavation of a side slope is avoided, the applicability is high, and the construction efficiency is high.

Description

Technical Field

[0001] This utility model belongs to the field of water conservancy and hydropower engineering, municipal engineering, and road construction technology. It relates to the construction technology of building structural foundations on earth-rock backfill slopes during construction. Specifically, it is a micro steel pipe pile foundation for earth-rock backfill slopes. Background Technology

[0002] In water conservancy and hydropower projects, municipal engineering, and road construction, temporary facility foundations are often constructed on high backfilled slopes. After natural settlement, backfilled slopes still pose risks of continued settlement and local instability. The risk is high if large-scale infrastructure is installed on such slopes; there is a possibility of foundation overturning due to settlement and local instability, and the risk is even greater for the foundations of important temporary structures. Summary of the Invention

[0003] This utility model discloses a micro steel pipe pile foundation for soil and rock backfill slopes, addressing the shortcomings of existing technologies. The purpose of this utility model is to provide a micro steel pipe pile foundation design structure for soil and rock backfill slopes that offers lower construction costs, simpler construction operations, shorter construction periods, and better stability after completion.

[0004] To achieve the above objectives, this utility model adopts the following technical solution:

[0005] A micro steel pipe pile foundation for a backfilled soil and rock slope, wherein the backfilled soil and rock slope includes an original rock area and a backfilled soil and rock area formed by backfilling, characterized in that: the micro steel pipe pile foundation is arranged above the backfilled soil and rock area and supported and fixed in the rock area; the micro steel pipe pile foundation includes micro steel pipe piles and structural foundation, wherein multiple sets of micro steel pipe piles are arranged vertically side by side, and the top of each set of micro steel pipe piles is integrally fixed with the structural foundation formed by pouring.

[0006] Each set of micro steel pipe piles is composed of steel pipes, steel bar bundles, and non-shrink mortar cast on site. The steel bar bundles are inserted through the steel pipes and consolidated by the non-shrink mortar cast on site. The bottom of the steel pipes and steel bar bundles are fixed into the original rock, and the top is consolidated with the structural foundation formed by the cast-in-place. The structural foundation is a horizontal platform foundation formed by cast-in-place.

[0007] Furthermore, the steel pipe wall is provided with openings at uniform intervals.

[0008] Furthermore, the steel bar bundle consists of at least three steel bars welded side by side, with the top bent outward at 15° and anchored to the steel bars arranged in the structural foundation and then cast into place.

[0009] Furthermore, the bottom of the micro steel pipe pile extends into the original rock to a depth of not less than 2m.

[0010] Furthermore, the steel pipe wall is provided with evenly spaced openings with a diameter of not less than 2cm, which are staggered along the length of the steel pipe and spaced 30cm apart.

[0011] Furthermore, at least three sets of the aforementioned micro steel pipe piles are arranged vertically side by side.

[0012] This utility model relates to a micro-steel pipe pile foundation for backfilled soil and rock slopes. Micro-steel pipe piles serve as the load-bearing structure of the foundation, enhancing the load-bearing performance of the backfilled soil. Holes are drilled in the walls of the micro-steel pipe piles, and cement grout is delivered to the surrounding backfill soil under low pressure, further reinforcing the foundation. The micro-steel pipe piles, together with the surrounding consolidated soil and rock, form a stable structure, which is beneficial to slope stability. The construction process of micro-steel pipe piles is simple, requiring no large equipment investment, significantly reducing foundation treatment costs. It also eliminates the need for extensive slope excavation, making it particularly suitable for backfilled slopes where excavation is not feasible.

[0013] This utility model relates to a micro steel pipe pile foundation for backfilled soil and rock slopes. It uses micro steel pipe pile foundations to treat the foundation of backfilled soil and rock slopes. Compared with excavation and pile foundations, it can save a lot of costs, and this solution is more suitable when the slope space is limited.

[0014] Compared with existing technologies, this utility model has the following advantages: it eliminates the need for large-scale slope excavation and is suitable for confined spaces; it has lower construction costs, employs anchor drilling rigs for root pipe drilling, resulting in high equipment efficiency; it creates openings in the walls of the micro steel pipe piles, using low pressure to deliver cement grout to the surrounding backfill soil, and the micro steel pipe piles together with the surrounding consolidated soil and rock form a stable structure, further reinforcing the foundation and contributing to slope stability; the steel pipe piles and the surrounding consolidated soil together serve as the structural foundation, resulting in high bearing capacity and reinforcing the backfill slope.

[0015] The application of this invention in the construction of soil-rock backfill slope foundations can meet the bearing capacity requirements of the foundation and the load-bearing requirements of the superstructure, avoiding large-scale excavation of the soil-rock backfill slope, and is highly applicable in confined spaces. Its construction is simple and convenient, with low difficulty in organizing equipment resources and low cost. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the layout structure of the micro steel pipe pile foundation for soil and rock backfill slope of this utility model;

[0017] Figure 2 This is a schematic diagram of the micro steel pipe pile structure for backfilling slopes in this utility model.

[0018] Figure 3 This is a schematic diagram of the plan layout of the micro steel pipe piles for backfilling slopes in this utility model.

[0019] Figure 4 This is a schematic diagram of the top cross section of the micro steel pipe pile for backfilling slopes according to this utility model;

[0020] Figure 5 This is a schematic diagram of the cross-section of the middle section of the micro steel pipe pile for backfilling slopes according to this utility model.

[0021] Figure reference numerals:

[0022] 1 is a micro steel pipe pile, 1-1 is a steel pipe, 1-2 is a steel pipe hole, 1-3 is a steel bar bundle, 1-4 is non-shrink mortar, 2 is a backfill slope line, 3 is a temporary excavation line for backfill slope foundation construction, 4 is a backfill line after backfill slope foundation construction, 5 is a structural foundation, 6 is a bedrock line, 7 is a soil and rock backfill area, and 8 is a rock area. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments. These specific embodiments are further explanations of the principle of the present invention and are not intended to limit the present invention in any way. Any technology that is the same as or similar to the present invention does not exceed the protection scope of the present invention.

[0024] Refer to the attached diagram.

[0025] like Figures 1 to 5 As shown, a method for a micro steel pipe pile foundation for a backfilled soil and rock slope is described. The micro steel pipe pile foundation for a backfilled soil and rock slope includes: micro steel pipe pile 1; 3mm thick steel pipe 1-1; steel pipe opening 1-2; 28mm diameter steel bar bundle 1-3; M40 non-shrink mortar 1-4; backfill slope line 2; temporary excavation line for backfill slope foundation construction 3; backfill line after backfill slope foundation construction 4; structural foundation 5; bedrock line 6; soil and rock backfill area 7; rock area 8.

[0026] In the backfill area 7, a temporary construction platform is first excavated along the temporary excavation line 3 for the backfill slope foundation construction. Simultaneously, a steel pipe 1-1 with a diameter of 108mm and a wall thickness of 3mm is used to create a hole 1-2. An anchor drilling rig is used to drill the hole, and the pre-fabricated 3mm steel pipe 1-1 serves as the drilling casing. After the drilling rig reaches the bedrock 6, the drilling depth in the rock area 8 is controlled to be no less than 2m. After measuring the actual hole depth, steel reinforcement bundles 1-3 with a diameter of 28mm are fabricated. The pre-fabricated steel reinforcement bundles 1-3 are placed inside the steel pipe 1-1, and grouting is performed using high-flowability M40 non-shrink mortar 1-4. Grouting can be done manually or using a grouting machine. Under the pressure of the mortar's own weight, the mortar will diffuse into the nearby soil and rock area, achieving the effect of consolidating the surrounding soil. Grouting work is stopped when the injected mortar no longer settles. After grouting is completed, avoid disturbance. After 3 to 5 days of waiting for strength, start the construction of the structural foundation 5. After the structural foundation 5 is completed and reaches 50% of the design strength, backfill the temporary excavation area of ​​the backfill slope foundation construction temporary excavation line 3 to the original backfill line 4 after the backfill slope foundation construction.

[0027] The micro steel pipe pile 1 uses a steel pipe 1-1 with a diameter of 108mm and a wall thickness of 3mm. A larger diameter steel pipe 1-1 can be used depending on the weight of the structure. The opening 1-2 of the steel pipe has a hole size of not less than 2cm and is arranged alternately along the length of the steel pipe 1-1 at a spacing of 30cm. The internal steel reinforcement bundles 1-3 are processed into a whole by spot welding, and the exposed part is bent at 15° to form mutual anchorage with the steel reinforcement arranged in the structural foundation 5. M40 non-shrink mortar 1-4 is used for grouting, either manually or with a grouting machine. The mortar is mixed with a mortar mixer, and the mortar injection speed and volume are observed during grouting to prevent mortar waste.

[0028] For micro steel pipe piles, the drilling depth needs to be 2m into the rock, generally not exceeding 1 / 3 of the rock burial depth.

[0029] The arrangement of miniature steel pipe piles 1 needs to be determined based on the stress characteristics of the foundation structure.

[0030] Backfill slope line 2 is the slope line formed by the natural collapse of the backfill slope.

[0031] The temporary excavation line 3 for backfilling slope foundation construction must ensure the stability of the slope during the implementation stage after excavation. If local instability occurs due to rockfall, temporary support measures should be taken to ensure safety during construction.

[0032] Backfill line 4 is constructed after the foundation construction is completed and after curing for about 7 days and reaching 50% of the design strength. This process forms a relatively stable backfill slope, which can be carried out by a combination of manual labor and equipment.

[0033] The structural foundation 5 needs to be equipped with structural steel bars, which are anchored to the steel bars inside the micro steel pipe pile 1 to ensure good stress distribution between the micro steel pipe pile 1 and the structural foundation 5. The steel bar configuration of the structural foundation 5 needs to be determined by calculation based on the stress condition of the foundation itself.

[0034] Bedrock line 6 is a relatively intact rock line, and the rock below this rock line has sufficient strength to withstand the load transmitted by the micro steel pipe pile 1.

[0035] The arrangement of miniature steel pipe piles 1 can be adjusted according to the stress characteristics of the structural foundation 5. Generally, miniature steel pipe piles 1 should be arranged in the position of the structural foundation 5 where the stress is greater; the number of them should be determined by calculation based on the stress characteristics of the structural foundation 5 and its superstructure.

[0036] The construction steps for the micro steel pipe pile foundation of the soil and rock backfill slope of this utility model are as follows:

[0037] Step 1: Manually excavate the micro steel pipe pile 1 construction platform on the backfill slope according to the requirements of temporary excavation line 3 for backfill slope foundation construction; Simultaneously start the on-site processing of micro steel pipe pile 1, including: drilling of steel pipe 1-1, etc. The processed steel pipe 1-1 is processed in standard sections of 3m each.

[0038] Step 2: Measure and mark the points according to the arrangement of micro steel pipe piles 1, and use an anchoring drill to drill holes. The pre-formed steel pipe 1-1 is used as the root pipe and is lowered into the hole. The drilling depth, noise and drilling speed of the anchoring drill on the backfill slope are different. After judging on site that the bedrock line 6 has been entered, continue drilling for no less than 2m as required.

[0039] Step 3: Measure the depth after drilling stops in Step 2, and process anchor bar bundles 1-3 according to this depth. If anchor bar bundles 1-3 are too long, consider welding them during the on-site anchor bar bundle installation process, and stagger the welding extension positions.

[0040] Step 4: Prepare cement, sand, water, mortar mixer, admixtures, and electronic scale. Mix non-shrink mortar according to the M40 mortar mix ratio (1-4), and grout using a grouting machine. Observe the injection volume while grouting, inject mortar at a uniform speed, without limiting the injection volume, ensuring that the injected mortar overflows from the holes to achieve the purpose of consolidating the surrounding soil and rock backfill area. Record the injection volume of each individual micro steel pipe pile.

[0041] Step 5: Complete all the micro steel pipe piles 1 arranged for the structural foundation 5 according to steps 1-4, and wait 3-5 days for them to reach the required strength. Clean the foundation surface and pour the cushion layer. Make a steel mesh on the poured cushion layer, erect the formwork, and pour the structural foundation concrete.

[0042] Step 6: After the concrete for the structural foundation 5 is poured, cover it with wet burlap sacks and cure it for 7 days until it reaches 50% of the design strength. Then backfill it according to the original slope line and compact the slope manually.

[0043] Step 7: After completing Step 6 above, the micro steel pipe pile foundation of the soil and rock backfill slope is completed, and subsequent structures can be implemented.

Claims

1. A micro steel pipe pile foundation for a soil-rock backfill slope, wherein the soil-rock backfill slope includes an original rock area and a soil-rock backfill area formed by backfilling, characterized in that: The micro steel pipe pile foundation is arranged above the soil and rock backfill area and supported and fixed in the rock area; the micro steel pipe pile foundation includes micro steel pipe piles and structural foundation, and multiple sets of micro steel pipe piles are arranged vertically side by side, with the top of each set of micro steel pipe piles being integrally fixed with the structural foundation formed by pouring. Each set of micro steel pipe piles is composed of steel pipes, steel bar bundles, and non-shrink mortar cast on site. The steel bar bundles are inserted through the steel pipes and consolidated by the non-shrink mortar cast on site. The bottom of the steel pipes and steel bar bundles are fixed into the original rock, and the top is consolidated with the structural foundation formed by the cast-in-place. The structural foundation is a horizontal platform foundation formed by cast-in-place.

2. The micro steel pipe pile foundation for soil and rock backfill slope according to claim 1, characterized in that: The steel pipe wall is provided with evenly spaced openings.

3. The micro steel pipe pile foundation for soil and rock backfill slope according to claim 2, characterized in that: The steel bar bundle consists of at least three steel bars welded side by side, with the top bent outward at 15° and anchored to the steel bars arranged in the structural foundation and then cast into place.

4. The micro steel pipe pile foundation for soil and rock backfill slope according to claim 2, characterized in that: The bottom of the micro steel pipe pile extends into the original rock to a depth of not less than 2m.

5. The micro steel pipe pile foundation for soil and rock backfill slope according to claim 2, characterized in that: The steel pipe wall is provided with evenly spaced openings with a diameter of not less than 2cm, which are staggered along the length of the steel pipe and spaced 30cm apart.

6. The micro steel pipe pile foundation for soil and rock backfill slope according to claim 2, characterized in that: At least three sets of the micro steel pipe piles are arranged vertically side by side.

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