Pipeline support foundation structure in collapsible loess area

Abstract

The utility model discloses a pipeline support foundation structure in a collapsible loess area, relates to the technical field of pipeline support foundation construction, solves the problem that a pipeline foundation in the collapsible loess area is prone to uneven settlement, and comprises a shallow reinforcing area, a transition buffer area and a concrete cast-in-place pile, the transition buffer area is located at the bottom of the shallow reinforcing area, and the concrete cast-in-place pile is located in the transition buffer area. The concrete cast-in-place piles fixedly penetrate through the interior of the transition buffer area, a concrete bearing platform is fixedly connected to the top face of the shallow reinforcing area, and bearing platform columns are integrally arranged on the top face of the concrete bearing platform; the shallow reinforcing area comprises a composite geomembrane and a broken stone hardcore, and the composite geomembrane is laid on the broken stone hardcore. The overall treatment process flow of the foundation structure is scientific and reasonable, strict standards are achieved from material selection to construction details, engineering quality is guaranteed, meanwhile, environmental protection and resource saving in the construction process are achieved, and good economic benefits and social benefits are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to pipeline support ground construction field especially to a collapsible loess area pipeline support ground structure. BACKGROUND

[0002] In the field of pipeline engineering, especially in the collapsible loess area with complex geological conditions, how to ensure the safe and stable operation of the pipeline is an important research topic. Although the existing ground treatment technology can improve the soil bearing capacity to a certain extent and reduce settlement, it still faces great challenges under extreme weather conditions. With the economic development of northwest China, higher requirements are put forward for infrastructure construction in such areas, especially in terms of ensuring the long-term safety and stability of the pipeline. Traditional ground treatment techniques have gradually shown their limitations. At present, the commonly used ground treatment methods in collapsible loess areas include replacement method, dynamic compaction method, pile foundation method and other ways.

[0003] In the process of realizing the utility model, the inventor found that at least the following problems exist in the prior art: the replacement method improves the foundation performance by replacing the soft soil layer, but the construction period is longer and the cost is higher; the dynamic compaction method uses heavy hammer to impact the ground to make the soil compact, but the reinforcement effect on deep soil is limited; the pile foundation method can effectively improve the foundation bearing capacity and reduce uneven settlement, but its cost is relatively higher. Therefore, a collapsible loess area pipeline support ground structure is proposed. UTILITY MODEL CONTENTS

[0004] In order to improve the problem of uneven settlement of pipeline foundation in collapsible loess area, the utility model provides a collapsible loess area pipeline support ground structure.

[0005] The utility model provides a collapsible loess area pipeline support ground structure, adopts the following technical scheme:

[0006] A collapsible loess area pipeline support ground structure, including shallow reinforcement area, transition buffer area and concrete bored pile, the transition buffer area is located at the bottom of the shallow reinforcement area, the concrete bored pile is fixed and penetrates inside the transition buffer area, the top surface of the shallow reinforcement area is fixedly connected with the concrete pile cap, and the top surface of the concrete pile cap is integrally provided with a pile cap column; the shallow reinforcement area includes a composite geomembrane and a gravel cushion layer, the composite geomembrane is laid above the gravel cushion layer, the transition buffer area includes a first sand-gravel mixed layer, a impermeable membrane and a second sand-gravel mixed layer, the second sand-gravel mixed layer is filled below the first sand-gravel mixed layer, and the impermeable membrane is laid between the first sand-gravel mixed layer and the second sand-gravel mixed layer.

[0007] By adopting the technical scheme, the foundation overall treatment process is scientific and reasonable, has strict standards from material selection to construction details, ensures the engineering quality, realizes the environmental protection and resource saving in the construction process, and has good economic and social benefits.

[0008] Optionally, a pile hole is provided in the shallow reinforcement area and the transition buffer area, and the composite geomembrane is made of high-density polyethylene composite material.

[0009] By adopting the technical scheme, the effective combination of the high-density polyethylene composite geomembrane and the gravel cushion layer in the shallow reinforcement area not only prevents the infiltration of surface water, but also accelerates the drainage of surface water, thereby greatly reducing the settlement deformation of the collapsible loess foundation caused by moisture, and effectively protecting the pipeline from the influence of the unstable foundation.

[0010] Optionally, the concrete bored pile is fixedly connected with the concrete pile cap penetrating the shallow reinforcement area and the transition buffer area.

[0011] By adopting the technical scheme, the prestressed concrete bored pile penetrates into the rock stable layer to form a strong support system, significantly enhances the ability of the foundation to resist external loads, and especially shows stronger toughness in the face of natural disasters such as earthquakes and floods, thereby greatly reducing the risk of pipeline rupture.

[0012] Optionally, a plurality of steel reinforcement cages are embedded in the concrete bored pile in a ring array.

[0013] By adopting the technical scheme, the steel reinforcement cage is combined with the spiral stirrup to form a steel reinforcement cage, which is placed in the pile hole to realize the pouring of the concrete bored pile.

[0014] Optionally, the first sand and gravel mixed layer and the second sand and gravel mixed layer are a mixture of natural river sand and pebbles with a fineness modulus of 2.8-3.2.

[0015] By adopting the technical scheme, the transition buffer area is designed with double-layer sand and gravel mixture, and a seepage prevention membrane is arranged in the middle, which further isolates fillers of different particle sizes and reduces the migration speed of water in the vertical direction. This not only strengthens the clear hierarchy inside the foundation and improves the overall durability and long-term stability of the foundation, but also indirectly prolongs the service life of the pipeline.

[0016] Optionally, the concrete bored pile is distributed in a rectangular array, the diameter of the concrete bored pile is 20 cm, and the pile spacing of the concrete bored pile is 2 m.

[0017] By adopting the technical scheme, after the pile position is determined, a rotary excavator is used to drill a hole directly to a rock stable layer to form a pile position hole, and a shallow reinforcement area, a transition buffer area and a concrete pile cap are formed into an integral structure by using a concrete pile.

[0018] Optionally, the transition buffer area is provided with a rock stable layer, the concrete pile is fixedly inserted into the rock stable layer, and a high-pressure grouting barrier is filled between the concrete pile and the rock stable layer.

[0019] By adopting the technical scheme, for a region with high underground water level and complex geological conditions, the continuous grouting barrier formed by the increased high-pressure jet grouting not only can completely isolate the influence of underground water on the foundation, but also can form an additional safety line to ensure the integrity of the foundation even under extreme conditions.

[0020] In summary, the utility model has the following beneficial effects:

[0021] 1. The utility model discloses a shallow reinforcement area and a transition buffer area, and the effective combination of the high-density polyethylene composite geomembrane and the gravel cushion layer of the shallow reinforcement area not only prevents the infiltration of surface water, but also accelerates the drainage of ground water, thereby greatly reducing the settlement deformation of the collapsible loess foundation caused by the moisture effect, and effectively protecting the pipeline from the influence of the unstable foundation.

[0022] 2. The utility model discloses a concrete pile, and the prestressed concrete pile penetrates into the rock stable layer to form a strong support system, thereby significantly enhancing the ability of the foundation to resist external loads, especially showing stronger toughness in the face of natural disasters such as earthquakes and floods, and greatly reducing the risk of pipeline rupture. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0024] Figure 2 It is a schematic diagram of the cross-sectional structure of the shallow reinforcement area of the utility model.

[0025] Figure 3 It is a schematic diagram of the cross-sectional structure of the transition buffer area of the utility model.

[0026] Figure 4 It is a schematic diagram of the cross-sectional structure of the concrete pile of the utility model.

[0027] MARKING OF THE DRAWINGS:

[0028] 1, shallow reinforcement area; 101, composite geomembrane; 102, gravel cushion; 103, pile hole; 2, transition buffer zone; 201, first gravel mixed layer; 202, impermeable membrane; 203, second gravel mixed layer; 3, concrete bored pile; 301, reinforcement cage main reinforcement; 302, spiral stirrup; 4, concrete pile cap; 5, pile cap column; 6, rock stable layer; 601, water barrier. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application are described clearly and completely below. Figures 1-4 It is apparent that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0030] Please refer to Figures 1-3 A pipeline support foundation structure in a collapsible loess area, comprising a shallow reinforcement area 1, a transition buffer zone 2 and a concrete bored pile 3, the transition buffer zone 2 is located at the bottom of the shallow reinforcement area 1, the shallow reinforcement area 1 comprises a composite geomembrane 101 and a gravel cushion 102, the composite geomembrane 101 is laid above the gravel cushion 102. The transition buffer zone 2 comprises a first gravel mixed layer 201, an impermeable membrane 202 and a second gravel mixed layer 203, the second gravel mixed layer 203 is filled below the first gravel mixed layer 201, and the impermeable membrane 202 is laid between the first gravel mixed layer 201 and the second gravel mixed layer 203. By adopting the above technical solution, the overall foundation treatment process is scientific and reasonable, there are strict standards from material selection to construction details, which ensures the engineering quality, realizes the environmental protection and resource saving in the construction process, and has good economic and social benefits.

[0031] Refer to Figure 2 and Figure 3A pile hole 103 is provided through the shallow reinforcement zone 1 and the transition buffer zone 2. The composite geomembrane 101 is made of high-density polyethylene composite material. The concrete cast-in-place pile 3 penetrates the shallow reinforcement zone 1 and the transition buffer zone 2 and is fixedly connected to the concrete cap 4. The first gravel mixture layer 201 and the second gravel mixture layer 203 are mixtures of natural river sand and pebbles with a fineness modulus between 2.8 and 3.2. The effective combination of the high-density polyethylene composite geomembrane 101 and the crushed stone cushion layer 102 in the shallow reinforcement zone 1 not only prevents surface water... The infiltration also accelerates the drainage of surface water, thereby greatly reducing the settlement and deformation caused by moisture in collapsible loess soil and effectively protecting the pipeline from the effects of unstable foundation. The transition buffer zone 2 adopts a double-layer gravel mixture design, with an impermeable membrane 202 in the middle, which further isolates fillers of different particle sizes and reduces the migration speed of water in the vertical direction. This not only strengthens the layering of the foundation and improves the overall durability and long-term stability of the foundation, but also indirectly extends the service life of the pipeline.

[0032] Reference Figure 2 and Figure 4 The concrete piles 3 are fixedly inserted into the transition buffer zone 2. The top surface of the shallow reinforcement zone 1 is fixedly connected to the concrete foundation 4, and the top surface of the concrete foundation 4 is integrally set with the foundation column 5. The concrete piles 3 are distributed in a rectangular array, and the diameter of the concrete piles 3 is 20 cm, and the pile spacing of the concrete piles 3 is set to 2 meters. The concrete piles 3 have several main steel cage bars 301 embedded in a ring array inside. The outer wall of the main steel cage bars 301 is fixed with spiral stirrups 302. After the pile position is determined, a rotary excavator is used to drill directly to the rock stable layer 6 to form the pile position hole 103. The concrete piles 3 are used to form an integral structure of the shallow reinforcement zone 1, the transition buffer zone 2 and the concrete foundation 4. The main steel cage bars 301 and the spiral stirrups 302 are combined to form a steel cage, which is placed in the pile position hole to realize the pouring of the concrete piles 3.

[0033] Reference Figure 1 and Figure 4 A rock stabilization layer 6 is set at the bottom of the transition buffer zone 2. Concrete cast-in-place piles 3 are fixedly inserted into the rock stabilization layer 6, and a grouting barrier 601 is filled under high pressure between the concrete cast-in-place piles 3 and the rock stabilization layer 6. The prestressed concrete cast-in-place piles 3 penetrate into the rock stabilization layer 6, forming a strong support system, which significantly enhances the foundation's ability to resist external loads. In particular, it exhibits stronger toughness in the face of natural disasters such as earthquakes and floods, greatly reducing the risk of pipeline breakage. In areas with high groundwater levels and complex geological conditions, the continuous grouting barrier 601 formed by the added high-pressure jet grouting can not only completely isolate the impact of groundwater on the foundation, but also form an additional safety barrier to ensure the integrity of the foundation can be maintained even under extreme conditions.

[0034] The implementation principle of the utility model is: remove the weeds and other floating objects on the construction site, ensure the construction interface is neat and smooth, then, lay high density polyethylene composite geomembrane 101, and ensure the interface is closed with special adhesive to prevent water leakage, then, pour 50cm thick gravel cushion 102 to form a shallow reinforcement area 1, the effective combination of high density polyethylene composite geomembrane 101 and gravel cushion 102 in shallow reinforcement area 1 not only prevents the infiltration of surface water, but also accelerates the removal of ground water, thereby greatly reducing the settlement deformation caused by the moisture effect of collapsible loess foundation, effectively protecting the pipeline from the influence of unstable foundation, using vibrating roller compaction, filling the first layer of sand and gravel mixture in order, also using sectional compaction method until reaching the height of 60cm, forming the first sand and gravel mixture layer 201, then placing the impermeable membrane to fill the second layer of the same sand and gravel material, forming the second sand and gravel mixture layer 203, the transition buffer area 2 uses double-layer sand and gravel mixture design, plus the impermeable membrane 202 set in the middle, further isolating the fillers of different particle sizes, reducing the migration speed of moisture in the vertical direction, which not only strengthens the clear hierarchy inside the foundation, improves the overall durability and long-term stability of the foundation, but also indirectly prolongs the service life of the pipeline, after determining the pile position, using the rotary excavator to drill the well straight to the rock stable layer, then, placing the prepared steel reinforcement cage main reinforcement 301 and spiral stirrup 302 into the well bottom, pouring enough C30 concrete into the well until completely filled, forming the concrete bored pile 3, after the concrete reaches the specified hardness index, building and installing the reinforced concrete pile cap 4, ensuring that it is tightly combined with the pile body, finally, high-pressure jet grouting is implemented between each pile position to generate the grouting barrier 601, the prestressed concrete bored pile 3 penetrates into the rock stable layer 6, forming a strong support system, significantly enhancing the foundation's ability to resist external loads, especially showing stronger toughness in the face of natural disasters such as earthquakes and floods, greatly reducing the risk of pipeline rupture, for areas with high underground water level and complex geological conditions, the continuous grouting barrier 601 formed by the increased high-pressure jet grouting not only can completely isolate the influence of underground water on the foundation, but also can form an additional safety line to ensure the integrity of the foundation even under extreme conditions.

[0035] The above only describes the preferred embodiments of the utility model, and is not used to limit the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, still can modify the technical scheme recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A pipeline support foundation structure in collapsible loess area, comprising a shallow reinforcement area (1), a transition buffer area (2) and a concrete bored pile (3), characterized in that: The transition buffer area (2) is located at the bottom of the shallow reinforcement area (1), the concrete bored pile (3) is fixedly penetrated in the transition buffer area (2), the top surface of the shallow reinforcement area (1) is fixedly connected with the concrete bearing platform (4), and the top surface of the concrete bearing platform (4) is integrally provided with the bearing platform column (5). The shallow reinforcement area (1) comprises the composite geomembrane (101) and the gravel cushion (102), the composite geomembrane (101) is laid above the gravel cushion (102), the transition buffer area (2) comprises the first gravel mixed layer (201), the anti-seepage film (202) and the second gravel mixed layer (203), the second gravel mixed layer (203) is filled below the first gravel mixed layer (201), and the anti-seepage film (202) is laid between the first gravel mixed layer (201) and the second gravel mixed layer (203).

2. The pipeline support foundation structure in a collapsible loess area according to claim 1, characterized in that: The shallow reinforcement area (1) and the transition buffer area (2) are provided with the pile hole (103) penetrating through the inside, the composite geomembrane (101) is made of high-density polyethylene composite material.

3. The pipeline support foundation structure in a collapsible loess area according to claim 1, characterized in that: The concrete bored pile (3) is fixedly connected with the concrete bearing platform (4) and penetrates through the shallow reinforcement area (1) and the transition buffer area (2).

4. The foundation structure for pipe support in a collapsible loess area according to claim 1, wherein: The concrete bored pile (3) is embedded with a plurality of steel reinforcement cages (301) in a ring array in the inside, and the outer wall of the plurality of steel reinforcement cages (301) is fixedly provided with the spiral stirrups (302).

5. The foundation structure for pipe support in collapsible loess area according to claim 1, characterized in that: The concrete bored pile (3) is distributed in a rectangular array, the diameter of the concrete bored pile (3) is 20 cm, and the pile spacing of the concrete bored pile (3) is 2 m.

6. The foundation structure for pipe support in a collapsible loess area according to claim 1, wherein: The transition buffer area (2) is provided with the rock stabilizing layer (6) at the bottom, the concrete bored pile (3) is fixedly penetrated in the rock stabilizing layer (6), and the high-pressure grouting barrier (601) is filled between the concrete bored pile (3) and the rock stabilizing layer (6).

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