Geotextile bag flexible retaining wall suitable for soft soil stratum

Abstract

The utility model discloses a geobag flexible retaining wall suitable for a soft soil stratum. The geobag flexible retaining wall comprises an arch ring, a retaining wall bearing platform, a pile foundation, an arch end buttress, a protection foot, an inverted filter layer and an expansion joint. The retaining wall bearing platform comprises a buttress bottom plate and a soilbag bottom plate, the buttress bottom plate and the soilbag bottom plate are fixed to the multiple pile foundations, and the arch ring is formed by arranging a plurality of soilbag bodies in an arch shape and stacking the soilbag bodies in a staggered joint mode. The geobag flexible retaining wall has good horizontal slippage resistance and vertical deformation resistance; the soil engineering bags are stacked to form an arch structure, horizontal acting force behind the wall is transmitted to the arch end buttresses through the arch effect, the soil engineering bags stacked in a staggered-joint mode generate the build-in effect under the arch effect, the anti-sliding performance of the retaining wall is improved, the contact area of the retaining wall and a pile foundation is increased through the expanded bottom plate, the vertical deformation resisting capacity is improved in cooperation with the pile foundation, and the anti-sliding performance of the retaining wall is improved. Compared with a concrete hard retaining wall, the geobag flexible retaining wall is light in weight and beneficial to control of vertical deformation. Vegetation can be planted on the surfaces of the geotechnical bags, and good ecological performance is achieved.

Description

Technical Field

[0001] This utility model relates to the field of river regulation engineering technology, and in particular to a geotextile bag flexible retaining wall suitable for soft soil layers. Background Technology

[0002] In river regulation projects, especially in rivers with poor geological conditions, particularly those with deep soft soil layers, the selection of the cross-sectional type of the riverbank retaining wall needs to consider factors such as foundation bearing capacity, foundation settlement, horizontal earth pressure, and water pressure. Simultaneously, factors such as the surrounding ecological environment and landscape requirements, project land occupation, and project cost also need to be considered.

[0003] Currently, riverbank retaining walls mainly employ two types of cross-sectional designs: one is rigid retaining walls, represented by gravity retaining walls and buttress retaining walls; the other is ecological retaining walls, represented by ecological blocks and ecological frame retaining walls. Rigid retaining walls have strong erosion resistance and high structural stability, capable of withstanding significant earth and water pressure. However, they suffer from poor ecological performance, lack of accessibility to water and aesthetic appeal, and require high foundation bearing capacity, potentially leading to uneven settlement and deformation, resulting in higher project investment. Ecological retaining walls, on the other hand, offer good ecological performance and a pleasant landscape, adapting to foundation settlement and deformation, with lower foundation bearing capacity requirements and lower project investment. However, they have weaker erosion resistance and poorer structural stability.

[0004] For example, CN109555081A discloses a buttress-type ecological revetment structure suitable for soft soil foundations. This structure uses a pile-foundation buttress-type retaining wall along the riverbank to resist horizontal loads, and the ecological block retaining wall exhibits good ecological and aesthetic appeal. However, this structure is essentially still a rigid buttress-type retaining wall. The ecological blocks further increase the weight of the retaining wall, raising the requirements for the foundation's bearing capacity, while the pile foundation's resistance to horizontal forces is relatively poor.

[0005] Therefore, it is necessary to invent a geotextile flexible retaining wall suitable for soft soil layers to solve the above problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a flexible retaining wall made of geotextile bags suitable for soft soil layers, which addresses the shortcomings of the existing technology. On the one hand, horizontal forces such as earth pressure and water pressure are borne by the arch end supports, and vertical forces such as gravity are borne by the pile foundation. On the other hand, the material inside the geotextile bag can be adjusted according to the water flow conditions. In river sections with high scouring force, rubble material with better scouring performance is selected, while in river sections with low scouring force, soil material with good ecological and landscape properties is selected.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A geotextile bag flexible retaining wall suitable for soft soil strata, including

[0009] Multiple pile foundations are arranged in a linear array along an arched arc and vertically inserted into the soft soil layer of the riverbank foundation.

[0010] The retaining wall foundation includes a pier base plate and a geotextile bag base plate, and the pier base plate and the geotextile bag base plate are fixed on multiple pile foundations.

[0011] An arch ring is located on top of the bottom plate of the geotextile bag, and the arch ring is formed by multiple geotextile bags arranged in an arch shape and stacked in a staggered manner.

[0012] The arch end support is rigidly connected to the top of the support base plate, and the end of the arch ring is attached to the side of the arch end support.

[0013] The outer convex side of the arch is fitted with a filter layer, and the space between the filter layer and the bank slope protection is filled with backfill soil. The inner concave side of the arch is provided with a foot protection.

[0014] Preferably, the multiple geotextile bags that make up the arch are arranged in a horizontally staggered manner, and the multiple geotextile bags that make up the arch are arranged in a vertically staggered manner.

[0015] The arch protrudes towards the backwater side of the retaining wall in plan view and backs onto the bank slope protection soil structure in elevation view.

[0016] Preferably, the number of arches is set to multiple, and the total length of the multiple arches connected in sequence matches the width of the retaining wall.

[0017] Preferably, the cross-section of the arch end support is hexagonal, the two ends of the arch ring abut against one of the two sides of the arch end support, the longitudinal section of the arch end support is parallelogram, and the arch end support is inclined to the backwater side of the retaining wall on the vertical surface.

[0018] Preferably, the arch end support is made of reinforced concrete, the arch end support and the filter layer have the same inclination angle, which is equal to the inclination angle of the arch ring, and the number of arch end supports is set to multiple, and the distance between two adjacent arch end supports is set to 10-20m.

[0019] Preferably, the foot protection is made of scattered rubble arranged on the water-facing side of the retaining wall and separated by arch-end supports, and the width of the foot protection is at least 3m.

[0020] Preferably, the filter layer is a gravel filter or a geotextile filter.

[0021] Preferably, an expansion joint is reserved between the bottom plate of the support and the bottom plate of the geotextile bag, and the width of the expansion joint is set to 1-2cm.

[0022] Preferably, the expansion joint is filled with a flexible solid material, and a rubber waterstop is installed on the water-facing side of the expansion joint.

[0023] Preferably, both the support pier bottom plate and the geotextile bag bottom plate are made of reinforced concrete, and the support pier bottom plate and the geotextile bag bottom plate have the same thickness. A crushed stone cushion layer of at least 10cm thickness is provided between the bottom of the retaining wall foundation and the soft soil layer.

[0024] This utility model has the following beneficial effects:

[0025] 1. Geotextile bag flexible retaining walls have good resistance to horizontal sliding and vertical deformation. By stacking geotextile bags into an arched structure, the horizontal force behind the wall is transferred to the arch end support through the arch effect. The staggered stacked geotextile bags generate an embedded effect under the arch effect, which improves the anti-sliding performance of the retaining wall. The enlarged base plate increases the contact area between the retaining wall and the pile foundation, which works with the pile foundation to improve the ability to resist vertical deformation. Compared with rigid concrete retaining walls, geotextile bag flexible retaining walls are lighter and are more conducive to controlling vertical deformation.

[0026] 2. The geotextile bag flexible retaining wall is inclined towards the bank slope, reducing active earth pressure behind the wall, increasing the structure's resistance to sliding, and shifting the wall's center of gravity towards the toe, thus increasing the structure's resistance to overturning. This structural layout also facilitates the installation of drainage holes, allowing seepage water to drain along the wall surface and reducing hydrostatic pressure. When uneven settlement occurs in the foundation, the geotextile bag itself can be individually fine-tuned to prevent rigid cracking. Simultaneously, the stress within the retaining wall is redistributed, dispersing concentrated stress to adjacent areas and reducing differential settlement. Therefore, the retaining wall adapts to uneven foundation settlement through a triple mechanism of flexible materials, prefabricated structure, and coordinated deformation.

[0027] 3. The geotextile bags used in the flexible retaining wall have good water permeability and air permeability. Ecologically sound and aesthetically pleasing soil materials are selected as the filling material, and the surface can be planted with vegetation suitable for local conditions, thus providing excellent ecological benefits. Simultaneously, the retaining wall has an arched structure convex towards the bank, providing a mild and suitable growth environment for plants and aquatic organisms in the turbulent water flow.

[0028] 4. Geotextile bag flexible retaining walls are low in cost, easy to construct and maintain. The retaining walls are prefabricated geotextile bag structures, which facilitate daily maintenance and repair. Attached Figure Description

[0029] Figure 1 This is a top view of the overall structure of the geotextile bag flexible retaining wall provided by this utility model.

[0030] Figure 2 This is a schematic diagram of the distribution structure of the retaining wall support and expansion joint in this utility model.

[0031] Figure 3 This utility model Figure 1 A schematic diagram of the AA cross-section of the structure shown.

[0032] Figure 4 This utility model Figure 1 A schematic diagram of the BB cross-section of the structure shown.

[0033] Figure 5 The diagram shows the stress analysis of the geotextile bag arc arch structure as provided in this embodiment of the utility model.

[0034] Figure 6 The stress cloud diagram of the overall structure of the geotextile bag flexible retaining wall provided by this utility model is calculated using finite element method.

[0035] Among them are:

[0036] 1. Geotextile bag body; 2. Arch end support; 3. Toe protection; 4. Filter layer; 5. Support bottom plate; 5a. Geotextile bag bottom plate; 6. Pile foundation; 7. Expansion joint; 8. Soft soil layer; 9. Backfill behind the wall. Detailed Implementation

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0038] In the description of this utility model, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this utility model. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the protection scope of this utility model.

[0039] like Figure 1-4 As shown, a geotextile flexible retaining wall suitable for soft soil strata includes a retaining wall cap, an arch ring, arch end supports 2, and pile foundations 6. Multiple pile foundations 6 are arranged in a linear array along the arched curve and vertically inserted into the soft soil stratum 8 of the riverbank foundation. The pile foundations 6 are reinforced concrete cast-in-place piles. The even distribution of multiple pile foundations 6 improves the vertical bearing capacity and reduces the settlement deformation of the retaining wall in the soft soil stratum 8. The pile foundations 6 penetrate deep into the soft soil stratum 8, and together with the crushed stone cushion layer and retaining wall cap, increase the contact area and provide reliable support.

[0040] The retaining wall foundation includes a support base plate 5 and a geotextile bag base plate 5a, which are fixed to multiple pile foundations 6. The support base plate 5 and the geotextile bag base plate 5a together form the retaining wall foundation, which transfers the upper load to the pile foundations 6 and also serves as the foundation for the pile foundations 6. It has the functions of coordinating deformation, enhancing stability, and protecting the pile foundations.

[0041] The arch is located on top of the geotextile bag bottom plate 5a, and is composed of multiple geotextile bags 1 arranged in an arch shape and stacked in a staggered manner. The filling material inside the geotextile bag 1 is selected according to external conditions. In sections of the embankment with strong scouring force, materials such as boulders, gravel, and construction waste are used, while in sections of the embankment with weak scouring force and high requirements for ecological landscape performance, materials such as sand and loam are used. For geotextile bag flexible retaining walls with a sloping layout, ecological vegetation can be planted on the surface of the geotextile bag 1. The arched structure of the retaining wall protruding towards the bank can provide a mild and suitable growth environment for plants and aquatic organisms, and has good ecological properties.

[0042] The arch end support 2 is rigidly connected to the top of the support base plate 5, and the end of the arch ring is attached to the side of the arch end support 2; the arch end support 2 bears the lateral pressure transmitted by the geotextile bag to a certain extent.

[0043] A filter layer 4 is fitted to the outer convex side of the arch, and backfill soil 9 is filled between the filter layer 4 and the bank slope protection. A foot protection 3 is installed on the inner concave side of the arch. The foot protection 3 is located at the bottom of the arch, between two adjacent arch end supports 2, and riprap is used to reduce the erosion of the geotextile bags by water flow.

[0044] Specifically, in the above technical solution, the multiple geotextile bags 1 that make up the arch ring are arranged in a horizontally staggered manner in the horizontal direction, and the multiple geotextile bags 1 that make up the arch ring are arranged in a vertically staggered manner in the longitudinal direction.

[0045] The arch is designed as a circular arc structure protruding towards the backwater side of the retaining wall on the plane, and backs onto the slope protection soil structure on the elevation.

[0046] Specifically, in the above technical solution, the number of arches is set to multiple, and the total length of the multiple arches connected in sequence matches the width of the retaining wall.

[0047] Specifically, in the above technical solution, the cross-section of the arch end support 2 is hexagonal, and the two ends of the arch ring abut against one of the two sides of the arch end support 2 to provide good support. The shorter side is located between two adjacent sets of arch rings to facilitate construction and avoid stress concentration. The longitudinal section of the arch end support 2 is parallelogram, and the arch end support 2 is inclined towards the backwater side of the retaining wall on the elevation.

[0048] Specifically, in the above technical solution, the arch end support 2 is made of reinforced concrete. The inclination angles of the arch end support 2 and the filter layer 4 are the same and equal to the inclination angle of the arch ring, ensuring that the inclination angles of the geotextile retaining wall structure are consistent throughout. Figure 6 As shown, the geotextile flexible retaining wall is composed of multiple arched retaining wall structures. The horizontal earth pressure and water pressure behind the wall are transferred to the arch end support 2 by the arch structure, so as to increase the overall resistance of the retaining wall to horizontal forces and improve its anti-sliding performance. The number of arch end supports 2 is set to multiple, and the distance between two adjacent arch end supports 2 is set to 10-20m.

[0049] Specifically, in the above technical solution, the toe protection 3 is made of scattered rubble arranged on the water-facing side of the retaining wall, that is, the side away from the bank slope soil structure, and is separated by arch end supports 2. The width of the toe protection 3 is set to at least 3m. Specifically, when the toe protection 3 is arranged, its top is basically level with the normal water level of the river channel and extends into the river channel to the thalweg line.

[0050] Specifically, in the above technical solution, the filter layer 4 adopts a gravel layer filter or a geotextile filter.

[0051] Specifically, in the above technical solution, an expansion joint 7 is reserved between the bottom plate 5 of the support pier and the bottom plate 5a of the geotextile bag, and the width of the expansion joint 7 is set to 1-2 cm. This creates a discontinuity between the bottom plate 5a of the geotextile bag and the bottom plate 2 of the support pier, so as to accommodate foundation deformation and avoid cracks caused by uneven settlement of the concrete structure.

[0052] Specifically, in the above technical solution, the interior of the expansion joint 7 is filled with a flexible solid material, and a rubber waterstop is installed on the water-facing side of the expansion joint 7. The flexible solid material includes, but is not limited to, foam and wood panels.

[0053] Specifically, in the above technical solution, both the support base plate 5 and the geotextile bag base plate 5a are made of reinforced concrete, and the support base plate 5 and the geotextile bag base plate 5a have the same thickness, which is generally set to 20-50cm. In this embodiment, the thickness is 30cm. At least 10cm thick gravel cushion layer is provided between the bottom of the retaining wall foundation and the soft soil layer 8.

[0054] like Figure 5 As shown, a force analysis is performed on a unit height arch element with thickness T. An arc-shaped auxiliary line is drawn along the trajectory of the middle of its cross-section. The central angle of the arc-shaped auxiliary line is then calculated. The central angle is half, the length of the retaining wall is L (taken as the straight line length of the arc auxiliary line), the resultant force of horizontal water pressure and soil pressure on the back of the arch unit is p, the average stress between the geotextile bags is σ, and the pressure N on the arch is expressed as N = pR.

[0055] Based on the calculation of the arch ring of an arch dam, the following formula is obtained:

[0056]

[0057] From the formula, we can deduce that when the length L of the retaining wall is constant, the half-central angle... The larger the diameter, the smaller the arch thickness T, and correspondingly, the larger the engineering workload. According to the theory of elastic thin arches, the optimal central angle of the geotextile arch structure corresponding to the arc auxiliary line is... Approximately 133°, that is The preferred angle is 66.5°. For geotextile flexible retaining walls, the retaining wall length L is the spacing between the arch end supports, preferably 10-20m, calculated according to the arch radius formula. The optimal radius R of the arch is 11-22m.

[0058] like Figure 6 As shown, finite element simulation calculations were performed on the overall structure of the geotextile flexible retaining wall. The calculation results show that the arched structure composed of the geotextile body 1 can effectively transfer the horizontal force to the arch end support 2, which bears the horizontal force. The geotextile retaining wall has a unit weight of about 60% of that of concrete, which reduces the self-weight of the structure and further reduces the bearing capacity requirements of the pile foundation 6.

[0059] During construction, the geotextile bag flexible retaining wall provided by this utility model involves first inserting multiple pile foundations 6 into the soft soil layer 8 along multiple arched arc paths. A crushed stone cushion layer is then laid on top of the soft soil layer 8, followed by the installation of support base plates 5 and geotextile bag base plates 5a. Arch-end supports 2 are rigidly connected to the top of the support base plate 5. Multiple geotextile bags 1 are arranged in an arched pattern and stacked in a staggered manner on the geotextile bag base plate 5a, forming an inclined arch structure. A filter layer 4 is installed on the outer convex side of the arch, and soil 9 is filled between the filter layer 4 and the bank slope protection wall to evenly distribute the load on the geotextile bags and improve their stability. On the inner concave side of the arch, scattered rubble is used to arrange the toe protection 3, ensuring its top is basically level with the normal water level of the river channel and extends into the river channel to the deep thalweg line. This is separated by the arch-end supports 2 to reduce the erosion of the geotextile bags by the water flow. Based on actual needs, ecological vegetation can be selectively planted on the surface of geotextile bags to carry out ecological slope protection.

[0060] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and alterations to these embodiments without departing from the principles and spirit of this utility model will still fall within the protection scope of this utility model.

Claims

1. A geotextile bag flexible retaining wall suitable for soft soil strata, characterized in that: include Multiple pile foundations (6) are arranged in a linear array along an arched arc and vertically inserted into the soft soil layer (8) of the riverbank foundation; The retaining wall foundation includes a pier base plate (5) and a geotextile bag base plate (5a), and the pier base plate (5) and the geotextile bag base plate (5a) are fixed on a plurality of said pile foundations (6); An arch ring is located on top of the bottom plate (5a) of the geotextile bag, and the arch ring is formed by multiple geotextile bag bodies (1) arranged in an arch shape and stacked in a staggered manner; The arch end support (2) is rigidly connected to the top of the support base plate (5), and the end of the arch ring is attached to the side of the arch end support (2). The outer convex side of the arch is fitted with a filter layer (4), and the space between the filter layer (4) and the bank slope protection is filled with backfill soil (9). The inner concave side of the arch is provided with a foot protection (3).

2. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The multiple geotextile bags (1) that make up the arch ring are arranged in a horizontally staggered manner in the horizontal direction, and the multiple geotextile bags (1) that make up the arch ring are arranged in a vertically staggered manner in the longitudinal direction. The arch protrudes towards the backwater side of the retaining wall in plan view and backs onto the bank slope protection soil structure in elevation view.

3. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The number of arches is set to multiple, and the total length of the multiple arches connected in sequence matches the width of the retaining wall.

4. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The cross section of the arch end support (2) is hexagonal, and the two ends of the arch ring abut against one of the two sides of the arch end support (2). The longitudinal section of the arch end support (2) is parallelogram, and the arch end support (2) is inclined to the backwater side of the retaining wall on the vertical surface.

5. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The arch end support (2) is made of reinforced concrete. The arch end support (2) and the filter layer (4) have the same inclination angle, which is equal to the inclination angle of the arch ring. The number of arch end supports (2) is set to multiple, and the distance between two adjacent arch end supports (2) is set to 10-20m.

6. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The foot protection (3) is made of scattered stones arranged on the water-facing side of the retaining wall and separated by arch end support (2). The width of the foot protection (3) is at least 3m.

7. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The filter layer (4) is a gravel filter or a geotextile filter.

8. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: An expansion joint (7) is reserved between the bottom plate of the support pier (5) and the bottom plate of the geotextile bag (5a), and the width of the expansion joint (7) is set to 1-2cm.

9. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 8, characterized in that: The expansion joint (7) is filled with a flexible solid material and a rubber waterstop is installed on the water-facing side of the expansion joint (7).

10. A geotextile bag flexible retaining wall suitable for soft soil strata according to claim 1, characterized in that: The bottom plate of the support pier (5) and the bottom plate of the geotextile bag (5a) are both made of reinforced concrete, and the bottom plate of the support pier (5) and the bottom plate of the geotextile bag (5a) have the same thickness. A crushed stone cushion layer of at least 10cm thickness is provided between the bottom of the retaining wall foundation and the soft soil layer (8).

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