Narrow highway has retaining wall outside riverbed section splicing wide composite system and construction method

Abstract

The present application provides a kind of narrow highway existing retaining wall outside riverbed section splicing wide composite system and construction method, splicing wide composite system includes: counter pressure body, it is set to the wall toe outside existing retaining wall, counter pressure body is set to riverbed foundation and its upper surface is above flood level, counter pressure body is opened with multiple pile foundation holes, a part of counter pressure body is set to the wall toe of existing retaining wall;Pile foundation, pile foundation is set in pile foundation hole, the lower end of pile foundation is embedded in bearing stratum below riverbed foundation, and its upper end is connected to bearing platform;Retaining plate, retaining plate is set to bearing platform, retaining plate is connected to existing embankment inside existing retaining wall by anchor rod, and bubble light soil is filled between retaining plate and existing retaining wall;Concrete panel, concrete panel is set to the top of bubble light soil and concrete panel is set between retaining plate and existing retaining wall, and pavement structure layer is laid above concrete panel.The present application can complete road splicing wide under the premise that flow channel does not continuously flow.

Description

Technical Field

[0001] This invention relates to the field of highway reconstruction and expansion engineering technology, specifically to a composite system for widening the riverbed section outside the existing retaining wall of a narrow highway and its construction method. Background Technology

[0002] In existing highway reconstruction and expansion projects, widening the outer side of high retaining walls in river sections is a technically complex engineering challenge with significant environmental constraints. Such projects often face the following prominent challenges: First, due to river ecological protection or flood control requirements, the prohibition of diverting cofferdams prevents the construction of temporary cofferdams and floating work platforms, which are essential for traditional pile foundation construction, severely limiting the application of conventional pile-forming equipment and processes. Second, the outer side of the toes of existing high retaining walls is often located on soft riverbed foundations with low bearing capacity, high compressibility, and susceptibility to water erosion, further weakening the stability of the original foundation and placing extremely high demands on settlement control of the widened roadbed. Third, the collaborative working mechanism between the existing retaining wall and the widening structure is not yet fully guaranteed, resulting in poor interface bonding performance. Significant differential settlement can easily lead to the risk of overall structural slippage or overturning. Furthermore, river areas typically have high groundwater levels, and the poor drainage system within the embankment can easily cause an increase in the moisture content of the fill soil and a decrease in effective stress, thus affecting the long-term stability of the widened structure.

[0003] Therefore, there is an urgent need for a composite system and construction method for widening the riverbed section outside the existing retaining wall of narrow highways, so as to achieve safe, efficient and economical widening construction in complex environments such as continuous river flow and weak foundation. Summary of the Invention

[0004] The purpose of this invention is to provide a composite system for widening riverbed sections outside existing retaining walls of narrow highways. This system aims to solve the problems of poor stability of existing retaining walls, poor interface performance between existing retaining walls and widening structures, and poor drainage within the embankment during highway widening in river sections. The specific technical solution is as follows:

[0005] A composite system for widening the riverbed section outside the existing retaining wall of a narrow highway includes:

[0006] The counterweight body is located on the outer side of the toe of the existing retaining wall. The counterweight body is located on the riverbed foundation and its upper surface is above the flood level. Multiple pile foundation holes are opened on the counterweight body. A part of the counterweight body is located on the toe of the existing retaining wall.

[0007] The pile foundation is set in a pile foundation hole, the lower end of the pile foundation is embedded in the bearing layer below the riverbed foundation, and its upper end is connected to the pile cap;

[0008] A retaining plate is provided on a bearing platform. The retaining plate is connected to the existing embankment inside the existing retaining wall by anchor bolts. The space between the retaining plate and the existing retaining wall is filled with air-aerated lightweight soil.

[0009] A concrete panel is placed on top of the aerated lightweight soil and between the retaining wall and the existing retaining wall. A road structure layer is laid on top of the concrete panel.

[0010] Preferably, the upper surface of the concrete panel is flush with the upper surface of the existing retaining wall; the upper surface of the retaining plate is higher than the upper surface of the road structure layer.

[0011] Preferably, the counter-pressure body has an engagement opening on the side near the wall toe, and the wall toe is disposed in the engagement opening to achieve mutual engagement between the counter-pressure body and the wall toe.

[0012] Preferably, it also includes a drainage pipe, which is buried in the bubble-light soil. One end of the drainage pipe passes through the retaining plate, and the other end passes through the existing retaining wall and extends into the existing embankment.

[0013] Preferably, the retaining plate is a stepped, layered cast-in-place structure, with each layer of retaining plate connected to the existing embankment by anchor bolts, and drainage pipes are buried in the bubble-filled lightweight soil of each layer of retaining plate and the existing retaining wall.

[0014] Preferably, the portion of the anchor bolt located in the existing embankment has multiple expansion bearings spaced apart along the length of the anchor bolt.

[0015] Preferably, the counterweight body comprises multiple stacked gabions filled with concrete.

[0016] Preferably, the gabion has through holes, and the through holes of the upper and lower gabions are aligned to form pile foundation holes, and protective walls are embedded in the pile foundation holes.

[0017] The present invention also provides a construction method for the composite system of widening the riverbed section outside the existing retaining wall of the narrow highway, comprising:

[0018] A1. Under the condition that the river is not flowing, gabions are stacked on the riverbed foundation outside the wall toe to the flood level; wherein, the through holes of the upper and lower layers of gabions are aligned to form pile foundation holes, and the pile foundation holes are pre-embedded with protective walls, and a portion of the gabions are stacked on the wall toe.

[0019] A2. The skip-hole method is used to construct the pile foundation, in which concrete is poured immediately after the excavation of each hole to form the pile foundation.

[0020] A3. After all pile foundation construction is completed, concrete is poured into the gabion to form a counter-pressure body;

[0021] A4. The construction of the foundation is completed using the counterweight as a construction platform. The foundation is supported by pile foundations, and the pile foundations, foundation, and counterweight form an integrated structure.

[0022] A5. Construct retaining walls on the foundation and fill with air-aerated lightweight soil, while simultaneously completing the construction of drainage pipes, anchor bolts, and expansion bearings;

[0023] A6. Pour a concrete panel on the upper surface of the aerated lightweight soil, and lay the road structure layer on the concrete panel to complete the road widening.

[0024] Preferably, step A5 specifically involves:

[0025] A5.1 Divide the retaining wall into N layers along the height direction, and number each layer of retaining wall from top to bottom as 1, 2, 3..., N, and take n = 1;

[0026] A5.2, Tie the reinforcing steel of the nth layer of retaining wall, and at the same time complete the construction of the drainage pipe, anchor bolts and expansion support plate of this layer;

[0027] A5.3. After completing the pouring of the nth layer of retaining wall, use the poured retaining wall as a template to fill the nth layer of air-filled lightweight soil and cure it until the strength meets the standard.

[0028] A5.4 If n is greater than or equal to N, then the construction is complete; if n is less than N, then set n = n + 1 and re-enter step A5.2.

[0029] The application of the technical solution of the present invention has the following beneficial effects:

[0030] The counterweight body in this invention can, on the one hand, reinforce the existing retaining wall with counterweight, and the counterweight body after the concrete has hardened can play a role in preventing erosion and protecting the toe of the existing retaining wall, thereby increasing the structural stability of the existing retaining wall; on the other hand, the counterweight body can serve as a construction platform for pile foundations and pile caps, and can complete the road widening without interrupting the flow in the channel.

[0031] In this invention, aerated lightweight soil is filled between the retaining slab and the existing retaining wall. Simultaneously, the retaining slab is anchored to the existing embankment using anchor bolts with multiple expansion bearing plates. This reduces the self-weight of the widening structure and enhances the connection between the existing retaining wall and the widening structure, achieving synergistic stress distribution. Furthermore, pile foundations transfer the overhead forces and the structure's own weight to the deep bearing layer, addressing the issues of weak foundation and insufficient bearing capacity, thus fully ensuring the stability of the widening structure.

[0032] In this invention, drainage pipes are buried in the bubble-bubble lightweight soil and the existing embankment, which can drain the groundwater inside the existing embankment and the newly widened embankment, and prevent the groundwater from affecting the stability of the embankment structure.

[0033] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0034] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of the splicing composite system of the present invention;

[0036] Figure 2 yes Figure 1 Cross-sectional structural diagram of the central pile foundation, counterweight body, and pile cap;

[0037] Figure 3 It is a vertical sectional view of the counter-pressure body;

[0038] Figure 4 It is a cross-sectional view of the counter-pressure body along the horizontal direction;

[0039] Among them, 1. retaining plate, 2. anchor bolt, 3. drainage pipe, 4. air-aerated lightweight soil, 5. flood level, 6. counterweight body, 6.1. gabion, 6.2. through hole, 6.3. interlocking joint, 7. pile cap, 8. riverbed foundation, 9. pile foundation, 10. existing retaining wall, 10.1. wall toe, 11. expansion joint, 12. pavement structure layer, 13. concrete panel, 14. pile foundation hole, 15. retaining wall. Detailed Implementation

[0040] To facilitate understanding of the present invention, a more complete description is provided below, along with preferred embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0042] Example:

[0043] See Figures 1-4 This embodiment provides a composite system for widening the riverbed section outside the existing retaining wall of a narrow highway, including:

[0044] The counterweight body 6 is located on the outside of the toe 10.1 of the existing retaining wall 10. The counterweight body 6 is located on the riverbed foundation 8 and its upper surface is located above the flood level 5. The counterweight body 6 has multiple pile foundation holes 14. A part of the counterweight body 6 is located on the toe 10.1 of the existing retaining wall 10 to achieve counterweight reinforcement of the existing retaining wall 10.

[0045] The pile foundation 9 is set in the pile foundation hole 14. The lower end of the pile foundation 9 is embedded in the bearing layer below the riverbed foundation 8, and its upper end is connected to the pile cap 7. The pile foundation 9, the pile cap 7 and the counterweight body 6 are an integral structure. The pile foundation 9 serves as a load-bearing structure to transmit the forces from above and its own weight to the deep bearing layer.

[0046] A retaining plate 1 is installed on the foundation 7. The retaining plate 1 is connected to the existing embankment inside the existing retaining wall 10 by anchor bolts 2. The anchor bolts 2 make the retaining plate 1 and the existing embankment form a stable connection, increasing the bonding performance between the structures. The space between the retaining plate 1 and the existing retaining wall 10 is filled with aerated lightweight soil 4. The aerated lightweight soil 4 is the load-bearing embankment for the widened road surface. The aerated lightweight soil 4 can also reduce the self-weight of the entire widening structure.

[0047] A concrete panel 13 is placed on top of the aerated lightweight soil 4 and between the retaining plate 1 and the existing retaining wall 10. A road structure layer 12 is laid on top of the concrete panel 13. That is, the concrete panel is used to support the road structure layer above it and provide a flat bearing and construction surface for the road structure layer.

[0048] like Figure 1 As shown, the upper surface of the concrete panel 13 is flush with the upper surface of the existing retaining wall 10 to ensure that the upper surface of the new road structure layer 12 is flush with the upper surface of the old road structure layer 12, thus ensuring the smoothness of the road surface; furthermore, the upper surface of the retaining plate 1 is higher than the upper surface of the road structure layer 12, and the retaining plate 1 can serve as the boundary line of the road structure layer 12 and as a formwork for construction when constructing the road structure layer.

[0049] like Figures 1-3 As shown, the counter-pressure body 6 has an interlocking opening 6.3 on the side near the wall toe 10.1. The wall toe 10.1 is disposed in the interlocking opening 6.3. The counter-pressure body 6 and the wall toe 10.1 are interlocked with each other, so that a part of the counter-pressure body 6 is disposed on the wall toe 10.1 of the existing retaining wall 10 to perform counter-pressure reinforcement on the existing retaining wall 10.

[0050] like Figure 1 As shown, the widening composite system also includes a drainage pipe 3, which is buried in the bubble-filled lightweight soil 4. One end of the drainage pipe 3 passes through the retaining plate 1, and the other end extends through the existing retaining wall 10 into the interior of the existing embankment to drain groundwater from the embankment. Furthermore, the drainage pipe 3 can have permeable holes in its upper part, and the surface of the pipe is wrapped with geotextile to prevent the permeable holes from being blocked, thereby achieving groundwater drainage from the existing embankment and the embankment below the widened surface (i.e., the bubble-filled lightweight soil).

[0051] Furthermore, the retaining wall 1 is a stepped, layered cast-in-place structure. Each layer of the retaining wall 1 is connected to the existing embankment via anchor bolts 2, and drainage pipes 3 are embedded in the aerated lightweight soil 4 of each layer of the retaining wall 10. The retaining wall is a stepped, layered cast-in-place structure, and each layer of the retaining wall can serve as a template for filling the aerated lightweight soil, adapting to narrow working surfaces.

[0052] like Figure 1 As shown, the portion of the anchor bolt 2 located within the existing embankment has multiple expansion bearing plates 11 spaced apart along its length to enhance the anchoring effect. Preferably, the interval between adjacent expansion bearing plates 11 along the anchor bolt length is 1.5-2m, and the anchoring length of the expansion bearing plates 11 within the existing embankment is ≥3m.

[0053] like Figures 1-4 As shown, the counter-pressure body 6 includes multiple stacked gabions 6.1 filled with concrete. The gabions 6.1 and the solidified concrete inside them constitute the counter-pressure body, creating a counter-pressure effect and enhancing the erosion resistance. Furthermore, the upper and lower layers of gabions 6.1 in the counter-pressure body are stacked in a staggered manner, which can increase the structural stability of the stacked gabions 6.1 and better resist the impact of water flow.

[0054] like Figure 3 As shown, the gabion 6.1 has through holes 6.2. The through holes 6.2 of the upper and lower gabions 6.1 are aligned to form a pile foundation hole 14. A protective wall 15 is embedded in the pile foundation hole 14. The protective wall can resist the deformation of the gabion and protect the shape integrity of the pile foundation hole.

[0055] This implementation also provides a construction method for the composite system of widening the riverbed section outside the existing retaining wall of the aforementioned narrow highway, including:

[0056] A1. Under the condition of continuous river flow, gabions 6.1 are stacked on the riverbed foundation 8 outside the wall toe 10.1 to a level above the flood level 5; wherein, the through holes 6.2 of the upper and lower layers of gabions 6.1 are aligned to form pile foundation holes 14, and the pile foundation holes 14 are pre-embedded with retaining walls 15, and a portion of the gabions 6.1 are stacked on the wall toe 10.1; the stacked gabions 6.1 can serve as a construction platform for subsequent pile foundations, and at the same time can be used to reinforce the existing retaining wall 10 with counter-pressure;

[0057] A2. The skip-hole method is used to construct the pile foundation 9, wherein concrete is poured immediately after the excavation of a single hole to form the pile foundation 9, so as to avoid disturbing the existing retaining wall 10.

[0058] A3. After all the pile foundations 9 are completed, concrete is poured into the gabion 6.1 to form a counter-pressure body 6. After the concrete is poured into the gabion 6.1, the integrity and scour resistance can be enhanced, and the existing retaining wall can be better reinforced and protected against scour.

[0059] A4. The construction of the foundation 7 is completed using the counterweight 6 as a construction platform. The foundation 7 is supported by pile foundations 9. The pile foundations 9, the foundation 7, and the counterweight 6 form an integrated structure to form a rigid support platform. Furthermore, the foundation, pile foundation, and counterweight are all connected by steel bars.

[0060] A5. Construct retaining plate 1 on pile cap 7 and fill with aerated lightweight soil 4, while simultaneously completing the construction of drainage pipe 3, anchor bolt 2 and expansion support plate 11; wherein, the retaining plate serves as the template for filling aerated lightweight soil.

[0061] A6. Pour a concrete panel 13 on the upper surface of the aerated lightweight soil 4, and lay the road structure layer 12 on the concrete panel 13 to complete the road widening.

[0062] Since the retaining plate 1 in this embodiment is a stepped, layered cast-in-place structure, step A5 specifically involves:

[0063] A5.1 Divide the retaining plate 1 into N layers in the height direction, and number each layer of retaining plate from top to bottom as 1, 2, 3..., N, and take n=1; Specifically, the height of each layer of retaining plate can be set according to the actual situation, preferably the height of each layer of retaining plate is less than or equal to 3 meters;

[0064] A5.2, Tie the reinforcing bars of the nth layer retaining plate 1, and at the same time complete the construction of the drainage pipe 3, anchor bolt 2 and expansion support plate 11 of this layer;

[0065] A5.3. After completing the pouring of the nth layer retaining plate 1, use the poured retaining plate 1 as a template to fill the nth layer of air-filled lightweight soil 4, and cure it until the strength meets the standard.

[0066] A5.4 If n is greater than or equal to N, then the construction is complete; if n is less than N, then set n = n + 1 and re-enter step A5.2.

[0067] This example uses a mountain road widening project as an example. The river channel is 15m wide, the flood level is +3.5m, and the existing retaining wall is 12m high. Construction is carried out according to steps A1-A6 above, with multiple layers of gabions stacked to +4.0m. The pile foundation diameter is 1.2m and the depth is 18m. The density of the aerated lightweight soil is 600kg / m³. 3 Monitoring showed that the displacement of the existing retaining wall during construction was less than 2mm, and the settlement of the widened section after construction was less than 5cm, which met the design requirements.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite system for widening a narrow highway's existing retaining wall-side riverbed section, characterized in that... include: A counterweight body (6) is provided on the outside of the wall toe (10.1) of the existing retaining wall (10). The counterweight body (6) is provided on the riverbed foundation (8) and its upper surface is located above the flood level (5). Multiple pile foundation holes (14) are provided on the counterweight body (6). A part of the counterweight body (6) is provided on the wall toe (10.1) of the existing retaining wall (10). The pile foundation (9) is set in the pile foundation hole (14), the lower end of the pile foundation (9) is embedded in the bearing layer below the riverbed foundation (8), and its upper end is connected to the pile cap (7); Retaining plate (1), the retaining plate (1) is set on the foundation (7), the retaining plate (1) is connected to the existing embankment inside the existing retaining wall (10) by anchor rod (2), and the space between the retaining plate (1) and the existing retaining wall (10) is filled with air-filled lightweight soil (4); A concrete panel (13) is placed on top of the aerated lightweight soil (4) and between the retaining wall (1) and the existing retaining wall (10). A road structure layer (12) is laid on top of the concrete panel (13).

2. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway as described in claim 1, characterized in that, The upper surface of the concrete panel (13) is flush with the upper surface of the existing retaining wall (10); the upper surface of the retaining plate (1) is higher than the upper surface of the road structure layer (12).

3. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway as described in claim 1, characterized in that, The counter-pressure body (6) has a biting opening (6.3) on the side near the wall toe (10.1), and the wall toe (10.1) is disposed in the biting opening (6.3) to realize the interlocking of the counter-pressure body (6) and the wall toe (10.1).

4. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway as described in claim 1, characterized in that, It also includes a drainage pipe (3), which is buried in the bubble lightweight soil (4). One end of the drainage pipe (3) passes through the retaining plate (1), and the other end extends through the existing retaining wall (10) into the interior of the existing embankment.

5. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway according to claim 4, characterized in that, The retaining plate (1) is a stepped layered cast-in-place structure. Each layer of retaining plate (1) is connected to the existing embankment through anchor rods (2), and drainage pipes (3) are buried in the bubble lightweight soil (4) of each layer of retaining plate (1) and the existing retaining wall (10).

6. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway according to claim 5, characterized in that, The portion of the anchor bolt (2) located in the existing embankment is provided with multiple expansion bearing plates (11) spaced apart along the length of the anchor bolt.

7. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway according to any one of claims 1-6, characterized in that, The counter-pressure body (6) includes a plurality of stacked gabions (6.1) filled with concrete.

8. The composite system for widening the riverbed section outside the existing retaining wall of a narrow highway according to claim 7, characterized in that, The gabion (6.1) has through holes (6.2), and the through holes (6.2) of the upper and lower gabions (6.1) are aligned to form a pile foundation hole (14), and a retaining wall (15) is embedded in the pile foundation hole (14).

9. A construction method for a composite system for widening the riverbed section outside the existing retaining wall of a narrow highway as described in any one of claims 1-8, characterized in that, include: A1. Under the condition that the river is not flowing, gabions (6.1) are stacked on the riverbed foundation (8) outside the wall toe (10.1) to the flood level (5); wherein, the through holes (6.2) of the upper and lower layers of gabions (6.1) are aligned to form pile foundation holes (14), and the pile foundation holes (14) are pre-embedded with protective walls (15), and a portion of the gabions (6.1) are stacked on the wall toe (10.1); A2. The pile foundation is constructed using the skip-hole method (9), wherein concrete is poured immediately after the excavation of a single hole to form the pile foundation (9); A3. After all the pile foundations (9) are completed, concrete is poured into the gabion (6.1) to form a counter-pressure body (6); A4. The construction of the foundation (7) is completed using the counterweight body (6) as a construction platform. The foundation (7) is supported by pile foundations (9). The pile foundations (9), the foundation (7) and the counterweight body (6) form an integrated structure. A5. Construct retaining wall (1) on the foundation (7) and fill it with air-bubbly lightweight soil (4), and at the same time complete the construction of drainage pipe (3), anchor rod (2) and expansion support plate (11); A6. Pour a concrete panel (13) on the upper surface of the aerated lightweight soil (4), and lay a road structure layer (12) on the concrete panel (13) to complete the road widening.

10. The construction method according to claim 9, characterized in that, Step A5 specifically involves: A5.1 Divide the retaining plate (1) into N layers in the height direction, and number each retaining plate layer sequentially from top to bottom as 1, 2, 3..., N, and take n = 1; A5.2, Tie the reinforcing bars of the nth layer retaining plate (1), and at the same time complete the construction of the drainage pipe (3), anchor rod (2) and expansion support plate (11) of this layer; A5.

3. Complete the pouring of the nth layer retaining plate (1), and use the poured retaining plate (1) as a template to fill the nth layer of air-filled lightweight soil (4), and cure it until the strength meets the standard. A5.4 If n is greater than or equal to N, then the construction is complete; if n is less than N, then set n = n + 1 and re-enter step A5.2.

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