Implementation method of anti-suspension and anti-sliding retaining wall based on hollow slab bridge

Abstract

The invention relates to the technical field of bridge engineering and structural reinforcement, and discloses a hollow slab bridge-based anti-suspension and anti-sliding retaining wall implementation method, which comprises the following steps of: 1, measuring and positioning a filling slope, and determining the range of a cast-in-place pile; 2, a cast-in-place pile is constructed, a top beam is poured, and a pre-stressed anchor rod reinforcing hole is reserved in the top beam; 3, pre-stressed anchor rods with intelligent tensioning terminals are arranged; 4, a retaining wall is built on the top beam, and a retaining wall + row pile + anchor cable composite supporting system is formed; and 5, filling materials in a layered manner, and arranging a slope top intercepting ditch and a slope toe drainage ditch with a pore water pressure gauge. According to the method, pile position geological risk points are simulated through the BIM model, the influence of unfavorable geology such as soft soil and karst on cast-in-place pile construction is recognized in advance, construction blindness is reduced, and the occurrence rate of accidents such as hole collapse and deviation is reduced; the construction sequence of cast-in-place piles, top beams, anchor rods and retaining walls is strictly followed, it is ensured that all structural layers are tightly connected, and the problem of stress disjunction occurring in traditional step-by-step construction is avoided.

Description

Technical Field

[0001] This invention relates to the field of bridge engineering and structural reinforcement technology, and in particular to a method for implementing anti-suspension sliding retaining walls for hollow slab bridges. Background Technology

[0002] In modern bridge engineering, hollow slab bridges are widely used due to their advantages such as simple structure, light weight, and convenient construction. However, in soft soil foundations, earthquake-prone areas, or under long-term loads, these bridges are prone to uneven settlement of abutments, resulting in partial suspension of the beams. At the same time, environmental erosion and vehicle loads can weaken the friction of the abutments and cause slippage of the bridge span structure. These problems not only reduce the service life of the bridge but may also lead to serious safety accidents.

[0003] Current technical solutions for anti-slip of hollow slab bridges have many limitations: First, traditional support often relies on a single structure (such as a simple retaining wall, piles or anchors), and the components lack a coordinated force-bearing mechanism, making it difficult to cope with the combined problems of slippage and suspension at the same time, resulting in insufficient anti-slip and load-bearing capacity; Second, there is a lack of advance prediction of geological risks during construction, and the pile placement is highly arbitrary, which can easily lead to construction accidents due to sudden geological changes. Summary of the Invention

[0004] To overcome the above deficiencies, this invention provides a method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge, thus solving the aforementioned problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge, comprising the following steps:

[0006] Step 1: Measure and locate the backfill slope, determine the centerline and opening range of the cast-in-place piles, and simulate the geological risk points at the pile location using a BIM model;

[0007] Step 2: Construct cast-in-place piles and pour a capping beam on top of them, leaving prestressed anchor reinforcement holes on the capping beam;

[0008] Step 3: After the capping beam reaches the required strength, install prestressed anchor rods with intelligent tensioning terminals at the corresponding positions of the cast-in-place piles and the capping beam, and leave drainage outlets at the same time;

[0009] Step 4: Construct a retaining wall above the capping beam to form a composite support system of "retaining wall + piles + anchor cables";

[0010] Step 5: Fill the slope with slope filling material in layers, set up a water interception ditch at the top of the slope, and set up a slope toe drainage ditch on one side of the capping beam and cast-in-place piles. Bury a pore water pressure gauge in the slope toe drainage ditch.

[0011] As a further description of the above technical solution:

[0012] The retaining wall is a rubble concrete retaining wall, and the retaining wall and the cast-in-place piles are connected by a capping beam to jointly bear horizontal and vertical forces.

[0013] As a further description of the above technical solution:

[0014] The cast-in-place piles are driven into stable strata, and the spacing and depth of the piles are optimized according to geological conditions and bridge load.

[0015] As a further description of the above technical solution:

[0016] The prestressed anchor rods are arranged in multiple rows and directions, with one end anchored to a stable soil layer and the other end connected to the cap beam or cast-in-place pile. The tension force is precisely controlled through an intelligent tensioning terminal.

[0017] As a further description of the above technical solution:

[0018] The slope filling material is sandy soil, and the compaction degree of the layered filling is not less than 0.93.

[0019] As a further description of the above technical solution:

[0020] A flexible connection device is provided between the retaining wall and the hollow slab bridge. The flexible connection device is a rubber pad or a spring device.

[0021] As a further description of the above technical solution:

[0022] The capping beam and the cast-in-place piles are connected by pre-embedded steel bars, and the retaining wall and the capping beam are connected by pre-embedded steel bars or anchor bolts to form an integral load-bearing structure.

[0023] As a further description of the above technical solution:

[0024] The intercepting ditch is located on the left side of the retaining wall, and the slope toe drainage ditch is located on the right side of the capping beam and the cast-in-place piles. The two work together to reduce the soil pressure and water pressure behind the wall.

[0025] As a further description of the above technical solution:

[0026] In the aforementioned composite support system of "retaining wall + pile + anchor", the retaining wall is used to directly support the backfill, the cast-in-place piles are used to support the retaining wall and transmit horizontal forces, and the prestressed anchor rods are used to control the deformation of the cast-in-place piles and transmit forces to the deep stable soil layer.

[0027] The present invention has the following beneficial effects:

[0028] 1. In this invention, the geological risk points of the pile location are simulated by BIM model, and the impact of adverse geological conditions such as soft soil and karst on the construction of cast-in-place piles is identified in advance, reducing the blindness of construction and reducing the incidence of accidents such as hole collapse and deviation; the construction sequence of "cast-in-place pile-cap beam-anchor rod-retaining wall" is strictly followed to ensure that the connection of each structural layer is tight and to avoid the problem of stress disconnection that occurs in traditional step-by-step construction; the intercepting ditch, slope toe drainage ditch and pore water pressure gauge are set up at the same time to form an "active drainage + real-time monitoring" system, which can dynamically grasp the changes in water pressure behind the wall and give early warning of water accumulation risk.

[0029] 2. In this invention, a prestressed anchor rod with an intelligent tensioning terminal is introduced to achieve precise control of tension force and solve the problem of excessive stress loss during manual tensioning; the flexible connection device between the retaining wall and the bridge can buffer vibration and impact and avoid structural cracking caused by rigid connection; the pre-embedded steel bars connecting the cap beam with the retaining wall and the cast-in-place pile enhance the overall rigidity, and the coordinated drainage of the intercepting ditch and the slope toe drainage ditch reduces the soil pressure behind the wall. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an implementation method for an anti-suspension sliding retaining wall based on a hollow slab bridge proposed in this invention.

[0031] Legend:

[0032] 1. Fill slope; 2. Cutoff ditch at the top of the slope; 3. Fill material; 4. Retaining wall; 5. Crown beam; 6. Prestressed anchor rod; 7. Cast-in-place pile; 8. Drainage ditch at the toe of the slope. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Reference Figure 1 The present invention provides an embodiment of a method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge, comprising the following steps:

[0035] Step 1: Measure and locate the position of the backfill slope 1, determine the centerline and borehole range of the cast-in-place pile 7, and simulate the geological risk points at the pile location using a BIM model; the measurement and location clearly define the construction boundaries of the backfill slope 1 and the cast-in-place pile 7, providing accurate spatial coordinates for subsequent structural construction; at the same time, by using the BIM model to simulate the geological risk points at the pile location in advance (such as soft soil, karst, etc.), potential hazards such as borehole collapse and deviation during construction can be predicted, reducing the blindness of construction and ensuring the safety of cast-in-place pile construction;

[0036] Step 2: Construct the cast-in-place piles 7 and pour the capping beam 5 on top of them. Reinforcing holes for prestressed anchor rods 6 are left on the capping beam 5. The cast-in-place piles 7 provide the foundation for vertical bearing and horizontal resistance of the composite support system. Pouring the capping beam 5 on top of the cast-in-place piles 7 connects the dispersed piles 7 into an integral pile structure, enhancing their collaborative load-bearing capacity. Reinforcing holes for prestressed anchor rods 6 are left on the capping beam 5 to provide interfaces for subsequent anchor rod installation, ensuring a reliable connection between the anchor rods and the pile structure.

[0037] Step 3: After the capping beam 5 reaches its strength, prestressed anchor rods 6 with intelligent tensioning terminals are installed at the corresponding positions of the cast-in-place piles 7 and the capping beam 5, while drainage outlets are left. Installing prestressed anchor rods 6 after the capping beam 5 reaches its design strength can avoid structural deformation caused by insufficient strength of the capping beam 5. Anchor rods with intelligent tensioning terminals can accurately control the tension force, ensuring that the anchor rods are always in the design stress state, effectively offsetting the lateral thrust of the backfill on the piles. Leaving drainage outlets provides a drainage channel for water seepage behind the wall, reducing the impact of water pressure on the structure.

[0038] Step 4: Construct retaining wall 4 above cap beam 5 to form a composite support system of "retaining wall + pile + anchor cable"; through the synergistic effect of retaining wall to prevent slippage, pile to transmit force and anchor cable to stabilize, the structure's anti-slip and anti-suspension capabilities are improved from multiple dimensions.

[0039] Step 5: Layered filling material 3 is constructed, a water interception ditch 2 is set at the top of the slope, and a slope toe drainage ditch 8 is set on one side of the capping beam 5 and the cast-in-place pile 7. A pore water pressure gauge is embedded in the slope toe drainage ditch 8. Layered filling material 3 can enhance the compaction of the fill soil, reduce later settlement, and avoid slope slippage caused by loose fill soil. The water interception ditch 2 at the top of the slope intercepts surface water, and the slope toe drainage ditch 8 diverts seepage water behind the wall. The two work together to reduce the soil pressure and water pressure behind the wall. The pore water pressure gauge in the slope toe drainage ditch 8 can monitor water pressure changes in real time, provide data support for structural safety early warning, and ensure the overall stability of the slope.

[0040] Furthermore: Retaining wall 4 is a rubble concrete retaining wall, which is connected to the cast-in-place pile 7 through a capping beam 5, and together they bear horizontal and vertical forces; the rubble content is 27% and the particle size is 28cm (meeting the T / CECS 749—2020 standard). The rubble concrete retaining wall utilizes the combined characteristics of rubble and concrete to provide anti-sliding resistance, taking into account both strength and economy. The capping beam 5 rigidly connects the retaining wall 4 and the cast-in-place pile 7, enhancing the integrity of the retaining wall 4 and the cast-in-place pile 7. The soil pressure and vertical load borne by the retaining wall 4 are transferred to the cast-in-place pile 7 through the capping beam 5, so that the two can work together to bear horizontal forces (such as the lateral pressure of the backfill) and vertical forces (such as the self-weight of the retaining wall 4), avoiding instability of the single retaining wall 4 due to excessive stress, and improving the anti-sliding and bearing capacity of the system.

[0041] Furthermore: the cast-in-place piles 7 are driven deep into stable strata, and the spacing and depth of the cast-in-place piles 7 are optimized according to geological conditions and bridge loads; the cast-in-place piles 7 are driven deep into stable strata, and the upper load (force transmitted by retaining wall 4, backfill pressure, etc.) is transferred to the deep stable strata through the friction between the pile body and the surrounding soil and the bearing capacity of the pile end; the spacing and depth are optimized according to geological conditions (such as soft soil, rock strata) and bridge loads to ensure a reasonable load transfer path; avoid the settlement or slippage caused by the concentration of load in shallow soft foundation, adapt to different geological environments, provide reliable vertical support and horizontal resistance for the composite support system, and improve overall stability.

[0042] Furthermore, the prestressed anchor rods 6 adopt a multi-row, multi-directional layout, with one end anchored to a stable soil layer and the other end connected to the capping beam 5 or the cast-in-place piles 7. The tension force is precisely controlled through an intelligent tensioning terminal. The tension force is controlled in stages (e.g., 10%→30%→100%, meeting the requirements of CECS 22:2005). The multi-row, multi-directional layout of the prestressed anchor rods 6 can apply pre-tightening force to the piles and capping beam 5 from different angles, forming a three-dimensional anchoring system. The intelligent tensioning terminal monitors and precisely controls the tension force in real time, ensuring that the anchor rods are always in the designed stress state, offsetting the pushing of the piles by the backfill lateral pressure, solving the problems of insufficient accuracy and difficulty in controlling stress loss in traditional manual tensioning, ensuring long-term effective anchoring of the anchor rods, and improving the system's resistance to deformation.

[0043] Furthermore: Slope filling material 3 is sandy soil, and the compaction degree of layered filling is not less than 0.93; sandy soil has high permeability, which can reduce the accumulation of rainwater or seepage water in the fill (reduce pore water pressure); the layered compaction degree ≥0.93 (meeting JGJ 79-2012 standard) can enhance the density and integrity of the fill, reduce later settlement, and prevent the fill from slipping due to looseness; improve the stability of the slope itself, and sandy soil is easy to compact and convenient to construct, solving the landslide risk caused by the poor permeability and easy water accumulation of traditional fill materials.

[0044] Furthermore, a flexible connection device, namely a rubber pad, is installed between the retaining wall 4 and the hollow slab bridge. The rubber pad can buffer the vibration impact caused by vehicle loads or earthquakes, while allowing the bridge to undergo a certain horizontal displacement when it settles or changes in temperature. This avoids stress concentration between the retaining wall 4 and the bridge due to rigid connection, protects the retaining wall 4 and the bridge structure from vibration or displacement damage, adapts to the bridge's slight deformation requirements, solves the problem of easy cracking of traditional rigid connections, and extends the service life of the structure.

[0045] Furthermore: the capping beam 5 is connected to the cast-in-place piles 7 by pre-embedded steel bars, and the retaining wall 4 is connected to the capping beam 5 by pre-embedded steel bars or anchor bolts to form an integral load-bearing structure; the capping beam 5 is connected to the cast-in-place piles 7 by pre-embedded steel bars, so that multiple cast-in-place piles 7 form an integral pile row structure; the retaining wall 4 is connected to the capping beam 5 by pre-embedded steel bars or anchor bolts, so that the load of the retaining wall 4 is transferred to the capping beam 7 and the pile row, realizing the overall load-bearing of "retaining wall 4-capping beam 7-pile row", eliminating the weak points between the components, ensuring the uniform transfer of load, avoiding the failure of a single component due to overload, and enhancing the collaborative working ability and overall rigidity of the composite system.

[0046] Furthermore: the intercepting ditch 2 is set on the left side of the retaining wall 4, and the slope toe drainage ditch 8 is set on the right side of the capping beam 5 and the cast-in-place pile 7. The two work together to reduce the soil pressure and water pressure behind the wall; the slope of the intercepting ditch 2 and the slope toe drainage ditch 87 is ≥2% (meeting the T / CECS 749—2020 standard). The slope top intercepting ditch 2 intercepts surface water on the slope to prevent rainwater from directly eroding the fill or seeping into the back of the retaining wall 4; the slope toe drainage ditch 8 drains the seepage water behind the retaining wall 4 and the accumulated water in the fill. The two work together to reduce the moisture content and pore water pressure of the soil behind the wall, and reduce the water pressure pushing the retaining wall 4; solve the structural instability problem caused by the imperfection of the traditional drainage system, and improve the durability of the system.

[0047] Furthermore, in the composite support system of "retaining wall + pile + anchor cable", the retaining wall 4 is used to directly support the backfill, the cast-in-place pile 7 is used to support the retaining wall and transmit horizontal force, and the prestressed anchor 6 is used to control the deformation of the cast-in-place pile 7 and transmit the force to the deep stable soil layer. The three complement each other, solving the problem that traditional single structures (such as simple retaining wall 4 or pile) cannot simultaneously cope with slippage and suspension, improving the stability of the system from multiple dimensions and adapting to complex geological and load conditions.

[0048] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge, characterized in that: Includes the following steps: Step 1: Measure the location of the backfill slope (1), determine the centerline and opening range of the cast-in-place pile (7), and simulate the geological risk points of the pile location through BIM model; Step 2: Construct cast-in-place piles (7) and pour a capping beam (5) on top of them, leaving prestressed anchor rod (6) reinforcement holes on the capping beam (5); Step 3: After the capping beam (5) reaches the required strength, prestressed anchor rods (6) with intelligent tensioning terminals are installed at the corresponding positions of the cast-in-place piles (7) and the capping beam (5), and drainage outlets are left at the same time; Step 4: Construct a retaining wall (4) above the cap beam (5) to form a composite support system of "retaining wall + pile + anchor cable"; Step 5: Layered filling of slope material (3), setting up intercepting ditch (2) at the top of the slope, setting up slope toe drainage ditch (8) on one side of capping beam (5) and cast-in-place pile (7), and burying pore water pressure gauge in slope toe drainage ditch (8).

2. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The retaining wall (4) is a rubble concrete retaining wall. The retaining wall (4) and the cast-in-place pile (7) are connected by a capping beam (5) to jointly bear horizontal and vertical forces.

3. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The cast-in-place piles (7) are driven into stable strata. The spacing and depth of the cast-in-place piles (7) are optimized according to geological conditions and bridge load.

4. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The prestressed anchor rod (6) adopts a multi-row, multi-directional layout, with one end anchored to a stable soil layer and the other end connected to the cap beam (5) or the cast-in-place pile (7). The tension force is precisely controlled through an intelligent tensioning terminal.

5. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The slope filling material (3) is sandy soil, and the compaction degree of the layered filling is not less than 0.

93.

6. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: A flexible connection device is provided between the retaining wall (4) and the hollow slab bridge. The flexible connection device is a rubber pad or a spring device.

7. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The capping beam (5) is connected to the cast-in-place pile (7) by pre-embedded steel bars, and the retaining wall (4) is connected to the capping beam (5) by pre-embedded steel bars or anchor bolts to form an integral load-bearing structure.

8. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: The intercepting ditch (2) is set on the left side of the retaining wall (4), and the slope toe drainage ditch (8) is set on the right side of the capping beam (5) and the cast-in-place pile (7). The two work together to reduce the soil pressure and water pressure behind the wall.

9. The method for implementing an anti-suspension sliding retaining wall based on a hollow slab bridge according to claim 1, characterized in that: In the composite support system of "retaining wall + pile + anchor", the retaining wall (4) is used to directly support the backfill, the cast-in-place pile (7) is used to support the retaining wall and transmit horizontal force, and the prestressed anchor (6) is used to control the deformation of the cast-in-place pile (7) and transmit the force to the deep stable soil layer.

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