Pavement device for preventing and treating bridgehead bump and parameter determination method thereof

Abstract

The application belongs to the technical field of road and bridge joint construction, and particularly discloses a paving device for preventing and treating bridge-head bumping and a parameter determination method thereof, wherein the paving device comprises a bottom layer structure, the bottom layer structure comprises a bridge-head first-span beam, a foam filling structure and a semi-rigid backing plate; the bridge-head first-span beam comprises a planar section and a sloping section connected with the planar section, the bottom of the sloping section is arranged on the upper surface of the abutment and is connected with the coping of the abutment; the abutment and the opposite side of the bridge-head first-span beam are provided with a roadbed; the foam filling structure is filled on the sloping section, the upper surface of the foam filling structure is in the same plane with the upper surface of the roadbed; and the semi-rigid backing plate is fixedly laid on the foam filling structure and the roadbed. The deformation characteristics of the foam filling structure under the load are utilized to make the bridge-head pavement paving layer produce a cooperative settlement deformation with the bridge-head roadbed soil, so that the differential settlement problem between the bridge and the road causing the bridge-head bumping is fundamentally solved, and the phenomenon of bridge-head bumping does not occur in long-term use.

Description

Technical Field

[0001] This invention discloses a paving device for preventing bridge approach slab ... Background Technology

[0002] Approach slab slab slab refers to the phenomenon of vehicles bouncing and jumping when passing over the junction of a road and a bridge due to structural differential settlement. The cause is excessive settlement difference between the bridge abutment structure and the backfill soil, resulting in steps appearing on the road surface at the expansion joints of the approach roads. Highway bridges have strict requirements for post-construction settlement of the abutment structure, generally using pile foundations or spread foundations to control settlement. However, the backfill soil is filled after the abutment construction and, due to the influence of the abutment, cannot be compacted properly. Under the influence of traffic loads and self-weight loads, the lateral settlement of the backfill soil exceeds that of the abutment.

[0003] In existing technologies, the technical measures to prevent bridge abutment slab settlement fall into two main categories: setting up bridge approach slabs and roadbed transition sections, and using lightweight embankment fillers. The bridge approach roadbed transition section involves setting up a 10m to 30m inverted trapezoidal filler area at the connection between the bridge abutment and the roadbed. It is filled with filler with a bearing capacity and compaction requirements higher than the roadbed soil, and a rigid approach slab is installed. One side of the approach slab is placed on the bridge abutment corbel, and the other side is placed on the roadbed transition section level with the bridge abutment, thereby reducing roadbed settlement from the perspective of roadbed compaction. The lightweight embankment filler uses EPS lightweight filler with a unit weight less than that of the fill soil to fill the bridge approach roadbed, thereby reducing roadbed settlement from the perspective of reducing the self-weight load of the filler.

[0004] Current technical measures all aim to reduce roadbed settlement and decrease the settlement difference between bridge abutments and roadbed. While these measures can alleviate the phenomenon of vehicles slab landing at bridge approach to some extent, they do not fundamentally solve the problem of roadbed settlement exceeding bridge abutment settlement. Summary of the Invention

[0005] The purpose of this application is to provide a paving device and a method for determining the parameters of the device for preventing bridge approach slab settlement, so as to solve the problem that the existing technology for preventing bridge approach slab settlement does not fundamentally solve the problem that the roadbed settlement is greater than the bridge abutment settlement, resulting in the appearance of steps on the road surface at the expansion joint of the bridge approach road after long-term use, and the technical problem of bridge approach slab settlement.

[0006] A first aspect of the present invention provides a pavement device for preventing bridge approach slab settlement, comprising a substructure, the substructure comprising a bridge approach first span beam, a foam filling structure and a semi-rigid pad;

[0007] The first span of the bridgehead includes a planar section and a sloping section connected to the planar section. The bottom of the sloping section is located on the upper surface of the abutment and is connected to the cap of the abutment.

[0008] A roadbed is provided on the opposite side of the abutment and the first span beam at the bridgehead;

[0009] The foam filling structure is filled on the slope section, and its upper surface is on the same plane as the upper surface of the roadbed;

[0010] The semi-rigid pad is fixedly laid on the foam-filled structure and the roadbed.

[0011] Preferably, the semi-rigid pad includes a counterweight area, a normal area, and a wire mesh;

[0012] The counterweight area is located vertically above the foam-filled structure;

[0013] The ordinary zone is located vertically above the roadbed;

[0014] The wire mesh covers the outer surfaces of the counterweight area and the ordinary area.

[0015] Preferably, the roadbed includes a transition structure and a base layer structure;

[0016] The transition structure is located on the opposite side of the abutment and the first span beam at the bridgehead;

[0017] The base layer structure is disposed on the transition structure, and the upper surface of the base layer structure is on the same plane as the upper surface of the foam filling structure.

[0018] Preferably, the foam used in the foam-filled structure is polystyrene foam.

[0019] Preferably, it also includes a surface layer structure;

[0020] The surface layer structure is disposed on the bottom layer structure.

[0021] Preferably, the slope section includes a slope body and two first abutment walls with triangular cross-sections;

[0022] The two first ear walls are respectively disposed on both sides of the slope, and the upper surface of the first ear walls is on the same plane as the upper surface of the foam filling structure.

[0023] Preferably, the abutment further includes two second ear walls with a square cross-section;

[0024] The two second ear walls are respectively disposed at the top ends of the back wall of the platform cap, and the upper surface of the second ear wall is on the same plane as the upper surface of the first ear wall.

[0025] Preferably, the foam filling structure is fixedly connected to the slope section.

[0026] A second aspect of the present invention provides a method for determining the parameters of the above-mentioned pavement device for preventing bridge approach slab settlement, comprising:

[0027] The dimensions of the foam-filled structure are determined based on the load of the semi-rigid pads laid on the foam-filled structure and the deformation modulus of the foam to be used.

[0028] Based on the dimensions, determine the slope of the slope section of the first span beam at the bridgehead and the height of the abutment cap.

[0029] Preferably, after determining the slope of the slope section of the first span beam at the bridge abutment and the height of the abutment cap based on the dimensions, the method further includes:

[0030] Based on the dimensions, determine the dimensions of the first ear wall located on both sides of the slope section and the dimensions of the second ear wall located at both ends of the top of the back wall of the cap.

[0031] The method for determining the parameters of the pavement device for preventing bridge approach slab slab settlement of the present invention has the following advantages compared with the prior art:

[0032] This invention utilizes the deformation characteristics of foam-filled structures under load. By controlling the deformation modulus of the foam-filled structure, the pavement layer at the bridge approach can undergo settlement deformation in tandem with the subgrade soil at the bridge approach, fundamentally solving the problem of differential settlement between bridges and roads that causes bridge approach bumps. Even with long-term use, there will be no step-like issues at the expansion joints of the bridge approach, thus fundamentally preventing bridge approach bumps. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the pavement device for preventing bridge approach slab settlement according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the first span beam at the bridge approach in the pavement device for preventing bridge approach slab settlement according to an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the bridge abutment structure in the pavement device for preventing bridge approach slab settlement according to an embodiment of the present invention;

[0036] Figure 4 This is a perspective view of the pavement device for preventing bridge approach slab settlement according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the semi-rigid pad in the pavement device for preventing bridge approach slab settlement according to an embodiment of the present invention, wherein (a) is a schematic diagram of the connection between the counterweight area and the ordinary area; and (b) is a schematic diagram of the overall structure of the semi-rigid pad.

[0038] Figure 6 for Figure 1 Longitudinal cross-sectional view.

[0039] In the diagram: 1 is the slope section; 2 is the semi-rigid pad; 3 is the foam filling structure; 4 is the base structure; 5 is the surface structure; 6 is the planar section; 7 is the abutment; 8 is the transition structure; 9 is the first abutment wall; 10 is the second abutment wall; 11 is the anchoring reinforcement; 12 is the counterweight area; 13 is the ordinary area; 14 is the wire mesh. Detailed Implementation

[0040] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0041] The first aspect of the present invention provides a pavement device for preventing bridge approach slab settlement, such as... Figures 1 to 6 As shown, this includes the underlying structure;

[0042] The underlying structure includes the first span beam at the bridgehead, foam-filled structure 3, and semi-rigid pad 2;

[0043] The structure of the first span of the bridgehead is as follows Figure 2 As shown, it includes a planar segment 6 and a slope segment 1 connected to the planar segment 6. The bottom of the slope segment 1 is located on the upper surface of the abutment 7 and connects to the cap of the abutment 7. The structure of the abutment 7 is as follows: Figure 3 As shown;

[0044] A roadbed is provided on the opposite side of abutment 7 and the first span beam at the bridgehead;

[0045] Foam filling structure 3 is filled on slope section 1, and its upper surface is on the same plane as the upper surface of the roadbed.

[0046] The semi-rigid pad 2 is fixedly laid on the foam-filled structure 3 and the roadbed. The foam used in the foam-filled structure 3 is polyurethane foam, polystyrene foam, polyvinyl chloride foam, polyethylene foam, etc. Because polystyrene foam has a low density coefficient and good impact resistance, it has sufficient ability to buffer external impact forces by changing and restoring its shape. Therefore, polystyrene foam is preferred in this invention.

[0047] This invention utilizes the deformation characteristics of the foam filling structure 3 under load. By controlling the deformation modulus of the foam filling structure 3, the pavement layer at the bridge approach can undergo settlement deformation in tandem with the subgrade soil at the bridge approach, fundamentally solving the problem of differential settlement between bridge and road that causes bridge approach bumps. Even with long-term use, there will be no step-like issues at the expansion joints of the bridge approach, thus fundamentally preventing bridge approach bumps.

[0048] The present invention sets up a semi-rigid pad 2 to coordinate the deformation of the bridge section foam filling structure 3 and the roadbed settlement deformation. At the same time, it acts as a stress absorption layer between the rigid structure of the bridge section and the flexible structure of the roadbed section to prevent reflective cracks between the two parts of the structure, further improve the transition of the overall road surface deformation, and thus improve driving comfort.

[0049] In this embodiment of the invention, the first span of the bridgehead is an integral structure, that is, the planar section 6 and the slope section 1 are cast in one piece, thereby ensuring the stability of the structure.

[0050] To further ensure coordinated and uniform settlement deformation between the bridge approach pavement layer and the bridge approach subgrade soil, the semi-rigid pad 2 of this invention has the following structure: Figure 5 As shown, it includes a counterweight area 12, a general area 13, and a wire mesh 14;

[0051] The counterweight area 12 is located vertically above the foam filling structure 3;

[0052] Ordinary zone 13 is located vertically above the roadbed;

[0053] Wire mesh 14 covers the outer surface of the counterweight area 12 and the ordinary area 13.

[0054] The present invention provides a counterweight area 12 located vertically above the foam filling structure 3, which compresses the foam in the foam filling structure 3 and pre-applies a vertical force to it to ensure the tightness of the foam structure. At the same time, steel wire mesh 14 is wrapped around the outer surface of the counterweight area 12 and the ordinary area 13, thereby improving the tensile strength of the semi-rigid pad 2.

[0055] In one specific embodiment, the counterweight zone 12 is composed of low-dose cement-stabilized crushed stone mixed with lead particles, and the ordinary zone 13 is composed of low-dose cement-stabilized crushed stone; the counterweight zone 12 and the ordinary zone 13 are integral, with a surface wrapped with wire mesh 14, resulting in a semi-rigid pad 2. Since galvanized hexagonal wire mesh has better strength and stability, it is used in this embodiment. The resulting semi-rigid pad 2 is connected to the foam-filled structure 3 and the roadbed by anchoring steel bars 11, as shown below. Figure 6 As shown.

[0056] The roadbed in this embodiment of the invention includes a transition structure 8 and a base structure 4;

[0057] The transition structure 8 is located on the opposite side of the abutment 7 and the first span beam at the bridgehead;

[0058] The base structure 4 is set on the transition structure 8, and the upper surface of the base structure 4 is on the same plane as the upper surface of the foam filling structure 3. The upper surface of the base structure 4 is also on the same plane as the upper surface of the planar segment 6.

[0059] For example, transition structure 8 is a soil-filled transition structure.

[0060] Embodiments of the present invention also include a surface layer structure 5;

[0061] The surface structure 5 is set on the bottom structure, namely the planar section 6 of the first span beam at the bridgehead, the semi-rigid pad 2, and the surface structure 5 on which a continuous road surface is laid above the roadbed.

[0062] Furthermore, to ensure that the boundary position of the foam-filled structure 3 remains unchanged when a load is applied, the slope section 1 of this embodiment includes a slope and two first ear walls 9 with triangular cross sections;

[0063] Two first abutment walls 9 are respectively set on both sides of the slope, and the upper surface of the first abutment wall 9 is on the same plane as the upper surface of the foam filling structure 3, and also on the same plane as the planar segment 6 of the first span beam at the bridge abutment. The function of the first abutment wall 9 is to give the foam filling structure 3 in the slope segment 1 a clear boundary, so that it will not be squeezed out of the slope segment 1 under the action of load. In this embodiment of the invention, the thickness of the first abutment wall 9 can be determined according to the requirements for bridge railing installation, and the upper part of it can be normally installed with bridge railing.

[0064] The bridge abutment 7 in this embodiment of the invention also includes two second ear walls 10 with square cross sections;

[0065] Two second ear walls 10 are respectively set at the top of the back wall of the cap, and the upper surface of the second ear wall 10 is on the same plane as the upper surface of the first ear wall 9, and it is also on the same plane as the upper surface of the roadbed, keeping it horizontal.

[0066] The thickness of the second abutment wall 10 is the same as that of the first abutment wall 9, and the bridge railing can be installed normally on the upper part. The foam filling structure 3 of the present invention fully fills the space formed by the first span of the bridge abutment, the first abutment wall 9, the abutment 7, and the second abutment wall 10. The top of the foam filling structure 3 is horizontal, and one end starts from the slope of the first span of the bridge abutment, and the bottom gradually changes along the slope, ending at the junction of the top of the abutment 7 and the base structure 4 in the roadbed.

[0067] In this embodiment of the invention, the foam filling structure 3 is fixedly connected to the slope section 1. Exemplarily, the slope surface of the slope section 1 is roughened and bonded to the foam filling structure 3 with an adhesive.

[0068] The foam-filled structure 3 of the bridge abutment pavement of the present invention can generate settlement deformation in coordination with the roadbed, fundamentally eliminating the phenomenon of bridge abutment slab jumping caused by differential settlement between structures.

[0069] A second aspect of the present invention provides a method for determining the parameters of the above-mentioned pavement device for preventing bridge approach slab settlement, comprising:

[0070] Step 1: Determine the dimensions of the foam filling structure 3 based on the load of the semi-rigid pad 2 laid on the foam filling structure 3 and the deformation modulus of the foam to be used.

[0071] Before this step, it is necessary to first determine the binary function relationship between the load of the foam filling structure 3, the deformation modulus of the foam to be used, and the dimensions of the foam filling structure 3, where the load of the foam filling structure 3 is actually the load of its upper rigid pad.

[0072] The method for determining the above-mentioned bivariate functional relationship is as follows:

[0073] (1) Based on the height of the bridge abutment roadbed fill, the distribution of soil layers within the depth of the fill influence, the roadbed treatment measures adopted, and the traffic load corresponding to the road design grade, the settlement s1 of the bridge abutment roadbed is calculated using the layer summation method.

[0074] (2) Considering the load of counterweight zone 12, the load of upper and lower structures, pedestrian and vehicle loads, and the foundation design form, calculate the settlement s2 of abutment 7 in accordance with regulations.

[0075] (3) Based on the deformation modulus E0 of the filling material of the foam filling structure 3, the load of the counterweight zone 12, and the corresponding traffic load of the road design level, set the thickness h at the thickest point of the foam filling structure 3, and calculate the deformation s3 of the foam filling structure 3.

[0076] (4) Let s3+s2=s1, and obtain the bivariate function relationship between the thickness h at the thickest part of the foam-filled structure 3, the deformation modulus E0, and the load P in the counterweight zone 12.

[0077] After determining the above binary function relationship, the lead particle content ratio of the counterweight zone 12 is set, the load P is determined, and the deformation modulus E0 of the foam filling material of the foam filling structure 3 is set, thereby obtaining the thickness h at the thickest part of the longitudinal section of the foam filling structure 3 and determining the size of the foam filling structure 3.

[0078] Step 2: Determine the slope of the first span beam at the bridgehead and the height of the abutment cap based on the dimensions.

[0079] Step 3: Determine the dimensions of the first ear wall 9 set on both sides of the slope section 1 and the dimensions of the second ear wall 10 set at both ends of the top of the back wall of the platform cap, based on the dimensions.

[0080] A third aspect of the present invention also discloses a construction method for a pavement device for preventing bridge approach slab settlement obtained after determining parameters using the above-described parameter determination method, specifically including:

[0081] Step S1: Based on the design height of the abutment cap of bridge abutment 7 and the height h of the first ear wall 9 and the second ear wall 10, construct bridge abutment 7 and pour the abutment cap, the first ear wall 9 and the second ear wall 10.

[0082] Step S2: Clear the site and construct the roadbed filling transition structure 8 according to the design requirements;

[0083] Step S3: Construct the first span of the bridge abutment using either cast-in-place or precast methods. Based on the slope and range of the slope section 1 of the first span of the bridge abutment obtained from the design, pour and construct the slope surface.

[0084] Step S4: Roughen the slope of the first span beam at the bridgehead, roughen the top surface of the abutment cap of abutment 7, clean the floating slag and keep it dry and dust-free, apply adhesive, set up a formwork on one side of the subgrade soil, and construct EPS foam material to form foam-filled structure 3.

[0085] Step S5: Construct the base structure 4 of the road surface on the transition structure 8 of the roadbed fill. The top elevation of the base structure 4 is consistent with that of the foam filling structure 3.

[0086] Step S6: Lay a bottom layer of wire mesh 14 on the upper part of the base structure 4 and the foam filling structure 3. According to the lead particle content ratio of the counterweight zone 12 of the semi-rigid pad layer, lay the counterweight zone 12 of the semi-rigid pad 2 on the upper part of the foam filling structure 3. Lay the ordinary zone 13 of the semi-rigid pad 2 on the upper part of the base structure 4 of the road. Lay wire mesh 14 on the surface of the semi-rigid pad 2.

[0087] Step S7: Drill holes in the semi-rigid pad 2, construct anchor steel bars 11 according to the design spacing, and connect the semi-rigid pad 2 to the foam filling structure 3 and the base structure 4 of the road surface.

[0088] Step S8: Lay the continuous pavement surface structure 5 on top of the first span beam plane section 6, semi-rigid pad 2, and pavement base structure 4. Construction is complete.

[0089] The construction method of this invention is simple and efficient. Furthermore, by proposing a design and construction method for a bridge approach slab paving device to prevent slab slab settlement, this technical problem can be systematically calculated, quantitatively designed, and systematically constructed.

[0090] The paving device for preventing bridge approach slab settlement of the present invention can also be applied to the treatment of differential settlement of culverts and culvert backs, and can be applied to differential settlement zones.

[0091] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A pavement device for preventing bridge approach slab settlement, characterized in that, The underlying structure includes the first span beam at the bridgehead, a foam-filled structure, and a semi-rigid pad. The first span of the bridgehead includes a planar section and a sloping section connected to the planar section. The bottom of the sloping section is located on the upper surface of the abutment and is connected to the cap of the abutment. A roadbed is provided on the opposite side of the abutment and the first span beam at the bridgehead; The foam filling structure is filled on the slope section, and its upper surface is on the same plane as the upper surface of the roadbed; The semi-rigid pad is fixedly laid on the foam-filled structure and the roadbed; The semi-rigid pad includes a counterweight area, a normal area, and a wire mesh. The counterweight area is located vertically above the foam-filled structure; The ordinary zone is located vertically above the roadbed; The wire mesh covers the outer surfaces of the counterweight area and the ordinary area.

2. The paving device for preventing bridge approach slab settlement according to claim 1, characterized in that, The roadbed includes a transition structure and a base layer structure; The transition structure is located on the opposite side of the abutment and the first span beam at the bridgehead; The base layer structure is disposed on the transition structure, and the upper surface of the base layer structure is on the same plane as the upper surface of the foam filling structure.

3. The paving device for preventing bridge approach slab settlement according to claim 1, characterized in that, The foam used in the foam-filled structure is polystyrene foam.

4. The paving device for preventing bridge approach slab settlement according to claim 1, characterized in that, It also includes surface structure; The surface layer structure is disposed on the bottom layer structure.

5. The paving device for preventing bridge approach slab settlement according to claim 1, characterized in that, The slope section includes the slope body and two first abutment walls with triangular cross sections; The two first ear walls are respectively disposed on both sides of the slope, and the upper surface of the first ear walls is on the same plane as the upper surface of the foam filling structure.

6. The paving device for preventing bridge approach slab settlement according to claim 5, characterized in that, The abutment also includes two second ear walls with square cross-sections; The two second ear walls are respectively disposed at the top ends of the back wall of the platform cap, and the upper surface of the second ear wall is on the same plane as the upper surface of the first ear wall.

7. The paving device for preventing bridge approach slab settlement according to claim 1, characterized in that, The foam filling structure is fixedly connected to the slope section.

8. A method for determining the parameters of a pavement device for preventing bridge approach slab slab settlement as described in any one of claims 1-7, characterized in that, include: The dimensions of the foam-filled structure are determined based on the load of the semi-rigid pads laid on the foam-filled structure and the deformation modulus of the foam to be used. Based on the dimensions, determine the slope of the slope section of the first span beam at the bridgehead and the height of the abutment cap.

9. The method for determining the parameters of the pavement device for preventing bridge approach slab settlement according to claim 8, characterized in that, After determining the slope of the slope section of the first span beam at the bridgehead and the height of the abutment cap based on the aforementioned dimensions, the process also includes: Based on the dimensions, determine the dimensions of the first ear wall located on both sides of the slope section and the dimensions of the second ear wall located at both ends of the top of the back wall of the cap.

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