A grid tension connector and grid mounting method, and an abutment-subgrade structure

Abstract

The application discloses a bridge abutment-subgrade structure and belongs to the technical field of subgrade engineering, which solves at least one problem of poor flatness of a grid in the prior art. In the structure, structural grid is arranged in a light flowing concrete layer along a horizontal direction, and construction grid is arranged between two adjacent light flowing concrete layers. An upper box and a lower box are arranged in a fixed frame and are connected to each other in a clamping mode, the grid is arranged between the upper box and the lower box, a connecting rod is arranged on an outer wall of the fixed frame, and the connecting rod is connected to the I-shaped panel in an extendable mode. One end of the construction grid is connected to a connecting short rod. One end of a plurality of structural grids is connected to a connecting long rod. The geometric profile of the integral flexible bridge abutment is a wedge-shaped body. The included angle between a line connecting a center point of a bottom surface of a pedestal and a center point of a back bottom edge of the integral flexible bridge abutment and the bottom surface of the integral flexible bridge abutment is not greater than 45 DEG. The bridge abutment-subgrade structure can be used in a road bridge transition section.

Description

[0001] The present application is a divisional application of the parent application No. 202210901423.5, titled "Grid tension connecting piece and grid installation method, and abutment-embankment structure", filed on July 28, 2022. TECHNICAL FIELD

[0002] The present application belongs to the technical field of embankment engineering, and particularly relates to an abutment-embankment structure. BACKGROUND

[0003] In the prior art, for the laying of the grid (for example, geogrid), a panel or a sandbag is usually used for fixing.

[0004] However, by using the above method, only the grid can be properly fixed during the laying process, and tensioning cannot be performed, so that the grid cannot be laid flat. SUMMARY

[0005] In view of the above analysis, the present application aims to provide an abutment-embankment structure, which solves at least one problem of poor flatness of the grid in the prior art.

[0006] The main purpose of the present application is achieved by the following technical solutions:

[0007] The present application provides an abutment-embankment structure, which comprises a pedestal, an embankment filled with soil, and an integral flexible abutment directly connected with the embankment filled with soil, the pedestal being arranged on the integral flexible abutment;

[0008] The integral flexible abutment comprises an abutment base body, a structural mesh, a structural mesh, a connecting long bar, a connecting short bar, and a grid tension connecting piece;

[0009] The abutment base body comprises a plurality of layers of lightweight flowing concrete layers stacked in sequence;

[0010] The structural mesh is arranged in the lightweight flowing concrete layer along the horizontal direction, and the structural mesh is arranged between the adjacent two layers of lightweight flowing concrete layers;

[0011] The grid tension connecting piece comprises a U-shaped panel and an engagement piece; the engagement piece comprises a fixed frame, an upper box, a lower box, and a connecting rod, the upper box and the lower box are arranged in the fixed frame and are connected with each other in engagement, the grid is arranged between the upper box and the lower box, the connecting rod is arranged on the outer wall of the fixed frame, and the connecting rod is connected with the U-shaped panel in an extendable manner;

[0012] One end of the structural mesh is connected with the connecting short bar, and the other end is arranged between the upper box and the lower box;

[0013] One end of the structural mesh is connected with the connecting short bar, and the other end is arranged between the upper box and the lower box;

[0014] The geometric profile of the integral flexible abutment is a wedge, and the length of the bottom edge of the wedge is not less than 0.8 times the overall height of the integral flexible abutment, and the length of the top edge of the wedge is not less than 1.5 times the overall height of the integral flexible abutment, the line between the center point of the bottom surface of the abutment and the center point of the back bottom edge of the integral flexible abutment is defined as an auxiliary line, the angle between the auxiliary line and the bottom surface of the integral flexible abutment is not greater than 45°, and the back slope ratio of the integral flexible abutment is 1:1-1:1.5.

[0015] Further, the vertical spacing of the adjacent two layers of structural reinforcement mesh is determined by the following method:

[0016] Step A: initially determine the vertical spacing of the adjacent two layers of structural reinforcement mesh in the integral flexible abutment, and then determine the total cross-sectional area of the structural reinforcement mesh and the lightweight flowing concrete layer in a certain reinforced unit cross section, the cross-sectional area of the structural reinforcement mesh, and the cross-sectional area of the lightweight flowing concrete layer in the structural reinforcement mesh;

[0017] Step B: calculate the elastic modulus of the structural reinforcement mesh and the lightweight flowing concrete layer composite;

[0018] Step C: calculate the total settlement of the integral flexible abutment;

[0019] The total settlement of the integral flexible abutment is the maximum total settlement, and when the maximum total settlement of the integral flexible abutment is less than the maximum allowable settlement of the integral flexible abutment, the arrangement density of the structural reinforcement mesh meets the requirements, otherwise the vertical spacing of the structural reinforcement mesh needs to be adjusted, and the calculation is performed again until the maximum settlement value of the integral flexible abutment is less than the maximum allowable settlement of the integral flexible abutment, and the arrangement density of the structural reinforcement mesh is determined to meet the requirements.

[0020] Further, in step B, the elastic modulus of the structural reinforcement mesh and the lightweight flowing concrete layer composite is calculated by the following formula:

[0021]

[0022]

[0023] E = E + E y The horizontal composite elastic modulus of the structural reinforcement mesh and the lightweight flowing concrete layer composite is MPa;

[0024] E = E + E z The vertical composite elastic modulus of the structural reinforcement mesh and the lightweight flowing concrete layer composite is MPa;

[0025] E = E + E c The elastic modulus of the lightweight flowing concrete layer is MPa;

[0026] E = E + E r The elastic modulus of the structural reinforcement mesh is MPa;

[0027] v yz — the ratio of the z-direction linear strain to the y-direction linear strain of the elastomer under the action of the y-direction stress;

[0028] v xy — the ratio of the y-direction linear strain to the x-direction linear strain of the elastomer under the action of the x-direction stress;

[0029] v c — the Poisson's ratio of the lightweight flowable concrete layer;

[0030] v r — the Poisson's ratio of the structural reinforcement net;

[0031] a — the total cross-sectional area of the structural reinforcement net and the lightweight flowable concrete layer, mm 2 ;

[0032] a1 — the cross-sectional area of the structural reinforcement net, mm 2 ;

[0033] a2 — the cross-sectional area of the lightweight flowable concrete layer, mm 2 .

[0034] Further, in step C, the total settlement of the monolithic flexible abutment is calculated using the following formula:

[0035]

[0036] wherein: S — the total settlement of the monolithic flexible abutment, mm;

[0037] S max — the maximum settlement of the monolithic flexible abutment, mm;

[0038] E z — the vertical composite elastic modulus of the structural reinforcement net and the lightweight flowable concrete layer composite, MPa;

[0039] I — the moment of inertia (mm 4 ), and wherein, b is the length of the structural reinforcement net and the lightweight flowable concrete layer composite along the x-direction, mm, and ξ is the length of the structural reinforcement net and the lightweight flowable concrete layer composite along the z-axis direction, mm;

[0040] γ — the weight per unit volume of the structural reinforcement net and the lightweight flowable concrete layer composite, kN / m 3 ;

[0041] z — the distance from the top surface of the monolithic flexible abutment, mm;

[0042] y — the distance along the longitudinal direction of the monolithic flexible abutment, mm;

[0043] l — Total length of the integral flexible bridge abutment along the y direction, in mm;

[0044] h — Total height of the integral flexible bridge abutment, mm.

[0045] Furthermore, the length of the structural reinforcement mesh is 0.8 to 0.9 times the overall height of the abutment.

[0046] Furthermore, the length of the connecting short bar shall not be less than 20cm, and the angle between it and the horizontal plane shall not be greater than 45°.

[0047] Furthermore, the height of the U-shaped panel is 0.10 to 0.15 times the height of the integral flexible bridge abutment, the length is 0.15 to 0.20 times the height of the integral flexible bridge abutment, the width is 0.05 to 0.1 times the height of the integral flexible bridge abutment, and the thickness of the sidewall is not less than 0.2m.

[0048] Furthermore, the structural reinforcement mesh, the construction reinforcement mesh, and the connecting long reinforcement are all made of carbon fiber bundle warp-knitted mesh.

[0049] Furthermore, the carbon fiber bundle warp-knitted grid includes carbon fiber bundles and a resin coating applied to the surface of the carbon fiber bundles, with a single grid size of 20-40 mm and a width of not less than 3 m.

[0050] Furthermore, the inner wall of the U-shaped panel is provided with a support rod along the horizontal direction and a joint sleeved on the outer wall of the support rod. The joint rotates relative to the support rod and slides along the axial direction of the support rod. The connecting rod is threadedly connected to the joint. Adjusting the relative position between the connecting rod and the U-shaped panel causes the connecting rod to move closer to the U-shaped panel, and the grid is stretched flat.

[0051] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0052] A) The grid tensioning connector provided by the present invention can tension the grid by adjusting the relative position between the U-shaped panel and the connecting rod, thereby ensuring the grid is tensioned flat.

[0053] B) The grid tensioning connector provided by the present invention first places the mesh of the grid onto the connecting part, and the bottom of the protrusion can limit the grid to prevent the grid from falling out of the connecting part. Then, the upper box and the lower box are brought close to each other, and the interlocking protrusion is inserted into the interlocking groove. Finally, the upper box and the lower box are inserted into the fixing frame, thereby realizing the connection between the grid and the interlocking connector.

[0054] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0055] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0056] Fig. 1 This is a schematic diagram of the interlocking member in the grid tensioning connector provided in Embodiment 1 of the present invention;

[0057] Fig. 2 This is a schematic diagram of the U-shaped panel in the grid tensioning connector provided in Embodiment 1 of the present invention;

[0058] Fig. 3 This is a partial schematic diagram of the interlocking member in the grid tensioning connector provided in Embodiment 1 of the present invention;

[0059] Fig. 4 This is a schematic diagram of the bridge abutment-roadbed structure provided in Embodiment 2 of the present invention;

[0060] Fig. 5 This is a geometric outline diagram of the integral flexible bridge abutment in the bridge abutment-roadbed structure provided in Embodiment 2 of the present invention;

[0061] Fig. 6 This is a schematic diagram of the connection between the connecting long bar and the sleeve in the bridge abutment subgrade structure provided in Embodiment 2 of the present invention.

[0062] Figure label:

[0063] 1-Earth fill subgrade; 2-Reinforced base course; 3-Compactor pile; 4-Lightweight flowing concrete layer; 5-Anchor; 6-Anchoring zone; 7-Structural reinforcement mesh; 8-Construction reinforcement mesh; 9-Connecting long reinforcement; 10-Connecting short reinforcement; 11-Sleeve; 12-U-shaped panel; 13-Connecting protrusion; 14-Connecting hole; 15-Support rod; 16-Joint; 17-Connecting rod; 18-Outer wall protrusion; 19-Inner wall protrusion; 20-Socket; 21-Fixing frame; 22-Upper box; 23-Lower box; 24-Interlocking protrusion; 241-Connecting part; 242-Protrusion part; 25-Interlocking groove; 26-Platform; 27-Beam slab; 28-Road structure layer. Detailed Implementation

[0064] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0065] Example 1

[0066] This embodiment provides a grid tensioning connector, see [link / reference]. Figs. 1 to 3, including the L-shaped panel 12 and the occlusion piece, the occlusion piece including a fixed frame 21, an upper box 22, a lower box 23 and a connecting rod 17, the upper box 22 and the lower box 23 being arranged in the fixed frame 21 and being occluded to each other, a grid being arranged between the upper box 22 and the lower box 23, and the connecting rod 17 being arranged on the outer wall of the fixed frame 21, the connecting rod 17 being telescopically connected with the L-shaped panel 12.

[0067] In implementation, the grid installation method includes the following steps:

[0068] Step 1: one end of the grid is fixed by a fixing piece (for example, a connecting long rib or a connecting short rib);

[0069] Step 2: the other end of the grid is arranged between the upper box 22 and the lower box 23, so that the upper box 22 and the lower box 23 clamp the grid;

[0070] Step 3: the relative position between the connecting rod 17 and the L-shaped panel 12 is adjusted, so that the connecting rod 17 moves towards the L-shaped panel 12, the grid is tensioned and flattened, and the installation of the grid is completed.

[0071] Compared with the prior art, the grid tensioning connecting piece provided by the embodiment can tension the grid by adjusting the relative position between the L-shaped panel 12 and the connecting rod, thereby ensuring the tensioning and flattening of the grid.

[0072] Exemplarily, the thickness of the side wall of the fixed frame 21 is not less than 0.5 cm, the length of the upper box 22 and the lower box 23 is not less than 0.8 m, the width is not less than 0.2 m, and the height is not less than 0.5 m.

[0073] It can be understood that, in order to avoid interference between the fixed frame 21 and the grid, the side of the fixed frame 21 facing the filled embankment 1 is provided with a notch, and the grid passes through the notch and is connected with the occlusion piece.

[0074] In order to realize the engagement of the upper box 22 and the lower box 23, the upper box 22 and the lower box 23 are provided with an engagement protrusion 24 and an engagement groove 25 which are matched with each other. The height of the engagement protrusion 24 is greater than 0.5 times the height of the upper box 22 or the lower box 23. The engagement protrusion 24 includes a connecting portion 241 and a protruding portion 242. The cross-sectional shape of the protruding portion 242 can be trapezoidal or umbrella-shaped. One end of the connecting portion 241 is connected to one of the upper box 22 and the lower box 23, and the other end of the connecting portion 241 is connected to the protruding portion 242. The engagement groove 25 is arranged on the other of the upper box 22 and the lower box 23. The transverse width of the connecting portion 241 is less than the lower base width of the protruding portion 242. The number of the protruding portions 242 is multiple. In the range covered by the engagement member, one mesh of the grid corresponds to at least one protruding portion 242. The protruding portion 242 penetrates the mesh of the grid, so that the mesh of the grid is sleeved on the connecting portion 241. The lower base width of the protruding portion 242 is equal to the height of the engagement protrusion 24. The width of the connecting portion 241 is not greater than 0.8 times the lower base width of the protruding portion 242. The height of the connecting portion 241 is the same as the height of the mesh of the grid. By using the engagement member with the above structure, the mesh of the grid is sleeved on the connecting portion 241 first, and the lower base of the protruding portion 242 can limit the grid to prevent the grid from coming out of the connecting portion 241. Then, the upper box 22 and the lower box 23 are moved close to each other, and the engagement protrusion 24 is inserted into the engagement groove 25. Finally, the upper box 22 and the lower box 23 are inserted into the fixed frame 21, so as to realize the connection between the grid and the engagement member.

[0075] In actual application, a plurality of curb panels 12 are usually arranged at the edge of the abutment base body. In order to realize the connection between the plurality of curb panels 12 and ensure the integrity of the end surface of the abutment base body, one of the upper end surface and the lower end surface of the curb panel 12 is provided with a connecting protrusion 13, and the other end surface is provided with a connecting hole 14. The length of the connecting protrusion 13 is not greater than 0.7 times the length of the curb panel 12. The width of the connecting hole 14 and the connecting protrusion 13 is 0.1-0.2 m. The height of the connecting protrusion 13 is not less than the thickness of the side wall of the curb panel 12. By inserting the connecting protrusion 13 into the connecting hole 14, the connection between the adjacent two curb panels 12 is realized, and the integrity of the end surface of the abutment base body is ensured.

[0076] In order to realize the telescopic connection between the curb panel 12 and the connecting rod 17, specifically, the inner wall of the curb panel 12 is provided with a support rod 15 and a joint 16 sleeved on the outer wall of the support rod 15 in the horizontal direction. The joint 16 can rotate relative to the support rod 15 and can slide along the axial direction of the support rod 15. The connecting rod 17 is threadedly connected with the joint 16. In this way, by rotating the joint 16, the threaded connection length between the connecting rod 17 and the joint 16 can be adjusted, and the telescopic connection between the curb panel 12 and the connecting rod 17 can be realized, so as to ensure the tension and flattening of the grid.

[0077] Exemplarily, the diameter of the support rod 15 is not less than 1 cm, the inner diameter of the joint 16 is not less than 3 cm, the length of the connecting rod 17 is 1.0-1.5 m, and the length of the thread at the end of the connecting rod 17 is not less than 5 cm.

[0078] It can be understood that, in order to ensure the tension between the joint 16 and the connecting rod 17 and prevent the joint 16 from coming out of the connecting rod 17, the outer wall of the connecting rod 17 is provided with an outer wall protrusion 18, and the inner wall of the joint 16 is provided with an inner wall protrusion 19. The inner wall protrusion 19 is located on the side of the outer wall protrusion 18 away from the clamping member. The outer diameter of the outer wall protrusion 18 is not less than 2 cm and not greater than the inner diameter of the joint 16, so as to axially limit the inner wall protrusion 19, thereby ensuring the tension between the joint 16 and the connecting rod 17 and preventing the joint 16 from coming out of the connecting rod 17.

[0079] In actual application, in order to facilitate the rotation of the joint 16, the outer wall of the joint 16 is provided with a socket 20, the axial direction of the socket 20 is perpendicular to the axial direction of the joint 16, and the inner diameter of the socket 20 is not less than 1.5 cm. An operator can insert a wrench into the socket 20 to conveniently rotate the joint 16.

[0080] As for the material of the grid tension connecting member, the grid panel 12 can be made of industrial solid waste such as slag, steel slag and coal gangue as aggregate. The upper box 22 and the lower box 23 are made of polypropylene as raw material. The fixed frame 21 and the connecting rod 17 can be made of Q335 steel.

[0081] Embodiment Two

[0082] The embodiment provides a grid installation method using the grid tension connecting member provided in the embodiment one. The grid installation method comprises the following steps:

[0083] Step 1: fixing one end of the grid through a fixing member (for example, a connecting long rib or a connecting short rib);

[0084] Step 2: placing the other end of the grid between the upper box 22 and the lower box 23, so that the upper box 22 and the lower box 23 clamp the grid;

[0085] Step 3: adjusting the relative position between the connecting rod 17 and the grid panel 12, so that the connecting rod 17 moves towards the grid panel 12, the grid is tensioned and flattened, and the installation of the grid is completed.

[0086] Compared with the prior art, the grid installation method provided in the embodiment has basically the same beneficial effects as the grid tension connecting member provided in the embodiment one, which will not be described herein.

[0087] Specifically, the above step 2 comprises the following steps:

[0088] Step 21: the grid mesh is sleeved on the connecting part 241 after passing through the protrusion 242;

[0089] Step 22: the upper box 22 and the lower box 23 are moved close to each other, and the engagement protrusion 24 is inserted into the engagement groove 25;

[0090] Step 23: the upper box 22 and the lower box 23 are integrally inserted into the fixed frame 21, so that the upper box 22 and the lower box 23 clamp the grid.

[0091] Example Three

[0092] The embodiment provides a bridge abutment-filling subgrade structure, referring to Figs. 4 to 6 , including a filling subgrade 1 and an integral flexible bridge abutment directly connected with the filling subgrade 1, the integral flexible bridge abutment has a rigidity greater than that of the filling subgrade 1, the filling subgrade 1 is divided into a plurality of encryption areas along a line direction, and the rigidity of the plurality of encryption areas gradually decreases along a direction away from the bridge abutment, the integral flexible bridge abutment includes a bridge abutment base body, a structural reinforcement net 7, a structural reinforcement net 8, a connecting long reinforcement 9 and a connecting short reinforcement 10, the bridge abutment base body is a layered structure and includes a plurality of lightweight flowing concrete layers 4 (for example, the lightweight flowing concrete layer 4) stacked in sequence, the structural reinforcement net 7 is arranged in the lightweight flowing concrete layer 4 along a horizontal direction, the length of the structural reinforcement net 7 is 0.8-0.9 times the overall height of the bridge abutment, the structural reinforcement net 8 is arranged between two adjacent lightweight flowing concrete layers 4 and is laid through layers, one end of the structural reinforcement net 8 is connected with the connecting short reinforcement 10, and the other end is arranged between the upper box 22 and the lower box 23, the length of the connecting short reinforcement 10 is not less than 20 cm, and the included angle with the horizontal plane is not greater than 45°, one end of the plurality of structural reinforcement nets 7 is connected with the connecting long reinforcement 9, and the other end is arranged between the upper box 22 and the lower box 23, the vertical spacing between adjacent structural reinforcement nets 7 is 0.3-0.5 m, and the vertical spacing between adjacent two structural reinforcement nets 8 is 1.5-2.0 m.

[0093] In the prior art, because there is a large rigidity difference between the rigid bridge abutment and the filling subgrade, a transition subgrade is usually arranged between the rigid bridge abutment and the filling subgrade, the transition subgrade is made of graded gravel or lightweight filler and is arranged between the rigid bridge abutment and the filling subgrade, so as to compensate for the rigidity difference between the rigid bridge abutment and the filling subgrade.

[0094] Compared with the prior art, the abutment-subgrade structure provided by the embodiment can fix the structural reinforcement net 7 and the constructional reinforcement net 8 close to one end of the filled subgrade 1, and tension the other end through the grid tension connecting piece, so as to ensure the tension flatness of the structural reinforcement net 7 and the constructional reinforcement net 8. It should be noted that, through the interaction between the grid tension connecting piece and the connecting long reinforcement 9, the structural reinforcement net 7 and the constructional reinforcement net 8 can basically maintain a fixed position during the pouring process of the lightweight flowing concrete layer 4, and the force applied by the grid tension connecting piece to the structural reinforcement net 7 and the constructional reinforcement net 8 is not a concentrated force, which can avoid damage to the structural reinforcement net 7 and the constructional reinforcement net 8 due to the concentrated force and reduce the influence on the working performance of the structural reinforcement net 7 and the constructional reinforcement net 8.

[0095] Meanwhile, referring to Fig. 1 , the stiffness transition can be divided into at least two transition zones, the first transition zone is a region provided with both the structural reinforcement net 7 and the constructional reinforcement net 8, and the second transition zone is a region provided with only the constructional reinforcement net 8. The gradual change of the overall flexible abutment stiffness reduces the requirement for the stiffness of the filled subgrade, simplifies the foundation treatment process, and replaces the rigid abutment and the transition subgrade with the overall flexible abutment. Meanwhile, the overall flexible abutment can ensure that the pressure at the bottom of the abutment seat is diffused and attenuated in the overall region of the structural reinforcement net 7 and the constructional reinforcement net 8 (i.e., the region with a larger reinforcement density).

[0096] In addition, through the arrangement of the structural reinforcement net 7, the constructional reinforcement net 8, the connecting long reinforcement 9 and the connecting short reinforcement 10, the structural reinforcement net 7, the constructional reinforcement net 8, the connecting long reinforcement 9, the connecting short reinforcement 10 and the lightweight flowing concrete layer 4 are integrated during the pouring process, which can also avoid concrete cracking caused by the drying shrinkage of the lightweight flowing concrete layer 4, and ensure the integrity and stability of the overall flexible abutment.

[0097] Exemplarily, the height of the I-shaped panel 12 is 0.10-0.15 times the height H of the overall flexible abutment, the length is 0.15-0.20 times the height H of the overall flexible abutment, and the width is 0.05-0.1 times the height H of the overall flexible abutment. The thickness of the side wall is not less than 0.2 m.

[0098] In order to form a rigid gradual change structure again in the second transition zone, from bottom to top, in the two adjacent lightweight flowing concrete layers 4, the end face of the lightweight flowing concrete layer 4 located in the upper layer protrudes from the end face of the lightweight flowing concrete layer 4 located in the lower layer away from the bridge end, so as to form a ladder-shaped overall flexible abutment.

[0099] The geometric profile of the integral flexible abutment is a wedge, specifically, the geometric profile of the integral flexible abutment can be a wedge, and in the vertical direction, the stepped portion of the integral flexible abutment can replace the transition subgrade and the partially filled subgrade, omit the transition subgrade, and the geometric profile of the integral flexible abutment and the gradually changing stiffness of the densification area can realize smooth reduction of the stiffness of the integral flexible abutment itself, and further reduce the stiffness difference between the integral flexible abutment and the filled subgrade, effectively weaken the interface effect between the abutment and the subgrade.

[0100] It should be noted that the geometric profile of the integral flexible abutment is a wedge, and the length of the bottom edge of the wedge is not less than 0.8 times the overall height of the integral flexible abutment, and the length of the top edge of the wedge is not less than 1.5 times the overall height of the integral flexible abutment, the line between the center point of the bottom surface of the abutment 26 and the center point of the back of the integral flexible abutment is defined as an auxiliary line a, the angle between the auxiliary line a and the bottom surface of the integral flexible abutment is β, and β is not greater than 45°, and the back slope ratio of the integral flexible abutment is 1:1-1:1.5.

[0101] Exemplarily, the lightweight flowing concrete layer 4 described above can be made of ramie fiber foam lightweight flowing concrete. The components of the ramie fiber foam lightweight flowing concrete include, by mass percentage, fly ash 40-50%, Portland cement 30-40%, ramie fiber 0.1-0.5%, early strength agent 2-3%, cement foaming agent 1-2%, foam stabilizer 1-2%, and water reducing agent 0.5-1%. The length of the ramie fiber is 6-18 mm, the water-binder ratio of the ramie fiber foam lightweight flowing concrete is 0.4-0.6, and the density is not greater than 1.0 g / cm 3 The cubic compressive strength standard value is not less than 20 MPa. The use of such ramie fiber foam lightweight flowing concrete can appropriately improve the flexibility of the integral flexible abutment on the basis of ensuring the stiffness of the integral flexible abutment, thereby further reducing the stiffness difference between the integral flexible abutment and the filled subgrade 1. The use of ramie fiber instead of steel reinforcement achieves the purpose of reinforcing the foam lightweight flowing concrete, and is more ecological and low-carbon than using steel as the reinforcing material. In addition, by adding early strength agent to the ramie fiber foam lightweight flowing concrete to accelerate the process of flowing self-compaction, simplify the subgrade treatment process, and eliminate the need for bridgehead plate setting, the purpose of controllable engineering quality and high efficiency construction can be achieved, which is beneficial to saving construction period.

[0102] In order to prevent the integral flexible abutment from falling during the bearing process, the integral flexible abutment described above further includes an anchoring member 5 (for example, a prestressed anchor cable), which penetrates the lightweight flowing concrete layer 4, the structural reinforcement net 7 and the construction reinforcement net 8 in the vertical direction and extends into the foundation, and is driven into the bearing layer to form an anchoring area 6 with a certain reinforcing depth. Exemplarily, the number of anchoring members 5 is multiple, and the multiple anchoring members 5 are arranged transversely along the integral flexible abutment.

[0103] Wherein, the anchor 5 takes Q335 steel material as raw material, adopts steel pipe with diameter not less than 150mm and wall thickness not less than 5mm, the length of the anchor 5 into the bearing layer is not less than 2.0m, the anchoring length of the anchoring area 6 is not less than 1.0m, and the standard value of the cubic compressive strength of the cast-in-place concrete in the anchoring area 6 is not less than 30MPa; the distance between two adjacent anchors 5 along the longitudinal direction of the line is not greater than 1.5m, and the distance between two adjacent anchors 5 along the transverse direction of the line is not greater than 2.0m.

[0104] Considering that the thickness of the abutment base is large, the length of one connecting long bar 9 cannot connect all the structural bar meshes 7 in the thickness direction of the abutment base, therefore, multiple connecting long bars 9 are needed to be connected to form a structure with a longer length. Specifically, two adjacent connecting long bars 9 are connected through a sleeve 11, the outer wall of the connecting long bar 9 is provided with threads at both ends or the whole body, the inner wall of the sleeve 11 is provided with threads, and the two adjacent connecting long bars 9 are both threadedly connected with the sleeve 11, so as to connect multiple connecting long bars 9 to form a structure with a longer length. In actual application, the length of the connecting long bar 9 is not less than the pouring thickness of each lightweight flowing concrete layer 4, the connecting long bar 9 is connected in sections during pouring, and the sleeve 11 is not less than 10cm in length and not less than 5mm in wall thickness.

[0105] Specifically, the vertical spacing of the above-mentioned two adjacent layers of structural bar meshes 7 is determined by the following method:

[0106] Step A: initially determine the vertical spacing of two adjacent layers of structural bar meshes in the integral flexible abutment, and then determine the total cross-sectional area a of the structural bar mesh and the lightweight flowing concrete layer in a certain reinforced unit cross section, the cross-sectional area a1 of the structural bar mesh 7, and the cross-sectional area a2 of the lightweight flowing concrete layer in the structural bar mesh;

[0107] Step B: calculate the elastic modulus of the structural bar mesh and the lightweight flowing concrete layer composite;

[0108]

[0109]

[0110] In the formula: E y —The horizontal composite elastic modulus (MPa) of the structural bar mesh and the lightweight flowing concrete layer composite;

[0111] E z —The vertical composite elastic modulus (MPa) of the structural bar mesh and the lightweight flowing concrete layer composite;

[0112] E c —The elastic modulus (MPa) of the lightweight flowing concrete layer;

[0113] Er — Elastic modulus of structural reinforcement (MPa);

[0114] v yz — Ratio of z-direction linear strain to y-direction linear strain of elastomer under y-direction stress;

[0115] v xy — Ratio of y-direction linear strain to x-direction linear strain of elastomer under x-direction stress;

[0116] v c — Poisson's ratio of lightweight flowable concrete layer;

[0117] v r — Poisson's ratio of structural reinforcement;

[0118] a — Total cross-sectional area of structural reinforcement and lightweight flowable concrete layer (mm 2 );

[0119] a1 — Cross-sectional area of structural reinforcement (mm 2 );

[0120] a2 — Cross-sectional area of lightweight flowable concrete layer (mm 2 ).

[0121] Step C: Calculate total settlement of monolithic flexible abutment;

[0122]

[0123] wherein: S — Total settlement of monolithic flexible abutment (mm);

[0124] S max — Maximum settlement of monolithic flexible abutment (mm);

[0125] E z — Vertical composite elastic modulus of structural reinforcement and lightweight flowable concrete layer composite (MPa);

[0126] I — Moment of inertia (mm 4 ), and wherein b is the length of structural reinforcement and lightweight flowable concrete layer composite along x-direction, mm, and ξ is the length of structural reinforcement and lightweight flowable concrete layer composite along z-axis direction, mm;

[0127] γ — Weight per unit volume of structural reinforcement and lightweight flowable concrete layer composite, kN / m 3 ;

[0128] z — Distance from top surface of monolithic flexible abutment (mm);

[0129] y —— the longitudinal distance of the integral flexible abutment (mm);

[0130] l —— the total length of the integral flexible abutment in the y direction (mm);

[0131] h —— the total height of the integral flexible abutment (mm).

[0132] The total settlement S of the integral flexible abutment is the maximum total settlement S max , and when the maximum total settlement S max of the integral flexible abutment is less than the maximum allowable settlement [S] of the integral flexible abutment, the arrangement density of the structural reinforcement mesh meets the requirements, otherwise the vertical spacing of the structural reinforcement mesh needs to be adjusted and the calculation is performed again according to the above design process until the maximum settlement S max of the integral flexible abutment is less than the maximum allowable settlement [S] of the integral flexible abutment, and then it can be determined that the arrangement density of the structural reinforcement mesh meets the requirements.

[0133] It should be noted that the maximum allowable settlement [S] of the integral flexible abutment can be calculated by the method in the prior art, and its value is related to the form of the bridge superstructure, the bridge span, the highway level, etc.

[0134] It should also be noted that the area where the structural reinforcement mesh 7 is arranged is the main stress area of the integral flexible abutment. In theory, the arrangement density of the structural reinforcement mesh 7 should be significantly greater than that of the construction reinforcement mesh 8, Fig. 1 and considering the clarity of the picture, the structural reinforcement mesh 7 is not arranged with obvious densification.

[0135] Exemplarily, the structural reinforcement mesh 7, the construction reinforcement mesh 8 and the connecting long reinforcement 9 are all made of carbon fiber bundle warp-knitted grid. The carbon fiber bundle warp-knitted grid is used to replace steel to achieve the purpose of reinforcing the abutment base, which is more ecological and low-carbon than using steel as the reinforcing material.

[0136] The carbon fiber bundle warp-knitted grid includes carbon fiber bundles and a resin coating coated on the surface of the carbon fiber bundles, the breaking elongation of the carbon fiber bundles is less than 2%, the longitudinal tensile strength and the transverse tensile strength of the carbon fiber bundle warp-knitted grid are both not less than 80 kN / m, the size of a single grid is 20-40 mm, and the width is not less than 3 m.

[0137] For the implementation mode of gradually decreasing stiffness of multiple densification areas, exemplarily, multiple extruded piles 3 are arranged in the densification area, the extruded piles 3 are arranged in the vertical direction, and along the direction away from the integral flexible abutment, the pile spacing of the extruded piles 3 in the multiple densification areas gradually increases, and / or along the direction away from the integral flexible abutment, the pile diameter of the extruded piles 3 in the multiple densification areas gradually decreases, so that the pile spacing of the extruded piles 3 and / or the pile diameter of the extruded piles 3 in different densification areas can be adjusted to achieve the gradually decreasing stiffness of the multiple densification areas.

[0138] Exemplarily, the compaction pile 3 is a column hammer type ramming construction waste compaction pile. The secondary compaction effect of the column hammer type ramming construction waste compaction pile is used to improve the rigidity of the filled subgrade 1 to different degrees, gradually compensate for the rigidity difference between the integral flexible abutment and the filled subgrade 1, and realize the multi-gradient smooth transition of the rigidity difference between the integral flexible abutment and the filled subgrade 1. In addition, the column hammer type ramming construction waste compaction pile is filled with a certain amount of waste concrete and waste bricks and other construction wastes, which can not only enhance the strength of the structure, but also achieve the goal of building a full life cycle green transportation structure.

[0139] Specifically, the following method is adopted for determining the pile spacing and pile diameter of the compaction pile 3:

[0140] Step a: The pile diameter and pile spacing of the compaction pile are initially selected, and the filled subgrade area replacement rate m is calculated according to the following formula:

[0141]

[0142] In the formula: ξ — pile spacing of compaction pile (m);

[0143] m — filled subgrade area replacement rate;

[0144] d — pile diameter of compaction pile (m).

[0145] Step b: Calculate the filled subgrade allowable area replacement rate [m] and the minimum compaction coefficient D emin ;

[0146]

[0147] In the formula: [m] — filled subgrade allowable area replacement rate;

[0148] [f sp ] — filled subgrade bearing capacity allowable value (kPa);

[0149] f cu — average value of compressive strength of pile body (kPa);

[0150] f sk — characteristic value of pile body compressive strength (kPa);

[0151] A p — single pile cross-sectional area (mm 2 );

[0152] β p — pile body vertical compressive bearing capacity correction coefficient, 0.2-0.5;

[0153] β s— The bearing capacity correction coefficient of the soil-filled subgrade between piles, taken as 0.1-0.4;

[0154] η — The strength reduction coefficient of the pile body, taken as 0.2-0.3.

[0155]

[0156] D = 0.5 (D1+D2) emin — The minimum compaction coefficient, preferably greater than 0.80;

[0157] γ d0 — The dry bulk density of the three hole center points after the compaction pile compacts the hole, kN / m 3 ;

[0158] γ dmax — The maximum dry bulk density determined by the compaction test, kN / m 3 .

[0159] Step c: compare the soil-filled subgrade area replacement rate m with the allowable soil-filled subgrade area replacement rate [m], when m≥[m], and the minimum compaction coefficient D emin meets the design requirements, then the pile diameter and pile spacing of the compaction pile are preliminarily selected to meet the design requirements, otherwise, adjust the pile diameter and pile spacing of the compaction pile to recalculate until the obtained soil-filled subgrade area replacement rate m is not less than the allowable soil-filled subgrade area replacement rate [m], and the minimum compaction coefficient D emin meets the design requirements.

[0160] Taking two encryption areas as an example, that is, the encryption area is divided into a first encryption area and a second encryption area, the pile body diameter of the compaction pile 3 is 0.3-0.5 m, the pile length is 1.2-1.5 m, the pile arrangement mode is equilateral triangle arrangement, the material of the compaction pile 3 includes construction waste such as waste concrete and waste bricks and stones, the pile spacing of the first encryption area is 0.8-1.0 m; the pile spacing of the second encryption area is 1.2-1.5 m.

[0161] It can be understood that the above bridge substructure also includes a pedestal 26 (cast-in-place concrete pedestal 26), a beam slab 27 and a pavement structure layer 28, the pedestal 26 is arranged on the integral flexible bridge abutment, one end of the beam slab 27 and one end of the pavement structure layer 28 are both arranged on the pedestal 26, wherein the height of the pedestal 26 is not less than 0.1 times the height H of the integral flexible bridge abutment, the width of the pedestal 26 is not less than 0.2 times the height H of the integral flexible bridge abutment, and the distance between the pedestal 26 and the first layer of rectangular face slab 12 is not less than 0.1 times the height H of the integral flexible bridge abutment.

[0162] Considering the arrangement of the abutment 26, a gap exists between the pavement structure layer 28 and the integral flexible abutment and fill embankment 1, therefore, the reinforced base 2 is arranged between the pavement structure layer 28 and the integral flexible abutment and fill embankment 1, and the upper surface and the lower surface of the reinforced base 2 are both provided with double twisted steel wire meshes. In this way, the gap between the pavement structure layer 28 and the integral flexible abutment and fill embankment 1 can be filled by the reinforced base 2, and the flatness and stability of the pavement structure layer 28 are ensured.

[0163] The reinforced base 2 is filled with graded gravel with a maximum particle size less than 35 mm, and the compaction degree is controlled to be more than 96%; the double twisted steel wire mesh is made of low-carbon steel wire coated with PVC, the diameter of the low-carbon steel wire is not less than 2.5 mm, the area of a single mesh is not more than 80 cm 2 , and the transverse tensile strength of the double twisted steel wire mesh is not less than 20 KN / m, and the longitudinal tensile strength is not less than 25 KN / m.

[0164] The above merely describes the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Any changes or replacements within the technical scope disclosed by the present application can be easily thought by those skilled in the art, and should be covered within the protection scope of the present application.

Claims

1. A bridge abutment-roadbed structure, characterized in that, It includes a platform, an earth-filled roadbed, and an integral flexible bridge abutment directly connected to the earth-filled roadbed, with the platform set on the integral flexible bridge abutment. The integral flexible bridge abutment includes an abutment base, structural reinforcement mesh, structural reinforcement mesh, connecting long bars, connecting short bars, and grid tensioning connectors. The abutment base consists of multiple layers of lightweight flowing concrete stacked sequentially. The structural reinforcement mesh is horizontally positioned within the lightweight flowing concrete layers, while the structural reinforcement mesh is positioned between adjacent lightweight flowing concrete layers. The grid tensioning connectors include U-shaped panels and interlocking components. The interlocking components include a fixed frame, an upper box, a lower box, and connecting rods. The fixed frame has a notch on the side facing the fill subgrade, through which the grid mesh connects to the interlocking components. The upper and lower boxes are located within the fixed frame and interlock with each other, with the grid mesh positioned between the upper and lower boxes. The connecting rods are located on the outer wall of the fixed frame and are telescopically connected to the U-shaped panels. One end of the structural reinforcement mesh is connected to the connecting short bars, and the other end is positioned between the upper and lower boxes. One end of multiple structural reinforcement meshes is connected to the connecting long bars, and the other end is positioned between the upper and lower boxes. The geometric profile of the integral flexible bridge abutment is a wedge shape, and the length of the bottom edge of the wedge is not less than 0.8 times the overall height of the integral flexible bridge abutment, and the length of the top edge of the wedge is not less than 1.5 times the overall height of the integral flexible bridge abutment. The line connecting the center point of the bottom surface of the abutment and the center point of the bottom edge of the abutment back of the integral flexible bridge abutment is defined as an auxiliary line. The angle between the auxiliary line and the bottom surface of the integral flexible bridge abutment is not greater than 45°. The slope of the abutment back of the integral flexible bridge abutment is 1:1 to 1:1.

5. The vertical spacing between two adjacent structural reinforcement mesh layers is determined using the following method: Step A: Initially determine the vertical spacing between two adjacent structural reinforcement mesh layers within the integral flexible abutment, and then determine the total cross-sectional area of ​​the structural reinforcement mesh and the lightweight flowing concrete layer within a certain reinforced unit cross-section, the cross-sectional area of ​​the structural reinforcement mesh, and the cross-sectional area of ​​the lightweight flowing concrete layer within the structural reinforcement mesh; Step B: Calculate the elastic modulus of the composite of the structural reinforcement mesh and the lightweight flowing concrete layer using the following formula: In the formula: E y - Horizontal composite elastic modulus of the structural reinforcement mesh and lightweight fluid concrete layer composite, MPa; E z - Vertical composite elastic modulus of the structural reinforcement mesh and lightweight fluid concrete layer composite, MPa; E c - Elastic modulus of lightweight flowable concrete layer, MPa; E r - Elastic modulus of the structural reinforcement mesh, MPa; v yz - The ratio of the linear strain in the z-direction to the linear strain in the y-direction of an elastic body under stress in the y-direction; v xy - The ratio of the linear strain in the y-direction to the linear strain in the x-direction of an elastic body under stress in the x-direction; v c - Poisson's ratio for lightweight, fluid concrete layers; v r - Poisson's ratio of the structural reinforcement mesh; a - Total cross-sectional area of ​​the structural reinforcement mesh and the lightweight flowable concrete layer, mm² 2 a1 - Cross-sectional area of ​​the structural reinforcement mesh, mm 2 a2 - Cross-sectional area of ​​lightweight flowable concrete layer, mm 2 ; Step C: Calculate the total settlement of the integral flexible bridge abutment using the following formula: Where: S - total settlement of the integral flexible bridge abutment, mm; S max - Maximum settlement of the integral flexible bridge abutment, mm; I- Moment of inertia, mm 4 ,and Where b is the length of the structural mesh and lightweight flowing concrete layer composite along the x-direction, mm; ξ is the length of the structural mesh and lightweight flowing concrete layer composite along the z-axis, mm; γ is the weight per unit volume of the structural mesh and lightweight flowing concrete layer composite, kN / m. 3 z - Distance from the top surface of the integral flexible bridge abutment, mm; y - Longitudinal distance along the integral flexible bridge abutment, mm; l - Total length of the integral flexible bridge abutment along the y direction, mm; h - Total height of the integral flexible bridge abutment, mm; The total settlement of the integral flexible bridge abutment is the maximum total settlement. If the maximum total settlement of the integral flexible bridge abutment is less than the maximum allowable settlement of the integral flexible bridge abutment, then the arrangement density of the structural reinforcement mesh meets the requirements. Otherwise, the vertical spacing of the structural reinforcement mesh needs to be adjusted and recalculated until the maximum settlement of the integral flexible bridge abutment is less than the maximum allowable settlement of the integral flexible bridge abutment, thus confirming that the arrangement density of the structural reinforcement mesh meets the requirements.

2. The bridge abutment-subgrade structure according to claim 1, characterized in that, The length of the structural reinforcement mesh is 0.8 to 0.9 times the overall height of the abutment.

3. The bridge abutment-subgrade structure according to claim 1, characterized in that, The length of the connecting short bar is not less than 20cm, and the angle between it and the horizontal plane is not greater than 45°.

4. The bridge abutment-subgrade structure according to claim 1, characterized in that, The height of the U-shaped panel is 0.10 to 0.15 times the height of the integral flexible bridge abutment, the length is 0.15 to 0.20 times the height of the integral flexible bridge abutment, the width is 0.05 to 0.1 times the height of the integral flexible bridge abutment, and the thickness of the sidewall is not less than 0.2m.

5. The bridge abutment-subgrade structure according to claim 1, characterized in that, The structural reinforcement mesh, construction reinforcement mesh, and connecting long reinforcement bars are all made of carbon fiber bundle warp-knitted mesh.

6. The bridge abutment-subgrade structure according to claim 5, characterized in that, The carbon fiber bundle warp-knitted grid includes carbon fiber bundles and a resin coating applied to the surface of the carbon fiber bundles. The size of a single grid is 20-40 mm, and the width is not less than 3 m.

7. The bridge abutment-subgrade structure according to any one of claims 1 to 6, characterized in that, The inner wall of the U-shaped panel is provided with a support rod along the horizontal direction and a joint sleeved on the outer wall of the support rod. The joint rotates relative to the support rod and slides along the axial direction of the support rod. The connecting rod is threadedly connected to the joint. Adjusting the relative position between the connecting rod and the U-shaped panel causes the connecting rod to move closer to the U-shaped panel, and the grid is stretched flat.

Images