Reinforcing structure and reinforcing method of a diaphragm wall with enlarged foot

Abstract

The application provides a reinforced structure and a reinforcing method for a core wall and an enlarged foot, and belongs to the field of water conservancy and hydropower engineering reinforcement. By limiting the outer side of the connecting structure to be an outward convex curved surface, stress concentration at the connecting part can be significantly reduced, stress distribution is more uniform, and crack resistance is enhanced. By setting the lower reinforcing layer and the upper reinforcing layer as structures with different stiffness, stable load conduction can be achieved, and the crack resistance of the reinforced structure is improved. By setting a flexible reinforcing layer and limiting its material, the tensile and deformation resistance of the reinforced structure can be improved, the formation of cracks and leakage channels can be prevented, and the anti-seepage performance can be greatly optimized. The reinforced structure provided by the application can effectively avoid the crack problem caused by stress concentration after reinforcing the connection between the core wall and the enlarged foot, and has good anti-seepage effect.

Description

Technical Field

[0001] This invention relates to the field of reinforcement of water conservancy and hydropower projects, and in particular to a reinforcement structure and method for a core wall and an enlarged foot. Background Technology

[0002] In earth-rock dam structures, the connection between the abutment and the asphalt concrete core wall serves as a critical transition zone for structural stress, and its design directly determines the reliability of the overall seepage control system and its load-bearing capacity. Traditionally, this area is often constructed using angled geometric features to achieve structural connection. However, this transition method inherently involves abrupt angle changes (usually acute or obtuse angles), leading to significant non-uniformity in the internal stress distribution of the material. Specifically, when the structure is subjected to seismic loads, its own weight, water pressure, or temperature loads, the peak stress at the corner, due to the interruption of geometric continuity, can reach 2-3 times that of the adjacent straight section, causing cracking at the connection. Firstly, seismic inertial forces easily cause stress concentration and cracking at the corner of the abutment. This stress concentration can also trigger a vicious cycle of seepage-erosion-instability. In the short term, a sudden increase in seepage pressure can lead to piping or contact scouring, while long-term seepage causes the dam's phreatic line to rise, reducing the stability of the downstream slope.

[0003] Therefore, how to reinforce the connection between the core wall and the enlarged foot to improve the seismic performance of the connection, effectively avoid cracks caused by stress concentration, extend the service life of the dam, and ensure the safe and stable operation of earth-rock dam projects has become an urgent technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a reinforcement structure and method for the core wall and the enlarged foot. The reinforcement structure provided by this invention, after reinforcing the connection between the core wall and the enlarged foot, can effectively avoid cracking caused by stress concentration and has a good seepage prevention effect.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: The present invention provides a reinforcement structure for the core wall and the enlarged foot, including two connecting structures 3 symmetrically fixed on both sides of the core wall-enlarged foot connection section; The outer surface of the connecting structure 3 is a convex arc surface with a horizontal axis. The connection structure 3 includes an upper reinforcing layer 7, a lower reinforcing layer 8, and a flexible reinforcing layer 5 disposed at the interface between the reinforcing layer 7 and the lower reinforcing layer 8; The flexible reinforcement layer 5 includes a bidirectional glass fiber geogrid; the flexible reinforcement layer 5 is coplanar with the core wall-enlarged foot connection interface; The upper reinforcing layer 7 and the lower reinforcing layer 8 are made of asphalt concrete, and the stiffness of the lower reinforcing layer 8 is greater than that of the upper reinforcing layer 7, with a stiffness difference of (1.2~1.8)×10. 9 N / m.

[0006] Preferably, the radius of curvature of the convex arc surface is 1.2 to 2.0 times the thickness of the core wall; the axis of the convex arc surface is the center line of the core wall-enlarged foot connection interface.

[0007] Preferably, the upper reinforcing layer 7 comprises the following components by mass percentage: 92.8-93.3% of the first aggregate and 6.7-7.2% of asphalt; The maximum particle size of the first aggregate is 16 mm, and the gradation index of the first aggregate is 0.45~0.50.

[0008] Preferably, the lower reinforcing layer 8 comprises the following components by mass percentage: 93.3-93.8% second aggregate and 6.2-6.7% asphalt; The maximum particle size of the second aggregate is 19 mm; the gradation index of the second aggregate is 0.50~0.55.

[0009] Preferably, one end of the flexible reinforcing layer 5 is inserted into the core wall, and the insertion depth is ≥30cm.

[0010] Preferably, the flexible reinforcing layer 5 further includes asphalt adhered to the bidirectional glass fiber geogrid.

[0011] The present invention also provides a core wall-enlarged foot fixed connection structure, comprising a concrete base, an enlarged foot and a core wall arranged sequentially from bottom to top, and a reinforcement structure as described in the above technical solution fixed to the core wall-enlarged foot connection section.

[0012] Preferably, it also includes modified bitumen rolls disposed on the outside of the joint between the reinforced structure and the core wall-enlarged foot connection section, as well as on the outside of the reinforced structure.

[0013] This invention also provides a method for reinforcing the core wall and the enlarged foot, using the reinforcement structure described above, comprising the following steps: A reinforcement layer is laid on both sides of the enlarged foot at the connection section between the core wall and the enlarged foot. A flexible reinforcing layer is laid on the upper surface of the lower reinforcing layer; A reinforcing layer is laid on the upper surface of the flexible reinforcing layer.

[0014] Preferably, it further includes covering the outside of the joint between the reinforced structure and the core wall-enlarged foot connection section, as well as the outside of the reinforced structure, with modified bitumen roll material.

[0015] This invention provides a reinforcement structure for a core wall and an enlarged foot, comprising two connecting structures 3 symmetrically fixed on both sides of the core wall-enlarged foot connection section; the outer surface of each connecting structure 3 is a convex arc surface with a horizontal axis; each connecting structure 3 includes an upper reinforcement layer 7, a lower reinforcement layer 8, and a flexible reinforcing layer 5 disposed at the interface between the reinforcement layer 7 and the lower reinforcement layer 8; the flexible reinforcing layer 5 includes a bidirectional glass fiber geogrid; the flexible reinforcing layer 5 is coplanar with the core wall-enlarged foot connection interface; the materials of the upper reinforcement layer 7 and the lower reinforcement layer 8 are asphalt concrete, and the stiffness of the lower reinforcement layer 8 is greater than that of the upper reinforcement layer 7, with a stiffness difference of (1.2~1.8)×10. 9 N / m. This invention significantly reduces stress concentration at the connection points by defining the outer surface of the connecting structure as a convex arc surface, resulting in a more uniform stress distribution and enhanced crack resistance. By setting the stiffness of the lower reinforcing layer 8 to be greater than that of the upper reinforcing layer 7 and limiting the stiffness difference, the upper reinforcing layer 7, with its lower stiffness (and better flexibility), avoids additional stress concentration caused by deformation inconsistencies, achieving seamless stress connection with the core wall. Due to the high concentrated compressive stress at the foot, the lower reinforcing layer 8, with its greater stiffness and strong compressive strength, can quickly disperse concentrated stress, preventing stress accumulation at the connection point and providing rigid load-bearing support. Limiting the stiffness difference avoids stress refraction and accumulation caused by sudden stiffness changes, thus achieving stable load transmission and improving the crack resistance of the reinforced structure. By setting a flexible reinforcing layer 5 and limiting its material, the tensile and deformation resistance of the reinforced structure can be improved, preventing the formation of cracks and leakage channels, thereby significantly optimizing seepage prevention performance. The results of the embodiments show that after the reinforcement structure provided by the present invention reinforces the connection between the core wall and the enlarged foot, the shear strain is reduced by 90.79% compared with the unreinforced structure, the effective bearing area is expanded by 46.23%, the tensile strength is increased by 62%, the seepage prevention performance is improved by 89%, and the stress concentration coefficient of the reinforcement structure is only 1.18, which can effectively avoid the crack problem caused by stress concentration and has a good seepage prevention effect. Attached Figure Description

[0016] Figure 1 The following is a front view and AA cross-sectional view of the core wall-enlarged foot connection structure in Example 1 of the present invention; wherein, 1 is the core wall, 2 is the enlarged foot, 3 is the connection structure, 4 is the concrete base, 5 is the flexible reinforcement layer, 6 is the modified bitumen roll material, 7 is the upper reinforcement layer, and 8 is the lower reinforcement layer. Detailed Implementation

[0017] The present invention provides a reinforcement structure for the core wall and the enlarged foot, including two connecting structures 3 symmetrically fixed on both sides of the core wall-enlarged foot connection section.

[0018] The present invention symmetrically fixes the connecting structure 3 on both sides of the core wall-enlarged foot connecting section, which can strengthen the connection between the core wall and the enlarged foot.

[0019] In this invention, the outer surface of the connecting structure 3 is a convex arc surface with a horizontal axis.

[0020] In one embodiment of the present invention, the radius of curvature of the convex arc surface can be 1.2 to 2.0 times, 1.3 to 1.8 times, 1.4 to 1.7 times, or 1.5 to 1.6 times the thickness of the core wall. In another embodiment, the axis of the convex arc surface is the centerline of the interface between the core wall and the enlarged foot. Limiting the radius of curvature of the convex arc surface to the above-mentioned range can better improve the crack resistance of the reinforced structure.

[0021] In one embodiment of the present invention, the two connecting structures 3 can be fixed by interface bonding. In another embodiment of the present invention, the length of the connecting structure 3 can be 1.2 to 2 times the thickness of the core wall.

[0022] In this invention, the connection structure 3 includes an upper reinforcing layer 7, a lower reinforcing layer 8, and a flexible reinforcing layer 5 disposed at the interface between the reinforcing layer 7 and the lower reinforcing layer 8.

[0023] like Figure 1 As shown, the connection structure 3 provided by the present invention includes an upper reinforcing layer 7.

[0024] In one embodiment of the present invention, the upper reinforcing layer 7 is made of asphalt concrete; the upper reinforcing layer 7 may include the following components by mass percentage: 92.8-93.3% of the first aggregate and 6.7-7.2% of asphalt.

[0025] In one embodiment of the present invention, the upper reinforcing layer 7 may comprise, by mass percentage, 92.8-93.3% of the first aggregate, or 92.9-93.2% or 93.0-93.1%. The maximum particle size of the first aggregate may be 16 mm; the gradation index of the first aggregate may be 0.45-0.50, or 0.46-0.49 or 0.47-0.48; and the type of the first aggregate may be dolomite.

[0026] In one embodiment of the present invention, the components of the upper reinforcing layer 7 may include 6.7-7.2% asphalt, 6.8-7.1% asphalt, or 6.9-7.0% asphalt by weight percentage. In an embodiment of the present invention, the asphalt is SG70 base asphalt.

[0027] The present invention limits the composition of the upper reinforcement layer to the above range to obtain an upper reinforcement layer with relatively low rigidity, thereby adapting it to the core wall.

[0028] like Figure 1 As shown, the reinforcement structure 3 provided by the present invention includes a lower reinforcement layer 8.

[0029] In one embodiment of the present invention, the material of the lower reinforcing layer 8 is asphalt concrete; the lower reinforcing layer 8 may include the following components by mass percentage: 93.3~93.8% of second aggregate and 6.2~6.7% of asphalt.

[0030] In one embodiment of the present invention, the components of the lower reinforcing layer 8, by mass percentage, may include 93.3-93.8%, 93.4-93.7%, or 93.5-93.6% of the second aggregate. The maximum particle size of the second aggregate may be 19 mm; the gradation index of the second aggregate may be 0.50-0.55, 0.51-0.54, or 0.52-0.53; and the type of the second aggregate may be dolomite.

[0031] As one embodiment of the present invention, the components of the lower reinforcing layer 8 may include 6.2-6.7% asphalt, 6.3-6.6% asphalt, or 6.4-6.5% asphalt by mass percentage.

[0032] The present invention limits the composition of the lower reinforcement layer to the above-mentioned range to obtain a lower reinforcement layer with relatively high rigidity, thereby adapting to the enlarged foot.

[0033] In this invention, the stiffness of the lower reinforcing layer 8 is greater than the stiffness of the upper reinforcing layer 7, and the stiffness difference is (1.2~1.8)×10. 9 N / m, preferably (1.4~1.6)×10 9 N / m, more preferably 1.5×10 N / m. 9 N / m. In this invention, the upper reinforcing layer 7 has lower rigidity (better flexibility), which avoids additional stress concentration caused by deformation inconsistency and achieves seamless stress connection with the core wall. Because the enlarged foot is subjected to high concentrated compressive stress, the lower reinforcing layer 8 has greater rigidity and stronger compressive strength, which can quickly disperse concentrated stress, avoid stress accumulation at the connection point, and provide rigid load-bearing support. This invention limits the stiffness difference between the lower reinforcing layer 8 and the upper reinforcing layer 7 to the above-mentioned range to avoid stress refraction and accumulation problems caused by abrupt changes in stiffness, thereby achieving smooth load transmission and improving the crack resistance of the reinforced structure.

[0034] In one embodiment of the present invention, the porosity of the upper reinforcing layer 7 and the lower reinforcing layer 8 can be independently ≤3%, or can be 2~3%. Limiting the porosity of the upper reinforcing layer 7 and the lower reinforcing layer 8 to the above range can improve the seepage prevention performance of the reinforced structure.

[0035] like Figure 1 As shown, the reinforcement structure 3 provided by the present invention includes a flexible reinforcement layer 5 disposed at the interface between the reinforcement layer 7 and the lower reinforcement layer 8; the flexible reinforcement layer 5 includes a bidirectional glass fiber geogrid; the flexible reinforcement layer 5 is coplanar with the core wall-enlarged foot connection interface.

[0036] In one embodiment of the present invention, one end of the flexible reinforcing layer 5 is inserted into the core wall, and the insertion depth is ≥30cm, but can also be 30~40cm, or 32~36cm. By inserting one end of the flexible reinforcing layer 5 into the core wall, the present invention can further fix the flexible reinforcing layer and improve the overall strength of the reinforced structure.

[0037] In one embodiment of the present invention, the bidirectional glass fiber geogrid in the flexible reinforcement layer 5 is composed of bidirectional glass fiber geogrid strips that intersect each other in an X-shape. In another embodiment of the present invention, the diameter of each bundle of filaments in the warp and weft directions of the bidirectional glass fiber geogrid can be 1.0~1.5mm. In another embodiment of the present invention, the width of the bidirectional glass fiber geogrid strips can be 10~15cm, 11~14cm, or 12~13cm.

[0038] In one embodiment of the present invention, the flexible reinforcement layer 5 further includes asphalt adhered to the bidirectional glass fiber geogrid; the amount of asphalt adhered to the bidirectional glass fiber geogrid can be 1.2~1.5 kg / m. 2 It can also be 1.3~1.4 kg / m 2 The present invention allows the flexible reinforcement layer 5 to better bond with the upper and lower reinforcement layers by adhering asphalt to the bidirectional glass fiber geogrid.

[0039] In this invention, the flexible reinforcing layer 5 can improve the tensile and deformation resistance of the reinforced structure and prevent the formation of cracks and leakage channels. By limiting the material and parameters of the flexible reinforcing layer 5 to the aforementioned range, this invention can significantly optimize the seepage prevention performance of the reinforced structure.

[0040] This invention significantly reduces stress concentration at the connection points by defining the outer surface of the connecting structure as a convex arc surface, resulting in a more uniform stress distribution and enhanced crack resistance. By setting the stiffness of the lower reinforcement layer to be greater than that of the upper reinforcement layer and limiting the stiffness difference, the lower reinforcement layer (with better flexibility) avoids additional stress concentration caused by deformation inconsistencies, achieving seamless stress connection with the core wall. Due to the high concentrated compressive stress at the foot, the lower reinforcement layer, with its greater stiffness and strong compressive strength, quickly disperses the concentrated stress, preventing stress accumulation at the connection point and providing rigid load-bearing support. Limiting the stiffness difference avoids stress refraction and accumulation caused by abrupt changes in stiffness, thus achieving stable load transmission and improving the crack resistance of the reinforced structure. By setting a flexible reinforcement layer and limiting its material, the tensile and deformation resistance of the reinforced structure can be improved, preventing the formation of cracks and leakage channels, thereby significantly optimizing seepage prevention performance.

[0041] The present invention also provides a core wall-enlarged foot fixed connection structure, comprising a concrete base, an enlarged foot and a core wall arranged sequentially from bottom to top, and a reinforcement structure as described in the above technical solution fixed to the core wall-enlarged foot connection section.

[0042] As one embodiment of the present invention, the core wall-enlarged foot fixed connection structure further includes a modified bitumen roll material disposed on the outside of the joint between the reinforcement structure and the core wall-enlarged foot connection section.

[0043] This invention does not impose any special limitations on the material of the modified bitumen roll; any modified bitumen roll commonly used by those skilled in the art can be used. In an embodiment of this invention, the modified bitumen roll is TGC-3000SBS modified bitumen roll.

[0044] This invention also provides a method for reinforcing the core wall and the enlarged foot, using the reinforcement structure described above, comprising the following steps: A reinforcement layer is laid on both sides of the enlarged foot at the connection section between the core wall and the enlarged foot. A flexible reinforcing layer is laid on the upper surface of the lower reinforcing layer; A reinforcing layer is laid on the upper surface of the flexible reinforcing layer.

[0045] As one embodiment of the present invention, the reinforcement structure is laid simultaneously during the construction of the core wall and the enlarged foot, forming an integrated structure with the core wall and the enlarged foot, thereby improving the overall structure.

[0046] As one embodiment of the present invention, laying a lower reinforcement layer on both sides of the enlarged foot of the core wall-enlarged foot connection section may include: pre-treating the surface of the enlarged foot of the core wall-enlarged foot connection section before laying the lower reinforcement layer.

[0047] As one embodiment of the present invention, the pretreatment may include sequential cleaning and application of adhesive.

[0048] In one embodiment of the present invention, the cleaning can be performed by brushing with a soft brush and / or blowing with compressed air. In this invention, the purpose of the cleaning is to remove loose materials such as dust, gravel, and twigs from the surface of the foot.

[0049] In one embodiment of the present invention, the adhesive may be emulsified asphalt. In this invention, the purpose of applying the adhesive is to enhance the adhesion between the subsequent reinforcement layer and the enlarged foot.

[0050] In one embodiment of the present invention, the coating thickness of the adhesive can be 1-2 mm. The present invention does not impose any particular limitation on the specific coating operation; any coating operation commonly used by those skilled in the art can be used to uniformly coat the adhesive onto the cleaned enlarged foot surface.

[0051] As one embodiment of the present invention, the operation of laying the lower reinforcement layer may include: using the cross-section at the junction of the core wall and the enlarged foot as the dividing interface, spreading the lower reinforcement layer mixture above the surface of the enlarged foot of the core wall-enlarged foot connection section below the dividing interface to form a lower arc surface, and then compacting it to obtain the lower reinforcement layer.

[0052] In an embodiment of the present invention, the equipment used for paving the under-reinforcement layer mixture is an arc-shaped paver.

[0053] In one embodiment of the present invention, the paving temperature can be 150~155℃, 151~154℃, or 152~153℃. In the present invention, the paving temperature is the temperature at which the asphalt mixture is laid from under the screed of the paver to form the paving layer.

[0054] In an embodiment of the present invention, the loose paving coefficient is 1.2.

[0055] In this invention, an arc-shaped scraper is used to smooth the contour during the paving process to ensure that the lower arc surface is smooth and without sharp corners.

[0056] In one embodiment of the present invention, the internal temperature of the asphalt mixture during the entire compaction process can be no less than 110°C; the porosity of the lower reinforcement layer after compaction can be ≤3%, or 2~3%, or 2.3~2.5%.

[0057] In one embodiment of the present invention, the compaction direction can be the direction from the lower arc surface to the center of the circle.

[0058] In an embodiment of the present invention, the compaction includes initial compaction and secondary compaction performed sequentially. In an embodiment of the present invention, the initial compaction is performed by static compaction once using a 10-ton roller; the secondary compaction is performed by vibratory compaction four times using a 0.8mm amplitude.

[0059] After the lower reinforcement layer is laid, the present invention lays a flexible reinforcing layer on the upper surface of the lower reinforcement layer.

[0060] As one embodiment of the present invention, the operation of laying the flexible reinforcement layer may include: laying a bidirectional glass fiber geogrid on the upper surface of the lower reinforcement layer, spraying asphalt, and then compacting it to obtain the flexible reinforcement layer.

[0061] In one embodiment of the present invention, the specific operation of laying the bidirectional fiberglass geogrid can be as follows: inserting bidirectional fiberglass geogrid strips into the core wall-enlarged foot connection interface, and laying the bidirectional fiberglass geogrid by making the bidirectional fiberglass geogrid strips intersect each other in an X-shape. In another embodiment of the present invention, the operation of laying the bidirectional fiberglass geogrid can be as follows: after the enlarged foot and lower reinforcement layer are constructed, one end of the bidirectional fiberglass geogrid strip is pre-embedded at the core wall-enlarged foot connection interface, and compacted to form a tight bond with the lower reinforcement layer. Subsequently, the upper reinforcement layer is laid, forming an integral structure with the core wall construction.

[0062] In one embodiment of the present invention, the temperature of the asphalt during spraying can be 160~170℃; it can also be 165℃; the amount of asphalt used can be 1.2~1.5 kg / m³. 2 It can also be 1.3~1.4 kg / m 2 .

[0063] As one embodiment of the present invention, the compaction operation can be: using a small road roller to lightly roll and vent air, so that the grid and the lower reinforcement layer are tightly bonded together.

[0064] After the flexible reinforcement layer is laid, the present invention lays a reinforcement layer on the upper surface of the flexible reinforcement layer.

[0065] As one embodiment of the present invention, the operation of laying the upper reinforcement layer may include: spreading the reinforcement layer mixture on the upper surface of the flexible reinforcement layer to form an upper arc surface and then compacting it to obtain the upper reinforcement layer.

[0066] In an embodiment of the present invention, the equipment used for paving the reinforcement layer mixture is an arc-shaped paver.

[0067] In one embodiment of the present invention, the temperature of the asphalt mixture used for paving the reinforcing layer can be 155~160℃, 156~159℃, or 157~158℃. In the present invention, the paving temperature is the temperature at which the asphalt mixture is laid from under the screed of the paver to form the paving layer.

[0068] In an embodiment of the present invention, the loose paving coefficient is 1.2.

[0069] In this invention, an arc-shaped scraper is used to smooth the contour during the paving process to ensure that the upper arc surface is smooth and without sharp corners.

[0070] In this invention, the selection range of compaction parameters and compaction operation after paving the upper reinforcement layer mixture are the same as those after paving the lower reinforcement layer mixture, and will not be repeated here.

[0071] As one embodiment of the present invention, the reinforcement method of the core wall and the enlarged foot further includes: covering the outside of the joint between the reinforcement structure and the core wall-enlarged foot connection section and the outside of the reinforcement structure with modified bitumen roll material.

[0072] As one embodiment of the present invention, the operation of covering the modified bitumen roll may include: filling the joint between the reinforced structure and the core wall and the enlarged foot with a high-elasticity polyurethane sealant and then curing it, and then bonding the modified bitumen roll to the outside of the joint and the outside of the reinforced structure.

[0073] In an embodiment of the present invention, the coverage width of the modified asphalt roll is 35cm; the modified asphalt roll is bonded to the outside of the joint and the outside of the reinforcement structure using hot asphalt.

[0074] This invention does not impose any special limitations on the application of modified bitumen rolls; the key is to ensure that the modified bitumen rolls are laid flat, without wrinkles, and without curling edges.

[0075] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0076] Example 1 A reinforcement structure for the core wall and the enlarged foot consists of two connecting structures 3 symmetrically fixed on both sides of the core wall-enlarged foot connection section; The connecting structure 3 consists of an upper reinforcing layer 7 (composed of 93.1 wt% first aggregate and 6.9 wt% SG70 base asphalt, with a maximum particle size of 16 mm and a gradation index of 0.47, the first aggregate being dolomite), a lower reinforcing layer 8 (composed of 93.6 wt% second aggregate and 6.4 wt% SG70 base asphalt, with a maximum particle size of 19 mm and a gradation index of 0.52, the second aggregate being dolomite), and a flexible reinforcing layer 5 disposed at the interface between the reinforcing layer 7 and the lower reinforcing layer 8; The outer surface of the connecting structure 3 is a convex arc surface with a horizontal axis (the radius of curvature of the convex arc surface is 1.2 times the thickness of the core wall); the axis of the convex arc surface is the center line of the core wall-enlarged foot connection interface; The flexible reinforcement layer 5 consists of a bidirectional glass fiber geogrid and asphalt adhered to the bidirectional glass fiber geogrid; the asphalt adhesion amount on the bidirectional glass fiber geogrid is 1.3 kg / m². 2 The flexible reinforcing layer 5 is coplanar with the interface connecting the core wall and the enlarged foot; one end of the flexible reinforcing layer 5 is inserted into the core wall to a depth of 35cm. The flexible reinforcement layer 5 is composed of bidirectional glass fiber geogrid strips that intersect each other in an X-shape; the diameter of each bundle of filaments in the warp and weft directions of the bidirectional glass fiber geogrid can be 1.3 mm; the width of the strips is 13 m. The stiffness of the lower reinforcing layer 8 is greater than that of the upper reinforcing layer 7, and the stiffness difference is 1.5 × 10⁻⁶. 9 N / m; The porosity of the upper reinforcing layer 7 is 2.5%; the porosity of the lower reinforcing layer 8 is 2.3%.

[0077] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that the components of the lower reinforcing layer 8 in the connection structure 3 are replaced with the components of the upper reinforcing layer 7; otherwise, they are the same as in Example 1.

[0078] Comparative Example 2 The only difference between Comparative Example 2 and Example 1 is that the components of the upper reinforcing layer 7 in the connection structure 3 are replaced with the components of the lower reinforcing layer 8; otherwise, they are the same as in Example 1.

[0079] Comparative Example 3 The only difference between Comparative Example 3 and Example 1 is that the flexible reinforcing layer 5 is not provided; otherwise, they are the same as Example 1.

[0080] Application Example 1 A core wall-enlarged foot fixed connection structure comprises a concrete base, an enlarged foot and a core wall arranged sequentially from bottom to top, a reinforcement structure as described in Embodiment 1 fixed to the core wall-enlarged foot connection section, and modified bitumen roll material disposed on the outside of the joint between the reinforcement structure and the core wall-enlarged foot connection section and on the outside of the reinforcement structure. A method for reinforcing the core wall and the enlarged foot, using the reinforcement structure described in Example 1, comprises the following steps: The surfaces on both sides of the enlarged foot connecting the core wall and the enlarged foot are cleaned with soft brushes and compressed air to remove dust, gravel, branches, and other loose materials. Then, a 1.5mm layer of emulsified asphalt (category cationic slow-setting emulsified asphalt (CRS-1 type, manufactured by China Petroleum & Chemical Corporation) is evenly applied using a roller. The section below the dividing interface between the core wall and the enlarged foot, and above the surface of the enlarged foot, is then paved using an arc-shaped paver. The lower reinforcement layer mixture was prepared at a temperature of 155℃ with a loose paving coefficient of 1.2. During the paving process, an arc-shaped scraper was used to smooth the outline, ensuring a smooth, angle-free lower arc surface. After the lower arc surface was formed, a small vibratory compactor was used to compact it along the tangent of the outward convex arc (initial compaction and secondary compaction were performed sequentially; the initial compaction was carried out once with a 10-ton road roller, and the secondary compaction was carried out four times with a vibratory roller with an amplitude of 0.8mm. Throughout the compaction process, the internal temperature of the mixture was monitored with an infrared thermometer and maintained at 115℃). This resulted in the lower reinforcement layer (porosity of 2.3%). After the lower reinforcement layer is laid, a bidirectional fiberglass geogrid is laid on the upper surface of the lower reinforcement layer (the bidirectional fiberglass geogrid strips are inserted into the core wall-enlarged foot connection interface, and the bidirectional fiberglass geogrid strips are laid in an X-shape by intersecting each other). Then, asphalt (the asphalt is SBS modified asphalt (ID grade) conforming to GB / T15180 standard, 165℃ hot asphalt, and the dosage is 1.3kg / m²) is sprayed onto the surface of the bidirectional fiberglass geogrid. 2 Use a small road roller to lightly roll and vent the air, so that the grid and the lower reinforcement layer are tightly bonded together to obtain a flexible reinforcement layer; After the flexible reinforcement layer is laid, the upper reinforcement layer mixture is spread on the upper surface of the flexible reinforcement layer using an arc-shaped paver (the paving temperature is 158℃ and the paving looseness coefficient is 1.2). During the paving process, the outline is smoothed with an arc-shaped scraper to ensure that the upper arc surface is smooth and without corners. After the upper arc surface is formed, a small vibratory tamper is used to compact it along the tangent of the outward convex arc (initial compaction and secondary compaction are carried out in sequence. The initial compaction is carried out by static compaction with a 10-ton road roller once, and the secondary compaction is carried out by vibratory compaction with an amplitude of 0.8mm four times. The internal temperature of the mixture is monitored throughout the compaction process by an infrared thermometer and kept at 112℃). The upper reinforcement layer is obtained. After the upper reinforcement layer is laid, high-elasticity polyurethane sealant is filled and cured at the joint between the reinforcement structure and the core wall-enlarged foot. Then, modified bitumen roll material (TGC-3000SBS) is bonded (covering a width of 35cm) to the outside of the joint and the outside of the reinforcement structure. The modified bitumen roll material is bonded to the outside of the joint and the outside of the reinforcement structure using hot bitumen.

[0081] Comparative Application Example 1 The only difference between the core wall-enlarged foot fixed connection structure in Comparative Example 1 and Application Example 1 is that the connection structure 3 in Comparative Example 1 is used; otherwise, they are the same as in Application Example 1. In the reinforcement method, the components and laying parameters of the lower reinforcement layer described in Application Example 1 are replaced with the components and laying parameters of the upper reinforcement layer, and the rest is the same as in Application Example 1.

[0082] Comparative Application Example 2 The only difference between the core wall-enlarged foot fixed connection structure in Comparative Example 1 and Application Example 1 is that the connection structure 3 in Comparative Example 2 is used; otherwise, they are the same as in Application Example 1. In the reinforcement method, the components and laying parameters of the upper reinforcement layer described in Application Example 1 are replaced with the components and laying parameters of the lower reinforcement layer, and the rest is the same as in Application Example 1.

[0083] Comparative Application Example 3 The only difference between the core wall-enlarged foot fixed connection structure in Comparative Example 3 and Application Example 1 is that the connection structure 3 in Comparative Example 3 is used; otherwise, they are the same as in Application Example 1. In the reinforcement method, the step of laying the flexible reinforcement layer 5 is omitted, and the rest is the same as in application example 1.

[0084] The shear strain of the core-enlarged foot fixed connection structure obtained in Application Example 1 was 0.0011, a decrease of 90.83% compared to the unreinforced shear strain of 0.012. The effective load-bearing area expanded by 46.23%, the tensile strength increased by 62% from 0.8 to 1.3, and the seepage prevention performance increased from 1.0 × 10⁻⁶. -4 Up to 1.1×10 -5 Performance improved by 89%.

[0085] In contrast to Application Example 1, where the core wall-enlarged foot fixed connection structure uses the components of the upper reinforcing layer 7 throughout, the lower layer (at the enlarged foot) lacks sufficient load-bearing capacity, leading to stress concentration and microcracks. In Application Example 2, where the core wall-enlarged foot connection structure uses the components of the lower reinforcing layer 8 throughout, the upper layer's deformation is inconsistent with the core wall, resulting in stress concentration and leakage. Furthermore, in Application Example 2, the core wall-enlarged foot connection structure lacks a flexible reinforcing layer 5, resulting in insufficient tensile strength, and the extension of microcracks leads to stress concentration rebound and seepage failure. The concentration factor of the reinforcement structure in Application Example 1 of this invention is reduced from 1.85 in the single-component application example 1 to 1.18, achieving layer-by-layer stress dissipation and uniform distribution.

[0086] After the connection between the core wall and the enlarged foot is reinforced using the connection structure provided by this invention, the shear strain is reduced by 90.79% compared with the unreinforced state, the effective bearing area is expanded by 46.23%, the tensile strength is increased by 62%, the seepage prevention performance is improved by 89%, and the stress concentration coefficient of the reinforced structure is only 1.18, which can effectively avoid the cracking problem caused by stress concentration and has a good seepage prevention effect.

[0087] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A reinforcement structure for a core wall and an enlarged foot, comprising two connecting structures (3) symmetrically fixed on both sides of the core wall-enlarged foot connection section; The outer surface of the connecting structure (3) is a convex arc surface with a horizontal axis; The connection structure (3) includes an upper reinforcing layer (7), a lower reinforcing layer (8), and a flexible reinforcing layer (5) disposed at the interface between the reinforcing layer (7) and the lower reinforcing layer (8). The flexible reinforcement layer (5) includes a bidirectional glass fiber geogrid; the flexible reinforcement layer (5) is coplanar with the core wall-enlarged foot connection interface; The upper reinforcing layer (7) and the lower reinforcing layer (8) are made of asphalt concrete, and the stiffness of the lower reinforcing layer (8) is greater than that of the upper reinforcing layer (7), with a stiffness difference of (1.2~1.8)×10. 9 N / m.

2. The reinforced structure according to claim 1, characterized in that, The radius of curvature of the convex arc surface is 1.2 to 2.0 times the thickness of the core wall; the axis of the convex arc surface is the center line of the core wall-enlarged foot connection interface.

3. The reinforced structure according to claim 1, characterized in that, The upper reinforcing layer (7) comprises the following components by mass percentage: 92.8-93.3% of the first aggregate and 6.7-7.2% of asphalt; The maximum particle size of the first aggregate is 16 mm, and the gradation index of the first aggregate is 0.45~0.

50.

4. The reinforced structure according to claim 1, characterized in that, The lower reinforcement layer (8) comprises the following components by mass percentage: 93.3-93.8% of the second aggregate and 6.2-6.7% of the asphalt; The maximum particle size of the second aggregate is 19 mm; the gradation index of the second aggregate is 0.50~0.

55.

5. The reinforced structure according to claim 1, characterized in that, One end of the flexible reinforcing layer (5) is inserted into the core wall, and the insertion depth is ≥30cm.

6. The reinforced structure according to claim 1 or 5, characterized in that, The flexible reinforcement layer (5) also includes asphalt adhered to the bidirectional glass fiber geogrid.

7. A core wall-enlarged foot fixed connection structure, characterized in that, It includes a concrete base, an enlarged foot, and a core wall arranged sequentially from bottom to top, as well as a reinforcement structure as described in any one of claims 1 to 6, fixed to the core wall-enlarged foot connection section.

8. The core wall-enlarged foot fixed connection structure according to claim 7, characterized in that, It also includes modified bitumen rolls disposed on the outside of the joint between the reinforced structure and the core wall-enlarged foot connection section, as well as on the outside of the reinforced structure.

9. A method for reinforcing the core wall and the enlarged foot, characterized in that, Using the reinforcement structure according to any one of claims 1 to 6 includes the following steps: A reinforcement layer is laid on both sides of the enlarged foot at the connection section between the core wall and the enlarged foot. A flexible reinforcing layer is laid on the upper surface of the lower reinforcing layer; A reinforcing layer is laid on the upper surface of the flexible reinforcing layer.

10. The reinforcement method according to claim 9, characterized in that, Also includes: Modified bitumen rolls are used to cover the outside of the joint between the reinforced structure and the core wall-enlarged foot connection section, as well as the outside of the reinforced structure.

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