Transition device for handling bridgehead bump and method of use thereof

Abstract

The application discloses a transition device for processing bridge head bumping and a use method thereof. The transition device is obliquely arranged between a high fill embankment between an abutment and a low fill embankment to connect a bridge and a pavement structure. The transition device comprises a double-layer deck arranged on the high fill embankment, a lifting mechanism for supporting and lifting the double-layer deck, and extrusion mechanisms arranged on both sides of the double-layer deck. The lifting mechanism can lift the double-layer deck to form a grouting layer between the double-layer deck and the high fill embankment, and then balance the settlement by lifting the double-layer deck. The extrusion mechanism can apply extrusion force to the material with a positive Poisson's ratio, so as to make the material expand in a direction perpendicular to the double-layer deck, thereby lifting the top plate of the double-layer deck to finely adjust the settlement top plate. The transition device can adapt to the later settlement of the high fill embankment, does not need large-scale demolition work, is convenient to construct and low in cost, can reduce vehicle impact, improves driving safety and comfort, and protects the bridge structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pavement structure and bridge engineering, and particularly relates to a transition device for treating bridge-head bumping and a use method thereof. BACKGROUND

[0002] In the high-filling bridge-head road section, the bridge-head bumping phenomenon is common, especially in soft soil areas. In the transition area between the bridge and the pavement structure, i.e. the high-filling embankment, due to its structural characteristics (high compressibility and weak bearing capacity), superimposed by long-term vehicle load, vehicle climbing impact and other factors, significant uneven settlement is easily generated. The bridge main body is a rigid structure with a very small settlement amount, and the transition section length of the short-span bridge is limited, so the settlement difference is difficult to naturally eliminate, and finally the bridge-head bumping is formed. This problem not only seriously reduces the driving comfort, but also directly endangers the driving safety, and the vehicle impact load can aggravate the fatigue damage of the bridge structure (such as the support and the abutment), threatening the long-term safety of the bridge.

[0003] The existing solutions for treating bridge-head bumping have obvious limitations: the conventional rigid cover plate is a fixed structure, which cannot adapt to the late settlement of the soft soil embankment, is easy to reappear the bumping hidden danger, and has no buffer structure to reduce the impact of the vehicle impact on the soft soil embankment; the traditional grouting reinforcement needs to remove the cover plate to carry out large-scale operation, which has a large amount of engineering, especially for slight settlement, and the excessive construction leads to high cost and long period, and if not treated, the small settlement will gradually accumulate to form a significant height difference, continuously affecting the passing quality of the pavement structure, and falling into the dilemma of "unprofitable construction and affecting the passing". SUMMARY

[0004] In view of the problems and deficiencies of the prior art, the present application provides a transition device for treating bridge-head bumping and a use method thereof, to adapt to the settlement of the high-filling embankment, simplify the construction process, reduce the cost, improve the driving safety and comfort, and protect the bridge structure.

[0005] The present application is realized by the following technical solutions:

[0006] A transition device for treating bridge-head bumping, the transition device is obliquely installed between the abutment and the low-filling embankment of the high-filling embankment to connect the bridge and the pavement structure; the transition device comprises a double-layer cover plate laid on the high-filling embankment, a lifting mechanism for supporting and lifting the double-layer cover plate, and an extrusion mechanism arranged on both sides of the double-layer cover plate;

[0007] The double-layered plank is provided with a plurality of grouting holes, and comprises a top plate, a bottom plate, a limiting mechanism arranged between the top plate and the bottom plate, and a positive Poisson's ratio material filled between the top plate and the bottom plate; the lifting mechanism can lift the double-layered plank to form a grouting layer between the double-layered plank and the high-filled embankment; and the extrusion mechanism can apply extrusion force to the positive Poisson's ratio material to make the positive Poisson's ratio material expand in a direction perpendicular to the double-layered plank.

[0008] By constructing the cooperative structure of "double-layered plank + lifting mechanism + extrusion mechanism", the defects of the conventional rigid plank that cannot adapt to the late settlement of the soft-soil low-filled embankment and has no buffering capacity are fundamentally solved. The positive Poisson's ratio material in the double-layered plank can effectively absorb the impact load of vehicles, reduce the transmission of the load to the high-filled embankment and the bridge structure, slow down the settlement speed of the high-filled embankment, reduce the fatigue damage of the bridge support and abutment caused by impact, and improve the driving comfort; the limiting mechanism can constrain the relative displacement of the top plate and the bottom plate, ensure the stability of the double-layered plank structure, and avoid the extrusion failure of the positive Poisson's ratio material due to misalignment; the lifting mechanism can lift the double-layered plank to form a grouting layer, realize the active compensation of the settlement of the high-filled embankment, and complete the reinforcement without removing the plank; the extrusion mechanism can apply transverse extrusion force to the positive Poisson's ratio material to make it expand in the vertical direction, flexibly adjust the height of the double-layered plank, realize the precise correction of slight settlement, and avoid the accumulation of settlement difference to form the hidden trouble of bumping. The overall structure takes into account the settlement adaptability, buffering protection and convenient maintenance, effectively connects the bridge and the pavement structure, and completely improves the bumping problem at the bridge head in the soft-soil area.

[0009] Further, the lifting mechanism is provided with a plurality of lifting mechanisms and is arranged in an array along the double-layered plank.

[0010] The double-layered plank is provided with a lifting hole, and the lifting mechanism comprises a straight-thread boss, a rigid base embedded in the high-filled embankment, and a threaded lifting rod. The straight-thread boss is provided with an equal-diameter internal thread hole, and the straight-thread boss comprises an integrally formed upper thread cylinder and a lower thread cylinder. The upper thread cylinder is located in the lifting hole and is welded and fixed to the bottom plate. The outer diameter of the lower thread cylinder is larger than the inner diameter of the lifting hole to form a limiting step. The rigid base is provided with an accommodating groove matched with the lower thread cylinder at the top. The threaded lifting rod is screwed with the internal thread hole and abuts to the rigid base at the bottom. The operation part of the threaded lifting rod rotates the threaded lifting rod to separate the double-layered plank from the high-filled embankment to form a grouting layer.

[0011] The stability and adjustment accuracy of the device are further improved by optimizing the distribution form and structural design of the lifting mechanism. The lifting mechanism is arrayed along the double-layer deck, which can uniformly transmit the lifting force to each area of the double-layer deck, avoid local stress concentration leading to deck deformation or cracking, and ensure smooth and controllable lifting process; the one-piece upper and lower threaded barrels of the straight-thread boss structure not only realize reliable force transmission through the welding and fixation of the upper threaded barrel and the bottom plate, but also prevent the double-layer deck from falling off or deviating during lifting by the limiting step of the lower threaded barrel larger than the inner diameter of the lifting hole, providing double protection for structural safety; the screw lifting rod and the equal-diameter internal threaded hole are screwed together, which can realize precise adjustment of the height of the double-layer deck through rotation operation, flexibly control the thickness of the grouting layer according to the actual settlement of the soft soil low fill roadbed, and does not require large-scale mechanical operation, which is convenient to operate and has high adjustment accuracy; the rigid base is embedded in the high fill roadbed to provide a stable support foundation for the lifting mechanism, avoid adjustment failure due to foundation deformation during lifting, ensure that the grouting layer can long-term and stably support the double-layer deck after formation, and prolong the service life of the device.

[0012] Further, the accommodating groove of the rigid base is fixedly provided with a low-resistance pressure plate, which includes a fixed seat fixed to the rigid base, a rotating disc sleeved outside the fixed seat, and a plurality of rolling balls installed between the fixed seat and the rotating disc. The top of the rotating disc is provided with a load-bearing surface for bearing the screw lifting rod.

[0013] By adding a low-resistance pressure plate, the operation convenience and component protection capability of the lifting mechanism are significantly optimized. The rolling ball structure between the fixed seat and the rotating disc of the low-resistance pressure plate can convert the sliding friction of the screw lifting rod during rotation into rolling friction, greatly reducing the rotation resistance, reducing the energy consumption of manpower or machinery during operation, and reducing the operation difficulty of the construction personnel; the load-bearing surface on the top of the rotating disc can form uniform contact with the bottom of the screw lifting rod, avoiding deformation or damage of the end of the screw lifting rod due to local stress concentration, and preventing cracks at the bottom of the accommodating groove of the rigid base due to uneven stress, effectively protecting the structural integrity of the core components of the lifting mechanism and the rigid base; avoiding the wear of the internal threaded hole caused by the stress deviation of the straight-thread boss, ensuring the transmission reliability of the lifting mechanism after long-term use.

[0014] Further, a compression pipe is sleeved to the lower threaded barrel between the bottom plate and the rigid base to isolate the grout of the grouting layer from the outside of the lower threaded barrel.

[0015] The key problem that the grouting liquid easily enters the lower threaded cylinder to cause the failure of the lifting mechanism during the grouting process is solved by arranging the compression pipe sleeved with the lower threaded cylinder between the bottom plate and the rigid base. The compression pipe is in a contracted state when the double-layer deck is not lifted, which does not affect the initial installation and settlement adaptation of the double-layer deck. When the lifting mechanism drives the double-layer deck to lift to form a grouting space, the compression pipe expands to completely isolate the grouting space from the lower threaded cylinder, prevent the reinforcing grouting liquid from seeping into the lower threaded cylinder and the equal-diameter internal thread hole of the straight-thread boss, avoid the blockage of the thread cooperation gap after the grouting liquid solidifies, and ensure that the subsequent threaded lifting rod can still be smoothly screwed and adjusted. At the same time, the compression pipe can also avoid the direct contact between the grouting liquid and the outer wall of the lower threaded cylinder, reduce the corrosion of the grouting liquid to the lower threaded cylinder, protect the structural performance of the straight-thread boss, reduce the workload of cleaning the grouting liquid during later maintenance, and improve the long-term operation reliability and maintenance convenience of the device.

[0016] Further, the lifting hole includes a first hole section arranged on the top plate and a second hole section arranged on the bottom plate, the upper threaded cylinder penetrates through the second hole section and extends to the first hole section to limit the double-layer deck, the upper threaded cylinder and the second hole section are in interference fit, and the upper threaded cylinder and the first hole section are in clearance fit.

[0017] By designing the lifting hole as a sectional structure, the connection stability and adjustment flexibility of the straight-thread boss and the double-layer deck are further strengthened. The first hole section and the second hole section of the lifting hole have clear division of labor. The interference fit between the second hole section and the upper threaded cylinder can realize the close connection between the straight-thread boss and the bottom plate, avoid looseness or gap between them, ensure the efficient transmission of the lifting force from the straight-thread boss to the bottom plate, and prevent the local collapse of the deck due to connection failure during lifting. The clearance fit between the first hole section and the upper threaded cylinder provides a small amount of lateral adjustment space for the double-layer deck during lifting or settlement, avoids wear or cracks between the upper threaded cylinder and the top plate due to rigid impact, protects the structural integrity of the top plate, and does not affect the relative displacement between the top plate and the bottom plate. At the same time, the sectional lifting hole can also form longitudinal limiting for the straight-thread boss to prevent the axial deviation of the straight-thread boss during long-term use, ensure that the lifting mechanism is always in the preset working position, and ensure the adjustment accuracy and structural stability.

[0018] Further, the limiting mechanism includes a first limiting cylinder welded to the top plate and a second limiting cylinder welded to the bottom plate, the second limiting cylinder is sleeved to the first limiting cylinder and is in sliding fit with the first limiting cylinder.

[0019] By designing the sliding fit structure of the "first limiting cylinder + second limiting cylinder", the relative displacement of the top plate and the bottom plate of the double-layer deck is effectively constrained, and the problem of transverse displacement extrusion failure of the positive Poisson's ratio material is solved. The first limiting cylinder is welded and fixed with the top plate, and the second limiting cylinder is welded and fixed with the bottom plate, which ensures that the limiting mechanism is firmly connected with the main structure of the double-layer deck, and the force transmission is reliable; the second limiting cylinder is sleeved to the first limiting cylinder and forms a sliding fit, which can strictly limit the relative displacement of the top plate and the bottom plate in the horizontal direction, ensure that the two are always aligned, avoid the uneven stress on both sides of the positive Poisson's ratio material, maintain the expansion performance and buffering effect of the material, and allow the top plate and the bottom plate to move freely in the vertical direction, without affecting the action of the extrusion mechanism to promote the expansion of the positive Poisson's ratio material or the action of the lifting mechanism to lift the whole double-layer deck, thereby improving the structural stability and functional reliability of the double-layer deck.

[0020] Further, the limiting mechanism further comprises a spring inside the first limiting cylinder and the second limiting cylinder, and the spring is installed between the top plate and the bottom plate through a connecting seat.

[0021] By adding a spring inside the limiting mechanism, the buffering performance and structural reset ability of the double-layer deck are further improved. The spring is installed between the top plate and the bottom plate through a connecting seat, and can be elastically deformed when the vehicle generates impact load, thereby absorbing part of the vibration energy, reducing the transmission of the load to the soft soil low fill roadbed and the bridge structure, reducing the fatigue damage risk of the bridge support and abutment, and improving the driving comfort.

[0022] Further, the extrusion mechanism is provided along the outer side of the double-layer deck, the outer side of the double-layer deck is provided with a plurality of extrusion threaded holes, the extrusion mechanism comprises an integrally formed vertical pressing plate and a horizontal insertion plate, the vertical pressing plate and the horizontal insertion plate are connected in a T-shaped structure, the horizontal insertion plate is located between the top plate and the bottom plate, and the thickness of the horizontal insertion plate is less than the distance between the top plate and the bottom plate, at least four strip-shaped holes are formed on the vertical pressing plate, the extension direction of the strip-shaped hole is perpendicular to the double-layer deck, the extrusion bolt penetrates through the strip-shaped hole and is screwed into the extrusion threaded hole, and the extrusion bolt is rotated to adjust the depth of the horizontal insertion plate inserted into the double-layer deck, thereby adjusting the transverse extrusion force on the positive Poisson's ratio material.

[0023] By optimizing the distribution form, structure design and adjustment mode of the extrusion mechanism, the extrusion force of the positive Poisson's ratio material is ensured to be uniform and controllable, and the precise fine adjustment of settlement is realized. A plurality of extrusion mechanisms are distributed along the outer side of the double-layer deck plate, which can form multi-point and uniform transverse extrusion on the positive Poisson's ratio material, avoid excessive expansion or local non-expansion of the material due to excessive local stress, ensure the uniformity of the deck plate lifting height, ensure the smoothness of the transition surface, and eliminate the hidden danger of bumping; the vertical pressing plate and the horizontal plug-in plate of the T-shaped structure can realize precise force transmission, the horizontal plug-in plate can be stably inserted between the top plate and the bottom plate, the tightening force of the extrusion bolt is converted into uniform extrusion force on the positive Poisson's ratio material, and loss or deviation in the extrusion force transmission process is avoided; the strip-shaped hole on the vertical pressing plate provides a moving space for the relative movement between the top plate and the bottom plate. The insertion depth of the horizontal plug-in plate can be flexibly adjusted according to the settlement amount, thereby controlling the expansion amount of the positive Poisson's ratio material and adapting to different degrees of slight settlement; the extrusion bolt penetrates through the strip-shaped hole and is screwed into the extrusion threaded hole, the entire adjustment process does not need to disassemble the double-layer deck plate, the operation is convenient, and the maintenance cost and construction period are greatly reduced.

[0024] A method for using a transition device for treating bridge head bumping, comprising the following steps:

[0025] Step 1: high fill subgrade pretreatment and rigid base setting, cleaning and leveling the surface of the high fill subgrade between the abutment and the low fill subgrade, excavating a containing groove at the layout point of the lifting mechanism on the high fill subgrade according to the preset installation position of the double-layer deck plate, and burying the rigid base into the containing groove;

[0026] Step 2: double-layer deck plate assembly and positioning installation, taking the bottom plate, installing the spring into the inner side of the second limiting cylinder on the bottom plate through the connecting seat; then taking the top plate, aligning the first limiting cylinder at the bottom of the top plate with the second limiting cylinder on the bottom plate, buckling the top plate to the bottom plate, and inserting the first limiting cylinder into the second limiting cylinder to form a sliding fit, completing the assembly of the limiting mechanism; filling the positive Poisson's ratio material between the top plate and the bottom plate or pre-laying the positive Poisson's ratio material on the bottom plate, completing the overall assembly of the double-layer deck plate; placing the assembled double-layer deck plate above the high fill subgrade in an inclined manner, so that one end of the double-layer deck plate is lapped to the end of the abutment and the other end is lapped to the top surface of the low fill subgrade, and at the same time, the lower threaded cylinder of the straight threaded boss on the bottom plate is aligned with the containing groove of the rigid base, completing the positioning of the double-layer deck plate;

[0027] Step 3: extrusion mechanism installation, inserting the horizontal plug-in plate of the extrusion mechanism between the top plate and the bottom plate along the outer side of the double-layer deck plate, and forming an adjustment space between the vertical pressing plate and the double-layer deck plate; after penetrating the strip-shaped hole of the vertical pressing plate, the extrusion bolt is screwed into the extrusion threaded hole on the outer side of the double-layer deck plate;

[0028] Step 4: Positive Poisson's ratio material expansion adjustment, when the settlement of the double-layer deck reaches the first preset value and is less than the second preset value, rotate the extrusion bolt to move the vertical pressure plate towards the double-layer deck, causing the horizontal insertion plate to exert a horizontal extrusion force on the positive Poisson's ratio material located between the top plate and the bottom plate, prompting the positive Poisson's ratio material to expand in a direction perpendicular to the double-layer deck, thereby increasing the distance between the top plate and the bottom plate, until a smooth transition surface is formed between the top plate of the double-layer deck and the pavement structure;

[0029] Step 5: Lifting mechanism operation and grouting layer formation, when the settlement of the double-layer deck reaches the second preset value, screw the threaded lifting rod into the equal-diameter threaded hole of the straight-thread boss, so that the bottom of the threaded lifting rod abuts against the rotating disc bearing surface of the low-resistance pressure disc; rotate the threaded lifting rod through the operation part of the threaded lifting rod, and use the threaded transmission to lift the double-layer deck in a direction perpendicular to the surface of the high fill embankment until the double-layer deck forms a preset thickness of grouting space with the surface of the high fill embankment; at this time, the compression tube between the bottom plate and the rigid base is naturally unfolded, isolating the grouting space from the lower threaded cylinder; inject reinforcing slurry into the grouting space through the grouting hole of the double-layer deck, and form a grouting layer after the slurry solidifies, thereby supporting and lifting the double-layer deck.

[0030] By using the steps in a clear phased manner, the installation and adjustment process of the transition device is ensured to be standardized and efficient, and the synergistic effect of each component is fully utilized. The high fill embankment pretreatment and rigid base embedding steps can remove impurities on the surface of the high fill embankment, level the site, provide a stable foundation for device installation, and provide long-term reliable support for the lifting mechanism to avoid device failure due to unstable foundation. In the double-layer deck assembly step, the precise assembly of the limiting mechanism can ensure the stability of the relative position of the top plate and the bottom plate, and the standardized filling of the positive Poisson's ratio material can ensure its uniform performance. The overall assembly process is clear and easy for construction personnel to operate, reducing assembly errors. The extrusion mechanism installation step is simple and convenient, and subsequent adjustment does not require disassembly, providing convenience for later settlement correction. The positive Poisson's ratio material expansion adjustment step can achieve precise micro-correction for slight settlement, avoiding the accumulation of settlement difference. The lifting mechanism operation and grouting layer formation step can form a stable support for larger settlement to balance the settlement difference, and the entire process does not require large-scale removal of existing structures, significantly shortening the construction period, reducing engineering quantity and cost, ensuring that the device is quickly put into use, reducing the impact on the traffic of the pavement structure.

[0031] Further, a method for using a transition device for treating bridgehead bump also includes:

[0032] Step 6: Adjustment of later continuous settlement, periodically detect the settlement amount of the double-layer deck, when the settlement amount is between the first preset value and the second preset value, and the distance between the top plate and the bottom plate does not reach the maximum set distance, perform step 4;

[0033] When the settlement amount is greater than the second preset value or the settlement amount is greater than the first preset value and the spacing between the top plate and the bottom plate reaches the maximum set spacing, the reverse rotation extrusion bolt is used to move the vertical pressing plate away from the double-layer deck, reduce the lateral extrusion force applied to the positive Poisson's ratio material, reduce the spacing between the top plate and the bottom plate, provide a redundant amount for the next operation step 4, and then proceed to step 5.

[0034] By constructing a scientific post-adjustment mechanism, the long-term adaptation to the continuous settlement of the soft soil low fill roadbed is realized, and the effective use cycle of the device is prolonged. The setting that the second preset value is greater than the first preset value clearly defines the adjustment boundary of different settlement stages, avoids misjudgment of the adjustment time; the requirement of regular detection of the settlement amount can timely find the settlement change, prevent the formation of obvious height difference due to settlement accumulation, ensure the long-term flatness of the transition surface, and guarantee the safety and comfort of driving; the case-by-case operation for different settlement amounts not only adjusts the expansion of the positive Poisson's ratio material to cope with smaller settlement, fully utilizes the adjustment capacity of the material, reduces the grouting operation frequency, and reduces the maintenance cost, but also reserves the material adjustment redundancy by reversing the extrusion bolt, and then performs grouting to cope with larger settlement, avoids the device failure caused by the exhaustion of the adjustment capacity of the positive Poisson's ratio material, and prolongs the adaptation cycle of the device; the whole adjustment logic is clear and has strong operability, which is convenient for construction personnel to execute, ensures the efficient development of the post-maintenance work, and maintains the long-term use effect of the transition device.

[0035] The beneficial effects of the present application are:

[0036] Through the design of multi-structure cooperation and phased adjustment, the high fill roadbed bridgehead bumping problem and the limitations of existing schemes are solved in all directions, and the overall beneficial effect is remarkable.

[0037] From the device structure, the double-layer deck is matched with the lifting mechanism and the extrusion mechanism to form a "fine adjustment + strong support" settlement response system: the positive Poisson's ratio material is filled between the top plate and the bottom plate, and cooperates with the spring in the limiting mechanism, which can not only absorb the impact load of the vehicle, reduce the settlement speed of the high fill roadbed, and reduce the fatigue damage to the bridge support and abutment, but also can accurately apply a lateral extrusion force through the T-shaped vertical pressing plate and horizontal insertion plate of the extrusion mechanism to promote the vertical expansion of the positive Poisson's ratio material, and realize the fine adjustment of the settlement top plate; the lifting mechanism is arrayed distributed, the limiting steps of the straight thread bosses are matched with the interference / gap of the segmented lifting holes to ensure that the double-layer deck is uniformly stressed and structurally stable when being lifted, the ball design of the low-resistance pressure disc reduces the operation resistance of the threaded lifting rod, and the compression pipe avoids the blockage of the threaded structure by grouting slurry, ensuring the reliability of the lifting and grouting operation.

[0038] From the use method, the high fill roadbed pretreatment and the rigid base station embedding provide a stable foundation for the device, the assembly process of the double-layer clamping plate and the extrusion mechanism is simple, and in the later period, the continuous settlement can be adapted without large-scale demolition operation through the staged adjustment (material expansion adjustment is carried out when the settlement reaches the first preset value and is less than the second preset value, the interval is first reduced and then grouting is carried out when the second preset value or the interval is full), and the construction and maintenance costs are greatly reduced.

[0039] Overall, the scheme takes into account the settlement adaptability, buffer protection and convenient operation and maintenance, can long-term maintain the smooth transition of the bridge and the pavement structure, significantly improves the driving safety and comfort, prolongs the service life of the bridge, and completely gets rid of the dilemma of the traditional scheme that "construction is not cost-effective, and non-construction affects traffic". BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 A connection diagram for illustrating a schematic embodiment of a transition device for handling bridge head bumping in the present application;

[0041] Figure 2 for illustrating Figure 1 A partial enlarged view at A in the figure;

[0042] Figure 3 A cross-sectional view for illustrating a schematic embodiment of a partial position of a transition device for handling bridge head bumping in the present application;

[0043] Figure 4 for illustrating Figure 3 A partial enlarged view at B in the figure;

[0044] Figure 5 for illustrating Figure 3 A partial enlarged view at C in the figure;

[0045] Figure 6 A structure diagram for illustrating a schematic embodiment of a transition device for handling bridge head bumping in the present application;

[0046] Figure 7 for illustrating Figure 6 A partial enlarged view at D in the figure;

[0047] Figure 8 A cross-sectional view for illustrating a schematic embodiment of a transition device for handling bridge head bumping in the present application.

[0048] List of components and reference numerals:

[0049] 01, abutment; 02, low fill subgrade; 03, bridge; 04, pavement structure; 05, high fill subgrade; 1, double-layered clamping plate; 11, grouting hole; 12, top plate; 13, bottom plate; 14, lifting hole; 141, first hole section; 142, second hole section; 2, lifting mechanism; 21, straight thread boss; 211, internal thread hole; 212, upper threaded cylinder; 213, lower threaded cylinder; 214, limiting step; 22, rigid base; 221, accommodating groove; 23, threaded lifting rod; 24, operation part; 25, low-resistance pressure plate; 251, fixing seat; 252, rotating disc; 253, ball; 26, compression tube; 3, extrusion mechanism; 31, vertical pressing plate; 32, transverse insertion plate; 33, strip-shaped hole; 4, limiting mechanism; 41, first limiting cylinder; 42, second limiting cylinder; 43, spring; 5, material with positive Poisson's ratio; 6, grouting layer. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0051] It should be noted that the left, right, up, down, front, back and other orientation terms in the embodiments of the present application are only relative concepts or are with reference to the normal use state of the product, i.e., the running direction of the product, and should not be considered as limiting.

[0052] In addition, it should be noted that the dynamic terms such as "relative motion" mentioned in the embodiments of the present application not only include positional changes, but also include motions in which the position does not change relatively, but the state changes, such as rotation and rolling.

[0053] Finally, it should be noted that when a component is referred to as "located" or "disposed" on another component, it can be on the other component or can exist with a centering component at the same time. When a component is referred to as "connected to" another component, it can be directly connected to the other component or can exist with a centering component at the same time.

[0054] As Figures 1 to 8The transition device for processing bridge head bumping is shown, the core function is to realize the smooth connection of bridge 03 and pavement structure 04 and deal with the late settlement of high fill subgrade 05, the transition device is composed of double-layer deck 1 laid on high fill subgrade 05, lifting mechanism 2 for supporting and lifting double-layer deck 1 and extrusion mechanism 3 arranged on both sides of double-layer deck 1, which cooperates to form a integrated solution of "buffer protection-settlement coarse adjustment-settlement fine adjustment". Wherein, double-layer deck 1 is the core bearing and adjusting component, a plurality of grouting holes 11 are arranged in the inside, the whole is composed of top plate 12, bottom plate 13, limiting mechanism 4 and positive Poisson ratio material 5, limiting mechanism 4 is installed between top plate 12 and bottom plate 13 to constrain the relative displacement of the two to ensure the stability of the structure, and the positive Poisson ratio material 5 is filled between the top plate 12 and the bottom plate 13, which has the characteristics of "lateral compression and vertical expansion", which can not only absorb the impact load of the vehicle to reduce the transmission to the soft soil low fill subgrade 02 and the bridge 03 structure, avoid fatigue damage of the bridge 03 support and abutment 01 due to long-term impact, slow down the settlement speed of the high fill subgrade 05, but also can be used as the core material for slight settlement adjustment; the limiting mechanism 4 specifically includes the first limiting cylinder 41 welded to the top plate 12 and the second limiting cylinder 42 welded to the bottom plate 13, the second limiting cylinder 42 is sleeved to the first limiting cylinder 41 and forms a sliding fit, and a spring 43 is also installed in the inner side of the second limiting cylinder 42 through a connecting seat, the spring 43 can elastically deform to absorb vibration energy and improve driving comfort when the vehicle impacts.

[0055] The lifting mechanism 2 is the core component for coping with large settlement, and is provided with multiple lifting mechanisms 2 arranged in an array along the double-layer deck 1 to ensure uniform stress and avoid local deformation during lifting. The double-layer deck 1 is provided with a lifting hole 14. The lifting mechanism 2 includes a straight thread boss 21, a rigid base 22 embedded in the high fill roadbed 05, and a threaded lifting rod 23. The straight thread boss 21 is provided with an equal-diameter internal thread hole 211 in the inside. The equal-diameter internal thread hole 211 is composed of an upper thread cylinder 212 and a lower thread cylinder 213 which are integrally formed. The upper thread cylinder 212 is located in the lifting hole 14 and is welded and fixed to the bottom plate 13 to ensure firm connection. The outer diameter of the lower thread cylinder 213 is larger than the inner diameter of the lifting hole 14 to form a limiting step 214 to prevent the double-layer deck 1 from falling off during lifting. The rigid base 22 is provided with a containing groove 221 at the top to accommodate the lower thread cylinder 213. The containing groove 221 serves as the fixed base of the lifting mechanism 2 to provide stable support for the threaded lifting rod 23. The threaded lifting rod 23 is screwed with the equal-diameter internal thread hole 211 of the straight thread boss 21 and the bottom abuts against the rigid base 22. By rotating the threaded lifting rod 23 through the operation part 24, the double-layer deck 1 can be moved in a direction perpendicular to the surface of the high fill roadbed 05 through threaded transmission, so that the double-layer deck 1 is separated from the high fill roadbed 05 to form a grouting space, and active compensation of large settlement is realized. To optimize the performance of the lifting mechanism 2, the containing groove 221 of the rigid base 22 is fixedly provided with a low-resistance pressure plate 25. The pressure plate 25 is composed of a fixed seat 251 fixed to the rigid base 22, a rotating disc 252 sleeved on the outside of the fixed seat 251, and a plurality of balls 253 between the fixed seat 251 and the rotating disc 252. The rotating disc 252 is provided with a load-bearing surface at the top to bear the threaded lifting rod 23. The balls 253 can convert sliding friction into rolling friction to reduce the operation resistance of the threaded lifting rod 23 and make the stress uniform. The bottom plate 13 and the rigid base 22 are further provided with a compression tube 26 sleeved on the lower thread cylinder 213. The compression tube 26 is not contracted when not lifted, does not affect the initial installation, and is naturally expanded when the grouting space is formed to isolate the grout outside the lower thread cylinder 213, so as to avoid the grout from seeping into the straight thread boss 21 to block the fitting gap. The lifting hole 14 is also designed to be segmented, including a first hole segment 141 provided on the top plate 12 and a second hole segment 142 provided on the bottom plate 13. The upper thread cylinder 212 penetrates through the second hole segment 142 and extends to the first hole segment 141 to form a longitudinal limiting position. The upper thread cylinder 212 and the second hole segment 142 are in interference fit to ensure that the straight thread boss 21 is tightly connected with the bottom plate 13. The upper thread cylinder 212 and the first hole segment 141 are in clearance fit to provide a small amount of lateral adjustment space for the double-layer deck 1 to prevent rigid collision and wear, and allow the relative displacement between the top plate 12 and the bottom plate 13.

[0056] The extrusion mechanism 3 is arranged along the outer side edge of the double-layer deck 1, and is used to apply a transverse extrusion force to the normal Poisson's ratio material 5 to achieve slight settlement fine adjustment. The outer side surface of the double-layer deck 1 is provided with a plurality of extrusion threaded holes as mounting bases. The extrusion mechanism 3 is composed of a vertically extruding plate 31 and a transversely inserting plate 32, and is connected in a T-shaped structure to ensure stable force transmission. The transversely inserting plate 32 is located between the top plate 12 and the bottom plate 13, and the thickness is less than the distance between the two plates to provide space for insertion and movement. At least four strip-shaped holes 33 extending in a direction perpendicular to the double-layer deck 1 are arranged on the vertically extruding plate 31. After the extrusion bolt is inserted through the strip-shaped hole 33, it is screwed into the extrusion threaded hole. The distance between the vertically extruding plate 31 and the double-layer deck 1 can be adjusted by rotating the extrusion bolt, thereby driving the transversely inserting plate 32 to change the depth of insertion between the top plate 12 and the bottom plate 13, accurately controlling the transverse extrusion force on the normal Poisson's ratio material 5, and promoting the expansion of the normal Poisson's ratio material 5 in a direction perpendicular to the double-layer deck 1 to achieve fine adjustment of the height of the top plate 12.

[0057] The method for using the transition device follows the process of "pretreatment-assembly-installation-adjustment-reinforcement-later maintenance", which can be flexibly adjusted according to the settlement stage. First, the surface of the high fill embankment 05 between the abutment 01 and the low fill embankment 02 is cleaned and leveled, and weeds, gravel and loose soil layers are removed. According to the preset installation position of the double-layer deck 1 and the array distribution scheme of the lifting mechanism 2, the corresponding points are excavated and embedded with rigid base 22. The levelness and height are adjusted to ensure that the top of all rigid bases 22 is on the same horizontal plane, and the surrounding soft soil is compacted to ensure firm installation. Then, the double-layer deck 1 is assembled and positioned. First, the bottom plate 13 is taken to install the spring 43 into the second limiting cylinder 42 through the connecting seat, to ensure that the axis of the spring 43 coincides with the axis of the second limiting cylinder 42. Then, the top plate 12 is taken to make the first limiting cylinder 41 on the bottom plate 13 align with the second limiting cylinder 42 to buckle, and the first limiting cylinder 41 is inserted into the second limiting cylinder 42 to form a sliding fit to complete the assembly of the limiting mechanism 4. Then, the normal Poisson's ratio material 5 is filled between the top plate 12 and the bottom plate 13 (or pre-laid on the bottom plate 13) to ensure uniform distribution without gaps. After assembly, the double-layer deck 1 is placed inclined above the high fill embankment 05, with one end lapped to the end of the abutment 01 and the other end lapped to the top surface of the low fill embankment 02 to ensure smooth connection, and the lower threaded cylinder 213 of the straight threaded boss 21 on the bottom plate 13 is aligned with the accommodating groove 221 of the rigid base 22 to complete positioning. Then, the extrusion mechanism 3 is installed. The transversely inserting plate 32 is slowly inserted between the top plate 12 and the bottom plate 13 along the outer side edge of the double-layer deck 1 to avoid scratching the normal Poisson's ratio material 5. The position of the vertically extruding plate 31 is adjusted to form an adjustment distance with the double-layer deck 1. The extrusion bolt is inserted through the strip-shaped hole 33 and screwed into the extrusion threaded hole. The vertically extruding plate 31 is kept horizontal to ensure that each extrusion mechanism 3 is firmly installed and uniformly stressed.

[0058] In the later use, the settlement amount of the double-layer deck 1 is monitored regularly. When the settlement amount reaches the first preset value and is less than the second preset value, the rotating extrusion bolt moves the vertical pressing plate 31 towards the double-layer deck 1, drives the horizontal insertion plate 32 to exert a horizontal extrusion force on the Poisson's ratio material 5, and promotes the Poisson's ratio material 5 to expand in the vertical direction to push the top plate 12 upwards to increase the spacing, until the top plate 12 forms a smooth transition surface with the pavement structure 04 and the bridge 03 to eliminate the bumping hazard; when the settlement amount reaches the second preset value, the threaded lifting rod 23 is screwed into the equal-diameter internal thread hole 211 of the straight thread boss 21, the bottom abuts to the bearing surface of the rotating disc 252 of the low-resistance pressing disc 25, and the rotating operation part 24 drives the double-layer deck 1 to lift by thread transmission, forms a grouting space, and naturally expands the compression tube 26 to isolate the grout, and the reinforcing grout is injected through the grouting hole 11 (it should be noted that a sealing plug can be arranged on the grouting hole 11 to seal the grouting hole 11 when not grouting), and after solidification, the grouting layer 6 and the rigid base 22 jointly support the double-layer deck 1 to restore the design height; when the settlement continues, if the settlement amount is between the first preset value and the second preset value and the spacing between the top plate 12 and the bottom plate 13 does not reach the maximum set spacing, the above-mentioned expansion adjustment step of the Poisson's ratio material 5 is repeated; if the settlement amount is greater than the second preset value or greater than the first preset value and the spacing reaches the maximum set spacing, the extrusion bolt is first rotated in the reverse direction to move the vertical pressing plate 31 away from the double-layer deck 1, reduce the extrusion force on the Poisson's ratio material 5, make it shrink to reduce the spacing and reserve adjustment redundancy, and then the lifting mechanism 2 is operated and the grouting layer 6 is formed, to ensure that the double-layer deck 1 always maintains smooth connection with the bridge 03 and the pavement structure 04.

[0059] In an embodiment of a municipal pavement structure short-span bridge in a soft soil area, the high fill embankment 05 between the bridge 03 and the low fill embankment 02 has high compressibility, and after the conventional rigid deck is used in the early stage, obvious bumping phenomenon occurs, and the transition device is needed to realize settlement adaptation and smooth connection. The installation and use of the device throughout the process are described in detail below.

[0060] First, the high fill subgrade 05 pretreatment and rigid base 22 embedding are carried out: the surface of the high fill subgrade 05 between the abutment 01 and the low fill subgrade 02 is cleaned, the weeds, gravel and loose soil layer are removed, then the site is leveled by light equipment, according to the preset installation position of the double-layer deck 1, combined with the array distribution scheme of the lifting mechanism 2, the groove is excavated at the corresponding lifting mechanism 2 distribution point of the high fill subgrade 05, the rigid base 22 is placed in the groove, the levelness of the rigid base 22 is adjusted to ensure that the top of all the bases is flush, then the soft soil around the groove is compacted to ensure that the rigid base 22 is fixed firmly, and a low-resistance pressure plate 25 is fixed at the bottom of the receiving groove 221 of the rigid base 22, the fixing seat 251 of the low-resistance pressure plate 25 is connected with the rigid base 22, the rotating disc 252 is sleeved outside the fixing seat 251, and the ball 253 is installed between the fixing seat 251 and the rotating disc 252. The bearing surface of the rotating disc 252 top is reserved for the bearing of the lifting rod 23.

[0061] Then the double-layer deck 1 assembly and positioning installation are carried out: first, the bottom plate 13 is taken, the spring 43 is installed in the second limiting barrel 42 on the bottom plate 13 through the connecting seat, and the axis of the spring 43 is consistent with the axis of the second limiting barrel 42; then the top plate 12 is taken, the first limiting barrel 41 at the bottom of the top plate 12 is aligned with the second limiting barrel 42 on the bottom plate 13, the top plate 12 is buckled to the bottom plate 13, the first limiting barrel 41 is inserted into the second limiting barrel 42 to form a sliding fit, and the limiting mechanism 4 assembly is completed; the polyurethane-based positive Poisson's ratio material 5 is filled or installed between the top plate 12 and the bottom plate 13, and the material distribution is uniform without gap during the filling process, and the overall assembly of the double-layer deck 1 is completed; a plurality of grouting holes 11 and lifting holes 14 are provided in the double-layer deck 1 in advance, the lifting hole 14 includes a first hole section 141 provided on the top plate 12 and a second hole section 142 provided on the bottom plate 13; the assembled double-layer deck 1 is placed above the high fill subgrade 05 in an inclined manner, one end of the double-layer deck 1 is lapped to the end of the abutment 01, the other end is lapped to the top surface of the low fill subgrade 02, the lower threaded cylinder 213 of the straight threaded boss 21 on the bottom plate 13 is aligned with the receiving groove 221 of the rigid base 22, the upper threaded cylinder 212 of the straight threaded boss 21 penetrates through the second hole section 142 of the lifting hole 14 and extends to the first hole section 141, the upper threaded cylinder 212 is in interference fit with the second hole section 142 and in clearance fit with the first hole section 141, the outer diameter of the lower threaded cylinder 213 is larger than the inner diameter of the lifting hole 14 to form a limiting step 214, and the compression tube 26 is sleeved outside the lower threaded cylinder 213 between the bottom plate 13 and the rigid base 22.

[0062] Subsequently, the installation of the extrusion mechanism 3 is carried out: several extrusion mechanisms 3 are arranged along the outer side of the double-layer plank 1, and the outer side of the double-layer plank 1 is provided with several extrusion screw holes; the vertical pressing plate 31 and the transverse insertion plate 32 of the extrusion mechanism 3 are in a T-shaped structure formed integrally, the transverse insertion plate 32 is inserted between the top plate 12 and the bottom plate 13, the thickness of the transverse insertion plate 32 is less than the distance between the top plate 12 and the bottom plate 13, so that the vertical pressing plate 31 and the double-layer plank 1 form an adjustable distance; the extrusion bolt is inserted through at least four strip-shaped holes 33 (the extension direction of the strip-shaped hole 33 is perpendicular to the double-layer plank 1) on the vertical pressing plate 31, and the extrusion bolt is screwed into the extrusion screw hole of the double-layer plank 1, so as to ensure that each extrusion mechanism 3 is firmly installed.

[0063] When the settlement of the double-layer plank 1 reaches the first preset value and is less than the second preset value, the expansion adjustment of the positive Poisson's ratio material 5 is carried out: the extrusion bolt is rotated to move the vertical pressing plate 31 towards the double-layer plank 1, the transverse insertion plate 32 is driven to apply a transverse extrusion force to the positive Poisson's ratio material 5 between the top plate 12 and the bottom plate 13, so as to promote the expansion of the positive Poisson's ratio material 5 in a direction perpendicular to the double-layer plank 1, increase the distance between the top plate 12 and the bottom plate 13, and continuously adjust until a smooth transition surface is formed between the top plate 12 of the double-layer plank 1 and the pavement structure 04.

[0064] When the settlement of the double-layer plank 1 reaches the second preset value, the lifting mechanism 2 operation and the formation of the grouting layer 6 are carried out: the threaded lifting rod 23 is screwed into the equal-diameter internal screw hole 211 of the straight-threaded boss 21, so that the bottom of the threaded lifting rod 23 abuts against the bearing surface of the rotating disc 252 of the low-resistance pressing disc 25; the threaded lifting rod 23 is rotated through the operation part 24 of the threaded lifting rod 23, and the double-layer plank 1 is lifted in a direction perpendicular to the surface of the high fill embankment 05 by the threaded transmission, until the double-layer plank 1 and the surface of the high fill embankment 05 form a grouting space, at this time the compression pipe 26 between the bottom plate 13 and the rigid base 22 is naturally unfolded, and the grouting space is isolated from the lower threaded cylinder 213; the cement-fly ash composite reinforcement slurry is injected into the grouting space through the grouting hole 11 of the double-layer plank 1, and after the slurry is solidified, the grouting layer 6 is formed, thereby achieving the support and lifting of the double-layer plank 1.

[0065] In the later period, the settlement of the double-layer plank 1 is detected regularly, and the adjustment of the continuous settlement is carried out: when the settlement is between the first preset value and the second preset value, and the distance between the top plate 12 and the bottom plate 13 does not reach the maximum set distance, the expansion adjustment of the positive Poisson's ratio material 5 is repeatedly carried out; when the settlement is greater than the second preset value or the settlement is greater than the first preset value and the distance between the top plate 12 and the bottom plate 13 reaches the maximum set distance, the extrusion bolt is reversely rotated to move the vertical pressing plate 31 away from the double-layer plank 1, thereby reducing the transverse extrusion force on the positive Poisson's ratio material 5 to reduce the distance between the top plate 12 and the bottom plate 13, providing a redundant amount for the next expansion adjustment, and then the lifting mechanism 2 operation and the formation of the grouting layer 6 are repeatedly carried out.

[0066] In this embodiment, all the technical features work together. The array distribution of the lifting mechanism 2 ensures that the double-layered plate 1 is uniformly stressed. The low-resistance pressure plate 25 reduces the operation resistance. The compression tube 26 avoids the paste from blocking the threaded structure. The limiting mechanism 4 ensures the stability of the double-layered plate 1 structure. The extrusion mechanism 3 realizes precise fine adjustment. Combined with the phased use method, the problem of high fill subgrade 05 bridgehead bumping is effectively solved. Without large-scale demolition work, the bridge 03 and the pavement structure 04 are smoothly connected after construction, and the driving comfort and safety are significantly improved. There is no new fatigue damage to the bridge 03 support.

[0067] In an embodiment, the top plate and the bottom plate of the double-layered plate 1 are rigid structures. Multiple double-layered plates 1 can be used at the connection between the bridge 03 and the pavement structure 04 to facilitate construction and installation. An expansion gap can be reserved between the two adjacent double-layered plates 1. As shown in the figure, an asphalt layer can be laid above the bridge 03, the pavement structure 04, and the double-layered plate 1. Figure 1

[0068] In an embodiment, the grouting hole 11 is the core channel of the grouting layer formed between the double-layered plate 1 and the high fill subgrade 05. Its structure design, sealing scheme, and reuse operation are all adapted to the settlement adjustment needs of the device. The grouting hole 11 is provided in the double-layered plate and penetrates the top plate 12 and the bottom plate 13. The grouting hole is a circular hole, the hole wall is smooth, and the hole on the top plate side is chamfered at 15° to facilitate the installation of the sealing device and the butt joint of the grouting pipe. The grouting hole 11 is sealed by using a “detachable sealing plug + paste sealing mark” double scheme. The detachable sealing plug is made of butyronitrile rubber and has a columnar structure. A rubber ring that expands with rainwater is embedded in the sealing plug. During installation, the grouting hole 11 is inserted from the top plate side.

[0069] During grouting operation, the sealing plug is hooked out with a special hook, the grouting pipe with a check valve is inserted into the grouting hole 11, and the grouting is performed in the order of “low fill subgrade side to abutment side”. The cement-fly ash composite paste (cement: fly ash: water = 1:0.5:0.4) is injected until the adjacent grouting hole overflows.

[0070] After grouting, the sealing is divided into two categories: when short-term adjustment is needed, the grouting pipe is pulled out and a new sealing plug is inserted immediately; when long-term adjustment is not needed, fast-setting cement paste (water-cement ratio 0.35) is injected into the grouting hole. After initial setting, a stainless steel nameplate (with grouting date and hole depth) is attached, and red epoxy zinc-rich paint is applied for marking.

[0071] Next time grouting, according to the mark positioning, use a handheld drill to drill a hole along the center of the mark. After blowing away the debris with a high-pressure air gun, repeat the grouting operation to ensure that the grouting layer completely fills the settlement gap.

[0072] ​The above merely provides an example of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application should be included in the scope of claims of the present application.

Claims

1. A transition device for handling bridge approach slab settlement, characterized in that, The transition device is installed at an angle on the high embankment between the bridge abutment and the low embankment subgrade to connect the bridge and the road surface structure; the transition device includes a double-layer approach slab laid on the high embankment subgrade, a lifting mechanism for supporting and lifting the double-layer approach slab, and a pressing mechanism disposed on both sides of the double-layer approach slab. The double-layer slab has several grouting holes. The double-layer slab includes a top plate, a bottom plate, a limiting mechanism installed between the top plate and the bottom plate, and a positive Poisson's ratio material filled between the top plate and the bottom plate. The lifting mechanism can lift the double-layer slab to form a grouting layer between the double-layer slab and the high embankment. The extrusion mechanism can apply extrusion force to the positive Poisson's ratio material, causing the positive Poisson's ratio material to expand in a direction perpendicular to the double-layer slab. The lifting mechanism is provided in multiple forms and is arranged in an array along the double-layer plate; The double-layer slab has a lifting hole. The lifting mechanism includes a straight threaded boss, a rigid base embedded in the high embankment, and a threaded lifting rod. The straight threaded boss has an internal threaded hole of equal diameter. The straight threaded boss includes an integrally formed upper threaded cylinder and a lower threaded cylinder. The upper threaded cylinder is located in the lifting hole and welded to the base plate. The outer diameter of the lower threaded cylinder is larger than the inner diameter of the lifting hole, forming a limiting step. The top of the rigid base has a receiving groove adapted to the lower threaded cylinder. The threaded lifting rod is screwed into the internal threaded hole and its bottom abuts against the rigid base. The operating part of the threaded lifting rod rotates the threaded lifting rod to drive the double-layer slab to separate from the high embankment to form the grouting layer. The extrusion mechanism is provided along the outer edge of the double-layer plate. The outer surface of the double-layer plate is provided with a plurality of extrusion threaded holes. The extrusion mechanism includes an integrally formed vertical pressure plate and a horizontal insertion plate. The vertical pressure plate and the horizontal insertion plate are connected in a T-shape. The horizontal insertion plate is located between the top plate and the bottom plate, and the thickness of the horizontal insertion plate is less than the distance between the top plate and the bottom plate. The vertical pressure plate is provided with at least 4 strip holes. The extension direction of the strip holes is perpendicular to the double-layer plate. The extrusion bolt passes through the strip holes and is screwed to the extrusion threaded holes. The extrusion bolt is rotated to adjust the depth of the horizontal insertion plate inserted between the double-layer plates, thereby adjusting the lateral extrusion force on the positive Poisson's ratio material.

2. A transition device for handling bridge approach slab settlement according to claim 1, characterized in that, The bottom of the receiving groove of the rigid base is fixed with a low-resistance pressure plate. The low-resistance pressure plate includes a fixed seat fixed to the rigid base, a turntable sleeved on the outside of the fixed seat, and balls installed between the fixed seat and the turntable. The top of the turntable is provided with a bearing surface for bearing the threaded lifting rod.

3. A transition device for handling bridge approach slab settlement according to claim 1, characterized in that, A compression pipe is provided between the base plate and the rigid base, which is sleeved onto the lower threaded cylinder to isolate the grout from the lower threaded cylinder.

4. A transition device for handling bridge approach slab settlement according to claim 1, characterized in that, The lifting hole includes a first hole section in the top plate and a second hole section in the bottom plate. The upper threaded cylinder passes through the second hole section and extends to the first hole section to limit the double-layer plate. The upper threaded cylinder and the second hole section are interference fit, and the upper threaded cylinder and the first hole section are clearance fit.

5. A transition device for handling bridge approach slab settlement according to claim 1, characterized in that, The limiting mechanism includes a first limiting cylinder welded to the top plate and a second limiting cylinder welded to the bottom plate. The second limiting cylinder is sleeved onto the first limiting cylinder and slides in cooperation with the first limiting cylinder.

6. A transition device for handling bridge approach slab settlement according to claim 5, characterized in that, The limiting mechanism also includes a spring located inside the first limiting cylinder and the second limiting cylinder, and the spring is installed between the top plate and the bottom plate via a connecting seat.

7. A method of using a transition device for handling bridge approach slab settlement, applied to the transition device as described in any one of claims 1-6, characterized in that, Includes the following steps: Step 1: Pre-treatment of high embankment and installation of rigid abutment. Clean and level the surface of the high embankment between the abutment and the low embankment. According to the preset installation position of the double-layer approach plate, excavate the receiving trench at the layout point of the lifting mechanism corresponding to the high embankment and embed the rigid abutment into the receiving trench. Step 2: Assembly and positioning of the double-layer slab. Take the bottom plate and install the spring inside the second limiting cylinder on the bottom plate through the connecting seat. Then take the top plate and align the first limiting cylinder at the bottom of the top plate with the second limiting cylinder on the bottom plate. Fasten the top plate to the bottom plate and insert the first limiting cylinder into the second limiting cylinder to form a sliding fit, thus completing the assembly of the limiting mechanism. Fill the space between the top plate and the bottom plate with positive Poisson's ratio material or lay positive Poisson's ratio material on the bottom plate in advance to complete the overall assembly of the double-layer slab. Place the assembled double-layer slab at an angle above the high embankment, so that one end of the double-layer slab overlaps the end of the bridge abutment and the other end overlaps the top surface of the low embankment. At the same time, align the lower threaded cylinder of the straight threaded boss on the bottom plate with the receiving groove of the rigid base to complete the positioning of the double-layer slab. Step 3: Install the extrusion mechanism. Along the outer edge of the double-layer plate, insert the horizontal insert plate of the extrusion mechanism between the top plate and the bottom plate, forming an adjustable gap between the vertical pressure plate and the double-layer plate; after passing the extrusion bolt through the strip hole of the vertical pressure plate, screw it into the extrusion thread hole on the outer side of the double-layer plate. Step 4: Poisson's ratio material expansion adjustment. When the settlement of the double-layer slab reaches the first preset value and is less than the second preset value, rotate the compression bolt to move the vertical pressure plate toward the double-layer slab, and drive the horizontal insertion plate to apply lateral compression force to the Poisson's ratio material located between the top plate and the bottom plate, causing the Poisson's ratio material to expand in the direction perpendicular to the double-layer slab, so as to increase the distance between the top plate and the bottom plate, until a smooth transition surface is formed between the top plate of the double-layer slab and the road structure. Step 5: Lifting mechanism operation and grouting layer formation. When the settlement of the double-layer slab reaches the second preset value, screw the threaded lifting rod into the equal-diameter threaded hole of the straight threaded boss, so that the bottom of the threaded lifting rod abuts against the turntable bearing surface of the low-resistance pressure plate; rotate the threaded lifting rod through the operating part of the threaded lifting rod, and use the threaded transmission to drive the double-layer slab to be lifted in a direction perpendicular to the surface of the high embankment roadbed, until the double-layer slab and the surface of the high embankment roadbed form a grouting space of preset thickness; at this time, the compression pipe between the bottom plate and the rigid base naturally unfolds, isolating the grouting space from the lower threaded cylinder; inject reinforcing grout into the grouting space through the grouting holes of the double-layer slab, and after the grout solidifies, a grouting layer is formed, realizing the support and lifting of the double-layer slab.

8. A method of using a transition device for handling bridge approach slab settlement according to claim 7, characterized in that, Also includes: Step 6: Adjustment of continuous settlement in the later stage. The settlement of the double-layer slab is detected regularly. When the settlement is between the first preset value and the second preset value, and the distance between the top plate and the bottom plate has not reached the maximum set distance, proceed to step 4. When the settlement exceeds the second preset value or exceeds the first preset value and the distance between the top plate and the bottom plate reaches the maximum set distance, the compression bolt is rotated in the opposite direction to move the vertical pressure plate away from the double-layer plate, reducing the lateral compression force applied to the positive Poisson's ratio material, thereby reducing the distance between the top plate and the bottom plate and providing redundancy for the next operation step 4, and then proceeding to step 5.

Images